scholarly journals MORPHOLOGICAL CHANGES IN THE LIVER VASCULAR SYSTEM OF RATS UNDER THE INFLUENCE OF THIOACETAMIDE

2021 ◽  
Vol 19 (3) ◽  
pp. 285-293
Author(s):  
E. I. Lebedeva ◽  

Background. Angiogenesis plays a key role in the progression of liver fibrosis. However, the available data on morphological changes in the liver vascular system are insufficient and contradictory. Objective. The aim of the work is to study the morphological changes in the liver vascular system of rats under the influence of thioacetamide. Material and methods. Fibrosis and cirrhosis of the liver in Wistar rats were induced with thioacetamide given at a dose of 200 mg/kg of animal weight for 17 weeks. To study morphological changes, we used classical and immunohistochemical staining methods. Microscopic analysis was performed using OLYMPUS BX51 microscope and image analysis software ImageScope Color and cellSens Standard. Results. The introduction of a solution of thioacetamide through the stomach leads to a gradual increase in the progression of pathological changes. In addition, it permits to track all stages of cirrhosis development and morphological restructuring of the liver vascular system. Throughout the experiment there was intensive capillarization of the parenchyma sinusoids and neoangiogenesis in the portal tracts and connective tissue septa manifested by the formation of many venules and small veins. We also observed an increase in the area of interlobular veins, which in some places had reached gigantic proportions. Three morphological phenotypes of CD34-positive cells were revealed. In the interlobular arteries as well as interlobular, central and sublobular veins, these cells had an elongated shape and a rod-shaped dark-colored nucleus. During the transformation of liver fibrosis into cirrhosis CD34-positive cells of an elongated shape with light roundedelongated nuclei were observed in the sinusoids closer to the periphery of individual false nodules. Rounded cells with dark-colored nuclei were present in the connective tissue near the hepatic triads, in the connective tissue septa among the cells of the infiltrate and between the sharply increased number of bile ducts. Conclusions. The established complex phenotypic changes in sinusoidal endothelial cells prove a close connection between fibrogenesis and neoangiogenesis. They probably play a leading role in the development of fibrosis and restructuring of the venous system of the portal vein.

2021 ◽  
pp. 484-488
Author(s):  
Sidelnikova

A morphometric study of liver changes at different invasive doses was conducted in rodents (Oryctolagus cuniculus). In a comparative aspect, the thickness of connective tissue formed around the portal tracts and the thickness of cellular infiltrates in the same area were studied at an invasive dose of 100, 50 and 10 metacercariae of Ophistorchis felineus (Rivolta, 1884). The experiment was conducted on sexually mature male rabbits at the age of 6 months, in each observation group of 10 individuals. Clinically healthy animals were infested with Ophistorchis felineus per os metacercariae once. The intermediate stage of the parasite was isolated from a dead fish (ide, Leuciscus idus (Linnaeus, 1758) and dace fish, Leuciscus leuciscus) obtained from the Tom River in Tomsk. The invasion that took place after 1 month was confirmed by a positive analysis of feces for parasite eggs by the Ragaser and KatoMiura methods. The animals were sacrificed after 5 weeks from the period of infestation. Histological preparations of the liver were made, stained with hematoxylin and eosin, according to Van Gieson. Histological preparations were studied by light microscopy with morphometry. The results obtained characterize a twofold change in the morphometric parameters of connective tissue thickness and cellular infiltration around the portal tracts of the liver lobes with an increase in the invasive dose.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1163
Author(s):  
Yajun Yu ◽  
Liangshan Li ◽  
Jiale Zhao ◽  
Xiangeng Wang ◽  
Jun Fu

This paper takes a local drum-type corn thresher as an example. In order to make the threshing principle transform to the plate-tooth type, the width of the spike-tooth threshing component is increased gradually, and three threshing components of different shape and size are selected as the research objects. Based on the preliminary experimental research, the corn threshing process is simulation analyzed using the self-developed corn threshing process analysis software. The effects of the width of the threshing component on the corn ears threshing rate and kernel damage rate under different rates of drum rotation were studied from a macroscopic perspective. The results show that with the increase of drum rotation rate, both the corn ear threshing rate and kernel damage rate increase; with the increase of threshing component width, the threshing rate increases and the damage rate decreases; and when the component width is too large, the stacking between adjacent components has an impact on the threshing performance. The effects of threshing component width on the amount of kernel threshing and the total compressive force during the simulation time were investigated from microscopic perspective at different rates of drum rotation, and the results show that the microscopic analysis is consistent with the macroscopic analysis. Therefore, the optimization of the structural parameters and operating parameters of the threshing component was achieved. When the width of the threshing component was 25 mm and the roller speed was 187.50 rpm, the threshing performance was optimal, with a 98.04% corn ears threshing rate and a 2.56% kernel damage rate. This paper verifies the practical applicability of the corn threshing process analysis software and provides a reference for the optimal design of threshing devices.


1994 ◽  
Vol 126 (1) ◽  
pp. 247-258 ◽  
Author(s):  
O Ayalon ◽  
H Sabanai ◽  
M G Lampugnani ◽  
E Dejana ◽  
B Geiger

The integrity of the endothelial layer, which lines the entire cavity of the vascular system, depends on tight adhesion of the cells to the underlying basement membrane as well as to each other. It has been previously shown that such interactions occur via membrane receptors that determine the specificity, topology, and mechanical properties of the surface adhesion. Cell-cell junctions between endothelial cells, in culture and in situ, involve both Ca(2+)-dependent and -independent mechanisms that are mediated by distinct adhesion molecules. Ca(2+)-dependent cell-cell adhesion occurs mostly via members of the cadherin family, which locally anchor the microfilament system to the plasma membrane, in adherens junctions. Ca(2+)-independent adhesions were reported to mainly involve members of the Ig superfamily. In this study, we performed three-dimensional microscopic analysis of the relative subcellular distributions of these two endothelial intercellular adhesion systems. We show that cadherins are located at adjacent (usually more apical), yet clearly distinct domains of the lateral plasma membrane, compared to PECAM-1. Moreover, cadherins were first organized in adherens junctions within 2 h after seeding of endothelial cells, forming multiple lateral patches which developed into an extensive belt-like structure over a period of 24 h. PECAM-1 became associated with surface adhesions significantly later and became progressively associated with the cadherin-containing adhesions. Cadherins and PECAM-1 also differed in their detergent extractability, reflecting differences in their mode of association with the cytoskeleton. Moreover, the two adhesion systems could be differentially modulated since short treatment with the Ca2+ chelator EGTA, disrupted the cadherin junctions leaving PECAM-1 apparently intact. These results confirm that endothelial cells possess distinct intercellular contact mechanisms that differ in their spatial and temporal organization as well as in their functional properties.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mochamad Arief Budihardjo

Morphological variations of geosynthetic clay liner (GCL) samples, hydrated with two different permeates, distilled water and NaCl solution (100 mM concentration), were observed in detail using microscopic analysis. After the GCL samples were hydrated with the NaCl solution, they were observed with an optical microscope. While the surface of the treated GCL samples was similar to the surface of the untreated GCL, a crystal deposit was found on the surface of the treated samples. Using a scanning electron microscope (SEM), a more solid appearance was observed for the bentonite particles contained in the GCL after the sample was hydrated with distilled water in comparison to the GCL sample that was hydrated with the NaCl solution. It appears that salt solution hydration results in less swelling of the bentonite particles. Furthermore, the energy-dispersive X-ray spectrometer (EDS) results showed that distilled water hydration had no effect on the distribution of the elements contained in the GCL samples. However, bound chlorine was observed, which demonstrated that the bentonite particles had absorbed the NaCl solution. In addition, changes in the hydraulic conductivity of the hydrated GCL samples were also observed.


2018 ◽  
Vol 22 (4) ◽  
pp. 682-685
Author(s):  
E.N. Usychenko ◽  
Yu.I. Bazhora ◽  
E.M. Usychenko ◽  
V.A. Gudz

The data on the polymorphism of cytokine genes associated with individual reactivity on the effects of hepatitis C virus, predict the rate of progression of liver fibrosis. The purpose of this work is study the association of the polymorphic marker G308A of the TNFα gene with its quantitative content and degree of liver fibrosis in patients with chronic hepatitis C. A total of 100 patients with CSF were examined. The polymorphism of G308A gene’s TNFα was studied by amplification of the corresponding genome zones by PCR. The assessment of the degree of fibrosis was performed using the non-invasive Fibrotest method. The study of the quantity of TNFα cytokine in serum of patients was performed by ELISA. The distribution of genotypes on the investigated polymorphic loci was verified using Pearson's χ2 criterion. The frequencies of alleles and genotypes in the groups were compared using Pearson's χ2 criterion with Yates correction for continuity with the number of degrees of freedom 1. In order to detect the correlation dependencies between the individual parameters, the Spearman correlation coefficient was applied. It was found that a smaller degree of fibrosis was observed in carriers of the GG TNFα genotype, and a greater degree of fibrosis in the carriers of the genotype AA TNFα (moderate feedback between the degree of fibrosis and the genotypes of TNFα). The higher content of TNFα is noted in the carriers of the AA genotype TNFα, the lower content of TNFα - in the carriers of the GG TNFα genotype (moderate feedback between the TNFα genotypes and the TNFα content). It has been established that a higher TNFα content is observed in patients with F1-F0 fibrosis, a lower TNFα content in patients with F2-F3 fibrosis (a strong correlation between the degree of fibrosis and the amount of TNFα cytokine). It is assumed that the production of the cytokine is determined at the genetic level, and the severity of changes in the cytokine profile in chronic hepatitis C affects the course of the pathological process. An increase in the TNFα content in chronic hepatitis C may be a marker for significant morphological changes in the hepatic tissue and high activity of the inflammatory process.


2019 ◽  
Vol 1 (17) ◽  
Author(s):  
U. Ayman ◽  
S. K. Das

Background: Papillomatosis is a viral disease manifested with benign cutaneous growths (skin epithelium hyperplasia) in different body parts which is encountered in cattle, goat, dog, rabbit, horse, rodent and also in human. The purpose of the present study is to detect the histo-morphological changes of cutaneous papillomatosis in indigenous cattle. Methods: Ten (10) random samples from skin lesions of warts were collected from adult indigenous cattle (10 cattle) that were diagnosed as cutaneous papillomatosis by clinical examination at Veterinary Teaching Hospital, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh. For gross observations, location of appearance of warts, color and size was taken into consideration. Immediately after collection of sample, they were preserved in Bouin’s fluid followed by dehydration, clearing and infiltration and finally embedded by paraffin wax. Then samples were sectioned using rotatory microtome and stained with Harris’s Haematoxylin and Eosin Y to facilitate microscopic study. Results: The results of present study revealed that cutaneous papillomas were mostly located on the head and neck, around eyes, under the chin and perineal region in indigenous cattle. Grossly, warts in cattle are bumpy or cauliflower-like masses of various sizes and numbers that projected from the skin having grey, rough, scaly, and dry surface. When incised, its cut surface has an external layer- keratinized epithelium and an internal core- moist white connective tissue. Histopathological changes indicate hyperplastic features of the affected skin layers of epidermis. Further, the microscopic analysis also revealed orthokeratotic hyperkeratosis, acanthosis and down word hyperplasia, fibrovascular area, keratohyalin granules and koilocytes at different layers of the affected skin. Conclusion: The results of this present study might be useful for the classification and treatment of this common malady based on its histological changes.


The effectiveness of using various methionine preparations for activating pancreatic function is ambiguous; the reasons may include differences in dosage and duration of methionine administration. The question remains, in what extent the methionine application is efficacious for increasing functional activity of a healthy pancreas. The aim of our study was to investigate morphological changes in pancreas after prolonged administration of methionine. The experiments were carried out on 24 males of Wistar rats at the age of 15 months. During 21 days, the experimental animals received methionine at a daily dose of 250 mg/kg of body weight in addition to the standard diet. Histological preparations were made from pancreatic tissue according to standard method. Morphometry was performed using the computer program «Image J». The rats were taken out of the experiment under ether anesthesia. The studies were carried out in accordance with the provisions of the "European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes" (Strasbourg, 1986). Upon completion of the experiment, histomorphological sings of an increase in functional activity were registered in both exocrine (enlarged acini’s areas and their epithelium height, higher nuclear-cytoplasmic ratio of exocrinocytes, and higher number of nucleoli in cell nuclei) and endocrine (enlarged sizes of the Langerhans islets and increased number of endocrinocytes in the islets) parts of the rat pancreas. In the experimental rats, the relative area of ​​the connective tissue and the stromal-parenchyma index of the pancreas, as well as the width of the interlobular and interacinus layers of connective tissue decreased. A decrease in the mass of connective tissue in the pancreas can be considered as one of the signs of its function activation, an improvement in metabolism between acini, and an increase in regenerative capabilities. Thus, additional administration of prophylactic doses of methionine to healthy animals results in distinct morphological signs of increased pancreatic activity.


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