RECESSIVE LETHALS: A NEW CLASS OF NONSENSE SUPPRESSORS IN Escherichia coli

Two new nonsense suppressors in Escherichia coli were found in partial diploids carrying F′14 and were shown to be on the episome. These suppressors can exist only in cells which also contain the su^- allele, i.e., su⁺/su^- heterozygotes. Presumably the mutations cause an alteration of an essential cellular component, the complete loss of which is lethal. Su7, an amber suppressor, has an efficiency of 76 per cent and su8, an ochre suppressor, an efficiency of 4 per cent.     

Choice and dose of corticosteroid for antenatal treatments

Although antenatal glucocorticoids are standard of care for women at risk of preterm delivery before 32 to 34 weeks' gestation, the choice and dosing of the corticosteroid has not been standardized. An analysis of the trial data demonstrates that the risk of neonatal death is decreased with betamethasone, but not dexamethasone. Other clinical data also indicate that betamethasone is the drug of choice for antenatal treatment. The pharmacology of the corticosteroids suggests that a lower total glucocorticoid dose per treatment may be as effective as the current treatment recommendations. However, a change from current practice will require further randomized controlled trials.     

Neonatal polycythemia: is partial exchange transfusion justified?

In clinical practice, neonatal polycythemia has been used as a marker for neonatal hyperviscosity, implicated as a cause of long-term neurologic delay and damage in the growing child. Clinicians have focused on the newborn infant's hematocrit (Hct) level as the criterion for therapeutic intervention. Partial exchange transfusion is traditionally used as the method to lower the Hct and treat hyperviscosity; however, it is unclear whether this is an effective approach in preventing the long-term neurologic consequences. This article re-evaluates this clinical approach to the diagnosis and treatment of neonatal polycythemia and suggests that this controversial therapy needs re-evaluation.     

World health system performance revisited: the impact of varying the relative importance of health system goals

Background

In 2002, the World Health Organization published a health system performance ranking for 191 member countries. The ranking was based on five indicators, with fixed weights common to all countries.

Methods

We investigate the feasibility and desirability of using mathematical programming techniques that allow weights to vary across countries to reflect their varying circumstances and objectives.

Results

By global distributional measures, scores and ranks are found to be not very sensitive to changes in weights, although differences can be large for individual countries.

Conclusions

Building the flexibility of variable weights into calculation of the performance index is a useful way to respond to the debates and criticisms appearing since publication of the ranking.     

A generic model for the assessment of disease epidemiology: the computational basis of DisMod II

Reliable and comparable analysis of risks to health is key for preventing disease and injury. Causal attribution of morbidity and mortality to risk factors has traditionally been conducted in the context of methodological traditions of individual risk factors, often in a limited number of settings, restricting comparability.