Endothelial nitric oxide synthase gene T-786C and 27-bp repeat gene polymorphisms in retinopathy of prematurity

PURPOSE: Retinopathy of prematurity (ROP), which is associated with abnormal retinal vessel development, is the leading cause of visual loss in preterm infants. Endothelial nitric oxide synthase (eNOS) is believed to play a central role in both retinal angiogenesis and vasculogenesis. The aim of this study was to investigate functional genetic polymorphisms of eNOS in the pathogenesis of ROP. METHODS: eNOS T(−786)C and 27-bp repeat (eNOS, b: wild-type, a: mutant) genotypes were determined using allele-specific polymerase chain reaction in 105 low birth weight (LBW) preterm infants treated for ROP (treated group). A control group was set up and composed of 127 LBW infants with stage 1 or 2 ROP that did not not require treatment (untreated group). RESULTS: The genotype distribution of eNOS 27-bp repeat polymorphism was found to significantly differ (p=0.015) between the two groups, whereas the genotype distribution of eNOS T(−786)C did not differ (p=0.984) between the groups. There was no difference in the distribution of either the “a” allele (p=0.153) nor of the C allele (p=0.867) in a groups comparison. Multiple logistic regression analysis revealed that male gender (p=0.046) and eNOS aa genotype (p=0.047 versus ab genotype and p=0.022 versus bb genotype) were significantly associated severe ROP that required treatment. The haplotype estimations based on the detected genotype distributions showed that the prevalence of aT and bT haplotypes was significantly increased in the group treated for ROP. CONCLUSIONS: Functional eNOS 27-bp repeat polymorphism might be associated with the risk of severe ROP, however we found no association between the eNOS T(−786)C and the pathogenesis of ROP

A Study of Memetic Search with Multi-parent Combination for UBQP

We present a multi-parent hybrid genetic–tabu algorithm (denoted by GTA) for the Unconstrained Binary Quadratic Programming (UBQP) problem, by incorporating tabu search into the framework of genetic algorithm. In this paper, we propose a new multi-parent combination operator for generating offspring solutions. A pool updating strategy based on a quality-and-distance criterion is used to manage the population. Experimental comparisons with leading methods for the UBQP problem on 25 large public instances demonstrate the efficacy of our proposed algorithm in terms of both solution quality and computational efficiency

Lineage Diversion of T Cell Receptor Transgenic Thymocytes Revealed by Lineage Fate Mapping

Background: The binding of the T cell receptor (TCR) to major histocompatibility complex (MHC) molecules in the thymus determines fates of $TCR\alpha\beta$ lymphocytes that subsequently home to secondary lymphoid tissue. TCR transgenic models have been used to study thymic selection and lineage commitment. Most TCR transgenic mice express the rearranged $TCR\alpha\beta$ prematurely at the double negative stage and abnormal TCRαβ populations of T cells that are not easily detected in non-transgenic mice have been found in secondary lymphoid tissue of TCR transgenic mice. Methodology and Principal Findings: To determine developmental pathways of TCR-transgenic thymocytes, we used Cre-LoxP-mediated fate mapping and show here that premature expression of a transgenic $TCR\alpha\beta$ diverts some developing thymocytes to a developmental pathway which resembles that of gamma delta cells. We found that most peripheral T cells with the HY-TCR in male mice have bypassed the RORγt-positive $CD4^{+}8^{+}$ (double positive, DP) stage to accumulate either as $CD4^{-}8^{-}$ (double negative, DN) or as $CD8\alpha^{+}$ T cells in lymph nodes or gut epithelium. Likewise, DN $TCR\alpha\beta$ cells in lymphoid tissue of female mice were not derived from DP thymocytes. Conclusion: The results further support the hypothesis that the premature expression of the $TCR\alpha\beta$ can divert DN thymocytes into gamma delta lineage cells

Gyermekkori Langerhans-sejtes histiocytosissal szerzett magyarországi tapasztalataink

BACKGROUND: Langerhans cell histiocytosis (LCH) in children is relatively rare, and the long-term analysis of therapy results has not been done yet in Hungary. PURPOSE: In this review we summarise the incidence, clinical features, prognostic risk factors and treatment results of children's LCH in Hungary, using data from the National Childhood Cancer Registry in Hungary in a 20-year period between 1981 and 2000. RESULTS: From January 1981 to December 2000, 111 children under 18 years of age were newly diagnosed with LCH in Hungary. The male-female ratio was 1.36:1, the mean age: 4 years 11 months. The minimal and median follow-up time was 3.48 years and 10.98 years respectively. 38 children had single-system disease, while in 73 cases we found systemic dissemination already at the time of diagnosis. Twenty-two patients were treated only by local surgery, 7 by surgery with local irradiation and 5 children received only local irradiation. In two cases remission was obtained with local steroid administration. 75 patient received chemotherapy. During the twenty years 14 children died, 9 due to the progression of the disease. Sixteen of the 111 patients had relapse with a mean of 2.16+/-1.29 years after the first diagnosis. Three patients with relapse got chemotherapy generally used in lymphoma and remission was achieved. The overall survival of all patients (n=111) was 88.3+/-3.1% at 5 years and 87.3+/-3.2% at 10 and 20 years. CONCLUSION: Childhood LCH is a well treatable disease and the survival rate is high. Even disseminated diseases have a quite good prognosis in childhood