Search PubMed⌕ Search

Biomedical subjects

A K Hati

Publications and source records attributed to A K Hati.

At least 37 records · Page 2Linked to original sources

A simple medium without blood modified for successful isolation & cultivation of LD bodies.

A simple growth medium for primary isolation and subsequent cultivation of Leishmania donovani promastigotes without using whole blood is described. This medium is modified from Aljeboori's biphasic medium (used originally only for cultivation), containing only beef extract, peptone, sodium chloride, bactoagar and foetal calf serum (FCS). We have modified the medium by adding glucose and ascertaining the pH in the solid phase and by drastically reducing (91%) FCS in the liquid phase. The medium helps in isolation of L. donovani promastigotes from kala-azar patients, in addition to luxurious growth of parasites. The medium is simple, reliable, reproducible and convenient, with minimal interference in using the parasitic cells for immunological, molecular and isoenzyme studies.

Animals↗

Neutralization of pathophysiological manifestations of Russell's viper envenoming by antivenom raised against gamma-irradiated toxoid.

Rabbits were immunized against gamma-irradiated (100 krads) Russell's viper venom toxoid adsorbed to aluminium phosphate gel. The antivenom (0.1 ml) neutralized 5 LD50, 8 minimum hemorrhagic doses (MHD) and 14 minimum necrotic doses (MND) of venom. The coagulant and protease activities of the viper venom were neutralized more effectively than phospholipase A activity, by the toxoid antivenom.

Animals↗

Correlation between the preferred biting site of Culex quinquefasciatus and the region of the body affected by clinical filariasis.

Entomological and filariasis surveys were conducted simultaneously in a rural and an urban environment in West Bengal from September 1986 to August 1987. The aim of the surveys was to see if any correlation existed between the preferred biting site of Culex quinquefasciatus, the filarial vector, and the region of the body affected by clinical filariasis. Significantly more mosquitoes (> 55%) attacked the thighs, legs and feet of human volunteers than other sites on their bodies, whether the volunteers were indoors or outdoors, in rural or urban environments. Significantly more patients had clinical filariasis of these lower body parts than of the upper parts. The vector's preferred biting sites and the anatomical sites most affected by clinical filariasis were therefore the same.

Adult↗

Sarcoptes scabiei in animals spreading to man.

An outbreak of Sarcoptes scabiei in animals was observed from mid-November 1991 to mid-December 1991 in two adjacent villages, Fewgram and Nurpur, in Birbhum District, West Bengal State, India, starting from goats to cattle, then to sheep and even to dogs. Nineteen goats and one cattle died of manage infection. The infection spread to man in the last week of December 1991, and affected forty-two human beings, tending and rearing animals. The animals treated with deltamenthrin (synthetic pyrethroid) and amitraz (triazapentadiene) were completely cured. In man, the disease seemed to be self-limited in some cases and 2% hexachlorobenzene was successfully used for treatment of the others. The outbreak was effectively controlled in March 1992.

Adult↗

Observations on the breeding habitats of Aedes aegypti in Calcutta following an episode of dengue haemorrhagic fever.

A year-long (Nov. 1990-Oct. 1991) search for Ae. aegypti larvae was made of all water containers in and around fixed 100 houses at Bowbazar area in Calcutta following an episode of DHF. Out of 10151 containers searched, 615 (6%) were positive. Masonry tanks were the major (64.2%) and preferred (17%) breeding sites of Ae. aegypti. Indoor containers (6.7%) were more conducive to breeding of the vector species than the outdoor ones (3%). Breteau index showing wide variation (25 in December '90 to '93 in August 1991) proved to be the best for measurement of density of larval population of Ae. aegypti and paralleled the fluctuation in both rainfall and humidity. Role of temperature was not pronounced. It was noted that cases of DHF occurred even with the lowest Breteau index in December.

Aedes↗

A retrospective study on scorpion sting in a pediatric age group in a hospital in Calcutta.

During 1985-1989, in Calcutta Medical College Hospitals, of 152 children of 1-6 year age group admitted with the history of scorpion sting 18 (11.8%) died. Maximum numbers of stings were inflicted in the fingers. Important clinical features recorded were circulatory failure, breathlessness, profuse sweating, vomiting, local oedema and convulsion. Incidences of scorpion stings were much more frequent in the summer and rainy seasons than in the winter season.

Animals↗

Neutralization potency of Russell's viper venom toxoid antivenom, as compared with standard antivenom.

Rabbits were immunized with gamma (gamma) irradiated Russell's viper venom toxoid, adsorbed to aluminium phosphate adjuvant. Antibody (raised against toxoid inoculation) titer was compared to a commercial antivenom on the basis of its ability to neutralize hemorrhagic, necrotic and lethal effects of viper venom. Toxoid immunization (on day 0, 15 and 30) produced antivenom which showed approximately one-third antilethal, half antihemorrhagic and antinecrotic titers as compared to those of the commercial hyperimmunized, concentrated horse antivenom.

Animals↗

Epidemiology of snake bite in the district of Burdwan, West Bengal.

An epidemiological field survey on snake bite was conducted on 26 randomly selected villages with a population of 18,892 in the district of Burdwan, West Bengal to assess the magnitude of the problem in a decade (1980-1989). Total number of snake bite, number of presumably poisonous snake bite and deaths due to snake bite poisoning were 307, 48 and 31 respectively. The death rate among snake bite victims was 10.09%. Males (54.72%) were bitten more than females (45.23%) and highest incidence of snake bite was found in the age group of 21-30 years and during the months of July and August. Majority of the snake bites (53%) were encountered in the lower extremities. Among the snake bite patients 201 (65.47% went to the traditional healers (ozhas) and 68 (22.14%) persons received hospital treatment, while 12 (3.09%) people neither went to the ozhas nor to hospital and 26 (8.46%) persons went to hospital after consulting the ozhas. If the present data are extrapolated for the total population of the district, average number of snake bite and death per year would be 7,857 (0.16%) and 793 (0.016%) respectively. Deaths due to snake bite per 100,000 population varied from 5.28 to 31.75 (average 16.4) over 10 years.

Adolescent↗

Longitudinal study on distribution of Phlebotomus argentipes sandflies at different heights in cattleshed.

Distribution of Ph. argentipes at three levels (level I, 0-0.91 m; level II, 0.91-1.82 m; and level III 1.82-2.74 m) above the ground in 6 cattlesheds was studied during July 1989 to June 1990. Of the 8044 Ph. argentipes caught, 3151 (39.2%), 3936 (48.9%) and 957 (11.9%) were from levels I, II, and III respectively. Both male and fed, half-fed, gravid and unfed female sandflies were found at all the three levels and in all the three seasons viz., rainy, winter and summer, of the year. The maximum height of occurrence of sandflies was 2.51 m (8.3 ft) above the ground level.

Animals↗

A simple method for cryopreservation of Leishmania donovani promastigotes.

Cryopreservation of promastigotes of L. donovani in NNN and Tobie's media was attempted. The media containing the promastigotes were kept directly at -80 degrees C. The cryopreserved media were examined for living promastigotes after 9, 12, 15, 20, 23, 26, 29, 32, 42, 56, 65 and 126 days after the culture tubes were brought directly from -80 degrees C to room temperature and examined after 30 min. All tubes showed living promastigotes which were used for further growth with no apparent morphological changes in subsequent subcultures. Viability was optimum. This method of short term cryopreservation is simple, reliable and reproducible for cryopreservation of culture adapted parasites and also important because different strains can be stocked without using any other chemical, or special equipment and liquid nitrogen chamber, for further use in immunological or other purposes.

Animals↗

Transmission of viable Mycobacterium leprae by Aedes aegypti from lepromatous leprosy patients to the skin of mice through interrupted feeding.

Female Aedes aegypti which took partial blood meals from the skin lesions of untreated lepromatous leprosy (LL) patients were then allowed to continue feeding on 72-96-hr-old Swiss albino suckling mice (Rockefeller strain). The bitten portion of skin was removed, divided into two parts and processed for the extraction of bacilli by two different methods using chloroform and petroleum ether. The proboscis of some of the fed mosquitoes was dissected out and examined for viable bacilli (stained by fluorescein diacetate and ethidium bromide) and acid-fast bacilli (AFB). Out of 50 probosces dissected 45 were found positive for AFB, with bacillary counts ranging up to 246 (average 40.20 +/- SD 41.80) per proboscis. The average percentage of viable bacilli (green solid) in the probosces immediately after feeding on LL patients was 43.90 and thereafter it decreased gradually to 3 on the seventh day. In the petroleum ether extract of mouse skin viable bacilli were observed in numbers up to 37 (average 15.25 +/- SD 10.25) per smear. The number of fluorescing bacilli (green and red) correlated with the total number of AFB.

Aedes↗