Search PubMed⌕ Search

Biomedical subjects

O Yilmaz

Publications and source records attributed to O Yilmaz.

At least 37 records · Page 2Linked to original sources
PubMed2001

Orthotic management of the lower limb in children with hereditary motor sensory neuropathy (HMSN).

The lower limbs of 55 paediatric patients, with the diagnosis of hereditary motor sensory neuropathy (HMSN) referred to the Orthotics and Biomechanics Department of Hacettepe University, were assessed for appropriate orthotic intervention. Since in the natural history of HMSN symptoms and complaints are variable there is a wide range of interventions possible. The biomechanics of deforming forces and the consequential incidence of deformities in these 55 children, its orthotic implications and the efficacy of orthotic applications are discussed in detail.

Child↗
PubMed2001

Association of mitogen-activated protein kinase pathways with gingival epithelial cell responses to Porphyromonas gingivalis infection.

Mitogen-activated protein (MAP) kinase pathways are key factors in host signaling events and can also play important roles in the internalization of pathogenic bacteria by host cells. Porphyromonas gingivalis, a periodontal pathogen, can efficiently invade human gingival epithelial cells (GECs). In this study, we examined the activation of MAP kinase pathways in GECs infected with P. gingivalis. c-Jun N-terminal kinase (JNK) was activated after 5 min of infection with P. gingivalis, whereas noninvasive Streptococcus gordonii did not have a significant effect on JNK activation. In contrast, extracellular signal-regulated kinase (ERK) 1/2 was downregulated in a dose-dependent manner by P. gingivalis, but not by S. gordonii, after a 15-min exposure. Nonmetabolically active P. gingivalis cells were unable to modulate MAP kinase activity. U0126, a specific inhibitor of MEK1/2 (ERK1/2 kinase), and toxin B, a specific inhibitor of Rho family GTPases, had no effect on P. gingivalis invasion. Genistein, a tyrosine protein kinase inhibitor, blocked uptake of P. gingivalis. The transcriptional regulator NF-kappaB was not activated by P. gingivalis. These results suggest that P. gingivalis can selectively target components of the MAP kinase pathways. ERK1/2, while not involved in P. gingivalis invasion of GECs, may be downregulated by internalized P. gingivalis. Activation of JNK is associated with the invasive process of P. gingivalis.

Butadienes↗
PubMed2000

Antimicrobial and biological effects of ipemphos and amphos on bacterial and yeast strains.

In this study, the antimicrobial effects of monophosphazenes such as SM ipemphos and amphos were examined on bacterial and yeast strains. In addition, the biological effects of these compounds were tested on the lipid level of Saccharomyces cerevisiae and Candida albicans cells. The SM has an antimicrobial effect on the bacterial and yeast strains within the range of 100 and 1500 microg. When the concentration was increased, the inhibition zone expanded on the growth media ( p < 0.01; p < 0.001). The ipemphos did not affect the bacterial and yeast cells in the 100 and 600 microg range. In addition, the amphos did not show an antimicrobial effect on the bacterial cells between 100 and 300 microg or on yeast cells at any of the administered concentrations. In vitro media, the biological effects of these molecules were compared with vitamin E, melatonin and fish oil on the yeast cells. We have found that monophosphazenes have growth effects on the cells in vitro media. The lipid level of S. cerevisiae cells was decreased by 300 microg doses of vitamin E, fish oil, and ipemphos (respectively; p < 0.05, p < 0.01, and p < 0. 001). In addition, the lipid levels of the same yeast cells were depressed by 1000-microg doses in all supplemented groups. However, it was observed that the highest decrease in lipid level of S. cerevisiae cells occurred in the amphos group ( p < 0.001). The lipid levels of the C. albicans cells were significantly reduced ( p < 0.01) by 300 microg of amphos and melatonin. In contrast, the vitamin E and fish oil significantly raised ( p < 0.01; p < 0.001) the lipid level of the same yeast cell, as compared with the control. In addition, the lipid level of these cells was increased by administration of 1000 microg vitamin E, and melatonin ( p < 0.01). In conclusion, while high concentrations of ipemphos and amphos have an antimicrobial effect on bacterial and yeast cells, amphos did not affect the yeast cells. While ipemphos and amphos increased cell growth in media, they reduced the lipid level of C. albicans and S. cerevisiae. In addition, the antioxidants such as vitamin E, melatonin, and fish oils affected the lipid level of yeast cells.

Anti-Bacterial Agents↗
PubMed2000

Methyl-prednisolone in neurologic complications of Mycoplasma pneumonia.

In patients with Mycoplasma pneumonia extrapulmonary manifestations such as encephalitis, meningitis, cerebellar and brain stem involvement, cranial nerve lesions, peripheral neuropathy, polymyositis have been observed. We report a 16-year-old girl with M. pneumonia infection, acute behavioral changes and coma. Treatment with high dose methyl-prednisolone and clarithromycin led to rapid clinical improvement.

Adolescent↗
PubMed2000

Choanal polyp of sphenoidal origin.

Sphenochoanal polyp is a rare entity which originates in the sphenoid sinus cavity and extends into the choana via the ostium. It presents in a similar manner to the more common antrochoanal polyp. Radiological examination is necessary to differentiate between these two types. We present a case of sphenochoanal polyp and review the clinical, radiological and pathological features. The role of endoscopic sinus surgery is emphasised.

Adult↗
PubMed2000

Nicotine modulates nitric oxide in rat brain.

Nicotine exerts its central actions by regulating cationic fluxes through nicotinic acetylcholine receptors (nAChRs). By this effect, the drug likely also modifies events occurring beyond the nAChR, including the regulation of nitric oxide (NO) synthesis. The present study was undertaken to assess the effects of acute and chronic nicotine administration (0.4 mg/kg, s.c.) on levels of NO(-)(2)+NO(-)(3), stable metabolites of NO, in brain regions of male and female rats. Nicotine increased levels of the metabolites, and therefore presumably of NO, with sex differences in the degree of stimulation, the brain regions affected, and the variance between the effects of acute and chronic administration. Prior inhibition of NO synthase eliminated the effect of nicotine in all regions studied. While nicotine appeared to increase NO indirectly via glutamate receptors in the cortex and hippocampus, this was not true of the corpus striatum, where blocking NMDA-type glutamate receptors with MK-801 had no effect. The findings support the view that NO is likely involved in some of the central effects of nicotine.

Analysis of Variance↗
PubMed2000

Nitric oxide synthetase inhibition hinders facilitation of active avoidance learning by nicotine in rats.

Nicotine produces dose-dependent enhancement of performance in an active avoidance test, and also increases the levels of NO2- and NO3-, which are stable metabolites of nitric oxide (NO), in various brain regions of rats. On the basis of these two observations, we hypothesized that the beneficial effect of nicotine on learning could result from increased NO in relevant brain regions. We therefore tested active avoidance performance in rats given L-Nomega-nitroarginine (L-NA) to inhibit NO synthetase (NOS) prior to nicotine administration. Male Sprague-Dawley rats received L-NA (30 or 50 mg/kg), nicotine (0.4 mg/kg), saline or combinations of these treatments before learning trials. Rats were also tested on the inclined plane, to assess the possible effects due to impairment of motor function by drug treatments on active avoidance learning. L-NA treatment impaired the acquisition of active avoidance learning, and this defect was partially overcome by the co-administration of nicotine. Nicotine facilitated learning and significantly increased the number of correct responses. The threshold for the effect of NOS inhibition on performance exceeded 30 mg/kg L-NA, whereas 50 mg/kg impaired learning and also eliminated the nicotine-induced enhancement of learning. On the fifth day of learning trials, no facilitation of learning by nicotine was observed in rats receiving either dose of L-NA. Our results suggest that NO is involved in the facilitation of active avoidance learning by nicotine.

Animals↗
PubMed1999

Influence of dietary selenium and vitamin E on the levels of fatty acids in brain and liver tissues of lambs.

In this study, the effects of dietary vitamin E, selenium, and their combination on the levels of fatty acid composition of the brain and liver tissues were examined. In brain tissue, the amounts of most fatty acids increased in vitamin E, combination and selenium groups compared with control group values. While the proportions of myristic, pentadecanoic, palmitic, linoleic, and total saturated fatty acids were decreased in vitamin E, Se and combination groups, eicosapentaenoic, total unsaturated and MUFA were increased in the same groups. In addition, the proportions arachidonic, eicosapentaenoic, total unsaturated, omega 6 and MUFA in the combination group were higher than in the control group. In liver tissue, the amounts of myristic, pentadecanoic, palmitic, eicosedienoic, eicosapentaenoic, docosahexaenoic, omega 3 and PUFA were higher in the combination group than in the control group. Also the proportions of eicosapentaenoic, docosahexaenoic acids in supplemented groups were higher than those in the control group. We conclude that dietary vitamin E and selenium have an influence on the levels of fatty acids in the brain and liver.

Animals↗
PubMed1999

The impact of oral feeding on the severity of acute pancreatitis.

BACKGROUND: In the management of acute pancreatitis, oral feeding is prohibited and either enteral or parenteral feeding is commenced for the patients in an effort to not increase the secretion of the pancreatic enzymes. PURPOSE: This study was undertaken in an attempt to determine the impact of oral feeding on the severity of acute pancreatitis and to compare this impact with that of parenteral feeding. MATERIALS AND METHODS: Twenty-four female Sprague-Dawley rats were divided into two groups. In both groups, acute pancreatitis was induced by ligation of the main biliopancreatic duct. The rats in group I were fed orally and the rats in group II were fed parenterally. The rats were sacrificed at 48 hours, and blood samples were obtained from the heart upon exposure of the abdominal and thoracic cavities. The pancreas and the left lung were removed for histopathological examination. The levels of lactic dehydrogenase (LDH), serum glutamic oxaloacetic transaminase (SGOT), glucose, calcium and blood urea nitrogen, base deficit, partial oxygen pressure, leukocyte count, and hematocrit level among Ranson criteria and the level of amylase were measured. The pancreas and the lung were examined under a light microscope. RESULTS: The levels of LDH, SGOT, and calcium for the rats in group I were significantly higher when compared with the rats in group II (P <0.05). Similarly, the levels of amylase for the rats in group I were found to be higher when compared with the rats in group II, but the difference was not significant. Inflammatory changes observed in the pancreas were less severe whereas inflammatory changes observed in the lung were more severe for the rats in group I when compared with the rats in group II. CONCLUSION: The blood levels of the enzymes were adversely affected for the rats fed orally. In contrast, inflammatory changes observed in the pancreas were more severe for the rats fed parenterally. The study suggests that certain hormones released from the duodenum upon stimulation by oral nutrient intake lessens the severity of pancreatitis through protective effects on the pancreas, whereas the elevated levels of the enzymes cause endothelial damage resulting in destruction in distant organs such as the lung.

Acute Disease↗
PubMed1999

The in vivo and in vitro comparative nephrotoxicity of cefazolin and gentamicin.

Biochemical, histopathological and cell culture evaluations compared the nephrotoxicity of cefazolin with that of gentamicin. New Zealand rabbits were dosed with 250 mg cefazolin/animal i.m. twice daily, 3 mg gentamicin/kg i.m. twice daily, or 0.9% NaCl solution for 10 d. The rabbits in drug-treated groups had necrosis of proximal kidney tubules and elevated urinary-gamma glutamyl transferase (uGGT) levels. The results of the histopathological examinations, uGGT analyses and effects in cell culture indicated the nephrotoxicities of both antibiotics were similar.

Animals↗
PubMed1999

The effect of aminophylline infusion on the exercise capacity in patients with syndrome X.

Aminophylline was known to decrease effort angina and ischaemia in patients with coronary artery disease and stable angina. This effect has been explained by the antagonization of the vasodilatation caused by adenosine and the prevention of the transmural myocardial maldistribution (steal phenomenon). In this study, treadmill exercise tests (with Bruce protocol) were performed in 14 patients (11 women, 3 men, mean age 51 +/- 9.9 years) diagnosed with syndrome X (typical anginal chest pain, abnormal stress test, normal coronary angiography) before (basal condition) and after the acute i.v. aminophylline infusion (total dosage 6 mg/kg within 15 minutes). It was shown that aminophylline lengthened the time before the occurrence of ischaemia in patients with syndrome X by increasing the ischaemia threshold in spite of the occurrence of tachycardia but it had no effect on the total exercise duration. Aminophylline infusion also exerted a beneficial effect on exercise-induced chest pain. It has been suggested that the role of the adenosine receptor could be important in the pathogenesis of syndrome X.

Aminophylline↗
PubMed1998

Does large-bowel enema reduce septic complications in acute pancreatitis?

BACKGROUND: The source of septic complications in acute pancreatitis was unknown until recent years. The pathogenesis of bacterial translocation from the gut has been accepted as the main source of pancreatic or peripancreatic infection. This study was designed to investigate the role of large bowel enema during acute pancreatitis in preventing bacterial translocation. MATERIALS AND METHODS: Twenty-four Spraque-Dawley rats were used in this study. The rats were divided into two groups. Group I animals received biliopancreatic duct ligation plus colon cleansing by rectal enemas; group II animals received only biliopancreatic duct ligation. Rectal enemas were applied to the first group of animals three times, at 6, 24, and 48 hours after the operation using 10 cc sodium hydrogen phosphate solutions. All animals were sacrificed 72 hours later, and tissue samples were taken from mesenteric lymph nodes, pancreas, spleen, and liver for bacteriologic cultures via a midline laparatomy. Blood and cecum cultures were also prepared. RESULTS: Positive mesenteric lymph node cultures were found in all 12 animals in group II but in only 3 of 11 animals of group I (P <0.05). Distant organ cultures were positive in 9 of group II, but the only infected distant organ culture found in group I was the positive liver culture (P <0.05). CONCLUSION: As a result of this study, we believe that large bowel enema can reduce the frequency of septic complications in acute pancreatitis by reducing bacterial translocation.

Acute Disease↗
PubMed1998

Intersession interval affects performance in the Morris Water Maze.

We have recently reported an effect that shows a sexually dimorphic difference in cognitive style rather than ability. The preparation for potentially producing this proximal perceptual style effect is one where rats are first given 4-trial daily acquisition sessions for 12 days with the platform always in the same position, but sometimes visible (perceptual, "look-out" condition) and sometimes hidden (conceptual, "navigational" condition). On the first, probe trial of the 13th day, the platform's position is shifted to a point very close (proximal) to the rat's starting position, and made visible. The proximal perceptual style (PPS) effect has emerged sexually dimorphically in that only females swam straight to the newly positioned proximal platform. Other studies have shown that the PPS effect is eliminated (with females behaving like males) by nicotine and prepubertal ovariectomy, and does not occur in prepubertal females. Also, as no sex-related effects emerged during acquisition during these studies, the PPS effect appears to be a function of cognitive style rather than ability. The present study varied age, and, in an effort to economize on time, shortened acquisition to 6 days by having morning and afternoon sessions each day. To our surprise, this relatively subtle psychological manipulation eliminated the PPS effect, and also yielded some sex- and age-related effects during acquisition: A male advantage was observed and prepubertal rats had longer escape latencies; there was no significant interaction between sex and age.

Analysis of Variance↗
PubMed1998

A no-touch technique for calcified ascending aorta during coronary artery surgery.

Despite improvements in cardiovascular surgery techniques over the years, the incidence of neurologic complications has not declined, and stroke remains a possible (and devastating) sequela to coronary artery surgery. In this report, we describe a moderate hypothermic fibrillatory arrest technique that avoids cross-clamping or otherwise touching the aorta; use of the internal thoracic arteries and the right gastroepiploic artery provides optimum revascularization and minimizes the risk of cerebrovascular accident. Over a 1-year period, we used the technique in 21 patients who had heavy calcifications of the ascending aorta. No hemodynamic problems, lower-limb ischemia, or neurologic complications were seen. Only 1 patient underwent reoperation (for bleeding), and another--whose revascularization was incomplete--had a high postoperative level of myocardial creatine kinase MB isoenzyme and a new Q wave, but no hemodynamic deterioration. This technique seems reasonable, because it appears to provide good myocardial protection and to reduce neurologic complications, without comprising myocardial revascularization.

Adult↗
PubMed1997

Protective role of intraperitoneally administrated vitamin E and selenium on the levels of total lipid, total cholesterol, and fatty acid composition of muscle and liver tissues in rats.

The aim of this work was to determine the protective effects of intraperitoneally administrated vitamin E and Se on total lipid, total cholesterol, and fatty acid composition of rat liver and muscle tissues. Total lipid content of muscle tissue in Se and combination groups decreased as compared to the control group. However, the level of total lipid in the liver tissues was seen to decrease only in the combination group (P < 0.05). While the amount of total cholesterol in liver tissue was lower (P < 0.05) in the vitamin E and combination groups, the amount of total cholesterol in muscle tissue decreased (P < 0.05) in the combination group. The amount of linoleic acid in muscle tissue slightly decreased (P < 0.05), whereas the eicosenoic and eicosatrienoic acid amounts significantly increased (P < 0.01, P < 0.001) in the vitamin E group as compared to the control group. The amounts of most fatty acid decreased (P < 0.05) in the combination group. The proportions of eicosenoic, eicosatrienoic, and total polyunsaturated fatty acid (PUFA) within the total fatty acid were higher (P < 0.05) in vitamin E group, whereas these fatty acids proportions were lower (P < 0.05) in the Se group. Although the proportions of palmitic, linolenic, and total saturated fatty acids were low (P < 0.05), oleic and total unsaturated fatty acid proportions were higher (P < 0.05) in the combination group than in the control group. The amount of palmitic acid and total saturated fatty acid in liver tissue decreased (P < 0.01 and P < 0.05, respectively) in the vitamin E and combination groups. However, the amount of linoleic acid only decreased (P < 0.05) in the combination group. The amount of PUFA was slightly higher (P < 0.05) in vitamin E. The proportions of stearic acid and linoleic acid decreased (P < 0.05) both in the Se and combination groups. However, the proportions of eicosatrienoic, omega 6, and PUFA were slightly higher (P < 0.05) in the vitamin E group, but total saturated fatty acid proportion significantly decreased (P < 0.01) in both the vitamin E and combination groups. In conclusion, the level of total lipid and cholesterol in muscle and liver tissues were reduced by administrating vitamin E and Se together. Additionally, the fatty acid synthesis in the muscle and liver tissues was decreased by this process. However, it was observed that the protective effect of intraperitoneally administrated vitamin E was higher than Se on fatty acid composition in muscle and liver tissues.

Animals↗
PubMed1997

The effects of dietary selenium and vitamin E and their combination on the fatty acids of erythrocytes, bone marrow and spleen tissue lipids of lambs.

The object was to determine the influence of dietary vitamin E, selenium and their combination on the fatty acid content of erythrocytes, bone marrow and spleen lipids of Akkaraman lambs. After supplementation for 15 days, the amount of all fatty acids was slightly higher (p < 0.05) in the vitamin E as compared to the control group, whereas the amount of longer fatty acids was significantly higher (p < 0.01, p < 0.001) in the selenium and combination groups. On the thirtieth day, the amount of all fatty acids was slightly high (p < 0.5) in all the supplemented groups in comparison with the control group. In the bone marrow lipids, the amount of longer fatty acids was decreased (p < 0.05, p < 0.01, p < 0.001) in the vitamin E and combination groups as compared to the control. Although the amount of some fatty acids was high (p < 0.05, p < 0.01) in the selenium group compared to the control, linoleic (18:2), linolenic (18:3) and the polyunsaturated fatty acids (PUFA) were lower (p < 0.05, p < 0.001). In the spleen lipids, the amount of longer fatty acids was slightly decreased (p < 0.05) in the vitamin E group as compared with the control; however the amount of longer fatty acids was significantly higher (p < 0.05, p < 0.01) in the selenium and combination groups in comparison to the control group. Thus dietary supplementation with selenium was more effective than dietary vitamin E supplementation in altering the fatty acid content of the erythrocyte, bone marrow and spleen lipids.

Animals↗
PubMed1997

The effects of selenium, vitamin E and their combination on the composition of fatty acids and proteins in Saccharomyces cerevisiae.

The aim of our studies was to test the effect and role of vitamin E and selenium supplements on yeast cell. In this study, the effects of selenium (Se), vitamin E (Vit. E), and their combination (Se plus Vit. E) on the composition of fatty acids and proteins were examined in Saccharomyces cerevisiae strains WET136 and 522. S. cerevisiae cells were grown up in YEPD medium supplemented with Se, Vit. E or their combination. It was found that the level of stearic acid was increased in all supplemented groups (p < 0.05; p < 0.001). The content of saturated and unsaturated fatty acids was decreased (p < 0.05; p < 0.01; p < 0.001) in Vit. E and Vit. E plus Se supplemented S. cerevisiae. On the other hand, Se alone caused an increase (p < 0.001) in the saturated fatty acids but a decrease (p < 0.05; p < 0.001) in the unsaturated fatty acids. Total proteins in S. cerevisiae were significantly increased (p < 0.001) by Vit. E supplement. There was no significant change observed in S. cerevisiae supplemented with Se. These findings indicate that membrane composition of S. cerevisiae is affected by both Vit. E and Se supplements.

Fatty Acids↗