Biomedical subjects

O Tosun

Publications and source records attributed to O Tosun.

4 recordsLinked to original sources

PubMed2006

Methylenetetrahydrofolate reductase C677T polymorphism in adult patients with lymphoproliferative disorders and its effect on chemotherapy.

Methylenetetrahydrofolate reductase (MTHFR) is one of the most critical enzyme in folic acid metabolism, and it converts 5,10-MTHF to 5-MTHF. 5,10-MTHF is required for conversion of uridilate to thymidylate. On the other side, MTHFR enzyme causes methylation of homocysteine into methionine, leading to methylation of DNA. Chemotherapeutic agents have different effects, but DNA is the target for most of them. Because folate is the cornerstone in DNA synthesis, we analysed herein if the polymorphisms in MTHFR gene can alter the susceptibility of lymphoproliferative disease risk and if it has an effect on chemotherapy response. One hundred fifty-six patients with lymphoid malignancies and 82 healthy controls were included into the study. Neither gene frequencies nor allel frequencies were found to increase lymphoproliferative disease risk significantly in both overall group and subgroups. Although it was not statistically significant, we found a 2.7-fold increased risk in acute lymphocytic leukaemia (ALL)/Burkitt lymphoma patients with TT genotype [odds ratio (OR), 2.7; 95% confidence interval (CI), 0.88-8.2] than CC genotype but a 1.7-fold decreased risk with TT genotype in diffuse large B-cell lymphoma (DLBCL; OR, 0.58; 95% CI, 0.17-1.88) and a 1.8-fold decreased risk in Hodgkin's lymphoma with TT genotype (OR, 0.55; 95% CI, 0.10-2.87) than CC genotype. The chemotherapy response was analysed in DLBCL, Hodgkin's lymphoma and ALL/Burkitt's lymphoma because these patients received standard chemotherapy protocols. No significant difference was detected between responder and non-responders according to MTHFR T677C polymorphism, but the patients who had TT genotype respond 1.75-fold worse than CC (OR, 0.57; 95% CI, 0.07-4.64) in ALL patients (p=0.59), and in DLBCL, CT genotype revealed a 1.8-fold worse response than CC genotype (OR, 0.54; 95% CI, 0.17-1.7), but TT genotype revealed 2.6-fold better response rates than patients with CC genotype (OR, 2.6; 95% CI, 0.26-26.8). As a conclusion, MTHFR C677T polymorphism does not increase the risk of lymphoproliferative disease, and it does not have an effect on chemotherapy response significantly; however, the patients with TT genotype have a slightly increased risk for ALL, and they also respond worse than CC genotype. TT genotype slightly decreases the risk of DLBCL, and the patients have much favorable response rates.

Adolescent↗

PubMed2006

Brucellar spondylodiscitis: a case report.

Brucellosis is a common zoonosis which still remains as a major health problem in certain parts of the world. Osteoarticular involvement is the most frequent complication of brucellosis, in which the diagnosis of brucellar spondylodiscitis is often difficult since the clinical presentation may be obscured by many other conditions. Herein, we reported an uncommon case of spondylodiscitis due to brucella in an elderly male who had diabetes mellitus and degenerative spinal disease as underlying conditions. The diagnosis was established by using magnetic resonance imaging after the brucella-agglutination test was found to be positive. The diagnosis was also confirmed by positive blood culture. A high degree of suspicion in the diagnosis of brucellar spondylitis is essential to reduce the delay for the treatment. Thus, it should be essentially included in the differential diagnosis of longstanding back pain particularly in regions where brucellosis is endemic. Screening serologic tests for brucella should be used more widely in cases with low index of suspicion, especially in endemic areas.

Aged↗

PubMed2006

The effect of MDR1 (ABCB1) polymorphism on the pharmacokinetic of tacrolimus in Turkish renal transplant recipients.

There is marked interindividual variability in trough blood levels of tacrolimus (TRL) following standard dosing. TRL is a substrate for P-glycoprotein (P-gp), the product of the multidrug resistance-1 (MDR1)(ABCB1) gene. P-gp acts as a membrane efflux pump, which affects TRL absorption from the gut. Some of the single nucleotide polymorphisms (SNP) of ABCB1 gene are associated with pharmacokinetic characteristics of TRL. The objective of this study was to determine the role of ABCB1 C3435T polymorphism on TRL dose requirements, trough values and dose-adjusted trough TRL concentrations among Turkish renal transplant recipients. Renal transplant recipients receiving TRL (n=92) were genotyped for ABCB1. TRL daily doses, trough concentrations, dose-adjusted trough concentrations, demographic features, and clinical data were obtained at 1, 6, and 12 months after renal transplantation. The frequency of the ABCB1 3435 CC genotype was 30.4%, whereas 47.8% of patients were 3435 CT and 21.7% of patients were 3435 TT. TRL daily doses were significantly lower among patients with the 3435 TT genotype at months 1 and 6. At 6 and 12 months after transplantation patients who were homozygous for the ABCB1 3435 CC showed significantly lower dose-adjusted trough TRL concentrations compared with subjects of 3435 TT and CT genotypes. Knowledge of ABCB1 genotype may be useful to adjust the optimal dose of TRL in transplant patients, thereby rapidly achieving target concentrations.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

An unusual case of hydatid disease located in the erector spinae muscle.

We present a case of hydatid disease localized to the erector spinae muscle. A 60-year-old male was admitted to our hospital with back pain. The diagnosis was made preoperatively by US, CT, and MRI. They showed hydatid disease in erector spinae muscle. Cysts and some part of the erector spinae muscle were resected. Postoperatively pathology confirmed the diagnosis.

Back↗