Socio-environmental determinants of the delay in the first dental visit: results of two population-based cohort studies in Brazil

The objective of this study was to describe the timing of the first dental visit and investigate the association of socioeconomic and behavioral factors with dental visit delay among 10/11-year-old children from two live-birth population cohorts with extremely contrasting socioeconomic profiles. Follow-up data (2004-2005) from cohorts of Ribeirão Preto (RP) (n=790) and São Luís (SL) (n=673) were evaluated. Delay in dental visit was defined as not visiting a dentist before the age of 7. Covariates included family socioeconomic characteristics, mother-related health behavior, and child-related characteristics. Prevalence ratios with robust standard errors were estimated. In both cohorts, less than 5% of children had visited a dentist before the age of two and about 35% of them had not visited a dentist before the age of seven. Lower mother's schooling and lack of private health insurance were associated with the delay in first dental visit for both cohorts. A small number of mother's prenatal care visits and being from a single-father family or a family without parents were only associated in the RP cohort, while having ≥4 siblings and lifetime dental pain were associated in the SL cohort. The association with dental pain probably reveals a preventive care-seeking behavior. Therefore, the percentage of delayed first dental visit of children was very high even among those with the most educated mothers. Further studies are necessary to analyze recent changes and underlying factors related to access to first dental visit after the implementation of the National Oral Health Policy in 2006.

Birth by cesarean section and mood disorders among adolescents of a birth cohort study in northern Brazil

The increasing number of cesarean sections worldwide has encouraged research on the long-term effects of this birth type on the offspring's mental health. The objective of this study was to investigate whether there is an association between birth by cesarean section and the development of mood disorders (depression and bipolar disorders) in adolescents. A cohort study was carried out with 1603 adolescents from 18 to 19 years old who participated in the third phase of a birth cohort study in São Luís, MA, in 2016. Information on birth type and weight, prematurity, mother's age and schooling, parity, marital status, and smoking behavior during pregnancy, were collected at birth. The study outcomes were depression, bipolar disorder, and "mood disorder" construct. A Directed Acyclic Graph (DAG) was developed to select the variables for minimal adjustment for confounding and collision bias. Associations were estimated through propensity score weighting using a two-step estimation model, and confounders for cesarean birth were used in the predictive model. There was no significant association in the relationship between birth type and depression (95%CI: -0.037 to 0.017; P=0.47), bipolar disorder (95%CI: -0.019 to 0.045; P=0.43), and mood disorder (95%CI: -0.033 to 0.042; P=0.80) in adolescents of both sexes. Birth by cesarean section was not associated with the development of mood disorders in adolescents.

Paraventricular nucleus administration of DuP753 or PD123319 inhibits the effects of angiotensin on water and sodium intake

We determined the effects of DuP753 and PD123319 (both nonpeptides and selective antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar(l), Ala(8)]ANG II (a non-selective peptide antagonist of angiotensin receptors)on water and 3 per cent NaCl intake induced by administration of angiotensin II (ANG II) into the paraventricular nucleus (PVN) of sodium-depleted Holtzman rats weighing 250-300 g. Twenty hours before the experiments, the rats were depleted of sodium using furosemide (10 ng/rat, sc). The volume of drug solution injected was 0.5 mul over a period of 10-15 sec. Water and sodium intake were measured at 0.25, 0.5, 1.0 and 2.0 h. Pre-treatment with DuP753 (l4 rats) at a dose of 60 ng completely abolished the water intake induced by injection of 12 ng of ANG II (15 rats) (6.4 ñ 0.6 vs 1.4 ñ 0.3 ml/2 h), whereas [Sar(l), Ala(8)]ANG II (l2 rats) and PDl23319 (10 rats) at the doses of 60 ng partially blocked water intake (6.4 ñ 0.6 vs 2.9 ñ 0.5 and 2.7 ñ 0.2 ml/2 h, respectively). In the same animals, [Sar(l), Ala(8)]ANG II, DuP753, and PDl23319 blocked the sodium intake induced by ANG II (9.2 ñ 1.6 vs 3.3 ñ 0.6, 1.8 ñ 0.3, and 1.4 ñ 0.2 ml/2 h, respectively). These results indicate that both DuP753 and PD123319, administered into the PVN, blocked the water and sodium intake induced by administration of ANG II into the same site.

Progesterone administration to ovariectomized rats reduces water and salt intake induced by central administration of angiotensin II

We tested the effects of estradiol, progesterone and testosterone on water and salt intake induced by angiotensin II (ANG II) injected into the third ventricle of female Holtzman rats weighing 250-300 g. The water and salt ingestion observed after 120 min in the control experiments (injection of 0.5µl of 0.15 M NaCl into the third ventricle) was 1.6 ñ 0.3 ml (N = 10) and 0,3 ñ 0.1 ml (N = 8) in intact rats, respectively, and 1.4 ñ 0.3 ml (N = 10) and 0.2 ñ 0.1 (N = 8) in ovariectomized rats, respectively. ANG II injected in intact rats (4, 6, 12, 25, and 50 ng, icv, in 0,5 µl saline) induced an increase in water intake (4.3 ñ 0.6, 5.4 ñ 0.7, 7.8 ñ 0.8, 10.4 ñ 1.2, 11.2 ñ 1.4 ml/120 min, respectively) ( N = 43). The same doses of icv ANG II in intact increased the 3 per cent NaCl intake (0.9 ñ 0,2, 1.4 ñ 0,3, 2,3 ñ 0.4, 2,2 ñ 0,3, and 2.5 ñ 0.4 ml/120 min, respectively) (N = 42). When administered to ovariectomized rats ANG II induced comparable amounts of water intake (4.0 ñ 0.5, 4.8 ñ 0.6 ñ 0.7, 9.6 ñ 0.8, and 10.9 ñ 1.2 ml/120 min, respectively (

Interaction between cholinergic and opiate receptors of the lateral hypothalamus in the control of renal excretion in rats

The present study was carried out to investigate the participation and interaction between cholinergic and opiate receptors of the lateral hypothalamus (LH) in the regulation of Na+, K+ and water excretion. Malew Holtzman rats were implanted with chronic cerebral cannulas into the LH. Urine was collected over a period of 2h after injection of carbachol, FK-33824 + carbachol or naloxone + carbachol into the LH. Carbachol (8nmol) reduced urinary volume and increased Na + excretion. Previous injection of FK-333824(100ng) into the LH increased the antidiuretic effect of carbachol, but blocked the increase in Na+ excretion and decreased K+ excretion. Naloxone. Naloxone (10microng) produced no changes in the effect of carbacho9l on renal excretion. These data show an inhibitory effect of opiate receptors on the changes in urinary Na+ and K+ excretion that are induced by chronergic stimulation of the LH in rats, and a potentiating effect on antidiuresis