scholarly journals Age and sex dependent variability of type 2 dopamine receptors in the human brain: A large-scale PET cohort

2021 ◽  
Author(s):  
Tuulia Malén ◽  
Tomi Karjalainen ◽  
Janne Isojärvi ◽  
Aki Vehtari ◽  
Paul-Christian Bürkner ◽  
...  

BACKGROUND: The dopamine system contributes to a multitude of functions ranging from reward and motivation to learning and movement control, making it a key component in goal-directed behavior. Altered dopaminergic function is observed in neurological and psychiatric conditions. Numerous factors have been proposed to influence dopamine function, but due to small sample sizes and heterogeneous data analysis methods in previous studies their specific and joint contributions remain unresolved. METHODS: In this cross-sectional register-based study we investigated how age, sex, body mass index (BMI), as well as cerebral hemisphere and regional volume influence striatal type 2 dopamine receptor (D2R) availability in the human brain. We analyzed a large historical dataset (n=156, 120 males and 36 females) of [11C]raclopride PET scans performed between 2004 and 2018. RESULTS: Striatal D2R availability decreased through age for both sexes and was higher in females versus males throughout age. BMI and striatal D2R availability were weakly associated. There was no consistent lateralization of striatal D2R. The observed effects were independent of regional volumes. These results were validated using two different spatial normalization methods, and the age and sex effects also replicated in an independent sample (n=135). CONCLUSIONS: D2R density is dependent on age and sex, which may contribute to the vulnerability of neurological and psychiatric conditions involving altering D2R expression.

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 2393-PUB
Author(s):  
KENICHIRO TAKAHASHI ◽  
MINORI SHINODA ◽  
RIKA SAKAMOTO ◽  
JUN SUZUKI ◽  
TADASHI YAMAKAWA ◽  
...  

2021 ◽  
Vol 11 (6) ◽  
pp. 497
Author(s):  
Yoonsuk Jung ◽  
Eui Im ◽  
Jinhee Lee ◽  
Hyeah Lee ◽  
Changmo Moon

Previous studies have evaluated the effects of antithrombotic agents on the performance of fecal immunochemical tests (FITs) for the detection of colorectal cancer (CRC), but the results were inconsistent and based on small sample sizes. We studied this topic using a large-scale population-based database. Using the Korean National Cancer Screening Program Database, we compared the performance of FITs for CRC detection between users and non-users of antiplatelet agents and warfarin. Non-users were matched according to age and sex. Among 5,426,469 eligible participants, 768,733 used antiplatelet agents (mono/dual/triple therapy, n = 701,683/63,211/3839), and 19,569 used warfarin, while 4,638,167 were non-users. Among antiplatelet agents, aspirin, clopidogrel, and cilostazol ranked first, second, and third, respectively, in terms of prescription rates. Users of antiplatelet agents (3.62% vs. 4.45%; relative risk (RR): 0.83; 95% confidence interval (CI): 0.78–0.88), aspirin (3.66% vs. 4.13%; RR: 0.90; 95% CI: 0.83–0.97), and clopidogrel (3.48% vs. 4.88%; RR: 0.72; 95% CI: 0.61–0.86) had lower positive predictive values (PPVs) for CRC detection than non-users. However, there were no significant differences in PPV between cilostazol vs. non-users and warfarin users vs. non-users. For PPV, the RR (users vs. non-users) for antiplatelet monotherapy was 0.86, while the RRs for dual and triple antiplatelet therapies (excluding cilostazol) were 0.67 and 0.22, respectively. For all antithrombotic agents, the sensitivity for CRC detection was not different between users and non-users. Use of antiplatelet agents, except cilostazol, may increase the false positives without improving the sensitivity of FITs for CRC detection.


2021 ◽  
Author(s):  
ManyPrimates ◽  
Alba Motes Rodrigo ◽  
Charlotte Canteloup ◽  
Sonja J. Ebel ◽  
Christopher I Petkov ◽  
...  

Traditionally, primate cognition research has been conducted by independent teams on small populations of a few species. Such limited variation and small sample sizes pose problems that prevent us from reconstructing the evolutionary history of primate cognition. In this chapter, we discuss how large-scale collaboration, a research model successfully implemented in other fields, makes it possible to obtain the large and diverse datasets needed to conduct robust comparative analysis of primate cognitive abilities. We discuss the advantages and challenges of large-scale collaborations and argue for the need for more open science practices in the field. We describe these collaborative projects in psychology and primatology and introduce ManyPrimates as the first, successful collaboration that has established an infrastructure for large-scale, inclusive research in primate cognition. Considering examples of large-scale collaborations both in primatology and psychology, we conclude that this type of research model is feasible and has the potential to address otherwise unattainable questions in primate cognition.


Diagnostics ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 505
Author(s):  
Jorge D. Machicado ◽  
Eugene J. Koay ◽  
Somashekar G. Krishna

Radiomics, also known as quantitative imaging or texture analysis, involves extracting a large number of features traditionally unmeasured in conventional radiological cross-sectional images and converting them into mathematical models. This review describes this approach and its use in the evaluation of pancreatic cystic lesions (PCLs). This discipline has the potential of more accurately assessing, classifying, risk stratifying, and guiding the management of PCLs. Existing studies have provided important insight into the role of radiomics in managing PCLs. Although these studies are limited by the use of retrospective design, single center data, and small sample sizes, radiomic features in combination with clinical data appear to be superior to the current standard of care in differentiating cyst type and in identifying mucinous PCLs with high-grade dysplasia. Combining radiomic features with other novel endoscopic diagnostics, including cyst fluid molecular analysis and confocal endomicroscopy, can potentially optimize the predictive accuracy of these models. There is a need for multicenter prospective studies to elucidate the role of radiomics in the management of PCLs.


Author(s):  
Tianye Jia ◽  
Congying Chu ◽  
Yun Liu ◽  
Jenny van Dongen ◽  
Evangelos Papastergios ◽  
...  

AbstractDNA methylation, which is modulated by both genetic factors and environmental exposures, may offer a unique opportunity to discover novel biomarkers of disease-related brain phenotypes, even when measured in other tissues than brain, such as blood. A few studies of small sample sizes have revealed associations between blood DNA methylation and neuropsychopathology, however, large-scale epigenome-wide association studies (EWAS) are needed to investigate the utility of DNA methylation profiling as a peripheral marker for the brain. Here, in an analysis of eleven international cohorts, totalling 3337 individuals, we report epigenome-wide meta-analyses of blood DNA methylation with volumes of the hippocampus, thalamus and nucleus accumbens (NAcc)—three subcortical regions selected for their associations with disease and heritability and volumetric variability. Analyses of individual CpGs revealed genome-wide significant associations with hippocampal volume at two loci. No significant associations were found for analyses of thalamus and nucleus accumbens volumes. Cluster-based analyses revealed additional differentially methylated regions (DMRs) associated with hippocampal volume. DNA methylation at these loci affected expression of proximal genes involved in learning and memory, stem cell maintenance and differentiation, fatty acid metabolism and type-2 diabetes. These DNA methylation marks, their interaction with genetic variants and their impact on gene expression offer new insights into the relationship between epigenetic variation and brain structure and may provide the basis for biomarker discovery in neurodegeneration and neuropsychiatric conditions.


2020 ◽  
Vol 34 (04) ◽  
pp. 6957-6964
Author(s):  
Shuo Zhou ◽  
Wenwen Li ◽  
Christopher Cox ◽  
Haiping Lu

The increasing of public neuroimaging datasets opens a door to analyzing homogeneous human brain conditions across datasets by transfer learning (TL). However, neuroimaging data are high-dimensional, noisy, and with small sample sizes. It is challenging to learn a robust model for data across different cognitive experiments and subjects. A recent TL approach minimizes domain dependence to learn common cross-domain features, via the Hilbert-Schmidt Independence Criterion (HSIC). Inspired by this approach and the multi-source TL theory, we propose a Side Information Dependence Regularization (SIDeR) learning framework for TL in brain condition decoding. Specifically, SIDeR simultaneously minimizes the empirical risk and the statistical dependence on the domain side information, to reduce the theoretical generalization error bound. We construct 17 brain decoding TL tasks using public neuroimaging data for evaluation. Comprehensive experiments validate the superiority of SIDeR over ten competing methods, particularly an average improvement of 15.6% on the TL tasks with multi-source experiments.


2015 ◽  
Vol 370 (1664) ◽  
pp. 20140092 ◽  
Author(s):  
Bruno Gingras ◽  
Henkjan Honing ◽  
Isabelle Peretz ◽  
Laurel J. Trainor ◽  
Simon E. Fisher

Advances in molecular technologies make it possible to pinpoint genomic factors associated with complex human traits. For cognition and behaviour, identification of underlying genes provides new entry points for deciphering the key neurobiological pathways. In the past decade, the search for genetic correlates of musicality has gained traction. Reports have documented familial clustering for different extremes of ability, including amusia and absolute pitch (AP), with twin studies demonstrating high heritability for some music-related skills, such as pitch perception. Certain chromosomal regions have been linked to AP and musical aptitude, while individual candidate genes have been investigated in relation to aptitude and creativity. Most recently, researchers in this field started performing genome-wide association scans. Thus far, studies have been hampered by relatively small sample sizes and limitations in defining components of musicality, including an emphasis on skills that can only be assessed in trained musicians. With opportunities to administer standardized aptitude tests online, systematic large-scale assessment of musical abilities is now feasible, an important step towards high-powered genome-wide screens. Here, we offer a synthesis of existing literatures and outline concrete suggestions for the development of comprehensive operational tools for the analysis of musical phenotypes.


2020 ◽  
Author(s):  
Taylor Winter ◽  
Benjamin Riordan ◽  
Anthony Surace ◽  
Damian Scarf ◽  
Paul Jose

Aims. Quantifying differences between minority and majority groups, such as sexual minorities (SM) and heterosexuals, is difficult due to small sample sizes. Bayesian analyses is one solution to addressing small sample sizes in minority group research, whereby previous research can be used to inform our models. In the present tutorial, we offered an overview of Bayesian statistics and described an approach to constructing informed priors using a large survey when estimating values in a smaller survey. In an applied example, we determined whether SMs in New Zealand reported more stress relative to heterosexuals and whether stress mediates the link between SM status and alcohol use.Design. Two cross-sectional, stratified, and nationally representative health surveys from the US (National Survey of Drug Use and Health (NSDUH)) and New Zealand (New Zealand Health Survey (NZHS)).Settings. United States, New ZealandParticipants. We used data from 83,661 (SMs = 5593) survey respondents in the US and 24,098 respondents in NZ (SMs = 619).Measurements. Demographic items (sex, age, ethnicity, sexual identity), the Kessler psychological distress scale, and the Alcohol Use Disorder Identification Test (AUDIT).Findings. Using a larger survey to inform priors reduced the uncertainty of estimates derived from small subgroups in a smaller survey relative to uninformed priors.Conclusion. Informed Bayesian analyses are an important tool for researchers studying minority groups and the application of informative priors allows for more reliable estimates of health disparities.


2021 ◽  
Vol 9 (02) ◽  
pp. 56-60
Author(s):  
Rajendra Kumar Chaudhari ◽  
Apeksha Niraula ◽  
Basanta Gelal ◽  
Jouslin Kishore Baranwal ◽  
Deependra Prasad Sarraf ◽  
...  

INTRODUCTION: Type 2 diabetes mellitus is a metabolic disorder of multiple etiology characterized by chronic hyperglycemia with a derangement in carbohydrate, fat and protein metabolism resulting from defects in insulin secretion and action. Ferritin is a ubiquitous intracellular protein complex that reflects the iron stores of the body. Studies have shown that the increased body iron stores are associated with the development of glucose intolerance often leading to metabolic syndrome and type 2 diabetes (T2DM). The objective of the study was to find out association of serum ferritin level with T2DM and assess the correlation between serum ferritin and HbA1c. MATERIAL AND METHODS: A hospital based comparative cross-sectional study was conducted in 43 diabetic patients and 42 age and sex matched healthy controls. Fasting blood glucose (FBG), postprandial blood glucose (PBG), Glycated hemoglobin (HbA1c) and serum ferritin were estimated in cobas c311 autoanalyser using standard protocol. RESULTS: Mean age of healthy control and T2DM were found 54.83 ± 6.48 and 55.95±10.92 years respectively. Mean FBG (mg/dL) (170.41 ± 71.7 v/s 98.38 ± 9.7), PBG (mg/dL) (266.16 ± 110.09 v/s 123.20 ± 17.0), HbA1c (%) (8.17 ± 1.83 v/s 4.9 ± 0.29 and median ferritin (μg/L) 207.90 (138, 306.0) v/s 127.95 (85.75, 210.25) were significantly higher in T2DM compared to the healthy controls. Spearman’s correlation depicted that ferritin level was positively correlated with HbA1c level but the correlation was statistically insignificant. CONCLUSION: Serum ferritin level was found significantly higher in T2DM compared to healthy age and sex matched controls in our study.


2021 ◽  
Vol 5 (4) ◽  
Author(s):  
Kellan E Baker ◽  
Lisa M Wilson ◽  
Ritu Sharma ◽  
Vadim Dukhanin ◽  
Kristen McArthur ◽  
...  

Abstract We sought to systematically review the effect of gender-affirming hormone therapy on psychological outcomes among transgender people. We searched PubMed, Embase, and PsycINFO through June 10, 2020 for studies evaluating quality of life (QOL), depression, anxiety, and death by suicide in the context of gender-affirming hormone therapy among transgender people of any age. We excluded case studies and studies reporting on less than 3 months of follow-up. We included 20 studies reported in 22 publications. Fifteen were trials or prospective cohorts, one was a retrospective cohort, and 4 were cross-sectional. Seven assessed QOL, 12 assessed depression, 8 assessed anxiety, and 1 assessed death by suicide. Three studies included trans-feminine people only; 7 included trans-masculine people only, and 10 included both. Three studies focused on adolescents. Hormone therapy was associated with increased QOL, decreased depression, and decreased anxiety. Associations were similar across gender identity and age. Certainty in this conclusion is limited by high risk of bias in study designs, small sample sizes, and confounding with other interventions. We could not draw any conclusions about death by suicide. Future studies should investigate the psychological benefits of hormone therapy among larger and more diverse groups of transgender people using study designs that more effectively isolate the effects of hormone treatment.


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