Phylogenetic structure of Guinea-Bissau ethnic groups for mitochondrial DNA and Y chromosome genetic systems

The maternal and paternal genetic profile of Guineans is markedly sub-Saharan West African, with the majority of lineages belonging to L0-L3 mtDNA sub-clusters and E3a-M2 and E1-M33 Y chromosome haplogroups. Despite the sociocultural differences among Guinea-Bissau ethnic groups,marked by the supposedly strict admixture barriers, their genetic pool remains largely common. Their extant variation coalesces at distinct timeframes, from the initial occupation of the area to later inputs of people. Signs of recent expansion in mtDNA haplogroups L2a-L2c and NRY E3a-M2 suggest population growth in the equatorial western fringe, possibly supported by an early local agricultural centre, and to which the Mandenka and the Balanta people may relate. Non-West African signatures are traceable in less frequent extant haplogroups, fitting well with the linguistic and historical evidence regarding particular ethnic groups: the Papel and Felupe-Djola people retain traces of their putative East African relatives; U6 and M1b among Guinea-Bissau Bak-speakers indicate partial diffusion to Sahel of North African lineages; U5b1b lineages in Fulbe and Papel represent a link to North African Berbers, emphasizing the great importance of post-glacial expansions; exact matches of R1b-P25 and E3b1-M78 with Europeans likely trace back to the times of the slave trade.

CORRELATING THE CURVE DISTANCE BETWEEN THE DISTAL of THE CANINES TO THE COMBINED WIDTH of THE SIX ANTERIOR TEETH WHEN SELECTING DENTURE TEETH FOR DIFFERENT ETHNIC GROUPS

Statement of problem. To select the width of denture teeth, the distance between the marks indicating the location of the canines is usually measured around the curvature of the wax occlusal rim; however, most manufacturers' mold charts provide the measurements of the artificial 6 anterior teeth as if they were on a straight line.Purpose. The purpose of this study was to investigate whether the curve distance between the distal surfaces of the maxillary canines can be related to the combined width (straight measurement) of the 6 anterior teeth in 4 ethnic groups.Material and methods. Maxillary stone casts were obtained for 160 dentate subjects of 4 ethnic groups (40 whites, 40 blacks, 40 multiracial - descendants of white and black parents, and 40 Asians). The width of each maxillary anterior tooth was measured on the casts with sliding calipers. The combined width of the 6 anterior teeth (CW) corresponded to the sum of the width of each anterior tooth. The curve distance between the distal surfaces of the canines (CD) was measured by using dental tape and sliding calipers. The Pearson correlation coefficient and regression analysis were used to evaluate the relationship between CD and CW in each ethnic group (alpha=.05).Results. The mean CD and CW values (in mm) obtained were: whites (CD=52.12; CW=45.65); blacks (CD=56.10; CW=48.13); multiracial (CD=53.58; CW=46.54); and Asians (CD=53.29; CW=46.60). Significant (P<.001) correlations between CD and CW measurements were observed for all ethnic groups studied (whites, r=0.957; blacks, r=0.803; multiracial, r=0.917; and Asians, r=0.881). The following linear regression equations were obtained: whites [CD=1.1(CW)+0.3]; blacks [CD=0.95(CW)+9.3]; multiracial [CD=1.2(CW)-1.1]; and Asians [CD=1.0(CW)+5].Conclusions. The curve distance between the distal surfaces of the maxillary canines can be accurately related to the combined width of the 6 anterior teeth in the selection of denture teeth for the studied ethnic groups. (J Prosthet Dent 2012;107:400-404)

Hispanic poverty from the current population survey and poverty of other self-identified ethnic groups from census information

Includes bibliography

Prevalence of HTLV-I antibody among two distinct ethnic groups inhabiting the Amazon region of Brazil

Soroprevalências para HTLV-I de 3,63% (02/55), 12,9% (10/82) e 13,88% (10/72) foram demonstradas entre os Tiryió, Mekranoiti e Xicrin, respectivamente - indígenas habitantes da Amazônia -, utilizando-se a técnica de "Western Blot" (WBEI). Por outro lado, a imunomicroscopia eletrônica indireta (IIME) revelou como positivos 2 Tiryió, 9 Mekranoiti e 6 Xicrins. Das 44 amostras de soro oriundas de migrantes japoneses, nenhuma resultou positiva pelas duas técnicas antes mencionadas. Foram reativos por ambos os métodos, 1, 8 e 6 amostras dos índios Tiryió, Mekranoiti e Xicrin, respectivamente. Nossos resultados representam uma forte evidência de que o HTV-I e/ou variante(s) antigenicamente similar(es) circula(m) entre populações que habitam a região amazônica do Brasil.

Occurrence of periodontal pathogens in ethnic groups from a native Brazilian reservation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Frequency of LCT -13910C>T single nucleotide polymorphism associated with adult-type hypolactasia/lactase persistence among Brazilians of different ethnic groups

Abstract Background Adult-type hypolactasia, the physiological decline of lactase some time after weaning, was previously associated with the LCT -13910C>T polymorphism worldwide except in Africa. Lactase non-persistence is the most common phenotype in humans, except in northwestern Europe with its long history of pastoralism and milking. We had previously shown association of LCT -13910C>T polymorphism with adult-type hypolactasia in Brazilians; thus, we assessed its frequency among different Brazilian ethnic groups. Methods We investigated the ethnicity-related frequency of this polymorphism in 567 Brazilians [mean age, 42.1 ± 16.8 years; 157 (27.7%) men]; 399 (70.4%) White, 50 (8.8%) Black, 65 (11.5%) Brown, and 53 (9.3%) Japanese-Brazilian. DNA was extracted from leukocytes; LCT -13910C>T polymorphism was analyzed by PCR-restriction fragment length polymorphism. Results Prevalence of the CC genotype associated with hypolactasia was similar (57%) among White and Brown groups; however, prevalence was higher among Blacks (80%) and those of Japanese descent (100%). Only 2 (4%) Blacks had TT genotype, and 8 (16%) had the CT genotype. Assuming an association between CC genotype and hypolactasia, and CT and TT genotypes with lactase persistence, 356 (62.8%) individuals had hypolactasia and 211 (37.2%) had lactase persistence. The White and Brown groups had the same hypolactasia prevalence (~57%); nevertheless, was 80% among Black individuals and 100% among Japanese-Brazilians (P < 0.01). Conclusion The lactase persistence allele, LCT -13910T, was found in about 43% of both White and Brown and 20% of the Black Brazilians, but was absent among all Japanese Brazilians studied.

Nonviolent factors: Variables associated with ethnic violence, and factors which are associated with nonviolent response to grievances toward members of other ethnic groups

Ethnic violence appears to be the major source of violence in the world. Ethnic hostilities are potentially all-pervasive because most countries in the world are multi-ethnic. Public health's focus on violence documents its increasing role in this issue.^ The present study is based on a secondary analysis of a dataset of responses by 272 individuals from four ethnic groups (Anglo, African, Mexican, and Vietnamese Americans) who answered questions regarding variables related to ethnic violence from a general questionnaire which was distributed to ethnically diverse purposive, nonprobability, self-selected groups of individuals in Houston, Texas, in 1993.^ One goal was psychometric: learning about issues in analysis of datasets with modest numbers, comparison of two approaches to dealing with missing observations not missing at random (conducting analysis on two datasets), transformation analysis of continuous variables for logistic regression, and logistic regression diagnostics.^ Regarding the psychometric goal, it was concluded that measurement model analysis was not possible with a relatively small dataset with nonnormal variables, such as Likert-scaled variables; therefore, exploratory factor analysis was used. The two approaches to dealing with missing values resulted in comparable findings. Transformation analysis suggested that the continuous variables were in the correct scale, and diagnostics that the model fit was adequate.^ The substantive portion of the analysis included the testing of four hypotheses. Hypothesis One proposed that attitudes/efficacy regarding alternative approaches to resolving grievances from the general questionnaire represented underlying factors: nonpunitive social norms and strategies for addressing grievances--using the political system, organizing protests, using the system to punish offenders, and personal mediation. Evidence was found to support all but one factor, nonpunitive social norms.^ Hypothesis Two proposed that the factor variables and the other independent variables--jail, grievance, male, young, and membership in a particular ethnic group--were associated with (non)violence. Jail, grievance, and not using the political system to address grievances were associated with a greater likelihood of intergroup violence.^ No evidence was found to support Hypotheses Three and Four, which proposed that grievance and ethnic group membership would interact with other variables (i.e., age, gender, etc.) to produce variant levels of subgroup (non)violence.^ The generalizability of the results of this study are constrained by the purposive self-selected nature of the sample and small sample size (n = 272).^ Suggestions for future research include incorporating other possible variables or factors predictive of intergroup violence in models of the kind tested here, and the development and evaluation of interventions that promote electoral and nonelectoral political participation as means of reducing interethnic conflict. ^

Cervical cancer screening in Hispanic women as compared with other ethnic groups on an urban campus

Although Pap screening has decreased morbidity and mortality from cervical cancer, reported statistics indicate that among ethnic groups, Hispanic women are one of the least likely to follow screening guidelines. Human papillomavirus (HPV), a major risk factor for cervical cancer, as well as pre-cancerous lesions, may be detected by early Pap screening. With a reported 43% prevalence of HPV infection in college women, regular Pap screening is important. The purpose of this descriptive, cross-sectional survey was to examine self-reported cervical cancer screening rates in a target population of primarily Mexican-American college women, and to discover if recognized correlates for screening behavior explained differences in screening rates between this and two other predominant groups on the University of Houston Downtown campus, non-Hispanic white and African-American. The sample size consisted of 613 women recruited from summer 2003 classes. A survey, adapted from an earlier El Paso study, and based on constructs of the Health Belief Model (HBM), was administered to women ages 18 and older. It was found that although screening rates were similar across ethnic groups, overall, the Hispanic group obtained screening less frequently, though this did not reach statistical significance. However, a significant difference in lower screening rates was found in Mexican American women ages <25. Additionally, of the predicted correlates, the construct of perceived barriers from the HBM was most significant for the Mexican American group for non-screening. For all groups, knowledge about cervical cancer was negatively correlated with ever obtaining Pap screening and screening within the past year. This implies that if health counseling is given at the time of women's screening visits, both adherence to appropriate screening intervals and risk factor avoidance may be more likely. Studies such as these are needed to address both screening behaviors and likelihood of follow-up for abnormal results in populations of multicultural, urban college women. ^

A systematic review of community-based colorectal cancer screening randomized controlled trials with multi-ethnic groups

Background. The CDC estimates that 40% of adults 50 years of age or older do not receive time-appropriate colorectal cancer screening. Sixty percent of colorectal cancer deaths could be prevented by regular screening of adults 50 years of age and older. Yet, in 2000 only 42.5% of adults age 50 or older in the U.S. had received recommended screening. Disparities by health care, nativity status, socioeconomic status, and race/ethnicity are evident. Disparities in minority, underserved populations prevent us from attaining Goal 2 of Healthy People 2010 to “eliminate health disparities.” This review focuses on community-based screening research among underserved populations that includes multiple ethnic groups for appropriate disparities analysis. There is a gap in the colorectal cancer screening literature describing the effectiveness of community-based randomized controlled trials. ^ Objective. To critically review the literature describing community-based colorectal cancer screening strategies that are randomized controlled trials, and that include multiple racial/ethnic groups. ^ Methods. The review includes a preliminary disparities analysis to assess whether interventions were appropriately targeted in communities to those groups experiencing the greatest health disparities. Review articles are from an original search using Ovid Medline and a cross-matching search in Pubmed, both from January 2001 to June 2009. The Ovid Medline literature review is divided into eight exclusionary stages, seven electronic, and the last stage consisting of final manual review. ^ Results. The final studies (n=15) are categorized into four categories: Patient mailings (n=3), Telephone outreach (n=3), Electronic/multimedia (n=4), and Counseling/community education (n=5). Of 15 studies, 11 (73%) demonstrated that screening rates increased for the intervention group compared to controls, including all studies (100%) from the Patient mailings and Telephone outreach groups, 4 of 5 (80%) Counseling/community education studies, and 1 of 4 (25%) Electronic/multimedia interventions. ^ Conclusions. Patient choice and tailoring education and/or messages to individuals have proven to be two important factors in improving colorectal cancer screening adherence rates. Technological strategies have not been overly successful with underserved populations in community-based trials. Based on limited findings to date, future community-based colorectal cancer screening trials should include diverse populations who are experiencing incidence, survival, mortality and screening disparities. ^

AN INVESTIGATION OF THE RELIABILITY AND VALIDITY OF THE CENTER FOR EPIDEMIOLOGIC STUDIES DEPRESSION SCALE IN THREE ETHNIC GROUPS

Epidemiologic studies of mental disorder have called attention to the need for identifying untreated cases and to the inadequacies of the instruments available for this purpose. Accurate case ascertainment devices are the basis of sound epidemiology. Without these, neither case classification nor analytic studies of risk factors is possible.^ The purpose of this research was to examine the reliability and validity of an instrument designed to measure depressive symptoms in community populations--the Center for Epidemiologic Studies Depression Scale (CES-D Scale). Two particular foci of the study were whether or not the scale had the same statistical structure across three ethnic groups and whether or not the magnitude and pattern of rates of symptoms for these groups were affected by one source of response error, that due to response tendencies. The effects of age and education on the pattern and magnitude of rates also were examined. In addition, the reliability and validity of the measures of response tendencies were assessed.^ The study population consisted of residents of Alameda County, California. A stratified sample of approximately 700 whites, blacks and Mexican-Americans was interviewed in the summer and fall of 1978.^ The results of the analysis indicated that the scale was reliable and measured a similar content domain across the three ethnic groups. The unadjusted sex- and ethnic-specific rates of depressive symptoms showed an ethnic pattern for both sexes: rates for whites were lowest, those for Mexican-Americans were highest, and those for blacks were intermediate. Measures of response tendencies--need for social approval, trait desirability, and acquiescence--affected the magnitude of the rates for most comparisons. Likewise, the pattern of rates changed somewhat from that originally observed. The one fairly consistent observation was that rates for Mexican-American women were higher than those for the other two female subgroups in most of the comparisons. These results must be considered in the context of the reliability and validity assessment of the measures of response tendencies which indicated the tenuousness of these measures.^ Age affected the ethnic pattern of rates for men in an inconsistent way; for women, Mexican-Americans continued to have higher rates than whites or blacks in all age categories. Education affected the magnitude of rates for women but not for men. For both men and women, Mexican-Americans had higher rates in all educational strata. Rates for women showed an inverse association with education while those for men did not. ^

Different response to Plasmodium falciparum malaria in West African sympatric ethnic groups

The comparison of malaria indicators among populations that have different genetic backgrounds and are uniformly exposed to the same parasite strains is one approach to the study of human heterogeneities in the response to the infection. We report the results of comparative surveys on three sympatric West African ethnic groups, Fulani, Mossi, and Rimaibé, living in the same conditions of hyperendemic transmission in a Sudan savanna area northeast of Ouagadougou, Burkina Faso. The Mossi and Rimaibé are Sudanese negroid populations with a long tradition of sedentary farming, while the Fulani are nomadic pastoralists, partly settled and characterized by non-negroid features of possible caucasoid origin. Parasitological, clinical, and immunological investigations showed consistent interethnic differences in Plasmodium falciparum infection rates, malaria morbidity, and prevalence and levels of antibodies to various P. falciparum antigens. The data point to a remarkably similar response to malaria in the Mossi and Rimaibé, while the Fulani are clearly less parasitized, less affected by the disease, and more responsive to all antigens tested. No difference in the use of malaria protective measures was demonstrated that could account for these findings, and sociocultural or environmental factors do not seem to be involved. Known genetic factors of resistance to malaria did not show higher frequencies in the Fulani. The differences in the immune response were not explained by the entomological observations, which indicated substantially uniform exposure to infective bites. The available data support the existence of unknown genetic factors, possibly related to humoral immune responses, determining interethnic differences in the susceptibility to malaria.

Major histocompatibility complex class II DR alleles DRB1*1501 and those encoding HLA-DR13 are preferentially associated with a diminution in maternally transmitted human immunodeficiency virus 1 infection in different ethnic groups: determination by an automated sequence-based typing method.

Transmission of human immunodeficiency virus 1 (HIV-1) from an infected women to her offspring during gestation and delivery was found to be influenced by the infant's major histocompatibility complex class II DRB1 alleles. Forty-six HIV-infected infants and 63 seroreverting infants, born with passively acquired anti-HIV antibodies but not becoming detectably infected, were typed by an automated nucleotide-sequence-based technique that uses low-resolution PCR to select either the simpler Taq or the more demanding T7 sequencing chemistry. One or more DR13 alleles, including DRB1*1301, 1302, and 1303, were found in 31.7% of seroreverting infants and 15.2% of those becoming HIV-infected [OR (odds ratio) = 2.6 (95% confidence interval 1.0-6.8); P = 0.048]. This association was influenced by ethnicity, being seen more strongly among the 80 Black and Hispanic children [OR = 4.3 (1.2-16.4); P = 0.023], with the most pronounced effect among Black infants where 7 of 24 seroreverters inherited these alleles with none among 12 HIV-infected infants (Haldane OR = 12.3; P = 0.037). The previously recognized association of DR13 alleles with some situations of long-term nonprogression of HIV suggests that similar mechanisms may regulate both the occurrence of infection and disease progression after infection. Upon examining for residual associations, only only the DR2 allele DRB1*1501 was associated with seroreversion in Caucasoid infants (OR = 24; P = 0.004). Among Caucasoids the DRB1*03011 allele was positively associated with the occurrence of HIV infection (P = 0.03).

Races and ethnic groups in American life,

"Published under the direction of the President's research committee on social trends."--Foreword.