495 research outputs found
The effect of hypertensive disorders in pregnancy on small for gestational age and stillbirth: a population based study
BACKGROUND: Hypertensive disorders in pregnancy are leading causes of maternal, fetal and neonatal morbidity and mortality worldwide. However, studies attempting to quantify the effect of hypertension on adverse perinatal outcomes have been mostly conducted in tertiary centres. This population-based study explored the frequency of hypertensive disorders in pregnancy and the associated increase in small for gestational age (SGA) and stillbirth. METHODS: We used information on all pregnant women and births, in the Canadian province of Nova Scotia, between 1988 and 2000. Pregnancies were excluded if delivery occurred < 20 weeks, if birthweight was < 500 grams, if there was a high-order multiple pregnancy (greater than twin gestation), or a major fetal anomaly. RESULTS: The study population included 135,466 pregnancies. Of these, 7.7% had mild pregnancy-induced hypertension (PIH), 1.3% had severe PIH, 0.2% had HELLP (hemolysis, elevated liver enzymes, low platelets), 0.02% had eclampsia, 0.6% had chronic hypertension, and 0.4% had chronic hypertension with superimposed PIH. Women with any hypertension in pregnancy were 1.6 (95% CI 1.5–1.6) times more likely to have a live birth with SGA and 1.4 (95% CI 1.1–1.8) times more likely to have a stillbirth as compared with normotensive women. Adjusted analyses showed that women with gestational hypertension without proteinuria (mild PIH) and with proteinuria (severe PIH, HELLP, or eclampsia) were more likely to have infants with SGA (RR 1.5, 95% CI 1.4–1.6 and RR 3.2, 95% CI 2.8–3.6, respectively). Women with pre-existing hypertension were also more likely to give birth to an infant with SGA (RR 2.5, 95% CI 2.2–3.0) or to have a stillbirth (RR 3.2, 95% CI 1.9–5.4). CONCLUSIONS: This large, population-based study confirms and quantifies the magnitude of the excess risk of small for gestational age and stillbirth among births to women with hypertensive disease in pregnancy
X-Ray Spectroscopy of Stars
(abridged) Non-degenerate stars of essentially all spectral classes are soft
X-ray sources. Low-mass stars on the cooler part of the main sequence and their
pre-main sequence predecessors define the dominant stellar population in the
galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense,
of X-ray spectra from the solar corona. X-ray emission from cool stars is
indeed ascribed to magnetically trapped hot gas analogous to the solar coronal
plasma. Coronal structure, its thermal stratification and geometric extent can
be interpreted based on various spectral diagnostics. New features have been
identified in pre-main sequence stars; some of these may be related to
accretion shocks on the stellar surface, fluorescence on circumstellar disks
due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot
stars clearly dominate the interaction with the galactic interstellar medium:
they are the main sources of ionizing radiation, mechanical energy and chemical
enrichment in galaxies. High-energy emission permits to probe some of the most
important processes at work in these stars, and put constraints on their most
peculiar feature: the stellar wind. Here, we review recent advances in our
understanding of cool and hot stars through the study of X-ray spectra, in
particular high-resolution spectra now available from XMM-Newton and Chandra.
We address issues related to coronal structure, flares, the composition of
coronal plasma, X-ray production in accretion streams and outflows, X-rays from
single OB-type stars, massive binaries, magnetic hot objects and evolved WR
stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures
(partly multiple); some corrections made after proof stag
The Cost Implications of Less Tight Versus Tight Control of Hypertension in Pregnancy (CHIPS Trial).
The CHIPS randomized controlled trial (Control of Hypertension in Pregnancy Study) found no difference in the primary perinatal or secondary maternal outcomes between planned "less tight" (target diastolic 100 mm Hg) and "tight" (target diastolic 85 mm Hg) blood pressure management strategies among women with chronic or gestational hypertension. This study examined which of these management strategies is more or less costly from a third-party payer perspective. A total of 981 women with singleton pregnancies and nonsevere, nonproteinuric chronic or gestational hypertension were randomized at 14 to 33 weeks to less tight or tight control. Resources used were collected from 94 centers in 15 countries and costed as if the trial took place in each of 3 Canadian provinces as a cost-sensitivity analysis. Eleven hospital ward and 24 health service costs were obtained from a similar trial and provincial government health insurance schedules of medical benefits. The mean total cost per woman-infant dyad was higher in less tight versus tight control, but the difference in mean total cost (DM) was not statistically significant in any province: Ontario (24 469.06; DM 296 to 30 593.69 versus 5817; 95% confidence interval, -12 349; P=0.0725); or Alberta (25 510.49; DM 154 to $12 781; P=0.0637). Tight control may benefit women without increasing risk to neonates (as shown in the main CHIPS trial), without additional (and possibly lower) cost to the healthcare system. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01192412
Cross-sectional associations between multiple lifestyle behaviors and health-related quality of life in the 10,000 steps cohort
Background: The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Methods: Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. Results: A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Conclusions: Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index. © 2014 Duncan et al
Central synapses release a resource-efficient amount of glutamate.
Why synapses release a certain amount of neurotransmitter is poorly understood. We combined patch-clamp electrophysiology with computer simulations to estimate how much glutamate is discharged at two distinct central synapses of the rat. We found that, regardless of some uncertainty over synaptic microenvironment, synapses generate the maximal current per released glutamate molecule while maximizing signal information content. Our result suggests that synapses operate on a principle of resource optimization
Unhappy doctors? A longitudinal study of life and job satisfaction among Norwegian doctors 1994 – 2002
BACKGROUND: General opinion is that doctors are increasingly dissatisfied with their job, but few longitudinal studies exist. This study has been conducted to investigate a possible decline in professional and personal satisfaction among doctors by the turn of the century. METHODS: We have done a survey among a representative sample of 1 174 Norwegian doctors in 2002 (response rate 73 %) and compared the findings with answers to the same questions by (most of) the same doctors in 1994 and 2000. The main outcome measures were self reported levels of life satisfaction and job satisfaction according to the Job Satisfaction Scale (JSS). RESULTS: Most Norwegian doctors are happy. They reported an average life satisfaction of 5.21 in 1994 and 5.32 in 2002 on a scale from 1 (extremely dissatisfied) to 7 (extremely satisfied). Half of the respondents reported a very high level of general life satisfaction (a score of 6 or 7) while only one third said they would have reported this high level of satisfaction five years ago. The doctors thought that they had a higher level of job satisfaction than other comparable professional groups. The job satisfaction scale among the same doctors showed a significant increase from 1994 to 2002. Anaesthesiologists and internists reported a lower and psychiatrists and primary care doctors reported a higher level of job satisfaction than the average. CONCLUSION: Norwegian doctors seem to have enjoyed an increasing level of life and job satisfaction rather than a decline over the last decade. This challenges the general impression of unhappy doctors as a general and worldwide phenomenon
Swiss residents' arguments for and against a career in medicine
BACKGROUND: In some Western countries, the medical profession is continuously losing prestige, doctors are claiming of high demands, low rewards, and difficult structural working conditions. This study aimed to investigate the arguments given by Swiss residents for and against a career in medicine. METHODS: As part of a prospective cohort study of Swiss medical school graduates on career development, 567 fourth-year residents were asked to answer the free-response item of what arguments there still were in favour of or against a career in medicine. They also indicated whether they would choose the medical profession all over again (yes/no). The statements were transcribed, content categories inductively formulated, and their descriptions written down in a code manual. Arguments were encoded according to the code manual and assigned to eight content categories (Mayring's content analysis). Frequency distributions were given for categories and tested with Chi(2)-tests for differences in gender, speciality fields, and whether or not the respondent would again choose a career in medicine. RESULTS: The 567 participants made 1,640 statements in favour of and 1,703 statements against a career in medicine. The content analysis of the residents' answers yielded eight categories with arguments both for and against a career in medicine. Of all "statements for" responses, 70% fell into the two top-ranking categories of Personal experiences in day-to-day working life (41.2%) and Interpersonal experiences in professional relationships (28.8%). The top-ranking category of the "statements against" arguments was General work-related structural conditions (32%), followed by Social prestige and health-policy aspects (21%). Main arguments in favour of a career in medicine were interdisciplinary challenge, combination of basic sciences and interpersonal concerns, helping suffering people, guarantee of a secure job; arguments against comprised high workload, time pressure, emotional stress, poorly structured continuing education, increasing bureaucracy, work-life imbalance, low income, and decreasing social prestige. The statements revealed few differences depending on gender, medical field, and attitude towards choosing the medical profession again; one out of five young doctors would not do so. CONCLUSION: Residents' chief complaint is deteriorating structural working conditions, including unfavourable work-life balance. Making medicine an attractive profession again will require sustainable changes in health-policy framework and social reward
Cellular and Network Contributions to Excitability of Layer 5 Neocortical Pyramidal Neurons in the Rat
There is a considerable gap between investigating the dynamics of single neurons and the computational aspects of neural networks. A growing number of studies have attempted to overcome this gap using the excitation in brain slices elicited by various chemical manipulations of the bath solution. However, there has been no quantitative study on the effects of these manipulations on the cellular and network factors controlling excitability. Using the whole-cell configuration of the patch-clamp technique we recorded the membrane potential from the soma of layer 5 pyramidal neurons in acute brain slices from the somatosensory cortex of young rats at 22°C and 35°C. Using blockers of synaptic transmission, we show distinct changes in cellular properties following modification of the ionic composition of the artificial cerebrospinal fluid (ACSF). Thus both cellular and network changes may contribute to the observed effects of slice excitation solutions on the physiology of single neurons. Furthermore, our data suggest that the difference in the ionic composition of current standard ACSF from that of CSF measured in vivo cause ACSF to depress network activity in acute brain slices. This may affect outcomes of experiments investigating biophysical and physiological properties of neurons in such preparations. Our results strongly advocate the necessity of redesigning experiments routinely carried out in the quiescent acute brain slice preparation
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Prediction of adverse maternal outcomes in pre-eclampsia: development and validation of the fullPIERS model.
BACKGROUND: Pre-eclampsia is a leading cause of maternal deaths. These deaths mainly result from eclampsia, uncontrolled hypertension, or systemic inflammation. We developed and validated the fullPIERS model with the aim of identifying the risk of fatal or life-threatening complications in women with pre-eclampsia within 48 h of hospital admission for the disorder. METHODS: We developed and internally validated the fullPIERS model in a prospective, multicentre study in women who were admitted to tertiary obstetric centres with pre-eclampsia or who developed pre-eclampsia after admission. The outcome of interest was maternal mortality or other serious complications of pre-eclampsia. Routinely reported and informative variables were included in a stepwise backward elimination regression model to predict the adverse maternal outcome. We assessed performance using the area under the curve (AUC) of the receiver operating characteristic (ROC). Standard bootstrapping techniques were used to assess potential overfitting. FINDINGS: 261 of 2023 women with pre-eclampsia had adverse outcomes at any time after hospital admission (106 [5%] within 48 h of admission). Predictors of adverse maternal outcome included gestational age, chest pain or dyspnoea, oxygen saturation, platelet count, and creatinine and aspartate transaminase concentrations. The fullPIERS model predicted adverse maternal outcomes within 48 h of study eligibility (AUC ROC 0·88, 95% CI 0·84-0·92). There was no significant overfitting. fullPIERS performed well (AUC ROC >0·7) up to 7 days after eligibility. INTERPRETATION: The fullPIERS model identifies women at increased risk of adverse outcomes up to 7 days before complications arise and can thereby modify direct patient care (eg, timing of delivery, place of care), improve the design of clinical trials, and inform biomedical investigations related to pre-eclampsia. FUNDING: Canadian Institutes of Health Research; UNDP/UNFPA/WHO/World Bank Special Programme of Research, Development, and Research Training in Human Reproduction; Preeclampsia Foundation; International Federation of Obstetricians and Gynecologists; Michael Smith Foundation for Health Research; and Child and Family Research Institute
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