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Biomedical subjects

S Raman

Publications and source records attributed to S Raman.

At least 163 records · Page 9Linked to original sources
PubMed1983

Diffuse nonsecretory osteosclerotic myeloma with extensive erythrophagocytosis.

A 51-year-old, black man presented with severe anemia and weakness. X-ray studies showed diffuse osteosclerosis involving most of his skeleton. He was documented to have similar bone changes on x-ray 5 years previously. Peripheral blood findings were suggestive of a myelophthisic anemia. Open biopsy of the iliac bone showed osteosclerotic myeloma. Secretion of abnormal protein could not be demonstrated through many examination of serum or urine. A unique finding at the autopsy was the presence of extensive erythrophagocytosis by the neoplastic plasma cells and macrophages.

Erythrocytes↗
PubMed1983

Steroid modulation of response of plasma bicarbonate concentration to NH4Cl loading: gamma distribution analysis.

Studies have been carried out in awake chronically cannulated adrenalectomized rats subjected to steroid replacement protocols. Our objective was to determine the effects of mineralocorticoid or glucocorticoid or combined replacement on acid-base composition of the extracellular fluid compartment in response to an acute ammonium chloride acid load. We obtained six blood samples from each animal over a 26-h period and, with the help of a specially derived mathematical model, we were able to obtain a continuous dynamic assessment of changes of plasma bicarbonate concentration during induction and recovery of the metabolic acidosis. Assessment of minimum values for plasma bicarbonate concentration, time to reach the minima, and time for 90% recovery showed that dexamethasone did not exert as much protection as aldosterone. The approach we have used, in a sense being a continuous display of plasma bicarbonate concentration, should be useful in further exploring the nature of the interrelations between acid production, net acid excretion, and the resultant plasma acid-base composition.

Adrenalectomy↗
PubMed1979

Loop of Henle bicarbonate accumulation in vivo in the rat.

We have carried out perfusion studies on hydropenic and bicarbonate-loaded rats to provide direct in vivo observations on bicarbonate accumulation in the short loops of Henle. Analysis of early distal tubular fluid was made during bicarbonate-free saline perfusion from the end proximal to the early distal site, documenting accumulation of "new" bicarbonate. During perfusion in hydropenic rats, steady-state bicarbonate concentrations were suggested by early distal values of approximately equal to mM, which were independent of perfusion rate and virtually indistinguishable from bicarbonate concentration measured during free flow when filtered bicarbonate was allowed to enter the loop. Thus, loop bicarconate accumulation was apparently sufficient to allow new bicarbonate to enter at a rate comparable to that delivered to the early distal site during free flow, recognizing of course that free-flow delivery rates are the result of complex components of filtration and bidirectional fluxes. In bicarbonate-loaded rats, however, bicarbonate accumulation rates although higher than in hydropenia, were much lower than free-flow delivery rates. Furthermore, early distal bicarbonate concentrations during bicarbonate loading fell as perfusion rate increased, presumably because of a limitation to increasing ionic bicarbonate entry.

Animals↗
PubMed1979

Student performance in internal medicine: the effect of previous clerkship experience.

To test the assumption that students who have completed other clerkships are likely to perform better in internal medicine, the authors undertook a prospective study of 160 senior students from two classes. Groups of students with little or no senior clerkship experience before their internal medicine clerkship were compared with groups of students who had extensive clerkship experience in disciplines other than medicine. Groups were compared with respect to ward-performance scores and scores on identical multiple-choice examinations. Neither ward-performance nor multiple-choice scores revealed differences attributable to previous clerkship experience. It is concluded that despite areas of instruction and experience which overlap between medicine and other disciplines, previous clerkship experience apparently does not have a beneficial effect on student performance in internal medicine, as measured by these two commonly used methods of evaluation.

Analysis of Variance↗
PubMed1977

Statistical models for renal micropuncture studies.

Statistical issues relating to data analysis of re-collection micropuncture experiments are presented. In the presence of significant animal-treatment interaction, namely, differential response of each animal at different levels of the treatment, the conventional paired or unpaired t testing would not be entirely appropriate. Accordingly, two analysis of variance (ANOVA) models have been derived for the appropriate paired and unpaired designs of micropuncture experiments. Interactive computer programs have been written for both these analyses, and the results are illustrated with experimental data. An example is presented in which the results are statistically significant with paired t testing and by analysis of variance for unequal number of tubules but not when the animal-treatment interaction is included in the analysis of variance model. To investigate linkage in renal transport mechanisms, we propose the use of partial correlation analysis. Experimental results from our laboratory are used to illustrate these techniques.

Analysis of Variance↗
PubMed1977

Specific active immunochemotherapy in lung cancer: a survival study.

A radomized clinical trial of chemotherapy, immunization and immunochemotherapy among 55 patients with stages I and II carcinoma of the lung is reported. The survival rate in the immunized groups was significantly better (P = 0.001) than that in the nonimmunized groups. The results are discussed in the light of the reactivity of the patients to the specific cancer antigen.

Adult↗
PubMed1976

Immunochemotherapy of lung cancer.

After surgical resection of their primary lung cancer, 33 patients were randomized into one of three groups. The first received high-dose methotrexate once per month with citrovorum rescue, for 3 months. The second group were immunized monthly with a homogenate of Freund's complete adjuvant and carefully characterized soluble antigen derived from allogeneic lung cancer cells of appropriate histology, for 3 months. The third group received a combination of methotrexate and immunization monthly, for 3 months. Each patient was monitored immunologically before, during, and after the treatment period, by use of delayed hypersensitivity reactions to recall and cancer antigens, in vitro lymphocyte response to mitogens, and mixed lymphocyte blocking factor activity. The group that received methotrexate showed little change in skin reactivity, a reduction of blocking factor activity, and significant rebound overshoot in in vitro lymphocyte performance. The immunized group showed a tendency to production of blocking factor activity, striking conversion and enhancement of skin reactivity, and little change in in vitro lymphocyte performance. The immunochemotherapy group showed dramatic increases in specific skin reactivity to cancer antigens, up to 2 years after treatment, in vitro lymphocyte rebound overshoot, and reduction of blocking factor activity production. Classic life table analysis of the probability of freedom from metastases in patients with stage-I cancer indicate that the disease-free interval in patients who received methotrexate is longer than in historic and concomitant controls but not as long as in those who received immunization. The best group appear to be those who received combination immunochemotherapy. We emphasize that the small numbers in this pilot study do not yet allow firm conclusions to be made.

Adult↗