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1.
J Clin Immunol ; 44(5): 107, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38676811

RESUMO

PURPOSE: Patients with adenosine deaminase 1 deficient severe combined immunodeficiency (ADA-SCID) are initially treated with enzyme replacement therapy (ERT) with polyethylene glycol-modified (PEGylated) ADA while awaiting definitive treatment with hematopoietic stem cell transplant (HSCT) or gene therapy. Beginning in 1990, ERT was performed with PEGylated bovine intestinal ADA (ADAGEN®). In 2019, a PEGylated recombinant bovine ADA (Revcovi®) replaced ADAGEN following studies in older patients previously treated with ADAGEN for many years. There are limited longitudinal data on ERT-naïve newborns treated with Revcovi. METHODS: We report our clinical experience with Revcovi as initial bridge therapy in three newly diagnosed infants with ADA-SCID, along with comprehensive biochemical and immunologic data. RESULTS: Revcovi was initiated at twice weekly dosing (0.2 mg/kg intramuscularly), and monitored by following plasma ADA activity and the concentration of total deoxyadenosine nucleotides (dAXP) in erythrocytes. All patients rapidly achieved a biochemically effective level of plasma ADA activity, and red cell dAXP were eliminated within 2-3 months. Two patients reconstituted B-cells and NK-cells within the first month of ERT, followed by naive T-cells one month later. The third patient reconstituted all lymphocyte subsets within the first month of ERT. One patient experienced declining lymphocyte counts with improvement following Revcovi dose escalation. Two patients developed early, self-resolving thrombocytosis, but no thromboembolic events occurred. CONCLUSION: Revcovi was safe and effective as initial therapy to restore immune function in these newly diagnosed infants with ADA-SCID, however, time course and degree of reconstitution varied. Revcovi dose may need to be optimized based on immune reconstitution, clinical status, and biochemical data.


Assuntos
Adenosina Desaminase , Agamaglobulinemia , Terapia de Reposição de Enzimas , Imunodeficiência Combinada Severa , Humanos , Adenosina Desaminase/deficiência , Adenosina Desaminase/genética , Imunodeficiência Combinada Severa/terapia , Lactente , Agamaglobulinemia/terapia , Masculino , Feminino , Recém-Nascido , Animais , Resultado do Tratamento , Reconstituição Imune , Proteínas Recombinantes/uso terapêutico
2.
Front Pediatr ; 12: 1365187, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38516355

RESUMO

We report the case of a 1-week-old male born full-term, who had two inconclusive severe combined immunodeficiency (SCID) newborn screens and developed scalp cellulitis and Escherichia coli bacteremia. He did not pass early confirmatory hearing screens. Initial blood counts and lymphocyte flow cytometry revealed profound neutropenia and lymphopenia with a T-/B-/NK- phenotype. Red blood cell adenosine deaminase 1 activity was within normal limits. A presumptive diagnosis of reticular dysgenesis was considered. Granulocyte colony-stimulating factor was started, but there was no improvement in neutrophil counts. Subsequent lymphocyte flow cytometry at around 4 weeks of age demonstrated an increase in T-, B- and NK-cell numbers, eliminating suspicion for SCID and raising concern for congenital neutropenia and bone marrow failure syndromes. Genetic testing revealed a novel variant in RAC2 [c.181C>A (p.Gln61Lys)] (Q61K). RAC2, a Ras-related GTPase, is the dominant RAC protein expressed in hematopoietic cells and is involved with various downstream immune-mediated responses. Pathogenic RAC2 variants show significant phenotypic heterogeneity (spanning from neutrophil defects to combined immunodeficiency) across dominant, constitutively activating, dominant activating, dominant negative, and autosomal recessive subtypes. Given the identification of a novel variant, functional testing was pursued to evaluate aberrant pathways described in other RAC2 pathogenic variants. In comparison to wild-type RAC2, the Q61K variant supported elevated superoxide production under both basal and PMA-stimulated conditions, increased PAK1 binding, and enhanced plasma membrane ruffling, consistent with other dominant, constitutively active mutations. This case highlights the diagnostic challenge associated with genetic variants identified via next-generation sequencing panels and the importance of functional assays to confirm variant pathogenicity.

3.
J Allergy Clin Immunol Glob ; 3(1): 100187, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38187866

RESUMO

Background: Oral food challenge (OFC) is the criterion standard for diagnosing food allergy (FA). It is important to have parameters to aid in selecting ideal OFC candidates. Objective: We sought to characterize outcomes and predictors of OFCs for common food allergens. Methods: We completed a retrospective chart review of all OFCs for IgE-mediated FA performed at Duke University pediatric allergy clinics from June 2017 through May 2022. Patients were deemed eligible for milk, egg, and nut OFC if testing revealed a specific IgE level not exceeding 2 kU/L and a skin prick test (SPT) resulting in a wheal size not exceeding 5 mm. Different parameters were followed for selecting candidates for baked challenge. Results: A total of 663 OFCs were conducted on 510 patients (59% male). The most common foods challenged were peanut (26%), plain egg (23%), baked egg (8%), and milk (8%), with pass rates of 84%, 88%, 62%, and 84%, respectively. Of the patients who failed OFC, 84% had objective symptoms, 23% had multisystemic reactions, and 15% required epinephrine. Although the presence of a personal or family history of atopy or prior failed OFC was not associated with outcomes, a history of anaphylaxis (regardless of the trigger) was associated with increased risk of failure. Conclusion: Although there are no established consensus guidelines, our study provides a benchmark illustrating that cutoffs of a specific IgE level not exceeding 2 kU/L and SPT finding not exceeding 5 mm result in a failure rate of approximately 13% for nonbaked milk, nonbaked egg, and nuts. The high rate of failed baked egg OFCs is likely related to selection bias, but our results illustrate the low negative predictive value of ovomucoid.

4.
J Affect Disord ; 351: 631-640, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38290583

RESUMO

We examine structural brain characteristics across three diagnostic categories: at risk for serious mental illness; first-presenting episode and recurrent major depressive disorder (MDD). We investigate whether the three diagnostic groups display a stepwise pattern of brain changes in the cortico-limbic regions. Integrated clinical and neuroimaging data from three large Canadian studies were pooled (total n = 622 participants, aged 12-66 years). Four clinical profiles were used in the classification of a clinical staging model: healthy comparison individuals with no history of depression (HC, n = 240), individuals at high risk for serious mental illness due to the presence of subclinical symptoms (SC, n = 80), first-episode depression (FD, n = 82), and participants with recurrent MDD in a current major depressive episode (RD, n = 220). Whole-brain volumetric measurements were extracted with FreeSurfer 7.1 and examined using three different types of analyses. Hippocampal volume decrease and cortico-limbic thinning were the most informative features for the RD vs HC comparisons. FD vs HC revealed that FD participants were characterized by a focal decrease in cortical thickness and global enlargement in amygdala volumes. Greater total amygdala volumes were significantly associated with earlier onset of illness in the FD but not the RD group. We did not confirm the construct validity of a tested clinical staging model, as a differential pattern of brain alterations was identified across the three diagnostic groups that did not parallel a stepwise clinical staging approach. The pathological processes during early stages of the illness may fundamentally differ from those that occur at later stages with clinical progression.


Assuntos
Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/patologia , Depressão , Imageamento por Ressonância Magnética/métodos , Canadá , Neuroimagem
5.
IBRO Neurosci Rep ; 16: 135-146, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38293679

RESUMO

Neural network-level changes underlying symptom remission in major depressive disorder (MDD) are often studied from a single perspective. Multimodal approaches to assess neuropsychiatric disorders are evolving, as they offer richer information about brain networks. A FATCAT-awFC pipeline was developed to integrate a computationally intense data fusion method with a toolbox, to produce a faster and more intuitive pipeline for combining functional connectivity with structural connectivity (denoted as anatomically weighted functional connectivity (awFC)). Ninety-three participants from the Canadian Biomarker Integration Network for Depression study (CAN-BIND-1) were included. Patients with MDD were treated with 8 weeks of escitalopram and adjunctive aripiprazole for another 8 weeks. Between-group connectivity (SC, FC, awFC) comparisons contrasted remitters (REM) with non-remitters (NREM) at baseline and 8 weeks. Additionally, a longitudinal study analysis was performed to compare connectivity changes across time for REM, from baseline to week-8. Association between cognitive variables and connectivity were also assessed. REM were distinguished from NREM by lower awFC within the default mode, frontoparietal, and ventral attention networks. Compared to REM at baseline, REM at week-8 revealed increased awFC within the dorsal attention network and decreased awFC within the frontoparietal network. A medium effect size was observed for most results. AwFC in the frontoparietal network was associated with neurocognitive index and cognitive flexibility for the NREM group at week-8. In conclusion, the FATCAT-awFC pipeline has the benefit of providing insight on the 'full picture' of connectivity changes for REMs and NREMs while making for an easy intuitive approach.

6.
Blood ; 143(15): 1476-1487, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38194689

RESUMO

ABSTRACT: Mutations in the small Rho-family guanosine triphosphate hydrolase RAC2, critical for actin cytoskeleton remodeling and intracellular signal transduction, are associated with neonatal severe combined immunodeficiency (SCID), infantile neutrophilic disorder resembling leukocyte adhesion deficiency (LAD), and later-onset combined immune deficiency (CID). We investigated 54 patients (23 previously reported) from 37 families yielding 15 novel RAC2 missense mutations, including one present only in homozygosity. Data were collected from referring physicians and literature reports with updated clinical information. Patients were grouped by presentation: neonatal SCID (n = 5), infantile LAD-like disease (n = 5), or CID (n = 44). Disease correlated to RAC2 activity: constitutively active RAS-like mutations caused neonatal SCID, dominant-negative mutations caused LAD-like disease, whereas dominant-activating mutations caused CID. Significant T- and B-lymphopenia with low immunoglobulins were seen in most patients; myeloid abnormalities included neutropenia, altered oxidative burst, impaired neutrophil migration, and visible neutrophil macropinosomes. Among 42 patients with CID with clinical data, upper and lower respiratory infections and viral infections were common. Twenty-three distinct RAC2 mutations, including 15 novel variants, were identified. Using heterologous expression systems, we assessed downstream effector functions including superoxide production, p21-activated kinase 1 binding, AKT activation, and protein stability. Confocal microscopy showed altered actin assembly evidenced by membrane ruffling and macropinosomes. Altered protein localization and aggregation were observed. All tested RAC2 mutant proteins exhibited aberrant function; no single assay was sufficient to determine functional consequence. Most mutants produced elevated superoxide; mutations unable to support superoxide formation were associated with bacterial infections. RAC2 mutations cause a spectrum of immune dysfunction, ranging from early onset SCID to later-onset combined immunodeficiencies depending on RAC2 activity. This trial was registered at www.clinicaltrials.gov as #NCT00001355 and #NCT00001467.


Assuntos
Síndromes de Imunodeficiência , Síndrome da Aderência Leucocítica Deficitária , Doenças da Imunodeficiência Primária , Imunodeficiência Combinada Severa , Humanos , Recém-Nascido , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/metabolismo , Neutrófilos/metabolismo , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/metabolismo , Proteínas rac de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteína RAC2 de Ligação ao GTP , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/metabolismo , Superóxidos/metabolismo
7.
Autism Adulthood ; 5(4): 457-467, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38116048

RESUMO

Vocational programs typically focus on building the skills of autistic youth. However, there is growing recognition that the supportive environment (or ecosystem) around an individual plays an important role in finding and maintaining work. Programs at the ecosystem-level can be established by coordinating support before high school ends. Cocreation of a vocational program by support providers can facilitate an integrated effort to prepare autistic youth for employment. In this study, we describe and evaluate the Job-Train Program (JTP), a vocational program for autistic high school students codesigned with educators and a community-based social services agency. A school board, community-based social services agency, and academics partnered to cocreate JTP. JTP combined skill teaching and paid supported employment on a university campus. This pilot study evaluated JTP using qualitative and quantitative data. Twelve autistic youth were recruited, aged 15-18 years (10 males, 2 females) with an average intelligence quotient of 101.9 (standard deviation = 14.4), from the Wechsler Abbreviated Scale of Intelligence-2. Youth and parents completed self-report measures (pre-post), including the primary outcome, Canadian Occupational Performance Measure (COPM). Post-JTP, interviews, focus groups, and surveys collected additional information from youth (n = 11), parents (n = 10), job coaches (n = 5), and employers (n = 8). Youth COPM scores indicated significant improvements in self-perceived ratings of skill performance (z = -2.5, p = 0.01) and satisfaction (z = -2.6, p = 0.01). Qualitative data corroborated COPM results noting youth skill improvements in self-esteem, independence, communication, and understanding work. Findings demonstrated a promising vocational training model for autistic high school students informing the development of integrated service pathways to support preparation for employment.


Why was this program developed?: When autistic young people leave school, they can experience difficulties in getting a job. We need to test whether job training might be helpful for autistic young people when they are leaving school. Current support focuses mostly on developing educational skills, but it is important that we think about the strengths and abilities of the individual within their environment. In this study, we worked with educators from schools and a community service agency (who support autistic adults) to develop a job training support program for autistic youth. What does this program do?: We designed the 13-week Job-Train Program (JTP) to provide training and paid work experience, develop work abilities, and increase support around the autistic youth. Participants took part in weekly group sessions about work skills, and they did 8 weeks of paid work, supported by a job coach on a university campus. How did researchers evaluate the program?: Twelve autistic high school students (age 15­18) took part, and eight university departments hosted work experiences. We used several approaches to see if the program was helping and to identify areas where we could improve the program in the future. Ten parents and 11 autistic youth completed the Canadian Occupational Performance Measure (COPM) before and after the program, so we could see if there were any changes in work-related skills. We also completed interviews with youth, focus groups with parents, and surveys with job coaches to gather feedback. What were the early findings?: Scores on the COPM questionnaire showed that the young people rated themselves as more skilled and they were more satisfied with their skills after the program. Parent ratings showed a similar pattern. When we spoke to youth, parents, and job coaches, they mentioned improvements in responsibility and independence. Eight employers in university departments gained awareness of autistic youth as employees and all were willing to be part of the program again. Parents suggested that having more training of advocacy skills would help youth with gaining work in the future. What were the weaknesses of this project?: We did not assess how well the job coaches did in delivering the program or exactly how they made accommodations within the work experience jobs. Autistic individuals and their parents were not included in program development. What are the next steps?: We now plan to include autistic youth and their parents in further refining the program. We also plan to follow up with the youth who took part, to see how they are doing in the long term. We also will improve the support provided by job coaches. How will this work help autistic adults now or in future?: The JTP approach may help autistic youth as they go into employment and could provide high-quality support for the transition to adulthood. We also show that university campuses could be great places for autistic youth to gain experience, so in the future hope that universities and schools work together more to help support autistic youth.

9.
Clin Neurophysiol ; 154: 85-99, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37595482

RESUMO

OBJECTIVE: To examine potential long-term effects of extremely low birth weight (ELBW; ≤ 1000 g) on adult brain structure, brain function, and cognitive-behavioral performance. METHODS: A subset of survivors from the prospectively-followed McMaster ELBW Cohort (n = 23, MBW = 816 g) and their peers born at normal birth weight (NBW; ≥ 2500 g; n = 14, MBW = 3361 g) provided T1-weighted magnetic resonance imaging (MRI) brain scans, resting electroencephalographic (EEG) recordings, and behavioral responses to a face-processing task in their early thirties. RESULTS: Visual discrimination accuracy for human faces, resting EEG alpha power, and long-distance alpha coherence were lower in ELBW survivors than NBW adults, and volumes of white matter hypointensities (WMH) were higher. Across groups, face-processing performance was correlated positively with posterior EEG spectral power and long-distance alpha and theta coherence, and negatively with WMH. The associations between face-processing scores and parietal alpha power and theta coherence were reduced after adjustment for WMH. CONCLUSIONS: Electrocortical activity, brain functional connectivity, and higher-order processing ability may be negatively affected by WMH burden, which is greater in adults born extremely preterm. SIGNIFICANCE: Decrements in electrocortical activity and behavioral performance in adult ELBW survivors may be partly explained by increased WMH volumes in this vulnerable population.


Assuntos
Encéfalo , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Adulto , Humanos , Recém-Nascido de Peso Extremamente Baixo ao Nascer/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Percepção Visual , Imageamento por Ressonância Magnética , Eletroencefalografia
10.
PLoS One ; 18(6): e0287289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37319261

RESUMO

In utero, the developing brain is highly susceptible to the environment. For example, adverse maternal experiences during the prenatal period are associated with outcomes such as altered neurodevelopment and emotion dysregulation. Yet, the underlying biological mechanisms remain unclear. Here, we investigate whether the function of a network of genes co-expressed with the serotonin transporter in the amygdala moderates the impact of prenatal maternal adversity on the structure of the orbitofrontal cortex (OFC) in middle childhood and/or the degree of temperamental inhibition exhibited in toddlerhood. T1-weighted structural MRI scans were acquired from children aged 6-12 years. A cumulative maternal adversity score was used to conceptualize prenatal adversity and a co-expression based polygenic risk score (ePRS) was generated. Behavioural inhibition at 18 months was assessed using the Early Childhood Behaviour Questionnaire (ECBQ). Our results indicate that in the presence of a low functioning serotonin transporter gene network in the amygdala, higher levels of prenatal adversity are associated with greater right OFC thickness at 6-12 years old. The interaction also predicts temperamental inhibition at 18 months. Ultimately, we identified important biological processes and structural modifications that may underlie the link between early adversity and future deviations in cognitive, behavioural, and emotional development.


Assuntos
Redes Reguladoras de Genes , Proteínas da Membrana Plasmática de Transporte de Serotonina , Feminino , Gravidez , Humanos , Criança , Pré-Escolar , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Córtex Pré-Frontal/diagnóstico por imagem , Família
11.
Front Neurosci ; 17: 1066373, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37008220

RESUMO

Introduction: Environmental perturbations during critical periods can have pervasive, organizational effects on neurodevelopment. To date, the literature examining the long-term impact of early life adversity has largely investigated structural and functional imaging data outcomes independently. However, emerging research points to a relationship between functional connectivity and the brain's underlying structural architecture. For instance, functional connectivity can be mediated by the presence of direct or indirect anatomical pathways. Such evidence warrants the use of structural and functional imaging in tandem to study network maturation. Accordingly, this study examines the impact of poor maternal mental health and socioeconomic context during the perinatal period on network connectivity in middle childhood using an anatomically weighted functional connectivity (awFC) approach. awFC is a statistical model that identifies neural networks by incorporating information from both structural and functional imaging data. Methods: Resting-state fMRI and DTI scans were acquired from children aged 7-9 years old. Results: Our results indicate that maternal adversity during the perinatal period can affect offspring's resting-state network connectivity during middle childhood. Specifically, in comparison to controls, children of mothers who had poor perinatal maternal mental health and/or low socioeconomic status exhibited greater awFC in the ventral attention network. Discussion: These group differences were discussed in terms of the role this network plays in attention processing and maturational changes that may accompany the consolidation of a more adult-like functional cortical organization. Furthermore, our results suggest that there is value in using an awFC approach as it may be more sensitive in highlighting connectivity differences in developmental networks associated with higher-order cognitive and emotional processing, as compared to stand-alone FC or SC analyses.

12.
J Exp Psychol Anim Learn Cogn ; 49(2): 87-95, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37079823

RESUMO

In three experiments, rats were given experience of flavored solutions AX and BX, where A and B represent distinctive flavors and X a flavor common to both solutions. In one condition, AX and BX were presented on the same trial separated by a 5-min interval (intermixed preexposure). In another condition, each daily trial consisted of presentations of only AX or only BX (blocked preexposure). The properties acquired by stimulus X were then tested. Experiment 1 showed that after intermixed preexposure X was less able to interfere with a conditioned response established to a different flavor. Experiment 2 showed that X was less effective at overshadowing when trained in compound with another flavor. Simple conditioning, with X as the conditioned stimulus, was not sensitive to the form of preexposure (Experiment 3). These results indicate that the opportunity to compare similar stimuli that is provided by presenting them in close succession can change the properties of features they hold in common, making these features less effective when tested in compound with other stimuli. A loss of effectiveness by such features would contribute to the perceptual learning effect, the enhancement of subsequent discrimination, that is generated by prior exposure to closely spaced similar stimuli. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Aprendizagem por Discriminação , Paladar , Ratos , Animais , Paladar/fisiologia , Aprendizagem por Associação/fisiologia , Condicionamento Clássico , Condicionamento Operante
13.
Dev Psychopathol ; 35(2): 876-890, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35440357

RESUMO

Although associations among borderline personality disorder (BPD), social rejection, and frontal EEG alpha asymmetry scores (FAA, a neural correlate of emotion regulation and approach-withdrawal motivations) have been explored in different studies, relatively little work has examined these relations during adolescence in the same study. We examined whether FAA moderated the relation between BPD features and rejection sensitivity following a validated social exclusion paradigm, Cyberball. A mixed, clinical-community sample of 64 adolescents (females = 62.5%; Mage = 14.45 years; SD = 1.6; range = 11-17 years) completed psychodiagnostic interviews and a self-report measure of BPD (Time 1). Approximately two weeks later (Time 2), participants completed a resting EEG recording followed by Cyberball. FAA moderated the relation between BPD features and overall feelings of rejection following Cyberball: individuals with greater relative left FAA had the highest and lowest feelings of social rejection depending on whether they had high and low BPD feature scores, respectively. Results remained after controlling for age, sex, gender, depression, and BPD diagnosis. These results suggest that FAA may moderate the relation between BPD features and social rejection, and that left frontal brain activity at rest may be differentially associated with those feelings in BPD. Findings are discussed in terms of the link between left frontal brain activity in the regulation and dysregulation of social approach behaviors, characteristic of BPD.


Assuntos
Transtorno da Personalidade Borderline , Feminino , Humanos , Adolescente , Transtorno da Personalidade Borderline/psicologia , Status Social , Emoções , Isolamento Social , Eletroencefalografia
14.
Nat Plants ; 8(12): 1385-1393, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36536014

RESUMO

Resurrecting extinct species is a fascinating and challenging idea for scientists and the general public. Whereas some theoretical progress has been made for animals, the resurrection of extinct plants (de-extinction sensu lato) is a relatively recently discussed topic. In this context, the term 'de-extinction' is used sensu lato to refer to the resurrection of 'extinct in the wild' species from seeds or tissues preserved in herbaria, as we acknowledge the current impossibility of knowing a priori whether a herbarium seed is alive and can germinate. In plants, this could be achieved by germinating or in vitro tissue-culturing old diaspores such as seeds or spores available in herbarium specimens. This paper reports the first list of plant de-extinction candidates based on the actual availability of seeds in herbarium specimens of globally extinct plants. We reviewed globally extinct seed plants using online resources and additional literature on national red lists, resulting in a list of 361 extinct taxa. We then proposed a method of prioritizing candidates for seed-plant de-extinction from diaspores found in herbarium specimens and complemented this with a phylogenetic approach to identify species that may maximize evolutionarily distinct features. Finally, combining data on seed storage behaviour and longevity, as well as specimen age in the novel 'best de-extinction candidate' score (DEXSCO), we identified 556 herbarium specimens belonging to 161 extinct species with available seeds. We expect that this list of de-extinction candidates and the novel approach to rank them will boost research efforts towards the first-ever plant de-extinction.


Assuntos
Plantas , Sementes , Filogenia , Extinção Biológica
15.
Neuroimage Clin ; 35: 103120, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35908308

RESUMO

Many previous intervention studies have used functional magnetic resonance imaging (fMRI) data to predict the antidepressant response of patients with major depressive disorder (MDD); however, practical constraints have limited many of those attempts to small, single centre studies which may not adequately reflect how these models will generalize when used in clinical practice. Not only does the act of collecting data at multiple sites generally increase sample sizes (a critical point in machine learning development) it also generates a more heterogeneous dataset due to systematic differences in scanners at different sites, and geographical differences in patient populations. As part of the Canadian Biomarker Integration Network in Depression (CAN-BIND-1) study, 144 MDD patients from six sites underwent resting state fMRI prior to starting escitalopram treatment, and again two weeks after the start. Here, we consider ways to use machine learning techniques to produce models that can predict response (measured at eight weeks after initiation), based on various parcellations, functional connectivity (FC) metrics, dimensionality reduction algorithms, and base learners, and also whether to use scans from one or both time points. Models that use only baseline (pre-treatment) or only week 2 (early-response) whole-brain FC features consistently failed to perform significantly better than default models. Utilizing the change in FC between these two time points, however, yielded significant results, with the best performing analytical pipeline achieving 69.6% (SD 10.8) accuracy. These results appear contrary to findings from many smaller single-site studies, which report substantially higher predictive accuracies from models trained on only baseline resting state FC features, suggesting these models may not generalize well beyond data used for development. Further, these results indicate the potential value of collecting data both before and shortly after treatment initiation.


Assuntos
Transtorno Depressivo Maior , Imageamento por Ressonância Magnética , Biomarcadores , Encéfalo/diagnóstico por imagem , Canadá , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Escitalopram , Humanos , Imageamento por Ressonância Magnética/métodos
16.
J Exp Psychol Anim Learn Cogn ; 48(4): 349-357, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35587893

RESUMO

Although noted as a proponent of associative learning theory, Bob Rescorla acknowledged that other mechanisms might be responsible for the within-event learning produced when two stimuli co-occur. To investigate this possibility, he conducted experiments in which rats experienced a compound of a novel flavor and a palatable nutrient, and demonstrated that a preference for the flavor established by this training did not show the pattern of extinction that might be expected of a preference based on a flavor-nutrient association. A review is presented of subsequent work on the extinction of such conditioned flavor preferences in rats. The results are found to depend on the motivational state of the rat in training and on test, on the match between the procedures on training and test, and on the details of the test procedure (the nature of the choice offered to the rat). When conditions are arranged appropriately, the extinction effect (a loss of the conditioned response) expected by standard associative theory can be obtained. What remains a problem for this theory is the observation (made originally by Rescorla himself) is that the effects of extinguishing a conditioned flavor preference are remarkably persistent. The failure to obtain recovery from the effects of the extinction procedure remains as a signal that this form of learning may involve processes other than the association formation used to explain many other forms of learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Condicionamento Clássico , Paladar , Masculino , Ratos , Animais , Aprendizagem , Motivação
17.
Ocul Immunol Inflamm ; 30(7-8): 1553-1558, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33974477

RESUMO

INTRODUCTION: In this study, we investigated the presence of motilin receptors (MR) in adnexal tissue including the human main lacrimal gland. METHOD: 17 adnexal human specimens comprising of 11 isolated human main lacrimal gland specimens, four full-thickness human eyelid excisions and two exenterations containing full-thickness eyelid and portions of the main lacrimal gland were immunolabelled with a rabbit polyclonal human MR antibody. RESULTS: Our results demonstrated that all main lacrimal gland specimens (13/13, 100%) were positive for MR expression with a predominance (10/13 (77%) of grade 1+ punctate distribution. Motilin receptors were not found in eccrine glands, cutaneous sebaceous glands, glands of Zeis or glands of Moll (0/6, 0%). We also confirmed MR expression in the accessory lacrimal gland tissue. CONCLUSION: In summary, we discovered the MR receptor in the lacrimal and accessory lacrimal gland - the significance of which, in the lacrimal gland, remains unclear - but motilin may play a role in the muscarinic control of aqueous tear secretion.


Assuntos
Aparelho Lacrimal , Motilina , Receptores dos Hormônios Gastrointestinais , Receptores de Neuropeptídeos , Coelhos , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Neuropeptídeos/metabolismo
18.
Learn Behav ; 50(4): 447-455, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34668157

RESUMO

In Experiment 1, rats received 16 nonreinforced trials of exposure to a flavor (A) that was subsequently used as the conditioned stimulus in flavor-aversion conditioning. In the critical condition, Flavor A was presented in compound with a different novel flavor on each of the eight daily trials. This treatment produced latent inhibition, in that this preexposure retarded conditioning just as did 16 trials with A alone. Rats in the control conditions, given no preexposure or exposure just to the sequence of novel flavors, learned readily. Experiment 2 examined the effects of these forms of preexposure on performance on a summation test, in which Flavor A was presented in compound with a separately conditioned flavor (X). The preexposure procedure in which A was presented along with novel flavors rendered A effective in inhibiting the response conditioned to X on that test. The conclusion, that this form of training can establish the target stimulus as a conditioned inhibitor, is predicted by the account of latent inhibition put forward by Hall and Rodríguez (2010) which proposes that the latent inhibition effect is a consequence both of a reduction in the associability of the stimulus and of a process of inhibitory associative learning that opposes the initial expectation that a novel event will be followed by some consequence.


Assuntos
Aprendizagem da Esquiva , Ratos , Animais
19.
Cereb Cortex ; 32(6): 1223-1243, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34416758

RESUMO

Understanding the neural underpinnings of major depressive disorder (MDD) and its treatment could improve treatment outcomes. So far, findings are variable and large sample replications scarce. We aimed to replicate and extend altered functional connectivity associated with MDD and pharmacotherapy outcomes in a large, multisite sample. Resting-state fMRI data were collected from 129 patients and 99 controls through the Canadian Biomarker Integration Network in Depression. Symptoms were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS). Connectivity was measured as correlations between four seeds (anterior and posterior cingulate cortex, insula and dorsolateral prefrontal cortex) and all other brain voxels. Partial least squares was used to compare connectivity prior to treatment between patients and controls, and between patients reaching remission (MADRS ≤ 10) early (within 8 weeks), late (within 16 weeks), or not at all. We replicated previous findings of altered connectivity in patients. In addition, baseline connectivity of the anterior/posterior cingulate and insula seeds differentiated patients with different treatment outcomes. The stability of these differences was established in the largest single-site subsample. Our replication and extension of altered connectivity highlighted previously reported and new differences between patients and controls, and revealed features that might predict remission prior to pharmacotherapy. Trial registration:ClinicalTrials.gov: NCT01655706.


Assuntos
Transtorno Depressivo Maior , Encéfalo/diagnóstico por imagem , Canadá , Depressão , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Humanos , Imageamento por Ressonância Magnética
20.
Phys Med Biol ; 67(5)2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-34965517

RESUMO

Clinically oriented studies commonly acquire diffusion MRI (dMRI) data with a single non-zerob-value (i.e. single-shell) and diffusion weighting ofb= 1000 s mm-2. To produce microstructural parameter maps, the tensor model is usually used, despite known limitations. Although compartment models have demonstrated improved fits in multi-shell dMRI data, they are rarely used for single-shell parameter maps, where their effectiveness is unclear from the literature. Here, various compartment models combining isotropic balls and symmetric tensors were fitted to single-shell dMRI data to investigate model fitting optimization and extract the most information possible. Full testing was performed in 5 subjects, and 3 subjects with multi-shell data were included for comparison. The results were tested and confirmed in a further 50 subjects. The Markov chain Monte Carlo (MCMC) model fitting technique outperformed non-linear least squares. Using MCMC, the 2-fibre-orientation mono-exponential ball and stick model (BSME2) provided artifact-free, stable results, in little processing time. The analogous ball and zeppelin model (BZ2) also produced stable, low-noise parameter maps, though it required much greater computing resources (50 000 burn-in steps). In single-shell data, the gamma-distributed diffusivity ball and stick model (BSGD2) underperformed relative to other models, despite being an often-used software default. It produced artifacts in the diffusivity maps even with extremely long processing times. Neither increased diffusion weighting nor a greater number of gradient orientations improvedBSGD2fits. In white matter (WM), the tensor produced the best fit as measured by Bayesian information criterion. This result contrasts with studies using multi-shell data. However, in crossing fibre regions the tensor confounded geometric effects with fractional anisotropy (FA): the planar/linear WM FA ratio was 49%, whileBZ2andBSME2retained 76% and 83% of restricted fraction, respectively. As a result, theBZ2andBSME2models are strong candidates to optimize information extraction from single-shell dMRI studies.


Assuntos
Processamento de Imagem Assistida por Computador , Substância Branca , Anisotropia , Teorema de Bayes , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Substância Branca/diagnóstico por imagem
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