Comparison of radiorespirometric Budemeyer assay with ATP assay and mouse foot pad test in detecting viable Mycobacterium leprae from clinical samples.

PURPOSE: This study compares the results of radiorespirometric Buddemeyer assay with adenosine triphosphate (ATP) assay and mouse foot pad (MFP) test to validate the sensitivity of Buddemeyer assay in detecting viable M. leprae in clinical samples. METHODS: Viability was assessed using all the three methods in 60 skin biopsy specimens, including 20 untreated lepromatous leprosy (BL-LL), 13 treated BL-LL, 12 untreated borderline tuberculoid to mid borderline (BT-BB) and 15 treated BT-BB cases. RESULTS: Of the 20 untreated BL-LL cases tested, positivity indicating the presence of viable M. leprae was detected in 85, 60 and 85% with Buddemeyer, ATP and MFP test, respectively. Among the 13 treated BL-LL cases, scores were 61, 54 and 0%; among the 12 untreated BT-BB cases, the scores were 58, 16 and 16% and among the 15 treated BT-BB cases, the scores were 46, 20, 0%, respectively. CONCLUSION: The detection sensitivity (positive scores) with three tests were closely comparable in the two untreated groups of cases. On the other hand, in the two treated groups, a good proportion of cases scored positive in the in vitro tests but none in the MFP test. Among the two in vitro methods, the Buddemeyer assay emerged as a better test, in terms of sensitivity and specificity.

Studies on digoxin--14C-acetate incorporation in to digoxin and degenerative changes in the brain in rats administered digoxin.

The human hypothalamus produces an endogenous membrane Na+-K+ ATPase inhibitor digoxin. Digoxin is a steroidal glycoside and could be synthesised by the isoprenoid pathway. The other metabolites of the isoprenoid pathway are cholesterol, dolichol and ubiquinone. We have tried to find out the extent of incorporation of 14C acetate into digoxin in rat brain. The effects of digoxin administration on the rat brain was also studied. The results show that the percentage incorporation of 14C acetate into digoxin is low but detectable. The maximum incorporation was observed for cholesterol, followed by dolichol and finally ubiquinone. The histopathological changes observed after digoxin administration were focal degeneration of the ganglion cells in the cerebrum and cerebellum. The carbohydrate components of the glycoproteins were reduced and the concentration of serotonin, dopamine, and epinephrine showed a significant increase. The role of digoxin in mediating neuronal cell death is discussed.