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    Atypical presentation in patients with 17 ?-hydroxylase deficiency caused by a deletion in the CYP17A1 gene: short stature
    (2020) Bolu, Semih; Eröz, Recep; Tekin, Mehmet; Doğan, Mustafa
    Background. Patients with 17?-hydroxylase deficiency (17 OHD) usually present with tall stature and eunuchoid features, rather than growth retardation. However, unlike the classic form of the disease, short stature due to a lack of pubertal growth spurt and sex hormone deficiency was present in our four cases. We wanted to emphasize that short stature might be the cause of first presentation in patients with 17 OHD. Cases. We report five patients of Kurdish origin with 17 OHD, four of whom had short stature; two presented because of short stature and two were detected as having short stature. The external genitalia had a female appearance and was prepubertal in all cases. Hypertension was also detected in four of the patients. Serum biochemical and hormonal analyses were performed for each patient. Laboratory data suggesting severe growth hormone (GH) deficiency were obtained from one patient, while the other had a familial history suggesting constitutional delay of growth and puberty (CDGP). Whole exome sequence analysis of the CYP17A1 gene was performed on all patients. STR fragment analysis and multiplex ligation dependent probe amplification (MLPA) analysis was also performed to detect mutations associated with congenital adrenal hyperplasia (CAH) in the CYP17A1 gene. No mutation was detected in the whole exome sequence analysis of the CYP17A1 gene in all five patients, although wide deletions were identified in the 1st–6th exons of this gene at MLPA analysis. Conclusions. Patients with 17?-hydroxylase deficiency can present with short stature because they have no pubertal growth spurt during adolescence. Therefore, 17 OHD should be considered in the differential diagnosis of patients with delayed puberty and short stature.
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    Influence of Canola Oil Methyl Ester and Diesel Fuel Blends on A Single Cylinder Diesel Engine Performance and Noise Emissions
    (Gazi Univ, 2016) Sarıdemir, Suat; Tekin, Mehmet
    Nowadays, the noise emissions caused by the diesel engines, which is widely used, constitute the adverse effects on the living organisms for both long and short-term. In this study, the single cylinder diesel engine power, torque and noise emissions were experimentally investigated for the fuel mixture which was a canola oil methyl ester with the standard diesel fuel. The torque, power values, the noise emissions were compared when canola oil methyl ester, which was mixed with the standard diesel fuel at the rate of 0%, 20%, 40%, was subjected to the full load, different speed test. It was observed that the engine torque, power and noise emissions were decreased as the rate of canola oil methyl ester increased in the the standard diesel fuel.
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    Prediction of engine performance and exhaust emissions with different proportions of ethanol-gasoline blends using artificial neural networks
    (Taylor & Francis Ltd, 2019) Tekin, Mehmet; Sarıdemir, Suat
    The main purpose of this study is to experimentally investigate the use of ANNs (artificial neural networks) modelling to predict engine power, torque and exhaust emissions of a spark ignition engine which operates with gasoline and methanol blends. For the ANN modelling, the standard back-propagation algorithm was found to be the optimal choice for training the model. Afterwards, the performance of the ANN predictions was evaluated with the experimental results by comparing the predictions. Fuel type and engine speed have been used as the input layer, while engine torque, power, exhaust emissions, Tex and BSFC have also been used separately as the output layer. It was found that the ANN model is able to predict the engine performance, exhaust emissions, Tex and BSFC with a correlation coefficient of 0.9991887425, 0.9990868573, 0.9986749623, 0.9988624137, 0.9976761492, 0.9992943894 and 0.9978899033 for the Power, Torque, CO, CO2, HC, Tex and BSFC for testing data, respectively.
  • Küçük Resim
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    A rare cause of delayed puberty and primary amenorrhea: 17 alpha-hydroxylase enzyme deficiency
    (Springer, 2021) Bestas, Asli; Bolu, Semih; Unal, Edip; Aktar Karakaya, Amine; Eroz, Recep; Tekin, Mehmet; Haspolat, Yusuf Kenan
    Aim 17 alpha-hydroxylase enzyme deficiency is a rare form of congenital adrenal hyperplasia (CAH) and is caused by mutations in the CYP17A1 gene. The main clinical findings are delayed puberty and primary amenorrhea in girls, and disorders of sex development in boys. It can also cause hypertension and hypokalemia in both genders. In this study, we aimed to present the clinical, laboratory and genetic results of 13 patients from eight different families who were diagnosed with complete 17 alpha-hydroxylase enzyme deficiency. Methods The age, symptoms, anthropometric measurements, blood pressure, Tanner stages, and hormonal and chromosome analysis results at the time of admission were recorded from the medical records of the patients. Whole gene next-generation sequencing of CYP17A1 gene was performed to detect mutations. Multiplex ligation dependent probe amplification (MLPA) method were used to detect deletions in the seven patients who had no point mutation were detected in the CYP17A1 gene. Results The average age of the patients at the time of admission was 14.8 (range: 12.9-16.6) years. Also at this time, all patients were in adolescence and were raised as females. The karyotypes of eight patients were 46,XY, and of five patients were 46,XX. Ten patients presented with delayed puberty and primary amenorrhea, one patient with delayed puberty and hypertension, and two patients with hypertension and/or hypokalemia. Hypertension and hypokalemia were detected in nine and seven patients, respectively. Conclusions P450c17 enzyme deficiency should be considered in patients presenting with delayed puberty or primary amenorrhea in the adolescence period and diagnosed with hypergonadotropic hypogonadism, if hypertension and hypokalemia accompany. Early diagnosis prevents the occurrence of important health problems such as hypertension, psychological problems, and gender identity disorders, which affect the majority of these patients.