Search PubMed⌕ Search

Biomedical subjects

V Kumar

Publications and source records attributed to V Kumar.

At least 829 records · Page 46Linked to original sources
PubMed1979

Immunosuppression by Friend leukemia virus is H-2 restricted by alloreactive T lymphocytes.

Friend leukemia virus suppresses mitogen-responsive cells in vitro by activating thymus-dependent suppressor cells. The interaction between T suppressor and mitogen-responsive cells is H-2D restricted by a third cell type, called an interfering cell. The interfering cells could be characterized as alloreactive T cells that functionally mature in the spleen at 2 weeks of age and that can be functionally inhibited by mitomycin C, irradiation, and cortisol. Interfering cells are stimulated by H-2D (and not H-2L) alloantigens of the mitogen-responsive cells. H-2D differences between interfering and T suppressor cells are unimportant. Induction of "tolerance" to H-2 alloantigens in semi-allogeneic radiation marrow chimeras resulted in the specific loss of interfering cell function. It is possible that interfering or similar cells participate in other forms of H-2 restriction.

Animals↗
PubMed1979

Mitochondrial antibodies--heterogeneity and effects on mitochondrial respiration.

Sera containing antimitochondrial antibodies (MTA) were tested for binding to intact mitochondria, sonic fragments (SMP), Complex I + III and to oligomycin sensitive ATPase (OS-ATPase) from bovine heart by indirect immunofluorescence. Antigens capable of binding to MTA were present in mitochondria and its fragments tested. Maximum binding was observed with SMP. It appears that one or more antigen binding sites are present on the matrix side of the inner mitochondrial membrane or some location exterior to the inner membrane. Normal human serum or sera containing MTA did not effect the respiration of intact mitochondria or sonic particles. However, NADH-cytochrome c reductase activity of complex I + III was enhanced by 10-60% by sera containing MTA antibodies.

Absorption↗
PubMed1979

Topical induction of delayed hypersensitivity in the bladder.

Delayed hypersensitivity reactions have been elicited by topical application of dinitrofluorobenzene to the bladder mucosa of sensitized dogs and rats. The resultant animal models may be of value in assessing the role of topically induced delayed hypersensitivity in the attempted immunotherapy of bladder cancer.

Adjuvants, Immunologic↗
PubMed1978

Mechanisms of genetic resistance to Friend virus leukemia in mice. IV. Identification of a gene (Fv-3) regulating immunosuppression in vitro, and its distinction from Fv-2 and genes regulating marrow allograft reactivity.

Friend leukemia viru (FV) suppresses the proliferative response of normal lymphocytes to mitogens. The in vitro suppressive effect of FV on lymphocyte mitogenesis is mediated by T-suppressor cells and is under host genetic control. Lymphocytes from strains of mice of the C57BL background (e.g., C57BL/6) are resistant while cells from other strains (e.g., 129 and DBA/2) are susceptible. Genetic analyses utilizing resistant and susceptible parental strains, their F1, intercross and backcross progeny indicated that susceptibility to in vitro suppression is regulated by a single autosomal gene, dominant for susceptibility to suppression. This gene, which is not linked to the H-2 complex, segregated independently of the Fv-2 gene which controls resistance to spleen focus formation in vivo. The gene is also unlinked to the Ir-like genes which regulate the ability of H-2d mice to reject H-2b bone marrow grafts. The gene is therefore designated as Fv-3. Fv-3 may mediate its effect by regulating the numbers and/or functions of T-suppressor cells.

Animals↗
PubMed1978

Extrahepatic portal hypertension: a review of 70 cases.

Among 70 children with extrahepatic portal hypertension, more than 350 episodes of bleeding occurred. Of the 32 children who were not operated upon, six (19%) died of bleeding. Twelve children in the nonoperated group are thriving and well, although six of them have rebled 1-2 times. The operated group of 38 children had a total of 43 procedures. Central splenorenal and cavomesenteric anastomosis prevented further bleeding in 10 of 12 cases in which follow-up is available. Operative mortality was 24%, the majority of which were in emergency procedures.

Adolescent↗
PubMed1978

Mechanism of genetic resistance to Friend virus leukemia in mice. V. Relevance of Fv-3 gene in the regulation of in vivo immunosuppression.

Infection with the Friend murine leukemia virus complex (F-MuLV) suppressed humoral antibody synthesis in vivo and lymphocyte mitogenesis in vitro. Both these effects of F-MuLV were under host genetic control. In vitro suppression of lymphocyte mitogenesis was regulated by a single autosomal gene called Fv-3 that is dominant for susceptibility. Genetic analyses, with the use of the susceptible DBA/2 and resistant B10.D2/n parents, their F1, intercross, and backcross progeny, indicated that a single autosomal gene dominant for susceptibility regulated the in vivo susceptibility to immunosuppression by F-MuLV. Individual [(DBA/2xB10.D2)F1xB10.D2] mice were typed both for susceptibility to F-MuLV-induced suppression of lymphocyte mitogenesis in vitro (an Fv-3 function) and susceptibility to immunosuppression by F-MuLV in vivo. Such an analysis indicated that the same mice that were susceptible or resistant to immunosuppression in vivo were susceptible or resistant to suppression of lymphocyte mitogenesis in vitro. Spearman's rank analysis of the data also indicated that the in vivo and in vitro immunosuppressive effects of F-MuLV were correlated with and not independent of each other. Thus Fv-3, which regulates the effect of F-MuLV on lymphocytes in vitro, also appears to regulate the effect of F-MuLV on antibody-forming cells in vivo.

Animals↗
PubMed1978

Coexistence of bullous pemphigoid and systemic lupus erythematosus.

A vesiculobullous eruption with clinical and histological features of bullous pemphigoid developed in a 28-year-old woman with proven systemic lupus erythematosus (SLE). Serum of this patient contained elevated titers of antinuclear antibodies but basement membrane antibodies could not be detected at first, though they did appear in blister fluid. Normal monkey skin explants cultured on this patient's sera gave positive direct immunofluorescence (IF) at the basement membrane zone (BMZ) for IgG deposits. The use of tissue culture methods may be helpful because of the capacity of this test system to reveal the presence of the antibodies to the BMZ despite the presence of the antinuclear antibodies that appear to interfere with their demonstration in standard indirect IF tests.

Adult↗
PubMed1978

Casein-induced experimental amyloidosis. IX. Alterations in marrow dependent function.

CBA/J mice receiving multiple injections of sodium caseinate (CAS) or bovine serum albumin (BSA) were assayed for marrow dependent functions by measuring their ability (i) to reject bone marrow allografts and (ii) to resist Friend virus (FV)-induced suppression of lymphocyte mitogenesis. Mice that developed amyloidosis following 25-30 injections completely lost the ability to reject allogeneic marrow cells, whereas nonamyloid BSA-treated mice had enhanced rejection of marrow allografts. There was increased resistance to the suppressive effects of FV in spleen cells from 'preamyloid' mice receiving CAS injections and nonamyloid mice receiving 10-40 BSA injections. Amyloid mice appeared to be as susceptible to the effects of FV-induced suppression as control (untreated) animals. These data indicate that alterations in marrow dependent function may be related to the pathogenesis of amyloid disease.

Amyloidosis↗
PubMed1978

Localization of larvae of Metastrongylus apri (Gmelin, 1790) Vostokov, 1905, the lungworm of pigs, in the annelid Eisenia foetida Savigny, 1826.

The first stage larvae of Metastrongylus apri could be recovered from the crop of Eisenia foetida after 24 hours of their infection. These were found invading the calciferous glands of the annelid as early as 48 hours post-infection. The larvae were subsequently found localized in the calciferous glands. hearts, dorsal vessel, anterior part of crop and part of the oesophagus anterior to the calciferous glands of the annelid. In general, the larvae had a preference for the circulatory vessels of the annelid so that great majority of them inhabit in the vascular system and the blood sinuses of the above mentioned organs.

Animals↗
PubMed1978

In vitro activation of suppressor cells from spleens of mice treated with radioactive strontium.

Mice were treated with two 100-muCi injections of 89Sr to deplete marrow-dependent (M) cells. Mice so treated responded normally to immunization with sheep red blood cells (SRBC) in vivo; moreover, spleen cells from 89Sr-treated mice were able to respond to SRBC after infusion into irradiated recipient mice. However, spleen cells from mice treated with 89Sr did not respond to SRBC in vitro and mixtures of normal spleen cells with the latter were also not able to respond in vitro. The discrepancy between in vivo and in vitro responses was abolished by culturing spleen cells for 24 hr before testing their ability to respond to SRBC in the adoptive transfer in vivo. Pretreatment of spleen cells from 89Sr-treated mice with 1000 R of gamma-radiation lessened their suppressive activity. The suppressor cells were detected in spleens of athymic nude mice treated with 89Sr. The suppressive activity, after the 24-hr culture period, was not abolished by irradiation and was active in vivo as well as in vitro. Thus, depletion of M cells by 89Sr results in the appearance within the spleen of thymus-independent suppressor cells, which require a short period of in vitro cultivation before becoming functionally active.

Animals↗