Browsing by Author "Milićević, N.M. (7004246518)"

Rectal mucosa is relatively susceptible to pathological processes and frequently it is affected by various diseases. However, there is a notable lack of quantitative data regarding normal rectal mucosa, which would provide a reference for histoquantitative studies of the pathologically changed tissue. Therefore, we obtained the tissue from 27 healthy patients subjected to diagnostic rectoscopy during active screening for asymptomatic cancer of the large intestine, in which no disease was found. Using computer-aided morphometric analysis, we studied all structural elements of the rectal mucosa. The patients were divided into four groups according to the age and sex: adult males, elderly males, adult females and elderly females. The patients under 60 years of age were grouped as adult and those older than 60 years as aged subjects. A decreased height of surface epithelium was registered in both elderly male and female groups. This finding, however, was significant only when adult and elderly male groups were compared. The tendency towards reduction of the mucosal height was also registered comparing male adult and elderly groups. The number of crypts per 0.1 mm2 of tissue increased with aging in both males and females, whereby the crypts were always more numerous in males than in females. The increase in number of crypts in male subjects was accompanied by a decrease in their diameter and perimeter. The changes associated with ageing were discrete and affected only the male subjects.

Young adult male Wistar rats were given 30 mg per kg of cyclosporin (CS) for 21 consecutive days. A panel of monoclonal antibodies was used to study the phenotype of thymic epithelial cells. After treatment with CS, subcapsular epithelial cells, although phenotypically similar to medullary epithelial cells, were changed in a similar manner to phenotypically distinct epithelial cells of the deep cortex. These cells became enlarged, stockier and their cytoplasmic prolongations were thicker and coarser compared with control cells and their number was not decreased. In contrast, the number of medullary epithelial cells was markedly reduced, whereby the cells with the most mature phenotype (CK8+10-19- and CK8+10+19-) were the most prominently depleted. No proliferation of thymic epithelial cells was detected as monitored by incorporation of 5-bromodeoxyuridine. © 1992.

Young adult male Wistar rats were given 30 mg per kg of cyclosporin (CS) for 21 consecutive days. A panel of monoclonal antibodies was used to study the phenotype of thymic epithelial cells. After treatment with CS, subcapsular epithelial cells, although phenotypically similar to medullary epithelial cells, were changed in a similar manner to phenotypically distinct epithelial cells of the deep cortex. These cells became enlarged, stockier and their cytoplasmic prolongations were thicker and coarser compared with control cells and their number was not decreased. In contrast, the number of medullary epithelial cells was markedly reduced, whereby the cells with the most mature phenotype (CK8+10-19- and CK8+10+19-) were the most prominently depleted. No proliferation of thymic epithelial cells was detected as monitored by incorporation of 5-bromodeoxyuridine. © 1992.

Histoquantitative methods were applied to study the changes of splenic structure and proportions of splenic tissue compartments in cisplatin-treated (6 mg/kg body wt) male Wistar rats. Six days after treatment the significant reduction of volume density of white pulp was observed, which was due to the very prominent decrease of volume density of follicles. The volume density of periarteriolar lymphatic sheaths did not change substantially. Volume density of the marginal zone was also significantly reduced. A significant increase of volume density of connective tissue was observed. Morphometrical parameters of the follicles were also markedly altered: The number of follicles per mm2 of spleen section area, the numerical density of the follicles in the spleen, and the total number of the follicles were significantly reduced. © 1994 Academic Press, Inc.

Histoquantitative methods were applied to study the changes of splenic structure and proportions of splenic tissue compartments in cisplatin-treated (6 mg/kg body wt) male Wistar rats. Six days after treatment the significant reduction of volume density of white pulp was observed, which was due to the very prominent decrease of volume density of follicles. The volume density of periarteriolar lymphatic sheaths did not change substantially. Volume density of the marginal zone was also significantly reduced. A significant increase of volume density of connective tissue was observed. Morphometrical parameters of the follicles were also markedly altered: The number of follicles per mm2 of spleen section area, the numerical density of the follicles in the spleen, and the total number of the follicles were significantly reduced. © 1994 Academic Press, Inc.

Young adult male Wistar rats received a single injection of nickel chloride 0·5 mmol per kg) and were killed 72 h later. Histological examination showed that numerous, large, vacuolated cells appeared in the thymic cortex, which was almost totally depleted of lymphocytes. Enzyme histochemistry revealed that these cells were strongly acid phosphatase-positive macrophages. They contained aldehyde fuchsin-positive granules of varying size. Histochemical tests showed that these macrophages contained products of lipid peroxidation. According to the enzyme and histochemical characteristics, the macrophages which appeared in the thymic cortex during nickel-induced acute involution were identical to the special type of macrophage found in the cortico-medullary zone of the normal rat thymus. © 1989.

Young adult male Wistar rats received a single injection of nickel chloride 0·5 mmol per kg) and were killed 72 h later. Histological examination showed that numerous, large, vacuolated cells appeared in the thymic cortex, which was almost totally depleted of lymphocytes. Enzyme histochemistry revealed that these cells were strongly acid phosphatase-positive macrophages. They contained aldehyde fuchsin-positive granules of varying size. Histochemical tests showed that these macrophages contained products of lipid peroxidation. According to the enzyme and histochemical characteristics, the macrophages which appeared in the thymic cortex during nickel-induced acute involution were identical to the special type of macrophage found in the cortico-medullary zone of the normal rat thymus. © 1989.

Young adult Wistar rats received 40 mg/kg of cyclosporin perorally for 21 days. Cyclosporin induced almost total disappearance of thymic medulla, whereas the cortex remained preserved. Although the density of cortical macrophages did not change significantly, their characteristics altered markedly and they became enlarged and rounded. In addition to an increase in acid phosphatase and nonspecific esterase activities, cortical macrophages developed very strong succinic dehydrogenase and chloroacetate esterase activities and a fine, granular, aldehyde fuchsinpositive cytoplasmic content. However, these cytoplasmic granules were PAS-negative and were not sudanophilic. Cortical macrophages retained their normal antigenic properties (which were studied by the use of ED1, ED2 and R-MC 41 monoclonal antibodies). Phagocytic cells in the remaining medullary islands retained their usual characteristics. The changes in cortical macrophages after cyclosporin treatment are discussed, especially in relation to the characteristics of macrophages of the cortico-medullary zone in the normal rat thymus. © 1989 Springer-Verlag.

Naphthol AS D chloroacetate esterase (NASDCE)-positive macrophages are positioned in the cortico-medullary zone (CMZ) of the normal rat thymus. These cells contain the very strongly NASDCE-positive granules of varying size in the cytoplasm. An identical distibution within the thymic parenchyma and an identical morphological appearance is observed in CMZ macrophages after staining with aldehyde fuchsin. The incubation of thymic sections in 10% formalin at pH 7.0 for 48 h does not inhibit the activity of NASDCE in CMZ macrophages. The activity of nonspecific esterase is almost totally abolished by this treatment: only the single, largest globular inclusion within some of the cells remains weakly or moderately positive. The granular content of the CMZ macrophages does not stain metachromatically with toluidine blue and these cells are endogenous peroxidase-negative. NASDCE-positive thymic macrophages are easily distinguished from: a) NASDCE-positive mast-cells, which are confined to the capsular and septal connective tissue and contain densely packed metachromatic granules, and b) NASDCE-positive neutrophilic granulocytes, which have a specific morphological appearance and show very strong endogeneous peroxidatic activity. © 1985 Springer-Verlag.

Fractional doses of cyclophosphamide (Cy; 5 × 60 mg per kg) given to rats caused more severe initial destruction of thymic cortex and medulla, with a corresponding decrease of thymic mass, than did a single dose of the same amount (300 mg per kg). After the fractional dose, regeneration was retarded and repopulation was suppressed, so that on day 15 the thymus was almost totally alymphoid, in contrast to the initial regeneration seen after the single dose. On day 20 after the fractional dose of Cy an initial degree of regeneration corresponding to that seen on day 15 after the single dose, was found. The delayed restriction of regenerative capacity was more marked after the divided dose than after the single dose of Cy. © 1984.

Fractional doses of cyclophosphamide (Cy; 5 × 60 mg per kg) given to rats caused more severe initial destruction of thymic cortex and medulla, with a corresponding decrease of thymic mass, than did a single dose of the same amount (300 mg per kg). After the fractional dose, regeneration was retarded and repopulation was suppressed, so that on day 15 the thymus was almost totally alymphoid, in contrast to the initial regeneration seen after the single dose. On day 20 after the fractional dose of Cy an initial degree of regeneration corresponding to that seen on day 15 after the single dose, was found. The delayed restriction of regenerative capacity was more marked after the divided dose than after the single dose of Cy. © 1984.

Restriction of thymic regenerative capacity, in contrast to the data in the literature, was found 30 days after a single (300 mg per kg) or fractionated doses (5 × 60 mg per kg) of Cyclophosphamide. Detailed cellular analysis revealed myelometaplastic changes in the thymic parenchyma, especially in the outer cortex and cortico-medullary zone. Plasmoid elements also appeared in the outer cortex. The capsular and septal connective tissue was markedly thickened. The thymic mass was decreased. The changes were more marked after the fractionated than after the single dose of Cyclophosphamide. © 1984.

Restriction of thymic regenerative capacity, in contrast to the data in the literature, was found 30 days after a single (300 mg per kg) or fractionated doses (5 × 60 mg per kg) of Cyclophosphamide. Detailed cellular analysis revealed myelometaplastic changes in the thymic parenchyma, especially in the outer cortex and cortico-medullary zone. Plasmoid elements also appeared in the outer cortex. The capsular and septal connective tissue was markedly thickened. The thymic mass was decreased. The changes were more marked after the fractionated than after the single dose of Cyclophosphamide. © 1984.

Model-based stereology was used to study the changes of splenic structure and proportions of splenic tissue compartments in FK506-treated male Wistar rats (0.1 mg/kg three times a week for 14 days). The point- counting method was utilized to study the volume densities of the following tissue compartments: red pulp; white pulp (this compartment was divided in two subcompartments: follicles and periarteriolar lymphocyte sheath); marginal zone; and connective tissue. The following stereological parameters of lymphoid follicles were also determined: areal numerical density (the number of follicles per mm2 of tissue section); the numerical density (number of follicles per mm3 of tissue); and the mean follicle diameter. After FK506 treatment a significant reduction of volume density of white pulp was observed, which was due to the very prominent decline in the amount of peri-arteriolar lymphocyte sheath, whereby the cellular density of this tissue compartment was decreased. In the marginal zone of FK506-treated spleens the presence of numerous, large, densely packed lymphoblastic cells of very uniform appearance was registered. These observations are in very good keeping with the changes of splenic morphology registered in cyclosporin A-treated rats, which further documents the parallelism in actions between these immunosuppressive agents.

Secondary lymphoid follicles in peripheral lymphoid organs (parathymic, mesenteric and inguinal lymph nodes and spleen) from young adult Wistar rats of both sexes were studied. Different numbers of tingible body macrophages containing aldehyde fuchsin-positive cytoplasmic granules of varying size, were present in the germinal centers. An identical staining pattern to that obtained with aldehyde fuchsin in terms of the number, distribution and size of positive cells was seen after staining for succinic dehydrogenase. © 1986 Springer-Verlag.