scholarly journals Structural, Functional, and Metabolic Brain Differences as a Function of Gender Identity or Sexual Orientation: A Systematic Review of the Human Neuroimaging Literature

Author(s):  
Alberto Frigerio ◽  
Lucia Ballerini ◽  
Maria Del C. Valdés Hernández

This systematic review explored structural, functional, and metabolic features of the cisgender brain compared with the transgender brain before hormonal treatment and the heterosexual brain compared to the homosexual brain from the analysis of the neuroimaging literature up to 2018. Our main aim was to help identifying neuroradiological brain features that have been related to human sexuality to contribute to the understanding of the biological elements involved in gender identity and sexual orientation. We analyze 30 studies on gender identity and 21 on sexual orientation. Our results suggest that some neuroanatomical, neurophysiological, and neurometabolic features in transgender individuals resemble those of their experienced gender despite the majority resembling those from their natal sex. In homosexual individuals the majority resemble those of their same sex heterosexual population rather than their opposite sex heterosexual population. However, it is always difficult to interpret findings with non-invasive neuroimaging. Given the gross nature of these measures, it is possible that more differences too subtle to measure with available tools yet contributing to gender identity and sexual orientation could be found. Conflicting results contributed to the difficulty of identifying specific brain features which consistently differ between cisgender and transgender or between heterosexual and homosexual groups. The small number of studies, the small sample size of each study, and the heterogeneity of the investigations made it impossible to meta-analyze all the data extracted. Further studies are necessary to increase the understanding of the neurological substrates of human sexuality.

Author(s):  
Alberto Frigerio ◽  
Lucia Ballerini ◽  
Maria Del C. Valdés Hernández

Human sexuality is a complex reality, including gender identity and sexual orientation. A widespread approach to study human sexuality is to compare groups with opposite sexual approaches such as cisgenders vs transgenders and heterosexuals vs homosexuals. Neuroimaging studies have found brain differences between these groups of individuals. Nevertheless, they reported conflicting results and limitations such as small samples’ sizes and the considerable overlap between such groups makes it difficult to draw accurate conclusions. This systematic review explored structural, functional and metabolic features of the ‘cisgender brain’ compared with the ‘transgender brain’ before hormonal treatment and the ‘heterosexual brain’ compared to the ‘homosexual brain’ from the analysis of the neuroimaging literature up to 2018. Our main aim is to help identifying biological brain features that have been related to human sexuality to contribute to the understanding of the biological elements involved in gender identity and sexual orientation. Our results suggest that the majority of neuroanatomical, neurophysiological, and neurometabolic features in transgender individuals resemble those of their natal sex rather than those of their experienced gender and in homosexual individuals these resemble those of their same sex heterosexual population rather than their opposite sex heterosexual population. However, it is always difficult to interpret null findings with non-invasive neuroimaging. Given the gross nature of these measures, it is still possible that there are differences that are too subtle to measure with available tools yet have the impact of contributing to gender identity and sexual orientation. Moreover, conflicting results, also contributed to the impossibility of identifying specific brain features which consistently differ between cis- and transgender nor between hetero- and homosexual groups. The small number of studies, the small sample size of each study, and the heterogeneity of the investigations made impossible to meta-analyse all the data extracted. Further studies are necessary to increase the understanding of the neurological substrate of human sexuality.


Author(s):  
Alberto Frigerio ◽  
Lucia Ballerini ◽  
Maria Del C. Valdés Hernández

This review systematically explored structural, functional, and metabolic features of the cisgender brain compared with the transgender brain before hormonal treatment and the heterosexual brain compared to the homosexual brain from the analysis of the neuroimaging literature up to 2018, and identified and discussed subsequent studies published up to March 2021. Our main aim was to help identifying neuroradiological brain features that have been related to human sexuality to contribute to the understanding of the biological elements involved in gender identity and sexual orientation. We analyze 39 studies on gender identity and 24 on sexual orientation. Our results suggest that some neuroanatomical, neurophysiological, and neurometabolic features in transgender individuals resemble those of their experienced gender despite the majority resembling those from their natal sex. In homosexual individuals the majority resemble those of their same sex heterosexual population rather than their opposite sex heterosexual population. However, it is always difficult to interpret findings with non-invasive neuroimaging. Given the gross nature of these measures, it is possible that more differences too subtle to measure with available tools yet contributing to gender identity and sexual orientation could be found. Conflicting results contributed to the difficulty of identifying specific brain features which consistently differ between cisgender and transgender or between heterosexual and homosexual groups. The small number of studies, the small-to-moderate sample size of each study, and the heterogeneity of the investigations made it impossible to meta-analyze all the data extracted. Further studies are necessary to increase the understanding of the neurological substrates of human sexuality.


BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e038978
Author(s):  
Joan L Robinson ◽  
Dolores Freire ◽  
Liza Bialy

ObjectiveA systematic review was conducted of studies comparing time to cerebrospinal fluid (CSF) sterilisation or rate of recurrence with different treatment strategies for CSF shunt infections.MethodsA librarian-directed search was conducted of Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid Medline Daily and Ovid Medline, Ovid Embase, Wiley Cochrane Library, CINAHL Plus with Full Text via EBSCOhost, Scopus Advanced Search, and Web of Science Core Collection from 1990 to May 2019. Studies of any design that compared outcomes in groups of any age with different management strategies were included. Studies that compared complete versus incomplete shunt removal were excluded. Quality assessment was performed with the Newcastle-Ottawa Scale.ResultsThe search identified 2208 records, of which 8 met the inclusion criteria. All were cohort studies of moderate quality. Four studies compared the duration of antibiotics; none demonstrates that a longer course prevented recurrences. Two studies analysed addition of rifampin, with one showing a decrease in recurrences while the other had a small sample size. No studies analysed the addition of intraventricular antibiotics, but one showed equally good results with once versus twice daily administration. One study reported no difference in recurrences with placement of antibiotic-impregnated catheters. Recurrence rates did not differ with shunt replacement minimum of 7 days vs less than 7 days after CSF became sterile. There were no recurrences in either group when shunt replacement was performed after sterile CSF cultures were obtained at 24 vs 48 hours after antibiotics were discontinued. A new shunt entry site did not decrease recurrences.DiscussionThe main limitations are the lack of high-quality studies, the small sample sizes and the heterogeneity which precluded meta-analysis. Addition of rifampin for staphylococcal infections may decrease relapse but requires further study.


Author(s):  
Peter Cox ◽  
Sonal Gupta ◽  
Sizheng Steven Zhao ◽  
David M. Hughes

AbstractThe aims of this systematic review and meta-analysis were to describe prevalence of cardiovascular disease in gout, compare these results with non-gout controls and consider whether there were differences according to geography. PubMed, Scopus and Web of Science were systematically searched for studies reporting prevalence of any cardiovascular disease in a gout population. Studies with non-representative sampling, where a cohort had been used in another study, small sample size (< 100) and where gout could not be distinguished from other rheumatic conditions were excluded, as were reviews, editorials and comments. Where possible meta-analysis was performed using random-effect models. Twenty-six studies comprising 949,773 gout patients were included in the review. Pooled prevalence estimates were calculated for five cardiovascular diseases: myocardial infarction (2.8%; 95% confidence interval (CI)s 1.6, 5.0), heart failure (8.7%; 95% CI 2.9, 23.8), venous thromboembolism (2.1%; 95% CI 1.2, 3.4), cerebrovascular accident (4.3%; 95% CI 1.8, 9.7) and hypertension (63.9%; 95% CI 24.5, 90.6). Sixteen studies reported comparisons with non-gout controls, illustrating an increased risk in the gout group across all cardiovascular diseases. There were no identifiable reliable patterns when analysing the results by country. Cardiovascular diseases are more prevalent in patients with gout and should prompt vigilance from clinicians to the need to assess and stratify cardiovascular risk. Future research is needed to investigate the link between gout, hyperuricaemia and increased cardiovascular risk and also to establish a more thorough picture of prevalence for less common cardiovascular diseases.


2004 ◽  
Vol 58 (4) ◽  
pp. 644-666 ◽  
Author(s):  
Travor Brown

Abstract The past decade has been marked by increased awareness concerning employment discrimination against gays and lesbians. Yet, to the author’s knowledge, there has been limited research regarding the response of Canadian labour organizations to the workplace needs of gay and lesbian members. Limitations of these previous studies include small sample size, lack of theoretical framework, and the absence of empirical testing of hypotheses. The present study builds on these works through the use of Craig’s model, the inclusion of multi-disciplinary research, and the empirical testing of data collected from more than 240 Canadian collective agreements. Key findings include that larger, public sector bargaining units with equality clauses in their collective agreements were most likely also to contain clauses that prohibited discrimination based on sexual orientation. The paper concludes with suggestions for future research.


2016 ◽  
Vol 175 (2) ◽  
pp. R65-R80 ◽  
Author(s):  
Irina Bancos ◽  
Shrikant Tamhane ◽  
Muhammad Shah ◽  
Danae A Delivanis ◽  
Fares Alahdab ◽  
...  

ObjectiveTo perform a systematic review of published literature on adrenal biopsy and to assess its performance in diagnosing adrenal malignancy.MethodsMedline In-Process and Other Non-Indexed Citations, MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trial were searched from inception to February 2016. Reviewers extracted data and assessed methodological quality in duplicate.ResultsWe included 32 observational studies reporting on 2174 patients (39.4% women, mean age 59.8 years) undergoing 2190 adrenal mass biopsy procedures. Pathology was described in 1621/2190 adrenal lesions (689 metastases, 68 adrenocortical carcinomas, 64 other malignancies, 464 adenomas, 226 other benign, 36 pheochromocytomas, and 74 others). The pooled non-diagnostic rate (30 studies, 2013 adrenal biopsies) was 8.7% (95%CI: 6–11%). The pooled complication rate (25 studies, 1339 biopsies) was 2.5% (95%CI: 1.5–3.4%). Studies were at a moderate risk for bias. Most limitations related to patient selection, assessment of outcome, and adequacy of follow-up. Only eight studies (240 patients) could be included in the diagnostic performance analysis with a sensitivity and specificity of 87 and 100% for malignancy, 70 and 98% for adrenocortical carcinoma, and 87 and 96% for metastasis respectively.ConclusionsEvidence based on small sample size and moderate risk of bias suggests that adrenal biopsy appears to be most useful in the diagnosis of adrenal metastasis in patients with a history of extra-adrenal malignancy. Adrenal biopsy should only be performed if the expected findings are likely to alter the management of the individual patient and after biochemical exclusion of catecholamine-producing tumors to help prevent potentially life-threatening complications.


Author(s):  
Li Wang ◽  
Yiwen Zhang ◽  
Jiajun Zhong ◽  
Yuan Zhang ◽  
Shuisheng Zhou ◽  
...  

Objective: The efficacy of mesenchymal stem cell (MSC) therapy in acetaminophen-induced liver injury has been investigated in animal experiments, but individual studies with a small sample size cannot be used to draw a clear conclusion. Therefore, we conducted a systematic review and meta-analysis of preclinical studies to explore the potential of using MSCs in acetaminophen-induced liver injury. Methods: Eight databases were searched for studies reporting the effects of MSCs on acetaminophen hepatoxicity. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. SYRCLE’s risk of bias tool for animal studies was applied to assess the methodological quality. A meta-analysis was performed by using RevMan 5.4 and STATA/SE 16.0 software. Results: Eleven studies involving 159 animals were included according to PRISMA statement guidelines. Significant associations were found for MSCs with the levels of alanine transaminase (ALT) (standardized mean difference (SMD) − 2.58, p < 0.0001), aspartate aminotransferase (AST) (SMD − 1.75, p = 0.001), glutathione (GSH) (SMD 3.7, p < 0.0001), superoxide dismutase (SOD) (SMD 1.86, p = 0.022), interleukin 10 (IL-10) (SMD 5.14, p = 0.0002) and tumor necrosis factor-α (TNF-α) (SMD − 4.48, p = 0.011) compared with those in the control group. The subgroup analysis showed that the tissue source of MSCs significantly affected the therapeutic efficacy (p < 0.05). Conclusion: Our meta-analysis results demonstrate that MSCs could be a potential treatment for acetaminophen-related liver injury.


2013 ◽  
Vol 57 (10) ◽  
pp. 5013-5018 ◽  
Author(s):  
Donald W. Whang ◽  
Loren G. Miller ◽  
Neil M. Partain ◽  
James A. McKinnell

ABSTRACTBloodstream infections due to vancomycin-resistant enterococci (VRE-BSI) result in substantial patient mortality and cost. Daptomycin and linezolid are commonly prescribed for VRE-BSI, but there are no clinical trials to determine optimal antibiotic selection. We conducted a systematic review for investigations that compared daptomycin and linezolid for VRE-BSI. We searched Medline from 1966 through 2012 for comparisons of linezolid and daptomycin for VRE-BSI. We included searches of EMBASE, clinicaltrials.gov, and national meetings. Data were extracted using a standardized instrument. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using a fixed-effects model. Our search yielded 4,243 publications, of which 482 contained data on VRE treatment. Most studies (452/482) did not present data on BSI or did not provide information on linezolid or daptomycin. Among the remaining 30 studies, 9 offered comparative data between the two agents. None were randomized clinical trials. There was no difference in microbiologic (n= 5 studies, 517 patients; OR, 1.0; 95% CI, 0.4 to 1.7;P= 0.95) and clinical (n= 3 studies, 357 patients; OR, 1.2; 95% CI, 0.7 to 2.0;P= 0.7) cures between the two antibiotics. There was a trend toward increased survival with linezolid compared to daptomycin treatment (n= 9 studies, 1,074 patients; OR, 1.3; 95% CI, 1.1 to 1.8;I2= 0 [whereI2is a measure of inconsistency]), but this did not reach statistical significance (P= 0.054). There are limited data to inform clinicians on optimal antibiotic selection for VRE-BSI. Available studies are limited by small sample size, lack of patient-level data, and inconsistent outcome definitions. Additional research, including randomized clinical trials, is needed before conclusions can be drawn about treatment options for VRE therapy.


2005 ◽  
Vol 16 (07) ◽  
pp. 473-484 ◽  
Author(s):  
Ruth A. Bentler

A systematic review of the literature was undertaken to find evidence of real-world effectiveness of directional microphone and digital noise reduction features in current hearing aids. The evidence was drawn from randomized controlled trials, nonrandomized intervention studies, and descriptive studies. The quality of each study was evaluated for factors such as blinding, power of statistical analyses, and use of psychometrically strong outcome measures. Weaknesses in the identified studies included small sample size, resultant poor power to detect potentially worthwhile differences, and overlapping experimental conditions. Nine studies were identified for directional microphones, and the evidence (albeit weak) supports effectiveness. Two studies were identified for the noise reduction feature, and the evidence was equivocal. For the researcher, such a systematic review should encourage the careful consideration of appropriate methodologies for assessing feature effectiveness. For the clinician, the outcomes reported herein should encourage use of such a systematic review to drive clinical practice.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Mollie McDermott ◽  
Lesli E Skolarus ◽  
James F Burke

Introduction: Rates of tPA administration remain low nationally and globally despite its demonstrated efficacy. We performed a systematic review and meta-analysis of interventions to increase the rate of tPA administration. Methods: We searched PubMed and EMBASE to identify all studies (excluding case reports) published between 1995 and January 8, 2015 documenting interventions to increase the utilization of tPA. We screened each study with pre-specified inclusion and exclusion criteria. Design elements and study data were extracted from eligible studies. The principal summary measure was the percentage change in rate of tPA administration. Fixed and random effects meta-analytic models were built to summarize the effect of intervention compared to control as well as intervention subtypes. Results: Our search yielded 1457 results of which 25 met eligibility criteria. We identified 13 pre-post studies and 11 randomized or quasi-experimental studies. Included studies utilized EMS (n=14), telemedicine (n=6), and public education (n=5). Intervention settings included urban (n=13), rural (n=4), and combined (n=4). In a fixed effect model, tPA administration was significantly higher in the intervention arm across all studies that limited enrollment to ischemic stroke patients (n=14) with a risk ratio (RR) of 1.71. Interventions involving EMS were associated with an increased rate of tPA administration with a RR of 1.51, (95% CI: 1.43-1.59, p<0.0001); promoting public education RR = 2.62, (95% CI: 1.54-4.43, p<0.01); and utilizing telemedicine RR = 2.97, (95% CI: 2.61-3.39, p<0.0001). Conclusions: Interventions to increase tPA use appear to have considerable efficacy. Comparative inferences between intervention types are limited by small sample size and intervention heterogeneity.


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