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Neuroscience and Biobehavioral Reviews Oct 2021Post-mortem studies allow for the direct investigation of brain tissue in those with autism and related disorders. Several review articles have focused on aspects of... (Review)
Review
Post-mortem studies allow for the direct investigation of brain tissue in those with autism and related disorders. Several review articles have focused on aspects of post-mortem abnormalities but none has brought together the entire post-mortem literature. Here, we systematically review the evidence from post-mortem studies of autism, and of related disorders that present with autistic features. The literature consists of a small body of studies with small sample sizes, but several remarkably consistent findings are evident. Cortical layering is largely undisturbed, but there are consistent reductions in minicolumn numbers and aberrant myelination. Transcriptomics repeatedly implicate abberant synaptic, metabolic, proliferation, apoptosis and immune pathways. Sufficient replicated evidence is available to implicate non-coding RNA, aberrant epigenetic profiles, GABAergic, glutamatergic and glial dysfunction in autism pathogenesis. Overall, the cerebellum and frontal cortex are most consistently implicated, sometimes revealing distinct region-specific alterations. The literature on related disorders such as Rett syndrome, Fragile X and copy number variations (CNVs) predisposing to autism is particularly small and inconclusive. Larger studies, matched for gender, developmental stage, co-morbidities and drug treatment are required.
Topics: Autism Spectrum Disorder; Autistic Disorder; Autopsy; Brain; Cerebellum; DNA Copy Number Variations; Humans
PubMed: 34273379
DOI: 10.1016/j.neubiorev.2021.07.014 -
EBioMedicine Jun 2022Emerging evidence suggests that dysbiosis in gut microbiota may contribute to the occurrence or development of several rheumatic diseases. Since gut microbiota dysbiosis... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Emerging evidence suggests that dysbiosis in gut microbiota may contribute to the occurrence or development of several rheumatic diseases. Since gut microbiota dysbiosis is potentially modifiable, it has been postulated to be a promising preventive or therapeutic target for rheumatic diseases. However, the current understanding on the potential associations between gut microbiota and rheumatic diseases is still inadequate. Therefore, we aimed to synthesise the accumulating evidence for the relation of gut microbiota to rheumatic diseases.
METHODS
The PubMed, Embase and Cochrane Library were searched from inception to March 11, 2022 to include observational studies evaluating the associations between gut microbiota and rheumatic diseases. Standardised mean difference (SMD) of α-diversity indices between rheumatic diseases and controls were estimated using random-effects model. β-diversity indices and relative abundance of gut microbes were summarised qualitatively.
FINDINGS
Of the included 92 studies (11,998 participants), 68 provided data for α-diversity. Taken together as a whole, decreases in α-diversity indices were consistently found in rheumatic diseases (observed species: SMD = -0.36, [95%CI = -0.63, -0.09]; Chao1: SMD = -0.57, [95%CI = -0.88, -0.26]; Shannon index: SMD = -0.33, [95%CI = -0.48, -0.17]; Simpson index: SMD = -0.32, [95%CI = -0.49, -0.14]). However, when specific rheumatic diseases were examined, decreases were only observed in rheumatoid arthritis (observed species: SMD = -0.51, [95%CI = -0.78, -0.24]; Shannon index: SMD = -0.31, [95%CI = -0.49, -0.13]; Simpson index: SMD = -0.31, [95%CI = -0.54, -0.08]), systemic lupus erythematosus (Chao1: SMD = -1.60, [95%CI = -2.54, -0.66]; Shannon index: SMD = -0.63, [95%CI = -1.08, -0.18]), gout (Simpson index: SMD = -0.64, [95%CI = -1.07, -0.22]) and fibromyalgia (Simpson index: SMD = -0.28, [95%CI = -0.44, -0.11]), whereas an increase was observed in systemic sclerosis (Shannon index: SMD = 1.25, [95%CI = 0.09, 2.41]). Differences with statistical significance in β-diversity were consistently reported in ankylosing spondylitis and IgG4-related diseases. Although little evidence of disease specificity of gut microbes was found, shared alterations of the depletion of anti-inflammatory butyrate-producing microbe (i.e., Faecalibacterium) and the enrichment of pro-inflammatory microbe (i.e., Streptococcus) were observed in rheumatoid arthritis, Sjögren's syndrome and systemic lupus erythematosus.
INTERPRETATION
Gut microbiota dysbiosis was associated with rheumatic diseases, principally with potentially non-specific, shared alterations of microbes.
FUNDING
National Natural Science Foundation of China (81930071, 81902265, 82072502 and U21A20352).
Topics: Dysbiosis; Gastrointestinal Microbiome; Humans; Lupus Erythematosus, Systemic; Rheumatic Diseases; Sjogren's Syndrome
PubMed: 35594658
DOI: 10.1016/j.ebiom.2022.104055 -
Journal of the American Society of... May 2022Vascular calcification is associated with cardiovascular morbidity and mortality in people with CKD. Evidence-based interventions that may attenuate its progression in...
BACKGROUND
Vascular calcification is associated with cardiovascular morbidity and mortality in people with CKD. Evidence-based interventions that may attenuate its progression in CKD remain uncertain.
METHODS
We conducted a systematic review of prospective clinical trials of interventions to attenuate vascular calcification in people with CKD, compared with placebo, another comparator, or standard of care. We included prospective clinical trials (randomized and nonrandomized) involving participants with stage 3-5D CKD or kidney transplant recipients; the outcome was vascular calcification measured using radiologic methods. Quality of evidence was determined by the Cochrane risk of bias assessment tool and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method.
RESULTS
There were 77 trials (63 randomized) involving 6898 participants eligible for inclusion (median sample size, 50; median duration, 12 months); 58 involved participants on dialysis, 15 involved individuals with nondialysis CKD, and 4 involved kidney transplant recipients. Risk of bias was moderate over all. Trials involving magnesium and sodium thiosulfate consistently showed attenuation of vascular calcification. Trials involving intestinal phosphate binders, alterations in dialysate calcium concentration, vitamin K therapy, calcimimetics, and antiresorptive agents had conflicting or inconclusive outcomes. Trials involving vitamin D therapy and HMG-CoA reductase inhibitors did not demonstrate attenuation of vascular calcification. Mixed results were reported for single studies of exercise, vitamin E-coated or high-flux hemodialysis membranes, interdialytic sodium bicarbonate, SNF472, spironolactone, sotatercept, nicotinamide, and oral activated charcoal.
CONCLUSIONS
Currently, there are insufficient or conflicting data regarding interventions evaluated in clinical trials for mitigation of vascular calcification in people with CKD. Therapy involving magnesium or sodium thiosulfate appears most promising, but evaluable studies were small and of short duration.
Topics: Female; Humans; Magnesium; Male; Prospective Studies; Renal Dialysis; Renal Insufficiency, Chronic; Vascular Calcification
PubMed: 35232774
DOI: 10.1681/ASN.2021101327 -
The American Journal of Clinical... Oct 2022A low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet is increasingly used to manage symptoms in irritable bowel syndrome (IBS).... (Meta-Analysis)
Meta-Analysis
BACKGROUND
A low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet is increasingly used to manage symptoms in irritable bowel syndrome (IBS). Although this approach may alter the colonic microbiome, the nature of these changes has not been comprehensively synthesized.
OBJECTIVES
The aim of this study was to conduct a systematic review with meta-analysis of randomized controlled trials examining the impact of a low FODMAP diet on the composition and function of the microbiome in patients with IBS.
METHODS
A systematic search was conducted for randomized controlled trials evaluating the effects of a low FODMAP diet on the colonic microbiome in patients with IBS in MEDLINE, EMBASE, CENTRAL, and Web of Science from inception to April 2022. Outcomes included diversity of the microbiome, specific bacterial abundances, fecal SCFA concentration, and fecal pH. For fecal SCFA concentrations and pH, meta-analyses were performed via a random-effects model.
RESULTS
Nine trials involving 403 patients were included. There were no clear effects of the low FODMAP diet on diversity of the microbiome. A low FODMAP diet consistently led to lower abundance of Bifidobacteria, but there were no clear effects on diversity of the microbiome or abundances of other specific taxa. There were no differences in total fecal SCFA concentration between the low FODMAP diet and control diets (standardized mean difference: -0.25; 95% CI: -0.63, 0.13; P = 0.20), nor were there differences for fecal concentrations of specific SCFAs or fecal pH.
CONCLUSIONS
In patients with IBS, the effects of a low FODMAP diet on the colonic microbiome appear to be specific to Bifidobacteria with no consistent impacts on other microbiome metrics, including diversity, fecal SCFA concentrations, and fecal pH. Further, adequately powered trials are needed to confirm these findings.This review was registered at https://www.crd.york.ac.uk/prospero/ as CRD42020192243.
Topics: Bifidobacterium; Diet; Diet, Carbohydrate-Restricted; Disaccharides; Fermentation; Humans; Irritable Bowel Syndrome; Microbiota; Monosaccharides; Oligosaccharides
PubMed: 35728042
DOI: 10.1093/ajcn/nqac176 -
Journal of Affective Disorders Jun 2018Epigenetic mechanisms have been suggested to play a key role in the pathophysiology of bipolar disorder (BD), among which microRNAs (miRNAs) may be of particular... (Review)
Review
BACKGROUND
Epigenetic mechanisms have been suggested to play a key role in the pathophysiology of bipolar disorder (BD), among which microRNAs (miRNAs) may be of particular significance according to recent studies. We aimed to summarize miRNA studies in BD to identify consistent findings, limitations, and future directions of this emerging field.
METHODS
We performed a comprehensive search on PUBMED and Medline for studies investigating an association between BD and miRNAs. The included studies report miRNA alterations in postmortem brain tissues and in the periphery, cell culture and preclinical findings, genetic associations, and the effects of medications.
RESULTS
Several studies report changes in miRNA expression levels in postmortem brain and in the periphery of patients, although most of the results so far have not been replicated and are not concordant between different populations. Genetic studies also suggest that miRNA genes are located within susceptibility loci of BD, and also a putative role of miRNAs in modulating genes previously shown to confer risk of BD.
LIMITATIONS
We did not perform a systematic review of the literature, and miRNAs represent only one facet of the plethora of epigenetic mechanisms that might be involved in BD's pathophysiology.
CONCLUSIONS
miRNA findings in BD significantly vary between studies, but are consistent to suggest a key role for these molecules in BD's pathophysiology and treatment, particularly miR-34a and miR-137. Accordingly, miRNA might represent important biomarkers of illness to be used in the clinical settings, and potentially also for the development of novel therapeutics for BD in the near future.
Topics: Bipolar Disorder; Brain; Epigenomics; Genetic Markers; Humans; MicroRNAs; Transcriptome
PubMed: 28969861
DOI: 10.1016/j.jad.2017.09.025 -
International Journal of Molecular... Apr 2022Ovarian endometriosis may increase the risk of malignancy. Several studies have suggested atypical endometriosis as the direct precursor of endometriosis-associated... (Review)
Review
Ovarian endometriosis may increase the risk of malignancy. Several studies have suggested atypical endometriosis as the direct precursor of endometriosis-associated ovarian cancer. We performed an advanced, systematic search of the online medical databases PubMed and Medline. The search revealed = 40 studies eligible for inclusion in this systematic review. Of these, = 39 were finally included. The results from included studies are characterized by high heterogeneity, but some consistency has been found for altered expression in phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway, ARID1a, estrogen and progesterone receptors, transcriptional, nuclear, and growth factors in atypical endometriosis. Although many targets have been proposed as biomarkers for the presence of atypical endometriosis, none of them has such strong evidence to justify their systematic use in clinical practice, and they all need expensive molecular analyses. Further well-designed studies are needed to validate the evidence on available biomarkers and to investigate novel serum markers for atypical endometriosis.
Topics: Biomarkers; Carcinoma, Ovarian Epithelial; Endometriosis; Female; Humans; Ovarian Neoplasms; Phosphatidylinositol 3-Kinases; Precancerous Conditions
PubMed: 35457244
DOI: 10.3390/ijms23084425 -
Journal of Affective Disorders Apr 2017Major depressive disorder is a significant contributor to global disability and mortality. The mechanisms of depression are vast and not fully understood, and as a... (Review)
Review
BACKGROUND
Major depressive disorder is a significant contributor to global disability and mortality. The mechanisms of depression are vast and not fully understood, and as a result current treatment of depression is suboptimal. Aberrant sphingolipid metabolism has been observed in some cases of depression, specifically alterations in ceramide concentrations. The role of ceramides and other sphingolipids in depression is a novel concept. This review summarizes and evaluates the current state of evidence for a role of ceramides in depression pathophysiology and the potential for novel depression pharmacotherapies targeting ceramide metabolism.
METHODS
Medline, Embase, and PsycINFO databases were searched through October 2016 for English-language studies using combinations of the search terms: ceramide, depression, sphingolipid, and depressive symptoms.
RESULTS
Of the 489 articles screened, 14 were included in the qualitative synthesis of this review article. Pre-clinical and clinical evidence suggest that ceramide species may contribute to depression pathophysiology. In human studies, ceramides C18:0 and C20:0 are the species most strongly linked to depression. Evidence for altered ceramide metabolism in depression is present, but data for a causal role of ceramides in depression are lacking.
LIMITATIONS
This review was limited by potential reporting bias. Furthermore, a lack of specificity of which ceramides were altered in depression was common.
CONCLUSIONS
Pharmacotherapy targeting ceramide metabolism may be a novel treatment option for depression. A number of pharmacological targets exists for ceramide reduction and a number of currently approved medications inhibit ceramide production. More evidence, pre-clinical and clinical, is warranted to determine the extent and consistency of the role of ceramides in depression.
Topics: Ceramides; Depression; Depressive Disorder; Humans
PubMed: 28189963
DOI: 10.1016/j.jad.2017.02.008 -
Journal of Investigative Medicine : the... Aug 2022Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by abdominal pain, bowel habits alterations, constipation, and/or diarrhea. Adverse... (Meta-Analysis)
Meta-Analysis Review
Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by abdominal pain, bowel habits alterations, constipation, and/or diarrhea. Adverse childhood experiences (ACEs) are events such as abuse and mental illness causing childhood trauma. Studies report higher prevalence of ACEs in patients with IBS with varied effect consistency and association strength. A systematic review and meta-analysis were conducted to evaluate current literature, assess heterogeneity and research gaps in this relationship. A search across PubMed, Embase, PsycINFO, and Google Scholar with keywords ('childhood adversity' OR 'childhood trauma' OR 'adverse childhood events') AND ('irritable colon' OR 'irritable bowel syndrome') yielded 106 studies. A restricted maximum likelihood model of 15 chosen studies with 272,686 participants found the association between ACEs and IBS to be uncertain given the considerable heterogeneity (I=93.58%, p<0.001). Objective reporting methods for ACE and IBS, study size, and study quality explained some heterogeneity. Twelve studies showed publication bias (Egger's test, p<0.001), which further weakened interpretation. Gender-stratified subanalysis of three studies found ACEs associated with IBS in females (pOR=2.20, 95% CI (1.13 to 4.29), I=66.90%) with substantial heterogeneity, but no association in males (pOR=1.30, 95% CI (0.62 to 2.78)). This meta-analysis explores the current literature to understand the biopsychosocial perspective of IBS and ACEs' role as risk factors. However, the risk of publication and design/study quality biases substantiates the need for further research. If an association is confirmed, further mechanistic research and development of targeted psychological therapies may be warranted.
Topics: Abdominal Pain; Child; Female; Humans; Irritable Bowel Syndrome; Male; Prevalence; Risk Factors
PubMed: 35086857
DOI: 10.1136/jim-2021-002109 -
The Journal of Headache and Pain May 2023Neuroimaging studies have made an important contribution to our understanding of headache pathophysiology. This systematic review aims to provide a comprehensive... (Review)
Review
BACKGROUND
Neuroimaging studies have made an important contribution to our understanding of headache pathophysiology. This systematic review aims to provide a comprehensive overview and critical appraisal of mechanisms of actions of headache treatments and potential biomarkers of treatment response disclosed by imaging studies.
MAIN BODY
We performed a systematic literature search on PubMed and Embase databases for imaging studies investigating central and vascular effects of pharmacological and non-pharmacological treatments used to abort and prevent headache attacks. Sixty-three studies were included in the final qualitative analysis. Of these, 54 investigated migraine patients, 4 cluster headache patients and 5 patients with medication overuse headache. Most studies used functional magnetic resonance imaging (MRI) (n = 33) or molecular imaging (n = 14). Eleven studies employed structural MRI and a few used arterial spin labeling (n = 3), magnetic resonance spectroscopy (n = 3) or magnetic resonance angiography (n = 2). Different imaging modalities were combined in eight studies. Despite of the variety of imaging approaches and results, some findings were consistent. This systematic review suggests that triptans may cross the blood-brain barrier to some extent, though perhaps not sufficiently to alter the intracranial cerebral blood flow. Acupuncture in migraine, neuromodulation in migraine and cluster headache patients, and medication withdrawal in patients with medication overuse headache could promote headache improvement by reverting headache-affected pain processing brain areas. Yet, there is currently no clear evidence for where each treatment acts, and no firm imaging predictors of efficacy. This is mainly due to a scarcity of studies and heterogeneous treatment schemes, study designs, subjects, and imaging techniques. In addition, most studies used small sample sizes and inadequate statistical approaches, which precludes generalizable conclusions.
CONCLUSION
Several aspects of headache treatments remain to be elucidated using imaging approaches, such as how pharmacological preventive therapies work, whether treatment-related brain changes may influence therapy effectiveness, and imaging biomarkers of clinical response. In the future, well-designed studies with homogeneous study populations, adequate sample sizes and statistical approaches are needed.
Topics: Humans; Cluster Headache; Headache; Brain; Migraine Disorders; Headache Disorders, Secondary
PubMed: 37221469
DOI: 10.1186/s10194-023-01590-5 -
Cells Dec 2023Atopic dermatitis (AD) is the most common chronic inflammatory skin disease and presents a major public health problem worldwide. It is characterized by a recurrent... (Review)
Review
Atopic dermatitis (AD) is the most common chronic inflammatory skin disease and presents a major public health problem worldwide. It is characterized by a recurrent and/or chronic course of inflammatory skin lesions with intense pruritus. Its pathophysiologic features include barrier dysfunction, aberrant immune cell infiltration, and alterations in the microbiome that are associated with genetic and environmental factors. There is a complex crosstalk between these components, which is primarily mediated by cytokines. Epidermal barrier dysfunction is the hallmark of AD and is caused by the disruption of proteins and lipids responsible for establishing the skin barrier. To better define the role of cytokines in stratum corneum lipid abnormalities related to AD, we conducted a systematic review of biomedical literature in PubMed from its inception to 5 September 2023. Consistent with the dominant T2 skewness seen in AD, type 2 cytokines were featured prominently as possessing a central role in epidermal lipid alterations in AD skin. The cytokines associated with T1 and T17 were also identified to affect barrier lipids. Considering the broad cytokine dysregulation observed in AD pathophysiology, understanding the role of each of these in lipid abnormalities and barrier dysfunction will help in developing therapeutics to best achieve barrier homeostasis in AD patients.
Topics: Humans; Dermatitis, Atopic; Cytokines; Epidermis; Skin; Lipids
PubMed: 38132113
DOI: 10.3390/cells12242793