PubMed HealthSearch

SEARCH · PubMed Health

Results for “African People”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Gammaglobulin groups of the Khoisan peoples of Southern Africa: evidence for polymorphism for a Gm1,5,13,14,21 haplotype among the San.

The Gm and Inv types were determined for eight San (Bushman) populations, two Khoikhoi (Hottentot) populations, one Coloured population, 112 San families in which the genotypes of the parents could be unambiguously determined, and for 65 San families in which the genotype of one or both parents could not be determined with certainty. The population and family data establish that the haplotype array of the San is composed of Gm1,21, Gm1,13, Gm1,5,13,14, and Gm1,5,13,14,21; Gm1,5,6 and Gm1,5,6,14 are also present but may have been acquired through admixture with Negroes. The Gm1,5,13,14,21 haplotype has not been found to be polymorphic in any other population. The haplotype array of the Khoikhoi is composed of Gm1,2,21, Gm1,13, and Gm1,5,13,14; Gm1,5,6 and Gm1,5,6,14 are also present but, as in the case of the San, may be due to admixture. The San and Khoikhoi differ from each other in that the former have the Gm1,21 and Gm1,5,13,14,21 haplotypes not present in the latter, and the Khoikhoi have the Gm1,2,21 haplotype not present in the San. These three haplotypes and Gm1,13 serve to distinguish the Khoisan people from other African peoples.

Africa, Southern

Comparison of sensitivity and specificity of counter electrophoresis, complement fixation and radioimmunoassay for detecting antibodies against hepatitis B core antigen.

Sensitivity and specificity of anti-HBc detection by counter-immunoelectrophoresis (CEP), complement fixation (CF) and radioimmunoassay (RIA) tests were compared in sera from 69 patients with chronic hepatitis, 61 black African people suffering from primary hepatocellular carcinoma and 50 controls composed of French country people. CEP and CF tests gave the same results in detecting anti-HBc antibodies. The RIA test was found to be more sensitive and seems to be more specific than CEP and CF.

Adult

[Psychotic masked depression or black mask for depression].

We have used as depression criteria those of Pichot and Hassan, described during the Sint-Moritz Symposium in 1973 on masked depression. According to their clinical experience in Zaïre and Senegal, the authors consider the possibility that the "bouffée délirante" (acute psychotic reaction), frequent in black Africa, is in fact a manifestation of depression. They remind the five criterias of Pichot and Hassan, i.e.: 1 degree evidence of depression symptoms; 2 degrees a background and a particular underlying personality; 3 degrees evolutional characteristics; 4 degrees familial antecedents and hereditary factors; 5 degrees the response to antidepressive treatment. They present ten cases of acute psychosis: five from Zaïre and five from Senegal. These ten patients have been successfully treated with antidepressive drugs imipramine type, without any neuroleptic drugs; the outcome has always been a rapid remission. Some socio-cultural references are described; it permits to better comprehend the psychological frame of African people. An attempt to psychodynamically interpret the results ends the article.

Adolescent

Characteristics of African blood.

Genetic markers in people of African ancestry and tables comparing Africans and Europeans are compiled to illustrate the blood differences. The existence of the African genetic characters, R0 (cDe), D-u and Ee (e-s, ce-s) in an Rh-Hr system are discussed. The high incidence of R0 (81.9%) in Africans is evident. Studies of ABO and the sickle cell trait in East Africa reveal the African tribes responsible for the original populating of Africa. The pygmoids of Uganda and Zaire, the Nilotes of West Nile, and the Bantu of Uganda are possibly responsible. Subgroups of A antigen in Africans and Europeans are compared, and their differences are outlined. These antigens appear to be different in the two races, and a reliable method for grouping A1 and A2 in Africans is described. For convenience, A2, Aint., Abantu, and other subgroups of A in Africans are renamed "non-A1." Attention to these subgroups on African paternity studies is emphasized. African problems in MNSs, Duffy, P, Lewis, and Sutter are presented. Immunoglobulines, Rh(D) immunization, enzyme autoantibodies, and a technique to detect them are discussed and described in detail. Studies on tropical splenomegaly syndrome show that it is an immune complex disease. Fluctuation titers of ABO iso-antibodies are observed to vary more strikingly in Africans than in Europeans. This is offered as a possible explanation of the high incidence of ABO hemolytic disease of the newborn in Africans.

ABO Blood-Group System

Relationship of lower limb height to sitting height in black populations of Africa and the United States.

This article examines a recently reported generalization. Materials from more than a score of invetigations are drawn upon. These materials show there is not a substantial research base for the claim that interbreeding in the United States between black people of African ancestry and white people of European ancestry has resulted in increased lower limb height relative to sitting height.

Adolescent

Influence of Ancestral and Geographic Factors on Intracerebral Hemorrhage Risks Among Africans and Americans.

BACKGROUND: We investigated whether risk factors for intracerebral hemorrhage (ICH) among indigenous Africans (IA) would vary in prevalence and effect compared with self-reported African, Hispanic, and White Americans by comparing data from 2 independent population-based case-control studies conducted in West Africa and the United States. METHODS: We compared ICH risk factors common to the SIREN (Stroke Investigative Research and Educational Network: 1100 case-control pairs) and the ERICH (Ethnic/Racial Variation of Intracerebral Hemorrhage: 999 case-control pairs African American participants, 998 case-control pairs, Hispanic Americans, 1000 case-control pairs, White Americans) studies. Ethnicity/Race was self-reported. The effect measure of interest is the odds ratio (OR). To test for differences in the effects of the risk factors between the SIREN IA study population and each of the ERICH study populations, a test for heterogeneity was computed using the R program, metagen (version 4.9-6). RESULTS: ICH occurred at a younger age among IA (54.3±13.4 years), African Americans (58.0±12.7), and Hispanic Americans (58.9±14.3), compared with White Americans (69.1±13.9). The largest distinction was for hypertension, where IA exhibited a much larger risk of ICH than the American study population (OR, 67.02 [95% CI, 33.30-134.85]), African American (OR, 3.71 [95% CI, 2.53-5.44]); Hispanic (OR, 3.55 [95% CI, 2.54-4.92]), and White population (OR, 2.69 [95% CI, 1.95-3.69]). Current alcohol use exhibited increased risk in IA (OR, 2.24 [95% CI, 1.36-3.67]), but not in African Americans (OR, 0.63 [95% CI, 0.46-0.86]), Hispanic (OR, 0.87 [95% CI, 0.65-1.17]), and White Americans (OR, 0.51 [95% CI, 0.38-0.69]). CONCLUSIONS: Identical or comparable risk factors do not consistently result in the same disease risk across different cultures and regions. Therefore, to improve our understanding of the genetic determinants and biological pathways driving ICH risk, it is crucial to study multiple populations, including IA, while accounting for the influence of environmental and social factors.

Adult

[Examination of the enzymatic functions of the normal liver in black Africans (Apropos of 50 Senegalese cases)].

In order to establish the hepatic enzymogram in healthy African black people, four enzymes have been studied in 50 apparently healthy male Africans: transaminases (GOT, GPT), alcaline phosphatases, ornithine carbamoyltransferase (OCT) and gamma-glutamyl transpeptidase (GGT). The findings do not show any difference with the usually admitted levels in European countries, except for alcaline phosphatases which are situated at the upper limit of the normal.

Adolescent

A comparison of cardiovascular measurements in the Gambia, Jamaica, and the United Republic of Tanzania.

Epidemiological studies of the cardiovascular characteristics of three typically rural communities in the Gambia, Jamaica, and the United Republic of Tanzania were carried out by means of standardized methodology. This paper reports comparisons of arterial blood pressure distribution and electrocardiographic findings in relation to age, sex, and body build. Marked differences in blood pressure were found, with higher values in Jamaicans than in Tanzanians, who in turn had higher values than Gambians. These differences are not explicable in terms of body build. Heart rates and ECG amplitudes were also strikingly different, with higher values in Jamaicans than in Tanzanians and Gambians. The differences in ECG amplitudes cannot be explained by differences in body build, heart rate, or blood pressure. The findings agree with the hypothesis that some factor or factors associated with development contributes to the risk of cardiovascular disease in peoples of African origin.

Adult

Tropical vasculitis and tuberculosis.

Attention is drawn to the association of Tropical aortitis, or vasculitis with active or previous tuberculous infection. This suggests that the two diseases may be related. It is recognised that environmental factors may be important since the incidence of this complex appears to be high in the indigenous populations of Southern and Central Africa and uncommon in people of African origin in industrialised nations. Unlike classical Takayasu's arteritis, there does not appear to be any preference for young people or for females.

Adult

Polygenic prediction of body mass index and obesity through the life course and across ancestries.

Polygenic scores (PGSs) for body mass index (BMI) may guide early prevention and targeted treatment of obesity. Using genetic data from up to 5.1 million people (4.6% African ancestry, 14.4% American ancestry, 8.4% East Asian ancestry, 71.1% European ancestry and 1.5% South Asian ancestry) from the GIANT consortium and 23andMe, Inc., we developed ancestry-specific and multi-ancestry PGSs. The multi-ancestry score explained 17.6% of BMI variation among UK Biobank participants of European ancestry. For other populations, this ranged from 16% in East Asian-Americans to 2.2% in rural Ugandans. In the ALSPAC study, children with higher PGSs showed accelerated BMI gain from age 2.5 years to adolescence, with earlier adiposity rebound. Adding the PGS to predictors available at birth nearly doubled explained variance for BMI from age 5 onward (for example, from 11% to 21% at age 8). Up to age 5, adding the PGS to early-life BMI improved prediction of BMI at age 18 (for example, from 22% to 35% at age 5). Higher PGSs were associated with greater adult weight gain. In intensive lifestyle intervention trials, individuals with higher PGSs lost modestly more weight in the first year (0.55 kg per s.d.) but were more likely to regain it. Overall, these data show that PGSs have the potential to improve obesity prediction, particularly when implemented early in life.

Adolescent

Anthropometric and cardio-metabolic trait variation and genetic associations in sub-Saharan Africa.

The genetics of complex traits in Africa has been historically understudied, which can contribute to healthcare inequalities. Here, we present observations of 27 anthropometric, cardiovascular, and blood biomarker measurements across 2,124 individuals from sub-Saharan Africa for whom we also have dense genotype data. First, we identified trait values that differ significantly across populations and subsistence lifestyles (e.g., hemoglobin levels and height). We then identified traits with high degrees of sexual dimorphism (e.g., weight and grip strength). ADMIXTURE analyses revealed substantial population structure in our dataset, and many of the phenotypes studied here are correlated with genetic ancestry components, particularly skin color and body size traits. A variance partitioning approach further revealed traits in which much of the SNP heritability is due to polymorphisms that also contribute to differences between ancestry components. Following genomic imputation, we performed genome-wide association studies (GWASs) for all 27 traits and identified >100 independent autosomal SNPs with genome-wide significant associations for at least one trait (p < 5 &#xd7; 10-8). Many of these trait-associated variants are rare outside of Africa (minor-allele frequency [MAF] < 1%). We found that 100 kb windows surrounding the top GWAS hits from our African-ancestry cohort were enriched for trait associations in an identically sized European cohort and vice versa. We performed a more detailed analysis of height prediction from genetic data, finding that genome-wide admixture proportions predict height in Africans better than polygenic predictors based on large-scale European height GWASs.

Female

Polymorphism of DNA sequence adjacent to human beta-globin structural gene: relationship to sickle mutation.

Restriction endonuclease mapping of the human globin genes revealed a genetic variation in a Hpa I recognition site about 5000 nucleotides from the 3' end of the beta-globin structural gene. Instead of a normal 7.6-kilobase (kb) fragment which contains the beta-globin structural gene, 7.0-kb and 13.0-kb variants were detected. Both variants were found in people of African origin and were not detected in Asians or Caucasians. The 13.0-kb variant is frequently associated with the sickle hemoglobin mutation and may be useful for the prediction of the sickle cell gene in prenatal diagnosis. Polymorphism in a restriction enzyme site could be considered as a new class of genetic marker and may offer a new approach to linkage analysis and anthropological studies.

Anemia, Sickle Cell

Tractor workflow: a scalable Nextflow framework for local ancestry-aware genome-wide association studies.

MOTIVATION: The routine exclusion of admixed individuals from traditional genome-wide association studies (GWAS) due to concerns about spurious associations has limited multi-ancestry genetic discovery. Tractor addresses this issue by incorporating local ancestry into association testing, enabling the identification of ancestry-enriched signals and generating ancestry-specific summary statistics. However, adoption has been constrained by the complexity of prerequisite steps, including phasing and local ancestry inference, which require substantial bioinformatics expertise and introduce key analytical decision points. RESULTS: We developed a scalable, automated Nextflow workflow that integrates phasing, local ancestry inference, and Tractor association testing into a reproducible end-to-end pipeline. To demonstrate its utility, we applied the workflow to 32 blood biomarkers in 6245 two-way African-European admixed individuals from the UK Biobank. This pipeline performed efficiently at scale, replicating known associations and uncovering key ancestry-specific loci. These associations were largely driven by variants present on African ancestral tracts but absent from European tracts, underscoring the value of local ancestry-aware methods in uncovering previously masked genetic signals. AVAILABILITY AND IMPLEMENTATION: The workflow is modular, customizable, and compatible with commonly used phasing and local ancestry tools, minimizing manual intervention while preserving analytical flexibility. By lowering technical barriers to implementation, this framework facilitates broader adoption of local ancestry-aware GWAS, paving the way for expanded genetic discovery.

Humans

The Neanderthal-Derived 3p21 Haplotype at LZTFL1 in Modern-Day Moroccans Is Associated With COVID-19 Severity and Further Suggests the Presence of Neanderthals in North Africa.

There is considerable variability in the clinical presentation of COVID-19 among patients infected with SARS-CoV-2. Genome-wide association studies (GWASs) have identified the 12q24.13 and 3p21.31 regions, derived from Neanderthal DNA, as the human genetic loci most strongly associated with COVID-19 severity. We examined in this study the 3p locus in the Moroccan population by analysing allele and haplotype frequencies at the LZTFL1 gene and their associations with COVID-19 outcomes. Three SNPs at LZTFL1, tagging the Neanderthal-derived COVID-19 risk haplotype, were sequenced by Sanger's method in 102 ambulatory participants and 105 hospitalized patients and have been compared to 118 controls negative for SARS-CoV-2 infection using logistic regression analysis. Results showed that the prevalence of the lead variant rs11385942 in this locus was 8.9%, whereas the variants rs35044562 and rs13078854, which tag the Neanderthal haplotype, were present in only 6.3%. Our study showed that only the rs35044562-T and rs13078854-A alleles were associated with a 2.5-fold increased risk of severe COVID-19 (p&#xa0;=&#xa0;0.028). These two alleles, in LD with the rs11385942-AA one, form the haplotype inherited from the Neanderthal, the only haplotype associated with COVID-19 severity in the Moroccan population (p&#xa0;=&#xa0;0.030), whereas sub-Saharan African and the rare local haplotype also containing the rs11385942 variant do not influence the COVID-19 outcomes 19 (p&#xa0;>&#xa0;0.05). Furthermore, our study showed that the Neanderthal haplotype at 3p21 locus exists in the inhabitants of Morocco at a frequency close to that of Europeans and suggests a close connection between North Africa and Eurasia.

Adult

Recovering the precolonial population structure of Khoe-San descendant populations.

San populations from Botswana and Namibia retain exceptional linguistic, cultural, and genetic diversity, but few Khoisan-speaking groups remain south of the Kalahari Desert. However, historically, far southern Africa was home to many San and Khoekhoe groups. Popular opinion often implies that such populations do not contribute to the ancestry of contemporary South Africans. Here, we characterize the genetic ancestry of self-identified South African Coloured groups and reconstruct precolonial and colonial population structures from 620 newly sampled individuals. These groups retain the majority of Khoe-San genetic ancestry (>48%), suggesting the persistence of Khoe-San ancestry to the present day. By isolating the Khoe-San ancestry component, we show that it is intermediate between the &#x2260;Khomani San and Nama and distinct from Kalahari Khoe-San populations. We also find that signatures of the Indian Ocean slave trade can be traced to Indonesian islands such as Sulawesi, Java, and Flores, while the South Asian ancestry is regionally nonspecific.

Humans

Discovery of Respiratory Pathogens in People Living With HIV in the African Cohort Study.

INTRODUCTION: Respiratory infection outbreaks pose a threat to the readiness of the United States and allied armed forces. Predicting and preventing such outbreaks requires understanding of the epidemiology of potential respiratory pathogens in communities where service members live and work. We conducted pan-viral surveillance of respiratory specimens from people living with HIV or without HIV but under the risk enrolled in the U.S. Military HIV Research Program's African Cohort Study to determine the prevalence and possible clinical presentation of viruses in this population. METHODS: The African Cohort Study is an open-ended prospective cohort study that enrolls people with and without HIV aged &#x2265;15&#x2009;years at 12 clinical sites in Kenya, Tanzania, Uganda, and Nigeria. The study follows participants every 6 months and collects social, demographic, clinical, and laboratory data. A total of 131 respiratory samples, collected from March 2022 to February 2023 from participants in South Rift Valley Province, Kenya, who had symptoms of respiratory illness or a positive COVID-19 test, were analyzed using a pan-viral hybridization metagenomic next-generation sequencing approach. Libraries were sequenced on the Illumina Next-generation Sequencing System NovaSeq 6000. Sample data were run through several pathogen discovery pipelines. RESULTS: Full genome and partial genome sequences were assembled for several respiratory viruses including SARS-CoV-2, human coronavirus HKU1, human adenovirus 62, human metapneumovirus, human mastadenovirus B (coinfection with SARS-CoV-2), human mastadenovirus C (coinfection with SARS-CoV-2), and human parechovirus 3 (coinfection with adenovirus 62). The results showed that SARS-CoV-2 lineages correspond with lineages circulating during March 2022 to February 2023 and revealed additional viral respiratory pathogens and viruses known to be associated with HIV. CONCLUSIONS: These preliminary results suggest that continued genomic surveillance efforts are needed for data-driven decisions on force health protection, prevention of emerging respiratory infections, and mitigation of impacts on military readiness caused by infectious diseases.

Humans

Primary cerebral neoplasia in Rhodesia.

In 17 years we have performed 6,505 neurosurgical procedures in the neurosurgical unit of the Salisbury Hospital Group. Only 62% were performed on Africanpatients and 38% on European patients, despite the fact that the African population exceeds the European population by 20 times. This is partly due to the tolerance of rural people towards disease and partly to a number of social factors. The European group has a greater percentage of elderly people than the African group and, although we could not estimate the incidence of tumors among the African group, we would expect their overall incidence per capita to be lower because malignant tumors tend to occur in older people. We do not suspect the existence of a genetic factor in tumor incidence. There were 205 primary intracranial neoplasms in Africans and 244 in Europeans. Histological study shows that 33% of all tumors were meningiomas in the African group compared to 19% in the European group. Gliomas comprised 61.3% of the European series and 48.8% of the African series but the distribution by Kernohan's grading of astrocytomas was the same in both groups. If age was a factor, Grades I and II should have predominated in the African group, but did not. The incidence for each tumor among our European patients followed the patterns reported in various European and USA series. Likewise the pattern emerging from our African series closely paralleled the reports of other workers in Africa. Acoustic neuromas appear to be rather rare among Africans. The average age of all adults with tumors was 15 years lower in the African group than in the European group. However, this is entirely related to the age structure of the population, and not to an earlier age of occurrence. The average ages of medulloblastoma cases were identical. In our European series the occurrence according to age was much the same as that reported by overseas workers. The sex incidence of tumors in the European group seems to be a fair reflection of the situation elsewhere; in the African group it is questionable because men go into the towns to work and leave their families in the country. There was no significant difference in the location of tumors in the two groups. Results of treatment were uniformly inferior in the African group, partly due to the lateness of arrival at the hospital so that the growth was already far advanced and also because many patients suffered poor health from concomitant disease.

Adolescent