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Biomedical subjects

G Hasçelik

Publications and source records attributed to G Hasçelik.

At least 19 recordsLinked to original sources

Varicella vaccination in children with lymphoma and solid tumours.

BACKGROUND: Varicella infection can be a severe disease, especially in immunosuppressed patients. Here, experience with live varicella vaccine to prevent varicella infection is reported in children who were undergoing treatment for lymphoma and solid tumours. METHODS: 40 children, aged between 12 months and 15 years with no clinical history of varicella, were vaccinated with live varicella vaccine. All received two doses of the vaccine subcutaneously 4 weeks apart. Serum samples were taken before the first dose and 6 weeks after the second dose of vaccine. RESULTS: Before vaccination, 32 patients were seronegative for varicella and eight were seropositive. Seroconversion was observed 6 weeks after the second dose in 24 of the 32 (75%) seronegative children. In 4 of 8 previously seropositive patients, antibody titres increased after immunisation. Zoster infection occurred 5 weeks after the second dose of vaccine in only one previously seronegative child. 7 children, who had responded to the vaccine, have been exposed to varicella in their families or in school without contracting clinical disease. CONCLUSION: Although the small number of patients in our group prevents us from drawing definitive conclusions, the varicella vaccine seems to be well tolerated and can be administered to children with lymphoma and solid tumours undergoing treatment.

Adolescent↗

Stenotrophomonas maltophilia: antimicrobial resistance and molecular typing of an emerging pathogen in a Turkish university hospital.

Despite its limited pathogenicity, Stenotrophomonas maltophilia is an emerging nosocomial pathogen. This study investigated the isolation frequency, antimicrobial resistance and genotypic relationships of 205 S. maltophilia isolates from 188 patients in a university hospital between 1998 and 2003. Susceptibility profiles for 11 antimicrobial agents were determined by the NCCLS agar dilution method for non-fermentative bacteria, while enterobacterial repetitive intergenic consensus sequence (ERIC)-PCR and pulsed-field gel electrophoresis (PFGE) were used for genotyping of the isolates. Of the 205 isolates, 56.1% were isolated in the last 2 years of the study. The risk of S. maltophilia isolation was higher in intensive care units, S. maltophilia was isolated mostly (86.8%) after hospitalisation for >or= 48 h, and 90.4% of the patients had underlying diseases. Resistance levels were>60% for all antimicrobial agents tested except co-trimoxazole. High genetic diversity was found among the S. maltophilia isolates, and cross-infection with S. maltophilia was not common. Although ERIC-PCR revealed fewer genotypes than PFGE, it proved to be a rapid and easy method for S. maltophilia genotyping, and was more economical than PFGE.

Anti-Bacterial Agents↗

In vitro activities of new quinolones against Brucella melitensis isolated in a tertiary-care hospital in Turkey.

We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucella melitensis. According to their minimum inhibitory concentration for 90% growth (MIC(90)) values, the most active agent was found to be sparfloxacin (MIC(90) 0.12 mg/L) followed by levofloxacin, ciprofloxacin, ofloxacin (MIC(90) 0.50 mg/L) and grepafloxacin (MIC(90) 1 mg/L), gemifloxacin (MIC(90) 2 mg/L) and gatifloxacin (MIC(90) 4 mg/L).

Anti-Infective Agents↗

Streptococcus pneumoniae penicillin resistance in Turkey.

Resistance of Streptococcus pneumoniae (750) to penicillin, erythromycin, chloramphenicol and trimethoprim/sulfamethoxazole isolated in 4 Turkish hospitals between 1996 and 1999 was evaluated according to year of isolation, patients' age groups and specimen. Penicillin susceptibility was determined by E-test strips and the other antibiotics were tested by disk diffusion test following the NCCLS guidelines in each center. Overall high and intermediate resistance to penicillin was 3% and 29%, respectively. There was a significant difference (p<0.001) between the centers with regard to penicillin resistance. However, there was no significant increase in resistance by year. Penicillin resistance varied significantly among children and adults (36% versus 25%) and according to the specimen. Highest rate of penicillin resistance was observed in respiratory specimens (36%) followed by ear exudates (33.5%). In blood isolates, resistance to penicillin was 28.6%. Overall resistance to erythromycin was 8%, to chloramphenicol 5% and to trimethoprim-sulfamethoxazole 47%. Although overall penicillin resistance in these Turkish S. pneumoniae isolates is high, resistance rates vary in each center and have not increased from 1996 to 1999.

Adult↗

Neutrophil chemotaxis in acutely infected and clinically stable cystic fibrosis patients.

PURPOSE: The aim of the present study was to evaluate the role of neutrophil chemotaxis in cystic fibrosis (CF) and to also determine whether an acute bacterial infection and the nutritional status of a child can affect neutrophil chemotaxis. METHODS: Twelve acutely infected and 12 clinically stable CF patients and 10 healthy age-matched controls were studied. Neutrophil chemotaxis and random migration were investigated in vitro in the peripheral blood of subjects by the Boyden chamber method and the results were expressed as chemotactic index (CI). The nutritional status of the cases was evaluated as body mass index (BMI). RESULTS: The CI values in the acutely infected group were found to be significantly lower than the clinically stable and healthy control groups (P < 0.05 and P < 0.005, respectively). There was no significant difference between the clinically stable CF group and the healthy control group (P > 0.1). No significant correlation was detected between the CI and BMI of the two groups of CF patients (P > 0.05). CONCLUSIONS: The present study confirms that neutrophil chemotaxis and random migration are normal in clinically stable CF patients. The decreased CI in the acutely infected patients indicates the possible role of infection itself on neutrophil chemotaxis.

Acute Disease↗

Effect of intraperitoneal and extraperitoneal insertion of mesh on bacterial translocation: does it make a difference?

OBJECTIVE: To asses the effect of insertion of mesh, with or without contact with the peritoneum, on the induction of bacterial translocation. DESIGN: Open experimental study. SETTING: Surgical research laboratory, Turkey. SUBJECTS: 158 Swiss albino mice. INTERVENTIONS: A defect in the abdominal wall was created. In the control group, the defect was closed primarily. In the extraperitoneal group, polypropylene mesh was sutured over the abdominal wall after primary closure of the peritoneum and in the intraperitoneal group, polypropylene mesh was sutured to close the created defect so that it was in contact with the intestines. MAIN OUTCOME MEASURES: Bacterial translocation at 4, 24 and 48 hours. RESULTS: Insertion of mesh in contact with the peritoneum led to increased bacterial translocation to mesenteric lymph nodes at 4 (p = 0.02) and 48 (p = 0.03) hours compared with insertion without contact. CONCLUSION: Contact between a foreign body and the peritoneum is required to induce bacterial translocation.

Abdominal Muscles↗

Experimental study of the effects of splenectomy and partial splenectomy on bacterial translocation.

BACKGROUND: The aim of this study is to evaluate the effect of splenectomy and partial splenectomy in a burn-induced bacterial translocation model and to study Kupffer cell (KC) morphology and number. METHODS: Mice were divided into sham-burn and burn groups. Each group was also subdivided to sham-splenectomy, partial-splenectomy, and splenectomy subgroups. At day 0, operations were performed. At the postoperative 10th day, a sham burn or burn injury was made in all animals. Twenty-four hours later, cultures for bacterial translocation were obtained and livers were evaluated for the quantity and morphology of KCs. RESULTS: Burned-splenectomized animals had significantly decreased bacterial translocation when compared with sham-splenectomized animals (p = 0.031). Interestingly, in both the sham-burned and burned groups, splenectomy subgroups had significantly higher numbers of KCs compared with partial-splenectomy and sham-splenectomy subgroups (p<0.00000). Burn injury caused a significant decrease of KC numbers in all subgroups compared with their correspondent sham-burned subgroups (p<0.05). CONCLUSION: Results revealed that splenectomy decreases bacterial translocation and also increases the number of KCs.

Animals↗

Seroprevalence of Helicobacter pylori infection in an Asymptomatic Turkish population.

OBJECTIVES: Helicobacter pylori infection is recognized as being strongly associated with chronic gastritis, duodenal ulceration and probably gastric carcinoma. Seroepidemiological studies have shown that a large proportion of healthy people have antibodies against H. pylori. A serological study was conducted in an asymptomatic Turkish population to investigate the seropositivity rate of H. pylori and to detect the relationship with age. SUBJECTS AND METHODS: A total of 657 serum samples collected from 331 male and 326 female people in different age groups who had no gastrointestinal complaints were studied by a commercial ELISA test for the presence of H. pylori-IgG antibodies. RESULTS: Three hundred and forty-eight subjects (53%) were seropositive. The overall seropositivity rates did not differ with sex. Antibody prevalence increased progressively with age. The seropositivity rates were as follows: 17.4% < 1 year old; 15.5% aged 1-4; 30.6% aged 5-9; 47.3% aged 10-14; 58.4% aged 15-19; 62.6% aged 20-29; 67.6% aged 30-39; 81.3% aged 40-49; and 66.3% over 50 years of age. CONCLUSIONS: This study indicated that more than 30% of the subjects acquired infection before teenage and that about 70% of adults had antibodies against H. pylori in our population. The high prevalence and early acquisition of H. pylori infection may be related in part to socioeconomic status and traditional living conditions in Turkey.

Adolescent↗

Circulating intercellular adhesion molecule-1 and E-selectin levels in gastric cancer.

A diversity of adhesive interactions occur between the cancer cell and host extracellular matrix which potentiate neoplastic expansion and metastatic dissemination. In miscellaneous malignant diseases, tumour progression has been observed to be associated with alterations in adhesion molecule expression. Recently, circulating soluble intercellular adhesion molecules have been identified. In this study, serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin) were determined in patients with gastric cancer. The study group consisted of 27 patients with previously untreated gastric adenocarcinoma. Four patients had stage II, two patients stage III and 21 patients stage IV disease according to the TNM classification. Nineteen patients had distant metastasis. The sera obtained from 18 healthy volunteers served as controls. Serum sICAM-1 and sE-selectin concentrations were determined by enzyme-linked immunosorbent assay (ELISA). In addition, we also studied other tumour-associated antigens, i.e. CEA and CA 19-9. Serum sICAM-1 levels were significantly increased in patients with gastric cancer (P < 0.0001). However, sE-selectin levels did not differ from the controls. sICAM-1 concentrations were also significantly higher in patients with distant metastasis and peritoneal spread (P = 0.0045 and P = 0.0157 respectively), whereas sE-Selectin levels were elevated only in patients with peritoneal metastasis (P = 0.033). Serum concentrations of sICAM-1 and sE-selectin correlated with CEA levels (P = 0.0013 and P = 0.003 respectively). Elevated levels of sE-selectin were associated with poorer prognosis (P = 0.0099), whereas sICAM-1 had no significant impact on survival. Our results suggest that increased sICAM-1 serum levels may reflect widespread disease and contribute directly to the progression of gastric cancer. Further investigation of the molecular mechanisms of adhesive tumour-host interactions may lead to a better understanding of the natural history of gastric cancer.

Adult↗

Effect of omentectomy on peritoneal defence mechanisms in rats.

OBJECTIVE: To assess the effect of omentectomy on peritoneal defence mechanisms in rats. DESIGN: Randomised study. MATERIAL: Sixty Wistar Albino rats. INTERVENTIONS: Rats were divided in three groups of 20. All rats underwent midline laparotomy and 10 rats in each group had omentectomy. Samples were taken two hours (early period) and 30 days (late period) after omentectomy. MAIN OUTCOME MEASURES: Effect of omentectomy on bactericidal activity of peritoneal fluid (PBA), chemotactic indices (CI) of polymorphonuclear leucocytes (PMNL), phagocytic activity of PMNL in the peritoneal fluid (PHA), total cell counts, and cell types of peritoneal washing fluid. RESULTS: In the early period omentectomy reduced total cell counts from 3440 (1400-4800) x 10(6)/10 ml to 1480 (800-2080) x 10(6)/10 ml (p = 0.0022), and the CI of PMNL from 2.86 (2.32-4.02) to 1.43 (1.29-1.77) (p = 0.0002), and increased the PHA from 11.9 (8.3-17) to 17 (16-19) (p = 0.0006). The PBA was not significantly altered. The proportion of macrophages decreased (p = 0.0001), while the proportion of lymphocytes increased in the peritoneal fluid (p = 0.0002). In the late period total cell counts in the control and omentectomy groups were 3440 (1400-4800) x 10(6) and 3160 (1040-5120) x 10(6)/10 ml fluid, respectively (p = 0.52). Omentectomy reduced the CI of PMNL from 2.86 (2.32-4.02) to 2.01 (1.82-1.49) (p = 0.0003). The difference between the proportion of PHA of either group was not significant (p = 0.06). PBA in the control and omentectomy groups was 99.03 (70-100) and 99.48 (71.5-100), respectively (p = 0.97). Although the total cell count in the peritoneal fluid did not differ, the proportion of macrophages decreased (p = 0.0003) while the proportion of lymphocytes increased (p = 0.0002). The proportion of PMNL did not change in either of the experimental settings. CONCLUSIONS: The omentum has an important role in local peritoneal defence mechanisms in experimental conditions. Its removal may effect some of these mechanisms adversely.

Animals↗

Evaluation of the microbiology of chronic sinusitis.

Chronic sinusitis is one of the most common diseases treated in outpatient centres. In this prospective study, 49 patients with the diagnosis of chronic maxillary sinusitis were evaluated microbiologically by using sinus swab, irrigation fluid and sinus mucosal tissue specimens obtained during endoscopic sinus surgery. There was no bacterial growth in seven cases. In the remaining 42 cases a total of 89 bacteria were isolated, 28 of them being classical pathogens and 61 being non-classical pathogens. Among the classical pathogens Staphylococcus aureus was the most common one. The correlation between the isolates obtained from maxillary sinus and isolates obtained from throat, nose and nasopharynx did not have a predictive value. Since the overall rate of classical pathogen isolation from patients with chronic sinusitis was not significantly high, the possible role of factors other than bacterial growth should be identified in the pathogenesis of chronic sinusitis.

Adolescent↗

Helicobacter pylori infection in symptomatic and asymptomatic children: a prospective clinical study.

It is well known that Helicobacter pylori infection is extremely common throughout the world, but most infected persons do not develop ulceration and remain asymptomatic. This study was undertaken in order to determine the prevalence of H. pylori infection, the age distribution, and the factors that may affect the frequency of H. pylori infection. We evaluated the presence of antibody against H. pylori in children and adolescents, we also assessed the efficacy of non-invasive and invasive methods for detection of H. pylori infection in children who had undergone upper gastrointestinal endoscopy. We evaluated 43 males and 18 females whose ages ranged from 1 to 17 years (mean age: 9.4 +/- 4.2). 29 of all cases were symptomatic and 32 were asymptomatic. H. pylori infection was present in 49% of the studied cases. The data were analysed by Fisher's exact chi-square and Mantel-Haenszel tests. It was found that H. pylori infection graphically increased with age in both groups from 25% at ages 3-5 to 80% at ages 16-20. But no association was determined statistically between age and H. pylori positivity (p < 0.05). H. pylori infection was determined in 14 (48%) and 16 (50%) cases in symptomatic and asymptomatic groups respectively. There was no significant difference between H. pylori and either group (p > 0.05). According to the endoscopy findings, the symptomatic group was divided into two subgroups: children with peptic ulcer and children with non-ulcer dyspepsia (NUD). An attempt was made to compare ulcer, non ulcer dyspepsia and asymptomatic cases with H. pylori positivity, but no significant relation could be established between the groups (p > 0.05). 14 (23%) of the cases had previous gastric and/or intestinal complaints in their parents (positive family history). There was a significant, statistically positive relation between family history and symptoms (p < 0.01). Nevertheless, no association was found between H. pylori infection and family history (p > 0.05). There were no significant differences in H. pylori infection related to sex, type of housing, location of housing, socio-economic status (SES) or source of water supply. It is concluded that H. pylori infection has a high prevalence in our country. Although endoscopic evaluation is an invasive method, under our conditions, histopathological examination with 97% is shown to be much more sensitive in determination of H. pylori infection. Since no community difference was determined in the prevalence of H. pylori infection, all children should be considered to be under the threat of the same risk.

Adolescent↗

Effects of vitamin A on immunological deficiencies in rats with obstructive jaundice.

OBJECTIVE: To investigate the ability of an immunostimulant, vitamin A, to reverse dysfunction of the mononuclear phagocyte system and impaired peritoneal neutrophil chemotaxis in rats with obstructive jaundice. DESIGN: Open laboratory study. SETTING: Medical School, Turkey. MATERIAL: 60 male Wistar-Albino rats. INTERVENTIONS: Two different experimental studies with 30 rats each were performed. Ten of the 20 rats in which the common bile duct was ligated and divided, were given vitamin A (vitamin A group) and the other 10 were given saline (saline group). Ten rats which underwent laparotomy with mobilisation of the common bile duct (sham group) were given saline. Rats in the vitamin A group were given 200 IU/g/day vitamin A and other groups of rats had an equal volume of saline intraperitoneally for 20 days. MAIN OUTCOME MEASURES: Function of the mononuclear phagocytic system was studied by the use of 99mTc sulphur colloid uptake, peritoneal neutrophil chemotaxis was measured by the Boyden chamber method, and liver function tests were studied 21 days after operation. RESULTS: Hepatic uptake of 99mTc sulphur colloid decreased, and lung uptake increased in the saline group compared with the sham and vitamin A groups (p < 0.05). Neutrophil chemotaxis was reduced in the saline and vitamin A groups compared with the sham group (p < 0.05). Serum aspartate aminotransferase and alanine aminotransferase activities and unconjugated bilirubin concentrations in the saline group were higher than in the vitamin A and sham groups (p < 0.05). CONCLUSION: Vitamin A stimulates mononuclear phagocytic function in jaundiced rats. It also improves liver function and may enhance peritoneal neutrophil chemotaxis.

Adjuvants, Immunologic↗