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1.
Biochem J ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39373581

RESUMO

Histone deacetylase 7 (HDAC7) is a member of the class IIa family of classical HDACs with important roles in cell development, differentiation, and activation, including in macrophages and other innate immune cells. HDAC7 and other class IIa HDACs act as transcriptional repressors in the nucleus but, in some cell types, they can also act in the cytoplasm to modify non-nuclear proteins and/or scaffold signalling complexes. In macrophages, HDAC7 is a cytoplasmic protein with both pro- and anti-inflammatory functions, with the latter activity involving activation of the pentose phosphate pathway (PPP) enzyme 6-phosphogluconate dehydrogenase (6PGD) and the generation of anti-inflammatory metabolite ribulose-5-phosphate. Here, we used ectopic expression systems and biochemical approaches to investigate the mechanism by which HDAC7 promotes 6PGD enzyme activity. We reveal that HDAC7 enzyme activity is not required for its activation of 6PGD and that the N-terminal protein-protein interaction domain of HDAC7 is sufficient to initiate this response. Mechanistically, the N-terminus of HDAC7 increases the affinity of 6PGD for NADP+, promotes the generation of a shorter form of 6PGD, and enhances the formation of higher order protein complexes, implicating its scaffolding function in engagement of the PPP. This contrasts with the pro-inflammatory function of HDAC7 in macrophages, in which it promotes deacetylation of the glycolytic enzyme pyruvate kinase M2 for inflammatory cytokine production.

2.
Alzheimers Dement ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39258539

RESUMO

The magnetic resonance imaging (MRI) Core has been operating since Alzheimer's Disease Neuroimaging Initiative's (ADNI) inception, providing 20 years of data including reliable, multi-platform standardized protocols, carefully curated image data, and quantitative measures provided by expert investigators. The overarching purposes of the MRI Core include: (1) optimizing and standardizing MRI acquisition methods, which have been adopted by many multicenter studies and trials worldwide and (2) providing curated images and numeric summary values from relevant MRI sequences/contrasts to the scientific community. Over time, ADNI MRI has become increasingly complex. To remain technically current, the ADNI MRI protocol has changed substantially over the past two decades. The ADNI 4 protocol contains nine different imaging types (e.g., three dimensional [3D] T1-weighted and fluid-attenuated inversion recovery [FLAIR]). Our view is that the ADNI MRI data are a greatly underutilized resource. The purpose of this paper is to educate the scientific community on ADNI MRI methods and content to promote greater awareness, accessibility, and use. HIGHLIGHTS: The MRI Core provides multi-platform standardized protocols, carefully curated image data, and quantitative analysis by expert groups. The ADNI MRI protocol has undergone major changes over the past two decades to remain technically current. As of April 25, 2024, the following numbers of image series are available: 17,141 3D T1w; 6877 FLAIR; 3140 T2/PD; 6623 GRE; 3237 dMRI; 2846 ASL; 2968 TF-fMRI; and 2861 HighResHippo (see Table 1 for abbreviations). As of April 25, 2024, the following numbers of quantitative analyses are available: FreeSurfer 10,997; BSI 6120; tensor based morphometry (TBM) and TBM-SYN 12,019; WMH 9944; dMRI 1913; ASL 925; TF-fMRI NFQ 2992; and medial temporal subregion volumes 2726 (see Table 4 for abbreviations). ADNI MRI is an underutilized resource that could be more useful to the research community.

3.
Plant Cell ; 36(10): 4511-4534, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39102899

RESUMO

Elevated temperatures impair pollen performance and reproductive success, resulting in lower crop yields. The tomato (Solanum lycopersicum) anthocyanin reduced (are) mutant harbors a mutation in FLAVANONE 3-HYDROXYLASE (F3H), resulting in impaired flavonol antioxidant biosynthesis. The are mutant has reduced pollen performance and seed set relative to the VF36 parental line, phenotypes that are accentuated at elevated temperatures. Transformation of are with the wild-type F3H gene, or chemical complementation with flavonols, prevented temperature-dependent reactive oxygen species (ROS) accumulation in pollen and restored the reduced viability, germination, and tube elongation of are to VF36 levels. Overexpression of F3H in VF36 prevented temperature-driven ROS increases and impaired pollen performance, revealing that flavonol biosynthesis promotes thermotolerance. Although stigmas of are had reduced flavonol and elevated ROS levels, the growth of are pollen tubes was similarly impaired in both are and VF36 pistils. RNA-seq was performed at optimal and stress temperatures in are, VF36, and the F3H overexpression line at multiple timepoints across pollen tube elongation. The number of differentially expressed genes increased over time under elevated temperatures in all genotypes, with the greatest number in are. These findings suggest potential agricultural interventions to combat the negative effects of heat-induced ROS in pollen that lead to reproductive failure.


Assuntos
Flavonóis , Regulação da Expressão Gênica de Plantas , Germinação , Homeostase , Tubo Polínico , Pólen , Espécies Reativas de Oxigênio , Solanum lycopersicum , Termotolerância , Solanum lycopersicum/genética , Solanum lycopersicum/fisiologia , Solanum lycopersicum/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Flavonóis/metabolismo , Termotolerância/genética , Pólen/genética , Pólen/fisiologia , Tubo Polínico/crescimento & desenvolvimento , Tubo Polínico/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo
4.
Alzheimers Dement ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115941

RESUMO

Phase four of the Alzheimer's Disease Neuroimaging Initiative (ADNI4) magnetic resonance imaging (MRI) protocols aim to maintain longitudinal consistency across two decades of data acquisition, while adopting new technologies. Here we describe and justify the study's design and targeted biomarkers. The ADNI4 MRI protocol includes nine MRI sequences. Some sequences require the latest hardware and software system upgrades and are continuously rolled out as they become available at each site. The main sequence additions/changes in ADNI4 are: (1) compressed sensing (CS) T1-weighting, (2) pseudo-continuous arterial spin labeling (ASL) on all three vendors (GE, Siemens, Philips), (3) multiple-post-labeling-delay ASL, (4) 1 mm3 isotropic 3D fluid-attenuated inversion recovery, and (5) CS 3D T2-weighted. ADNI4 aims to help the neuroimaging community extract valuable imaging biomarkers and provide a database to test the impact of advanced imaging strategies on diagnostic accuracy and disease sensitivity among individuals lying on the cognitively normal to impaired spectrum. HIGHLIGHTS: A summary of MRI protocols for phase four of the Alzheimer's Disease Neuroimaging Initiative (ADNI 4). The design and justification for the ADNI 4 MRI protocols. Compressed sensing and multi-band advances have been applied to improve scan time. ADNI4 protocols aim to streamline safety screening and therapy monitoring. The ADNI4 database will be a valuable test bed for academic research.

5.
Drug Test Anal ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39162327

RESUMO

Anabolic-androgenic steroids (AASs) are a subclassification of image performance enhancing drugs (IPEDs). While AAS use is most prevalent among people in athletics, there is also high lifetime prevalence of AAS use among prisoners. This study reports the qualitative detection of AASs in seized samples from the Scottish prisons from 2019-2023. Additionally, methods were developed for the quantitative analysis of AASs using gas chromatography-mass spectrometry (GC-MS) and applied to 61 samples of tablets or powders seized from Scottish prisons between July 2022 and July 2023. Since 2022, there has been an increase in AAS detections in the Scottish prisons. Oxymetholone was the most prevalent AAS, followed by metandienone (methandrostenolone, methandienone), methyltestosterone, oxandrolone, mestanolone (methylandrostanolone), stanozolol, and androstenedione. Multiple AASs were found in 21 samples and 10 samples contained other drugs, including amitriptyline, sertraline, zopiclone, mirtazapine, sildenafil, etizolam, Δ9-tetrahydrocannabinol, and the synthetic cannabinoid MDMB-INACA. Most AAS samples were tablets (77.0%), although they were also detected in powders, herbal material, e-cigarettes, and a fragmented soap bar-type sample. There was a large variation in the concentration of AASs in the tablets and powders seized from the Scottish prisons, demonstrating AASs are another highly variable component of the polydrug use situation in prisons, the effects of which need to be examined further.

6.
bioRxiv ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39149357

RESUMO

Rising temperature extremes during critical reproductive periods threaten the yield of major grain and fruit crops. Flowering plant reproduction depends on development of sufficient numbers of pollen grains and on their ability to generate a cellular extension, the pollen tube, which elongates through the pistil to deliver sperm cells to female gametes for double fertilization. These critical phases of the life cycle are sensitive to temperature and limit productivity under high temperature (HT). Previous studies have investigated the effects of HT on pollen development, but little is known about how HT applied during the pollen tube growth phase affects fertility. Here, we used tomato as a model fruit crop to determine how HT affects the pollen tube growth phase, taking advantage of cultivars noted for fruit production in exceptionally hot growing seasons. We found that exposure to HT solely during the pollen tube growth phase limits fruit biomass and seed set more significantly in thermosensitive cultivars than in thermotolerant cultivars. Importantly, we found that pollen tubes from the thermotolerant Tamaulipas cultivar have enhanced growth in vivo and in vitro under HT. Analysis of the pollen tube transcriptome's response to HT allowed us to develop hypotheses for the molecular basis of cellular thermotolerance in the pollen tube and we define two response modes (enhanced induction of stress responses, and higher basal levels of growth pathways repressed by heat stress) associated with reproductive thermotolerance. Importantly, we define key components of the pollen tube stress response identifying enhanced ROS homeostasis and pollen tube callose synthesis and deposition as important components of reproductive thermotolerance in Tamaulipas. Our work identifies the pollen tube growth phase as a viable target to enhance reproductive thermotolerance and delineates key pathways that are altered in crop varieties capable of fruiting under HT conditions.

7.
J LGBT Youth ; 21(3): 526-548, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39131490

RESUMO

Due to systemic racism and homophobia, Lesbian, Gay, Bisexual, and Queer (LGBQ+) youth of color are disproportionately affected by HIV (human immunodeficiency virus) / AIDS (acquired immunodeficiency syndrome) and viral hepatitis (VH). Innovative approaches that acknowledge strengths such as ethnic identity need to be examined to understand specific protective factors that can support LGBQ+ youth of color. This study aimed to examine the moderating effects of ethnic identity and LGBQ+ identity on indicators of HIV knowledge (i.e., VH knowledge, sexual negotiation skills, and perception of sexual risk). Youth who identified as Hispanic/Latinx, African American/Black, and mixed racial-identity (N = 564) were included in the delimited sample. Using linear regression modeling, results showed that there was a positive association between sexual negotiation skill, sexual risk perception, ethnic identity and HIV knowledge. Ethnic identity displayed a positive and significant moderating effect between predictors and HIV knowledge. Three-way interactions between predictors by ethnic identity x LGBQ+ interaction showed equally interesting associations with HIV knowledge. Study implications include the need for strengthening ethnic identity and pride among LGBQ+ youth of color within HIV prevention programming.

8.
Sch Psychol ; 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39052398

RESUMO

Although numerous studies have examined how child demographic characteristics may impact ratings of attention-deficit/hyperactivity disorder (ADHD) symptoms, there is limited research on how these factors are related to ratings of impairment. This study examined child characteristics (assigned sex, age, race, ethnicity) that may affect parent and teacher ratings of ADHD symptom-related impairments in relationships with family and/or teacher, peer relationships, behavior disruption, academic impairment, homework performance, and self-esteem. The study was conducted using independent U.S. national samples of parents (n = 2,075) and teachers (n = 1,070). Informants rated impairments related to inattention and hyperactivity-impulsivity using the ADHD Rating Scale-5. Rasch analyses were used to examine differential item functioning in relation to child characteristics. Separate analyses were conducted for inattention- and hyperactivity-impulsivity-related impairment for both the parent and teacher samples. For teacher ratings, only two items (behavior disruption, homework impairment) demonstrated differential item functioning with intermediate or large effect sizes (≥ .426 logits) in relation to any child characteristic; whereas for parent ratings, all six items displayed differential item functioning with at least intermediate effect sizes in relation to one or more child characteristics. The findings indicated several areas in which child characteristics may have an impact on ratings of ADHD-related impairment, particularly based on parent ratings, which have potential implications for the diagnostic assessment of ADHD and highlight the need for further research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

9.
Forensic Sci Int ; 361: 112145, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38991327

RESUMO

Drug use is prevalent in prisons with drugs associated with depressant effects found to be more prevalent than stimulants. Synthetic cathinones (SCats; often sold as "bath salts", "ecstasy", "molly", and "monkey dust") are the second largest category of new psychoactive substances (NPS) currently monitored by the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and are commonly used as substitutes for regulated stimulants, such as amphetamine, cocaine, and MDMA. N,N-dimethylpentylone (also known as dimethylpentylone, dipentylone, and bk-DMBDP) was detected for the first time in the Scottish prisons in seven powder samples seized between January and July 2023. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UPLC-QToF-MS), and nuclear magnetic resonance imaging (NMR). Dimethylpentylone was detected alongside other drugs in four samples, including the novel benzodiazepine desalkylgidazepam (bromonordiazepam) and the synthetic cannabinoid receptor agonists (SCRAs) MDMB-INACA and MDMB-4en-PINACA.


Assuntos
Alcaloides , Cromatografia Gasosa-Espectrometria de Massas , Drogas Ilícitas , Prisões , Humanos , Alcaloides/análise , Drogas Ilícitas/análise , Drogas Ilícitas/química , Psicotrópicos/análise , Psicotrópicos/química , Drogas Desenhadas/análise , Drogas Desenhadas/química , Detecção do Abuso de Substâncias/métodos
10.
bioRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38948862

RESUMO

Single-strand breaks (SSBs) are one of the most common endogenous lesions and have the potential to give rise to cytotoxic double-strand breaks (DSBs) during DNA replication. To investigate the mechanism of replication fork collapse at SSBs and subsequent repair, we employed Cas9 nickase (nCas9) to generate site and strand-specific nicks in the budding yeast genome. We show that nCas9-induced nicks are converted to mostly double-ended DSBs during S-phase. We find that repair of replication-dependent DSBs requires homologous recombination (HR) and is independent of canonical non-homologous end joining. Consistent with a strong bias to repair these lesions using a sister chromatid template, we observe minimal induction of inter-chromosomal HR by nCas9. Using nCas9 and a gRNA to nick either the leading or lagging strand template, we carried out a genome-wide screen to identify factors necessary for the repair of replication-dependent DSBs. All the core HR genes were recovered in the screen with both gRNAs, but we recovered components of the replication-coupled nucleosome assembly (RCNA) pathway with only the gRNA targeting the leading strand template. By use of additional gRNAs, we find that the RCNA pathway is especially important to repair a leading strand fork collapse.

11.
Alzheimers Dement (Amst) ; 16(3): e12627, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39077685

RESUMO

INTRODUCTION: Age-related and Alzheimer's disease (AD) dementia-related neurodegeneration impact brain health. While morphometric measures from T1-weighted scans are established biomarkers, they may be less sensitive to earlier changes. Neurite orientation dispersion and density imaging (NODDI), offering biologically meaningful interpretation of tissue microstructure, may be an advanced brain health biomarker. METHODS: We contrasted regional gray matter NODDI and morphometric evaluations concerning their correlation with (1) age, (2) clinical diagnosis stage, and (3) tau pathology as assessed by AV1451 positron emission tomography. RESULTS: Our study hypothesizes that NODDI measures are more sensitive to aging and early AD changes than morphometric measures. One NODDI output, free water fraction (FWF), showed higher sensitivity to age-related changes, generally better effect sizes in separating mild cognitively impaired from cognitively unimpaired participants, and stronger associations with regional tau deposition than morphometric measures. DISCUSSION: These findings underscore NODDI's utility in capturing early neurodegenerative changes and enhancing our understanding of aging and AD. Highlights: Neurite orientation dispersion and density imaging can serve as an effective brain health biomarker for aging and early Alzheimer's disease (AD).Free water fraction has higher sensitivity to normal brain aging.Free water fraction has stronger associations with early AD and regional tau deposition.

12.
Health Sci Rep ; 7(7): e2204, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38974331

RESUMO

Background/Objectives: Transitions to and from Emergency Departments (EDs) can be detrimental to long-term care (LTC) residents and burden the healthcare system. While reducing avoidable transfers is imperative, various terms are used interchangeably including inappropriate, preventable, or unnecessary transitions. Our study objectives were to develop a conceptual definition of avoidable LTC-ED transitions and to verify the level of stakeholder agreement with this definition. Methods: The EXamining Aged Care Transitions study adopted an exploratory sequential mixed-method design. The study was conducted in 2015-2016 in 16 LTC facilities, 1 ED, and 1 Emergency Medical Service (EMS) in a major urban center in western Canada. Phase 1 included 80 participants, (healthcare aides, licensed practical nurses, registered nurses, LTC managers, family members of residents, and EMS staff). We conducted semistructured interviews (n = 25) and focus groups (n = 19). In Phase 2, 327 ED staff, EMS staff, LTC staff, and medical directors responded to a survey based on the qualitative findings. Results: Avoidable transitions were attributed to limited resources in LTC, insufficient preventive care, and resident or family wishes. The definition generated was: A transition of an LTC resident to the ED is considered avoidable if: (a) Diagnostic testing, medical assessment, and treatment can be accessed in a timely manner by other means; (b) the reasons for a transfer are unclear and the transition would increase the disorientation, pain, or discomfort of a resident, outweighing a clear benefit of a transfer; and (c) the transition is against the wishes expressed by the resident over time, including through informal and undocumented conversations. There was a high level of agreement with the definition across the four participant groups. Conclusions and Implications: To effectively reduce LTC resident avoidable transitions, stakeholders must share a common definition. Our conceptual definition may significantly contribute to improved care for LTC residents.

13.
Mov Disord Clin Pract ; 11(9): 1085-1094, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38923361

RESUMO

BACKGROUND: White matter (WM) abnormalities have been implicated in clinically relevant functional decline in multiple system atrophy (MSA). OBJECTIVE: To identify the WM and gray matter (GM) abnormalities in MSA and assess the utility of longitudinal structural and diffusion changes as surrogate markers for tracking disease progression in MSA. METHODS: Twenty-seven participants with early MSA [15 with clinically predominant cerebellar (MSA-C) and 12 with clinically predominant parkinsonian features (MSA-P)] and 14 controls were enrolled as a part of our prospective, longitudinal study of synucleinopathies. Using structural magnetic resonance imaging (MRI) and diffusion MRI (diffusion tensor and neurite orientation and dispersion density imaging), we analyzed whole and regional brain changes in these participants. We also evaluated temporal imaging trajectories based on up to three annual follow-up scans and assessed the impact of baseline diagnosis on these imaging biomarkers using mixed-effect models. RESULTS: MSA patients exhibited more widespread WM changes than GM, particularly in the cerebellum and brainstem, with greater severity in MSA-C. Structural and diffusion measures in the cerebellum WM and brainstem deteriorated with disease progression. Rates of progression of these abnormalities were similar in both MSA subtypes, reflecting increasing overlap of clinical features over time. CONCLUSION: WM abnormalities are core features of MSA disease progression and advance at similar rates in clinical MSA subtypes. Multimodal MRI imaging reveals novel insights into the distribution and pattern of brain abnormalities and their progression in MSA. Selected structural and diffusion measures may be useful for tracking disease progression in MSA clinical trials.


Assuntos
Progressão da Doença , Imageamento por Ressonância Magnética , Atrofia de Múltiplos Sistemas , Substância Branca , Humanos , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Atrofia de Múltiplos Sistemas/patologia , Feminino , Masculino , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Pessoa de Meia-Idade , Idoso , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Estudos Longitudinais , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos Prospectivos , Cerebelo/patologia , Cerebelo/diagnóstico por imagem , Imagem de Tensor de Difusão , Imagem de Difusão por Ressonância Magnética/métodos
14.
Alzheimers Dement ; 20(7): 5054-5061, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38899634

RESUMO

INTRODUCTION: Premenopausal bilateral oophorectomy (PBO) is associated with later-life cognition, but the underlying brain changes remain unclear. We assessed the impact of PBO and PBO age on white matter integrity. METHODS: Female participants with regional diffusion tensor imaging (DTI) metrics of fractional anisotropy (FA) and mean diffusivity (MD) were included (22 with PBO < 40 years; 43 with PBO 40-45 years; 39 with PBO 46-49 years; 907 referents without PBO < 50 years). Linear regression models adjusted for age and apolipoprotein E (APOE) genotype. RESULTS: Females with PBO < 40 years, compared to referents, had lower FA and higher MD in the anterior corona radiata, genu of the corpus collosum, inferior fronto-occipital fasciculus, superior occipital, and superior temporal white matter. Females who underwent PBO between 45 and 49 also had some changes in white matter integrity. DISCUSSION: Females who underwent PBO < 40 years had reduced white matter integrity across multiple regions in later-life. These results are important for females considering PBO for noncancerous conditions. HIGHLIGHTS: Females with premenopausal bilateral oophorectomy (PBO) < 40 years had lower FA versus referents. Females with PBO < 40 years had higher MD in many regions versus referents. Adjusting for estrogen replacement therapy use did not attenuate results. Females with PBO 45-49 years also had some white matter changes versus referents.


Assuntos
Encéfalo , Imagem de Tensor de Difusão , Ovariectomia , Pré-Menopausa , Substância Branca , Humanos , Feminino , Pessoa de Meia-Idade , Substância Branca/diagnóstico por imagem , Adulto , Encéfalo/diagnóstico por imagem , Anisotropia
15.
Mayo Clin Proc ; 99(5): 716-726, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38702125

RESUMO

OBJECTIVE: To evaluate the associations between prescription opioid exposures in community-dwelling older adults and gray and white matter structure by magnetic resonance imaging. METHODS: Secondary analysis was conducted of a prospective, longitudinal population-based cohort study employing cross-sectional imaging of older adult (≥65 years) enrollees between November 1, 2004, and December 31, 2017. Gray matter outcomes included cortical thickness in 41 structures and subcortical volumes in 6 structures. White matter outcomes included fractional anisotropy in 40 tracts and global white matter hyperintensity volumes. The primary exposure was prescription opioid availability expressed as the per-year rate of opioid days preceding magnetic resonance imaging, with a secondary exposure of per-year total morphine milligram equivalents (MME). Multivariable models assessed associations between opioid exposures and brain structures. RESULTS: The study included 2185 participants; median (interquartile range) age was 80 (75 to 85) years, 47% were women, and 1246 (57%) received opioids. No significant associations were found between opioids and gray matter. Increased opioid days and MME were associated with decreased white matter fractional anisotropy in 15 (38%) and 16 (40%) regions, respectively, including the corpus callosum, posterior thalamic radiation, and anterior limb of the internal capsule, among others. Opioid days and MME were also associated with greater white matter hyperintensity volume (1.02 [95% CI, 1.002 to 1.036; P=.029] and 1.01 [1.001 to 1.024; P=.032] increase in the geometric mean, respectively). CONCLUSION: The duration and dose of prescription opioids were associated with decreased white matter integrity but not with gray matter structure. Future studies with longitudinal imaging and clinical correlation are warranted to further evaluate these relationships.


Assuntos
Analgésicos Opioides , Vida Independente , Imageamento por Ressonância Magnética , Humanos , Feminino , Masculino , Idoso , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Idoso de 80 Anos ou mais , Estudos Prospectivos , Imageamento por Ressonância Magnética/métodos , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/efeitos dos fármacos , Substância Cinzenta/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/efeitos dos fármacos , Estudos Longitudinais , Estudos Transversais
16.
bioRxiv ; 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38712293

RESUMO

Introduction: Diffusion MRI is sensitive to the microstructural properties of brain tissues, and shows great promise in detecting the effects of degenerative diseases. However, many approaches analyze single measures averaged over regions of interest, without considering the underlying fiber geometry. Methods: Here, we propose a novel Macrostructure-Informed Normative Tractometry (MINT) framework, to investigate how white matter microstructure and macrostructure are jointly altered in mild cognitive impairment (MCI) and dementia. We compare MINT-derived metrics with univariate metrics from diffusion tensor imaging (DTI), to examine how fiber geometry may impact interpretation of microstructure. Results: In two multi-site cohorts from North America and India, we find consistent patterns of microstructural and macrostructural anomalies implicated in MCI and dementia; we also rank diffusion metrics' sensitivity to dementia. Discussion: We show that MINT, by jointly modeling tract shape and microstructure, has potential to disentangle and better interpret the effects of degenerative disease on the brain's neural pathways.

17.
NPJ Parkinsons Dis ; 10(1): 76, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570511

RESUMO

Dementia with Lewy bodies (DLB) is a neurodegenerative condition often co-occurring with Alzheimer's disease (AD) pathology. Characterizing white matter tissue microstructure using Neurite Orientation Dispersion and Density Imaging (NODDI) may help elucidate the biological underpinnings of white matter injury in individuals with DLB. In this study, diffusion tensor imaging (DTI) and NODDI metrics were compared in 45 patients within the dementia with Lewy bodies spectrum (mild cognitive impairment with Lewy bodies (n = 13) and probable dementia with Lewy bodies (n = 32)) against 45 matched controls using conditional logistic models. We evaluated the associations of tau and amyloid-ß with DTI and NODDI parameters and examined the correlations of AD-related white matter injury with Clinical Dementia Rating (CDR). Structural equation models (SEM) explored relationships among age, APOE ε4, amyloid-ß, tau, and white matter injury. The DLB spectrum group exhibited widespread white matter abnormalities, including reduced fractional anisotropy, increased mean diffusivity, and decreased neurite density index. Tau was significantly associated with limbic and temporal white matter injury, which was, in turn, associated with worse CDR. SEM revealed that amyloid-ß exerted indirect effects on white matter injury through tau. We observed widespread disruptions in white matter tracts in DLB that were not attributed to AD pathologies, likely due to α-synuclein-related injury. However, a fraction of the white matter injury could be attributed to AD pathology. Our findings underscore the impact of AD pathology on white matter integrity in DLB and highlight the utility of NODDI in elucidating the biological basis of white matter injury in DLB.

18.
Front Plant Sci ; 15: 1240981, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481402

RESUMO

Glyceollins, a family of phytoalexins elicited in legume species, play crucial roles in environmental stress response (e.g., defending against pathogens) and human health. However, little is known about the genetic basis of glyceollin elicitation. In the present study, we employed a metabolite-based genome-wide association (mGWA) approach to identify candidate genes involved in glyceollin elicitation in genetically diverse and understudied wild soybeans subjected to soybean cyst nematode. In total, eight SNPs on chromosomes 3, 9, 13, 15, and 20 showed significant associations with glyceollin elicitation. Six genes fell into two gene clusters that encode glycosyltransferases in the phenylpropanoid pathway and were physically close to one of the significant SNPs (ss715603454) on chromosome 9. Additionally, transcription factors (TFs) genes such as MYB and WRKY were also found as promising candidate genes within close linkage to significant SNPs on chromosome 9. Notably, four significant SNPs on chromosome 9 show epistasis and a strong signal for selection. The findings describe the genetic foundation of glyceollin biosynthesis in wild soybeans; the identified genes are predicted to play a significant role in glyceollin elicitation regulation in wild soybeans. Additionally, how the epistatic interactions and selection influence glyceollin variation in natural populations deserves further investigation to elucidate the molecular mechanism of glyceollin biosynthesis.

19.
J Plant Res ; 137(3): 307-314, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38517655

RESUMO

The present review explains briefly the importance of phosphorus in the biological activities and states that the most phosphorus of living organisms is absorbed by plants from the soil. Next, previous studies on the mechanisms of phosphate uptake by plants are reviewed as H+-dependent or Na+-dependent co-transport systems and the phosphate environment in which plants grow is discussed. The evolution of transporter genes and their regulation mechanisms of expression is discussed in relation to the phosphorus environment.


Assuntos
Fosfatos , Plantas , Fosfatos/metabolismo , Plantas/metabolismo , Plantas/genética , Transporte Biológico , Fósforo/metabolismo , Solo/química , Regulação da Expressão Gênica de Plantas
20.
Neuroimage ; 290: 120564, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38442778

RESUMO

Posterior cortical atrophy (PCA) and dementia with Lewy bodies (DLB) show distinct atrophy and overlapping hypometabolism profiles, but it is unknown how disruptions in structural and functional connectivity compare between these disorders and whether breakdowns in connectivity relate to either atrophy or hypometabolism. Thirty amyloid-positive PCA patients, 24 amyloid-negative DLB patients and 30 amyloid-negative cognitively unimpaired (CU) healthy individuals were recruited at Mayo Clinic, Rochester, MN, and underwent a 3T head MRI, including structural MRI, resting state functional MRI (rsfMRI) and diffusion tensor imaging (DTI) sequences, as well as [18F] fluorodeoxyglucose (FDG) PET. We assessed functional connectivity within and between 12 brain networks using rsfMRI and the CONN functional connectivity toolbox and calculated regional DTI metrics using the Johns Hopkins atlas. Multivariate linear-regression models corrected for multiple comparisons and adjusted for age and sex compared DTI metrics and within-network and between-network functional connectivity across groups. Regional gray-matter volumes and FDG-PET standard uptake value ratios (SUVRs) were calculated and analyzed at the voxel-level using SPM12. We used univariate linear-regression models to investigate the relationship between connectivity measures, gray-matter volume, and FDG-PET SUVR. On DTI, PCA showed degeneration in occipito-parietal white matter, posterior thalamic radiations, splenium of the corpus collosum and sagittal stratum compared to DLB and CU, with greater degeneration in the temporal white matter and the fornix compared to CU. We observed no white-matter degeneration in DLB compared to CU. On rsfMRI, reduced within-network connectivity was present in dorsal and ventral default mode networks (DMN) and the dorsal-attention network in PCA compared to DLB and CU, with reduced within-network connectivity in the visual and sensorimotor networks compared to CU. DLB showed reduced connectivity in the cerebellar network compared to CU. Between-network analysis showed increased connectivity in both cerebellar-to-sensorimotor and cerebellar-to-dorsal attention network connectivity in PCA and DLB. PCA showed reduced anterior DMN-to-cerebellar and dorsal attention-to-sensorimotor connectivity, while DLB showed reduced posterior DMN-to-sensorimotor connectivity compared to CU. PCA showed reduced dorsal DMN-to-visual connectivity compared to DLB. The multimodal analysis revealed weak associations between functional connectivity and volume in PCA, and between functional connectivity and metabolism in DLB. These findings suggest that PCA and DLB have unique connectivity alterations, with PCA showing more widespread disruptions in both structural and functional connectivity; yet some overlap was observed with both disorders showing increased connectivity from the cerebellum.


Assuntos
Doença de Alzheimer , Doença por Corpos de Lewy , Humanos , Doença por Corpos de Lewy/diagnóstico por imagem , Imagem de Tensor de Difusão , Fluordesoxiglucose F18 , Imageamento por Ressonância Magnética , Atrofia , Doença de Alzheimer/metabolismo
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