Biomedical subjects

O Yilmaz

Publications and source records attributed to O Yilmaz.

At least 19 recordsLinked to original sources

PubMed2006

Serum levels of IGF-I and IGFBP-III and their relation with carcinoembryonic antigen and carbohydrate antigen 19-9 in cases of esophageal cancer.

Tumour markers are used for diagnosis, staging, evaluation of response to treatment, prognosis and detection of recurrences in clinical oncology. In this study, we aim to investigate the levels of insulin-like growth factor (IGF)-I and IGF-binding protein (IGFBP)-III in cases with oesophageal carcinoma. We investigated their possible use as tumour markers and their relation to other tumour markers. Forty patients who were diagnosed as having oesophageal carcinoma by histopathological evaluation of endoscopic biopsies between January 2003 and July 2004 and 40 healthy people as the control group were included in the study. The serum levels of tumour markers including IGF-I, IGFBP-III, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were measured in both groups. Data were compared statistically, and the importance of IGF-I and IGFBP-III levels were investigated in cases with oesophageal carcinoma. IGF-I levels were significantly higher in patients with oesophageal carcinoma when compared with the control group (p < 0.05), whereas IGFBP-III levels were significantly lower (p < 0.05). The increase in CEA levels was not statistically significant when compared with the control group. The increase in CA 19-9 levels was statistically significant when compared with the control group (p < 0.05). No correlation was detected between levels of IGF-I and IGFBP-III and levels of CEA and CA 19-9. We suggest that the serum IGF-I level may be used as a tumour marker in oesophageal carcinoma. A low level of serum IGFBP-III is also significant in cases with oesophageal carcinoma. We believe that drugs which inhibit IGF-I function or which stimulate the function of IGFBP-III may open new horizons in extra-surgical modalities for the treatment of oesophageal cancer.

Adult↗

PubMed2006

Method for numerical simulation of two-term exponentially correlated colored noise.

A method for numerical simulation of two-term exponentially correlated colored noise is proposed. The method is an extension of traditional method for one-term exponentially correlated colored noise. The validity of the algorithm is tested by comparing numerical simulations with analytical results in two physical applications.

Journal Article↗

PubMed2006

The ability of 67Ga scintigraphy to detect the lesions of Echinococcus multilocularis infection: preliminary results.

AIM: To assess the ability of 67Ga scintigraphy to detect the lesions of Echinococcus multilocularis (EM) infection. MATERIALS AND METHODS: An animal model of EM infection was developed. The infected tissues taken from stock infection were placed into the abdominal cavity of uninfected animals operatively. The success of implantation was controlled 20-25 days after implantation. Five infected and 2 healthy animals were studied. All of the animals were examined by ultrasound before the scintigraphic evaluation. After the injection of 7.4 MBq (200 microCi) 67Ga citrate intravenously, static images from the whole anterior thorax and abdomen were obtained at 24, 48 and 72 hours. Visual and semiquantitative analyses were performed. In semiquantitative analysis, an irregular region of interest was drawn over the thorax as the background, excluding the heart and a second region of interest was drawn over the abdomen, excluding the liver and spleen. Abdomen/ background ratios were calculated using the mean counts. RESULTS: In the visual evaluation, it was noticed that there was considerably increased 67Ga uptake in the abdomens of the infected animals. In infected animals, mean abdomen/background ratios at 48 and 72 hours (3.76 +/- 1.04, 4.13 +/- 0.72, respectively) were increased compared with mean abdomen/background ratios at 24 hours (2.94 +/- 0.77). These increases in abdomen/background ratios were statistically significant at 72 hours (p = 0.04). Between the infected animals and control group, mean abdomen/background ratios were compared, and statistically significant differences were found in the images obtained at 48 and 72 hours. CONCLUSION: Imaging at 72 hours seems to be more suitable imaging time for the diagnosis of alveolar echinococcosis. 67Ga scintigraphy may successfully demonstrate the lesions of EM infection localized intraperitoneally. The method of 67Ga scintigraphy is useful because it is simple, non-invasive and relatively safe.

Animals↗

PubMed2006

Tumour necrosis factor-alpha levels in hepatitis B virus-related chronic active hepatitis and liver cirrhosis and its relationship to Knodell and Child-Pugh scores.

Although both chronic active hepatitis-B (CAH-B) and liver cirrhosis (LC) are characterised by various degrees of inflammation and hepatocyte necrosis, in advanced stage cirrhosis, marked fibrosis develops and inflammation and tissue necrosis diminishes. In this study, we aimed to investigate serum tumour necrosis factor-alpha (TNF-alpha) concentration in patients with CAH-B and LC and its relationship to disease activity. Serum samples were taken from 30 patients with CAH-B and 30 with LC at different stages of the disease. TNF-alpha concentrations were measured by the ELISA technique. Results were compared with those of 30 healthy controls. Mean plasma TNF-alpha levels were found as 2.47 +/- 2.98, 0.8 +/- 1.21 and 0.72 +/- 1.08 pg/ml in CAH-B, LC and control groups, respectively. TNF-alpha levels were significantly higher in CAH-B group than LC and control groups (p <0.01 and p < 0.05, respectively). Although mean plasma TNF-alpha level of cirrhotic patients at Child-A stage was markedly high (3.31 +/- 0.15), no significant difference has been found between LC and control groups (p > 0.05). TNF-alpha concentrations were positively correlated with hepatitis activity index (Knodell's score) in CAH-B group whereas negatively correlated with Child-Pugh score in LC group (r =0.73, p < 0.01 and r = -0.42, p < 0.05, respectively). Our study showed that TNF-alpha level increases in patients with CAH-B correlated with histologic activity index. So it can be used to evaluate disease activity. Additionally, marked reduction of TNF-alpha concentration in advanced cirrhosis suggested that TNF-alpha production is determined by hepatic damage and inflammation.

Adolescent↗

PubMed2005

Frequency of gastroesophageal reflux disease in nonatopic children with asthma-like airway disease.

Gastroesophageal reflux disease (GERD) is commonly associated with asthma; however, frequency in nonatopic children with asthmatic symptoms is unknown. The aim of this study was to determine the frequency of gastroesophageal reflux (GER) in nonatopic children with asthma-like airway disease that recur despite conventional asthma treatment and to evaluate the clinical response to lansoprazole treatment. Twenty-five nonatopic children aged between 1 and 16 years who have asthma-like airway disease and 25 healthy children were included in the study. All cases underwent 24 h pH monitoring with dual sensor catheters. Additionally, acid suppressor treatment was administered to patients diagnosed as having GERD and clinical response was evaluated. Major symptoms encountered in the patient group included wheezing and cough (88%, and 32%, respectively). Reflux episodes were more common in distal esophagus during the prone position (reflux index (RI) of 11.5+/-10.3 vs. 16.2+/-9.4 during supine vs. prone). All distal esophageal parameters were significantly higher in the patient group except number of reflux episodes lasting longer than 5 min (RI of 13.3+/-13.1 vs. 3.9+/-2.9 in the patient vs. control groups, respectively). There was a significant improvement in symptoms and requirement for medication with treatment (number of systems decreased from 2.3+/-0.6 to 0.4+/-0.6, P=0.00). In conclusion, GERD is significantly more common in nonatopic children with asthma-like airway disease compared to the controls and clinical improvement is significant after acid suppressor treatment. Thus, we suggest that children followed-up with the diagnosis of nonatopic asthma with recurrent exacerbations despite adequate asthma treatment have a high frequency of GER and that lansoprazole treatment may be considered early in management.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2005

Inhibition of vascular endothelial growth factor-induced retinal neovascularization by retinoic acid in experimental retinopathy of prematurity.

Vascular endothelial growth factor (VEGF) has an important role in the pathogenesis of retinopathy of prematurity (ROP) and inhibition of VEGF expression in the neovascular phase might prevent destructive neovascularization in ROP. It is suggested that retinoids exert a highly potent antiangiogenic activity by inhibiting VEGF expression. The aim of this study was to demonstrate the preventive effect of retinoic acid (RA) on the VEGF-induced retinal neovascularization in a rat model of ROP. Wistar albino rats were placed into incubators at birth and exposed to an atmosphere alternating between 50 % and 10 % O(2) every 24 hours. After 14 days, the animals were removed to room air and received either an intraperitoneal injection of RA (5 mg/kg/day) (n=9) or saline (n=4) daily for six days, and sacrificed at 21 days. Other rats (n=4) were raised in room air and served as age-matched controls. The globe of each eye was cut through the cornea and embedded in paraffin. Serial sections were stained with hematoxylin-eosin for quantification of neovascular nuclei. The avidin-biotin peroxidase method was performed for evaluation of VEGF expression. The average number of neovascular nuclei was significantly lower in the control group compared to that in the ROP groups. In addition, it significantly decreased in the RA-treated ROP group compared to that of the saline-administrated ROP group. VEGF immunostaining was overall negative in room air-exposed rats. The VEGF immunostaining score significantly decreased in the RA-treated ROP group compared to that in the saline-administered ROP group. RA treatment might be beneficial in preventing neovascularization resulting from oxygen-induced retinopathy by downregulation of VEGF expression.

Animals↗

PubMed2005

Erythropoietin attenuates lipopolysaccharide-induced splenic and thymic apoptosis in rats.

Apoptosis of lymphoid tissues during sepsis is well documented and linked to the pathobiology of organ failure and death. In this study, we evaluated the effect of a single dose of recombinant erythropoietin (EPO) on thymic and splenic apoptosis in an endotoxic sepsis model. Young male Wistar rats were divided into 3 groups and administered intraperitoneally (IP) either normal saline; lipopolysaccharide (LPS) 10 mg/kg; or EPO (5000 U/kg) 30 min before lipopolysaccharide. Six hours following LPS administration animals were sacrificed. Apoptosis was assessed by hematoxylin-eosin staining, terminal deoxynucleotide transferase-mediated fluorescein-dUTP nick end labeling (TUNEL), and caspase-3 immunostaining. When compared with animals given LPS, animals pretreated with EPO displayed reduced splenic and thymic TUNEL positivity of 44+/-3 (p<0.05) and 143+/-4 (p<0.05) nuclei per high power field (hpf), respectively. Caspase-3 positivity was also significantly reduced in the spleen and thymus, with 31+/-4 (p<0.05) and 93+/-3 (p<0.05) positive stained nuclei per hpf, respectively. Serum nitrite levels were elevated in animals given lipopolysaccharide. Pretreatment with EPO attenuated the increase in nitrite levels; however, this did not reach statistical significance. We conclude that a single dose of recombinant erythropoietin can reduce thymic and splenic apoptosis associated with lipopolysaccharide administration.

Animals↗

PubMed2005

Comparison of leptin levels in serum and follicular fluid during the oestrous cycle in cows.

Leptin is mainly synthesised in white adipose tissue. Besides its effects on body weight and metabolic homeostasis, leptin also has effects on puberty, sexual maturation and reproduction. In this study the relationship between leptin, IGF-1, oestradiol (E2) and progesterone levels were investigated in serum and follicular fluid from cows. This study included 72 healthy, Brown Swiss cows aged 4-5 years. Samples from the jugular vein and follicular fluids were collected. Phases of the oestrus cycle of cows were classified according to their serum progesterone levels (< 3.18 nmol/l, follicular phase and the others as luteal phase). Follicles were grouped as large (> or = 8 mm) or small (< 8 mm). Leptin, IGF-1, oestradiol and progesterone levels were measured from serum and follicular fluid. Leptin concentrations were found to be significantly higher in luteal-phase follicular fluid of small follicles (P < 0.05). These were classified as atretic follicles. There was a positive correlation between serum and follicular fluid leptin levels in the luteal phase. Serum leptin was found to have a positive correlation with follicular fluid progesterone level (P = 0.01) in the preovulatory follicles. The present study shows that there is a relationship between the concentration of leptin in follicular fluid and atresia in small follicles.

Animals↗

PubMed2005

Symptoms of the olive pollen allergy: do they really occur only in the pollination season?

BACKGROUND: Olive (Olea europaea; O.e.) pollen is a major cause of seasonal respiratory allergy. The O.e. pollination season lasts two months from the beginning of May till the end of June. It was expected that patients with allergic disease from O.e. sensitization were symptomatic only during this period. However, during the last few years, we have observed that the clinical symptoms appear not only during the O.e. pollination season but also during the rest of the year. OBJECTIVE: The aim of this study was to observe and document symptoms of respiratory allergic diseases in the O.e. sensitized patients during the O.e. pollination season and after it. METHODS: One hundred and twenty-seven patients with respiratory allergic disease were enrolled in the study. Allergenic sensitizations were shown by SPT. Finally, patients were split into two groups as monosensitized with O.e. (n=19) and polysensitized (n=108). Patients were assessed by using scores of respiratory allergic disease symptoms and percentage of peak expiratory flow rate values (PEFR %) (only for asthmatic patients) during the O.e. pollination season and after it. RESULTS: Of the patients with O.e. monosensitization, 13 had allergic rhinitis (AR) only while six had allergic asthma (AA) additionally. AR alone and accompanied by AA was present in 84 and 24 polysensitized patients respectively. Eleven patients with O.e. sensitization (57.9 %) and 86 patients with polysensitization (79.6 %) had AR symptoms throughout the year irrespective of the O.e. pollination season. Similarly, three of the O.e. monosensitized and ten of the polysensitized patients with AA had asthmatic symptoms during the O.e. pollination season and also after it. CONCLUSIONS: In the patient group sensitive to O.e. along with other pollen extracts, it was possible to observe symptoms outside the pollination season. However, patients with O.e. monosensitization also had symptoms to a great extent outside the season.

Adolescent↗

PubMed2004

Testis fixation in prepubertal rats: fibrin glue versus transparenchymal sutures reduces testicular damage.

Experimental studies have shown that different suture materials used in testis fixation cause some degree of inflammation in the testis. This study was planned to compare the histological changes that were caused by fibrin glue which is a tissue sealant and by silk and polypropylene for transparenchymal testis fixation. 28 prepubertal rats were divided into 4 groups. Testis was fixed to the tunica vaginalis by fibrin glue in group 1, by silk in group 2 and by polypropylene in group 3. Group 4 was planned as a control. Testicular inflammation and seminiferous tubular diameter were evaluated for histological changes. The least inflammation was observed in the fibrin glue group, while the most inflammation occurred in the silk group. Seminiferous tubular diameter was 241.55 +/- 45.90 in the fibrin glue group, 151.90 +/- 8.34 in the silk group and 161.36 +/- 9.96 in the polypropylene group. In conclusion, fibrin glue, when used for testis fixation, causes less inflammation and less destruction of seminiferous tubular diameter compared with silk and polypropylene.

Animals↗

PubMed2004

Prednisolone therapy in Duchenne muscular dystrophy prolongs ambulation and prevents scoliosis.

Steroids may have a beneficial effect on the course of Duchenne muscular dystrophy (DMD). However, results vary in different studies. This study consisted of 66 DMD boys who were in the therapy group and 22 DMD boys in the control group. The mean ages were 6.8 +/- 2.1 years (range 2.5-12.5) and 7.0 +/- 1.3 years (range 5.0-9.0), respectively. We assessed muscle strength, 10-m walking, ankle contracture, and loss of independent walking ability age and onset of scoliosis. Treatment regimen was oral prednisolone 0.75 mg/kg on alternate days, plus vitamin D 600-1200 units/day and a calcium-enriched diet. After a follow-up period of 2.75 +/- 1.1 years (range 1.5-5) and when compared with controls, there was a statistically significant change in muscle strength between the two groups after 12 months (P < 0.05). Although 10-m walking time decreased in therapy group (P < 0.05), there was not significance between the groups in the end. Boys in the control group developed significantly less ankle contractures (P < 0.05). None of the therapy group had scoliosis during the follow-up period (mean age 10.8 +/- 1.2 years), whereas seven boys of the control group had scoliosis at a mean age of 11.7 +/- 2 years. Loss of walking ability age was statistically different between groups (P < 0.05). Our results indicate that, alternate-day prednisolone regimen may prolong ambulation and scoliosis can be delayed or prevented.

Adolescent↗

PubMed2003

Cyclosporine A toxicity in association with reduced renal mass.

The long-term effect of cyclosporine A (CsA) in male Wistar rats with reduced renal mass was studied. The aim of the study was to highlight the relationship of CsA effect on rats, simulating patients with two functioning kidneys (eg, heart, liver transplant recipients) and one kidney (renal transplant recipients). The Wistar rats were subjected to unilateral nephrectomy (Unx, n = 14) and to 5/6 nephrectomy (STnx, n = 14). Half of these rats and half of the sham operated ones (control, n = 13) were administered CsA (10 mg/kg/d) for 28 days IP. The serum creatinine (S(CR)), total protein (S(P)), and urine protein (U(P)) values as well as the whole blood CsA levels were determined on the 28th day of the study. The remnant kidneys were evaluated by image analyses and semiquantitative methods after sacrifice on the 28th day. In the three non-CsA-treated groups (Unx, STnx, and control) S(CR) was significantly higher in STnx rats than in Unx rats (P =.011). Percent of renal scarring (PRS) was significantly higher in Unx (P =.02) and in STnx rats (P =.017), compared with the control group. Among CsA-treated three groups S(CR) was significantly higher in STnx rats compared with Unx (P =.017). In addition, segmental sclerosis rate (SSR) was higher in STnx rats, compared with the control group (P =.008), whereas S(P) was higher in the control group (P =.005). When CsA-treated groups were compared with non-CsA-treated ones, U(P) of the Unx rats not receiving CsA were significantly higher than the Unx rats receiving CsA (P =.026). Also, U(P) was higher in non-CsA-treated groups (P =.014), whereas S(CR) (P =.001), S(P) (P =.001), and PRS (P =.001) were higher in CsA-treated rats. In conclusion, we suggest that preserved renal mass is not enough to prevent CsA toxicity and that CsA should be administered to patients with both kidneys (eg, heart, pancreas recipients) as carefully as to patients with one functioning kidney (renal transplant recipients).

Animals↗

PubMed2003

Combination of paraesophageal hernia and Morgagni hernia in an old patient.

Paraesophageal hiatal hernia is an uncommon condition that requires urgent correction to prevent life-threatening complications. It is present in 14% of all hiatal hernias. The incidence of Morgagni hernia among all diaphragmatic defects is 3-4% and about 90% of the hernias occur on the right, 8% are bilateral and 2% are on the left. The combination of a Morgagni hernia and paraesophageal hernia is very rare and only four cases have been reported in the literature. All of them occurred in the right. This report describes an old case admitted to our clinic with dyspnea, chest pain and chronic gastrointestinal symptoms, found to have combined left Morgagni and paraesophageal hernia. Surgical repair was performed via transabdominal approach. This unusual case and surgical approaches are discussed in light of the data presented in the literature.

Aged↗

PubMed2003

Does sucralfate prevent apoptosis occurring in the ischemia/reperfusion-induced intestinal injury?

BACKGROUND/PURPOSE: We have shown in a previous study that sucralfate is beneficial in the prophylaxis and treatment of hypoxia/reoxygenation-induced intestinal injury. The aim of this study is to investigate whether sucralfate has any effect on the prevention of apoptosis in the ischemia/reperfusion (I/R)-induced intestinal injury. METHODS: Rats were randomized into three groups. Group 1 and 2 were subjected to I/R. Group 1 (treatment group) received sucralfate while group 2 (treatment control group) did not. Group 3 served as a normal control group (sham group). The terminal ileum was harvested for histopathologic investigation by light microscopy. The presence of apoptotic enterocytes (DNA fragmentation in cell nuclei) was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL) reaction. RESULTS: In treatment control group, 3 of 7 rats had severe inflammation. None of the sucralfate-treated rats showed severe inflammation, 6 of them only showed mild inflammatory changes (p < 0.05). The apoptotic percentage was found to be 37.1 +/- 9.4 in the sucralfate-treated group (group 1), whereas it was 45.4 +/- 3.9 in the untreated group (group 2) (p < 0.05). The sham group had a completely normal intestinal architecture. CONCLUSIONS: The present study shows that 1) the experimental model of I/R-induced intestinal injury induces enterocyte apoptosis; 2) sucralfate decreases enterocyte apoptosis in the experimental model of I/R-induced intestinal injury which may play a key role in the pathophysiological events leading to failure of the intrinsic gut barrier defense mechanisms.

Animals↗

PubMed2002

Esophageal tuberculosis abscess: an unusual cause of dysphagia.

Primary esophageal tuberculosis is extremely rare. It is almost always secondary to tuberculosis of other organs. Abscess formation of the tuberculosis in the esophageal wall has not been reported in the literature previously. In this report, we present a case of esophageal tuberculosis abscess, with presented dysphagia, diagnosed by histologic evaluation of surgery specimen, without any other organ involvement. The unusual cause and the interesting clinical course of dysphagia are described.

Abscess↗

PubMed2002

Histopathological evaluation of the urethra after the Snodgrass operation: an experimental study in rabbits.

OBJECTIVE: To investigate the histopathological outcome of the incised urethral plate after tubularized incised-plate urethroplasty (the Snodgrass procedure to repair hypospadias) in a hypospadiac rabbit model, as it can produce meatal and neourethral strictures, and healing with scarring. MATERIALS AND METHODS: The study comprised 10 male New Zealand White rabbits (2.2-2.4 kg); under general anaesthesia the ventral urethra was completely excised 1 cm from the meatus proximally and a model of hypospadias formed. A full-thickness incision was then made in the distal dorsal urethra and the two sides of the incision marked by Indian ink tattooing. After placing a feeding tube (5 F) as a urethral catheter, both urethral wings were sutured ventrally by a 7/0 polydioxanone running suture, and the penile skin approximated by 5/0 chromic catgut. At 21 days and 3 months after surgery the penises were harvested, assessed histopathologically, and compared with those from control untreated rabbits of the same age and weight. RESULTS: In the study group the incised area of the dorsal urethra was re-epithelialized; the regional tissue and vascularity were normal. CONCLUSION: In this rabbit model the dorsal urethral incisions healed with no scar tissue; only the ventral suture lines had minimal fibrosis and inflammatory reaction.

Animals↗

PubMed2002

Heat shock protein 70 expression in neonatal rats after hypoxic stress.

OBJECTIVES: The tissue damage due to hypoxia in newborns is to some extent age-dependent; organs of premature babies are more vulnerable to hypoxic insult than full-term neonates. The aim of this immunohistochemical study was to investigate the role of heat shock protein 70 (HSP70), a stress-inducible protein, in developing the response to hypoxia in premature newborns. METHODS: Postnatal day-7 rats (corresponding to a human fetus of 32-34 weeks' gestation) and day-12 rats (corresponding to a full-term newborn infant) (n = 7) were subjected to mild hypoxia at 33 degrees C. Control rats (n = 7) for each group breathed room air for 4 h. After 4 h of recovery, the animals were killed, and brains, hearts and kidneys were removed for immunohistochemical staining. RESULTS: Immunohistochemically, HSP70 expression was found to be induced in the hippocampus and myocardium after exposure to hypoxia. The level of HSP70 expression in the hippocampus after hypoxic stress was significantly higher in the 12-day rats than in the 7-day rats (p = 0.03). However, HSP70 expression in the myocardium did not show any significant difference between the two groups. In addition, no significant induction of HSP70 expression was apparent in the kidney of rats exposed to hypoxia or in any organ of the control animals. CONCLUSIONS: We conclude that diminished HSP70 expression in the hippocampus of premature newborns may play a critical role in developing the response to hypoxic stress. However, HSP70 expression in the heart and the kidney after exposure to hypoxia did not appear to be related to fetal maturity.

Animals↗

PubMed2001

Inhibition of epithelial cell apoptosis by Porphyromonas gingivalis.

Porphyromonas gingivalis is periodontal pathogen that is capable of invading gingival epithelial cells (GECs). Apoptotic responses of primary cultures of GECs to P. gingivalis were investigated with a DNA fragmentation ELISA assay. P. gingivalis induced a transient increase in GEC DNA fragmentation; however, after prolonged incubation GECs did not undergo apoptosis. Furthermore, P. gingivalis blocked apoptosis in GECs following stimulation with camptothecin. Immunoblotting of GECs with Bcl-2 or Bax antibodies showed that P. gingivalis up-regulated Bcl-2 levels in GECs, whereas Bax levels were transiently elevated and declined after 24 h stimulation. Streptococcus gordonii did not affect levels of either molecule. RT-PCR demonstrated that induction of Bcl-2 occurs at the transcriptional level. The results suggest that P. gingivalis can inhibit apoptosis in GECs by up-regulation of the anti-apoptotic molecule Bcl-2. The prevention of host cell apoptosis may represent a strategy for P. gingivalis survival within invaded GECs.

Apoptosis↗