Immobilization of catalase by entrapping in alginate beads and catalase biosensor preparation for the determination of hydrogen peroxide decomposition

In this study, catalase enzyme was immobilized by entrapping in alginate beads in the presence of gelatin. In the optimization studies of the bioactive layer immobilized some parameters such as enzyme amount, alginate, gelatin, and crosslinking agent glutaraldehyde amount were determined as 700 U/mL, 2.0%, 18 mg/mL, and 5.0%, respectively. Effects of pH and temperature on the immobilization were also investigated. In the characterization studies of the immobilized enzyme storage and thermal stability experiments were done. The immobilized enzyme was used for the decomposition of hydrogen peroxide in milk samples and also by using a catalase biosensor prepared by the decomposition level of hydrogen peroxide was detected.     

Syndromic etiology in children at schools for the deaf in Turkey

OBJECTIVE: The aim of this study was to determine the syndromic etiology of bilateral severe sensorineural hearing disorders in children and current etiological causes to reduce the cases in the unknown group. METHODS: This study was conducted on 550 students of five schools for the deaf in Istanbul and Zonguldak, Turkey. Otologic, audiologic, dysmorphologic, ophthalmologic and dental examinations were performed in all children. Familial and medical histories were obtained. RESULTS: The etiology of hearing loss was genetic in 346 (62.90%), acquired in 107 (19.45%) and unknown in 97 (%17.63) cases. A total of 619 malformations were defined in 550 children and 99 of them belonged to a syndrome. We identified 33 different syndromes for these 99 syndromic children. Syndromic etiology was found in 18.0% of the total and 28.61% of the subjects with genetic etiology. Most common syndrome was Waardenburg syndrome which occurred in 33 children. CONCLUSION: The incidence of hereditary hearing impairment is very high in developing countries compared to developed countries. Prevention is essential to reduce the incidence, multidisciplinary approach and genetic counselling are necessary in this regard.     

Correlation of hMLH1 and HPP1 hypermethylation in gastric, but not in esophageal and cardiac adenocarcinoma

Using methylation-specific real-time PCR, we determined the prevalence of aberrant methylation in the mismatch repair gene hMLH1 and in the recently described HPP1 gene among 50 esophageal, 50 cardiac and 50 gastric ADCs. Additionally, expression of hMLH1 protein was detected immunohistochemically and correlated with DNA MSI. Hypermethylation of hMLH1 was found in 14% of esophageal, 28% of cardiac and 32% of gastric ADCs, whereas HPP1 hypermethylation was found more frequently in the 3 tumor types (64% vs. 38% vs. 54%). In gastric ADC, HPP1 hypermethylation was found more frequently in tumors with concomitant hMLH1 hypermethylation (81%) than in those without hMLH1 hypermethylation (41%, p = 0.008). Complete loss of hMLH1 protein expression, which was present in 10 carcinomas (5 cardiac and 5 gastric), was invariably correlated with hMLH1 hypermethylation and MSI. In conclusion, our data indicate that MSI and loss of the mismatch repair protein hMLH1, which is mainly caused by hMLH1 gene hypermethylation, are more prevalent in stomach and cardia carcinogenesis than in that of the esophagus. Moreover, in gastric cancer, hMLH1 hypermethylation is correlated with hypermethylation of the HPP1 gene.     

Benign fibrous histiocytoma of the eyelid with an unusual clinical presentation

Benign fibrous histiocytoma is a common soft tissue tumor that can be deep or superficially located. Although the deep type of fibrous histiocytoma has a predilection for the orbit, the eyelids are an unusual location for the cutaneous type. A 42-year-old woman had bilateral yellowish nodular masses of the eyelids for two years. Pathological examination after excision revealed benign fibrous histiocytoma. Our case is an unusual clinical presentation of cutaneous fibrous histiocytoma as well as a rare location such as the eyelids.     

Some pyridazinone and phthalazinone derivatives and their vasodilator activities

In this study, 6-[(4-arylidene-2-phenyl-5-oxoimidazolin-1-yl)phenyl]-4,5-dihydro-3(2H)-pyridazinone and 4-[(4-arylidene-2-phenyl-5-oxoimidazolin-1-yl)phenyl]-1(2H)-phthalazinone derivatives were synthesized by reacting 6-(4-aminophenyl)-4,5-dihydro-3(2H)-pyridazinone or 4-(4-aminophenyl)-1(2H)-phthalazinone compound with different 4-arylidene-2-phenyl-5(4H)-oxazolone derivatives. The vasodilator activities of the compounds were examined both in vitro and in vivo. Some pyridazinone derivatives showed appreciable activity.     

p53 overexpression as a prognostic indicator in endometrial carcinoma

PURPOSE: To investigate the prognostic value of p53 overexpression in endometrial adenocarcinoma cases of different stages and histologic subtypes. METHODS: One hundred and eleven surgically staged endometrial carcinoma (EC) cases from 1996 to 2000 constituted this retrospective study group. Prognostic factors determined through the evaluation of surgery specimens by co-author pathologist, were surgical stage, tumor size, histology, histologic and nuclear grade, myometrial invasion, adnexal/serosal metastasis, peritoneal cytology, retroperitoneal lymph node involvement p53 overexpression was assessed via immunohistochemical staining. Tissues that expressed p53 were considered as positive p53 staining. In terms of degree of staining, 1-29%, 30-90% and 80-100% of tumoral tissue stained with p53 were considered to be mild, moderate and high p53 staining, respectively. RESULTS: Mean age and follow-up period of the study group were 58.2 +/- 10.6 years and 33.4 +/- 2.7 months, respectively. Percentages of cases surgically staged as early (I-II) and advanced (III-IV) FIGO stages were 65.8% (n: 73) and 34.2% (n: 38), respectively. Cases with positive p53 staining had a significantly high mean survival period compared with those with negative p53 staining (86.6 +/- 6.0 vs 49.1 +/- 8.1, p < 0.001). p53 overexpression was statistically detected to be high in Stage III-IV tumors, non-endometrioid histologic subtypes (p = 0.019), histologic and nuclear grade 2-3 tumors (p < 0.001), adnexal/serosal metastasis (p = 0.001), lymph node involvement (p = 0.012), and positive peritoneal cytology (p = 0.017). The degree of p53 staining was remarkably correlated with survival. In cases with mild and high p53 staining, mean survival times were 47.1 +/- 7.0 months and 57.0 +/- 13.1 months, respectively (p = 0.0003) compared to those with high p53 staining. On univariate analysis, all of the prognosticators, including p53 staining (p < 0.001) and degree of p53 staining (p < 0.001) appeared to be independent risk factors for poor prognosis. On multivariate analysis, only pelvic lymph node involvement (p = 0.03), serosal/adnexal involvement (p = 0.004), and positive peritoneal cytology (p = 0.01) were found to be independent prognosticators of survival while p53 expression (p = 0.743) and degree of p53 staining (p = 0.802) were not detected as independent prognosticators. CONCLUSION: p53 overexpression is strongly related to poor prognostic indicators in endometrial adenocarcinoma. Although in this study p53 overexpression was not detected as an independent prognosticator, additional studies with large data set are needed to evaluate the prognostic value of p53 expression.     

Late diagnosis of severe colchicine intoxication

A 4-year-old Turkish girl was referred to our hospital with the findings of encephalopathy and pancytopenia. She had a history of severe abdominal cramps and gastrointestinal bleeding. A confused state, muscle pain and weakness, erythema-bullous and erythema-nodosum-like skin lesions, and alopecia were observed at her hospitalization. All of these symptoms resolved on follow-up. On laboratory investigation severe thrombocytopenia and leukopenia, mild anemia, a moderate increase in aspartate aminotransferase and alanine aminotransferase levels were detected. After reevaluating her medical history, it was learned that she had accidentally taken 1.3 to 1.5 mg/kg of colchicine 3 to 4 days before her first hospitalization. The possibility of misdiagnosis of colchicine intoxication should be borne in mind, and pediatricians must be aware of its toxic effects, especially in areas where patients with familial Mediterranean fever are present.     

Factors affecting outcome of one-stage anterior hypospadias repair: analysis of 422 cases

The repair of hypospadias is among the most difficult problems in urology, as it demands the construction of a well-functioning urethra and a good cosmetic appearance. We performed a retrospective analysis of 422 cases subjected to one-stage anterior hypospadias repair between 1982 and 1999 in our clinic and investigated the effects of factors like degree of hypospadias, surgical technique, and the surgeon's experience on outcome. The operations used were MAGPI (91), urethral advancement (10), Mathieu (260), modified Allen-Spence (50), onlay island flap (5), and double-faced island flap (6) procedures. The early complication rate was 18%, while the final success rate following secondary interventions was 95%. The complications included fistula formation in 49 cases (12%), flap necrosis in 12 (3%), meatal problems in 12 (3%), residual chordee in 4 (1%), and urethral stricture in 1 (<1%). Complication rates were significantly higher if the meatus was proximal or there was severe chordee and in the first 6 years of the study. The flap procedures were associated with a higher complication rate. It is concluded that one-stage procedures are successful in the repair of anterior hypospadias in experienced hands with proper patient selection. Accepted: 21 March 2001