Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1980-1984  (35,241)
  • Chemistry  (33,681)
  • Biochemistry and Biotechnology  (1,710)
  • Engineering General  (1,377)
  • Cat
Source
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    The blood vessels of the cat girdle placenta. Observations on corosion casts, scanning electron microscopical and histological studies (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 209-216 
    Details
    ISSN: 1432-0568
    Keywords: Placenta ; Fetal microvasculature ; Corrosion casts ; Scanning electron microscopy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fetal microvascular architecture of the feline near-term placenta was investigated using scanning electron micrographs of partially fractured corrosion casts from plastic-filled vessels. The findings were compared with those on corresponding semithin histological sections. The branches of both umbilical arteries and veins roughly follow a course parallel to the zonary girdle on the allantochorionic side of the feline placenta in an acute-angled pattern of ramifications. They join the double-layered capilary networks in the chorionic lamellae of the labyrinth, which generally exhibit a chorio-uterine orientation and are partially twirled. On the allantochorionic side of the labyrinth, these fetal capillary networks are “suspended” on the maternal stem-artery-system of the placenta; on the uterine side, they have peduncular or tuft-like endings of capillary loops and are flattened by the uterine septa, which at this level converge into the maternal veins. The chorionic capillary lamellae have a variable breadth and length and therefore need shorter or longer arterioles and venules from the allantochorionic side to become irrigated at any level of the labyrinth. As a result, the feline placenta is characterized by a generally one-way crosscurrent type of materno-fetal blood flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319006
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    An anatomical study of the projections from the dorsal column nuclei to the midbrain in cat (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 29-43 
    Details
    ISSN: 1432-0568
    Keywords: Anatomy ; Anterograde tracing ; Dorsal column nuclei ; Midbrain ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The termination of the fibers from the dorsal column nuclei (DCN) to the midbrain has been investigated in the cat with the degeneration method, the anterograde horseradish peroxidase (HRP) method and autoradiography after 3H-leucine injections. The results show that the DCN project to several midbrain regions. The external nucleus of the inferior colliculus (IX) receives the heaviest projection from both the gracile and cuneate nuclei. The DCN fibers form three joint terminal zones in IX. Each terminal zone contains clusters with dense aggregations of DCN fibers. Fairly dense terminal networks are found in the posterior pretectal nucleus (PP) and the compact part of the anterior pretectal nucleus (PAc) as well. More scattered DCN fibers are present in the cuneiform nucleus (CF), the lateral part of the periaqueductal gray (PAG1), the red nucleus (NR), the nucleus of the brachium of the inferior colliculus (B), the mesencephalic reticular formation (MRF) and the intermediate and deep layers of the superior colliculus (SI, SP). The projections to all regions are mainly contralateral. Most of the few ipsilateral fibers terminate in IX. A somatotopic organization was seen in IX and NR. The gracile fibers terminate preferentially in the caudal and lateral part of IX and the cuneate ones preferentially in its rostral and medial part. In the red nucleus the gracile fibers terminate ventral to the cuneate ones. In the pretectal region there was a predominance for gracile fibers. There also appeared to be quantitative differences in the projections from various levels of the gracile nucleus, with more midbrain projecting fibers originating in the rostral than in the middle and caudal parts of the nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319455
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Anatomy of the cecum of the cat (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 177-186 
    Details
    ISSN: 1432-0568
    Keywords: Cecum ; Cat ; Macroscopic anatomy ; Light, scanning and transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a series of comparative anatomical studies on the ceca of various mammals the cat was chosen as representative of a “typical” carnivore. In the domestic cat, the cecum is conspicuously small and macroscopically relatively undifferentiated in comparison to most herbivores. Microscopically (light, scanning and transmission electron microscopy), however, it is characterized by an abundance of goblet cells and enterocytes rich in organelles, suggestive of functional activity. In addition to the morphological description, which also includes arterial supply and mesenteries of the cecum, the discussion is focussed on 1) the possible functional significance of the numerous goblet cells 2) a general categorization of the different types of ileal-caeco-colical junctions and 3) speculations concerning the justification for considering the carnivore cecum as being rudimentary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The termination of spinomesencephalic fibers in cat (1984)
    Springer
    Anatomy and embryology 170 (1984), S. 265-277 
    Details
    ISSN: 1432-0568
    Keywords: Midbrain ; Spinal cord ; Cat ; Degeneration-HRP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The projections to the midbrain from the spinal cord have been investigated in the cat with the degeneration technique and by using horseradish peroxidase (HRP) as an anterograde tracer. Two types of spinal cord lesions were performed: 1) Cordotomies at cervical or thoracic levels transecting the ventral and lateral funiculi. 2) Transections of the ventral, ventrolateral, dorsolateral or dorsal funiculus, respectively, at cervical levels. In the anterograde tracing experiments HRP was injected into the spinal cord at cervical, lumbar or sacral levels. The results show large projections to the lateral and ventrolateral parts of the periaqueductal gray (PAG1), the posterior pretectal nucleus (PP) and the nucleus of Darkschewitsch (D). More moderate projections go to the medial division of the periaqueductal gray (PAGm), the cuneiform nucleus (CF), the mesencephalic reticular formation (MRF), lateral part of the deep layer of the superio colliculus (SP) and magnocellular medial geniculate nucleus (GMmc), while scattered spinal fibers are present in the dorsal part of the periaqueductal gray (PAGd), the external inferior collicular nucleus (IX), the intermediate layer of the superior colliculus (SI), the lateral part of the red nucleus (NR) and in the Edinger-Westphal portion of the oculomotor nucleus (3). In addition a few fibers are present in the interstitial nucleus of Cajal (CA) and anterior pretectal nucleus (PAc). The results indicate that at midcervical levels most of the spinomesencephalic fibers ascend in the ventral funiculus, with only a moderate fraction ascending in the ventral half of the lateral funiculus. Almost no fibers ascend in the dorso-lateral funiculus and none appear to pass in the dorsal funiculus. No distinct somatotopic pattern was found in the spinomesencephalic projections, but more fibers from cervicobrachial segments terminate in the rostral than in the caudal parts of the terminal fields in PAG, CF, SP and IX, while the lumbar fibers were more numberous in the caudal parts. PP seems to receive spinal fibers mainly from the caudal half of the cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318730
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    An autoradiographic study of topographical relationships between pallidal and cerebellar projections to the cat thalamus (1984)
    Springer
    Experimental brain research 54 (1984), S. 95-106 
    Details
    ISSN: 1432-1106
    Keywords: Cerebellothalamic projections ; Pallidothalamic projections ; Ventral nuclei of thalamus ; Autoradiography ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Injections of 3H-leucine were made in the entopeduncular nucleus or dentate nucleus of the cerebellum in eight cats. The terminal projection zones of both pathways in the thalamus were studied using the sagittal plane and their relationships to one another as well as to cytoarchitectural boundaries of thalamic nuclei were compared. The data indicate that the territories controlled by the two projection systems are almost entirely segregated. The segregation is mainly along the antero-posterior axis as the main pallidal projection zone occupies the medio-ventral VA while the main dentate projection zone lies posterior to it in the VL. Furthermore, the dorsolateral part of the VA not occupied by pallidal projections receives dentate projections. In the VM, both afferent systems terminate in the lateral part of the nucleus with pallidal territory located anteriorly and dentate territory located posteriorly, again without overlap. As the delineations of nuclear subdivisions in the ventral thalamus of the cat have been a subject of some controversy, it is suggested that the boundaries of the VA, VL and VM in the cat thalamus be defined on the basis of basal ganglia and cerebellar projection zones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235822
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Distribution of corticospinal neurons with collaterals to lower brain stem reticular formation in cat (1984)
    Springer
    Experimental brain research 54 (1984), S. 107-120 
    Details
    ISSN: 1432-1106
    Keywords: Corticospinal collaterals ; Sensorimotor cortex ; Corticobulbar pathways ; Fluorescent tracers ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fluorescent retrograde double-labeling technique has been used to determine whether corticospinal neurons in the cat sensorimotor cortex distribute collaterals to the lower brain stem reticular formation. In this study the fluorescent tracers Nuclear Yellow and Diamidino Yellow 2HCl were used in combination with Fast Blue. One tracer was injected unilaterally in the spinal cord and the other was injected ipsilaterally in the bulbar medial reticular formation. The distribution of the retrogradely labeled neurons was studied in the contralateral hemisphere. In the sensorimotor cortex a large population of neurons was found which were labeled from the spinal cord and were double-labeled from the brain stem. These branching neurons were concentrated in the rostromedial part of area 4 and the adjoining lateral part of area 6. In this region the percentages of corticospinal neurons which were double-labeled from the brain stem ranged from 5% laterally to 30% medially. In two cats it was demonstrated by means of the anterograde transport of HRP that the corticobulbar fibers from this region which must include the corticospinal collaterals are distributed to the reticular formation of the lower brain stem. In view of the fact that the double-labeled neurons are concentrated in the anterior part of the motor cortex, those branching neurons are in all likelihood involved in the control of neck, back and shoulder movements. This control is probably exerted by way of two routes i.e. by way of the direct corticospinal connections to spinal interneurons, and by way of the indirect cortico-reticulospinal connections established by the cortical fibers to the bulbar reticular formation. The present findings suggest that this dual control may be exerted by one and the same cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235823
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Specialized subregions in the cat motor cortex: Anatomical demonstration of differential projections to rostral and caudal sectors (1984)
    Springer
    Experimental brain research 53 (1984), S. 259-276 
    Details
    ISSN: 1432-1106
    Keywords: Motor cortex ; Thalamocortical ; Corticocortical ; HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary (1) Ipsilateral cortico-cortical and thalamo-cortical projections to the cat motor cortex were determined from the locations of retrogradely labeled neurons following single small intracortical injections of HRP in area 4γ. These projections were also examined by studying the distribution of anterogradely transported axonal label following multiple injections of HRP or of tritiated amino acids in areas 1–2 of SI and in area 2pri (SII). (2) The number of retrogradely labeled cells in areas 1–2 and in area 2pri differed markedly between HRP injection sites located in the precruciate (anterior sigmoid gyrus) and postcruciate (posterior sigmoid gyrus) subregions of area 4γ. These associational projections from primary and secondary somatosensory cortices were dense to postcruciate subrogions but weak to the precruciate subregions. (3) The associational projections from areas 1–2 and from area 2pri to the postcruciate subregion of area 4γ were topographically organized, but no clear topographic organization could be demonstrated for the precruciate projection. (4) Anterograde terminal labeling following injection of either HRP or tritiated amino acids into areas 1–2 and area 2pri confirmed the preferential projection of somatosensory cortex to the postcruciate subregion of motor cortex. The projection from somatosensory areas 1–2 was uniform over its terminal field, but that from area 2pri was more patchy and complex. (5) HRP injections in area 4γ gave rise to lamellae of labeled neurons in the ventrolateral nucleus of thalamus (VL). A topographic relationship was found between the site of injection and the location of the lamella of labeled neurons. (6) The percentage of retrogradely labeled neurons in the shell zone surrounding the border of the ventrolateral nucleus and the ventrobasal complex (VB) was greater following postcruciate than precruciate injections, whereas fewer retrogradely labeled neurons were found in central lateral nucleus (CL) after postcruciate injections than after precruciate injections. (7) These observations support the hypothesis that differential cortical and thalamic projections to different subregions of area 4γ may give rise to the different physiological properties of neurons observed in these subregions (Vicario et al. 1983; Martin et al. 1981).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238155
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Pyramidal control of skin potential responses in the cat (1984)
    Springer
    Experimental brain research 54 (1984), S. 283-288 
    Details
    ISSN: 1432-1106
    Keywords: Skin potential response ; Cat ; Pyramidal tract ; Reticulospinal tracts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pyramidal command of Skin Potential Response (SPR) was investigated in 20 cats paralyzed by gallamine and under a halothane anaesthetic. For each animal, a transection of the medulla sparing only the pyramidal tract was carried out. The pyramidal tract and Mesencephalic Reticular Formation (MRF) were stimulated before and after the transection. Results taken before transection show that the SPR can be elicited from stimulation of the pyramidal tract and the MRF. After transection, stereotaxic stimulations of the pyramidal tract still evoked the SPR even after aspiration of the medullary tissue posterior to the section and overlying the pyramids. Control reticular stimulations with higher stimulus intensities failed to evoke the SPR. These results show that stimulation of the pyramidal tract can elicit the SPR independently of reticulospinal neurons. It is hypothesized that a group of corticospinal fibers could transmit volleys having autonomic activity on preganglionic autonomic neurons of the intermediate zone of the grey matter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236228
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Afferents to the cortical pupillo-constrictor areas of the cat, traced with HRP (1984)
    Springer
    Experimental brain research 54 (1984), S. 377-381 
    Details
    ISSN: 1432-1106
    Keywords: Pupillo-constrictor areas ; Afferents ; HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Afferents of the cortical pupillo-constrictor areas (PCAs) of the cat were studied using the horseradish peroxidase method. PCAs receive heavy cortical inputs from areas 7, 19, 21, the lateral suprasylvian area, the splenial visual area, and subcortically from the claustrum, the intralaminar nuclei, the pulvinar-lateral posterior nuclear complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236240
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The control of rapid limb movement in the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 134-144 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Tracking ; Isometric ; Updating ; Delayed feedback
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In cats trained to track a moving display by making rapid, isometric force adjustments, responses are characterized by extremely short reaction times (60–70 ms) and a stereotyped temporal configuration. The animal uses early derivatives of display movement to scale force responses to target stimuli of different sizes according to a learned relationship between initial display motion and required force (Ghez and Vicario 1978a, 1978b). In the present study we altered that relationship by using double stimulation and delayed feedback to assess the animals' ability to update their responses. 2. In experiments where a second target stimulus followed the first after a controlled interval (15–120 ms) on random trials, the animal modified its response in the appropriate direction with little or no increase in reaction time. When the second stimulus called for a return to baseline, the animal aborted the ongoing response. When the second stimulus called for a doubling of force, the animal increased its phasic force output; however, this increase was not sufficient to reach the new target level and late responses were emitted. 3. The control response which followed each experimental double stimulation trial showed consistent differences from other controls in the amplitude of both peak force and peak dF/dt. Control responses following trials calling for a return were reduced in size; those following stimuli requiring response doubling were increased. We concluded that the experimental trials not only elicited modification of ongoing responses but also caused the animal to alter its internalized gain function relating initial display derivatives to required force. 4. In experiments where feedback was delayed after giving a first target stimulus such that the compensatory display failed to reflect the animal's initial response, the animal emitted a new updated response 70–80 ms after the first. The display trajectory which caused the cat to update its response on delayed feedback trial was identical to that of control trials with long reaction times. In this case, however, the information eliciting response updating had to be derived as a difference between the actual display trajectory and that expected by the animal, based on its experience with the tracking task. This suggests that the animal develops an internal model of display properties which is used to determine when a new response is required.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    The transformation of cross-reinnervated slow-twitch muscle after deafferentation in the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 152-157 
    Details
    ISSN: 1432-1106
    Keywords: Deafferentation ; Cross reinnervation ; Contractile properties ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cross-reinnervations were effected between the extensor digitorum longus and soleus muscles in the cat hind limb. At the same time dorsal root section or ganglionectomy was performed over segments L6-S1. Completeness of the deafferentation was subsequently confirmed either by dissection or by dorsal root recording. The isometric and forcevelocity properties of the muscles were measured. In animals with a unilateral cross plus deafferentation the conversion of the contractile properties of the normally slow-twitch soleus to those resembling a fast-twitch muscle was typical of that seen with an intact afferent supply. In cats with a bilateral cross-reinnervation and unilateral deafferentation there was no significant difference in the degree of transformation between the two sides. It is concluded that at least for the conversion of a slow-twitch to a fast-twitch muscle afferent feedback does not play a major role.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Contralateral corticofugal projections to cat visual thalamus (1984)
    Springer
    Experimental brain research 53 (1984), S. 462-466 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Contralateral connections ; Thalamus ; Cat ; Sub-cortical commissures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Contralateral corticofugal projections from visual cortical areas to thalamic nuclei were demonstrated in the cat using anterograde transport of tritiated proline. Thalamic nuclei receiving projections from contralateral visual cortex include both subdivisions of the lateral-posterior nucleus, the posterior nucleus of Rioch, and the posterior nuclear complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238176
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    An HRP study of the cat's spinal respiratory motoneurones during postnatal development (1984)
    Springer
    Experimental brain research 56 (1984), S. 458-467 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Postnatal development ; Phrenic motoneurones ; Intercostal motoneurones ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The localization and morphology of spinal respiratory motoneurones (phrenic and intercostal) were studied in the cat by retrograde labelling using Horseradish Peroxidase (HRP), at different stages of postnatal development. At birth, the distribution of the phrenic and intercostal motoneurones in the cervical and thoracic ventral horn, respectively, is similar to that observed in adult animals. At birth, the phrenic and intercartilaginous motoneurone somata have respectively 60% and 40% of their adult volume, appearing much more developed than the motoneurones involved in the motor control of limbs. During postnatal development, the phrenic and intercartilaginous motoneurones undergo a characteristic sagittal elongation without evident modification along their transverse axes. From birth, the ratio of the somatic volume to that of its corresponding motor column markedly decreases inside of the phrenic column compared to the data obtained in the limb's muscle motor columns by other authors. Similar determinations in intercostal motor columns give intermediate values between those obtained from the phrenic column and from the motor system. These results indicate that the motoneurones innervating the respiratory muscles have some specific features of development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237986
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Brainstem afferents to the lateral geniculate nucleus of the cat (1984)
    Springer
    Experimental brain research 54 (1984), S. 253-258 
    Details
    ISSN: 1432-1106
    Keywords: Lateral geniculate nucleus ; Pretectal nuclei ; Superior colliculus ; Parabigeminal nucleus ; Reticular formation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ascending connections from the brainstem to the dorsal division of the lateral geniculate nucleus were examined using retrograde transport of horseradish peroxidase. Labelled cells were identified in a variety of structures, including the nucleus of the optic tract (NOT), the posterior pretectal nucleus (NPP), the superior colliculus (SC), the parabigeminal nucleus (PBN), the midbrain reticular formation (MRF), locus coeruleus and nucleus sub-coeruleus, the substantia nigra (SN), and parts of the raphe complex. The projections from NOT, NPP, MRF, LC and PBN were all bilateral in origin. The most intense labelling was observed in the nucleus of the optic tract and the superior colliculus. Colliculo-geniculate cells were located primarily in the superficial gray lamina II1 and II2 of Kaneseki and Sprague (1974), but sparse labelling was also observed in lamina II3 and in statum opticum (lamina III). Consistent with the report of Harrell et al. (1982), these cells represent a morphologically diverse population, which includes stellate cells, granule cells, and both vertical and horizontal fusiform cells. A similarly diverse population of cell types contributes to the geniculate projection arising from NOT. These results confirm and extend earlier descriptions of the brainstem projections to the cat LGNd, and serve to emphasize the diversity of brainstem influences over the geniculate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236224
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Neck muscle afferent input to spinocerebellar tract cells of the central cervical nucleus in the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 286-300 
    Details
    ISSN: 1432-1106
    Keywords: Central cervical nucleus ; Spinocerebellar tract ; Neck muscle afferents ; Spinal cord ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular and intracellular recordings were made from spinocerebellar tract neurones of the central cervical nucleus (CCN) in C1–C3 segments of the anaesthetized cat. These neurones were identified by antidromic activation from the cerebellar peduncle. Stimulation of the ipsilateral dorsal root elicited extracellular spikes or EPSPs with a monosynaptic latency in almost all CCN neurones in the same segment (segmental input). Late excitatory effects were also observed in about one third of CCN neurones. The monosynaptic EPSP was occasionally followed by an IPSP. The excitatory input from the dorsal root to CCN neurones was extended over several segments for some CCN neurons (extrasegmental input). Monosynaptic excitation was evoked in CCN neurones after stimulation of dorsal neck muscle nerves as well; i.e. splenius (SPL), biventer cervicis and complexus (BCC), rectus capitus dorsalis, and obliquus capitus caudalis. Thresholds for this excitation were near the threshold of the nerve, suggesting that it originated from group I fibres. The component of excitation added after strong stimulation of neck muscle nerves would be attributed to group II fibres. When a CCN neurone received excitatory input from the nerve of one muscle, it was generally not affected by stimulation of other nerves in the same segment. Such muscle specificity of segmental input was the principal pattern of connexion of neck muscle afferents with CCN neurones. In some cases, however, excitatory convergence from SPL and BCC nerves onto single CCN neurones or excitation from the SPL nerve and inhibition from the BCC nerve were also observed. Nearly half of the CCN neurones received input from one muscle nerve of the same segment and not from the afferent of the same muscle of different segments, indicating a segment specificity of input. In the remaining CCN neurones, weaker excitatory effects were induced from afferents of different segments as well. In such extrasegmental effects, inputs to CCN neurones from caudal segments predominated in frequency over those from rostral segments. The origin of extrasegmental input was generally confined to the same muscle. Low threshold muscle afferents from the SPL and BCC were intraaxonally stained with HRP. The collaterals of the stained fibre distributed branchlets and terminals to the CCN, laminae VII, VIII, and motor nuclei. Two fibres responding to local muscle prodding or stretch showed a similar morphology. The findings indicated that muscle spindle afferents from primary endings projected to the CCN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237279
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    A physiological study of identification, axonal course and cerebellar projection of spinocerebellar tract cells in the central cervical nucleus of the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 272-285 
    Details
    ISSN: 1432-1106
    Keywords: Central cervical nucleus ; Spinocerebellar tract ; Cerebellum ; Spinal cord ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spinocerebellar tract (SCT) neurones in and around the central cervical nucleus (CCN) were physiologically identified by antidromic activation of these cells on stimulation of the cerebellum. Among the Spinocerebellar tract cells thus identified, those ascending the contralateral spinal funiculi were found in the CCN and ventralwards, whereas those ascending the ipsilateral funiculi existed mostly dorsal to the CCN partly overlapping with crossed cells in the nucleus. Mapping sites from which CCN cells were antidromically activated showed that axons of the CCN-SCT cross at the same segment, ascend the ventral funiculus initially, the lateral funiculus at rostral C1 and the lateral border of the medulla to reach the cerebellar peduncle, enter the cerebellum mainly via the restiform body but possibly also via the superior peduncle. Systematic mapping of stimulation within the cerebellum indicated that the CCNSCT projects to the medial part of the anterior lobe and the posterior lobe bilaterally. Projection to lobules I–II was found in almost all CCN-SCT cells examined. Three fourths of CCN-SCT cells projected to the posterior lobe, as revealed by less extensive mapping. Mapping of axonal regions of the same single CCN-SCT cells showed that they project multifocally in the cerebellum, where projection to lobules I–II was common and that to other areas varied with individual cells. Conduction velocites decreased within the cerebellum probably as the result of repeated branching. Mossy fibre responses evoked on stimulation of the C2 dorsal root in cats with the transected dorsal funiculi were shown to be mediated mostly via the CCN-SCT. Mapping the field potential showed that the response was by far the largest in lobules I–II. This suggested that the terminals provided by the CCN-SCT are the densest in these lobules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237278
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Endogenous peroxidase-like activity in the feline dorsal column nuclei and spinal cord (1984)
    Springer
    Experimental brain research 55 (1984), S. 325-332 
    Details
    ISSN: 1432-1106
    Keywords: Endogenous peroxidase ; Light and electron microscopy ; Spinal cord ; Dorsal column nuclei ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Endogenous peroxidase-like activity was investigated with a combined light and electron microscopical technique in 15 cats. The lateral cervical nucleus, the dorsal column nuclei, and segments C6 and L5 of the spinal cord were incubated with diaminobenzidine-tetrahydrochloride (DAB) or tetramethylbenzidine (TMB). After histochemical reaction with DAB a considerable amount of activity was found in nerve cells, astrocytes and pericytes. The neuronal labelling was mainly located in mitochondria of axon terminals and in dendrites whereas the astrocytic and pericytic activity was found in cytoplasmic dense bodies. The quantity of stained structures differed considerably between the animals. In TMB reacted tissue endogenous peroxidase-like activity was only sparsely seen. It was found mainly in frozen sections, in which the neuropil and perivascular structures sometimes contained granules and irregular filaments. The significance of the findings is discussed in relation to observations in tracer studies using horseradish peroxidase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237283
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Effects of accessory optic system lesions on vestibulo-ocular and optokinetic reflexes in the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 49-59 
    Details
    ISSN: 1432-1106
    Keywords: Accessory optic system ; Vestibulo ocular reflex ; Optokinetic nystagmus ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Horizontal vestibulo-ocular reflex (VOR) and optokinetic nystagmus (OKN) were studied before and after lesions within the accessory optic system (AOS) in the cat. Post-lesion retinal input to the AOS was evaluated using the autoradiographic technique. Unilateral lesion of the lateral terminal nucleus of the AOS (LTN) and the resulting retinal deafferentation of the medial terminal nucleus of the AOS (MTN) induced a spontaneous nystagmus in the dark whose slow phase was directed ipsilaterally to the lesion. VOR gain was reduced for both directions with a maximal decrease for stimulation directed ipsilaterally to the lesion. OKN gain obtained for both directions of binocular stimulation was decreased, mainly when the stimulus was directed contralaterally to the lesion. After two postoperative weeks, spontaneous nystagmus disappeared and the VOR symmetry recovered simultaneously. A symmetrical OKN was only observed after one month. In spite of the known visual selectivity for vertical direction in LTN-MTN cells, the results of this study support a functional involvement of these nuclei in horizontal VOR and OKN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240497
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Differences between cats in response properties of horizontal semicircular canal primary afferents (1984)
    Springer
    Experimental brain research 56 (1984), S. 162-166 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nerve afferents ; Semicircular canal biophysics ; Semicircular canal time constants ; Vestibular neurophysiology ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The response properties of cat horizontal canal afferents (N = 81) were characterized by three parameters: their long time constants (τ), low frequency gain constants (G1), and middle frequency gain constants (Gm). An average value of each of these parameters was calculated for each of eight animals and comparisons were made across animals. There were significant differences between individual animals in their average values of τ and Gm. There was also a significant negative correlation between τ's and Gm's. An animal with a larger average τ tended to have a smaller average Gm. We also used anatomic data on membranous canal duct diameter from the literature to independently estimate the potential effect of interanimal anatomic variability on the predicted range of τ and Gm values in a population. We then compared the data from our 81 afferents with the predictions from the anatomic data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237453
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Inspiratory on-switch evoked by stimulation of the mesencephalon: Activity of phrenic and laryngeal motoneurones (1984)
    Springer
    Experimental brain research 55 (1984), S. 197-204 
    Details
    ISSN: 1432-1106
    Keywords: Phrenic and laryngeal motoneurones ; Inspiratory on-switch ; Stimulation ; Mesencephalic structures ; Patterned response ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In anaesthetized cats (chloralose-urethan) the effects of brief tetanic electrical stimulation (50 to 100 ms) of the mesencephalic central gray matter and reticular formation on the inspiratory on-switch were studied during the expiratory (E) phase on the gross and unitary activities of phrenic, laryngeal inspiratory and laryngeal expiratory nerves. On the inspiratory laryngeal and phrenic nerves, stimulation elicited a short latency gross response concomitant with the train: the inspiratory Primary Response (Prim.R.) which is followed by an inspiratory Patterned Response (Patt.R.) of longer duration which corresponded to the inspiratory on-switch. The Patt.R. generally appeared from the Prim.R. within a latent period (Silent Phase: Sil.P.) as long as 100 ms. On the expiratory laryngeal nerve, stimulation elicited a brief activation (expiratory Prim.R.) concomitant with the beginning of the inspiratory laryngeal Prim.R. and which rapidly stopped as the latter continued during the stimulus train. The inspiratory Prim.R. corresponded to a simultaneous activation of both early and late (so defined during their spontaneous discharge) inspiratory motoneurones. The laryngeal motoneurones were more strongly activated than the phrenic ones. During the inspiratory Patt.R. all the phrenic motoneurones presented a recruitment delay earlier, compared with the spontaneous one, whereas the recruitment drastically changed from an inspiratory laryngeal motoneurone to another. Thus, the two pools of motoneurones presented different properties of activation. During the inspiratory Sil.P. no concomitant expiratory laryngeal activation was observed when most of the inspiratory motoneurones were inactive. As some inspiratory laryngeal motoneurones did not stop firing, the existence of some central respiratory neurones exhibiting a similar persistent activity and subserving the inspiratory on-switch mechanisms may be hypothesized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237270
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Ascending projections from the nucleus of the brachium of the inferior colliculus in the cat (1984)
    Springer
    Experimental brain research 54 (1984), S. 203-211 
    Details
    ISSN: 1432-1106
    Keywords: Ascending auditory pathway ; Inferior colliculus ; Medial geniculate body ; Cat ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ascending projections from the nucleus of the brachium of the inferior colliculus (NBIC) in the cat were studied by the autoradiographic tracing method. Many fibers from the NBIC ascend ipsilaterally in the lateral tegmentum along the medial border of the brachium of the inferior colliculus. At midbrain levels, fibers from the NBIC end in the superior colliculus, the pretectum, the central gray and the peripeduncular tegmental region bilaterally with ipsilateral predominance. NBIC fibers to the superior colliculus are distributed densely to laminae VI an III throughout the whole rostrocaudal extent of the colliculus. In the pretectum, NBIC fibers terminate in the anterior and medial nuclei and the nucleus of the posterior commissure. NBIC fibers to the dorsal thalamus are distributed largely ipsilaterally. Many NBIC fibers end in the dorsal and medial divisions of the medial geniculate body, but few in the ventral division. The NBIC also sends fibers to the suprageniculate, limitans and lateralis posterior nuclei and the lateral portion of the posterior nuclear complex; these regions of termination of NBIC fibers constitute, as a whole, a single NBIC recipient sector. Additionally, the NBIC sends fibers to the centralis lateralis, medialis dorsalis, paraventricular and subparafascicular nuclei of the thalamus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Locomotion in adult cats with early vestibular deprivation: Visual cue substitution (1984)
    Springer
    Experimental brain research 54 (1984), S. 395-405 
    Details
    ISSN: 1432-1106
    Keywords: Neonatal ; Bilabyrinthectomy ; Recovery ; Locomotion ; Vision ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four cats labyrinthectomized shortly after birth (DELAB) exhibited the classical vestibular syndrome and recovery, while their motor development was otherwise unimpaired. As adults, they were tested for visual vestibular substitution in a locomotor task with either orientation requirements (tilted platforms) or balance requirements (narrow platforms). Visual motion cues or static visual cues were controlled using normal or stroboscopic lighting, or darkness. Measurements of the average speed of locomotion showed that: Although all cats increase their speed when more visual cues become available, a marked deficit occurs in darkness only in the DELAB cats. With either vestibular cues alone or static visual cues alone, cats are able to reach the same level of performance in the tilted platform test, which suggests a total visual-vestibular interchangeability in orientation. DELAB cats perform very poorly in the narrow rail test. When continuous vision is allowed in the narrow rail test the DELABs' performance rises but does not match that of the control group. A specific deficit in balance for the DELAB group is thus reduced by normal continuous vision as compared to stroboscopic vision, suggesting a significant, though imperfect, substitution of motion visual cues for the missing dynamic vestibular cues. Dynamic visual cues play only a minor role in most situations, when locomotory speed is high. This results support the view that both the vestibular and the visual system can subserve two distinct functions: dynamic information may stabilize the stance in narrow unstable situations, during slow locomotion. and static orientation cues may mainly control the direction for displacement. Possible interactions between head positioning and body orientation in the DELAB cats are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235464
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Shortage of binocular cells in area 17 of visual cortex in cats with congenital strabismus (1984)
    Springer
    Experimental brain research 55 (1984), S. 470-482 
    Details
    ISSN: 1432-1106
    Keywords: Congenital microstrabismus ; Cat ; Visual cortex ; Binocularity ; Visual axis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-nine pigmented offspring of an innately esotropic female cat exhibited varying deficits in the number of binocular cells recorded in area 17 of the visual cortex as compared to 12 normal cats. Misalignment of the two eyes in these cats was found in the awake as well as in the paralysed state. Pupillography combined with measurements of visual disparity yielded abnormal esotropia of up to 8.4° under paralysis, which corresponds to an abnormal convergence of the freely moving eyes of up to 14° (average 7.4°). In the majority of animals cortical binocularity was found reduced by the two eyes controlling independent sets of separate units (U-shaped ocular dominance distribution) whereas in 7 cats the reduction was due to a partial loss of one eye's influence. The proportion of monocular units correlated with the degree of crossover of the visual axes (r = 0.73). Anatomical investigation of the retinofugal projections revealed normal appearance in three previously recorded cats in which more than 50% of cortical units had been monocularly driven. The small angles of esotropia and the “normal” appearance of eye position judged by the pupillary positions in the orbit of these cats, might suggest that we found an animal model for microstrabismus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235278
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Electroretinographic responses and retrograde changes of retinal morphology after intracranial optic nerve section. A quantitative analysis in the cat (1984)
    Springer
    Experimental brain research 55 (1984), S. 483-493 
    Details
    ISSN: 1432-1106
    Keywords: Optic nerve section ; Cat ; Pattern ERG ; Retinal morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous experiments have shown that the ERG response to alternating gratings vanishes gradually within 4 months after transection of the optic nerve, changes begin after 2–3 weeks. The response to gratings of low spatial frequencies deteriorates earlier than the response to gratings of high spatial frequencies (Maffei and Fiorentini 1981). Quantitative analysis of ganglion cell sizes in retinal wholemounts shows that ganglion cell shrinkage and ganglion cell loss begin at three weeks in the periphery of the retina, particularly in the temporal retina. The same morphological alteration subsequently becomes apparent also in the area centralis and the nasal retina, respectively. The main and early cell loss occurs among medium sized ganglion cells, supposedly the beta-cells. Among the alpha-cells only shrinkage is observed up to two months postoperatively. Light- and electron microscopic examination of cross sections through the retina show that pathological changes are restricted to the innermost layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235279
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Evidence for glutamate as a neurotransmitter in the cat vestibular nerve: radioautographic and biochemical studies (1984)
    Springer
    Experimental brain research 56 (1984), S. 523-531 
    Details
    ISSN: 1432-1106
    Keywords: Glutamatergic synapses ; Vestibular nerve lesion ; Vestibular nuclei ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Evidence that glutamate acts as a neuro-transmitter in vestibular nerve fibers was sought (1) by electron microscope radioautographic identification of the uptake sites of [3H]-glutamic acid after incubation of slices of cat vestibular nuclei, and (2) by measuring changes in sodium-dependent high affinity glutamate uptake in nerve endings containing homogenates from normal and deafferented vestibular nuclei 8 to 11 days after unilateral vestibular nerve lesion. Electron microscopic radioautography revealed that glutamate had been taken up by numerous nerve endings projecting over the whole vestibular nuclear complex. The biochemical approach indicated that after section of the vestibular nerve, a significant decrease in high affinity glutamate uptake occurred in the vestibular nuclei, which lost their exclusively ipsilateral projection. This decrease varied from one area of the deafferented vestibular nuclei to another, reaching −58% in the lateral area of the central part corresponding to the ventral lateral vestibular nucleus and the rostral part of the descending vestibular nucleus. It is concluded that glutamate (or aspartate) is used by the vestibular nerve fibers as a neurotransmitter in the vestibular nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237993
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Origin of signals conveyed by the ventral spino-cerebellar tract and spino-reticulo-cerebellar pathway (1984)
    Springer
    Experimental brain research 54 (1984), S. 426-431 
    Details
    ISSN: 1432-1106
    Keywords: Spinal cord ; Scratch reflex ; Ventral spino-cerebellar tract ; Spino-reticulo-cerebellar pathway ; Cerebellum ; Cooling the nervous tissue ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary (1) The “fictitious” scratch reflex was evoked in decerebrate curarized cats by pinna stimulation. Activity of neurons of the ventral spinocerebellar tract (VSCT) from the L4 and L5 segments of the spinal cord as well as of neurons of the spinoreticulo-cerebellar pathway (SRCP) from the lateral reticular nucleus of the medulla oblongata was recorded. Cooling and destruction of different parts of the lumbo-sacral enlargement of the spinal cord were performed. (2) Cooling of the L5 or L6 segment abolished the rhythmic activity in the greater part of the spinal hindlimb centre but did not affect the generation of rhythmic oscillations in the remaining (rostral) segments of the lumbo-sacral enlargement. Under these conditions, neither the rhythmic activity of VSCT neurons located rostral to the thermode nor that of SRCP neurons changed. (3) A normal rhythmic activity of SRCP neurons also persisted after destruction of grey matter in the L3 and L4 segments. It can be concluded that activity of these neurons is independent of whichever part of the enlargement generates rhythmic oscillations. (4) From these observations a hypothesis is advanced that the main content of signals conveyed by the VSCT and SRCP to the cerebellum is the information regarding activity of the generator of rhythmic oscillations that is located in the L3-L5 spinal segments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235467
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Corticocortical connections to the motor cortex from the posterior parietal lobe (areas 5a, 5b, 7) in the cat demonstrated by the retrograde axonal transport of horseradish peroxidase (1984)
    Springer
    Experimental brain research 54 (1984), S. 476-484 
    Details
    ISSN: 1432-1106
    Keywords: Corticocortical connections ; Motor cortex ; Areas 4, 5a, 5b, 7 ; Posterior parietal lobe ; Retrograde transport of HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurons in the parietal region of the cerebral cortex, projecting to the ipsilateral distal forelimb area of the motor cortex (area 4γ) were identified in the cat brain using the horseradish peroxidase (HRP) retrograde tracing method. After making microinjections of HRP into the distal forelimb area of the motor cortex, clusters of HRP-labeled cell bodies were observed in different regions of the ipsilateral parietal cortex. In particular these clusters of labeled cells were found in areas 5a, 5b and 7. The area 5a cluster is formed from closely packed irregularly-shaped cells, the area 5b cluster is made up of dispersed medium-sized pyramidal cells, while area 7 contains a cluster of widely dispersed small pyramidal cells. Typically, labeled cell bodies were found in lamina III of cortex. Labeled cell bodies were neither observed in the contralateral cortex nor in the visual cortex (areas 17, 18 and 19). Since parietal cortex receives projections from primary somatosensory and visual cortex, the projections from parietal to motor cortex may well form the neural substrate for the processing of convergent sensory information used in voluntary movements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235473
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    The use of retrograde transport of horseradish peroxidase for studying the dendritic trees and axonal courses of particular groups of tract cells in the spinal cord (1984)
    Springer
    Experimental brain research 54 (1984), S. 529-537 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Rat ; Spinal tract neurons ; Retrograde HRP transport ; Procedure and evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Modifications have been made in Mesulam's method for labelling neurons by retrograde transport of horseradish peroxidase, with tetramethylbenzidine as chromogen, with the object of increasing the extent of labelling of dendrites and axons. A procedure was devised specifically for studying spinomedullary and medullospinal tract systems, involving implanting easily-made HRP-agar pellets into areas of controlled damage in particular spinal fascicles, and sealing the site of implant with cyanoacrylate glue. Lesions of other fascicles were often made to limit transport to the implanted fascicle. Fourth-order dendrites were regularly labelled over long (30 cm or more) transport distances: axons were also labelled over this whole distance, often allowing exact study of the initial course of particular axons. Controls in both cat and rat showed that the uptake of HRP under these circumstances occurred almost wholly from the region of axonal damage at the site of implant which can be characterized histologically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235478
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Peripheral nerve phospholipids in acrylamide neuropathy (1984)
    Springer
    Archives of toxicology 55 (1984), S. 178-181 
    Details
    ISSN: 1432-0738
    Keywords: Cat ; Phospholipids ; Acrylamide ; Neuropathy ; Lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Treatment of cats with acrylamide, either 7.5 or 15 mg/kg IM, once a day for 10 days, resulted in increases of 31 and 47% in the phospholipid content of sciatic nerve, respectively, from a control level of 41.1±2.7 mg/kg wet weight. Determination of the distribution of individual phospholipids indicated no significant differences between control cats and those receiving a cumulative dose of 150 mg/kg acrylamide. In a separate experiment, cats were treated with the 150 mg/kg dose of acrylamide and the sciatic nerve was divided into proximal and distal portions at the level of the triceps surae nerve. Significant increases in phospholipid content were observed in both the proximal and distal portions of peripheral nerve of the acrylamide-intoxicated cats. This effect was present even when the phospholipid content was expressed in terms of total protein, dry weight or total lipid. Total weight of nerve segments, however, was significantly decreased in the neuropathic animals. The data are consistent with a focal degeneration of axons with relative sparing of phospholipids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316124
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    The representation of contrast and other stimulus parameters by single neurons in area 17 of the cat (1984)
    Springer
    Pflügers Archiv 401 (1984), S. 304-314 
    Details
    ISSN: 1432-2013
    Keywords: Visual cortex ; Contrast/response function ; Orientation and direction sensitivity ; Ocularity ; Binocular responses ; Feature specific responses ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The responses of neurons in area 17 were tested as a function of various stimulus parameters. The thresholds of individual cortical neurons were at contrasts between 0.01 and 0.1 (increment of 0.5×10−1 cd/m−2 on a background of 3 cd/m−2), the dynamic ranges were 1.0–2.0 log units of increment, and all cells showed a response decrease at increments above a certain maximum (supersaturation response). The averaged contrast/response curve for all neurons was S-shaped in the logarithmic plot, had a dynamic range of 2.5 log units, reached its maximum at a contrast of 0.75 and supersaturated above this level. The contrast/ sensitivity curves changed their slope under different stimulus conditions. They became flatter when the non-dominant eye was stimuated as compared to dominant eye stimulation or when the stimulation was done at a non-optimal orientation or direction, and they became steeper when both eyes were stimulated. But the maximum was reached at the same contrast and supersaturation was seen above maximum contrast no matter whether a cell was stronlgy (e.g. binocular stimulation at optimal orientation) or weakly excited (non-dominant or non-optimal orientation stimulation). After normalization, the averaged population contrast/response curves were virtually identical at all stimulus conditions. It was concluded, that range as well as maximum and supersaturation of cortical contrast/response curves are determined before the input reaches the cortex, and that the cortical cells summate, essentially, linearly. The findings furthermore demonstrate that the supersaturation of the cortical input must be due to subtractive inhibition, and that the same is true for the orientation sensitive inhibition in the cortex itself. Both, the peripheral contrast and the cortical orientation dependant inhibition cannot be explained by multiplicative inhibition. The fact, that the responses of neurons depend on many variables relativates their significance for feature representation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Angioarchitecture of the pancreas of the cat (1984)
    Springer
    Cell & tissue research 235 (1984), S. 675-682 
    Details
    ISSN: 1432-0878
    Keywords: Endocrine pancreas ; Angioarchitecture ; Cat ; Scanning and transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By the use of scanningand transmission electron microscopy, the possible sources of errors in interpretation of the microcirculation of the pancreas can be reduced in comparison to the classical India-ink injection method. Sphincter-like structures in the capillary wall of the cat pancreas are established by pericytes. These sphincters encircle the junctional zones between the endocrine and exocrine capillaries. They are assumed to be regulatory structures of blood flow and to regulate indirectly hormone secretion according to demand.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226968
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Scanning electron-microscopic study of Reissner's fiber in the caudal spinal cord of the cat and rabbit (1984)
    Springer
    Cell & tissue research 237 (1984), S. 181-183 
    Details
    ISSN: 1432-0878
    Keywords: Reissner's fiber ; Scanning electron microscopy ; Spinal cord ; Cat ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal portion of Reissner's fiber was examined by scanning electron microscopy (SEM) in the spinal cord of the cat and rabbit. In some preparations of both species the fiber displayed in the sinus terminalis of the central canal either stump-like terminations or structural modifications such as knot-like swellings and convolutions. In the same area homogeneous material could also be found, which obviously originated from the disintegrating fiber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Ultrastructure of dynamic and static skeletofusimotor endings in a cat muscle spindle (1984)
    Springer
    Cell & tissue research 238 (1984), S. 151-158 
    Details
    ISSN: 1432-0878
    Keywords: Skeletofusimotor innervation ; Muscle spindles ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Endings of four β skeletofusimotor axons in a spindle of the cat tenuissimus muscle were examined in semithin (1-μm thick) and ultrathin transverse serial sections. Two (dynamic) β axons terminated on the nuclear bag1 intrafusal muscle fiber and on extrafusal fibers of the dark type. Two (static) β axons terminated on the nuclear chain intrafusal fibers and extrafusal fibers of the intermediate type. The degree of indentation of axon terminals into the muscle surface, thickness of the sole plate and extent of folding of subjunctional membranes differed among intrafusal and extrafusal terminations of the same axon. Endings of β axons on the bag1 and chain fibers were also morphologically dissimilar. Motor axons may not determine ending morphology. Rather the form and structure of a β bag1 or chain ending may be determined by the type of intrafusal fiber on which the ending lies and the ending's distance from the primary sensory axon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215156
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Ethidium binding to deoxyribonucleic acid: Spectrophotometric analysis of analogs with amino, azido, and hydrogen substituents (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 83-110 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The DNA-ligand interactions of a series of phenanthridinium compounds with various combinations of amino, azido, and hydrogen functions at R3 and R8 were examined to determine the contribution of these particular substituents to ligand binding. Spectrophometric titrations using calf-thymus DNA emphasized the importance of amino substituents in conferring a strong interaction and also stabilizing the interaction against reversal by high ionic strength. Although azido groups were not as effective as amino groups, they were more effective than hydrogen functions in enhancing the interaction. Furthermore, an amino substitution at R8 was consistently, though only slightly, more effective than an amino substituent at R3. The results from superhelical titrations using plasmid pBR322 DNA demonstrated that analogs with amino and/or azido functions at both R3 and R8 produced the greatest unwinding, and compounds with an amino or an azido function at R8 proved more effective than those with the corresponding amino or azido substituent at R3.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Contributions of the PO ester and CO torsion angles of the phosphate group to 31P-nuclear magnetic shielding constant in nucleic acids: Theoretical and experimental study of model compounds (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 377-388 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The magnetic shielding constant of the 31P nucleus of the dimethylphosphate anion is calculated by an ab initio method for different values of the torsion angles about the PO ester bond and different orientations of the methyl groups. The results obtained tend to show that both types of conformational parameters contribute to the value of σ31P. The largest shielding is obtained when the methyl groups are staggered with respect to the PO bond; the smallest, for the eclipsed arrangement. Measurements carried out on the 16 deoxyribodinucleoside monophosphates show that in the majority of cases σ31P is shifted toward lower field for the dimers having large values of 3JPH3′ and 3JPH5′(5″). The theoretical results are discussed in relation to experimental data for polynucleotides and nucleic acids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Low-frequency Raman scattering by anharmonic DNA modes with A⇌B character modeled with a classical double-well oscillator (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 471-491 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The optical modes of DNA that displace one strand against the other are modeled by the motion of an oscillator in an asymmetric quartic double-well potential whose minima represent the A- and B-conformations. Assuming that the variation of the polarizability during vibration derives mainly from the tilting of the base rings relative to the helix axis, the total polarizability tensor is shown to possess approximately ellipsoidal symmetry and to depend nonlinearly on the instantaneous displacement of the two strands. The Raman spectrum of a collection of randomly oriented molecules is calculated. It consists of one or more peaks with characteristic shape. The depolarization ratio is 3/4, independent of molecular conformation and frequency. The results are discussed in the light of existing experimental and theoretical information.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230306
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Conformational study of trinucleoside tetraphosphate d(pCpGpCp): Transition of right-handed form to left-handed form (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 511-536 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using the semiempirical potential functions, conformational energies of the model compounds DMP-, d(pCp), d(pGp), and d(pCpGpCp) are calculated, and the B → Z transition is discussed along the pseudorotational path of the sugar ring. For dimethylmonophosphate anion, DMP-, the energy contour map is presented and the stabilities of the phosphodiester conformations discussed. For the sugar ring without the base attached, the minimum energies for each sugar-puckering form are calculated along the pseudorotational path. The energy barrier of the interconversion between the C(3′)-endo form and the C(2′)-endo form is calculated to be about 2.0 kcal/mol. From the conformational energy calculations of the interconversions of mononucleoside diphosphates, d(pCp) and d(pGp), between the C(2′)-endo conformer and the C(3′)-endo conformer, the purine sugar segment is known to be more convertible than the pyrimidine sugar segment. The results also support the finding that the pseudorotational transition occurred with the O(1′)-endo form more easily than with the O(1′)-exo form. Based on the results of conformational studies of DMP-, d(pCp), and d(pGp), a topological transition of the handedness of the model compound, d(pCpGpCp), is studied. The left-handed Z-form is found to be less stable by about 8.5 kcal/mol than is the right-handed B-form. The energy barrier of the Z → B transition is calculated to be about 17.4 kcal/mol. The contributions of the electrostatic and nonbonded energies to the energy barrier are discussed in connection with the conformation changes of the model compound, d(pCpGpCp).
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Microwave dielectric absorption of DNA in aqueous solution (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 593-599 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dielectric properties of aqueous solutions of DNA were measured at frequencies ranging from 0.1 to 12 GHz. The results are analyzed using the Maxwell mixture theory and yield a value for the hydration of the DNA of about 0.4 g/g, which is in the range observed in other investigations. No evidence was found for an additional absorption effect at microwave frequencies, which has been predicted to occur in certain DNA analogs due to the vibrational excitation of the double helix by the applied microwave field.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Self-association of the neuroregulatory peptide substance P and its C-terminal sequences (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 747-758 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Self-association of substance P and its C-terminal partial peptide sequences was studied by CD, quasi-electric light scattering, and sedimentation experiments. CD spectra of these peptides are strongly influenced by self-association. They exhibit strong characteristic negative ellipticities, suggesting the formation of a presumably B-type ordered structure. The tendency to form multimers depends on chain length and constitution and has its maximum at the octapeptide (SP 8). The peptide multimers have a broad distribution of sizes in the range of 30- and 800-nm diameter. Subdivision of this distribution into two size classes gives mean diameters of 60-100 nm (predominating)/200-800 nm for substance P and 30-50 nm/200-800 nm for SP 8 multimers.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    13C-NMR chemical shifts and the conformations of rigid polypeptides (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 819-829 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C-nmr chemical shifts of backbone carbonyl and side-chain β-carbons in polypeptides provide structural information. Recent utilization of substituent effects on 13C-nmr chemical shifts (principally γ-effects) has permitted the rationalization of their sequence and conformation dependence when observed in linear, flexible polypeptides. In this report, we apply the γ-effect method to study the 13C-nmr chemical shifts observed in solution and in the solid state for the backbone carbonyl and side-chain β-carbons in conformationally rigid polypeptides, which are usually cyclic. As found previously for flexible, linear polypetides, the relative 13C-nmr chemical shifts observed for the backbone carbonyl and side-chain β-carbons in conformationally rigid polypeptides are predictable from knowledge of their peptide residue sequence (primary structure) and conformation (secondary structure) via the γ-effect method.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230419
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Eu(III) ion binding to poly(L-glutamate) anion studied by environment-sensitive laser spectroscopy (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 847-852 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230502
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Circular dichroism studies of α-aminoisobutyric acid-containing peptides: Chain length and solvent effects in alternating Aib-L-Ala and Aib-L-Val sequences (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 877-886 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The CD spectra of the peptides Boc-X-(Aib-X)n-OMe (n = 1, 2, 3) and Boc-(Aib-X)5-OMe, where X = L-Ala or L-Val have been examined in several solvents. The X = Ala and Val peptides behave similarly in all solvents, suggesting that the Aib residues dominate the folding preferences of these peptides. The decapeptides adopt helical conformations in methanol and trifluoroethanol, with characteristic negative CD bands at 222 and 205 nm. In the heptapeptides, similar spectra with reduced intensities are observed. Comparison with nmr studies suggest that estimates of helical content in oligopeptides by CD methods may lead to erroneous conclusions. The pentapeptides yield solvent-dependent spectra indicative of conformational perturbations. Peptide association in dioxane results in an unusual spectrum with a single negative band at 210 nm for the decapeptides. Disaggregation is induced by the addition of methanol or water to dioxane solutions. Aggregation of the heptapeptides is less pronounced in dioxane, suggesting that a critical helix length may be necessary to promote association stabilized by helix dipole-dipole interactions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Interaction of poly-5-bromouridylic acid. II. Thermodynamic analysis of its interaction with adenosine and 9-methyladenine (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 831-841 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction of poly-5-bromouridylic acid [poly(BU)] with adenosine and 9-methyladenine was studied by equilibrium dialysis, optical melting, and microcalorimetry. The stacking free energy, ω, was estimated as -17.6 kJ/mol for adenosine·2poly(BU) and -18.8 kJ/mol for 9-methyladenine·2poly(BU) from the binding isotherms constructed from equilibrium dialysis results. The binding isotherms constructed from a series of melting curves also gave ω values for adenosine·2poly(BU). The thermal stability of the complex depends on monomer concentration, and the partial molar enthalpies of the complex formation at the midpoint of the transition were evaluated from the Tm coefficients as a function of free monomer concentration. The values of -92.0 and -90.4 kJ/mol were obtained for adenosine·2poly(BU) and 9-methyladenine·2poly(BU) in 0.4M NaCl-0.02M Na-cacodylate-5 × 10-4M EDTA (pH 7.0), respectively. Microcalorimetric measurements provided lower integral heats of reaction values for these complexes, i.e., -73.2 kJ/mol for adenosine·2poly(BU) and -71.5 kJ/mol for 9-methyladenine·2poly(BU). A comparison with a polyribouridylic acid system provided a quantitative understanding of a stabilization by bromination in terms of thermodynamic parameters.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230420
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230201
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Comment on breathing and bending in DNA (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 191-194 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Structure of hydrated Na+ ions around a region of A- or B-DNA helix (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 257-270 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A molecular-dynamics simulation was used to carry out an introductory study of the hydration of a section of a rigid single A- or B-DNA helix with one Na+ counterion per nucleotide. Four Na+ ions and four nucleotides and periodic boundary conditions were used to mimic an infinite helix. The atoms of the helix and the Na+ ions were assumed to be Lennard-Jones spheres that also carried charges. Stillinger four-point charge model water molecules were used. We carried out five calculations, for 26 and 46 water molecules in B-DNA and 20, 32, and 46 in A-DNA fragments. The arrangements of the Na+ ions are found to have some similarities to those obtained by Clementi and Corongiu. In the calculations with 46 water molecules, we found that two Na+ ions can be bridged by about two water molecules and form a hydrated bound pair, which in turn forms a bridge between the guanine N7 and a near phosphate group. These bound pairs may be important in stabilizing the helix structure of DNA molecules.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    The C-terminal extrahelical peptide of type I collagen and its role in fibrillogenesis in vitro: Effects of Ethylurea (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 313-323 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethylurea was used to weaken hydrophobic interactions during collagen fibrillogenesis in vitro. Intact and enzyme-digested type I collagen was studied. In all preparations, ethylurea decreased the extent and rate of fibril formation, inhibition being greatest in the enzyme-digested collagens. With intact collagen (and probably also with carboxypeptidasedigested collagen), there was no evidence the ethylurea altered the mechanism of fibril growth; in pepsin-digested collagen, however, the growth mechanism was altered by ethylurea, possibly reflecting a conformational change of the “hydrophobic cluster” in the C-terminal peptide. Such a structural change could occur in a hydrophobic environment once the distal portion of the C-terminal peptide (presumed to be essential for its structural stability) is removed by pepsin. The results further emphasize the importance of hydrophobic interactions in collagen fibril nucleation and growth in vitro.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    X-Ray crystallographic analysis of a ternary intercalation complex between proflavine and the dinucleoside monophosphates CpA and UpG (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1025-1041 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report the crystal-structure analysis of a complex involving the drug proflavine and the two dinucleoside monophosphates cytidylyl-3′,5′-adenosine (CpA) and uridylyl-3′,5′-guanosine (UpG). The planar drug molecule is intercalated between C⃛G and U⃛A Watson-Crick base pairs, in a double-helical fragmentlike arrangement. Sugar conformations at the 3′-ends of the two strands are dissimilar. The backbone conformations fall within the ranges of values noted previously for dinucleoside intercalation complexes, and some correlations involving these are noted. The separation of the two strands and the basic twist angle of 16°, compared to other reported complexes, are indicative of sequence-dependent effects of the drug binding.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Mean-square helical hydrophobic moments in partially ordered proteins (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1057-1066 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Helical hydrophobic moment ratios, 〈h2〉/〈H2〉, have been evaluated for 34 polypeptides under conditions where the helix content is dictated solely by the short-range interactions operative in aqueous media. The mean-square helical hydrophobic moment is denoted by 〈h2〉, and 〈H2〉 is the averaged of the squared hydrophobicites. This ratio would be one in absence of any correlation in the hydrophobicities of amino acid residues in helices. The 〈h2〉/〈H2〉 tend to be substantially larger than values of the analogous ratio formulated for the mean-square dipole moments of typical synthetic polymers. For 24 of the 34 polypeptide chains considered, 〈h2〉/〈H2〉 is found to be greater than one, indicating a tendency to form helices with amphiphilic character. The ratio is exceptionally large in the case of the δ-hemolysins. It is also large for two other surface-active peptides, for two of the four apolipoproteins examined, and for myohemerythrin. A much smaller 〈h2〉/〈H2〉 is found for melittins. If melittins is to form helices with large 〈h2〉/〈H2〉, the configurational statistics must be governed by effects in addition to those short-range interactions that occur when water is the solvent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230701
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    β-Bend conformation of CH3CO-Pro-Pro-Gly-Pro-NHCH3: Implications for posttranslational proline hydroxylation in collagen (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1193-1206 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Conformational-energy computations have been carried out for the N-acetyl-N′-methylamides of the Pro-Pro, Pro-Gly, and Gly-Pro dipeptides and of the Pro-Pro-Gly-Pro tetrapeptide, serving as models for the conformational analysis of single-stranded poly(Gly-Pro-Pro). The probability of β-bend formation for the Pro-Gly sequence is very high, viz., 0.72 for the terminally blocked Pro-Gly dipeptide, and rises to 0.86 in the tetrapeptide. The β-bend conformations of the Pro-Gly sequence are of low energy in single-chain poly(Gly-Pro-Pro) as well. The β-bend structure had been postulated earlier to be a requirement for post-translational proline hydroxylation during the biosynthesis of collagen. The present results lend strong support to this proposal by demonstrating that the β-bend structure is energetically favorable and hence can be accommodated easily in single-stranded poly(Gly-Pro-Pro).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230705
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Circular dichroic studies on Cu(II) interactions with a protamine, scylliorhinine Z3 (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1241-1248 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction of Cu(II) with the protamine scylliorhinine Z3 was studied by means of CD measurements. At a 1:1 molar ratio, three complexes are formed. (1) In the pH range 5-6.5, the results suggest the formation of a five-membered chelate ring through the coordination of two nitrogen atoms, the N-terminal and the contiguous peptide nitrogen. (2) At pH ≥ 6.4, there is involvement of the lateral NH2 group of Arg; at pH 6.5-8, the formation of a 3N cupric complex is strongly suggested. (3) At pH ≥ 8, results indicate the formation of a 4N complex as a major species in Cu(II)-Z3 solution. The transformation from a 2N to a 3N complex, and from a 3N to a 4N complex was followed with the help of the σ(αNH2) → Cu(II) charge-transfer dichroic band transitions. At Cu(II):Z3 molar ratios ≥ 2 and at pH 〉 8, a new dichroic band appears, indicating the involvement of the tyrosine residue side chain in metal-ion complexation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230708
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Liquid crystallinity in collagen solutions and magnetic orientation of collagen fibrilsPresented at the Macromolecular Symposium of the International Union of Pure and Applied Chemistry, July 12-16, 1982, Amherst, Massachusetts. (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1261-1267 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies of the optical birefringence of solutions of acid-soluble collagen from rat-tail tendon at 22°C in the pH range 1.0-6.0 show that collagen exhibits an isotropic to mesophase transition only between pH 2.4 and 3.0 at 10% weight concentration. Such liquid crystalline order is probably essential for the orientation of collagen in a magnetic field. When solutions of neutral salt-soluble collagen were precipitated at pH 7.0 by warming to 37°C (“heat gelling”) in a magnetic field of ca. 20 kG, the resulting fibrils wee oriented perpendicular to the direction of the field. Heat gelling is shown to be a useful technique for maintaining the orientation induced in precursor solutions even after the sample is removed from the magnetic field.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Ionic and structural effects on the thermal helix-coil transition of DNA complexed with natural and synthetic polyamines (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1295-1306 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyamines are ubiquitous cellular components that interacts strongly with nucleic acids. Although many of the interactions of oligocations with DNA can be rationalized with polyelectrolyte theories that treat counterions as point charges, some structural effects are evident. We have explored the effects of polyamine structure on one important aspect of DNA behavior, its thermal melting transition, by using a series of spermidine analogs NH3(CH2)3NH2(CH2)nNH33+, where n varies from 2 to 8 [Jorstad et al. (1980) J. Bacteriol. 141, 456-463]. For spermidine itself, n = 4. Tm for calf-thymus DNA in the presence of each of these analogs, and the other naturally occurring polyamines putrescine2+ and spermine4+, was measured over a wide range of NaCl concentrations and polyamine:DNA phosphate ratios. There are modest, but significant structural effects. particularly with the shorter n = 2 and 3 derivatives, whose geometry my not allow full electrostatic interaction with DNA. Longer analogs, on the other hand, are not much different than spermidine in their effects on Tm, though a moderate maximum occurs at n = 5. Since polyamines are important in the cellular condensation and packaging of DNA, we have also delineated the critical polyamine and salt concentrations that are required to cause DNA aggregation. Here again, there are significant structural effects, which are not easily rationalized by any simple considerations.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230713
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Circular dichroism of core DNA in mononucleosomes: A theoretical model (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1315-1323 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The observed difference between the CD spectrum of B-DNA mononucleosomes and that of free DNA has been attributed to the tertiary structure of the core DNA. This conjecture is tested here. The tertiary structure is modeled as an optical system consisting of two identical, planar, linear retarders rotated with respect to each other. The retarders have the same linear birefringence and linear dichroism as oriented B-DNA. Such an optical system is circularly dichroic. The predicted wavelength dependence and magnitude of the CD are in reasonably close agreement with the experimental results.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230715
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Induced optical activity in the complex of poly(L-arginine) with azo dyes (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1367-1377 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The absorption and CD spectra of the complexes of poly(L-arginine) (PLA) and azo dyes have been measured in aqueous solution. On complexation, Blue-shifted additional absorption bands were observed. In the wide pH 4-11 range, induced CD was observed at the visible wavelengths corresponding to the blue-shifted absorption bands. The induced CD arose from the dimeric dye molecules bound to PLA in the α-helical structure. When a modified analysis of induced CE is made by the excition chirality method, the origin of the induced CD can be assigned to the dipole coupling. The PLA-dye complexes showed the counterlockwise (negative, S) chirality of the transition dipole moments of dyes.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230719
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    pH-jump titration of the tyrosyl groups of bovine plasma albumin (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1347-1365 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ionization properties of the tyrosyl groups of bovine plasma albumin in various conformational states - the native state (N), the two acid states (F and E), and the state (B) stable at slightly alkaline pH - were studied by means of a stopped-flow-pH-jump technique. The technique allows us to obtain the tyrosyl titration curve in a conformational state that is unstable in the pH region of the titration. The pH jumps from the N and B states to various alkaline pH's, where the tyrosines ionize to bring about a time-dependent increase in absorption at 296 nm, indicating that a number of the tyrosines buried initially become susceptible to ionization as a result of the alkaline transition occurring above pH 10.8. Extrapolation of the observed absorption change to zero time gives a spectrophotometric titration curve in the initial conformational state. Only 30-401% of the 19 tyrosines of the protein can ionize both in the N and the B state at pH 12. The pH jumps from the F and E states, on the other hand, give a decrease in absorption between pH 9 and 11.7, indicating that the tyrosyl groups initially exposed are remarked by refolding after the pH jumps, and the zero-time titration curves show that essentially all the tyrosyl groups ionize normally in these acid states. The results are discussed in relation to the known results of the tyrosyl exposure of the protein measured by other techniques, and the consistency among them demonstrates the effectiveness of the pH-jump titration method. Hydrogen bonding between the abnormal tyrosyl and carboxylate groups as a mechanism to stabilize native albumin is suggested from characteristics of the alkaline transition, which also involves the exposure of the tyrosyl groups, and from the tyrosyl titration curves in the native and acid states.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230718
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Fluctuational base-pair opening in DNA at temperatures below the helix-coil transition region (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1137-1139 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230614
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Synthesis of oligopeptides consisting of L-leucyl-L-leucyl-L-ananyl and L-methionyl-L-methionyl-L-leucyl repeating units with an improved preparation of Nps-amino acids (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1397-1409 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two series of peptides with hydrophobic side chains, Nps-(L-Leu-L-Leu-L-Ala)n-OEt and Nps-(L-Met-L-Met-LLeu)n-OEt (n = 1-6), were synthesized by the fragment condensation method using dicyclohexylcarbodiimide in the presence of N-hydroxysuccinimide. The tripeptide fragments were prepared stepwise by dicyclohexylcarbodiimide-mediated reaction of Nps-amino acids, which were synthesized by an improved rapid procedure.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230721
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Dielectric properties of aqueous solutions of sonicated DNA above 40 MHz (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1457-1463 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dielectric properties of sonicated calf-thymus DNA sodium salt in aqueous solutions have been studied in the frequency range from 40 MHz to 2 GHz by time domain spectroscopy (TDS). A dielectric dispersion not previously reported was found, which has a characteristic frequency of about 150 MHz. All of the dielectric parameters are insensitive to the size of DNA fragments and to helix-to-coil transitions. The study of this dispersion as a function of DNA concentration and temperature allows us to conclude that it may be due to counterion fluctuation on short sections, probably in a direction transverse to the macromolecular axis.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Polypeptide matrices as active catalytic supports for stereoselective electron-transfer reactions (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1465-1479 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The oxidation of L-adrenaline (epinephrine) in the presence of [Fe(tetpy)(OH)2]+ ions bound to poly(L-glutamate) or to poly(D-glutamate) has been studied at pH 7 (tetpy = 2,2′:6′,2″:6″,2‴-tetrapyridyl). Electron transfer from the substrate to the central metal ion, which is rate-determining, proceeds stereoselectively only when extensive and possibly specific interactions between adrenaline and the peptidic residues of the ordered polymer in the close environment of the active sites occur. This ensures different steric constraints for the two diastereomeric precursor complexes, which are thought to affect the separation and orientation of the redox centers differently, leading to the observed phenomena. Some data on the catalytic oxidation of L-dopa(3,4-dihydroxyphenylalanine) are also presented, showing stereoselective effects similar to those observed with L-adrenaline, despite the diverse distance of the chiral center from the reacting OH groups. A mechanistic interpretation of the results is discussed in the light of a few general considerations concerning the structural features of the catalytic systems. Possible explanations for the finding that stereoselectivity occurs at the expense of the efficiency of catalysis are also considered.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230804
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Determination of peptide conformation via vibrational coupling: Application to diastereoisomeric alanyl dipeptides (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1917-1930 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solution-phase Raman spectra of diastereomeric alanyl dipeptides, D-Ala-L-Ala and L-Ala-L-Ala, and various mono- and dideuterated isotopomers in H2O and D2O, are reported. Spectral differences between the diastereomeric forms are interpreted, using the Raman analog of the coupled oscillator model, in terms of geometric differences between certain vibrations in the diastereomeric forms. Application of the coupled-oscillator formalism allows the determination of a dihedral angle between the coupling vibrations. The results are compared with vibrational coupling employed by other workers in the determination of the vibrational spectra of peptides.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Theoretical studies on the conformation of saccharides. VIII. Solvent effect on the stability of β-cellobiose conformers (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1951-1960 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformational equilibria of five β-cellobiose conformers have been studied theoretically in 10 solvents. The stability of the conformers in dilute solution has been compared by using the method that has already been tested for 2-methoxytetrahydropyran, β-maltose, and D-glucose. The solvation energy consists of electrostatic, dispersion, and cavity terms which have been determined from the properties of the solute calculated by the PCILO quantum-chemical method and physicochemical properties of the solvents. The calculated abundance of conformers depends on the solvent (e.g., in dioxane C1:C2:C3:C4:C5 = 60.0:34.1:2.9:2.0:1.0; in dimethylsulfoxide, 75.5:22.1:1.8:0.5:0.2; and in water, 82.2:16.2:1.3:0.2:0.1). The results obtained indicate that the preponderant conformer in the aqueous solution is similar to the one adopted by β-cellobiose in the crystalline form. The role of individual contributions to the solvation energy have been analyzed. Based on the determined abundance of conformers, averaged residual optical activity and nmr parameters have been calculated and compared with observable properties. The marked differences observed between solvent-induced conformational changes for β-cellobiose and β-maltose have been discussed from the viewpoint of the solubility of the cellulose.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231011
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Theoretical studies on protein-nucleic acid interactions. II. Hydrogen bonding of amino acid side chains with bases and base pairs of nucleic acids (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1995-2008 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: With a view to understanding the role of hydrogen bonds in the recognition of nucleic acids by proteins, hydrogen bonding between the bases and base pairs of nucleic acids and the amino acids (Asn, Gln, Asp and Glu, and charged residues Arg+, Glu-, and Asp-) has been studied by a second-order perturbation theory. Binding energies have been calculated for all possible configurations involving a pair of hydrogen bonds between the base (or base pair) and the amino acid residue. Our results show that the hydrogen bonding in these cases has a large contribution from electrostatic interaction. In general, the charged amino acids, compared to the uncharged ones, form more stable complexes with bases or base pairs. The hydrogen-bond energies are an order of magnitude smaller than the Coulombic interaction energies between basic amino acids (Lys+, Arg+, and His+) and the phosphate groups of nucleic acids. The stabilities of the complexes of amino acids Asn, Gln, Asp, and Glu with bases are in the order: G-X 〉 C-X 〉 A-X U-X or T-X, and G · C-X 〉 A · T(U)-X, where X is one of these amino acid residues. It has been shown that Glu- and Asp- can recognize guanine in single-stranded nucleic acids; Arg+ can recognize G · C base pairs from A · T base pairs in double-stranded structures.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231014
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Conformation of control and acetylated HeLa stripped chromatin after reassociation with H1 (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 2195-2210 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of histone H1 on the conformation and stability of control and acetylated HeLa high-molecular-weight chromatin that had been stripped of H1 and nonhistone proteins was compared by circular dichroism (CD) and thermal denaturation measurements. Two different preparations of H1, originating from rat thymus and chicken erythrocyte, were used in the reconstitution studies. The control and acetylated stripped chromatin had identical CD and thermal denaturation properties, as did their reconstitutes with rat thymus H1. Reconstitutes of the two chromatins with chicken erythrocyte H1 had similar CD properties, but thermal denaturation studies showed that the acetylated reconstitute was destabilized compared to the control reconstitute. Reconstitutes of both chromatins with chicken erythrocyte H1 had a more condensed and stabilized structure than the reconstitutes with rat thymus H1. Thus, acetylation caused a decrease in the stability of chromatin in the presence of erythrocyte H1, but more marked differences were detected in the structure of stripped chromatin after reassociation with different H1 preparations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Kinetics of formation of fibrin oligomers. III. Ligation kinetics concurrent with and subsequent to oligomer assembly (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 127-138 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Human fibrinogen was treated with thrombin in the presence of fibrinoligase (Factor XIIIa) and calcium ion at pH 8.5, ionic strength 0.45, and the ensuing polymerization was interrupted at various time intervals (t) both before and after the clotting time (tc) by solubilization with a solution of sodium dodecyl sulfate and urea. Aliquots of the solubilized protein were subjected to gel electrophoresis on polyacrylamide gels after disulfide reduction by dithiothreitol and on agarose gels without reduction. The degree of γ-γ ligation was determined from the former. The latter provided the size distribution of ligated end-to-end sequences produced by splitting the ligated staggered overlapped oligomers down the middle, for degrees of polymerization, x, from 1 to 10. Addition of fibrinoligase (in which the activating thrombin had been inhibited by p-nitrophenyl-p′-guanidinobenzoate, NPGB) to Kabi fibrinogen showed the presence of small amounts of ligatable oligomers. Addition of fibrinoligase to a polymerizing mixture in which the action of thrombin had been stopped before clotting by NPGB produced the same distribution of ligated end-to-end sequences that was obtained when fibrinoligase was originally present, at least for reaction times up to 0.7 of the clotting time. The kinetics of γ-γ ligation by fibrinoligase acting on a polymerized mixture stabilized by NPGB were followed. The reaction was first order in the concentration of ligatable γ-γ junctions and the initial velocity was proportional to the enzyme concentration. The time evolution of size distribution of ligated end-to-end sequences agreed with a theory based on random ligation of ligatable junctions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Mean-square hydrophobic moment for partially helical polypeptides (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 201-212 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mean-square helical hydrophobic moment, 〈h2〉, is defined for polypeptides in analogy to the mean-square dipole moment, 〈μ2〉, for polymer chains. For a freely jointed polymer chain, 〈μ2〉 is given by Σmi2, where mi denotes the dipole moment associated with bond i. In the absence of any correlations in the hydrophobic moments of individual amino acid residues in the helix, 〈h2〉 is specified by ΣHi2, where Hi denotes the hydrophobicity of residue i. The tendency for correlations in orientations of residue hydrophobic moments in helices therefore dictates the size of 〈h2〉/〈H2〉, where 〈H2〉 denotes the average value of ΣHi2 for all helices. The value of 〈h2〉/〈H2〉 will be greater than one in amphiphilic helices. A necessary prerequisite for this diagnostic usage of 〈h2〉/〈H2〉 is that the residue hydrophobic moment be oriented prependicular to the principal axis of the helix. Matrix-generation schemes are formulated that permit rapid evaluation of 〈h2〉 and 〈H2〉. The behavior of 〈h2〉/〈H2〉 is illustrated by calculations performed for model sequential copolypeptides.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Monte Carlo determination of the distribution of ions about a cylindrical polyelectrolyte (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 271-285 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report a calculation of the distribution of small ions around a charged cylinder representing a polyelectrolyte molecule in solution. The Monte Carlo method of Metropolis, Rosenbluth, and Teller was used to avoid the inaccuracies known to be associated with the Poisson-Boltzmann equation. The systems examined contained a long polyelectrolyte cylinder with charge parameter, χ, equal to 4.2, corresponding approximately to a DNA molecule. In one model, the cylinder had charges on its axis and an exclusion radius to the center of the small ions equal to 10 Å, while the small ions had various radii in the range from 1 to 10 Å and one or two protonic charges. Various systems were studied; some had one species of small ion alone, others had mixtures of different types. The results showed good agreement with the solution of the Poisson-Boltzmann equation when only the species with 1-Å radius was present, but considerable discrepancies appeared with larger ions as a result of excluded volume interactions between the latter. Deviations from the Poisson-Boltzmann equation also appeared when both positive and negative small ions were present; the deviations were in the direction of a higher concentration of both counter- and co-ions, but particularly co-ions, close to the polyelectrolyte. In another model, the charges were arranged along two helices on the surface of the cylinder; the resulting radial distribution of small ions was not much different from that found when the charges were situated on the axis. In all cases there was a striking accumulation of counterions in a layer of concentration exceeding 1 mol/L at the surface of the polyion.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230208
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Variation of longitudinal acoustic velocity at gigahertz frequencies with water content in rat-tail tendon fibers (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 337-351 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Brillouin scattering was used to determine the longitudinal acoustic velocity along the axis of collagen fibers as the relative humidity decreased from 95 to 0%. Between 0 and 86%, the velocity decreased linearly at a modest rate. Above 86%, the decrease was steep. The changing mass of the absorbed water accounts for most of the velocity change in the lower humidity range. The remaining deviation is probably due to variation of the elastic coupling between molecules. At low humidity, the adsorbed water is known to be attached to the collagen molecules, whereas the additionally adsorbed water at high humidity has the properties of bulk liquid. The high-humidity sonic velocity variation is ascribed to the presence of free water. It is possible to identify the five water regimes of Pineri et al. [(1978) Biopolymers 17, 2799-2815] with the variations of the sonic velocity with water content.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Studies of collagen fold formation in aqueous solutions of α-gelatin III (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 353-361 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Optical rotation, viscosity, and density studies are reported on solutions of α-gelatin in solvent mixtures of water and various monohydric alcohols. Reversion to the collagen fold by the protein is shown to be order in all cases, but changes in magnitude as a function of concentration of the particular alcohol are observed. The structuring effects of the alcohol on water are seen to be reflected in the extent of helix regeneration by the protein. Shorter chain alcohols appear to influence the initial rate of reversion by direct interaction with the protein.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230301
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    A high-resolution 13C-nmr study of collagenlike polypeptides and collagen fibrils in solid state studied by the cross-polarization-magic angle-spinning method. Manifestation of conformation-dependent 13C chemical shifts and application to conformational characterization (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 2279-2297 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have recorded high-resolution 13C-nmr spectra of collagen fibrils in the solid state by the cross-polarization-magic-angle-spinning(CP-MAS)method and analyzed the spectra with reference to those of collagenlike polypeptides. We used two kinds of model polypeptides to obtain reference 13C chemical shifts of major amino acid residues of collagen (Gly, Pro, Ala, and Hyp): the 31-helical polypeptides [(Gly)nII, (Pro)nII, (Hyp)n, and (Ala—Gly—Gly)nII], and the triple-helical polypeptides [(Pro—Gly—Pro)n and (Pro—Ala—Gly)n]. Examination of the 13C chemical shifts of these polypeptides, together with our previous data, showed that the 13C chemical shifts of individual amino acid residues are the same, within experimental error (±0.5 ppm), among different polypeptides with different primary sequences, if the conformations are the same. We found that the 13C chemical shifts of Ala residues of the 31-helical (Ala—Gly—Gly)n and triple-helical (Pro—Ala—Gly)n are significantly displaced, compared with those of the α-helix, β-sheet, and silk I form, and can be utilized as excellent probes to examine conformational features of collagen-like polypeptides. Further, the 13C chemical shifts of Gly and Pro residues in the triple-helical polypeptides are substantially displaced from those found in (Gly)nII and (Pro)nII of the 31-helix, reflecting further conformational change from the 31-helix to the supercoiled triple helix. In particular, the 13C chemical shifts of Gly C = O carbons of the triple-helical polypeptides are substantially displaced upfield (4.1-5.1 ppm), with respect to those of the 31-helical polypeptides. These displacements are interpreted by that Gly C = O of the former is not involved in NH … O = C hydrogen bonds, while this carbon of the latter is linked by these kinds of hydrogen bonds.On the basis of these 13C chemical shifts, as reference data for the collagenlike structure, we were able to assign the 13C-nmr peaks of Gly, Ala, Pro, and Hyp residues of collagen fibrils, which are in good agreement with the values expected from the model polypeptides mentioned above. We also discuss a plausible conformational change of collagen fibrils during denaturation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Proton magnetic resonance studies on dermorphin and its peptide fragments (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 2349-2360 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dermorphin (Tyr—D-Ala—Phe—Gly—Tyr—Pro—Ser—NH2), a potent natural peptide opioid, its synthetic L-Ala2 analog, and all the N fragments from the tripeptide (Tyr—D-Ala—Phe—NH2) to the parent hexapeptide amide were characterized for the first time by means of proton nmr spectroscopy at 11.74 T. Assignments of most protons of dermorphin were facilitated by the study of the N-terminal fragments. Comparison of spectroscopic parameters with relative pharmacological activity is proposed as a possible means of studying flexible agonists in solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231116
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Magnetic circular dichroism of adenine, hypoxanthine, and guanosine 5′-diphosphate to 180 nm (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 2715-2724 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The magnetic circular dichroism (MCD) of adenine, hypoxanthine, and guanosine 5′-diphosphate reveals that, for each species, the uv-absorption band near 200 nm is composed of at least two electronic transitions. The theory of MCD shows that the dipoles of these transitions are not parallel to one another. The transitions are assigned within the framework of current theories of the electronic structure of the purines. Knowledge of the presence of more than one transition within an absorption envelope is important in interpreting the corresponding natural CD of DNA and RNA.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Evidence for an interwound form for the superhelix in circular DNA (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 2963-2966 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360231219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Aggregation of poly(γ-benzyl-α,L-glutamate) (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 719-734 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aggregation of poly(γ-benzyl-α,L-glutamate) and its enantiomer in toluene has been investigated by following the viscosity as a function of temperature, concentration, molecular weight, molecular-weight distribution, helix chirality, and shear rate. The temperature and concentration data for a 138,000-molecular-weight sample was fitted to an open, reversible end-to-end aggregation model. The aggregation numbers resulting from this fit were consistent with the sudden onset in non-Newtonian flow resulting from only a 0.2-wt% increase in concentration. The association equilibrium constant was then used to predict viscosity for comparison with other data, in particular, the effect of molecular weight and molecular-weight distribution. A mixture of right-and left-handed helices showed the aggregation was not chiral selective. The stiffness of end-to-end aggregated (hydrogen-bonded) molecules differed little from their covalent counterparts, at least below a molecular weight of ∼106. We conclude that polybenzylglutamate aggregation in toluene can be described by an open end-to-end aggregation model.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Quasielastic light-scattering studies on dinucleosomal-sized DNA: Ionic-strength dependence (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 797-808 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quasielastic light-scattering (QELS) studies were performed on a monodisperse preparation of dinucleosomal-sized DNA having an average of 375 base pairs. The QELS data were obtained at several time intervals at each angle examined over the range 30° 〈 θ 〈 60° for the ionic strength solvents 500, 50, 10, and 1 mM in KCl. What results from this study is that two relaxation domains persist over the entire ionic strength range where the “splitting” between these two domains increases as the ionic strength is lowered. The ordinate intercept of Dapp vs Cp/2Cs, where Cp is the polyion concentration and Cs is the added salt concentration, is shown to give the “true” hydrodynamic value for the diffusion coefficient. The “splitting phenomenon” is interpreted in terms of two models currently in vogue: small ion-polyion coupled modes and translational-rotational coupled modes for rigid rods in congested solutions. Although neither model is in perfect agreement with the experimental results, the small ion-polyion coupled mode theory appears to provide a better quantitative description of the observations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230417
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984) 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    mini-chiuz (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. A4 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Interstellare Moleküle und Mikrowellenspektroskopie IITeil I dieses Beitrags erschien in dieser Zeitschr. 18, 1 (1984). (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 55-61 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Vom Handwerk des Chemiehistorikers (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 62-67 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Chronik (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 68-69 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    R. B. Woodward und die moderne organische Chemie (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 109-119 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Methods of Enzymatic Analysis. Bd. 1: Fundamentals. Bd. 2.: Samples and Reagents. Hrsg. von H. U. Bergmeyer. 3. Aufl., Verlag Chemie, Weinheim - Deerfield Beach, Florida 1983. XXIV, 574 S. bzw. XIV, 539 S., zahlr. Abb. und Tab., DM 230, - bzw. 245,- (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 143-143 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984) 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Chronik (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 179-180 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    mini-chiuz (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 60A 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Über die Erhaltung der Kraft. Faksimile-Druck des handschriftlichen Textes sowie ein Teilband mit kommentierter Transkription. Von Hermann Helmholtz. Physik-Verlag, Weinheim 1983. 2 Bde. im Schuber, zus. 206 S., Leinen, DM 80, - (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 177-178 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Chronik (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 211-212 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Methods of Enzymatic Analysis. Bd. 5. Enzymes 3: Peptidases, Proteinases and Their Inhibitors. Hrsg. von H.-U. Bergmeyer und H. Fritz. 3. Aufl. Verlag Chemie GmbH, Weinheim - Deerfield Beach - Florida/USA - Basel 1984. XXVII, 598 S., geb. DM 270,- (1984)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 18 (1984), S. 214-214 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19840180607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Interactions of molecules with nucleic acids. VII. Intercalation and T·A specificity of daunomycin in DNA (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 139-158 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Intercalation complexes of daunomicin(+1) with tetramer duplexes in DNA are studied with the theoretically determined intercalation sites (I, -0.4), (II, -0.4), and (III, -1.4). These sites occur with base pairs separated by 6.76 Å for helical angles of 26°, 22°, and 8° about the intercalation site. Site I is preferred, and this is in agreement with experimental unwinding angles. Optimum binding positions and conformations are established, and these are in agreement with experimental results from crystal structures. A systematic procedure is devised to study base-pair and base-sequence specificity, which results in the demonstration that the most stable sequences are mainly ↑BP1, T·A, DAUN, A·T, BP4↓ and ↑BP1, T·A, DAUN, G·C, BP4↓, i.e., with the TpA and CpG (pyrimidine)p(purine) sequences about the intercalation site. These 32 possible sequences are found among the 40 most stable complexes. These theoretical calculations of intercalation complexes with daunomicin(+1) provide the first example in which a drug specifically selects the base pair T·A and prefers it in a particular sequence about the intercalation site. This specificity is in agreement with some experimental results. Problems associated with the interpretation of specificity are discussed in terms of the base, base-pair, and base-sequence resulting from the DNA site and the DNA-drug interactions. T·A specificity is rationalized by noting that the 2′deoxyribo-5′-monophosphate backbone attached to A is slightly more negative than that on the other nucleotides. Hence, a preference exists for binding to the protonated daunosamine (+1) groups. Stereographic projections of daunomycinone and daunomycin(+1) in a bond model and in a space-filling model with steric contours illustrate the results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Small-angle x-ray scattering studies on yeast inorganic pyrophosphatase and its interactions with divalent metal ions, inorganic phosphate, and hydroxymethane bisphosphonate (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 159-165 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Small-angle x-ray scattering studies have been carried out on the enzyme yeast inorganic pyrophosphatase (PPase), and its overall conformational changes on interaction with divalent metal ions (Mg2+ and Mn2+) and with phosphoryl ligands [inorganic phosphate (Pi) and hydroxymethane bisphosphonate (PCHOHP), a nonhydrolyzable inorganic pyrophosphate analog] were assessed. The enzyme undergoes an apparent reduction in size on simultaneous addition of Mg2+ and high Pi concentration, although neithough neither Mg2+ nor Pi added separately induced any measurable conformational changes. By contrast, simultaneous addition of Mn2+ and Pi to PPase does not result in an observable conformational change. However, the overall structure of the enzyme appears to enlarge in the simultaneous presence of Mn2+ ions and PCHOHP. The significance of the structural changes seen in PPase under various conditions is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Interacalation of ethidium ion into DNA and RNA oligonucleotides (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 213-233 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermodynamics of ethidium ion binding to the double strands formed by the ribooligonucleotides rCA5G + rCU5G and the analogous deoxyribo-oligonucleotides dCA5G + dCT5G were determined by monitoring the absorbance versus temperature at 260 and 283 nm at several concentrations of oligonucleotides and ethidium bromide. A maximum of three ethidium ions bind to the oligonucleotides, which is consistent with intercalation and nearest-neighbor exclusion. For the ribo-oligonucleotide the binding mechanism is complex. Either two sites (assumed to be the intercalation sites at the two ends of the oligonucleotide) bind more strongly by a factor of 140 than the third site, or all sites are identical, but there is strong anticooperativity on binding (cooperativity parameter, 0.1). In sharp contrast, the binding to the same sequence (with thymine substituted for uracil) in the deoxyribo-oligonucleotide showed all sites equivalent and no cooperativity. For the ribo-oligonucleotides the enthalpy for ethidium binding is -14 kcal/mol. The equilibrium constants at 25°C depend on the model; either K = 6 × 105M-1 for the two strong sites (4 × 103M-1 for the weak site) or K = 2.5 × 105M-1 for the intrinsic constant of the anticooperative model. For the equivalent deoxyribo-oligonucleotide the enthalpy of binding is -9 kcal/mol and the equilibrium constant at 25°C is a factor of 10 smaller (K = 2.5 × 104M-1).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Distribution of counterions around a cylindrical polyelectrolyte and manning's condensation theory (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 287-312 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The distribution of counterions around a charged polyion cylinder is calculated by several methods. First, the Debye-Hückel approximation is used, and it is shown that Manning's condensation hypothesis is necessry to avoid overneutralization of the polyion charges by the counterions when the linear-charge-density parameter, ξ, of the polyion exceeds the critical value of unity. However, it appears that this method of getting this result involves inconsistent application of Debye-Hückel theory. Therefore, we turn to the analytical solution of the Poisson-Boltzmann equation that was obtained by Alfrey, Berg, and Morawetz for a polyion cylinder plus a neutralizing number of counterions but without added salt. One of the integration constants of this solution is a radius, which we call RM, within which lies precisely the fraction of counterions that Manning assumes to condense in his theory. This radius can be rather large, however, so that the “Manning fraction” of condensed ions actually forms a diffuse cloud whose size varies with the polyelectrolyte concentration; RM varies as κ-1/2, where κ is the Debye-Hückel screening parameter. The Manning fraction, 1 - 1/ξ, and its associated radius are unique in their behavior with dilution; smaller fractions stay within finite radii, while with larger fractions the corresponding radii increase as κ-1. Thus, the condensation hypothesis does have a simple mathematical foundation in the Poisson-Boltzmann equation. Finally, by comparison with numerical solutions, we find that these conclusions are not significantly changed even when salt is added to the polyelectrolyte. A short table of numerical solutions of the Poisson-Boltzmann equation in cylindrical geometry is given, together with tables of coefficients tht enable one to discover the particular solution that applies for a given polyion radius and charge density.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Matrix-method calculation of linear and circular dichroism spectra of nucleic acids and polynucleotides (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 435-470 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Calculations of the optical properties (absorption, linear dichroism, circular dichroism, and anisotropic components of the CD) are presented for polynucleotides of random or regular sequence within the formalism of the matrix method using a set of parameters that includes only the ππ* transitions of the aromatic bases. Experimental solution spectra agree favorably with calculated CD spectra for A-RNA, A-DNA, and B-DNA, when coordinates derived from x-ray studies on fibers are used. Excessive hypochromicity is predicted when parameters intended to reproduce the vacuum-uv absorption of the chromophores are included in the calculations, but total elimination of these parameters leads to an insufficient hypochromicity for the long-wavelength absorption band. Using alternative conformations for DNA in low-salt aqueous solution did not improve the agreement between experimental and calculated spectra, but some features of the optical properties predicted for these variant structures suggest that the tilt of the bases with respect to the helical axis may be larger than that of the fiber B-form.In the case of polynucleotides with regular structure, which have been traditionally less easy to understand in terms of the standard nucleic acid conformations, a series of alternative structures has been examined. Unexpectedly, the calculated spectrum for the Z-DNA structure compares almost quantitatively with the experimental spectrum of poly(dGC·dGC) in low salt. This result, which confirms a recent report [Vasmel, H. & Greve, J. (1981) Biopolymers 20, 1329-1332], is in contrast with the current identification of Z-DNA with the high-salt form of poly(dGC·dGC). Finally, the optical properties of single-stranded polyribonucleotides appear to be better explained when alternative structures [91-helix for poly(rA) and 61-helix for poly(rC)] are introduced instead of the A-RNA form.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Total intensity light scattering from short, optically anisotropic wormlike chains (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 607-608 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230314
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Dimensions of short, rodlike macromolecules from translational and rotational diffusion coefficients. Study of the gramicidin dimer (1984)
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 611-615 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360230402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...