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R K Gupta

Publications and source records attributed to R K Gupta.

At least 469 records · Page 26Linked to original sources
PubMed1990

Association between allo-immunoreactive and xeno-immunoreactive subunits of a glycoprotein tumor-associated antigen.

Using allogeneic antibody, we previously described a tumor-associated antigen (TAA) in the urine of 68% of melanoma patients. The TAA was purified from urine of a melanoma patient and used as immunogen to develop a murine monoclonal antibody (AD1-40F4) and xenopolyclonal antibodies in a baboon. Sera from melanoma patients treated with whole melanoma cell vaccine were used as the source of human antibody to the glycoprotein antigen. Treatment with 2-mercaptoethanol and separation by sodium dodecyl sulfate/polyacrylamide gel electrophoresis resolved the high-molecular-mass glycoprotein TAA into smaller subunits. Immunoblot analysis indicates that the murine monoclonal antibody (AD1-40F4) recognized a 90-100-kDa subunit of the antigen while human anti-TAA antibodies primarily recognized a 65-kDa subunit in addition to the 90-100-kDa subunit. Baboon polyclonal antibodies recognized the same subunits plus a 120-kDa subunit. Blocking studies indicated that the murine monoclonal and baboon polyclonal antibodies recognized the closely related epitopes on the 90-100-kDa subunit, while human antibodies recognized an epitope entirely distinct from that recognized by the mouse antibody. These results demonstrate the epitope complexity associated with the high-molecular-mass glycoprotein TAA.

Animals↗
PubMed1990

Immunochemical characterization of a tumor-associated antigen defined by a monoclonal antibody.

A murine monoclonal antibody of the subclass IgG2b, designated MAb JSI, was produced utilizing standard hybridoma technology. Female BALB/c mice were immunized with a fetal antigen that had been partially purified from the spent serum-free culture media of a human melanoma cell line. Utilizing MAb JSI, the antigen was isolated from serum of melanoma patients by affinity chromatography utilizing an acid elution and studied following exposure to trypsin, protease, and heat in an enzyme-linked immunosorbent assay (ELISA). The antigenic activity was destroyed following treatment with trypsin and protease as well as by exposure to heat (100 degrees C). By immunoperoxidase staining, MAb JSI reacted with melanoma, carcinoma, and sarcoma cell lines, but not with cell lines derived from normal skin or lungs. Affinity-isolated antigen was subjected to polyacrylamide gel electrophoresis and stained with Coomassie blue. Under dissociating conditions, a band in the 31,000 to 42,700 Da range was identified that was shown to be reactive with MAb JSI in ELISA. The antigenic determinant defined by MAb JSI appears to be a protein, with expression on a number of malignant tissues.

Animals↗
PubMed1990

Immunogenicity of glutaraldehyde inactivated pertussis vaccine.

The immunogenicity of different types of glutaraldehyde inactivated pertussis vaccine (GIPV) preparations made by inactivation of Bordetella pertussis organisms with different concentrations of glutaraldehyde for variable periods at room temperature and conventional heat inactivated pertussis vaccine (HIPV) was evaluated with regard to production of agglutinins and neutralizing antibodies against pertussis toxin (PT). The different types of GIPV preparations had variable intracerebral mouse potency which depended upon the conditions of inactivation with glutaraldehyde. The agglutinin production in mice against various types of GIPV preparations and HIPV were very similar irrespective of the potency of the preparations. The agglutinins were produced against all the three major agglutinogens 1, 2 and 3 as the preparations were made from B. pertussis strain 10536 (serotype 1,2,3). The titres of agglutinins produced against adjuvanted preparations were slightly higher than those against non-adjuvanted preparations. Neutralizing antibodies against PT were produced for eight out of nine types of GIPV preparations while these antibodies were not produced for conventional HIPV.

Agglutination Tests↗
PubMed1990

Testing of adsorbed diphtheria-pertussis-tetanus (DPT) vaccine for freedom from abnormal toxicity.

A total of 112 samples of adsorbed DPT vaccine were tested in mice for freedom from abnormal toxicity by three procedures: (a) single human dose by intraperitoneal route; (2) single human dose by subcutaneous route; and (3) half the single human dose by intraperitoneal route. The percentage of samples passing by the three methods was 25, 90 and 54.5, respectively. Method 3, which is being recommended now by the World Health Organization, is supported by the results of this study to be neither very stringent nor very lenient to pass the adsorbed DPT vaccine for freedom from abnormal toxicity.

Animals↗
PubMed1990

Role of magnetic resonance (MR) in the diagnosis and management of intracranial tuberculomas.

Thirty-one patients with intracranial tuberculomas were diagnosed on the basis of magnetic resonance (MR) imaging. The diagnosis was confirmed in 30; one case was a false-positive. A total of 44 tuberculomas was found in these patients of which 41 were distributed in the cerebral hemispheres, two in the brainstem and one in the cerebellum. No correlation was found between the type of lesion seen on CT and those seen on MR imaging. CT was negative in one patient with a low brainstem tuberculoma. The final diagnosis was based on the response to antituberculous drug treatment as judged by serial MR imaging in 29 patients and by biopsy in one; and one was false-positive. Thirty-nine tuberculomas, all under 2.5 cm in size, showed complete resolution after 5-8 months of treatment. The remaining five lesions were larger than 2.5 cm; four showed a 50% reduction in size after 12 months of treatment and one was completely excised. Three types of response are described to the treatment with anti-tuberculous drugs. The diagnosis of intracranial tuberculomas can be made more objectively with MR imaging.

Adolescent↗
PubMed1990

Hemodynamic effects of quinapril, a novel angiotensin-converting enzyme inhibitor.

The hemodynamic effects of quinapril, a novel nonsulfhydryl-containing angiotensin-converting enzyme (ACE) inhibitor, were assessed in 10 patients with mild-to-moderate essential hypertension. Compared with placebo, quinapril (20 mg) administered twice daily for 4 weeks significantly lowered blood pressure by decreasing total peripheral resistance without producing tachycardia, an increase in cardiac output, or a rise in plasma catecholamines. Quinapril significantly reduced renal, but not forearm, vascular resistance. Renal blood flow, glomerular filtration rate, and filtration fraction remained unchanged. Left ventricular wall stress was markedly reduced by quinapril, but during the relatively short treatment period, only a nonsignificant trend toward reduction in left ventricular mass was observed. These findings suggest that quinapril is an effective antihypertensive agent that lowers peripheral resistance without increasing cardiac output or disturbing autoregulation of renal hemodynamics.

Adult↗
PubMed1990

Hypertension and peripheral insulin resistance. Possible mediating role of intracellular free magnesium.

To investigate the association of hypertension and insulin resistance, we utilized 31P-NMR spectroscopy to noninvasively assess intracellular free magnesium levels (Mgif) in erythrocytes of normotensive (n = 20) and essential hypertensive (n = 20) subjects given an oral 100 g glucose load. In hypertensive compared with normotensive subjects, fasting glucose and insulin levels were similar, but the integrated insulinemic responses to glucose were 45% greater (312 +/- 13.4 v 215 +/- 7.5 microU/mL, P less than .001). In hypertension, Mgif levels were significantly reduced (183 +/- 9 v 251 +/- 9 mumol/L, P less than .001), and for all subjects were closely and inversely related to systolic (r = -0.77, P less than .001) and diastolic (r = -0.81, P less than .001) blood pressures, and to the integrated insulin response (r = -0.72, P less than .001). Furthermore, while insulin responses were also related to the underlying systolic (r = 0.69, P less than .001) and diastolic (r = .73, P less than .001) pressures, these relations were no longer significant when adjusted for Mgif levels. We hypothesize that hypertension and peripheral insulin resistance may be different clinical expressions of a common abnormal intracellular ionic environment, characterized at least in part by suppressed levels of intracellular free magnesium.

Erythrocytes↗
PubMed1990

Mutagenic potential of permethrin in the Drosophila melanogaster (Diptera: Drosophilidae) sex-linked recessive lethal test.

When permethrin was tested for mutagenicity in Drosophila melanogaster Meigen with the sex-linked recessive lethal test, it was nonmutagenic under conditions of this study. The frequencies of spontaneous mutation for permethrin and the negative control were 0.135% and 0.133%, respectively; the spontaneous mutation frequency for positive control was 12.6%. The difference between the mutation frequency of permethrin and the negative control was not significant.

Animals↗
PubMed1990

Resistance of permethrin to weathering in fabrics treated for protection against mosquitoes (Diptera: Culicidae).

Two different methods of treating cotton and nylon-cotton fabrics with permethrin were evaluated for protection from mosquito bites after laboratory weathering. Cotton fabric treated by the individual dynamic absorption method provided consistently better protection than cotton fabric treated by the aerosol method. The nylon-cotton fabric provided similar protection regardless of the treatment method. After weathering, the toxic effects of both types of permethrin-treated fabrics treated by both methods diminished much more rapidly than did the repellent effect. Low residual amounts of permethrin in the fabrics provided 85% protection from bites against Aedes aegypti (L.) and 93% protection against Anopheles stephensi Liston. Permethrin-treated fabrics were effective in providing protection from mosquito bites for long periods, even after exposure to weathering, and appear to be an effective means of reducing nuisance effects and disease transmission by mosquitoes.

Analysis of Variance↗
PubMed1990

Hemagglutination activities of purified pertussis toxin and filamentous hemagglutinin against erythrocytes from various animals.

The hemagglutinating (HA) activities of purified pertussis toxin (PT) and filamentous hemagglutinin (FHA) were evaluated against unfixed and glutaraldehyde-fixed erythrocytes from ox, goose, horse, monkey, sheep, chicken, and rabbit. Both PT and FHA showed HA activities against fixed and unfixed erythrocytes from all the animals studied. The HA titers of FHA were higher than those of PT. The HA activities of FHA and PT were not destroyed completely even after heating these preparations at 56 C for 30 min. A simple test for the assay of PT in culture supernatants of Bordetella pertussis on the basis of HA activity has been described.

Animals↗
PubMed1990

Iron bound to low MW ligands: interactions with mitochondria and cytosolic proteins.

The iron in the low MW pool of the cell is the precursor of iron in haem and is bound primarily to ATP. This precursor-product relationship suggested that reticulocytes might accumulate ATP-iron if their haem synthesis were blocked. However reticulocytes, treated with succinylacetone or rotenone and taking up iron from transferrin, accumulated iron in nonhaem cytosolic proteins and in mitochondria and not in the low MW pool. This was demonstrated by NMR and also by disrupting the cell with shear stress, separating the cytosol and pellet and fractionating the cytosol with ammonium sulfate. This constancy of the low MW iron pool in the face of blocked haem synthesis could not be explained by saturation of cytosolic ATP or by sluggish exchange of the low MW pool with other compartments. Rather, nonhaem cytosolic proteins and mitochondria appeared to have a higher affinity for iron and to exchange it rapidly with that in the low MW pool.

Animals↗
PubMed1990

Protection against Klebsiella pneumoniae induced lobar pneumonia in rats with lipopolysaccharide and related antigens.

The immunoprotective role of lipopolysaccharide and related antigens from Klebsiella pneumoniae was studied in a lobar pneumonia model developed in rats. Various antigens were obtained by different chemical treatments of the lipopolysaccharide. All these antigens (purified lipopolysaccharide, reduced lipopolysaccharide, lipopolysaccharide--bovine serum albumin complex, and lipid A--bovine serum albumin complex were tested for pyrogenicity and the Shwartzman reaction. The lipopolysaccharide and the various related antigens were pyrogenic and elicited a positive Shwartzman reaction at high concentrations. However, at low concentrations, the same preparations did not show any side effects. All these antigens, on the other hand, were protective against bacterial challenge in Klebsiella pneumoniae induced lobar pneumonia in rats, as the bacterial colonization of lungs in the immunized animals was significantly lower when compared with the controls. The alveolar macrophages from these animals also showed significantly more uptake of Klebsiella pneumoniae as compared with those obtained from control animals.

Animals↗
PubMed1990

Development of 19F NMR for measurement of [Ca2+]i and [Pb2+]i in cultured osteoblastic bone cells.

Lead (Pb) has been shown to perturb cellular calcium (Ca) homeostasis, altering sizes and flux rates of cellular pools of exchangeable Ca and impairing Ca-mediated cell processes. To date, however, a direct effect of Pb on intracellular-free Ca2+ has not yet been demonstrated. Heavy metals bind to the commonly used fluorescent Ca ion indicators with greater affinity than does Ca and thereby interfere with the expected Ca-dependent fluorescence. In this study, the fluorinated Ca ion indicator, 1,2-bis(2-amino-5-fluorophenoxy)ethane N,N,N',N'-tetraacetic acid (5F-BAPTA), and 19F NMR were used to measure the free intracellular Ca ion concentration ([Ca2+]i) in the rat osteoblastic bone cell line, ROS 17/2.8. Both Pb and Ca bind to 5F-BAPTA with high affinity, but the Pb-5F-BAPTA comple produces a 19F NMR signal at a chemical shift distinct from 5F-BAPTA and the Ca-5F-BAPTA complex. The apparent dissociation constants for Pb-5F-BAPTA and Ca-5F-BAPTA are 2 X 10(-10) M and 5 X 10(-7) M, respectively, at 30 degrees C, pH 7.1, and Mg2+ (0.5 mM). Thus, this methodology allows for the simultaneous identification and quantification of free Pb and free Ca ion concentrations. Determinations of [Ca2+]i were based on 19F NMR measurements of 5F-BAPTA-loaded ROS 17/2.8 osteoblastic bone cells that were attached to collagen-coated microcarrier beads. Cells were continuously superfused with freshly oxygenated medium at 30 degrees C. Under these conditions, the [Ca2+]i of ROS 17/2.8 cells was observed to be 128 +/- 14 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗