The purpose of this study was to determine Brazilian dentists' knowledge of emergency management of dento-alveolar trauma. A two-part questionnaire containing questions on demographic data and knowledge were mailed to 230 general dental practitioners (GDPs) and 70 endodontists. Questionnaires were returned by 42.6% of the GDPs and 62.8% of the endodontists. The survey data were statistically analyzed using Mann-Whitney U-test for practitioners' knowledge and Pearson's correlation coefficient for association between knowledge scores and practitioner age or years since graduation. The mean knowledge score of endodontists was significantly greater than for GDPs (P<0.0001). Dentists with trauma experience in their practices and those who had attended postgraduate courses on dental trauma had a significant higher mean knowledge score. In contrast, there was a poor correlation between the knowledge score and the ages of the respondents (r=0.086) or the years since graduation (r=0.108). In conclusion, this survey showed a poor knowledge of dental trauma management among the surveyed dentists and highlights the need to develop strategies to improve the knowledge base in this area of dentistry for the benefit of the dental trauma patient.

-The present study assessed the possible involvement of the renin-angiotensin system (RAS) and the sympathetic nervous system (SNS) in thyroxine (T 4)-induced cardiac hypertrophy. Hemodynamic parameters, heart weight (HW), ratio of HW to body weight (HW/BW), and myocyte width were evaluated in absence of thyroid hormone (hypothyroidism) and after T 4 administration. Male Wistar rats were used. Some were subjected to thyroidectomies, whereas hyperthyroidism was induced in others via daily intraperitoneal injection of T 4 (25 or 100 g ⅐ 100 g BW Ϫ1 ⅐ day Ϫ1 ) for 7 days. In some cases, T4 administration was combined with the angiotensin I-converting enzyme inhibitor enalapril (Ena), with the angiotensin type 1 (AT1) receptor blocker losartan (Los) or with the ␤-adrenergic blocker propanolol (Prop). Hemodynamics and morphology were then evaluated. Systolic blood pressure (SBP) was not altered by administration of either T4 alone or T4 in combination with the specific inhibitors. However, SBP decreased significantly in hypothyroid rats. An increased heart rate was seen after administration of either T4 alone or T4 in combination with either Los or Ena. Although the higher dose of T 4 significantly increased HW, HW/BW increased in both T 4-treated groups. Ena and Prop inhibited the increase in HW or HW/BW in hyperthyroid rats. Morphologically, both T 4 dose levels significantly increased myocyte width, an occurrence prevented by RAS or SNS blockers. There was a good correlation between changes in HW/BW and myocyte width. These results indicate that T4-induced cardiac hypertrophy is associated with both the SNS and the RAS. cardiac myocytes; thyroid hormone; angiotensin-converting enzyme; angiotensin II receptors CHANGES IN HEMODYNAMIC LOADING appear to be an important stimulus for cardiac growth. However, dissociation between elevated arterial pressure and increased myocardial mass has been demonstrated in hypertensive cardiac hypertrophy in animals and humans (25). This dissociation suggests that, in addition to blood pressure, various stimuli are involved in the development and regression of cardiac hypertrophy (25). Over the past several decades, many neural and hormonal stimuli have been implicated in cardiac muscle growth, including, but not limited to, ␣-and ␤-adrenergic agonists, ANG II, glucocorticoids, insulin, growth hormone, glucagon, and thyroxine (T 4 ) (25).Mechanisms of cardiac hypertrophy produced by elevated T 4 include a direct effect of the hormone on the heart and indirect effects related to stimulation of the adrenergic nervous system or altered left ventricular loading conditions. Decreased systemic vascular resistance and the subsequent increase in cardiac work contribute to this T 4 -induced hypertrophy (15, 25). However, in support of a direct effect of thyroid hormone on heart growth, some authors have observed that T 4 -induced cardiac hypertrophy in isolated heart preparations is accompanied by increased (31) quantity and rate of protein and ribosome synthesis (33).It is well established t...

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Key Points Question Which cardiometabolic risk factors are associated with ambient air pollution in China? Findings In this population-based cross-sectional study including 15 477 Chinese adults, the strongest associations for exposure to air pollution were detected for individuals with hyperbetalipoproteinemia and the weakest associations for those with overweight or obesity. The metabolic risk factors may have exacerbated the associations of air pollutants with the prevalence of cardiovascular disease. Meaning These findings may help researchers, physicians, and policy makers evaluate the hazardous effects of air pollutants more completely and design targeted strategies for primary prevention of cardiovascular disease.