Association between perceived stress and health-risk behaviours in workers.

Individuals who experience stress can engage in health-risk behaviours that may decrease work performance. The aim of this study was to determine perceived stress levels in Brazilian workers and verify whether perceived stress was associated with health-risk behaviours. Stress levels of 1,270 workers (1,019 men, 251 women) were assessed using the Perceived Stress Scale. The health-risk behaviours investigated were low intake of vegetables and fruits, daily smoking, high-risk alcohol consumption, physical inactivity, and the presence of obesity. The Student's t-test or one-way analysis of variance was used to assess differences in stress levels. Ordinal regression was used to determine the association between the degrees of stress and health-risk behaviours. Women had higher perceived stress levels than men. In addition, perceived stress levels were higher in those who had low socioeconomic status, were unmarried, had a negative perception of their health, were smokers, or had obesity. Smoking and the presence of two or more health-risk behaviours were associated with 1.84 (95% CI: 1.24-2.73) times and 1.49 (95% CI: 1.18-1.89) times higher odds of experiencing higher degrees of stress, respectively. In women, such an association was observed with the presence of obesity (odds ratio: 2.0; 95% CI: 1.01-3.98).

Short- and medium-term prognosis of HIV-infected patients receiving intensive care: a Brazilian multicentre prospective cohort study.

OBJECTIVES: The characteristics of critically ill HIV-positive patients and the causes of their admission to intensive care units (ICUs) are only known through retrospective and unicentric studies. This study aims to fill this knowledge gap. METHODS: This is a prospective, multicentre cohort study of short- and medium-term prognostic factors. The setting consisted of ICUs of three tertiary referral hospitals from the three largest metropolitan areas in Brazil in the period January 2014 to November 2015. In all, 161 HIV patients over 18 years old were included. RESULTS: The clinical data of the outcomes (ICU mortality, hospital mortality and 90-day survival) were extracted from medical records using the REDCap®ï¸ web-based form and analysed with the MedCalc®ï¸ application. Median age was 41.7 [interquartile range (IQR): 34-50] years, the Simplified Acute Physiologic Score 3 (SAPS 3) was 64 (IQR: 56-74), and the Sequential Organ Failure Assessment Score (SOFA) was 6 (IQR: 4-9) points. The main causes of admission were sepsis (54.5%) and acute respiratory failure (13.7%). ICU and hospital mortality rates were 32.3% and 40.4%, respectively. In a multivariate analysis, time until ICU admission ≥ 3 days (P = 0.0013), performance status (Eastern Cooperative Oncology Group score, P = 0.0344), coma (Glasgow Coma Scale ≤ 8 points, P = 0.0213) and sepsis (P = 0.0003) were associated with increased hospital mortality. Coma (P = 0.0002) and sepsis (P = 0.0008) were independently associated with 90-day survival. CONCLUSIONS: Delayed ICU admission and the severity of critical illness determine the short- and medium-term mortality rates of HIV-infected patients admitted to the ICU, rather than factors associated with HIV infection. These results suggest that prognostic factors of HIV-infected patients in the ICU are similar to those of non-HIV-infected populations.

Direct Trace Fitting of Experimental Data Using the Master Equation: Testing Theory and Experiments on the OH + C2H4 Reaction.

Laser flash photolysis coupled with laser-induced fluorescence observation of OH has been used to observe the equilibration of OH + C2H4 ↔ HOC2H4 over the temperature range 563-723 K and pressures of bath gas (N2) from 58 to 250 Torr. The time-resolved OH traces have been directly and globally fitted with a master equation in order to extract ΔRH00, the binding energy of the HOC2H4 adduct, with respect to reagents. The global approach allows the role that OH abstraction plays at higher temperatures to be identified. The resultant value ofΔRH00, 111.8 kJ mol-1, is determined to be better than 2 kJ mol-1 and is in agreement with our ab initio calculations (carried out at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level), 111.4 kJ mol-1, and other state of the art calculations. Parameters for the abstraction channel are also in good agreement with previous experimental studies. To effect this analysis, the MESMER master equation code was extended to directly incorporate secondary chemistry: diffusional loss from the observation region and reaction with the photolytic precursor. These extensions, which, among other things, resolve issues related to the merging of chemically significant and internal energy relaxation eigenvalues, are presented.

Impulse oscillometry in the assessment of children's lung function.

PURPOSE: To review available evidence in the literature on impulse oscillometry in the assessment of lung function in children with respiratory diseases, especially asthma. DATA COLLECTION: Research in the Medline, PubMed, and Lilacs databases, with the keywords forced oscillation, impulse oscillometry, asthma and impulse oscillometry. RESULTS: The Impulse Oscillometry System (IOS) allows the measurement of resistance and reactance of airways and is used as a diagnostic resource. A significant association between the findings of the IOS and those of spirometry is observed. In asthma, the IOS has already been used to assess the bronchodilator response and the therapeutic response to different drugs and has shown to be a sensitive technique to evaluate disease control. There are limitations to this assessment, such as children with attention deficit and in some cases it is difficult to interpret the results from a clinical point of view. CONCLUSION: The IOS is a useful tool for the measurement of the lung function of children. It is an easy test, although its interpretation is not straightforward.

Exploring the features on the OH + SO2 potential energy surface using theory and testing its accuracy by comparison to experimental data.

Ab initio theory has been used to identify the pre-reaction complex in the atmospherically important reaction between OH + SO2, (R1), where the binding energy of the pre-reaction complex was determined to be 7.2 kJ mol-1. Using reaction rate theory, implemented with the master equation package MESMER, the effects of this complex on the kinetics of R1 at temperatures above 250 K have been investigated. From simulations and fitting to the experimental kinetic data, it is clear that the influence of this pre-reaction complex is negligible and that the kinetics are controlled by the inner transition-state that leads to the product, HOSO2. While the effect of this complex on the thermal kinetics is small it potentially provides an efficient route to remove energy from vibrationally excited OH. The fitting to the past experimental data reveals that this inner transition-state is submerged with a barrier -0.25 kJ mol-1 below the entrance channel, which is outside the range predicted from the best theoretical calculations. The data fitting also yielded ΔR1H0K equal to -(109 ± 5.6) kJ mol-11 and a more precise expression for k∞1(T), (5.95 ± 0.83) × 10-13 × (T/298)-0.11±0.27.

Kinetics of the Reaction of OH with Isoprene over a Wide Range of Temperature and Pressure Including Direct Observation of Equilibrium with the OH Adducts.

The reaction of the OH radical with isoprene, C5H8 (R1), has been studied over the temperature range 298-794 K and bath gas pressures of nitrogen from 50 to 1670 Torr using laser flash photolysis (LFP) to generate OH and laser-induced fluorescence (LIF) to observe OH removal. Measurements have been made using both a conventional LFP/LIF apparatus and a new high pressure system. The measured rate coefficient at 298 K ( k1,298K = (9.90 ± 0.09) × 10-11 cm3 molecule-1 s-1) in the high pressure apparatus is in excellent agreement with the literature, confirming the accuracy of measurements made with this instrument. Above 700 K, the OH decays were no longer single exponentials due to regeneration of OH from adduct decomposition and the establishment of the OH + C5H8 ⇌ HOC5H8 equilibrium (R1a, R-1a). This equilibrium was analyzed by comparison to a master equation model of reaction R1 and determined the well depth for OH addition to carbon C1 and C4 to be equal to 153.5 ± 6.2 and 143.4 ± 6.2 kJ mol-1, respectively. These well depths are in excellent agreement with the present ab initio-CCSD(T)/CBS//M062X/6-311++G(3df,2p)-calculations (154.1 kJ mol-1 for the C1 adduct). Addition to the less stable C2 and C3 adducts is not important. The data above 700 K also indicated that a minor but significant direct abstraction channel, R1b, was also operating with k1b = (1.3 ± 0.3) × 10-11 exp(-3.61 kJ mol-1/ RT) cm3 molecule-1 s-1. Additional support for the presence of this abstraction channel comes from our ab initio calculations and from room-temperature proton transfer mass spectrometry product analysis. The literature data on reaction R1 together with the present data were assessed using master equation analysis, using the MESMER package. This analysis produced a refined data set that generates our recommended k1a( T, [ M]). An analytical representation of k1a( T, [ M]) and k-1a( T, [ M]) is provided via a Troe expression. The reported experimental data (the sum of addition and abstraction), k1∞ = (9.5 ± 0.2) × 10-11( T/298 K)-1.33±0.07 + (1.3 ± 0.3) × 10-11 exp(-3.61 kJ mol-1/ RT) cm3 molecule-1 s-1, significantly extend the measured temperature range of R1.

Estimating the burden of acute gastrointestinal illness due to Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus associated with private wells and small water systems in Canada.

Waterborne illness related to the consumption of contaminated or inadequately treated water is a global public health concern. Although the magnitude of drinking water-related illnesses in developed countries is lower than that observed in developing regions of the world, drinking water is still responsible for a proportion of all cases of acute gastrointestinal illness (AGI) in Canada. The estimated burden of endemic AGI in Canada is 20·5 million cases annually - this estimate accounts for under-reporting and under-diagnosis. About 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. There is evidence that individuals served by private systems and small community systems may be more at risk of waterborne illness than those served by municipal drinking water systems in Canada. However, little is known regarding the contribution of these systems to the overall drinking water-related AGI burden in Canada. Private water supplies serve an estimated 12% of the Canadian population, or ~4·1 million people. An estimated 1·4 million (4·1%) people in Canada are served by small groundwater (2·6%) and surface water (1·5%) supplies. The objective of this research is to estimate the number of AGI cases attributable to water consumption from these supplies in Canada using a quantitative microbial risk assessment (QMRA) approach. This provides a framework for others to develop burden of waterborne illness estimates for small water supplies. A multi-pathogen QMRA of Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus, chosen as index waterborne pathogens, for various source water and treatment combinations was performed. It is estimated that 103 230 AGI cases per year are due to the presence of these five pathogens in drinking water from private and small community water systems in Canada. In addition to providing a mechanism to assess the potential burden of AGI attributed to small systems and private well water in Canada, this research supports the use of QMRA as an effective source attribution tool when there is a lack of randomized controlled trial data to evaluate the public health risk of an exposure source. QMRA is also a powerful tool for identifying existing knowledge gaps on the national scale to inform future surveillance and research efforts.

Estimating the number of cases of acute gastrointestinal illness (AGI) associated with Canadian municipal drinking water systems.

The estimated burden of endemic acute gastrointestinal illness (AGI) annually in Canada is 20·5 million cases. Approximately 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. A number of randomized controlled trials have been completed to estimate the influence of tap water from municipal drinking water plants on the burden of AGI. In Canada, 83% of the population (28 521 761 people) consumes tap water from municipal drinking water plants serving >1000 people. The drinking water-related AGI burden associated with the consumption of water from these systems in Canada is unknown. The objective of this research was to estimate the number of AGI cases attributable to consumption of drinking water from large municipal water supplies in Canada, using data from four household drinking water intervention trials. Canadian municipal water treatment systems were ranked into four categories based on source water type and quality, population size served, and treatment capability and barriers. The water treatment plants studied in the four household drinking water intervention trials were also ranked according to the aforementioned criteria, and the Canadian treatment plants were then scored against these criteria to develop four AGI risk groups. The proportion of illnesses attributed to distribution system events vs. source water quality/treatment failures was also estimated, to inform the focus of future intervention efforts. It is estimated that 334 966 cases (90% probability interval 183 006-501 026) of AGI per year are associated with the consumption of tap water from municipal systems that serve >1000 people in Canada. This study provides a framework for estimating the burden of waterborne illness at a national level and identifying existing knowledge gaps for future research and surveillance efforts, in Canada and abroad.

Pandemic influenza immunization in primary antiphospholipid syndrome (PAPS): a trigger to thrombosis and autoantibody production?

OBJECTIVE: The objective of this report is to conduct short- and long-term evaluation of a large panel of antiphospholipid (aPL) autoantibodies following pandemic influenza A/H1N1 non-adjuvant vaccine in primary antiphospholipid syndrome (PAPS) patients and healthy controls. METHODS: Forty-five PAPS and 33 healthy controls were immunized with H1N1 vaccine. They were prospectively assessed at pre-vaccination, and three weeks and six months after vaccination. aPL autoantibodies were determined by an enzyme-linked immunosorbent assay (ELISA) and included IgG/IgM: anticardiolipin (aCL), anti-beta2glycoprotein I (anti-ß2GPI); anti-annexin V, anti-phosphatidyl serine and anti-prothrombin antibodies. Anti-Sm was determined by ELISA and anti-double-stranded DNA (anti-dsDNA) by indirect immunofluorescence. Arterial and venous thrombosis were also clinically assessed. RESULTS: Pre-vaccination frequency of at least one aPL antibody was significantly higher in PAPS patients versus controls (58% vs. 24%, p = 0.0052). The overall frequencies of aPL antibody at pre-vaccination, and three weeks and six months after immunization remained unchanged in patients (p = 0.89) and controls (p = 0.83). The frequency of each antibody specificity for patients and controls remained stable in the three evaluated periods (p > 0.05). At three weeks, two PAPS patients developed a new but transient aPL antibody (aCL IgG and IgM), whereas at six months new aPL antibodies were observed in six PAPS patients and none had high titer. Anti-Sm and anti-dsDNA autoantibodies were uniformly negative and no new arterial or venous thrombosis were observed throughout the study. CONCLUSIONS: This is the first study to demonstrate that pandemic influenza vaccine in PAPS patients does not trigger short- and long-term thrombosis or a significant production of aPL-related antibodies (ClinicalTrials.gov, #NCT01151644).

Ascaris lumbricoides infection in urban schoolchildren: specific IgE and IL-10 production.

BACKGROUND: Helminth infections and allergies are diseases with intense Th2 lymphocytes participation and characterised by a high IgE and Interleukin-(IL) IL-4, IL-5 production and eosinophilia. However, helminths also induce IL-10 production, which may alter the outcome of allergic diseases in infected patients. OBJECTIVE: This experimental study analyses the relationship between IL-10 production by cell culture from geohelminth infected and non-infected children and specific IgE to Ascaris lumbricoides (Asc) or Blomia tropicalis (BT). METHODS: IL-10 content in supernatant from peripheral blood mononuclear cell culture from nine helminth infected and eleven non-infected patients was determined by ELISA after in vitro stimulation with Asc or BT extracts. RESULTS: A positive association was observed between total IgE levels and anti-Ascaris and anti-Blomia tropicalis specific IgE, independent of infection status. For both helminth-infected and non-infected groups, there was no difference in IL-10 production in response to Asc extract, even though anti-Ascaris IgE levels were higher in the latter group. In response to BT stimulus, a lower production of IL-10 by the geohelminth-infected group was observed, but with no relationship between IL-10 production and specific IgE to BT. CONCLUSION: The results suggest that anti-Ascaris IgE in non-infected patients may be associated to a resistance to parasites. Levels of specific IgE to parasite antigens or B. tropicalis allergen were not impaired by IL-10 production in children from an urban area in which geohelminthiasis is endemic.

Increased arterial stiffness assessed by pulse wave velocity in Behçet's disease and its association with the lipid profile.

OBJECTIVE: To evaluate the structural and functional properties of vessels in Behçet's Disease (BD) using carotid-femoral pulse wave velocity (PWV) and an echo-tracking system. METHODS: BD patients without traditional cardiovascular risk factors were selected. All BD patients performed PWV and carotid ultrasound. BD patients were divided into groups based on the presence of systemic (vascular and/or ocular and/or central nervous system involvement) and vascular involvement. Healthy controls age- and sex-matched with the same exclusion criteria were selected. RESULTS: A total of 23 BD patients (mean age 35.0 ± 7.6 years) had significantly higher PWV levels compared with controls (8.48 ± 1.14 vs. 7.53 ± 1.40 m/s, P = 0.017). Intima-media thickness (594.87 ± 138.61 vs. 561.08 ± 134.26 µm, P = 0.371), diastolic diameter (6383.78 ± 960.49 vs. 6447.65 ± 1159.73 µm, P = 0.840), distension (401.95 ± 117.72 vs. 337.91 ± 175.36 µm, P = 0.225) and relative distension (6.26 ± 2.83 vs. 5.42 ± 2.46 µm, P = 0.293) were similar in both groups. The systemic disease group had significantly higher levels of PWV (8.79 ± 1.21 vs. 7.88 ± 0.72 m/s, P = 0.036) compared to those with exclusive mucocutaneous manifestations. BD patients with vascular involvement had similar PWV and echo-tracking parameters compared to those without vascular involvement (P > 0.05), but had higher total and LDL cholesterol levels (P = 0.019 and P = 0.012, respectively). The multivariate linear regression analysis identified triglycerides as the most important factor in increasing PWV levels (P = 0.001) in BD. CONCLUSIONS: PWV is more useful than carotid ultrasound in detecting structural and functional vascular damage in BD and emphasizes the role of the disease itself in promoting these alterations. Our findings also reinforce the need for rigorous control of all risk factors in BD, particularly lipoproteins.

Obstetric simulation for undergraduate medical education: how to improve students' self-confidence and expectation according to gender.

OBJECTIVE: The aim of this study was to evaluate the effects of obstetric simulation training on undergraduate medical students to improve their self-confidence. METHODS: Fifth-year undergraduate medical students were invited to a 2-week course of simulation in obstetrics during their clerkship. The sessions included were as follows: (1) care for the second and third periods of childbirth, (2) partograph analysis and pelvimetry, (3) premature rupture of membranes at term, and (4) diagnosis and management of third-trimester bleeding. Before the first session and at the end of the training period, a questionnaire about self-confidence in obstetric procedures and skills was applied. RESULTS: A total of 115 medical students were included, of whom 60 (52.2%) were male and 55 (47.8%) were female. Comparing initial and final scores, the median results of the subscales "comprehension and preparation" (18 vs. 22, p<0.001), "knowledge of procedures" (14 vs. 20, p<0.001), and "expectation" (22 vs. 23, p<0.01) were significantly higher at the end of the training period in all items of the questionnaire than in the beginning. Differences were found based on the students' gender, i.e., female students had a significantly higher sum of scores than the male students in the initial subscale for "expectation" (median, 24 vs. 22, p<0.001) and "interest" (median, 23 vs. 21, p=0.032), and a higher sum of scores in the subscale for "expectation" (median, 23 vs. 21, p=0.010) in the final questionnaire. CONCLUSION: Obstetric simulation enhances the improvement of students' self-confidence in understanding both the physiology of childbirth and the obstetric care procedures. Further studies are needed to understand the influence of gender on obstetric care.

Juvenile onset systemic lupus erythematosus: a possible role for vitamin D in disease status and bone health.

PURPOSE: In juvenile onset systemic lupus erythematosus (JoSLE), evidence for the association between vitamin D status, lupus activity, and bone health is very limited and not conclusive. The aim of this study was, therefore, to assess in JoSLE patients the possible relevance of vitamin D deficiency in disease and bone parameters. METHODS: Fifty-seven JoSLE patients were initially compared to 37 age, race and body mass index (BMI) -matched healthy controls. The serum concentration of 25 hydroxyvitamin D (25OHD) was determined by radioimmunoassay. Patients with 25OHD deficiency (≤20 ng/mL) were compared to those with levels >20 ng/mL. Disease activity was evaluated by SLE Disease Activity Index (SLEDAI). Bone mineral density (BMD) and body composition (BC) were measured using dual-energy X-ray absorptiometry (DXA). RESULTS: 25OHD levels were similar in patients and controls (21.44 ± 7.91 vs 22.54 ± 8.25 ng/mL, p = 0.519), regardless of supplementation (65% of patients and none in controls). Thirty-one patients with 25OHD deficiency (≤20 ng/mL) were further compared to the 26 JoSLE patients with levels >20 ng/mL. These two groups were well-balanced regarding vitamin D confounding variables: age (p = 0.100), ethnicity (p = 1.000), BMI (p = 0.911), season (p = 0.502), frequency of vitamin D supplementation (p = 0.587), creatinine (p = 0.751), renal involvement (p = 0.597), fat mass (p = 0.764), lean mass (p = 0.549), previous/current use of glucocorticoids(GC) (p = 1.0), immunosuppressors (p = 0.765), and mean current daily dose of GC (p = 0.345). Patients with vitamin D deficiency had higher SLEDAI (3.35 ± 4.35 vs 1.00 ± 2.48, p = 0.018), lower C4 levels (12.79 ± 6.78 vs 18.38 ± 12.24 mg/dL, p = 0.038), lower spine BMD (0.798 ± 0.148 vs 0.880 ± 0.127 g/cm(2), p = 0.037) and whole body BMD (0.962 ± 0.109 vs 1.027 ± 0.098 g/cm(2), p = 0.024). CONCLUSION: JoSLE vitamin D deficiency, in spite of conventional vitamin D supplementation, affects bone and disease activity status independent of therapy and fat mass reinforcing the recommendation to achieve adequate levels.

Assessing caries, dental plaque and salivary flow in asthmatic adolescents using inhaled corticosteroids.

BACKGROUND: A number of studies have reported that inhaled corticosteroids may cause a greater incidence of caries, reduced salivary flow, changes in saliva composition and an increased frequency of dental plaque, probably through alterations in the oral microbiota. The objective was to compare the frequency of caries, dental plaque and non-stimulated salivary flow rate among asthmatic adolescents using inhaled corticosteroids and non-asthmatic adolescents, as well as the salivary biochemical parameters (pH and leucocytes) in both groups. METHODS: This research has a descriptive cross-sectional design to compare dental health of 40 asthmatics on inhaled corticosteroids and 40 non-asthmatic adolescents (median age 13 years). RESULTS: The findings were a higher number of tooth surfaces affected by dental caries (median 4 versus 1.5), and more dental plaques (median 70.5 versus 60.7) among asthmatic adolescents. They also had a significantly higher frequency of salivary leucocytes. The non-stimulated salivary flow was similar in both groups. CONCLUSIONS: The results suggest an association between the use of inhaled corticosteroids and an increased risk of dental caries and bacterial plaque, which calls for special attention of these patients by doctors and dental health professionals.

A 10-year unsuspected lumbar schwannoma: a case report.

One case of unsuspected schwannoma is reported in a 69-year old man with chronic lumbosacral pain. The tumour had been mistaken for a lumbar lipoma for a decade. The definitive diagnosis was established after surgery based on the characteristic histopathological findings. The purpose of this report is to alert primary care physicians to peripheral sheath nerve tumours, in addition to highlight the role of pain and image features in the suspicion of tumours with long-term evolution.

Comparative in vitro and in vivo evaluations of oral sustained-release formulations of diclofenac sodium in beagle dogs.

PURPOSE: Two sustained release formulations (microspheres and Voltaren SR75) were evaluated for their drug release characteristics in dissolution (in vitro study) and after oral administration to beagle dogs (in vivo study) by HPLC. METHODS: The dissolution study was carried out according to the paddle method and the pharmacokinetic study was conducted using HPLC analysis in a crossover design in six female beagle dogs after oral administration of 75 mg diclofenac sodium (DFS). RESULTS: The dissolution profiles showed 45% release for Voltaren SR75 and around 95% for the microspheres. Oral administration of DFS resulted in AUC(0-24) and Cmax values of 20.4 microg h/mL and 3.04 microg/mL for microspheres and 33.5 microg h/mL and 5.59 microg/mL for Voltaren, respectively. The Tmax was 3.0 h for both formulations. A significant difference in AUC(0-24) and Cmax was observed for DFS absorption from microspheres and Voltaren. CONCLUSIONS: The results from the dissolution assay demonstrated the faster release of diclofenac sodium from microspheres. The bioavailability of DFS in microspheres was about 61% that of Voltaren, for the parameters AUC and Cmax, and they are therefore not bioequivalent to Voltaren in relation to the extent of absorption. However, the rate of drug absorption (Tmax) was similar for the two formulations.

Toward multifaceted roles of sucrose in the regulation of stomatal movement.

Plant atmospheric CO2 fixation depends on the aperture of stomatal pores at the leaf epidermis. Stomatal aperture or closure is regulated by changes in the metabolism of the two surrounding guard cells, which respond directly to environmental and internal cues such as mesophyll-derived metabolites. Sucrose has been shown to play a dual role during stomatal movements. The sucrose produced in the mesophyll cells can be transported to the vicinity of the guard cells via the transpiration stream, inducing closure in periods of high photosynthetic rate. By contrast, sucrose breakdown within guard cells sustains glycolysis and glutamine biosynthesis during light-induced stomatal opening. Here, we provide an update regarding the role of sucrose in the regulation of stomatal movement highlighting recent findings from metabolic and systems biology studies. We further explore how sucrose-mediated mechanisms of stomatal movement regulation could be useful to understand evolution of stomatal physiology among different plant groups.

Obstetric simulation for undergraduate medical education: how to improve students' self-confidence and expectation according to gender

SUMMARY OBJECTIVE: The aim of this study was to evaluate the effects of obstetric simulation training on undergraduate medical students to improve their self-confidence. METHODS: Fifth-year undergraduate medical students were invited to a 2-week course of simulation in obstetrics during their clerkship. The sessions included were as follows: (1) care for the second and third periods of childbirth, (2) partograph analysis and pelvimetry, (3) premature rupture of membranes at term, and (4) diagnosis and management of third-trimester bleeding. Before the first session and at the end of the training period, a questionnaire about self-confidence in obstetric procedures and skills was applied. RESULTS: A total of 115 medical students were included, of whom 60 (52.2%) were male and 55 (47.8%) were female. Comparing initial and final scores, the median results of the subscales "comprehension and preparation" (18 vs. 22, p<0.001), "knowledge of procedures" (14 vs. 20, p<0.001), and "expectation" (22 vs. 23, p<0.01) were significantly higher at the end of the training period in all items of the questionnaire than in the beginning. Differences were found based on the students' gender, i.e., female students had a significantly higher sum of scores than the male students in the initial subscale for "expectation" (median, 24 vs. 22, p<0.001) and "interest" (median, 23 vs. 21, p=0.032), and a higher sum of scores in the subscale for "expectation" (median, 23 vs. 21, p=0.010) in the final questionnaire. CONCLUSION: Obstetric simulation enhances the improvement of students' self-confidence in understanding both the physiology of childbirth and the obstetric care procedures. Further studies are needed to understand the influence of gender on obstetric care.

Peroxisome proliferator-activated receptor gamma coactivator-1 promotes cardiac mitochondrial biogenesis.

Cardiac mitochondrial function is altered in a variety of inherited and acquired cardiovascular diseases. Recent studies have identified the transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) as a regulator of mitochondrial function in tissues specialized for thermogenesis, such as brown adipose. We sought to determine whether PGC-1 controlled mitochondrial biogenesis and energy-producing capacity in the heart, a tissue specialized for high-capacity ATP production. We found that PGC-1 gene expression is induced in the mouse heart after birth and in response to short-term fasting, conditions known to increase cardiac mitochondrial energy production. Forced expression of PGC-1 in cardiac myocytes in culture induced the expression of nuclear and mitochondrial genes involved in multiple mitochondrial energy-transduction/energy-production pathways, increased cellular mitochondrial number, and stimulated coupled respiration. Cardiac-specific overexpression of PGC-1 in transgenic mice resulted in uncontrolled mitochondrial proliferation in cardiac myocytes leading to loss of sarcomeric structure and a dilated cardiomyopathy. These results identify PGC-1 as a critical regulatory molecule in the control of cardiac mitochondrial number and function in response to energy demands.