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Dive into the research topics where Osman Çağlayan is active.

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Featured researches published by Osman Çağlayan.


Clinica Chimica Acta | 1996

Leukocyte lipid peroxidation, superoxide dismutase, glutathione peroxidase and serum and leukocyte vitamin C levels of patients with type II diabetes mellitus

İdris Akkuş; Sadinaz Kalak; Hüseyin Vural; Osman Çağlayan; Elif Menekşe; Gülsüm Can; Bilal Durmuş

In the present study, leukocyte lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and serum and leukocyte vitamin C levels of patients with type II diabetes mellitus and healthy controls were investigated. Patients consisted of 53 cases (23 male, 30 female) aged 35-75 years and controls of 34 subjects (15 male, 19 female) aged 34-66 years. Leukocyte lipid peroxidation of diabetics was significantly increased (P < 0.05) whereas vitamin C level was decreased (P < 0.05) compared to those of controls. There was no significant difference in the other parameters. Also, there was no correlation between the above parameters and HbA1c and glucose levels. Our results show that leukocytes of diabetics are affected by oxidative stress which might be a reason for decreased microbicidal activity.


Pediatric Surgery International | 2002

Effect of antioxidant therapy on collagen synthesis in corrosive esophageal burns.

Engin Günel; F. Çağlayan; Osman Çağlayan; Aydan Canbilen; Murat Tosun

Abstract To investigate the efficacy of antioxidant therapy on collagen synthesis in corrosive esophageal burns, 110 Sprague-Dawley rats were divided into five groups of 22 animals each. A standard esophageal caustic burn was produced by 1 ml of 10% sodium hydroxide solution for the rats in groups B to E; group A was instilled only with 0.9% saline after preparation of the distal esophageal segment. Group A animals (controls) were uninjured and untreated. Group B had untreated esophageal burns. Esophageal burns were treated in group C with vitamin E (10 mg/kg IM), in group D with vitamin C (10 mg/kg IP), and in group E with methylprednisolone (30 mg/kg IM) on each of 5 days. Eight rats from each group were killed 4 days after initiation of the study and the abdominal esophagus was studied for tissue malondialdehyde (MDA; μmol/g protein) levels. The other rats were killed 28 days after initiation of the study and determination of hydroxyproline (HP) (μg/g tissue) levels in esophageal tissue was performed for 8 rats in each group. Histopathologic evaluation was also performed in the other 6 rats from each group. MDA levels in esophageal tissue were significantly lower in groups C (9.24 ± 2.62, P < 0.01) and group E (6.26 ± 2.22, P < 0.001) than in group B (12.35 ± 1.80). HP levels were significantly lower in groups A (0.75 ± 0.21, P < 0.001), C (1.11 ± 0.15, P < 0.01), and E (0.96 ± 0.15, P < 0.001) than in group B (1.40 ± 0.20). Histopathologically, collagen deposition in the submucosa and tunica muscularis was lower in groups C and E than in group B (P < 0.05, and 0.01, respectively). Our results demonstrate that treatment with antioxidant drugs such as vitamin E and methylprednisolone decreased tissue HP levels, and thus inhibited new collagen synthesis and stricture formation in rats with alkali-induced caustic esophageal burns.


Journal of Pediatric Surgery | 1998

Treatment of intestinal reperfusion injury using antioxidative agents

Engin Günel; F. Çağlayan; Osman Çağlayan; Alaeddin Dilsiz; Selçuk Duman; Murat Aktan

BACKGROUND/PURPOSE A number of antioxidants are present in human tissues, which comprise the secondary defence system against the oxygen-free radicals and oxidative stress. Therefore, this study was undertaken in an animal model to investigate the effects of antioxidants such as vitamin E, vitamin C, methyl prednisolone, and mannitol, on the treatment of intestinal reperfusion injury when given during ischemia. METHODS The study was performed on six groups of animals, each composed of six rabbits: Group I, mesenteric ischemia group; group R, ischemia-reperfusion group; group E, ischemia-reperfusion plus Vitamin E treatment; group C, ischemia-reperfusion plus vitamin C treatment; group CS, ischemia-reperfusion plus corticosteroid treatment; and Group M, ischemia-reperfusion plus mannitol treatment. Malondialdehyde (MDA) and glutathione (GSH) levels of the intestinal mucosa were assayed to reflect the free radical formation. RESULTS Mucosal injury scores in the M and C groups were significantly lower than the R group (P< .01 and P< .01, respectively), and in the E and CS groups, mucosal injury scores were not significantly different from R group. MDA levels in the M and C groups were significantly lower than the R group (P < .01 and P < .01, respectively). GSH levels in the E, C, and M groups, were significantly higher than R group (P < .01, P < .05, and P < .01, respectively). CONCLUSION The results of this study showed that antioxidant drugs, such as vitamin C and mannitol, may play a role in attenuating reperfusion injury of the gut demonstrated by depression of tissue MDA levels and by elevation of tissue GSH levels.


Journal of Pediatric Surgery | 1999

Reactive oxygen radical levels in caustic esophageal burns

Engin Günel; F. Çağlayan; Osman Çağlayan; Ishak Akillioǧlu

PURPOSE This study was designed to determine the tissue levels of reactive oxygen radicals in caustic esophageal burns in a rat model. METHODS Forty rats were divided into four groups of 10 animals each. The control rats were uninjured in group A, and the others were injured rats in groups B, C, and D. Through a median laparatomy incision, a 1.5-cm abdominal esophageal segment was isolated and tied with 2-0 chromic sutures in all groups as described by Gehanno. One milliliter of 10% sodium hydroxide solution in groups B, C, and D and 0.9% saline solution in group A were instilled through the isolated segment via a no. 24 cannula for 3 minutes, then the esophagus was rinsed for 1 minute with distilled water. The studied 1.5 cm of the abdominal esophagus was removed from each animal 24 hours after caustic injury in group B, 48 hours after in group C, and 72 hours after in group D. In group A, studied uninjured segments were removed for biochemical investigation. Tissue malondialdehyde (MDA) and glutathione (GSH) levels were determined for each group. RESULTS The mean MDA levels in esophageal tissue were significantly higher in groups B, C, and D than in group A (P < .05). Moreover, the mean GSH levels in the same esophageal tissues were significantly lower in groups C and D than in groups A and B (P < .05). CONCLUSION The reactive oxygen radicals may be play an important role in early phase of caustic esophageal burns by increasing the tissue damage.


Pediatric Surgery International | 1998

Serum D-lactate levels as a predictor of intestinal ischemia-reperfusion injury

Engin Günel; Osman Çağlayan; F. Çağlayan

Abstract Currently, no serum marker has proved helpful in diagnosing intestinal ischemia and reperfusion (I/R) injury. An experimental study was conducted to determine the value of serum D-lactate in detecting intestinal I/R injury. Thirty New Zealand White rabbits were divided into three groups of 10 animals each: sham-operation controls (S); I/R; and I/R plus mannitol treatment (M). Serum samples were obtained before operation (T0), at the end of the ischemic period (T1), after the first 30 min of reperfusion (T2), and at the end of the reperfusion period (T3). In Group S, mean D-lactate levels for T0, T1, and T2 were 0 μg/dl, while T3 was 5.8 ± 4.7 μg/dl. Before the operation (T0), serum mean D-lactate levels were 0 μg/dl in all groups (S, I/R, M). Levels increased after 1 h of ischemia (T1) in groups I/R (83.5 ± 25.6 μg/dl) and M (89.8 ± 19.9 μg/dl), but not in group S (0 μg/dl). The mean T2 level in group I/R (231.6 ± 78.6 μg/dl) was statistically higher than in group M (140.1 ± 53.5 μg/dl) (P = 0.007). At the end of the reperfusion period, the mean T3 level in group I/R (698.4 ± 360.4 μg/dl) was significantly higher than in group M (158.7 ± 61.4 μg/dl) (P = 0.000). In group I/R, mean D-lactate levels changed significantly at each time point (T1 vs T2, P = 0.001; T2 vs T3, P = 0.004). However, in group M the increase from T1 to T2 was significant (P = 0.012), but that from T2 to T3 was not (P = 0.293). As a result, the mean T3 level was significantly higher than the T2 level in group I/R (P = 0.004), but not in group M. This study confirmed a significance rise in D-lactate levels in animals with I/R injury compared to sham-operated and I/R injury plus M treatment. We suggest that serum D-lactate levels could be a useful marker of intestinal I/R injury before laparatomy.


Clinica Chimica Acta | 1997

Effect of moderate alcohol intake on lipid peroxidation in plasma, erythrocyte and leukocyte and on some antioxidant enzymes

İdris Akkuş; Fatih Gültekin; Mehmet Aköz; Osman Çağlayan; Sinan Bahçaci; Ü.Gülsüm Can; Mahmut Ay; Ahmet Gürel

Plasma, erythrocyte and leukocyte lipid peroxidation, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and plasma gamma-glutamyl transferase (GGT) levels were investigated in 36 healthy non-drinkers aged between 18-55 years (mean 38.7) and 72 alcohol drinkers aged between 20-48 years (mean 35.3) in order to determine the oxidative effect of alcohol. Erythrocyte lipid peroxidation of the drinkers (measured in terms of MDA) was found to be significantly (P < 0.05) reduced compared to that of controls. However, when Tukey-HSD and F test with ANOVA were performed, that significance disappears in those who consume less than 140 g of alcohol per day and persists in those who consume more than 140 g of alcohol per day (P < 0.05). Plasma GGT level was significantly increased compared to that of controls (P < 0.001). Also, there was a significant (P = 0.01) correlation between serum GGT level and the amount of alcohol. There were no significant differences between all the other parameters of both groups. Reduced lipid peroxidation of erythrocytes without any accompanying increase in the activities of antioxidant enzymes shows that another mechanism might be responsible for this finding. This mechanism was thought to be an alteration in lipid composition of erythrocyte membranes.


Pediatric Surgery International | 1998

Acute-phase changes in children recovering from minor surgery

Engin Günel; Osman Çağlayan; F. Çağlayan; T. K. Şahin

Abstract The metabolic response to surgical stress is a nonspecific increase in hepatic synthesis of some specialized acute-phase proteins and a decrease in plasma concentrations of visceral proteins following surgical trauma. This study was undertaken determine which specific proteins were the better clinical indices in monitoring the metabolic response to surgical stress in children recovering from minor surgery. Forty-four patients undergoing elective inguinal surgical procedures under general anesthesia were studied. Blood samples were collected preoperatively (−1) and at 1(+1) and 5(+5) days postoperatively to determine albumin (AL), Prealbumin (PA), C-reactive protein (CRP), and a1-acid glycoprotein (AGP) values, and to calculate the prognostic inflammatory and nutritional index (PINI). Mean AL values were the same on all days. Mean PA  +1 was significantly lower than PA −1 and PA +5 (P < 0.001). Median CRP +1 and mean AGP +1 values were significantly higher than median CRP −1 and mean AGP −1 (P < 0.0001), respectively. Although there was a decrease after postoperative day 1, median CRP +5 and mean AGP +5 values were still significantly higher than preoperative values (P < 0.01 and P < 0.0001). Moreover, the median PINI +1 was also greater than PINI −1 and PINI +5 (P < 0.0001), but the median PINI+5 was significantly higher than PINI −1 (P < 0.01). Median percent changes of PINI values were significantly higher than those of the other parameters from both preoperatively to postoperative day 1 and preoperatively to postoperative day 5. Although several specific proteins (AL, PA, CRP, and AGP) have been evaluated as indicators of the acute metabolic response, we suggest that the PINI is more valuable for reflecting the response to surgical stress in patients recovering from minor surgery.


Pediatric Surgery International | 1998

Helicobacter pylori and hypergastrinemia in children with recurrent abdominal pain

Engin Günel; D. Fındık; Osman Çağlayan; F. Çağlayan; Z. Topgaç

Abstract Recurrent abdominal pain (RAP) is a significant problem in the pediatric population, and there has been much recent interest in the role that Helicobacter pylori (Hp) might play in this disorder. In this case control study, the authors aimed to determine whether Hp is an agent responsible for RAP, and to assess fasting gastrin concentrations in children with and without RAP in the Hp-positive and -negative groups. The study was conducted in 42 patients with RAP and 50 healthy children attending routine day-case surgery as a control group, aged 3 to 15 years, over a 12-month period. Of the 42 children with RAP, 30 were seropositive (71.4%) for Hp IgG, and of 50 children in the control group, 32 were seropositive (64%) for Hp IgG (P > 0.05). We found that Hp infection was as high in healthy children as in children with RAP. The mean fasting gastrin levels in 62 Hp-seropositive children (60.4 ng/l) were not different from those in 30 Hp-seronegative children (57.3 ng/l) and those in 42 children with RAP (58.2 ng/l) were also not significantly different from those in 50 healthy children (62.9 ng/l). Thus, no association between childhood Hp infection, hypergastrinemia, and RAP was found in our Turkish population.


International Journal of Pediatric Otorhinolaryngology | 2012

Surgical management with or without a nasogastric tube in esophageal repairs

Müslim Yurtçu; Hatice Toy; Hamdi Arbag; Osman Çağlayan

OBJECTIVE The aim of the study was to compare surgical management with or without a nasogastric tube (NGT) to prevent anastomotic stricture that occurred following esophageal repairs (ERs). METHODS Twelve New Zealand rabbits were divided equally into 2m: with a NGT (experimental group) and without a NGT (control group). A 1-cm-length of the cervical esophagus was resected through a cervical incision and then anastomosis was performed using the NGT and keeping it in place for 6 days in the experimental group. The same procedures were performed in the control group. Both groups were fed parenterally for 6 days and orally after esophagography on postoperative day 7 as long as there was no esophageal leakage. The rabbits were sacrificed to evaluate diameter of the esophageal lumen (DOTEL), bursting pressure (BP), tissue hydroxyproline (HP) and wound healing scores (WHSs) in the anastomosis lines 8 weeks later. RESULTS In the experimental group, DOTEL, BP, and HP were significantly lower than they were in the control group. WHSs in the experimental group were not higher than they were in the control group. CONCLUSIONS Surgical management without a NGT is more effective than management with a NGT in ERs as shown by increased DOTEL, BP, and HP levels.


Bozok Tıp Dergisi | 2018

Tip 1 Diyabet Meillitus'da Serum. Lökösit ve Eritrosit Lipid Peroksidasyonu ve Antioksidan Durum

Ummugulsum Can; Osman Çağlayan; Idris Mehmetoglu

OZET Giris: Tip 1 diyabet mellitus metabolik bir hastalik olup, patogenezinde oksidatif stres rol oynamaktadir. Oksidatif stres serbest oksijen radikalleri ve lipid peroksidlerinin artisi ve antioksidan kapasitesinin azalmasina baglidir. Bu calismada tip 1 diyabet mellitus’da oksidatif stresin etkisini degerlendirmek icin serum, lokosit ve eritrosit lipid peroksidasyonu, ve lokosit ve eritrosit glutatyon peroksidaz ve superoksid dizmutaz aktivitelerine ilaveten serum ve lokosit vitamin C seviyelerini saglikli kontroller ile karsilastirdik. Yontem: Calismaya hasta grubu olarak 34 cocuk ve adolesan (20 kiz ve 14 erkek) ve kontrol grubu 29 cocuk ve adolesan (13 kiz ve 16 erkek) dahil edildi. Lipid peroksidasyonunun son urunu malondialdehid, tiyobarbiturik asid reaktivite yontemi, vitamin C seviyeleri dinitrofenilhidrazin metodu ile olculdu. Glutatyon peroksidaz ve superoksid dizmutaz duzeyleri ticari kit kullanilarak tesbit edildi. Analiz sonuclarinin istatiksel analizleri SPSS 20.0 bilgisayar programi ile yapildi. Bulgular: Tip 1 diyabet mellitus cocuk ve adolesanlar kontroller ile karsilastirildiginda serum, lokosit ve eritrosit malondialdehid seviyeleri artmasina karsin lokosit ve eritrosit glutatyon peroksidaz ve superoksid dizmutaz aktiviteleri, ve serum ve lokosit vitamin C seviyelerinde azalma tesbit edilmisti. Fakat bu degisikliklerde istatistiksel olarak anlamli fark gozlenmedi (p > 0.05). Bu parametreler ile HbA1c ve glukoz seviyeleri arasinda korelasyon yoktu. Sonuc: Tip I diyabet mellitus cocuk ve adolesanlarda lipid peroksidasyon artisina ve antioksidan sisteminde azalmaya egilim olmakla birlikte bu durumun duzenli kullanilan insulin tedavisi ile duzeltildigi ve diger faktorler tarafinda etkilendigi kanaatindeyiz. Anahtar Sozcukler: Diabetes mellitus; Lipid peroksidasyonu; Superoksit dismutaz; Glutatyon peroksidaz; C vitamini

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