Person: KOÇ, MEHMET
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
KOÇ
First Name
MEHMET
Name
25 results
Search Results
Now showing 1 - 10 of 25
Publication Metadata only Histopathological changes and tumour necrosis factor-alpha, transforming growth factor-beta and tenascin expression in patients with primary type I membranoproliferative glomerulonephritis in remission(WILEY, 2009) ARIKAN, İZZET HAKKI; Arikan, Hakki; Koc, Mehmet; Cakalagaoglu, Fulya; Tuglular, Serhan; Ozener, Cetin; Akoglu, EmelAim: Primary type I membranoproliferative glomerulonephritis (MPGN) is a rare cause of glomerular disease with a high relapse rate and poor prognosis. The aim of this study was: (i) to evaluate the histopathological findings associated with remission; and (ii) to document the possible clinical and histopathological factors predicting relapses. Methods: Eleven type I MPGN patients (five men, six women; mean age, 38.8 +/-13.5 years) who were in remission for at least 1 year after the cessation of immunosuppressive drugs were re-biopsied. The intensity of immunostaining for tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta 1, and tenascin was graded from 0 (no staining) to 3+ (maximum staining). Results: Mean baseline mesangial cellularity score and tubulointerstitial infiltration score were reduced and mesangial matrix expansion score was increased at protocol re-biopsies compared to baseline. The glomerular and tubulointerstitial staining scores for TGF-beta 1 and tenascin were higher than that of baseline. Reduced tubulointerstitial TNF-alpha expression was found in re-biopsy specimens compared to baseline. Patients have been followed for a mean time of 51.5 +/- 22.2 months after the protocol biopsy. Eight patients had a relapse. Mesangial cellularity score and glomerular tenascin expression at re-biopsy specimens were higher in relapsed patients compared to those without a relapse. Conclusion: Our study shows that mesangial cellularity and tubulointerstitial cell infiltration are reducing whereas mesangial matrix expansion, glomerular and tubulointerstitial TGF-beta 1 and tenascin expression are increasing with remission. The higher mesangial cell proliferation and glomerular tenascin scores in remission are associated with the development of relapse.Publication Open Access Acute Renal Failure due to Bladder Injury after Cesarean Section: Case Report and Review of the Literature(TURK NEFROLOJI DIYALIZ TRANSPLANTASYON DERGISI, 2019-11-05) AŞICIOĞLU, EBRU; Atas, Dilek Barutcu; Asicioglu, Ebru; Durgay, Meryem; Arikan, Hakki; Koc, Mehmet; Tuglular, Serhan; Ozener, CetinA 31-year-old woman who had an uncomplicated cesarean section five days prior to admission presented with abdominal distention. Evaluation revealed acute renal failure and abdominal ascites. Diagnostic paracentesis showed urinary ascites, which confirmed a bladder injury. The patient was conservatively treated by placement of a Foley catheter that resulted in complete resolution of the renal failure.Publication Open Access Toll-like receptor expression in monocytes in patients with chronic kidney disease and haemodialysis: relation with inflammation(OXFORD UNIV PRESS, 2011-03-01) AŞICIOĞLU, EBRU; Koc, Mehmet; Toprak, Ahmet; Arikan, Hakki; Odabasi, Zekaver; Elbir, Yesim; Tulunay, Aysin; Asicioglu, Ebru; Eksioglu-Demiralp, Emel; Glorieux, Griet; Vanholder, Raymond; Akoglu, EmelBackground. Inflammation is one of the main contributors to atherosclerosis in haemodialysis (HD) patients. Activation of Toll-like receptors (TLRs) leads to inflammatory response. In this study, we aimed to evaluate the expression of TLRs on monocytes and relate their expression with inflammation in chronic kidney disease (CKD) and HD patients. Methods. Thirty-four age- and gender-matched controls and stage 3-4 CKD patients and thirty-two HD patients were included in each study group. The effect of HD on the expression of Toll-like receptor-2 (TLR-2) and Toll-like receptor-4 (TLR-4) on CD14(+) monocytes was determined at the beginning (baseline), during (120 min) and following (300 min and 24 h) HD and compared with control and stage 3-4 CKD groups. The HD procedure was performed by using low-flux polysulphone dialysers. In addition, serum IL-6 levels were evaluated in both groups at baseline and after a HD session. Results. The percentage of CD14(+) monocytes expressing TLR-2 were similar in all of the study groups, whereas the percentage of CD14(+) monocytes expressing TLR-4 were significantly lower in both stage 3-4 CKD and HD patients at baseline than in controls. The mean fluorescence intensities (MFI) of TLR-2 were significantly lower in controls than in stage 3-4 CKD and HD patients at baseline. The MFI of TLR-4 was similar in all of the groups. The percentage of CD14(+) monocytes expressing TLR-2 did not change during and after HD. The MFI of TLR-2 decreased at 120 min of HD compared with baseline (1837 +/- 672 vs 1650 +/- 578, P < 0.05), and recovered back to baseline values at 300 min and at 24 h post-HD. MFI of TLR-4 increased at 24 h compared with baseline (941 +/- 294 vs 1087 +/- 441, P < 0.05). Serum IL-6 levels correlated with MFI of TLR-2 and TLR-4 in stage 3-4 CKD patients and in HD patients at baseline and after HD in univariate analysis. Stepwise multiple regression analysis revealed that MFI of TLR-2 was an independent determinant of serum IL-6 concentrations in stage 3-4 CKD and in HD patients at baseline, at 300 min and at 24 h post-HD. Conclusions. Our study demonstrates that TLR-2 is associated with the inflammatory response of non-dialysed and dialysed CKD patients.Publication Metadata only Waist circumference is associated with carotid intima media thickness in peritoneal dialysis patients(SPRINGER, 2013) VELİOĞLU, ARZU; Asicioglu, Ebru; Kahveci, Arzu; Arikan, Hakki; Koc, Mehmet; Tuglular, Serhan; Ozener, Cetin IshakAtherosclerosis is responsible for the high mortality rate in end-stage renal disease patients. Defining risk factors for atherosclerosis may lead to reduction in cardiovascular disease through modification of these factors. Peritoneal dialysis (PD) patients are subjected to high glucose loads on a daily basis, which results in considerable weight gain and an increase in waist circumference (WC). WC as an indicator of abdominal obesity is a risk factor for atherosclerosis in the general population. Carotid artery intima media thickness (CIMT) measurement is a reliable method for the detection of early atherosclerosis. The aim of this study was to investigate the relationship between WC and CIMT and to define risk factors associated with CIMT in PD patients. Fifty-five PD patients and 40 healthy controls were included. Atherosclerosis was assessed using measurement of CIMT. Fasting blood was collected for analysis. Anthropometric parameters (age, weight, BMI, and WC) were measured. Peritoneal dialysis patients had higher WC (93.9 +/- A 1.7 vs. 87.3 +/- A 1.2 cm, p < 0.05) and CIMT (0.70 +/- A 0.02 vs. 0.57 +/- A 0.01 mm, p < 0.01) than the control group. On univariate analysis, age, WC, plaque formation, and D/P creatinine were positively correlated with CIMT, whereas residual renal function, albumin, ultrafiltration volume, and D/D0 glucose were negatively correlated. On multivariate analysis, only age, WC, and plaque formation showed correlation (p < 0.001). Carotid artery intima media thickness is associated with age, plaque formation, and WC in PD patients. WC measurement is a simple, inexpensive, reproducible, and reliable method of evaluating atherosclerosis risk in PD patients and should be assessed at every visit. Appropriate counsel should be provided to patients with greater WC who are deemed to be at risk for atherosclerosis.Publication Metadata only Elevated Plasma Levels of PAI-1 Predict Cardiovascular Events and Cardiovascular Mortality in Prevalent Peritoneal Dialysis Patients(TAYLOR & FRANCIS LTD, 2009) ARIKAN, İZZET HAKKI; Arikan, Hakki; Koc, Mehmet; Tuglular, Serhan; Ozener, Cetin; Akoglu, EmelBackground. Elevated plasminogen activator inhibitor-1 (PAI-1) levels are associated with increased cardiovascular (CV) risk in the general population. It has been shown that peritoneal dialysis (PD) patients have increased plasma levels of PAI-1. The aim of this study was to investigate whether PAI-1 independently predicted CV outcome in PD patients. Material and Methods. Seventy-two PD patients (53% females, mean age 49.9 +/- 16.1 years) were studied. Twelve patients who underwent kidney transplantation and 14 patients who transferred to hemodialysis during follow-up were excluded from the analysis. The remaining 46 patients (54% female, mean age 54 +/- 16 years, dialytic age 42 +/- 30 months) were followed a mean time of 45.4 +/- 19.4 months (range 8-71 months). Baseline PAI-1, clinical, and laboratory parameters were assessed in all patients. Survival analyses were made with Kaplan-Meier and Cox regression analysis, with all-cause mortality and CV mortality and CV events (CVEs) as clinical end points. Results. During the follow-up, 29 patients died (17 from CV causes), and 28 fatal and non-fatal CVEs were recorded. The patients were divided according to plasma PAI-1 levels (i.e., <= or >41 ng/mL). The significant independent predictors of all-cause of mortality were age (>60 years; p = 0.018), CRP (>5 mg/L; p = 0.015), and serum albumin (<3.5 g/L; p = 0.011). Multivariable Cox regression analysis showed that plasma PAI-1 >41 ng/mL was independently predictive of higher CV mortality (p = 0.021) and CVEs (p = 0.001). The only other independent predictor of CV mortality was only CRP (>5 mg/L; p = 0.008). Conclusions. Plasma levels of PAI-1 >41 ng/mL is a significant predictor of CV mortality and CVEs in PD patients.Publication Metadata only Baseline carotid intima-media thickness is associated with cardiovascular morbidity and mortality in peritoneal dialysis patients(WILEY, 2021) VELİOĞLU, ARZU; Asicioglu, Ebru; Velioglu, Arzu; Arikan, Hakki; Koc, Mehmet; Tuglular, Serhan; Ozener, CetinCarotid intima-media thickness (CIMT) is an early marker of atherosclerosis and is increased in peritoneal dialysis (PD) patients. Association of CIMT with cardiovascular disease (CVD) or mortality is less clear. Fibroblast growth factor-23 (FGF-23) is a hormone associated with vascular calcification, atherosclerosis, and mortality in the hemodialysis population. We investigated whether baseline CIMT and FGF-23 are associated with CVD and mortality in PD patients. Fifty-five PD patients were included. CVD was defined as ischemic heart disease, stroke, or peripheral artery disease. Intact FGF-23 was measured in plasma. CIMT was measured by ultrasonography. Twenty-one patients developed CVD and 12 died over 47.1 +/- 33.8 months. Patients with CVD were older (55.9 +/- 10.5 vs. 42.5 +/- 12.9 years, P < .01), had lower albumin (3.8 +/- 0.5 vs. 4.2 +/- 0.3 g/dL, P < .01) and higher CIMT (0.87 +/- 0.22 vs. 0.61 +/- 0.11 mm, P < .01). Patients with mortality were also older (53.5 +/- 11.5 vs. 45.8 +/- 13.8 years, P = .05), had lower albumin (3.7 +/- 0.6 vs. 4.1 +/- 0.3 g/dL, P < .01), higher CRP (15.0 +/- 8.5 vs. 7.6 +/- 8.4 mg/L, P < .01) and CIMT (0.9 +/- 0.3 vs. 0.6 +/- 0.1 mm, P < .01). Albumin and CIMT were associated with CVD and CIMT > 0.75 mm was associated with cardiovascular mortality. FGF-23 did not show any correlations. CIMT at baseline is associated with CVD and mortality in PD patients.Publication Open Access The Intensity of PLA2R and C4d_x000D_ Immunoexpression in Primary_x000D_ Membranous Nephropathy(2019) FİLİNTE, DENİZ; Deniz FİLİNTE;Hakkı ARIKAN;Mehmet KOÇ;Handan KAYA;İshak Çetin ÖZENER;Gamze AKBAŞObjective: Antibodies against the phospholipase A2 receptor (PLA2R) on podocyte membranes result in the formation of immune complexes that cause loss of function of theglomerular basement membrane in primary membranous nephropathy (PMN). It has alsobeen demonstrated that there is a deposition of complement 4d (C4d) in the glomeruli inPMN. The present study aims to evaluate PLA2R and C4d immunoexpressions in PMN casesand search the correlation with the clinical parameters.Methods: In this study, clinicopathological data and paraffin-embedded specimens werecollected from 51 patients. The formalin-fixed paraffin-embedded tissues were stained usingroutine hematoxylin-eosin, periodic acid-Schiff, and silver methenamine stains and immunostained for anti-PLA2R and C4d. Ten normal kidney tissues and 10 focal segmental glomerulosclerosis (FSGS) cases were selected as controls for PLA2R and C4d immunoexpression.Results: Of the PMN cases, 51 (100%) cases were positive for PLA2R, including 15 (29%)cases that scored 2+, and 36 (71%) cases that scored 3+. Forty of the 51 cases (78%) werepositive for C4d. The percentages of cases staining positively for C4d, per scoring group,were as follows: 31 (61%) cases faintly (1+) positive and 9 (18%) cases moderately (2+)positive. No strong positivity was observed. All of the control cases (100%) were negativefor PLA2R and C4d. There was no statistically significant difference between the intensity ofthe staining of PLA2R and the staining of C4d, proteinuria levels, creatinine levels, and complement 3 (C3) positivity. Similarly, there was no statistically significant difference betweenthe intensity of the staining of C4d and proteinuria levels, creatinine levels, and C3 positivity.Conclusion: Immunohistochemical detection of PLA2R and C4d is a safe and easy methodfor the diagnosis of PMN. In cases where fresh tissue is not available for the detection of IgGand C3 using the immunofluorescence method, positivity for PLA2R and C4d with immunohistochemistry may be beneficial for the diagnosis of PMN.Publication Metadata only Peri̇ton di̇yali̇zi̇ hastasında leclerci̇a adecarboksi̇lata peri̇toni̇ti̇(2015-10-21) BARUTÇU ATAŞ, DİLEK; VELİOĞLU, ARZU; ARIKAN, İZZET HAKKI; KOÇ, MEHMET; TUĞLULAR, ZÜBEYDE SERHAN; AŞICIOĞLU, EBRU; BARUTÇU ATAŞ D., VELİOĞLU A., AŞICIOĞLU E., AYKENT M. B., ARIKAN İ. H., KOÇ M., TUĞLULAR Z. S., ÖZENER İ. Ç.Giriş: Peritonit, sürekli ayaktan periton diyalizinin (SAPD) en sık ve önemli komplikasyonudur. Leclercia adecarboksilata, Enterobactericea ailesinden gram negatif, hareketli bir basildir. Periton diyalizi (PD) ilişkili peritonitin çok nadir bir sebebidir. Olgu Sunumu: Kronik glomerulonefrite bağlı son dönem böbrek yetmezliği (SDBY) nedeniyle 12 yıldır SAPD tedavisi gören 72 yaşında kadın hasta ateş, bulantı, kusma, karın ağrısı ve diyalizatta bulanıklaşma şikayeti ile hastaneye başvurdu. Fizik muayenede kan basıncı 90/60 mm/Hg, ateş 38,8 C°, batında yaygın hassasiyet saptandı. Diyaliz sıvısında silme lökosit izlendi. Laboratuvar tetkiklerinde WBC 4.600/µL, CRP 135 mg/L (N: 0-5) ve prokalsitonin 63 ng/mL (N: 0-0.5) izlendi. Kan ve periton sıvısı kültürleri alındıktan sonra ampirik olarak intraperitoneal sefuroksim ve oral siprofloksasin başlandı. Ertesi gün hastada klinik kötüleşme oldu ve periton sıvısı kültüründe Acinetobacter Baumanii ve Leclercia Adecarboksilata üremesi bildirildi. Antibiyograma göre tedaviye intravenöz imipenem ile devam edildi. Klinik düzelme sağlandı, Diyalizat hücre sayısı tedavinin 5. gününde negatifleşti. 2 hafta sonra antibiyotik rezistansını önlemek için imipenem kesilerek intraperitoneal amikasin ve oral siprofloksasine geçildi. Toplam üç hafta süren antibiyotik tedavisi sonrası hasta tamamen iyileşti ve tekrarlayan kültürlerde üreme olmadı. PD katateri çekilmeyen hastanın takiplerinde relaps peritonit izlenmedi. Tartışma: Gram negatif mikroorganizmalarla ilişkili peritonitlerde mortalite daha yüksektir ve daha sık olarak PD kateterinin çıkarılması gerekmektedir. Leclercia Adecarboxilata tek başına ya da bizim hastamızda olduğu gibi polimikrobial infeksiyonların bir komponenti olarak izole edilebilir. Epidemiyolojisi tam olarak bilinmemekle birlikte hastaların çoğunluğu immunsupresiftir. Ancak Leclercia Adecarboksilatanın etken olduğu infeksiyonların çoğunluğu hayati tehdit oluşturmaz. Acinetobacter Baumanii gibi tehlikeli bir mikroorganizma ile birlikte üretilmesine rağmen uygun antibiyotik tedavisi ile başarılı bir sonuç alınmıştır.Publication Metadata only Determinants of hemoglobin variability in stable peritoneal dialysis patients(SPRINGER, 2014) VELİOĞLU, ARZU; Arikan, Hakki; Asicioglu, Ebru; Velioglu, Arzu; Nalcaci, Serdar; Birdal, Gurdal; Guler, Derya; Koc, Mehmet; Tuglular, Serhan; Ozener, CetinSignificant within-patient hemoglobin (Hb) level variability is well recognized in particularly hemodialysis patients. Several factors such as hospitalizations, intercurrent diseases and IV iron therapy are found to be related to Hb variability (Hb-var). In this observational study, we aimed to identify predictors and outcome of Hb-var in peritoneal dialysis (PD) patients without hospitalization, intercurrent disease and IV iron therapy during the study period. All patients were in the maintenance phase of short-acting erythropoiesis-stimulating agents (ESAs) therapy. The target range of Hb was 11-12 g/dL according to KDOQI Guidelines in 2007. The desired range of Hb was 11-12.5 g/dL. Patients' demographic and laboratory data were collected at baseline. Atherosclerotic disease was assessed using carotid intima-media thickness (CIMT). We assessed Hb variability with various methods using SD Hb(mean), SD Hb(range) and the velocity of Hb change. Hb deflect(positive), Hb deflect(negative), Hb values and ESA dosing were recorded monthly for 6 months. This study included 50 prevalent PD patients (mean age 46.9 +/- A 13.7 years, 25 women). The mean velocity of Hb change was negatively correlated with age and positively correlated with frequent ESA dose changes. Higher albumin and residual renal function (RRF) were also positively correlated with Hb deflect(positive). Patients with CIMT a parts per thousand yen0.7 cm had lower SD Hb range compared to CIMT < 0.7 cm. Cumulative survival was better in patients with Hb levels consistently a parts per thousand yen10 g/dL compared to patients who had Hb < 10 g/dL for at least 1 month. However, Hb-var was not associated with mortality. In PD patients without hospitalization, intercurrent disease(s) or IV iron therapy, young age, higher albumin or RRF and lower CIMT were associated with greater oscillations in response to ESA therapy. Careful and appropriate ESA dose changes considering these parameters could minimize Hb variability in these patients.Publication Metadata only Peritoneal Fluid Trefoil Factor-3 Peptide Levels and Associated Factors in Chronic Peritoneal Dialysis Patients(TURK NEFROLOJI DIYALIZ TRANSPLANTASYON DERGISI, 2018) AŞICIOĞLU, EBRU; Aktas, Gokmen; Arikan, Hakki; Erken, Ertugrul; Asicioglu, Ebru; Koc, Mehmet; Ozener, CetinOBJECTIVE: TFF3 is a small peptide hormone secreted from mucous producing cells and many epithelial cells. TFF3 inhibits apoptosis, promotes migration and facilitates restoration against injury. In our cross-sectional study, TFF3 levels in peritoneal fluids of peritoneal dialysis (PD) patients were measured and associated factors were investigated. MATERIAL and METHODS: Peritoneal fluid after a 12-hour dwell and concurrent serum samples of 48 chronic PD patients were collected. Serum and peritoneal fluid TFF3 levels were measured by ELISA. The SPSS15.0 package was used for statistical analysis of database files. RESULTS: The study included 48 patients (men/women; 24/24, mean age: 51.6813.9 years) with a median PD vintage of 43 months (3-200). Median effluent TFF3 level was 17.07 ng/ml (2.38-99.4). There was no relationship between the number of peritonitis episodes and TFF3 levels. There was a positive correlation between effluent TFF3 levels and PD vintage (r=0.349, p<0.015). There was also a positive correlation between effluent TFF3 and serum PTH. Median serum TITS was 1.56 ng/ml (0.79-11.05). There was no association between serum TFF3 levels and clinical features. After multivariate analysis, the only association was between effluent TFF3 and PD vintage. CONCLUSION: Effluent TFF3 levels increasing with dialysis vintage may be related to local production or peritoneal transport.
- «
- 1 (current)
- 2
- 3
- »