Neuromuscular Responses during Knee Extension Exercise in Combination with Different Blood Flow Restriction Initial Pressures

Specifications of blood flow restriction training technique have been widely discussed to create a valid and reliable protocol. One of the unexplored variables is the effect of different initial restrictive pressures (tightness of cuffs, IRP) in combination with resistance exercise on neuromuscular responses and strength. PURPOSE: The purpose of this study was to determine any differences in amplitude (RMS) and median frequency (MDF) of electromyography (EMG) signals, as well as changes in strength during knee extension exercises with IRPs of 40-45 mmHg and 60-65 mmHg. METHODS: Twenty male subjects (age = 25.7 ± 4.3 yrs), participated in this study. They were required to attend the lab on 3 different occasions, with the first one being a familiarization session. On the subsequent sessions, participant\u27s upper leg was measured starting from the lateral epicondyle to the greater trochanter of the femur. An EMG electrode was placed at one-third the distance over the longitudinal axis of the vastus lateralis (VL) after shaving, abrading and cleaning with isopropyl alcohol. Initial restrictive pressure was randomly selected and participants completed a pre-exercise maximum voluntary contraction (MVC) test to determine their torque. For dynamic exercises, load was set at 20% MVC and each participant performed one set of 30 repetitions and three sets of 15 repetitions, separated by one minute rest. Post-exercise MVC was performed to assess the changes in leg strength following exercises. RESULTS: Results showed significant main effects (p\u3c0.01) in leg strength for condition (40-45 mmHg vs. 60-65 mmHg) and trial (pre vs. post MVC). A significant main effect was observed for condition for MVC EMG amplitude (p\u3c0.01). In addition, there were significant main effects for contractions (p\u3c0.01) in both EMG amplitude and MDF during dynamic exercises. CONCLUSION: The significant decreases in knee extension strength at IRP of 60-65 mmHg compared to IRP of 40-45mmHg from pre- to post-exercise suggest that subjects experienced more fatigue at 60-65 mmHg because of the decreased availability of oxygen to the working muscle. The use of different IRP will affect the level of blood flow and oxygen supply to skeletal muscle possibly causing variation in neuromuscular adaptation due to changes in total and type of muscle fiber recruitment

A Comparison of Hypertrophy Potential between the Vastus Lateralis and Rectus Femoris during Level Walking in Combination with Vascular Restriction.

Recent research has found that by compressing blood flow to working muscle during lower body exercise involving short bouts of walk training results in an increased muscle volume and improved quadriceps strength. However, the effects of vascular restriction (VR) during walking on neuromuscular adaptations as assessed by electromyography (EMG) activity may provide insight on how low intensity training with vascular restriction can be applied to various modes of exercise. PURPOSE: The purpose of this study was to explore and compare muscle activation changes of the quadriceps muscles during walking using EMG with and without blood flow restriction. METHODS: EMG electrodes were placed along the longitudinal axis of the vastus lateralis (VL) and rectus femoris (RF) of the right thigh of seven male volunteers (mean ± SD age = 22.7 ± 6.8 years; height = 178 ±5.4 cm; weight = 82.6 ± 7.7 kg). Placement of the electrode was marked at a point of 33.3% on VL, and RF 50% of the distance between the lateral femoral epicondyle and the greater trochanter. On two separate testing sessions, subjects walked on a treadmill for two, 10 minutes bouts separated by a 5 min rest period at a speed of 80.4 m*min-1 with and without blood flow restriction. RESULTS: There were significant main effects for both condition (with and without VR) and muscles (VL and RF), as well as an interaction between condition and muscles (condition*muscle) for EMG amplitude (RMS). On the other hand, there were no significant main effects or interactions for EMG median frequency (MDF). CONCLUSION: The findings suggest that walking with VR might cause neural adaptation in both VL and RF, but the VL might have a better potential for hypertrophic response when performing slow walking with blood flow restriction. Walking speed and the pressure used for compression during walking might change the pattern of response, therefore, both need to be given careful consideration in the design of future studies

Neuromuscular Responses of the Vastus Lateralis to Slow Walking With Vascular Restriction.

Motor unit recruitment of individual muscles could substantially differ with changes in speed and load. However, the recruitment patterns associated with low intensity walk training with vascular restriction at sustained loads and constant speed could be different than normal walking. Vascular restricted (VR) walk training is an effective method for increasing muscular strength; however the changes in motor unit recruitment and firing frequency have not been investigated to understand the mechanisms underlying the neuromuscular adaptations. Purpose: The purpose of this study was to analyze differences in electrical activity of the vastus lateralis during VR and non vascular restricted (non-VR) walking sessions. Methods: Seven healthy males [means ± (SD): age 22.7±(6.8) yrs, height 178±(5.4) cm, weight 181.7±(16.9) lbs.] performed both a VR walking session and a non-VR walking session for 20 minutes on a treadmill at a speed of 80.4 m-minˉ¹. During each walking period the subjects wore surface EMG electrodes that were placed along the longitudinal axis of the vastus lateralis (VL) of the right thigh at a distance of 33.3% between the lateral femoral epicondyle and the greater trochanter. A repeated measures ANOVA was used to determine the differences in both EMG amplitude (RMS) and median frequency of firing (MDF). Results: The VR walking session resulted in significantly greater RMS values compared to the non-VR walking session (p \u3c 0.05); however there was no main effect for time or interaction between condition and time. For EMG MDF, there were no significant main effects for condition or time, and no significant interaction. Conclusion: The results indicate that walking during VR of the lower limbs may have a greater impact on neural adaptation of the VL due to increased motor unit activation as indicated by an increased RMS value. This might occur because blood flow restriction affects motor unit recruitment patterns resulting in the recruitment of more high-threshold, fast-twitch muscle fibers

Prevalencia de nacimientos pre-termino por peso al nacer: revision sistematica

OBJETIVO Estimar a prevalência de nascimentos pré-termo por faixas de peso ao nascer e obter uma equação para correção de estimativas. MÉTODOS Revisão sistemática da literatura nacional, de 1990 a 2012, para identificar estudos com coleta primária de informações sobre peso ao nascer e idade gestacional. Foram selecionados 12 que contribuíram com tabulações da prevalência de nascimentos pré-termo para faixas de 100 g de peso ao nascer. Os resultados desses estudos foram combinados pelo método de polinômios fracionais, sendo obtidas curvas separadas para meninos e meninas, comparadas com os resultados do Sistema de Informações sobre Nascidos Vivos para os anos 2000, 2005, 2010 e 2011. RESULTADOS As estimativas da prevalência de nascimentos pré-termo, obtidas a partir dos estudos primários, foram superiores às do Sistema de Informações sobre Nascidos Vivos para praticamente todas as faixas de peso ao nascer. A prevalência relatada pelo Sistema de Informações sobre Nascidos Vivos foi de 7,1% em 2010, cerca de 38% menor do que a estimativa de 11,7% obtida com a equação de correção. CONCLUSÕES Os dados do Sistema de Informações sobre Nascidos Vivos quanto à prevalência de nascimento pré-termo não refletem a verdadeira dimensão da prematuridade no Brasil. Assim sendo, para sua utilização, será necessária a aplicação do fator de correção, conforme proposto.OBJETIVO Estimar la prevalencia de nacimientos pre-término por rangos de peso al nacer y obtener una ecuación para corrección de estimaciones. MÉTODOS Revisión sistemática de la literatura nacional, de 1990 a 2012, para identificar estudios con colecta primaria de informaciones sobre peso al nacer y edad de gestación. Se seleccionaron 12 que contribuyeron con tabulaciones de la prevalencia de nacimientos pre-término para grupos de 100 g de peso al nacer. Los resultados de estos estudios fueron combinados por el método de polinomios fraccionales siendo obtenidas curvas separadas para niños y niñas, comparadas con los resultados del Sistema de Informaciones sobre Nacidos Vivos para los años 2000, 2005, 2010 y 2011. RESULTADOS Las estimaciones de la prevalencia de nacimientos pre-término, obtenidas a partir de los estudios primarios, fueron superiores a las del Sistema de Informaciones sobre Nacidos Vivos para prácticamente todos los grupos de peso al nacer. La prevalencia relatada por el Sistema de Informaciones sobre Nacidos Vivos fue de 7,1% en 2010, cerca de 38% menor que la estimativa de 11,7% obtenida con la ecuación de corrección. CONCLUSIONES Los datos del Sistema de Informaciones sobre Nacidos Vivos sobre prevalencia de nacimiento pre-término no reflejan la verdadera dimensión de la prematuridad en Brasil. Siendo así, para su utilización, será necesaria la aplicación del factor de corrección, conforme propuesto.OBJECTIVE To estimate the prevalence of preterm birth by categories of birth weight, and to obtain an equation to correct the estimates. METHODS Systematic review of the Brazilian literature published from 1990 to 2012, to identify studies with primary collection of data on birth weight and gestational age. Twelve studies were selected and contributed for tabulations of preterm prevalence according to 100 g birth weight categories. These results were combined using sex-specific fractional polynomial equations and the resulting curves were compared with results from the Live Birth Information System for the years 2000, 2005, 2010 and 2011. RESULTS For all birth weight categories, preterm prevalence estimates based on primary studies had a higher prevalence than those of the the Live Birth Information System. The prevalence reported by the Live Birth Information System was of 7.2% in 2010, about 38.0% lower than the estimated prevalence of 11.7% obtained with the correctional equation. CONCLUSIONS Information reported by the Live Birth Information System on preterm prevalence does not reflect the true magnitude of the problem in Brazil, and should not be used without the correction factors proposed in the present analyses

Epidemiology of Invasive Fungal Infections in Latin America

The pathogenic role of invasive fungal infections (IFIs) has increased during the past two decades in Latin America and worldwide, and the number of patients at risk has risen dramatically. Working habits and leisure activities have also been a focus of attention by public health officials, as endemic mycoses have provoked a number of outbreaks. An extensive search of medical literature from Latin America suggests that the incidence of IFIs from both endemic and opportunistic fungi has increased. The increase in endemic mycoses is probably related to population changes (migration, tourism, and increased population growth), whereas the increase in opportunistic mycoses may be associated with the greater number of people at risk. In both cases, the early and appropriate use of diagnostic procedures has improved diagnosis and outcome

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030