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1.
Cereb Cortex ; 34(2)2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38185996

RESUMEN

In addition to amyloid beta plaques and neurofibrillary tangles, Alzheimer's disease (AD) has been associated with elevated iron in deep gray matter nuclei using quantitative susceptibility mapping (QSM). However, only a few studies have examined cortical iron, using more macroscopic approaches that cannot assess layer-specific differences. Here, we conducted column-based QSM analyses to assess whether AD-related increases in cortical iron vary in relation to layer-specific differences in the type and density of neurons. We obtained global and regional measures of positive (iron) and negative (myelin, protein aggregation) susceptibility from 22 adults with AD and 22 demographically matched healthy controls. Depth-wise analyses indicated that global susceptibility increased from the pial surface to the gray/white matter boundary, with a larger slope for positive susceptibility in the left hemisphere for adults with AD than controls. Curvature-based analyses indicated larger global susceptibility for adults with AD versus controls; the right hemisphere versus left; and gyri versus sulci. Region-of-interest analyses identified similar depth- and curvature-specific group differences, especially for temporo-parietal regions. Finding that iron accumulates in a topographically heterogenous manner across the cortical mantle may help explain the profound cognitive deterioration that differentiates AD from the slowing of general motor processes in healthy aging.


Asunto(s)
Enfermedad de Alzheimer , Adulto , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Mapeo Encefálico , Hierro/metabolismo , Imagen por Resonancia Magnética , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/metabolismo , Placa Amiloide/metabolismo , Encéfalo/metabolismo
2.
Plant J ; 115(2): 529-545, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37029760

RESUMEN

The plant secondary cell wall is a thickened matrix of polysaccharides and lignin deposited at the cessation of growth in some cells. It forms the majority of carbon in lignocellulosic biomass, and it is an abundant and renewable source for forage, fiber, materials, fuels, and bioproducts. The complex structure and arrangement of the cell wall polymers mean that the carbon is difficult to access in an economical and sustainable way. One solution is to alter the cell wall polymer structure so that it is more suited to downstream processing. However, it remains difficult to predict what the effects of this engineering will be on the assembly, architecture, and properties of the cell wall. Here, we make use of Arabidopsis plants expressing a suite of genes to increase pectic galactan chain length in the secondary cell wall. Using multi-dimensional solid-state nuclear magnetic resonance, we show that increasing galactan chain length enhances pectin-cellulose spatial contacts and increases cellulose crystallinity. We also found that the increased galactan content leads to fewer spatial contacts of cellulose with xyloglucan and the backbone of pectin. Hence, we propose that the elongated galactan side chains compete with xyloglucan and the pectic backbone for cellulose interactions. Due to the galactan topology, this may result in comparatively weak interactions and disrupt the cell wall architecture. Therefore, introduction of this strategy into trees or other bioenergy crops would benefit from cell-specific expression strategies to avoid negative effects on plant growth.


Asunto(s)
Arabidopsis , Celulosa , Celulosa/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Galactanos/metabolismo , Pectinas/metabolismo , Pared Celular/metabolismo , Carbono/metabolismo
3.
Plant J ; 114(4): 875-894, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36891885

RESUMEN

Significant changes have occurred in plant cell wall composition during evolution and diversification of tracheophytes. As the sister lineage to seed plants, knowledge on the cell wall of ferns is key to track evolutionary changes across tracheophytes and to understand seed plant-specific evolutionary innovations. Fern cell wall composition is not fully understood, including limited knowledge of glycoproteins such as the fern arabinogalactan proteins (AGPs). Here, we characterize the AGPs from the leptosporangiate fern genera Azolla, Salvinia, and Ceratopteris. The carbohydrate moiety of seed plant AGPs consists of a galactan backbone including mainly 1,3- and 1,3,6-linked pyranosidic galactose, which is conserved across the investigated fern AGPs. Yet, unlike AGPs of angiosperms, those of ferns contained the unusual sugar 3-O-methylrhamnose. Besides terminal furanosidic arabinose, Ara (Araf), the main linkage type of Araf in the ferns was 1,2-linked Araf, whereas in seed plants 1,5-linked Araf is often dominating. Antibodies directed against carbohydrate epitopes of AGPs supported the structural differences between AGPs of ferns and seed plants. Comparison of AGP linkage types across the streptophyte lineage showed that angiosperms have rather conserved monosaccharide linkage types; by contrast bryophytes, ferns, and gymnosperms showed more variability. Phylogenetic analyses of glycosyltransferases involved in AGP biosynthesis and bioinformatic search for AGP protein backbones revealed a versatile genetic toolkit for AGP complexity in ferns. Our data reveal important differences across AGP diversity of which the functional significance is unknown. This diversity sheds light on the evolution of the hallmark feature of tracheophytes: their elaborate cell walls.


Asunto(s)
Helechos , Helechos/genética , Filogenia , Proteínas de Plantas/química , Glicoproteínas/metabolismo , Pared Celular/metabolismo
4.
Plant Physiol ; 192(1): 119-132, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-36797772

RESUMEN

The role of glycoproteins as key cell surface molecules during development and stress is well established; yet, the relationship between their structural features and functional mechanisms is poorly defined. FASCICLIN-LIKE ARABINOGALACTAN PROTEINs (FLAs), which impact plant growth and development, are an excellent example of a glycoprotein family with a complex multidomain structure. FLAs combine globular fasciclin-like (FAS1) domains with regions that are intrinsically disordered and contain glycomotifs for directing the addition of O-linked arabinogalactan (AG) glycans. Additional posttranslational modifications on FLAs include N-linked glycans in the FAS1 domains, a cleaved signal peptide at the N terminus, and often a glycosylphosphatidylinositol (GPI) anchor signal sequence at the C terminus. The roles of glycosylation, the GPI anchor, and FAS1 domain functions in the polysaccharide-rich extracellular matrix of plants remain unclear, as do the relationships between them. In this study, we examined sequence-structure-function relationships of Arabidopsis (Arabidopsis thaliana) FLA11, demonstrated to have roles in secondary cell wall (SCW) development, by introducing domain mutations and functional specialization through domain swaps with FLA3 and FLA12. We identified FAS1 domains as essential for FLA function, differentiating FLA11/FLA12, with roles in SCW development, from FLA3, specific to flowers and involved in pollen development. The GPI anchor and AG glycosylation co-regulate the cell surface location and release of FLAs into cell walls. The AG glycomotif sequence closest to the GPI anchor (AG2) is a major feature differentiating FLA11 from FLA12. The results of our study show that the multidomain structure of different FLAs influences their subcellular location and biological functions during plant development.


Asunto(s)
Arabidopsis , Proteínas de Plantas , Proteínas de Plantas/metabolismo , Mucoproteínas/genética , Mucoproteínas/metabolismo , Arabidopsis/metabolismo , Glicoproteínas/metabolismo , Polisacáridos/metabolismo
5.
J Geriatr Psychiatry Neurol ; : 8919887241254470, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769750

RESUMEN

BACKGROUND: Neuropsychiatric symptoms affect the majority of dementia patients. Past studies report high rates of potentially inappropriate prescribing of psychotropic medications in this population. We investigate differences in neuropsychiatric diagnoses and psychotropic medication prescribing in a local US cohort by sex and race. METHODS: We utilize Medicare claims and prescription fill records in a cohort of 100% Medicare North and South Carolina beneficiaries ages 50 and above for the year 2017 with a dementia diagnosis. We identify dementia and quantify diagnosis of anxiety, depression and psychosis using validated coding algorithms. We search Medicare claims for antianxiety, antidepressant and antipsychotic medications to determine prescriptions filled. RESULTS: Anxiety and depression were diagnosed at higher rates in White patients; psychosis at higher rates in Black patients. (P < .001) Females were diagnosed with anxiety, depression and psychosis at higher rates than males (P < .001) and filled more antianxiety and antidepressant medications than males. (P < .001) Black and Other race patients filled more antipsychotic medications for anxiety, depression and psychosis than White patients. (P < .001) Antidepressants were prescribed at higher rates than antianxiety or antipsychotic medications across all patients and diagnoses. Of patients with no neuropsychiatric diagnosis, 11.4% were prescribed an antianxiety medication, 22.8% prescribed an antidepressant and 7.6% prescribed an antipsychotic. CONCLUSIONS: The high fill rate of antianxiety (benzodiazepine) medications in dementia patients, especially females is a concern. Patients are prescribed psychotropic medications at high rates. This practice may represent potentially inappropriate prescribing. Patient/caregiver education with innovative community outreach and care delivery models may help decrease medication use.

6.
Cereb Cortex ; 33(9): 5307-5322, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-36320163

RESUMEN

The selective vulnerability of brain networks in individuals at risk for Alzheimer's disease (AD) may help differentiate pathological from normal aging at asymptomatic stages, allowing the implementation of more effective interventions. We used a sample of 72 people across the age span, enriched for the APOE4 genotype to reveal vulnerable networks associated with a composite AD risk factor including age, genotype, and sex. Sparse canonical correlation analysis (CCA) revealed a high weight associated with genotype, and subgraphs involving the cuneus, temporal, cingulate cortices, and cerebellum. Adding cognitive metrics to the risk factor revealed the highest cumulative degree of connectivity for the pericalcarine cortex, insula, banks of the superior sulcus, and the cerebellum. To enable scaling up our approach, we extended tensor network principal component analysis, introducing CCA components. We developed sparse regression predictive models with errors of 17% for genotype, 24% for family risk factor for AD, and 5 years for age. Age prediction in groups including cognitively impaired subjects revealed regions not found using only normal subjects, i.e. middle and transverse temporal, paracentral and superior banks of temporal sulcus, as well as the amygdala and parahippocampal gyrus. These modeling approaches represent stepping stones towards single subject prediction.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/patología , Imagen por Resonancia Magnética , Encéfalo/patología , Genotipo , Envejecimiento
7.
Psychosom Med ; 85(2): 118-129, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36728859

RESUMEN

OBJECTIVE: Early life stress (ELS) occurring during childhood and adolescence is an established risk factor for later cardiovascular disease and dysregulated reactivity to acute social stress. This study examined whether ELS associations with baseline cardiovascular functioning, cardiovascular stress reactivity and recovery, and emotional stress reactivity vary across levels of emotion-oriented, task-oriented, and avoidant coping styles. METHODS: The sample included 1027 adolescents and young adults (mean age = 19.29 years; 50% female; 64% Black, 34% non-Hispanic White) who reported on their ELS exposure and coping styles. Participants completed a standardized acute social stress test (the Trier Social Stress Test [TSST]), with heart rate (HR) and blood pressure (BP) measured before, during, and after the TSST. Self-reports of negative emotions during the TSST indexed emotional stress reactivity. RESULTS: Multiple regression models adjusting for demographic factors and body mass index showed that ELS was associated with lower HR stress reactivity, avoidant coping was related to lower systolic BP and diastolic BP during stress and lower systolic BP during recovery, and higher emotion-oriented coping and lower task-oriented coping predicted greater emotional stress reactivity. A consistent pattern emerged where emotion-oriented coping amplified the associations between ELS and maladaptive stress responses (blunted cardiovascular stress reactivity and recovery; enhanced emotional stress reactivity), whereas lower levels of emotion-oriented coping were associated with resilient profiles among those who experienced ELS (lower resting HR, lower emotional stress reactivity, average HR and BP stress reactivity and recovery). However, low levels of emotion-oriented coping also conferred a risk of higher BP during recovery for those with high levels of ELS. CONCLUSIONS: These results suggest that low to moderate levels of emotion-oriented coping promote optimal cardiovascular and emotional reactivity to acute stress among individuals exposed to ELS.


Asunto(s)
Experiencias Adversas de la Infancia , Adolescente , Adulto Joven , Humanos , Femenino , Adulto , Masculino , Estrés Psicológico , Adaptación Psicológica , Emociones/fisiología , Autoinforme
8.
BMC Neurol ; 23(1): 325, 2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37700254

RESUMEN

BACKGROUND: Medicare claims and electronic health record data are both commonly used for research and clinical practice improvement; however, it is not known how concordant diagnoses of neurodegenerative diseases (NDD, comprising dementia and Parkinson's disease) are in these data types. Therefore, our objective was to determine the sensitivity and specificity of neurodegenerative disease (NDD) diagnoses contained in structured electronic health record (EHR) data compared to Medicare claims data. METHODS: This was a retrospective cohort study of 101,980 unique patients seen at a large North Carolina health system between 2013-2017, which were linked to 100% North and South Carolina Medicare claims data, to evaluate the accuracy of diagnoses of neurodegenerative diseases in EHRs compared to Medicare claims data. Patients age > 50 who were enrolled in fee-for-service Medicare were included in the study. Patients were classified as having or not having NDD based on the presence of validated ICD-CM-9 or ICD-CM-10 codes associated with NDD or claims for prescription drugs used to treat NDD. EHR diagnoses were compared to Medicare claims diagnoses. RESULTS: The specificity of any EHR diagnosis of NDD was 99.0%; sensitivity was 61.3%. Positive predictive value and negative predictive value were 90.8% and 94.1% respectively. Specificity of an EHR diagnosis of dementia was 99.0%, and sensitivity was 56.1%. Specificity of an EHR diagnosis of PD was 99.7%, while sensitivity was 76.1%. CONCLUSIONS: More research is needed to investigate under-documentation of NDD in electronic health records relative to Medicare claims data, which has major implications for clinical practice (particularly patient safety) and research using real-world data.


Asunto(s)
Demencia , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Estados Unidos/epidemiología , Humanos , Anciano , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/epidemiología , Registros Electrónicos de Salud , Medicare , Estudios Retrospectivos , Demencia/diagnóstico , Demencia/epidemiología
9.
Alzheimers Dement ; 19(6): 2376-2388, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36469005

RESUMEN

INTRODUCTION: Racial/ethnic disparities exist in many aspects of health care, but data on racial/ethnic disparities for neurodegenerative diseases (NDDs), such as dementia and Parkinson's disease (PD), are limited. METHODS: We used North and South Carolina Medicare claims from 2013 to 2017 to evaluate disparities in incidence of NDDs and in health-care utilization and outcomes for patients with NDDs. RESULTS: Disparities in incidence of NDD between Black and White beneficiaries narrowed by 0.37 per 100 person-years from 2014 to 2017. After thorough covariate adjustment, Black beneficiaries had a 4% higher risk of all-cause hospitalization, spent 8% more days in skilled nursing facilities and 14% fewer days in hospice facilities, were 38% less likely to receive physical/occupational therapy services, were 8% less likely to receive dementia medications, and were 19% less likely to receive PD medications than White beneficiaries. DISCUSSION: Effective system-level approaches to promote health equity in NDD diagnosis, treatment, and outcomes are clearly needed. HIGHLIGHTS: Racial disparities in neurodegenerative disease incidence narrowed between 2014 and 2017. Black patients were less likely than White patients to receive hospice services. Black patients were less likely than White patients to receive physical therapy. Black patients were less likely than White patients to receive Alzheimer's disease or Parkinson's disease medications. There is a shortage of neurologists in counties with high dementia incidence.


Asunto(s)
Enfermedad de Alzheimer , Equidad en Salud , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Estados Unidos/epidemiología , Humanos , Anciano , Incidencia , Promoción de la Salud , Enfermedad de Parkinson/epidemiología , Enfermedad de Parkinson/terapia , Medicare , Aceptación de la Atención de Salud , Disparidades en Atención de Salud
10.
New Phytol ; 233(4): 1750-1767, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34862967

RESUMEN

Secondary cell walls (SCWs) in stem xylem vessel and fibre cells enable plants to withstand the enormous compressive forces associated with upright growth. It remains unclear if xylem vessel and fibre cells can directly sense mechanical stimuli and modify their SCW during development. We provide evidence that Arabidopsis SCW-specific Fasciclin-Like Arabinogalactan-proteins 11 (FLA11) and 12 (FLA12) are possible cell surface sensors regulating SCW development in response to mechanical stimuli. Plants overexpressing FLA11 (OE-FLA11) showed earlier SCW development compared to the wild-type (WT) and altered SCW properties that phenocopy WT plants under compression stress. By contrast, OE-FLA12 stems showed higher cellulose content compared to WT plants, similar to plants experiencing tensile stress. fla11, OE-FLA11, fla12, and OE-FLA12 plants showed altered SCW responses to mechanical stress compared to the WT. Quantitative polymerase chain reaction (qPCR) and RNA-seq analysis revealed the up-regulation of genes and pathways involved in stress responses and SCW synthesis and regulation. Analysis of OE-FLA11 nst1 nst3 plants suggests that FLA11 regulation of SCWs is reliant on classical transcriptional networks. Our data support the involvement of FLA11 and FLA12 in SCW sensing complexes to fine-tune both the initiation of SCW development and the balance of lignin and cellulose synthesis/deposition in SCWs during development and in response to mechanical stimuli.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Pared Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Lignina/metabolismo , Estrés Mecánico
11.
Plant Physiol ; 187(4): 2156-2173, 2021 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-34618080

RESUMEN

Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) play an important role in a variety of plant biological processes including growth, stress response, morphogenesis, signaling, and cell wall biosynthesis. The GPI anchor contains a lipid-linked glycan backbone that is synthesized in the endoplasmic reticulum (ER) where it is subsequently transferred to the C-terminus of proteins containing a GPI signal peptide by a GPI transamidase. Once the GPI anchor is attached to the protein, the glycan and lipid moieties are remodeled. In mammals and yeast, this remodeling is required for GPI-APs to be included in Coat Protein II-coated vesicles for their ER export and subsequent transport to the cell surface. The first reaction of lipid remodeling is the removal of the acyl chain from the inositol group by Bst1p (yeast) and Post-GPI Attachment to Proteins Inositol Deacylase 1 (PGAP1, mammals). In this work, we have used a loss-of-function approach to study the role of PGAP1/Bst1 like genes in plants. We have found that Arabidopsis (Arabidopsis thaliana) PGAP1 localizes to the ER and likely functions as the GPI inositol-deacylase that cleaves the acyl chain from the inositol ring of the GPI anchor. In addition, we show that PGAP1 function is required for efficient ER export and transport to the cell surface of GPI-APs.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Glicosilfosfatidilinositoles/genética , Glicosilfosfatidilinositoles/metabolismo , Proteínas de la Membrana/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Transporte de Proteínas/fisiología , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Variación Genética , Genotipo , Proteínas de la Membrana/genética , Monoéster Fosfórico Hidrolasas/genética , Transporte de Proteínas/genética
12.
Retina ; 42(7): 1338-1346, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35723922

RESUMEN

PURPOSE: To assess retinal microvascular alterations in individuals with amnestic mild cognitive impairment (MCI) and nonamnestic MCI. METHODS: One hundred twelve eyes of 59 amnestic MCI participants, 32 eyes of 17 nonamnestic MCI participants, and 111 eyes of 56 controls with normal cognition were included. Optical coherence tomography angiography vessel density and perfusion density in the Early Treatment Diabetic Retinopathy Study 3-mm circle and ring were assessed. Retinal thickness parameters including retinal nerve fiber layer thickness, ganglion cell-inner plexiform layer thickness, central subfield thickness, and subfoveal choroidal thickness were also analyzed. Multivariable generalized estimating equations were used for statistical analysis. RESULTS: Perfusion density in the 3-mm inner ring was significantly lower in amnestic MCI patients when compared with nonamnestic MCI participants (0.29 ± 0.03 vs. 0.34 ± 0.09, P = 0.025) and controls with normal cognition (0.29 ± 0.03 vs. 0.39 ± 0.02, P < 0.001), after adjustment for age and sex as covariates. Vessel density, retinal nerve fiber layer thickness, ganglion cell-inner plexiform layer thickness, central subfield thickness, and subfoveal choroidal thickness did not differ among or between diagnostic groups. CONCLUSION: Perfusion density was significantly reduced in individuals with amnestic MCI, compared with those with nonamnestic MCI and controls with normal cognition.


Asunto(s)
Disfunción Cognitiva , Tomografía de Coherencia Óptica , Angiografía , Disfunción Cognitiva/diagnóstico , Humanos , Fibras Nerviosas , Células Ganglionares de la Retina , Tomografía de Coherencia Óptica/métodos
13.
J Am Psychiatr Nurses Assoc ; 28(2): 171-180, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-32964788

RESUMEN

OBJECTIVE: Patients with somatic symptom disorders (SSD) are prevalent in primary care, urgent care, and emergency rooms and present with reduced quality of life, increased disability, and suicidality . Criteria for SSD include (1) somatic symptoms that cause distress and disrupt life; (2) concurrent physical illness with thoughts and feelings that are disproportionate to the seriousness of the illness; and (3) distress which is persistent and causes suffering. The frequency of SSD in the general population is 5% to 7%; however, in primary care, it is 5% to 35% . Because patients present with anxiety, depression, and/or pain, providers are flummoxed when diagnostic findings do not match symptom intensity. The purpose of this project was to provide an intervention for patients with SSD and measure its effectiveness on their somatic symptoms. METHOD: This study provided a single-session, 30-minute psychoeducational intervention for patients to explain brain pathways for pain and the body's response to stress, including scientific benefits of exercise and healthy diet. Patients were asked questions using the motivational interviewing technique OARS (open-ended question, affirmation, reflection, summary) and were encouraged to talk about their concerns. The study used a pre- and post-intervention visual analogue scale and a self-reported Patient Health Questionnaire-15 both before and 3 weeks post-intervention. RESULTS: Measurements showed significant symptom improvement immediately after the intervention with sustained improvement 3 weeks post-intervention. CONCLUSIONS: This intervention demonstrates an effective treatment for this insidious illness, which plagues up to 35% of patients in primary care.


Asunto(s)
Síntomas sin Explicación Médica , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Humanos , Dolor , Atención Primaria de Salud , Calidad de Vida , Trastornos Somatomorfos/diagnóstico , Trastornos Somatomorfos/epidemiología , Trastornos Somatomorfos/terapia
14.
Mol Biol Evol ; 37(8): 2155-2172, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32359163

RESUMEN

Approaches for studying the evolution of globular proteins are now well established yet are unsuitable for disordered sequences. Our understanding of the evolution of proteins containing disordered regions therefore lags that of globular proteins, limiting our capacity to estimate their evolutionary history, classify paralogs, and identify potential sequence-function relationships. Here, we overcome these limitations by using new analytical approaches that project representations of sequence space to dissect the evolution of proteins with both ordered and disordered regions, and the correlated changes between these. We use the fasciclin-like arabinogalactan proteins (FLAs) as a model family, since they contain a variable number of globular fasciclin domains as well as several distinct types of disordered regions: proline (Pro)-rich arabinogalactan (AG) regions and longer Pro-depleted regions. Sequence space projections of fasciclin domains from 2019 FLAs from 78 species identified distinct clusters corresponding to different types of fasciclin domains. Clusters can be similarly identified in the seemingly random Pro-rich AG and Pro-depleted disordered regions. Sequence features of the globular and disordered regions clearly correlate with one another, implying coevolution of these distinct regions, as well as with the N-linked and O-linked glycosylation motifs. We reconstruct the overall evolutionary history of the FLAs, annotated with the changing domain architectures, glycosylation motifs, number and length of AG regions, and disordered region sequence features. Mapping these features onto the functionally characterized FLAs therefore enables their sequence-function relationships to be interrogated. These findings will inform research on the abundant disordered regions in protein families from all kingdoms of life.


Asunto(s)
Evolución Molecular , Proteínas Intrínsecamente Desordenadas/genética , Mucoproteínas/genética , Familia de Multigenes , Plantas/genética , Proteínas de Plantas/genética , Dominios Proteicos
15.
Plant Cell Environ ; 44(3): 915-930, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33190295

RESUMEN

Freezing triggers extracellular ice formation leading to cell dehydration and deformation during a freeze-thaw cycle. Many plant species increase their freezing tolerance during exposure to low, non-freezing temperatures, a process termed cold acclimation. In addition, exposure to mild freezing temperatures after cold acclimation evokes a further increase in freezing tolerance (sub-zero acclimation). Previous transcriptome and proteome analyses indicate that cell wall remodelling may be particularly important for sub-zero acclimation. In the present study, we used a combination of immunohistochemical, chemical and spectroscopic analyses to characterize the cell walls of Arabidopsis thaliana and characterized a mutant in the XTH19 gene, encoding a xyloglucan endotransglucosylase/hydrolase (XTH). The mutant showed reduced freezing tolerance after both cold and sub-zero acclimation, compared to the Col-0 wild type, which was associated with differences in cell wall composition and structure. Most strikingly, immunohistochemistry in combination with 3D reconstruction of centres of rosette indicated that epitopes of the xyloglucan-specific antibody LM25 were highly abundant in the vasculature of Col-0 plants after sub-zero acclimation but absent in the XTH19 mutant. Taken together, our data shed new light on the potential roles of cell wall remodelling for the increased freezing tolerance observed after low temperature acclimation.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Pared Celular/fisiología , Glicosiltransferasas/metabolismo , Aclimatación , Arabidopsis/enzimología , Arabidopsis/fisiología , Proteínas de Arabidopsis/fisiología , Pared Celular/metabolismo , Congelación , Glicosiltransferasas/fisiología , Monosacáridos/metabolismo , Polisacáridos/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier
16.
Ann Bot ; 128(3): 261-280, 2021 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-33758905

RESUMEN

BACKGROUND: Flowers which imitate insect oviposition sites probably represent the most widespread form of floral mimicry, exhibit the most diverse floral signals and are visited by two of the most speciose and advanced taxa of insect - beetles and flies. Detailed comparative studies on brood-site mimics pollinated exclusively by each of these insect orders are lacking, limiting our understanding of floral trait adaptation to different pollinator groups in these deceptive systems. METHODS: Two closely related and apparent brood-site mimics, Typhonium angustilobum and T. wilbertii (Araceae) observed to trap these distinct beetle and fly pollinator groups were used to investigate potential divergence in floral signals and traits most likely to occur under pollinator-mediated selection. Trapped pollinators were identified and their relative abundances enumerated, and thermogenic, visual and chemical signals and morphological traits were examined using thermocouples and quantitative reverse transcription-PCR, reflectance, gas chromatography-mass spectrometry, floral measurements and microscopy. KEY RESULTS: Typhonium angustilobum and T. wilbertii were functionally specialized to trap saprophagous Coleoptera and Diptera, respectively. Both species shared similar colour and thermogenic traits, and contained two highly homologous AOX genes (AOX1a and AOX1b) most expressed in the thermogenic tissue and stage (unlike pUCP). Scent during the pistillate stage differed markedly - T. angustilobum emitted a complex blend of sesquiterpenes, and T. wilbertii, a dung mimic, emitted high relative amounts of skatole, p-cresol and irregular terpenes. The species differed significantly in floral morphology related to trapping mechanisms. CONCLUSIONS: Functional specialization and pollinator divergence were not associated with differences in anthesis rhythm and floral thermogenic or visual signals between species, but with significant differences in floral scent and morphological features, suggesting that these floral traits are critical for the attraction and filtering of beetle or fly pollinators in these two brood-site mimics.


Asunto(s)
Araceae , Odorantes , Animales , Flores , Insectos , Polinización
17.
Ethn Health ; 26(8): 1143-1162, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30987436

RESUMEN

OBJECTIVES: African American prostate cancer survivors experience post-treatment decisional regret more often than European Americans, which can lead to negative long-term effects on quality of life. A prominent driver of health-related decision-making is emotion, yet little work has examined the impact emotions may have on decisional regret. The goal of this study was to explore experiences, perceptions, and emotions of prostate cancer survivors in relation to their diagnostic and treatment decision-making processes, prostate cancer treatment, and outcomes. Additionally, we sought to identify factors that might explain differences in prostate cancer outcomes between African and European Americans. DESIGN: This mixed-methods study utilized a convergent parallel design, in which quantitative and qualitative data were collected simultaneously and then integrated to more robustly explain relationships between variables. Survivors were eligible for the study if they had been previously diagnosed with localized prostate cancer and were no more than six months post-treatment. The study was guided by the Risk as Feelings Model, which predicts the relationship between emotion and cognition in high-risk decision-making. RESULTS: No men experienced decisional regret following treatment, even if they experienced side effects. While all men reported being surprised about their prostate cancer diagnosis, strong negative emotions were more common among men under 65. Family support and spirituality appeared to mitigate negative emotions. Perceived authenticity of provider communication was the most influential mediator in men's decision-making and positive perceptions of their outcomes. CONCLUSIONS: To mitigate the impact emotional responses have on decision-making and post-treatment regret, providers should explore alternate therapies (e.g. counseling for men diagnosed with prostate cancer at a young age) and include family members in prostate cancer treatment discussions. Most importantly, providers should be aware of the importance of quality communication on men's cognitive and emotional processes and their perceptions of treatment outcomes.


Asunto(s)
Próstata , Neoplasias de la Próstata , Toma de Decisiones , Emociones , Humanos , Masculino , Neoplasias de la Próstata/terapia , Calidad de Vida
18.
Int J Mol Sci ; 22(3)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33572987

RESUMEN

Glycosyltransferases (GTs) catalyze the synthesis of glycosidic linkages and are essential in the biosynthesis of glycans, glycoconjugates (glycolipids and glycoproteins), and glycosides. Plant genomes generally encode many more GTs than animal genomes due to the synthesis of a cell wall and a wide variety of glycosylated secondary metabolites. The Arabidopsis thaliana genome is predicted to encode over 573 GTs that are currently classified into 42 diverse families. The biochemical functions of most of these GTs are still unknown. In this study, we updated the JBEI Arabidopsis GT clone collection by cloning an additional 105 GT cDNAs, 508 in total (89%), into Gateway-compatible vectors for downstream characterization. We further established a functional analysis pipeline using transient expression in tobacco (Nicotiana benthamiana) followed by enzymatic assays, fractionation of enzymatic products by reversed-phase HPLC (RP-HPLC) and characterization by mass spectrometry (MS). Using the GT14 family as an exemplar, we outline a strategy for identifying effective substrates of GT enzymes. By addition of UDP-GlcA as donor and the synthetic acceptors galactose-nitrobenzodiazole (Gal-NBD), ß-1,6-galactotetraose (ß-1,6-Gal4) and ß-1,3-galactopentose (ß-1,3-Gal5) to microsomes expressing individual GT14 enzymes, we verified the ß-glucuronosyltransferase (GlcAT) activity of three members of this family (AtGlcAT14A, B, and E). In addition, a new family member (AT4G27480, 248) was shown to possess significantly higher activity than other GT14 enzymes. Our data indicate a likely role in arabinogalactan-protein (AGP) biosynthesis for these GT14 members. Together, the updated Arabidopsis GT clone collection and the biochemical analysis pipeline present an efficient means to identify and characterize novel GT catalytic activities.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Glicosiltransferasas/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Pared Celular/genética , Pared Celular/metabolismo , Genoma de Planta , Glicosiltransferasas/metabolismo , Mucoproteínas/genética , Mucoproteínas/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Especificidad por Sustrato
19.
Psychother Res ; 30(6): 728-738, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31438777

RESUMEN

Objective: Adolescent substance use is prevalent and associated with additional risk behaviours. Research shows that evidence-based brief interventions with adolescents and their main caregiver may mitigate the progression of substance use. Method: We used the ADAPT-ITT framework to develop a needs-based, culturally-sensitive intervention. Five focus groups with adolescents (n = 30), three focus groups with separate main caregivers of adolescents who use substances (n = 21), key informant interviews and an expert meeting, were conducted. Results: Adolescents described the need to decrease risk behaviours, while adolescents and caregivers requested additional support. The core components of the original intervention were retained, with some additions. The newly adapted RAD-PAL intervention was viewed as acceptable. Conclusion: Despite apparent acceptability, we need to test feasibility and efficacy in a trial.


Asunto(s)
Conducta del Adolescente , Cuidadores/psicología , Intervención en la Crisis (Psiquiatría) , Trastornos Relacionados con Sustancias/terapia , Adolescente , Femenino , Grupos Focales , Humanos
20.
Int J Psychol ; 55(6): 1016-1025, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32285449

RESUMEN

Substance use is prevalent among South African adolescents, but few interventions exist to reduce risk of harm. This study assesses the feasibility, acceptability and preliminary effects of a brief intervention for reducing adolescent substance use and other risk behaviours. This single-arm feasibility test recruited 30 substance-using adolescents and their primary caregiver. Participants received separate interventions (2 sessions for adolescents, 1 session for caregivers), with a subsample randomly selected for post-intervention interviews. Feasibility was measured by the proportion of eligible adolescents who were enrolled and retained in the study. Interviews explored acceptability, and changes in outcomes from baseline to 1-month follow-up assessed preliminary effects of the intervention. Thirty of 43 (69.8%) eligible adolescents and their caregivers were enrolled, with 29 adolescents (96.7%) and 28 caregivers (93.3%) completing the intervention. Twenty-eight adolescents (93.3%) and 29 caregivers (96.7%) were retained at follow-up. Frequency of alcohol, cannabis use and delinquent-type behaviours decreased significantly from baseline to follow-up. Participants appreciated the intervention content and delivery and felt that it facilitated behaviour change. Suggestions for improving the intervention were provided. This study found that the intervention is feasible, acceptable and had promising effects on adolescent behaviour. Efficacy must be established with a randomised controlled trial.


Asunto(s)
Conducta del Adolescente/psicología , Intervención en la Crisis (Psiquiatría)/métodos , Trastornos Relacionados con Sustancias/terapia , Adolescente , Estudios de Factibilidad , Femenino , Humanos , Masculino , Proyectos Piloto , Asunción de Riesgos , Sudáfrica
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