Sayit Altikat - Academia.edu (original) (raw)

Papers by Sayit Altikat

The invasive measurement techniques that puncture the skin during the detection are generally use... more The invasive measurement techniques that puncture the skin during the detection are generally used for blood glucose and haemoglobin A1C (HbA1C) detection. In this paper, artificial neural network structures were used for the detection of relationship between blood glucose, HbA1C and palm perspiration rate as a non-invasive measurement technique. For this purpose, a comparative study was realized by using feed

The invasive measurement techniques which puncture the skin are used for blood data values detect... more The invasive measurement techniques which puncture the skin are used for blood data values detection generally. In this paper, artificial neural network structures were used for the classification of the relationship between blood data values and palm perspiration rate as a non-invasive measurement technique. For this purpose, a comparative study was realized by using feed forward multilayer, Elman, probabilistic, radial basis and learning vector quantisation neural network structures. The quartz crystal microbalance type and humidity sensors were used for detection of palm perspiration rate. A data set for 91 volunteers is used for this study. Data of 21 volunteers are used for training the neural networks and the remaining data were used as test data.

Journal of environmental protection and ecology

ABSTRACT Export Date: 18 October 2014

Polish journal of pharmacology

The study investigated in vitro effects of halothane, isoflurane, ketamine, sevoflurane, prilocai... more The study investigated in vitro effects of halothane, isoflurane, ketamine, sevoflurane, prilocaine, diazepam, and midazolam on enzymatic activity of human red blood cell glucose-6-phosphate dehydrogenase (G6PD; E.C. 1.1.1.49). G6PD was purified from human red blood cells by 2',5'-ADP-sepharose 4B affinity gel. Enzymatic activity was spectrophotometrically measured at 340 nm according to the method of Beutler. I50 values were determined from drug activity (%) - drug concentration curves. I50 values were as follows: 0.72 mM for isoflurane, 1.82 mM for sevoflurane, 0.38 mM for diazepam, and 0.0019 mM for midazolam. But halothane, ketamine and prilocaine had no inhibitory effect on the G6PD activity in in vitro.

Molecular Medicine Reports, 2013

Bortezomib is a highly selective and reversible inhibitor of the 26S proteasome. It has been appr... more Bortezomib is a highly selective and reversible inhibitor of the 26S proteasome. It has been approved for the treatment of patients with relapsed and refractory multiple myeloma. A number of studies have been conducted to evaluate the activity and safety of bortezomib either alone or in combination with several cytotoxic agents and radiation. In the current study, the efficacy of bortezomib alone or in combination with cisplatin and 5‑fluorouracil was evaluated in 4T1 breast cancer cells, a highly metastatic murine cancer cell line. Using MTT assay, IC50 values of cisplatin and 5‑fluorouracil were determined to be 14.2 and 8.9 µM for cisplatin and 5‑fluorouracil, respectively. The effects of different concentrations of cisplatin and 5‑fluorouracil in combination with two different concentrations of bortezomib were examined in the 4T1 cells. Statistically significant differences were found when 1 or 5 µM cisplatin was combined with 10 or 50 nM bortezomib. Similarly, 1 µM 5‑fluorouracil or 5 µM 5‑fluorouracil in combination with 10 nM bortezomib caused significant cell death as compared to treatment with single agents. However, 1 or 5 µM 5‑fluorouracil did not potentiate the effects of higher concentrations of bortezomib (50 nM). The effect of the combination of cisplatin, 5‑fluorouracil and bortezomib was determined by soft agar assay. It was confirmed that a combination of cisplatin and bortezomib was more effective than each drug as a monotherapy. Therefore, the combination of cisplatin and bortezomib should be tested further in clinical settings.

… (ELECO), 2011 7th …, 2011

... 97, pp. 391–401, 2004. [14] NH Hanif, WH Lan, HB Daud, J. Ahmad, “Classification of control m... more ... 97, pp. 391–401, 2004. [14] NH Hanif, WH Lan, HB Daud, J. Ahmad, “Classification of control measures for asthma using artificial neural networks”, Malaysia: Scientific and Technical Publishing Company, ACTA Press, 2009. ...

Protein Expression and Purification, 2003

... Purification of Glucose 6-Phosphate Dehydrogenase From Goose Erythrocytes and Kinetic Propert... more ... Purification of Glucose 6-Phosphate Dehydrogenase From Goose Erythrocytes and Kinetic Properties. Şükrü BEYDEMİR Atatürk University, Arts and Science Faculty, Department of Chemistry, Erzurum - TURKEY Hayrullah YILMAZ Dicle University, Faculty of Education ...

Journal of Enzyme Inhibition and Medicinal Chemistry, 2006

Catalase enzyme (H202: oxidoreductase; E.C. 1.11.1.6) was purified from human skin homogenate usi... more Catalase enzyme (H202: oxidoreductase; E.C. 1.11.1.6) was purified from human skin homogenate using ammonium sulfate precipitation and DEAE-Sephadex A50 ion exchange chromatography at 4 degrees C and some characteristics of the enzyme were investigated. The human skin enzyme, having a specific activity of 1354.5 EU/mg proteins was purified with a yield of 43.13% and 1110-fold. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed a single band for the enzyme. Inhibition by piroxicam, ketoprofen, diclofenac sodium, sulfamethoxazole and nidazole occurred with I50 values of 0.414, 1.29, 1.8, 3.83, and 8.64 mM, respectively.

Journal of Enzyme Inhibition and Medicinal Chemistry, 2005

Effects of nicotine, and nicotine þ vitamin E on glucose 6-phosphate dehydrogenase (G-6PD) activi... more Effects of nicotine, and nicotine þ vitamin E on glucose 6-phosphate dehydrogenase (G-6PD) activity in rat muscle, heart, lungs, testicle, kidney, stomach, brain and liver were investigated in vivo and in vitro on partially purified homogenates. Supplementation period was 3 weeks (n ¼ 8 rats per group): nicotine [0.5 mg/kg/day, intraperitoneal (ip)]; nicotine þ vitamin E [75 mg/kg/day, intragastric (ig)]; and control group (receiving only vehicle). The results showed that nicotine (0.5 mg/kg, ip) inhibited G-6PD activity in the lungs, testicle, kidney, stomach and brain by 12.5% (p , 0.001), 48% (p , 0.001), 20.8% (p , 0.001), 13% (p , 0.001) and 23.35% (p , 0.001) respectively, and nicotine had no effects on the muscle, heart and liver G6PD activity. Also, nicotine þ vitamin E inhibited G-6PD activity in the testicle, brain, and liver by 32.5% (p , 0.001), 21.5% (p , 0.001), and 16.5% (p , 0.001) respectively, and nicotine þ vitamin E activated the muscle, and stomach G-6PD activity by 36% (p , 0.05), and 20% (p , 0.001) respectively. In addition, nicotine þ vitamin E did not have any effects on the heart, lungs, and kidney G-6PD activity. In addition, in vitro studies were also carried out to elucidate the effects of nicotine and vitamin E on G-6PD activity, which correlated well with in vivo experimental results in lungs, testicles, kidney, stomach, brain and liver tissues. These results show that vitamin E administration generally restores the inactivation of G-6PD activity due to nicotine administration in various rat tissues in vivo, and also in vitro.

$Research paper thumbnail of Comparison of the effects of dexketoprofen trometamol, meloxicam and diclofenac sodium on fibular fracture healing, kidney and liver: An experimental rat model$

Injury, 2014

Nonsteroidal anti-inflammatory drugs (NSAIDs) are particularly used in patients with bone fractur... more Nonsteroidal anti-inflammatory drugs (NSAIDs) are particularly used in patients with bone fractures, but there are limited studies on whether one NSAID is superior to another. In this study, we used histopathological and biochemical parameters to determine whether there are differences between the effects of the administration of clinical doses of dexketoprofen trometamol (DEXT), meloxicam (MEL) and diclofenac sodium (DIC) on the healing of closed fibular fractures and the toxicity of both the liver and kidney. Twenty-eight male Sprague-Dawley rats were randomly divided into four groups of seven each. Closed diaphyseal fractures were formed in the left fibulas of all of the rats. The NSAIDs dexketoprofen trometamol (DEXT) (Arveles(®)), meloxicam (MEL) (Melox(®)) and diclofenac sodium (DIC) (Voltaren(®)) were intramuscularly administered to Groups I, II, and III, respectively, for a period of 10 days after the fibular fractures were performed. No pharmacological agents were administered to Group IV (Control group). Blood samples were collected from all of the rats after the fractures were performed, and the rats were sacrificed on day 28. The histopathological findings were compared, and the blood samples were evaluated to determine any differences between the levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA). Our results suggest that DEXT and MEL impair the healing of bone fractures and that DIC does not histopathologically affect the healing process of bone fractures. We also found that DEXT, MEL, and DIC impaired the renal histopathology compared with the control group. However, the liver histopathological analysis showed that DEXT and MEL caused a higher degree of parenchymal necrosis compared with DIC. Based on our results, DIC can be considered a relatively safe medication in patients with fractures.

Alcohol and Alcoholism, 2002

The effects of ethanol on erythrocyte glucose 6-phosphate dehydrogenase (G6PD) activity were inve... more The effects of ethanol on erythrocyte glucose 6-phosphate dehydrogenase (G6PD) activity were investigated under in vitro and in vivo conditions. For in vitro studies, glucose 6-phosphate dehydrogenase was purified from human erythrocyte and rats were used for in vivo studies. Enzyme activity was determined spectrophotometrically by the Beutler method. The in vitro study showed that the I(50) value was 17 mM for ethanol. In the case of the in vivo study, a 2 ml/kg dose of ethanol significantly inhibited the G6PD activity. The inhibition rate after ethanol administration was 59%, 40% and 6% at 1, 3 and 6 h after, respectively. The results of this study suggest that ethanol has a significant inhibitory effect on the G6PD activity both in vivo and in vitro.

Environmental Science and Pollution Research, 2014

The effect of arsenic bioaccumulation in liver, kidney, skin, muscle, and intestinal tissues of m... more The effect of arsenic bioaccumulation in liver, kidney, skin, muscle, and intestinal tissues of mirror carp (Cyprinus carpio carpio) was investigated on lipid peroxidation and certain antioxidant enzyme activities. In this study, three aquarium groups were formed from mirror carp: control group, 0.5-, and 1-mg/L arsenic concentrations. The fish were dissected after 1 month. Arsenic bioaccumulation, malondialdehyde (MDA) levels, catalase (CAT), and superoxide dismutase (SOD) enzyme activities were determined in the tissues. Results showed that arsenic was accumulated in liver, kidney, muscle, skin, and intestinal tissues. As the final product of lipid peroxidation, MDA levels were determined to have increased in all tissues with the exception of muscle. On the other hand, CAT and SOD enzyme activities in the fish tissues were decreased as compared to the control group. In the muscle tissue, differences were observed in the enzyme activities depending on arsenic concentration. Considering the increases in enzyme inhibition and MDA levels, liver was observed to be the main tissue affected in response to the arsenic toxicity.