Seasonal changes in selected immune response of Mystus gulio and Mystus vittatus.

Estuaries are considered as highly potential area for that including feeding, spawning and nursery rearing of most of the finfishes and shellfishes. In the present investigation, two species of catfish (M.gulio and M.vittatus) were selected to study the impact of season on their immune organs (kidney and spleen) and selected immune response from Vellar estuary. The physico-chemical parameters (pH, temperature, salinity and rainfall) were measured during the sampling period 2009-10. The non-specific immune parameters (WBC count, lysozyme activity and NBT assay) were analyzed. The immune organs (head-kidney and spleen) variation was also observed by histological studies. Our results stated that the WBCs count of M. gulio and M. vittatus increased during summer (10.3 and 10.1 X 106 ml-1) season and decreased in monsoon (6.8 and 7.0 X 106 ml-1). In contrast, lysozyme activity was highest in post monsoon (1540 and 1525 U min-1 ml-1) and lowest in summer (1000 and 960 U min-1 ml-1). The activity of NBT was highest in monsoon (0.68 and 0.65 at 540 nm) and lowest in summer (0.012 and 0.2 at 540 nm). The histological observation implies that the cell variations were different in respect to different seasons.

Infection and immunization trials of Asian seabass (Lates calcarifer) against fish pathogen Vibrio anguillarum.

Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio sp. Fish disease will be controlled by proper vaccination trials and maintenance of fish form. Pathogenicity for Asian seabass (Lates calcarifer) against V. anguillarum results in necrosis and haemorrhagic areas near the base of fins, exopthalmia and ulcers on the skin surface. Around 50, 100, 200 )l of formalin killed bacterial cells were injected (Intraperitoneal) to three different size (5-10, 20-30, 35-50g) of seabass fishes respectively and control sere as saline were maintained separately. The Relative Percentage Survival (RPS) for vaccinated fishes was 60, 75, and 62.5 respectively and the vaccinations for 20-30 g fishes stay alive. These results stated that the vaccination for fishes with 20- 30 g size may fabricate good immune response.

A pilot study on willingness to participate in future preventive HIV vaccine trials.

BACKGROUND & OBJECTIVES: In India, phase-I human clinical trials for a preventive HIV vaccine are being conducted at Pune and Chennai Centres. In order to find out the willingness of populations at risk to participate in future preventive HIV vaccine trials (HIVVTs) and to assess the factors that enhance or deter them from participation, a study was conducted at Chennai and Madurai in Tamil Nadu. METHODS: This cross-sectional study was conducted among transport workers, people attending sexually transmitted infection clinics, injection drug users, men having sex with men, women in sex industry and a representative sample of monogamous married women, by employing measurement scales. A structured questionnaire on knowledge and attitudes about the HIV vaccine was used to measure the participants' knowledge and attitudes about HIV vaccine and HIVVTs. RESULTS: Of the 112 participants, 67 (60%) were men. Mean age of the respondents was 32 yr; 68 per cent were high school educated. Majority of respondents were willing to participate in a future HIVVT and the reasons were altruism, protection from HIV, and support for the researchers. Major concerns were vaccine efficacy, side effects of the vaccine and the impact of a HIV vaccine on the participants' lives. Majority (85%) agreed that sex without condom would not be safe despite the availability of an HIV vaccine. INTERPRETATION & CONCLUSION: It is likely that high-risk volunteers will be willing to enroll in HIVVTs. Barriers and concerns should be dealt with carefully by providing correct information. Also there is a need for more education to ensure participants' understanding of key concepts of HIV vaccine trial.

Sublethal effects of textile dye stuff effluent on selected oxidative enzymes and tissue respiration of Cyprinus carpio (Linn.).

Toxic effects of sublethal concentration of dye stuff effluent on succinic dehydrogenase (SDH) and lactic dehydrogenase (LDH) activities and tissue respiration were studied in C. carpio. While the sublethal exposure significantly reduced SDH activity and tissue respiration, LDH activity increased in gill, brain, liver, muscle and kidney. The maximum inhibition of SDH activity (74%) was recorded in gill and the minimum (38%) in liver. The percentage reduction of oxygen consumption in the tested tissues was in the order of gill greater than brain greater than liver greater than muscle greater than kidney. The muscle showed the highest level (96%) of increase in LDH activity whereas the kidney cells showed the minimum increase. Exposure to sublethal concentration suppressed the aerobic respiration and triggered the anaerobic respiration.

Effects of textile dye stuff effluent on food utilization of Cyprinus carpio (Linn.).

Dye stuff effluent at 15% caused 100% mortality within 24 hr; 96 hr LC50 value being 10% concentration. Prolonged exposure of C. carpio to chosen sublethal concentrations (1, 3, 5, 7 or 9%) reduced the food intake and increased the maintenance cost. Exposure also caused significant reduction in growth rate and conversion efficiency; these values averaged to 11 mg/g/day and 28% in the control group (0% concentration) respectively and decreased to 0.8 mg/g/day and 4% respectively at 9% concentration.