Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yasar Yildirim is active.

Publication


Featured researches published by Yasar Yildirim.


American Journal of Roentgenology | 2015

Acoustic Radiation Force Impulse Imaging for Evaluation of Renal Parenchyma Elasticity in Diabetic Nephropathy

Cemil Göya; Faruk Kılınç; Cihad Hamidi; Alpaslan Yavuz; Yasar Yildirim; Mehmet Güli Çetinçakmak; Salih Hattapoğlu

OBJECTIVE. The goal of this study is to evaluate the changes in the elasticity of the renal parenchyma in diabetic nephropathy using acoustic radiation force impulse imaging. SUBJECTS AND METHODS. The study included 281 healthy volunteers and 114 patients with diabetic nephropathy. In healthy volunteers, the kidney elasticity was assessed quantitatively by measuring the shear-wave velocity using acoustic radiation force impulse imaging based on age, body mass index, and sex. The changes in the renal elasticity were compared between the different stages of diabetic nephropathy and the healthy control group. RESULTS. In healthy volunteers, there was a statistically significant correlation between the shear-wave velocity values and age and sex. The shear-wave velocity values for the kidneys were 2.87, 3.14, 2.95, 2.68, and 2.55 m/s in patients with stage 1, 2, 3, 4, and 5 diabetic nephropathy, respectively, compared with 2.35 m/s for healthy control subjects. Acoustic radiation force impulse imaging was able to distinguish between the different diabetic nephropathy stages (except for stage 5) in the kidneys. The threshold value for predicting diabetic nephropathy was 2.43 m/s (sensitivity, 84.1%; specificity, 67.3%; positive predictive value, 93.1%; negative predictive value 50.8%; accuracy, 72.1%; positive likelihood ratio, 2.5; and negative likelihood ratio, 0.23). CONCLUSION. Acoustic radiation force impulse imaging could be used for the evaluation of the renal elasticity changes that are due to secondary structural and functional changes in diabetic nephropathy.


Medical Genetics | 2015

Romano-Ward sendromunda KCNQ1 geninde bir duplikasyon mutasyonu

Salih Coşkun; Yasar Yildirim; Abdullah Çim; Yahya Islamoglu; Umut Altunoglu; Z. Oya Uyguner; Osman Gokalp

Long QT syndrome (LQTS), a rare congenital cardiac condition associated with life‐threatening ventricular arrhythmias is characterized by a prolonged QT interval on electrocardiograph corrected for heart rate [corrected QT (QTc)]. LQTS has been historically categorized into the autosomal dominant Romano–Ward syndrome (RWS) and the autosomal recessive Jervell and Lange‐Nielsen syndrome (JLNS). JLNS is associated with prelingual sensorineural deafness. Both types of LQTS can be caused by mutations in channel genes (e.g. KCNQ1) responsible for potassium homeostasis in cardiac myocytes and cochlea. Autosomal dominant mutations often cause the RWS phenotype and homozygous or compound heterozygous mutations contribute to JLNS. Two First Nations communities in northern British Columbia are affected disproportionately with LQTS largely due to the V205M mutation in KCNQ1, however, the pathology and phenotypic expression for those V205M homozygous has been unknown. Here, we show that four V205M homozygous individuals have a significantly higher ‘peak’ QTc, and a more severe cardiac phenotype compared with 41 V205M heterozygous carriers and 57 first to third degree relatives without mutations. Given the lack of prelingual deafness the homozygous V205M LQTS patients present with a phenotype more typical of RWS than JLNS.


Renal Failure | 2014

Evaluation of volume overload by bioelectrical impedance analysis, NT-proBNP and inferior vena cava diameter in patients with stage 3&4 and 5 chronic kidney disease

Zülfükar Yilmaz; Yasar Yildirim; Ferhat Oto; Fatma Aydin; Emre Aydin; Ali Kemal Kadiroglu; Mehmet Emin Yilmaz

Abstract Background: Determination of fluid overload is important in chronic kidney disease. Early diagnosis and treatment of volume overload may decrease morbidity and mortality. We aimed to determine body composition by using bioelectrical impedance analysis, and studying other clinical characteristics, inferior vena cava diameter, and N-terminal pro-B natriuretic peptide associated with hydration status in chronic kidney disease Stages 3&4 and 5 in patients not undergoing dialysis. Method: We examined 62 patients with Stages 3&4 and 68 patients with Stage 5 chronic kidney disease. Plasma NT-proBNP was measured and analyzed after log transformation. Inferior vena cave diameter was measured with echocardiography and indexed for body surface area. Hydration status was assessed using multi-frequency bioelectrical impedance analysis. Overhydration was defined as overhydration/extracellular water >0.15. Results: Overhydration was more frequent in Stage 5 than in Stages 3&4 patients. Systolic and diastolic blood pressure, inferior vena cava index, and log NT-proBNP were higher in overhydrated compared to non-overhydrated patients. A significant positive correlation existed between overhydration/extracellular water and log NT-proBNP, systolic and diastolic blood pressures, and inferior vena cava index. In multiple linear regression analysis, the variables associated with hydration status were male sex, extracellular water/total body water, and extracellular water/intracellular water (greater overhydration), while serum albumin levels had a negative association with overhydration. Conclusion: Overhydration is more prevalent in Stage 5 chronic kidney disease patients than in Stages 3&4 patients. Bioelectrical impedance analysis, inferior vena cava diameter, and NT-proBNP analysis in chronic kidney disease are useful methods to determine the volume overload.


Medicina-buenos Aires | 2014

Evaluation of fluid status related parameters in hemodialysis and peritoneal dialysis patients: Clinical usefulness of bioimpedance analysis

Zülfükar Yilmaz; Yasar Yildirim; Fatma Aydin; Emre Aydin; Ali Kemal Kadiroglu; Mehmet Emin Yilmaz; Halit Acet

BACKGROUND AND OBJECTIVE Fluid overload is a common and serious problem that leads to severe complications in dialysis patients. We aimed to compare hydration status as measured with bioimpedance analysis (BIA) method in hemodialysis (HD) and peritoneal dialysis (PD) patients, as well as investigating the association between blood pressure, left ventricular mass index (LVMI) and hydration status. MATERIALS AND METHODS We examined 43 HD and 33 PD patients. Blood pressure was recorded. In each group, echocardiographic examinations were performed on all patients. Hydration status was assessed using multifrequency bioelectrical impedance analysis. Overhydration was defined as an overhydration (OH)/extracellular water (ECW) ratio of >0.15. RESULTS The OH/ECW ratio was significantly higher in PD patients compared to post-HD patients. Overhydration was statistically more frequent in PD than in post-HD patients (30.3% vs. 11.6%, P=0.043). Systolic blood pressure (SBP) in both post-HD and PD groups, and LVMI in the PD group were found to be significantly higher in overhydrated patients than non-overhydrated patients. In multiple linear regression analyses, increased OH/ECW ratio was independently associated with higher SBP and LVMI. CONCLUSIONS Fluid overload may be an even more prevalent and serious problem in PD patients. Overhydration is closely associated with increased blood pressure and LVMI. OH/ECW ratio, a derived parameter of fluid load measured by BIA, was a significant and independent determinant of SBP and LVMI.


Cell Biochemistry and Function | 2011

Routine enzymes in the monitoring of type 2 diabetes mellitus.

Osman Evliyaoglu; Erkan Kibrisli; Yasar Yildirim; Osman Gökalp; Leyla Çolpan

We examined the relationships of glucose and HbA1c levels with the routinely screened serum enzyme activities in type 2 diabetes mellitus, and we designed an in vitro study to evaluate the direct effect of glucose levels on enzyme activities. The study was performed on a consecutive series of outpatients with type 2 diabetes who were followed up at Dicle University Medical Faculty Hospital from May 2009 to May 2010 for the first time. Effects of aspartate transaminase, aminotransferase, gamma‐glutamyl transferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) activities, glucose and HbA1c levels and in vitro glucose (492, 287, 184, 131, 82 mg dl−1, respectively) on enzymes were determined. The patients were categorized on the basis of glucose and HbA1c levels and grouped according to a range of values. In patients with high HbA1c levels (>10.1%), ALP, GGT activities and creatine kinase (CK)‐MB/CK (p = 0.008, 0.026, 0.014) ratio were increased significantly when compared with those in the control group. In patients with high glucose levels (>200 mg dl−1), ALP, GGT activities and CK‐MB/CK ratio (p = 0.003, 0.001, 0.001) were increased significantly when compared with those in the control group. Glucose, which was added to serum in different concentrations in vitro, did not directly affect enzyme activities such as ALP, GGT and CK. We concluded that increased glucose levels could damage the liver and the heart muscle cells. Monitoring of blood glucose levels is a more valuable parameter than monitoring HbA1c in the momentary evaluation of diabetes. Copyright


Case reports in nephrology | 2012

A Rare Cause of Secondary Amyloidosis: Common Variable Immunodeficiency Disease

Ali Kemal Kadiroglu; Yasar Yildirim; Zülfükar Yilmaz; Hasan Kayabasi; Yahya Avcı; M. Serdar Yıldırım; M. Emin Yilmaz

The common variable immunodeficiency disease (CVID) is the most common symptomatic primary antibody deficiency. It is the most frequently observed cause of panhypogammaglobulinemia in adults. Here, we present a case of systemic amyloidosis that developed secondary to the common variable immunodeficiency disease causing recurrent infections in a young female patient. A 24-year-old female patient, who was under treatment at the gynecology and obstetrics clinic for pelvic inflammatory disease, was referred to our clinic when she was observed to have swellings in her legs, hands, and face. She had proteinuria at a rate of 3.5 gr/day, and her serum albumin was 1.5 gr/dl. The levels of immunoglobulins are IgG: 138 mg/dl, IgA: 22,6 mg/dl, and IgM: 16,8 mg/dl. The renal USG revealed that the kidneys were observed to be enlarged. Since the patient had recurrent infections, hypogammaglobulinemia, nephrotic range proteinuria, and enlarged kidneys in the renal USG, she was thought to have type AA amyloidosis and therefore underwent a renal biopsy. The kidney biopsy revealed amyloid (+). So the patient was diagnosed with AA type of amyloidosis secondary to common variable immunodeficiency disease. A treatment regimen (an ACE inhibitor and a statin) with monthly administration of intravenous immunoglobulin was started.


Medical Science Monitor | 2016

The Relationship of Fluid Overload as Assessed by Bioelectrical Impedance Analysis with Pulmonary Arterial Hypertension in Hemodialysis Patients

Süreyya Yılmaz; Yasar Yildirim; Mahsuk Taylan; Melike Demir; Zülfükar Yilmaz; Ali Veysel Kara; Fatma Aydin; Hadice Selimoglu Sen; Aziz Karabulut; Fusun Topcu

Background Pulmonary arterial hypertension (PAH) is common disease among hemodialysis (HD) patients and is associated with increased morbidity and mortality. However, its pathogenesis has not been completely elucidated. We aimed to evaluate the frequency of PAH in HD patients, as well as the relationship between fluid status and PAH. Material/Methods We enrolled 77 HD patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status. BIA was performed before and 30 min after the midweek of HD. Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Echocardiographic examinations were performed before and after the HD. Pulmonary arterial hypertension was defined as systolic pulmonary artery pressure at rest (sPAP) higher than 35 mmHg. Results PAH was found in 33.7% of the HD patients. OH/ECW and the frequency of fluid overload were significantly higher in HD patients with PAH than those without PAH, whereas serum albumin and hemoglobin levels were significantly lower. sPAP level was significantly higher in HD patients with fluid overload than in those without fluid overload after hemodialysis session. Furthermore, sPAP, OH/ECW levels, and the frequency of PAH were significantly reduced after HD. We also found a significant positive correlation between sPAP and OH/ECW. Multivariate logistic regression analysis demonstrated fluid overload to be an independent predictor of PAH after HD. Conclusions PAH is prevalent among HD patients. This study demonstrated a strong relationship between fluid overload and PAH in HD patients.


Pulmonary Medicine | 2015

Evaluation of Anthropometric and Metabolic Parameters in Obstructive Sleep Apnea

Yasar Yildirim; Süreyya Yılmaz; Mehmet Güven; Faruk Kılınç; Ali Veysel Kara; Zülfükar Yilmaz; Gökhan Kırbaş; Alpaslan Tuzcu; Fatma Aydin

Aims. Sleep disorders have recently become a significant public health problem worldwide and have deleterious health consequences. Obstructive sleep apnea (OSA) is the most common type of sleep-related breathing disorders. We aimed to evaluate anthropometric measurements, glucose metabolism, and cortisol levels in patients with obstructive sleep apnea (OSA). Materials and Methods. A total of 50 patients with a body mass index ≥30 and major OSA symptoms were included in this study. Anthropometric measurements of the patients were recorded and blood samples were drawn for laboratory analysis. A 24-hour urine sample was also collected from each subject for measurement of 24-hour cortisol excretion. Patients were divided equally into 2 groups according to polysomnography results: control group with an apnea-hypopnea index (AHI) <5 (n = 25) and OSA group with an AHI ≥5 (n = 25). Results. Neck and waist circumference, fasting plasma glucose, HbA1c, late-night serum cortisol, morning serum cortisol after 1 mg dexamethasone suppression test, and 24-hour urinary cortisol levels were significantly higher in OSA patients compared to control subjects. Newly diagnosed DM was more frequent in patients with OSA than control subjects (32% versus 8%, p = 0.034). There was a significant positive correlation between AHI and neck circumference, glucose, and late-night serum cortisol. Conclusions. Our study indicates that increased waist and neck circumferences constitute a risk for OSA regardless of obesity status. In addition, OSA has adverse effects on endocrine function and glucose metabolism.


Medical Science Monitor | 2016

Pulmonary Function in Patients with End-Stage Renal Disease: Effects of Hemodialysis and Fluid Overload.

Süreyya Yılmaz; Yasar Yildirim; Zülfükar Yilmaz; Ali Veysel Kara; Mahsuk Taylan; Melike Demir; Mehmet Coşkunsel; Ali Kemal Kadiroglu; Mehmet Emin Yilmaz

Background Respiratory system disorders are one of the most prevalent complications in end-stage renal disease patients on hemodialysis. However, the pathogenesis of impaired pulmonary functions has not been completely elucidated in these patients. We designed a study to investigate acute effects of hemodialysis treatment on spirometry parameters, focusing on the relationship between pulmonary function and fluid status in hemodialysis patients. Material/Methods We enrolled 54 hemodialysis patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status before and 30 min after the midweek of hemodialysis (HD). Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Spirometry was performed before and after hemodialysis. Results Forced vital capacity (FVC), FVC%, and forced expiratory volume in the first second (FEV1) levels were significantly increased after hemodialysis. FVC, FVC%, FEV1, FEV1%, mean forced expiratory flow between 25% and 75% of the FVC (FEF25–75), FEF25–75%, peak expiratory flow rate (PEFR), and PEFR% were significantly lower in patients with fluid overload than in those without. OH/ECW ratio was negatively correlated with FVC, FVC%, FEV1, FEV1%, FEF25–75, FEF25–75%, PEFR, and PEFR%. Stepwise multiple regression analysis revealed that male sex and increased ultrafiltration volume were independently associated with higher FVC, whereas increased age and OH/ECW ratio were independently associated with lower FVC. Conclusions Fluid overload is closely associated with restrictive and obstructive respiratory abnormalities in HD patients. In addition, hemodialysis has a beneficial effect on pulmonary function tests, which may be due to reduction of volume overload.


Human & Experimental Toxicology | 2017

Influence of coumarin and some coumarin derivatives on serum lipid profiles in carbontetrachloride-exposed rats

Ezel Taşdemir; Mukadder Atmaca; Yasar Yildirim; Hakkı Murat Bilgin; Berjan Demirtaş; Basra Deniz Obay; Mustafa Kelle; Hüda Diken Oflazoğlu

In the present study, coumarin and some coumarin derivatives (esculetin, scoparone, and 4-methylumbelliferone) were investigated for their lipid-lowering effect in rats. Male Sprague–Dawley rats (150–200 g) were divided into six groups and each group comprised of five rats. Hepatic injury-dependent hyperlipidemia was induced by carbon tetrachloride (CCl4, 1.25 ml/kg). Coumarin and coumarin derivatives esculetin (35 mg/kg), scoparone (35 mg/kg), 4-methylumbelliferone (35 mg/kg), or coumarin (30 mg/kg) were administered to experimental groups at 12-h intervals. Animals received the derivatives esculetin, scoparone or 4-methylumbelliferone prior to the administration of a single toxic dose of CCl4. Serum total cholesterol (TC), triglyceride (TG), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol (LDL-C) levels significantly increased in CCl4-treated group (p < 0.05, p < 0.01, p < 0.01, and p < 0.05, respectively), while levels of serum high-density lipoprotein cholesterol (HDL-C) decreased (p < 0.01). 4-Methylumbelliferone had no recovery effects on serum TC levels, however, significantly prevented CCl4-induced hyperlipidemia by reducing TG and VLDL-C levels (p < 0.05 and p < 0.05, respectively). In addition, coumarin had no recovery effect on any of the serum lipid parameters against CCl4-induced hyperlipidemia. Among the coumarin derivatives only esculetin and scoparone significantly prevented serum HDL-C in CCl4-induced dyslipidemia. The results from this study indicate that the chemical structure of coumarins plays an important role on the regulation of serum lipid profiles.

Collaboration


Dive into the Yasar Yildirim's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge