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Autoimmunity Reviews Feb 2024Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by an elusive etiology and pathophysiology. This study aims to... (Meta-Analysis)
Meta-Analysis
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition characterized by an elusive etiology and pathophysiology. This study aims to evaluate the pathological role of neuroinflammation in ME/CFS by conducting an exhaustive analysis of 65 observational studies. Four neuroimaging techniques, including magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), electroencephalography (EEG), and positron emission tomography (PET), were employed to comparatively assess brain regional structure, metabolite profiles, electrical activity, and glial activity in 1529 ME/CFS patients (277 males, 1252 females) and 1715 controls (469 males, 1246 females). Clinical characteristics, including sex, age, and fatigue severity, were consistent with established epidemiological patterns. Regional alterations were most frequently identified in the cerebral cortex, with a notable focus on the frontal cortex. However, our meta-analysis data revealed a significant hypoactivity in the insular and thalamic regions, contrary to observed frequencies. These abnormalities, occurring in pivotal network hubs bridging reason and emotion, disrupt connections with the limbic system, contributing to the hallmark symptoms of ME/CFS. Furthermore, we discuss the regions where neuroinflammatory features are frequently observed and address critical neuroimaging limitations, including issues related to inter-rater reliability. This systematic review serves as a valuable guide for defining regions of interest (ROI) in future neuroimaging investigations of ME/CFS.
Topics: Female; Humans; Male; Brain; Electroencephalography; Fatigue Syndrome, Chronic; Magnetic Resonance Imaging; Neuroimaging; Neuroinflammatory Diseases; Positron-Emission Tomography
PubMed: 38016575
DOI: 10.1016/j.autrev.2023.103484 -
European Journal of Neurology Nov 2023The gut microbiome has been reported to be closely related to Alzheimer's disease (AD) progression. Here, a comprehensive meta-analysis of gut microbial characteristics... (Review)
Review
BACKGROUND AND PURPOSE
The gut microbiome has been reported to be closely related to Alzheimer's disease (AD) progression. Here, a comprehensive meta-analysis of gut microbial characteristics in AD, mild cognitive impairment (MCI) and subjective cognitive decline (SCD) was performed to compare gut microbial alterations at each stage.
METHODS
A total of 10 databases (CNKI, WanFang, VIP, SinoMed, WOS, PubMed, Embase, Cochrane Library, PsycINFO and Void) were searched and 34 case-control studies were included. α and β diversity and the relative abundance of gut microbiota were analysed as outcome indices. Data analysis was performed using Review Manager (5.4.1) and R.
RESULTS
Chao1 and Shannon index levels in AD were significantly lower compared with healthy controls (HCs), and the Chao1 index was significantly lower in MCI compared with HCs. There was a significant difference in β diversity of gut microbiomes in patients (SCD, MCI, AD) compared with HCs. The relative abundance of Firmicutes at the phylum level was significantly lower in patients with AD and MCI than HCs. However, the relative abundance of Bacteroidetes at the phylum level was significantly higher in patients with MCI than HCs. There was an increasing trend for Enterobacteriaceae and a decreasing trend for Ruminococcaceae, Lachnospiraceae and Lactobacillus during AD; Lactobacillus showed a decreasing trend early in SCD.
CONCLUSION
Our results indicated that there were gut microbiological abnormalities in AD, even as early as the SCD stage. The dynamic, consistent changes in gut microbes with the disease process showed that they might serve as potential biomarkers for early identification and diagnosis of AD.
PubMed: 37399128
DOI: 10.1111/ene.15961 -
Journal of Sport and Health Science May 2024B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins. Exercise...
BACKGROUND
B cells represent a crucial component of adaptive immunity that ensures long-term protection from infection by generating pathogen-specific immunoglobulins. Exercise alters B cell counts and immunoglobulin levels, but evidence-based conclusions on potential benefits for adaptive immunity are lacking. This systematic review assessed current literatures on the impact of acute exercise and exercise training on B cells, immunoglobulins, and markers of secretory immunity in human biofluids.
METHODS
According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, MEDLINE, Web of Science, and Embase were searched on March 8, 2023. Non-randomized controlled trials and crossover trials investigating the impact of acute exercise or exercise training on B cell counts and proportions, immunoglobulin levels, salivary flow rate, or secretory immunoglobulin A secretion rate were included. Quality and reporting of exercise training studies were assessed using the Tool for the Assessment of Study Quality and reporting in Exercise. Study characteristics, outcome measures, and statistically significant changes were summarized tabularly.
RESULTS
Of the 67 eligible studies, 22 applied acute exercise and 45 applied exercise training. All included outcomes revealed significant alterations over time in acute exercise and exercise training context, but only a few investigations showed significant differences compared to control conditions. Secretory and plasma immunoglobulin A levels were most consistently increased in response to exercise training.
CONCLUSION
B cell-related outcomes are altered by acute exercise and exercise training, but evidence-based conclusions cannot be drawn with high confidence due to the large heterogeneity in populations and exercise modalities. Well-designed trials with large sample sizes are needed to clarify how exercise shapes B cell-related immunity.
Topics: Humans; Adaptive Immunity; B-Lymphocytes; Biomarkers; Exercise; Immunoglobulin A, Secretory; Saliva
PubMed: 37832643
DOI: 10.1016/j.jshs.2023.10.002 -
Molecular Psychiatry Oct 2023Aberrant anatomical brain connections in attention-deficit/hyperactivity disorder (ADHD) are reported inconsistently across diffusion weighted imaging (DWI) studies.... (Meta-Analysis)
Meta-Analysis
Aberrant anatomical brain connections in attention-deficit/hyperactivity disorder (ADHD) are reported inconsistently across diffusion weighted imaging (DWI) studies. Based on a pre-registered protocol (Prospero: CRD42021259192), we searched PubMed, Ovid, and Web of Knowledge until 26/03/2022 to conduct a systematic review of DWI studies. We performed a quality assessment based on imaging acquisition, preprocessing, and analysis. Using signed differential mapping, we meta-analyzed a subset of the retrieved studies amenable to quantitative evidence synthesis, i.e., tract-based spatial statistics (TBSS) studies, in individuals of any age and, separately, in children, adults, and high-quality datasets. Finally, we conducted meta-regressions to test the effect of age, sex, and medication-naïvety. We included 129 studies (6739 ADHD participants and 6476 controls), of which 25 TBSS studies provided peak coordinates for case-control differences in fractional anisotropy (FA)(32 datasets) and 18 in mean diffusivity (MD)(23 datasets). The systematic review highlighted white matter alterations (especially reduced FA) in projection, commissural and association pathways of individuals with ADHD, which were associated with symptom severity and cognitive deficits. The meta-analysis showed a consistent reduced FA in the splenium and body of the corpus callosum, extending to the cingulum. Lower FA was related to older age, and case-control differences did not survive in the pediatric meta-analysis. About 68% of studies were of low quality, mainly due to acquisitions with non-isotropic voxels or lack of motion correction; and the sensitivity analysis in high-quality datasets yielded no significant results. Findings suggest prominent alterations in posterior interhemispheric connections subserving cognitive and motor functions affected in ADHD, although these might be influenced by non-optimal acquisition parameters/preprocessing. Absence of findings in children may be related to the late development of callosal fibers, which may enhance case-control differences in adulthood. Clinicodemographic and methodological differences were major barriers to consistency and comparability among studies, and should be addressed in future investigations.
Topics: Adult; Humans; Child; White Matter; Attention Deficit Disorder with Hyperactivity; Diffusion Tensor Imaging; Brain; Corpus Callosum; Anisotropy
PubMed: 37479785
DOI: 10.1038/s41380-023-02173-1 -
Journal of Magnetic Resonance Imaging :... Oct 2023Diffusion-weighted imaging has been applied to investigate alterations in multiple sclerosis (MS). In the last years, advanced diffusion models were used to identify... (Review)
Review
Diffusion-weighted imaging has been applied to investigate alterations in multiple sclerosis (MS). In the last years, advanced diffusion models were used to identify subtle changes and early lesions in MS. Among these models, neurite orientation dispersion and density imaging (NODDI) is an emerging approach, quantifying specific neurite morphology in both grey (GM) and white matter (WM) tissue and increasing the specificity of diffusion imaging. In this systematic review, we summarized the NODDI findings in MS. A search was conducted on PubMed, Scopus, and Embase, which yielded a total number of 24 eligible studies. Compared to healthy tissue, these studies identified consistent alterations in NODDI metrics involving WM (neurite density index), and GM lesions (neurite density index), or normal-appearing WM tissue (isotropic volume fraction and neurite density index). Despite some limitations, we pointed out the potential of NODDI in MS to unravel microstructural alterations. These results might pave the way to a deeper understanding of the pathophysiological mechanism of MS. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 3.
Topics: Humans; Neurites; Diffusion Tensor Imaging; Diffusion Magnetic Resonance Imaging; Multiple Sclerosis; White Matter; Brain
PubMed: 37042392
DOI: 10.1002/jmri.28727 -
The Journal of Maternal-fetal &... Dec 2023The majority of expectant mothers report sleep alterations during pregnancy and almost 40% report poor sleep quality. There is growing evidence that sleep quality (SQ)... (Review)
Review
BACKGROUND
The majority of expectant mothers report sleep alterations during pregnancy and almost 40% report poor sleep quality. There is growing evidence that sleep quality (SQ) during pregnancy influences maternal health. This review focuses on how SQ during pregnancy relates to maternal health-related quality of life (HRQoL). The review also aims to identify whether this relation varies between pregnancy trimesters, and for different subdomains of HRQoL.
METHODS
A systematic review was performed according to PRISMA guidelines and registered on Prospero in August 2021 with ID no: CRD42021264707. Pubmed, Psychinfo, Embase, Cochrane, and trial registries were searched up to June 2021. Studies with any design that investigated the relation between SQ and quality of life/HRQoL in pregnant women, published in English, and peer-reviewed, were included. Two independent reviewers screened titles, abstracts, and full texts, and extracted data from the included papers. The quality of the studies was evaluated using the Newcastle-Ottawa Scale.
RESULTS
Three hundred and thirteen papers were identified in the initial search, of which 10 met the inclusion criteria. Data included 7330 participants from six different countries. The studies had longitudinal ( = 1) or cross-sectional designs ( = 9). In nine studies SQ was reported subjectively by self-report questionnaires. Actigraphic data was available from two studies. HRQoL was assessed by validated questionnaires in all studies. Due to high levels of clinical and methodological heterogeneity in included studies, a narrative synthesis was employed. Nine studies found that poor sleep quality was related to a lower overall HRQoL during pregnancy. Effect sizes were low to medium. This relation was reported most during the third trimester. Especially sleep disturbances and subjective low SQ seemed to be related consistently to lower HRQoL. Furthermore, an indication was found that SQ might have a relation with the mental and physical domain of HRQoL. The social and environmental domain may also be associated with overall SQ.
CONCLUSION
Despite the scarcity of studies available, this systematic review found evidence that low SQ is related to low HRQoL during pregnancy. An indication was found that the relationship between SQ and HRQoL during the second trimester might be less prominent.
Topics: Humans; Female; Pregnancy; Quality of Life; Sleep Quality; Cross-Sectional Studies; Pregnant Women; Sleep; Sleep Initiation and Maintenance Disorders
PubMed: 37197986
DOI: 10.1080/14767058.2023.2212829 -
Critical Reviews in Food Science and... 2024Despite enormous research efforts, a sufficiently sensitive and reliable biomarker for the assessment of zinc (Zn) status has not been identified to date. Zn affects... (Meta-Analysis)
Meta-Analysis
Despite enormous research efforts, a sufficiently sensitive and reliable biomarker for the assessment of zinc (Zn) status has not been identified to date. Zn affects fatty acid metabolism and alters the activity of certain desaturases; thus, desaturase activity has been proposed as a potential new biomarker of Zn status. This systematic review complied and assessed studies that examined changes in fatty acid desaturase 1 (FADS1) and fatty acid desaturase 2 (FADS2) activities in relation to modifications in dietary Zn intake. A systematic search was performed in PubMed, Web of Science, Scopus, Web of Knowledge, and Central with strictly defined search, inclusion, and exclusion criteria. Twenty-one studies were included, 8 animal and 13 human trials (5 randomized controlled trials, two non-randomized controlled trials, and 6 cross-sectional studies). This systematic review was performed using PRISMA guidelines and where feasible a random-effects meta-analysis was conducted. No significant correlation was seen between the delta 6 desaturase and Zn status (-0.0958, 95% CIs (-0.2912; 0.1074), p = 0.2928). Delta 6 desaturase seems to respond in a greater magnitude than Zn status to Zn-containing interventions (the standardized mean difference for delta 6 desaturase was -0.6052, 95% CIs (-2.7162; 1.5058), p = 0.4289, while for plasma/serum Zn it was 0.0319, 95% CIs (-0.9133; 0.9770), p = 0.9213). Finally, two separate meta-analyses on same studies that assessed the correlations between LA:DGLA and Zn intake and Zn status and Zn intake revealed that the magnitude of correlations was only slightly different (the pooled correlation coefficient between the LA:DGLA ratio and Zn intake had a value of -0.1050, 95% CIs (-0.5356; 0.3690), p = 0.454, while between plasma Zn and Zn intake had a value of -0.0647, 95% CIs (-0.4224; 0.3106), p = 0.5453). According to the descriptive analysis, the magnitude of variation in desaturase activities in response to Zn intake was not consistent among studies, FADS1 and FADS2 activity corresponded to dietary Zn manipulations, both in animals and humans. A plausible explanation for this observation might be the difference between the studies in study populations, types of dietary interventions, study durations, etc. In addition, several potential confounders and covariates are identified from the qualitative synthesis, such as gender, age, the type of fat provided within the dietary intervention, the size of Zn particles, among others. Further high-quality studies are needed to additionally clarify the suggested associations and applicability of utilizing fatty acid desaturase activities as Zn status biomarkers.
Topics: Animals; Humans; Fatty Acid Desaturases; Linoleoyl-CoA Desaturase; Zinc; Cross-Sectional Studies; Biomarkers; Polymorphism, Single Nucleotide
PubMed: 35880429
DOI: 10.1080/10408398.2022.2103790 -
Journal of Oral Rehabilitation Feb 2024The present review aimed to investigate the association between salivary biomarkers and temporomandibular disorders (TMD). TMD is a multifactorial condition... (Review)
Review
Salivary Biomarkers and Temporomandibular Disorders: A Systematic Review conducted according to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions.
BACKGROUND
The present review aimed to investigate the association between salivary biomarkers and temporomandibular disorders (TMD). TMD is a multifactorial condition characterised by pain and dysfunction in the temporomandibular joint (TMJ) and surrounding structures. Salivary biomarkers have emerged as potential diagnostic tools due to their non-invasiveness and easy accessibility. However, the literature on salivary biomarkers in relation to TMD is limited and inconsistent.
METHODS
Electronic databases of Pubmed, Embase, Web of Science, Scopus, Cochrane Library, PsychINFO, CINAHL and Medline were searched using specific search terms and Boolean operators. The search was limited to articles published in English that assessed salivary biomarkers in individuals diagnosed with TMD. Two reviewers independently screened the articles and extracted data. ROB-2 was used to assess the risk of bias.
RESULTS
Eleven clinical papers met the inclusion criteria and were included in the review. The findings provided consistent evidence of a clear association between salivary biomarkers and TMD. Various biomarkers, including cortisol, IL-1, glutamate and several others, were assessed. Some studies reported higher levels of cortisol and IL-1 in TMD patients, indicating potential involvement in stress and inflammation. Glutamate levels were found to be elevated, suggesting a role in pain modulation. Other biomarkers also showed alterations in TMD patients compared to controls: CONCLUSION: The findings from the included studies suggest that salivary biomarkers may play a role in TMD pathophysiology. Though a definitive conclusion can be drawn regarding the specific salivary biomarkers and their association with TMD, the results must be interpreted with caution considering the heterogeneity of the biomarkers assessed. Further research with larger sample sizes, standardised methodology and rigorous study designs is needed to elucidate the role of salivary biomarkers in TMD.
Topics: Humans; Hydrocortisone; Temporomandibular Joint Disorders; Pain; Glutamates; Interleukin-1
PubMed: 37731276
DOI: 10.1111/joor.13589 -
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 -
Journal of Lower Genital Tract Disease Jan 2024Vulvodynia is defined as vulvar pain of at least 3 months' duration, without clear identifiable cause, which may have potential associated factors. It can have a...
INTRODUCTION
Vulvodynia is defined as vulvar pain of at least 3 months' duration, without clear identifiable cause, which may have potential associated factors. It can have a significant impact on women's quality of life due to a combination of physical pain, emotional distress, and limited treatment options. Despite affecting a considerable number of women worldwide, the causes and underlying mechanisms of vulvodynia remain poorly understood. Given the recognized association of the vaginal microbiota with various gynecologic disorders, there has been growing interest in exploring the potential role of the vaginal microbiota in the etiology of vulvodynia. This systematic review aims to evaluate the current literature on the association between the vaginal microbiota and vulvodynia.
MATERIAL AND METHODS
A systematic search of multiple databases, including PubMed, Scopus, Web of Science, Cochrane Library, and Ovid MEDLINE, was conducted to identify relevant peer-reviewed studies up to May 12, 2023. The following search terms were used across these databases: "vulvodynia," "vestibulodynia," "vulvar vestibulitis," "microbiome," "microbiota," and "flora."
RESULTS
A total of 8 case-control studies were included, the quality of which was assessed using the Newcastle-Ottawa Scale. Data extraction and synthesis were performed using a standardized protocol. In most studies, no major differences were found between the vaginal bacterial composition of women with vulvodynia and that of controls. No specific bacterial taxa were consistently associated with vulvodynia. The relationship between vaginal microbiota diversity and vulvodynia remains to be fully understood.
CONCLUSIONS
The role of vaginal microbiota in vulvodynia, if any, remains unclear. Because of the cross-sectional nature of the included studies, it is not possible to make any causal inferences. Further research, using larger and more diverse study populations and advanced sequencing techniques, is necessary to gain a better understanding of the potential relationship between the vaginal microbiota and vulvodynia.
Topics: Female; Humans; Vulvodynia; Quality of Life; Cross-Sectional Studies; Bacteria; Vulvar Vestibulitis; Pain; Microbiota
PubMed: 37963335
DOI: 10.1097/LGT.0000000000000780