Parathyroid hormone has an important role in blood pressure regulation in vitamin D–insufficient individuals

ObjectiveThe aim of the present study was to evaluate whether vitamin D status is related to blood pressure (BP) in adults.MethodsWe evaluated the relationship between vitamin D status, intact parathyroid hormone (iPTH) and BP in 332 adults. Anthropometric measurements, BP, and a fasting blood sample was obtained. Participants were stratified into the following BP categories: 1) normal BP; 2) high BP; 3) normal BP through medication. Vitamin D insufficiency was defined as 25-hydroxvitamin D ≤ 75 nmol/L; high iPTH as > 65 pg/mL. The relationships between vitamin D status, iPTH and BP were adjusted for body mass index, waist circumference, blood lipids, physical activity, and sunscreen use.ResultsNo differences in prevalences of vitamin D insufficiency and high iPTH were observed among BP groups. No significant association was observed between BP and vitamin D status. Positive correlations were observed between iPTH and systolic BP (r = 0.168; P = 0.002) and between iPTH and diastolic BP (r = 0.168; P = 0.002). iPTH remained correlated with BP even with adjustments.ConclusionsThe present study contributes to the understanding of calcemic hormones and BP regulation.     

Urinary nickel as bioindicator of workers' Ni exposure in a galvanizing plant in Brazil

Objectives: We measured urinary nickel (U-Ni) in ten workers (97 samples) from a galvanizing plant that uses nickel sulfate, and in ten control subjects (55 samples) to examine the association between occupational exposure to airborne Ni and Ni absorption. Methods: Samples from the exposed group were taken before and after the work shift on 5 successive workdays. At the same time airborne Ni (A-Ni) was measured using personal samplers. Ni levels in biological material and in the airborne were determined by a graphite furnace atomic absorption spectrometry validated method. In the control group the urine samples were collected twice a day, in the before and after the work shift, on 3 successive days. Results: Ni exposure low to moderate was detected in all the examined places in the plant, the airborne levels varying between 2.8 and 116.7 μg/m³ and the urine levels, from samples taken postshift, between 4.5 and 43.2 μg/g creatinine (mean 14.7 μg/g creatinine). Significant differences in U-Ni creatinine were seen between the exposed and control groups (Student's t test, P ≤ 0.01). A significant correlation between U-Ni and A-Ni (r = 0.96; P ≤ 0.001) was detected. No statistical difference was observed in U-Ni collected from exposed workers in the 5 successive days, but significant difference was observed between pre- and postshift samples. Conclusions: Urinary nickel may be used as a reliable internal dose bioindicator in biological monitoring of workers exposed to Ni sulfate in galvanizing plants regardless of the day of the workweek on which the samples are collected. Received: 28 January 1999 / Accepted: 10 July 1999     

Women and contraception: knowledge and use of contraceptive methods

This article analyzes knowledge and use of contraceptive methods in women ages 10 to 49 years residing in the southern region of the city of S?o Paulo in 1992. A total of 1,157 childbearing-age women were studied, focusing on variables that might define them as to: knowledge in the use of contraceptive methods and reasons for choosing a given method. We observed that 86% of the women referred knowledge of some contraceptive method, while the most common was the pill (95.3%), followed by condoms (92.6%). Meanwhile, 14% of the interviewees denied knowledge of any contraceptive method. Of the sexually active women (66.4%), 34.9% reported never having used contraceptive methods. Of those who had, 35.3% used the pill, while 42.9% had resorted to sterilization. Only 5.2% used condoms. Despite the high level of knowledge concerning contraceptive methods, especially oral contraceptives and condoms, we observed limited use of same as compared to the high sterilization rate around the age of 27, thus leaving contraception limited to the pill and female sterilization.     

Role of nitric oxide and beta-adrenoceptors of the central nervous system on the salivary flow induced by pilocarpine injection into the lateral ventricle

Our studies have focused on the effect of L-NG-nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), and L-arginine, the substrate of NOS, on salivary secretion induced by the administration of pilocarpine into the lateral cerebral ventricle (LV) of rats. The present study has also investigated the role of the beta-adrenergic agonists and antagonist injected into LV on the salivary secretion elicited by the injection of pilocarpine into LV. Male Holtzman rats with a stainless-steel cannula implanted into the LV were used. The amount of salivary secretion was studied over a 7-min period after injection of pilocarpine, isoproterenol, propranolol, salbutamol, salmeterol, L-NAME and L-arginine. The injection of pilocarpine (10, 20, 40, 80 and 160 microg/microl) into LV produced a dose-dependent increase in salivary secretion. The injection of L-NAME (40 microg/microl) into LV alone produced an increase in salivary secretion. The injection of L-NAME into LV previous to the injection of pilocarpine produced an increase in salivary secretion. L-Arginine (30 microg/microl) injected alone into LV produced no change in salivary secretion. L-Arginine injected into LV attenuated pilocarpine-induced salivary secretion. The isoproterenol (40 nmol/microl) injected into LV increased the salivary secretion. When injected previous to pilocarpine at a dose of 20 and 40 microg/microl, isoproterenol produced an additive effect on pilocarpine-induced salivary secretion. The 40-nmol/microl dose of propranolol injected alone or previous to pilocarpine into LV attenuated the pilocarpine-induced salivary secretion. The injection of salbutamol (40 nmol/microl), a specific beta-2 agonist, injected alone into LV produced no change in salivary secretion and when injected previous to pilocarpine produced an increase in salivary secretion. The 40-nmol/microl dose of salmeterol, a long-acting beta-2 agonist, injected into LV alone or previous to pilocarpine produced no change in salivary secretion. The results have shown that central injections of L-NAME and L-arginine interfere with the salivary secretion, which implies that might participate in pilocarpine-induced salivary secretion. The interaction between cholinergic and beta-adrenergic receptors of the central nervous system (CNS) for the control of salivary secretion can also be postulated.     

View of the different social agents on the social participation in the health system in northeastern Brazil. A qualitative approximation

BACKGROUND: Social participation in the health system constitutes one of the basic principles of Brazilian health sector reform. This paper analyses the concepts held by different groups of stakeholders with respect to social participation in health and identifies their opinions on hindering and enabling factors for this participation. METHODS: A qualitative study was conducted using individual interviews (II) and focus groups (FG) with different groups of stakeholders: 135 users (II, GF), 14 community leaders (II, GF), 12 Municipal Health Council (MHC) members (II), 8 policymakers and (II) 37 health personnel (II, GF) were interviewed. A narrative content analysis of the results was conducted. Two municipalities in North-eastern Brazil, Cabo de Santo Agostinho and Camaragibe, made up the area of study. RESULTS: In all groups, a distinction between individual and group participation emerged and reached different levels of elaboration. Many informants' ideas described also their own ways of action. Individual participation concepts and the utilization of health services were predominant among users. Population and institutional factors were identified as obstacles to participation: users and community leaders referred both type of factors, while the health personnel and MHC members put more emphasis on the former. Some informants among the health personnel did not identify any barriers. Policymakers emphasised the lack of political will. The enabling factors mentioned reflected the same logic. CONCLUSIONS: Concepts and perceived hindering factors to participation which were described appear to show different ways of interaction among the diverse stakeholders and the health services. The results point towards a limited effect of the health policy on social participation. Elements that could contribute to an improvement are identified.     

The hypothalamic paraventricular nucleus and carotid receptors modulate hyperglycemia induced by hemorrhage

The aim of this study was to assess the role of cholinergic transmission in the paraventricular nucleus of the hypothalamus (PVN) and carotid body receptors in mediating a rise in plasma glucose levels in response to hemorrhagic hypotension in rats. Methylatropine (1x10(-9) mol) or 0.15 M NaCl (0.2 microl) was injected into the PVN of Wistar rats weighing 250-300 g bearing a chronic jugular catheter for blood sampling and hemorrhage (1.2 ml/100 g/2 min). Polyethylene cannulae (PE-10) were inserted into the left femoral artery for cardiovascular monitoring. In the other experimental protocol, hemorrhage was performed on rats submitted to bilateral carotid receptor denervation (H-CD). The results show that the hyperglycemic response to hemorrhage was decreased by either methylatropine (H-MA) treatment or bilateral carotid receptor denervation (10.3+/-0.4 mM, control, n=15 vs. 7.7+/-0.2 mM, H-MA, n=12, and 7.6+/-0.3 mM, H-CD, n=5, p<0.01). Furthermore, methylatropine did not affect the recovery of blood pressure after hemorrhage-induced hypotension, suggesting that the metabolic and pressor adjustments have different efferent pathways. Our data demonstrate that cholinergic input from the PVN and carotid receptors (chemo- and/or baroreceptors) might participate in the same neural pathway activated by hemorrhage-induced hypotension that produces hyperglycemia.     

MG2 and lactoferrin form a heterotypic complex in salivary secretions

Protein-protein interactions are necessary for homeostasis to be maintained and for biological systems to be integrated. Heterotypic complexes occur in saliva, and a complex between MG2 and SIgA has been suggested to promote microbial clearance from the oral cavity. In this study, we used a peptide display library to investigate previously unrecognized heterotypic complexes involving MG2 and other proteins. The library was panned with MG2 12 times, and analyses of clones identified the sequence Ala-Leu-Leu-Cys-, which occurs in salivary lactoferrin. Blotting experiments confirmed that MG2 and lactoferrin form a heterotypic complex in vitro and in vivo. Periodate treatment of MG2 did not affect the interaction. A synthetic lactoferrin peptide containing the motif Ala-Leu-Leu-Cys-blocked the interaction between MG2 and lactoferrin, confirming the specificity of the interaction identified by panning. This complex may enhance the properties of these salivary components in the oral environment.