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Biomedical subjects

M Yilmaz

Publications and source records attributed to M Yilmaz.

At least 73 records · Page 4Linked to original sources
PubMed2000

Palliative decompression of obstructive hilar malignancies utilizing an extrahilar biliary approach.

Hilar cancers carry a dismal prognosis. Palliation of obstructive jaundice in patients with hilar cancer can be achieved by either surgical or nonsurgical means. Selection of the appropriate palliative measures is a challenging problem. Segmental bilioenteric anastomosis procedures were performed on 19 patients with hilar cancer. Seventeen of the bypasses were done to the segment III duct, known as the ligamentum teres approach, and two bypasses were to the segment V duct. Five patients, who had already been stented percutaneously or endoscopically, were operated on after the stents were clogged and a duodenal obstruction ensued. There were two postoperative deaths (10.5%) and four postoperative complications (21%). All of the 17 surviving patients experienced improvement in the level of jaundice postoperatively and the levels of serum total and direct bilirubin decreased by 78.9% and 84.2%, respectively. Two patients developed late cholangitis before death and were treated by external biliary drainage; one developed duodenal obstruction and was treated by gastrointestinal anastomosis. The mean length of hospital stay was 15.2 days. Mean survival was 8.2 months and the mean period of well-being was 7.8 months. Median survival was 7 months and median period of well being was 7 months. Three patients are still alive at 8, 8, and 24 months. These data suggest that the ligamentum teres approach offers effective palliation for patients with unresectable hilar cancer.

Adult↗
PubMed2000

Correlation between atopic diseases and tuberculin responses.

BACKGROUND: In recent decades, the prevalence of atopic diseases has risen steadily in developed countries. The reasons for this increase are not clear. It has been hypothesized that a reduction in infections and immunization programs may contribute to the increase in the prevalence of atopic diseases. We investigated the relationship between tuberculin response and atopic disease. METHODS: A total of 538 (73.0%) atopic and 198 (27.0%) nonatopic children vaccinated with BCG were included in the study. All the children included in the study had neither been given BCG nor tuberculin skin-tested in the previous 6 months, nor did they have a condition known to cause anergy. All the children were given five tuberculin units PPD, and PPD indurations were recorded after 48 h. RESULTS: The PPD induration size was 6.8 +/- 5.6 mm (mean +/- SD) in atopic children and 7.4 +/- 5.9 mm in nonatopic children. The difference between the two groups was not significant (P > 0.05). The PPD induration sizes of children with asthma, rhinitis, and atopic dermatitis were found to be similar. The children with atopic dermatitis had lower PPD induration size, but this was not statistically significant (P> 0.05). The rates of negative (< 5 mm skin induration) and intermediate (5-9 mm) responses were 32.6% and 30.5% in atopic children and 30.2% and 32.4% in nonatopic children, respectively. Positive tuberculin responses (PPD > 10 mm) were recorded in 36.9% of atopic children and 37.4% of nonatopic children. Total serum IgE levels of atopic and nonatopic children were 623.35 and 46.78 IU/ml, respectively. There was no correlation between serum total IgE level and PPD induration size (r = - 0.0012, P = 0.737). CONCLUSIONS: We did not find any relationship between tuberculin response and atopy status later in life in BCG-immunized subjects. We need further studies to clarify the effect of BCG on the development of atopy.

Adolescent↗
PubMed2000

TP53 mutation is an independent prognostic marker for poor outcome in both node-negative and node-positive breast cancer.

TP53 gene-mutation and protein expression of p53 are described as being of prognostic importance for the outcome of breast cancer. The present study was therefore carried out to evaluate whether TP53 mutation would be a feasible prognostic marker in the routine diagnostic evaluation of breast cancer, and, in particular, to analyse the relationship between TP53 mutation and nodal status. Tumour material was obtained from women with sporadic early breast cancer. Gene mutations in exon 2-11 were identified using denaturing gradient gel electrophoresis (DGGE) as the initial scanning procedure and characterized by sequencing. All patients were treated according to the guidelines of the Danish Breast Cancer Cooperative Group for the DBCG 89 protocols. The results were correlated with clinico-pathological parameters and the prognosis evaluated by uni- and multivariate analysis using local control, freedom from distant metastasis, disease-free survival, and overall survival as endpoints. The study included 294 patients. TP53 mutations were found in 23% of cases. Mutations were significantly more frequent in tumours from patients who were node-positive and with tumours characterized as being ductal, large of size, with a high degree of anaplasia, and oestrogen receptor negative. Using univariate analysis, it was found that distant metastasis, disease-free, and overall survival were correlated to tumour size, nodal status, degree of anaplasia, oestrogen receptor status, and TP53 mutation. In addition, overall survival was also correlated to age and menopausal status. When analysed according to nodal status, TP53 mutation was found to have a significantly poor survival probability in each of the subgroups. A Cox proportional hazard analysis, including all 294 patients, demonstrated that positive nodal status and TP53 mutation were the only parameters that had an independent poor influence on the risk of developing distant metastasis and reduced recurrence-free survival. The same factors together with postmenopausal status were found to be significantly associated with increased risk of death. TP53 mutation is a strong marker for the prediction of overall and disease-free survival in breast cancer, irrespective of nodal status. A better understanding of the role of the p53 pathway, including analysis of different types of TP53 mutations, is required in order further to investigate the prognostic potential of this marker.

Adult↗
PubMed2000

Secondary epispadias repair with rectus abdominis musculocutaneous flap.

Genital defects in patients with epispadias cause functional, aesthetic, and psychological problems. Successful reconstruction of epispadias should improve the body image and enable the patient to perform sexually. Although various operative techniques have been defined for reconstruction of epispadias--predominantly using local tissue flaps--classic reconstructive methods are sometimes not sufficient in severe cases. Secondary reconstruction is inevitable after failed reconstructive attempts with classic techniques. The authors used the rectus abdominis musculocutaneous flap for severe secondary epispadias repair. The urethra, dorsal chordee, osteo-escutcheon contour defect, and the tissue defect created after dissection of the dorsal surface of the penis were reconstructed successfully using the rectus abdominis musculocutaneous flap. The neourethra was constructed using the skin island of the flap, and the muscle segment was used to reconstruct the dorsal defects. A straightened and lengthened penis and a new urethra without stricture were created during one operative procedure using this method.

Adult↗
PubMed2000

Investigation of perfusion reserve using 99Tc(m)-MIBI in the lower limbs of diabetic patients.

This study aimed to investigate the microvascular pathology in the lower limbs of diabetic patients without symptoms or findings of peripheral ischaemia by measuring perfusion reserve scintigraphically. It was carried out in 47 female subjects who had no evidence of peripheral arterial disease in their history, physical examination or Doppler ultrasonography. The diabetic group consisted of 25 women (mean age 54.2 +/- 3.54 years) with type II diabetes mellitus of more than 10 years' duration. A control group consisted of 22 healthy non-diabetic women (mean age 50.14 +/- 6.75 years). Each subject flexed their right foot maximally both dorsally and plantar 60 times. In the middle of this exercise, 370 MBq technetium-99m-methoxyisobutylisonitrile (99Tc(m)-MIBI) was injected intravenously. Ten minutes after the injection, a posterior image of both calves was obtained using a gamma camera. Rectangular regions of interest were symmetrically drawn over both calves. The total count in the resting calf was subtracted from the total count in the exercising calf, and the percentage increase, termed the perfusion reserve, was determined. A significant difference was found between the perfusion reserves of the diabetic and control groups (76.04 +/- 12.96% and 95.91 +/- 12.83%, respectively; P<0.001). In conclusion, microvascular pathology may be determined scintigraphically by measuring the perfusion reserve in the lower limb muscles in diabetic patients. This method may also be used to evaluate perfusion abnormalities in other circulatory disorders.

Diabetes Mellitus↗
PubMed2000

Heterogeneity in the clinical phenotype of TP53 mutations in breast cancer patients.

TP53 mutation is a strong independent marker for survival in breast cancer with some heterogeneity in the clinical phenotype of various types of mutations. Based on 315 patients with breast carcinoma, we suggest a new model for the differentiation of TP53 mutations. Although TP53 mutation in general was associated with aggressive tumor/patient characteristics, missense mutations outside any conserved or structural domain did not affect the clinical outcome (risk of disseminated disease and death). In contrast, patients with missense mutations affecting amino acids directly involved in DNA or zinc binding displayed a very aggressive clinical phenotype. Null mutations (including missense mutations disrupting the tetramerization domain) and the remaining missense mutations displayed an intermediate aggressive clinical phenotype. When patients with primary early breast cancer were divided into three groups (wild-type together with missense mutations outside structural/conserved domains, null mutations and missense mutations with intermediate clinical phenotype, and very aggressive missense mutations), disease-specific survival rates were 89%, 58%, and 35% (5-year actuarial values, P < 0.0001), respectively. In a Cox proportional hazards analysis, separation of TP53 mutations according to these criteria eliminated the prognostic importance of all investigated classical factors except nodal status.

Alleles↗
PubMed2000

Isolated cardiac metastasis of osteosarcoma.

Osteosarcoma metastasis to the heart caused by tumor thrombosis is very rare. A 7-year-old girl with an osteosarcoma of the right humerus, refused the treatment, at first, then, 1 year later, referred to the hospital with metastasis to the heart. The mass invading the pulmonary arteries was successfully removed with open-heart surgery.

Biopsy, Needle↗
PubMed1999

Investigation of metabolism and perfusion in arterialized venous replantation: experimental study in rabbits.

Replantation of amputated digits at distal levels is difficult because the vessels are either too small or absent in the amputated part. Clinically unconventional anastomoses have been tried in such instances. Arterialization of the venous system in the amputated part was also utilized for this purpose. In this study, a digital replantation model utilizing the amputated rabbit ear was used to evaluate the survival, metabolism, and perfusion of unconventionally replanted parts. Mean survival areas were measured and perfusion studies with technetium 99m, blood gases, pH, blood glucose and lactate levels, tissue glucose and lactate levels, and histological evaluations were performed. Surviving areas did not reveal a significant difference. Perfusion of the arterialized venous replants were not as good as the conventionally replanted ears. The blood glucose and lactate levels in the afferent vein were initially near normal arterial levels but almost reached normal venous levels in the samples taken 24 hours after the arterialized venous replantation. Tissue glucose levels were lower than the conventionally perfused tissue, and the lactate levels were higher, but these two metabolite levels were normalized in later samples. The results of the metabolic and perfusion studies are interpreted to elucidate the survival mechanisms in the arterialized venous replants. As a result, arterialized venous replantation may be supported by the favorable results of metabolic and perfusion studies in our experimental model.

Animals↗
PubMed1999

A new semiquantitative method for comparing brain tumor uptake of Tc-99m sestamibi and TI-201.

PURPOSE: We describe a new method for measuring brain tumor uptake of TI-201 and Tc-99m sestamibi (MIBI) that permits the semiquantitative comparison of tracer uptake to yield comparable "tumor bulk" ratios. We tested this method in patients treated recently and remotely with chemotherapy to determine if this method could identify differences between these two patient groups. METHODS: Eleven patients with high-grade astrocytoma underwent TI-201 and Tc-99m MIBI SPECT. Each patient received 5 mCi TI-201 intravenously followed by SPECT using a dual-head gamma camera. This was immediately followed by an intravenous injection of 20 mCi Tc-99m MIBI and repeated SPECT. Four patients had recent therapy (from 1 day to 6 weeks before SPECT) and seven had remote treatment (>1 year before SPECT). Regions of interest were outlined in the tumor area using a computer-automated program to include all counts above background activity. Tumor activity counts were obtained from this region of interest. The tumor region of interest was mirrored to the contralateral uninvolved cerebral hemisphere to obtain background control count activity. A hypothetical volume of the number of pixels with background count activity necessary to constitute the tumor count activity (tumor bulk) was calculated using the ratio of total tumor counts (Ct), subtracting background (Cb), and dividing by the average counts per pixel in the control region (Cab). This was multiplied by the number of pixels (P), the pixel volume (Vp), and summed over all sections (i) involved with tumor. This method yields the equation tumor bulk = RESULTS: The mean Tc-99m MIBI to TI-201 tumor bulk ratio was 1.03 (range, 0.81 to 1.12) in four patients who had recently received chemotherapy. The mean Tc-99m MIBI to TI-201 tumor bulk ratio was 1.55 (range, 1.46 to 1.64) in seven patients who had remote therapy. The difference in the Tc-99m MIBI to TI-201 tumor bulk ratio between the two groups was significant (P = 0.0001). Patients who received recent chemotherapy had relatively lower Tc-99m MIBI uptake compared with TI-201. In remotely treated patients, uptake of the Tc-99m MIBI was greater compared with TI-201. CONCLUSION: This method allows semiquantitative comparison of different tracer uptake values independent of tracer dose and reduces the variability in drawing a region of interest when measuring tumor uptake. Among the patients studied, those who had recent chemotherapy showed a low Tc-99m MIBI to TI-201 ratio. This method of measuring "tumor bulk" can provide a useful index of viable tumor size in evaluating early tumor response and during ongoing chemotherapy.

Adult↗
PubMed1999

Congenital broncho-oesophageal fistula associated with bronchiectasis in adults. Report of two cases and review of the literature.

Congenital broncho-oesophageal fistula is a rare entity in adult patients. This anomaly may cause various symptoms such as respiratory infections, coughing bouts when eating or drinking and even haemoptysis. Even rarer than its occurrence with the above-mentioned symptoms is its presentation with bronchiectasis. A congenital broncho-oesophageal fistula presenting with bronchiectasis in a 28-year-old male and 36-year-old female are described. In reported cases, symptoms of chronic recurrent pulmonary suppuration were initially attributed to alternative aetiologies. In both cases, with such an unusual presentation, the observation of the fistulous tract was coincidental. Surgical division of the fistula associated with lobectomy resulted in complete resolution of symptoms.

Adult↗
PubMed1999

Effect of low-dose methyl prednisolone on serum cytokine levels following extracorporeal circulation.

The systemic inflammatory response to cardiopulmonary bypass (CPB) is associated with increased production of cytokines. This systemic inflammatory response characterized by the activation of interleukin-6 (IL-6) and interleukin-8 (IL-8) during and after CPB is well documented. A prospective, randomized, double-blind study was performed so as to understand the effects of low-dose methyl prednisolone sodium succinate (MPSS) on the circulating levels of serum cytokines and clinical outcome. Twenty patients were randomly divided into two groups on the basis of the administration of low-dose (1 mg/kg) MPSS (n = 10) and placebo (n = 10) into the pump prime solution. All patients were scheduled to undergo a primary elective coronary artery bypass grafting operation. Patients receiving concurrent corticosteroids, salicylates, dipyridamol or anticoagulants were excluded from the study. Other exclusion criteria were concurrent chronic obstructive pulmonary disease, chronic renal failure, insulin-dependent diabetes, congestive cardiac failure, peptic ulcer history, prior cardiac operations, recent (in a one-month period) myocardial infarction and steroid dependency. Mild systemic hypothermia (30-32 degrees C, rectal) was assured during the CPB. Four blood samples were drawn from the radial artery catheter immediately before starting CPB (T1), following protamine administration (T2) and at 24 (T3) and 48 h (T4) after completion of CPB. In each sample, creatine kinase-myocardial band (CK-MB), white blood cell (WBC), IL-6 and IL-8 levels were measured. IL-6 and IL-8 concentrations were measured by enzyme immunoassay and enzyme-linked immunoabsorbant assay methods. Serum IL-6 T2 and serum IL-6 T3 levels were significantly higher than IL-6 T1 levels in both groups (p < 0.001) and (p < 0.01), and there was no significant elevation in serum IL-8 levels in either group. Serum IL-6 levels were significantly higher in the placebo group than in the MPSS group at T3 (p < 0.009). There was no significant difference in CK-MB T1 levels between the groups. Although there was no significant difference between CK-MB T1 and T2 levels in the MPSS group, the CK-MB T2 and CK-MB T3 levels were significantly higher than T1 levels in the placebo group (p < 0.001) and (p < 0.05). There was significant elevation of WBC levels at T2 and T3 in both groups without notable difference between the groups (p < 0.05). This study has shown that low-dose MPSS suppresses CPB-induced inflammatory response. Further clinical studies (on larger and higher risk groups) may reveal more information on relations between morbidity and cytokine levels which may have some predictive value on clinical outcome following CPB.

Adult↗
PubMed1999

Heparin-coated circuits reduce complement activation and inflammatory response to cardiopulmonary bypass.

BACKGROUND: Clinical procedures involving extracorporeal blood circulation are potentially complicated by the interaction of various blood systems with foreign surfaces. In cardiopulmonary bypass, exposure of blood to synthetic surfaces generally leads to activation of cellular and humoral blood systems with activation of complement cascade. This reaction can be associated with a variety of postoperation clinical complications such as increased pulmonary capillary permeability, anaphylactic reactions and various degrees of organ failure which contributes to mortality in routine cardiac operations. Application of biocompatible materials in an extracorporeal circuit modifies the normal pattern of blood activation, and therefore potentially may reduce clinical complications in routine cardiac surgery. METHODS: To evaluate whether the use of heparin coated extracorporeal circuits could reduce this activation process we performed a study on forty coronary artery bypass graft patients perfused randomly with heparin-coated circuits (Duraflo II, n = 20) or with non-coated circuits (De Bakey roller pump, control n = 20). Standardized heparinization was maintained for both groups of patients during cardiopulmonary bypass. RESULTS: The use of heparin-coated circuits resulted in reduction of systemic leukocyte activation of cardiopulmonary bypass reflected by reduced leukocyte and neutrophil counts 24 hours after operation (p < 0.05). Furthermore, blood samples taken from both the right and left atrium after reperfusion revealed that the differences in neutrophil counts between the right and left atrium occur less in the heparin-coated circuit in contrast to the control group (p < 0.05). The pattern of complement activation, probably initiating this inflammatory reaction, was modified by heparin coating in two different aspects. There was a significant reduction of C3 during and after cardiopulmonary bypass in patients perfused with heparin coated circuits as compared with the control group, also there was reduction of C4 after protamine administration in the same groups (p < 0.05). The reductions in blood and complement activation with heparin-coated circuit indicate a substantial improvement in biocompatibility, and consequently reducing clinical complications associated with cardiopulmonary bypass. CONCLUSIONS: In conclusions using the Duraflo II heparin-coated circuit in open heart surgery can reduce the complement activation and inflammatory response to cardiopulmonary bypass.

Aged↗
PubMed1998

Allelic loss of 16q23.2-24.2 is an independent marker of good prognosis in primary breast cancer.

Allelic loss, detected as a loss of heterozygosity (LOH) on the long arm of chromosome 16, is an early and frequent event in breast cancer. Despite this, the clinical significance of LOH on 16q has been very poorly studied. In this study, corresponding blood and tumor samples from 199 clinically well-characterized primary breast cancer patients were analyzed for LOH with the highly polymorphic microsatellite marker D16S511, located at 16q23.2-24.2. 61% of 168 informative tumors showed LOH. Univariate and multivariate analysis found a highly significant association between LOH at 16q23.2-24.2 and freedom from distant metastases, disease-free survival, and overall survival, respectively. No association was found with other clinical parameters such as menopausal status, tumor size, lymph node status, histopathology, and lymph node capsule invasion. This makes allelic loss of 16q23.2-24.2 an independent marker of good prognosis for primary breast cancer.

Adult↗