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Biomedical subjects

H Koç

Publications and source records attributed to H Koç.

47 records · Page 3Linked to original sources
PubMed1994

Peripheral T cell receptors alpha beta and gamma delta in patients with Hodgkin's lymphoma.

Antigen recognition by T cells is determined by an antigen specific T cell receptor (TCR). Two heterodimeric TCR structures associated with CD3 have been defined: TCR alpha beta and TCR gamma delta. TCR alpha beta and its function are well described but the role of TCR gamma delta in normal and lymphoproliferative disorders is not well established. In newly diagnosed or relapsed/refractory Hodgkin's disease (HD), a disease associated with defective T cell functions and increased sIL-2R, we determined levels of seven TCR alpha beta variable regions [beta V5(a), beta V5(b), beta V6(a), beta V12(a), alpha beta V(a), alpha V2(a)] and TCR gamma delta by using monoclonal antibodies (MCA). TCR gamma delta levels did not show any difference, but several variable regions of the TCR alpha beta differed when groups are compared with each other and the control group.

Adolescent↗
PubMed1993

The clinical correlations of serum tumor necrosis factor-alpha in acute leukemias: a predictor of response and relapse?

The clinical correlations of serum tumor necrosis factor alpha (TNF-alpha), a cytokine which can be released from leukemic blasts, has not been extensively studied. We have analyzed serum TNF-alpha in 20 ANLL, one CML-myeloblastic crisis, and 14 ALL adult patients by using a commercial ELISA kit. Sterile serum samples were taken on day 0, day 7, during remission and relapse with a mean follow-up period of 4.2 (1-19) months. After a median of 7 days following chemotherapy, serum TNF-alpha decreased both in responding ANLL (p = 0.004) and ALL (p > 0.05) but remained high in refractory leukemias. Values on day 7 were significantly different between responding and refractory patients in both ANLL (p = 0.0027) and ALL (p = 0.0099). At relapse, serum TNF-alpha increased starting at a median of 3 months preceding clinical symptoms in ANLL (p = 0.002). However, the relapse of ALL coincided with a slight increase which was not significant (p > 0.05). Together these findings indicate that serum TNF-alpha can be used as an early predictor of clinical response and relapse in ANLL.

Acute Disease↗
PubMed1992

P-glycoprotein expression in refractory hematological neoplasms and circumvention of resistance with verapamil or cyclosporine A containing protocols.

Either p-glycoprotein (pgp) or the encoding gene mdr1 expression has been reported to be correlated with multidrug resistance and poor treatment response. To investigate the incidence of pgp in refractory hematological neoplasms we analyzed malignant cells from 40 patients by an immunoperoxidase method using the monoclonal antibody C219. Pgp was positive in 75% of acute nonlymphoblastic leukemia (ANLL) and 50% of acute lymphoblastic leukemia (ALL). Pgp positivity was similarly distributed in both Tdt (-) and (+) ANLLs (64% versus 100%). Addition of Verapamil (VRP) (12 patients) or Cyclosporine A (CsA) (7 patients) to the previous chemotherapy protocol resulted in complete response in 7 (58%) and 3 (43%) of the patients respectively. Partial response was observed in one patient who received CsA. Both chemosensitizers were tolerated well with few reversible side effects. The preliminary results of this study have been presented in the 15th International Cancer Congress, August 1990 Hamburg, Germany.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Testicular changes in newborn rats exposed to phototherapy.

In this study we investigated the long-term effects of 72-h continuous phototherapy on the reproductive system of newborn rats. The animals' weight, fertilization rates, and number of newborn and histopathological changes in the gonads in a normal group not exposed to phototherapy and in the test animals were compared. At the age of 24 weeks there were no significant differences between the two groups, apart from the histology of the testicles of the male rats who were exposed to the phototherapy. The study group showed a significantly reduced diameter of the seminiferous tubules when compared to the controls (P < 0.001). It can be postulated that phototherapy may cause histological degenerative changes in the structure of the rat's testes, even though there were no changes in fertilization rates. Further studies are necessary to reveal the effects of phototherapy on humans and to determine the effects, if any, on fertility.

Animals↗
PubMedDate not supplied

A case of osteopetrosis with pelvic ectopic spleen: an unusual association.

A three-month-old girl was admitted to the hospital with a history of pallor. On physical examination, the liver was enlarged and a solid mass was palpated in the left abdomen. Laboratory evaluation revealed anemia and thrombocytopenia. Bone marrow was hypocellular with reduced number of megakaryocytes. Radiographic findings and scintigraphic study of the long bones were consistant with osteopetrosis. In the imaging studies, including ultrasonography, computerized tomography, magnetic resonance imaging and scintigraphic study, an ectopic spleen expanded into the bony pelvis was observed. We report here unique case of infantile osteopetrosis associated with pelvic ectopic spleen.

Choristoma↗