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  • 1995-1999
  • 1985-1989  (2,495)
  • 1989  (2,495)
  • Life and Medical Sciences  (1,888)
  • Engineering  (566)
  • Magnetic resonance imaging
  • Nuclear reactions
Material
Years
  • 1995-1999
  • 1985-1989  (2,495)
Year
  • 1
    ISSN: 1432-1440
    Keywords: Periarteritis nodosa ; Magnetic resonance imaging ; Cerebral lesions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The course is reported of a patient with periarteritis nodosa who initially presented with neurological symptoms. Multiple cerebral lesions were documented by the first magnetic resonance imaging (MRI) investigation. The majority of these had disappeared completely in the follow-up MRI studies. In contrast to neurological improvement the patient eventually died due to multiorgan failure. Postmortem histological examination revealed no pathological findings in the brain except one single necrotic area already known from MRI. Remissions of histological and angiographic alterations in periarteritis nodosa have been described as “local healing” leading to fibrosis and scarring. Our findings suggest that restitutio ad integrum may occur, at least in cerebral lesions.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Surgical and radiologic anatomy 11 (1989), S. 155-161 
    ISSN: 1279-8517
    Keywords: Brain stem ; Magnetic resonance imaging ; Anatomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé A partir d'une exploration IRM de la fosse postérieure de 30 sujets volontaires sains une corrélation anatomoradiologique a été effectuée. L'examen fut pratiqué sur un appareil CGR Magniscan de 0,5 Tesla avec une séquence d'inversion récupération (TI: 21 ms, Tr. 2 000 ms, Ti: 500 ms). Cette séquence nous paraît être celle qui visualise le mieux la substance grise, la substance blanche et le liquide cérébrospinal. Afin d'étudier la configuration des principales structures du tronc cérébral 8 plans de coupes horizontales et 3 sagittales sont proposés.
    Notes: Summary Magnetic resonance imaging of 30 normal volunteers' posterior fossae was performed on a CGR Magniscan machine with a magnetic field strength of 0,5 Tesla. We chose the inversion recovery signal with a Tr of 2,000 ms, a TE of 21 ms and an inverse time of 500 ms. This sequence gives a better definition of the grey matter, the white matter and the CSF. To study the brain stem we suggest 8 horizontal and 3 sagittal sections.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Abdominal imaging 14 (1989), S. 308-310 
    ISSN: 1432-0509
    Keywords: Hemangioma, spleen ; Thrombocytopenia ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In contrast to the only previously published description, the magnetic resonance appearance of a splenic hemangioma was markedly heterogeneous on T2-weighted images due to extensive infarction and large vascular pools. Magnetic resonance images correlated precisely with the pathological findings. The hemangioma caused thrombocytopenia, a well-documented albeit rare hematologic phenomenon associated with visceral hemangioma.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 129-133 
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Computed tomography ; Brain stem tumour ; Brain stem haemorrhage ; Brain stem infarction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ninety-six magnetic resonance imaging (MRI) studies demonstrating solitary brain stem lesions were reviewed in order to establish distinguishing features between tumours and other lesions. Histological confirmation of the radiological diagnoses was obtained in 33% of patients. The morphology of the lesion rather than its signal characteristics was the most useful feature in differential diagnosis, except after haemorrhage. However, areas of abnormal T2 recovery time were significantly more extensive than areas of abnormal T1 recovery time in tumours at presentation. In other lesions and in tumours following radiotherapy induced regression, the extent of abnormal T1 and T2 signal was the same. Possible reasons for this observation are discussed. The accuracy of computed tomography (CT) and MRI were similar for lesions causing brain stem expansion but for small lesions MRI was more sensitive and provided better topographical information.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Cerebral angiography ; Atrial myxoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of left atrial myxoma presenting exclusively with neurological symptoms, studied with magnetic resonance imaging (MRI) combined with cerebral angiography and computed tomography (CT) is reported. Typical angiographic findings suggested the diagnosis of myxoma. MRI showed multiple ischemic lesions disseminated throughout the entire brain, some of which had been clinically asymptomatic. Because of its sensitivity in identifying small cerebral infarcts, MRI should prove in the future to be a first-choice technique in the evaluation of the presence of and extent of cerebral involvement in embolic left atrial myxoma.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 213-216 
    ISSN: 1432-1920
    Keywords: Magnetic resonance imaging ; Spine ; 3DFT ; Gradient echo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A prospective study of 16 patients was performed to compare quantitatively a contiguous single slice 2DFT version with a 3DFT version of a short TR, variable flip angle, gradient echo (GRASS) pulse sequence. The 3DFT GRASS scans had higher signal-to-noise ratios (SNR) of cord and CSF compared to the single slice 2DFT GRASS scans. The 3DFT GRASS scans, however, had lower CSF-cord and CSF-disc contrast than the single slice 2DFT version. The 3DFT GRASS sequence demonstrated comparable contrast only on the end slices of an imaging volume suggesting influence of an entry phenomenon. The lower CSF-cord and CSF-disc contrast of the 3DFT GRASS technique diminished its usefulness in the diagnosis of cervical disc disease compared to the single slice 2DFT GRASS technique. Two different slice thicknesses (3 mm and 5 mm) were investigated with the 2DFT GRASS technique and found to be comparable although the 3 mm scans had sharper disc and dural margins because of less partial volume artifact.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 382-385 
    ISSN: 1432-1920
    Keywords: Cervical spine ; Disk herniation ; Myelography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eleven operated herniated disks in 10 patients were evaluated preoperatively with plain films, myelography and magnetic resonance imaging. Plain X-ray was a valuable supplement to MRI for studying the bony changes. Myelography showed 7 of 11 herniated disks while MRI gave correct diagnosis in all. It is concluded that MRI can replace myelography and computerized tomography in the preoperative evaluation of cervical herniated disk. The other examinations may be supplementary in some cases.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 430-432 
    ISSN: 1432-1920
    Keywords: Amnesia ; Glioblastoma ; Hippocampal formation ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report a unique case of glioblastoma which caused permanent amnesia. Magnetic resonance imaging showed the lesion to be limited to the hippocampal formation bilaterally. Although glioblastoma extends frequently into fiber pathways and expands into the opposite cerebral hemisphere, making a “butterfly” lesion, it is unusual for it to invade the limbic system selectively to this extent.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-1920
    Keywords: Thoracic disc herniation ; Spine, intervertebral discs ; Spine, MR studies ; Spinal cord, compression ; Contrast media ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The Gd-DTPA-enhanced magnetic resonance findings in two patients with herniated thoracic intervertebral discs are reported. The first patient was a 56-year-old woman with a small subligamentous T6-7 disc herniation, slightly lateralized to the right. The second patient was a 51-year-old man with a central and right posterolateral disc herniation, including a large calcified fragment, at the T8-9 level. The nonenhanced MR examination revealed the presence of an extradural mass lesion in both patients, impinging upon the dural sac and compressing and displacing the spinal cord posteriorly. The lesion was slightly hypointense on both T1- and T2-weighted spin echo sequences. Following intravenous injection of Gd-DTPA in a dosage of 0.1 mmol/kg body weight, enhancement of the posterior longitudinal ligament was noted and triangular areas of contrast uptake were seen to occur in the epidural space above and below the herniated disc. At surgery, they were found to correspond to dilated and congested epidural veins.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 276-277 
    ISSN: 1432-1920
    Keywords: Cockayne syndrome ; White matter ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary MRI findings are reported from two patients with Cockayne syndrome (CS) type I, aged 11 and 37 years. Changes were compatible with diffuse white matter hypomyelination. Basal ganglia calcification was present in both, marked cerebellar atrophy in the older patient. MRI may support the diagnosis of CS in the appropriate clinical context. The view that CS is a dysmyelinating disorder is further substantiated.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 177-179 
    ISSN: 1432-1920
    Keywords: Malignant fibrous histiocytoma ; Computed tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rare case of primary MFH of the brain is described together with the CT and MRI findings. The radiological appearance of this tumor is discussed in conjunction with the material published in other case reports.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 293-298 
    ISSN: 1432-1920
    Keywords: Pituitary microadenoma ; Magnetic resonance imaging ; Gadolinium DTPA ; Computed tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten patients with biochemical evidence of a hormonally active pituitary adenoma were examined by dynamic contrast enhanced computed tomography (CT) and then by pre and post Gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging (MRI). Excluding one false positive case, CT and unenhanced MRI were comparable in the detection of microadenoma. Post Gd-DTPA examination gave more clear evidence of the actual adenoma in two patients and aided in the demonstration of a third. However, in two others all imaging techniques failed to demonstrate the microadenoma subsequently found at surgery. On the post enhancement MRI it was easier to assess the relationship of a tumour to the cavernous sinus and to visualise the relationships of the parasellar carotid arteries.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 403-407 
    ISSN: 1432-1920
    Keywords: Vertebral artery ; Basilar artery ; Arterial occlusion ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Magnetic resonance (MR) images of nine patients with intracranial vertebral artery occlusion (five proved, four presumed) have been reviewed. In two of nine, both vertebral arteries were occluded and in five of the nine, the basilar artery was also blocked. All occluded arteries showed absence of flow void and were clearly demonstrated as mildly hypo-∼mildly hyperintense structures to brainstem parenchyma on the T1-weighted images. In two of five patients with basilar artery occlusion, retrograde filling of the distal basilar artery was detected. Thus, MR imaging, in particular the T1-weighted image, is a pertinent diagnostic modality for evaluating intracranial vertebral artery occlusion. Angiography does not seem to be required for confirmation.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 190-192 
    ISSN: 1432-1920
    Keywords: Epidural lipomatosis ; Lumbar myelography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Epidural lipomatosis may be unassociated with steroid use and should be considered in the differential diagnosis of lumbar radiculopathy. This may cause widening of the spinal canal on plain film and complete block on myelography. CT or MRI is diagnostic.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 98-101 
    ISSN: 1432-1920
    Keywords: Brain cysts ; Anomalies, congenital ; Magnetic resonance imaging ; Computed tomography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of large asymptomatic cysts of the lateral ventricle are presented. The cyst walls or cyst contours were demonstrated well by proton density-weighted or T2-weighted spin echo images. These cysts are being detected as incidental findings in increasing frequency with the increasing use of MR imaging. Our data and review of the literature suggest that surgical intervention is not necessarily warranted, but that careful clinical evaluation is indicated. The diagnostic problem of intraventricular cysts is also discussed.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Neuroradiology 31 (1989), S. 258-262 
    ISSN: 1432-1920
    Keywords: Neuro-Behçet's syndrome ; Behçet's syndrome ; Brain stem type neuro-Behçet's syndrome ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Brain stem type neuro-Behçet's syndrome was studied with enhanced CT and MRI during the acute and chronic stage of the illness. During the acute stage, brain CT revealed a low density lesion in the brain stem extending from the lower pons up to the midbrain ventrolaterally with marginal enhancement effect. T2-weighted image showed a high signal intensity lesion in the brain stem which mainly involved the basis ponti, tegmentum, tectum and cerebral peduncle. During the chronic stage, the lesion became low in signal intensity with T2-weighted image and reduced in its size without enhancement in brain CT. The prolonged relaxation time of the lesions was gradually normalized with steroid treatment. Sequential brain CT with enhancement and MRI study with T1- and T2-weighted images were useful to detect the lesions and to evaluate the activity in the neuro-Behçet's syndrome.
    Type of Medium: Electronic Resource
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  • 17
    ISSN: 1432-1920
    Keywords: Brain ; Magnetic resonance imaging ; Cavernous angioma ; Arteriovenous malformation ; (AVM) ; Venous angioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twelve patients with cerebral vascular malformations (5 cavernous angiomas, 1 thrombosed arteriovenous malformation, and 6 venous angiomas) were studied with magnetic resonance (MR) imaging. All lesions were clearly depicted. Characteristic MR findings were obtained mainly on T2-weighted images: a markedly low intensity area was always seen. The margins of arteriovenous malformation (AVM) and venous angioma were irregular while those of cavernous angioma were smooth in all planes on T2-weighted images. Gradient-echo (GrE) pulse sequences were more sensitive than T2-weighted spin echo (SE) in lesion detection. MR imaging could play an important role in the differential diagnosis of cerebral vascular malformations.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 18 (1989), S. 253-259 
    ISSN: 1432-2161
    Keywords: Fibrous metaphyseal defect ; Magnetic resonance imaging ; Determination of origin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sixteen patients with fibrous metaphyseal defects were examined with both plain radiography and magnetic resonance (MR) imaging. Depending on the age of the fibrous metaphyseal defects, characteristic radiomorphologic changes were found which correlated well with MR images. Following intravenous Gadolinium-DTPA injection, fibrous metaphyseal defects invariably exhibited a hyperintense border and signal enhancement. Healed lesions exhibited a transition to normal bone marrow. A line through the maximum longitudinal diameter of a fibrous metaphyseal defect invariably led to a point of tendinous or ligamentous insertion. Coronal MR images demonstrated the maximum longitudinal extension and the respective inserting tendon or ligamentous structure at the epiphyseal line.
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  • 19
    ISSN: 1432-2161
    Keywords: Magnetic resonance imaging ; Pulse sequences ; Primary bone tumour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A prospective magnetic resonance imaging (MRI) study was carried out in 13 patients (19 examinations) with primary bone tumours to assess the relative value of each of four pulse sequences in showing the extent and nature of the lesion. The four pulse sequences used were a T1-weighted spin-echo (SE544/44), a T2-weighted spin echo (SE1500/80), a short TI inversion recovery (STIR) (IR500/100/44), and a partial saturation (PS) (PS500/22) with field echo data collection. For soft tissue disease the combination of PS and STIR gave better definition of the boundary of the tumour than the more conventional T1 and T2-weighted spin echo sequences. For the demonstration of bone cortex, periosteal change and calcification, T1 and T2-weighted spin echo sequences were better. However, for calcified tissues, plain radiographs were better than either MRI combination. On the assumption that plain films will be available in all cases, PS and STIR sequences could therefore be substituted for T1 and T2-weighted spin echo sequences allowing an increase in soft tissue detectability for lesions in both red and yellow marrow.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 18 (1989), S. 523-526 
    ISSN: 1432-2161
    Keywords: Spine ; Scheuermann disease ; Magnetic resonance imaging ; Disc degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Comparison of the radiographic signs of Scheuermann disease and the corresponding disc degeneration on thoracolumbar magnetic resonance (MR) images was made in 21 young patients. Marginal sclerosis, Schmorl nodes and narrowed disc spaces, but not irregular or wedge-shaped end-plates, were significantly associated with disc degeneration. Fifty-five percent of the discs in the patients with Scheuermann disease were abnormal on MRI, compared with 10% in asymptomatic controls. Our study confirms that thoracolumbar disc degeneration is enhanced in 20-year-old patients with low back pain who have radiological evidence of Scheuermann disease.
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  • 21
    ISSN: 1432-2161
    Keywords: Disc ; Disc disease ; Disc extrusion ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Magnetic resonance (MR) imaging is useful in evaluating a variety of spinal pathologies including intervertebral disc disease. Herniated discs are commonly believed to undergo premature degeneration and produce low intensity signal on T2-weighted images. We reviewed 154 patients who were studied for disc herniations or other pathology. Fifty-nine (38%) had disc herniations and 7 of these (5%) had a fragment that was hyperintense with respect to the adjacent intervertebral disc on T2-weighted images. It is hypothesized that some disc fragments may contain a higher water content that causes prolongation of the T2 signal. The bright signal which is therefore seen on long TR long TE (T2-weighted) images may be a useful sign suggesting herniation or extrusion.
    Type of Medium: Electronic Resource
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 18 (1989), S. 585-590 
    ISSN: 1432-2161
    Keywords: Soft tissue tumors ; Bone tumors ; Magnetic resonance imaging ; Low field strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Extremely low field magnetic resonance imaging (MRI) was evaluated in 16 patients with bone and soft tissue tumors, both benign and malignant. Twelve of the lesions were located in the lower extremity, 2 in the gluteal and 2 in the shoulder region. The findings were compared to the results of computed tomography (CT). Low signal-to-noise ratio and poor spatial resolution result in an image quality which is inferior to that obtained with MR imaging at higher field strengths. In spite of this, the diagnostic information seems to be at least comparable to that obtained from CT.
    Type of Medium: Electronic Resource
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  • 23
    ISSN: 1432-2161
    Keywords: Magnetic resonance imaging ; Gadolinium-DTPA ; Rheumatoid arthritis ; Dynamic magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thirty-four joints (19 knees, 15 wrists) of 31 patients suffering from rheumatoid arthritis and related disorders were examined prior to and following intravenous administration of Gadolinium-DTPA (0.1 mmol/kg body weight). T1-weighted spin-echo sequences and the gradient-echo technique FLASH were applied. FLASH scanning was used for the registration of the time-dependent changes of signal intensity following Gd-DTPA. Synovial proliferations exhibited a rapid and marked increase of signal intensity whereas fatty tissue, bone marrow, muscle and synovial effusion demonstrated only minor changes, causing enhanced contrast between synovial pannus and joint effusion or other neighbouring structures. Within the synovial pannus, ratios (absolute signal increase) of 131.3±53.4% and 122.9±51.1% were found in T1-weighted spin-echo and in FLASH sequences respectively. The average signal increase gradient of pannus (108.2±70.6%/min) was significantly (p〈0.001) different from muscle (13.4±7.8%/min), fatty tissue (10.2±8.4%/min), bone marrow (5.5±7.1%/min), and joint effusion (14.7±7.8%/min).
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 149 (1989), S. 162-163 
    ISSN: 1432-1076
    Keywords: Antithrombin III ; l-Asparaginase ; Magnetic resonance imaging ; Osteonecrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report a child with acute lymphocytic leukaemia who developed simultaneous osteonecrosis of vertebrae and cerebral thrombosis duringl-asparaginase therapy. Fibrinogen, antithrombin III and plasminogen were decreased. Fresh frozen plasma in addition to antithrombin III concentrates were used to replenish these haemostatic proteins.l-asparaginase induced coagulopathy may cause osteonecrosis.
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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 236 (1989), S. 177-181 
    ISSN: 1432-1459
    Keywords: Cheiro-oral syndrome ; Magnetic resonance imaging ; Computed tomography ; Central gyrus ; Thalamus-Brain stem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four cases of the cheiro-oral syndrome are reported, with a review of the clinical symptoms and signs and the neuroradiological methods used to demonstrate the responsible lesion. In each case, angiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The lesion was found in the thalamus in three cases and in the pons in one. Infarction had occurred in three cases and haemorrhage in one. Angiography revealed normal findings in all cases. CT at the onset of the symptoms demonstrated a small haemorrhage in the thalamus in one case but was not helpful in the others, and MRI was required to identify infarction. The anatomical sites responsible for the cheirooral syndrome have been reported to be in the central gyrus, in the thalamus, and in the brain stem. The clinical symptoms and signs reported in the literature and in our four cases are reviewed to evaluate aetiological factors and clinical features according to the three different sites of lesions causing this syndrome.
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  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 236 (1989), S. 255-259 
    ISSN: 1432-1459
    Keywords: Japanese B encephalitis ; X-ray computed tomography ; Magnetic resonance imaging ; Geriatrics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neurological, computed tomography (CT) and magnetic resonance imaging (MRI) findings were recorded from 13 patients with Japanese encephalitis (JE) in the Kurume region diagnosed by serological criteria. The patients averaged 63 years of age, and 5 were older than 70 years. The serological data mostly indicated a primary response. Hemiplegia and tetraplegia were common, together with extrapyramidal signs. A few cases had a stroke-like onset and cerebral haemorrhage during the course of JE. CT and MRI in 7 cases revealed abnormalities in the thalamus and basal ganglia including the putamen. The CT and MRI findings from the acute stage to the convalescent stage were considered to be characteristic of JE.
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  • 27
    ISSN: 1432-1459
    Keywords: Sinus thrombosis ; Computed tomography ; Magnetic resonance imaging ; Thalamus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The case is reported of a patient with primary thrombosis of the internal cerebral veins who presented initially with unilateral and later developed bilateral thalamic lesions revealed by computed tomography. Magnetic resonance imaging and angiography confirmed the diagnosis. Upon anti-coagulation the patient recovered nearly completely.
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  • 28
    ISSN: 1432-1459
    Keywords: Multiple sclerosis ; Diagnosis ; Electrophysiological tests ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixty multiple sclerosis (MS) patients (33 definite, 13 probale and 14 suspected were investigated by computed tomography (CT), magnetic resonance imaging (MRI), multimodality evoked potentials (EPs) and cerebrospinal fluid (CSF) electrophoresis. MRI abnormalities were found in 50 cases, while at least one abnormal evoked potential was detected in each of 52 cases. Brain-stem auditory evoked potentials were more sensitive than MRI for the detection of brainstem involvement. All the patients with oligoclonal bands had abnormal MRI and none of the patients with normal MRI had oligoclonal bands in the CSF. The number and the extent of MRI lesions were significantly correlated with the duration of disease and with the degree of disability. Our observations stress the importance of the combined use of MRI and EPs in detecting silent CNS lesions in MS patients.
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  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 236 (1989), S. 115-116 
    ISSN: 1432-1459
    Keywords: Palatal myoclonus ; Inferior olive ; Magnetic resonance imaging ; Pseudohypertrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four patients with palatal myoclonus (PM) were studied with magnetic resonance imaging (MRI). Increased signal intensity and bilateral enlargement of the inferior olives were recognized in two patients with bilateral PM, pontine haemorrhage and neuro-Behçet disease, and a similar olivary change on the contralateral side was noted in a case of pontine infarction with unilateral PM. These findings were consistent with the pathology. The changes were more obvious in proton density-weighted images than in T2-weighted images, which thus differ from the changes in common gliosis. The other patient with the syndrome of PM and progressive ataxia did not show any olivary change. These changes on MRI are considered to indicate pseudo-hypertrophy of the inferior olives, although this is not consistently shown by the imaging method.
    Type of Medium: Electronic Resource
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  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 236 (1989), S. 117-119 
    ISSN: 1432-1459
    Keywords: Cavernous angioma ; Optic tract ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A cavernous angioma of the right optic tract in a 35-year-old man is presented. The patient suffered from headaches and had a left homonymous visual field defect after subarachnoid haemorrhage and an intracerebral haematoma in the right temporomedial region, revealed by computed tomography (CT). Follow-up CT showed a small contrast-enhanced lesion in the right suprasellar and parasellar cistern. Angiography on three occasions did not reveal a vascular lesion. Magnetic resonance imaging was helpful both for diagnosis and planning surgical therapy. It showed typical signs of a cavernous angioma of the right optic tract; the diagnosis was confirmed by surgery and histological examination. This appears to be the first reported case of a cavernous angioma of the optic tract.
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  • 31
    ISSN: 1432-1459
    Keywords: Chronic inflammatory demyelinating polyneuropathy ; Cranial nerve lesions ; Magnetic resonance imaging ; Nerve biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five cases of chronic inflammatory demyelinating polyneuropathy are described in which cranial nerve involvement accompanied a more generalized neuropathy. Clinical, electrophysiological, radiological and nerve biopsy findings are presented. Cranial nerve lesions in this form of polyneuropathy may be related to lesions of the peripheral nerves or of the central nervous system, when they may be accompanied by MRI evidence of more widespread CNS demyelinating lesions. In cases of early onset, the occurrence of focal cranial nerve lesions may serve to distinguish chronic inflammatory from inherited demyelinating polyneuropathies.
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  • 32
    ISSN: 1432-1459
    Keywords: Carbon monoxide poisoning ; Midbrain syndrome ; Visual evoked potentials ; Computed tomography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Five patients (aged 19–52 years) were treated for a midbrain syndrome due to acute carbon monoxide poisoning and had clinical follow-up investigations for up to 18 months. Three patients recovered with minor neurological and neuropsychological deficits and resumed their premorbid life-style. One patient had normal findings, while the fifth remained in a permanent vegetative state. Initial CT of the brain may fail to detect low-density lesions in the globus pallidus. If present, these lesions may either have disappeared, diminished, or remained unchanged at follow-up. Long-term outcome seems to show a closer link to white matter changes, which are at present best investigated by magnetic resonance imaging. The additional value of determining visual evoked responses at repeated follow-up is suggested by the present investigation.
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  • 33
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    Child's nervous system 5 (1989), S. 172-176 
    ISSN: 1433-0350
    Keywords: Pineal cyst ; Pineal tumor ; Pineal lesion ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Thirty-two cases of pineal cyst diagnosed by magnetic resonance imaging (MRI) were reviewed and are described. The pineal cyst was demonstrated to be an area with slightly less intensity than the surrounding tissue and with slightly greater intensity than the CSF on T1-weighted images. On the T2-weighted images this lesion was identified as a high-intensity area with smooth margins and was homogeneous in nature. In three cases presenting with headache, compression of the vein of Galen was identified, and compression of the quadrigeminal plate was demonstrated in five cases. No patients presented with both pineal and quadrigeminal lesions. Of the cases, 63% were not detected by CT scanning alone. There were two cases in which the cyst ruptured and collapsed spontaneously during follow-up. It is emphasized that the presence of this lesion, which was more frequent than previously expected, should be kept in mind when diagnosing pineal tumors and should not be misdiagnosed. Surgery should not be undertaken unless the lesion produces symptoms due to the compression of the quadrigeminal plate, aqueduct, or the vein of Galen.
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  • 34
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    Child's nervous system 5 (1989), S. 371-373 
    ISSN: 1433-0350
    Keywords: Temporal encephalocele ; Cerebral angiography ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An unusual case of temporal encephalocele is presented in this report. A large temporal mass was detected prenatally by ultrasound and following delivery by caesarian section. It was determined to be a large temporal encephalocele with extensive invasion into the subtemporal, facial and cervical regions. This case is presented because of the unique pathology of this congenital malformation and the extensive surgery that was required. The management and the clinical and radiological features are discussed.
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  • 35
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    European archives of psychiatry and clinical neuroscience 238 (1989), S. 225-230 
    ISSN: 1433-8491
    Keywords: Magnetic resonance imaging ; Friedreich's ataxia ; Spinal cord atrophy ; MRI evaluation of the brain stem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The severity of Friedreich's ataxia was graded in ten patients by clinical examination and in five by use of posturography. These data were compared with neuroradiology findings. CT-confirmed infratentorial atrophy occured only in advanced cases of Friedreich's ataxia; the correlation with the clinical score was poor. On mid-sagittal MRI planes the diameters of fourth ventricle, brain stem at the level of the inferior olive and spinal cord at the levels of the foramen magnum and C3 were measured. Patients with Friedreich's ataxia had significant MRI-confirmed atrophy of the cranial spinal cord as compared with a normal, age-matched control group. This was also observed in patients with Friedreich's ataxia in the early stages. A reliable correlation between atrophy of the cranial spinal cord and the clinical score, however, could again not be found. MRI exploration of the cranial spinal cord may be recommended as an additional diagnostic marker in Friedreich's ataxia.
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  • 36
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    Journal of neurology 236 (1989), S. 487-488 
    ISSN: 1432-1459
    Keywords: Baló's concentric sclerosis ; Magnetic resonance imaging ; Oligoclonal CSF IgG banding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An intra vitam diagnosis of Baló's concentric sclerosis in a 39-year-old male is described. To our knowledge this is the first reported case of ante-mortem diagnosis based solely on magnetic resonance imaging (MRI) findings. MRI showed features unique to this process. After high-dose intravenous therapy with prednisone, the clinical symptoms improved, and MRI showed marked changes of the concentric lesions.
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  • 37
    ISSN: 1432-1459
    Keywords: Status epilepticus ; Computed tomography ; Magnetic resonance imaging ; Single-photon emission computed tomography ; Cerebral oedema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 35-year-old female patient suffering from epilepsy was examined during status epilepticus with simple partial and complex partial seizures by means of EEG, CT, MRI and ictal SPECT. All these examinations showed focal abnormalities with identical location due to oedema and hypervascularisation; these were, however, absent during examinations carried out before and after status epilepticus.
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  • 38
    ISSN: 1619-7089
    Keywords: Bone marrow diseases ; Radionuclide imaging ; Magnetic resonance imaging ; Lymphoma ; Plasmacytoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In 63 patients with primary extramedullary malignant lymphoma or plasmacytoma, a study was performed in order to evaluate bone marrow involvement. All patients underwent a 99mTc microcolloid bone marrow whole body imaging (scintigraphy), using a gamma camera interfaced with a computer, followed by nuclear magnetic resonance bone marrow imaging (MRI), (1.5 Tesla). MR images were made of the lumbosacral region, the pelvic region, both femoral and other parts of the skeleton, according to focal lesions in the scintigraphy. A posterior iliac crest bone marrow biopsy was used as a standard reference. In the present study, both scintigraphy and MRI showed a dissiminated or focal involvement or a combination of both. In 53 of the 63 patients (84%) the results were in accordance. Pathological MR signals or pathological findings in scintigraphy did not always correspond to tumorous bone marrow involvement, and were shown to reflect reactive changes in the central part of the skeleton in combination with a periphery radionuclide extention interpreted as a periphery compensatory hematopoetic proliferation. The negative predictive value of scintigraphy and MRI was 92% and 100%, respectively. When combining the results of both examinations, the positive predictive value increased from 49% to 58%, if the bone marrow biopsy is accepted as gold standard. The results indicate that bone marrow investigation performed simultaneously using scintigraphy and MRI is superior both to the use of either of the methods alone and to the traditional iliac crest bone marrow biopsy.
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  • 39
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    Langenbeck's archives of surgery 374 (1989), S. 349-357 
    ISSN: 1435-2451
    Keywords: Magnetic resonance imaging ; Thoracic aortic surgery ; Follow-up
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zwecks überprüfung, inwieweit die Kernspintomographie, die mit gutem Erfolg bereits in der präoperativen Diagnostik eingesetzt wird, eine sinnvolle Bereicherung des diagnostischen Instrumentariums bei der postoperativen Kontrolle thorakaler Aortenerkrankungen darstellt, haben wir zwischen dem 1. 4. 1986 und 30. 3. 1988 30 Patienten (20 männlich, 10 weiblich, mittleres Alter 53 Jahre ± 13,7 Jahre) nach Operation an der thorakalen Aorta kernspintomographisch untersucht. Es lagen 19 arteriosklerotische Aneurysmen, 10 Dissektionen sowie ein Tumor der , Aorta descendens vor. In allen 30 Patienten gelang es, kernspintomographisch postoperativ die Ergebnisse der chirurgischen Maßnahmen zu dokumentieren. Es konnten im frühen postoperativen Stadium Komplikationen ausgeschlossen bzw., wie in einem Fall eine retrograde Aortendissektion oder einem anderen ein Hämatoperikard nachgewiesen werden. In der postoperativen Verlaufskontrolle aortaler Dissektionen ließ sich eine aneurysmatische Dilatation der dissezierten Aorta distal der implantierten Prothese in allen Fällen darstellen. Wahres und falsches Lumen konnten differenziert werden. In einem Fall ließ sich die Ausbildung eines Aortenbulbusaneurysmas nachweisen. Zusammengefaßt lassen sich postoperative Komplikationen der thorakalen Aortenchirurgie mit der Kernspintomographie zuverlässig nachweisen und bildlich in 3 Ebenen darstellen. Nichtinvasibilität, das Fehlen einer ionisierenden Strahlung und das ausbleibende Risiko einer Kontrastmittelapplikation machten die Kernspintomographie zu einer idealen Methode für Folgeuntersuchungen nach Operation an der thorakalen Aorta.
    Notes: Summary Operations of the thoracic aorta for aneurysms, dissections, or congenital malformations may lead to early or late complications. Therefore, postoperative control for documentation of the surgical results, for exclusion of early changes and for comparison with later controls is mandatory. To demonstrate that magnetic resonance imaging (MRI), which we already had used with good results for preoperative studies is also able to detect postoperative abnormalities, we examined 30 patients with thoracic aortic disease (20 male, 10 female, mean age 53 ± 13.7 years) with this diagnostic tool. There were 19 arteriosclerotic aneurysms, 10 dissections, and one aortic tumor. With MRI it was possible in all patients to visualize the results of the surgical treatment postoperatively. Early postoperative complications could be excluded, or demonstrated in one case of a retrograde aortic dissection or a hematopericardium. These pathological findings could also be shown by arterial digital subtraction angiography or echocardiography. Using MRI for follow-up of aortic dissections, the development of an aneurysm of the aortic root in a Marfan-patient could be detected. In all these patients, it was possible to differentiate true and false lumen and to detect the origin of major side branches. The diagnostic advantages of MRI, which we compared with other imaging methods, as echocardiography, computed tomography or angiography are that postoperative complications of thoracic aortic aneurysm surgery can be reliably detected and visualized in 3 different planes. Non-invasiveness, the omission of ionizing radiation and no risk of contrast media application underline that magnetical resonance imaging is an ideal method for follow-up after operation of the thoracic aorta.
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  • 40
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    European archives of oto-rhino-laryngology and head & neck 246 (1989), S. 265-268 
    ISSN: 1434-4726
    Keywords: Petrous bone ; Magnetic resonance imaging ; Gadolinium ; Cholesteatoma ; Temporal bone neoplasms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty cases of intrapetrous lesions were studied by a 1.5 T magnetic resonance (MR) unit. In all cases, comparisons were made between MR, CT and clinical findings. Our present material included 9 cholesteatomas, 1 cholesterol cyst, 3 primary epidermoid carcinomas, 2 metastatic neoplasms, 1 glomus jugulare tumor and 4 facial neurinomas. Gadolinium was injected in 7 cases and seemed to be the best method for studying the intrapetrous tumors. MR permitted accurate topographic study and assessment of tumoral extension, as well as a ready demonstration of tumor vascularity. The present findings also showed that MR is not capable of defining small bony detail or calcifications.
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  • 41
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    Journal of Morphology 199 (1989), S. 165-174 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: During ontogeny, the apical and basal components of dicamptodontid teeth exhibit three major developmental stages: nonpedicellate, subpedicellate, and pedicellate. Premetamorphic larvae tend to have nonpedicellate teeth, incompletely or recently metamorphosed individuals tend to have subpedicellate teeth, and fully transformed adults usually have pedicellate teeth. In concert with this transition, cusp morphology is modified from a larval monocuspid, to an incipiently bicuspid, to definitive adult bicuspid, and finally to an adult monocuspid condition. Thus, the larval and adult monocuspid conditions are ontogenetically distinct. The morphology of the larval monocuspid, adult bicuspid, and adult monocuspid conditions differs between Dicamptodon and Rhyacotriton. However, the incipient bicuspid condition in these two genera is very similar in appearance, suggesting that Dicamptodon and Rhyacotriton may be more closely related to each other than to the family Ambystomatidae in which they both sometimes are placed. The method of establishing ontogenetic trajectories seems to be preferable to comparisons based on adult structure, since similarities in the morphology of adults often is owing to convergent or parallel evolution.
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  • 42
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    Journal of Morphology 199 (1989), S. 207-221 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Comparative morphological analysis of the female reproductive tract in macroglossine bats was undertaken to test the hypothesis that nectarivory arose at least twice within Old World fruit bats. Given that features of the female reproductive tract are not directly involved in adaptations for feeding, this data set should provide a test of the monophyly of macroglossine bats. A cladistic analysis of variation in the structure of the ovaries, oviducts, uterus, and external genitalia supports the hypothesis that Megaloglossus has developed a nectar-feeding habit independent of other macroglossine genera. Most of the variation in female reproductive organs among pteropodids is found in the development of derived external and internal features of the uterus. Fusion of uterine cornua, expansion of the common uterine body, and elaboration of the cervical region are found in a group which includes species of Pteropus, Dobsonia, Nyctimene, and the macroglossines (excluding Megaloglossus). Results of this study are concordant with independent data sets, thus providing a phylogenetic framework to evaluate critically structural and functional design in the evolution of pteropodid feeding mechanisms.
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  • 43
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    Journal of Morphology 200 (1989), S. 269-300 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Descriptive data are provided for ontogeny of bone to metamorphosis in the myobatrachine species Uperoleia trachyderma; in pre- and postmetamorphic specimens of U. lithomoda, Crinia signifera, and Pseudophryne bibroni; and in postmetamorphic specimens of U. laevigata. Data derived from postmetamorphic U. laevigata indicate that dermal and endochondral elements ossify independently of each other in Uperoleia. Crinia signifera does not show the same degree of independence of ossification of dermal and endochondral elements as Uperoleia, whereas dermal and endochondral elements are not independent in P. bibroni. Ten (or possibly eleven) features are identified as being influenced by heterochrony within Uperoleia, confirming that the genus represents a highly pedomorphic lineage, four elements are influenced by heterochrony in Crinia, but only two in Pseudophryne.
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  • 44
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    Journal of Morphology 200 (1989), S. 301-319 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Investigation of eight developmental stages by means of serial sections and subsequent graphic or wax model reconstructions, as well as by means of cleared-and-stained and dissected material, revealed that the ethmoidal endocranium in Pipa pipa consists in early states of a single horizontal ethmoid plate lacking labial cartilages. Later in the course of development, structures comparable with those in other anurans appear, though modified and of reduced size. These adult structures arise from the new cartilaginous tissue located above the former larval ethmoid plate, whereas the latter entirely disappear. This phenomenon can be observed also in P. carvalhoi and in Xenopus laevis; hence, it supposedly occurs in all pipids. On the other hand, in anuran larvae, which develop cornua trabecularum in the ethmoidal region, these persist in adults as part of the nasal septum. Positional and developmental differences suggest that, although the ethmoid plate and the cornua trabecularum arise from the same region of the cranial neural crest, they are not fully corresponding structures. Comparison with adults of other pipid genera confirmed the conclusion of some earlier investigators that P. pipa is the most specialized among pipids.
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  • 45
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The Harderian gland of the musk shrew Suncus murinus is elongated anteroposteriorly from in front of the eye to behind the ear. The gland is divided into two portions: an anterior portion (A portion) and a posterior portion (P portion). The single secretory duct of the gland emerges from the anterior end of the P portion, receives several secretory ducts of the A portion during the course along it, runs around the ventral aspect of the eyeball, and finally opens into the anterior corner of conjunctival sacs. The two portions of the gland show a fundamentally similar histological structure, having a poorly developed intraglandular duct system and wide tubular alveoli. The quantity of lipid vacuoles and stromal connective tissue in the A portion is greater than in the P portion. The lipid vacuoles in both portions are surrounded by unit membranes, but their contents appear different.The lacrimal gland of the musk shrew is located along the ventral side of the P portion of the Harderian gland. The lacrimal duct emerges from its anterior end, runs around the ventral and anterior aspects of the ear, crosses the A portion of the Harderian gapos; and, and finally opens at the posterior corner of conjunctival sacs. The lobules of the lacrimal gland comprise a branched duct system and terminal acini with two types of secretory cells: (1) acidic cells positive both for the periodic acid-Schiff reaction (PAS) and for Alcian blue (AB) and (2) neutral cells positive for PAS and negative for AB. Both cell types tend to make separate acini, but when present in the same acinus, the acidic cells occupy relatively peripheral positions in the acinus. Both cell types lack intercellular canaliculi.On the basis of the present study as well as previous descriptions in the literature, the author suggests that the mammalian lacrimal glands can be divided into two sets: (1) a Glandula lacrimalis superior with multiple secretory ducts associated with the upper eyelid and (2) a Glandula lacrimalis inferior with a single secretory duct opening into the lateral corner of the conjunctival sacs. These glands have a fundamentally similar histological structure; but in the rabbit, which possesses both sets of lacrimal glands, they are different. On the other hand, the secretory cells of lacrimal glands generally have no intercellular secretory canaliculi, which are characteristically present between the serous secretory cells of the salivary glands.
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  • 46
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The leg musculature from 11, 14, and 17 day chick embryos was analyzed histochemically to investigate the temporal and spatial distribution of various types of sulfated glycosaminoglycans present during skeletal muscle development. Types of glycans were identified by selective degradation with specific glycosidases and nitrous acid coupled with Alcian blue staining procedures for sulfated polyanions and with [35S]sulfate autoradiography. On day 11, radiolabeled chondroitin sulfate glycosaminoglycans are localized extracellularly in both the myogenic and connective tissue cell populations. By day 17, incorporation of [35S]sulfate into chondroitin sulfate is substantially reduced, although Alcian blue-stained chondroitin sulfate molecules are still detectable. With increasing age and developmental state of the tissues, radiolabeled and stained dermatan sulfate and heparan sulfate progressively increase in relative quantity compared to chondroitin sulfate both in muscle and in associated connective tissue elements. These changes in glycosaminoglycans correlate well with similar changes previously determined biochemically and further document the alterations in extracellular matrix components during embryonic skeletal myogenesis.
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  • 47
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    Journal of Morphology 201 (1989), S. 119-129 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The aquiferous system of representatives of the orders Dictyocer-atida, Dendroceratida, and Verongida has been studied to note its relevance to the systematics of the groups. The volume of the choanocyte chamber, the size and shape of the choanocytes, the number of choanocytes per chamber, the relative development of the mesohyl, and the features of endopinacocytes are estimated from scanning and transmission electron microscopic observations of representatives of most families of the three orders. Although the Dysideidae have a reticulate skeleton and were classified in the order Dictyoceratida, they are actually closer to the Aplysillidae (Dendroceratida) than to dictyoceratids. The anatomy and cytology of the Halisarcidae differ profoundly from those of these three orders and are clearly more closely related to nonkeratose sponges. Some changes in classification lead to a pattern with highly homogeneous orders that clearly differ in their anatomic and cytologic features, which does not support the hypothesis of a common origin of the “keratose” sponges.
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  • 48
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    Journal of Morphology 201 (1989), S. 161-178 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The wall of the asymmetrical saclike lungs of the fishes Polypterus and Erpetoichthys consists of several functionally different tissue layers. Their lumen is lined by a surface epithelium composed of (1) highly attenuated cells, termed pneumocytes I; (2) pneumocytes II with lamellar bodies, presumably indicating surfactant production; (3) mucous cells; and (4) ciliated cells. Underlying the pneumocytes I is a dense capillary net. The thin continuous endothelium of this net, together with the pneumocytes I, constitute the very thin blood-air barrier. The basement membrane of epithelium and endothelium fuse in the area of the blood-air barrier (thickness 210 m̈m). Secretory and ciliary cells form longitudinal rows in the epithelium. Below the zone with a gas-exchanging tissue, a layer of connective tissue containing collagen and special elastic fibers occurs. The blood vessels that give rise to or drain the superficial capillary plexus are located in this connective tissue. The outermost layer of the lung consists of muscle cells, a narrow inner zone with smooth muscle cells, and an outer, broader zone with cross-striated muscle cells. The lung is innervated by myelinated and nonmyelinated nerve fibers. The morphology of the gas-exchange tissue in the lungs of these primitive bony fish is fundamentally very similar to that of the lungs of tetrapod vertebrates. The morphologic observations are in close agreement with physiologic data, disclosing well-developed respiratory capacities. Structural simplicity can be regarded as a model from which the lungs of the higher vertebrates derived. In addition to respiratory function, the lungs seem also to have hydrostatic tasks.
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  • 49
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    Journal of Morphology 201 (1989), S. 179-186 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Effect of turning of the egg during incubation on development of the area vasculosa of the chick embryo was investigated. The size of the area vasculosa was determined by two methods: direct measurement with calipers and measurement of a template cut from the eggshell by use of an automatic surface area recorder. The effects of turning and additionally the effects of lowered temperature (36°C) on both growth of the area vasculosa by day 7 and embryo growth by day 14 of incubation were investigated. The effects of turning during a critical period for turning, from 3 to 7 days of incubation, were also recorded. Generally, failure to turn eggs retarded growth of the area vasculosa. Turning during the critical period stimulated the extent of growth of the area vasculosa by day 7 of incubation and of subsequent embryonic growth by day 14. Incubation at low temperature resulted both in reduced expansion of the area vasculosa and retarded embryonic growth in a pattern similar to that observed for unturned eggs. It is suggested that turning stimulates development of blood vessels in the area vasculosa via localized increases in blood pressure. The effect of a reduced area vasculosa is considered to retard embryonic development through restricted nutrient uptake from the yolk. The prevailing hypothesis that turning prevents deleterious membrane adhesions is questioned in light of these observations. It is suggested that the physiological basis for the need for turning lies in maximizing the growth rate of the area vasculosa to maximize yolk use and embryonic growth rate.
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  • 50
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    Journal of Morphology 200 (1989), S. 123-130 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Recessive mutant gene c in axolotls results in a failure of the heart to function because of abnormal embryonic induction processes. The myocardium in this mutant lacks organized sarcomeric myofibrils. The present study was undertaken to determine if developmental abnormalities were evident in other areas of the heart besides the myocardium. A detailed comparative survey of the structure of developing normal and mutant hearts, including the endocardium, its cellular derivatives, and the extracellular matrix, known as cardiac jelly, showed that in the mutant there are fewer than the normal number of endocardial cells lining the heart lumen, the number of mesenchyme cells is reduced, and the cardiac jelly area is greatly enlarged in the posterior part of the truncus adjacent to the ventricle.
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  • 51
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    Journal of Morphology 200 (1989), S. 163-174 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Plethodontid salamanders have unique nasolabial grooves that may function as “capillary tubes” to convey chemicals to the vomeronasal organ when these animals nose-tap. 3H-proline was placed at the base of these grooves in Plethodon cinereus, and autoradiography revealed large concentrations of radioactive material in the vomeronasal organs. There was no significant accumulation of radioactive material in the main olfactory epithelium. Salamanders with blocked nasolabial grooves lacked significant accumulation of material in their nasolabial grooves or vomeronasal epithelia, although some salamanders had radioactive material in the posterior portion of their vomeronasal organ that had entered through the internal nares. Anteriorly placed vomeronasal organs situated adjacent to the posterior limits of the nasolabial grooves may insure that nose-tapping primarily stimulates the vomeronasal sensory epithelium.
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  • 52
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    Journal of Morphology 200 (1989) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 53
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    Journal of Morphology 200 (1989), S. 231-245 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A new mechanical model for function of the pharyngeal jaw apparatus in generalized perciform fishes is developed from work with the family Haemulidae. The model is based on anatomical observations, patterns of muscle activity during feeding (electromyography), and the actions of directly stimulated muscles. The primary working stroke of the pharyngeal apparatus involves simultaneous upper jaw depression and retraction against a stabilized and elevating lower jaw. The working stroke is characterized by overlapping activity in most branchial muscles and is resolved into three phases. Four muscles (obliquus dorsalis 3, levator posterior, levator externus 3/4, and obliquus posterior) that act to depress the upper jaws become active in the first phase. Next, the retractor dorsalis, the only upper jaw retracting muscle, becomes active. Finally, there is activity in several muscles (transversus ventrales, pharyngocleithralis externus, pharyngohyoideus, and protractor pectoralis) that attach to the lower jaws. The combined effect of these muscles is to elevate and stabilize the lower jaws against the depressing and retracting upper jaws.The model identifies a novel mechanism of upper jaw depression, here proposed to be the primary component of the perciform pharyngeal jaw bite. The key to this mechanism is the joint between the epibranchial and toothed pharyngobranchial of arches 3 and 4. Dorsal rotation of epibranchials 3 and 4 about the insertion of the obliquus posterior depresses the lateral border of pharyngobranchials 3 and 4 (upper jaw). The obliquus dorsalis 3 muscle crosses the epibranchial-pharyngo-branchial joint in arches 3 and 4, and several additional muscles effect epibranchial rotation. Five upper jaw muscles cause upper jaw depression upon electrical stimulation: the obliquus dorsalis 3, levator posterior, levator externus 3/4, obliquus posterior, and transversus dorsalis. This result directly contradicts previous interpretations of function for the first three muscles. The presence of strong depression of the upper pharyngeal jaws explains the ability of many generalized perciform fishes to crush hard prey in their pharyngeal apparatus.
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  • 54
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    Journal of Morphology 200 (1989), S. 255-267 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Changes in body morphology during growth and reproduction in the hydromedusa Eleutheria dichotoma are described in terms of variations in eight different characters: umbrella diameter, total surface area, tentacle area, umbrella area, tentacle knob diameter, number of embryos, and diameter and area of buds. Sexually (sex) and vegetatively (veg) reproducing medusae differ significantly in their body morphometrics. Statistically significant allometric relations exist between umbrella diameter and (1) central area (sex and veg); (2) tentacle area (veg); (3) total area (veg); (4) tentacle knob diameter (veg); (5) bud diameter; and (6) number of embryos. A significant correlation between umbrella diameter and area is also found in undetached buds. During sexual reproduction, umbrella area shows positive allometry and loses its correlations to total area, tentacle area, and tentacle knob diameter. Linear and nonlinear bivariate allometric coefficients allow estimation of total body size from only one or two easily measurable attributes, e.g., umbrella and tentacle knob diameter. Curve fitting by the classic allometric equation (y = bxc) is only negligibly worse than that obtained with a “full” equation (y = a + c), and statistical confidence is better.Chemical analyses for carbon and nitrogen content allow estimation of biomass from the projection area of the body surface. The relation factors are 1.06 μgC mm-2 (sex) and 1.14 μgC mm-2 (veg) for carbon and 0.293 μgN mm-2 (sex) and 0.287 μgN mm-2 (veg) for nitrogen. The C:N ratios are 3.6 and 4.0 for sexual and vegetative medusae, respectively. The use of allometric regression formulas to calculate surface areas and to relate these to carbon content provides quick estimations of body size in a microscopic animal.
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  • 55
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    Journal of Morphology 202 (1989), S. 13-28 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The neuronal organization of the accessory olfactory bulb (AOB), which receives sensory information from the vomeronasal organ, was described in a squamate reptile (Podarcis hispanica) by means of light microscopy. Using the Golgi-impregnation method, seven neuronal types could be distinguished:Periglomerular cells constitute a morphologically heterogeneous population of small neurons located between and around the glomeruli.The mitral cells are diffusely distributed in the AOB. Their cell bodies are usually located within the mitral cell layer, but some of them could be also observed in the plexiform layers. Mitral cells were classified into three subgroups on the basis of their sizes and dendritic tree morphologies. Thus, the “outer mitral cells” have the biggest cell bodies, and their distal secondary dendrites are mainly distributed rostrocaudally in the external plexiform layer. The “inner mitral cells” have large cell bodies, and their secondary dendrites are distributed dorsoventrally and are located deeper than those of the other two subgroups. The third type, the “small mitral cells,” is the smallest one among mitral cells in the AOB, and from their cell bodies, only two main dendritic trunks arise.The granule cells are composed of several categories based on their different cell body locations and dendritic tree morphologies. Thus, the “superficial granule cells” are located exclusively in the external plexiform layer and have small dendritic fields. The “middle granule cells” have fusiform cell bodies - situated in the internal plexiform layer - and present a wide dendritic projection area. Finally, the “deep granule cells” are distributed throughout the granule cell layer and include a great variety of dendritic tree morphologies.The distribution and morphological features of all neuronal types constituting the AOB of Podarcis were compared with those reported on other vertebrates. The results suggest that the lamination pattern and neuronal organization of the AOB in lizards are more similar to that of mammals than to that of the remaining vertebrates.
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  • 56
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    Journal of Morphology 202 (1989), S. 69-88 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Iridescent butterfly scales are structurally colored, relying upon the interaction of light with detailed architecture to produce their color. In some iridescent scales, the reflective elements are contained within the body of the scale and come in two basic forms, lattices that produce diffraction colors (analogous to those produced by opal), and stacks of laminae that produce thin-film interference colors (analogous to those produced by soap or oil films). Both structures are remarkably complex and precise, yet each is only part of the total edifice built by the cell that makes the scale.To understand better how a cell can produce lattices or thin-film laminae, I studied the development of iridescent scales from two lycaenid butterflies. The presence of diffraction and thin-film scales in the same family (and in some cases on the same individual) suggests that the two types must be developmentally related; yet these results yield no clear explanation as to how. The diffraction lattice appears to be shaped within the boundaries of the scale cell by means of a convoluted series of membranes in which the smooth endoplasmic reticulum plays an important part. The thin-film interference laminae appear to result from the condensation of a network of filaments and tubes secreted outside the boundaries of the cell. This paper outlines the developmental histories of both types of scale and discusses the developmental implications of the mechanisms by which they form.
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  • 57
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Wing folding spicules, elytral binding patches, and elytral locking devices of adult male and female seed weevils, Smicronyx fulvus LeConte and S. sordidus LeConte, involved in stridulation are described. Sound is produced by both sexes of the two species when the plectrum, paired conical teeth located along the anterior margin of the dorsally elevated seventh sternite, is struck against an elongate file, the pars stridens, on the under surface of the apical portion of each elytron. A second plectrum, on the sixth tergite, is well-developed in males of both species and is used by males to produce sound before and during mating.Sex-specific and species-specific differences in the sound produced is attributed to structural variation in the pars stridens and the elytra. The pars stridens determines frequencies, while the elytra may further modify the sound. The frequency range for male S. fulvus is 1,000 cycles per second (cps) through 13,000 cps and for male S. sordidus is 2,500 cps through 13,000 cps. The frequency range for female S. fulvus is 2,000 cps through 11,500 cps and for female S. sordidus is 900 cps through 11,500 cps.
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  • 58
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    Journal of Morphology 202 (1989), S. 53-68 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A study of neuromast ontogeny and lateral line canal formation in Oreochromis aureus and Cichlasoma nigrofasciatum reveals the existence of two classes of neuromasts: those that arise just before hatching (presumptive canal neuromasts, dorsal superficial neuromasts, gap neuromasts, and caudal fin neuromasts) and pairs of neuromasts that arise on each lateral line scale lateral to each canal segment at the same time as canal formation. In the anterior trunk canal segment, each presumptive canal neuromast is accompanied by a dorsoventrally oriented superficial neuromast forming an orthogonal neuromast pair. It is suggested that each of these dorsoventrally oriented superficial neuromasts is homologous to the transverse superficial neuromast row described by Münz (Zoomorphology 93:73-86, '79) in other cichlids. It is further suggested that the longitudinal lines described by Münz (Zoomorphology 93:73-86, '79) are derived from the pair of superficial neuromasts that arise during canal formation. Distinct changes in neuromast topography are documented. Neuromast formation, scale formation, and lateral line canal formation are three distinct and sequential processes. The distribution of neuromasts is correlated with myomere configuration; there is always one presumptive canal neuromast on each myomere. A single scale forms beneath each presumptive canal neuromast. Canal segment formation is initiated with the enclosure of each presumptive canal neuromast by an epithelial bridge which later ossifies. The distinction of these three processes raises questions as to the causal relationships among them.
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  • 59
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    Journal of Morphology 199 (1989), S. 299-311 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Gonadal differentiation in premetamorphic Bombina orientalis is described and staged. The pattern of events during differentiation in Bombina differs in several respects from that previously described in other anurans. The Bombina gonad initially develops on the ventral surface of the vena cava, where there is no pre-existent somatic genital ridge prior to the arrival of the germ cells. The sexually undifferentiated gonad does not have a distinct cortex and medulla; instead, medullary cells ingress from the mesonephric blastema during sexual differentiation. Formation of a testis or an ovary appears to depend on the ability (or lack of ability) of the medulla to invade the germ cell-containing cortex. In the germ line, sexual differetiation can be recognized by a premeiotic increase in oogonial cell volume.
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  • 60
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: The lungs of the New Caldeonian gecko Rhacodactylus leachianus were examined by means of gross dissection and light and electron microscopy. This tropical species, which is the largest living gecko, possesses two simple, single-chambered lungs. Right and left lungs are of similar size and shape. The lung volume (27.2 ml · 100 g-1) is similar to that of the tokay (Gekko gecko) but differs in that the gas exchange tissue is approximately homogeneously distributed, and the parenchymal units (ediculae) are very large, ∼2 mm in diameter. The parenchymal depth varies according to the location in the lung, being deepest near the middle of the lung and shallowest caudally. Scanning and transmission electron microscopy reveal an unusual distribution of ciliated cells in patches on the edicular walls as well as on the trabeculae. Secretory cell are very numerous, particularly in the bronchial epithelium, where they greatly outnumber the ciliated cells. The secretory cells form a morphological continuum characterized by small secretory droplets apically and large vacuoles basally. This continuum includes cells resembling type II pneumocytes but which are devoid of lamellar bodies. Type I pneumocytes similar to those of other reptiles cover the respiratory capillaries, where they form a thin, air-blood barrier together with the capillary endothelial cells and the fused basement laminae. The innervation, musculature, and vascular distribution in R. leachianus are also characterized. Apparent simplification of the lungs in this taxon may be related to features of its sluggish habits, whereas peculiarities of cell tissue composition may reflect demands of its mesic habitat.
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  • 61
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    Journal of Morphology 199 (1989) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 62
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    Journal of Morphology 199 (1989) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 63
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    Journal of Morphology 199 (1989), S. 41-52 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The molting cycle of Artemia is described and subdivided in stages A-D3 according to the system of Drach. Determination of the stages is done in living animals by light microscopic observation of changes in the texture of the setal matrix of the exopodites. A parallel ultrastructural investigation of the integument was carried out to control the proposed staging scheme. The duration of each stage was calculated.
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  • 64
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    Journal of Morphology 199 (1989), S. 71-92 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The extracellular matrix surrounding the sea urchin embryo (outer ECM) contains fibers and granules of various sizes which are organized in recognizable patterns as shown by ultrastructural studies, particularly stereoimaging techniques. The use of the ruthenium red method for retaining and staining the ECM, with modification of the Luft (Anatomical Record 171:347-368, 1971) method for invertebrate embryos, allows for the clarification of certain structures, particularly fiber compaction in the interzonal region, and microvillus-associated bodies.The inner ECM in the sea urchin embryo includes the basal lamina and blastocoel matrix. Stereoimages show that the fibers which are loosely distributed in the blastocoel matrix become compacted around the periphery of the blastocoel to form the basal lamina.The ruthenium red method was also used on a number of marine invertebrate embryos and larvae, representing different phyla, to facilitate comparisons between their surface coats. The similarities observed in the specimens shown suggest that ECMs are widely found on marine invertebrate eggs, embryos, and larvae, and that they resemble vertebrate ECMs and may, therefore, have similar functions.
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  • 65
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    Journal of Morphology 199 (1989), S. 151-164 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The coronate larva of the ascophoran bryozoan Watersipora arcuata has a ring of 32 large, multiciliated coronal cells that are used for swimming. Fourteen pairs of small cells are intercalated between the lateral margins of adjacent coronal cells. These intercoronal cells are arranged in a precise pattern and are polymorphic: seven pairs have multiple cilia and seven pairs are mono- or oligociliated. Three pairs of multiciliated intercoronal cells have their cilia arranged as a whorl that is recessed in a pocket formed between the adjacent coronal cells, and they are thought to be photoreceptors that sense general light intensity. Two other pairs of multiciliated cells with cohesive tufts of cilia may be chemo- or mechanoreceptors. Roles of the other intercoronal cells in this species are not evident, but it is proposed that the majority, if not all, of them are sensory. The close proximity of all the intercoronal cells to the equatorial nerve ring is compatible with this interpretation. Analyses of the literature on cleavage patterns, pigment cup ocelli, and flagellar tufts that serve as balancers in coronate larvae lead us to propose that (1) an intercoronal cell is the sensory element of most, if not all, pigment cup ocelli of bryozoan larvae; and (2) intercoronal cells are not modified coronal cells but probably are specialized supra- and/or infracoronal ones that have migrated to an intercoronal position.
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  • 66
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    Journal of Morphology 199 (1989), S. 245-247 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 67
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    Journal of Morphology 199 (1989), S. 223-243 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The projectile tongue of caudate amphibians has been studied from many perspectives, yet a quantitative kinetic model of tongue function has not yet been presented for generalized (nonplethodontid) terrestrial salamanders. The purposes of this paper are to describe quantitatively the kinnematics of the feeding mechanism and to present a kinetic model for the function of the tongue in the ambystomatid salamander Ambystoma tigrinum. Six kinematic variables were quantified from high-speed films of adult A. tigrinum feeding on land and in the water. Tongue protrusion reaches its maximum during peak gape, while peak tongue height is reached earlier, 15 ms after the mouth starts to open. Tongue kinematics change considerably during feeding in the water, and the tongue is not protruded past the plane of the gape. Electrical stimulation of the major tongue muscles showed that tongue projection in A. tigrinum is the combined result of activity in four muscles: the geniohyoideus, Subarcualis rectus 1, intermandibularis posterior, and interhyoideus. Stimulation of the Subarcualis rectus 1 alone does not cause tongue projection. The kinetic model produced from the kinematic and stimulation data involves both a dorsal vector (the resultant of the Subarcualis rectus 1, intermandibularis posterior, and interhyoideus) and a ventral vector (the geniohyoideus muscle), which sum to produce a resultant anterior vector that directs tongue motion out of the mouth and toward the prey. This model generates numerous testable predictions about tongue function and provides a mechanistic basis for the hypothesis that tongue projection in salamanders evolved from primitive intraoral manipulative action of the hyobranchial apparatus.
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  • 68
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    Notes: We have attempted to develop an objective, semiquantitative classification of fiber types in turtle neck and limb muscle using microphotometry and multivariate statistical techniques. We first stained serial sections for myosin adenosine triphosphatase (ATPase) (with acid and alkaline preincubation and without preincubation), NADH-diaphorase, and two glycolysis-associated markers, α-glycerophosphate dehydrogenase (α-GPDH) and glycogen phosphorylase A (GPA). This allowed us to characterize individual muscle fibers in terms of their contraction speed and metabolic properties. Next we used microphotometry to measure the optical density of the reaction product in each fiber, and we subjected the resulting optical density matrix to cluster and discriminant function analyses in order to assign fibers to groups (fiber types) and to determine which stains contribute most to the distinction between groups. As a control, we processed a well characterized mammalian muscle (rat sternomastoid) simultaneously. Our results suggest that both neck and limb muscle in Pseudemys can best described as falling into three groups: (1) slow oxidative (SO) fibers; (2) fast oxidative glycolytic (FOG) fibers, with relatively high oxidative and glycolytic capacities; and (3) fast glycolytic (Fg) fibers, with low oxidative, low/intermediate α-GPDH, and high GPA activities. These three fiber types differ from like-named types in rat muscle both in the pH lability of their myosins and in their metabolic profiles.
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  • 69
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    Journal of Morphology 200 (1989) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 70
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    Journal of Morphology 200 (1989), S. 1-8 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Distribution and density of the chloride cells in the newly hatched larvae of teleosts vary depending on species and environmental salinity at hatching. In the euryhaline freshwater ayu (Plecoglossus altivelis), chloride cells are concentrated in the skin posterior to the pectoral fins and gradually decrease in number toward the head and tail. In the stenohaline sea water flounder (Kareius bicoloratus), most chloride cells are localized at the inner membrane of gill chambers and in the skin near the openings of gill chambers, but only a few cells appear in the skin of the yolk sac. In the stenohaline freshwater carp (Cyprinus carpio), only a few small chloride cells are scattered in the body skin. The density and abundance of chloride cells appears to be correlated with the different requirements for osmoregulation in teleost larvae.
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  • 71
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This investigation relates the occlusal morphology of the continuously growing molars of common wombats (Vombatus ursinus) to the underlying enamel ultrastructure that was investigated using the techniques of light microscopy, scanning electron microscopy, and transmission electron microscopy. The main feature of the occlusal enamel was a prominent ridge, which followed the contour of the dentine-enamel junction (DEJ). It was found that the occlusal morphology depended upon the orientation of the dentinal and enamel tissues, variations in prism orientation, Hunter-Schreger bands (HSB), and presence or absence of cleavage. Cleavage of enamel promoted by sheets of parallel prisms occurred along the face between the DEJ and the ridge, whereas on the face between the ridge and the cementum-enamel junction (CEJ) cleavage was inhibited by HSB. The slope of the latter face was mainly due to a decrease in wear resistance going from the ridge, where prisms were intercepted transversely, toward the CEJ, where they were intercepted obliquely. Occasionally small surface undulations were observed on the face between the ridge and the CEJ. These undulations were found to correspond to gradually decussating enamel regions. The pronounced cleavage of enamel parallel to the face between the DEJ and the ridge played an important role in conferring on the continuously growing molars a distinct property to develop and maintain a self-sharpening ridge throughout the life of the tooth.
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  • 72
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    Journal of Morphology 200 (1989), S. 215-230 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The internal anatomy of juveniles and adults of Hypochthonius rufulus selected as a model species representing the lower Oribatida was investigated histologically and compared with the published characteristics of higher oribatid internal anatomy. In this species, the cuticle is weak and flexible, consisting of epicuticle and endocuticle on the body, but including an exocuticle between the epicuticle and endocuticle of the legs. Walls of the mesenteron in the digestive tract are of uniform thickness and structure without any regional thickening, and there are no proventricular glands. The hindgut is apparently divided into five parts: colon 1 and 2, rectum 1 and 2, and anal atrium; food bolus exhibits a multilamellar structure in this section. The glandular system is less diversified than in some other oribatids. Tracheae are apparently lacking. Females possess only two relatively large eggs, filling one-half of opistosoma, and they lack ovipositors. Eggs are present in females during the whole year. Gonad buds appear first in the protonymph stage. Only one male was found among 146 adults studied. No male external organ (aedeagus or penis) is present.
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  • 73
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    Journal of Morphology 200 (1989), S. 199-213 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have investigated the structural organization of the wind-sensitive giant interneurons in the thoracic ganglia of adult American cockroaches. These seven bilaterally paired interneurons have long been thought to play a role in directing the wind-elicited escape response of the animal. Each of the giant interneurons was labeled individually by intracellular injection of cobaltic hexamine chloride. An individual giant interneuron could be reliably identified from animal to animal based on its branching pattern in thoracic ganglia. The axons of the giant interneurons are situated on each side of the nerve cord in two recognizable subgroups. Comparisons of the axonal arbors of the dorsal and ventral subgroups showed that they project into distinct but partly overlapping regions of thoracic ganglia. Three of the giant interneurons were found to have axonal arbors that cross the longitudinal midline of thoracic and abdominal ganglia. Bilateral pairs of these giant interneurons were labeled concomitantly, and many of the individual neurites from these cells appeared to be closely apposed. All these morphological characteristics are discussed in relation to the connectivity and functional significance of the giant interneurons.
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  • 74
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    Journal of Morphology 200 (1989), S. 247-253 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of the adductor muscle of the boring clam (Tridacna crocea) was investigated. The adductor was composed of opaque and translucent portions. The opaque portion contained smooth muscle cells; the translucent portion contained obliquely striated cells. Smooth muscle cells were classified, according to the statistically analyzed diameters of their thick myofilaments, into two types, S-1 and S-2. S-1 cells had thick myofilaments, 50-60 nm in diameter. S-2 cells had thick myofilaments of two sizes, about 55-65 nm and 85-100 nm in diameter, respectively. Obliquely striated muscle cells in the translucent portion were also classified into two types: O-1 cells, with thick myofilaments 30-35 nm in diameter, and O-2 cells, with myofilaments of 50-60 nm.
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  • 75
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    Journal of Morphology 201 (1989) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
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  • 76
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    Journal of Morphology 201 (1989), S. 23-37 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sensory and motor innervation of the proboscis by branches of the maxillary and labial nerves of the worker honey bee has been investigated in specimens stained vitally by methylene blue or viewed by scanning electron microscopy. A chordotonal organ consisting of a single scolopidium is present in the maxillary palp. Flexion of the maxillary palp occurs only passively, induced by the flexion of the galea. This chordotonal organ may function as a proprioceptor for the movement of the galea. Another chordotonal organ exists in the prementum of the labium. It contains, on the average, 12 sensory cells and presumably responds to the bending of the labial palp. A nerve-net of bipolar cells arises from the sensory branches of the maxillary nerve. Free nerve endings derived from the periphery of this nerve-net expand broadly on the intersegmental membranes connected to the stipes. The right and left nerves to the dilator muscles of the salivarium exchange branches, resulting in the reciprocal innervation of each muscle.
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  • 77
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    Journal of Morphology 201 (1989), S. 59-68 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The tectorial structures of the inner ear of the proteid salamander Proteus anguinus were studied with transmission and scanning electron microscopy in order to analyze the ultrastructure of the otoconial membranes and otoconial masses of the maculae and the tectorial membrane of the papilla amphibiorum. Both otoconial and tectorial membranes consist of two parts: (1) a compact part and (2) a fibrillar part that joins the membrane with the sensory epithelium. Masses of otoconia occupy the lumina above these membranes.There are two types of calcium carbonate crystals in the otoconial masses within the inner ear of Proteus anguinus. The relatively small otoconial mass of the utricular macula occupies an area no greater than the diameter of the sensory epithelium, and it is composed of calcite crystals. On the other hand, the enormous otoconial masses of the saccular macula and the lagenar macula are composed of aragonite crystals. In the sacculus and lagena, globular structures 2-9 m̈m in diameter were discovered on the lower surfaces of the otoconial masses above the sensory epithelia. These globules show a progression from smooth-surfaced, small globules to large globules with spongelike, rough surfaces. It is hypothesized that these globules are precursors of the aragonite crystals and that calcite crystals develop similarly in the utriculus. The presence of globular precursors in adult animals suggests that the formation of new crystals in the otoconial membranes of the sacculus and lagena of Proteus is a continuous, ongoing process.
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  • 78
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    Journal of Morphology 201 (1989) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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  • 79
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When homozygous, recessive mutant gene c in Ambystoma mexicanum results in a failure of embryonic heart function. This failure is apparently due to abnormal inductive influences from the anterior endoderm resulting in an absence of normal sarcomeric myofibril formation. Biochemical and immunofluorescent studies were undertaken to evaluate the contractile proteins actin and tropomyosin in normal and mutant hearts. For the immunofluorescent studies, cardiac tissues were fixed in periodate-lysine-paraformaldehyde, frozen sectioned, and immunostained by an indirect method with monospecific polyclonal antibodies produced against highly purified chicken heart actin and tropomyosin. In normal hearts, both antiactin and antitropomyosin stained the myofibrillar I-bands intensely. In mutant hearts, intensity of staining with antiactin antibody was similar to normal, although sarcomeric patterns were not observed. Staining intensity for tropomyosin with antitropomyosin antibody was significantly reduced in mutant hearts when compared to normal. Biochemical studies were used to evaluate antibody specificity, antigenic variability, and relative protein concentrations of actin and tropomyosin in normal and mutant cardiac tissues. Tissue homogenates were electrophoresed in two dimensions, and second-dimension slab gels were either Coomassie Blue silver-stained or transblotted onto nitrocellulose and the proteins stained with antibodies. Stained gels and immunoblots of cardiac proteins reveal that the amounts of actin isoforms are identical in normal and mutant hearts. However, these methods demonstrate a significantly reduced amount of tropomyosin in mutant tissue. This confirms earlier studies suggesting reduced amounts of tropomyosin in mutant hearts based upon immunological assays. Thus, failure of normal myofibrillogenesis in gene c mutant hearts does not appear to result from a change in actin isoform composition but may be related to a deficiency in tropomyosin.
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  • 80
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    Journal of Morphology 202 (1989) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 81
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Knee joints from adult, juvenile, hatchling, and embryonic (full term) American alligators were dissected to reveal the cruciate ligaments and the medial and lateral menisci. Two anterior cruciate (major and minor), a posterior cruciate, an intermeniscal, and a meniscofemoral ligament were identified. In addition, we found a fourth internal ligament which has not been reported previously. Menisci and ligaments from left knees were fixed in formalin and processed for routine histological observation. Those from right knees were stained in bulk by using a gold chloride method and were either frozen and sectioned at 100 m̈m on a sliding microtome or were processed for paraffin sections at 30 m̈m. The morphology of the collagenous, cartilaginous, and vascular constituents of the tissues was similar to that of the dog, cat, and human. Nerve fibers were observed in all tissues sampled. Structures resembling Golgi tendon organs and Pacinian corpuscles were identified, reinforcing the theory that neural elements within cruciate ligaments and menisci may provide afferent input that affects the function of the knee joint.
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  • 82
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    Journal of Morphology 202 (1989), S. 205-223 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructural changes occurring in the adenohypophysis (AH) of the anadromous sea lamprey, Petromyzon marinus, during metamorphosis (stages one through seven) were examined. The rostral pars distalis initially contains one granulated (secretory) cell type A and one nongranulated type I cell. A second granulated cell (type B) appears during the later stages (stages six and seven) of metamorphosis. The most pronounced ultrastructural changes take place in the caudal pars distalis (CPD). Initially, most cells (80-90%) are nongranulated cells type II and some type I. Granulated type C and D cells form the remainder of the CPD. Almost all cells during stages three and four demonstrate a marked increase in synthetic activity evident by conspicuous Golgi regions, abundant rough endoplasmic reticulum (RER), and increased cell volume. Most cells are sparsely granulated. Secretory cell types C and D and, two new cell types, E and F, are present. Synthetic activity subsides by stage five. Most cells (80-90%) during stages five through seven are granulated. Type E are most prevalent with variable numbers of types C and D and few type F. Nongranulated cells now represent only 10-20% of the CPD. The increase in granulated cells occurs at the expense of type II cells that differentiate into granulated cell types. The fine structure of the pars intermedia throughout metamorphosis remains similar to that of the larva. Most cells are granulated, highly vesiculated type G cells. A few nongranulated type I cells are also present. The functional significance of the secretory cells in the AH is related to the requirement for an intact pituitary gland for the initiation and completion of metamorphosis.
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  • 83
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    Journal of Morphology 202 (1989) 
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 84
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    Journal of Morphology 202 (1989), S. 255-269 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The gastrodermis of the black coral Antipathes aperta is associated with eight distinct types of cells, including two types of microbasic b-mastigophores (nematocysts), spumous and vesicular mucus cells, and ganglion cells that are essentially the same as in the epidermis. Three additional types of cells are unique to the gastrodermis, and are readily distinguished from those of the epidermis by their electron-opaque inclusions. These include lipoidal cells, zymogen digestive cells, and an unusual type of epitheliomuscular collar cell. The pharyngeal region is characterized by the presence of electron-opaque nematocysts, a scattering of zymogen cells, and a large number of collar cells. The latter are distinguished in part by the presence of dense microfibrillar processes that surround the microvilli and extend into adjacent collars. This interconnection results in the formation of an extensive pharyngeal meshwork. These collar cells are additionally distinguished by the placement of the collar and flagellum adjacent to a flared cup of cytoplasm. This portion of the cell is capable of endocytosis of relatively large unicellular prey, and apparently is capable of forming digestive vesicles as well. The pharyngeal gastrodermis grades into simple lobate septal filaments toward the base of the coelenteron, where large, granular nematocysts all but replace the smaller electron-opaque types Collar cells are found here as well, but in fewer numbers compared to the zymogen cells. Ultrastructural results are compared with those of other coelenterates and discussed in terms of food and modes of nutrition.
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  • 85
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In Holland, bugs of the species Hebrus pusillus and H. ruficeps have one generation per year and overwinter as unmated adults. Males have two testes with two follicles + vasa efferentia each, paired vasa deferentia and seminal vesicles, an ejaculatory duct, and a protrusible phallus comprising an articulatory apparatus, phallotheca, endosoma, and paired claspers. The skeletomusculature of this system is described (it has 12 paired and four unpaired muscles) and its functions in generating and transferring sperm (summarized in Figs. 70-75) are reconstructed from study of living bugs, dissections, whole mounts, and serial sections.Males of both species produce sperm 〉2 mm long from stem spermatogonia in the germarium of each follicle. Initial definitive spermatogonia divide synchronously three times to form clones of eight, interconnected, primary spermatocytes. These enlarge up to 43-fold in males of H. pusillus and 78-fold in those of H. ruficeps, undergo meiosis, and, after adult emergence, complete their differentiation into bundles of 32 sperm which coil transversely about the periphery of each follicle at its base. These begin to enter the vasa efferentia in mid August, rupture, and release their sperm into the seminal vesicles where they are stored overwinter. Most spermatocyte and spermatid cysts remaining in the testes degenerate in fall, leaving only stem spermatogonia and a few early spermatocysts in the germaria.Males of H. pusillus begin to mate the first warm days of spring but only the most persistent succeed. A male jumps on the back of a female, induces her to lower her ovipositor, and, within 12 min (@ 18-24°C), introduces the endosoma of his phallus up its shaft and fills his seminal duct with sperm. The female draws this into her gynatrial sac at the end of copulation and transfers it into her spermatheca in about 30 min, the sperm reversing themselves within it so that their heads face towards its mouth. The male may stay on her back for up to 2 hours and may copulate again up to three times before leaving to mate with other females.Males of H. pusillus may be sexually active for months after overwintering, because spermatogonia in their germaria reactivate in spring to produce additional sperm. Those of H. ruficeps do not and males mate successfully only until their supply of overwintered sperm is exhausted.The chromosome complement of H. pusillus males is 2N = 22 + XY. The X and Y chromosomes are of unequal length, form a pseudo pair at metaphase I, and segregate to opposite poles at anaphase I - the first instance of pre-reductional segregation of sex chromosomes to be recorded in the Gerromorpha. The chromosome complement of H. ruficeps may be 2N = 24 + XO but the nature of two chromosomes was not resolved. The single X segregates to half the spermatids at anaphase II.
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  • 86
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    Journal of Morphology 202 (1989), S. 409-424 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The solum nasi of Microcebus murinus is characterized by the presence of a zona annularis, continuity between the anterior transverse lamina and the paraseptal cartilage, a continuous paraseptal cartilage, a palatine cartilage and a posterior transverse lamina. It lacks a fibula reuniens and possibly a cartilage of the nasopalatine duct as well as a palatine papillary cartilage. The morphology in M. murinus closely resembles that seen in Tupaia and Galago. This affinity results from the retention of primitive traits. However, Galago is reported to lack a zona annularis, thus displaying a specialization not shared with M. murinus. Therefore, the zona annularis provides a useful trait for distinguishing between the ontogenies of M. murinus and Galago.
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  • 87
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    Journal of Morphology 202 (1989), S. 435-455 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In each of 30 dipteran species, representing 13 acalyptrate and 7 calyptrate families, the cardia is formed from specialized cells at the junction between foregut and midgut. Foregut epithelium forms the stomodeal valve; midgut epithelium envelops the valve to form the cardia's outer wall. Cytological characteristics within these epithelia differ from region to region and from species to species. Since the cardia secretes the peritrophic membrane, cardias with diverse patterns of cellular differentiation may be expected to produce peritrophic membranes with similarly diverse properties. Close relatives often share more details of cardia structure than do distantly related taxa. Within the monophyletic Calyptratae, a common pattern of cellular differentiation includes three distinct zones of columnar midgut cells enclosing a flanged stomodeal valve. Among species in the paraphyletic Acalyptratae, midgut typically includes a single zone of tall columnar cells, while the valve may be spheroidal, cylindrical, conical, or flanged. The correlation of phylogenetic distance with divergence in cardia organization implies a strong influence of ancestry upon current structure, regardless of current diet. However, at least some of the observed diversity in cardia structure is associated with dietary divergence. Calyptrate flies with derived blood-feeding behavior display cellular differentiation that is simplified from that seen in calyptrate relatives with less specialized feeding habits. This evolutionary modification suggests that cardia organization and hence peritrophic membrane structure can adapt to dietary changes, with possible significance for the spatial organization of digestive processes and interactions with ingested microorganisms.
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  • 88
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    Journal of Morphology 202 (1989), S. 239-253 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The tentacular epidermis of the black coral Antipathes aperta is organized into three distinct regions, containing at least nine different types of cells. The outermost region is dominated by spirocytes along with two types of nematocytes, organized into discrete wart-like batteries. The two nematocyte types both contain microbasic b-mastigophore nematocysts. The outer boundary of the wart is marked by the presence of both spumous and vesicular mucus cells. The ciliation of the wart is contributed principally by the spirocytes. Warts are enveloped and separated from one another by an unusual neurosensory cell complex that extends from the tentacular surface to the mesogleal connective tissue foundation. Funnel-like, flagellated cells composing the complex connect with ganglion cells composing the dominant portion of the nerve net system. Branches of this complex also penetrate the central portion of the wart, making direct contact with the cnidae. The tentacular mid-region is composed of nematocytes and spirocytes in various stages of maturation, along with epitheliomuscular cell (EMC) somata. The EMC's narrow apically extend toward the tentacle surface, forming contacts with the cnidae. The basal end of the EMC expands to form the larger portion of the tentacular musculature. The inner region of tentacular epidermis is marked by a neuromuscular complex sheathed by extensions of mesoglea. The ganglion cells occur as a plexus deep within the tentacle and form polarized junctions with the EMC's, but neuromuscular synapses are not well enough defined for documentation. Polarized synapses lacking well-defined membrane thickenings characterize the interneuronal junctions. Granular cells lining the mesogleal surface appear to be responsible for mesogleal fibrillogenesis.
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  • 89
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    Journal of Morphology 202 (1989), S. 325-338 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The stages of differentiation of the inner ear sensory epithelia of the neotenous cave urodele, Proteus anguinus, was studied with light and electron microscopy. Comparative ultrastructural analysis among specimens of different sizes confirms that new sensory cells may be generated throughout life, particularly along the periphery of the saccular macula. The inner ear of Proteus contains at least four types of sensory cells that differ in their apical ciliary part.The lungs and air-filled buccal cavity may function as transducers of sound pressure in underwater conditions. Sound waves might be transmitted from the buccal cavity to the connected oval window. The very complex orientation of the sensory hair cells of the saccular macula and the large overlying saccular otoconial mass suggest that this macula facilitates orientation of Proteus in its underground aqueous habitat.
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  • 90
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    Journal of Morphology 202 (1989), S. 351-359 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the Uloboridae, web reduction is accompanied by changes in opisthosomal shape, leg length, and web-monitoring tactics. These morphological changes make reduced-web spiders more cryptic and alter their leg leverage and centers of mass. When compared with the orb-weaver Uloborus glomosus, the irregular, reduced-web spider, Miagrammopes animotus, invests more mass in its prosoma and first legs. However, the latter species' elongate opisthosoma posteriorly shifts this region's center of mass, causing the relative position of its composite center of mass and the distribution of weight between its first and fourth legs to be similar to that of the orb-weaver. Like these species, the opisthosomal center of mass of the triangle-weaver, Hyptiotes cavatus, lies near its midpoint. However, the shorter first legs and rounder, heavier opisthosoma of Hyptiotes posteriorly shift its composite center of mass and distribute more of its weight onto its fourth legs. Consequently, the morphology of M. animotus can be adequately explained by its adaptiveness for web manipulation, balance, and weight distribution and the crypsis that these features confer as an ancillary advantage. In contrast, anatomical changes in H. cavatus are better explained as adaptations for web manipulation and crypsis.
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  • 91
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    Journal of Morphology 202 (1989), S. 425-433 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Eosinophilopoiesis in the musk shrew, Suncus murinus, a representative of the order Insectivora, was studied by light and electron microscopy. To examine biochemical features of cytoplasmic granules, extraction with proteolytic enzymes was carried out on ultrathin sections of bone marrow. In this species, eosinophils are produced in the same manner in both spleen and bone marrow. Developing eosinophils were distinguished as belonging to four stages, recognized by ultrastructural changes in cytoplasmic organelles as well as the eosinophilic granules during maturation. Granulogenesis began by budding of vacuoles containing flocculent material from the concave face of the Golgi apparatus, in the promyelocyte to myelocyte stage. The matrix of developing granules transformed into a finely granular structure, and the large spherical granules of mature eosinophils were homogeneous without crystalline cores. It was shown by proteolytic enzyme extraction that the proteinaceous cores of mature granules were uniformly removed; there was no evidence that they contained crystalloid inclusions. These results indicate that shrew eosinophils can be regarded as cells that retain a prototype of eosinophil granules, probably like those of ancestral mammals rather than those of higher living Mammalia.
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  • 92
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    Journal of Morphology 199 (1989), S. 363-378 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The chelonian carapace is composed of the endochondral ribs and vertebrae associated with a specialized dermis. The ribs are found in an aberrant position compared to those of all other tetrapods; they are superficial and dorsal to the limb girdles. This morphological arrangement, which constitutes the unique chelonian Bauplan, is examined from a developmental perspective. Embryos of Chelydra serpentina were studied during stages of carapace development. Tissue morphology, autoradiography, and indirect immunofluorescent localization of adhesion molecules indicate that the outgrowth of the embryonic carapace occurs as the result of an epithelial-mesenchymal interaction in the body wall. A carapacial ridge composed of mesenchyme of the dermis and overlying ectoderm is formed dorsal to the ectodermal boundary between somitic and lateral plate mesoderm. It is the anlage of the carapace margin, in which the ribs will eventually terminate. The ectoderm of the carapacial ridge is thickened into a pseudostratified columnar epithelium, which overlies a condensation in the mesenchyme of the dermis. Patterns of cell proliferation and the distribution of N-CAM and fibronectin in the carapacial ridge are consistent with patterns seen in other structures initiated by epithelial-mesenchymal interactions such as feathers and limb buds.Based on an analogy to this developmental mechanism in the development of the limb skeleton, a further analogy with the evolution of the limbs from lateral fin folds is used to form a hypothesis on the evolution of the carapace from elements of the primitive reptilian integument.
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  • 93
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    Journal of Morphology 200 (1989), S. 29-36 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Autologous tongues were transplanted onto the liver of the anuran Rana catesbeiana, specimens of which were sacrificed at intervals from 6 hr to 5 months after transplantation. Light and electron microscopy as well as histochemistry disclose that the grafts start to organize into cysts after 14 days. The taste organs occur in all grafts irrespective of the age of the graft. All surviving taste organs exhibit intense adenosine triphosphatase (ATPase) activity and contain fluorescent basal cells of the usual type. Ultrastructurally, the taste organs are composed of three distinct types of cells that lack nerves. The taste and basal cells retain the characteristic dense-core granules in their cytoplasm through the experimental periods. The present results suggested that the taste organs of Rana can survive ectopically in the liver for up to 5 months.
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  • 94
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    Journal of Morphology 200 (1989), S. 63-69 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Epithelium of the sea anemone Acontiophorum niveum is modified into four general arrangements of microappendages: (1) uniform microvilli covering pedal disc and column, (2) an interspersion of microvilli, ciliary cones, and kinocilia on tentacles, (3) flagella among an understory of microvilli from the oral disc, actinopharynx, filaments, and acontia, and (4) sparse flagella among irregular microvilli from endoderm. These arrangements are similar to those described previously in the epithelia of other anthozoans.
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  • 95
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    Journal of Morphology 200 (1989), S. 87-92 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Inserting on the buccal and esophageal foregut of Gammarus minus are numerous pairs of serially arranged dorsal dilator muscles, a single pair of lateral muscles, and two pairs of posterior muscles. Muscles of the cardiac stomach include three dorsal sets, a single pair associated with the pterocardiac ossicles, and two pairs inserting on the ventral aspect. A single pair of muscles inserts on the lateral aspect of the pyloric stomach. The extrinsic muscles of the foregut originate from exoskeletal apodemes of the cephalothoracic cuticle, sockets of the mandible, and a maxillary bridge that lies just ventral to the cardiac stomach. The extrinsic musculature of the hindgut is restricted to the rectal region and consists of paired dorsal and ventral series in an X-configuration. A single unpaired muscle inserts on the ventral midline. Extrinsic muscles of the hindgut originate from the integument of the last pleonic segment. The general arrangement of extrinsic gut muscles in G. minus is similar but not identical to that of other amphipods studied. However, the pattern is quite different from that of other malacostracans.
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  • 96
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    Journal of Morphology 199 (1989), S. 1-13 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study examines the morphology of sporadic congenital microphthalmia in 1-day-old chicks, with particular emphasis on the neural retina. On the basis of the size of the eyeball it is possible to classify microphthalmia into two groups, severe and mild. In severe microphthalmia (less than 5 mm in equatorial diameter), the eyeball is severely malformed, but in most cases it shows evidence of an organized neural retina. Although ganglion cells and an optic nerve head are present in a small proportion of these retinae, we could not trace an optic nerve projection to the brain. These results indicate that some ganglion cells are able to be sustained after the period of naturally occurring cell death, suggesting either that those ganglion cells have established some contact with the central nervous system or that the presence of their axons in a rudimentary optic nerve is adequate for survival. In mild microphthalmia (greater than 5 mm in equatorial diameter), the most consistent abnormality is a defect in the pecten, which together with other abnormalities such as orbital cysts and colobomas indicates that the major abnormality occurs in the region of the choroid fissure. Associated with these defects are abnormalities within the ganglion cell layer. In some cases the number of ganglion cells was reduced, and in others the numbers of both ganglion and displaced amacrine cells were reduced. Unexpectedly, there were localized regions completely devoid of cells in the ganglion cell layer. The timing of the congenital defect may provide some clue as to the presence of a critical period in which displaced amacrine cells are formed or are sensitive to events related to ganglion cell loss.
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  • 97
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    Journal of Morphology 199 (1989), S. 93-101 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The muscle-fiber architecture of 29 muscles from six rabbits (Oryctolagus cuniculus) was measured in order to describe the muscular properties of this cursorial animal, which possesses several specific skeletal adaptations. Several muscles were placed into one of four functional groups: hamstrings, quadriceps, dorsiflexors, or plantarflexors, for statistical comparison of properties between groups. Antagonistic groups (i.e., hamstrings vs. quadriceps or dorsiflexors vs. plantarflexors) demonstrated significant differences in fiber length, fiber length/muscle length ratio, muscle mass, pinnation angle, and number of sarcomeres in series (P〈.02). Discriminant analysis permitted characterization of the “typical” muscle belonging to one of the four groups. The quadriceps were characterized by their large pinnation angles and low fiber length mass ratios, suggesting a design for force production. Conversely, the hamstrings, with small pinnation angles, appeared to be designed to permit large excursions. Similar differences were observed between plantarflexors and dorsiflexors, which have architectural features that suit them for force production and excursion respectively. Although these differences were not absolute, they represented clear morphological distinctions that have functional consequences.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 98
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 125-150 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The larva of the ascophoran cheilstome Watersipora arcuata is described on the basis of serial 1-μ sections, light microscopy of whole mounts, and scanning electron microscopy. Using lightly osmicated specimens, it was possible to map almost every cell on the larval surface. Limited observations on hatching and larval behavior are provided in conjunction with the anatomical description. Tissues of the larva are partitioned between those that function exclusively during the larval period and are degraded at metamorphosis as transitory tissues and those that will have postmetamorphic fates in formation of the ancestrula. Significantly, W. arcuata has two possible anlagen for the ancestrular polypide, the infracoronal cells in the oral hemisphere and the epidermal blastemal cells in the aboral hemisphere, rather than only one or the other of these as reported in other species. Also detailed are the supracoronal flange and groove, which are unique to this genus and are involved in the transmission of mycoplasma-like organisms between successive generations of adults; two pairs of complex pigment cup ocelli; multiple intercoronal cells that are presumed to have varied sensory and mechanical functions; and the sensory, adhesive, and locomotory components of the pyriform organ. The larval anatomy of W. arcuata is compared with that of the larvae of the ctenostomes Alcyonidium gelatinosum (coronate), Bowerbankia imbricata (coronate), B. gracilis (coronate), and Flustrellidra hispida (shelled lecithotrophic) and of the cheilostomes Bugula neritina (coronate), Electra pilosa (cyphonautes), and Membranipora membranacea (cyphonautes). This study is the first detailed analysis of the larval structure of any ascophoran bryozoan and provides a necessary platform for subsequent analyses of embryology and metamorphosis.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989), S. 175-196 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The embryonic development of the hemipteran insect Rhodnius prolixus was studied by use of contemporary light and electron microscopy. Embryos were staged according to days postoviposition. Eggs laid on day one complete blastoderm formation and anatrepsis, the first phase of blastokinesis, by day 5. The embryo develops in a cephalocaudal orientation which is 180° to the anteroposterior axis of the egg. Subsequent development, prior to the second phase of blastokinesis (katatrepsis), leads to segmentation of the germ band, evagination of appendages, and histogenesis of germ layers. Concomitantly with these events, the amnion undergoes dramatic change. By day 7 the embryo begins a 180° revolution while migrating to the ventral surface of the yolk. This restores its polarity with respect to that of the egg and facilitates hatching. The serosa contracts, pulling the amnion and embryo anteriorly. Eventually the serosa is internalized at a point dorsal to the head and the lateral walls of the embryo grow up and surround the yolk. Development continues until day 15 when the embryo hatches as a first instar larva.
    Additional Material: 26 Ill.
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  • 100
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 199 (1989) 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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