Aquatic environmental microbial biofilms grow in a broad range of redox environments from oxic to methanogenic, and they often also establish internal redox gradients. In technical applications, biofilms are also subjected to controlled redox conditions. Studies on biofilms often make use of fluorescence microscopic imaging techniques together with lectin binding analysis to gain insights into structure, composition, and functions of the biofilms. Here we studied the direct influence of redox potentials on fluorescence lectin binding analyses (FLBA) for two commonly used lectin-fluorophore conjugates. An effect of the electrical potential on signal intensity was observed and found to be statistically significant. The signal intensity changes however, remained within the range of a few percent total. A significant drop in intensity was only observed for extremely oxidizing potentials, typically not found under environmental conditions. Our results showed that the fluorophore itself and not the lectin binding to the respective glycoconjugate causes fluorescence changes. The two tested lectin-fluorophores are shown to be suitable for studying the distribution and composition of EPS in environmental biofilms or technical applications and under varying redox conditions.
Hypertension and obesity are established and independent risk factors for cardiovascular diseases. There are important inter-relationships between these two factors that may explain the aetiology of coronary heart disease. To determine the prevalence of hypertension and obesity in a rural community setting in Malaysia, and to identify their associated factors, a cross-sectional study was conducted among residents aged 15 years and above in Mukim Dengkil, Selangor from June to October 1999. Sample size was 570, giving a response rate of 86.7%. Prevalence of hypertension was 26.8%, with the highest prevalence among those aged 60 years and above (57.3%), and 50 to 59 years old (53.3%). Factors found to be significantly associated with hypertension were male (χ²=4.71, df=1, p<0.05) and age (t=10.7, df=568, p<0.01). Prevalence of obesity was 11.4%, with the highest prevalence among those aged 40 to 49 years (22.7%) and 30 to 39 years (14.4%). The factors associated with obesity were age (p<0.01), female (χ²=12.45, df=1, p<0.05) and ethnicity (Fisher's Exact probability, p<0.05) with Chinese and Malays having a higher prevalence compared to other ethnic groups. However, there was no significant association between hypertension and obesity (OR=1.14, 95% CI=0.65, 2.02). The prevalence of hypertension and obesity in this study is high. There is a need for prevention programs for these risk factors in rural communities in Malaysia.