Search PubMed⌕ Search

Biomedical subjects

V Kulkarni

Publications and source records attributed to V Kulkarni.

46 records · Page 3Linked to original sources
PubMed1985

Heterogeneity of erythropoietin-dependent erythrocytosis: case report in a child and synopsis of primary erythrocytosis syndromes.

To investigate the pathogenesis of polycythaemia in a child with isolated, primary erythrocytosis, we measured serum erythropoietin activity and in vitro erythroid progenitor cell responsiveness to erythropoietin. Unstimulated erythropoietin activity was markedly elevated (1.8 IU/ml), and isovolaemic phlebotomy induced a four-fold increment above this level. In contrast to findings in our index case with this syndrome, normal erythroid colony growth patterns were present in patient marrow cultures. The primary mechanism of polycythaemia in this individual is similar to that reported in the index case: an inappropriately elevated regulatory set point for erythropoietin production. Since an additional defect of progenitor cell hypersensitivity to erythropoietin is not always present, we conclude that abnormalities at single or multiple sites of the erythropoietic regulatory axis may occur in primary erythropoietin-dependent erythrocytosis.

Bloodletting↗
PubMed1984

Chromosome analysis of isolated colony erythroblasts in chronic myelogenous leukaemia.

To isolate and karyotype the progeny of erythroid progenitors, we applied colony erythroblasts derived from plasma clot marrow cultures from two healthy adults and two patients with newly diagnosed Ph1+ chronic myelogenous leukaemia (CML) to discontinuous Stractan density gradients. Erythroid colony proliferation by patient cells was increased relative to that of normal donor cells (P less than 0.01). 'Endogenous' colonies appeared in patient but not in normal donor marrow cultures. Greater than 95% of nucleated cells equilibrating at rho greater than or equal to 1.071 were basophilic proerythroblasts. While analysis of chromosome spreads of normal donor cells in this fraction showed normal karyotypes, cells from patient marrow cultures were Ph1+, whether cultured in the presence or absence of added erythropoietin. These findings suggest that chromosome abnormalities of erythroid progenitors may be expressed by their progeny in tissue culture, and that Stractan may be a useful supporting medium for separating colony erythroblasts for chromosome analysis.

Adult↗
PubMed1983

Mechanisms of abnormal erythropoiesis in malignancy.

In order the investigate mechanisms of diminished red cell production in malignancy, we assayed erythroid progenitor cell proliferative responses to erythropoietin in plasma clot cultures of bone marrow cells from 34 cancer patients. Erythroid colony growth by marrow cells of 11 healthy donors (means of 58 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) was similar to that in cultures of cells from patients either with (means of 44 CFU-E and 22 BFU-E derived colonies/6 X 10(4) cells) or without (means of 50 CFU-E and 19 BFU-E derived colonies/6 X 10(4) cells) myelophthisis. Colony formation was normal at all erythropoietin concentrations tested, indicating that both the CFU-E and BFU-E retain normal erythropoietin sensitivity in vitro. CFU-E proliferation correlated negatively (r = -0.56; P less than 0.001) with the level of hemoglobin. In contrast to marrow cell proliferative responses to erythropoietin, serum erythropoietin levels were inappropriately reduced in all 19 patients in whom they were measured, a finding which may be important in the pathogenesis of anemia in patients with cancer.

Carcinoma, Squamous Cell↗
PubMed1983

Platelet-derived growth factor promotes proliferation of erythropoietic progenitor cells in vitro.

To investigate serum requirements for optimal erythropoiesis in vitro, we studied the response of erythroid progenitor cell proliferation in culture to platelet-derived growth factor (PDGF). Human bone marrow cells cultured with platelet-poor plasma-derived serum (PDS) form fewer erythroid colonies than do cells cultured with human whole blood serum or fetal calf serum (P less than 0.05). Treatment of washed platelets with thrombin releases a low molecular weight (less than 100,000) factor that enhances colony growth. This secreted factor appears to be PDGF, based upon the ability of partially purified and electrophoretically pure PDGF to restore colony-forming capacity of PDS-containing cultures to 70-96% of the level found in control cultures with whole blood serum or fetal calf serum. Enhancement of colony growth by PDGF was noted only in marrow cultures supplemented with erythropoietin and PDS. Presence of bioactive erythropoietin in PDGF preparations was excluded by assay in hypertransfused, polycythemic mice, and in fasted rats. Although PDGF stimulates erythroid burst formation in marrow cultures containing optimal concentrations of burst-promoting activity (BPA), it does not influence proliferation of circulating erythroid bursts, regardless of BPA concentration added to culture. We conclude that PDGF is a serum determinant of optimal erythroid progenitor cell proliferation in marrow culture. The activity of PDGF is distinct from that of the apparent erythroid specific growth factors erythropoietin and BPA.

Animals↗
PubMed1982

Correlation of clinical and in vitro erythropoietic responses to androgens in renal failure.

To assess in vitro erythropoietic cultures as a tool to discriminate between patients whose anemia improves with and those whose anemia fails to improve with androgens, bone marrows of 24 anemic patients receiving maintenance hemodialysis in hormone-depleted plasma clots were cultured. While erythroid colony proliferation in the presence and absence of androgens by cells of seven patients with good clinical outcomes who were initially studied was similar to that of normal donors, it was reduced (P less than 0.001) in cultures of cells from seven patients whose clinical responses were ultimately poor. Fewer than 25 colonies/6 X 10(4) cells at optimal erythropoietin concentrations, and less than a 25% enhancement in colony growth by androgens were observed in only those cultures derived from clinical nonresponder marrows. Using these criteria, nine of ten prospectively classified patients (five clinical responders and four nonresponders) were identified correctly.

Adult↗
PubMedDate not supplied

Effect of Y virilin on male infertility.

A prospective placebo controlled double blind study was conducted in patients attending male infertility clinics of our hospital to evaluate effects of a herbal formulation for male infertility--'Y-virilin'. In phase 1 forty patients with oligospermia with or without asthenospermia were randomly allocated to 2 treatment groups--Treatment Group A i.e. formulation under test and treatment Group B (Placebo). Therapy with these agents was given twice a day for 6 months. In phase 2, 12 patients with azospermia were administered either 'Y virilin' or the placebo (n = 6/Gp). In all patients along with semen analysis (sperm count, percentage of motile sperms and grade of motility) was done monthly for 6 months. Serum FSH levels were estimated before and at the end of therapy. A significant increase in sperm count was observed from 2-3 months in oligospermics receiving Y virilin as compared to basal values (p < 0.05). In Group B the follow-up sperm counts were either comparable to basal values or were lesser. However, the percentage and grade of motility did not differ in two groups at the end of respective treatment. No change was found in mean FSH value. During the therapy period incidence of conception was 20% in treatment Group A and 5% in Group B. Of the azospermic receiving 'Y-virilin' 50% showed a count of 10-20 millions/cmm while none from the placebo group. This study highlights the therapeutic potential of the tested formulation in the patients with infertility.

Double-Blind Method↗