Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1995-1999
  • 1985-1989  (175)
  • 1980-1984
  • 1965-1969  (29)
  • 1945-1949
  • 1925-1929
  • 1920-1924
  • 1800-1809
  • 1989  (175)
  • 1969  (29)
  • Genetics  (140)
  • Cat
Datenquelle
Materialart
Erscheinungszeitraum
  • 1995-1999
  • 1985-1989  (175)
  • 1980-1984
  • 1965-1969  (29)
  • 1945-1949
    • +
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    The apolipoprotein multigene family: Structure, expression, evolution, and molecular genetics (1989)
    Springer
    Journal of molecular medicine 67 (1989), S. 225-237 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Atherosclerosis ; Apolipoprotein ; Gene expression ; Genetics ; Evolution ; Gene duplication ; Lipid binding ; DNA polymorphism ; Hypercholesterolemia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The plasma apolipoproteins can be classified into two subgroups: the soluble apolipoproteins including apolipoprotein (apo) A-I, A-II, A-IV, C-I, C-II, C-III, and E, and the apoBs including apoB-100 and apoB-48. The soluble apolipoproteins have very similar genomic structures, each having a total of three introns at the same locations; apoA-IV is an exception in that it has lost its first intron. Using the exon/intron junctions as reference points, we can obtain an alignment of the coding regions of all the soluble apolipoprotein genes. The mature peptide regions of the genes are almost completely made up of tandem repeats of 11 codons. The part of mature peptide region encoded by exon 3 contains a common block of 33 codons, whereas the part encoded by exon 4 contains a much more variable number of internal repeats of 11 codons. On the basis of the degree of homology of the various sequences, and the pattern of the internal repeats in these genes, an evolutionary tree has been proposed for the soluble apolipoprotein genes. ApoB-100 differs considerably from the soluble apolipoproteins. It is the largest apolipoprotein containing 4536 amino acid residues. Two types of internal repeats are identified in apoB-100: amphipathic α-helical repeats and proline-containing repeats with high β-sheet content. The apoB gene contains 29 exons and 28 introns. Its evolutionary relationship to the soluble apolipoprotein genes is unclear. The 3′ end of the apoB gene contains a region of variable number of tandem 12–16-base pair repeats. We have applied the polymerase chain reaction technique to characterize this highly polymorphic locus. The same technique can be used to accurately type other variable number of tandem repeats loci. Finally, apoB-48 was shown to be the product of an RNA editing mechanism involving an intestinal mRNA that has an in-frame UAA stop codon resulting from a C→U change in the codon CAA encoding Gln-2153 in apoB-100 mRNA. Using a molecular approach to apolipoprotein synthesis, structure and genetic analysis, we have generated information important to our understanding of lipoprotein metabolism; we also uncovered unexpected experimental results that are relevant to general cell and molecular biology and molecular evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01717324
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Feline sporotrichosis: A case report (1989)
    Springer
    Mycopathologia 108 (1989), S. 149-154 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Sporotrichosis ; Sporothrix schenckii ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The isolation of Sporothrix schenckii from a female European cat it is described. The cat showed lengthened alopecic areas, with prominent nodules in the external surface of the thighs and abdomen. A mycological and histopathological studies of the lesions were carried out. The lesions resolved under treatment with 20% potassium iodide in doses of 0'1 ml/kg oral route in a 8 weeks period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00436219
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    The cerebellar nuclear afferent and efferent connections with the lateral reticular nucleus in the cat as studied with retrograde transport of WGA-HRP (1989)
    Springer
    Anatomy and embryology 179 (1989), S. 471-483 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Lateral reticular nucleus ; Cerebellar nuclei ; Retrograde transport of WGA-HRP ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The cerebellar nuclear projection from the lateral reticular nucleus (NRL) was studied in 29 cats by means of retrograde axonal transport after implantation of the crystalline wheat germ agglutinin-horseradish peroxidase (WGA-HRP) complex in the cerebellar nuclei. It was confirmed that all the cerebellar nuclei receive afferent fibres from the NRL with the strongest termination in the ipsilateral interposed nuclei. In addition, these experiments give evidence of a previously unrecognized topical pattern in the projection to the interposed nuclei, arranged according to the same principle as in the projection to the immediately overlying cerebellar cortex. Thus, the anterior interposed nucleus receives fibres from all parts of the main NRL, its rostral part especially from laterally situated neurons, while subsequent more caudal parts from more medially situated neurons, while the posterior interposed nucleus receives fibres mainly from the dorsomedial part of the main NRL. The cerebellar nuclear projection to the NRL was investigated in 15 cats using retrograde transport after ventral microiontophoretical ejections of the WGA-HRP complex in the main NRL. The contralateral rostral fastigial nucleus was confirmed as the main origin of this projection, but projecting neurons were, in addition, discovered rostrally in the anterior interposed and dentate nuclei on the same side. No topical differences could be observed following ejections in different parts of the NRL; the majority of the projecting neurons were always concentrated along the ventral and lateral borders of the fastigial nucleus and in the adjacent medial part of the anterior interposed nucleus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319590
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Neurovisceral sphingomyelinosis in a Siamese cat (1989)
    Springer
    Acta neuropathologica 79 (1989), S. 330-332 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Sphingomyelinosis ; Neuropathology ; Histochemistry ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This report presents the clinical, morphological and biochemical findings on an 11-month-old female Siamese cat with neurovisceral sphingomyelinosis. Gross pathological features and histochemical findings are compared with the human disease counterpart and the previously described animal models. Hepatomegaly was observed while splenomegaly was not. Although sphingomyelin in liver and spleen was biochemically elevated, histochemical results in this case were slightly different from those previously recorded in human and feline Niemann-Pick disease. These results suggest that this feline case might be a different type of animal Niemann-Pick disease to that reported previously.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294670
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Cytochemical studies of normal feline blood and bone marrow cells (1989)
    Springer
    Annals of hematology 58 (1989), S. 195-199 
    Details
    ISSN: 1432-0584
    Schlagwort(e): Cytochemistry ; Blood ; Bone marrow ; Leukocytes ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Blood and bone marrow cells of ten clinically healthy cats were stained for alkaline phosphatase (ALP), peroxidase (PO), chloroacetate esterase (CAE), alpha-naphthyl butyrate esterase (NBE), sudanophilia, and periodic acid-Schiff (PAS) reaction. Mature neutrophils in blood and bone marrow were devoid of ALP and NBE, but exhibited modest to strong PO, CAE, sudanophilia, and PAS reaction. In bone marrow, sudanophilia, PO, and CAE were prominent at the promyelocyte stage and diminished with cellular differentiation and maturation, while PAS reactivity increased with cell maturation usually from the myelocyte stage onwards. Myeloblasts were negative for all cytochemical reactions, but some large unidentifiable cells reacted strongly for ALP. Eosinophils were slightly reactive for ALP, CAE, and PAS, but not for PO, sudanophilia, and NBE. Basophil granules stained strongly for CAE, revealed PAS positivity, and stained negatively for PO, NBE, ALP, and sudanophilia. Slight ALP activity was detected in the intergranular cytoplasm of basophils. Lymphocytes and monocytes, with few exceptions, stained negatively. An occasional lymphocyte revealed slight globular NBE activity (NaF-resistant) and diffuse PAS reaction, while an occasional monocyte contained a few PO-positive and sudanophilic granules. Monocytes reacted modestly, whereas bone marrow macrophages reacted strongly for NBE (NaF-sensitive). Cells of the erythroid series stained negatively for all cytochemical reactions, megakaryocytes were PAS-positive, and platelets gave positive reactions for PAS and CAE.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00320772
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    The genetic predisposition to fibrocalculous pancreatic diabetes (1989)
    Springer
    Diabetologia 32 (1989), S. 45-51 
    Details
    ISSN: 1432-0428
    Schlagwort(e): Genetics ; insulin gene ; DQβ gene ; fibrocalculous pancreatic diabetes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Fibrocalculous pancreatic diabetes (previously known as tropical pancreatic diabetes) is a rare cause of diabetes confined to countries within the tropical belt. The aetiology of fibrocalculous pancreatic diabetes is thought to be environmental although the agent(s) is unknown. We have investigated a possible genetic basis of this disease by looking for restriction fragment length polymorphisms of genes implicated in the aetiology of diabetes mellitus. Seventy-six Dravidian patients with fibrocalculous pancreatic diabetes were studied, and the restriction fragment length polymorphisms obtained compared to racially matched control subjects (n=94), patients with Type 2 (non-insulin-dependent) diabetes (n=87) and Type 1 (insulin-dependent) diabetes (n=58). No association of fibrocalculous pancreatic diabetes was found with restriction fragment length polymorphisms of the insulin receptor gene. Although no association of fibrocalculous pancreatic diabetes was found with polymorphism of the HLA DRα/DQα/DXα genes, an association was found with the Taq 1 restriction fragment length polymorphisms of the DQβ gene (DQβ T2/T6 present in 39% of patients with fibrocalculous pancreatic diabetes compared to 19% in control subjects; p=0.01; corrected p value=0.04) which is similar to that found in Type 1 but not Type 2 diabetes. An association of fibrocalculous pancreatic diabetes was also found with the hypervariable region in the 5-prime flanking region of the insulin gene; 40% of patients possessed the class 3 allele compared to 9.5% of control subjects p=0.0001; corrected p value=0.0008). In Type 2 diabetes, similar results were obtained with 33% subjects possessing the class 3 allele (p value compared to control subjects=0.0005; corrected p value=0.004). This study suggests that fibrocalculous pancreatic diabetes has a genetic component in its aetiology. Furthermore, its origin might be related to an individual with part of the genetic predisposition to diabetes (Type 1 or Type 2) who additionally has evidence of chronic calcific pancreatitis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00265403
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Projections from the rostral mesencephalic reticular formation to the spinal cord (1989)
    Springer
    Experimental brain research 75 (1989), S. 265-279 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rostral interstitial nucleus of the MLF ; Interstitial nucleus of Cajal ; Spinal cord ; Motoneurons ; Neck muscles ; Axial muscles ; Vertical eye and head movements ; Autoradiography ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Eye and head movements are strongly interconnected, because they both play an important role in accurately determining the direction of the visual field. The rostral brainstem includes two areas which contain neurons that participate in the control of both movement and position of the head and eyes. These regions are the caudal third of Field H of Forel, including the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the interstitial nucleus of Cajal with adjacent reticular formation (INC-RF). Lesions in the caudal Field H of Forel in monkey and man result in vertical gaze paralysis. Head tilt to the opposite side and inability to maintain vertical eye position follow lesions in the INC-RF in cat and monkey. Projections from these areas to extraocular motoneurons has previously been observed. We reported a study of the location of neurons in Field H of Forel and INC-RF that project to spinal cord in cat. The distribution of these fiber projections to the spinal cord are described. The results indicate that: 1. Unlike the neurons projecting to the extra-ocular muscle motoneurons, the major portion of the spinally projecting neurons are not located in the riMLF or INC proper but in adjacent areas, i.e. the ventral and lateral parts of the caudal third of the Field H of Forel and in the INCRF. A few neurons were also found in the nucleus of the posterior commissure and ventrally adjoining reticular formation. 2. Neurons in caudal Field H of Forel project, via the ventral part of the ventral funiculus, to the lateral part of the upper cervical ventral horn. This area includes the laterally located motoneuronal cell groups, innervating cleidomastoid, clavotrapezius and splenius motoneurons. At lower cervical levels labeled fibers are distributed to the medial part of the ventral horn. Projections from the caudal Field H of Forel to thoracic or more caudal spinal levels are sparse. 3. Neurons in the INC-RF, together with a few neurons in the area of the nucleus of the posterior commissure, project bilaterally to the medial part of the upper cervical ventral horn, via the dorsal part of the ventral funiculus. This area includes motoneurons innervating prevertebral flexor muscles and some of the motoneurons of the biventer cervicis and complexus muscles. Further caudally, labeled fibers are distributed to the medial part of the ventral horn (laminae VIII and adjoining VII) similar to the projections of Field H of Forel. A few INC-RF projections were observed to low thoracic and lumbosacral levels. It is argued that the neurons in the caudal Field H of Forel, which project to the spinal cord are especially involved in the control of those fast vertical head movements which occur in conjunction with saccadic eye movements. In contrast the INC-RF projections to the spinal cord are responsible for slower, smaller movements controlling the position of the head in the vertical plane.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00247933
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Short latency somaesthetic responses in motor cortex, transmitted through the spino-thalamic system, in the cat (1989)
    Springer
    Experimental brain research 75 (1989), S. 639-643 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Motor cortex ; Somaesthetic responses ; Spinothalamic system ; Intracellular recording ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Evidence is presented that in the cat, the spinothalamic system contributes to short latency somaesthetic responses in motor cortex efferent cells. Intracellular recordings performed on identified pyramidal tract cells and corticospinal cells show that these cells are still activated and/or inhibited from the periphery after a set of central nervous lesions leaving intact only the ventral half of the spinal cord. The responses were attributed to the spinothalamic system. The ascending system is activated through collaterals of afferent fibres running in the dorsal columns of the spinal cord. This peripheral link to the motor cortex might participate in updating the motor command on the basis of information feedback from the periphery.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00249915
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Orientation bias of cat retinal ganglion cells: a reassessment (1989)
    Springer
    Experimental brain research 76 (1989), S. 182-186 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Retinal ganglion cells ; Orientation bias ; Receptive field centre ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary For cat retinal ganglion cells whose receptive field centres were distributed in specified sections of the left visual field, the deviations of the major axis from the radial, horizontal, and circumferential directions were determined. The percentage of cells with deviations within ± 20° from the radial, horizontal, and circumferential directions were, respectively, 33%, 68%, 16%. In addition, comparison between values of deviation from the horizontal direction for cells located at eccentricities of 10° and 20° from the area centralis showed a statistically significant trend: the bias for the horizontal increased with eccentricity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00253635
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Unitary characteristics of presumptive cholinergic tegmental neurons during the sleep-waking cycle in freely moving cats (1989)
    Springer
    Experimental brain research 76 (1989), S. 519-529 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Pontine tegmentum ; Cholinergic neurons ; Single units ; Sleep-waking states ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A total of 260 neurons were recorded in the rostral pontine tegmentum of freely moving cats during the sleep-waking cycle. Of these, 207 neurons (80%) were located in the dorsal pontine tegmentum containing monoaminergic and choline acetyltransferase (ChAT)-immunoreactive, or cholinergic neurons. In addition to presumably monoaminergic PS-off cells (n = 51) showing a cessation of discharge during paradoxical sleep (PS) and presumably cholinergic PGO-on cells (n = 40) exhibiting a burst of discharge just prior to and during ponto-geniculo-occipital (PGO) waves, we observed tonic (n = 108) and phasic (n = 61) neurons exhibiting, respectively, tonic and phasic patterns of discharge during wakefulness and/or paradoxical sleep. Of 87 tonic cells histologically localized in the dorsal pontine tegmentum rich in cholinergic neurons, 46 cells (53%) were identified as giving rise to ascending projections either to the intralaminar thalamic complex (n = 26) or to the ventrolateral posterior hypothalamus (n = 13) or to both (n = 9). Two types of tonic neurons were distinguished: 1) tonic type I neurons (n = 28), showing a tonic pattern and high rates of discharge during both waking and paradoxical sleep as compaired with slow wave sleep; and 2) tonic type II neurons (n = 20), exhibiting a tonic pattern of discharge highly specific to the periods of paradoxical sleep. Tonic type I neurons were further divided into two subclasses on the basis of discharge rates during waking: a) rapid (Type I-R; n = 17); and b) slow (Type I-S; n = 11) units with a discharge frequency of more than 12 spikes/s or less than 5 spikes/s, respectively. Like monoaminergic PS-off and cholinergic PGO-on cells, both tonic type II and type I-S cells were characterized by a long spike duration (median: 3.3 and 3.5 ms), as well as by a slow conduction velocity (median: 1.8 and 1.7 m/s). In the light of these data, we discuss the possible cholinergic nature and functional significance of these ascending tonic neurons in the generation of neocortical electroencephalographic desynchronization occurring during waking and paradoxical sleep.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248908
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 11
    Digitale Medien
    Digitale Medien
    Cat red nucleus activity preceding movement depends on initiation conditions (1989)
    Springer
    Experimental brain research 77 (1989), S. 271-282 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Red nucleus ; Motor initiation ; Single-unit activity ; Reaction time ; Delayed movement ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The activity of 98 Red Nucleus neurons was recorded in 3 cats operantly conditioned to perform a ballistic forelimb flexion movement triggered after a brief sound in a simple Reaction Time condition, or Delayed after the same sound in the presence of a tone cue. Fifty-eight task related neurons presented changes of activity in either one or both conditions. Forty-four of them were studied quantitatively and classified in 3 categories: 1) only 16% of the units presented similar changes of firing preceding the triggered or delayed movement; 2) most units (55%) presented different changes of activity in the two conditions: in the Delayed condition, the activation occurred earlier before the movement, and/or the change in magnitude was reduced or the pattern of activity was modified; 3) moreover, for 29% of the units, the change of activity observed before movement in the Reaction Time condition was severely reduced or even absent in the Delayed condition. For some of these neurons a building-up of activity was observed very early in the Reaction Time condition, during the preparatory period, well before the occurrence of the conditioned stimulus. These results show that the Red Nucleus activity preceding a movement is clearly dependent on its initiation conditions. The distinct patterns of unit firing observed in the Reaction Time condition and in the Delayed condition are tentatively related to the different preparation and initiation constraints determined by the behavioral conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00274984
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    The effects of postsynaptic inhibition on the monosynaptic reflex of the cat at different levels of motoneuron pool activity (1989)
    Springer
    Experimental brain research 77 (1989), S. 577-584 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Motoneuron pool ; Inhibition ; Monosynaptic reflex ; Recruitment level ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The motoneurons to the Soleus muscle in the decerebrate cat were activated by the crossed extensor reflex, elicited by stimulation of the contralateral common peroneal (CP) nerve. Monosynaptic reflexes were obtained from the Soleus motoneuron pool by stimulation of the cut L7-S1 dorsal roots. The amplitude of the reflex increased approximately linearly with the recruitment level of the motoneuron pool. Tonic postsynaptic inhibition was induced in the Soleus moto-neuron pool by repetitive antidromic stimulation of the Lateral Gastrocnemius (LG) and Medial Gastrocnemius (MG) nerves at a rate of 17–47 stimuli/s. This reduced the size of the monosynaptic reflex at rest by at least 40%. However, when the motoneurons were active, the amplitude of the monosynaptic reflex obtained during repetitive stimulation of the LG-MG nerve increased with the recruitment level along the same curve as the control reflexes. Thus, tonic postsynaptic inhibition of the motoneurons per se cannot control the amplitude of the monosynaptic reflex independently of the recruitment level of the motoneuron pool. These experimental results verify predictions from computer simulations and suggest by exclusion that presynaptic inhibition is needed to control the amplitude of the monosynaptic reflex independently of the recruitment level of the motor pool.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00249610
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    Note on the tonotopic organization in the cat medial geniculate body: influence of sampling of units (1989)
    Springer
    Experimental brain research 74 (1989), S. 220-226 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Cat ; Medial geniculate body ; Hearing ; Tonotopic organization ; Single unit recording
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The tonotopic organization observed in the present study for the pars lateralis (LV) of the medial geniculate body (MGB) in nitrous oxide anesthetized cats is generally consistent with that previously reported under barbiturate anesthesia. The present data, however, provide evidence for local deviations in characteristic frequency (CF) using appropriate sampling procedures of single units. Although the majority of pairs of units recorded simultaneously with the same microelectrode showed comparable CFs, a few pairs of such neighbouring units displayed CF disparities of up to 1.5 octaves. In addition, some units characterized by an elevated threshold had a CF deviating significantly from the general CF progression observed for the majority of units having low thresholds. This study points out the influence of the sampling procedure on the quality of the tonotopic organization observed in the MGB in addition to a possible effect of the level of anesthesia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248295
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    Axis of preferred motion is a function of bar length in visual cortical receptive fields (1989)
    Springer
    Experimental brain research 76 (1989), S. 307-314 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Moving stimuli ; Orientation specificity ; Preferred axes ; Spot-response-axis ; Striate cortex ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The responses of 82 simple cells and 41 complex cells in area 17 of anesthetized and paralysed cats were examined with light bars of different length. For 84% of the simple cells and 66% of the complex cells the preferred axis of orientation of a stationary flashing long bar (orientational selectivity) and the preferred axis of movement of a small spot were parallel. As a consequence, the axis of maximal response to a moving light spot was mostly orthogonal to the optimal axis of a moving bar. Thus, a single cell responds to two perpendicular axes of preferred movement one for a long bar and one for a light spot, respectively. For both axes independent direction preferences could be distinguished. Additional preferred axes of movement between the two orthogonal extremes could be found with moving bars of intermediate lengths. This can be explained by the fact that cells with a pronounced response to a moving spot showed a strong tendency for intermediate bar length to elicit responses consisting of a superposition of both components. Therefore, decreasing bar length resulted in a gradual rotation of the preferred direction of movement from orthogonal to parallel with respect to the orientational axis, rather than to a mere widening of the tuning curve. Accordingly, the change in orientation selectivity with decreasing bar length is a regular transition from the orientation dependent response to a response type that depends only on the movement axis of the spot. Thus, in a simple model, the resulting response characteristic can be interpreted as an average of both components weighted according to the length of the stimulus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00247890
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    Eye movements evoked by microstimulations in the brainstem of the alert cat (1989)
    Springer
    Experimental brain research 77 (1989), S. 94-102 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Eye movement ; Brainstem ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study maps the eye movements evoked by microstimulations in the medulla of 9 alert cats. Trains of square waves (20 μA amplitude, 0.2 msec duration, 200 Hz) were delivered through glass-covered tungsten microelectrodes (0.5–1 MΩ). Movements of both eyes were recorded by the magnetic field/eye coil technique. Stimulation of the prepositus hypoglossi nucleus (PH) evoked nystagmus with ipsilaterally-directed slow phases followed by after-nystagmus with contralaterally-directed slow phases. Stimulation of the medial vestibular nucleus (MVN) induced nystagmus whose slow phases were more often ipsilaterally-directed but at time contralaterally-directed. At nearly all sites where we stimulated the reticular formation underlying prepositus and vestibular nuclei (from P4.5 to P12), we recorded versional conjugate movements. They were most often ipsilaterally-directed. Some microstimulations in the region of the medial longitudinal fasciculus evoked recentering eye movements: regardless of the initial position of the gaze (to the left as well as to the right), microstimulations given at the same place induced a movement of both eyes toward their neutral position. The amplitude of this movement was proportional to the eccentricity of the pre-stimulation position of the gaze.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00250571
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    Central distributions of the efferent and afferent components of the pharyngeal branches of the vagus and glossopharyngeal nerves: an HRP study in the cat (1989)
    Springer
    Experimental brain research 78 (1989), S. 327-335 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Pharyngeal vagus nerve ; Pharyngeal glossopharyngeal nerve ; Nucleus ambiguus ; Retrofacial nucleus ; Lateral reticular formation ; Nucleus of solitary tract ; Alaminar spinal trigeminal nucleus ; Horseradish peroxidase ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The central distributions of efferent and afferent components of the pharyngeal branches of the vagus (PH-X) and glossopharyngeal (PH-IX) nerves in the cat were studied by soaking their central cut ends in a horseradish peroxidase (HRP) solution. HRP-labelled PH-X neurones were distributed ipsilaterally in the rostral part of the nucleus ambiguus (NA) and the retrofacial nucleus (RFN); HRP-labelled PH-IX neurones were found in the ipsilateral RFN and the bulbopontine lateral reticular formation (RF). Vagal pharyngeal neurones constituted a large population of brainstem motoneurones. The population of HRP-labelled glossopharyngeal neurones was divided into two components. Indeed, on the basis of their location and somal morphology, the most ventral cells were identified as cranial motoneurones and those scattered in the lateral RF as parasympathetic preganglionic neurones. Application of HRP to the PH-IX nerve resulted also in the labelling of fibres and terminals in the alaminar spinal trigeminal nucleus and the nucleus of the solitary tract (NTS). The afferent fibres entered the lateral medulla with the glossopharyngeal roots, ran dorsomedially, then turned caudally toward the NTS and the caudal part of the alaminar spinal trigeminal motor (V) nucleus. In the NTS, labelled fibres ran mainly along the solitary tract, projecting to terminals in the dorsal and dorsolateral nuclei of the NTS.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228904
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Response to rates of luminance change of sustained and transient cells in the cat lateral geniculate nucleus and optic tract (1989)
    Springer
    Experimental brain research 74 (1989), S. 116-130 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Lateral geniculate nucleus ; Optic tract ; Sustained cells ; Transient cells ; Temporal luminance modulation ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We recorded the response of sustained (X) and transient (Y) cells in the cat lateral geniculate nucleus (LGN) and optic tract to a stationary spot while the spot luminance was increased and decreased with a constant rate (linear luminance functions), or modulated sinusoidally. The spot filled the receptive field center, and was surrounded by an annulus of fixed luminance. The LGN X cells seemed to perform a differentiation-like operation in the time domain at slow temporal modulations, giving information about rate of luminance change. To the linear luminance functions the cells responded with a constant firing rate. The on-center cells were activated during increasing luminance, the off-center cells during decreasing luminance. This firing rate increased monotonically with rate of luminance change. To low-frequency sinusoidal modulations the cells had a marked negative phase shift. The response of the LGN Y cells had a transient component shortly after the luminance started to increase (on-center cells) or decrease (off-center cells), followed by a secondary, gradually changing component. The peak of the transient component occurred on average when the response of the X cells increased most rapidly. To low-frequency sinusoidal modulation the average negative phase shift of this peak was twice the average of the X cells. The Y system could accordingly provide information about rate of change in the response of the X system. In the optic tract the X fiber response resembled the LGN X cell response in most respects. The Y fibers had only a weak transient response component, so this component was accentuated in the thalamic relay. Also the sensitivity for rate of luminance change was increased in LGN.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248285
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    Excitatory interactions between phrenic motoneurons: intracellular study in the cat (1989)
    Springer
    Experimental brain research 74 (1989), S. 131-138 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Phrenic motoneurons ; Intracellular recording ; Interactions ; Recurrent EPSPs ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary 1. Intracellular recordings were made from 220 Phrenic Motoneurons (PM) in anaesthetized, spontaneously breathing cats, deafferented from C3 to C7, in order to look for somatic events related to the Recurrent Responses (RR) evoked in PM axons by repetitive stimulation of the phrenic nerve. RR appear sporadically at a constant latency, originate from a spinal nicotinic mechanism and can be evoked in a PM without the presence of an antidromic volley in its axon (Khatib et al. 1986). 2. Using stimuli effective for eliciting RR in axons, we failed to observe intracellularly somatic events corresponding to RR after the occurence of an antidromic action potential. RR were observed extracellularly in two cases, but in both cases the recording originated from axons. 3. We attempted to elicit somatic RR without a preceding antidromic action potential, using either parathreshold stimulation of the impaled PM, or suprathreshold stimulation of a phrenic strand which excluded the axon of the impaled PM. In both cases, RR-like events, with very stable latencies, appeared sporadically in 4/142 and 2/15 PMs respectively. 4. Parathreshold stimuli or stimulation of a strand were coupled with averaging of the synaptic noise in order to look for small events temporally related to the stimuli. Short latency small depolarizations, looking-like recurrent EPSPs, were revealed in 22/142 and 5/15 PMs respectively. 5. These results confirm the existence of interrelations between PMs, providing for re-excitation and coupling within the phrenic pool, in addition to centrally imposed synchronization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248286
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    Binocular depth perception, visual acuity and visual fields in cats following neonatal section of the optic chiasm (1989)
    Springer
    Experimental brain research 74 (1989), S. 272-278 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Cat ; Corpus callosum ; Optic chiasm ; Stereoacuity ; Visual acuity ; Visual fields
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We studied the role of the transcallosal pathway in stereopsis by measuring binocular and monocular depth perception in two cats that had undergone section of the optic chiasm at the age of 21 d. To ensure that the surgery did not impair vision to the extent that depth perception could not be evaluated, visual acuity and visual fields were also measured. In both of the chiasm-sectioned animals the visual fields were reduced and the visual acuity was substantially lower than in normal cats, with a maximum of about 2 cyc deg-1. Binocular depth thresholds of the chiasm-sectioned cats were worse than those of the normal cat but were better than their own monocular thresholds. These results suggest that the chiasm-sectioned animals were still able to use binocular cues to judge depth and indicate that the indirect pathway through the corpus callosum is sufficient to mediate binocular depth perception.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248860
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    Demonstration of axonal branching of fibres from certain precerebellar nuclei to the cerebellar cortex and nuclei: a retrograde fluorescent double-labelling study in the cat (1989)
    Springer
    Experimental brain research 75 (1989), S. 15-27 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Precerebellar nuclei ; Cerebellar cortex and nuclei ; Fluoro-Gold ; Rhodamine-B-isothiocyanate (RITC) ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The projections from certain brain stem precerebellar nuclei to the cerebellar cortex and nuclei have been examined in the cat by using the retrograde fluorescent double-labelling technique. Crystalline Fluoro-Gold was implanted into the left cerebellar nuclei from the contralateral side and rhodamine-B-isothiocyanate was injected into the overlying cerebellar cortex. The inferior olive, the lateral reticular nucleus, and the reticular tegmental pontine nucleus all contained double- as well as single-labelled neurons, and it was concluded that these nuclei have a high number of neurons whose axons branch to both the cerebellar cortex and nuclei. The neurons in the paramedian reticular nucleus and the pontine nuclei proper appear to project only to the cerebellar cortex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248525
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 21
    Digitale Medien
    Digitale Medien
    Modulation of short latency cutaneous excitation in flexor and extensor motoneurons during fictive locomotion in the cat (1989)
    Springer
    Experimental brain research 77 (1989), S. 57-68 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Cutaneous EPSPs ; Fictive locomotion ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We examined modulation of transmission in short-latency, distal hindlimb cutaneous reflex pathways during fictive locomotion in 19 decerebrate cats. Fictive stepping was produced either by electrical stimulation of the mesencephalic locomotor region (MLR) or by administration of Nialamide and 1-DOPA to acutely spinalized animals. Postsynaptic potentials (PSPs) produced by electrical stimulation of low threshold afferents (〈 2.5 times threshold) in the superficial peroneal (SP), sural, saphenous or medial plantar nerves were recorded intracellularly from various extensor (n = 28) and flexor (n = 24) motoneurons and averaged throughout the step cycle, together with voltage responses to intrasomatic constant current pulses (in order to monitor relative cell input resistance). Each motoneuron studied displayed rhythmic background oscillations in membrane potential and correlated variations in input resistance. The average input resistance of extensor motoneurons was lowest during mid-flexion, when the cells were relatively hyperpolarized and silent. Conversely, average input resistance of flexor motoneurons was highest during mid-flexion, when they were depolarized and active. The amplitude of the minimum-latency excitatory components of PSPs produced by cutaneous nerve stimulation were measured from computer averaged records representing six subdivisions of the fictive step cycle. Oligosynaptic EPSP components were consistently modulated only in the superficial peroneal responses in flexor motoneurons, which exhibited enhanced amplitude during the flexion phase. With the other skin nerves tested (sural, saphenous, and plantar), no consistent patterns of modulation were observed during fictive locomotion. We conclude that transmission through some, but not all, oligosynaptic excitatory cutaneous pathways is enhanced by premotoneuronal mechanisms during the flexion phase of fictive stepping in several cat hindlimb motor nuclei. The present results suggest that the patterns of interaction between the locomotor central pattern generator and excitatory cutaneous reflex pathways depend on the source of afferent input and on the identity of the target motoneuron population.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00250567
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 22
    Digitale Medien
    Digitale Medien
    Pharyngeal motoneurones: respiratory-related activity and responses to laryngeal afferents in the decerebrate cat (1989)
    Springer
    Experimental brain research 78 (1989), S. 336-344 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Vagal pharyngeal nerve ; Glossopharyngeal nerve ; Single fibre recordings ; Respiratory-related units ; Superior laryngeal nerve ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In decerebrate, paralyzed and artificially ventilated cats, we recorded the discharge of 64 motor axons supplying the pharyngeal muscles. Filaments containing motor axons, with discharges related to the respiratory cycle (phrenic nerve activity), were teased from the pharyngeal branches of the vagus and glossopharyngeal nerves. Most units (n = 41) fired only during expiration and exhibited a steady, a decreasing or a late augmenting discharge pattern. These units were found only in vagal filaments. Twenty three units discharged during inspiration and exhibited a steady, a late augmenting or a tonic discharge pattern. The inspiratory-related units were present in both the vagus (n=13) and glossopharyngeal (n=10) nerves. Nineteen of 20 pharyngeal inspiratoryrelated units tested were activated at short latency (range 3.4 to 8.0 ms) by stimulation of afferents in the superior laryngeal nerve (SLN). In 13 of these, such stimulation also suppressed their spontaneous activity. SLN stimulation elicited in all 17 pharyngeal expiratory-related units tested a short latency (range 0 to 8 ms) reduction of activity, followed in 7 units by an increase in activity. SLN stimulation occasionally evoked single or rhythmic multifibre bursts in the vagal pharyngeal filaments. These bursts, involving expiratory-related units, likely correspond to the buccopharyngeal stage of swallowing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228905
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 23
    Digitale Medien
    Digitale Medien
    Quantitative measurements of receptive field changes during antagonism of GABAergic transmission in primary somatosensory cortex of cats (1989)
    Springer
    Experimental brain research 78 (1989), S. 514-532 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Bicuculline ; Inhibition ; Latency ; Receptive field profile ; Somatosensory cortex ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In cortical area 3b of cats, responses of 76 single neurons to punctate indentations were recorded before and during iontophoretic administration of bicuculline methiodide (BMI), a GABAergic antagonist, at levels that did not affect spontaneous activity. Constant amplitude indentations were applied to selected sites along distalproximal and radial-ulnar axes that intersected the most sensitive area in the receptive field. Profiles of response magnitudes were used to measure receptive field dimensions before and during antagonism of GABAergic inhibition. Blockade of GABAergic transmission caused receptive field dimensions of 48 rapidly-adapting neurons to increase an average 141%, or nearly 2.5 times their original size. Analysis of the spatial distribution of inhibition indicated that in-field inhibition was larger than surround inhibition. During BMI administration, response latency was significantly longer for response elicited from the expanded territory than for responses elicited from within the original receptive field, suggesting that receptive field expansion might be mediated by multisynaptic intracortical connections. The magnitude of receptive field expansion was independent of receptive field size or peripheral location. In a substantial number of neurons, however, BMI produced asymmetric expansions that extended only in the proximal direction. For 9 slowly-adapting neurons, BMI produced measureable increases in receptive field dimensions, but these changes were significantly smaller than the changes in rapidly-adapting neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230239
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 24
    Digitale Medien
    Digitale Medien
    Actions of excitatory amino acid antagonists on synaptic potentials of layer II/III neurons of the cat's visual cortex (1989)
    Springer
    Experimental brain research 78 (1989), S. 489-500 
    Details
    ISSN: 1432-1106
    Schlagwort(e): NMDA receptor ; Visual cortex ; Excitatory amino acid ; Slice ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Actions of excitatory amino acid (EAA) antagonists on the responses of cells in layers II/III and IV of the cat's visual cortex to stimulation of layer VI and the underlying white matter were studied in slice preparations. Antagonists used were 2-amino-5-phosphonovalerate (APV), a selective antagonist for the N-methyl-D-aspartate (NMDA) type of EAA receptors, and kynurenate, a broadspectrum antagonist for the three types of EAA receptors. In extracellular recordings it was demonstrated that most of the layer II/III cells were sensitive to APV, while the great majority of the layer IV cells were not, By contrast, kynurenate suppressed the responses completely in both layers. Excitatory post-synaptic potentials (EPSPs) evoked by stimulation of layer VI and the while matter were recorded intracellularly from layer II/III neurons. To determine whether the EPSPs were elicited mono- or polysynaptically, the synaptic delay for each EPSP was calculated from a pair of onset latencies of EPSPs evoked by stimulation of the two sites. Forty-two percent of the layer II/III cells were classified as having monosynaptic EPSPs. In 60% of these monosynaptic cells, the rising slope of the EPSPs was reduced by APV while in the other 40%, it was not. In the former (APV-sensitive cells), subtraction of the APV-sensitive component from the total EPSP indicated that the onset latency of the NMDA receptor-mediated component was roughly equal to that of the non-NMDA component. In the latter (APV-resistant cells), only the slowly-decaying component was in part mediated by NMDA receptors. The conduction velocities of the afferent fibers innervating APV-resistant cells were slower than those of the APV-sensitive cells, suggesting that both types of cells are innervated by different types of afferents. The polysynaptic EPSPs of almost all layer II/III cells were sensitive to APV. The subtraction method indicated that the NMDA component had about the same magnitude as the non-NMDA components. When the slices were superfused by a Mg2+-free solution, the EPSPs were potentiated dramatically, but this potentiation was reduced to the control level during the administration of APV. Similarly, APV-sensitive components were potentiated during the administration of bicuculline, a selective antagonist for gamma-aminobutyric acid receptors of A type. These results suggest that NMDA receptors participate, at varying degrees, in excitatory synaptic transmission at most layer II/III cells in the cat's visual cortex, and their actions appear to be regulated by intracortical inhibition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230237
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 25
    Digitale Medien
    Digitale Medien
    Behavioural thermosensitivity after bilateral lesions of the lateral funiculi in the cervical spinal cord of the cat (1989)
    Springer
    Experimental brain research 78 (1989), S. 374-379 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Thermosensitivity ; Spinal cord ; Ascending pathways ; Behaviour ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The behavioural thermosensitivity of six cats was measured before and after single stage, symmetrical, bilateral, surgical lesions of the cervical spinal cord. The lesions were aimed at an area in the most ventral parts of the dorsal halves of the lateral funiculi. Unilateral lesions of that area have previously been found to cause reproducible, although subtotal, contralateral thermosensory defects, which were attributed to interruption of the thermosensory spinothalamic pathway. The lesions of three of the present cats were found to be incomplete, and those animals showed no postoperative thermosensory deficiency. Two of the cats with complete lesions showed marked post-operative defects, especially immediately after the operations, but the third cat with a complete lesion showed no postoperative thermosensory defect at all. The differences between the last three animals have been compared to the irregularity of previous reports about thermosensitivity after spinal cord lesions in man and animals, and may depend on the testing technique, rather than differences of thermosensitivity per se.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00228909
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 26
    Digitale Medien
    Digitale Medien
    The distribution of intrinsic cortical axons in area 3b of cat primary somatosensory cortex (1989)
    Springer
    Experimental brain research 78 (1989), S. 501-513 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Somatosensory cortex ; Interlaminar ; Corticortical ; SI ; Area 3b ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The morphology of single neurons in area 3b of cat primary somatosensory (SI) cortex was examined after horseradish peroxidase (HRP) injections. Neurons were labeled either by intracellular injection of HRP following intracellular recording or by small extracellular iontophoretic HRP injections. Both pyramidal and nonpyramidal neurons were labeled and reconstructed from serial sections. Their axons had local, interlaminar and interareal patterns of termination. Most neurons formed local axonal fields around their cell bodies and dendrites. Pyramidal neurons in cortical layer IV sent axons up into layers II and III, neurons in layers II and III sent axons down to layer V, and layer V neurons sent axons to layer VI as well as back to the upper layers. Layer VI neurons sent axons back to the upper cortical layers in a unique bowl-shaped pattern. The horizontal distribution of axons of pyramidal cells in layer III was extremely widespread. Axons of layer III neurons in area 3b terminated within 3b and area 1, but not in other areas of SI. Layer III neurons in area 1 distributed axon collaterals to all fields of SI as well as projecting a main axon to motor cortex. In general, the axon collaterals of area 3b pyramidal cells outside layer III remained confined to area 3b. Most of the nonpyramidal neurons labeled were basket cells in layers III and VI. These neurons formed dense axonal fields around their cell bodies, and none of their axons could be followed into the underlying white matter. The results of the present study demonstrate that area 3b somatosensory cortical neurons and their axons are vertically organized in a manner similar to that reported for other sensory cortical areas. They also show that widespread horizontal connections are formed by pyramidal neurons of layer III, and that these horizontal axons can travel for great distances in the cortical grey matter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230238
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 27
    Digitale Medien
    Digitale Medien
    Role of the sensorimotor cortex in postural adjustments accompanying a conditioned paw lift in the standing cat (1989)
    Springer
    Experimental brain research 78 (1989), S. 588-596 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Motor cortex ; Conditioned movement ; Posture ; Balance control ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The role of the sensorimotor cortex in the postural adjustments associated with conditioned paw lifting movements was investigated in the cat. Cats were trained to stand quietly on four strain gauge equipped platforms and to perform a lift-off movement with one forelimb when a conditioned tone was presented. The parameters recorded were the vertical forces exerted by the paws on each platform, the lateral and antero-posterior displacements of rods implanted on the T2, T12, L5 vertebrae as well as their rotation, and the EMG of triceps and biceps of both forelimbs. Before lesion, the postural adjustment consisted of a “nondiagonal” pattern where the CG was displaced laterally inside the triangle formed by the three remaining supporting limbs. Here a lateral bending of the thoracic column toward the supporting forelimb could be observed. The associated EMG pattern consisted of an early activation of the triceps lateral head in the moving limb which was probably responsible for the body displacement toward the opposite side, and a late biceps activation associated with the lift. In the supporting forelimb, a coactivation of the biceps and triceps was usually present. After contralateral sensorimotor lesion, the conditioned lifting movements were lost for 4–15 days after the lesion, before being subsequently recovered. The same lateral CG displacement and bending of the back was seen after lesion as before, which indicates that the goal of postural adjustment was preserved. However, the means of reaching it were modified. In most of the intact animals, the CG displacement was achieved in one step, whereas in the animals with lesions, the displacement was made either according to a slow ramp mode or in a discontinuous manner involving several steps. The mechanisms responsible for this disturbance are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230246
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 28
    Digitale Medien
    Digitale Medien
    The role of inhibitory processes in the formation of functional properties of neurons in vibrissal projection zone of the cat somatosensory cortex (1989)
    Springer
    Experimental brain research 76 (1989), S. 198-206 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Somatosensory cortex ; Directional sensitivity ; GABA inhibition ; Picrotoxin ; Bicuculline ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The role of intracortical inhibitory processes in the formation of neuronal receptive fields in the vibrissal projection zone of the somatosensory cortex was studied. Iontophoretic application of picrotoxin and bicuculline blocks the inhibition and causes the loss of directional sensitivity in neurons. Activation of inhibition by distant glutamate application gives opposite results — neurons become direction sensitive. A dependence was found between spatial location of activated cells and the pattern of changes of their detector properties. Inhibitory processes caused by natural afferent stimulation lead to similar changes in the functional properties of neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00253637
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    Effects of dark rearing on the development of visual callosal connections (1989)
    Springer
    Experimental brain research 78 (1989), S. 203-213 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Corpus callosum ; Development ; Vision ; Dark rearing ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary It is now well established that during normal postnatal development there is a partial elimination of the callosal projections of cortical areas 17 and 18 in the cat and that visual experience early in life can modulate this process. In the present experiments, we quantitatively studied the influence of light, per se, by rearing cats in total darkness. Dark rearing exaggerates the normally occurring partial elimination of immature callosal projections: it causes a significant reduction in the total number of neurons in both the supra-and infragranular layers that send an axon through the corpus callosum and slightly narrows the distribution of these neurons across areas 17 and 18. These data demonstrate that visual stimulation is not necessary either to initiate the partial elimination of immature callosal projections or to stabilize a large fraction of the callosal projections present at birth. However, normal visual stimulation is necessary for the stabilization of the normal complement of callosal projections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230700
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    Intercostal and abdominal muscle afferent influence on caudal medullary expiratory neurons that drive abdominal muscles (1989)
    Springer
    Experimental brain research 78 (1989), S. 219-222 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Control of respiration ; Intercostal muscle afferents ; Phrenic nerve ; Abdominal muscle afferents ; Expiratory neurons ; Abdominal muscle control ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Our objective was to determine if caudal ventral respiratory group (VRG) expiratory (E) neurons that drive abdominal expiratory motoneurons in the lumbar cord respond to intercostal and lumbar nerve afferent stimulation. Results showed that 92% of medullary E-neurons that were antidromically activated from the upper lumbar cord reduced their activity in response to stimulation of external and internal intercostal and lumbar nerve afferents. We conclude that afferent information from intercostal and abdominal muscle tendon organs has an inhibitory effect on caudal VRG E-neurons that drive abdominal expiratory motoneurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00230702
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    Synaptic potentials induced by postganglionic stimulations in cat bladder parasympathetic neurones (1989)
    Springer
    Pflügers Archiv 414 (1989), S. 235-244 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Cat ; Urinary bladder ; Parasympathetic ganglion neurone ; Postganglionic stimulation ; Synaptic potentials
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Intracellular recording techniques were used to examine and compare synaptic potentials evoked by stimulating pre- and postganglionic nerve trunks in cat bladder parasympathetic ganglia. In the 76 ganglion cells exammed, two types of responses were recorded on stimulating the postganglionic nerve: an antidromic action potential (type Post NS1;n=30) or a fast excitatory postsynaptic potential (f-EPSP; type PostNS2;n=46) which resulted in an orthodromic-like action potential. In some of the cells exhibiting a PostNS1 response (n=19), a fast depolarization was superimposed on the antidromic spike. This depolarization was due to the synaptic activation of nicotinic receptors. In many of the cells exhibiting either PostNS1 or PostNS2 responses, repetitive stimulation of the postganglionic nerve induced a slow hyperpolarization. Applying nicotinic (hexamethonium, methonium, 0.5–1 mM), muscarinic (atropine, 1 μM), alpha-adrenergic (phentolamine, 1 μM) and purinergic (caffeine, 0.5–1 mM) receptor antagonists completely inhibited the tetanus-induced slow hyperpolarization in some cells (n=5). In other cells (n=15), a slow hyperpolarization persisted in the presence of these antagonists. These results indicate that stimulation of the postganglionic nerve trunk of cat bladder parasympathetic ganglia can elicit not only an antidromic action potential, but also synaptic potentials which are mediated by the activation of cholinergic (nicotinic and muscarinic), noradrenergic and purinergic receptors, as well as a non-cholinergic, non-alpha-adrenergic and non-purinergic synaptic potential.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00580969
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    Population biology of two land snails (Mesomphix spp.): variation among six southern appalachian sites with differing disturbance histories (1989)
    Springer
    Oecologia 79 (1989), S. 372-382 
    Details
    ISSN: 1432-1939
    Schlagwort(e): Logging disturbance ; Land gastropods ; Ecology ; Genetics ; Population
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Ecological and genetic properties of two North American terrestrial gastropods (Mesomphix spp.) were characterized in paired control and previously logged watersheds in two North Carolina forests (Coweeta and the Great Smoky Mountains National Park) of the Southern Appalachian Biosphere Reserve Cluster. Shell growth was greater in the control sites, but density and mortality were largely independent of prior logging history and forest reserve. Based on starch gel electrophoresis data, both species showed their highest levels of genetic diversity in the Coweeta forest, the component of the reserve cluster which had the most extensive and variable history of logging disturbance. M. subplanus also exhibited higher levels of heterozygosity in logged than in control watersheds, and M. andrewsae showed over twice as many rare alleles in disturbed sites as in control sites. F-statistic analysis depicted both excess levels of homozygosity and moderate genetic differentiation among the populations, reflecting the effects of small population size and perhaps drift and inbreeding. Estimated gene flow was relatively low. These results correspond to the recent finding by Bryant et al. (1987) and others on the effects of bottlenecks, and to the contrasting history of habitat instability of the two major study forests.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00384317
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 33
    Digitale Medien
    Digitale Medien
    Convulsant properties of GABA antagonists and anticonvulsant properties of ethanol in selectively bred Long- and Short-Sleep mice (1989)
    Springer
    Psychopharmacology 98 (1989), S. 544-548 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Ethanol ; Bicuculline ; Picrotoxin ; Seizures ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The convulsant potency of bicuculline, a GABA antagonist, was shown to be greater in Short-Sleep (SS) mice than in Long-Sleep (LS) mice. LS mice, selectively bred for lengthy ethanol-induced narcosis, had longer latencies to myoclonus and clonus following administration of bicuculline and picrotoxin than did ethanol-resistant SS mice. SS mice were also more susceptible to pentylenetetrazol-induced myoclonus, but not clonus. F1 hybrids showed bicuculline seizure sensitivity intermediate to the two parent lines. Ethanol weakly inhibited bicuculline-induced myoclonus in both LS and SS mice. Clonus was clearly antagonized by ethanol in both lines, but to a similar degree. These data provide evidence for a GABAergic role in geno-type-dependent sensitivity to ethanol.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00441957
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 34
    Digitale Medien
    Digitale Medien
    Cocaine produces low dose locomotor depressant effects in mice (1989)
    Springer
    Psychopharmacology 99 (1989), S. 147-150 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Locomotor activity ; CNS depression ; Cocaine ; Mice ; Behavior ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Cocaine produces several behavioral effects, most notably locomotor stimulation. Biochemically, cocaine is known to inhibit reuptake at the three monoamine transporter sites, and may have highest affinity at the serotonin transporter. Serotonin augmentation has been associated with decreases in behavioral activity, but cocaine has not been reported to produce behavioral depressant effects except at high doses which cause stereotypy and disruption of behavior. This study examined the effects of relatively low doses of cocaine, in the range of 0.1–10 mg/kg, on locomotor activity in C57BL/6J and DBA/2J mice. A biphasic dose-response curve was seen for both strains. At the lowest doses, activity was depressed. As the dose of cocaine increased, activity returned to baseline, and at the highest doses, increases in locomotor activity were found. DBA/2J mice were depressed at a lower dose of cocaine than were C57BL/6J mice; however, C57BL/6J mice showed locomotor depression over a broader range of doses. Activity was maximally depressed at 0.1 mg/kg for DBA/2J mice, and maximally depressed at 0.3 mg/kg for C57BL/6J mice. Thus, low doses of cocaine are shown to produce significant decreases in locomotor activity in two strains of mice. It is postulated that these low doses of cocaine which depress locomotor activity do so via inhibition of serotonin uptake, resulting in potentiation of serotonergic activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00442799
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 35
    Digitale Medien
    Digitale Medien
    Oro-facial dyskinesia and the sub-commissural part of the globus pallidus in the cat: role of acetylcholine and its interaction with GABA (1989)
    Springer
    Psychopharmacology 99 (1989), S. 381-385 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Oro-facial dyskinesia ; Globus pallidus ; GABA ; Acetylcholine ; Behaviour ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The possible role of cholinergic mechanisms in the sub-commissural part of the globus pallidus (scGP) in the induction of oro-facial dyskinesia (OFD) was studied in cats. Local injections of the cholinergic agonist carbachol into the scGP elicited tongue protrusions in a dose dependent way (100–1000 ng/0.5 μl). The effect elicited by 1000 ng carbachol was selectively antagonized by the cholinergic antagonist scopolamine (10 μg/0.5 μl); this dose of scopolamine was ineffective when injected alone. The tongue protrusions resulted from both normal and abnormal movements: whereas normal movements simply consisted of protruding the flat tongue, abnormal movements implied a variety of movements, especially curling upwards the lateral side(s) or tip of the tongue inside or outside the oral cavity. The abnormal carbachol-induced tongue protrusions formed part of a syndrome marked by dyskinetic movements of the muscles of the eye, ear and cheek, and were identical to those seen previously after local injections of picrotoxin (250–500 ng). Intra-pallidal injections of the abovementioned dose of scopolamine had no effect on the tongue protrusions induced by local injections of 375 ng picrotoxin. However, local injections of 100 ng muscimol, which was previously found to attenuate significantly the effect of 375 ng picrotoxin and which was ineffective when injected alone, significantly attenuated the tongue protrusions induced by local injections of 1000 ng carbachol. These data suggest that the cholinergic effects are mediated via a GABAergic mechanism, but not vice versa. The results are discussed in view of GABAergic and anticholinergic therapies used in oro-facial dyskinesia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00445562
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 36
    Digitale Medien
    Digitale Medien
    Genotype-dependent effects of GABAergic agents on sedative properties of ethanol (1989)
    Springer
    Psychopharmacology 98 (1989), S. 518-523 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Ethanol ; GABA ; Bicuculline ; Sedation ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two lines of mice, selectively bred for differential sensitivity to the soporific effects of ethanol (ETOH), were administered GABAergic drugs in an effort to evaluate a role for GABA in ETOH sensitivity. ETOH sensitive Long-Sleep mice (LS) showed potentiated ETOH sedation when administered bicuculline, muscimol and aminooxyacetic acid (AOAA). ETOH-insensitive SS mice exhibited reduced ETOH sedation in the presence of the antagonists, bicuculline and picrotoxin, and potentiated sedation in the presence of muscimol and AOAA. These changes in narcosis duration were interpreted as central effects, since blood ethanol levels at waking from ETOH sedation varied with GABAergic drug treatment. Picrotoxin antagonized pentobarbital-induced nacrosis in both lines, but to a greater extent in SS mice. These and other experiments with a genetically heterogeneous stock suggest GABA involvement in genotype-dependent ETOH sensitivity, but do not support a simple role of GABA receptor involvement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00441952
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 37
    Digitale Medien
    Digitale Medien
    Modification of ethanol effects by bicuculline: genotype-dependent responses and inheritance (1989)
    Springer
    Psychopharmacology 98 (1989), S. 549-555 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Ethanol (ETOH) ; GABA ; Bicuculline ; Sedation ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Genetic influences on the interaction between ethanol (ETOH) and gamma-aminobutyric acid (GABA) neurotransmitter systems were eveluated with a survey of responses to coadministration of ETOH and a GABA antagonist, bicuculline, in a battery of inbred mouse strains. The selectively bred ETOH-sensitive Long-Sleep (LS) mice, the relatively ETOH-resistant Short-Sleep (SS) mice, and a genetically heterogeneous stock (GHS) were also evaluated. The effect of bicuculline on ETOH-induced sedation, hypothermia, and blood ethanol content upon recovery from sedation was assessed. Inheritance of these responses was also examined using F1 hybrids. The effect of bicuculline on ETOH-produced narcosis varied widely among stocks and included antagonism, potentiation, and no effect. Changes in ETOH-induced narcosis produced by bicuculline were accompanied by changes in blood ethanol concentrations consistent with an hypothesis of altered central nervous system sensitivity to ETOH. Knowledge of a strain's seizure susceptibility to the GABA antagonist or of its sensitivity to the hypnotic effects of ETOH were of no predictive value in estimating the outcome of coadministration studies, suggesting at least partially separate genetic influences on each phenotype. In cross-breeding studies there was commonly dominance toward a profile of bicuculline antagonism of ETOH narcosis but different patterns of dominance were observed for seizure susceptibility, again inicating separate genetic control. The results suggest considerable complexity of GABAergic involvement in genotype-dependent ETOH sensitivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00441958
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 38
    Digitale Medien
    Digitale Medien
    Homology and distribution of CO dehydrogenase structural genes in carboxydotrophic bacteria (1989)
    Springer
    Archives of microbiology 152 (1989), S. 335-341 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Carboxydotrophic bacteria ; Plasmids ; CO dehydrogenase subunits ; N-terminal sequences ; Oligonucleotides ; Hybridization ; Genetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The 17 (S), 30 (M) and 87 kDa (L) subunits of CO dehydrogenases from the CO-oxidizing bacteria Pseudomonas carboxydoflava, Pseudomonas carboxydohydrogena and Pseudomonas carboxydovorans OM5 were isolated and purified. The N-terminal sequences of same subunits from different bacteria showed distinct homologies. Dot blot hybridization employing oligonucleotide probes derived from the sequences of the S-subunit of P. carboxydovorans OM5 and the M-subunit of P. carboxydohydrogena and DNA of the plasmid-containing CO-oxidizing bacteria Alcaligenes carboxydus, Azomonas B1, P. carboxydoflava, P. carboxydovorans OM2, OM4 and OM5 indicated that all genes encoding these subunits reside on plasmids. That in P. carboxydovorans OM5 CO dehydrogenase structural genes are located entirely on plasmid pHCG3 was evident from the absence of hybridization employing DNA from the cured mutant strain OM5-12. CO dehydrogenase structural genes could be identified on the chromosome of the plasmid-free bacteria Arthrobacter 11/x, Bacillus schlegelii, P. carboxydohydrogena and P. carboxydovorans OM3. There was no example of a plasmid-harboring carboxydotrophic bacterium that did not carry CO dehydrogenase structural genes on the plasmid. The N-terminal sequences of CO dehydrogenase structural genes were found to be conserved among carboxydotrophic bacteria of distinct taxonomic position, independent of the presence of plasmids. It is discussed whether this might be the consequence of horizontal gene transfer.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00425170
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 39
    Digitale Medien
    Digitale Medien
    The use of eye movement dysfunctions in exploring the genetic transmission of schizophrenia (1989)
    Springer
    European archives of psychiatry and clinical neuroscience 239 (1989), S. 43-48 
    Details
    ISSN: 1433-8491
    Schlagwort(e): Schizophrenia ; Eye movements ; Genetics ; Twins ; Latent trait
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Eye movement dysfunctions have been found in a large number of schizophrenic patients and in about half of their first-degree relatives. The distribution of these traits within the families of schizophrenic patients suggests a model of genetic transmission that fits an autosomal dominant model, which we have called the “genetic latent trait model.” The model, with seven parameters, was fitted to a U.S. population and the model was cross-validated on an independent Norwegian sample. Although the model does not invalidate other, more conventional solutions to the puzzle of schizophrenic transmission, such as multifactorial transmission, the latent trait model does more easily permit linkage studies and therefore will allow refutation or support from the use of molecular genetics techniques.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01739743
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 40
    Digitale Medien
    Digitale Medien
    [3H]ICS 205-930 labels 5-HT3 recognition sites in membranes of cat and rabbit vagus nerve and superior cervical ganglion (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 340 (1989), S. 396-402 
    Details
    ISSN: 1432-1912
    Schlagwort(e): 5-HT3 receptors ; Radioligand binding ; [3H]ICS 205-930 ; Cat ; Rabbit ; Vagus nerve ; Superior cervical ganglion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The binding characteristics of [3H]ICS 205-930, a 5-hydroxytryptamine 5-HT3 receptor antagonist, were investigated in membranes prepared from cat and rabbit vagus nerve (VN) and superior cervical ganglion (SCG). The autoradiographic localisation of 5-HT3 recognition sites was also assessed using [3H]ICS 205-930 in slices from cat medulla oblongata, nodose ganglion and vagus nerve. [3H]ICS 205-930 bound to a homogeneous population of high affinity recognition sites in cat VN: Bmax = 201 ± 43 fmol/mg protein, pKD = 9.26 ± 0.17 and SCG: Bmax = 291 ± 40 fmol/mg, pKD = 9.35 ± 0.80 (n = 3). Competition experiments performed in membranes from cat VN and SCG with agonists and antagonists suggested the presence of a homogeneous population of [3H]ICS 205-930 recognition sites. Competition curves were steep and monophasic and were best fitted by a 1 receptor site model. The following rank order of affinity for [3H]ICS 205-930 binding sites was observed with antagonists: SDZ 206-830 = ICS 205-930 〉 BRL 43694 〉 SDZ 206–792 〉 quipazine 〉 MDL 72222 〉 metoclopramide 〉 mCPP and agonists: 2-methyl-5-HT = 5-HT 〉 phenylbiguanide. A similar profile was observed for a limited series of compounds in rabbit membranes. Drugs acting at 5-HT1, 5-HT2 and dopamine receptors (domperidone, spiperone and metergoline) showed very low affinities for [3H]ICS 205-930 recognition sites. The sites labelled with [3H]ICS 205-930 in vagus nerve and superior cervical ganglion of both species displayed the pharmacological profile of a 5-HT3 receptor. There was a significant correlation between the rank order of affinity of the tested compounds for [3H]ICS 205-930 recognition sites in cat and rabbit membranes and their rank order of affinity for 5-HT3 receptors from neuroblastoma-glioma NG 108-15 cells. Autoradiographic studies suggest that [3H]ICS 205-930 binding sites are present over and around the nodose ganglion cell somata, along certain fibers of the vagus nerve and in the terminal areas of this nerve in the medullar nucleus of the vagus. The present data demonstrate that [3H]ICS 205-930 identifies 5-HT3 receptors in preparations of cat and rabbit vagus nerve and superior cervical ganglion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00167040
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 41
    Digitale Medien
    Digitale Medien
    Carotid occlusion increases the release of endogenous GABA in the nucleus of the solitary tract (1989)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 340 (1989), S. 764-766 
    Details
    ISSN: 1432-1912
    Schlagwort(e): Nucleus of the solitary tract (NTS) ; GABA release ; Carotid occlusion ; Blood pressure ; Push-pull cannula ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In anaesthetized cats, the nucleus of the solitary tract was bilaterally superfused through push-pull cannulae with artificial cerebrospinal fluid (CSF) and the effect of carotid occlusion on the release of endogenous GABA was investigated. Bilateral carotid occlusion led to a rise in blood pressure which was associated with a very pronounced increase in the release rate of GABA in the nucleus of the solitary tract. The results demonstrate the hypertensive function of GABA in the nucleus of the solitary tract and the importance of GABAergic neurons of this nucleus for the central cardiovascular control.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00169687
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 42
    Digitale Medien
    Digitale Medien
    Genetical control and linkage relationships of isozyme markers in sugar beet (B. vulgaris L.) (1989)
    Springer
    Theoretical and applied genetics 78 (1989), S. 97-104 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Beta vulgaris ; Sugar beet ; Isozymes ; Genetics ; Linkage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Five isozyme systems were genetically investigated. The different separation techniques, the developmental expression and the use as marker system in sugar beet genetics and breeding is discussed. Isocitrate dehydrogenase was controlled by two genes. The gene products form inter- as well as intralocus dimers, even with the gene products of the Icd gene in B. procumbens and B. patellaris. Adenylate kinase was controlled by one gene. Three different allelic forms were detected, which were active as monomeric proteins. Glucose phosphate isomerase showed two zones of activity. One zone was polymorphic. Three allelic variants, active as dimers, were found. Phosphoglucomutase also showed two major zones of activity. One zone was polymorphic and coded for monomeric enzymes. Two allelic forms were found in the accessions studied. The cathodal peroxidase system was controlled by two independent genes, of which only one was polymorphic. The gene products are active as monomers. Linkage was found between red hypocotyl color (R) and Icd 2. Pgm 1, Gpi 2, Ak 1 and the Icd 2-R linkage group segregated independently.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00299761
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 43
    Digitale Medien
    Digitale Medien
    Optimising visual selection in early clonal generations of potato based on genetic and economic considerations (1989)
    Springer
    Theoretical and applied genetics 78 (1989), S. 665-671 
    Details
    ISSN: 1432-2242
    Schlagwort(e): Solanum tuberosum ; Genetics ; Breeding ; Plant appearance ; Economy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In 1985, 1986 and 1987, 600 clones were visually assessed at harvest on plant appearance. The clones were harvested 80 days after planting in the first year, in the following years after approximately 80 days as well as after 145 days. The correlation coefficients between years and between harvest times were low to medium. Simulating different selection intensities using the performance of these 600 clones in two successive years, the relation between selection pressure in the first year and the retained proportion of well performing clones in the second year was described. Including the costs of testing, the most economic selection procedure was calculated. This procedure consisted in testing 1,579 first-year clones and 499 second-year clones for every 100 third-year clones required. The optimal period of the main evaluation in the second clonal year is at ware potato harvest time. This selection procedure also provides good selection possibilities for underwater weight and foliage maturity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00262562
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 44
    Digitale Medien
    Digitale Medien
    Gap junctions between odontoblasts revealed by transjunctional flux of fluorescent tracers (1989)
    Springer
    Cell & tissue research 258 (1989), S. 611-616 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cell communication ; Dye-coupling ; Odontoblasts ; Gap junctions ; Dentin sensitivity ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cell communication between odontoblasts was investigated with the use of fluorescent-dye tracers; Lucifer Yellow CH (molecular weight = 457.3), and dextran-Lucifer Yellow CH (average molecular weight = 10000). Dyes were injected into cell bodies of individual odontoblasts via an intracellular microelectrode or into a group of cells through their processes, and passage to adjacent cells was examined with a fluorescence microscope. Lucifer Yellow CH appeared to diffuse very easily among odontoblasts, while dextran-Lucifer Yellow remained within the injected cell or cells. This efficient migration of Lucifer Yellow CH can be considered a functional manifestation of gap junctions between odontoblasts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218874
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 45
    Digitale Medien
    Digitale Medien
    NPY-, galanin-, VIP/PHI-, CGRP- and substance P-immunoreactive neuronal subpopulations in cat autonomic and sensory ganglia and their projections (1989)
    Springer
    Cell & tissue research 256 (1989), S. 259-273 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Autonomic ganglia ; Spinal ganglia ; Sensory neurons ; Neurotransmitters ; Sweat glands ; Blood vessels ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The neuronal subpopulations in the cat stellate, lower lumbar and sacral sympathetic ganglia were studied with regard to the cellular distribution of immunoreactivity to tyrosine hydroxylase (TH), acetylcholinesterase (AChE) and various neuronal peptides. Coexistence of neuropeptide Y (NPY)- and galanin (GAL)-like immunoreactivity (LI) was found in a high proportion of the neuronal cell bodies; these cells also contained immunoreactivity to TH, confirming their presumably noradrenergic nature. Some TH- and GAL-immunoreactive principal ganglion cells lacked NPY-LI. Two populations (scattered and clustered) of vasoactive intestinal polypeptide (VIP)- and peptide histidine isoleucine (PHI)-positive cell bodies were found in the sympathetic ganglia studied. The scattered VIP/PHI neurons also contained AChE-LI, calcitonin gene-related peptide (CGRP)-and, following culture, substance P (SP)-LI. The clustered type only contained AChE-LI. In the submandibular and sphenopalatine ganglia, neurons were AChE- and VIP/ PHI-immunoreactive but lacked CGRP- and SP-LI. Many GAL- and occasional TH-positive neurons were found in these ganglia. In the spinal ganglia, single NPY-immunoreactive sensory neuronal cells were observed, in addition to CGRP- and SP-positive neurons. The present results show that there are at least two populations of sympathetic cholinergic neurons in the cat. Retrograde tracing experiments indicate that the scattered type of cholinergic neurons contains four vasodilator peptides (VIP, PHI, CGRP, SP) and provides an important input to sweat glands, whereas the clustered type (containing VIP and PHI) mainly innervates blood vessels in muscles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218883
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 46
    Digitale Medien
    Digitale Medien
    A comparison of muscle precursor replication in crush-injured skeletal muscle of Swiss and BALBc mice (1989)
    Springer
    Cell & tissue research 255 (1989), S. 385-391 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Myogenesis ; Muscle regeneration ; Genetics ; Autoradiography ; Tritiated thymidine ; Mouse (Swiss;BALBc)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Muscle precursor replication in Swiss mice, in which muscle regeneration is exceptionally vigorous, was compared with previous data for regeneration in BALBc mice. The tibialis anterior muscles of 23 male and 15 female inbred Swiss SJL/J mice were crush injured, and tritiated thymidine injected into mice at various times after injury to label replicating muscle precursors. Lesion samples were taken 10 days after injury, processed for autoradiography, and grain counts of myotube nuclei analysed. Muscle regeneration was more vigorous in male compared with female Swiss mice, and in both was strikingly greater than that in BALBc mice in which there was extensive fibrous connective tissue throughout the lesions. Autoradiographic analysis showed that muscle precursor replication started at 24 hours in Swiss mice, 6 hours earlier than the onset at 30 hours in BALBc mice. Muscle precursor replication appeared to be more active 96 hours after injury in female Swiss compared with male BALBc and male Swiss mice respectively, although numbers of precursor cells replicating at other times were similar. It is not known whether the slight difference in onset of muscle precursor replication can alone account for the more complete muscle regeneration seen in Swiss mice. Similar studies were carried out in 11 male and 10 female F1 hybrid (SJL/J x BALBc) mice. Analysis of labelled myotube nuclei showed that muscle precursors did not synthesise DNA prior to 30 hours after injury, and regeneration resembled that of the parental BALBc strain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00224122
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 47
    Digitale Medien
    Digitale Medien
    Nerve-induced secretion of parotid acinar granules in cats (1989)
    Springer
    Cell & tissue research 257 (1989), S. 549-554 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Salivary secretion ; Parotid gland ; Exocytosis ; Secretory granules ; Autonomic nerve-stimulation ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Electron microscopy of cat parotid glands revealed great heterogeneity in the secretory granules of normal unstimulated acinar cells. Electrical stimulation of the parasympathetic nerve to the gland evoked a copious flow of parotid saliva which was accompanied by an extensive depletion of the secretory granules from the acinar cells. Exocytosis was captured as it was occurring by means of perfusion-fixation, and showed that the events occur in a conventional manner. Stimulation of the sympathetic nerve caused only a very small flow of saliva, and no acinar degranulation was detected. It can be concluded that the parasympathetic secretomotor axons provide the main drive for parotid acinar degranulation in the cat. This contrasts with the rat in which sympathetic impulses provide the main stimulus for parotid acinar degranulation. These dissimilarities serve to emphasise how extensively species differences may influence autonomic responses in salivary glands.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221465
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 48
    Digitale Medien
    Digitale Medien
    Tryptophan auxotrophic mutants in Aspergillus niger: Inactivation of the trpC gene by cotransformation mutagenesis (1989)
    Springer
    Molecular genetics and genomics 219 (1989), S. 282-288 
    Details
    ISSN: 1617-4623
    Schlagwort(e): Aspergillus ; Genetics ; Transformation ; trpC lacZ gene fusion ; Gene replacement
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Aspergillus niger tryptophan auxotrophic mutants have been isolated after UV irradiation of conidiospores. The mutants belong to two different complementation groups, trpA and trpB, which complement each other in heterokaryons. Neither of the mutations could be complemented with the cloned A. niger trpC gene. To obtain A. niger trpC mutants in a direct way, gene inactivation by cotransformation was performed. For this purpose an in-frame gene fusion between the A. niger trpC and Escherichia coli lacZ genes was constructed and shown to be functionally expressed after introduction into A. niger by cotransformation with the pyrA gene as selective marker. Among the β-galactosidase expressing cotransformants, obtained with either circular or linearized vectors, no trpC mutants were detected, even after enrichment. Such mutants, however, could be obtained by cotransformation of A. niger with specific fragments of the fusion gene. Biochemical analysis of the cotransformants indicated that in nearly all cases the fusion gene had replaced the wild-type trpC gene. Genetic analysis showed that the trpC mutation is not linked to any of the A. niger loci described so far. The trpC mutants can be complemented by the cloned A. niger trpC gene as well as by the A. nidulans trpC gene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00261189
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 49
    Digitale Medien
    Digitale Medien
    Histologic and physiologic evaluation of electrically stimulated peripheral nerve: Considerations for the selection of parameters (1989)
    Springer
    Annals of biomedical engineering 17 (1989), S. 39-60 
    Details
    ISSN: 1573-9686
    Schlagwort(e): Electrical stimulation ; Neural damage ; Peripheral nerve electrode ; Peroneal nerve ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: Abstract Helical electrodes were implanted around the left and right common peroneal nerves of cats. Three weeks after implantation one nerve was stimulated for 4–16 hours using charge-balanced, biphasic, constant current pulses. Compound action potentials (CAP) evoked by the stimulus were recorded from over the cauda equina before, during and after the stimulation. Light and electron microscopy evaluations were conducted at various times following the stimulation. The mere presence of the electrode invariably resulted in thickened epineurium and in some cases increased peripheral endoneurial connective tissue beneath the electrodes. Physiologic changes during stimulation included elevation of the electrical threshold of the large axons in the nerve. This was reversed within one week after stimulation at a frequency of 20 Hz, but often was not reversed following stimulation at 50–100 Hz. Continuous stimulation at 50 Hz for 8–16 hours at 400 μA or more resulted in neural damage characterized by endoneurial edema beginning within 48 hours after stimulation, and early axonal degeneration (EAD) of the large myelinated fibers, beginning by 1 week after stimulation. Neural damage due to electrical stimulation was decreased or abolished by reduction of the duration of stimulation, by stimulating at 20 Hz (vs. 50 Hz) or by use of an intermittent duty cycle. These results demonstrate that axons in peripheral nerves can be irreversely damaged by 8–16 hours of continuous stimulation at 50 Hz. However, the extent to which these axons may subsequently regenerate is uncertain. Therefore, protocols for functional electrical stimulation in human patients probably should be evaluated individually in animal studies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02364272
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 50
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989) 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100101
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 51
    Digitale Medien
    Digitale Medien
    Sex-, tissue-, and stage-specific expression of a vitelline membrane protein gene from region 32 of the second chromosome of Drosophila melanogaster (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 33-41 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Oogenesis ; Eggshell ; Gene family ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: This study isolated cDNA clones from egg-chamber and adult female Drosophila cDNA libraries using as probe a DNA fragment from a 200-kb “chromosome walk” in region 32E of the second chromosome of D. melanogaster. The present authors believe that these clones correspond to a new vitelline membrane protein (VMP) gene because (1) cDNA clones in Northern blots identify a transcript expressed in a tissue- and stage-specific manner: stage 10 egg-chambers; (2) the sequence of cDNAs and of the genomic subclone shows homology with the other VMP genes that have been identified to date; (3) the amino acid composition of the translational product has the high content of proline and alanine characteristic of VMPs. Two aspects emerging from this study are worth stressing: (1) the presence of a hydrophobic domain that is highly conserved in all the VMP genes; and (2) the particularly narrow period of expression of the isolated gene, which could be related to the mechanism of vitelline membrane assembly.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100106
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 52
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989) 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100201
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 53
    Digitale Medien
    Digitale Medien
    DNA methylation in fungi (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 63-69 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100202
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 54
    Digitale Medien
    Digitale Medien
    The role of polyfusomes in generating branched chains of cystocytes during Drosophila oogenesis (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 70-86 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Arrested cleavage ; Centrosome ; contractile ring ; Fusome ; Germarium ; Models of dividing cells ; Oocyte/nurse cell syncytium ; Ovarian tumor mutation ; POlytrohic meroistic ovary ; Ring canal ; Spindle elongation ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Three-dimensional models were constructed utilizing the information gained from electron micrographs of serial sections of two clones of cystocytes undergoing their terminal divisions. In each clone a polyfusome connected all eight cystocytes together. Each of the spindles was oriented so that one pole touched the polyfusomes, while the other pointed away from it. This positioning of spindles ensures that one cell of each dividing pair retains all previously formed canals, while the other receives none. The two cells that eventually come to contain the maximum number of canals and fusomal material are the ones that differentiate as pro-oocytes, while the others become nurse cells. The orientation of each spindle suggests that the polyfusome formed at one division determines the placement of the cytoskeletal fibers that anchor the spindles formed at the next division. There is a centripetal gathering together of new canals following each cycle of cystocyte division, which is thought to result from the subsequent contraction of the polyfusomal system. Females homozygous for the otu1 mutation are characterized by ovarian tumors, which result when germarial cystocytes undergo supernumerary divisions and fail to differentiate into either nurse cells or oocytes. An analysis of electron micrographs taken of serially sectioned, mutant germaria showed that most germ cells were single or belonged to clusters of two or three interconnected cells. Therefore otu1 cystocytes are unable to undergo a sustained series of arrested cleavages. These cystocytes contain fusomal material that shows ultrastructural differences from normal polyfusomes. We conclude: (1) that a normal polyfusomal system is a necessary prerequisite for the production of a branched chain of cystocytes and for their subsequent differentiation into pro-oocytes and nurse cells; and (2) that a product encoded by the otu+ gene is essential for the construction of a functional polyfusome.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100203
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 55
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989) 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100301
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 56
    Digitale Medien
    Digitale Medien
    Introduction (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 123-123 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100302
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 57
    Digitale Medien
    Digitale Medien
    A genetic switch, based on negative regulation, sharpens stripes in Drosophila embryos (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 124-142 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Cell determination in Drosophila ; Pair-rule gene expression ; Negative transcription control ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The pair-rule genes hairy, runt, even-skipped, and fushi tarazu express their mRNAs and proteins in striped patterns in the Drosophila embryo at the blastoderm stage. Previous studies have shown that the generation of these patterns depends upon products of the gap genes and upon interactions between the pair-rule genes themselves. Here we show that blocking protein synthesis induces expression of each of the pair-rule mRNAs in virtually all regions of the embryo. Our observations together with genetic studies carried out in other laboratories suggest that negative feedback between the pair-rule genes plays a key role in striped expression of pair-rule genes. We propose that stable proteins, present in all regions of the embryo, first activate transcription ofthese pair-rule genes constitutively. Then, various combinations of unstable proteins repress their transcription in a patterned fashion; each stripe of accumulated products of a given pair-rule gene marks a region where it was not repressed. We develop this idea in mathematical form and demonstrate that a network of mutual repression by pair-rule genes can make each blastoderm nucleus into a genetic switch with two stable states. If preexisting gap gene patterns provide initial bias to the blastoderm nuclei, then the “bistable switch behavior” of the nuclei can refine an initially weak spatial bias into a final pattern of sharp stripes.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100303
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 58
    Digitale Medien
    Digitale Medien
    Molecular genetics of transformer, a genetic switch controlling sexual differentiation in Drosophila (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 143-154 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Alternative splicing ; Drosophila development ; Sex determination ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The transformer gene is one of a set of regulatory genes that form the hierarchy controlling all aspects of somatic sexual differentiation in Drosophila melanogaster. The gene transformer occupies an intermediate position in this hierarchy. Analysis of this gene has allowed us to determine the mechanism by which it is regulated in a sex-specific manner and to examine the way in which the regulatory hierarchy is organized. The female-specific expression of the tra gene, previously inferred from genetic observations, is bused on sex-specific alternative splicing of tra pre-mRNA and is not the result of sex-specific transcriptional activation. The female-specific RNA produced by this alternative splicing is the functional mediator of tra activity. Multiple genetic, molecular, and transformation experiments show that female-specific activation of genes or gene products occurs in the order Sex lethal 〉 transformer 〉 transformer-2 〉 doublesex · intersex 〉 female differentiation. The results do not distinguish the level at which transformer might regulate the downstream gene transformer-2. Neither transformer nor any of the downstream genes feedback on, or participate in, alternative splicing of transformer RNA. The mechanism by which Sex lethal regulates transformer splicing appears to be a repression of the use of one of a pair of splice acceptor sites.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100304
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 59
    Digitale Medien
    Digitale Medien
    Histochemical analysis of extracellular matrix material in embryonic trisomy 1 mouse eye (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 287-291 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Robertsonian translocation chromosomes ; Lens ; Optic cup ; Triplication of chromosomes ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Trisomic animals produced from mice doubly heterozygous for Robertsonian translocation chromosomes [Rb(1.3)/Rb(1.10)] consistently show eye defects (e.g., aphakia, micro-phakia, and retention of lens stalk). To determine if changes in distribution or composition of extracellular matrix material may be a factor in development of these defects, eye structures of tnsomy (ts) 1 embryos and normal littermates were studied his-tochemically using the following methods: Alcian blue 8GX, pH 2.5; periodic acid-Schiff (PAS), Alcian blue/PAS combined; high-iron diamine (HID); and HID/Alcian blue combined. Eye development was divided into stages to account for the known delay in ts 1 mouse development.Differences were found in staining patterns as early as stage 1. In later stages, the most consistent difference was an increased period of contact between lens and optic cup due to retardation of interface matrix dissolution between these rudiments in ts 1 embryos. Eyes in which this occurred had abnormally shaped lenses. Overall, the ts 1 optic cup appeared to have fewer staining abnormalities and dysmorphology than did the lens or interface matrix.Triplication of a chromosome may indirectly alter temporal and spatial organization of extracellular matrix through action on cells responsible for the production of this material. Possible mechanisms of action are discussed.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100402
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 60
    Digitale Medien
    Digitale Medien
    5-Azacytidine-induced tumorous transformation and DNA hypomethylation in Nicotiana tissue cultures (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 298-303 
    Details
    ISSN: 0192-253X
    Schlagwort(e): 5-Azacytidine ; DNA methylation ; Plant tumorogenesis ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The phenomenon of habituotion is considered in plant tissue cultures to be a real process of chemical tumorogenesis: the cultures acquire the capacity of autonomous growth in a hormone-free medium under the influence of a variety of chemical and physical agents. Treatments with 5-azacytidine (AzaC) of in vitro cultured cells of the Nicotiana glauca × N. langsdorffii nontumorous hybrid (NNT)during the culture cycle led to the induction of a habituated phenotype. The repetitive DNA sequences showed a significant lower level of endogenous methylation in the treated cells in comparison with the normal ones. It is worth noting that it was impossible until now to habituate this strain by conventional methods and that the treatments were effective only in the first 5 days of subculturing; various evidence (cytological and biochemical) pointed out a phenomenon of DNA amplification, occurring in the same period. Moreover, analysis of DNA from control and treated cells shows the induction of variations in the endogenous methylation pattern by AzaC in a critical period of cell culture. These results suggest that demethylation can act as a switch from hormone-dependent to autonomous proliferation by activation of genes coding for or regulating the synthesis of growth factors.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100404
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 61
    Digitale Medien
    Digitale Medien
    Differential expression of the maize catalase genes during kernel development: The role of steady-state mRNA levels (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 304-310 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Maize ; Catalase ; Kernel ; Gene expression ; mRNA ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: In maize three isozymic forms of catalase, CAT-1, CAT-2, and CAT-3 are encoded by three distinct and unlinked structural genes (Catl, Cat2, and Cat3). Catalase activity profiles and zymogram analysis were used to examine the spatial and temporal expression of the three genes during kernel maturation. Three developmental stages of catalase expression were observed in the growing kernel. During stage 1 (6-12 days after pollination), both Catl and Cat3 were expressed; during stage 2 (15-18 days after pollination) only Cat1 expression was observed; and during stage 3 (21-30 days after pollination), Cat1 and Cat2 were expressed. The major constituent tissues of the kernel were examined to determine their contribution to total kernel catalase expression. Each of the tissues was found to have a unique pattern of catalase gene expression. RNA blot analysis, using catalase gene-specific nucleic acid probes, suggests that the differential expression of the three catalase genes observed in the kernel is regulated by controlling the distribution of steady-state mRNA species for the three genes.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100405
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 62
    Digitale Medien
    Digitale Medien
    Connexin32, a gap junction protein, is a persistent oogenetic product through preimplantation development of the mouse (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 318-323 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Mouse embryos ; Gap junctions ; Connexin43 ; mRNA ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Gap junctions appear de novo during compaction in the eight-cell stage of mouse development. This is a critical event in the life of the embryo, because gap junctional intercellular communication is an essential requirement for maintaining compaction and, hence, for development of the blastocyst. Recently, a family of genes encoding gap junction proteins (connexins) has been identified and cloned, and we have taken advantage of the availability of antibodies and cDNA probes to investigate the expression of these genes in early development. We found that a protein with antigenic and size similarity to the “liver” gap junction protein, connexin32, is present throughout preimplantation development from the zygote through the late morula. Connexin32 mRNA, however, could not be detected in any preimplantation stage. This, and the presence of connexin32 in zygotes before activation of embryonic transcription, leads us to conclude that this protein is inherited as an oogenetic product that persists well beyond the transition from the oogenetic to embryonic program of gene expression. Furthermore, we found that mRNA for another gap junction protein, connexin43, is fairly abundant in preimplantation embryos. We conclude that it is more likely connexin43, and not connexin32, that is used to assemble new connexons as the level of intercellular coupling increases after compaction.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100407
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 63
    Digitale Medien
    Digitale Medien
    Hemin increases production of β-like globin RNA transcripts in human erythroleukemia K-562 cells (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 311-317 
    Details
    ISSN: 0192-253X
    Schlagwort(e): β-globin ; Human erythroleukemia cells ; RNA transcripts ; K562 ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Previous studies have indicated that control and hemin-treated human eryth-roleukemia K-562 cells fail to produce adult-type β-globin mRNA transcripts and to translate them into nascent β-globin chains. Expression of the β-globin DNA sequences in K-562 cells can occur, however, under certain conditions. To readdress this issue and to examine the possibility of whether these cells produce immature and untranslatable β-globin RNA transcripts, we prepared total cyto-plasmic RNA from control and inducer-treated cells and performed Northern blot hybridization analysis using 5′ end-labeled fragments of the human β-globin DNA rather than 3′ end fragments as probes. Although hybridization of both cytoplasmic and nuclear K-562 RNA with a32P-labeled 3′ end fragment (1.6kb Bam H1 cut) coding for a large part of the first exon of β-globin failed to detect β-globin RNA transcripts, hybridization with a 5′ end 32P-labeled 2.0kb Bam H1 fragment (coding for the third exon and part of the second) revealed the presence of relatively small (〈7S) RNA molecules both in nuclear and cytoplasmic fraction. S1 nuclease mapping of both cytoplasmic and nuclear RNA with the use of 5′ end-labeled 2.0 kb Bam H1 fragment of human β-globin DNA indicated protection of a small portion located 64bp 5′ upstream from the Bam H1 site of the second exon. The amount of protected portion was relatively higher in K-562 cells undergoing erythroid maturation. These findings suggest that control and differentiating K-562 cells synthesize β-globin-like RNA transcripts that are 3′ end short, immature, and unable to give rise to adult β-globin chains. These results also indicate that K-562 cells may lack factors that are unique for transcription and processing of the human β-globin RNA transcripts.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100406
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 64
    Digitale Medien
    Digitale Medien
    Heat-shock proteins during pollen development in maize (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 324-332 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Heat-shock proteins ; Pollen ; Development ; Maize ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: In contrast to sporophytic tissues, mature pollen of higher plants does not synthesize the typical set of heat-shock proteins (HSPs) in response to a marked temperature upshift. Immature grains, however, seem able to do so, at least partially. We investigated the characteristics of HSP synthesis throughout the male gametophytic phase in maize and compared gametophytic and sporophytic heat-shock responses. One-dimensional Sodium dodecyl sulfate-polyacryl-amide gel electrophoresis technique (SDS-PAGE) of newly synthesized proteins revealed that immature pollen synthesizes HSPs, some of which are not induced in sporophytic tissues. The heat-shock response appeared to be related to microgametophytic developmental stages. The strongest response was found in uninucleate microspores: at this stage, in addition to the sporophytic 102, 84, 72, and 18 kD HSPs, three other polypeptides of 74, 56, and 46 kD were observed. In the binucleate and trinucleate stages, only a reduced synthesis of few HSPs could be induced, and differences between genotypes were observed. In germinating pollen, HSP synthesis was not induced under a voriety of heat-stress conditions; however, the consti-tutive synthesis of two polypeptides of the same molecular weight, 72 and 64 kD, as two HSPs was observed. The biological significance of these results is discussed.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100408
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 65
    Digitale Medien
    Digitale Medien
    Stage-specific gene expression in early chick embryo (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 333-338 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Cell migration ; Aphidicolin ; Blastula-Gastrula ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Inhibition of DNA replication by aphidicolin in the chick morula interferes with its progression to a normal blastula and prevents induction of the first morphogenetic cell movements of primitive streak formation. Embryos in aphidicolin synthesize some polypeptides typical of blastula but do not display all the characteristic features of morula to blastula transition. Inhibition of DNA replication inteferes with the sequential synthesis of maternally coded polypeptides and with the activation of the embryonic genome in the chick embryo.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100409
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 66
    Digitale Medien
    Digitale Medien
    Erratum (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 345-345 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100411
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 67
    Digitale Medien
    Digitale Medien
    Announcement (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 347-347 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100412
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 68
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989) 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100501
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 69
    Digitale Medien
    Digitale Medien
    Regulation of catalase-specific mRNA and its processing during development in mice (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 339-344 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Delayed processing ; Splicing ; Transcription ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: This study deals with the pattern of developmental expression of the catalase gene in mice. We have used a mouse catalase 2 kb cDNA (pMCT-1) and its 1.4 kb 5′ fragment as probes to characterize the transcripts during embryonic development and differentiation. Total RNA was isolated from 8 days postconceptus (p.c.) whole embryos and from livers and carcasses of 13, 15, and 18 day p.c. embryos as well as from the livers of newborn and adult mice of the S.W. strain. The RNA was applied on slot blots, and run on agarose gels to generate northern blots. Blots were hybridized with the 32P-labeled cDNA probe under different stringency conditions. Autoradiograms were scanned with a densitometer to quantify relative hybridization signals of RNA samples obtained from two or three individual mice representing each stage of development.The catalase transcript is detectable as early as 8 days p.c. with the beginning of somite formation. At this stage, it is primarily in the form of a 12.2 kb transcript. One additional band (2.4 kb) is also apparent at this stage although at a very low intensity. The intensity of the two bands increases with development, particularly during 13-18 days p.c. in liver and carcass. The 2.4 kb RNA band increases sharply from day 8 through 13, 15, and 18 days p.c. and is confined primarily to the liver. Interestingly, only the 2.4 kb RNA band is seen at and after birth. The 2.4 kb RNA is the known mature message of the catalase gene in mice. The presence of large catalase-specific RNA species (seen during development in utero only) is interpreted as the primary transcript of this gene. The complete and efficient processing of this primary transcript takes place only after birth and primarily in the liver, which may be related to the physiological role of this enzyme in oxygen metabolism, particularly stressful superoxides, expected with independent respiration. At a lower stringency wash of the northern blots, a 9.5 kb RNA was seen during a narrow window of in utero development. This 9.5 kb band may represent an uncharacterized catalase-related gene with a possible role in development and differentiation.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100410
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 70
    Digitale Medien
    Digitale Medien
    Expression of a methotrexate resistant dihydrofolate reductase gene in transgenic mice (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 349-355 
    Details
    ISSN: 0192-253X
    Schlagwort(e): SV40 promoter ; Expression vector ; Drug resistance ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: We have previously demonstrated systemic resistance to methotrexate (MTX) in transgenic mice carrying a foreign, mutant dihydrofolate reductase (DHFR, E.C. 1.5.1.3) gene. The new gene was introduced as a cDNA cloned into an expression vector driven by the simian virus 40 (SV40) early promoter. Previous physiologic studies suggested that transgenic mice tolerated drug doses invariably lethal to controls on the basis of gastrointestinal (GI) resistance to MTX. In the present study we evaluated foreign gene expression at the RNA level in the three major sites of MTX toxicity: intestine, liver, and bone marrow.The transgene was transcriptionally active in small bowel, and levels of expression were high in animals tolerating the largest doses of MTX. The gene was also expressed in the liver in some pedigrees, but was not detected in hemopoietic tissues of any of the pedigrees tested. Our studies correlate the site of expression of a drug resistant dhfr gene with an altered physiologic response to MTX, and demonstrate that transgenic mice can be used as a test system for expression of genes considered for use in somatic gene therapy.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100502
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 71
    Digitale Medien
    Digitale Medien
    Hyperinsulinemia in transgenic mice carrying multiple copies of the human insulin gene (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 356-364 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Glucose intolerance ; Insulin resistance ; Diabetes mellitus ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: We are investigating human insulin gene expression in transgenic mice. An 8.8 kilobase (kb) human genomic DNA fragment, including the insulin gene (1.4 kb) and 2 kb of 5′ human flanking sequences, was introduced into mouse embryos by pronuclear microinjection. Two lines of transgenic mice have been established, both of which carry the intact human gene in multiple copies. Animals from both lines have significantly higher insulin levels than control mice, and the degree of hyperinsulinemia shows a positive correlation with human gene copy number in the two lines. Expression of the human gene is confirmed by the detection of human C-peptide in plasma. Tissue specificity of expression is maintained, with human insulin mRNA detectable only in the pancreas. The transgenics maintain normal fasting blood glucose in spite of their high insulin levels, but preliminary studies show them to be glucose intolerant when given a glucose load. These mice provide a model system for further studies on the regulation of insulin gene expression and on the effects of chronic hyperinsulinemia on glucose homeostasis.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100503
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 72
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989) 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100601
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 73
    Digitale Medien
    Digitale Medien
    Introduction (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 411-411 
    Details
    ISSN: 0192-253X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100602
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 74
    Digitale Medien
    Digitale Medien
    Stepwise aggregation, compaction, and differentiation of uncompacted F9 cells (1989)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 10 (1989), S. 402-410 
    Details
    ISSN: 0192-253X
    Schlagwort(e): F9 ECC ; Aggregates ; Embryoid bodies ; Endoderm ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: To study the relationship between compaction and differentiation in aggregates of F9 embryonal carcinoma cells, a subline was developed which grows mostly uncompacted in monolayer culture in medium containing a low concentration of calcium (about 0.05 mM). When these cells were trypsinized and cultured in suspension in the same medium, they formed loose, open aggregates, which failed to differentiate into embryoid bodies after exposure to 10 nM retinoic acid, confirming the requirement of compaction for differentiation. If, after culture for 3 days, the uncompacted F9 aggregates were exposed to additional calcium (4 mM), all compacted within an hour. The number of days necessary for aggregates to acquire this ability to compact rapidly was reduced if the monolayer of cells from which the aggregates were derived had been exposed to additional calcium to cause compaction for several days prior to trypsinization and aggregation. Next, treatment of the compacted F9 aggregates with 10 nM retinoic acid was followed by differentiation into embryoid bodies. The number of days required for this was also reduced if the aggregates were formed from previously compacted cells, presumably because compaction of the aggregates occured sooner.The acceleration in compaction and differentiation in aggregates formed from previously compacted cells suggests that some of the proteins important for compaction, which are synthesized in a monolayer of compacted cells, persist through trypsinization and are carried over from monolayer to aggregates. Alternatively, an inhibitor of compaction is decreased in the compacted monolayer. Thus, the process of compaction in its entirety, including its relationship to subsequent differentiation, cannot be studied in aggregates formed from F9 cells grown as usual in the compacted state in monolayer culture. This work provides an alternative system in which aggregation, compaction, and differentiation of F9 cells can be made to occur in stepwise fashion and can be examined separately.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/dvg.1020100508
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 75
    Digitale Medien
    Digitale Medien
    Yeast taxonomy (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. S339 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050706
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 76
    Digitale Medien
    Digitale Medien
    Plenary lectures (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. S505 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050709
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 77
    Digitale Medien
    Digitale Medien
    Yeast biology (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. S303 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050705
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 78
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989) 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050101
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 79
    Digitale Medien
    Digitale Medien
    Calendar (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. ii 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050102
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 80
    Digitale Medien
    Digitale Medien
    Analysis of chromosomal DNA patterns of the genus Kluyveromyces (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 1-10 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Yeast ; genome size ; orthogonal-field-alternation gel electrophoresis ; mitochondrial DNA ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Using an improved procedure of pulsed field gel electrophoresis, yeast chromosomes were separated over a wide range of molecular size (250-4000 kbp) on single gels. The chromosomal DNA patterns of all the species belonging to the genus Kluyveromyces were examined. Within the species K. marxianus, the varieties lactis, drosophilarum and vanudenii showed closely related patterns; very different from them, the varieties bulgaricus and marxianus were related to each other, forming a distinct group; the strains commonly called ‘K. lactis’ and ‘K. fragilis’ were unambiguously different from each other in chromosome patterns. These differences were correlated with the presence of characteristic repetitive sequence elements in the mitochondrial DNA of the former group and not in the latter. Analysis of Candida macedoniensis, which had been considered to be an anamorph of K. marxianus var. marxianus, showed that these two yeast species were indeed similar in chromosome patterns and in mitochondrial DNA restriction patterns.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050103
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 81
    Digitale Medien
    Digitale Medien
    Yeast KEX2 protease and mannosyltransferase I are localized to distinct compartments of the secretory pathway (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 25-33 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Secretion ; Saccharomyces cerevisiae ; Golgi apparatus ; protein targetting ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The KEX2 protease (product of the KEX2 gene) functions late in the secretory pathway of Saccharomyces cerevisiae by cleaving the polypeptide chains of prepro-killer toxin and prepro-α-factor at paired basic amino acid residues. The intracellular vesicles containing KEX2 protease sedimented in density gradients to a position distinct from those containing mannosyltransferase I (product of the MNN1 gene), a marker enzyme for the Golgi complex. The recovery of intact compartments containing these enzymes approached 80% after sedimentation. We propose that the KEX2 protease and mannosyltransferase I reside within distinct compartments.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050105
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 82
    Digitale Medien
    Digitale Medien
    Cloning and characterization of Baker's yeast α-glucosidase: Over-expression in a yeast strain devoid of vacuolar proteinases (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 11-24 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Yeast ; α-glucosidase ; nucleotide sequence ; expression ; proteinase ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Two α-glucosidase (maltase) genes, designated GLUCPI and GLUCPII, have been cloned from an industrial strain of baker's yeast (Saccharomyces cerevisiae) by complementation of a maltase-negative mutant strain. The different genes were identified according to their alternatively expressed isoenzymes PI and PII in transformants after isoelectric focusing and activity staining in separated cell lysates. The gene encoding α-glucosidase PI (GLUCPI), which was not present in laboratory strains of S. carlsbergensis with a defined MAL1, 2, 3, 4 or 6 locus, was sequenced and compared with the recently published MAL6S gene. This comparison revealed single amino acid deviations at three positions in the predicted polypeptide sequence. In addition, the divergent promoter region of GLUCPI differed from MAL6S by a triple repeated 147-bp DNA segment. Maltose induction and glucose repression of α-glucosidase PI were not affected by the deletion of the repeated DNA segment. However, the absolute expression of α-glucosidase PI increased two- to four-fold. In addition, a two-fold increase in the maltase synthesis occurred when the cloned positive regulator gene MAL2-8cp was on the same plasmid. Furthermore, stability of the α-glucosidase in cultures in the stationary growth phase was greatly enhanced using a host strain lacking the proteinases A and B and the carboxypeptidases Y and S. Promoter trimming, MAL2-8cp stimulation and the use of a host strain deficient in four vacuolar proteinases resulted in α-glucosidase PI expression of about 13% of the soluble protein.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050104
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 83
    Digitale Medien
    Digitale Medien
    Cloning and analysis of the Kluyveromyces lactis TRP1 gene: A chromosomal locus flanked by genes encoding inorganic pyrophosphatase and histone H3 (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 35-50 
    Details
    ISSN: 0749-503X
    Schlagwort(e): TRP1 ; histone H3 ; histone H4 ; pyrophosphatase ; Kluyveromyces ; yeast ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The TRP1 gene of the yeast Kluyveromyces lactis has been cloned from a genomic library by complementation of the Saccharomyces cerevisiae trpl-289 mutation. The gene was located within the clone by transposon mutagenesis and the coding region identified by DNA sequencing. This has indicated that K. lactis TRP1 encodes a 210-amino acid polypeptide which shows 53% identity to the homologous S. cerevisiae protein. The K. lactis TRP1 gene has been disrupted by substituting the S. cerevisiae URA3 gene for a large part of the TRP1 coding sequence. Replacement of the chromosomal TRP1 locus with this construction has enabled the production of non-reverting trp1- strains of K. lactis, while a genetic analysis of the disrupted allele confirmed that the TRP1 gene had been cloned. DNA sequencing has also shown that the K. lactis TRP1 sequences is flanked by genes encoding inorganic pyrophosphatase and histone H3, which we have designated IPP and HHT1 respectively. Hybridization studies have shown that in common with S. cerevisiae, K. lactis has two copies of the histone H3 gene. Each H3 gene is closely linked to a gene encoding histone H4 and in both yeast species the IPP gene is tightly linked to one of the histone gene pairs.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050106
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 84
    Digitale Medien
    Digitale Medien
    Extraction and rapid inactivation of proteins from Saccharomyces cerevisiae by trichloroacetic acid precipitation (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 51-53 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Yeast ; protein ; extract ; trichloroacetic acid ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Methods currently used for the extraction of proteins from yeast involve relatively long time periods between sampling cells from a culture and analysis of their proteins by polyacrylamide gel electrophoresis-sodium dodecylsulphate. Often it is desirable to inactivate cellular metabolism rapidly after sampling and here we show that trichloroacetic acid precipitation techniques, often used for rapid extraction and inactivation of proteins from higher eukaryotes, can be adapted for use with organisms which have cell walls.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050107
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 85
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989) 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050201
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 86
    Digitale Medien
    Digitale Medien
    Calender (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. ii 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050202
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 87
    Digitale Medien
    Digitale Medien
    Sequence and mutational analysis of ESS1, a gene essential for growth in Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 55-72 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Gene disruption ; genetic mapping ; nonsense suppression ; multibudded phenotype ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: A newly isolated gene, ESS1, was shown to encode a protein required for vegetative growth in Saccharomyces cerevisiae. The nucleotide sequence of ESS1 revealed a 172 amino acid open reading frame predicting a highly basic, 19·5 kilodalton product. Although the gene was isolated by cross-hybridization with the vertebrate v-sis oncogene, the primary amino acid sequence bears only a slight resemblance to the p28sis protein. ESS1 was shown to be single copy in the yeast genome and transcriptionally active during logarithmic growth. It is located on the right arm of chromosome X, 6 centimorgans distal to ilv3. The genetic map location indicates it is not allelic to any previously characterized mutation in this organism. Both inactivation of ESS1 by gene disruption and overexpression by fusion to a heterologous promoter were detrimental to growth in both haploid and diploid cell types. Under non-permissive conditions, the terminal phenotype of strains containing a suppressible amber mutation within ESS1 was one of aberrant multibudded structures. Examination of this morphology indicates that loss of ESS1 function may lead to a defect in cytokinesis or cell separation.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050108
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 88
    Digitale Medien
    Digitale Medien
    Vanadate inhibition of mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 73-77 
    Details
    ISSN: 0749-503X
    Schlagwort(e): vandate ; mitochondria ; H+ ATPase ; S. cerevisiae ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The effects of vandate on mitochondrial respiration and H+ ATPase activity in Saccharomyces cerevisiae were studied. A 50% inhibition of oxygen uptake in isolated mitochondria was produced by 4·4 mM-V2O5. Activity of H+ ATPase in whole mitochondria was inhibited by 50% by 5·5 μM-V2O5, in submitochondrial particles by 55 μM-V2O5; and in the chloroform-released H+ ATPase by 0·5 mM-V2O5. Vandate was also found to relieve growth inhibition caused by the mitochondrial H+ ATPase inhibitors NN′-decyclohexylcarbodiimide and oligomycin. These results imply that vanadate could affect mitochondrial respiration by interacting with the H+ ATPase in S. cerevisiae.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050109
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 89
    Digitale Medien
    Digitale Medien
    Cloning of CDC33: A gene essential for growth and sporulation which does not interfere with cAMP production in Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 79-90 
    Details
    ISSN: 0749-503X
    Schlagwort(e): CDC33 ; cell division cycle ; cyclic AMP ; start gene ; yeast ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The CDC33 gene of Saccharomyces cerevisiae belongs to the class II ‘START’ genes. Its product is required for the initiation of a new cell division cycle (Hartwell, 1974). Many results suggest that the cAMP signalling pathway is one of the major controlling elements of ‘START’. Components of this pathway are encoded by class II ‘START’ genes. The aim of the present study is to determine whether or not the CDC33 gene interferes with the cAMP signalling pathway. We report here the molecular cloning of the CDC33 gene by complementation of the cdc33-1 thermosensitive mutant. The identity of the cloned gene is confirmed by site-specific reintegration and segregation analysis. This gene is transcribed into a 900-nucleotides mRNA and appears to be relatively abundant in the cell. We also show that the CDC33 gene product is essential for sporulation. cdc33-1 mutant cells are able to enter into the resting state. The cAMP intracellular pool is not modified when the cdc33-1 mutant is shifted to the restrictive temperature. The cdc33-1 mutation is not suppressed by other known elements of the cAMP cascade. All these results suggest that the CDC33 ‘START’ gene does not interfere with the cAMP signalling pathway which controls cell division.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050203
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 90
    Digitale Medien
    Digitale Medien
    Increase in gene expression by respiratory-deficient mutation (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 91-98 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Saccharomyces cerevisiae ; respiratory-deficient mutants ; increased gene expression ; mRNA level ; human lysozyme ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Respiratory-deficient mutants (rho- cells) of Saccharomyces cerevisiae produced about 10 times as much human(h-) lysozyme as did wild-type strains (rho+ cells) when the GAL10 promoter was used in an expression plasmid with the h-lysozyme gene. Introduction of intact mitochondria into the rho- cells resulted in a significant decrease in the production of h-lysozyme, indicating that the rho- mutation increased the expression of the h-lysozyme gene. The copy number of the expression plasmid was not responsible for the increased expression. The level of h-lysozyme mRNA in the rho- cells was also much higher than that in the rho+ cells especially at the stationary phase. The increased expression of the h-lysozyme gene was also observed when a glyceraldehyde-3-phosphate dehydrogenase gene promoter and the PHO5 promoter were used in the expression plasmid. The rho- mutation also increased the expression of the PHO5 gene under the control of the HIS5 promoter in a plasmid and the ACT1 gene in the yeast chromosome, but did not increase the expression of the ribosomal RNA gene. In contrast to the rho- mutants, pet mutants did not show higher gene expression compared with wild-type strains.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050204
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 91
    Digitale Medien
    Digitale Medien
    Size distribution and general structural features of N-linked oligosaccharides from the methylotrophic yeast, Pichia pastoris (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 107-115 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Pichia pastoris ; glycoproteins ; invertase ; oligosaccharides ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The secreted glycoproteins of Pichia pastoris contain more than 35% of their N-linked oligosaccharides as structures smaller than Man14GlcNAc2 (Man = mannose; GlcNAc = N-acetylglucosamine). On heterologous invertase produced in P. pastoris, approximately 85% of the oligosaccharides are in the size range Man8-14GlcNAc2. The structures appear to contain α-linked mannose. In addition, one-third of the structures contain net negative charge and can be radio-labelled in vivo with 32P. The largest oligosaccharides isolated from P. pastoris are significantly shorter than the hypermannosylated structures typical of S. cerevisiae, indicating that the factors which influence the processing of N-linked oligosaccharides in P. pastoris are different from those which influence processing in S. cerevisiae. The smaller N-linked oligosaccharides synthesized by P. pastoris resemble high-mannose oligosaccharides synthesized by animal cells, and this finding increases the utility of P. pastoris as a host for the production of heterologous glycoproteins.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050206
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 92
    Digitale Medien
    Digitale Medien
    RAG1 and RAG2: Nuclear genes involved in the dependence/independence on mitochondrial respiratory function for growth on sugars (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 99-106 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Kluyveromyces lactis ; mitochondrial respiration ; erythromycin ; sugar metabolism ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The analysis of five independent isolates of Kluyveromyces lactis shows that CBS 2359, CBS 683 and CBS 4574 could grow in the presence of mitochondrial inhibitors (antimycin A, oligomycin or erythromycin) and that CBS 2360 and CBS 141 were unable to grow in the presence of drugs. The resistant growth was observed only on glucose and not on other fermentable carbon sources (galactose, lactose).The phenotype ‘growth on glucose in the presence of mitochondrial inhibitors’ was called Rag+. This phenotype was found to be controlled by two unlinked nuclear genes: RAG1 and RAG2. Either of their recessive alleles, rag1 and rag2, led to the Rag- phenotype (i.e. the failure of growth on glucose in the presence of antimitochondrial drugs).Rag- strains represent the case in which fermentative growth becomes absolutely dependent on the functioning of the normal respiratory chain.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050205
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 93
    Digitale Medien
    Digitale Medien
    Masthead (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989) 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050301
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 94
    Digitale Medien
    Digitale Medien
    Calendar (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. ii 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050302
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 95
    Digitale Medien
    Digitale Medien
    Two pathways of DNA double-strand break repair in G1 cells of Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 131-139 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Yeast ; γ-irradiation ; post-irradiation recovery ; radiosensitive mutants ; DNA double-strand break repair ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: G1 cells of the diploid yeast Saccharomyces cerevisiae are known to be capable of a slow repair of DNA double-strand breaks (DSB) during holding the cells in a non-nutrient medium (Luchnik et al., 1977; Frankenberg-Schwager et al., 1980). In the present paper, S. cerevisiae cells γ-irradiated in the G1 phase of the cell cycle are shown to be capable of fast repair of DNA DSB; this process is completed within 30-40 min, of holding the cells in water at 28°C. For this reason, the kinetics of DNA DSB repair during holding the cells in a non-nutrient medium are biphasic, i.e., the first ‘fast’ phase is completed within 30-40 min, whereas the second, ‘slow’ phase is completed within 48 h. Mututions rad51, rad52, rad54 and rad55 inhibit the fast repair of DNA DSB, whereas mutations rad50, rad53 and rad57 do not significantly influence this process.It has been shown that the observed fast and slow repair of DNA DSB in the G1 diploid cells of S. cerevisiae are separate pathways of DNA DSB repair in yeast.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050208
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 96
    Digitale Medien
    Digitale Medien
    Mapping and characterizing a new DNA replication mutant in Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 117-129 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Cell cycle ; synchronization ; DNA replication ; killer ; in vitro replication ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: A detailed characterization of the mak 1-3 mutation of Saccharomyces cerevisiae has been made possible by modifying its genetic background. The mak1-3 mutation, which confers temperature sensitivity for growth, was originally identified as one of four mak1 mutations (Wickner and Leibowitz, 1976). Mak1-1, 1-2 and 1-4 mutants are deficient in DNA topoisomerase I activity and thus have been renamed ‘top1’ (Thrash et al., 1984). Studies presented here show that the map position of MAK1-3 on chromosome XVI distinguishes it from TOP1 which maps on chromosome XV (Wickner and Leibowitz, 1976). An investigation of in vivo macromolecular synthesis in the mak1-3 mutant shows that it is deficient in DNA replication at the restrictive temperature. Experiments in which DNA synthesis was measured in synchronized cell populations indicate that the mak1-3 mutant is deficient in the initiation step of DNA synthesis. Furthermore, crude extracts from the mak1-3 mutant cells support temperature-sensitive in vitro DNA synthesis on yeast chromosomal DNA replication origin containing plasmid pARS1, suggesting that the MAK1 gene product is directly required for in vitro DNA replication. The conclusion that mak1-3 is a newly identified DNA replication mutation is based on the observations that it (1) complements all DNA synthesis mutants examined, (2) maps to a previously undetected chromosomal location and (3) has a distinct terminal morphology. In light of these distinctions and of the role mak1-3 plays in DNA replication, it has been renamed ‘dnal’.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050207
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 97
    Digitale Medien
    Digitale Medien
    Structure and nuclear localization signal of the SK13 antiviral protein of Saccharomyces cerevisiae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 149-158 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Superkiller ; double-stranded RNA ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The yeast chromosomal genes SK12, SK13, SK14, SK16, SK17 and SK18 repress the replication of double-stranded RNA viruses, protecting the host from the otherwise lethal effects of the virus. We cloned and sequenced the SK13 gene and found that it encodes a 163 kDa protein including a typical nuclear localization signal. Cell fractionation experiments show that the SK13 gene product is indeed tightly associated with nuclei and that the putative nuclear localization sequence directs β-galactosidase into the nucleus. However, fusion of a part of the SK13 protein lacking this signal with β-galactosidase directs β-galactosidase into the nucleus, suggesting the presence of a second nuclear localization signal. The SK13 gene is only essential in the presence of an M double-stranded RNA virus.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050304
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 98
    Digitale Medien
    Digitale Medien
    Induction of cytochrome P-450 and catalase activity in Saccharomyces cerevisiae by UV and X-ray irradiation. Possible role for cytochrome P-450 in cell protection against oxidative damage (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 141-148 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Yeast ; cytochrome P-450 ; UV and X-ray irradiation ; oxidative damage ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: Cytochrome P-450 was induced both in the diploid wild-type D7 strain and in two isogenic DNA-repair-deficient strains (rad3 and rad56) of Saccharomyces cerevisiae following UV- and X-irradiation. The induction occurred only in logarithmic growth phase cells and it was transient showing a peak 3 h after irradiation. The maximal amount of cytochrome P-450 was directly proportional to the radiation does applied. Under the same experimental conditions an increase of the catalase activity was also observed, suggesting that activated oxygen species produced by irradiation might be implicated in the induction of both enzymes. The sensitivity to H2O2 of cells containing high cytochrome P-450 levels was enhanced when this enzyme was specifically inhibited by tetrahydrofuran and metyrapone. This supports the hypothesis that cytochrome P-450, as well as catalase, might be involved in cell protection against oxidative damage.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050303
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 99
    Digitale Medien
    Digitale Medien
    Kinetics of growth and glucose transport in glucose-limited chemostat cultures of Saccharomyces cerevisiae CBS 8066 (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 159-165 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Crabtree effect ; sugar transport ; growth kinetics ; yeast ; chemostat ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: The glucose transport capacity of Saccharomyces cerevisiae CBS 8066 was studied in aerobic glucose-limited chemostat cultures. Two different transport systems were encountered with affinity constants of 1 and 20 mM, respectively. The capacity of these carriers (Vmax) was dependent on the dilution rate and the residual glucose concentration in the culture. From the residual glucose concentration in the fermenter and the kinetic constants of glucose transport, their in situ contribution to glucose consumption was determined. The sum of these calculated in situ transport rates correlated well with the observed rate of glucose consumption of the culture.The growth kinetics of S. cerevisiae CBS 8066 in glucose-limited cultures were rather perculiar. At low dilution rates, at which glucose was completely respired, the glucose concentration in the fermenter was constant at 110 μM, independent of the glucose concentration in the reservoir. At high dilution rates, characterized by the occurrence of both respiration and alcoholic fermentation, the residual substrate concentration followed Monod kinetics. In this case, however, the overall affinity constant was dependent on the reservoir glucose concentration.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050305
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 100
    Digitale Medien
    Digitale Medien
    Structural comparison of the Pichia pastoris alcohol oxidase genes (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Yeast 5 (1989), S. 167-177 
    Details
    ISSN: 0749-503X
    Schlagwort(e): Methylotrophic yeasts ; alcohol oxidase ; Pichia pastoris ; genome evolution ; Life and Medical Sciences ; Genetics
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: In methylotrophic yeasts, alcohol oxidase is the first enzyme in the methanol-utilization pathway. The genome of one such yeast, Pichia pastoris, contains two alcohol oxidase genes, AOX1 and AOX2. Sequence analysis indicated that each gene encodes a similar protein of 663 amino acids. The protein-coding regions of the genes were 92% and 97% homologous at the nucleotide and predicted amino acid sequence levels, respectively. In contrast to homology observed within the protein-coding portions of the AOX genes, no homology was found in either the 5′ or 3′ non-coding regions. Although alcohol oxidase is found in peroxisomes of P. pastoris, the AOX amino acid sequences did not contain a peptide sequence similar to the peroxisomal transport sequence found at the C-terminus of some peroxisomally located proteins in higher eukaryotes.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/yea.320050306
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...