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Biomedical subjects

N Nath

Publications and source records attributed to N Nath.

153 records · Page 9Linked to original sources
PubMedDate not supplied

Antibody to hepatitis B core antigen in blood donors with a history of hepatitis.

Sera and questionnaires from 3,230 prospective U.S. volunteer blood donors were obtained in an earlier study to determine the prevalence of serologic markers of hepatitis B virus (HBV) and hepatitis A virus (HAV) among prospective blood donors with or without a history of either hepatitis or blood transfusion. These sera were reevaluated using a radioimmunoassay for antibody to hepatitis B core antigen (anti-HBc). Anti-HBc in the absence of hepatitis B surface antigen (HBsAg) or its antibody (anti-HBs) was detected in 30 of 1,151 (2.6%) prospective donors with a history of hepatitis, compared to four of 1,086 (0.4%) with no history of hepatitis (p less than 0.001). Although end-point dilution titers of anti-HBc greater than or equal to 1:100 and the presence of IgM anti-HBc were more frequently detected among donors with a history of hepatitis than among donors with no history of hepatitis, the difference was not statistically significant. Unlike a history of hepatitis, a history of transfusion or a history of exposure to persons with hepatitis had no significant association with the detection of anti-HBc in the absence of other HBV serologic markers.

Antibodies↗
PubMedDate not supplied

A simple technique for enhancing the sensitivity of a commercial solid-phase radioimmunoassay for hepatitis B surface antigen (HBsAg).

A simple procedural modification of a commercial solid-phase radioimmunoassay technique resulted in increased sensitivity for detecting HBsAg. The main feature of the modification consisted of agitation of the sample and solid-phase antibody during the first incubation. This was achieved by dispensing the bead and sample into a vial and rotating the vial gently during the incubation period. The modified technique resulted in the detection of HBsAg in the range of 1.0 to 1.2 ng/ml (ay subtype) and 0.16 to 0.38 ng/ml (ad subtype). Samples that were reactive by the rotation technique could be shown to be specific by using an immunological neutralization test. Plasma as well as serum could be tested by the rotation technique and gave comparable results when samples were incubated at 45 C or at room temperature. Three (1.3%) of 227 donor samples containing anti-HBc as the sole hepatitis B marker were specifically reactive for HBsAg by the modified procedure, although no sample was reactive by the standard technique.

Hepatitis B Surface Antigens↗
PubMedDate not supplied

Specificity of an assay for antibodies to hepatitis B surface antigen.

Eight percent of blood donors were found to have antibodies to hepatitis B surface antigen when tested by radioimmunoassay using commercial test kits. Four percent of positive reactions proved nonspecific when tested by the neutralization test using pooled surface antigen. The risks in relying solely on the reactivity in commercial-kit suggested that the specificity of the assay must be confirmed.

Antibodies, Viral↗
PubMedDate not supplied

Enzyme-linked immunoassay for hepatitis B surface antigen. An evaluation of commercial test kits.

A commercial, licensed test for hepatitis B surface antigen (HBsAg) based upon an enzyme-linked immunoassay principle was evaluated. The sensitivity, when tested under field conditions, was 0.65 and 0.9 ng/ml for ad and ay subtypes of HBsAg, respectively. Only 0.03 percent of 61,798 units of blood screened were reactive and specific for HBsAg while an additional 0.01% gave nonspecific (nonneutralizable) reactivity.

Blood Donors↗
PubMedDate not supplied

Use of a control serum containing a low level of HBsAg for monitoring proficiency in screening for HBsAg.

Aliquots of a serum preparation called "run control" containing low levels (1.4 ng/ml) of hepatitis B surface antigen (HBsAg) were tested by four American Red Cross Blood Services regions using a commercial test based on enzyme-linked immunosorbent assay (EIA). The run control was tested a total of 424 and 892 times by procedures A and C, respectively, as recommended by the manufacturer (Abbott Laboratories, North Chicago, IL) of the EIA test kit. Results of all the tests were analyzed and showed that the run control was stable and reliable under field conditions. Illustrative examples of different approaches for the use of the run control in monitoring quality control of HBsAg testing are discussed.

Blood Banks↗
PubMedDate not supplied

Glutathione and its redox system in diabetic polymorphonuclear leukocytes.

The level of reduced glutathione in diabetic polymorphonuclear leukocytes was found to be significantly decreased compared to normal. Although the activity of glutathione reductase remained unchanged, the activity of glutathione peroxidase was found to be decreased in the diabetic state. Ketosis was not found to additionally aggravate the glutathione system. Polymorphonuclear leukocytes obtained from insulin-treated patients showed significant restoration.

Adult↗
PubMedDate not supplied

Sialic acid content and sialidase activity of polymorphonuclear leucocytes in diabetes mellitus.

The level of sialic acid in the diabetic polymorphonuclear leucocytes was found to be significantly reduced as compared to normal. More pronounced effects were observed with ketoacidotic as compared to nonketoacidotic diabetic polymorphonuclear leucocytes. Activity of sialic acid degrading enzyme, sialidase, was found to be increased with more pronounced effect in the ketotic state. Diabetic patients treated either with intravenous insulin or oral hypoglycemic drugs showed restoration to normalcy in both sialic acid content and sialidase activity. The implications of the result are discussed.

Adult↗
PubMedDate not supplied

In vitro effect of certain compounds on the lysosomal release of polymorphonuclear leukocytes.

From studies on the release of acid phosphatase and B-glucuronidase, it was observed that quercetin, a vitamin P like compound and ascorbic acid stablise while dehydroascorbate, acetoacetate and B-hydroxybutyrate labilise the leukocytic lysosomes in vitro. These effects were compared with chloroquine and progesterone, known stabiliser and destabiliser, respectively. The possible mode of lysosomal labilisation by ketone bodies and dehydroascorbate has been suggested.

3-Hydroxybutyric Acid↗