Contrasting patterns of caries profile and dental treatment in pupils of 16–18 years in South African ethnic groups

Data on numbers of food items (using a 24‐hour recall) consumed by interracial groups of schoolchildren is given. 666 Black, 322 Coloured. 328 Indian and 285 White pupils aged 8 to 17 years were studied. White pupils ate three times more food items than rural Black, and twice as many as urban Black pupils; urban Blacks ate more than rural Blacks. These differences were significant. Coloured and Indian pupils had intermediate consumption patterns eating significantly fewer items than White pupils. Judging by their growth curves, the food consumed by pupils was adequate for satisfactory growth. Children consuming far fewer items of food were not prejudiced in health or growth attained at puberty than those consuming far greater varieties. It was concluded that the variety of food items eaten by White pupils was unnecessary when considering high health risks associated with affluent dietaries.

The debate over whether black South Africans are in the process of transition from an extended lineage-based consanguinal family system to a Western style nuclear conjugal system has focused primarily on household composition. Another way of assessing this supposed transition is to examine the strength of verbal commitment to Western conjugal family norms. A set of statements about appropriate family behaviour was devised and used to compare the responses of three groups of South Africans: urban whites, urban blacks and rural blacks. We found that urban blacks respond to some statements like rural blacks but to others like urban whites. In matters of family and kinship, urban blacks are still influenced by a distinctive African cultural approach to kinship as well as adapting their views in light of new urban experiences.

The main objective of this paper was to use femoral data to determine whether the different South African ethnic groups should be considered as a homogenous population, as has been assumed in previous studies. Furthermore regression equations for each ethnic group were constructed. Three standard femoral variables were used; bone length (BL), maximum head diameter (HD) and bicondylar width (BCB). The eight South African ethnic groups (Zulu, Tswana, Swazi, Sotho, Xhosa, Shan, Venda and Ndebele) were considered as the independent variable. They were also compared with femora from South Africans of European Descent (SAED). In total 230 male femora were obtained from the Dart’s Collection at Wits University, South Africa. There were not any significant differences in bone length between the eight South African ethnic groups. However, bone length for SAED was significantly longer than for six of the ethnic groups, all except Zulu and Ndebele. Similarly all of the ethnic groups were significantly smaller than SAED for head diameter and bicondylar width. The Zulu and Ndebele femora were significantly larger than the other six African ethnic groups for HD and BCB. Regression equations were derived for the maximum length of femur from the maximum head diameter for all the groups separately. Femora from SAED were significantly larger than for six of the eight African ethnic groups that were considered. However, the data from the Zulu and Ndebele femora suggest that they constitute a separate ethnic grouping. Thus we conclude that these eight South African ethnic groups cannot be considered as a homogenous population and that the Zulu and Ndebele groups should be considered as a distinct population.

DMFT scores, total sugar intakes and snacks habits were determined in 1918 South African Black pupils (923 rural, 995 urban) and 724 White pupils (English and Afrikaans speaking) aged 16-18 years inclusive. Mean DMFT scores of school groups of Black pupils (both sexes) ranged from 0.9 and 2.0 in rural areas, to 4.2-6.7 in urban areas (where data were far higher than such obtained 7 years ago), and were 9.2 and 10.2 for White pupils. Corresponding mean daily sugar intake were - rural Blacks, 69 g and 97 g, urban Blacks 118-141 g, respectively (all slightly higher than previously); and Whites 102 g and 123 g. Mean DMFT scores of girls were higher than those of boys; yet while mean sugar intakes of Blacks girls and boys were somewhat similar, White girls' intakes were much lower than those of White boys. In the ethnic-sex groups studied, mean DMFT scores for pupils in upper, compared with lower, third of sugar intake, were higher in nine of the 14 sub-groups. Mean DMFT scores in upper, compared with lower, third of exposure to snack practices were higher in 11 of the 14 groups. However, most of the differences were slight. In further research, more intensive enquiries should be pursued on roles of ethnic and familial factors, as well as on roles of inter-acting dietary components additional to sugar and sugar-containing foods.

Breath methane has been measured in 1016 people from four populations resident in Southern Africa which experience widely different risks of bowel cancer and other colonic diseases. Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers--rural black 84, urban black 72, white 52, Indian 41 (chi 2 121 p less than 0.001 3 df). There was a slight preponderance of female producers over male (female producers 63%, males 57%) and an age trend with fewer producers in the older age groups in the urban blacks and Indians, these comparisons being significant when tested by stepwise logistic regression analysis. Bowel cancer risk, determined from a variety of sources, was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but which bear no relation to bowel cancer risk in these populations.

Sugar intake and weight and height of pupils of 16 years in South African ethnic groups

Dental caries, debris (DI-S) and sugar intake were determined for 766 rural Black, urban Black, coloured, Indian and White children, using standardized techniques. In general sucrose intake, both quantity and frequency was low in rural Black children yet these children had relatively few caries-free individuals and higher than expected mean dmft scores. Comparison with earlier studies in the same localities has shown a worsening of dental caries in all groups except the White, in which the situation has improved. Sucrose consumption declined in rural Black, and White groups, remained steady in urban Black children and increased in coloured and Indian groups.

The authors examined the dimensionality and psychometric properties of the Multigroup Ethnic Identity Measure (MEIM) among Black South African adolescents (ages = 13–14; 52% female) representing several ethnic groups (Ndebele, Pedi, Sotho, Swati, Tsonga, Tswana, Venda, Xhosa, Zulu) and evaluated the measure for differential item functioning primarily among four ethnic groups (Sotho, Tswana, Xhosa, and Zulu). Results indicated that a two-dimensional model best represented the data, reflecting ethnic search/clarity and ethnic affirmations. Subsequently, we evaluated the equivalence of the MEIM among the four South African ethnic groups and a sample of African American adolescents (Mage = 15.57 years; SD = 1.22; 51% female). Further analyses revealed that configural and metric models were excellent across the four South African ethnic groups and the African American group. However, scalar invariance (i.e., intercept) was not found; the item intercepts were different for the South African ethnic groups and African Americans. Findings are discussed with consideration for conducting research on ethnic identity among youth in South Africa.

Food frequency related to folacin status in adolescents ,

Caries prevalence and distributions were studied in 761 South African high school pupils aged 17 years in four ethnic groups, living in urban (low F) and rural (low and high F) areas. Mean DMFT values were significantly higher among White pupils than all other groups. Comparison of mean DMFT among the Black pupils showed that urban Black dwellers had a significantly higher score than rural pupils when caries-free individuals were included in the analysis, but not when scores for only those with a DMFT of 1 or more were compared. No significant differences were found between the DMFT values of Black rural pupils living in high or low fluoride areas. Among Black rural pupils, dental caries was approximately three times more common in permanent second molars compared with permanent first molars. In urbanized Black, Coloured, Indian and White subjects, the molars were approximately equally affected.

Summary The locus of control (LOC) orientation of 1888 Black, Colored, Indian, and White South African students and pupils was investigated. The research population was controlled according to these ethnic groups, socioeconomic status, sex, and age. Rotter's Internal-External (I-E) Scale and Levenson's Internal, Powerful Others, and Chance (IPC) Scale were used. The results showed significant differences in the LOC expectancies of the four ethnic groups. Sex- and age-related differences were also found, but socioeconomic status-related differences were absent. The factor analyses of the I-E Scale scores revealed reasonably to highly consistent factors which were unique to each ethnic group. Furthermore, the Rotter External and the Levenson Internal scores were significantly negatively correlated. The findings suggest that the I-E Scale can be meaningfully used with South African ethnic groups, but that further substantiation and refinement of the factor structures is necessary.

Bowel behaviour was investigated in 81 rural black, 117 urban black, and 77 white children aged 1 to 4 years. The study was undertaken principally because intake of dietary fibre by urban blacks is now lower than that of whites: moreover, that of rural blacks has also fallen. Average daily defecation frequencies in rural and urban black children and white children were 1.9, 1.8, and 1.5, respectively. Black children voided smaller stools and more frequently than white children. In both ethnic groups most stools were soft. Median transit times, determined in 55 rural black, 80 urban black, and 45 white children, were approximately 6.5, 7, and 27 hours, respectively. Median transit times increased little with age in black compared with white children. The higher defecation frequency and the much shorter transit time in black children are not explicable in terms of the levels of fibre intake.

BackgroundThe failure of specific types of human papillomaviruses (HPV) to raise effective immune responses may be important in the pathogenesis of cervical cancer, the second most common cancer in South African women. Polymorphisms of a number of cytokine genes have been implicated in inducing susceptibility or resistance to cancers caused by infectious agents owing to their role in determining host immune response. Polymorphisms of IL-10 and IFN-γ genes are believed to influence the expression and/or secretion levels of their respective cytokines.Methods and ResultsIn this study, women with histologically proven cancer of the cervix (n = 458) and hospital-based controls (n = 587) were investigated for bi-allelic -1082 (A/G) polymorphisms of IL-10 and the bi-allelic +874(A/T) polymorphisms of IFN-γ. In addition, the distributions of the allelic frequencies were stratified in both the African and mixed race population groups of South Africa. We found striking differences in the allele distribution of IFN-γ (X2 = 0.02) among the two ethnic groups. A significant increase in the allele distribution of the IFN-γ AA genotype was found in the African group compared to the mixed population group (OR, 0.5; 95% CI, 0.2–1.0). For IL-10 there were no significant allelic differences between the two South African ethnic groups. Furthermore, when the ethnic groups were combined the IL-10 allelic frequencies in the combined South African data were similar to those observed in an Oriental population from Southern China and in an Italian population. However, the allele frequencies of the IFN-γ genotype among the two South African ethnic groups were different when compared to an Italian Caucasoid group. While crude analysis of these data showed both statistically significantly increased and diminished risks of cervical cancer among high producers of INF-γ and low producers of IL-10 respectively, these associations were no longer significant when the data were adjusted for confounding factors.ConclusionThese findings demonstrate a clear correlation between ethnicity and IFN-γ polymorphism across different population groups. However, these differences in ethnicity and gene polymorphisms in the aforementioned cytokines are suggested not to influence the development of invasive cervical cancer but may represent an important susceptibility biomarker for other diseases and should be explored further.

BackgroundCurrent knowledge of the aetiology of hereditary breast cancer in the four main South African population groups (black, coloured, Indian and white) is limited. Risk assessments in the black, coloured and Indian population groups are challenging because of restricted information regarding the underlying genetic contributions to inherited breast cancer in these populations. We focused this study on premenopausal patients (diagnosed with breast cancer before the age of 50; n = 78) and triple negative breast cancer (TNBC) patients (n = 30) from the four South African ethnic groups. The aim of this study was to determine the frequency and spectrum of germline mutations in BRCA1, BRCA2 and PALB2 and to evaluate the presence of the CHEK2 c.1100delC allele in these patients.MethodsIn total, 108 South African breast cancer patients underwent mutation screening using a Next-Generation Sequencing (NGS) approach in combination with Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large rearrangements in BRCA1 and BRCA2.ResultsIn 13 (12 %) patients a deleterious mutation in BRCA1/2 was detected, three of which were novel mutations in black patients. None of the study participants was found to have an unequivocal pathogenic mutation in PALB2. Two (white) patients tested positive for the CHEK2 c.1100delC mutation, however, one of these also carried a deleterious BRCA2 mutation. Additionally, six variants of unknown clinical significance were identified (4 in BRCA2, 2 in PALB2), all in black patients. Within the group of TNBC patients, a higher mutation frequency was obtained (23.3 %; 7/30) than in the group of patients diagnosed before the age of 50 (7.7 %; 6/78).ConclusionThis study highlights the importance of evaluating germline mutations in major breast cancer genes in all of the South African population groups. This NGS study shows that mutation analysis is warranted in South African patients with triple negative and/or in premenopausal breast cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1913-6) contains supplementary material, which is available to authorized users.

African people often use proverbial expressions to give advice or say something about life. Proverbial expressions are linguistic expressions with unique structures (form, style and formulae), and they have distinct functions in society. In general, proverbs have similar functions – to use folk wisdom to provide general advice on how to act and live, and to reflect on cultural values. South African linguistic communities also use proverbs as channels through which messages travel. Therefore, it is important to explain how proverbs are formed and used in South African speech communities. This chapter analyses proverbs from four South African ethnic groups – Sotho (Sepedi, Sesotho and Setswana), Tsonga (Xitsonga), Nguni (isiZulu, isiXhosa, isiNdebele and siSwati) and Venda (Tshivenda). The proverbial analysis looks at two aspects of the proverbs: the conceptual framework (what informed the formation of proverbs) and the social functions of proverbs.