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Biomedical subjects

V Kumar

Publications and source records attributed to V Kumar.

At least 757 records · Page 42Linked to original sources
PubMed1983

Studies in immunodermatology. IX. Effect of organic solvents and enzymes on the reactivity of stratum corneum antigens.

Explants of normal skin fail to react in direct immunofluorescence tests with stratum corneum antibodies. However, upon stripping with cellophane tape, the horny layer of such explants react in tissue culture. Swabbing of skin explants with ether and chloroform converts stratum corneum antigen (SCAg) from a nonreactive to a reactive form. Treatment with methanol, acetone or phosphate-buffered saline failed to bring about such a conversion. Treatment of skin explants with hyaluronidase and phosphilipase A converst SCAg of at least some skin explants to a reactive form. Treatment with trypsin, chymotrypsin and plasmin abolished the reactivity of SCAg upon prolonged incubation. However, upon short incubation with plasmin, SCAg was converted to a reactive form.

Antigens↗
PubMed1983

Possible drug-induced pemphigus-like antibodies with the clinical manifestation of erythema multiforme.

A patient with bullae and target lesions on the extremities and mucous membranes was seen with the clinical picture of erythema multiforme following an episode of pneumonia and a course of penicillin G potassium and tobramycin sulfate therapy. An unusually high titer of intercellular circulating (IC) antibodies was identified in the serum by indirect immunofluorescence (IF) microscopy, but direct lesional IF microscopy study results were negative. These IC antibodies were not true pemphigus antibodies and can best be termed pemphigus-like antibodies. These antibodies were characterized by their ability to fix complement, in contrast to pemphigus antibodies, which apparently fail to do so.

Antibodies↗
PubMed1983

Basics in standardization and practical applications of immunofluorescent microscopy: standardization of antinuclear antibody tests.

ANA tests are, at present, the primary example of the diagnostic use of an indirect IF method. Appropriately standardized and interpreted ANA tests afford the primary sero-diagnostic screening test for certain connective tissue diseases. In the present state of the art of ANA testing, it appears possible to achieve appropriate standardization in up to 70% of laboratories, however, further work remains to be done to achieve a 90% or higher frequency of reliable testing among clinical laboratories for a given antigenic substrate. The present indications for the preparation and use of this and other IF methods assay systems for clinical laboratory studies are as follows: a. For each antigen substrate used for ANA tests, the manufacturers of kits or the laboratories which prepare their own ANA test reagents, should take responsibility for assuring that the sensitivity of their test systems as measured by ANA titers falls in the range expected for that particular antigenic substrate. b. If adequate assurance of the appropriate sensitivity level of a given ANA test system is provided both by their manufacturers and users, then physicians should be supplied with data on the frequencies of biologic false positives for different age groups of males and females as well as frequencies of biologic false negatives for at least the major diseases for which ANA are of diagnostic significance. Part II of this report (Chorzelski et al., in press) presents data on this point. c. Since ANA tests detect a heterogeneous population of antibody specificities, several of which are now recognized as having distinct clinical significance (Tan, 1981), appropriately standardized tests for each of these diagnostically relevant antibodies to identified nuclear antigens needs to be made available to physicians by clinical laboratories. They need to be provided with data on the frequencies of false negatives, biologic false positives and, importantly, with data on the kinetics or dynamics of the relationships between demonstrable immune responses and the clinical manifestation of the diseases. Much of this remains to be done. d. Steps need to be taken toward standardization and evaluation of other immunofluorescent microscopic methods used in clinical laboratories, notably the tests for anti-smooth muscle antibodies (Doniack and Roitt, 1968), the anti-mitochondrial antibodies (Paronetto and Popper, 1976), antithyroid antibodies (Johnson et al., 1965), antibodies to epithelial antigens (Beutner et al., 1979; Beutner et al., 1970) and others, (Hekman, Rumke, 1976; Kaplan, 1976; Rose and Witebsky, 1968; Rule and Genkins, 1976).(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Antinuclear↗
PubMed1983

Natural killer cells in mouse lung: surface phenotype, target preference, and response to local influenza virus infection.

Natural killer (NK) and natural cytotoxic (NC) cells can be recovered from the spleens of mice. NK/NC cells are thought to serve as a first line of defense (before the development of immune responses) against tumor and virus infected cells; therefore organs such as the lung that are exposed to the environment may harbor NK/NC cells. Studies reported in this manuscript characterize a population of pulmonary cells (recovered from collagenase-treated lungs) that exhibited cytotoxic activity against 51Cr-labeled tumor targets in vitro. As with the spleen cell populations, the mononuclear cells from the lung lysed the NK-sensitive target YAC-1 as well as the NC-sensitive WEHI 164.1 tumor cells in vitro. By using flow cytometry, it was observed that 15 to 20% of nylon wool-passed (NWP) lung cells and 5 to 15% of NWP spleen cells from C57BL/6 mice could bind antibody for NK cell alloantigens (NK 1.2, defined by (CE X NZB)F1 anti-CBA sera). Treatment of lung and spleen cell populations with complement and antisera to NK 1.2, asialo GM1, and Ly-5 but not Thy-1 antigens significantly decreased lung and splenic NK (YAC-1) activity. Forty-eight hours after infection of mice by intratracheal inoculation of an infectious dose of influenza virus (PR/8/34) NK activity was stimulated in the lung and not the spleen. Therefore although NK cells in the lung and spleen are similar in antigenic phenotype and target preference there appears to be a pulmonary compartment of natural resistance cells the function of which can be modulated locally. These data are consistent with the hypothesis that the lung contains a separate compartment for NK/NC cells that may participate in the defense mechanisms of the lung.

Animals↗
PubMed1983

Anthropometry of angles of scapula.

Various angles viz. superior, medial, inferior, inferolateral, lateral, acromial and coracoid were studied in 42 scapulae of right side and 54 scapulae of left side. The angles have no correlation to that of opposite side. The correlation coefficient of each angle in relation to other angles on the same side was studied. Some of the angles showed significant correlation to that of the others.

Anthropometry↗
PubMed1982

The photo-gonadal response of a migratory bunting: evidence of an external coincidence system.

Male redheaded buntings (Emberiza bruniceps) were subjected to continuous darkness (DD) or short days (8L/16D) after photo-stimulation (15L/9D) for either 15 or 30 days. Two groups of birds (four each), after photo stimulation for 30 days, were continued on a regimen of 15L/9D. Another two groups (of four each) of photo-sensitive birds were also subjected to DD or 8L/16D; they served as controls. The effect of transfer to DD or 8L/16D on the size of testes was found not the be dependent upon the size attained at the time of transfer. The rate of testicular regression was nearly the same under both the treatments, i.e., in those birds transferred either to DD or to 8L/16D. The birds that were maintained on 15L/9D maintained enlarged testes; this excluded the possibility of the onset of photo-refractoriness during the treatment period. On the other hand, testes were not photo-stimulated in the photo-sensitive birds subjected to DD or 8L/16D. These results are consistent with the Bünning-Pittendrigh avian external coincidence model, but could be explained alternatively by a relatively simple internal coincidence model. Nevertheless, the application of the law of parsimony suggests the acceptance of the hypothesis of the external coincidence model.

Animals↗
PubMed1982

Analysis of low natural killer cell activity in 89Sr-treated mice.

Treatment of mice with the long-lived bone-seeking radioisotope 89Sr results in the selective irradiation and destruction of the bone marrow. This is accompanied by a marked reduction in natural killer cell activity against YAC-1 lymphoma [NK(YAC-1)]. To test for the presence of cellular suppressors of NK(YAC-1) in 89Sr-treated mice, in vitro and in vivo cell mixture protocols were used. In vitro, we did not observe any specific inhibitory effect of spleen cells from 89Sr-treated mice on NK(YAC-1) activity of normal spleen cells. The NK(YAC-1) activity of 89Sr-treated mice, measured in vivo by their ability to clear radiolabeled YAC-1 cells from the lungs, was impaired. However, spleen cells from 89Sr-treated mice, when adoptively transferred with normal spleen cells, failed to inhibit the NK(YAC-1) activity of the latter in the lung clearance assay. Further, when normal spleen cells were injected into 89Sr-treated mice, the ability of the transferred cells to mediate in vivo activity was not suppressed in the 89Sr-treated host. These experiments support the suggestion that the low NK(YAC-1) activity in 89Sr-treated mice is not mediated by suppressor cells, but may be due to the destruction of the marrow microenvironment which is essential for the generation of functional NK(YAC-1) cells.

Animals↗
PubMed1982

Beliefs and practices of urban mothers regarding "hot" and "cold" foods in childhood illnesses.

Beliefs and practices of 100 urban mothers regarding "hot" and "cold" foods during four common childhood illnesses were determined by using a pretested, partly structured interview schedule. Egg, by 60% of mothers, mango by 52%, lentils by 49%, jaggery by 46% were considered "hot" properties. "Hot" foods were preferred and "cold" foods restricted in the treatment of cough and cold and illnesses with rash. In diarrhoea, "cold" foods were preferred and "hot" foods restricted. The knowledge that many food combinations and certain procedures are believed to change the properties of common food may be utilized in promoting the consumption of nutritionally balanced diets. Introduction of culturally acceptable education in nutrition which incorporates the above knowledge is likely to help in the prevention of protein-energy malnutrition and to increase parental co-operation during therapy.

Abdomen↗
PubMed1982

Surface projection of arterial segments in the human kidney.

Study of intrarenal arterial segments of human kidney by the corrosion cast method has been carried out on 100 kidneys obtained within 24 h of death. The five arterial segments which are normally described, namely, apical, upper, middle, lower and posterior, were reduced to four in 46% of the kidneys due to either absence of the apical segment or fusion of the upper and middle or middle and lower segments. The number of segments was very rarely (1%) reduced to three due to the absence of the posterior and apical segments. The apical segment was absent in 15%. The upper and middle segments were combined in 14% and the middle and lower segments in 17%. The surface projections of different segments were variable depending upon the intrarenal branching pattern of the segmental arteries.

Arteries↗