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Biomedical subjects

M Tuncer

Publications and source records attributed to M Tuncer.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Cigarette smoking in renal transplant recipients.

Cigarette smoking may adversely influence patient and graft survival. In Europe and the United States the prevalence of cigarette smoking in dialysis patients is 35% to 40% and 25%, respectively. In Turkey, the estimated prevalence of cigarette smoking rate in the normal population is 26%. This study evaluated the rate of smoking in 63 cadaveric, and 158 living-related renal transplant recipients including (150 men, and 76 women of 38 +/- 12 years; range, 8 to 70) who were operated between 1986 and 2001. Demographic data were collected with a questionnaire delivered to patients during their routine outpatient visits. During this time period, 8 patients had died, 4 from hemophagocytic syndrome, 2 from cardiovascular disease, 1 from Kaposi sarcoma and 1 from a cerebrovascular accident. Twenty-three patients have lost their grafts. While at the time of transplantation 97 (42%) were smoking cigarettes, only 29 (12%) continued smoke after transplantation. Male gender significantly correlated with cigarette smoking (P =.000). Twelve smokers were single but 85 out of 97 were married, a statistically significant difference (P =.010). In contrast there was no significant relationship between pretransplant smoking and educational status (P =.354); graft loss and smoking (P =.129); or mortality and smoking (P =.224). There was a significant relationship between pretransplant and posttransplant smoking (P =.000). There was no relationship between pre- and post-transplant smoking and development of diabetes mellitus or hypertension. Interestingly the posttransplant serum albumin level was lower among smokers than nonsmokers (4.44 +/- 0.02 g/dL vs 4.30 +/- 0.02 g/dL; P =.019). There was a close relationship between transplantation duration and smoking.

Adult↗
PubMedDate not supplied

Is there any effect of compliance on clinical parameters of renal transplant recipients?

Noncompliance with regard to diet, medications and routine physician visits is frequently observed among some patient groups. This results in late graft dysfunction and behavior loss. In the present study, we defined compliance as attendance at 80% or more outpatient visits. The study included 63 cadaveric and 158 living-related renal transplant recipients namely, 150 men and 76 women of 8 to 70 years of age (median 38 +/- 12) who were operated between 1986 and 2001. Demographic data, number of visits attended per month, cigarette smoking, and alcohol intake were probed with a questionnaire that was delivered to the patients, 8 of whom died; hemophagocytic syndrome (n = 4), cardiovascular disease (n = 2), Kaposi' sarcoma (n = 1), and cerebrovascular bleeding (n = 1). Twenty-three patients had lost their graft. Compliance among men was lower than among women, a result that trended toward statistical significance (P =.087). Compliance was not related to marital status (P =.297), but tended to increase with educational background (P =.059). Graft loss (P =.546) and aging (P =.509) were not related to compliance. There was no relationship between compliance and mortality rate (P =.526). Interestingly, living-related kidney transplant recipients showed lower compliance than cadaveric kidney recipients, a result that was statistically significant (P =.04). Noncompliance was also related to cigarette smoking during the pre- and posttransplant periods (P =.008 and P =.03, respectively), as well as alcohol intake (P =.000). In conclusion, male gender and living-related donation are related to noncompliance, but (in contrast with literature) not young age, graft loss, or mortality. Compliance increases with educational status of the patients. Smoking and alcohol intake are closely related to noncompliance.

Adolescent↗
PubMedDate not supplied

Influence of tacrolimus plus mycophenolate mofetil regimens on acute rejection rate and diabetes mellitus development in renal transplant recipients.

In this study we investigated the influence of a tacrolimus (TAC) plus mycophenolate mofetil (MMF) immunosuppressive regimen on the acute rejection rate and side effect profile in renal transplant recipients. The study included 80 living-related and 40 cadaveric donor renal transplant recipients (82 men, 38 women) of mean age 35 +/- 10 years (range, 16 to 58) who were operated between August 1999 and September 2002. The mean HLA mismatches was 3 +/- 1 (range, 0 to 5). All patients received prednisolone, MMF (2 g/d for the first 14 days posttransplant and then 1 g/d) plus TAC (0.2 mg/kg/d). They were followed for the development of rejection attacks and side effects. Diabetes mellitus developed in 13 patients (9 men, 4 women; 10.8%). Initially, patients required insulin therapy but after 6 months, 5 recipients no longer needed insulin therapy and were switched to oral hypoglycermic agents and diet control. Hypertension was diagnosed in 58 patients (48.3%). Neither gender nor donor origin (P =.14; P =.79, respectively) produced a significant difference in diabetes mellitus development. Biopsy proven acute rejection episodes were observed in 16 out of 120 patients (13.3%). Six out of 120 patients lost their grafts throughout the study period including one death because of suicide, one because of cytomegalovirus disease and hemophagocytic syndrome, one due to posttransplant lymphoproliferative disease and two to a cardiac arrhythmia. Only one patient lost his graft due to acute accelerated vascular rejection. Biopsy-proven chronic rejection appeared in one patient. In conclusion, although the incidence of insulin-dependent diabetes mellitus during posttransplant 6 months, seems high it decreased to 1.6% upon reduction of the TAC dosage. TAC plus MMF immunosuppression seems effective and safe in terms of acute rejection rates and side effect profiles.

Administration, Oral↗
PubMedDate not supplied

Influence of inflammation on the relation between markers of iron deficiency in renal replacement therapy.

Iron deficiency is an important factor in the management of anemia in both dialysis and transplant patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been considered to be a marker of functional iron stores. In this study, parameters of the iron state were investigated in terms of agreement (assessed by kappa) with the diagnosis of iron deficiency and with inflammation. The study was performed in 38 hemodialysis, 31 continuous ambulatory peritoneal dialysis, and 21 anemic renal transplant patients. CRP and amyloid A protein (AAP) were studied as markers of inflammation. Iron deficiency was defined as ferritin <100 mg/L, TS <20%, or s-TfR >1.76 mg/mL. We observed that s-TfR levels were significantly related to both dialysis duration (r = 0.28 in dialysis and r = 0.60 in transplant patients, both P <.05) and PTH levels (r = 0.23 in dialysis and r = 0.55 in transplant patients, both P <.05). Among the transplant group, ferritin and TS, as well as TS and s-TfR were significantly related (r = 0.84 and r = -0.64, respectively), but not s-TfR and ferritin. Among the dialysis group, ferritin and TS, and also TS and s-TfR, were significantly related (r = 0.35 and r = -0.30, respectively), whereas s-TfR and ferritin were not. In the transplant group, the kappa value for agreement between ferritin and TS in the diagnosis of iron deficiency was 0.76 (P =.006), and 0.33 (P =.04), respectively. Among patients with CRP levels <0.3 mg/L or AAP levels <6.4 mg/L, the relation between parameters of iron state was more robust. The kappa value for agreement between ferritin and s-TfR was 0.49 (P =.006) in the dialysis group and 1 (P =.002) for that between ferritin and TS in the transplant group. Our results suggest that PTH levels may influence s-TfR levels. Discordance between ferritin, TS, and s-TfR as markers of iron deficiency might be explained by the effects of inflammation.

Adult↗
PubMedDate not supplied

Plasma homocysteine levels in renal transplant patients on tacrolimus therapy.

Increased plasma total homocysteine levels afford an independent risk factor to assess cardiovascular morbidity in patients with normal and impaired renal function, including stable transplant recipients. The purpose of this study was to evaluate plasma homocysteine levels and factors known to influence homocysteine metabolism (folate and Vitamin B(12)) in renal transplanted patients treated with tacrolimus. Plasma homocysteine, serum folate and serum vitamin B(12) concentrations were measured in 18 cadaveric renal transplant patients with stable function both before and 3 months after the renal transplantation. While the mean plasma homocysteine level in the renal transplant group was significantly higher than in the control group, no significant change was observed following renal transplantation under tacrolimus therapy (16.84 +/- 6.43 micromol/L vs 16.02 +/- 6.54 micromol/L). The levels of folate before and after transplantation were considerably lower than the control group; a significant effect of tacrolimus has not been observed (7.32 +/- 4.68 ng/mL and 7.55 +/- 5.20 ng/mL). Serum vitamin B(12) levels in the transplant group were significantly lower than the control group; a significant decline was seen 3 months after the renal transplantation (448.94 +/- 230.03 pg/mL vs 334.38 +/- 240.61 pg/mL). Consequently, although plasma homocysteine levels of renal transplant recipients are higher, a lowering effect of tacrolimus therapy was not observed on plasma homocysteine levels. The lower levels of folate and Vitamin B(12) in the transplant group compared to a control group supports therapy with folate and Vitamin B(12) to decrease homocysteine concentrations.

Adult↗
PubMedDate not supplied

Seroprevalence of antibodies to legionella pneumophila in hemodialysis patients.

Patients with chronic renal failure are at increased risk for infections because of impaired cellular immunity. This study was designed to determine the prevalence of antibodies to Legionella pneumophila serogroups 1 to 6 and to evaluate the possible risk factors for Legionnaires' disease in hemodialysis patients. Serum samples to be screened for antibodies against L pneumophila and risk factor data were collected from 252 hemodialysis patients. The overall prevalence of L pneumophila antibodies in hemodialysis patients was found to be 5.16% There was no statistically significant difference between L pneumophila seropositivity and potential risk factors. Further studies are needed to determine possible risk factors for Legionnaires' disease in hemodialysis patients.

Anemia↗
PubMedDate not supplied

Evaluation of the new EMIT tacrolimus assay in kidney and liver transplant recipients.

Tacrolimus (FK506) is a potent macrolide immunosuppressant used for prevention of organ transplant rejection following transplantation. Monitoring of blood tacrolimus concentrations is essential to assess organ rejection and toxicity, because of the agent's narrow therapeutic range, wide inter- and intraindividual pharmacokinetic variability as well as drug interactions mediated by alteration in cytochrome P450. Several methods have been developed to monitor tacrolimus; immunoassays, bioassays, and HPLC/MS. The purpose of this study was to compare two analytical methods: the well-established MEIA II tacrolimus immunoassay using the IMx analyzer and the new EMIT 2000 tacrolimus immunoassay on the Cobas Integra 400 system. Tacrolimus results obtained using the two methods have been compared on 180 whole blood samples from kidney and liver transplant patients. The analytical sensitivities of both methods were defined as 1.2 ng/mL for EMIT and 1.5 ng/mL for MEIA II. The within-run CVs (n = 15) obtained with four-level controls were 9.08%, 9.41%, 5.23% and 4.4% for EMIT 2000. The comparison showed the following relationship between two methods: MEIA = 1.08.EMIT + 0.20 (r =.893). In conclusion, the EMIT 2000 tacrolimus immunoassay is a reliable alternative for the MEIA II method to monitor tacrolimus in organ transplant recipients. It provides a valid quantitative measurement of tacrolimus with comparable % CVs in quality-control as well as patient blood samples. Additionally, the EMIT 2000 method provides a rapid analysis of a large number of samples in one run with a low turnaround time and possibilities to reanalyze critical samples.

Drug Monitoring↗
PubMedDate not supplied

Heterogeneity of 5-HT responsiveness in different segments of rabbit arteries.

The variation in sensitivity to serotonin (5-HT) as assessed by pD2 was investigated in isolated 25 arterial segments of different vascular regions obtained from rabbits. The responses of the vascular rings which were opened by a transverse cut to form rectangular strips were recorded isometrically. pD2 values for 5-HT of thoracic and abdominal aortic segments were significantly greater than those of visceral arterial branches. Maximal contractions produced by 5-HT in visceral segments were higher than those of thoracic and abdominal aortic segments. There was a positive correlation between the pD2 values for 5-HT and the radii and the thickness of the tunica media layer (r = 0.62 and r = 0.54, respectively, P less than 0.05). The results indicate that the activity of 5-HT varies regionally in different segments of the rabbit arteries and the sensitivity to 5-HT of the segments decreases as the radii of the vessels diminish.

Animals↗
PubMedDate not supplied

Ultrastructural findings of bone marrow in a case with malignant osteopetrosis following successful allogeneic bone marrow transplantation.

A nine-month-old female patient suffering from malignant osteopetrosis was evaluated by light and transmission electron microscopic study before and following allogeneic bone marrow transplantation (BMT). Bone marrow specimens were obtained from iliac crest biopsies. Before BMT, the bone marrow had an irregular appearance and was filled with bridging bony trabeculae devoid of cells. Following BMT, the marrow had an almost normal appearance with no myelofibrosis and a relatively regular distribution of hematopoletic cells. The osteocytes were visible in their lacunae in the bone matrix. Presence of bone resorbing and bone forming cell together demonstrated that the bone was beginning to gain its normal dynamic structure. These findings were in accordance with the clinical, laboratory and radiological data which showed the beneficial effect of the therapy.

Bone Marrow↗
PubMedDate not supplied

Autoimmune hemolytic anemia with warm antibodies in children: retrospective analysis of 51 cases.

In this paper, research based on 51 children with a positive antiglobulin test is presented. Eighteen of the children had acute anemia and 33 had chronic anemia. Two clinical patterns were distinguished: an acute transient type and a prolonged chronic type. Corticosteroid therapy was effective in all acute cases but its results were variable in the chronic cases. The acute form was more frequent in young children, while chronic autoimmune hemolytic anemia (AIHA) occurred mainly among children at puberty. In the chronic form of the disease, it was sometimes necessary to add immunosuppressive drugs and in two cases to perform a splenectomy.

Acute Disease↗
PubMedDate not supplied

Influence of temperature on the responses to serotonin (5-HT) in perfused rat lung.

The effects of serotonin (5-HT) on the perfusion pressure of the isolated rat lung was investigated at 2 different temperatures (37 degrees C and 15 degrees C). 5-HT (1-30 micrograms) increased the perfusion pressure dose-dependently and a biphasic vasoconstrictor response appeared with the doses of 3-30 micrograms at 37 degrees C. Both phases were only blocked by methysergide (5 X 10(-10) M) among the 5-HT antagonists tested. At 15 degrees C, 5-HT (0.3-30 micrograms) elicited a similar response but the second phase appeared with the higher doses of the agonist compared to that at 37 degrees C. The initial phase, which was significantly higher than that at 37 degrees C, was antagonized by ketanserin, mianserin, pizotifen and methysergide in a noncompetitive manner. The order of potencies of the 4 serotonergic antagonists was compared with their affinity for central 5-HT receptors. The results led us to conclude that receptors mediating the initial phase of the vasoconstrictor response to 5-HT at 15 degrees C are neither of the 5-HT1 nor of the 5-HT2 type, but are 5-HT1 ones at 37 degrees C in the rat pulmonary vascular bed.

Animals↗
PubMedDate not supplied

The reversal by metoclopramide of apomorphine-induced inhibition of responses to stimulation of the cardioaccelerator nerves in the cat.

The effect of metoclopramide on presynaptic dopamine receptors was investigated in the cat cardioaccelerator nerve preparation. Metoclopramide, a substituted benzamide derivative, antagonized inhibitory action of apomorphine on positive chronotropic responses induced by sympathetic nerve stimulation in cat hearts, in vivo. Neither phentolamine, an alpha-adrenergic blocking agent, nor indomethacin a prostaglandin synthesis inhibitor, antagonized the effect of apomorphine. Apomorphine did not alter the positive chronotropic effects of intravenously administered noradrenaline. Metoclopramide potentiated stimulation-induced positive chronotropic responses. These results suggest that metoclopramide blocks the presynaptic dopamine receptors at the cat heart.

Animals↗
PubMedDate not supplied

Kostmann's syndrome with chronic pneumonia and lymphocytosis: effect of recombinant human G-CSF.

Kostmann's syndrome is a congenital disorder characterized by impairment of myeloid differentiation in bone marrow with severe absolute neutropenia. A 17-month-old girl was admitted to the hospital with complaints of recurrent skin infections since birth and severe pneumonia of the right lung which had been resistant to antibiotics since the patient was eight months old. Anemia, severe neutropenia and maturational arrest of granulocytes at the myelocyte stage in bone marrow were detected. At the age of 20 months, a right pneumonectomy was performed because of resistant cystic infection. Postoperatively, she was diagnosed with Kostmann's syndrome. Recombinant human granulocyte-colony-stimulating factor (rhG-CSF) was administered intravenously at a dose of 3 micrograms/kg/day, gradually increasing to 60 micrograms/kg/day in sequential seven-day courses to obtain a neutrophil count of more than 500 cells/mm3. Absolute neutrophil counts increased to greater than 1000 cells/mm3 at a dose of 60 micrograms/kg/day, and at that time bone marrow aspiration revealed an increase in neutrophilic granulocytic precursors beyond the myelocyte stage. In order to maintain the neutrophil response, a dose of 20 micrograms/kg/day rhG-CSF subcutaneously was continued successfully. The patient has tolerated rhG-CSF treatment without complications, and infectious attacks have significantly decreased.

Agranulocytosis↗