Effect of autonomic blocking agents on the respiratory-related oscillations of ventricular action potential duration in humans

Ventricular action potential duration (APD) is an important component of many physiological functions including arrhythmogenesis. APD oscillations have recently been reported in humans at the respiratory frequency. This study investigates the contribution of the autonomic nervous system to these oscillations. In 10 patients undergoing treatment for supraventricular arrhythmias, activation recovery intervals (ARI; a conventional surrogate for APD) were measured from multiple left and right ventricular (RV) endocardial sites, together with femoral artery pressure. Respiration was voluntarily regulated and heart rate clamped by RV pacing. Sympathetic and parasympathetic blockade was achieved using intravenous metoprolol and atropine, respectively. Metroprolol reduced the rate of pressure development (maximal change in pressure over time): 1,271 (± 646) vs. 930 (± 433) mmHg/s; P < 0.01. Systolic blood pressure (SBP) showed a trend to decrease after metoprolol, 133 (± 21) vs. 128 (± 25) mmHg; P = 0.06, and atropine infusion, 122 (± 26) mmHg; P < 0.05. ARI and SBP exhibited significant cyclical variations (P < 0.05) with respiration in all subjects with peak-to-peak amplitudes ranging between 0.7 and 17.0 mmHg and 1 and 16 ms, respectively. Infusion of metoprolol reduced the mean peak-to-peak amplitude [ARI, 6.2 (± 1.4) vs. 4.4 (± 1.0) ms, P = 0.008; SBP, 8.4 (± 1.6) vs. 6.2 (± 2.0) mmHg, P = 0.002]. The addition of atropine had no significant effect. ARI, SBP, and respiration showed significant coupling (P < 0.05) at the breathing frequency in all subjects. Directed coherence from respiration to ARI was high and reduced after metoprolol infusion [0.70 (± 0.17) vs. 0.50 (± 0.23); P < 0.05]. These results suggest a role of respiration in modulating the electrophysiology of ventricular myocardium in humans, which is partly, but not totally, mediated by β-adrenergic mechanisms

Differences in Self-Rated Versus Parent Proxy–Rated Vision-Related Quality of Life and Functional Vision of Visually Impaired Children

PURPOSE: To investigate disagreement between children's self-reported vision-related quality of life (VQoL) and functional vision (FV), and their parents' proxy-reports. DESIGN: Cross-sectional study. METHODS: 152 children aged 7-18 years with visual impairment (VI) (defined by the World Health Organization), and their parents, were recruited from 22 National Health Service (NHS) Ophthalmology Departments in the United Kingdom. Age-appropriate versions of 2 vision-specific instruments capturing VQoL and FV, were administered to children alongside modified versions for completion by parents on behalf of their child (i.e. parent proxy-report). Disagreement between self- and parent proxy-report was examined using the Bland-Altman (BA) method, and a threshold of disagreement based on 0.5 standard deviation. Disagreement was analysed according to participants' age, gender and clinical characteristics, using logistic regression analyses. RESULTS: Children rated themselves as having better outcomes than their parents did, although parents both under- and over-estimated their child's VQoL (mean score difference = 7.7). With each year of increasing age, there was a 1.18 (1.04 - 1.35) higher odds of children self-rating their VQoL better than their parents (p = 0.013). Although parents consistently under-estimated their child's FV (mean score difference = -4.7), no characteristics were significantly associated with differences in disagreement. CONCLUSIONS: Disagreement between child self-report on the impact of VI, and their parents' proxy-reports varies by age. This implies that self-report from children must remain the gold standard. Where self-reporting is not possible, parent proxy-reports may provide useful insights, but must be interpreted with caution

Myocardial ischemia in the absence of epicardial coronary artery disease in Friedreich's ataxia

We present the first in vivo detection of microvascular abnormality in a patient with Friedreich's ataxia (FA) without epicardial coronary artery disease using cardiac magnetic resonance (CMR). The patient had exertional chest pain and dyspnea prompting referral for cardiac evaluation. These symptoms were reproduced during intravenous adenosine infusion, and simultaneous first-pass perfusion imaging showed a significant subendocardial defect; both symptoms and perfusion deficit were absent at rest. Epicardial coronaries were free of disease by invasive angiography; together, these findings support the notion of impaired myocardial perfusion reserve in FA

A patient-reported outcome measure of functional vision for children and young people aged 8 to 18 years with visual impairment

Purpose: To develop age-appropriate extensions of a patient-reported outcome measure for capturing the functional impact of visual impairment on daily activities of children and young people aged 8 up to 18 years. Design: Questionnaire development and validation study. Setting: Pediatric Ophthalmology departments at Great Ormond Street Hospital and Moorfields Eye Hospital, and, in the final study phase, 20 further UK hospitals. Participants: Children and young people (aged 6-19 years) with visual impairment (acuity of the logarithm of the minimum angle of resolution (LogMAR) worse than 0.50 in the better eye) due to any cause but without significant non-ophthalmic impairments. Methods: We used our prototype FVQ_CYP for 10-15 year olds as the foundation. Twenty-nine semi-structured interviews confirmed relevance of existing, and identified new, age-specific items. Twenty-eight cognitive interviews captured information regarding comprehensibility and format. The FVQ_Child (8-12 years) and FVQ_Young Person (13-18 years), were evaluated with a national sample of 113 children and 96 young people using Rasch analysis. Results: Issues emerging from interviews with children and young people were largely congruent with those elicited originally with 10-15 year olds. The 28-item FVQ_Child and 38-item FVQ_Young Person versions have goodness-of-fit statistics within the interval 0.5, 1.5 and person separation values of 5.87 and 6.09 respectively. Twenty-four overlapping ‘core’ items enabled their calibration on the same measurement scale. Correlations with acuity (r = 0.47) demonstrated construct validity. Conclusions: The FVQ_C and FVQ_Young Person are robust age-appropriate versions of the FVQ_CYP which can be used cross-sectionally or sequentially/longitudinally across the age-range of 8-18 years in clinical practice and research

ERCC1 expression and RAD51B activity correlate with cell cycle response to platinum drug treatment not DNA repair

Background: The H69CIS200 and H69OX400 cell lines are novel models of low-level platinum-drug resistance. Resistance was not associated with increased cellular glutathione or decreased accumulation of platinum, rather the resistant cell lines have a cell cycle alteration allowing them to rapidly proliferate post drug treatment. Results: A decrease in ERCC1 protein expression and an increase in RAD51B foci activity was observed in association with the platinum induced cell cycle arrest but these changes did not correlate with resistance or altered DNA repair capacity. The H69 cells and resistant cell lines have a p53 mutation and consequently decrease expression of p21 in response to platinum drug treatment, promoting progression of the cell cycle instead of increasing p21 to maintain the arrest. Conclusion: Decreased ERCC1 protein and increased RAD51B foci may in part be mediating the maintenance of the cell cycle arrest in the sensitive cells. Resistance in the H69CIS200 and H69OX400 cells may therefore involve the regulation of ERCC1 and RAD51B independent of their roles in DNA repair. The novel mechanism of platinum resistance in the H69CIS200 and H69OX400 cells demonstrates the multifactorial nature of platinum resistance which can occur independently of alterations in DNA repair capacity and changes in ERCC1

Violence against primary school children with disabilities in Uganda: a cross-sectional study.

BACKGROUND: 150 million children live with disabilities globally, and a recent systematic review found 3 to 4 times the levels of violence versus non-disabled children in high income countries. However, almost nothing is known about violence against disabled children in lower income countries. We aim to explore the prevalence, patterns and risk factors for physical, sexual and emotional violence among disabled children attending primary school in Luwero District, Uganda. METHODS: We performed a secondary analysis of data from the baseline survey of the Good Schools Study. 3706 children and young adolescents aged 11-14 were randomly sampled from 42 primary schools. Descriptive statistics were computed and logistic regression models fitted. RESULTS: 8.8% of boys and 7.6% of girls reported a disability. Levels of violence against both disabled and non-disabled children were extremely high. Disabled girls report slightly more physical (99.1% vs 94.6%, p = 0.010) and considerably more sexual violence (23.6% vs 12.3%, p = 0.002) than non-disabled girls; for disabled and non-disabled boys, levels are not statistically different. The school environment is one of the main venues at which violence is occurring, but patterns differ by sex. Risk factors for violence are similar between disabled and non-disabled students. CONCLUSIONS: In Uganda, disabled girls are at particular risk of violence, notably sexual violence. Schools may be a promising venue for intervention delivery. Further research on the epidemiology and prevention of violence against disabled and non-disabled children in low income countries is urgently needed

Seatbelt use and risk of major injuries sustained by vehicle occupants during motor-vehicle crashes: A systematic review and meta-analysis of cohort studies

BackgroundIn 2004, a World Health Report on road safety called for enforcement of measures such as seatbelt use, effective at minimizing morbidity and mortality caused by road traffic accidents. However, injuries caused by seatbelt use have also been described. Over a decade after publication of the World Health Report on road safety, this study sought to investigate the relationship between seatbelt use and major injuries in belted compared to unbelted passengers.MethodsCohort studies published in English language from 2005 to 2018 were retrieved from seven databases. Critical appraisal of studies was carried out using the Scottish Intercollegiate Guidelines Network (SIGN) checklist. Pooled risk of major injuries was assessed using the random effects meta-analytic model. Heterogeneity was quantified using I-squared and Tau-squared statistics. Funnel plots and Egger's test were used to investigate publication bias. This review is registered in PROSPERO (CRD42015020309).ResultsEleven studies, all carried out in developed countries were included. Overall, the risk of any major injury was significantly lower in belted passengers compared to unbelted passengers (RR 0.47; 95%CI, 0.29 to 0.80; I-2=99.7; P=0.000). When analysed by crash types, belt use significantly reduced the risk of any injury (RR 0.35; 95%CI, 0.24 to 0.52). Seatbelt use reduces the risk of facial injuries (RR=0.56, 95% CI=0.37 to 0.84), abdominal injuries (RR=0.87; 95% CI=0.78 to 0.98) and, spinal injuries (RR=0.56, 95% CI=0.37 to 0.84). However, we found no statistically significant difference in risk of head injuries (RR=0.49; 95% CI=0.22 to 1.08), neck injuries (RR=0.69: 95%CI 0.07 to 6.44), thoracic injuries (RR 0.96, 95%CI, 0.74 to 1.24), upper limb injuries (RR=1.05, 95%CI 0.83 to 1.34) and lower limb injuries (RR=0.77, 95%CI 0.58 to 1.04) between belted and non-belted passengers.ConclusionIn sum, the risk of most major road traffic injuries is lower in seatbelt users. Findings were inconclusive regarding seatbelt use and susceptibility to thoracic, head and neck injuries during road traffic accidents. Awareness should be raised about the dangers of inadequate seatbelt use. Future research should aim to assess the effects of seatbelt use on major injuries by crash type

The Reform of Employee Compensation in China’s Industrial Enterprises

Although employee compensation reform in Chinese industrial sector has been discussed in the literature, the real changes in compensation system and pay practices have received insufficient attention and warrant further examination. This paper briefly reviews the pre- and post-reform compensation system, and reports the results of a survey of pay practices in the four major types of industrial enterprises in China. The research findings indicate that the type of enterprise ownership has little influence on general compensation practices, adoption of profit-sharing plans, and subsidy and allowance packages. In general, pay is linked more to individual performance and has become an important incentive to Chinese employees. However, differences are found across the enterprise types with regard to performance-related pay. Current pay practices are positively correlated to overall effectiveness of the enterprise

Non-adherence to the single dose nevirapine regimen for the prevention of mother-to-child transmission of HIV in Bindura town, Zimbabwe: a cross-sectional analytic study

<p>Abstract</p> <p>Background</p> <p>The Prevention of Mother to Child Transmission of HIV (PMTCT) programme was introduced at Bindura Hospital in 2003. Seven additional satellite PMTCT clinics were set up in the district to increase service coverage but uptake of PMTCT interventions remained unsatisfactory. In this study we determined the prevalence of and factors associated with non-adherence to the single dose nevirapine (SD-NVP) regimen for PMTCT in Bindura town.</p> <p>Methods</p> <p>An analytic cross-sectional study was conducted in four health institutions in Bindura town. Participants were mother-baby pairs on the PMTCT programme attending routine six weeks post natal visits in the participating health institutions from March to July 2008. We interviewed 212 mothers using a structured questionnaire.</p> <p>Results</p> <p>The non-adherence rate to the maternal nevirapine dose was 30.7%, while non-adherence to the newborn nevirapine dose was 26.9%. The combined mother-baby pair nevirapine non-adherence was 42.9%. Non-adherence to the maternal dose of nevirapine was associated with lack of maternal secondary education (POR = 2.38; 95%CI: 1.05-3.39) and multi-parity (POR = 2.66; 95%CI: 1.05-6.72), while previous maternal exposure to the PMTCT programme (POR = 0.22; 95%CI: 0.08-0.57) and giving the mother a NVP tablet to take home during antenatal care (POR = 0.03; 95%CI: 0.01-0.09) were associated with improved maternal adherence to nevirapine. Non-adherence to the infant dose of nevirapine was associated with maternal non-disclosure of HIV results to sexual partner (POR = 2.75; 95%CI: 1.04-7.32) and home deliveries (POR = 48.76; 95%CI: 17.51-135.82).</p> <p>Conclusions</p> <p>Non-adherence to nevirapine prophylaxis for PMTCT was high in Bindura. Ensuring institutional deliveries, encouraging self-disclosure of HIV results by the mothers to their partners and giving HIV positive mothers nevirapine doses to take home early in pregnancy all play significant roles in improving adherence to PMTCT prophylaxis.</p

Investigation on the Plasma-Induced Emission Properties of Large Area Carbon Nanotube Array Cathodes with Different Morphologies

Large area well-aligned carbon nanotube (CNT) arrays with different morphologies were synthesized by using a chemical vapor deposition. The plasma-induced emission properties of CNT array cathodes with different morphologies were investigated. The ratio of CNT height to CNT-to-CNT distance has considerable effects on their plasma-induced emission properties. As the ratio increases, emission currents of CNT array cathodes decrease due to screening effects. Under the pulse electric field of about 6 V/μm, high-intensity electron beams of 170–180 A/cm2 were emitted from the surface plasma. The production mechanism of the high-intensity electron beams emitted from the CNT arrays was plasma-induced emission. Moreover, the distribution of the electron beams was in situ characterized by the light emission from the surface plasma