Pattern & correlates of neurocognitive dysfunction in Asian Indian adults with severe obstructive sleep apnoea.

Background & objectives: No published data are available on neurocognitive dysfunction in Asian Indians with obstructive sleep apnoea (OSA). We therefore, studied the pattern and correlates of neurocognitive dysfunction in Indian adults with severe OSA. Methods: Fifty patients aged 25-65 yr with severe OSA (apnoea-hypopnoea index > 30) and 25 age, sex, and education level-matched normal controls were studied. Both groups were administered a standardized battery of neurocognitive tests. Results: Patients with severe OSA had significantly impaired performance on tests of alertness, working memory, response inhibition, problem solving, and executive function. However, the difference in executive function between the groups disappeared after adjusting for delayed information processing. The test scores did not correlate with apnoea-hypopnoea index, arousal index, or Epworth sleepiness score. However, the percentage of time spent at < 90 per cent oxygen saturation had a weak correlation with the number of stroop errors (Spearman’s rho = 0.64; P = 0.033), number of trials required (rho = 0.05; P = 0.02), and perseverative errors on Wisconsin card sorting test (rho = 0.36; P = 0.02). Interpretation & conclusions: Our results suggested that delayed information processing rather than impaired abstract thinking was probably the cause of impaired performance on composite tests of neurocognitive function in patients with severe OSA.

Visceral leishmaniasis: acute liver failure in an immunocompetent Asian-Indian adult.

Fulminant liver failure due to visceral leishmaniais is very rare, and has been described only in children. We report an immunocompetent adult man who developed acute liver failure due to leishmaniais and dramatically recovered with amphotericin-B therapy.

Differential properties of enantiomers of commercially available racemates.

The existence of left- or right-handedness of a compound is referred to as chirality. Each form (left- or right-handed) of a chiral compound is called an 'enantiomer' or an 'isomer'. A collection containing only one enantiomeric form of a chiral molecule is called an optically pure, chirally pure, enantiomerically pure or unichiral compound while collection of equal amounts of the two enantiomeric forms (R and S) is called a racemate. Many of the drugs currently used in medical practice are racemates. However it is well documented that the two enantiomers of a racemate can differ in their pharmacokinetic/pharmacodynamic and efficacy/ safety profiles. Replacing existing racemates with unichiral drugs may result in improved safety and/or efficacy profile of various racemates. This article presents an overview of differential properties of enantiomers of some commercially available racemates.