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Biomedical subjects

D Weatherall

Publications and source records attributed to D Weatherall.

At least 19 recordsLinked to original sources

Red cells II: acquired anaemias and polycythaemia.

Iron deficiency affects 30% of the world's population. Iron metabolism is tightly regulated, with both gut transport and storage being coordinated. Hereditary haemochromatosis due to mutations in the HFE gene leads to increased absorption of iron and multiple end-organ damage. Myelodysplastic disorders are acquired clonal stem-cell disorders that cause ineffective erythropoiesis. Aplastic anaemia is caused by an intrinsic defect of haemopoietic stem cells; both inherited and acquired forms occur. Primary polycythaemia is a myeloproliferative disorder, a non-malignant stem-cell disease.

Anemia↗

From genotype to phenotype: genetics and medical practice in the new millennium.

The completion of the human genome project will provide a vast amount of information about human genetic diversity. One of the major challenges for the medical sciences will be to relate genotype to phenotype. Over recent years considerable progress has been made in relating the molecular pathology of monogenic diseases to the associated clinical phenotypes. Studies of the inherited disorders of haemoglobin, notably the thalassaemias, have shown how even in these, the simplest of monogenic diseases, there is remarkable complexity with respect to their phenotypic expression. Although studies of other monogenic diseases are less far advanced, it is clear that the same level of complexity will exist. This information provides some indication of the difficulties that will be met when trying to define the genes that are involved in common multigenic disorders and, in particular, in trying to relate disease phenotypes to the complex interactions between many genes and multiple environmental factors.

Africa↗

The impact of genetics on medical education and training.

This paper explores, mainly from the UK perspective, some of the issues relating to the current, and potential, impact of advances in genetics and molecular biology on the education and research training of healthcare professionals. We start by describing some of the expectations for progress in the use of genomic technologies and genetic data in healthcare delivery and the need for policy development to ensure timely translation of advances in science and technology into improved patient care. We review briefly the likely evolution of clinical genetics service provision to build the requisite scientific basis in primary care and explore how user needs could be addressed. Strategic issues for the future medical curriculum are introduced and linked with the concerns about the current status of clinical academic research. The issues for research training, career progression, nurturing of research 'at the bedside', definition of the research agenda and weaknesses in both academic infrastructure and support costs are reviewed in the context of the urgent imperative for medicine to harness the accelerating pace of progress in genomics.

Curriculum↗

Emergence of Western diseases in the tropical world: the experience with chronic cardiovascular diseases.

Our knowledge of the disease burden components of tropical populations is fragmentary. Historically, the infectious diseases have been emphasized but, as some populations have undergone socio-economic changes, vital statistics have described a change in the pattern of disease. The picture is of a decline in infectious and a rise in chronic non-communicable disease. We focus here on the emergence of chronic cardiovascular diseases, and use hypertension as the paradigmic example. Early blood pressure surveys showed a virtual absence of hypertension among rural Africans and moderate prevalences in the Caribbean. Prevalence was highest among US and UK blacks. In a recent comparative study of blood pressure and its determinants in Nigeria, Jamaica and the US there was a steep gradient in prevalence from 15% through 26% to 33%. Body mass index and salt intake were the major determinants, accounting for 70% of the variance in hypertension prevalence. Additional information on mechanism comes from the exploration of the renin-angiotensin system across these populations. Angiotensinogen levels rise steadily from Africa to the US and are modestly associated with body mass index (BMI), and even more modestly with polymorphisms of the angiotensinogen gene. 30% of the variation in angiotensin-converting enzyme levels is attributable to the insertion/deletion polymorphism, and angiotensin-converting enzyme levels are modestly related to BMI and blood pressure. Thus, the steep gradient in prevalence is not attributable to the genetics as manifested in the renin-angiotensin system. The usefulness of these and other data on cardiovascular diseases include planning for primordial prevention in Africa and amelioration of existing epidemics in the Caribbean, the US and the UK. Additional long term surveillance data to define the burden and distribution of causes are necessary in Africa. Lastly, education and advocacy to transfer the information to policy makers and planners is required.

Africa↗

The future role of molecular and cell biology in medical practice in the tropical countries.

Molecular and cell biology have a great deal to offer tropical medicine in the future. As well as helping to understand the population genetics and dynamics of both infectious and non-infectious diseases, they promise to provide a new generation of diagnostic and therapeutic agents, and to play a major role in the development of new vaccines and other approaches to the control of disease in tropical communities.

Developing Countries↗

The molecular basis for phenotypic variability of the common thalassaemias.

The thalassaemias, the commonest monogenic diseases in humans, and the first to be analysed at the molecular level, show remarkable phenotypic heterogeneity. As much of this variability can be ascribed to acquired pathology resulting from complications of the profound anaemia that accompanies these diseases, it is often difficult to define the precise relationships between different mutations and their clinical manifestations. Some progress has been made, however. In this article, what has been learnt about genotype/phenotype relationships for the two common forms of thalassaemia is summarized.

Gene Dosage↗

Genetic control of diabetes mellitus.

Genetic inheritance predisposing individuals to diabetes mellitus was discussed in this work group. The two forms of the disease, Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) were discussed separately since the pattern of inheritance and genes involved appear to be distinctly different. Within these subtypes there is considerable genetic heterogeneity, and superimposed environmental factors confound the analysis. New technologies that will allow finer molecular analysis, as well as new candidates genes, were presented.

Animals↗