Reversal of Postprandial Endothelial Dysfunction by Cyclooxygenase Inhibition in Healthy Volunteers

The aim of this study was to evaluate the role of cyclooxygenase (COX) in venous vascular reactivity changes after an oral lipid overload (OLO). Venous endothelial function (dorsal hand vein technique) was evaluated in fasting, 30 minutes after COX inhibition (aspirin-fasting), 2 to 4 hours after an OLO (1000 kcal, 58% fat), and again after COX inhibition (aspirin-OLO, 600 mg/200 mL water) in 10 healthy adults (age, 28.1 +/- 1.3 years; body mass index, 22.3 +/- 0.6 kg/m(2)). Fasting, 2- to 4-hour post-OLO, and 60-minute postaspirin plasma glucose, insulin, and lipids were also evaluated. The OLO increased triglycerides and insulin, reduced low-density lipoprotein and high-density lipoprotein, but glycemia and total cholesterol remained unchanged. There were no metabolic differences between OLO and aspirin-OLO. In fasting, aspirin reduced acetylcholine-induced venodilation (107.0% +/- 14% versus 57.3% +/- 11%; P < 0.001). Vascular reactivity was blunted after the OLO (phenylephrine dose: 0.3 +/- 0.2 fasting versus 1.9 +/- 0.8 nmol/min after OLO; P < 0.001) and was partially corrected by aspirin (0.4 +/- 0.2; P < 0.001). Similar changes were observed in maximum venodilation after acetylcholine (107.0% +/- 14% fasting versus 60.4% +/- 9% after OLO, P < 0.001; aspirin-OLO: 95.9% +/- 6%; P < 0.001). The responses to sodium nitroprusside remained unchanged during the study. We conclude that the OLO reduction in the endothelium-dependent venoconstruction and venodilation is partially the result of the action of COX.

Vascular endothelial growth factor (VEGF) and VEGF-receptor expression in placenta of hyperglycemic pregnant women

Hyperglycemia occurs in a variety of conditions such as overt diabetes, gestational diabetes and mild hyperglycemia, all of which are generally defined based on the oral glucose tolerance test and glucose profiles. Whereas diabetes has received considerable attention in recent decades, few studies have examined the mechanisms of mild hyperglycemia and its associated disturbances. Mild gestational hyperglycemia is associated with macrosomia and a high risk of perinatal mortality. Morphologically, the placenta of these women is characterized by an increase in the number of terminal villi and capillaries, presumably as part of a compensatory mechanism to maintain homeostasis at the maternal-fetal interface. In this study, we analised the expression of VEGF and its receptors VEGFR-1 (Flt-1) and VEGFR-2 (KDR) in placentas from mildly hyperglycemic women. This expression was compared with that of normoglycemic women and women with gestational and overt diabetes. Immunohistochemistry revealed strong staining for VEGF and VEGFR-2 in vascular and trophoblastic cells of mildly hyperglycemic women, whereas the staining for VEGFR-1 was discrete and limited to the trophoblast. The pattern of VEGF and VEGF-receptor reactivity in placentas from women with overt diabetes was similar to that of normoglycemic women. In women with gestational diabetes, strong staining for VEGFR-1 was observed in vascular and trophoblastic cells whereas VEGF and VEGFR-2 were detected only in the trophoblast. The expression of these proteins was confirmed by western blotting, which revealed the presence of an additional band of 75 kDa. In the decidual compartment, only extravillous trophoblast reacted with all antibodies. Morphological analysis revealed collagen deposition around large arteries in all groups with altered glycemia. These findings indicate a placental response to altered glycemia that could have important consequences for the fetus. The change in the placental VEGF/VEGFR expression ratio in mild hyperglycemia may favor angiogenesis in placental tissue and could explain the hypercapillarization of villi seen in this gestational disturbance. (C) 2010 Elsevier Ltd. All rights reserved.

Retinoic Acid and VEGF Delay Smooth Muscle Relative to Endothelial Differentiation to Coordinate Inner and Outer Coronary Vessel Wall Morphogenesis

Rationale: Major coronary vessels derive from the proepicardium, the cellular progenitor of the epicardium, coronary endothelium, and coronary smooth muscle cells (CoSMCs). CoSMCs are delayed in their differentiation relative to coronary endothelial cells (CoEs), such that CoSMCs mature only after CoEs have assembled into tubes. The mechanisms underlying this sequential CoE/CoSMC differentiation are unknown. Retinoic acid (RA) is crucial for vascular development and the main RA-synthesizing enzyme is progressively lost from epicardially derived cells as they differentiate into blood vessel types. In parallel, myocardial vascular endothelial growth factor (VEGF) expression also decreases along coronary vessel muscularization. Objective: We hypothesized that RA and VEGF act coordinately as physiological brakes to CoSMC differentiation. Methods and Results: In vitro assays (proepicardial cultures, cocultures, and RALDH2 [retinaldehyde dehydrogenase-2]/VEGF adenoviral overexpression) and in vivo inhibition of RA synthesis show that RA and VEGF act as repressors of CoSMC differentiation, whereas VEGF biases epicardially derived cell differentiation toward the endothelial phenotype. Conclusion: Experiments support a model in which early high levels of RA and VEGF prevent CoSMC differentiation from epicardially derived cells before RA and VEGF levels decline as an extensive endothelial network is established. We suggest this physiological delay guarantees the formation of a complex, hierarchical, tree of coronary vessels. (Circ Res. 2010;107:204-216.)

Effect of insertion method on knoop hardness of high viscous glass ionomer cements

The aim of this study was to assess the Knoop hardness of three high viscous glass ionomer cements: G1 - Ketac Molar; G2 - Ketac Molar Easymix (3M ESPE) and G3 - Magic Glass ART (Vigodent). As a parallel goal, three different methods for insertion of Ketac Molar Easymix were tested: G4 - conventional spatula; G5 - commercial syringe (Centrix) and G6 - low-cost syringe. Ten specimens of each group were prepared and the Knoop hardness was determined 5 times on each specimen with a HM-124 hardness machine (25 g/30 s dwell time) after 24 h, 1 and 2 weeks. During the entire test period, the specimens were stored in liquid paraffin at 37ºC. Significant differences were found between G3 and G1/G2 (two-way ANOVA and Tukey's post hoc test; p<0.01). There was no significant difference in the results among the multiple ways of insertion. The glass ionomer cement Magic Glass ART showed the lowest hardness, while the insertion technique had no significant influence on hardness.

Changes in ruminal fermentation and mineral serum level in animals kept in high temperature environments

In order to evaluate the effect of environmental temperature on ruminal fermentation and on mineral levels of growing ruminants, it was used 12 male calves (initial average weight 82.9 ± 7.7 kg, 100 days of age), were employed in a randomized block design (by weight) experiment, with repeated weight measurement and two environmental temperatures: thermoneutral (24ºC) and heat-stressed (33ºC), during 38 days. The animals exposed to 33ºC presented lower dry matter ingestion, lower T3 (triiodothyronine) serum level, higher ammoniacal nitrogen (NH3-N) level in the rumen liquid, and higher rectal and body temperatures during all the experimental period when compared to the animals kept in thermoneutral environment (24ºC). The animals kept under heat stress environment (33ºC) presented higher calcium serum level, which was the highest on 31st day and the lowest on the 38th day of the experiment; phosphorus level was the lowest during all the experimental period; sodium level was lower on the 17th, 31st and 38th experimental days. Potassium and zinc levels were lower after 24 days; copper level was lower until the 24th day; magnesium level was higher until the 17th day, if compared to the ones from the animals kept in thermoneutral environment (24ºC). The heat-stressed animals presented higher levels of ammoniacal nitrogen in the ruminal liquid and a decrease in the phosphorus, sodium, potassium and zinc serum levels. These results show the necessity of changes on feed management to ruminants in temperatures over the thermal comfort limits so that performance loss is decreased.

Recalled and recorded bowel habits confirm early onset and high frequency of constipation in day-care nursery children

CONTEXT: Mothers recall early-onset constipation in children attending gastroenterology clinics. OBJECTIVES: To study the bowel habit of young children in the community to determine, first, whether early-onset constipation is confirmed in this setting and, second, the agreement between recalled and recorded bowel habit. METHODS:Defecation data of 57 children aged 6.0-40.7 mo were obtained by maternal recall (questionnaire on predominant stool characteristics) and by record (1,934 defecations registered prospectively at home and in the nursery). The bowel habit was classified according to stool frequency and proportion of stool characteristics (soft, hard and/or runny). Two criteria were used to classify recorded data, since the cutoff point for hard stools to identify constipation is undefined in children: predominant criterion and adult criterion, respectively with >50% and >25% of stools with altered consistency. Bowel habit categories were: adequate, constipation, functional diarrhea and "other bowel habit". Nonparametric statistics, and the Kappa index for agreement between recalled and recorded bowel habit, were used. RESULTS: Constipation occurred in 17.5%, 10.5%, 19.3% of the children by recall, the predominant and the adult criteria, respectively. Constipation was the main recalled alteration, vs 12.3% "other bowel habit". Only one child classified as having functional diarrhea (by the adult criterion). Agreement between recalled and recorded bowel habit was fair for constipation, by the predominant and the adult criteria (K = 0.28 and 0.24, respectively), but only slight (K <0.16) for other bowel habit categories. Individual data, however, pointed to a better relationship between recalled constipation and the adult rather than the predominant criterion. CONCLUSIONS: Frequent early-onset constipation was confirmed. Fair agreement between recalled and recorded constipation by the two used criteria indicates that recalled data are quite reliable to detect constipation.

Effect of gender on training-induced vascular remodeling in SHR

There is accumulating evidence that physical inactivity, associated with the modern sedentary lifestyle, is a major determinant of hypertension. It represents the most important modifiable risk factor for cardiovascular diseases, which are the leading cause of morbidity and mortality for both men and women. In addition to involving sympathetic overactivity that alters hemodynamic parameters, hypertension is accompanied by several abnormalities in the skeletal muscle circulation including vessel rarefaction and increased arteriole wall-to-lumen ratio, which contribute to increased total peripheral resistance. Low-intensity aerobic training is a promising tool for the prevention, treatment and control of high blood pressure, but its efficacy may differ between men and women and between male and female animals. This review focuses on peripheral training-induced adaptations that contribute to a blood pressure-lowering effect, with special attention to differential responses in male and female spontaneously hypertensive rats (SHR). Heart, diaphragm and skeletal muscle arterioles (but not kidney arterioles) undergo eutrophic outward remodeling in trained male SHR, which contributed to a reduction of peripheral resistance and to a pressure fall. In contrast, trained female SHR showed no change in arteriole wall-to-lumen ratio and no pressure fall. On the other hand, training-induced adaptive changes in capillaries and venules (increased density) were similar in male and female SHR, supporting a similar hyperemic response to exercise.

Time course of training-induced microcirculatory changes and of vegf expression in skeletal muscles of spontaneously hypertensive female rats

Exercise-induced vessel changes modulate arterial pressure (AP) in male spontaneously hypertensive rats (SHR). Vascular endothelial growth factor (VEGF) is important for angiogenesis of skeletal muscle. The present study evaluated the time course of VEGF and angiogenesis after short- and long-term exercise training of female SHR and Wistar Kyoto (WKY) rats, 8-9 weeks (200-250 g). Rats were allocated to daily training or remained sedentary for 3 days (N = 23) or 13 weeks (N = 23). After training, the carotid artery was catheterized for AP measurements. Locomotor (tibialis anterior and gracilis) and non-locomotor skeletal muscles (temporalis) were harvested and prepared for histologic and protein expression analyses. Training increased treadmill performance by all groups (SHR = 28%, WKY = 64%, 3 days) and (SHR = 141%, WKY = 122%, 13 weeks). SHR had higher values of AP than WKY (174 ± 4 vs 111 ± 2 mmHg) that were not altered by training. Three days of running increased VEGF expression (SHR = 28%, WKY = 36%) simultaneously with an increase in capillary-to-fiber ratio in gracilis muscle (SHR = 19%, WKY = 15%). In contrast, 13 weeks of training increased gracilis capillary-to-fiber ratio (SHR = 18%, WKY = 19%), without simultaneous changes in VEGF expression. Training did not change VEGF expression and capillarity of temporalis muscle. We conclude that training stimulates time- and tissue-dependent VEGF protein expression, independent of pressure levels. VEGF triggers angiogenesis in locomotor skeletal muscle shortly after the exercise starts, but is not involved in the maintenance of capillarity after long-term exercise in female rats.

High resolution study of 104Pd(d,t)103Pd

Information collected in the present high resolution study of 104Pd(d,t)103Pd is interpreted within the systematics of the A ~ 100 region. The paper complements data previously presented by the S.Paulo Group, which were taken with the Pelletron-Enge-Spectrograph facility. A one-to-one correspondence to gamma ray results for 103Pd, collected by the Nuclear Data Sheets (NDS), was achieved and at least four open questions were settled. More reliable spectroscopic strengths were extracted in the present study.

Obtaining high purity silica from rice hulls

Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), particle size analysis by laser diffraction (LPSA) and thermal analysis.

High prevalence of drug-resistant tuberculosis and other mycobacteria among HIV-infected patients in Brazil: a systematic review

There is a little-noticed trend involving human immunodeficiency virus (HIV)-infected patients suspected of having tuberculosis: the triple-treatment regimen recommended in Brazil for years has been potentially ineffective in over 30% of the cases. This proportion may be attributable to drug resistance (to at least 1 drug) and/or to infection with non-tuberculous mycobacteria. This evidence was not disclosed in official statistics, but arose from a systematic review of a few regional studies in which the diagnosis was reliably confirmed by mycobacterial culture. This paper clarifies that there has long been ample evidence for the potential benefits of a four-drug regimen for co-infected patients in Brazil and it reinforces the need for determining the species and drug susceptibility in all positive cultures from HIV-positive patients.

Nanochromics: old materials, new structures and architectures for high performance devices

Due to the development of nanoscience, the interest in electrochromism has increased and new assemblies of electrochromic materials at nanoscale leading to higher efficiencies and chromatic contrasts, low switching times and the possibility of color tuning have been developed. These advantages are reached due to the extensive surface area found in nanomaterials and the large amount of organic electrochromic molecules that can be easily attached onto inorganic nanoparticles, as TiO2 or SiO2. Moreover, the direct contact between electrolyte and nanomaterials produces high ionic transfer rates, leading to fast charge compensation, which is essential for high performance electrochromic electrodes. Recently, the layer-by-layer technique was presented as an interesting way to produce different architectures by the combination of both electrochromic nanoparticles and polymers. The present paper shows some of the newest insights into nanochromic science.

Ichthyofauna of Rio Jurubatuba, Santos, São Paulo: a high diversity refuge in impacted lands

Ichthyofaunistic surveys in the Atlantic Rainforest have been published in relatively few works, in spite of the major biological importance of this once vast biome which is rapidly vanishing due to disordered human population growth and natural resources overexploitation. The present study aimed to access the fish fauna of a relatively well preserved basin between the cities of Santos and Cubatão (SP), an area highly modified by human activities where recent ichthyofaunistic surveys are still missing. Collections were made during three field trips in Rio Jurubatuba, a medium sized costal river, and Riacho Sabão, one of its main tributaries. A total of 2773 specimens were sampled, representing 25 species from 14 families. Six species were primary marine using the upper reaches of Rio Jurubatuba. Twelve of the 19 freshwater species are endemic of the Atlantic Rainforest and four are present in regional lists of endangered species. Only five species occurred in both Rio Jurubatuba and Riacho Sabão. The most diverse family was Characidae, followed by Poeciliidae, Rivulidae and Heptapteridae. Phalloceros caudimaculatus was the most abundant species, followed by Poecilia vivipara and Geophagus brasiliensis. The study area is considered well preserved and due to its critical location, urges for conservation policies to protect its fish diversity.

High-energy events and short-term changes in superficial beach sediments

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Factors associated with depression symptoms in high school students in São Paulo, Brazil

OBJECTIVE: To assess factors associated with depression symptoms in high school students. METHODS: A cross-sectional study involving high school students was conducted in the city of São Paulo, Brazil, 2001. A total of 724 students aged 14-18 years answered questionnaires on life and health conditions. Another questionnaire was applied to working (44.8%) and unemployed (22.9%) students to collect information on working conditions. Factors associated to depressive disorders were analyzed using multiple logistic regression controlled for occupational status. RESULTS: Overall prevalence rate of depression was 7.5%. Rates according to gender were 39 (10.3%) in females and 15 (4.3%) in males. The multiple logistic regression analysis showed that factors associated with depressive disorders were: poor self-perception of health (OR=5.78), being female (OR = 2.45), and alcohol consumption (OR=2.35). CONCLUSIONS: The study results showed that sociodemographic, lifestyle and health variables were associated with symptoms of depression in this population. These ndings suggest that it is important to have mental health professionals available in high schools for early detection of mental conditions and student counseling.