Women with TT genotype for eNOS gene are more responsive in lowering blood pressure in response to exercise

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Autonomic control of cardiorespiratory interactions in fish, amphibians and reptiles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Autonomic control of heart rate is virtually independent of temperature but seems related to the neuroanatomy of the efferent vagal supply to the heart in the bullfrog, Lithobathes catesbeianus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ex vivo evaluation of the effectiveness of bleaching agents on the shade alteration of blood-stained teeth

Aim To evaluate ex vivo effectiveness of the three formulations of bleaching materials for intracoronal bleaching of root filled teeth using the walking bleach technique.Methodology Extracted premolar teeth were stained artificially with human blood. After biomechanical preparation, the root canals were filled and a 3-mm thick intermediate base of zinc phosphate cement was placed at the level of the cementoenamel junction. The teeth were divided into four groups (n = 12): C (control, without bleaching material), A1 (sodium perborate + distilled water), A2 (sodium perborate + 10% carbamide peroxide) and A3 (sodium perborate + 35% carbamide peroxide). The bleaching materials were changed at 7 and 14 days. Evaluation of shade was undertaken with aid of the VITA Easyshade (TM) (Delta E*ab) and was performed after tooth staining and at 7, 14 and 21 days after bleaching, based on the CIELAB system. Data were analysed by ANOVA for repeated measurements, Tukey and Dunnett tests (alpha = 0.05).Results The Tukey test revealed that group A1 (10.58 +/- 4.83 Delta E*ab) was statistically different from the others (A2, 19.57 +/- 4.72 Delta E*ab and A3, 17.58 +/- 3.33 Delta E*ab), which were not different from each other. At 7 days: A1 was significantly different from A2; at 14 and 21 days: A2 and A3 were significantly better than A1; the Dunnett test revealed that the control group was different from A1, A2 and A3 at all periods (P < 0.05).Conclusion Sodium perborate associated with both 10% and 35% carbamide peroxide was more effective than when associated with distilled water.

Interaction between paraventricular nucleus and septal area in the control of physiological responses induced by angiotensin II

We determined the effects of losartan (40 nmol) and PD 123319 (40 nmol) (both non-peptides and selective antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar¹, Ala8] angiotensin II (ANG II) (40 nmol) (a non-selective peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on the water and salt appetite, diuresis and natriuresis and mean arterial pressure (MAP) induced by administration of 10 nmol of ANG II into the medial septal area (MSA) of male Holtzman rats weighing 250-300 g. The volume of drug solution injected was 0.5 µl over a period of 10-15 s. The responses were measured over a period of 120 min. ANG II alone injected into the MSA induced an increase in all the above parameters (8.1 ± 1.2, 1.8 ± 0.3, and 17.1 ± 1.0 ml, 217 ± 25 µEq/120 min, and 24 ± 4 mmHg, respectively, N = 10-12) compared with vehicle-treated rats (1.4 ± 0.2, 0.6 ± 0.1, and 9.3 ± 0.5 ml, 47 ± 5 µEq/120 min, and 4.1 ± 0.8 mmHg, respectively, N = 10-14). Pretreatment with losartan and [Sar¹, Ala8] ANG II completely abolished the water and sodium intake, and the pressor increase (0.5 ± 0.2, 1.1 ± 0.2, 0.5 ± 0.2, and 0.8 ± 0.2 ml, and 1.2 ± 3.9, 31 ± 4.6 mmHg, respectively, N = 9-12), whereas losartan blunted the urinary and sodium excretion induced by ANG II (13.9 ± 1.0 ml and 187 ± 10 µEq/120 min, respectively, N = 9). Pretreatment with PD 123319 and [Sar¹, Ala8] ANG II blocked the urinary and sodium excretion (10.7 ± 0.8, 9.8 ± 0.7 ml, and 67 ± 13 and 57 ± 17 µEq/120 min, respectively, N = 9), whereas pretreatment with PD 123319 partially blocked the water and sodium intake, and the MAP induced by ANG II administration (2.3 ± 0.3, 1.1 ± 0.1 ml, and 12 ± 3 mmHg, respectively, N = 9-10). These results suggest the angiotensinergic effect of the MSA on the AT1 and AT2 receptors of the PVN in terms of water and sodium homeostasis and MAP modulation.

Association between diastolic blood pressure and cumulative work time

A pressão arterial diastólica foi analisada enquanto indicador genérico de envelhecimento, e sua associação com o tempo de serviço foi estudada após o controle da idade como possível fator de confundimento. O estudo foi realizado entre operários de um curtume brasileiro em julho de 1993. Foi testada a associação entre pressão diastólica e tempo de serviço, ajustando um modelo de regressão linear de segunda ordem, em que a pressão diastólica era função da idade e do tempo de serviço do operário. Ao ajustar o modelo, pode-se prever que, no início do trabalho no curtume, em média, cada período de um ano está associado com um aumento de cerca de 1,5 mmHg na pressão diastólica. O ajuste obtido realça um componente diretamente associado ao trabalho como parte do coeficiente de aumento da pressão no grupo estudado. Esse componente é o dobro daquele diretamente associado com a idade.

Control of breathing in anuran amphibians

The primary role of the respiratory system is to ensure adequate tissue oxygenation, eliminate carbon dioxide and help to regulate acid-base status. To maintain this homeostasis, amphibians possess an array of receptors located at peripheral and central chemoreceptive sites that sense respiration-related variables in both internal and external environments. As in mammals, input from these receptors is integrated at central rhythmogenic and pattern-forming elements in the medulla in a manner that meets the demands determined by the environment within the constraints of the behavior and breathing pattern of the animal. Also as in mammals, while outputs from areas in the midbrain may modulate respiration directly, they do not play a significant role in the production of the normal respiratory rhythm. However, despite these similarities, the breathing patterns of the two classes are different: mammals maintain homeostasis of arterial blood gases through rhythmic and continuous breathing, whereas amphibians display an intermittent pattern of aerial respiration. While the latter is also often rhythmic, it allows a degree of fluctuation in key respiratory variables that has led some to suggest that control is not as tight in these animals. In this review we will focus specifically on recent advances in studies of the control of ventilation in anuran amphibians. This is the group of amphibians that has attracted the most recent attention from respiratory physiologists. (c) 2006 Elsevier B.V. All rights reserved.

Vagal control of heart rate and cardiac shunts in reptiles: Relation to metabolic state

The vagus is clearly of primary importance in the regulation of reptilian cardiorespiratory systems. Vagal control of pulmonary blood flow and cardiac shunts provides reptiles with an additional means of regulating arterial oxygen levels that is not present in endothermic vertebrates (birds and mammals). Within a given species, there exists a clear correlation between withdrawal of vagal tone on the cardiovascular system and elevated metabolic rate. Undisturbed and resting reptiles are normally characterised by high vagal tone, low pulmonary blood flow and large right-left (R-L) cardiac shunts. The low oxygen levels that result from the large R-L shunt may serve to regulate metabolism. However, when metabolism is increased by temperature, exercise or digestion, the R-L cardiac shunt is reduced, which serves to increase oxygen delivery. This response is partially elicit ed by reduction of vagal tone. Interspecies comparisons reveal a similar pattern. Thus, species that are able to sustain the highest metabolic rates possess the highest degree of anatomical ventricular separation and, therefore, less cardiac shunting. It is interesting to note that when cardiac shunts occur in mammals, due for example to developmental defects, they are associated with reduced maximal metabolic rates and impaired exercise tolerance. It appears, therefore, that full separation of ventricular blood flows was a prerequisite for the evolution of high aerobic metabolic rates and exercise stamina in mammals and birds.

Improvement of the Mo/TiO2-Al2O3 catalyst by the control of the sol-gel synthesis

Traditional hydrotreating catalysts are constituted by molybdenum deposited on Al2O3 promoted by nickel and phosphorous. Several studies have shown that TiO2-Al2O3 mixed oxides are excellent supports for the active phases. Results concerning the preparation, characterization and testing of molybdenum catalyst supported on titania-alumina are presented. The support was prepared by sol-gel route using titanium and aluminum isopropoxides, the titanium one chelated with acetylacetone (acac) to promote similar hydrolysis ratio for both the alcoxides. The effect of nominal molar ratio [Ti]/[Ti+Al] on the microstructural features of nanometric particles was analyzed by X-Ray Diffraction, N-2 Adsorption Isotherms and Transmission Electron Microscopy. The catalytic activity of Mo impregnated supports was evaluated using the thiophene hydrodesulfurization at different temperatures and atmospheric pressure. The pores size distribution curve moves from the micropores to the mesopores by increasing the Ti contents, allowing the fine tuning of average size from 2.5 to 6 nm. Maximal (367 m(2).g(-1)) and minimal (127 m(2).g(-1)) surface area were found for support containing [Ti]/[Ti+Al] ratio equal to 0.1 and 1, respectively. The good mesopore texture of alumina-titania support with [Ti]/[Ti+Al] molar ratio between 0.3 and 0.5 was found particularly valuable for the preparation of well dispersed MoS2 active phase, leading to HDS catalyst with somewhat higher activity than that prepared using a commercial alumina support.

Application of low-pressure gas chromatography-ion-trap mass spectrometry to the analysis of the essential oil of Turnera diffusa (Ward.) Urb.

Turnera diffusa Willd. var. afrodisiaca (Ward) Urb. (syn. T. aphrodisiaca) belongs to the family of Turneraceae and is an aromatic plant growing wild in the subtropical regions of America and Africa. It is widely used in the traditional medicine as e.g. anti-cough, diuretic, and aphrodisiac agent. This work presents a 3 min chromatographic analysis using low-pressure (LP) gas chromatography (GC)-ion-trap (IT) mass spectrometry (MS). The combination of a deactivated 0.6 m x 0.10 mm i.d., restrictor with a wide-bore CP-Wax 52 capillary column (10 m x 0.53 mm i.d., 1 mum) reduces the analysis time by a factor of 3-7 in comparison to the use of a conventional narrow bore column. Chromatographic conditions have been optimized to achieve the fastest separation with the highest signal/noise ratio in MS detection. These results allow fast and reliable quality control of the essential oil to be achieved. (C) 2003 Elsevier B.V. All rights reserved.

Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

Background: Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances.Methods/Design: An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow.Discussion: Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers.

Influence of lateral pressure to the implant bed on osseointegration: an experimental study in dogs

AimTo study osseointegration and bone-level changes at implants installed using either a standard or a reduced diameter bur for implant bed preparation.Material and methodsIn six Labrador dogs, the first and second premolars were extracted bilaterally. Subsequently, mesial roots of the first molars were endodontically treated and distal roots, including the corresponding part of the crown, were extracted. After 3 months of healing, flaps were elevated and recipient sites were prepared in all experimental sites. The control site was prepared using a standard procedure, while the test site was prepared using a drill with a 0.2 mm reduced diameter than the standard one used in the contra-lateral side. After 4 months of healing, the animals were euthanized and biopsies were obtained for histological processing and evaluation.ResultsWith the exception of one implant that was lost, all implants were integrated in mineralized bone. The alveolar crest underwent resorption at control as well as at test sites (buccal aspect similar to 1 mm). The most coronal contact of bone-to-implant was located between 1.2 and 1.6 mm at the test and between 1.3 and 1.7 mm at the control sites. Bone-to-implant contact percentage was between 49% and 67%. No statistically significant differences were found for any of the outcome variables.ConclusionsAfter 4 months of healing, lateral pressure to the implant bed as reflected by higher insertion torques (36 vs. 15 N cm in the premolar and 19 vs. 7 N cm in the molar regions) did not affect the bone-to-implant contact.To cite this article:Pantani F, Botticelli D, Garcia IR Jr., Salata LA, Borges GJ, Lang NP. Influence of lateral pressure to the implant bed on osseointegration: an experimental study in dogs.Clin. Oral Impl. Res. 21, 2010; 1264-1270.doi: 10.1111/j.1600-0501.2009.01941.x.