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1.
Nat Plants ; 10(9): 1418-1434, 2024 09.
Artículo en Inglés | MEDLINE | ID: mdl-39256563

RESUMEN

Germination involves highly dynamic transcriptional programs as the cells of seeds reactivate and express the functions necessary for establishment in the environment. Individual cell types have distinct roles within the embryo, so must therefore have cell type-specific gene expression and gene regulatory networks. We can better understand how the functions of different cell types are established and contribute to the embryo by determining how cell type-specific transcription begins and changes through germination. Here we describe a temporal analysis of the germinating Arabidopsis thaliana embryo at single-cell resolution. We define the highly dynamic cell type-specific patterns of gene expression and how these relate to changing cellular function as germination progresses. Underlying these are unique gene regulatory networks and transcription factor activity. We unexpectedly discover that most embryo cells transition through the same initial transcriptional state early in germination, even though cell identity has already been established during embryogenesis. Cells later transition to cell type-specific gene expression patterns. Furthermore, our analyses support previous findings that the earliest events leading to the induction of seed germination take place in the vasculature. Overall, our study constitutes a general framework with which to characterize Arabidopsis cell transcriptional states through seed germination, allowing investigation of different genotypes and other plant species whose seed strategies may differ.


Asunto(s)
Arabidopsis , Regulación de la Expresión Génica de las Plantas , Germinación , Semillas , Germinación/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Semillas/genética , Semillas/crecimiento & desarrollo , Análisis de la Célula Individual , Redes Reguladoras de Genes , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
2.
J Exp Bot ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39225376

RESUMEN

Cannabis sativa L. is one of the oldest domesticated crops. Hemp-type cultivars, which predominantly produce non-intoxicating cannabidiol (CBD), have been selected for their fast growth, seed, and fibre production, while drug-type chemovars were bred for high accumulation of tetrahydrocannabinol (THC). We investigated how the generation of CBD-dominant chemovars by introgression of hemp- into drug-type Cannabis impacted plant performance. The THC-dominant chemovar showed superior sink strength, higher flower biomass and demand-driven control of nutrient uptake. By contrast, the CBD-dominant chemovar hyperaccumulated phosphate in sink organs leading to reduced carbon and nitrogen assimilation in leaves, which limited flower biomass and cannabinoid yield. RNA-seq analyses determined organ- and chemovar-specific differences in expression of genes associated with nitrate and phosphate homeostasis as well as growth-regulating transcription factors that were correlated with measured traits. Among these were genes positively selected for during Cannabis domestication encoding an inhibitor of the phosphate starvation response SPX DOMAIN GENE3, nitrate reductase and two nitrate transporters. Altered nutrient sensing, acquisition or distribution are likely a consequence of adaption to growth on marginal, low-nutrient input lands in hemp. Our data provide evidence that such ancestral traits may become detrimental for female flower development and consequently overall CBD yield in protected cropping environments.

3.
Plant Methods ; 20(1): 142, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39285284

RESUMEN

BACKGROUND: Grains make up a large proportion of both human and animal diets. With threats to food production, such as climate change, growing sustainable and successful crops is essential to food security in the future. Germination is one of the most important stages in a plant's lifecycle and is key to the success of the resulting plant as the grain undergoes morphological changes and the development of specific organs. Micro-computed tomography is a non-destructive imaging technique based on the differing x-ray attenuations of materials which we have applied for the accurate analysis of grain morphology during the germination phase. RESULTS: Micro Computed Tomography conditions and parameters were tested to establish an optimal protocol for the 3-dimensional analysis of barley grains. When comparing optimal scanning conditions, it was established that no filter, 0.4 degrees rotation step, 5 average frames, and 2016 × 1344 camera binning is optimal for imaging germinating grains. It was determined that the optimal protocol for scanning during the germination timeline was to scan individual grains at 0 h after imbibition (HAI) and then the same grain again at set time points (1, 3, 6, 24 HAI) to avoid any negative effects from X-ray radiation or disruption to growing conditions. CONCLUSION: Here we sought to develop a method for the accurate analysis of grain morphology without the negative effects of possible radiation exposure. Several factors have been considered, such as the scanning conditions, reconstruction, and possible effects of X-ray radiation on the growth rate of the grains. The parameters chosen in this study give effective and reliable results for the 3-dimensional analysis of macro structures within barley grains while causing minimal disruption to grain development.

4.
Sci Immunol ; 9(97): eadn6509, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39028827

RESUMEN

Most patients treated with US Food and Drug Administration (FDA)-approved chimeric antigen receptor (CAR) T cells eventually experience disease progression. Furthermore, CAR T cells have not been curative against solid cancers and several hematological malignancies such as T cell lymphomas, which have very poor prognoses. One of the main barriers to the clinical success of adoptive T cell immunotherapies is CAR T cell dysfunction and lack of expansion and/or persistence after infusion. In this study, we found that CD5 inhibits CAR T cell activation and that knockout (KO) of CD5 using CRISPR-Cas9 enhances the antitumor effect of CAR T cells in multiple hematological and solid cancer models. Mechanistically, CD5 KO drives increased T cell effector function with enhanced cytotoxicity, in vivo expansion, and persistence, without apparent toxicity in preclinical models. These findings indicate that CD5 is a critical inhibitor of T cell function and a potential clinical target for enhancing T cell therapies.


Asunto(s)
Antígenos CD5 , Inmunoterapia Adoptiva , Linfocitos T , Animales , Inmunoterapia Adoptiva/métodos , Antígenos CD5/inmunología , Ratones , Humanos , Linfocitos T/inmunología , Linfocitos T/trasplante , Receptores Quiméricos de Antígenos/inmunología , Receptores Quiméricos de Antígenos/genética , Línea Celular Tumoral , Sistemas CRISPR-Cas , Femenino
5.
J Exp Bot ; 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39046316

RESUMEN

Opium poppy is a crop of great commercial value as a source of several opium alkaloids for the pharmaceutical industries including morphine, codeine, thebaine, noscapine and papaverine. Most enzymes involved in benzylisoquinoline alkaloids (BIAs) biosynthesis in opium poppy have been functionally characterized, and opium poppy currently serves as a model system to study BIA metabolism in plants. BIA biosynthesis in opium poppy involves two biosynthetic gene clusters associated respectively with the morphine and noscapine branches. Recent reports have shown that genes in the same cluster are co-expressed, suggesting they might also be co-regulated. However, the transcriptional regulation of opium poppy BIA biosynthesis is not well studied. Opium poppy BIA biosynthesis involves three cell types associated with the phloem system: companion cells, sieve elements and laticifers. The transcripts and enzymes associated with BIA biosynthesis are distributed across cell types, requiring the translocation of key enzymes and pathway intermediates between cell types. Together, these suggest that the regulation of BIA biosynthesis in opium poppy is multilayered and complex, involving biochemical, genomic, and physiological mechanisms. In this review, we highlight recent advances in genome sequencing and single cell and spatial transcriptomics with a focus on how these efforts can improve our understanding of the genomic and cell-specific regulation of BIA biosynthesis. Such knowledge is vital for opium poppy genetic improvement and metabolic engineering efforts targeting the modulation of alkaloid yield and composition.

6.
Cancer Res Commun ; 4(6): 1467-1480, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38757809

RESUMEN

Hemangiosarcoma and angiosarcoma are soft-tissue sarcomas of blood vessel-forming cells in dogs and humans, respectively. These vasoformative sarcomas are aggressive and highly metastatic, with disorganized, irregular blood-filled vascular spaces. Our objective was to define molecular programs which support the niche that enables progression of canine hemangiosarcoma and human angiosarcoma. Dog-in-mouse hemangiosarcoma xenografts recapitulated the vasoformative and highly angiogenic morphology and molecular characteristics of primary tumors. Blood vessels in the tumors were complex and disorganized, and they were lined by both donor and host cells. In a series of xenografts, we observed that the transplanted hemangiosarcoma cells created exuberant myeloid hyperplasia and gave rise to lymphoproliferative tumors of mouse origin. Our functional analyses indicate that hemangiosarcoma cells generate a microenvironment that supports expansion and differentiation of hematopoietic progenitor populations. Furthermore, gene expression profiling data revealed hemangiosarcoma cells expressed a repertoire of hematopoietic cytokines capable of regulating the surrounding stromal cells. We conclude that canine hemangiosarcomas, and possibly human angiosarcomas, maintain molecular properties that provide hematopoietic support and facilitate stromal reactions, suggesting their potential involvement in promoting the growth of hematopoietic tumors. SIGNIFICANCE: We demonstrate that hemangiosarcomas regulate molecular programs supporting hematopoietic expansion and differentiation, providing insights into their potential roles in creating a permissive stromal-immune environment for tumor progression.


Asunto(s)
Hemangiosarcoma , Hemangiosarcoma/patología , Hemangiosarcoma/veterinaria , Hemangiosarcoma/genética , Perros , Animales , Humanos , Ratones , Microambiente Tumoral , Células Madre Hematopoyéticas/patología , Hematopoyesis , Diferenciación Celular
7.
BMJ Open ; 14(4): e082902, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38663922

RESUMEN

INTRODUCTION: Although limited, recent research suggests that contact sport participation might have an adverse long-term effect on brain health. Further work is required to determine whether this includes an increased risk of neurodegenerative disease and/or subsequent changes in cognition and behaviour. The Advanced BiomaRker, Advanced Imaging and Neurocognitive Health Study will prospectively examine the neurological, psychiatric, psychological and general health of retired elite-level rugby union and association football/soccer players. METHODS AND ANALYSIS: 400 retired athletes will be recruited (200 rugby union and 200 association football players, male and female). Athletes will undergo a detailed clinical assessment, advanced neuroimaging, blood testing for a range of brain health outcomes and neuropsychological assessment longitudinally. Follow-up assessments will be completed at 2 and 4 years after baseline visit. 60 healthy volunteers will be recruited and undergo an aligned assessment protocol including advanced neuroimaging, blood testing and neuropsychological assessment. We will describe the previous exposure to head injuries across the cohort and investigate relationships between biomarkers of brain injury and clinical outcomes including cognitive performance, clinical diagnoses and psychiatric symptom burden. ETHICS AND DISSEMINATION: Relevant ethical approvals have been granted by the Camberwell St Giles Research Ethics Committee (Ref: 17/LO/2066). The study findings will be disseminated through manuscripts in clinical/academic journals, presentations at professional conferences and through participant and stakeholder communications.


Asunto(s)
Atletas , Biomarcadores , Fútbol Americano , Neuroimagen , Pruebas Neuropsicológicas , Humanos , Estudios Prospectivos , Biomarcadores/sangre , Masculino , Fútbol Americano/lesiones , Neuroimagen/métodos , Femenino , Atletas/psicología , Jubilación , Cognición , Proyectos de Investigación , Encéfalo/diagnóstico por imagen , Fútbol/lesiones
8.
Comput Biol Med ; 172: 108233, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38452471

RESUMEN

BACKGROUND: Cancer cachexia is a severe metabolic syndrome marked by skeletal muscle atrophy. A successful clinical intervention for cancer cachexia is currently lacking. The study of cachexia mechanisms is largely based on preclinical animal models and the availability of high-throughput transcriptomic datasets of cachectic mouse muscles is increasing through the extensive use of next generation sequencing technologies. METHODS: Cachectic mouse muscle transcriptomic datasets of ten different studies were combined and mined by seven attribute weighting models, which analysed both categorical variables and numerical variables. The transcriptomic signature of cancer cachexia was identified by attribute weighting algorithms and was used to evaluate the performance of eleven pattern discovery models. The signature was employed to find the best combination of drugs (drug repurposing) for developing cancer cachexia treatment strategies, as well as to evaluate currently used cachexia drugs by literature mining. RESULTS: Attribute weighting algorithms ranked 26 genes as the transcriptomic signature of muscle from mice with cancer cachexia. Deep Learning and Random Forest models performed better in differentiating cancer cachexia cases based on muscle transcriptomic data. Literature mining revealed that a combination of melatonin and infliximab has negative interactions with 2 key genes (Rorc and Fbxo32) upregulated in the transcriptomic signature of cancer cachexia in muscle. CONCLUSIONS: The integration of machine learning, meta-analysis and literature mining was found to be an efficient approach to identifying a robust transcriptomic signature for cancer cachexia, with implications for improving clinical diagnosis and management of this condition.


Asunto(s)
Caquexia , Neoplasias , Animales , Ratones , Caquexia/genética , Caquexia/metabolismo , Minería de Datos , Perfilación de la Expresión Génica , Aprendizaje Automático , Metaanálisis como Asunto , Músculo Esquelético , Neoplasias/complicaciones , Neoplasias/genética , Neoplasias/metabolismo
9.
bioRxiv ; 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38464005

RESUMEN

The rampant rise of multidrug resistant (MDR) bacterial pathogens poses a severe health threat, necessitating innovative tools to unravel the complex genetic underpinnings of antimicrobial resistance. Despite significant strides in developing genomic tools for detecting resistance genes, a gap remains in analyzing organism-specific patterns of resistance gene co-occurrence. Addressing this deficiency, we developed the Resistance Gene Association and Inference Network (ReGAIN), a novel web-based and command line genomic platform that uses Bayesian network structure learning to identify and map resistance gene networks in bacterial pathogens. ReGAIN not only detects resistance genes using well-established methods, but also elucidates their complex interplay, critical for understanding MDR phenotypes. Focusing on ESKAPE pathogens, ReGAIN yielded a queryable database for investigating resistance gene co-occurrence, enriching resistome analyses, and providing new insights into the dynamics of antimicrobial resistance. Furthermore, the versatility of ReGAIN extends beyond antibiotic resistance genes to include assessment of co-occurrence patterns among heavy metal resistance and virulence determinants, providing a comprehensive overview of key gene relationships impacting both disease progression and treatment outcomes.

10.
Dis Esophagus ; 37(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38525940

RESUMEN

There is currently no consensus as to how to manage esophageal anastomotic leaks. Intervention with endoscopic vacuum-assisted closure (EVAC), stenting, reoperation, and conservative management have all been mooted as potential options. To conduct a systematic review and network meta-analysis (NMA) to evaluate the optimal management strategy for esophageal anastomotic leaks. A systematic review was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines with extension for NMA. NMA was performed using R packages and Shiny. In total, 12 retrospective studies were included, which included 511 patients. Of the 449 patients for whom data regarding sex was available, 371 (82.6%) were male, 78 (17.4%) were female. The average age of patients was 62.6 years (standard deviation 10.2). The stenting cohort included 245 (47.9%) patients. The EVAC cohort included 123 (24.1%) patients. The conservative cohort included 87 (17.0%) patients. The reoperation cohort included 56 (10.9%) patients. EVAC had a significantly decreased complication rate compared to stenting (odds ratio 0.23 95%, confidence interval [CI] 0.09;0.58). EVAC had a significantly lower mortality rate than stenting (odds ratio 0.43, 95% CI 0.21; 0.87). Reoperation was used in significantly larger leaks than stenting (mean difference 14.66, 95% CI 4.61;24.70). The growing use of EVAC as a first-line intervention in esophageal anastomotic leaks should continue given its proven effectiveness and significant reduction in both complication and mortality rates. Surgical management is often necessary for significantly larger leaks and will likely remain an effective option in uncontained leaks with systemic features.


Asunto(s)
Fuga Anastomótica , Metaanálisis en Red , Reoperación , Stents , Humanos , Fuga Anastomótica/cirugía , Fuga Anastomótica/etiología , Fuga Anastomótica/terapia , Reoperación/estadística & datos numéricos , Reoperación/métodos , Femenino , Masculino , Persona de Mediana Edad , Terapia de Presión Negativa para Heridas/métodos , Anciano , Esófago/cirugía , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Esofagectomía/efectos adversos , Esofagectomía/métodos , Tratamiento Conservador/métodos , Estudios Retrospectivos , Resultado del Tratamiento
11.
J Thorac Cardiovasc Surg ; 167(5): e131-e139, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37678606

RESUMEN

OBJECTIVE: Ex vivo lung perfusion has emerged as a platform for organ preservation, evaluation, and restoration. Gene delivery using a clinically relevant adeno-associated vector during ex vivo lung perfusion may be useful in optimizing donor allografts while the graft is maintained physiologically active. We evaluated the feasibility of adeno-associated vector-mediated gene delivery during ex vivo lung perfusion in a rat transplant model. Additionally, we assessed off-target effects and explored different routes of delivery. METHODS: Rat heart-lung blocks were procured and underwent 1-hour ex vivo lung perfusion. Before ex vivo lung perfusion, 4e11 viral genome luciferase encoding adeno-associated vector 9 was administered via the left bronchus (Br group, n = 4), via the left pulmonary artery (PA group, n = 3), or directly into the circuit (Circuit group, n = 3). Donor lungs in the Control group (n = 3) underwent ex vivo lung perfusion without adeno-associated vector 9. Only the left lung was transplanted. Animals underwent bioluminescence imaging weekly before being killed at 2 weeks. Tissues were collected for luciferase activity measurement. RESULTS: All recipients tolerated the transplant well. At 2 weeks post-transplant, luciferase activity in the transplanted lung was significantly higher among animals in the Br group compared with the other 3 groups (Br: 1.1 × 106 RLU/g, PA: 8.3 × 104 RLU/g, Circuit: 3.8 × 103 RLU/g, Control: 2.5 × 103 RLU/g, P = .0003). No off-target transgene expression was observed. CONCLUSIONS: In this work, we demonstrate that a clinically relevant adeno-associated vector 9 vector mediates gene transduction during ex vivo lung perfusion in rat lung grafts when administered via the airway and potentially the pulmonary artery. Our preliminary results suggest a higher transduction efficiency when adeno-associated vector 9 was delivered via the airway, and delivery during ex vivo lung perfusion reduces off-target effects after graft implant.


Asunto(s)
Trasplante de Pulmón , Roedores , Ratas , Animales , Perfusión/métodos , Pulmón , Trasplante de Pulmón/métodos , Luciferasas/genética , Luciferasas/metabolismo , Luciferasas/farmacología
12.
Transplant Cell Ther ; 30(2): 171-186, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37866783

RESUMEN

Chimeric antigen receptor T cell (CAR-T) immunotherapy has revolutionized the treatment of relapsed and refractory B cell-derived hematologic malignancies. Currently, there are 6 Food and Drug Administration-approved commercial CAR-T products that target antigens exclusively expressed on malignant B cells or plasma cells. However, concurrent advancement for patients with rarer and more aggressive T cell-derived hematologic malignancies have not yet been achieved. CAR-T immunotherapies are uniquely limited by challenges related to CAR-T product manufacturing and intrinsic tumor biology. In this review tailored for practicing clinician-scientists, we discuss the major barriers of CAR-T implementation against T cell-derived neoplasms and highlight specific scientific advancements poised to circumvent these obstacles. We summarize salient early-stage clinical trials implementing novel CAR-T immunotherapies specifically for patients with relapsed and/or refractory T cell neoplasms. Finally, we highlight novel manufacturing and treatment strategies that are poised to have a meaningful future clinical impact.


Asunto(s)
Neoplasias Hematológicas , Neoplasias , Receptores Quiméricos de Antígenos , Estados Unidos , Humanos , Linfocitos T , Receptores de Antígenos de Linfocitos T/genética , Inmunoterapia/efectos adversos , Neoplasias Hematológicas/terapia
13.
Plant Physiol ; 194(1): 168-189, 2023 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-37862163

RESUMEN

Oat (Avena sativa) is a cereal crop whose grains are rich in (1,3;1,4)-ß-D-glucan (mixed-linkage glucan or MLG), a soluble dietary fiber. In our study, we analyzed oat endosperm development in 2 Canadian varieties with differing MLG content and nutritional value. We confirmed that oat undergoes a nuclear type of endosperm development but with a shorter cellularization phase than barley (Hordeum vulgare). Callose and cellulose were the first polysaccharides to be detected in the early anticlinal cell walls at 11 days postemergence (DPE) of the panicle. Other polysaccharides such as heteromannan and homogalacturonan were deposited early in cellularization around 12 DPE after the first periclinal walls are laid down. In contrast to barley, heteroxylan deposition coincided with completion of cellularization and was detected from 14 DPE but was only detectable after demasking. Notably, MLG was the last polysaccharide to be laid down at 18 DPE within the differentiation phase, rather than during cellularization. In addition, differences in the spatiotemporal patterning of MLG were also observed between the 2 varieties. The lower MLG-containing cultivar AC Morgan (3.5% w/w groats) was marked by the presence of a discontinuous pattern of MLG labeling, while labeling in the same walls in CDC Morrison (5.6% w/w groats) was mostly even and continuous. RNA-sequencing analysis revealed higher transcript levels of multiple MLG biosynthetic cellulose synthase-like F (CSLF) and CSLH genes during grain development in CDC Morrison compared with AC Morgan that likely contributes to the increased abundance of MLG at maturity in CDC Morrison. CDC Morrison was also observed to have smaller endosperm cells with thicker walls than AC Morgan from cellularization onwards, suggesting the processes controlling cell size and shape are established early in development. This study has highlighted that the molecular processes influencing MLG content and deposition are more complex than previously imagined.


Asunto(s)
Endospermo , Hordeum , Endospermo/metabolismo , Avena , Grano Comestible/genética , Grano Comestible/metabolismo , Canadá , Polisacáridos/metabolismo , Glucanos/metabolismo , Hordeum/genética , Hordeum/metabolismo , Pared Celular/metabolismo
14.
Methods Mol Biol ; 2698: 233-257, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37682479

RESUMEN

The inference of gene regulatory networks can reveal molecular connections underlying biological processes and improve our understanding of complex biological phenomena in plants. Many previous network studies have inferred networks using only one type of omics data, such as transcriptomics. However, given more recent work applying multi-omics integration in plant biology, such as combining (phospho)proteomics with transcriptomics, it may be advantageous to integrate multiple omics data types into a comprehensive network prediction. Here, we describe a state-of-the-art approach for integrating multi-omics data with gene regulatory network inference to describe signaling pathways and uncover novel regulators. We detail how to download and process transcriptomics and (phospho)proteomics data for network inference, using an example dataset from the plant hormone signaling field. We provide a step-by-step protocol for inference, visualization, and analysis of an integrative multi-omics network using currently available methods. This chapter serves as an accessible guide for novice and intermediate bioinformaticians to analyze their own datasets and reanalyze published work.


Asunto(s)
Perfilación de la Expresión Génica , Multiómica , Redes Reguladoras de Genes , Reguladores del Crecimiento de las Plantas , Proteómica
15.
Exp Physiol ; 108(11): 1386-1399, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37731204

RESUMEN

The purpose of this study was to examine the effect of an acute bout of prolonged sitting with and without exercise breaks on cerebrovascular function in 7- to 13-year-old children. Forty-two children and adolescents were recruited to a crossover trial, with 15 girls (mean age 10.1 ± 2.5 years) and 16 boys (mean age 10.5 ± 1.3 years) completing the two trial conditions: SIT, uninterrupted sitting for 3 h and CYCLE, 3 h of sitting interrupted hourly with a 10-min moderate intensity exercise break. Cerebrovascular function was measured Pre and Post SIT and CYCLE from blood flow ( Q ̇ ${\dot{Q}}$ ), diameter, and shear rate of the internal carotid artery (ICA) at rest and in response to CO2 . Blood velocity in the middle (MCA) and posterior (PCA) cerebral arteries was assessed at rest, during a neurovascular coupling task (NVC) and in response to CO2 . We demonstrate that SIT but not CYCLE reduced ICA cerebrovascular reactivity to CO2 (%Δ ICA Q ̇ ${\dot{Q}}$ /Δ end-tidal CO2 : SIT: Pre 5.0 ± 2.4%/mmHg to Post 3.3 ± 2.8%/mmHg vs. CYCLE: Pre 4.4 ± 2.3%/mmHg to Post 5.3 ± 3.4%/mmHg, P = 0.05) and slowed the MCA blood velocity onset response time to hypercapnia (SIT: Pre 57.2 ± 32.6 s to Post 76.6 ± 55.2 s, vs. CYCLE: Pre 64.1 ± 40.4 s to Post 52.3 ± 28.8 s, P = 0.05). There were no changes in NVC. Importantly, breaking up prolonged sitting with hourly exercise breaks prevented the reductions in cerebrovascular reactivity to CO2 and the slowed intracranial blood velocity onset response time to hypercapnia apparent with uninterrupted sitting in children. NEW FINDINGS: What is the central question of this study? What are the effects of interrupting prolonged sitting on cerebrovascular function in children? What is the main finding and its importance? Prolonged sitting results in declines in cerebrovascular reactivity, a valuable index of cerebrovascular health. Breaking up prolonged sitting with hourly 10 min exercise breaks prevented these changes. These initial findings suggest excessive sedentary behaviour does impact cerebrovascular function in childhood, but taking exercise breaks prevents declines.


Asunto(s)
Dióxido de Carbono , Hipercapnia , Masculino , Femenino , Adolescente , Humanos , Niño , Ejercicio Físico/fisiología , Circulación Cerebrovascular/fisiología , Estudios Cruzados
16.
Int J Sports Physiol Perform ; 18(9): 1053-1061, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37553108

RESUMEN

PURPOSE: To investigate the effects of a training camp with heat and/or hypoxia sessions on hematological and thermoregulatory adaptations. METHODS: Fifty-six elite male rugby players completed a 2-week training camp with 5 endurance and 5 repeated-sprint sessions, rugby practice, and resistance training. Players were separated into 4 groups: CAMP trained in temperate conditions at sea level, HEAT performed the endurance sessions in the heat, ALTI slept and performed the repeated sprints at altitude, and H + A was a combination of the heat and altitude groups. RESULTS: Blood volume across all groups increased by 140 mL (95%CI, 42-237; P = .006) and plasma volume by 97 mL (95%CI 28-167; P = .007) following the training camp. Plasma volume was 6.3% (0.3% to 12.4%) higher in HEAT than ALTI (P = .034) and slightly higher in HEAT than H + A (5.6% [-0.3% to 11.7%]; P = .076). Changes in hemoglobin mass were not significant (P = .176), despite a ∼1.2% increase in ALTI and H + A and a ∼0.7% decrease in CAMP and HEAT. Peak rectal temperature was lower during a postcamp heat-response test in HEAT (0.3 °C [0.1-0.5]; P = .010) and H + A (0.3 °C [0.1-0.6]; P = .005). Oxygen saturation upon waking was lower in ALTI (3% [2% to 5%]; P < .001) and H + A (4% [3% to 6%]; P < .001) than CAMP and HEAT. CONCLUSION: Although blood and plasma volume increased following the camp, sleeping at altitude impeded the increase when training in the heat and only marginally increased hemoglobin mass. Heat training induced adaptations commensurate with partial heat acclimation; however, combining heat training and altitude training and confinement during a training camp did not confer concomitant hematological adaptations.


Asunto(s)
Aclimatación , Rugby , Humanos , Masculino , Aclimatación/fisiología , Adaptación Fisiológica , Hipoxia , Hemoglobinas , Calor
17.
J Athl Train ; 58(5): 423-429, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37523420

RESUMEN

CONTEXT: Deficits in plyometric abilities are common after anterior cruciate ligament reconstruction (ACLR). Vertical rebound tasks may provide a targeted evaluation of knee function. OBJECTIVE: To examine the utility of a vertical hop test for assessing function after ACLR and establishing factors associated with performance. DESIGN: Cross-sectional study. SETTING: Rehabilitation program. PATIENTS OR OTHER PARTICIPANTS: Soccer players with a history of ACLR (n = 73) and matched control individuals (n = 195). MAIN OUTCOME MEASURE(S): The 10-second vertical hop test provided measures of jump height, the Reactive Strength Index (RSI), and asymmetry. We also examined possible predictors of hop performance, including single-legged vertical drop jump, isokinetic knee-extension strength, and the International Knee Documentation Committee questionnaire score. RESULTS: Between-limbs differences were identified only for the ACLR group, and asymmetry scores increased in those with a history of ACLR (P < .001) compared with the control group. The single-legged vertical drop jump, RSI, and knee-extension torque were significant predictors of 10-second hop height (R2 = 20.1%) and RSI (R2 = 47.1%). CONCLUSIONS: Vertical hop deficits were present after ACLR, even after participants completed a comprehensive rehabilitation program. This may have been due to reduced knee-extension and reactive strength. Vertical hop tests warrant inclusion as part of the return-to-sport test battery.

18.
Nucleic Acids Res ; 51(15): 7798-7819, 2023 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-37351575

RESUMEN

Seeds are a vital source of calories for humans and a unique stage in the life cycle of flowering plants. During seed germination, the embryo undergoes major developmental transitions to become a seedling. Studying gene expression in individual seed cell types has been challenging due to the lack of spatial information or low throughput of existing methods. To overcome these limitations, a spatial transcriptomics workflow was developed for germinating barley grain. This approach enabled high-throughput analysis of spatial gene expression, revealing specific spatial expression patterns of various functional gene categories at a sub-tissue level. This study revealed over 14 000 genes differentially regulated during the first 24 h after imbibition. Individual genes, such as the aquaporin gene family, starch degradation, cell wall modification, transport processes, ribosomal proteins and transcription factors, were found to have specific spatial expression patterns over time. Using spatial autocorrelation algorithms, we identified auxin transport genes that had increasingly focused expression within subdomains of the embryo over time, suggesting their role in establishing the embryo axis. Overall, our study provides an unprecedented spatially resolved cellular map for barley germination and identifies specific functional genomics targets to better understand cellular restricted processes during germination. The data can be viewed at https://spatial.latrobe.edu.au/.


Asunto(s)
Hordeum , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Germinación/genética , Hordeum/genética , Hordeum/metabolismo , Semillas/genética , Semillas/metabolismo , Factores de Transcripción/metabolismo , Transcriptoma/genética
19.
Harmful Algae ; 125: 102432, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37220985

RESUMEN

Remote sensing using satellite imagery has been promoted as a method to broaden the scale and frequency of cyanobacterial monitoring. This relies on the ability to establish relationships between the reflectance spectra of water bodies and the abundance of cyanobacteria. A challenge to achieving this comes from a limited understanding of the extent to which the optical properties of cyanobacteria vary according to their physiological state and growth environment. The aim of the present study was to determine how growth stage, nutrient status and irradiance affect pigment concentrations and absorption spectra in two common bloom forming cyanobacterial taxa: Dolichospermum lemmermannii and Microcystis aeruginosa. Each species was grown in laboratory batch culture under a full factorial design of low or high light intensity and low, medium, or high nitrate concentrations. Absorption spectra, pigment concentrations and cell density were measured throughout the growth phases. The absorption spectra were all highly distinguishable from each other, with greater interspecific than intraspecific differences, indicating that both D. lemmermannii and M. aeruginosa can be readily differentiated using hyperspectral absorption spectra. Despite this, each species exhibited different responses in the per-cell pigment concentrations with varying light intensity and nitrate exposure. Variability among treatments was considerably higher in D. lemmermannii than in M. aeruginosa, which exhibited smaller changes in pigment concentrations among the treatments. These results highlight the need to understand the physiology of the cyanobacteria and to take caution when estimating biovolumes from reflectance spectra when species composition and growth stage are unknown.


Asunto(s)
Cianobacterias , Microcystis , Nitratos , Nutrientes , Técnicas de Cultivo Celular por Lotes
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