摘要:

The immunocytochemical localization of α-fetoprotein (AFP)-producing cells was observed in pre- and postnatal and carbon tetrachloride (CCl4)-treated rat livers in comparison with that of albumin (ALB)-producing cells. According to immunoblotting data, considerable numbers of AFP-positive hepatocytes were observed in the differentiating liver between prenatal day 19 and postnatal day 0 (6 h after birth). Analyses by serial section profiles of these cells revealed that certain AFP-positive hepatocytes are also stained with ALB antiserum. Immunoelectron microscopy of the AFP-producing cells revealed that immunoreactive gold particles are preferentially localized in rough endoplasmic cisternae, Golgi apparatus and Golgi-derived vesicles near the cell surface. In addition, the release of the content of the Golgi-derived vesicles into the differentiating bile canaliculi as well as into the space of Disse by exocytosis is apparent. In CCL-treated rat liver, immunoreactions to AFP are localized exclusively in newly formed hepatocytes of the regenerative tissue. These AFP-positive cells have not established the hepatic cell cords, and the adjacent ones are conjugated to each other mainly by simple attachment devices as in the case of those in pre- and postnatal rat liver

ISSN:1422-6405    

DOI:10.1159/000147243

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Light- and electron-microscopical techniques were used to study the structure of the inferior conjunctiva of monkeys including the third eyelid (nictitating membrane). The cell layers of the conjunctival epithelium were 8–10 at the margin, 6–8 near the limbus and 2–4 in other areas except in the third eyelid where there were 1–4 layers. The epithelium was 90–100 µm thick at the margin and 35–40 µm at the other areas except at the third eyelid where it was 10–45 µm thick; near the limbus it was 55–60 µm thick. The morphological differences between the epithelia of the various areas of the inferior conjunctiva are highlighted. The similarities and differences between the human and monkey inferior conjunc

ISSN:1422-6405    

DOI:10.1159/000147244

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery.

ISSN:1422-6405    

DOI:10.1159/000147245

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Pancreatic vascular casts of the common tree shrew (Tupaia glis) were prepared by infusion of Batson’s No. 17 plastic mixture into the blood vessels and examined by scanning electron microscopy (SEM). Routine histological study of the pancreas was also performed. It was found that the A and D cells appeared to occupy the core whereas the B cells were found at the periphery of the islets of Langerhans. With SEM, the insular arteriole, a branch of the interlobular artery, was shown to penetrate deeply into the core of the islets before branching off into the glomerular capillary network supplying the islets. These capillaries reunited at the periphery of the islets to become vasa efferentia and then gave off capillaries to anastomose with those in the exocrine part of the pancreas, the insuloacinar portal system. Such an insuloacinar portal system found in the pancreas of the tree shrew was similar to that found in the horse and monkey. However, there were some intralobular arterioles which did not end in the islets but directly branched into the interacinar capillary network and periductular plexus. The capillaries in the exocrine part not only gathered into intralobular venules which confluently formed the interlobular vein but also supplied the duct system. The periductular plexus also collected blood into the intralobular venule and interlobular vein, respectivel

ISSN:1422-6405    

DOI:10.1159/000147246

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The ultrastructure and the appearance of glycogen were studied in the extraocular muscles of 14 externally normal human embryos (Carnegie stages 13–21). At stage 16, myofibrils with an immature Z line and glycogen granules appeared in the cytoplasm of the myoblast. The myoblasts came into cluster at stage 18, and fusion between the myotubes was observed at stage 20. At this stage, an M line appeared in the myofibrils. At stage 21, an A band with a Z line and an H band with an M line were observed, the sarcoplasmic reticulum appeared in the cytoplasm of the muscle fibers and glycogen increased in volume in the cytoplasm. In the previous study, we showed that the muscle-specific isoenzymes, such as creatine kinase, β-enolase and glycogen phosphorylase, appeared from stage 18 to 20 in the extraocular muscles. The previous findings and the present results suggest that the fusion of the muscle cells occurs in the period when some molecular markers of muscle differentiation are expressed in vi

ISSN:1422-6405    

DOI:10.1159/000147247

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Apocrine glands of the anal sacs in cats (Felis silvestris f. catus) were examined by transmission and scanning electron microscopy. The secretory cells exhibit a typical equipment with organelles that varied according to the season as well as the animal’s sex and state of reproduction. This can be mainly explained by seasonal differences in secretory activity. The cytological dynamics observed are, particularly, related to the smooth endoplasmic reticulum, which, for the first time, can be demonstrated in its crystalloid form in apocrine gland

ISSN:1422-6405    

DOI:10.1159/000147248

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

In the masticatory muscles, the development of bundles of the tendon was examined: they were composed of many collagen fibers and a few elastic fibers. In the masseter muscle, the property of the tendon differs in the distribution and size of collagen fibers and elastic fibers in comparison with those of other masticatory muscles. This difference is concerned with the kinetic force for the stress or the stretch of each tendon and muscle during jaw movement.

ISSN:1422-6405    

DOI:10.1159/000147249

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The autonomic innervation of the major and minor salivary glands was studied in five species of cebid monkeys using acetylcholinesterase (AChE) and catecholamine histochemistry. Catecholamine-containing and AChE-positive nerve fibres were observed in the vessels and secretory endpieces of all glands, with no apparent predominance of one type over the other. In the intralobular ducts, however, the cholinergic innervation predominates. In the major salivary and minor sublingual glands the density of the nervous supply was higher, whereas in the secondary mandibular and posterior lingual glands it was less dense. The morphological patterns of salivary gland innervation found in Cebidae are compared with those of the related family Callitrichidae.

ISSN:1422-6405    

DOI:10.1159/000147250

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Prothymosin α (ProTα) distribution in human and rat lymph nodes and human tonsils was studied by means of immunohistochemical methods, using specific antibodies raised against thymosin αL· We observed ProTα immunoreactivity in lymphoid cells of the germinal centers both in humans and rats. In human tonsils, positive cells were also seen in the basal layer of the surface epithelium. These results support the hypothesis that ProTα expression is restricted to actively proliferating cells. Immunoelectron microscopy revealed that ProTα was located in the nucleus, mainly in the border between euchromatin and heterochr

ISSN:1422-6405    

DOI:10.1159/000147251

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The effects of different ages on large vacuolar bodies in the parathyroid glands of golden hamsters after short-term treatment with calcium were investigated. In the parathyroid glands of the young and adult animals 15 min and the senile animals 15 and 60 min after administration of calcium, the percent area occupied by large vacuolar bodies was significantly increased as compared to that of the young, adult and senile control animals, respectively. These findings suggest that the percent area occupied by large vacuolar bodies is increased in response to acute hypercalcemia. It is thought that in the parathyroid glands suppressed by hypercalcemia there is a relationship between the percent area occupied by large vacuolar bodies and aging.

ISSN:1422-6405    

DOI:10.1159/000147252

出版商:S. Karger AG    

年代:1992

数据来源: Karger