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101.
Clément Medrinal Guillaume Prieur Yann Combret Aurora Robledo Quesada David Debeaumont Tristan Bonnevie Francis Edouard Gravier Elise Dupuis Lozeron Jean Quieffin Olivier Contal Bouchra Lamia 《Archives of physical medicine and rehabilitation》2018,99(8):1454-1461
Objective
To evaluate the effect of quadriceps functional electrical stimulation (FES)-cycling on exertional oxygen uptake (o2) compared with placebo FES-cycling in patients with chronic obstructive pulmonary disease (COPD).Design
A randomized, single-blind, placebo-controlled crossover trial.Setting
Pulmonary rehabilitation department.Participants
Consecutive patients (N=23) with COPD Global Initiative for Chronic Obstructive Lung Disease stage 2, 3, or 4 (mean forced expiratory volume during the first second, 1.4±0.4L [50.3% predicted]) who had recently begun a respiratory rehabilitation program.Intervention
Two consecutive 30-minute sessions were carried out at a constant load with active and placebo FES-cycling.Main Outcome Measures
The primary outcome was mean o2 during the 30-minute exercise session. The secondary outcomes were respiratory gas exchange and hemodynamic parameters averaged over the 30-minute endurance session. Lactate values, dyspnea, and perceived muscle fatigue were evaluated at the end of the sessions.Results
FES-cycling increased the physiological response more than the placebo, with a greater o2 achieved of 36.6mL/min (95% confidence interval [CI], 8.9–64.3mL/min) (P=.01). There was also a greater increase in lactate after FES-cycling (+1.5mmol/L [95% CI, .05–2.9mmol/L]; P=.01). FES-cycling did not change dyspnea or muscle fatigue compared with the placebo condition.Conclusions
FES-cycling effectively increased exercise intensity in patients with COPD. Further studies should evaluate longer-term FES-cycling rehabilitation programs. 相似文献102.
Morgan K. Boes Rachel E. Bollaert Richard M. Kesler Yvonne C. Learmonth Mazharul Islam Matthew N. Petrucci Robert W. Motl Elizabeth T. Hsiao-Wecksler 《Archives of physical medicine and rehabilitation》2018,99(3):484-490
Objective
To determine whether a powered ankle-foot orthosis (AFO) that provides dorsiflexor and plantar flexor assistance at the ankle can improve walking endurance of persons with multiple sclerosis (MS).Design
Short-term intervention.Setting
University research laboratory.Participants
Participants (N=16) with a neurologist-confirmed diagnosis of MS and daily use of a prescribed custom unilateral passive AFO.Interventions
Three 6-minute walk tests (6MWTs), 1 per footwear condition: shoes (no AFO), prescribed passive AFO, and portable powered AFO (PPAFO). Assistive devices were worn on the impaired limb.Main Outcome Measures
Distance walked and metabolic cost of transport were recorded during each 6MWT and compared between footwear conditions.Results
Each participant completed all three 6MWTs within the experimental design. PPAFO use resulted in a shorter 6MWT distance than did a passive AFO or shoe use. No differences were observed in metabolic cost of transport between footwear conditions.Conclusions
The current embodiment of this PPAFO did not improve endurance walking performance during the 6MWT in a sample of participants with gait impairment due to MS. Further research is required to determine whether expanded training or modified design of this powered orthosis can be effective in improving endurance walking performance in persons with gait impairment due to MS. 相似文献103.
The total margin of exposure of ethanol and acetaldehyde for heavy drinkers consuming cider or vodka
Heavy drinkers in Scotland may consume 1600 g ethanol per week. Due to its low price, cider may be preferred over other beverages. Anecdotal evidence has linked cider to specific health hazards beyond other alcoholic beverages. To examine this hypothesis, nine apple and pear cider samples were chemically analysed for constituents and contaminants. None of the products exceeded regulatory or toxicological thresholds, but the regular occurrence of acetaldehyde in cider was detected. To provide a quantitative risk assessment, two collectives of exclusive drinkers of cider and vodka were compared and the intake of acetaldehyde was estimated using probabilistic Monte–Carlo type analysis. The cider consumers were found to ingest more than 200-times the amount of acetaldehyde consumed by vodka consumers. The margins of exposure (MOE) of acetaldehyde were 224 for the cider and over 220,000 for vodka consumers. However, if the effects of ethanol were considered in a cumulative assessment of the combined MOE, the effect of acetaldehyde was minor and the combined MOE for both groups was 0.3. We suggest that alcohol policy priority should be given on reducing ethanol intake by measures such as minimum pricing, rather than to focus on acetaldehyde. 相似文献
104.
Data generated using standardized testing protocols for toxicity studies generally provide reproducible and reliable results for establishing safe levels and formulating risk assessments. The findings of three OECD guideline-type oral toxicity studies of different duration in rats are summarized in this publication; each study evaluated different titanium dioxide (TiO2) particles of varying sizes and surface coatings. Moreover, each study finding demonstrated an absence of any TiO2 -related hazards. To briefly summarize the findings: 1) In a subchronic 90-day study (OECD TG 408), groups of young adult male and female rats were dosed with rutile-type, surface-coated pigment-grade TiO2 test particles (d50 = 145 nm − 21% nanoparticles by particle number criteria) by oral gavage for 90 days. The no-adverse-effect level (NOAEL) for both male and female rats in this study was 1000 mg/kg bw/day, the highest dose tested. The NOAEL was determined based on a lack of TiO2 particle-related adverse effects on any in-life, clinical pathology, or anatomic/microscopic pathology parameters; 2) In a 28-day repeated-dose oral toxicity study (OECD TG 407), groups of young adult male rats were administered daily doses of two rutile-type, uncoated, pigment-grade TiO2 test particles (d50 = 173 nm by number) by daily oral gavage at a dose of 24,000 mg/kg bw/day. There were no adverse effects measured during or following the end of the exposure period; and the NOAEL was determined to be 24,000 mg/kg bw/day; 3) In an acute oral toxicity study (OECD TG 425), female rats were administered a single oral exposure of surface-treated rutile/anatase nanoscale TiO2 particles (d50 = 73 nm by number) with doses up to 5000 mg/kg and evaluated over a 14-day post-exposure period. Under the conditions of this study, the oral LD50 for the test substance was >5000 mg/kg bw. In summary, the results from these three toxicity studies – each with different TiO2 particulate-types, demonstrated an absence of adverse toxicological effects. Apart from reporting the findings of these three studies, this publication also focuses on additional critical issues associated with particle and nanotoxicology studies. First, describing the detailed methodology requirements and rigor upon which the standardized OECD 408 guideline subchronic oral toxicity studies are conducted. Moreover, an attempt is made to reconcile the complex issue of particle size distribution as it relates to measurements of nanoscale and pigment-grade TiO2 particles. Clearly this has been a confusing issue and often misrepresented in the media and the scientific literature. It is clear that the particle-size distribution for pigment-grade TiO2, contains a small (“tail”) component of nanoscale particles (i.e., 21% by particle number and <1% by weight in the test material used in the 90-day study). However, this robust particle characterization finding should not be confused with mislabeling the test materials as exclusively in the nanoscale range. Moreover, based upon the findings presented herein, there appears to be no significant oral toxicity impact contributed by the nanoscale component of the TiO2 Test Material sample in the 90-day study. Finally, it seems reasonable to conclude that the study findings should be considered for read-across purposes to food-grade TiO2 particles (e.g., E171), as the physicochemical characteristics are quite similar. 相似文献
105.
Biological effect of food additive titanium dioxide nanoparticles on intestine: an in vitro study 下载免费PDF全文
Zheng‐Mei Song Ni Chen Jia‐Hui Liu Huan Tang Xiaoyong Deng Wen‐Song Xi Kai Han Aoneng Cao Yuanfang Liu Haifang Wang 《Journal of applied toxicology : JAT》2015,35(10):1169-1178
Titanium dioxide nanoparticles (TiO2 NPs) are widely found in food‐related consumer products. Understanding the effect of TiO2 NPs on the intestinal barrier and absorption is essential and vital for the safety assessment of orally administrated TiO2 NPs. In this study, the cytotoxicity and translocation of two native TiO2 NPs, and these two TiO2 NPs pretreated with the digestion simulation fluid or bovine serum albumin were investigated in undifferentiated Caco‐2 cells, differentiated Caco‐2 cells and Caco‐2 monolayer. TiO2 NPs with a concentration less than 200 µg ml–1 did not induce any toxicity in differentiated cells and Caco‐2 monolayer after 24 h exposure. However, TiO2 NPs pretreated with digestion simulation fluids at 200 µg ml–1 inhibited the growth of undifferentiated Caco‐2 cells. Undifferentiated Caco‐2 cells swallowed native TiO2 NPs easily, but not pretreated NPs, implying the protein coating on NPs impeded the cellular uptake. Compared with undifferentiated cells, differentiated ones possessed much lower uptake ability of these TiO2 NPs. Similarly, the traverse of TiO2 NPs through the Caco‐2 monolayer was also negligible. Therefore, we infer the possibility of TiO2 NPs traversing through the intestine of animal or human after oral intake is quite low. This study provides valuable information for the risk assessment of TiO2 NPs in food. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
106.
Baoyong Sha Wei Gao Xingye Cui Lin Wang Feng Xu 《Journal of applied toxicology : JAT》2015,35(10):1086-1101
Titanium dioxide (TiO2) nanomaterials (NMs) have found widespread applications owing to their attractive physical and chemical properties. As a result, the potential adverse impacts of nano‐TiO2 exposure on humans have become a matter of concern. This review presents the state‐of‐the‐art advances on the investigations of the adverse effects of NMs, including the potential exposure routes of nano‐TiO2 (e.g. respiratory system, skin absorption and digestive system), the physico‐chemical characterizations of nano‐TiO2 (e.g. crystal structure, shape,size, zeta potential, treatment media, aggregation and agglomeration tendency, surface characteristics and coatings), risk evaluation of nanotoxicity (e.g. cytotoxicity, ecotoxicity, phototoxicity, and phytotoxicity) and potential mechanisms of adverse effects (e.g. generation of reactive oxygen species, oxidative stress and organelle dysfunction). The review aims to facilitate scientific assessments of health risks to nano‐TiO2, which would guide the safe applications of NMs in our daily life. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
107.
[目的]了解某大型商场的空气质量状况,分析其变化规律及影响因素. [方法]于2013年对北京市某商场空气质量进行监测,监测点为2个商品售卖区和1个餐饮区,监测指标包括温度、湿度、可吸入颗粒物(PM10)、甲醛、一氧化碳(CO)、二氧化碳(CO2),通过远程数据传输技术收集数据并分析. [结果]监测指标中,CO2合格率(100%)最高;其次是温度、PM10、CO和甲醛,合格率分别为98.82%、96.81%、84.73%、69.41%;湿度合格率最低(仅29.36%).商场内不同季节湿度变化明显(P<0.05); PM10浓度与室外PM10浓度、客流量存在正相关(r=0.681,r=-0.162;P<0.05);餐饮区CO和CO2浓度高于其他2个监测点,浓度较高的时段与营业高峰时段一致;甲醛浓度波动较大,甲醛最高浓度达0.214 mg/m3,与商场内湿度呈正相关(r=0.740,P< 0.05),不同监测点甲醛浓度差异有统计学意义(P<0.05).[结论] PM10、CO、甲醛是该商场空气质量的主要危害因素.室外PM10浓度和客流量是影响商场内PM10浓度的主要因素;餐饮活动是CO的主要污染来源,客流量增加引起餐饮活动增多间接影响CO浓度;甲醛污染在商场内持续存在,湿度升高加速甲醛释放,局部装修加剧污染程度.商场应采取集中空调分区域运行,及时调整新风量等措施提高空气质量. 相似文献
108.
目的探讨断乳至性成熟期经口持续摄入纳米二氧化硅对小鼠卵巢发育的影响。方法将40只21日龄清洁级ICR雌性小鼠随机分为4组,即对照组和0.25、0.50、1.00 g/kg纳米二氧化硅染毒组,每组10只。采用经口灌胃方式进行染毒,每日1次,持续染毒5周。实验结束后记录小鼠体重增长情况、观察阴门开放时间和动情周期,病理切片计数各级卵泡数量及计算各级卵泡的构成比,并测定卵巢中丙二醛(MDA)含量和超氧化歧化酶(SOD)、谷胱苷肽过氧化物酶(GSH-Px)活力。结果与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢重量和脏器系数下降、阴门开放时间推迟、卵巢黄体构成比下降、闭锁卵泡构成比升高,差异有统计学意义(P0.05);而各剂量纳米二氧化硅染毒组小鼠体重增长和动情周期均无明显改变。与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中MDA含量明显上升,SOD活力均明显下降,而0.50、1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中GSH-Px活力均升高,差异具有统计学意义(P0.05)。结论经口摄入纳米二氧化硅可影响小鼠卵巢发育,其机制可能与氧化损伤有关。 相似文献
109.
《Respiratory investigation》2022,60(5):658-666
BackgroundThe effects of exercise training using both high fraction of inspired oxygen (FIO2) and high flow oxygen delivered through a high-flow nasal cannula (HFNC) on exercise capacity in patients with chronic respiratory failure (CRF) receiving long-term oxygen therapy (LTOT) are unknown.MethodsIn this randomized study, 32 patients with CRF receiving LTOT were assigned to undergo 4 weeks of exercise training on a cycle ergometer using an HFNC (flow: 50 L/min) with a FIO2 of 1.0 (HFNC group; n = 16) or ordinary supplemental oxygen via a nasal cannula (flow: 6 L/min) (oxygen group; n = 16). A 6-min walking test and a constant-load test were performed before and after 4 weeks of exercise training.ResultsFollowing 4 weeks of exercise training, change in the 6-min walking distance was significantly greater in the HFNC than in the oxygen group (55.2 ± 69.6 m vs. −0.5 ± 87.3 m; p = 0.04). However, there was no significant difference between the two groups in the degree of improvement in the duration of the constant-load exercise test after exercise training.ConclusionsConsidering the effect on daily activities (e.g., walking), exercise training using both high FIO2 and high flow through an HFNC is a potentially superior exercise training modality for patients with CRF receiving LTOT.Clinical Trial Registration — http://www.clinicaltrials.gov. Unique identifier: NCT02804243 相似文献
110.