摘要:

A study of the embryonic development of the pineal gland of the chicken was performed with the optical microscope. The time of apparition of the first outline, as a derivative of the roof of the third ventricle, was fixed at 3 days. The major portion of the pineal parenchyma is derived from the frontal wall of the outline. All the vesicles and follicles were formed by solid mammilliform projections which subsequently presented a central lumen. In no case was a communication of the follicular cavities with the pineal recess observed. Three categories of vesicles or follicles can be distinguished according to their origin.

ISSN:1422-6405    

DOI:10.1159/000144980

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

Cyclic histological changes in the testis, ovary, thyroid and adrenal of the North American eastern prairie population of Canada geese (Branta canadensis interior) breeding in Ft. Churchill (Manitoba, Canada) and wintering in the Swan Lake refuge in Missouri (USA) were studied. The investigation was carried out during the following six periods of the yearly life cycle. Phase 1: pre-spring migration at Swan Lake (early March); phase 2: post-spring migration at Ft. Churchill (early May); phase 3: breeding (early June); phase 4: moult (early August); phase 5: pre-fall migration (early September); phase 6: post-fall migration at Swan Lake (mid-October). The development of the testis and the initiation of spermatogenesis up to the formation of secondary spermatocytes was begun in phase 1. All stages of spermatogenesis, including the formation of spermatids and spermatozoa, were reached by the end of phase 2 and remained so through most part of phase 3. The weight of testis recorded was highest in phases 2 and 3. Testicular regression characterized by progressive loss in weight, reduction of spermatogonia in the tubules and appearance of sudanophilic material in the intersititium commenced in phase 4 and lasted through phases 5 and 6. Though the initiation of ovarian development probably started in phase 1, the ovary weighed the highest in phase 2. At this time, the ovary contained numerous maturing ova in different stages of development and lipoidal atresia. Lipoidal atresia was more prominent among young small ova. The larger maturing ova were characterized by a more distinct granulosa layer around the oocyte. Numerous sudanophilic interstitial cells were present scattered throughout the ovarian stroma. Atretic follicles and scars from discharged follicles were found in all the phases. The thyroid showed a significant increase in weight during moult (phase 4). No marked histological changes were discernible in all the phases. The increase in weight during moult is

ISSN:1422-6405    

DOI:10.1159/000144981

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

The relationship between microtubules and the lipoprotein pigment found in senile Cynomolgus brain and senile human brain biopsy material was investigated. Numerous microtubules were present in all parts of the cytoplasm and within the pigment areas, running parallel or obliquely to the pigmet bodies and being associated with its lateral aspects. Microtubules also occurred in the periphery of neurons or appearing to enter the perineuronal oligodendrocytes. These observations indicate a possible role of microtubules in the transport of pigment bodies. The oligodendrocyte from human brain biopsy material has definitely taken the role of a phagocyte in ingesting pigment bodies. Its numerous microtubules may offer a fast moving system for disposing off pigment residues to the capillary endothelium.

ISSN:1422-6405    

DOI:10.1159/000144982

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

A photogrammetric computer analysis of 88 endocasts, representing 8 genera of Old World monkeys, reveals cortical asymmetry in lengths of the Sylvian fissure, superior temporal sulcus, lateral edge of the orbit and distance separating rectus and arcuate sulci. Hypothetical expansion of left prefrontal and parietal integration cortices explains these asymmetries.

ISSN:1422-6405    

DOI:10.1159/000144983

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

The present report deals with the occurrence of calcitonin cells (C cells) and cysts in the parathyroid IV of Suncus murinus. Histological preparations of the thyro-parathyroid complex reveal that (i) the parathyroid IV exhibits C cells either solitarily or in small groups (compact or follicular arrangement); (ii) the parathyroid IV also exhibits cysts (similar to those of the thyroid), the lining of these may contain either few C cells or it may be a continuous lining of C cells; (iii) the lumina of these cysts are filled with debris and desquamated cells with pycnotic nuclei, and (iv) sometimes few C cells are encountered hanging from the epithelial lining inside the lumen of the cyst.

ISSN:1422-6405    

DOI:10.1159/000144984

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

On 50 brains of newborns of either sex, the exterior and interior morphology was studied. The exterior morphology ofthe brain was conformable to the configuration ofthe skull. The insula is relatively large, but extremely inadequately grooved. The subcortical masses are well pronounced but there is in general a very slight difference between the white and gray matter of the brain. The convolutions and grooves of the cerebellum are very distinctly marked, the nucleus dentatus is large and white matter is prevalent. The brain stem is rather well formed, distinctly plastic, this being particularly true for the region of the rhomboid fossa and medulla oblongata.

ISSN:1422-6405    

DOI:10.1159/000144985

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

This investigation reports observations on the growth of Rana cyanophlyctis tadpoles following a whole body gamma-ray exposure. The effect on the body and hind limb size is perhaps the most significant of the period of latency. A dose of 2,000 R serves as a stressor and activates ACTH secretion in the tadpoles. The resultant somatotrophic hormone (STH) inhibition and subsequent recovery during the following days seem an integral part of the radiation syndrome.

ISSN:1422-6405    

DOI:10.1159/000144986

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

In the human fetus of 14 weeks, ganglia on either sides of the Müllerian utero-vaginal canal contained two types of cells. In the 16th week, axons invaded the basal zone of the stratified squamous epithelium at the sides of the upper vagina. In the 20th week, vesicular nuclei typified the large neurons in the midportion of the cervico-vaginal ganglion. During the 22nd week, capsulated ganglia invaded the wall of the upper vagina forming three concentrically disposed strata. Non-capsulated clusters invaded its lamina propria. At the 24th week, axons were shaded after reaching the superficial zone of the stratified vaginal epithelium. In the 28th week, satellites surrounded the mature neurons and sheath cells enveloped the axons. Ganglia invaded the splitted muscle layer of the upper vagina at 30 weeks. Intraepithelial fibres invaded the whole thickness of the endometrium, the columnar epithelium of the cervix and uterine tube at 40 weeks. Nerve cells were detected among the basal epithelial cells of the lower vagina and its subepithelial plexus

ISSN:1422-6405    

DOI:10.1159/000144987

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

The effectiveness of β-histine-HCl in modifying the size of developing myocardial infarcts was tested in the surgically ligated dog. Branches of the left coronary artery were ligated and a 6-hour continuous intravenous infusion of 0.24 mg/kg/min of β-histine was administered from 0 to 120 min after ligation. The effect of this treatment was evaluated histologically in studies on acute ischemia by the use of the hematoxylin-basic fuchsinpicric acid stain for early myocardial ischemia. The treatment was also evaluated grossly in a study on chronic ischemia where the dogs were permitted to survive for 30 days before sacrifice. In these experiments, the size of infarcts found in the β-histine-treated animals was compared with those found in the saline controls. Both studies showed that the control ligations produced a large uniform area of ischemia or infarction that was greatly reduced or prevented by immediate treatment with β-histine. Also, β-histine was capable of significantly reducing the size of developing infarcts for up to 120 min after liga

ISSN:1422-6405    

DOI:10.1159/000144988

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

40 corrosion casts of the dog splenic artery were prepared to observe the vascular segments in the dog spleen. 39 specimens (97.5%) revealed the presence of two segments, a dorsal and a ventral one. However, in 1 specimen (2.5%) no segmentation was seen.

ISSN:1422-6405    

DOI:10.1159/000144989

出版商:S. Karger AG    

年代:1978

数据来源: Karger