Experimentelle Pathologie最新文献

The ultrastructural changes in the liver cells of male Wistar rats induced by the oral and intraperitoneal application of hexachlorophene (HCP) were studied by using the freeze-fracture technique and by producing ultrathin sections.

The rats were given the HCP once at a dose of 30 mg/kg body weight and were sacrificed 60 hours after treatment.

The enlargement of bile canaliculi, the disorganization of tight junctions and the increase in number of gap junctions were the most prominent alterations observed in the liver cells. Furthermore, an increase in the smooth and rough endoplasmic reticulum and in the microbodies were found. Pathological alterations in the mitochondria were also seen.

In general, the effects of the intraperitoneal application on the liver were more pronounced than the effects of the oral application.

The influence of two kinds of transplantable melanomas on the content of fucose in the surface glycoproteins of hamster peritoneal macrophages was studied.

An increase in the content of fucose, more prominent in surface material of macrophages from animals with melanotic melanoma was found.

It has been suggested that this phenomenon is connected with the neoplastic process, and that the different susceptibility of the macrophages from experimental animals to macrophage inhibitory factor (MIF) is related to changes in the content of fucose in the surface glycoproteins.

After a single oral dose of 100 mg/kg of alpha-chlorohydrine, two distinct phases in the response of the testes to the treatment have been observed: (i) the immediate onset of testicular swelling lasting up to five days, accompanied with a steady increase in the weight of the testes and (ii) thereafter a constant decrease in the testes weight. Changes in the diameter of the seminiferous tubules and the thickness of the basement membrane were observed after the administration of the drug. Multinucleated giant cells were encountered 5 days after drug administration. Alkaline phosphatase, SDH, nucleic acids and proteins showed a fall after treatment with the drug. On the contrary, cholesterol, phospholipids and glycogen showed an increase after its administration. Acid phosphatase showed a fall in the initial stages only, but the activity was higher after 10, 20 and 40 days of the treatment with the drug.

The level of plasma and testes testosterone remained normal after chlorohydrin administration. The induction of lesions in hypophysectomised gonadotropin-stimulated animals suggests that the action of chlorohydrin is not mediated through gonadotropins. Alphachlorohydrin administered intratesticularly did not evoke any changes in the histo-architecture of the testis.

The transplantation of human adenocarcinomas of the gastrointestinal tract into nude mice is described. The human primary tumors were located in the stomach, colon or rectum. Successively transplantable lines could be established by means of implantations of tumor blocks in the left abdominal wall of nude mice. Some biological and histopathological criteria of the implanted tumors as compared to their human origins are given. Several experiments concerning the dependence of tumor growth in nude mice upon the region of implantation are reported. Moreover, first results with regard to development of tumor recidives in nude mice after resection are presented.

In previous investigations we could demonstrate that angiitis or angiolytic changes of the vascular wall with loosening or duplication of the basement membrane may be caused by a low calcium diet. In this paper we present experiments using the same experimental procedures which lead to massive necrotic changes of granulosa cells in the ovary. These phenomena are thought to be induced by loosening and swelling of the basement membrane which delimits the granulosa layers from the outermost tissue.

The aim of the present study was to follow the ultrastructural changes occurring in neuronal intracellular structures of the rat cerebral cortex after chronic administration of ethanol. The experiments were carried out with 15 Wistar rats. Nine of them received alcohol, while six served as control group. According to Ratcliffe's model, the animals received ethanol to drink in increasing concentrations so that they became adapted to it. Examinations were performed on 3 groups of animals: Group I receiving for 4 weeks ethanol in concentrations increasing from 2.5 to 10 per cent; Group II receiving for 8 weeks ethanol in concentrations increasing from 2.5 to 25 per cent; Group III receiving for 12 weeks ethanol in concentrations increasing from 2.5 to 25 per cent and given for the last 4 weeks simultaneously 42 per cent ethanol through a gastric tube every second day.

In the animals of group I, a marked decrease of the number of ribosomes and polysomes was observed in the neuronal cytoplasm and a slight reduction of the rough endoplasmic reticulum (RER). In the cells with a well-developed smooth endoplasmic reticulum (SER) mitochondria exhibited a number of abnormalities in the form of a reduced number of cristae, their aggregation in the central part of the matrix and the appearance of mitochondria markedly elongated in shape.

In experimental group II, the changes in the neuronal cytoplasm were more pronounced as compared with those in group I. In the peripheral part of the cytoplasm a wide extension of channels of the RER and proliferation of SER were observed. The above mentioned disturbances in the cytoplasm were usually accompanied by changes in the mitochondria consisting in their increased number and size, reduced electron density of the matrix, and greatly reduced number of cristae.

Most of the cortical neurones in group III exhibited abnormalities in the RER and SER similar to those described in animals of group II.

The most severe changes were observed in the mitochondria consisting in an increased size with deformation of monstrous shapes. Some mitochondria were greatly enlarged but of spherical shape with myelin-like structures inside.

The changes in the above mentioned structures suggest that ethanol easily penetrates through the blood-brain barrier and glial cells to the neurones. Although alcohol produces severe abnormalities in the mitochondria and enhances the spread of the SER, it does not lead to destruction of the neurones of the cerebral cortex.

The influence of maternal chronic alcoholism on fetal brain development was investigated in rats. A decrease in the activity of succinate, glycerin-1-phosphate, glucose-6-phosphate dehydrogenases and of tetrazolium reductases was found. The amount of total RNA was reduced in the neonates with alcohol damage. Moreover, a retardation of myelinisation at the time of birth was observed.

Oral administration of manganese chloride (25 mg/kg b. w. daily) to monkeys for a period of 18 months produced congestion and marked increase in weight of testis. Histopathologic examination revealed interstitial oedema and degeneration of seminiferous tubules. Activities of succinic dehydrogenase, glucose-6-phosphate dehydrogenase and acid phosphatase were significantly inhibited whereas NADH-diaphorase and alkaline phosphatase activities showed only slight inhibition in seminiferous tubules of treated monkeys. It was concluded that chronic exposure to manganese does not produce severe degenerative changes in the testis earlier than metal induced encephalopathy in primates.

Male Sprague Dawley rats were partially hepatectomized. At different times after operation, their thymocytes were isolated and incubated for 5 hours at 37 °C in an RPMI medium with 10% rat control serum and their incorporation of ³HTdR was then determined. 1 and 2 days after partial hepatectomy, the thymocytes incorporate much less ³H TdR; from day 3 to day 10 a stimulation of proliferation was observed. Thymocytes of control animals incorporate much less ³HTdR when incubated with sera from animals 1 day to 4 days post partial hepatectomy. Corticosterone, cortisol, testosterone, α-fetoglobulin, putrescine, sperimidine, spermine and cadaverine do not influence the incorporation of labelled thymidine into control thymocytes during an incubation of 5 hours.

Unaltered human arterial tissue as well as different types of macroscopically and microscopically characterized atherosclerotic lesions were microdissected under a preparation microscope. The prostacyclin formation was examined using its potent platelet aggregation inhibition in vitro according to Moncada's bioassay. In contrast to different PGI₂-formation in various experimental animal models the generation in the different lesion types in terms of wet weight was statistically significantly (p < 0.001) diminished in comparison to normal control tissue. However, the PGI₂-formation in different lesion types is comparable. Accepting the hypothesis delivered earlier by us, that the arterial wall is able to react upon exogenous noxes with a temporarily enhanced PGI₂-formation, followed (after ceasing) by a decrease of PGI₂-synthesis (exhaustion phenomenon) it can be concluded, that the critical stage is prior to the fatty streak formation, which is a preatherosclerotic lesion. Therefore, PGI₂-generation-exhaustion might be mainly responsible for initiation and progression of atherosclerosis, probably before any detectable morphological alterations.