Prevalence of Tuberculosis Infection among Adults of Thiruvananthapuram District of Kerala as Measured by Interferon Gamma Release Assay - A Cross-Sectional Study.

Background: To achieve the goals of the end tuberculosis (TB) strategy, strategies for management of TB infection (TBI) have to be expanded. The first step to devise policies is to understand the distribution and determinants of TBI in the community. The objectives of the study were to estimate the prevalence of TBI using Interferon Gamma Release Assay (IGRA) and its determinants among the adult population of Thiruvananthapuram district, Kerala. Materials and Methods: A community-based, cross-sectional study using the stratified cluster sampling was carried out among the adults. TBI was detected using IGRA conducted on whole blood sample. Data on determinants were collected using a structured questionnaire by the face-to-face interview. The prevalence of TBI was estimated. Univariate and multivariate analysis was conducted to identify the determinants. Results: Age standardized prevalence of TBI among 396 adults was 20.5% (95% confidence interval [CI] 16.52-24.48). On adjusting for the possible confounders, increasing age (adjusted odds ratio [OR] 1.028; 95% CI 1.008-1.048; P = 0.005), history of contact with active TB disease (adjusted OR 7.61; 95% CI 4.43-13.05; P < 0.001), childhood contact (adjusted OR 8.20; 95% CI 3.14-21.41; P < 0.001), and household contact (adjusted OR 10.12; 95% CI 5.39-18.98; P < 0.001) were found to be the determinants of TBI in this population. Conclusion: The present study observed that nearly one-fifth of the adult population in the Thiruvananthapuram district has TBI. For the programmatic management, factors such as increasing age and contact history may be considered for the elimination of TBI in the state.

Comparison of sealing ability of three different root canal sealers--an in vitro study.

The main objective of endodontic therapy is complete obturation of the root canal system after it has been adequately prepared and sterilised. A wide variety of root canal sealers are available for obturation of the root canal system. A number of different invitro methods have been used to evaluate the sealing ability of endodontic filling materials. By combining one or two tests it may be possible to obtain information about sealing ability of the test material. Therefore, the present invitro study compared the sealing ability of three different root canal sealers, namely Sealapex, AH-26 and ZnOE by two different methods, bacterial leakage and dye penetration. The results showed that AH-26 has the maximum sealing ability followed by Sealapex and ZnOE.

Dark Respiration Protects Photosynthesis Against Photoinhibition in Mesophyll Protoplasts of Pea (Pisum sativum).

The optimal light intensity required for photosynthesis by mesophyll protoplasts of pea (Pisum sativum) is about 1250 microeinsteins per square meter per second. On exposure to supra-optimal light intensity (2500 microeinsteins per square meter per second) for 10 min, the protoplasts lost 30 to 40% of their photosynthetic capacity. Illumination with normal light intensity (1250 microeinsteins per square meter per second) for 10 min enhanced the rate of dark respiration in protoplasts. On the other hand, when protoplasts were exposed to photoinhibitory light, their dark respiration also was markedly reduced along with photosynthesis. The extent of photoinhibition was increased when protoplasts were incubated with even low concentrations of classic respiratory inhibitors: 1 micromolar antimycin A, 1 micromolar sodium azide, and 1 microgram per milliliter oligomycin. At these concentrations, the test inhibitors had very little or no effect directly on the process of photosynthetic oxygen evolution. The promotion of photoinhibition by inhibitors of oxidative electron transport (antimycin A, sodium azide) and phosphorylation (oligomycin) was much more pronounced than that by inhibitors of glycolysis and tricarboxylic acid cycle (sodium fluoride and sodium malonate, respectively). We suggest that the oxidative electron transport and phosphorylation in mitochondria play an important role in protecting the protoplasts against photoinhibition of photosynthesis. Our results also demonstrate that protoplasts offer an additional experimental system for studies on photoinhibition.