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The Science of the Total Environment Dec 2023Growing studies have focused on the effects of ambient air pollution on thyroid hormones (THs), but the results were controversial. Therefore, a systematic review and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Growing studies have focused on the effects of ambient air pollution on thyroid hormones (THs), but the results were controversial. Therefore, a systematic review and meta-analysis was conducted by pooling current evidence on this association.
METHODS
Four databases were searched for studies examining the associations of particulate matter [diameter ≤10 μm (PM) or ≤2.5 μm (PM)] and gaseous [sulfur dioxide (SO), nitrogen dioxide (NO), ozone (O), carbon monoxide (CO)] pollutants with THs levels. Random effects models were used to pool the changes in THs levels with increasing air pollutant concentrations. Subgroup analyses were constructed by region, design, sample size, pollutant concentrations, evaluated methods, and potential risk exposure windows.
RESULTS
A total of 14 studies covering 357,226 participants were included in this meta-analysis. The pooled results showed significant associations of exposure to PM, PM, NO, SO, and CO with decreases in free thyroxine (FT4) with percent changes (PC) ranging from -0.593 % to -3.925 %. PM, NO, and CO were negatively associated with levels of FT4/FT3 (PC: from -0.604 % to -2.975 %). In addition, results showed significant associations of PM with hypothyroxinemia and high thyroid-stimulating hormone (TSH). Subgroup analyses indicated that PM and NO were significantly associated with FT4 in studies of Chinese, and similar significant findings were found in studies of PM and FT4/FT3 in areas with higher concentrations of air pollutants and larger samples. PM exposure in the first trimester was found to be associated with lower FT4 levels in pregnant women.
CONCLUSION
Our findings suggest that exposure to air pollution is associated with changes in THs levels. Enhanced management of highly polluted areas, identification of harmful components and sources of PM, and protection from harmful exposures in early pregnancy may be of great public health importance for the population's thyroid function.
Topics: Female; Humans; Pregnancy; Nitrogen Dioxide; Thyroid Gland; Environmental Exposure; Air Pollution; Air Pollutants; Particulate Matter; Ozone; Sulfur Dioxide; Thyroid Hormones; Environmental Pollutants
PubMed: 37660827
DOI: 10.1016/j.scitotenv.2023.166780 -
The Science of the Total Environment Apr 2023Accumulating evidence has linked exposure to ambient air pollution to a reduction in semen quality; however, the exposure-response associations are yet to be synthesized. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Accumulating evidence has linked exposure to ambient air pollution to a reduction in semen quality; however, the exposure-response associations are yet to be synthesized.
OBJECTIVE
To summarize the exposure-response associations between air pollution and semen quality.
METHODS
We systematically searched PubMed, Embase, and Web of Science for relevant studies published before April 20, 2022. Studies investigating the exposure-response association of PM, PM, SO, NO, CO, and O with semen quality written in English were included. Semen quality parameters included semen volume, sperm concentration, total sperm number, total motility, progressive motility, and normal forms. Random-effects and fixed-effects models were performed to synthesize associations in the meta-analysis.
RESULTS
The search returned 850 studies, 11 of which were eligible for meta-analysis. Each 10 μg/m increase of exposure to PM and SO was respectively associated with a 2.18 % (95 % confidence interval [CI]: 0.10 %-4.21 %) and 8.61 % (1.00 %-15.63 %) reduction in sperm concentration, and a 2.76 % (0.10 %-5.35 %) and 9.52 % (5.82 %-13.93 %) reduction in total sperm number. Each 10 μg/m increase of exposure to PM and PM was respectively associated with a 1.06 % (95 % CI: 0.31 %-1.82 %) and 0.75 % (0.43 %-1.08 %) reduction in total motility, and a 0.55 % (0.09 %-1.01 %) and 0.31 % (0.06 %-0.56 %) reduction in progressive motility. No association was observed for PM or PM with semen volume; PM, NO, CO, or O with sperm concentration or total sperm number; and gaseous air pollutants with total or progressive motility. The association between air pollution and normal forms was not summarized due to insufficient number of studies. No significant publication bias was detected.
CONCLUSIONS
Exposure to ambient PM, PM, and SO was inversely associated with sperm concentration, total sperm number, total motility, and/or progressive motility. Our findings add to the evidence that air pollution may lead to adverse effects on male reproductive system and suggest that reducing exposure to air pollution may help maintain better semen quality.
Topics: Male; Humans; Semen Analysis; Nitrogen Dioxide; Particulate Matter; Semen; Air Pollution; Air Pollutants; Environmental Exposure
PubMed: 36731563
DOI: 10.1016/j.scitotenv.2023.161892 -
Cells Apr 2023Betel quid and areca nut are complex mixture carcinogens, but little is known about whether their derived single-agent arecoline or arecoline -oxide (ANO) is...
Betel quid and areca nut are complex mixture carcinogens, but little is known about whether their derived single-agent arecoline or arecoline -oxide (ANO) is carcinogenic, and the underlying mechanisms remain unclear. In this systematic review, we analyzed recent studies on the roles of arecoline and ANO in cancer and strategies to block carcinogenesis. In the oral cavity, flavin-containing monooxygenase 3 oxidizes arecoline to ANO, and both alkaloids conjugate with -acetylcysteine to form mercapturic acid compounds, which are excreted in urine, reducing arecoline and ANO toxicity. However, detoxification may not be complete. Arecoline and ANO upregulated protein expression in oral cancer tissue from areca nut users compared to expression levels in adjacent normal tissue, suggesting a causal relationship between these compounds and oral cancer. Sublingual fibrosis, hyperplasia, and oral leukoplakia were diagnosed in mice subjected to oral mucosal smearing of ANO. ANO is more cytotoxic and genotoxic than arecoline. During carcinogenesis and metastasis, these compounds increase the expression of epithelial-mesenchymal transition (EMT) inducers such as reactive oxygen species, transforming growth factor-β1, Notch receptor-1, and inflammatory cytokines, and they activate EMT-related proteins. Arecoline-induced epigenetic markers such as sirtuin-1 hypermethylation, low protein expression of miR-22, and miR-886-3-p accelerate oral cancer progression. Antioxidants and targeted inhibitors of the EMT inducers used reduce the risk of oral cancer development and progression. Our review findings substantiate the association of arecoline and ANO with oral cancer. Both of these single compounds are likely carcinogenic to humans, and their mechanisms and pathways of carcinogenesis are useful indicators for cancer therapy and prognosis.
Topics: Arecoline; Cyclic N-Oxides; Mouth Neoplasms; Carcinogenesis; Humans; Animals; Mice; Areca; Oxygenases; Oxidation-Reduction; Acetylcysteine; Epigenesis, Genetic; Carcinogens
PubMed: 37190117
DOI: 10.3390/cells12081208 -
Current Drug Metabolism 2017The urge for the development and manufacture of new and effective antimicrobial agents is particularly demanding especially in the present scenario of emerging multiple... (Review)
Review
BACKGROUND
The urge for the development and manufacture of new and effective antimicrobial agents is particularly demanding especially in the present scenario of emerging multiple drug resistant microorganisms. A promising initiative would be to converge nanotechnology to develop novel strategies for antimicrobial treatment. These distinct nano scale properties confer impressive antimicrobial capabilities to nanomaterials that could be exploited. Nanotechnology particularly modulates the physicochemical properties of organic and inorganic nanoparticles, rendering them suitable for various applications related to antimicrobial therapy compared to their bulk counterparts. However, a major issue associated with such usage of nanomaterials is the safety concern on heath care system. Hence, a thorough put knowledge on biocompatible nanostructures intended for antimicrobial therapy is needed.
METHODS
A systematic review of the existing scientific literature is being attempted here which includes the properties and applications of a few nano structured materials for antimicrobial therapy and also the mechanism of action of nanomaterials as antimicrobial agents. Silver (Ag), Graphene, Quantum dots (QDs), Zinc oxide (ZnO) and chitosan nanoparticles are taken as representatives of metals, semiconductors, metal oxides and organic nanoparticles that have found several applications in antimicrobial therapy are reviewed in detail.
RESULTS AND CONCLUSION
An ideal anti microbial should selectively kill or inhibit the growth of microbes but cause little or no adverse effect to the host. Each of the engineered nanomaterials reviewed here has its own advantages and disadvantages. Nanomaterials in general directly disrupt the microbial cell membrane, interact with DNA and proteins or they could indirectly initiate the production of reactive oxygen species (ROS) that damage microbial cell components and viruses. Some like silver nanoparticles have broad spectrum antibacterial activity while others like cadmium containing QDs shows both antibacterial as well as antiprotozoal activity. Nano material formulations can be used directly or as surface coatings or as effective carriers for delivering antibiotics. Polycationic nature of Chitosan NPs helps in conjugation and stabilization of metallic nanoparticles which will enhance their effective usage in antimicrobial therapy.
Topics: Animals; Anti-Infective Agents; Humans; Nanoparticles; Zinc Oxide
PubMed: 28952436
DOI: 10.2174/1389200218666170925122201 -
The Journal of Hospital Infection Sep 2023This systematic review and network meta-analysis (NMA) comprehensively compared the effectiveness of different mouth rinses in reducing the viral load/infectivity of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review and network meta-analysis (NMA) comprehensively compared the effectiveness of different mouth rinses in reducing the viral load/infectivity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) (Part I), alleviating clinical symptoms or severity of disease (Part II), and decreasing the incidence of SARS-CoV-2 infection (Part III).
METHODS
Randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) with restrictions were searched up to 3 March 2023. Twenty-three studies (22 RCTs and one NRCT) met the inclusion criteria for this systematic review.
RESULTS
Five RCTs (454 patients and nine interventions) in Part I were eligible for NMA. The NMA results showed that, in comparison with no rinse, sodium chloride (NaCl) was the most effective mouth rinse for reducing the viral load, followed by povidone-iodine (PVP-I), ß-cyclodextrin + citrox (CDCM), hydrogen peroxide (HP), chlorhexidine gluconate (CHX), cetylpyridinium chloride (CPC), placebo and hypochlorous acid (HClO). However, these results were not significant. Based on surface under the cumulative ranking curve scores, PVP-I was likely to be the most efficacious mouth rinse for reducing SARS-CoV-2 viral load, followed by CDCM, HP, NaCl, CHX, CPC, placebo, no rinse and HClO.
CONCLUSION
Due to heterogeneity of the primary studies, the effectiveness of different mouth rinses to reduce viral infectivity, improve clinical symptoms or prevent SARS-CoV-2 infection remains inconclusive.
Topics: Humans; COVID-19; Mouthwashes; Povidone-Iodine; SARS-CoV-2; Sodium Chloride; Network Meta-Analysis; Hydrogen Peroxide; Mouth
PubMed: 37419189
DOI: 10.1016/j.jhin.2023.06.022 -
Journal of Hazardous Materials Aug 2022Chlorine dioxide (ClO) has emerged as a broad-spectrum, safe, and effective disinfectant due to its high oxidation efficiency and reduced formation of organochlorinated... (Review)
Review
Chlorine dioxide (ClO) has emerged as a broad-spectrum, safe, and effective disinfectant due to its high oxidation efficiency and reduced formation of organochlorinated by-products during application. This article provides an updated overview of ClO-based oxidation processes used in water treatment. A systematic review of scientific information and experimental data on ClO-based water purification procedures is presented. Concerning ClO-based oxidation derivative problems, the pros and cons of ClO-based combined processes are assessed and disinfection by-product (DBP) control approaches are proposed. The kinetic and mechanistic data on ClO reactivity towards micropollutants are discussed. ClO selectively reacts with electron-rich moieties (anilines, phenols, olefins, and amines) and eliminates certain inorganic ions and microorganisms with high efficiency. The formation of chlorite and chlorate during the oxidation process is a crucial concern when utilizing ClO. Future applications include the combination of ClO with ferrous ions, activated carbon, ozone, UV, visible light, or persulfate processes. The combined process can reduce by-product generation while still ensuring ClO sterilization and disinfection. Overall, this research could provide useful information and new insights into the application of ClO-based technologies.
Topics: Chlorine; Chlorine Compounds; Disinfectants; Disinfection; Oxides; Water Purification
PubMed: 35739725
DOI: 10.1016/j.jhazmat.2022.129195 -
International Journal of Dental Hygiene Feb 2018The aim of this systematic review was to assess the effect of a whitening dentifrice (WDF) relative to a regular dentifrice (RDF) on the reduction of natural extrinsic... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The aim of this systematic review was to assess the effect of a whitening dentifrice (WDF) relative to a regular dentifrice (RDF) on the reduction of natural extrinsic tooth surface discoloration (ETD).
MATERIALS AND METHODS
The MEDLINE-PubMed, Cochrane-CENTRAL and EBSCO-Dentistry and Oral Sciences databases were searched, up to April 2017. The inclusion criteria were as follows:(randomized)controlled clinical trials, healthy subjects ≥18 years of age, studies comparing WDF with RDF, a follow-up period of at least 6 weeks and studies scoring ETD as the stain area/extent, stain intensity or a composite score. Studies using an induced staining model were excluded.
RESULTS
Independent screening of 851 unique papers resulted in 21 eligible publications, which included 32 comparisons. The descriptive analysis illustrated that the majority of comparisons showed a significant effect on ETD, in favour of WDF over RDF. The meta-analysis substantiated this observation and revealed that the difference of means (diffM) comparing WDF and RDF was a reduction for stain area of -0.44 [(95% CI: -0.55; -0.339) (P<.00001)] according to the original Lobene Stain Index; this result is in favour of the WDF. For the modified Lobene Stain Index, the diffM was -0.41 [(95% CI: -0.71; -0.10) (P=.009)]. For overall stain intensity, the diffM was -0.35 [(95% CI: -0.44; -0.25) (P<.00001)], and the composite score was -0.39 [(95% CI: -0.57; -0.21) (P<.0001)] and -0.54 [(95% CI: -0.66; -0.43) (P<.00001)]. Subgroup analysis differentiating between products that contained added chemical antidiscoloration agents showed a similar pattern.
CONCLUSION
In this review, nearly all dentifrices that are specifically formulated for tooth whitening were shown to have a beneficial effect in reducing ETD, irrespective of whether or not a chemical discoloration agent was added.
Topics: Dentifrices; Humans; Tooth Bleaching; Tooth Bleaching Agents; Tooth Discoloration
PubMed: 28573755
DOI: 10.1111/idh.12289 -
Journal of Dentistry Sep 2014Pulpotomy is a common procedure to treat asymptomatic reversible pulpitis in primary molars. The aim of this study is to undertake a systematic review and a network... (Comparative Study)
Comparative Study Meta-Analysis Review
OBJECTIVE
Pulpotomy is a common procedure to treat asymptomatic reversible pulpitis in primary molars. The aim of this study is to undertake a systematic review and a network meta-analysis to compare the clinical and radiographic outcomes of different pulpotomy procedures in primary molars.
DATA
Three authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion.
SOURCES
An electronic literature search was performed within MEDLINE (via PubMed), ScienceDirect, Web of Science, Cochrane, and ClinicalKey databases until December 2012. Medications for pulpotomy including formocresol, ferric sulfate, calcium hydroxide, and mineral trioxide aggregate (MTA), and laser pulpotomy are compared using Bayesian network meta-analyses. The outcome is the odds ratio for clinical and radiographic failure including premature tooth loss at 12 and 24 months after treatments amongst different treatment procedures. 37 studies were included in the systematic review, and 22 of them in the final network meta-analyses. After 18-24 months, in terms of treatment failure, the odds ratio for calcium hydroxide vs. formocresol was 1.94 [95% credible interval (CI): 1.11, 3.25]; 3.38 (95% CI: 1.37, 8.61) for lasers vs. formocresol; 2.16 (95% CI: 1.12, 4.31) for calcium hydroxide vs. ferric sulfate; 3.73 (95% CI: 1.27, 11.67) for lasers vs. ferric sulfate; 0.47 (95% CI: 0.26, 0.83) for MTA vs. calcium hydroxide; 3.76 (95% CI: 1.39, 10.08) for lasers vs.
MTA CONCLUSIONS
After 18-24 months, formocresol, ferric sulfate, and MTA showed significantly better clinical and radiographic outcomes than calcium hydroxide and laser therapies in primary molar pulpotomies.
CLINICAL SIGNIFICANCE
The network meta-analyses showed that MTA is the first choice for primary molar pulpotomies. However, if treatment cost is an issue, especially when the treated primary molars are going to be replaced by permanent teeth, ferric sulfate may be the choice.
Topics: Aluminum Compounds; Calcium Compounds; Calcium Hydroxide; Drug Combinations; Ferric Compounds; Formocresols; Humans; Laser Therapy; Molar; Oxides; Pulpitis; Pulpotomy; Root Canal Irrigants; Silicates; Tooth, Deciduous; Treatment Outcome
PubMed: 24513112
DOI: 10.1016/j.jdent.2014.02.001 -
Environmental Health Perspectives Nov 2015Exposure to traffic-related air pollutants is an important public health issue. Here, we present a systematic review and meta-analysis of research examining the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND OBJECTIVE
Exposure to traffic-related air pollutants is an important public health issue. Here, we present a systematic review and meta-analysis of research examining the relationship of measures of nitrogen oxides (NOx) and of various measures of traffic-related air pollution exposure with lung cancer.
METHODS
We conducted random-effects meta-analyses of studies examining exposure to nitrogen dioxide (NO2) and NOx and its association with lung cancer. We identified 20 studies that met inclusion criteria and provided information necessary to estimate the change in lung cancer per 10-μg/m3 increase in exposure to measured NO2. Further, we qualitatively assessed the evidence of association between distance to roadways and traffic volume associated with lung cancer.
RESULTS
The meta-estimate for the change in lung cancer associated with a 10-μg/m3 increase in exposure to NO2 was 4% (95% CI: 1%, 8%). The meta-estimate for change in lung cancer associated with a 10-μg/m3 increase in NOx was similar and slightly more precise, 3% (95% CI: 1%, 5%). The NO2 meta-estimate was robust to different confounding adjustment sets as well as the exposure assessment techniques used. Trim-and-fill analyses suggest that if publication bias exists, the overall meta-estimate is biased away from the null. Forest plots for measures of traffic volume and distance to roadways largely suggest a modest increase in lung cancer risk.
CONCLUSION
We found consistent evidence of a relationship between NO2, as a proxy for traffic-sourced air pollution exposure, with lung cancer. Studies of lung cancer related to residential proximity to roadways and NOx also suggest increased risk, which may be attributable partly to air pollution exposure. The International Agency for Research on Cancer recently classified outdoor air pollution and particulate matter as carcinogenic (Group 1). These meta-analyses support this conclusion, drawing particular attention to traffic-sourced air pollution.
CITATION
Hamra GB, Laden F, Cohen AJ, Raaschou-Nielsen O, Brauer M, Loomis D. 2015. Lung cancer and exposure to nitrogen dioxide and traffic: a systematic review and meta-analysis. Environ Health Perspect 123:1107-1112; http://dx.doi.org/10.1289/ehp.1408882.
Topics: Air Pollutants; Environmental Exposure; Humans; Incidence; Lung Neoplasms; Nitrogen Dioxide; Nitrogen Oxides; Risk Factors; Vehicle Emissions
PubMed: 25870974
DOI: 10.1289/ehp.1408882 -
Conservation Biology : the Journal of... Feb 2021Amphibian populations globally are in decline. One great threat is the abstraction of water resources that alter surface-water hydrology. Conservation actions aimed at... (Review)
Review
Amphibian populations globally are in decline. One great threat is the abstraction of water resources that alter surface-water hydrology. Conservation actions aimed at restoring or manipulating surface water are employed as a management tool, but empirical evidence on the effectiveness of these approaches is scarce. In this systematic review, we summarized the global experience of manipulating water for amphibian conservation. We explored examples of manipulating water to conserve amphibian species and communities. Approaches varied in their frequency of implementation and in their success. Extending hydroperiod to match larval requirements showed encouraging results, as did off-season drying to control predators. Spraying water into the environment showed several potential applications, but successes were limited. Despite some promising interventions, we identified few (n = 17) empirically supported examples of successful water manipulation to benefit amphibians. It is unclear whether this stems from publication bias or if it is an artifact of language selection. However, manipulating water shows some potential in amphibian conservation, particularly at sites with a proximal water source and in regions where aridity is increasing due to climate change. Regardless of the scale of the intervention or its perceived probability of success, high-quality reporting of empirical results will further understanding of how water manipulations can benefit threatened amphibian populations.
Topics: Amphibians; Animals; Climate Change; Conservation of Natural Resources; Water
PubMed: 32189374
DOI: 10.1111/cobi.13501