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Sports Medicine - Open Dec 2021Protection against airborne infection is currently, due to the COVID-19-associated restrictions, ubiquitously applied during public transport use, work and leisure time....
The Impact of Ubiquitous Face Masks and Filtering Face Piece Application During Rest, Work and Exercise on Gas Exchange, Pulmonary Function and Physical Performance: A Systematic Review with Meta-analysis.
BACKGROUND
Protection against airborne infection is currently, due to the COVID-19-associated restrictions, ubiquitously applied during public transport use, work and leisure time. Increased carbon dioxide re-inhalation and breathing resistance may result thereof and, in turn, may negatively impact metabolism and performance.
OBJECTIVES
To deduce the impact of the surgical mask and filtering face piece type 2 (FFP2) or N95 respirator application on gas exchange (pulse-derived oxygen saturation (SpO), carbon dioxide partial pressure (PCO), carbon dioxide exhalation (VCO) and oxygen uptake (VO)), pulmonary function (respiratory rate and ventilation) and physical performance (heart rate HR, peak power output W).
METHODS
Systematic review with meta-analysis. Literature available in Medline/Pubmed, the Cochrane Library and the Web of Knowledge with the last search on the 6 of May 2021. Eligibility criteria: Randomised controlled parallel group or crossover trials (RCT), full-text availability, comparison of the acute effects of ≥ 1 intervention (surgical mask or FFP2/N95 application) to a control/comparator condition (i.e. no mask wearing). Participants were required to be healthy humans and > 16 years of age without conditions or illnesses influencing pulmonary function or metabolism. Risk of bias was rated using the crossover extension of the Cochrane risk of bias assessment tool II. Standardised mean differences (SMD, Hedges' g) with 95% confidence intervals (CI) were calculated, overall and for subgroups based on mask and exercise type, as pooled effect size estimators in our random-effects meta-analysis.
RESULTS
Of the 1499 records retrieved, 14 RCTs (all crossover trials, high risk of bias) with 25 independent intervention arms (effect sizes per outcome) on 246 participants were included. Masks led to a decrease in SpO during vigorous intensity exercise (6 effect sizes; SMD = - 0.40 [95% CI: - 0.70, - 0.09], mostly attributed to FFP2/N95) and to a SpO-increase during rest (5 effect sizes; SMD = 0.34 [95% CI: 0.04, 0.64]); no general effect of mask wearing on SpO occurred (21 effect sizes, SMD = 0.34 [95% CI: 0.04, 0.64]). Wearing a mask led to a general oxygen uptake decrease (5 effect sizes, SMD = - 0.44 [95% CI: - 0.75, - 0.14]), to slower respiratory rates (15 effect sizes, SMD = - 0.25 [95% CI: - 0.44, - 0.06]) and to a decreased ventilation (11 effect sizes, SMD = - 0.43 [95% CI: - 0.74, - 0.12]). Heart rate (25 effect sizes; SMD = 0.05 [95% CI: - 0.09, 0.19]), W (9 effect sizes; SMD = - 0.12 [95% CI: - 0.39, 0.15]), PCO (11 effect sizes; SMD = 0.07 [95% CI: - 0.14, 0.29]) and VCO (4 effect sizes, SMD = - 0.30 [95% CI: - 0.71, 0.10]) were not different to the control, either in total or dependent on mask type or physical activity status.
CONCLUSION
The number of crossover-RCT studies was low and the designs displayed a high risk of bias. The within-mask- and -intensity-homogeneous effects on gas exchange kinetics indicated larger detrimental effects during exhausting physical activities. Pulse-derived oxygen saturation was increased during rest when a mask was applied, whereas wearing a mask during exhausting exercise led to decreased oxygen saturation. Breathing frequency and ventilation adaptations were not related to exercise intensity. FFP2/N95 and, to a lesser extent, surgical mask application negatively impacted the capacity for gas exchange and pulmonary function but not the peak physical performance. Registration: Prospero registration number: CRD42021244634.
PubMed: 34897560
DOI: 10.1186/s40798-021-00388-6 -
Journal of Translational Medicine Sep 2020Since the 1990s, neuroimaging has been utilised to study Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating illness with unknown aetiology.... (Review)
Review
BACKGROUND
Since the 1990s, neuroimaging has been utilised to study Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating illness with unknown aetiology. While brain abnormalities in ME/CFS have been identified, relatively little is known regarding which specific abnormalities are consistently observed across research groups and to what extent the observed abnormalities are reproducible.
METHOD
To identify consistent and inconsistent neuroimaging observations in ME/CFS, this retrospective and systematic review searched for studies in which neuroimaging was used to investigate brain abnormalities in ME/CFS in Ovid MEDLINE, PubMed (NCBI), and Scopus from January 1988 to July 2018. A qualitative synthesis of observations was performed to identify brain abnormalities that were consistently and inconsistently reported.
RESULTS
63 full-text articles were included in the synthesis of results from 291 identified papers. Additional brain area recruitment for cognitive tasks and abnormalities in the brain stem are frequent observations in 11 and 9 studies using different modalities from different research teams respectively. Also, sluggish blood oxygenation level-dependent (BOLD) signal responses to tasks, reduced serotonin transporters, and regional hypometabolism are consistent observations by more than two research teams. Single observations include abnormal brain tissue properties, regional metabolic abnormalities, and association of brain measures with ME/CFS symptoms. Reduced resting cerebral blood flow and volumetric brain changes are inconsistent observations across different studies.
CONCLUSION
Neuroimaging studies of ME/CFS have frequently observed additional brain area recruitment during cognitive tasks and abnormalities in the brain stem. The frequent observation of additional brain area recruitment and consistent observation of sluggish fMRI signal response suggest abnormal neurovascular coupling in ME/CFS.
Topics: Brain; Fatigue Syndrome, Chronic; Humans; Magnetic Resonance Imaging; Neuroimaging; Retrospective Studies
PubMed: 32873297
DOI: 10.1186/s12967-020-02506-6 -
Journal of Environmental Management Apr 2024Onsite sanitation systems (OSS) are significant sources of greenhouse gases (GHG) including carbon dioxide (CO), methane (CH) and nitrous oxide (NO). While a handful of... (Meta-Analysis)
Meta-Analysis Review
Onsite sanitation systems (OSS) are significant sources of greenhouse gases (GHG) including carbon dioxide (CO), methane (CH) and nitrous oxide (NO). While a handful of studies have been conducted on GHG emissions from OSS, systematic evaluation of literature on this subject is limited. Our systematic review and meta-analysis provides state-of-the- art information on GHG emissions from OSS and identifies novel areas for investigation. The paper analyzes GHG emission rates from different OSS, the influence of various design, operational, and environmental factors on emission rates and proffers mitigation measures. Following the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines, we identified 16 articles which quantified GHG emissions from OSS. Septic tanks emit substantial amounts of CO and CH ranging from 1.74 to 398.30 g CO/cap/day and 0.06-110.13 g CH/cap/day, respectively, but have low NO emissions (0.01-0.06 g N₂O/cap/day). CH emissions from pit latrines range from 0.77 to 20.30 g CH/cap/day NO emissions range from 0.76 to 1.20 gNO/cap/day. We observed statistically significant correlations (p < 0.05) between temperature, biochemical oxygen demand, chemical oxygen demand, dissolved oxygen, storage period, and GHG emissions from OSS. However, no significant correlation (p > 0.05) was observed between soil volumetric water content and CO emissions. CH emissions (expressed as CO equivalents) from OSS estimated following Intergovernmental Panel for Climate Change (IPCC) guidelines were found to be seven times lower (90.99 g COe/cap/day) than in-situ field emission measurements (704.7 g COe/cap/day), implying that relying solely on IPCC guidelines may lead to underestimation of GHG emission from OSS. Our findings underscore the importance of considering local contexts and environmental factors when estimating GHG emissions from OSS. Plausible mitigation measures for GHG emissions from OSS include converting waste to biogas in anaerobic systems (e.g. biogas), applying biochar, and implementing mitigation policies that equally address inequalities in sanitation service access. Future research on GHG from OSS should focus on in-situ measurements of GHGs from pit latrines and other common OSS in developing countries, understanding the fate and transport of dissolved organics like CH in OSS effluents and impacts of microbial communities in OSS on GHG emissions. Addressing these gaps will enable more holistic and effective management of GHG emissions from OSS.
Topics: Greenhouse Gases; Carbon Dioxide; Biofuels; Sanitation; Soil; Methane; Nitrous Oxide; Greenhouse Effect
PubMed: 38574706
DOI: 10.1016/j.jenvman.2024.120736 -
The Science of the Total Environment Jun 2020The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg, Hg, and MeHg. Migration of Hg is... (Review)
Review
The fate and transport of Hg species in natural aquatic environment are strongly affected by photochemical transformation of Hg, Hg, and MeHg. Migration of Hg is determined by its complexation with organic and inorganic ligands that are widely present in the water. The presence of dissolved organic matter (DOM) is closely related to photochemical reactions of Hg. DOM can strongly bind to mercury (e.g., Hg and MeHg), thus affecting its speciation, mobility and toxicity, eventually dominating its bioavailability. This review summarizes extensive studies on photochemical behaviors of Hg including: (1) photo-oxidation; (2) photo-reduction; (3) photochemical methylation; and (4) MeHg photo-degradation. Photo-oxidation of Hg is mostly caused by oxidative free radicals (e.g., •OH, CO, O, and O), while photo-reduction of Hg is more complicated and it involves two pathways: (1) primary processes (direct photolysis of Hg or ligand-metal charge transfer of Hg-DOM complex); and (2) secondary processes (reduction of Hg-DOM complex induced by free radicals derived from DOM photolysis). Photochemical methylation of inorganic Hg occurs as follows: (1) Hg complexes with methyl donors (e.g., acetic acid, tert-butyl, alcohols, etc.) to form intermediates, followed by (2) an intramolecular methyl transfer. MeHg photo-degradation is the leading pathway for MeHg demethylation and it primarily proceeds via four different pathways. The information on DOM was also mentioned, but DOM is not the only factor that affects the photochemical behaviors of Hg. Other influencing factors such as: (1) pH value; (2) dissolved oxygen; (3) cations (Fe, K) and anions (NO, HCO, CO, Cl); and (4) suspended substance cannot be ignored.
PubMed: 32143045
DOI: 10.1016/j.scitotenv.2020.137540 -
FEMS Microbiology Reviews May 2022Oxygen (O2) is the ultimate oxidant on Earth and its respiration confers such an energetic advantage that microorganisms have evolved the capacity to scavenge O2 down to...
Oxygen (O2) is the ultimate oxidant on Earth and its respiration confers such an energetic advantage that microorganisms have evolved the capacity to scavenge O2 down to nanomolar concentrations. The respiration of O2 at extremely low levels is proving to be common to diverse microbial taxa, including organisms formerly considered strict anaerobes. Motivated by recent advances in O2 sensing and DNA/RNA sequencing technologies, we performed a systematic review of environmental metatranscriptomes revealing that microbial respiration of O2 at nanomolar concentrations is ubiquitous and drives microbial activity in seemingly anoxic aquatic habitats. These habitats were key to the early evolution of life and are projected to become more prevalent in the near future due to anthropogenic-driven environmental change. Here, we summarize our current understanding of aerobic microbial respiration under apparent anoxia, including novel processes, their underlying biochemical pathways, the involved microorganisms, and their environmental importance and evolutionary origin.
Topics: Ecosystem; Humans; Hypoxia; Oxygen; Respiration
PubMed: 35094062
DOI: 10.1093/femsre/fuac006 -
Endokrynologia Polska Jun 2024Iron is one of the essential microelements necessary for maintaining the body's homeostasis. It serves various roles, including being a crucial component in the proper...
Iron is one of the essential microelements necessary for maintaining the body's homeostasis. It serves various roles, including being a crucial component in the proper structure of many enzymes and supporting the transport of oxygen and electrons. Its deficiency can lead to anaemia, which is a common clinical condition often associated with thyroid diseases. Iron deficiency is one of the most common nutritional deficiencies, and its prevalence is strongly associated with socioeconomic status. It is the primary cause of anaemia in 42% of children and 50% of women. Importantly, iron deficiency is placed among the top 5 causes of disability in women. Thyroid peroxidase (TPO) is an enzyme essential for the production of thyroid hormones, and iron is a key factor in its proper functioning. Therefore, in the case of iron deficiency, the activity of this enzyme is also reduced. Iron is also a factor that is important in epigenetic modification processes, and its deficiency may contribute to genomic changes potentially promoting the development of autoimmune thyroid diseases. Adequate supplementation in patients with Hashimoto's disease is one of the crucial elements of effective therapy. In addition to iodine, selenium, and magnesium supplementation, attention should be paid to proper iron intake. Iron is an element that is a component of the heme enzyme- thyroid peroxidase, which owes its activity to the binding of haem, and its function is the production of thyroid hormones. Iron can be delivered to the body in haem and non-haem forms. The haem form is found particularly in haemoglobin-rich red meat, but also in eggs, fish, and poultry. On the other hand, non-haem iron can be found in legumes, grains, fruits, and vegetables. Our study aimed to gather and summarise knowledge from scientific literature regarding iron deficiency anaemia and its association with hypothyroidism in women, as well as the possible mechanisms and pathogenesis of these conditions. The paper also aims to highlight that considering the high risk of iron deficiency, assessing iron status along with ferritin should be an integral part of additional diagnostic measures in cases of hypothyroidism, particularly Hashimoto's disease.
PubMed: 38923898
DOI: 10.5603/ep.97860 -
BMC Pulmonary Medicine May 2021Acute exacerbation (AE) is a devastating phenomenon and reported to be complicated with systemic autoimmune disease-associated interstitial lung disease (ILD). The aim... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Acute exacerbation (AE) is a devastating phenomenon and reported to be complicated with systemic autoimmune disease-associated interstitial lung disease (ILD). The aim of this study was to investigate the incidence and prognosis of AE of systemic autoimmune disease-ILD and clarify relevant clinical information predictive of these outcomes.
METHOD
This study was designed as a systematic review and meta-analysis. A primary study except for a case report, which reported the incidence and/or prognosis of AE of systemic autoimmune disease-ILD, was eligible for the review. Electronic databases such as Medline and EMBASE were searched from 2002 through 23 February 2020. Two reviewers independently selected eligible reports and extracted relevant data. Risk of bias of individual studies was assessed similarly. The incidence and prognosis of the disease were analysed qualitatively. Univariate results of risk and prognostic factors were combined if feasible.
RESULTS
Out of a total of 2662 records, 24 studies were eligible. A total of 420 subjects with 45.7% of men developed AE of systemic autoimmune disease-ILD and the two major underlying systemic autoimmune diseases were rheumatoid arthritis (34.2%) and polymyositis/dermatomyositis (31.9%). The frequency ranged from 4.3 to 32.9% with the incident rate being 3.19 and 5.77 per 100 patient-years and all-cause mortality was between 30.0 and 58.3% at 90 days. Age at initial presentation was significantly associated with the development of AE of systemic autoimmune disease-ILD with an HR of 1.22 (95%CI 1.05-1.50) while a percentage of predicted diffusing capacity of the lung for carbon monoxide (%DLCO) was also significantly associated with the development of the disease with an HR of 0.95 (95%CI 0.90-1.00) and an OR of 0.97 (95%CI 0.95-0.99). Partial pressure of arterial oxygen/fraction of inspired oxygen ratio (PaO/FiO) at AE was significantly associated with all-cause mortality of AE of systemic autoimmune disease-ILD with an HR of 0.99 (95%CI 0.98-0.99).
CONCLUSION
AE of systemic autoimmune disease-ILD was not uncommon and demonstrated dismal prognosis. Age at initial presentation and %DLCO were deemed as risk factors while PaO/FiO at AE was considered as a prognostic factor of the disease. Registration CRD42019138941.
Topics: Arthritis, Rheumatoid; Autoimmune Diseases; Disease Progression; Humans; Lung Diseases, Interstitial; Pulmonary Gas Exchange; Risk Factors; Sex Factors
PubMed: 33952218
DOI: 10.1186/s12890-021-01502-w -
Environmental Science and Pollution... Mar 2024Coal-fired power plants (CFPPs) are one of the most significant sources of mercury (Hg) emissions certified by the Minamata Convention, which has attracted much... (Review)
Review
Coal-fired power plants (CFPPs) are one of the most significant sources of mercury (Hg) emissions certified by the Minamata Convention, which has attracted much attention in recent years. In this study, we used the Web of Science and CiteSpace to analyze the knowledge structure of this field from 2000 to 2022 and then reviewed it systematically. The field of Hg emissions from coal-fired power plants has developed steadily. The research hotspots can be divided into three categories: (1) emission characterization research focused on speciation changes and emission calculations; (2) emission control research focused on control technologies; (3) environmental impact research focused on environmental pollution and health risk. In conclusion, using an oxygen-rich atmosphere for combustion and installing high-efficiency air pollution control devices (APCDs) helped to reduce the formation of Hg. The average Hg removal rates of APCDs and modified adsorbents after ultra-low emission retrofit were distributed in the range of 82-93% and 41-100%, respectively. The risk level of Hg in combustion by-products was highest in desulfurization sludge (RAC > 10%) followed by fly ash (10% < RAC < 30%) and desulfurization gypsum (1% < RAC < 10%). Additionally, we found that the implementation of pollution and carbon reduction policies in China had reduced Hg emissions from CFPPs by 45% from 2007 to 2015, increased the efficiency of Hg removal from APCDs to a maximum of 96%, and reduced global transport and health risk of atmospheric Hg. The results conjunctively achieved by CiteSpace, and the literature review will enhance understanding of CFPP Hg emission research and provide new perspectives for future research.
Topics: Mercury; Air Pollutants; Coal; Power Plants; China; Bibliometrics
PubMed: 38379043
DOI: 10.1007/s11356-024-32369-z -
Cancers May 2024The study aims to investigate the role of hypoxia-inducible factors (HIFs) in the development, progression, and therapeutic potential of glioblastomas. (Review)
Review
BACKGROUND
The study aims to investigate the role of hypoxia-inducible factors (HIFs) in the development, progression, and therapeutic potential of glioblastomas.
METHODOLOGY
The study, following PRISMA guidelines, systematically examined hypoxia and HIFs in glioblastoma using MEDLINE (PubMed), Web of Science, and Scopus. A total of 104 relevant studies underwent data extraction.
RESULTS
Among the 104 studies, global contributions were diverse, with China leading at 23.1%. The most productive year was 2019, accounting for 11.5%. Hypoxia-inducible factor 1 alpha (HIF1α) was frequently studied, followed by hypoxia-inducible factor 2 alpha (HIF2α), osteopontin, and cavolin-1. Commonly associated factors and pathways include glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3) receptors, vascular endothelial growth factor (VEGF), phosphoinositide 3-kinase (PI3K)-Akt-mechanistic target of rapamycin (mTOR) pathway, and reactive oxygen species (ROS). HIF expression correlates with various glioblastoma hallmarks, including progression, survival, neovascularization, glucose metabolism, migration, and invasion.
CONCLUSION
Overcoming challenges such as treatment resistance and the absence of biomarkers is critical for the effective integration of HIF-related therapies into the treatment of glioblastoma with the aim of optimizing patient outcomes.
PubMed: 38893207
DOI: 10.3390/cancers16112089 -
Medicine Jun 2023Although many critically ill patients require inter-facility transport for definitive or specialized therapy, the medical equipment required to enhance transport safety...
BACKGROUND
Although many critically ill patients require inter-facility transport for definitive or specialized therapy, the medical equipment required to enhance transport safety remains unclear. This review was performed to summarize the evidence regarding devices used to improve the safety and survival in patients requiring such transport.
METHODS
We searched MEDLINE, the Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi for randomized controlled trials and observational studies comparing outcomes according to the presence or absence of devices (or new vs conventional devices) during transfer of critically ill patients.
RESULTS
Four studies focusing on continuous blood pressure monitoring, extracorporeal membrane oxygenation, pelvic circumferential compression devices, and cuffed tracheal tubes, respectively, met the inclusion criteria. A meta-analysis was not performed because the 4 studies focused on different devices. Near-continuous blood pressure monitoring increased interventions such as intravenous fluid administration during transport, shortened the intensive care unit and hospital lengths of stay, and reduced the incidence of multiple-organ failure compared with use of oscillometric devices. Despite the small sample size and varying severity of illness among the groups, transport of patients with severe respiratory failure under extracorporeal membrane oxygenation resulted in fewer hypoxemic events during transport than transport on conventional ventilators. During transport of patients with pelvic fractures, pelvic belts may help to reduce mortality and the transfusion volume. Cuffed (vs uncuffed) tracheal tubes may reduce post-transport tube replacement events in pediatric patients.
CONCLUSION
Studies on devices needed for inter-facility transport of critically ill patients are scarce, but some devices may be beneficial.
Topics: Child; Humans; Critical Illness; Intensive Care Units; Respiration, Artificial; Ventilators, Mechanical; Extracorporeal Membrane Oxygenation
PubMed: 37266640
DOI: 10.1097/MD.0000000000033865