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Biomedical subjects

D Oth

Publications and source records attributed to D Oth.

At least 55 records · Page 3Linked to original sources
PubMed1983

Cell-surface antigenic modifications with trinitrophenyl sulfonate versus trifluoromethyl-dinitrophenyl sulfonate.

The aim of the work was to justify the use of trifluoromethyl-dinitrobenzene sulfonate (CF3-DNBS) modification rather than trinitrobenzene-sulfonate (TNBS) modification, so as to be able to take advantage of the presence of fluorine atoms in the analogue, which allow the analysis of the hapten-carrier bonds by 19F-NMR nuclear magnetic resonance. Cell-surface antigenic modifications brought about by exposure to TNBS or CF3-DNBS were found to be immunologically cross-reactive, both in cell-mediated lymphocytotoxicity and in indirect immunofluorescence. The extent of haptenic derivatizations was found to be of the same order of magnitude, as appraised both by quantitative-absorption studies or by using radioactive hapten, provided that the less chemically reactive CF3-DNBS was used at the concentration of 10 mM and TNBS at the concentration of 1 mM. However, only TNBS-modified cells were sensitive to destruction by antibody-plus-complement-mediated cytotoxicity.

Animals↗
PubMed1983

[Visualization of different types of hapten-cell membrane interaction by fluorine high-field nuclear magnetic resonance].

Using a high field spectrometer (5.9 Tesla) 19F-NMR spectrum of soluble material from 4 trifluoromethyl 2,6 dinitrobenzene sulphonate (CF3-DNBS) treated murine lymphocytes was recorded. CF3-DNBS is a fluorinated analog of 2,4,6 trinitrobenzene sulphonate (TNBS), and these compounds have been found to create cross-reacting antigenic modifications of cell surface. At least 4 distinguishable signals have been detected, and we think that 19F-NMR could be used to study, at a molecular level, some immunochemical problems concerning modification with TNBS.

Animals↗
PubMed1982

Differential variations of sensitivities of TNP-modified lymphoma cells to lysis by cytotoxic lymphocytes and by antibodies.

Cultured RDM4 cells were modified with 1 mM trinitrobenzene sulphonate (TNBS) and assayed for lysis by either in vitro generated cytotoxic T-lymphocytes (CTL) or complement-mediated humoral immunity. It was observed that cells harvested from the exponentially growing phase culture (as assessed by an important incorporation of thymidine) were more sensitive to CTL, but less sensitive to humoral immunity, than cells harvested from resting phase culture. Radiolabelled [14C]TNBS permitted to show that exponentially growing cells bound about 5 times less TNBS than cells at the resting phase. It is therefore concluded that the efficiency of the CTL on TNP-modified cells is not proportional to the density of TNP-groups on the targets, and that CTL on the one hand, and complement-mediated humoral immunity on the other hand, must have very different cell surface requirements to be able to lyze the targets.

Animals↗
PubMed1982

A genetic study of serum levels of cobalt-activated acylase among susceptible, resistant and semiresistant strains of mice with experimental viral hepatitis.

Cobalt-activated acylase (Co-A) and transaminase activity were determined in the serum of A/Jax, DBA/2 and C3H mice several days after an intraperitoneal injection of 1,000 lethal doses of murine hepatitis virus type 3 (MHV3). A significant rise in the enzyme activity was observed 1 day after the injection, followed by a decrease on day 2. In the case of the genetically resistant A/Jax strain, the Co-A level regularly decreased to reach normal values on days 7-8. On the contrary, among the fully susceptible DBA/2 strain mice (all dead on day 5), a second rise in acylase (Co-A) level was observed on days 3 and 4, much higher than the day-1 values. Among the mice of C3H strain, which is recorded as 'semi-susceptible', some individuals behaved like the susceptible DBA/2. The comparison of serum acylase activity with other liver function tests showed a correlation between Co-A and transaminases (ALT and AST) with C3H and DBA/2 strains, but no correlation with A/JAX resistant strain. gamma-Glutamyltransferase was not detectable in the serum of different strains during the time of experimentations. Our results suggest that Co-A activity correlates with the clinical course, and that Co-A is a sensitive indicator enzyme in the early phase of viral hepatitis.

Aminopeptidases↗
PubMed1981

Spontaneous maze ambulation in two mouse strains.

A simple device is described, which permits us to quantify several parameters of spontaneous behaviour of small animals. Using this device with mice we obtained statistically satisfactory results, showing a strong genetic influence on the behavioural characteristics tested.

Animals↗
PubMed1979

Genetic study of mouse sensitivity to MHV3 infection: influence of the H-2 complex.

Genetic study of acute and chronic mouse hepatitis virus type 3 disease was carried out in segregating generations of a cross involving a susceptible (C57BL/6) and a resistant (A/J) mouse strain. The data obtained indicate that one or two recessive genes may be involved in resistance of acute and chronic diseases but suggest that the genes involved in both diseases are different. In this cross, no correlation was observed between H-2 and acute or chronic disease. In mice of congenic lines, however, A/Sn (H-2a), A.SW (H-2s), A.BY (H-2b), and A.CA (H-2f), it appeared that the presence of the H-2f allele conferred to heterozygote as well as to homozygote animals the capacity to resist the development of chronic disease. It seems, therefore, that MHV3 sensitivity in mice is under the influence of at least two major genes: one for the acute disease and the other, H-2 linked, for the chronic disease.

Acute Disease↗
PubMed1978

Further studies on the H-2 linked dependence of the adjuvant action of Brucella abortus.

The B 19S strain of Brucella abortus is found to act as an adjuvant to the anti-sheep red blood cell (SRBC) reaction in some congenic strains of mice but not in others. If the recipient is H-2b, there is no adjuvant effect (B 19S); neither is there (thymus-dependent anti-B 19S reaction as measured by thymocyte activation and change of electrophoretic mobility. In contrast, there is a thymus-independent anti-B 19S reaction (production of haemagglutinins) as good in the H-2b mice as in the others. Experiments with T cell deprived mice show that the adjuvant action of B 19S is thymus-dependent. As the anti-SRBC reaction without adjuvant is also thymus-dependent, it is difficult to distinguish anti-SRBC and anti-B 19S reactions from the adjuvant action of B 19S on the anti-SRBC reaction. Several explanations are possible, all involving H-2 (Ir?) controlled thymus dependent mechanisms.

Adjuvants, Immunologic↗
PubMed1977

Influence of milk source on transplantability of histocompatible mammary tumours in mice.

It is confirmed that C3H mammary tumours are much more easily transplantable in histocompatible recipients when these have been reared on C3H milk, than when they have been reared on milk from the inbred Swiss/B strain. By contrast, A.CA mammary tumours transplanted in histocompatible hosts reared on A.CA or Swiss/B milk, grow almost equally well in both sorts of recipient. Thus, rearing on Swiss/B milk has different effects on the transplantability of mammary tumours of C3H and A.CA. On the other hand, recipients which were reared on C3H or A.CA milks accept grafts of C3H mammary tumours about equally, suggesting that milks from A.CA and C3H have the same effect on the transplantability of C3H mammary tumours. The different action of Swiss/B milk on tumours of C3H and A.CA seems best attributed to differences between C3H and A.CA tumours or between mouse strain genotypes. By contrast, the transplantability of C3H mammary tumours is significantly changed when the recipients were reared on milk from the RIII strain instead of C3H. These facts suggest that the milk from RIII has an action which differs from that of both C3H and A.CA in this respect. The data are discussed on the basis of a differential tollerance-inducing action of mammary tumour viruses (MTVs) which infect C3H, A.CA and RIII, and have an important role in tumour induction.

Animals↗
PubMed1976

The action of various sera on colony formation and DNA synthesis of murine thymocytes in culture.

Murine thymus cells were caltivated up to 10 days in a semi-solid medium. Both macroscopically visible colonies and DNA synthesis (identified by 3H-thymidine incorporation) were counted with and without added sera. According to their origins the sera exerted different modifications of the cultivated cells behaviour. Changes of colony number and of thymidine incorporation were quite independent on each other.

Animals↗
PubMed1976

Cellular reaction induced by "nonantigenic" substances.

A previously designed isotopic in vivo method for measuring delayed hypersensitivity was used with nonantigenic (or weakly antigenic) phlogogenic substances. A strong reaction was observed in some circumstances, witnessing the fact that the method has a specific and a nonspecific component. The reaction is drastically augmented by a mild whole-body irradiation of the reacting animals. In the case of the studied substances (carbon, oil and bentonite) the reaction is bound by polymorphonuclear neutrophils (PMN), but it was found to be independent of the number of circulating PMN in the blood.

Animals↗
PubMed1976

Current questions on the tumour-associated antigens of chemically-induced tumours II. In search of practical uses.

With special reference to tumours which were chemically-induced in animals, we present a brief review on the applicability of the results obtained, as to immunoprophylaxis and to immunotherapy. A search is made onto what are the mostly representative animal models for human studies. From the present available data, experimental chemically-induced bladder and colonic tumours seem to be the "best" models for human counterparts.

Animals↗