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Biomedical subjects

N Gupta

Publications and source records attributed to N Gupta.

At least 289 records · Page 16Linked to original sources
PubMed1982

Activated partial thromboplastin time after heparin removal (aPTT/HR) in a new scheme of anticoagulant monitoring.

Activated partial thromboplastin time after heparin removal (aPTT/HR), a test employing anion exchange chromatography, was devised as an alternative to the prothrombin time after heparin removal (PT/HR) to monitor simultaneous anticoagulation with heparin and coumarins. The potential utility of the aPTT/HR was assessed by performing parallel PTs and aPTTs on 62 consecutive plasmas from coumarin-treated outpatients. All samples had 0.2 units/ml of heparin added and then removed to see if the maneuver influenced therapeutic group assignment. In no instance did reassignment occur. A conditional Irwin-Fisher test (P = 0.000604) and a special multinomial trial analysis (P = 0.002) indicated that the aPTT would be at least comparable to the PT for following coumarin antithrombotic prophylaxis. Since the heparin removal procedure had no influence on therapeutic categorization, the same statistical proof could be applied to the relationship between aPTT/HR and PT/HR. This study indicates that the aPTT can be used to monitor all stages of heparin and /or coumarin anticoagulation.

Anticoagulants↗
PubMed1980

Estrogen receptors in male breast cancer.

Estrogen receptor assays were performed on tumor specimens from 6 male patients with documented breast cancer. Five out of six (83%) males had positive ER assays with values ranging from 23-384 femtomoles per mg cytosol protein. A review of the literature showed that 32 out of 38 patients (84%) reported were positive for estrogen receptor. Four out of five ER positive males responded to orchiectomy. Estrogen receptors are present in a high percentage of males with breast cancer and may predict response to treatment, similar to female breast cancer.

Adenocarcinoma↗
PubMed1979

Job stress and employee behaviors.

The relationship between four job stresses (role ambiguity, role overload, underutilization of skills, and resource inadequacy) and two employee withdrawal behaviors (absenteeism and turnover) was investigated. The joint prediction of employee withdrawal from measures of job stress and selected backgroundd variables was also investigated. Data were obtained regarding 651 employees in five organizations through personal interviews and company records. Analysis indicated that job stress is related to employee withdrawal behaviors, that prediction of subsequent behaviors is stronger than prediction of prior behaviors, and that the predictive power of job stress and background variables taken together is as strong as, or stronger than, the predictive power of background variables alone. Confidence in the strength of the findings is enhanced by the use of multiple data sources and multiple data points.

Absenteeism↗
PubMed1978

Mass spectral studies of probe pyrolysis products of intact oligoribonucleotides.

Pyrolysis of underivatized homogeneous oligoribonucleotides in the source of a mass spectrometer leads to production of simple mass spectra which resemble the spectra of the bases themselves. It is proposed that pyrolysis occurs by hydrogen transfer to the base moiety followed by elimination of the neutral base. Ionization by electron impact gives rise to the observed spectra. Mixed oligoribonucleotides pyrolyze readily to give spectra of adenine and uracil, but evidence for the presence of guanine and cytosine in mixed polymers and native RNA's is difficult to obtain presumably because of their low vapor pressure. The method may be useful for detection of modified bases in tRNA and for studies of temperature effects on RNA pyrolysis.

Coliphages↗
PubMed1977

Salicylate metabolism in twins. Evidence suggesting a genetic influence and induction of salicylurate formation.

To evaluate the contribution of genetic influences on the individual variation in plateau serum salicylate levels, salicylate metabolism was studied in seven pairs of identical and six pairs of fraternal twins.Under the conditions of this study, after a single i.v. dose (40 mg/kg) of sodium salicylate, the serum salicylate concentration versus time curve approximated a straight line on linear coordinates (appeared approximately zero order). The slopes of the decay curves ranged between 0.64 and 1.02. The intrapair variation for identical twin pairs was significantly less than for fraternal twin pairs (P = 0.044). Likewise pleateau serum salicylic acid concentrations (milligrams/deciliter) and total salicylic acid excretion rate after multiple doses demonstrated significantly less intrapair variation for identical twins than for fraternal twins (P = 0.043 and 0.006). Plateau salicylurate excretion (milligram/kilogram per hour) differences after multiple dosing had a P = 0.067. Michaelis-Menton constant for salicylurate formation and hours to 50% excretion after the i.v. dose were not different when comparing identical and nonidentical twins. Salicylurate formation rates were increased after 3 days of oral therapy, and this induction phenomenon may account for much of the apparent discrepancy between genetic influences on salicylurate formation rates observed after single and multiple dose salicylate administration. This study suggests that the plateau concentration of serum salicylate varies among individuals given the same weight-adjusted dose in part because of genetically determined variations in their metabolism of salicylate.

Adolescent↗
PubMed1975

Correlation of plateau serum salicylate level with rate of salicylate metabolism.

The range of plateau serum salicylate concentrations was 4.4 to 33 mg/100 ml in patients with rheumatoid arthritis after they were treated with 50 mg/kg of aspirin daily for 5 days. Individual plateau serum levels correlated better with urinary excretion rates of the metabolite, salicylurate (whose maximum production is capacity-limited), than with total urinary excretion of salicylates. These observations suggest that large intersubject variations in plateau serum salicylate levels are determined, at least in part, by similar differences in the maximum rates of capacity-limited metabolic reactions. For optimal therapeutic responses, individualization of aspirin dosage by following serum salicylate levels is recommended.

Administration, Oral↗
PubMed1973

Delayed manifestation of ultraviolet reaction in the guinea-pig caused by anti-inflammatory drugs.

1. Exposure of depilated skin of guinea-pig to ultraviolet (u.v.) light for 20 s produces a prolonged inflammatory response.2. The erythaema becomes evident within 15-30 min after the exposure and progressively increases in intensity reaching its maximum by 4-6 hours. The erythaema persists over 24 hours.3. Increase in vascular permeability is biphasic with an early short-lived rise peaking at 0.5 h and a prolonged secondary response peaking at 9-12 h and lasting over 48 hours.4. In presence of aspirin, phenylbutazone and indomethacin, administered prior to u.v. exposure, the inflammatory reaction is partially suppressed, depending upon the dose. The drugs are ineffective in aborting or minimizing the response when given after the inflammation is established. Corticosteroids fail to influence the u.v. inflammation in this test. The significance of these findings is discussed.

Animals↗