Association of dental caries with HLA Class II allele in Brazilian adolescents.

The purpose of this study was to evaluate the association between the frequencies of DR and DQ HLA class II alleles and the prevalence of dental caries in Brazilian adolescents. The study sample consisted of 164 adolescents aged 15- 19 years. For the assessment of caries experience the DMFT index was used, according to World Health Organization criteria. DNA samples of the adolescents were extracted from oral mucosa cells. The amplification of the alleles HLA-DR and HLA-DQ was carried out by polymerase chain reaction with sequence-specific primers (PCR-SSP). The products of PCR-SSP were electrophoresed and analyzed in agarose gel. Statistical analysis was performed using simple and multiple logistic regression to test the association between the adolescents' caries experience and the presence of HLA-DR and -DQ alleles. Sociodemographic covariates were included in the model. The significance level for all analyses was p < 0.05. The prevalence of caries was 60.4% and the mean DMFT was 2.41 ± 2.53. Adolescents positive for HLA-DQ2 allele were less likely to have dental caries than their counterparts who were negative for this allele (OR = 0.33, CI 0.16-0.66), and those whose mothers presented low levels of education were 2.01 (CI 1.02-3.97) times more likely to have dental caries. There was no statistical difference between HLA-DR4, -DQ4, -DQ5, -DQ6 and dental caries. Our data provide evidence that genes within the MHC, especially the DQ2 group, may influence susceptibility to dental caries in Brazilian adolescents.

Cariogenic microorganisms and oral conditions in asthmatic children.

This study evaluated the caries risk of asthmatic patients on the basis of mutans streptococci (MS) and lactobacilli levels in saliva samples as well as the index of oral hygiene and dental caries (DMFT index). The study population was composed of 80 asthmatic children, aged 3-15 years, who use specific medication, and 80 matched, healthy control children. The parents were interviewed about oral health-related factors. The World Health Organization criteria were used for dental examinations. The Köhler and Bratthal methodology was used to detect salivary MS levels and dilutions of saliva were done for lactobacilli counting. No differences between asthma and control groups were observed for caries prevalence in children aged 3-6 and 7-10 years, except in severe cases in the younger group. However, higher caries prevalence for permanent dentition was observed in 11- to 15-year-old asthmatic children. An increased dental biofilm was observed in the asthma group, as well as salivary levels of MS. No differences were observed in levels of lactobacilli. No statistical correlations were found between medication, frequency of treatment, method of consumption and caries experience, dental biofilm and salivary levels of MS or lactobacilli. However, there was a correlation between MS levels and treatment duration. The logistic regression revealed that MS level is an important risk factor for increased caries experience. Asthma should be evaluated as a risk factor for caries experience because it can increase the levels of MS and the dental biofilm.

Genotypic Diversity of Streptococcus mutans in Caries-Free and Caries-Active Preschool Children.

Aim. The aim of the present paper was to evaluate the genotypic diversity of S. mutans in caries-free and caries-active preschool children in Brazil. Design. Twenty-eight preschool children were examined regarding caries experience by the dmft index. DNA from 280 isolates of S. mutans was extracted. S. mutans evaluated using to the PCR method, with primers for the glucosyltransferase gene. The genetic diversity of S. mutans isolates was analyzed by arbitrary primed-PCR (AP-PCR) reactions. The differences between the diversity genotypic and dmft/caries experience were evaluated by chi2 test and Spearman's correlation. Results. The Spearman correlation test showed a strong association between genotypic diversity and caries experience (r = 0.72; P < .001). There were more S. mutans genotypes in the group of preschool children with dental caries, compared with the caries-free group. Among the children with more than 1 genotype, 13 had dental caries (2 to 5 genotypes) and 4 were caries-free (only 2 genotypes). Conclusion. Our results support the previous findings of genetic diversity of S. mutans in preschool children being associated with dental caries. The investigation of such populations may be important for directing the development of programs for caries prevention worldwide.

Dexamethasone influences endocrine and ovarian function in dairy cattle.

Multiparous nonlactating Holstein cows were used to determine the effect of dexamethasone on ovarian follicular development and plasma hormone concentrations. Animals were randomly divided into two groups, control (C; n = 5) and treatment (T; n = 6), but managed as one group. Both groups were synchronized with two injections of PGF2alpha (25 mg i.m.) 11 d apart. One day after ovulation (d 0) the T group received a daily injection of dexamethasone (44 microg/kg of body weight; i.m.) until the first dominant follicle stopped growing or up to d 12 postovulation. The C group received vehicle injections. Blood samples were collected daily from all cows. Concentrations of LH and FSH did not differ between the C and T cows, whereas progesterone concentrations were lower in T than in C cows from d 4 onward. Treatment x day interaction influenced plasma insulin concentrations such that T cows had insulin concentrations 2.9- to 6.0-fold those of C cows between d 2 and 9. Dexamethasone decreased IGF-I and -II concentrations from d 5 onward. Concentrations of plasma leptin and the various IGF binding proteins were not affected by dexamethasone. Total number of follicles (> or = 5 mm) and plasma estradiol concentrations were less in T than in C cows on d 0, 1, and 4. The growth rate of the dominant follicles and maximum diameter of the dominant and subordinate follicles were not affected by dexamethasone. The diameter of the CL was 21 to 39% larger in T than in C cows between d 6 and 10. Treatment x day interaction influenced plasma cholesterol concentrations such that cholesterol levels decreased 46.8% in T cows and 19.5% in C cows between d 0 and 10. Plasma glucose concentrations were greater in T than in C cows between d 1 and 10. In summary, dexamethasone had significant effects on metabolism without a major impact on growth of the first-wave dominant follicle. Dexamethasone-induced suppression of luteal function was associated with decreased plasma IGF-I and -II concentrations.

The relationship between sweetness preference and dental caries in mother/child pairs from Maringá-Pr, Brazil.

AIM: Children's patterns of sugar consumption and dental health status have been associated to their mothers' patterns. As a liking for sweetness has been related to caries levels, this study was carried out to analyse the relationship between sweetness preference and caries experience in mother/child pairs. PARTICIPANTS AND METHODS: A cross-sectional survey was conducted on a sample of low socio-economic mothers and their 4-5-year-olds from Maringá-Pr, Brazil. Mothers' and children's preference for sugar was measured using the Sweet Preference Inventory. Their caries experience was assessed according to World Health Organization (WHO) guidelines. RESULTS: High levels of sweetness preference and caries experience were found in the sample studied. Although not strong, a significant correlation in patterns of sweetness preference (r=0.12, P<0.05) and caries experience (r=0.14, P<0.05) between mother/child pairs was identified. Among the social-demographic variables, only family income was statistically associated with the children's preference for sweetness (P<0.05). No significant association between sweetness preference and caries experience could be established. CONCLUSION: The findings of this study suggest that mothers may play an important role on the establishment of their children dietary preferences and patterns of dental health. Also, that the socio-economic status may influence children's preference for sugar.

The relationship between sweetness preference, levels of salivary mutans streptococci and caries experience in Brazilian pre-school children.

AIM: To analyse the relationship between preference for sweetness, levels of salivary mutans streptococci and levels of caries in low socio-economic 4-5-year-old Brazilian children. DESIGN: A cross-sectional survey. SUBJECTS AND METHODS: 298 children of both sexes, who, in 1998, were regularly attending public nurseries were randomly selected. Caries experience was assessed according to WHO guidelines. Saliva samples were analysed for mutans streptococci using the spatula method. Children's preference for sugar was measured using the 'Sweet Preference Inventory'. Personal interviews with the mothers were conducted. RESULTS: 255 children completed all aspects of the research, a response rate of 85.6%. 34.9% of them were caries-free. The mean dmf-s was 4.25 (SD 6.16), the decayed component being 3.56 (SD 5.82) and the filled surfaces, 0.69 (SD 1.85). For these pre-school children; male sex (P < 0.01), single parent (P < 0.01), habit of eating or drinking items that contained non-milk extrinsic sugar between meal times (P < 0.05) and high levels of salivary mutans streptococci (P < 0.001) were significantly associated with higher dmfs scores. There was no statistical relationship between sweetness preference and dental caries and with mutans streptococci levels. CONCLUSION: Levels of salivary mutans streptococci but not sweetness preference were potential good predictors of caries experience among 4-5 year-old-children living in urban area of Brazil.