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Evidence-based Medicine Oct 2012Currently systematic reviews focus on diagnosis or effectiveness of treatment. It is the understanding of disease aetiology that underpins medical education, practice... (Review)
Review
Currently systematic reviews focus on diagnosis or effectiveness of treatment. It is the understanding of disease aetiology that underpins medical education, practice and research. Whether an association meets causal criteria is usually assessed qualitatively. However, this can also be examined through evidence synthesis and systematic reviews to evaluate disease causation and mechanisms are much needed. It is important in such a review to specify the questions to be addressed regarding causal criteria such as strength, consistency, temporality, specificity, biological gradient, plausibility and experimental evidence. The next step is to conduct a thorough literature search to identify the relevant studies and to assess them for their quality, particularly in relation to the risk of bias, ascertainment of exposures and ascertainment of outcomes. Data synthesis can then examine if the observed associations in collated studies are consistent, strong and temporal using techniques such as meta-analysis, testing for heterogeneity and meta-regression. Biological plausibility and coherence with existing theories can also be examined systematically through an assessment of the basic scientific literature. Experimental evidence might also be collated and synthesised to determine if removal of a causal agent alters the outcome. Through these steps a systematic review can help to establish whether an association is causal or not.
Topics: Causality; Epidemiologic Methods; Humans; Review Literature as Topic
PubMed: 22491154
DOI: 10.1136/ebmed-2011-100287 -
Schizophrenia Bulletin Sep 2023Intestinal microbiota is intrinsically linked to human health. Evidence suggests that the composition and function of the microbiome differs in those with schizophrenia... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND HYPOTHESIS
Intestinal microbiota is intrinsically linked to human health. Evidence suggests that the composition and function of the microbiome differs in those with schizophrenia compared with controls. It is not clear how these alterations functionally impact people with schizophrenia. We performed a systematic review and meta-analysis to combine and evaluate data on compositional and functional alterations in microbiota in patients with psychosis or schizophrenia.
STUDY DESIGN
Original studies involving humans and animals were included. The electronic databases PsycINFO, EMBASE, Web of Science, PubMed/MEDLINE, and Cochrane were systematically searched and quantitative analysis performed.
STUDY RESULTS
Sixteen original studies met inclusion criteria (1376 participants: 748 cases and 628 controls). Ten were included in the meta-analysis. Although observed species and Chao 1 show a decrease in diversity in people with schizophrenia compared with controls (SMD = -0.14 and -0.66 respectively), that did not reach statistical significance. We did not find evidence for variations in richness or evenness of microbiota between patients and controls overall. Differences in beta diversity and consistent patterns in microbial taxa were noted across studies. We found increases in Bifidobacterium, Lactobacillus, and Megasphaera in schizophrenia groups. Variations in brain structure, metabolic pathways, and symptom severity may be associated with compositional alterations in the microbiome. The heterogeneous design of studies complicates a similar evaluation of functional readouts.
CONCLUSIONS
The microbiome may play a role in the etiology and symptomatology of schizophrenia. Understanding how the implications of alterations in microbial genes for symptomatic expression and clinical outcomes may contribute to the development of microbiome targeted interventions for psychosis.
Topics: Humans; Schizophrenia; Gastrointestinal Microbiome; Psychotic Disorders
PubMed: 37210594
DOI: 10.1093/schbul/sbad049 -
World Neurosurgery Oct 2022Multidisciplinary spine conferences (MSCs) are a strategy for discussing diagnostic and treatment aspects of patient care. Although they are becoming more common in... (Review)
Review
BACKGROUND
Multidisciplinary spine conferences (MSCs) are a strategy for discussing diagnostic and treatment aspects of patient care. Although they are becoming more common in hospitals, literature investigating how they impact patient care and outcomes is scarce. The aim of this study is to examine the impact of MSCs on surgical management and outcomes in elective spine surgical care.
METHODS
A systematic review of the literature was conducted to evaluate the impact of MSCs on patient management and outcomes. PubMed and Cochrane databases were searched using combinations and variations of search terms "Spine Conferences," "Multidisciplinary," and "Spine Team."
RESULTS
The literature search yielded 435 articles, of which 120 were selected for full-text review. Four articles (N = 529 patients) were included. Surgical plans were discussed in 211 patients. The decision was altered to conservative treatment in 70 patients (33.17%) and a different surgical strategy in 34 patients (16.11%). The differences were significant in 2 studies (P < 0.05). A 51% reduction in 30-day complications rates was observed when MSC was implemented in patients with adult complex scoliosis. Other spinal disorders showed a 30-day complication rate between 0% and 14% after MSC.
CONCLUSIONS
To our knowledge, this is the first systematic review of outcomes of MSCs in elective spine surgery and it confirms that MSCs impact management plan and outcomes. Consistent MSCs that include surgeons and nonsurgeons have the potential to enhance communication between specialists, standardize treatments, improve patient care, and encourage teamwork. More analysis is warranted to determine if patient outcomes are improved with these measures.
Topics: Adult; Hospitals; Humans; Scoliosis; Spine; Surgeons
PubMed: 35961589
DOI: 10.1016/j.wneu.2022.08.018 -
Critical Reviews in Oncology/hematology Jul 2018Paraoxonase-1 (PON1) is a lipolactonase implicated in the elimination of carcinogenic free radicals and in the scavenging mechanisms to maintain oxidative balance. The... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Paraoxonase-1 (PON1) is a lipolactonase implicated in the elimination of carcinogenic free radicals and in the scavenging mechanisms to maintain oxidative balance. The objective of the present systematic review and meta-analysis was to evaluate possible alterations in serum PON1 activity in patients with cancer.
METHODS
A systematic search of the observational studies in humans published in the last 15 years was performed through Medline databases following the PRISMA and STARLITE statements. Further, a keyword-based computerized search with restrictions on publication date, and a meta-analysis of case-control studies was performed.
RESULTS
In total, 23 studies were included most of which reported decreased PON1 activity in patients with cancer. This could indicate impaired defense ability against oxidative stress with potential implications in cell proliferation, promotion of genetic instability, and alterations in cellular sensitivity to chemotherapy.
CONCLUSION
This systematic review and meta-analysis confirms a consistent association between cancer and decreased serum PON1 activities. These findings may open fruitful lines of research with clinical relevance, and an understanding of molecular alterations underlying carcinogenesis.
Topics: Aryldialkylphosphatase; Case-Control Studies; Female; Humans; Male; Neoplasms; Oxidation-Reduction; Oxidative Stress
PubMed: 29891113
DOI: 10.1016/j.critrevonc.2018.04.005 -
Journal of Psychiatric Research Dec 2016Sleep and circadian abnormalities have been mostly demonstrated in bipolar patients. However, it is not clear whether these alterations are present in population at high... (Review)
Review
BACKGROUND
Sleep and circadian abnormalities have been mostly demonstrated in bipolar patients. However, it is not clear whether these alterations are present in population at high risk for bipolar disorder (BD), indicating a possible risk factor for this condition.
OBJECTIVE
This systematic review aims to define current evidence about sleep and rhythm alterations in people at risk for BD and to evaluate sleep and circadian disorders as risk factor for BD.
METHODS
The systematic review included all articles about the topic until February 2016. Two researchers performed an electronic search of PubMed and Cochrane Library. Keywords used were 'sleep' or 'rhythm' or 'circadian' AND 'bipolar disorder' or 'mania' or 'bipolar depression' AND 'high-risk' or 'risk'.
RESULTS
Thirty articles were analyzed (7451 participants at risk for BD). Sleep disturbances are frequent in studies using both subjective measures and actigraphy. High-risk individuals reported irregularity of sleep/wake times, poor sleep and circadian rhythm disruption. Poor sleep quality, nighttime awakenings, and inadequate sleep are possible predictive factors for BD. A unique study suggested that irregular rhythms increase risk of conversion. People at risk for BD showed high cortisol levels in different times of day. Studies about anatomopathology, melatonin levels, inflammatory cytokines and oxidative stress were not identified. The most important limitations were differences in sleep and rhythm measures, heterogeneity of study designs, and lack of consistency in the definition of population at risk.
CONCLUSION
Sleep and circadian disturbances are common in people at risk for BD. However, the pathophysiology of these alterations and the impact on BD onset are still unclear.
Topics: Bipolar Disorder; Chronobiology Disorders; Humans; Risk Factors; Sleep Wake Disorders
PubMed: 27661417
DOI: 10.1016/j.jpsychires.2016.09.005 -
Psychoneuroendocrinology Nov 2022Allostatic load (AL) refers to prolonged dysregulation related to chronic stress that affects brain regions such as the hippocampus, amygdala, and prefrontal cortex...
Allostatic load (AL) refers to prolonged dysregulation related to chronic stress that affects brain regions such as the hippocampus, amygdala, and prefrontal cortex (PFC). Higher levels of AL have been associated with poor health outcomes, including psychiatric disorders, cognitive decline, and chronic somatic conditions. However, still little is known about the relationship between AL and the brain, and the mechanisms explaining the damaging effects of stress-related biological dysregulations. Therefore, we aimed to perform a systematic review of studies investigating the association of the AL index with brain structure and functioning in adult populations. PubMed/MEDLINE, CINAHL, Academic Search Complete and Web of Science were searched from their inception until August, 9th 2021. A total of 13 studies were included in the qualitative synthesis. There was a high between-study heterogeneity with respect to the methods used to calculate the AL index and brain parameters. All studies confirmed the associations between a higher AL index and alterations in various brain areas, especially: 1) the hippocampus, white matter volume, gray matter volume, and density in the older adults; 2) the cortex, fornix, hippocampus and choroid plexus in patients with schizophrenia spectrum disorders; and 3) whole-brain white matter tracts, cortical gray matter volume, and cortical thickness in overweight subjects. Overall, the findings of this systematic review imply that an elevated AL index might be associated with various neurostructural and neurofunctional alterations. Some of these associations may appear regardless of clinical or non-clinical populations being investigated (e.g., white matter tracts), whereas others may appear in specific populations (e.g., cortical thinning in overweight/obesity and schizophrenia spectrum disorders). However, additional studies utilizing a consistent approach to calculating the AL index are needed to extend these findings and indicate populations that are most vulnerable to the damaging effects of AL.
Topics: Aged; Allostasis; Brain; Gray Matter; Humans; Overweight; White Matter
PubMed: 36113380
DOI: 10.1016/j.psyneuen.2022.105917 -
International Journal of Molecular... Mar 2023Gestational diabetes mellitus (GDM) is a severe pregnancy complication for both the woman and the child. Women who suffer from GDM have a greater risk of developing Type... (Meta-Analysis)
Meta-Analysis Review
Gestational diabetes mellitus (GDM) is a severe pregnancy complication for both the woman and the child. Women who suffer from GDM have a greater risk of developing Type 2 diabetes mellitus (T2DM) later in life. Identification of any potential biomarkers for the early prediction of gestational diabetes can help prevent the disease in women with a high risk. Studies show microRNA (miRNA) as a potential biomarker for the early discovery of GDM, but there is a lack of clarity as to which miRNAs are consistently altered in GDM. This study aimed to perform a systematic review and meta-analysis to investigate miRNAs associated with GDM by comparing GDM cases with normoglycemic controls. The systematic review was performed according to PRISMA guidelines with searches in PubMed, Web of Science, and ScienceDirect. The primary search resulted in a total of 849 articles, which were screened according to the prior established inclusion and exclusion criteria. Following the screening of articles, the review was based on the inclusion of 35 full-text articles, which were evaluated for risk of bias and estimates of quality, after which data were extracted and relative values for miRNAs were calculated. A meta-analysis was performed for the miRNA species investigated in three or more studies: MiR-29a, miR-330, miR-134, miR-132, miR-16, miR-223, miR-155, miR-122, miR-17, miR-103, miR-125, miR-210, and miR-222. While some miRNAs showed considerable between-study variability, miR-29a, miR-330, miR-134, miR-16, miR-223, and miR-17 showed significant overall upregulation in GDM, while circulating levels of miR-132 and miR-155 were decreased among GDM patients, suggesting further studies of these as biomarkers for early GDM discovery.
Topics: Pregnancy; Child; Humans; Female; Diabetes, Gestational; Circulating MicroRNA; Diabetes Mellitus, Type 2; MicroRNAs; Biomarkers
PubMed: 37047159
DOI: 10.3390/ijms24076186 -
Developmental Medicine and Child... Sep 2010This systematic review and critical evaluation of the literature was conducted to determine how gross muscle morphology and structure are altered in individuals with... (Review)
Review
AIM
This systematic review and critical evaluation of the literature was conducted to determine how gross muscle morphology and structure are altered in individuals with spastic cerebral palsy (CP).
METHOD
Electronic databases were searched for articles describing studies of muscle morphological and structural properties in individuals with spastic CP. Data describing muscle fascicle length, belly length, fascicle angle, cross-sectional area, volume, and thickness were extracted and effect sizes were computed for comparisons between individuals with spastic CP and typically developed individuals, between the paretic and non-paretic side in individuals with hemiplegia for all muscles examined, and across the full spectrum of gross motor function in individuals with spastic CP.
RESULTS
The final yield consisted of 15 articles that met the inclusion criteria. The main finding of the review was the consistent evidence for reduced muscle belly length, muscle volume, cross-sectional area, and muscle thickness in the comparisons between paretic and typically developed muscle and the paretic and non-paretic muscle across a range of muscles.
INTERPRETATION
Given the importance of muscle morphology and structure for generating muscle force, it is likely that the observed alterations that occur secondary to the neural lesion in individuals with spastic CP contribute to muscle weakness and the attendant loss of motor function in spastic CP.
Topics: Cerebral Palsy; Humans; Muscle, Skeletal; Organ Size; Paresis
PubMed: 20477832
DOI: 10.1111/j.1469-8749.2010.03686.x -
Journal of Psychiatric Research Nov 2020Although the precise pathophysiologies underlying autism spectrum disorder (ASD) has not yet been fully clarified, growing evidence supports the involvement of... (Review)
Review
BACKGROUND
Although the precise pathophysiologies underlying autism spectrum disorder (ASD) has not yet been fully clarified, growing evidence supports the involvement of neuroinflammation in the pathogenesis of this disorder, with microglia being particular relevance in the pathophysiologic processes.
OBJECTIVE
The present review aimed to systematically characterize existing literature regarding the role of microglia mediated neuroinflammation in the etiology of ASD.
METHODS
A systematic search was conducted for records indexed within Pubmed, EMBASE, or Web of Science to identify potentially eligible publications. Study selection and data extraction were performed by two authors, and the discrepancies in each step were settled through discussions.
RESULTS
A total of 14 studies comprising 1007 subjects met the eligibility criteria for this review, including 8 immunohistochemistry (IHC) studies, 5 genetic analysis studies, and 1 positron emission tomography (PET) studies. Although small in quantity, the included studies collectively pointed to a role of microglia mediated neuroinflammation in the pathogenesis of ASD.
CONCLUSION
Findings generated from this review consistently supported the involvement of neuroinflammation in the development of ASD, confirmed by the activation of microglia in different brain regions, involving increased cell number or cell density, morphological alterations, and phenotypic shifts.
Topics: Autism Spectrum Disorder; Brain; Humans; Inflammation; Microglia; Positron-Emission Tomography
PubMed: 32823050
DOI: 10.1016/j.jpsychires.2020.07.013 -
The American Journal of Clinical... Aug 2014Most studies that assess the effects of breakfast on subsequent mental abilities compared performance in subjects who had or had not consumed this meal. However,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Most studies that assess the effects of breakfast on subsequent mental abilities compared performance in subjects who had or had not consumed this meal. However, characteristics of breakfast itself may induce metabolic and hormonal alterations of the gastrointestinal tract and potentially modify cognitive performance. Moreover, as far as the evidence on the positive effects of having breakfast is becoming more robust, interest may shift to the specific characteristics of an adequate breakfast.
OBJECTIVE
The objective was to summarize existing evidence on the role of nutrient composition or energy intake at breakfast on the accomplishment of school-related tasks and cognition.
DESIGN
We conducted a systematic review of the literature through the PubMed database.
RESULTS
From the literature search, we identified 102 articles, 15 of which met the inclusion criteria. Of these, 3 studies provided information on the relation between cognitive and academic performance and energy intake at breakfast, 11 provided the same information for the macronutrient composition of breakfast, and 1 investigated both the aspects. Eleven studies considered breakfast meals differing in glycemic index/load. Selected studies were generally carried out in well-nourished children and adults of both sexes from general education. They were mostly experimental studies of short duration and had a limited number of subjects. Cognitive and academic performance was investigated by looking at multiple domains, including memory, attention, reasoning, learning, and verbal and math abilities, with a variety of test batteries scheduled at different time points in the morning. Breakfast options differed in terms of included foods and place and time of administration.
CONCLUSIONS
There is insufficient quantity and consistency among studies to draw firm conclusions. However, whereas the hypothesis of a better and more sustained performance with a breakfast providing >20% daily energy intake still needs substantiation, there does appear to be emerging, but still equivocal, evidence that a lower postprandial glycemic response is beneficial to cognitive performance.
Topics: Adolescent; Adolescent Nutritional Physiological Phenomena; Adult; Breakfast; Child; Child Nutritional Physiological Phenomena; Cognition; Educational Status; Energy Intake; Evidence-Based Medicine; Health Promotion; Humans; Learning; Memory; Nutrition Policy; Task Performance and Analysis
PubMed: 24808492
DOI: 10.3945/ajcn.114.083683