Acta morphologica Hungarica最新文献

Quantitative light and electron microscopic autoradiography demonstrated a dissimilar effect of insulin, prednisolone and diiodothyronine on the incorporation and localization of 3H-uridine in Tetrahymena. After treatment with insulin for 1 h, uridine was rapidly incorporated, and after initial accumulation in the cytoplasm its intracellular level tended to drop below the control. Total uridine incorporation was lower than in the control cells. In Tetrahymena treated with prednisolone or diiodothyronine, uridine incorporation was relatively slow, but the intracellular uridine level increased significantly over the control. Re-exposure to the hormone had no significant influence in the case of insulin, but altered the quantitative relations of uridine incorporation significantly in the case of the morphogenetic hormones prednisolone and T2.

Incipient dental caries--according to up-to-date concepts in dental research--means a demineralization without cavity formation. At this stage the carious process is reversible, and remineralization can be achieved in the presence of locally applied fluorides. In chrystalchemical experiments, however, by treating natural apatites with lanthanides, [Ce, La, Pr, Nd, Sm, Eu, Tb ... Y, Sc] a more resistant complex could be developed. In this study extracted human molar teeth were kept for 60 days in Cerium (III)-nitrate solution, in order to investigate the incorporation of Ce3+ into human sound and carious enamel by light-microscopic-, and electron microprobe methods. Ce3+ was incorporated in sound enamel as well as into the incipient carious lesion, showing the histological characteristics of a remineralizing lesion. The mean values of the microprobe analysis data showed an increase in Ce3+ changing place with the Ca2+ the developing cerium-apatite being more hard and resistant from a mineralophysical point of view.

A comparative histological study of 100 cases of oral lichen planus, originating from Cuba and Hungary, was carried out in order to define some characteristics, especially epithelial dysplasia and their possible relation with the clinical types. The ratio of dysplastic changes found was 11%, the presence of more than one layer of cells having a basaloid appearance being the most frequent feature, followed by loss of polarity of basal cells. In relation with the clinical types the ratio of dysplasia was higher in atrophic/erosive cases (25%).

Hepatic lesions in 25 male and 24 female Syrian golden hamsters with N-Nitrosobis(2-oxopropyl)amine (BOP)-induced pancreatic cancer have been studied. Although BOP produced pancreatic cancer in 100% of the animals, its hepatocarcinogenic potential proved to be very weak, only occasional preneoplastic foci, neoplastic nodules and hepatocellular carcinoma developed. However, a broad spectrum of mainly proliferative, non-neoplastic alterations were found in the liver. The major site of alterations was the portal space, especially the biliary ducts were affected: bile duct hyperplasia, oval cell proliferation and formation of biliary cysts were the most frequently encountered changes. In the large ducts of the female hamsters a goblet cell metaplasia occurred, but the male animals were devoid of this lesion. Our results demonstrate that although the BOP is considered as a selective pancreatotropic nitrosamine derivate, it may cause various proliferative changes in the biliary duct system of hamsters.

De novo origin of colon carcinomas has been demonstrated in a case of familial polyposis. Independent origin of the polyps and the synchronous carcinomas was confirmed by their different pheno- and genotypes. Characterization of the phenotype was based on the mucin profile of the polyps and the synchronous carcinoma. The phenotype of each polyp was different and represented either duodenal, colonic or embryonal type of differentiation. The phenotype of carcinoma proved to be adult colonic type. The DNA content of the polyps and carcinoma has been evaluated by cytophotometry. The multiclonal origin of each polyps and synchronous carcinomas has been supported by their different DNA indices. Occurrence of de novo arising carcinoma in familial polyposis calls for a frequent follow-up examination of patients with subtotal colectomy and strongly support the need for total colectomy.

In the Golgi preparation of visual Wulst of chicken four types of projection neurons were found: type 1a, 1b, 1c, and 1d neurons, which are distinguished on the basis of their dendritic ramification pattern and especially on the density of the dendritic spines. Type 1a has large dendritic tree with moderately dense spiny dendrites. Type 1b has very dense spiny dendrites. Type 1c is a small neuron with moderately dense spiny dendrites. Type 1d is a star-pyramid-like neuron with a short, bifurcating apical dendrite. The final dendritic pattern and spine density of projection neurons was found to develop at the end of the first month. In the Wulst short axon cells (interneurons-INs) of different types occur: large, medium-sized and small INs can be observed. Their axon-arborizations are significantly different from each other. Some of them are GABA-immuno-positive neurons, which are very probably inhibitory interneurons. Stellate-like neurons also occur in IHA and HIS. These neurons have sparsely spiny dendrites and locally arborizing axons.

Speculation on neuron connectivity in the cerebral cortex, made some ten years ago, were re-evaluated in the light of modern cross identification methods. The identification of individual neurons and their synapses, including physiological characterization, detailed light microscope analysis of the same neurons, and immunocytochemical analysis of these neurones on the light microscope level and of their synapses on the level of the electron microscope, indicate that the specificity of local neuronal connections was underestimated in the earlier studies. Although the new methods revealed a higher degree of specificity in the choice of their connections, there seems to remain ample room for epigenetic (or functionally induced) plasticity of re-arrangement in neuronal circuits during later - even in postnatal - stages of development.

The author, with the xylene exposure of mice, rats and rabbits (sc, ip, per os, inhalation), as well as with xylene inhalation following the partial hepatectomy of rats, or the ligation of their common bile duct, wanted to find out whether xylene did have a selective or elective hepatotoxic effect. Using morphological (routine histological, enzyme-histochemical, electron microscopical, morphometrical), biochemical, clinical and analytical-chemical methods, it was found, that the xylene increased the activity of the hepatic biotransformation system, its adaptation to the xylene exposure; the xylene had neither selective, nor elective hepatotoxic effect in the examined species. The effect of xylene increasing the biotransformation ability of the liver is not inhibited by partial hepatectomy and ligation of the common bile duct; the so-called enzyme induction, which evolves at the effect of xylene, hinders the mitotic activity following the partial hepatectomy (defensive ability against xenobiotics takes priority over regeneration).

The results of an immunohistochemical study on paraffin sections of the lymph nodes from 5 patients with the acquired immunodeficiency syndrome (AIDS) related complex (ARC) are presented. The distribution and frequency of follicular dendritic cells (FDC) and of interdigitating cells (IDC) were examined with the monoclonal antibodies J3D3 (directed against the C3b complement receptor, CD 35) and IOB1a (specific for the C3D, CD21) as well as with the polyclonal anti-S-100 protein antiserum in Bouin-fixed, paraffin-embedded sections using a Streptavidin-biotin-peroxidase technique. Disruption of the follicular FDC network was demonstrated. No major alteration of the IDC was noted. The immunomorphological patterns observed in this study were comparable with the previously reported lymph node alterations studied in frozen section.

T-cell colonies formed in liquid or semisolid cultures of stimulated human blood mononuclear cells were investigated under electron microscope. Typical gap junctions with five-layered structure were demonstrated between colony cells embedded in water miscible resin. The overall thickness of the junctional zones was less than 25 nm. The intercellular gap was demonstrated by lanthanum nitrate staining. Close membrane associations were observed after normal embedding with a junctional width of 20-35 nm corresponding to gap junctions. The functional importance of free communication between colony cells is discussed.