Neonatal infections in Asia.

OBJECTIVE: To study the epidemiology (including incidence, antibiotic sensitivity and mortality) of neonatal unit infections in countries in Asia. METHODS: One year prospective study of neonatal infections in eight neonatal units in Asia. RESULTS: There were 453 episodes of sepsis affecting 394 babies. Mortality from neonatal sepsis was 10.4%, with an incidence of 0.69 deaths/1000 live births. Group B streptococcus was the most common early-onset organism causing 38% of episodes of early-onset (<48 h old) sepsis, with a rate of 0.51 episodes per 1000 live births and a mortality of 22%. Gram-negative bacillary early-onset sepsis occurred at a rate of 0.15 episodes per 1000 live births with a mortality of 12%. There were 406 episodes of late-onset sepsis. The incidence was high at 11.6 per 1000 live births, and mortality was 8.9%. Coagulase-negative staphylococcus caused 34.1% of episodes, whereas Staphylococcus aureus caused only 5.4%. Gram-negative bacilli caused 189 episodes (46.6%). Only 44% of Gram-negative bacilli were sensitive to both gentamicin and a third-generation cephalosporin, whereas 30% were resistant to both antibiotics. Meningitis occurred in 17.2% of episodes of late sepsis, with a mortality of 20%. CONCLUSIONS: The incidence of late-onset sepsis was higher in Asia than in resource-rich countries, but the organisms isolated and mortality were similar. Over half of all Gram-negative bacilli were antibiotic resistant.

Effect of melatonin on chloride secretion by human colonic T84 cells.

The effect of melatonin on human colonic T84 cells was studied using the short-circuit current (I(SC)) technique. Basolateral, as well as apical, addition of melatonin stimulated I(SC) in a concentration-dependent manner (EC50 at about 100 microM). The I(SC) response to melatonin was nearly abolished when external Cl- was removed. The increase in I(SC) was also blocked by apical addition of two Cl- channel blockers, 4,4'-diisothiocyanatostibene-2,2'-disulfonic acid (DIDS) and diphenylamine-2-carboxylic acid (DPC), indicating that melatonin stimulated Cl- secretion. The effect of different melatonin analogs was compared and the order of potency appeared to be 2-iodomelatonin > melatonin > 6-hydroxymelatonin, indicating the involvement of melatonin receptors. However, inhibitors for Gi-protein, adenylate cyclase or phospholipase C were found to be ineffective in inhibiting the melatonin-induced I(SC). Pretreatment of the cells with melatonin was also found to exert little effect on subsequent forskolin- or VIP-induced I(SC), further excluding its interaction with adenylate cyclase. Our data suggest that melatonin may play a role in regulating colonic Cl- secretion via melatonin receptors; however, the signal transduction pathway(s) involved remains to be elucidated.