PubMed Health⌕ Search

Biomedical subjects

N Yilmaz

Publications and source records attributed to N Yilmaz.

At least 19 recordsLinked to original sources
PubMed2006

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat heart and ameliorating role of vitamin E and vitamin C.

Diazinon is one of the most widely used organophosphate insecticides (OPIs) in agriculture and public health programs. Reactive oxygen species (ROS) caused by OPIs may be involved in the toxicity of various pesticides. The aim of this study was to investigate how diazinon affects lipid peroxidation (LPO) and the antioxidant defense system in vivo and the possible ameliorating role of vitamins E and C. For this purpose, experiments were done to study the effects of DI on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in adult rat heart. Experimental groups were: (1) control group, (2) diazinon treated (DI) group, (3) DI+vitamins E and C-treated (DI+Vit) group. The levels of malondialdehyde (MDA) and the activities of SOD and CAT increased significantly in the DI group compared with the control group. The activity of SOD and the levels of MDA decreased significantly in the DI+Vit group compared with the DI group. The differences between the DI+Vit and control groups according to the MDA levels and the activities of both SOD and CAT were statistically significant. These results suggest that treating rats with a single dose of diazinon increases LPO and some antioxidant enzyme activities in the rat myocardium and, in addition, that single-dose treatment with a combination of vitamins E and C after the administration of diazinon can reduce LPO caused by diazinon, though this treatment was not sufficiently effective to reduce the values to those in control group.

Animals↗
PubMed2006

Surgical treatment outcomes in subdural effusion: a clinical study.

OBJECTIVE: In this study, patients who underwent surgery due to subdural effusion were retrospectively analyzed. The location, depth and etiology of the subdural effusion, the surgical approach that was used and the recurrence rates were studied in these patients. METHOD: A total of 32 patients who were followed up and treated for subdural effusion at the Neurosurgery Clinic of the Yüzüncü Yil University School of Medicine were included in the study; 18 (56%) of the patients were male and 14 (44%) were female. The surgical techniques applied were surgical burr hole drainage, repeated subdural transaxial puncture and subduroperitoneal shunt approaches. The patients were evaluated by computerized tomography of the brain in week 1 and in the third month after surgery. Recurrences were evaluated based on radiological findings and the clinical condition of the patients. RESULT: The consciousness level of the patients was proportional to the mass effect of the subdural effusion. Lower recurrence rates were found in patients with a large midline shift resulting from the subdural effusion. In addition, recurrence rates were higher in patients with cerebral atrophy and lower protein content in the subdural effusion fluid. It was observed that these patients responded better to the subduroperitoneal shunt treatment.

Cerebrospinal Fluid Shunts↗
PubMed2005

Urodynamic evaluation of lower urinary tract function in relation to total abdominal hysterectomy.

This study was performed to evaluate lower urinary tract functions in asymptomatic patients by urodynamic measurements after total abdominal hysterectomy and bilateral salpingo-oophorectomy. Twenty asymptomatic patients who had undergone hysterectomy for benign diseases were included in the study and urodynamic measurements were performed before and 6 weeks after total abdominal hysterectomy and bilateral salpingo-oophorectomy. There was no postoperative difference in first urge, normal urge, urgency and maximum bladder capacity but average urethral length, functional urethral length and maximum urethral closing pressure were decreased and also bladder discharging time was increased. Voided volume and residual urine volume were unchanged. It was concluded that total abdominal hysterectomy and bilateral salpingo-oophorectomy did not change the postoperative bladder loading functions in asymptomatic patients but that significant changes occurred in urethral functions.

Journal Article↗
PubMed2005

Rho-associated protein kinase II (rock II) expression in normal and preeclamptic human placentas.

Rho-associated kinases are serine/threonine kinases that have several functions which might contribute to various physiological and pathological states in cells. There are two isoforms of these enzymes known as rho-associated kinase I (rock I, ROKbeta) and II (rock II, ROKalpha). It has been shown that rock II may be a potential mediator of apoptosis. In addition, rocks play a crucial role in the formation of microvilli-like structures. Increased placental apoptosis and microvilli shedding were shown in preeclampsia. We hypothesized that altered rock expression may lead to the pathologies seen in preeclampsia. Therefore in this study we compared placental rock II expression between normotensive and preeclamptic women using immunohistochemistry and Western blot. Immunohistochemistry and Western blot experiments revealed that rock II is mainly localized in syncytiotrophoblast cells of the placental villi and increased in preeclampsia. In addition to 160 kDa rock II molecule we also detected biologically relevant smaller active form of rock II in preeclamptic but not in normal placentas. We suggest that increased rock II expression in preeclamptic placentas may contribute to etiology or pathogenesis of this syndrome. However, it is considered that rock II expression may also increase to compensate for placental functions changing in preeclampsia.

Adult↗
PubMed2005

Biochemical markers of bone turnover and bone mineral density in patients with beta-thalassaemia major.

In this study, bone formation markers (bone-specific alkaline phosphatase and osteocalcin) and bone resorption markers (pyridinoline and deoxypyridinoline) were analysed. Bone formation, as evidenced by the levels of serum alkaline phosphatase and osteocalcin, did not appear to be impaired, while bone resorption was grossly increased in all patient groups. The decrease of bone mineral density values was more prominent in the lumbar spine, thus making this site particularly interesting for such studies. The patients had significantly lower femoral neck and lumbar spine bone mineral density when compared with control (all p <0.001). Our conclusion is that, in spite of the severe bone destruction that occurs in thalassaemia major, the fact that bone formation remains intact calls for a more intensive treatment.

Absorptiometry, Photon↗
PubMed2005

Rehabilitation studies and recovery of a once lifeless estuary: the Golden Horn.

Within this study fluctuations in biodiversity of the Golden Horn from past to present are evaluated. Limited studies and observations dating back to 60 years ago pointed out the importance of the Golden Horn as a fishery. Unfortunately, in accordance with increase in unplanned settlements and industry around the Golden Horn in the 1960s, pollution stress became a demanding factor for this unique environment, affecting biodiversity adversely. Preliminary studies in the 1990s indicated survival of only a couple of pollution-resistant species, at the relatively cleaner outer estuary. Following intensification of "still ongoing" rehabilitation studies in 1998, a remarkable day-by-day recovery in marine life has began, in regard to improvements in water quality. Surveys conducted in 2002 using SCUBA, documented the level of diversification of life at the Golden Horn. Extended till Haliç Bridge, all appropriate substratums were intensely covered by macrobenthic forms and particularly filter feeders dominated the plankton-rich ecosystem. Detection of seahorses at the inner-middle parts of the estuary, in addition to numerous fish, invertebrate and macroalgae species, clearly depicted the level of recovery and change in the ecosystem. All results support the existence of a dynamic biological life at the Golden Horn, improving considerably with rehabilitation studies. Achieving the diversity of the 1940s is not possible, since the Black and Marmara seas, highly influencing water quality in the Golden Horn are also suffering from anthropogenic impacts and are far beyond their rich diversity in the 1940s. However, it is obvious that ecosystems should recover when mankind gave a chance to them. Recovery of the recently lifeless Golden Horn in such a short period of time is a very good example.

Animals↗
PubMed2003

Emergency treatment of acute symptomatic or ruptured abdominal aortic aneurysm. Outcome of a prospective intent-to-treat by EVAR protocol.

OBJECTIVE: Outcome of treatment of patients with ruptured or symptomatic non-ruptured aneurysm (rAAA and snrAAA), preferentially treated by emergency endovascular repair was assessed. The outcome was compared with a historical group of patients treated by open repair. PATIENTS AND METHODS: Two groups of patients presenting with acute symptomatic AAA were compared. Group I (study group) consisted of 40 consecutive prospectively enrolled patients from May 2001 until June 2002, in whom emergency endovascular abdominal aortic aneurysm repair (e-EVAR) was the preferential management. Short or wide neck or profound hypovolemic shock were exclusion criteria for e-EVAR. Group II (control group) consisted of 28 patients, retrospectively analysed, all treated by conventional surgical repair between January 1999 and May 2001. In group I, 26 patients had rAAA and in group II 22 patients. The other patients had snrAAA. RESULTS: In group I, 14 patients were treated by open repair. Unsuitable anatomy or profound hypovolemia was the cause of open repair in eight patients, while logistic reasons were the reasons for use of open repair in six patients (off-protocol use of open surgery). Thus, in this prospective series the feasibility of EVAR was 80% (32/40). Patient characteristics, proportion rAAA or hemodynamically unstable patients were comparable in group I and II. Volume of blood loss and need for fluid transfusion were significantly less in group I compared to group II. The perioperative mortality in group I was significantly less than in group II (20% vs. 43%, respectively, p = 0.04). If patients with rAAA were considered the mortality was 31% in group I and 50% in group II, which difference did not reach the level of statistical significance. CONCLUSION: e-EVAR was a feasible treatment in the majority of patients with rAAA and snrAAA. Blood loss and the requirements of fluid transfusion were significantly decreased. Most importantly in this institutional series significantly lower first-month mortality was observed in the group with preferential e-EVAR compared to a control group. A multi-center study assessing the outcome of preferential use of e-EVAR in patients with acute symptomatic AAA is required.

Acute Disease↗
PubMed2003

Determination of plasma fibronectin and serum C-reactive protein in patients with cerebrovascular events.

The relationship between the levels of C-reactive protein (CRP) and fibronectin (FN) and atherosclerotic diseases such as coronary heart disease has already been studied, but their relationship with cerebrovascular events has not. The aim of this study was to determine the levels of plasma FN and serum CRP in cerebrovascular events, and their relationship with the outcome of the disease. CRP and FN levels were analysed in 133 patients with acute cerebrovascular disease, together with 66 healthy controls. Cerebrovascular event patients were divided into subgroups according to disease severity. FN and CRP levels in patients with cerebrovascular disease were found to be significantly elevated compared with the control group (p<0.001). CRP levels correlated with disease severity, in contrast to FN levels. We conclude that FN is not a clinically useful marker in patients with acute differentiative cerebrovascular events, in contrast to CRP which may be useful in such cases.

Adult↗
PubMed2003

Association of immune function with bone mineral density and biochemical markers of bone turnover in patients with anklylosing spondylitis.

The lymphocyte-osteoclast interaction has recently been described. The aim of this study was to investigate the possible relationship between ankylosing spondylitis (AS) and bone metabolism. Bone metabolism was evaluated in the blood of 49 patients with AS by means of biochemical markers and bone mineral density (BMD) with a Lunar device. Bone formation markers, bone specific alkaline phosphatase (BALP), osteocalcin (BGP), bone resorption markers, pyridinoline (Pyd), deoxypyridinoline (Dpyd) and lymphocyte surface markers (CD3, CD19, CD4, CD8, CD16+56) were analysed with ELISA and flow-cytometry methods. The patients had significantly lower femoral neck and trochanter BMD than the controls. Dpyd concentrations were negatively correlated to CD3+% and CD3-/CD16+56% cells. Neither mineral nor hormone levels were significantly correlated with absolute T scores of BMD of the hip sites. BALP and BGP were negatively correlated to BMD when expressed as T scores. We conclude that AS is related to accelerated osteoclastic activity. Many lymphokines and growth factors produced by lymphocytes can influence osteoclastogenesis and probably play a role in rheumatologic/inflammatory disorders.

Adult↗
PubMed2002

Benthic community structure of the Bosphorus and surrounding area.

Abstract Spatial and temporal distribution of benthic communities around the Strait of Istanbul (Bosphorus) and the effect of lower layer discharge on these communities have been evaluated during studies between February-December 1999. Mytilus galloprovincialis was the dominant species with fasies at the Black Sea station that is not affected by the strait lower layer current system. On the other hand, another Black Sea station, influenced by the strait lower layer currents, has a similar biota to the strait stations. Species richness and diversity is highest in the strait than other areas. The dominant species is Maera grossimana. However, the station located at the Black Sea exit of the strait has a different biota, and various groups/species appeared to be dominant. Melinna palmata is the dominant species at the Sea of Marmara during the study period. Low dissolved oxygen values of lower layer and soft substratum of sediment resulted in wide distribution of Melinna palmata, adapted to these conditions. The closer stations to the strait in the Sea of Marmara have higher diversity as a result of hydrodynamic processes. On the other hand, coastal stations with low currents and inputs have lower index values, showing the negative effect of discharges and pollution.

Animals↗
PubMed2001

PPARalpha activators inhibit tissue factor expression and activity in human monocytes.

BACKGROUND: Tissue factor (TF), expressed on the surface of monocytes and macrophages in human atherosclerotic lesions, acts as the major procoagulant initiating thrombus formation in acute coronary syndromes. Peroxisome proliferator-activated receptor-alpha (PPARalpha), a nuclear receptor family member, regulates gene expression in response to certain fatty acids and fibric acid derivatives. Given that some of these substances reduce TF activity in patients, we tested whether PPARalpha activators limit TF responses in human monocytic cells. METHODS AND RESULTS: Pretreatment of freshly isolated human monocytes or monocyte-derived macrophages with PPARalpha activators WY14643 and eicosatetraynoic acid (ETYA) led to reduced lipopolysaccharide (LPS)-induced TF activity in a concentration-dependent manner (maximal reduction to 43+/-8% with 250 micromol/L WY14643 [P:<0.05, n=5] and to 42+/-12% with 30 micromol/L ETYA [P:>0.05, n=3]). Two different PPARgamma activators (15-deoxy(_Delta12,14)-prostaglandin J(2) and BRL49653) lacked similar effects. WY14643 also decreased tumor necrosis factor-alpha protein expression in supernatants of LPS-stimulated human monocytes. Pretreatment of monocytes with WY14643 inhibited LPS-induced TF protein and mRNA expression without altering mRNA half-life. Transient transfection assays of a human TF promoter construct in THP-1 cells revealed WY14643 inhibition of LPS-induced promoter activity, which appeared to be mediated through the inhibition of nuclear factor-kappaB but not to be due to reduced nuclear factor-kappaB binding. CONCLUSIONS: PPARalpha activators can reduce TF expression and activity in human monocytes/macrophages and thus potentially reduce the thrombogenicity of atherosclerotic lesions. These data provide new insight into how PPARalpha-activating fibric acid derivatives and certain fatty acids might influence atherothrombosis in patients with vascular disease.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed2001

Angiotensin-converting enzyme gene polymorphism and microvascular complications in Turkish type 2 diabetic patients.

The aim of this study was to investigate whether an association exists between the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism and microvascular complications of type 2 diabetes mellitus in Turkish patients. A total of 239 type 2 diabetic patients and 138 sex and age matched control subjects were included into the study. The I/D polymorphism was determined by polymerase chain reaction (PCR). Nephropathy status was determined according to urinary albumin/creatinine ratio (microg/mg) (<30 normoalbuminuria, 30-300 microalbuminuria, >300 macroalbuminuria) and retinopathy was evaluated by fundoscopic examination and by flourescein fundus angiography. The distribution of ACE I/D polymorphism and allele frequencies in diabetic patients were not significantly different from controls, DD genotype 32.2 versus 37.2%; ID genotype 50.6 versus 47.1%; and II 17.2 versus 15.2%; D allele 57.5 versus 61.2%; I allele 42.5 versus 38.8%. Genotype distribution between normo-, micro- and macroalbuminuric patients did not differ significantly (DD:ID:II (%), normoalbuminuria, 35:46:19; microalbuminuria, 28:55:17; macroalbuminuria, 31:55:14). There was also no difference in genotype distribution between patients with and without retinopathy (DD:ID:II (%), retinopathy positive, 32:51:17; retinopathy negative, 33:49:18). In conclusion, the ACE I/D polymorphism does not seem to be associated with diabetic nephropathy and retinopathy in Turkish type 2 diabetic patients.

Adult↗
PubMed2001

Are normal hemodynamic responses invariably associated with normal penile rigidity and potency?

The existence and importance of patients with low penile buckling pressure and normal penile hemodynamic status have been recently recognized. We assessed the ratio of inadequate erection for vaginal penetration (low buckling pressure) in patients with normal penile vascular system proved with penile Doppler ultrasonography. A total of 101 patients with normal penile vascular status were retrospectively scrutinized dependent on penile axial rigidity (buckling pressure). Ninety patients had sufficient penile axial rigidity (> or = 550 g) whereas in the remaining 11 patients (11%) inadequate penile buckling pressure for vaginal penetration (< 550 g) was determined. Penile geometric and mechanical properties should not be overlooked during the evaluation of penile vascular system lest the patient be incorrectly diagnosed as having psychogenic impotence.

Adult↗
PubMed2001

Differential effects of growth hormone therapy in malnourished hemodialysis patients.

BACKGROUND: Malnutrition is common in chronic hemodialysis patients and is associated with increased morbidity and mortality. Several factors such as metabolic acidosis, hyperparathyroidism, and insulin as well as growth hormone (GH) resistance may lead to enhanced protein catabolism. Recombinant human growth hormone (rhGH) has been proposed as treatment of malnutrition because of its anabolic effects. METHODS: In the present placebo-controlled, double blind study, the effects of three months of rhGH therapy on nutritional and anthropometric parameters, on bone metabolism and bone mineral density (BMD), as well as on polymorphonuclear leukocyte (PMNL) function and quality of life (QoL) were evaluated in 19 malnourished hemodialysis patients (10 females and 9 males) with a mean age of 59.3 +/- 13.4 years. RhGH (0.125 IU/kg) was given three times a week during the first four weeks and 0.25 IU/kg thereafter three times a week after each dialysis session. RESULTS: Insulin-like growth factor I (IGF-I) concentration rose significantly from 169.2 +/- 95.6 ng/mL to 262.9 +/- 144.4 ng/mL (p< 0.01) in the group receiving rhGH. Albumin, prealbumin, transferrin, cholesterol, high-density lipoprotein (HDL) cholesterol, cholinesterase, predialytic creatinine, and blood urea nitrogen showed no significant changes during the three months in both groups. Total body fat (%TBF) was slightly reduced after three months (P = NS) in the patients receiving GH, whereas lean body mass (LBM) remained stable during therapy. Procollagen I carboxy terminal peptide (PICP), a marker of bone formation, increased significantly after three months from 250.1 +/- 112.6 to 478.5 +/- 235.2 microg/L (P < 0.01) in the GH-treated patients, whereas parameters of bone resorption like telopeptide ICTP showed only a slight increase (50.3 +/- 18.5 vs. 70.0 +/- 39.5 microg/L, P = NS). BMD at the lumbar spine decreased significantly after three months in the treatment group (0.8 +/- 0.17 vs. 0.77 +/- 0.16 g/cm2, P < 0.01), whereas BMD at the femoral neck remained stable in both groups. Phagocytic activity of PMNLs increased significantly after three months of therapy with rhGH, whereas other parameters of PMNL function were not affected by GH. QoL was slightly improved in the GH treated group, but decreased markedly in the placebo group. CONCLUSIONS: Three months of treatment with rhGH in malnourished patients on chronic hemodialysis causes a significant increase in IGF-I levels without significant changes in nutritional and anthropometric parameters. In contrast, bone turnover was enhanced with an initial decrease in BMD at the lumbar spine, and phagocytic activity of PMNLs was increased.

Adult↗
PubMed2001

Methysergide attenuates leukocyte-independent plasma extravasation during endotoxemia.

PURPOSE: During endotoxemia, the early endothelial damage has been shown to be leukocyte independent. Therefore, it was the aim of our study to investigate the role of serotonin in mediating leukocyte-independent microvascular permeability during endotoxemia. Microvascular permeability was determined after inhibition of the L-selectin mediated leukocyte adherence by fucoidin and after inhibition of serotonin effects by the serotonin (5HT)-receptor antagonist methysergide. MATERIALS AND METHODS: In male Wistar rats, leukocyte rolling, leukocyte adherence, and macromolecular leakage were determined in mesenteric postcapillary venules using intravital microscopy. After pretreatment with the serotonin-receptor antagonist methysergide, animals in the FUCO/ETX/5HT-ANT group received a continuous infusion of endotoxin. Animals in the FUCO/ETX group underwent the same procedure but received saline 0.9% instead of methysergide. In both groups, leukocyte adherence was prevented by administration of fucoidin. Animals in the saline group received volume-equivalent saline 0.9%. RESULTS: In the endotoxin-challenged groups, fucoidin prevented leukocyte rolling and reduced leukocyte adherence to values comparable to saline group. In the FUCO/ETX group, macromolecular leakage increased significantly, starting at 60 minutes. Values in the saline group increased slightly, being significant at 120 minutes, whereas vascular permeability remained unchanged in the FUCO/ETX/5HT-ANT group. Differences in macromolecular leakage between the FUCO/ETX-group versus the FUCO/ETX/5HT-ANT group and the saline group were significant at 120 minutes. Differences in macromolecular leakage between the FUCO/ETX/5HT-ANT group and the saline group were not significant. CONCLUSIONS: The leukocyte-independent endothelial damage during early endotoxemia can be inhibited efficiently by the 5-HT-receptor antagonist methysergide, indicating that serotonin plays an important role in that pathophysiology.

Animals↗
PubMed2001

Tetanus IgG antibody levels in children aged 12 to 47 months in Turkey.

Tetanus is a serious disease with high mortality, which is very difficult to treat but can be prevented easily by vaccination. The number of tetanus cases reported in Turkey was 42 in 1996 and 51 in 1997. This study was carried out on children aged 12 to 47 months who have vaccination cards in the No. l Health Centre in Batikent district in Ankara, Turkey. Forty-one of the children had received 3 doses (Group 1) of tetanus vaccine, and 47 of them had received 4 doses of the vaccine (Group 2). Anti-toxoid IgG antibody in blood sera was quantified by using the enzyme-linked immunosorbent assay technique. In Group 1, antibody levels more than 0.01 IU/mL were found in 47%, 43%, and 45% of blood sera of children aged 12 to 23 months, 24 to 35 months, and 36 to 47 months, respectively. These rates in Group 2 were found to be 91%, 88%, and 60%, respectively. The protective antibody response (>1 IU/mL) was found to be higher for children in Group 2 than in Group 1, but both rates declined with age. Checking immunization status periodically and giving vaccine doses as required are essential to increase the antibody response. Further, it is a must in developing countries where vaccination efforts are hindered by cold-chain problems, underoptimum application practice, and high prevalence of concomitant infections.

Age Distribution↗
PubMed2001

Serum IL-1beta, sIL-2R, IL-6, IL-8 and TNF-alpha in schizophrenic patients, relation with symptomatology and responsiveness to risperidone treatment.

Activation of the inflammatory response system and varied levels of cytokines in acute schizophrenia have been suggested by recent studies. Psychopharmacologic agents can differentially effect cytokine production, which suggests that therapeutic function of neuroleptics may involve immunomodulation. The present study was carried out to examine: (i) serum concentrations of interleukin (IL)-1beta, soluble interleukin-2 receptor (sIL-2R), IL-6, IL-8 and tumour necrosis factor (TNF)-alpha in schizophrenic patients; (ii) their relation with psychopathological assessment; and (iii) the relation of the initial cytokine levels with responsiveness to risperidone therapy. Thirty-four drug-free schizophrenic patients with acute exacerbation and 23 age- and gender-matched healthy controls were recruited for this study. Psychopathological assessments at admission and throughout risperidone treatment for 60 days were recorded. Serum cytokine concentrations were determined with chemilumunescence assays. According to our results, serum IL-1beta, sIL-2R, IL-6, IL-8 and TNF-alpha concentrations adjusted for age, gender, body mass index and smoking were no different in patients with schizophrenia and controls and among subtypes of schizophrenia. However, the initial TNF-alpha concentrations had a significant effect on Brief Psychiatric Rating Scale and Scale Assessment of Positive Symptoms scores. The initial cytokine concentrations of the patients responsive to risperidone were not significantly different from those of non-responsive patients. The present study demonstrates that plasma levels of IL-1beta, sIL-2R, IL-6, IL-8 and TNF-alpha adjusted for confounding factors are not altered in drug-free schizophrenic patients at acute exacerbation. We suggest that, if cytokine production is altered in schizophrenia, these alterations may not be detectable in systemic circulation. According to our results, the therapeutic effect of risperidone is not related to basal levels of the aforementioned cytokines. However, serum TNF-alpha may contribute to symptomatology in schizophrenia

Adjuvants, Immunologic↗