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1.
Ecotoxicol Environ Saf ; 279: 116416, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38749195

RESUMO

Wetland plants play a crucial role in regulating soil geochemistry, influencing heavy metal (HM) speciation, bioavailability, and uptake, thus impacting phytoremediation potential. We hypothesized that variations in HM biogeochemistry within estuarine soils are controlled by distinct estuarine plant species. We evaluated the soils (pH, redox potential, rhizosphere pH, HM total concentration, and geochemical fractionation), plant parts (shoot and root), and iron plaques of three plants growing in an estuary affected by Fe-rich mine tailings. Though the integration of multiple plant and soil analysis, this work emphasizes the importance of considering geochemical pools of HM for predicting their fate. Apart from the predominance of HM associated with Fe oxides, Typha domingensis accumulated the highest Cr and Ni contents in their shoots (> 100 mg kg-1). In contrast, Hibiscus tiliaceus accumulated more Cu and Pb in their roots (> 50 mg kg-1). The differences in rhizosphere soil conditions and root bioturbation explained the different potentials between the plants by altering the soil dynamics and HM's bioavailability, ultimately affecting their uptake. This study suggests that Eleocharis acutangula is not suitable for phytoextraction or phytostabilization, whereas Typha domingensis shows potential for Cr and Ni phytoextraction. In addition, we first showed Hibiscus tiliaceus as a promising wood species for Cu and Pb phytostabilization.


Assuntos
Biodegradação Ambiental , Estuários , Metais Pesados , Poluentes do Solo , Solo , Typhaceae , Áreas Alagadas , Metais Pesados/metabolismo , Metais Pesados/análise , Poluentes do Solo/metabolismo , Poluentes do Solo/análise , Typhaceae/metabolismo , Solo/química , Rizosfera , Raízes de Plantas/metabolismo , Mineração
2.
Pediatr Exerc Sci ; : 1-8, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38925533

RESUMO

PURPOSE: To examine the effect of normobaric hypoxia on pulmonary oxygen uptake (V˙O2) and muscle oxygenation kinetics during incremental and moderate-intensity exercise in children. METHODS: Eight prepubertal boys (9-11 y) performed incremental cycle tests to exhaustion in both normoxia and hypoxia (fraction of inspired O2 of 15%) followed by repeat 6-minute transitions of moderate-intensity exercise in each condition over subsequent visits. RESULTS: Maximal oxygen uptake (V˙O2max) was reduced in hypoxia compared with normoxia (1.69 [0.20] vs 1.87 [0.26] L·min-1, P = .028), although the gas exchange threshold was not altered in absolute terms (P = .33) or relative to V˙O2max (P = .78). During moderate-intensity exercise, the phase II V˙O2 time constant (τ) was increased in hypoxia (18 [9] vs 24 [8] s, P = .025), with deoxyhemoglobin τ unchanged (17 [8] vs 16 [6], P ≥ .28). CONCLUSIONS: In prepubertal boys, hypoxia reduced V˙O2max and slowed V˙O2 phase II kinetics during moderate-intensity exercise, despite unchanged deoxyhemoglobin kinetics. These data suggest an oxygen delivery dependence of V˙O2max and moderate-intensity V˙O2 kinetics under conditions of reduced oxygen availability in prepubertal boys.

3.
BMC Med Educ ; 24(1): 33, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38183007

RESUMO

BACKGROUND: Academic publishing is a cornerstone of scholarly communications, yet is unfortunately open to abuse, having given rise to 'predatory publishers'- groups that employ aggressive marketing tactics, are deficient in methods and ethics, and bypass peer review. Preventing these predatory publishers from infiltrating scholarly activity is of high importance, and students must be trained in this area to increase awareness and reduce use. The scope of this issue in the context of medical students remains unknown, and therefore this sought to examine the breadth of the current literature base. METHODS: A rapid scoping review was undertaken, adhering to adapted PRISMA guidelines. Six databases (ASSIA, EBSCO, Ovid, PubMed, Scopus, Web of Science) were systematically searched for content related to predatory publishing and medical students. Results were single-screened, facilitated by online reviewing software. Resultant data were narratively described, with common themes identified. RESULTS: After searching and screening, five studies were included, representing a total of 1338 students. Two predominant themes- understanding, and utilisation- of predatory publishers was identified. These themes revealed that medical students were broadly unaware of the issue of predatory publishing, and that a small number have already, or would consider, using their services. CONCLUSION: There remains a lack of understanding of the threat that predatory publishers pose amongst medical students. Future research and education in this domain will be required to focus on informing medical students on the issue, and the implication of engaging with predatory publishers.


Assuntos
Educação Médica , Humanos , Agressão , Bases de Dados Factuais , Editoração , Estudantes
4.
Ann Surg Oncol ; 30(3): 1614-1625, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36183015

RESUMO

BACKGROUND: In esophageal cancer (EC), there is a paucity of knowledge regarding the interplay between the tumor immune microenvironment and response to neoadjuvant treatment and, therefore, which factors may influence outcomes. Thus, our goal was to investigate the changes in the immune microenvironment with neoadjuvant treatment in EC by assessing the expression of immune related genes and their association with prognosis. METHODS: We examined the transcriptome of paired pre- and post-neoadjuvant treated EC specimens. Based on these findings, we validated the presence of tumor-infiltrating neutrophils using CD15+ immunohistochemistry in a discovery cohort of patients with residual pathologic disease. We developed a nomogram as a predictor of progression-free survival (PFS) incorporating the variables CD15+ cell count, tumor regression grade, and tumor grade. RESULTS: After neoadjuvant treatment, there was an increase in genes related to myeloid cell differentiation and a poor prognosis associated with high neutrophil (CD15+) counts. Our nomogram incorporating CD15+ cell count was predictive of PFS with a C-index of 0.80 (95% confidence interval [CI] 0.68-0.9) and a concordance probability estimate (CPE) of 0.77 (95% CI 0.69-0.86), which indicates high prognostic ability. The C-index and CPE of the validation cohort were 0.81 (95% CI 0.69-0.91) and 0.78 (95% CI 0.7-0.86), respectively. CONCLUSIONS: Our nomogram incorporating CD15+ cell count can potentially be used to identify patients at high risk of recurrent disease and thus stratify patients who will benefit most from adjuvant treatment.


Assuntos
Neoplasias Esofágicas , Neutrófilos , Humanos , Neutrófilos/patologia , Terapia Neoadjuvante , Neoplasias Esofágicas/patologia , Prognóstico , Nomogramas , Microambiente Tumoral
5.
Glob Chang Biol ; 29(8): 2092-2107, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36625070

RESUMO

Warming temperatures and diminishing dissolved oxygen (DO) concentrations are among the most pervasive drivers of global coastal change. While regions of the Northwest Atlantic Ocean are experiencing greater than average warming, the combined effects of thermal and hypoxic stress on marine life in this region are poorly understood. Populations of the northern bay scallop, Argopecten irradians irradians across the northeast United States have experienced severe declines in recent decades. This study used a combination of high-resolution (~1 km) satellite-based temperature records, long-term temperature and DO records, field and laboratory experiments, and high-frequency measures of scallop cardiac activity in an ecosystem setting to quantify decadal summer warming and assess the vulnerability of northern bay scallops to thermal and hypoxic stress across their geographic distribution. From 2003 to 2020, significant summer warming (up to ~0.2°C year-1 ) occurred across most of the bay scallop range. At a New York field site in 2020, all individuals perished during an 8-day estuarine heatwave that coincided with severe diel-cycling hypoxia. Yet at a Massachusetts site with comparable DO levels but lower daily mean temperatures, mortality was not observed. A 96-h laboratory experiment recreating observed daily temperatures of 25 or 29°C, and normoxia or hypoxia (22.2% air saturation), revealed a 120-fold increased likelihood of mortality in the 29°C-hypoxic treatment compared with control conditions, with scallop clearance rates also reduced by 97%. Cardiac activity measurements during a field deployment indicated that low DO and elevated daily temperatures modulate oxygen consumption rates and likely impact aerobic scope. Collectively, these findings suggest that concomitant thermal and hypoxic stress can have detrimental effects on scallop physiology and survival and potentially disrupt entire fisheries. Recovery of hypoxic systems may benefit vulnerable fisheries under continued warming.


Assuntos
Pesqueiros , Pectinidae , Humanos , Animais , Ecossistema , Hipóxia , New York
6.
Biometals ; 35(1): 87-98, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34837588

RESUMO

Molybdenum (Mo) is an essential trace element for bacteria that is utilized in myriad metalloenzymes that directly couple to the biogeochemical cycling of nitrogen, sulfur, and carbon. In particular, Mo is found in the most common nitrogenase enzyme, and the scarcity and low bioavailability of Mo in soil may be a critical factor that contributes to the limitation of nitrogen fixation in forests and agroenvironments. To overcome this scarcity, microbes produce exudates that specifically chelate scarce metals, promoting their solubilization and uptake. Here, we have determined the structure and stability constants of Mo bound by protochelin, a siderophore produced by bacteria under Mo-depleted conditions. Spectrophotometric titration spectra indicated a coordination shift from a catecholate to salicylate binding mode for MoVI-protochelin (Mo-Proto) complexes at pH < 5. pKa values obtained from analysis of titrations were 4.8 ± 0.3 for MoVIO2H3Proto- and 3.3 ± 0.1 for MoVIO2H4Proto. The occurrence of negatively charged Mo-Proto complexes at pH 6 was also confirmed by mass spectrometry. K-edge Extended X-ray absorption fine structure spectroscopy confirmed the change in Mo coordination at low pH, and structural fitting provides insights into the physical architecture of complexes at neutral and acidic pH. These findings suggest that Mo can be chelated by protochelin across a wide environmental pH range, with a coordination shift occurring at pH < 5. This chelation and associated coordination shift may impact biological availability and mineral surface retention of Mo under acidic conditions.


Assuntos
Complexos de Coordenação , Oligoelementos , Complexos de Coordenação/química , Molibdênio/química , Salicilatos , Sideróforos/química
7.
BMC Pulm Med ; 22(1): 485, 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36550475

RESUMO

BACKGROUND: Cardiopulmonary exercise testing (CPET), and its primary outcome of peak oxygen uptake (VO2peak), are acknowledged as biomarkers in the diagnostic and prognostic management of interstitial lung disease (ILD). However, the validity and repeatability of CPET in those with ILD has yet to be fully characterised, and this study fills this evidence gap. METHODS: Twenty-six people with ILD were recruited, and 21 successfully completed three CPETs. Of these, 17 completed two valid CPETs within a 3-month window, and 11 completed two valid CPETs within a 6-month window. Technical standards from the European Respiratory Society established validity, and repeatability was determined using mean change, intraclass correlation coefficient and typical error. RESULTS: Every participant (100%) who successfully exercised to volitional exhaustion produced a maximal, and therefore valid, CPET. Approximately 20% of participants presented with a plateau in VO2, the primary criteria for establishing a maximal effort. The majority of participants otherwise presented with secondary criteria of respiratory exchange ratios in excess of 1.05, and maximal heart rates in excess of their predicted values. Repeatability analyses identified that the typical error (expressed as percent of coefficient of variation) was 20% over 3-months in those reaching volitional exhaustion. CONCLUSION: This work has, for the first time, fully characterised how patients with ILD respond to CPET in terms of primary and secondary verification criteria, and generated novel repeatability data that will prove useful in the assessment of disease progression, and future evaluation of therapeutic regimens where VO2peak is used as an outcome measure.


Assuntos
Teste de Esforço , Doenças Pulmonares Intersticiais , Humanos , Testes de Função Respiratória , Fenômenos Fisiológicos Respiratórios , Doenças Pulmonares Intersticiais/diagnóstico , Consumo de Oxigênio/fisiologia
8.
Chron Respir Dis ; 19: 14799731221121670, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36068015

RESUMO

BACKGROUND: The roles of physical activity (PA) and exercise within the management of cystic fibrosis (CF) are recognised by their inclusion in numerous standards of care and treatment guidelines. However, information is brief, and both PA and exercise as multi-faceted behaviours require extensive stakeholder input when developing and promoting such guidelines. METHOD: On 30th June and 1st July 2021, 39 stakeholders from 11 countries, including researchers, healthcare professionals and patients participated in a virtual conference to agree an evidence-based and informed expert consensus about PA and exercise for people with CF. This consensus presents the agreement across six themes: (i) patient and system centred outcomes, (ii) health benefits, iii) measurement, (iv) prescription, (v) clinical considerations, and (vi) future directions. The consensus was achieved by a stepwise process, involving: (i) written evidence-based synopses; (ii) peer critique of synopses; (iii) oral presentation to consensus group and peer challenge of revised synopses; and (iv) anonymous voting on final proposed synopses for adoption to the consensus statement. RESULTS: The final consensus document includes 24 statements which surpassed the consensus threshold (>80% agreement) out of 30 proposed statements. CONCLUSION: This consensus can be used to support health promotion by relevant stakeholders for people with CF.


Assuntos
Fibrose Cística , Consenso , Fibrose Cística/terapia , Exercício Físico , Promoção da Saúde , Humanos
9.
Lab Invest ; 101(1): 26-37, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873880

RESUMO

Most NUTM1-rearranged neoplasms (NRNs) have fusions between NUTM1 and BRD (bromodomain-containing) family members and are termed NUT carcinomas (NCs) because they show some squamous differentiation. However, some NRNs are associated with fusions between NUTM1 and members of the MAD (MAX dimerization) gene family of MYC antagonists. Here we describe a small round cell malignancy from the gastro-esophageal junction with a previously unreported fusion between NUTM1 and the MAD family member MXI1. In contrast to NCs, the MXI1-NUTM1 tumor did not show squamous differentiation and did not express MYC, TP63 or SOX2, genes known to be targets of BRD-NUTM1 proteins and critical for NC oncogenesis. Transcriptome analysis showed paradoxical enrichment of MYC target genes in the MXI1-NUTM1 tumor despite the lack of MYC expression. When expressed in vitro MXI1-NUTM1 partially phenocopied MYC, enhancing cell proliferation and cooperating with oncogenic HRAS to produce anchorage-independent cell growth. These data provide evidence that MAD family members, which are normally repressors of MYC activity, can be converted into MYC-like mimics by fusion to NUTM1. The pathological features and novel oncogenic mechanism of the MXI1-NUTM1 tumor show that identification of NUTM1 fusion partners can be important for accurate diagnostic classification of some NRN subtypes, and potentially may guide therapeutic options.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Neoplasias Esofágicas/genética , Junção Esofagogástrica/patologia , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Neoplasias Gástricas/genética , Proteínas Supressoras de Tumor/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade , Proteínas de Fusão Oncogênica , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Transcriptoma
10.
Genes Chromosomes Cancer ; 59(6): 375-385, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32060986

RESUMO

Structural alterations of NUTM1 were originally thought to be restricted to poorly differentiated carcinomas with variable squamous differentiation originating in the midline organs of children and adolescents. Termed NUT carcinomas (NCs), they were defined by a t(15;19) chromosomal rearrangement that was found to result in a BRD4-NUTM1 gene fusion. However, the use of DNA and RNA-based next-generation sequencing has recently revealed a multitude of new NUTM1 fusion partners in a diverse array of neoplasms including sarcoma-like tumors, poromas, and acute lymphoblastic leukemias (ALLs) that we propose to call NUTM1-rearranged neoplasms (NRNs). Intriguingly, the nosology of NRNs often correlates with the functional classification of the fusion partner, suggesting different oncogenic mechanisms within each NRN division. Indeed, whereas NCs are characterized by their aggressiveness and intransigence to standard therapeutic measures, the more positive clinical outcomes seen in some sarcoma and ALL NRNs may reflect these mechanistic differences. Here we provide a broad overview of the molecular, nosological, and clinical features in these newly discovered neoplastic entities. We describe how aberrant expression of NUTM1 due to fusion with an N-terminal DNA/chromatin-binding protein can generate a potentially powerful chromatin modifier that can give rise to oncogenic transformation in numerous cellular contexts. We also conclude that classification, clinical behavior, and therapeutic options may be best defined by the NUTM1 fusion partner rather than by tumor morphology or immunohistochemical profile.


Assuntos
Carcinoma/genética , Rearranjo Gênico , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Sarcoma/genética , Carcinoma/patologia , Fusão Gênica , Humanos , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Sarcoma/patologia
11.
Mod Pathol ; 33(9): 1811-1821, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32358589

RESUMO

There is now evidence that gene fusions activating the MAPK pathway are relatively common in pancreatic acinar cell carcinoma with potentially actionable BRAF or RET fusions being found in ~30%. We sought to investigate the incidence of RAF1 fusions in pancreatic malignancies with acinar cell differentiation. FISH testing for RAF1 was undertaken on 30 tumors comprising 25 'pure' acinar cell carcinomas, 2 mixed pancreatic acinar-neuroendocrine carcinomas, 1 mixed acinar cell-low grade neuroendocrine tumor and 2 pancreatoblastomas. RAF1 rearrangements were identified in 5 cases and confirmed by DNA and RNA sequencing to represent oncogenic fusions (GATM-RAF1, GOLGA4-RAF1, PDZRN3-RAF1, HERPUD1-RAF1 and TRIM33-RAF1) and to be mutually exclusive with BRAF and RET fusions, as well as KRAS mutations. Large genome-wide copy number changes were common and included 1q gain and/or 1p loss in all five RAF1 FISH-positive acinar cell carcinomas. RAF1 expression by immunohistochemistry was found in 3 of 5 (60%) of fusion-positive cases and no FISH-negative cases. Phospho-ERK1/2 expression was found in 4 of 5 RAF1-fusion-positive cases. Expression of both RAF1 and phospho-ERK1/2 was heterogeneous and often only detected at the tumor-stroma interface, thus limiting their clinical utility. We conclude that RAF1 gene rearrangements are relatively common in pancreatic acinar cell carcinomas (14.3% to 18.5% of cases) and can be effectively identified by FISH with follow up molecular testing. The combined results of several studies now indicate that BRAF, RET or RAF1 fusions occur in between one third and one-half of these tumors but are extremely rare in other pancreatic malignancies. As these fusions are potentially actionable with currently available therapies, a strong argument can be made to perform FISH or molecular testing on all pancreatic acinar cell carcinomas.


Assuntos
Carcinoma de Células Acinares/genética , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas c-raf/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Acinares/patologia , Bases de Dados Factuais , Feminino , Fusão Gênica , Rearranjo Gênico , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Adulto Jovem
12.
Environ Sci Technol ; 54(5): 2951-2960, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32023050

RESUMO

Permafrost contains a large (1700 Pg C) terrestrial pool of organic matter (OM) that is susceptible to degradation as global temperatures increase. Of particular importance is syngenetic Yedoma permafrost containing high OM content. Reactive iron phases promote stabilizing interactions between OM and soil minerals and this stabilization may be of increasing importance in permafrost as the thawed surface region ("active layer") deepens. However, there is limited understanding of Fe and other soil mineral phase associations with OM carbon (C) moieties in permafrost soils. To elucidate the elemental associations involved in organomineral complexation within permafrost systems, soil cores spanning a Pleistocene permafrost chronosequence (19,000, 27,000, and 36,000 years old) were collected from an underground tunnel near Fairbanks, Alaska. Subsamples were analyzed via scanning transmission X-ray microscopy-near edge X-ray absorption fine structure spectroscopy at the nano- to microscale. Amino acid-rich moieties decreased in abundance across the chronosequence. Strong correlations between C and Fe with discrete Fe(III) or Fe(II) regions selectively associated with specific OM moieties were observed. Additionally, Ca coassociated with C through potential cation bridging mechanisms. Results indicate Fe(III), Fe(II), and mixed valence phases associated with OM throughout diverse permafrost environments, suggesting that organomineral complexation is crucial to predict C stability as permafrost systems warm.


Assuntos
Pergelissolo , Alaska , Carbono , Compostos Férricos , Solo
13.
BMC Pulm Med ; 20(1): 23, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992237

RESUMO

BACKGROUND: Recent research has proposed an association between desaturation during a six minute walking test (6MWT) and osteoporosis in an elderly group of individuals with non-cystic fibrosis bronchiectasis. A causative pathway through activation of hypoxia-inducible factor 1-alpha (HIF-1α) has been proposed. COMMENTARY: Queries regarding the statistical approaches used are identified and discussed within this correspondence. These predominate around the use of linear regression models to predict osteoporosis in a group that is already osteoporotic, presenting with extreme values for bone mineral density (BMD). Further queries are raised regarding the HIF-1α pathway, and physical activity (PA) is proposed as an upstream mechanism for both reduced exercise tolerance and low BMD. CONCLUSIONS: It is suggested that osteoporosis cannot be predicted in a group that is already osteoporotic, and that PA is likely to be the causative mechanism between desaturation in the 6MWT and low BMD in non-cystic fibrosis bronchiectasis.


Assuntos
Bronquiectasia , Osteoporose , Idoso , Densidade Óssea , Exercício Físico , Tolerância ao Exercício , Humanos
14.
J Biol Chem ; 293(19): 7099-7107, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29483194

RESUMO

The key regulatory enzymes of glycogenolysis are phosphorylase kinase, a hetero-oligomer with four different types of subunits, and glycogen phosphorylase, a homodimer. Both enzymes are activated by phosphorylation and small ligands, and both enzymes have distinct isoforms that are predominantly expressed in muscle, liver, or brain; however, whole-transcriptome high-throughput sequencing analyses show that in brain both of these enzymes are likely composed of subunit isoforms representing all three tissues. This Minireview examines the regulatory properties of the isoforms of these two enzymes expressed in the three tissues, focusing on their potential regulatory similarities and differences. Additionally, the activity, structure, and regulation of the remaining enzyme necessary for glycogenolysis, glycogen-debranching enzyme, are also reviewed.


Assuntos
Encéfalo/enzimologia , Encéfalo/metabolismo , Glicogênio Fosforilase/metabolismo , Glicogenólise , Fosforilase Quinase/metabolismo , Animais , Metabolismo Energético , Glicogênio/metabolismo , Sistema da Enzima Desramificadora do Glicogênio/química , Sistema da Enzima Desramificadora do Glicogênio/metabolismo , Glicogênio Fosforilase/química , Ensaios de Triagem em Larga Escala , Humanos , Isoenzimas/metabolismo , Ligantes , Fosforilase Quinase/química , Fosforilação , Relação Estrutura-Atividade , Transcriptoma
15.
Phys Rev Lett ; 122(3): 035102, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30735422

RESUMO

The description of the local turbulent energy transfer and the high-resolution ion distributions measured by the Magnetospheric Multiscale mission together provide a formidable tool to explore the cross-scale connection between the fluid-scale energy cascade and plasma processes at subion scales. When the small-scale energy transfer is dominated by Alfvénic, correlated velocity, and magnetic field fluctuations, beams of accelerated particles are more likely observed. Here, for the first time, we report observations suggesting the nonlinear wave-particle interaction as one possible mechanism for the energy dissipation in space plasmas.

16.
BMC Pulm Med ; 19(1): 253, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856791

RESUMO

BACKGROUND: Regular participation in physical activity by people with cystic fibrosis (CF) promotes positive clinical and health outcomes including reduced rate of decline in lung function, fewer hospitalizations and greater wellbeing. However adherence to exercise and activity programs is low, in part due to the substantial daily therapy burden for young people with CF. Strict infection control requirements limit the role of group exercise programs that are commonly used in other clinical groups. Investigation of methods to promote physical activity in this group has been limited. The Active Online Physical Activity in Cystic fibrosis Trial (ActionPACT) is an assessor-blinded, multi-centre, randomized controlled trial designed to compare the efficacy of a novel web-based program (ActivOnline) compared to usual care in promoting physical activity participation in adolescents and young adults with CF. METHODS: Adolescents and young adults with CF will be recruited on discharge from hospital for a respiratory exacerbation. Participants randomized to the intervention group will have access to a web-based physical activity platform for the 12-week intervention period. ActivOnline allows users to track their physical activity, set goals, and self-monitor progress. All participants in both groups will be provided with standardised information regarding general physical activity recommendations for adolescents and young adults. Outcomes will be assessed by a blinded assessor at baseline, after completion of the intervention, and at 3-months followup. Healthcare utilization will be assessed at 12 months from intervention completion. The primary outcome is change in moderate-to-vigorous physical activity participation measured objectively by accelerometry. Secondary outcomes include aerobic fitness, health-related quality of life, anxiety and depression and sleep quality. DISCUSSION: This trial will establish whether a web-based application can improve physical activity participation more effectively than usual care in the period following hospitalization for a respiratory exacerbation. The web-based application under investigation can be made readily and widely available to all individuals with CF, to support physical activity and exercise participation at a time and location of the user's choosing, regardless of microbiological status. TRIAL REGISTRATION: Clinical trial registered on July 13, 2017 with the Australian and New Zealand Clinical Trials Register at (ACTRN12617001009303).


Assuntos
Fibrose Cística/terapia , Exercício Físico , Intervenção Baseada em Internet , Acelerometria , Adolescente , Ansiedade , Depressão , Humanos , Aptidão Física , Qualidade de Vida , Sono , Adulto Jovem
17.
Pediatr Exerc Sci ; 31(2): 213-222, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30885084

RESUMO

Purpose: This study had 2 objectives: (1) to examine whether the validity of the supramaximal verification test for maximal oxygen uptake ( V˙O2max ) differs in children and adolescents when stratified for sex, body mass, and cardiorespiratory fitness and (2) to assess sensitivity and specificity of primary and secondary objective criteria from the incremental test to verify V˙O2max . Methods: In total, 128 children and adolescents (76 male and 52 females; age: 9.3-17.4 y) performed a ramp-incremental test to exhaustion on a cycle ergometer followed by a supramaximal test to verify V˙O2max . Results: Supramaximal tests verified V˙O2max in 88% of participants. Group incremental test peak V˙O2 was greater than the supramaximal test (2.27 [0.65] L·min-1 and 2.17 [0.63] L·min-1; P < .001), although both were correlated (r = .94; P < .001). No differences were found in V˙O2 plateau attainment or supramaximal test verification between sex, body mass, or cardiorespiratory fitness groups (all Ps > .18). Supramaximal test time to exhaustion predicted supramaximal test V˙O2max verification (P = .04). Primary and secondary objective criteria had insufficient sensitivity (7.1%-24.1%) and specificity (50%-100%) to verify V˙O2max . Conclusion: The utility of supramaximal testing to verify V˙O2max is not affected by sex, body mass, or cardiorespiratory fitness status. Supramaximal testing should replace secondary objective criteria to verify V˙O2max .


Assuntos
Teste de Esforço/métodos , Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Adolescente , Índice de Massa Corporal , Aptidão Cardiorrespiratória/fisiologia , Criança , Feminino , Humanos , Modelos Logísticos , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade , Fatores Sexuais
18.
Int J Mol Sci ; 20(13)2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31323913

RESUMO

We describe a 7-year-old male with high functioning autism spectrum disorder (ASD) and maternally-inherited rare missense variant of Synaptotagmin-like protein 4 (SYTL4) gene (Xq22.1; c.835C>T; p.Arg279Cys) and an unknown missense variant of Transmembrane protein 187 (TMEM187) gene (Xq28; c.708G>T; p. Gln236His). Multiple in-silico predictions described in our study indicate a potentially damaging status for both X-linked genes. Analysis of predicted atomic threading models of the mutant and the native SYTL4 proteins suggest a potential structural change induced by the R279C variant which eliminates the stabilizing Arg279-Asp60 salt bridge in the N-terminal half of the SYTL4, affecting the functionality of the protein's critical RAB-Binding Domain. In the European (Non-Finnish) population, the allele frequency for this variant is 0.00042. The SYTL4 gene is known to directly interact with several members of the RAB family of genes, such as, RAB27A, RAB27B, RAB8A, and RAB3A which are known autism spectrum disorder genes. The SYTL4 gene also directly interacts with three known autism genes: STX1A, SNAP25 and STXBP1. Through a literature-based analytical approach, we identified three of five (60%) autism-associated serum microRNAs (miRs) with high predictive power among the total of 298 mouse Sytl4 associated/predicted microRNA interactions. Five of 13 (38%) miRs were differentially expressed in serum from ASD individuals which were predicted to interact with the mouse equivalent Sytl4 gene. TMEM187 gene, like SYTL4, is a protein-coding gene that belongs to a group of genes which host microRNA genes in their introns or exons. The novel Q236H amino acid variant in the TMEM187 in our patient is near the terminal end region of the protein which is represented by multiple sequence alignments and hidden Markov models, preventing comparative structural analysis of the variant harboring region. Like SYTL4, the TMEM187 gene is expressed in the brain and interacts with four known ASD genes, namely, HCFC1; TMLHE; MECP2; and GPHN. TMM187 is in linkage with MECP2, which is a well-known determinant of brain structure and size and is a well-known autism gene. Other members of the TMEM gene family, TMEM132E and TMEM132D genes are associated with bipolar and panic disorders, respectively, while TMEM231 is a known syndromic autism gene. Together, TMEM187 and SYTL4 genes directly interact with recognized important ASD genes, and their mRNAs are found in extracellular vesicles in the nervous system and stimulate target cells to translate into active protein. Our evidence shows that both these genes should be considered as candidate genes for autism. Additional biological testing is warranted to further determine the pathogenicity of these gene variants in the causation of autism.


Assuntos
Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Encéfalo/metabolismo , Predisposição Genética para Doença/genética , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , MicroRNAs/genética , Mutação de Sentido Incorreto/genética , Ligação Proteica , Proteínas de Transporte Vesicular/genética
20.
Blood ; 128(13): 1735-44, 2016 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-27516441

RESUMO

To elucidate the mechanisms underlying relapse from chemotherapy in multiple myeloma, we performed a longitudinal study of 33 patients entered into Total Therapy protocols investigating them using gene expression profiling, high-resolution copy number arrays, and whole-exome sequencing. The study illustrates the mechanistic importance of acquired mutations in known myeloma driver genes and the critical nature of biallelic inactivation events affecting tumor suppressor genes, especially TP53, the end result being resistance to apoptosis and increased proliferation rates, which drive relapse by Darwinian-type clonal evolution. The number of copy number aberration changes and biallelic inactivation of tumor suppressor genes was increased in GEP70 high risk, consistent with genomic instability being a key feature of high risk. In conclusion, the study highlights the impact of acquired genetic events, which enhance the evolutionary fitness level of myeloma-propagating cells to survive multiagent chemotherapy and to result in relapse.


Assuntos
Evolução Clonal , Genes Supressores de Tumor , Mieloma Múltiplo/genética , Mutação , Adulto , Idoso , Proliferação de Células , Variações do Número de Cópias de DNA , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Genes p53 , Genes ras , Instabilidade Genômica , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Mieloma Múltiplo/patologia , Mieloma Múltiplo/terapia , Fosfatidilinositol 3-Quinases/genética , Recidiva , Fatores de Risco , Transplante de Células-Tronco , Transplante Autólogo
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