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Environment International Mar 2024The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency... (Meta-Analysis)
Meta-Analysis
Effects of radiofrequency electromagnetic field (RF-EMF) exposure on male fertility: A systematic review of experimental studies on non-human mammals and human sperm in vitro.
BACKGROUND
The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Reproductive health outcomes have been identified among the priority topics to be addressed.
OBJECTIVES
To evaluate the effect of RF-EMF exposure on male fertility of experimental mammals and on human sperm exposed in vitro.
METHODS
Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 17, 2022. Two independent reviewers screened the studies, which were considered eligible if met the following criteria: 1) Peer-reviewed publications of sham controlled experimental studies, 2) Non-human male mammals exposed at any stage of development or human sperm exposed in vitro, 3) RF-EMF exposure within the frequency range of 100 kHz-300 GHz, including electromagnetic pulses (EMP), 4) one of the following indicators of reproductive system impairment:Two reviewers extracted study characteristics and outcome data. We assessed risk of bias (RoB) using the Office of Health Assessment and Translation (OHAT) guidelines. We categorized studies into 3 levels of overall RoB: low, some or high concern. We pooled study results in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses. For experimental animal studies, we conducted subgroup analyses for species, Specific Absorption Rate (SAR) and temperature increase. We grouped studies on human sperm exposed in vitro by the fertility status of sample donors and SAR. We assessed the certainty of the evidence using the GRADE approach after excluding studies that were rated as "high concern" for RoB.
RESULTS
One-hundred and seventeen papers on animal studies and 10 papers on human sperm exposed in vitro were included in this review. Only few studies were rated as "low concern" because most studies were at RoB for exposure and/or outcome assessment. Subgrouping the experimental animal studies by species, SAR, and temperature increase partly accounted for the heterogeneity of individual studies in about one third of the meta-analyses. In no case was it possible to conduct a subgroup analysis of the few human sperm in vitro studies because there were always 1 or more groups including less than 3 studies. Among all the considered endpoints, the meta-analyses of animal studies provided evidence of adverse effects of RF-EMF exposure in all cases but the rate of infertile males and the size of the sired litters. The assessment of certainty according to the GRADE methodology assigned a moderate certainty to the reduction of pregnancy rate and to the evidence of no-effect on litter size, a low certainty to the reduction of sperm count, and a very low certainty to all the other meta-analysis results. Studies on human sperm exposed in vitro indicated a small detrimental effect of RF-EMF exposure on vitality and no-effect on DNA/chromatin alterations. According to GRADE, a very low certainty was attributed to these results. The few studies that used EMP exposure did not show effects on the outcomes. A low to very low certainty was attributed to these results.
DISCUSSION
Many of the studies examined suffered of severe limitations that led to the attribution of uncertainty to the results of the meta-analyses and did not allow to draw firm conclusions on most of the endpoints. Nevertheless, the associations between RF-EMF exposure and decrease of pregnancy rate and sperm count, to which moderate and low certainty were attributed, are not negligible, also in view of the indications that in Western countries human male fertility potential seems to be progressively declining. It was beyond the scope of our systematic review to determine the shape of the dose-response relationship or to identify a minimum effective exposure level. The subgroup and the dose-response fitting analyses did not show a consistent relationship between the exposure levels and the observed effects. Notably, most studies evaluated RF-EMF exposure levels that were higher than the levels to which human populations are typically exposed, and the limits set in international guidelines. For these reasons we cannot provide suggestions to confirm or reconsider current human exposure limits. Considering the outcomes of this systematic review and taking into account the limitations found in several of the studies, we suggest that further investigations with better characterization of exposure and dosimetry including several exposure levels and blinded outcome assessment were conducted.
PROTOCOL REGISTRATION
Protocols for the systematic reviews of animal studies and of human sperm in vitro studies were published in Pacchierotti et al., 2021. The former was also registered in PROSPERO (CRD42021227729 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID = 227729) and the latter in Open Science Framework (OSF Registration DOI https://doi.org/10.17605/OSF.IO/7MUS3).
Topics: Animals; Humans; Male; Electromagnetic Fields; Mammals; Radio Waves; Reproduction; Semen; Infertility, Male
PubMed: 38492496
DOI: 10.1016/j.envint.2024.108509 -
Journal of Plastic, Reconstructive &... Apr 2024To restore breast sensibility, some centers are offering nerve reconstruction as a component of implant and flap-based breast reconstruction. To interpret and... (Review)
Review
BACKGROUND
To restore breast sensibility, some centers are offering nerve reconstruction as a component of implant and flap-based breast reconstruction. To interpret and contextualize the results of these procedures, it is necessary to understand the normal range of breast sensibility, the factors that affect it, and the best methods for its objective measurement.
METHODS
We conducted systematic and comprehensive searches across PubMed, Web of Science, and Cochrane Library databases using keywords and controlled vocabulary for the concepts of the breast, nipple, areola, and measurement. The search results were imported into Rayyan QCRI for a blinded screening of titles and abstracts. Studies were evaluated for bias using RevMan 5 software. The results of sensory measurements were pooled, and a quantitative summary of breast sensibility was generated.
RESULTS
A total of 36 articles were identified, including retrospective, cross-sectional, and prospective studies. Although there were some consistent findings across studies, such that breast sensibility is inversely related to breast volume, there was wide variability in the following parameters: population, breast condition, measurement modality, anatomic areas of measurement, and sensibility findings. This heterogeneity precluded the generation of normative breast sensibility measurements. Furthermore, we detected a high degree of bias in most studies, due to self-selection of participants and failure to record patient characteristics that may alter sensibility.
CONCLUSIONS
The literature lacks consistent data delineating normative values for breast sensibility. Standardized measurements of healthy volunteers with various breast characteristics are necessary to elucidate normative values and interpret efforts to restore sensibility in breast reconstruction.
Topics: Humans; Prospective Studies; Retrospective Studies; Cross-Sectional Studies; Nipples; Mammaplasty
PubMed: 38461623
DOI: 10.1016/j.bjps.2024.01.057 -
Seizure Apr 2024Epilepsy is increasingly recognised as a brain network disorder and many studies have investigated functional connectivity (FC) in children with epilepsy using... (Review)
Review
Epilepsy is increasingly recognised as a brain network disorder and many studies have investigated functional connectivity (FC) in children with epilepsy using functional MRI (fMRI). This systematic review of fMRI studies, published up to November 2023, investigated profiles of FC changes and their clinical relevance in children with focal epilepsy compared to healthy controls. A literature search in PubMed and Web of Science yielded 62 articles. We categorised the results into three groups: 1) differences in correlation-based FC between patients and controls; 2) differences in other FC measures between patients and controls; and 3) associations between FC and disease variables (for example, age of onset), cognitive and seizure outcomes. Studies revealed either increased or decreased FC across multiple brain regions in children with focal epilepsy. However, findings lacked consistency: conflicting FC alterations (decreased and increased FC) co-existed within or between brain regions across all focal epilepsy groups. The studies demonstrated overall that 1) interhemispheric connections often displayed abnormal connectivity and 2) connectivity within and between canonical functional networks was decreased, particularly for the default mode network. Focal epilepsy disrupted FC in children both locally (e.g., seizure-onset zones, or within-brain subnetworks) and globally (e.g., whole-brain network architecture). The wide variety of FC study methodologies limits clinical application of the results. Future research should employ longitudinal designs to understand the evolution of brain networks during the disease course and explore the potential of FC biomarkers for predicting cognitive and postsurgical seizure outcomes.
Topics: Humans; Epilepsies, Partial; Child; Magnetic Resonance Imaging; Brain; Nerve Net; Connectome
PubMed: 38432080
DOI: 10.1016/j.seizure.2024.02.021 -
Neurological Sciences : Official... May 2024Post-COVID conditions (PCCs) cover a wide spectrum of lingering symptoms experienced by survivors of coronavirus disease 2019 (COVID-19). Neurological and... (Review)
Review
Post-COVID conditions (PCCs) cover a wide spectrum of lingering symptoms experienced by survivors of coronavirus disease 2019 (COVID-19). Neurological and neuropsychiatric sequelae are common in PCCs. Advanced magnetic resonance imaging (MRI) techniques can reveal subtle alterations in brain structure, function, and perfusion that underlie these sequelae. This systematic review aimed to synthesize findings from studies that used advanced MRI to characterize brain changes in individuals with PCCs. A detailed literature search was conducted in the PubMed and Scopus databases to identify relevant studies that used advanced MRI modalities, such as structural MRI (sMRI), diffusion tensor imaging (DTI), functional MRI (fMRI), and perfusion-weighted imaging (PWI), to evaluate brain changes in PCCs. Twenty-five studies met the inclusion criteria, comprising 1219 participants with PCCs. The most consistent findings from sMRI were reduced gray matter volume (GMV) and cortical thickness (CTh) in cortical and subcortical regions. DTI frequently reveals increased mean diffusivity (MD), radial diffusivity (RD), and decreased fractional anisotropy (FA) in white matter tracts (WMTs) such as the corpus callosum, corona radiata, and superior longitudinal fasciculus. fMRI demonstrated altered functional connectivity (FC) within the default mode, salience, frontoparietal, somatomotor, subcortical, and cerebellar networks. PWI showed decreased cerebral blood flow (CBF) in the frontotemporal area, thalamus, and basal ganglia. Advanced MRI shows changes in the brain networks and regions of the PCCs, which may cause neurological and neuropsychiatric problems. Multimodal neuroimaging may help understand brain-behavior relationships. Longitudinal studies are necessary to better understand the progression of these brain anomalies.
Topics: Humans; Diffusion Tensor Imaging; COVID-19; Magnetic Resonance Imaging; Neuroimaging; Brain; Magnetic Resonance Spectroscopy; White Matter
PubMed: 38421524
DOI: 10.1007/s10072-024-07427-6 -
PloS One 2024Despite being neglected for several decades, and in many countries, public transport environments have transformed into a reflection of social disparities and...
BACKGROUND
Despite being neglected for several decades, and in many countries, public transport environments have transformed into a reflection of social disparities and inequalities. Among these issues, harassment-a pervasive and worldwide gendered dynamic-has been demonstrated to negatively impact women's behavioral trends, daily opportunities, and health impacts, as well as safety and security outcomes.
AIM
This systematic review aimed to examine a set of studies analyzing harassment against women in public transport environments, with a focus on key issues such as its prevalence, impact on transport dynamics, preventive strategies, and policing avenues documented in the scientific literature.
METHOD
A total of 575 indexed articles were filtered using the PRISMA methodology, resulting in a final selection of 28 original articles directly addressing the issue up to December 2023. Search strategies were developed and implemented across WOS, Scopus, NCBI, Google Scholar, and APA databases.
RESULTS
Besides high frequency, widespread underreporting, and adverse effects on women's safety, this review has identified correlations between harassment and travel behavioral adaptations. Furthermore, it reveals a noticeable disparity between the existing measures and those perceived as more effective by potential victims. These findings underscore the pressing need to listen to and promote the inclusion of women in decision-making regarding transport affairs.
CONCLUSION
The findings of this systematic review suggest that, despite a slightly limited body of research, the impact of transport harassment on women's health and welfare is consistently supported in the literature. In addition to being largely explained by existing inequalities rooted in social determinants, transit harassment further exacerbates gender gaps, gaining prospective importance for transport settings.
Topics: Humans; Female; Privacy; Prospective Studies; Violence; Women's Health; Sexual Harassment
PubMed: 38416765
DOI: 10.1371/journal.pone.0296830 -
Molecular Psychiatry Feb 2024Glutamatergic neurotransmission system dysregulation may play an important role in the pathophysiology of Alzheimer's disease (AD). However, reported results on...
Glutamatergic neurotransmission system dysregulation may play an important role in the pathophysiology of Alzheimer's disease (AD). However, reported results on glutamatergic components across brain regions are contradictory. Here, we conducted a systematic review with meta-analysis to examine whether there are consistent glutamatergic abnormalities in the human AD brain. We searched PubMed and Web of Science (database origin-October 2023) reports evaluating glutamate, glutamine, glutaminase, glutamine synthetase, glutamate reuptake, aspartate, excitatory amino acid transporters, vesicular glutamate transporters, glycine, D-serine, metabotropic and ionotropic glutamate receptors in the AD human brain (PROSPERO #CDRD42022299518). The studies were synthesized by outcome and brain region. We included cortical regions, the whole brain (cortical and subcortical regions combined), the entorhinal cortex and the hippocampus. Pooled effect sizes were determined with standardized mean differences (SMD), random effects adjusted by false discovery rate, and heterogeneity was examined by I statistics. The search retrieved 6 936 articles, 63 meeting the inclusion criteria (N = 709CN/786AD; mean age 75/79). We showed that the brain of AD individuals presents decreased glutamate (SMD = -0.82; I = 74.54%; P < 0.001) and aspartate levels (SMD = -0.64; I = 89.71%; P = 0.006), and reuptake (SMD = -0.75; I = 83.04%; P < 0.001. We also found reduced α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPAR)-GluA2/3 levels (SMD = -0.63; I = 95.55%; P = 0.046), hypofunctional N-methyl-D-aspartate receptor (NMDAR) (SMD = -0.60; I = 91.47%; P < 0.001) and selective reduction of NMDAR-GluN2B subunit levels (SMD = -1.07; I = 41.81%; P < 0.001). Regional differences include lower glutamate levels in cortical areas and aspartate levels in cortical areas and in the hippocampus, reduced glutamate reuptake, reduced AMPAR-GluA2/3 in the entorhinal cortex, hypofunction of NMDAR in cortical areas, and a decrease in NMDAR-GluN2B subunit levels in the entorhinal cortex and hippocampus. Other parameters studied were not altered. Our findings show depletion of the glutamatergic system and emphasize the importance of understanding glutamate-mediated neurotoxicity in AD. This study has implications for the development of therapies and biomarkers in AD.
PubMed: 38366114
DOI: 10.1038/s41380-024-02473-0 -
Pediatric Allergy and Immunology :... Feb 2024The increasing prevalence of IgE-mediated cow's milk allergy (CMA) in childhood is a worldwide health concern. There is a growing awareness that the gut microbiome (GM)... (Review)
Review
The increasing prevalence of IgE-mediated cow's milk allergy (CMA) in childhood is a worldwide health concern. There is a growing awareness that the gut microbiome (GM) might play an important role in CMA development. Therefore, treatment with probiotics and prebiotics has gained popularity. This systematic review provides an overview of the alterations of the GM, metabolome, and immune response in CMA children and animal models, including post-treatment modifications. MEDLINE, PubMed, Scopus, and Web of Science were searched for studies on GM in CMA-diagnosed children, published before 1 March 2023. A total of 21 articles (13 on children and 8 on animal models) were included. The studies suggest that the GM, characterized by an enrichment of the Clostridia class and reductions in the Lactobacillales order and Bifidobacterium genus, is associated with CMA in early life. Additionally, reduced levels of short-chain fatty acids (SCFAs) and altered amino acid metabolism were reported in CMA children. Commonly used probiotic strains belong to the Bifidobacterium and Lactobacillus genera. However, only Bifidobacterium levels were consistently upregulated after the intervention, while alterations of other bacteria taxa remain inconclusive. These interventions appear to contribute to the restoration of SCFAs and amino acid metabolism balance. Mouse models indicate that these interventions tend to restore the T 2/T 1 balance, increase the T response, and/or silence the overall pro- and anti-inflammatory cytokine response. Overall, this systematic review highlights the need for multi-omics-related research in CMA children to gain a mechanistic understanding of this disease and to develop effective treatments and preventive strategies.
Topics: Child; Animals; Cattle; Female; Mice; Humans; Infant; Milk Hypersensitivity; Gastrointestinal Microbiome; Immunity; Metabolome; Amino Acids
PubMed: 38363041
DOI: 10.1111/pai.14084 -
Frontiers in Endocrinology 2023We present a comprehensive overview of changes in thyroxine (T4) and thyroid stimulating hormone (TSH) serum concentrations after pre-gestational, gestational and/or...
We present a comprehensive overview of changes in thyroxine (T4) and thyroid stimulating hormone (TSH) serum concentrations after pre-gestational, gestational and/or lactation exposures of rodents to various chemicals that affect the thyroid hormone system. We show that T4 and TSH changes consistent with the idealized view of the hypothalamic-pituitary-thyroid (HPT) feedback loop (T4 decrements accompanied by TSH increases) are observed with only a relatively small set of chemicals. Most substances affect concentrations of various thyroid hormones without increasing TSH. Studies of altered T4 concentrations after gestational exposures are limited to a relatively small set of chemicals in which pesticides, pharmaceuticals and industrial chemicals are under-represented. Our risk-of-bias analysis exposed deficits in T4/TSH analytics as a problem area. By relating patterns of T4 - TSH changes to mode-of-action (MOA) information, we found that chemicals capable of disrupting the HPT feedback frequently affected thyroid hormone synthesis, while substances that produced T4 serum decrements without accompanying TSH increases lacked this ability, but often induced liver enzyme systems responsible for the elimination of TH by glucuronidation. Importantly, a multitude of MOA leads to decrements of serum T4. The current EU approaches for identifying thyroid hormone system-disrupting chemicals, with their reliance on altered TH serum levels as indicators of a hormonal mode of action and thyroid histopathological changes as indicators of adversity, will miss chemicals that produce T4/T3 serum decreases without accompanying TSH increases. This is of concern as it may lead to a disregard for chemicals that produce developmental neurotoxicity by disrupting adequate T4/T3 supply to the brain, but without increasing TSH.
Topics: Animals; Female; Rodentia; Thyroid Hormones; Thyroxine; Thyroid Gland; Thyrotropin
PubMed: 38352246
DOI: 10.3389/fendo.2023.1323284 -
Journal of Clinical and Experimental... Nov 2023Rumination, defined as intrusive and repetitive thoughts in response to negative emotions, uncertainty, and inconsistency between goal and current situation, is a...
INTRODUCTION
Rumination, defined as intrusive and repetitive thoughts in response to negative emotions, uncertainty, and inconsistency between goal and current situation, is a significant risk factor for depressive disorders. The rumination literature presents diverse findings on functional connectivity and shows heterogeneity in research methods. This systematic review seeks to integrate these findings and provide readers diverse perspectives.
METHOD
For this purpose, the literature on functional connectivity in rumination was reviewed according to the PRISMA guidelines. Regional connectivity and network connectivity results were scrutinized according to the presence of depression, research methods, and type of rumination. After screening 492 articles, a total of 36 studies were included.
RESULTS
The results showed that increased connectivity of the default mode network (DMN) was consistently reported. Other important findings include alterations in the connectivity between the DMN and the frontoparietal network and the salience network (SN) and impaired regulatory function of the SN. Region-level connectivity studies consistently show that increased connectivity between the posterior cingulate cortex and the prefrontal cortex is associated with rumination, which may cause the loss of control of the frontoparietal network over self-referential processes. We have seen that the number of studies examining brooding and reflective rumination as separate dimensions are relatively limited. Although there are overlaps between the connectivity patterns of the two types of rumination in these studies, it can be thought that reflective rumination is more associated with more increased functional connectivity of the prefrontal cortex.
CONCLUSIONS
Although there are many consistent functional connectivity outcomes associated with trait rumination, less is known about connectivity changes during state rumination. Relatively few studies have taken into account the subjective aspect of this thinking style. In order to better explain the relationship between rumination and depression, rumination induction studies during episode and remission periods of depression are needed.
Topics: Humans; Brain; Brain Mapping; Magnetic Resonance Imaging; Prefrontal Cortex; Rumination, Cognitive
PubMed: 38346167
DOI: 10.1080/13803395.2024.2315312 -
Scientific Reports Feb 2024Reports indicate that Plasmodium infections influence methemoglobin levels. However, findings have been inconclusive or have varied across different geographic and... (Meta-Analysis)
Meta-Analysis
Reports indicate that Plasmodium infections influence methemoglobin levels. However, findings have been inconclusive or have varied across different geographic and demographic contexts. This systematic review and meta-analysis aimed to consolidate existing data regarding the association between Plasmodium infections and alterations in methemoglobin levels related to the severity of the infection. A comprehensive literature search of several databases, including Ovid, ProQuest, Embase, Scopus, MEDLINE, and PubMed, was conducted to identify relevant studies that examined methemoglobin levels in patients with malaria. Qualitative synthesis and meta-analysis of the pooled standardized mean difference were conducted to synthesize the differences in methemoglobin levels between: (1) patients with malaria and those without malaria and (2) patients with severe malaria and those with uncomplicated malaria based on various themes including publication year, study design, study area, Plasmodium species, age group, symptomatic status, severity status, and method of malaria detection. Of the 1846 studies that were initially identified from the main databases and additional searches on Google Scholar, 10 studies met the eligibility criteria and were selected for this review. The systematic review distinctly highlighted an association between malaria and elevated methemoglobin levels, an observation consistent across diverse geographical regions and various Plasmodium species. Furthermore, the meta-analysis confirmed this by demonstrating increased methemoglobin levels in patients with malaria compared to those without malaria (P < 0.001, Hedges' g 2.32, 95% CI 1.36-3.29, I 97.27, 8 studies). Moreover, the meta-analysis found elevated methemoglobin levels in patients with severe malaria compared to those with uncomplicated malaria (P < 0.001, Hedges' g 2.20, 95% CI 0.82-3.58, I 96.20, 5 studies). This systematic review and meta-analysis revealed increased methemoglobin levels in patients with P. falciparum and P. vivax infections, with a notable association between elevated methemoglobin levels and severe malaria. Future research should focus on elucidating the specific mechanisms by which changes in methemoglobin levels are related to infections by P. falciparum and P. vivax, particularly in terms of severity, and how these alterations could potentially impact patient management and treatment outcomes.
Topics: Humans; Plasmodium falciparum; Plasmodium vivax; Methemoglobin; Malaria; Malaria, Vivax; Malaria, Falciparum; Plasmodium; Patient Acuity
PubMed: 38332023
DOI: 10.1038/s41598-024-53741-6