Relationship among salivary carbonic anhydrase VI activity and flow rate, biofilm pH and caries in primary dentition.

This study aimed to determine the activity of carbonic anhydrase isoenzyme VI (CAVI) in the saliva of preschool children with caries and to investigate the relationship between caries and salivary CAVI activity, salivary flow rate and biofilm pH before and after a 20% sucrose rinse. Thirty preschool children aged 45.3-80.3 months were divided into two groups: a caries-free group and a caries group. Clinical examinations were conducted by one examiner (κ = 0.95) according to WHO criteria (dmfs) and early caries lesions. From each subject, CAVI activity, salivary flow rate and plaque pH were determined before and after a sucrose rinse. The results were submitted to Wilcoxon, Mann-Whitney and Spearman correlation tests (α = 0.05). The results showed that prerinse CAVI activity and its variation were higher in the saliva from caries children than from caries-free children. No difference was found between the two groups in postrinse salivary CAVI activity. After rinsing, biofilm pH differences were lower in both groups (p = 0.0012 and p = 0.0037 for the caries and caries-free groups, respectively). Also, after the sucrose rinse, salivary flow rate significantly increased in caries and caries-free groups (p = 0.0003, p = 0.0037). The variation of salivary CAVI activity was negatively correlated with caries (r = -0.501, p = 0.005). Child's age showed a positive correlation with caries (r = 0.456, p = 0.011). These results suggest that variation of salivary CAVI activity and child's age are associated with dental caries in preschool children.

Association of polymorphisms in the carbonic anhydrase 6 gene with salivary buffer capacity, dental plaque pH, and caries index in children aged 7-9 years.

Carbonic anhydrase VI is a secreted enzyme that catalyzes the hydration of carbon hydroxide in saliva and other body fluids. This enzyme has been implicated in taste and gastrointestinal dysfunctions, tooth erosion, and caries. The purpose of this study was to analyze the allele and genotype distribution of three polymorphisms in the coding sequences of (CA6) gene and check for possible associations with salivary buffer capacity, number of decayed, missing, and filled teeth in deciduous and permanent teeth (dmft/DMFT, Decayed/Missing/Filled Teeth), plaque index (PI), and the plaque pH variation (DeltapH) in children aged 7-9 years. Two hundred and forty-five children from both genders, residents in area with fluoridated water (Piracicaba, São Paulo, Brazil) were divided into two groups: caries free and with caries. The clinical examinations were conducted by a single previously calibrated examiner (kappa=0.91) in an outdoor setting using a mirror and a probe, according to WHO criteria index (dmft/DMFT). Approximately 2 h after the first daily meal, the buffer capacity (BC) and the plaque pH were analyzed by means of a pH meter and an ion selective electrode. Plaque pH was measured immediately and 5 min after a mouth rinse with a 10% sucrose solution. The data were submitted to chi(2), Student's, and Mann-Whitney tests (alpha=0.05). The PI and DeltapH of the upper and lower teeth were significantly higher in the carious group than control (P<0.05). There was no difference between the groups in relation to BC. There was no association between the alleles and genotypes distributions for polymorphisms in the CA6 gene exons 2 and 3 and caries experience (P>0.05). There was a positive association between buffer capacity and the rs2274327 (C/T) polymorphism. The allele T and genotype TT were significantly less frequent in individuals with the highest buffer capacity (P=0.023 and 0.045, respectively). This finding encourages future studies relating CA6 gene polymorphisms and their association with malfunctions, such as taste and gastrointestinal alterations, or the differential effect of chemical modulators on the protein products originated from the distinct genotypes of the CA6 gene.

Mutans streptococci oral colonization in 12-30-month-old Brazilian children over a one-year follow-up period.

OBJECTIVES: The infection levels of mutans streptococci were investigated during a one-year follow-up in children aged 12 to 30 months attending school nurseries where a sucrose-rich diet was provided. METHODS: Oral levels of mutans streptococci obtained from 101 children at baseline and after a one-year follow-up were compared by age, number of teeth, feeding habits, and presence of visible plaque at baseline. Baseline predictors and changes in mutans streptococci levels during the study were compared to caries incidence after one year. RESULTS: Fluctuations in mutans streptococci levels during the follow-up period were not related to feeding habits or presence of visible plaque. Mutans streptococci levels increased after one year among children aged 12 to 24 months, while a significantly higher proportion of those aged 25-30 months showed a decrease in mutans streptococci levels during the study. Multiple logistic regression analysis suggested that high levels of mutans streptococci (> or = 100 cfu) at baseline were associated with a higher caries increment, while reduction in mutans streptococci was negatively associated with caries incidence. CONCLUSIONS: Our data suggest that despite early mutans streptococci infection and high exposure to sucrose, mutans streptococci may achieve relatively stable levels after 2 years of age. Heavy colonization by mutans streptococci in an early age was related to an extremely high caries incidence during childhood, while decreasing levels of mutans streptococci can be associated to the decrease in caries activity.

Efeito de uma mistura de valepotriatos na resposta de ansiedade induzida em voluntários submetidos a uma situaçäo de estresse psicológico / Effect of valepotriate in the response of induced anxiety in volunteers submitted to a psychological stressing situation

Três grupos de voluntários, após assinatura de um termo de consentimento de participaçäo em experimento, foram submetidos a minucioso exame clínico e complementar de laboratório, bem como a uma entrevista, para se determinar qualquer alteraçäo física ou psíquica que fosse impeditiva de participaçäo no experimento. Receberam, respectivamente, por via oral, placebo, diazepam (5mg) ou Valmane (50mg), em intervalos de 8 horas aproxidamente, iniciando-se o tratamento no dia anterior ao teste, sendo a última dose administrada duas horas antes do procedimento de eliciaçäo de ansiedade, o Stroop-Color Word Test filmado (VRSCWT). A resposta de ansiedade eliciada pela situaçäo foi avaliada pelo Inventário de Ansiedade Traço-Estado de Spielberger. Os valores de ansiedade durante e após a situaçäo de teste, no grupo tratado com Valmane, näo diferiram dos valores-controle ou dos do grupo tratado com diazepam. Os resultados sugerem que o Valmane, na dose utilizada, apresenta, na situaçäo do teste de eliciaçäo de ansiedade, tendência a uma açäo semelhante ao do diazepam, apesar de menos potente. Os resultados mostraram ainda que o diazepam foi eficaz em impedir o aumento de ansiedade eliciado pela situaçäo de teste