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Biomedical subjects

S C Pal

Publications and source records attributed to S C Pal.

At least 91 records · Page 5Linked to original sources

Rectal histology in acute bacillary dysentery.

A recent epidemic of acute Shigella dysentery in West Bengal (India) provided us with an opportunity to examine the rectal mucosal abnormalities seen in this condition. One hundred two patients were investigated using sigmoidoscopy, rectal biopsy, and rectal swab for culture. Pure culture of Shigella was obtained in 37 cases, and the rectal biopsy specimens from these patients were assessed in detail. The mean (+/- SD) duration of illness was 47.8 +/- 27.4 h (range 8-120 h), and most patients (31 of 37, 84%) had diarrhea with blood and mucus in the stools. Significant findings at histology were as follows. (a) Cellular infiltrate was predominantly round cell or mixed round cell and neutrophilic in the majority of patients (27, 73%). (b) Disorganization of crypts was seen in as many as 31 patients (84%); in most subjects the distorted architecture was mild, but in a few the defect was severe with crypt branching and dilatation. (c) In the majority of patients the inflammatory process extended to the muscularis mucosae and submucosa; edema with or without increased cellular infiltrate was seen in the muscularis mucosae in 92% and in the submucosa in 80%. (d) There was no difference in the rectal histology of patients with a short history of disease (less than 48 h) compared with those with a longer history, except for goblet cell depletion which was more in those with diarrhea for more than 48 h. (e) The mucosal abnormalities in patients with watery diarrhea were, in general, milder than in those with dysentery, although the difference was statistically not significant; 2 of 6 patients with watery diarrhea had severe colitis. (f) The mucosal abnormalities were more severe in patients with Shigella dysenteriae infection compared with Shigella flexneri.

Adolescent↗

Studies on interventions to prevent eltor cholera transmission in urban slums.

Transmission of eltor cholera infection in endemic communities continues without diminishing because of the absence of effective intervention measures. Two methods-chlorination of stored water and the use of a narrow-necked earthenware vessel (called a 'sorai') for storing the water-were found to be effective in reducing the transmission of infection among the family contacts of cholera patients. The cholera carrier rates in the chlorination and 'sorai' intervention groups were 7.3% and 4.4%, respectively, compared with 17.3% in the control group. The 'sorai' is cheap and was well accepted by the local communities; its narrow neck prevented the introduction of the hand and contamination of the stored water.

Adolescent↗

Campylobacter infection in domestic dogs.

Campylobacter jejuni, a recently recognised human enteric pathogen, was recovered from the faeces of 21.7 per cent of domestic dogs with diarrhoea as compared with only 3.1 per cent of normal healthy dogs. The recovery rate from non-diarrhoeic, but unhealthy, domestic dogs was 6.7 per cent. The differences in the incidence of C jejuni between breeds was not statistically significant. The majority of isolations were from puppies between birth and six months old. The incidence of C jejuni in domestic dogs did not appear to be sex specific. Domestic canine infections with C jejuni could possibly be an important source of human infection, especially to those in close contact.

Animals↗

Improved method of producing amoebic liver abscesses in hamsters for screening of systemically active amoebicides.

An improved method of producing hepatic amoebiasis in hamsters has been developed. A serially liver-passaged strain of Entamoeba histolytica from experimentally-infected hamsters was used for infection. Small pieces from the infected liver were examined for the presence of amoebae and contained approximately 20,000 active trophozoites per piece. Such liver pieces, when used as an inoculum, produced infection in all of the animals. The method has been successfully employed for screening of known amoebicides such as emetine, dehydroemetine, metronidazole, tinidazole, chloroquine, mepacrine, amodiaquine and ambilhar.

Amebicides↗

Seasonal distribution of Vibrio parahaemolyticus in freshwater environs and in association with freshwater fishes in Calcutta.

The seasonal distribution of Vibrio parahaemolyticus in freshwater environs and in association with freshwater fishes was studied in 1982 and 1983. The occurrence of this organism in water and sediments at the three sites studied was very infrequent and was restricted to the summer months, although it was not always isolated during these months. The association of V. parahaemolyticus with plankton was chiefly confined to the summer months and progressively declined with the onset of monsoons, remaining below detectable levels during the postmonsoon and winter months. The incidence and counts of V. parahaemolyticus were consistently higher in association with plankton than with water and sediment samples. V. parahaemolyticus could be recovered throughout the period of investigation from freshly caught and market samples of freshwater fishes. The highest recovery rate of this halophile from fishes was invariably from fecal samples. Most of the strains isolated in this study were untypable, and those which could be typed were predominantly serotypes encountered in the environment. All the isolates were Kanagawa negative. From this study, it could be concluded that the survival of V. parahaemolyticus in freshwater ecosystems is transient and dependent on a biological host.

Animals↗

Serotypes of Vibrio parahaemolyticus isolates from hydrobiologically dissimilar aquatic environments.

Serological analysis of the O and K antigens was performed on 324 isolates of Vibrio parahaemolyticus obtained from three hydrobiologically dissimilar aquatic environments. Only 50.9% of the strains could be serotyped. The largest number of untypable strains and the lowest serological diversity were observed from the freshwater collection. Three serotypes, O2:K28, O5:K17, and O2:K3, dominated among all biotopes. There appears to be some distinction between serotypes of environmental and clinical origins.

Fresh Water↗

Comparison of the modified Elek test and Wagatsuma agar for determination of the Kanagawa phenomenon of Vibrio parahaemolyticus.

The modified Elek test and Wagatsuma agar were compared for their ability to detect the Kanagawa activity of 142 strains of Vibrio parahaemolyticus. The performance of the modified Elek test was on a par with that of the Wagatsuma agar as far as positivity was concerned, and the test was far superior to Wagatsuma agar in eliminating doubtful results. The results of the modified Elek test were not unduly influenced by the different types of agar used.

Bacteriological Techniques↗

Tryptophanase activity in different toxigenic and nontoxigenic strains of Vibrio cholerae: effect of glucose.

Tryptophanase activity was measured in eight different toxigenic and nontoxigenic strains of Vibrio cholerae (V. cholerae) in presence and absence of inducer tryptophan (2 mM). Stimulation of enzyme activity was observed in both toxigenic and nontoxigenic strains of V. cholerae in presence of inducer. Tryptophanase activity remained much higher in toxigenic strains than that in nontoxigenic strains. Low levels of enzyme activity in nontoxigenic strains could be increased by the addition of exogenous cyclic AMP. A lower concentration of glucose (0.25 gm%) in culture medium produced no inhibitory effect on enzyme activity. But a higher concentration of glucose (3 gm%) repressed the tryptophanase activity. The repressive effect of glucose could be reversed by the addition of exogenous cyclic AMP.

Cyclic AMP↗