Inactivation of chloramphenicol by Staphylococcus aureus biotype C from humans & animals.

During an investigation, 55 biotype C (bovine and caprine biotype) Staphylococcus aureus isolated from 43 cows suffering from mastitis, and 20 biotype C Staph. aureus strains from the nares and the side of nail-tips of the right thumbs of 20 farm workers (milkers and animal attendants) on six small dairy farms in Assam and Meghalaya were isolated. Three strains from the former and six strains from the latter from among the isolates on two of the farms were found resistant to chloramphenicol, when tested with a routine susceptibility test. Test of the organisms by the agar dilution method indicated that the resistant strains had a minimal inhibitory concentration for chloramphenicol of 32 micrograms/ml or more, while, the chloramphenicol sensitive strains and two reference strains, Staph. aureus ATCC 25923 and Micrococcus luteus ATCC 9341, had < or = 8 micrograms/ml. Two bovine and five human chloramphenicol resistant strains showed positive results when tested by the Gots test. When these strains were tested by a standard method in broth, containing 30 micrograms chloramphenicol per ml, all showed evidence of inactivating chloramphenicol up to a non-detectable level within 36 h. Inactivation of chloramphenicol by Staph. aureus has clinical significance.

Effect of alpha,beta-arteether against primary amoebic meningoencephalitis in Swiss mice.

Artemisinin and its derivative alpha, beta-arteether have been evaluated for activity against experimental primary amoebic meningoencephalitis. In vivo experiments have shown that amphotericin B at dose of 2.5 mg/kg for 5 days produced 100% protection. Artemisinin and alpha, beta-arteether, even when tested at a high doses (60-120 mg/kg x 5 days and 90-180 mg/x 5 days) respectively, were not curative and showed only slight protection as indicated by extension of mean survival time.

A study of mycetoma in eastern India.

Forty consecutive cases of mycetoma were studied with respect to clinico-epidemiological, histopathological and radiological features. The age of the patients ranged from 17 to 57 years mean being 32.4 +/- 8.68. The disease was equally distributed amongst the sexes. Most of the patients had a rural background and the disease occurred mainly among farmers and housewives. Actinomycetes (32 cases. 80%) were found to be the main pathogenic organism and Eumycetes in 4 cases (20%) only. Clinical features were more or less the same irrespective of the aetiologic agent, consisting of local swelling with discharging sinuses. History of trauma was present in only 20% cases and 80% were incidental. Foot (28/40 i.e. 70%) was the commonest site of infection. Radiological bony involvement was detected in 14 out of 18 cases examined (38.88%). Out of the 32 radiographed patients of actinomyetoma 10(31.25%) showed bony involvement whereas all the four. Eumycetoma cases radiographed, had bony involvement. The notable bony changes were sclerosis, erosions, periosteal thickening and osteoporosis.

Histochemical changes in host tissues from Plasmodium cynomolgi B infected rhesus monkey (Macaca mulatta).

Plasmodium cynomolgi B has been used to infect the rhesus monkey to study the histochemical changes (lipid infiltration, glycogen, protein, DNA and RNA) in liver, kidney and spleen during early (exoerythrocytic) and late (chronic) stages of malarial infection. Infected liver showed significant lipid infiltration during exoerythrocytic and erythrocytic (acute phase) stage of infection. Kidney showed lipid deposition during acute phase of infection while spleen sections were negative for lipid depositions. As a result of malarial infection there was significant depletion of glycogen in liver during exoerythrocytic stage of infection. Glycogen content increased in liver and kidney during erythrocytic stage of infection. The spleen which is the main target of immunopathology in malaria showed no change in glycogen content. During exoerythrocytic phase host tissue organs showed no change in protein and nucleic acids while erythrocytic phase showed slightly increased proteins in liver and kidney. Nucleic acids became decreased in liver and spleen during erythrocytic phase of infection. The parasite used in this study has a defined prepatent period, can be cyclically passaged with ease and non fatal in nature.

Histological changes in hamster liver by ES antigen of Ascaris suum.

Polyacrylamide gel electrophoresis with SDS (PAGE-SDS) of the ES antigens of A. suum revealed several protein molecules which differed from those obtained in ES antigens of A. lumbricoides. Nature of liver damage caused by ES antigens of A. suum was studied in hamsters to find out the nature of damage and to compare with those caused by ES antigens of A. lumbricoides. Feeding of ES antigens of A. suum was carried out in 7 hamsters for 75 days. After such feeding gross hepatic damage was noticed. This was characterized by pericentrivenular degeneration and necrosis of liver parenchyma, the lesions being different and much more severe than those observed in hamster challenged by ES products of A. lumbricoides. The lesions appear to be immune mediated.

Prevalence of filariasis in rural areas of Shahjahanpur district (Uttar Pradesh).

Night blood survey was carried out during May, 1990 to December, 1991 in 18 villages of 5 Primary Health Centres of district Shahjahanpur (UP), to find out the prevalence of filariasis in the area. Out of 2141 individuals surveyed randomly, 217 were found positive for microfilariae of Wuchereria bancrofti. The microfilaria rate, filarial disease rate and filarial endemicity rates were 10.1, 11.4 and 18.8 per cent respectively. An entomological survey revealed Culex quinquefasciatus as the vector. The average man hour density was 25.8. It is clear from the results that filariasis is more endemic in rural areas than urban area of Shahjahanpur as observed by local filariasis control unit.

Role of serine esterase in hydrogen peroxide-mediated activation of phospholipase A2 in rabbit pulmonary arterial smooth muscle cells.

Exposure of rabbit pulmonary arterial smooth muscle cells to hydrogen peroxide cause dose-dependent stimulation of [14C] arachidonic acid (AA) release and enhancement of the cell membrane-associated phospholipase A2 activity as well as of the cell membrane-bound serine esterase activity tested against synthetic substrate p-tosyl-L-arginine methyl ester. While pretreatment of cells with serine protease inhibitors, viz. phenyl methyl sulphonyl fluoride, diisopropyl fluorophosphate and alpha-1-proteinase inhibitor, and antioxidant vitamin E prevents H2O2 stimulation of AA release and the cell membrane-bound serine esterase and PLA2 activities, that with actinomycin D and cycloheximide is devoid of any effect on H2O2 caused stimulation of AA release and the smooth muscle cell membrane associated serine esterase and PLA2 activities. Treatment of the smooth muscle cell membrane suspension with the serine protease trypsin markedly stimulates PLA2 activity. These results suggest that on exposure to H2O2 the smooth muscle cell membrane-bound serine esterase plays an important role in stimulating the cell membrane associated PLA2 activity thereby resulting in an increase in AA release.

Hepatic lesions caused by excretory and secretory products of Ascaris lumbricoides in golden hamster.

OBJECTIVE: To ascertain the role of excretory and secretory (ES) products of Ascaris lumbricoides in liver damage. METHODS: The ES products of A lumbricoides were collected in vitro and their SDS-PAGE analysis was done. Feeding and subcutaneous injection of ES products were done in hamsters. Estimation of serum proteins, alkaline phosphatase and alanine aminotransferase and histology of liver were carried out. Control animal experiments were done concurrently. RESULTS: The ES products of A lumbricoides contained several proteins ranging in molecular weight from 14 to 205 Kd. Prolonged feeding of ES products caused elevation of ALT and amyloid deposition in the liver, whereas short term feeding or subcutaneous challenge caused focal cell necrosis and granuloma formation in the liver. CONCLUSION: ES products of A lumbricoides can produce liver damage.

Comparative evaluation of blood schizontocidal activity of quinine and quinidine against drug resistant rodent malaria.

Blood schizontocidal activity of quinine and quinidine has been compared against sensitive as well as chloroquine/mefloquine/quinine resistant strains of Plasmodium berghei and a multiple resistant strain of P. yoelii nigeriensis in Swiss mice. Evaluation of results on ED50/ED90 basis has shown distinct superiority of quinidine over quinine against sensitive as well as drug resistant strain of rodent malaria.

Pattern of relapses in sporozoite induced Plasmodium cynomolgi B infection in rhesus monkeys.

The pattern of sequential relapses in 10 rhesus monkeys following inoculation of sporozoites of Plasmodium cynomolgi B has been studied after administering curative dose of chloroquine (5 mg/kg base X 7 days) to eliminate blood parasitaemia after each relapse. Observation for periods ranging from 109 to 245 days showed that the interval between first six relapses was 19.3 +/- 6.77 days (1st relapse), 20.9 +/- 8.43 days (2nd relapse), 22.8 +/- 8.55 days (3rd relapse), 27.8 +/- 10.0 days (4th relapse), 31.67 +/- 11.50 days (5th relapse) and 32.5 +/- 16.26 days (6th relapse). The results of this study indicate a gradual extension of the relapse interval in successive relapses.