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M Holub

Publications and source records attributed to M Holub.

At least 19 recordsLinked to original sources
PubMed1992

The effect of an antigenic stimulation on proliferative response in athymic mice.

The proliferation activity of the main cellular categories of bone marrow after infusion of 3H-thymidine was studied in nu/nu and +/+ 1-month- and 3-month-old BALB/c mice in comparison with lymphoid cells in the spleen and mesenteric lymph nodes. The stem cell defect in nu/nu mouse bone marrow is compensated by an increased proliferation in myeloid series and in agranulocytes. The increase of proliferation activity among lymphoid cells in peripheral lymphoid organs was observed only in the 3-month-old mice with a delay in the nudes.

Animals↗
PubMed1992

An electron microscopic study of the development of the thymus anlage of athymic (nu/nu) mice.

Using electron microscopy, we examined the anlage of dysgenetic embryo thymuses of nu/nu mice aged 14.5-15 days, 16 days and 18 days p.c., with thymus anlage of nu/+ mice serving as controls. On comparing both types, we noted differences at all intervals which increased in a time-related manner. Lymphoid cells were found only very occasionally in dysgenetic thymus anlage up to day 16 p.c. while there were no capillaries at all in any of the stages investigated. In epithelial reticular cells, undemarcated (membrane non limited) spaces of varying size and containing PAS+ material were found in the cytoplasm (glycogen-like particles seen in electron microscopy). Based on our findings, and on general assumptions, we believe that the primary process occurring in the dysgenetic thymus is abnormal epithelial stroma differentiation resulting not only in a lack of lymphoid cells but, also, in a limited or probably absent vascular bed.

Animals↗
PubMed1991

Impact of neonatal benzpyrene imprinting on thymocytic dexamethasone binding in ascitic tumor bearing rats.

1. Rats treated with a single dose of benzpyrene when newborn and inoculated with Walker's ascitic tumor cells when 6 weeks old showed 6 and 9 days later an unequivocal increase, whereas 15 and 20 days later an unequivocal decrease, in dexamethasone binding capacity (receptor number) relative to the control, i.e. a reversion of receptor activity in the course of tumor genesis. 2. The reversion of receptor activity showed a parallelism with the increase of tumor mortality over the control. 3. The experimental observations support the conclusion that neonatal exposure to benzpyrene has a depressive effect on general resistance that is reflected (or probably caused?) among others by a decrease in the binding capacity of glucocorticoid receptors.

Animals↗
PubMed1991

Thy 1 expression in the brain of nude mice.

The expression and cell distribution of Thy 1 antigen was studied in the brain of both normal and athymic (nude) young adult mice of the BALB/c strain by immunochemistry. In nude animals Thy 1 fluorescence was less intense and less regularly distributed in the molecular layer of the cerebellum and hippocampus. Thy 1 content determined by ELISA was lower by 10-16% in the cerebellum and 20-25% in the olfactory bulbs of nude mice. The total wet weight of the brain was lower by 16% than in control animals; the deficit in body weight ranged from 34-45%. It is supposed that the changes in Thy 1 expression in nude animals are caused mainly by the underdevelopment of late developing brain regions due to thermoregulatory problems and other postnatal strains occurring in the mutants.

Animals↗
PubMed1991

Ossification in nude mice. 2. A histological, histochemical and immunohistochemical study.

The autopodia of proximal limbs as well as the proximal growth plates of the tibia of newborn nu/nu including super nu/nu, nu/+ and +/+ mice were studied. No differences in the ossification of proximal limb autopodia (regarding the distribution of alkaline phosphatase, acid phosphatase or glycosaminoglycans) were observed in mice of genotypes studied. On the other hand, a thinner proximal tibial growth plate characterizes one-month-old nu/nu mice, and also the architecture and alkaline phosphatase pattern were altered. The results suggest a postnatal secondary effect of the nu/nu genotype on skeletal development.

Alkaline Phosphatase↗
PubMed1991

[Arachnoid cysts].

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Arachnoid Cysts↗
PubMed1991

Hematopoietic stem cells in +/+, nu/+, and nu/nu C57Bl/10 mice.

Mice with the nu mutation have been shown to have a reduced incidence of spleen colony-forming units (CFU-S), with a higher variability between individual mice compared to +/+ mice. The presence of these defects also in nu/+ mice indicates that this mutation is a codominant trait and that the hematopoietic changes may not be solely caused by thymus dysgenesis. The proportion of CFU-S synthesizing DNA (approximately 40%) has not been significantly different between +/+, nu/+, and nu/nu mice.

Animals↗
PubMed1990

Ossification in nude mice. 1. Macroscopical study.

Ossification was studied in cleared fetuses, newborns, 1- and 6-week-old nu/nu and nu/+ mice of the B 10 LP background. The same ossification pattern was observed in nu/nu and nu/+ in the embryonal period as well as in newborn animals and mice aged 1 or 6 weeks. On the other hand, 6-week-old nu/nu mice exhibited a lower X-ray density of the skeleton and a lower thickness of the proximal tibial growth plate than 6-week-old nu/+ litter mates. The results indicate the influence of postnatal factors on the skeletal development of nu/nu mice.

Animals↗
PubMed1990

Omental dendritic cells: Ia expression and relation to macrophages.

Rat omental dendritic cells (ODC) occur in two forms, mainly spindle-shaped, Ia-, on the surface, and stellar, Ia+ within the omentum. Like macrophages, most ODC label with W3/25 mAb and have a demonstrable activity of non-specific esterase, acid phosphatase and ATPase. Up to 30% of ODC are actively phagocytic. The proportion of Ia+ ODC rises 7 days after ip antigenic stimulation and there seems to be a reciprocal development of Ia positivity and phagocytic capacity between ODC and macrophages 3 and 5 days after ip immunization. ODC contribute to the overall fluctuation of Ia expression in the entire omentum after immunization. Ia+ ODC display a linear arrangement along preilymphatic spaces and may be related to the formation of new lymph vessels. They also constitute the stroma of pseudofollicles containing clusters of what are presumably T-helper lymphocytes closely attached to ODC, scattered suppressor T lymphocytes and B cells accumulating in later stages at the immune response.

Acid Phosphatase↗
PubMed1990

The dysgenetic thymus in nu/nu mice is a potent source of colony stimulating factor (CSF).

During in vitro incubation, the pulmonary and thymic tissue of mice released a colony stimulating factor (CSF) supporting the development of colonies of granulocytes and macrophages from bone marrow progenitors. Cardiac, splenic, renal and bone marrow tissues were not active. The dysgenetic thymus of nude mice was a very potent source of CSF during in vitro incubation.

Aging↗
PubMed1979

Skin-window study on the migration of leukocytes of newborns and infants.

Migration of leukocytes of newborns and of infants up to the age of 6 months was studied using the in vivo skin-window technique according to Rebuck. Using the non-specific stimulation (abrasion of the skin only) a slight age-dependent physiological increase of migration of cells was observed within the observation period; after a strong local irritation with diphtheria-tetanus-pertussis vaccine (Alditepera) there was a vigorous migratory response of cells in the skin lesion. Both quantitatively and qualitatively, the migration pattern (i.e. shift from PMN leukocyte to mononuclear cells in the exudate within a 1 d period after abrasion) was not influenced by immunization of infants with Alditepera, suggesting thus the nonspecific nature of this cellular response. The "normal" values of the chemotactic response of leukocytes of newborns and infants are given as a basis for evaluation of defects of this functional activity of leukocytes.

Age Factors↗
PubMed1979

Detection of thymosin 5 in calf and mouse thymus and in nude mouse dysgenetic thymus.

Thymosin 5 was traced in calf and mouse thymuses by fluorochrome-labelled rabbit anti-calf thymosin. The presence of thymosin 5 or its individual components was found 1. in groups of cortical epithelial cells in calf thymuses and in single cortical epithelial cells in mouse thymuses. 2. In some marginal (blastema) cells of the thymus cortex of calves and 14-day-old mice. 3. In perivascular epithelial cells of the calf thymus. 4. In occasional medullary epithelial cells of the calf and mouse thymus. In all cases there was a marked alternation of entirely negative and positive cell-containing thymic lobuli. In 4 of 13 cases comparatively strong positivity was found in tightyly arranged epithelial cells in an individual acinus in the dysgenetic thymus of nude mice, the positive cases being concentrated among the youngest mice studied.

Animals↗
PubMed1979

Cellular sources of thymic hormone (thymosin) in human thymus.

Antiserum against partially purified calf thymosin (5) was used for the localisation of this complex material in human thymus for comparison with calf thymi. Antithymosine IgG produced with human thymosin 5 by comparative immunoelectrophoresis one line identical with one of the lines of calf thymosin 5. Immunofluorescent evidence suggests the presence of the material in question, which also contains a biologically active principle, mainly in the epithelial cells of the thymus cortex. The contents of the traced material, however, fluctuates substantially between individual thymic lobules.

Animals↗
PubMed1978

Stimulation of fetal spleen cells with lipopolysaccharides.

LPS proved to be good B-cell mitogen for fetal pig spleen cells and induced proliferation as well as differentiation of virgin resting small lymphocytes within 48 hours of cultivation. The LPS-activated lymphocytes and blast-like cells were more intensely labeled with anti-Ig antibodies than control cells, most probably due to an increased density of surface Ig. A lower percentage of LPS-activated cells was found to be labeled with F(ab)2 fragment of anti-L than with anti-L antibodies having an intact Fc fragment. The latter finding suggests non-specific binding of antisera to Fc receptors which appear to be activated on LPS-stimulated lymphoid cells.

Animals↗