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Biomedical subjects

Ahmet Yilmaz

Publications and source records attributed to Ahmet Yilmaz.

At least 19 recordsLinked to original sources
PubMed2007

Tortuosity of coronary arteries: an indicator for impaired left ventricular relaxation?

OBJECTIVE: To investigate the relationship between coronary tortuosity and impaired left ventricular relaxation. METHODS: One hundred and four subjects who underwent coronary angiography were included in the study. Left anterior descending, left circumflex, and right coronary arteries were traced. Tortuosity was identified by the finding of >/=3 bends (defined as >/=45 degrees change in vessel direction) along main trunk of at least one artery. Study population were divided into tortuosity (n = 54) and no tortuosity (n = 50) groups. Subjects were all submitted to pulsed-wave Doppler and two-dimensional echocardiographic examination to assess left ventricular functions. RESULTS: For subjects with tortuosity, early transmitral inflow (E) velocity was lower, late transmitral inflow (A) velocity was higher, E/A ratio was smaller compared with subjects without tortuosity (P < 0.001). Subjects with tortuosity had longer deceleration time of E velocity (DT) and isovolumic relaxation time (IVRT) than did subjects without tortuosity (P < 0.001). End-diastolic interventricular septal and left ventricular posterior wall thicknesses were greater in subjects with tortuosity than those without tortuosity (P = 0.01 and P = 0.005). There was an inverse correlation between total number of arteries with tortuosity and E/A ratio (r = -0.750, P < 0.001). Total number of arteries with tortuosity displayed correlations with DT (r = 0.723, P < 0.001) and IVRT (r = 0.703, P < 0.001). CONCLUSIONS: This study depicts that coronary tortuosity is associated with impaired left ventricular relaxation.Thus, coronary tortuosity might be an indicator of impaired left ventricular relaxation.

Adult↗
PubMed2006

Herbals in cardiovascular practice: are physicians neglecting anything?

BACKGROUND: Herbal products have been widely used by many patients with cardiovascular problems solely expecting benefit out of them. Since, it is important to consider patients' needs and believes to prevent breaking off the relationship of patients and physicians, we conducted a survey on patients admitted to our outpatient Cardiology department. METHODS: A questionnaire was prepared including 49 questions. After giving informed consent, 310 participants were enrolled into our survey. Participants were asked about disease states, use of herbal products and their tendencies. RESULTS: There were 169 male (mean age: 54.7+/-13.3 years) and 141 female participants (mean age: 56.2+/-14.7 years). 54.5% (n=169) had hypertension (HT), 48.7% (n=151) had coronary artery disease (CAD). Among all participants, 38.7% (n=120) stated that they have used herbals in part of their lives. Presence of dyslipidemia was associated with herbal use. Three fourths of herbal users (73.3%, n=88) stated that they thought they benefited some extent from the use of herbals, and 25% (n=30) of herbal users stated that they did not take their medicine regularly. Herbal users more frequently agreed the statement "herbals are beneficial when added to medicine" compared to nonusers (20.8% vs. 15.8%, p<0.001). CONCLUSION: Considering the facts that increasing interest on herbals is likely to continue by the people and the potentially hazardous interactions between the herbals and the drugs might be risky for the patients, there seems a need for closer, careful and respectful look for physicians onto herbal users and herbals themselves for the safety of population.

Adult↗
PubMed2006

Torsades de pointes with a severely prolonged QT interval induced by an initial low dose sotalol intake.

Many drugs, including sotalol, have been implicated in prolonging QT interval and triggering torsades de pointes, a potentially fatal ventricular arrhythmia, especially during chronic therapy or in case of acute high dose toxicity. We report here a case with a severely prolonged QT interval and torsades de pointes after an initial intake of low dose sotalol (80 mg), indicating a probable inherent individual oversensitivity to sotalol.

Adult↗
PubMed2006

gamma-Glutamyltransferase is a promising biomarker for cardiovascular risk.

Oxidative stress plays a crucial role in a variety of clinical settings of atherogenesis, and mediates many pathways linked to atherosclerosis and inflammation. gamma-Glutamyltransferase (GGT), an enzyme responsible for the extracellular catabolism of antioxidant glutathione, may directly take part in atherogenesis and evolve as a potential biochemical risk indicator of cardiovascular morbidity and mortality. Classically, GGT has been thought of as a diagnostic tool for hepatobiliary disorders and alcohol abuse. More recently, growing body of data points out that serum GGT levels can aid detection of individuals at high risk for subsequent cardiovascular events, and thus have an application in primary and secondary prevention of cardiovascular disease. Although several investigations have shown that some drugs are effective in decreasing both serum lipids and GGT, and concomitantly the incidence of subsequent cardiovascular events; large-scale randomized trials are required to explore this impact directly. Based on current experimental and epidemiological studies, we postulate here that GGT present in the serum, even within its laboratory reference intervals regarded as physiologically normal, is a promising biomarker for cardiovascular risk.

Alcohol Drinking↗
PubMed2006

The spectrum of tuberculosis in dialysis patients.

Patients receiving dialysis therapy are known to be at increased risk of tuberculosis (TB). The aim of this study was to evaluate the frequency, clinical characteristics and course of TB disease in dialysis patients treated at our institution. Medical records of 330 regular haemodialysis (n=219) and continuous ambulatory peritoneal dialysis (n=111) patients (172 male, 158 female; mean age 55+/-16 y) who were cared for at our tertiary university hospital between December 2002 and January 2006 were retrospectively evaluated. Nine cases of TB (2.7%) occurred, in the following locations: vertebra (n=3), miliary (n=3), lymph nodes (n=1), peritoneum (n=2; one as peritionitis, 1 as an abscess). Four of these 9 patients died during the follow-up (mean time from diagnosis to death, 7 months); none of the deaths appeared to be caused by the disease itself. The incidence of TB disease in patients receiving renal replacement therapy is high, and occurs primarily in extrapulmonary sites.

Adult↗
PubMed2006

Impact of coronary collateral circulation on QT dispersion in patients with coronary artery disease.

OBJECTIVE: The aim of this study was to assess the effect of coronary collateral circulation (CCC) on QT dispersion (QTD) in coronary artery disease. BACKGROUND: A prolonged QTD has been linked to increased heterogeneity of ventricular repolarization implicated in the genesis of ventricular arrhythmias and has been associated with an adverse prognosis in patients with coronary artery disease. METHOD: CCC and corrected QTD (QTcD) were established in patients who had at least 85% stenosis in the left anterior descending coronary artery or in proximal part or in the body of the right coronary artery. Furthermore, left ventricular function score was determined for all the patients. RESULTS: While CCC was not present (CCC grade 0) in 32 patients, 68 patients were observed with CCC (CCC grade > or =1). Mean QTcD was higher in patients who had CCC grade > or =1 than in patients with grade 0 (64.3+/-3.5 and 46.8+/-2.7, respectively, P=0.002). We detected a significant correlation between the collateral score and QTcD (r=0.354, P=0.001). CCC grade > or =1 patients had higher mean left ventricular function scores than grade 0 patients (P=0.048). Left ventricular function score and QTcD were observed to be correlated (r=0.200, P=0.046). CONCLUSION: CCC in chronic coronary artery disease was not established to have a positive decreasing effect on QTcD. On the contrary, QTcD values were observed to be even higher in patients with well developed CCC. Further research including larger series and long-term follow-up is required to investigate this issue.

Arrhythmias, Cardiac↗
PubMed2006

Rapid diagnosis of Mycobacterium tuberculous peritonitis with real-time PCR in a peritoneal dialysis patient.

A 49-year-old female patient on continuous ambulatory peritoneal dialysis presented with fever, abdominal pain and loss of appetite. While peritoneal fluid bacterial cultures remained negative, she had no relief after 3 weeks of broad-spectrum antibiotics for possible bacterial peritonitis. In a peritoneal fluid sample, Mycobacterium tuberculosis DNA was detected by nucleic acid amplification using real-time PCR testing. The initiation of antituberculous therapy (isoniazid, rifampicin, ethambutol and pyrazinamide) was followed by resolution of fever and abdominal pain within one week. Nucleic acid amplification tests can play an important role in the species-specific diagnosis of tuberculous peritonitis.

Antitubercular Agents↗
PubMed2005

Hemopericardium-related fatalities: a 10-year medicolegal autopsy experience.

BACKGROUND: Patients with blunt or penetrating cardiac injury usually present with cardiac tamponade and hemorrhagic shock upon hospital arrival. Many victims die before they reach hospital. In this study, we present a detailed analysis of hemopericardium-related fatalities. METHODS: We retrospectively reviewed the medicolegal autopsy records of hemopericardium-related fatalities that occurred from 1994 to 2003. The parameters investigated were demographic characteristics, hospitalization before death, the cause of death, the manner of death, the mechanism of death, the location of the entrance wound, the number of wounds reaching the target and the site of target perforation. RESULTS: Seven women (mean age: 45 +/- 23 years) and 33 men (mean age: 34 +/- 12 years) were included in the study. Only 5 patients (12.5%) with cardiac activity reached the hospital. Twenty individuals (50%) were victims of stabbings, which was the most common cause of death. The most commonly encountered manner of death was homicide (79%). Thirty-one (77.5%) victims died of hemorrhagic shock and 9 (22.5%) of cardiac tamponade. Entrance wounds were frequently located on the left chest (n = 26). The perforated cardiac chambers were the left atrium (n = 1), the left ventricle (n = 12), the right atrium (n = 2) and the right ventricle (n = 15). One victim had coronary artery perforation. Nine victims had perforations on the intrapericardial part of the aorta. CONCLUSIONS: In our series, the hemopericardium-related deaths occurred predominantly in men. Stabbing was the most common cause of death. Entrance wounds were most commonly located on the left chest, and perforated sites were ventricles. Death at the scene was also frequent, and the mechanism of death was hemorrhagic shock.

Accidents, Aviation↗
PubMed2005

Genomic organization, annotation, and ligand-receptor inferences of chicken chemokines and chemokine receptor genes based on comparative genomics.

BACKGROUND: Chemokines and their receptors play important roles in host defense, organogenesis, hematopoiesis, and neuronal communication. Forty-two chemokines and 19 cognate receptors have been found in the human genome. Prior to this report, only 11 chicken chemokines and 7 receptors had been reported. The objectives of this study were to systematically identify chicken chemokines and their cognate receptor genes in the chicken genome and to annotate these genes and ligand-receptor binding by a comparative genomics approach. RESULTS: Twenty-three chemokine and 14 chemokine receptor genes were identified in the chicken genome. All of the chicken chemokines contained a conserved CC, CXC, CX3C, or XC motif, whereas all the chemokine receptors had seven conserved transmembrane helices, four extracellular domains with a conserved cysteine, and a conserved DRYLAIV sequence in the second intracellular domain. The number of coding exons in these genes and the syntenies are highly conserved between human, mouse, and chicken although the amino acid sequence homologies are generally low between mammalian and chicken chemokines. Chicken genes were named with the systematic nomenclature used in humans and mice based on phylogeny, synteny, and sequence homology. CONCLUSION: The independent nomenclature of chicken chemokines and chemokine receptors suggests that the chicken may have ligand-receptor pairings similar to mammals. All identified chicken chemokines and their cognate receptors were identified in the chicken genome except CCR9, whose ligand was not identified in this study. The organization of these genes suggests that there were a substantial number of these genes present before divergence between aves and mammals and more gene duplications of CC, CXC, CCR, and CXCR subfamilies in mammals than in aves after the divergence.

Amino Acid Motifs↗
PubMed2005

Stuttering due to ischemic stroke.

Acquired stuttering is a disorder of the fluency of speech. The mechanism underlying stuttering is unknown. It may occur after bilateral and unilateral cortical or subcortical brain damage. We report two cases who had stuttering resulting from left parietal infarction.

Aged↗
PubMed2005

The effects of continuous ambulatory peritoneal dialysis and hemodialysis on serum pepsinogen concentrations in patients with chronic renal failure.

Pepsinogen, the precursors of pepsin, is classified into two subtypes: pepsinogen I (PG I) and pepsinogen II (PG II). Patients with impaired renal function are associated with elevated concentrations of serum pepsinogen. Contradictory results have been reported about the effect of dialysis on the serum pepsinogen levels, as the previous studies were conducted only in a particular period of dialysis. We therefore investigated the effect of continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis on serum pepsinogen levels in patients with chronic renal failure (CRF) before and after dialysis treatment. Thirty-four patients with CRF were enrolled in this study and were treated by CAPD (n=22) or hemodialysis (n=12). As a control group, subjects with normal renal function were included (n=20). Serum PG I and PG II levels were measured in control subjects and CRF patients before dialysis treatment and after three-month dialysis treatment. Before dialysis treatment, serum PG I levels were significantly higher in CRF patients than control subjects. In patients treated by CAPD, the serum PG I levels were significantly decreased but its levels were still higher than the values of the control subjects, whereas PG I levels remained unchanged in patients treated by hemodialysis. There were no differences in serum PG II levels between control subjects and CRF patients before or after dialysis treatment. Thus, CAPD is more effective than hemodialysis in the clearance of PG I.

Adult↗
PubMed2005

Detection of two nucleotide substitutions and putative promoters in the 5' flanking region of the ovine IGF-I gene.

The objective of this study was to search for polymorphisms and gene regulatory sequences in the 5' flanking region of the sheep insulin-like growth factor I (IGF-I) gene. PCR-SSCP analysis of the 5' flanking region revealed three banding patterns. Family study indicated that these patterns in mixed breed sheep corresponded with three genotypes (with their frequencies in parentheses) AA (0.70), AB (0.25), and BB (0.05), which arose from a one-locus, two allele (A, B) polymorphism. Genotypic frequencies in 22 purebred Polypay sheep were AA (0.77) and AB (0.23). Calculated frequency of the A allele in Polypays was 0.89. No deviation from Hardy-Weinberg equilibrium was detected in this study. Fragments amplified using DNA from homozygous individuals were sequenced and aligned next to each other. A T to C transition and a G to C transversion were found at positions 179 and 181, respectively, of the amplified PCR product, resulting in recognition sites for Bsp143II and HaeI. Analysis of a fragment of 2,162 base pairs upstream of Exon 1, assembled from sheep ESTs and sequence of our amplified PCR products, revealed a promoter sequence approximately 100 bp downstream of the polymorphic sites. The assembled DNA fragment shared 70% sequence homology between sheep and human. These results suggest that sequence of the 5' flanking region of IGF-I gene and location of the IGF-I promoters are similar in human and sheep.

5' Flanking Region↗
PubMed2004

Identification and sequence analysis of chicken Toll-like receptors.

Toll-like receptors (TLRs) play an important role in the recognition of microbial components. Only chicken TLR2 and -4 have been reported in the literature. The objectives of this study were to identify new chicken TLRs and to evaluate evolutionary significance of these receptors. Searching chicken genomic databases and DNA sequencing revealed five new TLRs, TLR1 (type 1 and 2), -3, -5, and -7. No chicken orthologues of mammalian TLR8, -9, or -10 were found. As in mammals, all chicken TLRs (chTLRs) share identical protein secondary structure that consists of several leucine-rich domains, a transmembrane domain, and Toll/Interleukin-1 receptor domain(s). Phylogenetic analyses indicate that the identified chTLR genes are the orthologues of TLRs in mammals. Analyses of the number of synonymous substitutions per synonymous site and nonsynonymous substitutions per nonsynonymous site indicate that the nucleotide sequences coding for the leucine-rich repeats of chicken TLR1 type 1 and type 2 were significantly under positive Darwinian selection. In contrast, the sequences of other TLRs were under purifying selection. These results support the hypothesis that one of the major evolutionary strategies of the innate immune system is to recognize a few highly conserved microbial components with several conserved TLRs. The results also indicate that the sequence changes in the ligand-binding domains of TLR1 in chickens provide adaptive advantages during evolution.

Amino Acid Sequence↗
PubMed2004

Deaths due to hunger strike: post-mortem findings.

Hunger strike is described as voluntary refusal of food and/or fluids. Prolonged starvation may produce many adverse events including even death in rare circumstances. Here, we present three fatal cases (all males, 25-38 years) died from hunger strike. In all corpses, obvious muscle wasting with reduced subcutaneous and internal fat deposits, and atrophy in some organs were demonstrated at autopsy. The extraordinary long starvation period before death could presumably be linked to the thiamine uptake in this period, which had been discontinued by all subjects before the death occurred. Prolonged caloric deficiency with subsequent complications such as multiple organ failure, severe sepsis and ventricular fibrillation could account as major causes of death in these subjects. The competence of the physicians working with hunger strikers about the processes and potential problems is of great importance since they have to acknowledge about them to their patients.

Adipose Tissue↗
PubMed2004

Effects of 10alpha,25-dihydroxyvitamin D3 on doxorubicin-induced chromosomal aberrations in rat bone marrow cells.

The present study was carried out to evaluate the effects of 1alpha,25-dihydroxyvitamin D3 (VD) on chromosomal aberrations induced by doxorubicin (DXR). Wistar rats were divided into eight experimental groups of five animals each. Control group animals were treated with i.p. distilled water. The animals in three VD groups were given only VD for 4, 6 or 8 weeks. In the DXR groups the animals were given only DXR. In the combination groups VD doses were given for 4, 6 or 8 weeks for each group and DXR was injected 24 h before sacrificing the rats. DXR (50 mg/100 g b.w.) was injected intraperitoneally and VD by gavage 3 microg/kg/day twice weekly. Animals treated with both VD and DXR showed a low frequency of chromosomal aberrations and abnormal metaphases when compared with animals treated with DXR alone (p < 0.0001). The numbers of both chromosomal aberrations and abnormal metaphases were similar in weeks 6 and 8 (p > 0.05) and lower than those in week 4 for the VD groups (p < 0.0001). Under the present experimental conditions, the efficiency of VD in protecting cells against DXR-induced chromosome damage was found to be dose dependent. The protective effects of VD on chromosome aberrations induced by DXR are discussed in the light of literature data.

Animals↗
PubMed2004

The effects of peritoneal dialysis and hemodialysis on serum tumor necrosis factor-alpha, interleukin-6, interleukin-10 and C-reactive-protein levels.

BACKGROUND: Markers of an acute phase reaction, such as C-reactive protein (CRP) or tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6, are predictive for cardiovascular morbidity and mortality in normal subjects and in chronic renal failure patients. In this study, we aimed to investigate serum TNF-alpha, IL-6, IL-10 and CRP levels in continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) patients. MATERIALS AND METHODS: Serum levels of TNF-alpha, IL-6, IL-10 and CRP levels were measured in 30 patients who were just diagnosed with end-stage renal failure and treated, with 16 CAPD (nine female, seven male) and 14 HD (eight female, six male) patients, before CAPD or HD treatment and after 3 months from the beginning of CAPD or HD in patients with no clinical signs of infection. The control groups were 20 healthy persons of similar age and sex. Serum levels of TNF-alpha, IL-6, IL-10 and CRP were measured by enzyme-linked immunosorbent assay in stable CAPD and HD patients and in healthy persons. RESULTS: The mean serum levels of TNF-alpha, IL-6, IL-10 and CRP showed no significant differences between the CAPD and HD patients for the beginning values and the third month of treatment. However, serum TNF-alpha, IL-6, IL-10 and CRP levels were higher than the control group in the CAPD and HD patients regarding the beginning values and the third month of treatment (p < 0.001). CONCLUSIONS: CAPD and HD of the renal replacement therapy have no effects on serum CRP and cytokines.

C-Reactive Protein↗
PubMed2004

The effects of hemodialysis and peritoneal dialysis on serum homocysteine and C-reactive protein levels.

OBJECTIVES: In this study, we aimed to investigate plasma homocysteine (Hcy) and serum C-reactive protein (CRP) levels in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients, and the relation among them. MATERIALS AND METHODS: This study was carriedout on 52 HD patients, 26 CAPD patients and a control group of 22 healthy persons. Blood samples were taken from the patients for Hcy and CRP measurements. RESULTS: Serum CRP level was found to be high in 48.1% of HD patients, 69.2% of CAPD patients and 4.5% of the healthy control group. Plasma Hcy level was found out to be above the normal limits in 73.1% of HD patients, 65.4% of CAPD patients and 9% of the healthy control group. There was a significant positive relation (r = 0.384, p < 0.001) between the levels of plasma Hcy and serum CRP in HD and CAPD patients. CONCLUSION: The high levels of Hcy and CRP were found out to be higher in HD and CAPD patients than in the control group. In order to determine the risk rate of Hcy and CRP for coronary artery disease, extensive investigations are required in patients with chronic renal failure that also have coronary artery disease.

Adult↗