Effect of surface area to weight ratio of egg masses on the hatchability of Boophilus microplus eggs.

BACKGROUND & OBJECTIVES: On global basis, ticks transmit a number of pathogens than any other arthropod vector, and are among the most important vectors of diseases affecting humans, livestock and companion animals. Control of the vector has been focused on integrated management involving strategic use of insecticides, use of vaccines, use of herbal acaricides and breed resistance. It has been established that tick vaccine is working on limiting the egg laying potentiality and subsequent hatchability of the ticks fed on immunized animals. To generate entomological data following immunization of animals against ticks an experiment was conducted to establish the role of water content in egg masses for successful hatching into larvae. METHODS: Different size and shape of egg masses of Boophilus microplus, Izatnagar isolate were obtained by manipulating the egg laying process. The weight of the egg masses was measured, keeping their integrity and surface areas of respective egg masses were calculated with the aid of computer software. Larvae hatched from the respective egg masses were counted individually. RESULTS: It is clear that, with an increase in the exposed surface area of the cylindrical egg mass per unit weight, there is a reduction in the number of larvae hatched out. Also, the spherical egg masses significantly (0.026 at 95% confidence level) yielded more larvae per unit weight in comparison to the cylindrical egg masses. INTERPRETATION & CONCLUSION: It has been established that the larval count yielded from an egg mass is more or less dependent on the surface area : weight ratio of the respective egg masses rather than on either the surface area alone or weight of the egg mass alone.

Ingress of Bhavnagar City (India).

A preliminary survey of the coastal city-Bhavnagar was undertaken to assess salinity ingress probed through groundwater quality. Water samples from the wells and bores located in the study area were collected and analyzed. Bhavnagar City is found significantly affected by the seawater intrusion. The ground water showed very high values of SO4(-2), Cl(-1), PO4(-3) and, Na(+1), K(+1) compared to the permissible limits for drinking purposes. The quality of ground water in some of the areas was found highly saline and can not be used even for irrigation purpose. The results also indicated a gradual encroachment of seawater into the native ground water.

Correlation of fine needle aspiration cytology, smear and culture in tuberculous lymphadenitis: a prospective study.

BACKGROUND AND AIM: Bacteriological studies are necessary to confirm the diagnosis of tuberculous lymphadenitis, as cytological appearances mimic other granulomatous lesions. The objective was to assess the diagnostic role of culture of fine needle aspiration done on clinically suspected cases of tuberculous lymphadenitis and to determine the prevalence of drug resistance in M. tuberculosis isolates. SETTING AND DESIGN: A prospective, double-blind study over a period of one year in a tertiary care hospital. MATERIAL AND METHODS: Fine needle aspiration cytology and culture were done on 250 patients with clinical suspicion of tuberculous lymphadenitis. STATISTICAL ANALYSIS: Data was statistically analysed using chi square test. Sensitivity, specificity, positive predictive and negative predictive values and likelihood ratio were also calculated. RESULT: Of the 161 cytologically or microbiologically proven cases of tuberculous lymphadenitis, cytological changes consistent with tuberculosis were observed in 133 patients, out of which mycobacteria were isolated in 102 aspirates. Mycobacteria were also isolated from 28 aspirates cytologically missed as tuberculous lymphadenitis. Of the 130-mycobacterial isolates, 5 were non-tuberculous mycobacteria. Culture positivity was significantly higher (P<0.001) than smear positivity. Drug susceptibility studies showed resistance to one or more drugs in 61% of isolated strains with maximum resistance to isoniazid (16% primary and 48% secondary) and minimum to ethambutol (4% primary and 12% secondary). CONCLUSION: Culture for mycobacteria should be carried out on all aspirates from patients suspected with tuberculous lymphadenitis.

Bio-artificial liver from cultured human foetal hepatocytes: feasibility and prospects.

BACKGROUND: Conventional therapy for acute liver failure has not been able to improve survival beyond 40%. Apart from liver transplantation, the most promising development in this field is the utilization of cultured hepatocytes to make 'bio-artificial liver support systems' as a 'bridge to transplantation' or ideally as a 'bridge to total recovery'. This study examines the feasibility of culturing foetal hepatocytes without the use of growth factors and formulating a bio-artificial liver support device in our set-up. METHODS: Foetal hepatocytes were harvested from the liver obtained from mid trimester abortions at Armed Forces Medical College and Command Hospital (SC), Pune. The liver was perfused with Phosphate Buffered Saline (PBS) and collagenase type IV and was cut with a pair of sterile scissors into tiny pieces. Cells so separated, were washed with PBS plus foetal calf serum and stirred to disperse the cell aggregates. Filtered cell suspensions were inoculated in polystyrene flasks containing hepatocyte culture medium (MEM E: 75%, M199: 25%, BSA: 0.1%, Bovine Insulin 5 micrograms/ml, FCS: 10%, Penicillin: 10 i.u., Streptomycin 50 micrograms/ml, Hydrocortisone 5 micrograms/ml and incubated at 37 degrees C. The functional capabilities of the cultured hepatocytes were analyzed by studying production of albumin and a foetoprotein. Structural integrity of hepatocytes was assessed by light and electron microscopy. RESULTS: The hepatocyte yield varied from 2 to 60 x 10(6) cells/L with an average of 38 x 10(6) cells/L in the eight consecutive experiments. Initial hepatocyte viability varied from 25% to 90% with an average of 61%. The yield and the viability of hepatocytes were adversely affected by the condition of foetus at birth and use of intra-amniotic injections for inducing abortions. Hepatocyte monolayers and colonies formed in 75% experiments. The cultures could be maintained in incubation without the use of epidermal or hepatocyte growth factors for 2-25 days with a mean survival of 8.9 days. The cells in culture were found to be structurally normal and functionally active and could be cryo-preserved. These hepatocytes were inoculated into a hollow fiber module to formulate bio-artificial liver support device. The cultures ultimately developed either cellular disintegration or bacterial infections despite use of antibiotics in the culture medium. CONCLUSIONS: We conclude that it is feasible to maintain foetal hepatocyte cultures without the use of expensive growth factors for over 8 days. Bio-artificial liver formulated with cultured foetal hepatocytes is now a step closer to clinical trials.