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Biomedical subjects

R K Gupta

Publications and source records attributed to R K Gupta.

At least 451 records · Page 25Linked to original sources
PubMed1991

Non-operative treatment of fractures of the humeral shaft: a comparative study.

Forty cases of diaphyseal fracture of humerus were treated by functional cast bracing (FCB). Results were compared with a series of 25 patients treated by U cast method. Average time taken for union was 7.5 weeks with a range of 5-14 weeks by FCB method. Fractures treated by U cast method took on an average 10 weeks to unite. Stiffness at shoulder and elbow was uniformly found in patients treated by U cast. More than 50% patients had varus angulation less than 5 degrees after treatment by FCB. Only 16% had varus angulation less than 5 degrees by U cast method while 32% had varus angulation more than 15 degrees. FCB is distinctly superior method of treatment for diaphyseal fracture of humerus.

Adolescent↗
PubMed1991

Production of a safe, potent and immunogenic partially purified acellular pertussis vaccine using simple indigenous techniques.

Partially purified acellular pertussis vaccine was prepared from Bordetella pertussis strains 10536, 134, Tohama and 509 using simple indigenously available techniques. The Stainer-Scholte (SS) medium with methylated-beta-cyclodextrin was the most suitable for production of acellular pertussis vaccine. For preparation of the vaccine, 5 day cultures of B. pertussis grown under stationary conditions at 35 degrees C were treated twice with ammonium sulphate and prospective protective antigens were extracted. The extracts contained pertussis toxin (PT), filamentous hemagglutinin and agglutinogens. These extracts were treated with formaldehyde and glutaraldehyde separately for detoxification of PT. The formaldehyde treatment of acellular preparations affected the potency and did not destroy the toxic effects of PT completely. Active PT was found in formaldehyde detoxified acellular pertussis vaccine (FDAPV) preparations by the Chinese hamster ovary (CHO) cell assay, the test for leucocytosis promoting factor (LPF) and the histamine sensitization (HS) test. The FDAPV preparations did not pass the mouse weight gain test (MWGT). The glutaraldehyde treatment had lesser adverse effects on potency than the formaldehyde treatment and the glutaraldehyde detoxified preparations did not show active PT by CHO cell assay, the test for LPF and the HS test. The mice tolerated high doses (up to four human doses) of GDAPV which passed the MWGT showing higher weight gains. Both FDAPV and GDAPV showed immunogenicity against agglutinogens and PT in mice. The GDAPV is a safe and potent vaccine. The total protein content of GDAPV was about 5 times lesser than that of whole cell pertussis vaccine.

Adhesins, Bacterial↗
PubMed1991

Controlled release repellent formulations on human volunteers under three climatic regimens.

Two controlled-release repellent formulations containing 33% (3M) and 42% (Biotek) deet and an Army repellent containing 75% deet were evaluated in 3 different climatic regimens (tropical forested, tropical open and basic hot environments). The 3 repellents provided similar protection for different time periods after application under all 3 climates against Aedes aegypti, Ae. taeniorhynchus and Anopheles stephensi whereas there was no difference in protection period against An. albimanus.

Aedes↗
PubMed1991

Neurocysticercosis in children.

Twenty seven cases (13 male, 14 female) in the age group of 3-12 years with cerebral cysticercosis were studied and followed up to 3.9 years (mean 1.85 +/- 0.91 years). Seizures (partial 76% and generalized 23.8%) was the feature in 21 patients (77.7%) and raised intracranial tension in 15 (55.5%). Five patients (18.2%) had meningoencephalitis, while 4 (14.8%) had obstructive hydrocephalus due to intraventricular cysts in the 4th ventricle. Twenty two patients received cysticidal drugs (praziquantel or albendazole), while 8 had surgical intervention (CSF diversion, cyst removal, subtemporal decompression or extirpation of the cortical cyst). Mortality was 18.2%. Survivors had epilepsy in 18 patients (81.8%), dementia in 2 (9%), mental subnormality in 6 (27.2%) and hyperkinesia in 12 (54.5%).

Adolescent↗
PubMed1991

Clinico-hematological characteristics in patients with kala azar. A study from north-west India.

Clinico-hematological features were analysed in 23 patients with kala azar. Fever and hepatosplenomegaly were the main presenting features. All patients were moderate to severely anemic (Hb 4.3-8.1 g/dl), 17 were leucopenic and 15 were thrombocytopenic. Bone marrow showed moderate to severe megaloblastosis in 11 cases, an increased number of plasma cells in 20 and megakaryocytic hyperplasia with abnormal morphology in 19 patients. Megakaryocyte numbers per smear were significantly increased (p = 0.01) in thrombocytopenic patients as compared to patients with normal platelet counts. Spleen size, Hb level, platelet count and number of plasma cells in the bone marrow were related to parasite load. In general the degree of parasitisation, spleen size and duration of illness correlated with some of the main hematological features. Thus splenic sequestration and ineffective hematopoiesis appear to be the main etiopathogenetic factors in the emergence of bone marrow changes and peripheral cytopenias.

Adolescent↗
PubMed1990

31P NMR and saturation transfer studies of the effect of Pb2+ on cultured osteoblastic bone cells.

The mechanism of lead toxicity at the cellular level remains unknown, although an effect of lead on intracellular Ca2+ has been described. Since bone is a major target for lead, we have investigated the effect of lead on bioenergetic rates and on the intracellular free Mg2+ concentration in cultured osteoblastic bone cells. Using 31P NMR and the saturation transfer technique we have detected a sizable (18%) transfer of saturation from gamma ATP to Pi in a perfused osteoblastic osteosarcoma bone cell line, Ros 17/2.8, and have found a large (greater than 82%) reduction in the Pi----ATP rate upon treatment with 10 microM Pb2+. The NMR-measured unidirectional rate was much greater than the net rate of ATP synthesis through glycolysis and oxidative phosphorylation. By using iodoacetate we investigated the mechanism of the saturation transfer and found that it is catalyzed by the glycolytic enzyme couple glyceraldehyde-3-phosphate dehydrogenase/phosphoglycerate kinase. The net rate of glycolysis as measured by lactate production and that of oxidative phosphorylation as measured by O2 consumption were found to be significantly decreased by 18 and 74%, respectively, with lead treatment. In addition, from the chemical shifts of intracellular ATP resonances, we found a significant reduction of 21% in the intracellular free Mg2+ concentration upon Pb2+ treatment. The observed lead-induced reduction in ATP synthesis/utilization and the decrease in intracellular free Mg2+ may contribute to the impairment of bone formation during lead intoxication.

Adenosine Triphosphate↗
PubMed1990

Effect of lead on parathyroid hormone-induced responses in rat osteoblastic osteosarcoma cells (ROS 17/2.8) using 19F-NMR.

Using 19F-NMR and the intracellular divalent cation indicator, 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid, we have recently demonstrated that Pb2+ treatment elevates the intracellular free calcium ion concentration ([Ca2+]i) of rat osteoblastic osteosarcoma cells (ROS 17/2.8) (Proc. Natl. Acad. Sci. USA (1989) 86, 5133-5135). In this study, we have examined the effects of Pb2+ on the basal and parathyroid hormone (PTH)-stimulated levels of [Ca2+]i and cAMP in cultured ROS 17/2.8 cells. PTH treatment (400 ng/ml) stimulated a 150% elevation in [Ca2+]i from a control level of 105 +/- 25 nM to a concentration of 260 +/- 24 nM. Treatment of ROS 17/2.8 cells with Pb2+ (5 microM) alone produced a 50% elevation in the [Ca2+]i to 155 +/- 23 nM. Pb2+ treatment diminished subsequent elevation in [Ca2+]i in response to PTH administration thereby limiting the peak increase in [Ca2+]i to only 25% or 193 +/- 22 nM. In contrast to the dampening effect of Pb2+ on the peak rise in [Ca2+]i produced by PTH, Pb2+ (1 to 25 microM) had no effect on PTH-induced increments in intracellular cAMP levels. Hence, Pb2+ dissociated the PTH stimulation of adenylate cyclase from PTH effects on [Ca2+]i and shifted the regulation of [Ca2+]i beyond the control of PTH modulation. These observations further extend the hypothesis that an early toxic effect of Pb2+ at the cellular level is perturbation of [Ca2+]i homeostasis.

Animals↗
PubMed1990

Characterization of a 90-100 kDa tumor-associated antigen in the sera of melanoma patients.

Using allogeneic antibody, we previously described a high-molecular-weight glycoprotein in the urine of 68% of melanoma patients. This glycoprotein has been termed urinary-tumor-associated antigen (U-TAA). A murine monoclonal antibody (MAb) specific for U-TAA (ADI-40F4) has been developed. By the use of ADI-40F4, U-TAA was detected in serum samples from 63% (33/52) of stage II and stage III melanoma patients, but from only 5% (1/20) of normal controls. This report describes the physical and immunochemical properties of U-TAA in the serum. The antigen elutes from a DEAE-Sephacel column in association with IgG in the void volume and as free antigen in a second peak. The molecular mass of the free antigen is 590-620 kDa and it sediments in the region of 28-29% sucrose by density gradient ultracentrifugation. Free antigen has an isoelectric point of 6.1. This high molecular weight antigen is composed of smaller subunits linked by reducible bonds. The ADI-40F4 reactive epitope resides on a 90-100 kDa subunit. These results provide evidence that U-TAA which is produced by melanoma cells in vitro is present in the circulation of melanoma patients.

Antibodies, Monoclonal↗
PubMed1990

Detection and isolation of antigen-specific immune complexes from sera of melanoma patients.

Detection of antigen-specific circulating immune complexes (IC) in sera from cancer patients provides an approach for defining tumor antigens that induce a host immune response and could prove useful for purposes of immunoprognosis. In the present study, a sandwich ELISA was developed to detect antigen-specific IC in cancer patients, utilizing a murine monoclonal antibody designated MAb JSI. The MAb was produced by cell fusion using standard hybridoma technology following immunization with a partially purified fetal antigen that had been isolated from the spent culture medium of a melanoma cell line. The partially purified antigen appeared to be broadly expressed on melanomas, sarcomas, and carcinomas. The MAb was mass-produced in pristine-primed mice. MAb JSI reacted with the cultured melanoma cell M14 but not the autologous lymphoblastoid cell L14. Following purification by ammonium sulfate precipitation, the MAb was immobilized on polystyrene plates and utilized to capture antigen-specific immune complexes from sera of melanoma patients which were detected with anti-human globulins. The second antibody in the sandwich was shown to be endogenous human IgG. Antigen-specific immune complexes were present in melanoma patients but only infrequently in sera from normal individuals and patients with active autoimmune disease. Antigen-specific immune complexes detected in melanoma sera were isolated by affinity chromatography utilizing the MAb JSI. The assay described in this report is simple and reproducible, without plate effect (p = 0.97) or time effect (p = 0.34) and could provide a useful new approach to examine the role of antigen-specific circulating immune complex analysis in cancer patients.

Analysis of Variance↗
PubMed1990

NMR measurement of cytosolic free calcium, free magnesium, and intracellular sodium in the aorta of the normal and spontaneously hypertensive rat.

We have utilized multinuclear NMR spectroscopy to examine the relationship between cytosolic free Ca2+ ([Ca2+]in), free Mg2+ ([Mg2+]in) and intracellular Na+ ([Na+]in) levels of the intact thoracic aorta and primary hypertension using the Wistar-Kyoto and Sprague-Dawley rats as controls and the spontaneously hypertensive rat as a model for genetic hypertension. Cytosolic free [Ca2+] was measured using 19F NMR of the intracellular Ca2+ indicator 5,5'-difluoro-1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, free [Mg2+] using the 31P resonances of intracellular ATP, and intracellular [Na+] by 23Na NMR in combination with the extracellular shift reagent dysprosium tripolyphosphate. We have found that both the [Na+]in and [Ca2+]in levels were significantly increased in the hypertensive animals relative to normotensive controls (p less than 0.01). Mean systolic blood pressures (using tail cuff method) of control and hypertensive rats were 123 +/- 8 mm Hg (mean +/- 2 S.E., n = 7) and 159 +/- 6 mm Hg (mean +/- 2 S.E., n = 7), respectively. [Na+]in and [Ca2+]in were 21.9 +/- 6.4 mM (mean +/- 2 S.E., n = 7) and 277 +/- 28 nM (mean +/- 2 S.E., n = 5) for the spontaneously hypertensive rats versus 10.1 +/- 1.8 mM (mean +/- 2 S.E., n = 7) and 151 +/- 26 nM (mean +/- 2 S.E., n = 5) for control rats, respectively. A slight difference observed between intracellular free Mg2+ levels in hypertensives (180 +/- 38 microM, mean +/- 2 S.E., n = 4) and controls (246 +/- 76 microM, mean +/- 2 S.E., n = 4) was not statistically significant (p greater than 0.1). These data indicate alterations in the cell membrane ion transport function of the aortic smooth muscle in primary hypertension.

Animals↗
PubMed1990

Tumor-associated antigen immune complexes. A potential marker of recurrent melanoma.

To determine the potential utility of antigen-specific immune complex analysis, we developed a competitive enzyme-linked immunosorbent assay utilizing polyclonal human antibody to detect tumor-associated antigen-specific immune complexes. Sera from 10 normal volunteers and 19 patients with recurrent melanoma were studied. Patients with recurrent melanoma had a mean +/- SD percent inhibition of 27.6% +/- 29.8% in contrast to normal individuals with a mean value of 8.4% +/- 17.8%. A monoclonal antibody (MAb JSI) was developed following immunization with a partially purified antigen. Utilizing MAb JSI, we developed a "sandwich" enzyme-linked immunosorbent assay and studied sera from 45 normal volunteers and 44 patients with cancer with recurrent melanoma. Results were expressed as a percent maximum binding of a positive control. The mean +/- SD percent maximum binding for normal subjects was 4.9% +/- 7.7% in contrast to sera from patients with melanoma who had a mean of 38.3% +/- 33.3%. Serial analysis of four patients with melanoma with tumor-associated antigen-specific immune complexes demonstrated the presence of tumor-associated antigen-specific immune complexes up to 12 years prior to clinical recurrence.

Adult↗
PubMed1990

magnetic resonance diagnosis of spinal arachnoid cyst. A report of two cases.

Magnetic resonance (MR) findings in one case each of extradural and intradural arachnoid cyst are described. Thoracic segments were involved in both cases. The cysts were slightly more intense than cerebrospinal fluid in both cases on T1 weighted images. The nature and extent of the lesions were better demonstrated on MR images as compared with combined myelography and computed tomography.

Adolescent↗
PubMed1990

Magnetic resonance evaluation of spinal dysraphism in children.

Magnetic resonance (MR) imaging of the spine was performed as the initial imaging technique in 20 children when spinal dysraphism was suspected clinically and plain radiographs showed spina bifida. The correlation with surgical findings indicated that MR provided accurate information preoperatively in all the cases. Some unusual observations in cases with spina bifida cystica and occulta are discussed. It is concluded that plain radiograph and MR complete the preoperative radiologic evaluation of cases with spinal dysraphism.

Adolescent↗
PubMed1990

NMR studies of phosphate metabolism in the isolated perfused kidney of developing rats.

During growth, the capacity for renal phosphate (Pi) reabsorption varies as a function of Pi demand. These changes occur in the absence of changes in extracellular concentration of Pi and are also observed in renal cells cultured in defined media. These findings suggest a direct regulatory effect of intracellular Pi on its transport systems. We postulate that a low intracellular Pi concentration [( Pi]i) occurs in the developing kidney as a consequence of differences in Pi metabolism between growing and mature cells and that a low [Pi]i, in turn, leads to adaptive changes in renal Pi transport. In order to assess this hypothesis, we used 31P-nuclear magnetic resonance (NMR) to measure the intracellular concentrations of NMR-visible Pi and phospho-metabolites and the rates of Pi turnover due to adenosine triphosphate (ATP) synthesis, in isolated perfused kidneys of 3- to 4-week-old and 12- to 13-week-old rats. The [Pi]i was lower (1.7 +/- 0.1 vs 2.7 +/- 0.1 mM, P less than 0.05) in kidneys of growing than of adult rats, while the ATP (2.9 +/- 0.3 vs 2.8 +/- 0.5 mM) and adenosine diphosphate (ADP) (-0.2 mM) concentrations were similar at the two ages, consistent with a high phosphorylation potential in the kidneys of the younger animals. Radiofrequency irradiation of the gamma-P of ATP resulted in reduction in the intensity of the Pi resonance of 62 +/- 5% in the newborn and 38 +/- 3% in the adult (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗