摘要:

156 abdominal preparations were explored by arteriography, corrosion and dissection. Within the meanders of the splenic artery a basic pattern can be traced. The division of the artery can easily be summarized by introducing the term of a truncus lienogastroepiploicus. The short gastric arteries are always present, and usually they are longer and more important than may appear from their name. In nearly half of the preparations (52%) an artery for the extremitas lienalis posterior is found; an artery for the extremitas lienalis anterior is very exceptional. A posterior gastric artery can be identified (36%) but it must be distinguished from several other vessels. The arteria colli pancreatis (for the neck of the pancreas) is a constant vessel that may have a superior (usually arteria lienalis) or an inferior origin (arteria mesenterica superior). It commonly supplies the transverse pancreatic artery and often the prepancreatic arcade. The arteria corporis pancreatis, too, is a constant artery. The pancreatic tail is thoroughly irrigated by usually more than one arteria caudae pancreatis. An important part of the greater curvature is not accompanied by the left gastroepiploic artery, but is supplied by the arteriae gastricae breves.

ISSN:1422-6405    

DOI:10.1159/000146166

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The spatial relation between fibroblasts and myoblasts as well as myotubes in the extensor muscles of the forearm of mouse embryos was investigated with routine electron micoscopic techniques. From day 13 of embryonic development onwards, fibroblasts and myogenic cells may be distinguished by their ultrastructure from each other. Above all the fibroblasts are characterized by their long cell processes. Specialized cell contacts between them are visible. Fibroblasts often encircle some myogenic cells indicating the division of the muscles into smaller bundles. Over long distances, the intercellular gap between both cell types is narrow and measures about 15 nm. Sometimes specialized intercellular junctions can be seen. They resemble simple desmosomes and seem to be mechanical cell junctions. After the establishment of the basal lamina around the myogenic cells such specialized cell contacts are no longer visible. It seems possible that the fibroblasts act as mechanical counterpart for the organization of the myogenic cells.

ISSN:1422-6405    

DOI:10.1159/000146167

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The esterase activity in the sweat glands of Brahman (B), Brahman crossbred (BX) and Shorthorn (S) steers was studied in animals exposed to low heat loads while grazing. The percentage of sweat glands containing esterase in the secretory cells of the fundus differed between genotypes and ranked in order of their heat tolerance, i.e., B > BX > S. Esterase activity in some of those secretory cells was reduced in B bulls by acute exposure to high air temperatures in a climate chamber. While the significance of the esterase-containing cells in the fundus of the bovine sweat gland is uncertain, the results suggest that they could represent the resting or relatively inactive stage of the secretory cells.

ISSN:1422-6405    

DOI:10.1159/000146168

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

In the present study, the presence of immunoglobulins was immunohistochemically investigated in globule leucocytes in the tracheal respiratory epithelium of conventional rats, athymic nude rats and a germ-free rat. It was not possible to demonstrate any immunoglobulins in tracheal globule leucocytes. This and other dissimilarities with intestinal globule leucocytes are briefly discussed. On the other hand, peroxidase-antiperoxidase staining revealed the presence of surface immunoglobulins on the membrane of subepithelial mast cells. The previously postulated mast cell origin of the tracheal globule leucocytes is doubted, and the possibility that globule leucocytes should belong to the group of natural killer cells is discussed.

ISSN:1422-6405    

DOI:10.1159/000146169

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

In a study of mandibular form, 19 traditional linear dimensions were found to be consistently greater for macrocephalics than microcephalies. As such dimensions combine both size and shape parameters together, their interpretation proved difficult. In order to examine specifically mandibular shape only, each mandibular outline form was digitized and subjected to the technique of medial axis transformation. The data indicate that the shape contrasts between the mandibles of macrocepahlics and microcephalies are more complex than traditionally envisaged and emphasize the need for further study to ascertain the effect of genetic and environmental influences on mandibular form.

ISSN:1422-6405    

DOI:10.1159/000146170

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Changes in the diameter of collagen fibrils were observed with an electron microscope in the endo- and epineurium of sciatic nerves of mice during development from 12 days of gestation to 5 months after birth. It was noted that endoneurial collagen fibrils appeared in embryonic mice at 15 days of gestation, and at the same time, basal laminae began to appear sporadically on the Schwann cell plasmalemma. No fibroblasts were seen at this developmental stage. Collagen fibrils in the endoneurium remained as thin as they were when they first appeared, being in the narrow range of 250–300 A in diameter, while those in the epineurium became much thicker (400–450 A, 5 months after birth) as is also the case in dermal connective tissues. The present study shows that the endoneurial collagen fibrils were different in their developmental pattern from those of the epineurial or of other connective tissues, lending support to the concept that the endoneurial collagen fibrils are particular in nature, being so-called histological reticular fib

ISSN:1422-6405    

DOI:10.1159/000146171

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Tests are still lacking about the suitability of scanning electron microscopy (SEM) of vascular resin casts to show different functional states of peripheral blood vessels. With the aid of a vitalmicroscopic device, we tried to elaborate a vascular casting method using the model of the albino rat iris vasculature. Functional variations of the vasculature were induced by local application of epinephrine to one eye using the untreated fellow eye as a control. It was found that if our modification of Araldite plastic is injected via a systemic access and without preceding rinsing with fixatives or salt solutions there is a good correlation between the vessel diameters seen in SEM of resin casts and the vessel diameters found in the vitalmicroscopic observations. Thus, this method appears also suitable for studying the effect of vasoactive substances.

ISSN:1422-6405    

DOI:10.1159/000146172

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Paired cisternae of rough endoplasmic reticulum linked together by two parallel structures exhibiting periodic striations have been observed in the cytoplasm of small pre-antrum oocytes in the golden hamster. They are present only in oocytes from animals older than 3 weeks of age. Two or more such pairs may be associated with one another, and similar structures have been observed in contact with the nuclear envelope. The peak incidence of the paired membranes coincides with a sharp increase in rough .endoplasmic reticulum as the oocyte commences rapid growth. A suggested role for the paired membranes in production of new endoplasmic reticulum is discussed.

ISSN:1422-6405    

DOI:10.1159/000146173

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

This investigation was conducted to analyze growth in width of the rabbit calvarium. 15 male New Zealand white rabbits were subjected to regular stereometric examinations from 31 to 141 days of age after implantation of tantalum bone markers. The sagittal suture complex, i.e. the interfrontal and interparietal sutures, and the bilateral temporal sutures demonstrated similar growth rates in magnitude which moderately decelerated throughout the observation period. Transverse growth exhibited local growth fluctuations and short-term negative growth values in a well-balanced manner.

ISSN:1422-6405    

DOI:10.1159/000146174

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The gross anatomy, histology and histochemistry of the ferret prostate is described. The structure and course of the prostatic urethra and the ductus deferentes are also described. The prostate is the only accessory reproductive gland present in the ferret. The prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. Histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and small quantities of alkaline phosphatase and proteins. The findings in this study are discussed in relation to similar studies in other animals and man.

ISSN:1422-6405    

DOI:10.1159/000146175

出版商:S. Karger AG    

年代:1986

数据来源: Karger