37 research outputs found
Medico-legal matters and Australian doctors : an investigation of doctors' experience of medico-legal matters, their mental health and their practice of medicine
Single location muscle monitoring does not reflect the heterogeneous activation of the muscle group(s) during a given exercise. Vastus lateralis and rectus femoris O2 consumption (VO2) was investigated, noninvasively, at rest and during maximal voluntary contractions (MVC) using a 12-channel near-infrared continuous wave spectroscopy (NIR(CWS)) system (0.1 s acquisition time). VO2 either at rest or during MVC was found to be nonuniform in the 11 out of 12 measurement sites over a surface of 8 x 8 cm2. As expected, VO2 during exercise was significantly higher than VO2 at rest (P < 0.01). However, at each muscle measurement site no difference was found between the mean values (n = 12) of VO2 measured during a 5-s intermittent MVC and the VO2 values measured during 30-s continuous MVC (P = 0.25). These results strengthen the role of NIR(CWS) as a powerful tool for investigating the spatial and temporal features of muscle oxygenation changes as well as muscle VO2
Bleeding risk of haemodialysis and peritoneal dialysis patients
Background. Dialysis patients have an increased bleeding risk as compared with the general population. However, there is limited information whether bleeding risks are different for patients treated with haemodialysis (HD) or peritoneal dialysis (PD). From a clinical point of view, this information could influence therapy choice. Therefore the aim of this study was to investigate the association between dialysis modality and bleeding risk.Methods. Incident dialysis patients from the Netherlands Cooperative Study on the Adequacy of Dialysis were prospectively followed for major bleeding events over 3years. Hazard ratios with 95% confidence intervals (CIs) were calculated for HD compared with PD using a time-dependent Cox regression analysis, with updates on dialysis modality.Results. In total, 1745 patients started dialysis, of whom 1211 (69.4%) received HD and 534 (30.6%) PD. The bleeding rate was 60.8/1000 person-years for HD patients and 34.6/1000 person-years for PD patients. The time-dependent Cox regression analysis showed that after adjustment for age, sex, primary kidney disease, prior bleeding, cardiovascular disease, antiplatelet drug use, vitamin K antagonist use, erythropoietin use, arterial hypertension, residual glomerular filtratin rate, haemoglobin and albumin levels, bleeding risk for HD patients compared with PD increased 1.5-fold (95% CI 1.0-2.2).Conclusions. In this large prospective cohort of incident dialysis patients, HD patients had an increased bleeding risk compared with PD patients. In particular, HD patients with a history of prior bleeding had an increased bleeding risk.Clinical epidemiolog
Correction to: Putting genome-wide sequencing in neonates into perspective
The original version of this Article contained an error in the spelling of the author Pleuntje J. van der Sluijs, which was incorrectly given as Eline (P. J.) van der Sluijs. This has now been corrected in both the PDF and HTML versions of the Article
FTO genetic variants, dietary intake and body mass index: insights from 177,330 individuals.
FTO is the strongest known genetic susceptibility locus for obesity. Experimental studies in animals suggest the potential roles of FTO in regulating food intake. The interactive relation among FTO variants, dietary intake and body mass index (BMI) is complex and results from previous often small-scale studies in humans are highly inconsistent. We performed large-scale analyses based on data from 177,330 adults (154 439 Whites, 5776 African Americans and 17 115 Asians) from 40 studies to examine: (i) the association between the FTO-rs9939609 variant (or a proxy single-nucleotide polymorphism) and total energy and macronutrient intake and (ii) the interaction between the FTO variant and dietary intake on BMI. The minor allele (A-allele) of the FTO-rs9939609 variant was associated with higher BMI in Whites (effect per allele = 0.34 [0.31, 0.37] kg/m(2), P = 1.9 × 10(-105)), and all participants (0.30 [0.30, 0.35] kg/m(2), P = 3.6 × 10(-107)). The BMI-increasing allele of the FTO variant showed a significant association with higher dietary protein intake (effect per allele = 0.08 [0.06, 0.10] %, P = 2.4 × 10(-16)), and relative weak associations with lower total energy intake (-6.4 [-10.1, -2.6] kcal/day, P = 0.001) and lower dietary carbohydrate intake (-0.07 [-0.11, -0.02] %, P = 0.004). The associations with protein (P = 7.5 × 10(-9)) and total energy (P = 0.002) were attenuated but remained significant after adjustment for BMI. We did not find significant interactions between the FTO variant and dietary intake of total energy, protein, carbohydrate or fat on BMI. Our findings suggest a positive association between the BMI-increasing allele of FTO variant and higher dietary protein intake and offer insight into potential link between FTO, dietary protein intake and adiposity
Non-AIDS defining cancers in the D:A:D Study-time trends and predictors of survival : a cohort study
BACKGROUND:Non-AIDS defining cancers (NADC) are an important cause of morbidity and mortality in HIV-positive individuals. Using data from a large international cohort of HIV-positive individuals, we described the incidence of NADC from 2004-2010, and described subsequent mortality and predictors of these.METHODS:Individuals were followed from 1st January 2004/enrolment in study, until the earliest of a new NADC, 1st February 2010, death or six months after the patient's last visit. Incidence rates were estimated for each year of follow-up, overall and stratified by gender, age and mode of HIV acquisition. Cumulative risk of mortality following NADC diagnosis was summarised using Kaplan-Meier methods, with follow-up for these analyses from the date of NADC diagnosis until the patient's death, 1st February 2010 or 6 months after the patient's last visit. Factors associated with mortality following NADC diagnosis were identified using multivariable Cox proportional hazards regression.RESULTS:Over 176,775 person-years (PY), 880 (2.1%) patients developed a new NADC (incidence: 4.98/1000PY [95% confidence interval 4.65, 5.31]). Over a third of these patients (327, 37.2%) had died by 1st February 2010. Time trends for lung cancer, anal cancer and Hodgkin's lymphoma were broadly consistent. Kaplan-Meier cumulative mortality estimates at 1, 3 and 5 years after NADC diagnosis were 28.2% [95% CI 25.1-31.2], 42.0% [38.2-45.8] and 47.3% [42.4-52.2], respectively. Significant predictors of poorer survival after diagnosis of NADC were lung cancer (compared to other cancer types), male gender, non-white ethnicity, and smoking status. Later year of diagnosis and higher CD4 count at NADC diagnosis were associated with improved survival. The incidence of NADC remained stable over the period 2004-2010 in this large observational cohort.CONCLUSIONS:The prognosis after diagnosis of NADC, in particular lung cancer and disseminated cancer, is poor but has improved somewhat over time. Modifiable risk factors, such as smoking and low CD4 counts, were associated with mortality following a diagnosis of NADC
A new and highly sensitive continuous wave near infrared spectrophotometer with multiple detectors.
Lateral frontal cortex oxygenation changes during translation and language switching revealed by non-invasive near-infrared multi-point measurements.
Item does not contain fulltextThe organisation of language in the brain of multilingual people remains controversial. Using a high temporal resolution 12-channel near-infrared continuous wave spectroscopy system, we have demonstrated that it is possible to monitor non-invasively, comfortably and, without the interferences due to intrinsic limitations of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), cortical oxygenation changes in the Broca's area in response to translation of short sentences and language switching. Eight Dutch students proficient in English translated aloud from their native language into English or vice versa or alternating (switching) short visually presented sentences. These tasks provoked, in the left inferior frontal cortex which includes the Broca's area, a consistent and incremental rise in oxyhaemoglobin accompanied by a smaller decrease in deoxyhaemoglobin. The investigated cortical areas surrounding the Broca's area showed no uniform and consistent oxygenation changes upon the three different translation tasks. These results confirm that Broca's area is involved in the translation process and its so called activation is unaffected by the direction of the translation. In addition, these results strengthen the role of near-infrared multi-point measurements as a powerful tool for investigating the spatial and temporal features of the cortical oxygenation changes during language processing
Ventilatory response in metabolic acidosis and cerebral blood volume in humans.
Item does not contain fulltextThe relationship between alterations in cerebral blood volume (CBV) and central chemosensitivity regulation was studied under neutral metabolic conditions and during metabolic acidosis. Fifteen healthy subjects (5610 years) were investigated. To induce metabolic acidosis, ammonium chloride (NH(4)Cl) was given orally. CBV was measured using Near Infrared Spectroscopy during normo- and hypercapnia and related to inspired ventilation (V(i)). A mean acute metabolic acidosis of Delta pH - 0.04 was realized with a mean decreased arterialized capillary PCO(2) (P(c)CO(2)) of 0.20 kPa (1.5 mmHg) (both P<0.001). During normocapnia, CBV was 3.510.71 and 3.650.56 ml 100 g(-1) (meanS.D.), measured under neutral metabolic conditions and during acute metabolic acidosis, respectively (ns). Corresponding values of V(i) were 7.61.4 and 10.02.4 l min(-1) (P<0.01), respectively. The slopes of the CO(2)-responsiveness (DeltaCBV/DeltaP(c)CO(2) and DeltaV(i)/DeltaP(c)CO(2)), were not significantly different during both metabolic conditions. A significant correlation between DeltaCBV/DeltaP(c)CO(2) and DeltaV(i)/DeltaP(c)CO(2) was found during metabolic acidosis (P<0.01), but not under neutral metabolic conditions. CBV does not contribute in a predictable way to the regulation of central chemoreceptors
Effects of acetazolamide and furosemide on ventilation and cerebral blood volume in normocapnic and hypercapnic patients with COPD.
STUDY OBJECTIVES: Effects of chronic metabolic alkalosis and acidosis and their relation to central chemoregulation may differ between normocapnic and chronic hypercapnic patients with COPD. The relationship between responses of inspired ventilation (VI), mouth occlusion pressure (P(0.1)), and cerebral blood volume (CBV), to short-term changes in arterial PCO(2) was measured. PATIENTS AND METHODS: Seventeen patients with chronic hypercapnia and COPD (PaCO(2) > 6.0 kPa) and 16 normocapnic patients with COPD (PaCO(2) 1 kPa) was induced by administering adequate amounts of carbon dioxide in the inspired air. CBV was measured using near-infrared spectroscopy. RESULTS: Compared with baseline metabolic condition, chronic metabolic acidosis and alkalosis did not change ventilatory (Delta VI/Delta PaCO(2)) and cerebrovascular (Delta CBV/Delta PaCO(2)) reactivity. Base excess (BE) decreased by 6.8 +/- 1.1 mEq/L and 6.9 +/- 1.6 mEq/L, respectively, in the normocapnic and chronic hypercapnic COPD groups during metabolic acidosis, resulting in a not-quite-significant leftward shift of both the ventilatory and cerebrovascular carbon dioxide response curve. BE increased by 2.3 +/- 1.2 mEq/L and 1.2 +/- 1.3 mEq/L, respectively, during chronic metabolic alkalosis in both COPD groups, without concomitant shift. Poor correlations between ventilatory and cerebrovascular carbon dioxide responsiveness (Delta CBV/Delta PaCO(2) and Delta VI/Delta PaCO(2), Delta CBV/Delta PaCO(2) and Delta P(0.1)/Delta PaCO(2), respectively) were found irrespective of baseline, respiratory condition, and induced metabolic state. CONCLUSIONS: Normocapnic and chronic hypercapnic COPD patients have the same ventilatory and cerebrovascular carbon dioxide responsiveness irrespective of induced metabolic state
Can cerebral blood volume be measured reproducibly with an improved near infrared spectroscopy system?
Item does not contain fulltextIn some circumstances, cerebral blood volume (CBV) can be used as a measure for cerebral blood flow. A new near infrared spectroscope was used for determining the reproducibility of CBV measurements assessed by the O2-method. Twenty-seven healthy subjects were investigated. An intrasubject coefficient of variation (CV) was calculated, based on four identical episodes of desaturation-resaturation (O2-method) procedures for CBV measurements. Two trials were performed, with (trial 1) and without (trial 2) disconnecting the equipment. A mean CV of 12.6% and 10.0% was found in trial 1 and 2, respectively. Cerebral blood volume values yield 3.600.82 mL 100 g(-1). Cerebral blood volume could be measured reproducible in adults using near infrared spectroscopy, if the arterial desaturation is limited to approximately 5% from baseline level