Biomedical subjects

Ajay Gupta

Publications and source records attributed to Ajay Gupta.

41 records · Page 3Linked to original sources

PubMed2000

Race is a major determinant of secondary hyperparathyroidism in uremic patients.

In the general population, blacks have higher parathyroid gland mass and circulating parathyroid hormone (PTH) levels than whites. This may predispose black patients to more severe parathyroid disease when renal failure develops. Therefore, racial differences in the severity of uremic hyperparathyroidism were examined in a population of patients with end-stage renal disease (ESRD). Among ESRD patients receiving hemodialysis or peritoneal dialysis, two or more values of intact PTH (immunoradiometric assay, pg/ml) obtained at least 90 d apart were available in 1270 prevalent cases (61.1% blacks, 51% males, and 31.1% diabetic), including 466 incident cases with onset of ESRD after 1993. Maximum PTH levels were analyzed as a function of race, gender, age, diabetic status, and levels of serum calcium, phosphorus, alkaline phosphatase, and aluminum. Using a stepwise multiple regression model, the determinants of maximum PTH in the order of their importance were black race, serum phosphorus, absence of diabetes, younger age, serum calcium, and female gender. The maximum PTH levels averaged 641.7 in blacks and 346.0 in whites after adjusting for age, gender, diabetic status, serum calcium, and phosphorus (P < 0.0001). In blacks compared with whites, the odds ratio (95% confidence interval) for adynamic bone disease (maximum PTH <150 pg/ml) was 0.26 (0.17 to 0.41), whereas the odds ratio for hyperparathyroid bone disease (mean PTH >500 pg/ml) was 4.4 (2.10 to 9.25). Race is a major independent determinant of uremic secondary hyperparathyroidism. Among ESRD patients, blacks may be at an increased risk for hyperparathyroid bone disease and whites for adynamic bone disease.

Adult↗

PubMed2000

Optimization of epoetin therapy with intravenous iron therapy in hemodialysis patients.

Iron deficiency limits the efficacy of recombinant human erythropoietin (rhEPO) therapy in end-stage renal disease (ESRD) patients. Functional iron deficiency occurs with serum ferritin >500 ng/ml and/or transferrin saturation (TSAT) of 20 to 30%. This study examines the effects of a maintenance intravenous iron dextran (ivID) protocol that increased TSAT in ESRD hemodialysis patients from conventional levels of 20 to 30% (control group) to those of 30 to 50% (study group) for a period of 6 mo. Forty-two patients receiving chronic hemodialysis completed a 16- to 20-wk run-in period, during which maintenance ivID and rhEPO were administered in amounts to achieve average TSAT of 20 to 30% and baseline levels of hemoglobin of 9.5 to 12.0 g/dl. After the run-in period, 19 patients randomized to the control group received ivID doses of 25 to 150 mg/wk for 6 mo. Twenty-three patients randomized to the study group received four to six loading doses of ivID, 100 mg each, over a 2-wk period to achieve a TSAT >30% followed by 25 to 150 mg weekly to maintain TSAT between 30 and 50% for 6 mo. Both regimens were effective in maintaining targeted hemoglobin levels. Fifteen patients in the control group and 17 patients in the study group finished the study in which the primary outcome parameter by intention to treat analysis was the rhEPO dose needed to maintain prestudy hemoglobin levels. Maintenance ivID requirements in the study group increased from 176 to 501 mg/mo and were associated with a progressive increase in serum ferritin to 658 ng/ml. Epoetin dose requirements for the study group decreased by the third month and remained 40% lower than for the control group, resulting in an overall cost savings in managing the anemia. Secondary indicators of iron-deficient erythropoiesis were also assessed. Zinc protoporphyrin did not change in either group. Reticulocyte hemoglobin content increased only in the study group from 28.5 to 30.1 pg. It is concluded that maintenance of TSAT between 30 and 50% reduces rhEPO requirements significantly over a 6-mo period.

Dose-Response Relationship, Drug↗

PubMedDate not supplied

Change of carpal alignment under anaesthesia: role of physiological axial loading on carpus.

OBJECTIVE: to study the effect of physiological axial loading on the carpal alignment. DESIGN: Patients with distal radial fracture undergoing general anaesthesia for management of their injury were employed for the present study. The contralateral normal wrist was assessed for any change in carpal alignment following the elimination of the physiological axial load under anaesthesia with complete muscle relaxation. BACKGROUND: Axial load across the wrist is known to affect carpal alignment. Axial compression is known to dorsiflex the lunate due to its dorsally thinned wedge shape. However, cadaveric experiments have also shown the axial compression to flex the whole proximal carpal row. METHODS: Lateral radiographs of the uninjured wrist joint were performed in twenty patients with distal radial fracture. Radiographs were taken before and after giving general anaesthesia along with muscle relaxants and were repeated after applying the traction in line with the long axis of the radius. RESULTS: Anaesthesia caused scaphoid and lunate to dorsiflex with no change in scapholunate angle while, traction caused scaphoid to rotate further dorsally. CONCLUSIONS: Physiological axial loading due to the normal tone of the forearm muscles tends to flex the scaphoid and the lunate. This is contrary to the lunate's classical description of its tendency to dorsiflex under axial loading. Our results also failed to support the view that scapholunate interosseous ligament is in continuous tension due to the tendency of the scaphoid and lunate to move in the opposite directions. RELEVANCE: A dorsiflexed lunate need not be considered the hallmark for diagnosing the scapholunate dissociation.

Anesthesia↗

PubMedDate not supplied

Residence time distribution model for soil filters.

Pulse tracer tests were carried out to determine the residence time distribution (RTD) in earthworm-cultured and uncultured, laboratory-scale soil filters. A two-parallel-cell dispersion model for the mixing behavior in soil filters is presented; the model showed excellent fit to experimental data. Results showed a fitted Peclet number of 0.83 to 0.89 for the uncultured soil filter and 0.18 to 0.29 for the cultured soil filter. Results also determined that the cultured soil filter dispersion number (1/Pe) was relatively high, showing the significant effect of earthworms on mixing. Reactor performance data and dispersion model predictions based on present RTD model parameters also reveal good agreement, indicating the usefulness of RTD parameters for describing real situations.

Animals↗

PubMedDate not supplied

Aortoarteritis with systemic lupus erythematosus and secondary antiphospholipid antibody syndrome: a rare association.

A 41-year-old woman diagnosed with aortoarteritis since 1988 was admitted with unstable angina. She also had anemia, thrombocytopenia, aortic regurgitation and pulmonary artery hypertension. She gave a history of recurrent fetal loss and myocardial infarction, following which angioplasty to the left anterior descending artery had been done. After investigation, a diagnosis of aortoarteritis with systemic lupus erythematosus and associated antiphospholipid antibody syndrome was made. Aortoarteritis may coexist with systemic lupus erythematosus and associated antiphospholipid antibody syndrome.

Adult↗