Tropical enteropathy, which may be related to tropical sprue, has been described in many developing countries including parts of Africa. The jejunal changes of enteropathy are seen in Rhodesians of all social and racial categories. Xylose excretion, however, is related to socioeconomic status, but not race. Upper socioeconomic Africans and Europeans excrete significantly more xylose than lower socioeconomic Africans. Vitamin B12 and fat absorption are normal, suggesting predominant involvement of the proximal small intestine. Tropical enteropathy in Rhodesia is similar to that seen in Nigeria but is associated with less malabsorption than is found in the Caribbean, the Indian subcontinent, and South East Asia. The possible aetiological factors are discussed. It is postulated that the lighter exposure of upper class Africans and Europeans to repeated gastrointestinal infections may accound for their superior xylose absorption compared with Africans of low socioeconomic circumstances. It is further suggested that the milder enteropathy seen in Africa may be explained by a lower prevalence of acute gastroenteritis than in experienced elsewhere in the tropics. (+info)
Genetic polymorphism and interethnic variability of plasma paroxonase activity.
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A method for determining plasma paroxonase activity using an auto-analyser is described. Frequency distributions for British and Indian subjects show bimodality. A study of 40 British families confirms the presence of a genetic polymorphism with regard to plasma paroxonase activity. Two phenotypes can be defined, controlled by two alleles at one autosomal locus. The frequency of the low activity phenotype is less in the Indian population than in the British population. Malay, Chinese, and African subjects fail to show obvious bimodality. (+info)
Relative rates of AIDS among racial/ethnic groups by exposure categories.
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The relative rates of acquired immunodeficiency syndrome (AIDS) were calculated among racial/ethnic populations using Centers for Disease Control and Prevention HIV (human immunodeficiency virus)/Surveillance reports assuming that racial/ethnic distributions reflect that of the US Census Data from 1990. For comparison, a rate of 1 was assigned to whites in each calculation. The overall relative rates were whites--1, African Americans--4.7, Hispanics--3, Asian/Pacific Islanders--0.4, and Native Americans--0.5. Acquired immunodeficiency syndrome surveillance data show higher rates of AIDS for African Americans and Hispanics compared with whites, Asians/Pacific Islanders, and Native Americans. The relative rates for African Americans and Hispanics compared with whites were highest for injecting drug users, heterosexual contact, and pediatric patients. These results led us to explore possible explanations for increased AIDS reporting in African Americans and Hispanics. We then explored available national datasets regarding those variables. The analyses indicate that variables such as access and receptivity to HIV prevention and treatment efforts, race/ethnicity, sexual behaviors, sexually transmitted diseases, socioeconomic status, and substance abuse interact in a complex fashion to influence HIV transmission and progression to AIDS in affected communities. (+info)
Cerebral atherosclerosis in Japanese. Part 4: relationship between lipid content and macroscopic severity of atherosclerosis.
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In order to evaluate chemically the macroscopic scoring methods for severity of arteriosclerosis in the cerebral arteries, concentrations of total lipids, esterified and free cholesterol and lipid phosphorus were compared to the macroscopic severity of lesions in the cerebral arteries obtained from 376 Japanese persons after unexpected death. An increase of cholesterol content was correlated significantly with an increase of Baker's score and/or Gore's atherosclerotic index. The correlation coefficient between Baker's score and total or esterified cholesterol was the highest among the tested correlations (r = 0.82, n = 376). (+info)
Low-weight neonatal survival paradox in the Czech Republic.
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Analysis of vital statistics for the Czech Republic between 1986 and 1993, including 3,254 infant deaths from 350,978 first births to married and single women who conceived at ages 18-29 years, revealed a neonatal survival advantage for low-weight infants born to disadvantaged (single, less educated) women, particularly for deaths from congenital anomalies. This advantage largely disappeared after the neonatal period. The same patterns have been observed for low-weight infants born to black women in the United States. Since the Czech Republic had an ethnically homogenous population, virtually universal prenatal care, and uniform institutional conditions for delivery, Czech results must be attributed to social rather than to biologic or medical circumstances. This strengthens the contention that in the United States, the black neonatal survival paradox may be due as much to race-related social stigmatization and consequent disadvantage as to any hypothesized hereditary influences on birth-weight-specific survival. (+info)
Chemokine and chemokine receptor gene variants and risk of non-Hodgkin's lymphoma in human immunodeficiency virus-1-infected individuals.
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Normal B-lymphocyte maturation and proliferation are regulated by chemotactic cytokines (chemokines), and genetic polymorphisms in chemokines and chemokine receptors modify progression of human immunodeficiency virus-1 (HIV-1) infection. Therefore, 746 HIV-1-infected persons were examined for associations of previously described stromal cell-derived factor 1 (SDF-1) chemokine and CCR5 and CCR2 chemokine receptor gene variants with the risk of B-cell non-Hodgkin's lymphoma (NHL). The SDF1-3'A chemokine variant, which is carried by 37% of whites and 11% of blacks, was associated with approximate doubling of the NHL risk in heterozygotes and roughly a fourfold increase in homozygotes. After a median follow-up of 11.7 years, NHL developed in 6 (19%) of 30 SDF1-3'A/3'A homozygotes and 22 (10%) of 202 SDF1-+/3'A heterozygotes, compared with 24 (5%) of 514 wild-type subjects. The acquired immunodeficiency syndrome (AIDS)-protective chemokine receptor variant CCR5-triangle up32 was highly protective against NHL, whereas the AIDS-protective variant CCR2-64I had no significant effect. Racial differences in SDF1-3'A frequency may contribute to the lower risk of HIV-1-associated NHL in blacks compared with whites. SDF-1 genotyping of HIV-1-infected patients may identify subgroups warranting enhanced monitoring and targeted interventions to reduce the risk of NHL. (+info)
Serum total homocysteine concentrations in adolescent and adult Americans: results from the third National Health and Nutrition Examination Survey.
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BACKGROUND: The elevation of circulating total homocysteine concentrations in a fasting state is associated with an increased risk of occlusive vascular disease. OBJECTIVE: The primary goals of this study were to describe the distribution of serum total homocysteine concentrations in the United States and to test for differences in homocysteine concentrations among sex, age, and race-ethnicity categories. DESIGN: Using surplus sera from phase 2 of the third National Health and Nutrition Examination Survey, we measured serum total homocysteine concentrations for a nationally representative sample of 3766 males and 4819 females aged > or = 12 y. RESULTS: Age-adjusted geometric mean total homocysteine concentrations were 9.6 and 7.9 mmol/L in non-Hispanic white males and females, 9.8 and 8.2 mmol/L in non-Hispanic black males and females, and 9.4 and 7.4 mmol/L in Mexican American males and females, respectively. Age-adjusted geometric mean total homocysteine concentrations were significantly lower in females than in males in each race-ethnicity group (P < 0.01) and were significantly lower in Mexican American females than in non-Hispanic white and non-Hispanic black females (P < 0.01). There was a significant age-sex interaction (P < 0.01), reflecting the fact that homocysteine concentrations in females tended to diverge from those in males at younger ages and converge with those in males at older ages. CONCLUSIONS: The first data on homocysteine concentrations in a nationally representative sample of Americans confirm the age and sex differences reported previously in nonrepresentative samples. These data also indicate that differences between Mexican American and non-Hispanic females may influence circulating homocysteine concentrations. (+info)
Phylogenetic analysis of mitochondrial DNA in type 2 diabetes: maternal history and ancient population expansion.
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Several studies have suggested a maternal excess in the transmission of type 2 (non-insulin-dependent) diabetes. However, the majority of these reports rely on patients recalling parental disease status and hence are open to criticism. An alternative approach is to study mitochondrial DNA (mtDNA) lineages. The hypervariable region 1 of the rapidly evolving noncoding section of mtDNA is suitable for investigating maternal ancestry and has been used extensively to study the origins of human racial groups. We have sequenced this 347-bp section of mtDNA from leukocytes of subjects with type 2 diabetes (n = 63) and age- and race-matched nondiabetic control subjects (n = 57). Consensus sequences for the two study groups were identical. Pairwise sequence analysis showed unimodal distribution of pairwise differences for both groups, suggesting that both populations had undergone expansion in ancient times. The distributions were significantly different (chi2 = 180, df = 11, P < 0.001); mean pairwise differences were 4.7 and 3.8 for the diabetic and control subjects, respectively. These data suggest that the diabetic subjects belong to an ancient maternal lineage that expanded before the major expansion observed in the nondiabetic population. Phylogenetic trees constructed using maximum parsimony, neighbor-joining, Fitch-Margolish, or maximum likelihood methods failed to show the clustering of all (or a subset) of the diabetic subjects into one or more distinct lineages. (+info)