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Hasan Yüksel

Publications and source records attributed to Hasan Yüksel.

13 recordsLinked to original sources
PubMed2006

Stringent constraint on galactic positron production.

The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons. If these positrons are injected at even mildly relativistic energies, higher-energy gamma rays will also be produced. We calculate the gamma-ray spectrum due to inflight annihilation and compare it with the observed diffuse Galactic gamma-ray data. Even with a simplified but conservative treatment, we find that the positron injection energies must be less than or similar to 3 MeV, which strongly constrains models for Galactic positron production.

Journal Article↗
PubMed2006

Spontaneously ruptured uterine angioleiomyoma.

Angioleiomyoma is an uncommon type of leiomyoma of the uterus that originates from smooth muscle cells and contains thick-walled vessels. A 45-year-old woman with the complaint of lower abdominal pain was admitted to the hospital. In the operation a ruptured, bleeding uterine tumor was seen. She underwent total hysterectomy and bilateral salpingo-oophorectomy. On pathologic examination of the specimen, the tumor was diagnosed as angioleiomyoma. Here, an unusual clinical presentation of uterine angioleiomyoma was reported.

Angiomyoma↗
PubMed2006

Effects of oral continuous 17beta-estradiol plus norethisterone acetate replacement therapy on abdominal subcutaneous fat, serum leptin levels and body composition.

AIM: To evaluate the effects of oral continuous 17beta-estradiol plus norethisterone acetate (E2/NETA) replacement therapy on abdominal subcutaneous fat, serum leptin level (SLL) and body composition in postmenopausal women. MATERIALS AND METHODS: A 6-month, prospective, randomized, double-blind and placebo-controlled study was conducted. Forty-three healthy naturally postmenopausal women aged 43-65 years were randomly assigned to receive E2/NETA (2 mg E2 plus 1 mg NETA, n = 22) or placebo (n = 21). Fasting SLL by enzyme-linked immunosorbent assay, subcutaneous abdominal fat thickness (STh) by ultrasound and the anthropometric indices of body weight (BW), body mass index (BMI), waist and hip circumference (WC, HC) and waist-to-hip ratio (WHR) were recorded at the beginning and the end of the study. RESULTS: After 6 months of therapy, BW and SLL increased in the placebo group (p = 0.043 and 0.033, respectively). WC, HC and STh decreased significantly in the E2/NETA group (p = 0.002, 0.006 and 0.000, respectively) and they were also significantly lower in women receiving E2/NETA than in women taking placebo (p = 0.000, 0.034 and 0.000, respectively). At baseline, SLL and STh were positively correlated with all anthropometric indices except WHR. CONCLUSION: Oral continuous combined regimen of E2/NETA significantly reduced central fat accumulation as assessed by WC and STh, and attenuated the increase in SLL. The observed changes in SLL were highly and positively related to changes in STh. The oral continuous combined E2/NETA regimen appears to have protective effects on cardiovascular function and probably on metabolic diseases by its slimming effect upon WC in postmenopausal women.

Administration, Oral↗
PubMed2006

Effects of intravenous lidocaine on QTd and HRV changes due to tracheal intubation during sevoflurane induction.

The aim of the present study was to evaluate the effects of IV lidocaine on autonomic cardiac function changes in tracheal intubation (TI) during sevoflurane anaesthesia by using more reliable parameters, namely, the analysis of QT dispersion and heart rate variability (HRV) from Holter monitoring. In this prospective, double-blind study, 44 American Society of Anaesthesiologists class I-II patients scheduled for hysterectomy were randomly and equally divided into 2 groups; a control sevoflurane group (group S, n = 22) and a lidocaine sevoflurane group (group LS, n = 22). Before the induction of anaesthesia, the electrocardiograms (ECG) of all patients were recorded for 3 minutes as baseline parameters. In both groups, the anaesthesia was induced with 7% sevoflurane in O(2 )at 6L min(-1) via a facemask for 2 minutes. However, before the induction of sevoflurane anaesthesia in group LS, 1 mg kg(-1) of lidocaine was given intravenously (IV). For muscle relaxation during TI, vecuronium was given to all participants. Three minutes after administration of vecuronium, TI was performed and an ECG was recorded synchronously for another 3 minutes. The results from the later records were used as postintubation parameters. Baseline and postintubation data were analysed. When compared to baseline values, postintubation LF/HF and SDNN values were increased in group S (P = 0.005, P = 0.001, respectively), whereas postintubation LF and HF values were decreased in group LS (P = 0.014, P = 0.041, respectively). Under the influence of sevoflurane anaesthesia, TI resulted in sympathetic activation. However, this activation was attenuated by the administration of IV 1 mg kg(-1) lidocaine 5 minutes prior to TI.

Administration, Inhalation↗
PubMed2005

Detection of neutrinos from supernovae in nearby galaxies.

While existing detectors would see a burst of many neutrinos from a Milky Way supernova, the supernova rate is only a few per century. As an alternative, we propose the detection of approximately 1 neutrino per supernova from galaxies within 10 Mpc, in which there were at least 9 core-collapse supernovae since 2002. With a future 1 Mton scale detector, this could be a faster method for measuring the supernova neutrino spectrum, which is essential for calibrating numerical models and predicting the redshifted diffuse spectrum from distant supernovae. It would also allow a > or approximately 10(4) times more precise trigger time than optical data alone for high-energy neutrinos and gravitational waves.

Journal Article↗
PubMed2005

[The relationship between skin test results and serum eosinophilic cationic protein, nasal eosinophilia, and total IgE values in patients with allergic rhinitis].

OBJECTIVES: We investigated the relationship between positive skin test results and serum eosinophilic cationic protein (ECP), nasal eosinophilia, and total IgE levels in patients with allergic rhinitis. PATIENTS AND METHODS: The study included 36 patients with allergic rhinitis (26 females, 10 males; mean age 32.8 years; range 17 to 60 years) and with a positive skin test result. Serum ECP, nasal eosinophilia, and serum total IgE levels were assessed and compared with a control group of 18 healthy volunteers (15 females, 3 males; mean age 30.3 years; range 20 to 49 years) and correlation was sought with skin test results. RESULTS: Twenty-five patients were sensitive to only seasonal, four patients to only perennial, and seven patients to both seasonal and perennial allergens. Twelve patients were sensitive to one allergen, seven patients to two, and 17 patients to three or more allergens. Compared to controls, the mean serum ECP, nasal eosinophilia, and serum total IgE values were significantly higher in the patient group (p<0.05). These parameters did not show significant relationship with the type and number of allergens (p>0.05). CONCLUSION: Serum ECP, nasal eosinophilia, and serum total IgE levels increase in patients with allergic rhinitis. These parameters are not affected by sensitivity to seasonal or perennial allergens.

Adolescent↗
PubMed2004

Biochemical markers of bone metabolism and calciuria with inhaled budesonide therapy.

We investigated the changes in renal excretion of calcium, sodium, and potassium in asthmatic children treated with inhaled budesonide, an inhaled glucocorticoid. Twenty-two asthmatic patients (7 female, 15 male, mean age 10.1+/-4.3 years) treated with 400-600 microg/day inhaled budesonide and 23 healthy children (6 female, 17 male, mean age 10.2+/-2.8 years) were enrolled in the study. The parameters recorded were serum sodium, potassium, calcium, phosphorus, alkaline phosphatase (ALP), type I collagen carboxyterminal telopeptide (ICTP), osteocalcin, intact parathyroid hormone (PTH) levels, first spot morning urine calcium/creatinine ratio, sodium/potassium ratio, and daily renal calcium excretion rate (UCa-ER). These parameters were measured in the control group and pre- and post-budesonide treatment in asthmatic children. Serum electrolytes, ALP, PTH, ICTP, and UCa-ER were in the normal ranges and were not significantly different between controls and asthmatic children. Serum levels of ICTP increased, while levels of osteocalcin decreased after budesonide therapy in the asthmatic group ( P=0.001, P=0.005). UCa-ER was decreased after budesonide therapy in asthmatics ( P=0.000). In conclusion, moderate doses of inhaled budesonide cause hypocalciuria and decreased bone turnover. These results may be attributed to a mechanism compensating for decreased absorption of calcium in the gut due to the topical effect of swallowed budesonide rather than the systemic effects of the drug. Increased bone metabolism and decreased turnover may have an important role in this compensatory mechanism.

Administration, Inhalation↗
PubMed2004

Ovarian pregnancy with intrauterine device in situ.

INTRODUCTION: Since some reports have already suggested a higher rate of ovarian pregnancies in women using intrauterine device and some have not, an additional case report may be of interest for the literature purposes. CASE REPORT: In this case report we present an ovarian pregnancy in a patient with an intrauterine device in situ.

Adult↗
PubMed2003

Fulminant meningococcemia and acute renal failure in a 3-year-old boy.

Acute renal failure is a common occurrence in sepsis, but is rarely reported in meningococcemia. We present a young child diagnosed with fulminant meningococcemia who had several poor prognostic factors, including hypotension, thrombocytopenia, purpura fulminans, seizures, the absence of meningitis with meningococcemia, and acute renal failure, which was successfully treated with peritoneal dialysis. Peritoneal dialysis was started on the 5th day because the patient had been anuric for 48 h. At that time, analysis showed that the child was both hypokalemic and hypophosphatemic. His serum blood urea nitrogen was 61 mg/dl, creatinine 2.75 mg/dl, potassium 2.8 mEq/l, and phosphorus 0.7 mg/dl. Urine output began on the 12th day post admission and normalization of serum creatinine was achieved on the 26th day. In conclusion, renal failure is an important complication of meningococcemia and, to be effective, sometimes long-term peritoneal dialysis is required. Profound metabolic abnormalities, such as hypokalemia and hypophosphatemia, may occur paradoxically in the presence of oliguria.

Bacteremia↗
PubMed2003

Protective effect of leukotriene receptor antagonist montelukast on smoking-induced lung injury in Wistar rats.

Increased activation of alveolar macrophage, neutrophil and mast cell has been proven in cigarette smoking (CS)-related lung disorders (CSLD). An increased production of cysteinyl-leukotrienes (LTs), which are mediators secreted from the mentioned cells, in response to CS has been shown in humans. The protective effect of LT1 receptor-1 antagonist (LTR-1AT) on CSLD is, however, not known. In this study we aimed to determine whether there is any protective effect of a LTR-1AT, montelukast (MK), on CSLD in Wistar rats. Nine controls and twenty-three smoke-exposed rats were enrolled into this study. Controls were exposed to non-filtered air, and the smoke-exposed rats were exposed to CS for 6 h/day, 6 days/week for three weeks. The CS-exposed rats were also treated with 0.1 mg/kg/day of MK or saline. Morphometric criteria for lung injury were determined as the mean linear intercept of alveolar septa (Lm), the volume density of alveolar septa (Vvspt) and the density of the alveolar surface area per unit volume of lung parenchyma (Sva.pa). Lung mast cells (LMC), which are a major source of LTs, were also counted. Results showed that Lm of the control group was significantly lower and Vvspt, Sva.pa of the controls were significantly higher compared to those of the CS-exposed groups. Animals treated with MK had significant protection against CSLD. Lm was significantly higher and Vvspt, Sva.pa were lower in the saline group than in the MK-treated group. The number of LMC in the CS-exposed groups was also significantly higher than that in the control group. Based on these results, one can suggest that some part of the pathogenesis of CSLD may be related to an enhanced LTs synthesis and LTR-1AT. Therefore, montelukast may protect against active or passive smoking-induced lung injury and related disorders.

Acetates↗
PubMed2003

Diagnosis of asymptomatic atrial septal aneurysms using two-dimensional color Doppler and contrast transthoracic echocardiography.

OBJECTIVE: To evaluate the dimensions of atrial septal aneurysm (ASA), the presence and characteristics of interatrial shunt, the movement of the wall of the aneurysm, and correlation between these findings and sign and/or symptoms suggesting embolism in Manisa, a district of a western Anatolian city of Turkey. METHODS: Two thousand five hundred cases were examined by routine transthoracic echocardiography (TTE) in both pediatric and adult cardiology outpatient clinics. ASA was detected in 20 cases and evaluated by two-dimensional color Doppler echocardiography (CDE). The length of the base, the maximum radius and the maximum displacement of ASA were measured. The shunt between the atria was examined by CDE. In cases where a shunt could not be found, galactose and palmitic acid was injected. Standard 12-lead electrocardiogram (ECG) and exercise stress test were also performed. RESULTS: No clinical signs or symptoms were found, suggesting a systemic or cerebral embolism. The maximum displacement of ASA was between 2 and 5 mm. All of the aneurysms were localized in the right atrium, and the walls of the aneurysm did not move beyond the base of the left atrium during the maximum displacement. Interatrial shunt was detected in 14 of 20 patients (70%) by CDE and in the remaining six cases by contrast TTE. Frequent ventricular ectopic beats were observed in one patient. CONCLUSIONS: During routine TTE we observed 0.8% asymptomatic ASA in our population. The use of a contrast agent was found to be a valuable additional method in patients with ASA when the shunt could not be detected by CDE. The risk for embolism is not high when the maximum displacement of the wall of ASA was 5 mm or less and no bulge into the left atrium was observed. Based on our experience with this method, TTE is easy to perform, well-tolerated and acceptable.

Adolescent↗
PubMedDate not supplied

Effects of sevoflurane on QT dispersion and heart rate variability.

The purpose of this study was to use estimates of corrected QT dispersion (QTcd) and heart rate variability (HRV) to assess the effects of sevoflurane, an inhalation agent used frequently in clinical practice, on autonomic cardiac function. This study was conducted prospectively and in a blind manner on 20 women between 38 and 51 y of age who were classified as American Society of Anesthesiologists stage I-II and whose treatment required total abdominal hysterectomy. Electrocardiograms were recorded by 12-lead Holter monitor for 5 min before sevoflurane induction and again for 5 min at 10 min after tracheal intubation. Data on the first recording were considered as baseline; those on the second recording were viewed as final data. The study was terminated at this point, and surgery was allowed to proceed. QTcd and HRV values were assessed by a cardiologist, who was blinded to all data. All parameters were expressed as a mean value +/- standard deviation. Wilcoxon's test was used to compare baseline and final data. Statistical significance was considered as P<.05. No significant changes were observed between baseline and final QTcd values and between low- and high-frequency components (LF and HF) of HRV; nor were changes seen in the LF/HF ratio. With the patient under sevoflurane/ nitrous oxide anesthesia, no significant changes were detected in QTcd, LF, and HF values, and in the LF/HF ratio, whereas a significant increase (P=.001) was seen in standard deviation of the R-R interval, which was used as a measure of cardiac autonomic tone.

Adult↗