摘要:

The presence of luteinizing-hormone-releasing hormone (LHRH)-like and α-melanocyte-stimulating hormone (α-MSH)-like immunoreactive fibers, nerve terminals or cellular elements in the pineal gland of the sheep has been investigated by immunohistochemistry. No LHRH- or α-MSH-like immunoreactive fiber, nerve terminals or cellular elements have been demonstrated in the pineal organ of the sheep. However, LHRH- and α-MSH-like immunoreactive fibers are present in the posterior commissure. Immunoreactive LHRH and α-MSH nerve endings are evident in the medial and lateral habenular nuclei. Discrepancies with the results obtained in other mammals are indicative of species differences in the distribution of LHRH- and α-MSH-like immunoreactive material in the pineal r

ISSN:1422-6405    

DOI:10.1159/000146740

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The ultrastructural characterization of seven cell types in the pharyngeal hypophysis from adult subjects is described. By immunoelectron microscopy, two of the granular cell types were identified as growth-hormone- and prolactin-producing cells. The vascular supply of this gland was mainly composed of capillaries without fenestrations. Review of the literature allows a comparison with the ultrastructure of the sellar adenohypophysis and with the pharyngeal hypophysis of children.

ISSN:1422-6405    

DOI:10.1159/000146741

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Renal changes similar to those considered diagnostic for diabetes in humans are infrequently observed in spontaneous noninsulin-dependent (NID) diabetic monkeys. In the current study, renal cortical tissue blocks are rendered acellular to demonstrate glomerular basement membrane (GBM) and mesangial matrix (MM) changes in a naturally occurring NID diabetic rhesus monkey (Macaca mulatta). Transmission electron micrographs of these specimens show axial MM accumulations with numerous striated collagen fibrils that frequently extend onto internal (endothelial) surfaces of peripheral GBM. The outer (epithelial) component, although compact, appears bilaminar due to folded external surfaces not coinciding with similar irregularities on internal surfaces. By scanning electron microscopy, external surfaces of sclerotic GBMs are extensively wrinkled and, following cryofracture, show congestion and expanded MM. Afenestrated meshwork of MM, which appears less dense and compact than epithelial BM, extends from axial regions onto GBM internal surfaces. The true thickness of randomly sampled peripheral GBM thickness (∼ 400 nm) is approximately double that of normal rhesus GBM. Diabetic GBMs exhibit ruthenium red positivity for surface polyanions with linear site densities not significantly different from normal. These observations indicate that sclerotic GBMs in diabetic rhesus monkeys closely resemble those seen in human endsfage diabetic glomerulopathy and suggest that this nonhuman primate may offer an excellent model for studies of chronic diabetic BM diseas

ISSN:1422-6405    

DOI:10.1159/000146742

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The pituitary glands of normal and experimental male and female bats were examined by light and electron microscopy. Six cell types were identified in the anterior pituitary by differential staining techniques, ultrastructural characteristics and changes brought about during the different phases of the sexual cycle. Conventional methods like removal of thyroids, testes and adrenals, and animals in lactation withdrawal and treatment with propylthio-uracil, cyproterone acetate and metyrapone were employed. A marked predominance of somatotrophin and luteotrophin (LTH) cells were present in the intact adult female bat pituitary gland. LTH cells were also observed in milk retention experiments. The two gonadotrophic cell types were randomly distributed throughout the gland. Hypertrophy of two gonadotroph cells was observed in response to the physiological conditions of the animals, gonadectomy and administration of the male antifertility drug cyproterone acetate.Thyrotrophin and adrenocorticotrophin cells were identified by ablation of the respective target organs, thyroids and adrenals, and after treatment with propylthio-uracil and metyrapone. On the basis of the pathological conditions of the bats, the possible functional significance of the different cell types is also discussed.

ISSN:1422-6405    

DOI:10.1159/000146743

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The developmental changes of the anogenital distance and external genitalia were studied in 81 fetuses of the southern minke whale. It was difficult to sex the fetuses with less than 55.8 mm crown-rump length (CRL) even by histological means, but it was easy in the fetuses with more than 77.0 mm CRL and less than 110.0 mm CRL. The histologically determined male fetuses had a ratio of anogenital distance to CRL or body length of more than 5% while females had a value of less than 4%. At later stages with a CRL of more than 113.0 mm, male fetuses had an umbilicus-directed genital tubercle, while in females a tail-directed tubercle was observed.The present study suggests that the stage with sexual dimorphism might be earlier in the southern minke whale than that previously reported.

ISSN:1422-6405    

DOI:10.1159/000146744

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

In human cyclopia, a maxillopalatine mass separates the median orbit from the oral cavity.The palatine component of this bony mass has been studied in serial sections through the median third of the head in three perinatal human specimens presenting with a median orbit and proboscis. One head was sectioned in the sagittal plane and two in the coronal plane. The course of each neurovascular bundle arising from the maxillary artery and nerve was used to facilitate the identification of the various parts of the palatine bone. The data obtained were used to outline the palatine component of the maxillopalatine mass as it presented on the inferior aspect of a dried cyclops skull. The suggestion is made that the abnormalities of the palatine bone in human cyclopia are secondary to the absence of the presphenoid and of the nasal cavity.

ISSN:1422-6405    

DOI:10.1159/000146745

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Investigation of renal cortical tissue in 5 adult hartebeests (Alcelaphus buselaphus cokii), 3 impalas (Aepyceros melampus), 1 defassa waterbuck (Kobus defassa) and 5 goats (Capra hircus) revealed large granulated peripolar cells at the junction between the parietal and the visceral epithelial layers of the renal corpuscles. All four animal species under study contained 1 or more peripolar cells for the majority of renal corpuscles sectioned through the vascular pole. In the hartebeests, up to 3 parietal cells and the first podocyte were granulated. Peripolar cells contained intracytoplasmic electron-dense membrane-bounded granules – 200–2,800 nm in diameter in the hartebeests, 200–1,740 nm in the impalas, 150–950 nm in the waterbuck and 200–2,140 nm in the goats. Epithelioid granulated juxtaglomerular cells around afferent and efferent arterioles were rarely seen. When observed, they contained smaller granules than those of the peripolar cells. This distribution suggests that peripolar cells play a role in the regulation of body electrolytes and water, probably acting in concert with the renin-angiotensin-aldostero

ISSN:1422-6405    

DOI:10.1159/000146746

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Ultrastructural changes of the parathyroid glands of 18-day-old mouse fetuses after administration of calcium chloride (calcium) or ethylenediaminetetraacetic acid (EDTA) were examined. Many chief cells in the parathyroid glands of the calcium-treated mouse fetuses contained poorly developed Golgi complexes and cisternae of the granular endoplasmic reticulum and many secretory granules as compared with those of the control fetuses. Many chief cells in the glands of the EDTA-treated mouse fetuses contained well-developed Golgi complexes and cisternae of the granular endoplasmic reticulum and many prosecretory granules as compared with those of the control fetuses. These findings suggest that calcium or EDTA affects the secretory activity of the parathyroid gland of the mouse fetus.

ISSN:1422-6405    

DOI:10.1159/000146747

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Haversian bone remodelling used to be considered an attribute of adult bone. In the present paper, typical haversian remodelling was observed in the humerus, ulna, radius, femur, tibia, fibula and 6th and 7th ribs as soon as the 24th week. Its aspect suggests an already ancient occurrence. Remodelling was found in the same bone pieces of the neonate as well as in the clavicle and the other ribs. Mechanical factors may be responsible for starting the remodelling but their effects could be modulated by metabolic needs. Other still unknown factors might play a role too.

ISSN:1422-6405    

DOI:10.1159/000146748

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Scanning and transmission electron microscopy have been used to study the uterine epithelial cells from a pregnant human uterus approximately 8 days after ovulation.The ultrastructural appearance of the epithelial cells generally conforms with that previously described as showing receptivity, although some significant regional variability exists.

ISSN:1422-6405    

DOI:10.1159/000146749

出版商:S. Karger AG    

年代:1989

数据来源: Karger