Antigen-specific murine T-cell lymphomas: functional heterogenicity

Two ovalbumin (OVA)-specific helper lymphomas (designated ROT/6.1 and ROT/6.2) were established by transformation of enriched, OVA-immune T cells with the radiation leukemia virus (RadLV). Shortly after establishment these lymphomas provided carrier (OVA)-specific help for anti-hapten antibody response. However, 5 months later ROT/6.1 lost its OVA specificity and could augment anti-hapten antibody response in the presence of an unrelated carrier. ROT/6.2 retained its antigen-specific helper function over 10 months of repeated passaging. This OVA-specific helper line inhibited anti-hapten antibody response when given together with an unrelated carrier. Cloning of ROT/6.2 by limiting dilution revealed that only 3 of 10 clones tested had OVA-specific helper activity. None of the clones could induce antigen-specific DTH reaction. The interrelationship between the functional heterogenicity, specificity, and stability of the helper lines is discussed.     

Effect of Women’s Perceptions and Household Practices on Children’s Waterborne Illness in a Low Income Community

An ecosystem approach to human health was adopted in a community-based study carried out in Bebnine, an underserved town in Lebanon. The objective of the study is to examine the association between women’s household practices and diarrhea among children in a setting where contaminated drinking water and intestinal diseases are common. A total of 280 women were randomly selected and interviewed using a structured questionnaire. Data were collected on 712 children between the ages of 6 and 14. The study instrument included determinants of diarrhea such as sociodemographic characteristics, water, sanitation, hygiene practices, gender variables, and behavioral risk factors. Multivariate regression analysis was employed to examine the association between water handling practices and diarrhea. The prevalence of diarrhea is 5%. Female children are more likely to suffer from diarrhea than male children (OR = 2.58; 95% CI: 1.19–5.62). Treatment of drinking water at the household level and the use of drinking water for cooking and the preparation of hot beverages are protective against diarrhea (OR = 0.15; 95% CI: 0.03–0.65). Female caretakers’ behaviors such as daily bathing and seeking medical care at times of illness are protective against diarrhea in children. The findings suggest that diarrhea is a gendered health problem. Female children, who are generally more involved in household activities than male children, are at higher risk of suffering from diarrhea. Female caretakers’ personal hygiene, household practices, and perceptions of diarrhea are additional risk factors. Intervention activities would be more effective if based on a better understanding of gender roles and household power relations.     

Antibacterial effects of Octenicept,and benzalkonium chloride on Acinetobacter baumannii strains isolated from clinical samples and determination of genetic diversity of isolates by RAPD-PCR method

Molecular Biology Reports - Acinetobacter baumannii (A. baumannii) is among the important causes of nosocomial infections. Due to the emergence of antibiotic resistance, many problems have been...     

210 Computational study of substrates and mediators features of lacasses

Laccases are enzymes of the family multicopper oxidases, being widely used for biotechnological applications (Canas & Camarero, 2010). The enzymes’ catalytic cycle consists of the oxidation of the substrate with the concomitant reduction of molecular oxygen to water. In this process, the substrate is converted to a free radical, that can oxidize larger substrates acting as a mediator or it can undergo polymerization. Substrate binding is not specific, and there is a large diversity of substrates for laccases. Moreover, the binding site shows important differences among diverse species. The goal of the present work is to characterize the laccase binding pocket of different species, in order to establish their common pharmacophoric characteristics. For this purpose, we have carried out docking studies with a subset of substrates, covering the diversity of substrates using the Glide program (Friesner et al., 2004). We have also analyzed the characteristics of the binding site using diverse probes. We further have rationalized the differential values of km found among diverse species for a specific substrate. Finally, special attention has been devoted to the binding of the mediator 2,2′-azido-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), commonly used in industrial processes. Figure 1 shows, ABTS docked onto the fungal laccase, whereas Figure 2 shows ABTS docked onto the bacterial laccase. The analysis of the protein–ligand complex together with the corresponding optimized geometries of the possible substrate species carried out using DFT suggest that the bound species is the protonated form of ABTS as previously suggested (Enguita et al., 2004). Furthermore, the results of this study also suggest that its mechanism of oxidation occurs in a similar way to the rest of substrates/mediators, in contrast to previous suggestions (Fabbrini et al., 2002).