Biomedical subjects
Publications and source records attributed to James A Wright.
Under trialkylphosphine catalyzed Morita-Baylis-Hillman reaction conditions, epoxides react with enones to give rise to homologous aldol adducts.
The study was conducted to assess the effect of definition of episode on diarrhoeal morbidity and to develop a means of adjusting estimates of morbidity for the definition of episode used. This paper reports on a cohort study of 374 children, aged 9-32 months, in three African countries, which recorded frequency and consistency of stool over a seven-month period. Different definitions of episode were applied to these data to assess their effect on annualized diarrhoeal morbidity. Adjustment factors were then derived that corrected morbidity for non-standard definitions of episode. Applying non-standard definitions of episode gave estimates of an annualized number of episodes between 38% and 137% of the internationally-accepted definition. Researchers should be encouraged to use the standard definition of episode of diarrhoea and to use appropriate field protocols. Where this is not possible, correction factors should be applied, particularly where estimates of diarrhoeal morbidity are pooled in systematic reviews.
BACKGROUND: Coverage of the Measles-Mumps-Rubella combined vaccine (MMR) has declined in recent years in the UK, following adverse publicity about possible links between the vaccine, autism, and Crohn's disease. The objectives of this study were to assess geographical variation in trends in MMR coverage and to identify the factors affecting MMR uptake at population level. METHODS: We conducted an ecological study of immunization coverage by second birthday, based on routinely collected data from 1993-2004 for England. Trends in MMR uptake were assessed in 95 District Health Authorities in England over the study period. We investigated the relationship between MMR immunization uptake and deprivation, ethnicity, education, population density, rurality, and socioeconomic class. RESULTS: Since 2000, MMR coverage has declined significantly in virtually all areas of England. Population density and deprivation were both strongly correlated with low MMR uptake. The decline in coverage since 1993-94 was significantly related to the proportion of educated population and was greater in densely populated areas. CONCLUSION: Decline in MMR coverage now affects most areas of England. The lowest rates of MMR coverage remain in urban areas, particularly in inner cities, which also tend to show high levels of deprivation. Public health resources should continue to target inner city areas, as well as focus on the concerns of the better educated about vaccine safety.
The unprecedented reactivity of Co(4)(CO)(12) with enynes under aqueous conditions, representing the development of a mild and simple aqueous-phase cobalt-catalyzed PK reaction protocol, is described herein.
Depending on the thermolytic conditions, dicobalthexacarbonyl-complexed enynes underwent cyclizations to provide different carbocyclic frameworks. Bicyclopentanones were formed from enyne-Co2(CO)6 complexes, or from enynes that were treated with Co2(CO)8, or more effectively, with Co4(CO)12 in an alcoholic solvent under a H2 or N2 atmosphere. This transformation proceeded via a sequential cyclocarbonylation and 1,4-reduction and is the first account using the cobalt carbonyl cluster. Under these conditions a cobalt hydride was presumably generated, which mediated reduction of the enone to the saturated ketone. In contrast, thermolysis of dicobalthexacarbonyl-complexed enynes under a hydrogen atmosphere in toluene resulted in their reductive cyclization to form monocyclic alkenes in moderate yields, in addition to the bicyclopentenone product. In some cases, addition of a hydrosilane to the reaction induced a complete suppression of the bicyclopentenone formation. While the former results demonstrate a reaction that occurs after the cycloaddition, the latter depicts another example of an interruption of the normal route in the Pauson-Khand reaction pathway.