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PURPOSE: Given the substantial risk of treatment failure in inflammatory bowel disease (IBD), adjuvant therapies may play a role in disease management. We aim to carry out a systematic review to examine the effects of structured exercise on the inflammatory response in patients with IBD. Our secondary aim is to examine the effect of structured exercise programmes on body composition given both an increase in visceral obesity and the presence of sarcopenia have deleterious effects on outcomes in IBD. METHODS: A systematic review was carried out following the Methodological Expectations of Cochrane Intervention Reviews (MECIR) manual and the Cochrane Handbook for Systematic Reviews of Interventions. Title/Abstract and MeSH Terms were used to search for relevant studies. RESULTS: In total, 1516 records were screened for eligibility, and 148 records were reviewed for eligibility, of which 16 were included and a further 7 studies were identified from hand searching references. Four studies included body composition outcomes, and 14 studies reviewed the inflammatory response to exercise. CONCLUSION: Further studies of adequate duration are required to include patients with more active disease to demonstrate an inflammatory response to exercise. Body composition measurements including muscle mass and visceral adiposity may play a key role in response to medical therapy in IBD and should be included as exploratory outcomes in future studies. A meta-analysis was not carried out due to the significant heterogeneity amongst studies.
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Doenças Inflamatórias Intestinais , Humanos , Composição Corporal , Exercício Físico , Inflamação/complicações , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/terapiaRESUMO
OBJECTIVES: Written accounts, as well as a previous craniometric study, indicate that migrations of non-Europeans and conversions of Europeans to Islam define Ottoman communities in Early Modern Europe. What is less clear are the roles of migration and admixture in generating intra-communal variation. This study combines craniometric with strontium isotope data to compare the cranial affinities of locally born and immigrant individuals. We predict that locally born individuals are more likely than non-locals to show evidence of admixture. MATERIALS AND METHODS: Radiogenic strontium isotope data for 21 Ottomans were compared against archaeological faunal values. Sixteen individuals with intact crania were also measured and compared against two comparative source populations from Anatolia and Europe. Discriminant function analysis assigned unclassified Ottoans to either comparative group based on typicality probabilities, with potential admixture established via intermediate morphology between the two source populations. RESULTS: Strontium isotope values revealed relatively high proportions of non-locals, consistent with high mobility documented historically. The sexes differed, with more males classifying as "typically Anatolian" than females. Locals and non-locals also had different cranial affinity patterns, with most classifying either as "typically Anatolian" or "typically European." Contrary to expectation, none of the locals were identified as intermediate, suggesting admixture rates were relatively low. CONCLUSIONS: Consistent with historical records, the results revealed high levels of extra-regional migration, with most individuals identifiable as either typically Anatolian or European. Moreover, locals and non-locals differed craniometrically, with no signs of admixture between Anatolian migrants and European converts in locals. This suggests intra-communal divisions were maintained.
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Arqueologia , Crânio/anatomia & histologia , Isótopos de Estrôncio/análise , Antropologia Física , Cefalometria , História do Século XVI , História do Século XVII , Migração Humana , Humanos , RomêniaRESUMO
Historical records of mercury (Hg) deposition in lake sediments have commonly been used to monitor historic atmospheric concentrations. In the Australian environment, however, freshwater lakes are limited, restricting the region for which depositional archives of Hg can be derived. In this study we show that dendrochemistry can provide a record of atmospheric concentrations at very high resolution. We measured Hg concentrations in growth rings of two tree species from a site in western in Tasmania-Huon Pine ( Lagarostrobus franklinii) and Celery Top Pine ( Phyllocladus aspleniifolius). This region has been heavily mined over the past 150 years. Although much previous work has linked atmospheric Hg to gold mining, the evidence in this study suggests that copper smelters in Queenstown and Zeehan, not gold mining activities, were the main sources of Hg emissions to the atmosphere in this location. Huon Pine had significantly higher background Hg concentrations ( xÌ â¯= 5.62 ng/g) than Celery Top Pine ( xÌ â¯= 2.95 ng/g). No significant increase in Hg concentration during the peak copper smelting phase (1896 to 1935) was observed in Celery Top Pine, while a significant 1.4 fold-increase was observed in Huon Pine. Our results show that of species examined across the globe, Huon Pine is one of the most efficient bioaccumulators of Hg, making it a good proxy for tracking historical Hg emissions in western Tasmania. This ability to measure Hg in the environment is essential if Australia ratifies the Minamata Convention.
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Mercúrio , Austrália , Monitoramento Ambiental , Poluição Ambiental , Sedimentos Geológicos , Mineração , TasmâniaRESUMO
BACKGROUND: Mild cognitive impairment (MCI) is becoming an emerging problem for developing countries where there is an increase in expected age. There is no specific curative therapeutic treatment available for these patients. OBJECTIVE: The objective of this study was to evaluate short and long-term changes in the electroencephalogram (EEG) parameters and cognition of MCI patients with aerobic exercises. METHODS: A randomized controlled trial was conducted on 40 patients which were randomly divided into two groups, 'aerobic exercise treatment group (n = 21)' and 'no-aerobic control group (n = 19)'. Short-term effects of exercise were measured after single session of exercise and long-term effects were measured after an 18 sessions (6 weeks) treatment. The outcomes which were measured were, electroenphelogram paramaters (slowness and complexity of the EEG) and cognitive functions (using mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA), and trail making test (TMT) A and B). RESULTS: After one session of aerobic exercise there were significant improvements in slowness (delta waves; 0.678 ± 0.035 vs 0.791 ± 0.033; p = .015) and complexity (0.601 ± 0.051 vs 0.470 ± 0.042; p = .027) of the EEG in aerobic exercise treated group as compared to no-aerobic exercise group. After six weeks there were significant improvements in slowness (delta waves; 0.581 ± 0.036 vs 0.815 ± 0.025; p = .005) and complexity (0.751 ± 0.045 vs 0.533 ± 0.046; p = .001) of the EEG in the aerobic group as compared to no-aerobic group. Moreover, significant improvements were observed in the MMSE (p = .032), MoCA (p = .036), TMT-A (p = .005), and TMT-B (p = .007) in aerobic exercise group as compared to no-aerobic group. CONCLUSION: Aerobic exercise showed improvement in cognition after short and long-term treatment in MCI subjects and can be used as potential therapeutic candidate.
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Cognição , Disfunção Cognitiva/psicologia , Disfunção Cognitiva/terapia , Eletroencefalografia , Terapia por Exercício/métodos , Exercício Físico/fisiologia , Disfunção Cognitiva/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes NeuropsicológicosRESUMO
The effect of body posture on the human soleus H-reflex via electrical stimulation of the tibial nerve at the popliteal fossa was studied. All parameters that may influence the reflex were controlled stringently. H-reflexes were elicited in three different body postures while keeping the level of background muscle activation to a minimum. The H-reflex curve relative to the M-wave curve did not change significantly in any of the body postures. However, the maximal H-reflex amplitude significantly increased in the prone position compared with the sitting (p = 0.02) and standing positions (p = 0.01). The background level of electrical activity of the soleus muscle did not significantly change during varying body postures. Together, these findings indicate that the effectiveness of the spindle primary afferent synapse on the soleus motor neuron pool changes significantly in prone position as compared to sitting and standing positions. Given that we have controlled the confounding factors excluding the head position relative to the gravity and the receptors that may be differentially activated at varying body postures such as the proprioceptors, it is concluded that the tonic activity from these receptors may presynaptically interfere with the effectiveness of the spindle primary afferent synapses on the soleus motor neurons.
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Reflexo H/fisiologia , Neurônios Motores/fisiologia , Fusos Musculares/fisiologia , Músculo Esquelético/fisiologia , Postura/fisiologia , Adulto , Vias Aferentes/fisiologia , Estimulação Elétrica , Eletromiografia , Humanos , Masculino , Adulto JovemRESUMO
PURPOSE: The primary purpose of this study was to investigate whether a single session of spinal manipulation (SM) increases strength and cortical drive in the lower limb (soleus muscle) of elite Taekwondo athletes. METHODS: Soleus-evoked V-waves, H-reflex and maximum voluntary contraction (MVC) of the plantar flexors were recorded from 11 elite Taekwondo athletes using a randomized controlled crossover design. Interventions were either SM or passive movement control. Outcomes were assessed at pre-intervention and at three post-intervention time periods (immediate post, post 30 min and post 60 min). A multifactorial repeated measures ANOVA was conducted to assess within and between group differences. Time and session were used as factors. A post hoc analysis was carried out, when an interactive effect was present. Significance was set at p ≤ 0.05. RESULTS: SM increased MVC force [F(3,30) = 5.95, p < 0.01], and V-waves [F(3,30) = 4.25, p = 0.01] over time compared to the control intervention. Between group differences were significant for all time periods (p < 0.05) except for the post60 force measurements (p = 0.07). CONCLUSION: A single session of SM increased muscle strength and corticospinal excitability to ankle plantar flexor muscles in elite Taekwondo athletes. The increased MVC force lasted for 30 min and the corticospinal excitability increase persisted for at least 60 min.
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Atletas , Manipulação da Coluna , Força Muscular/fisiologia , Músculo Esquelético/cirurgia , Adolescente , Adulto , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Manipulação da Coluna/métodos , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto JovemRESUMO
OBJECTIVES: Debate persists regarding the biological makeup of European Ottoman communities settled during the expansion of the Ottoman Empire during the 16th and 17th centuries, and the roles of conversion and migration in shaping demography and population history. The aim of this study was to perform an assessment of the biological affinities of three European Ottoman series based on craniometric data. MATERIALS AND METHODS: Craniometric data collected from three Ottoman series from Hungary and Romania were compared to European and Anatolian comparative series, selected to represent biological affinity representative of historically recorded migration and conversion influences. Sex-separated samples were analyzed using D2 -matrices, along with principal coordinates and PERMANOVA analyses to investigate biological affinities. Discriminant function analysis was employed to assign Ottoman individuals to two potential classes: European or Anatolian. RESULTS: Affinity analyses show larger than expected biological differences between males and females within each of the Ottoman communities. Discriminant function analyses show that the majority of Ottoman individuals could be classified as either European or Anatolian with a high probability. Moreover, location within Europe proved influential, as the Ottomans from a location of more geopolitical importance (Budapest) diverged from more hinterland communities in terms of biological affinity patterns. DISCUSSION: The results suggest that male and female Ottomans may possess distinct population histories, with males and females divergent from each other in terms of their biological affinities. The Ottoman communities appear diverse in terms of constituting a mix of peoples from different biological backgrounds. The greater distances between sexes from the same community, and the differences between communities, may be evidence that the processes of migration and conversion impacted individual people and groups diversely.
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Cefalometria/métodos , Migração Humana/história , Crânio/anatomia & histologia , População Branca/etnologia , Adolescente , Adulto , Antropologia Física , Feminino , História do Século XVI , História do Século XVII , História do Século XX , Humanos , Hungria/etnologia , Masculino , Império Otomano/etnologia , Romênia/etnologia , Adulto JovemRESUMO
OBJECTIVE: Iliocaval thrombotic obstruction is a challenging condition, especially because thrombus age and corresponding pathological remodeling at presentation are unknown, which directly impacts management. Our aim was to assess the ability of magnetic resonance imaging (MRI) in determining age thresholds of experimentally created inferior vena cava (IVC) thrombosis in pigs. METHODS: We used a previously described swine model of IVC thrombosis. The animals underwent MRI at baseline, immediately after thrombosis creation, and after a follow-up period extending from 2 to 28 days. Thirteen pigs were divided into three groups according to disease chronicity: acute group (AG; n = 5), subacute group (SAG; n = 4), and chronic group (CG; n = 4), with a mean thrombosis age of 6.4 ± 2.5 days, 15.7 ± 2.8 days, and 28 ± 5.7 days, respectively. A T1-weighted volumetric interpolated breath-hold examination sequence was used to anatomically delineate IVC thrombus as a region of interest. Three other MRI sequences were used to assess the thrombus signal. RESULTS: The Kruskal-Wallis test showed a statistically significant difference in T1 relaxation times after contrast injection (P = .026) between the three groups of chronicity. The AG (360.2 ± 102.5 ms) was significantly different from the CG (336.7 ± 55.2 ms; P = .003), and the SAG (354.1 ± 89.7 ms) was significantly different from the AG (P = .027). There was a statistically significant difference in native T2 relaxation times (P = .038) between the three groups. The AG (160 ± 86.7 ms) was significantly different from the SAG (142.3 ± 55.4 ms; P = .027), and the SAG was significantly different from the CG (178.4 ± 11.7 ms; P = .004). CONCLUSIONS: This study highlighted MRI characteristics in a swine model that might have the potential to significantly differentiate subacute and chronic stages from an acute stage of deep vein thrombosis in humans. Further clinical studies in humans are warranted. CLINICAL RELEVANCE: In addition to providing a better understanding of venous thrombosis remodeling over time, magnetic resonance imaging has the potential to be a tool that could allow us to characterize the composition of venous thrombus over an interval, allowing for a refined analysis of the local evolution of venous thrombosis. We propose a noninvasive and innovative method to characterize different thresholds of chronicity with magnetic resonance imaging features of central deep vein thrombosis of the inferior vena cava experimentally obtained using a totally endovascular in vivo swine model, mimicking human pathophysiology. Being able to determine these features noninvasively is critical for vascular specialists when it comes to choosing between fibrinolytic therapy, percutaneous thrombectomy, or surgical management.
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Modelos Animais de Doenças , Veia Ilíaca , Imageamento por Ressonância Magnética Multiparamétrica , Veia Cava Inferior , Trombose Venosa , Animais , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/patologia , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/patologia , Veia Ilíaca/diagnóstico por imagem , Veia Ilíaca/patologia , Suínos , Fatores de Tempo , Valor Preditivo dos Testes , Sus scrofa , Doença Crônica , Doença AgudaRESUMO
Progress in the design and synthesis of nanostructured self-assembling systems has facilitated the realization of numerous nanoscale geometries, including fibers, ribbons, and sheets. A key challenge has been achieving control across multiple length scales and creating macroscopic structures with nanoscale organization. Here, we present a facile extrusion-based fabrication method to produce anisotropic, nanofibrous hydrogels using self-assembling peptides. The application of shear force coinciding with ion-triggered gelation is used to kinetically trap supramolecular nanofibers into aligned, hierarchical macrostructures. Further, we demonstrate the ability to tune the nanostructure of macroscopic hydrogels through modulating phosphate buffer concentration during peptide self-assembly. In addition, increases in the nanostructural anisotropy of fabricated hydrogels are found to enhance their strength and stiffness under hydrated conditions. To demonstrate their utility as an extracellular matrix-mimetic biomaterial, aligned nanofibrous hydrogels are used to guide directional spreading of multiple cell types, but strikingly, increased matrix alignment is not always correlated with increased cellular alignment. Nanoscale observations reveal differences in cell-matrix interactions between variably aligned scaffolds and implicate the need for mechanical coupling for cells to understand nanofibrous alignment cues. In total, innovations in the supramolecular engineering of self-assembling peptides allow us to decouple nanostructure from macrostructure and generate a gradient of anisotropic nanofibrous hydrogels. We anticipate that control of architecture at multiple length scales will be critical for a variety of applications, including the bottom-up tissue engineering explored here.
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Hidrogéis , Nanofibras , Peptídeos , Nanofibras/química , Peptídeos/química , Hidrogéis/química , Humanos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Anisotropia , AnimaisRESUMO
The Southern Annular Mode (SAM) is the leading mode of atmospheric variability in the extratropical Southern Hemisphere and has wide ranging effects on ecosystems and societies. Despite the SAM's importance, paleoclimate reconstructions disagree on its variability and trends over the Common Era, which may be linked to variability in SAM teleconnections and the influence of specific proxies. Here, we use data assimilation with a multi-model prior to reconstruct the SAM over the last 2000 years using temperature and drought-sensitive climate proxies. Our method does not assume a stationary relationship between the SAM and the proxy records and allows us to identify critical paleoclimate records and quantify reconstruction uncertainty through time. We find no evidence for a forced response in SAM variability prior to the 20th century. We do find the modern positive trend falls outside the 2σ range of the prior 2000 years at multidecadal time scales, supporting the inference that the SAM's positive trend over the last several decades is a response to anthropogenic climate change.
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OBJECTIVE: To determine the impact of minimum unit pricing (MUP) on the primary outcome of alcohol-related hospitalisation, and secondary outcomes of length of stay, hospital mortality and alcohol-related liver disease in hospital. DESIGN: Databases MEDLINE, Embase, Scopus, APA Psycinfo, CINAHL Plus and Cochrane Reviews were searched from 1 January 2011 to 11 November 2022. Inclusion criteria were studies evaluating the impact of minimum pricing policies, and we excluded non-minimum pricing policies or studies without alcohol-related hospital outcomes. The Effective Public Health Practice Project tool was used to assess risk of bias, and the Bradford Hill Criteria were used to infer causality for outcome measures. SETTING: MUP sets a legally required floor price per unit of alcohol and is estimated to reduce alcohol-attributable healthcare burden. PARTICIPANT: All studies meeting inclusion criteria from any country INTERVENTION: Minimum pricing policy of alcohol PRIMARY AND SECONDARY OUTCOME MEASURES: RESULTS: 22 studies met inclusion criteria; 6 natural experiments and 16 modelling studies. Countries included Australia, Canada, England, Northern Ireland, Ireland, Scotland, South Africa and Wales. Modelling studies estimated that MUP could reduce alcohol-related admissions by 3%-10% annually and the majority of real-world studies demonstrated that acute alcohol-related admissions responded immediately and reduced by 2%-9%, and chronic alcohol-related admissions lagged by 2-3 years and reduced by 4%-9% annually. Minimum pricing could target the heaviest consumers from the most deprived groups who tend to be at greatest risk of alcohol harms, and in so doing has the potential to reduce health inequalities. Using the Bradford Hill Criteria, we inferred a 'moderate-to-strong' causal link that MUP could reduce alcohol-related hospitalisation. CONCLUSIONS: Natural studies were consistent with minimum pricing modelling studies and showed that this policy could reduce alcohol-related hospitalisation and health inequalities. PROSPERO REGISTRATION NUMBER: CRD42021274023.
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Bebidas Alcoólicas , Etanol , Humanos , Custos e Análise de Custo , Políticas , Hospitais , Comércio , Consumo de Bebidas AlcoólicasRESUMO
INTRODUCTION: Clinical Nutrition is finding its place within medical training. In response to IrSPEN's objectives and ESPEN's manifesto, IrSPEN distributed an electronic survey investigating attitudes to Clinical Nutrition and unmet educational needs. METHODS: A 35-part questionnaire was designed and distributed to clinicians in Ireland. Questions elicited clinician demographics, education history and experience assessing and managing malnutrition. Descriptive statistics were reported, comparisons analysed using Chi-squared test and correlation between experience and confidence analysed with Spearman correlation coefficient. RESULTS: Of 168 respondents, 41% (n = 58) were male and most practice medicine in an academic centre (87.5%). Fifty-eight (34.7%) were regularly involved in nutrition support. Despite 20% (n = 33) of respondents regularly managing patients on parenteral nutrition (PN) and a fifth (n = 34) regularly managing complications of obesity, few had confidence in assessment for artificial nutrition (15.7% (n = 26), enteral nutrition; 8% (n = 13), PN). Trainees were less confident than attending staff in assessing and managing artificial enteral feeding (p = 0.022) and complications of PN (p = 0.01). Over 70% respondents reported they received <2 h clinical nutrition education. Only 32% (n = 52) received any formal training within postgraduate training (PGT), more often GI trainees (p = 0.01). A striking 98% felt additional focus on nutrition education in PGT is required. CONCLUSION: This survey elicits physician attitudes on nutrition education in undergraduate and postgraduate curricula in Ireland. Practicing physicians identify the need to increase clinical nutrition education. IrSPEN are actively engaging with Irish medical schools and training bodies to address these deficits with multidisciplinary engagement from expert physicians and allied dietetic colleagues.
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Internato e Residência , Médicos , Humanos , Masculino , Feminino , Currículo , Competência Clínica , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis. METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis. FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min. INTERPRETATION: Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit. FUNDING: None.
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Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/administração & dosagem , Fibrinolíticos/efeitos adversos , Humanos , Infusões Intravenosas , Injeções Intravenosas , Hemorragias Intracranianas/induzido quimicamente , Ensaios Clínicos Controlados Aleatórios como Assunto , Proteínas Recombinantes/administração & dosagem , Fatores de Tempo , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do TratamentoRESUMO
Hypotonicity of the upper esophageal sphincter (UES) has been reported only two times previously in the literature, with no reports of treatment options for this rarity. We present a third case of hypotonic UES found during high-resolution pharyngeal manometry. Although the patient had nearly absent resting pressures of the UES, pressures during and post-swallow were normal. It was hypothesized that the patient might be able to increase pre-swallow UES pressure using biofeedback. Using a chin up/out maneuver during manometry, the patient was able to achieve a more normal swallow pressure pattern. This case also highlights the need to complete manometry alongside other swallow imaging techniques for effective treatment planning and patient outcomes. Laryngoscope, 131:E1567-E1569, 2021.
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Biorretroalimentação Psicológica/métodos , Transtornos de Deglutição/terapia , Esfíncter Esofágico Superior/fisiopatologia , Manometria/métodos , Biorretroalimentação Psicológica/instrumentação , Deglutição/fisiologia , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/fisiopatologia , Humanos , Masculino , Manometria/instrumentação , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Globally, many biomes are being impacted by significant shifts in total annual rainfall as well as increasing variability of rainfall within and among years. Such changes can have potentially large impacts on plant productivity and growth, but remain largely unknown, particularly for much of the Southern Hemisphere. We investigate how growth of the widespread conifer, Callitris columellaris varied with inter-annual variation in the amount, intensity and frequency of rainfall events over the last century and between semi-arid (<500 mm mean annual rainfall) and tropical (>800 mm mean annual rainfall) biomes in Australia. We used linear and polynomial regression models to investigate the strength and shape of the relationships between growth (ring width) and rainfall. At semi-arid sites, growth was strongly and linearly related to rainfall amount, regardless of differences in the seasonality and intensity of rainfall. The linear shape of the relationship indicates that predicted future declines in mean rainfall will have proportional negative impacts on long-term tree growth in semi-arid biomes. In contrast, growth in the tropics showed a weak and asymmetrical ('concave-down') response to rainfall amount, where growth was less responsive to changes in rainfall amount at the higher end of the rainfall range (>1250 mm annual rainfall) than at the lower end (<1000 mm annual rainfall). The asymmetric relationship indicates that long-term growth rates of Callitris in the tropics are more sensitive to increased inter-annual variability of rainfall than to changes in the mean amount of rainfall. Our findings are consistent with observations that the responses of vegetation to changes in the mean or variability of rainfall differ between mesic and semi-arid biomes. These results highlight how contrasting growth responses of a widespread species across a hydroclimatic gradient can inform understanding of potential sensitivity of different biomes to climatic variability and change.
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Ecossistema , Chuva , Árvores/crescimento & desenvolvimento , Austrália , Estações do Ano , Análise Espaço-TemporalRESUMO
Compound climate extremes (CCEs) can have significant and persistent environmental impacts on ecosystems. However, knowledge of the occurrence of CCEs beyond the past ~ 50 years, and hence their ecological impacts, is limited. Here, we place the widespread 2015-16 mangrove dieback and the more recent 2020 inland native forest dieback events in northern Australia into a longer historical context using locally relevant palaeoclimate records. Over recent centuries, multiple occurrences of analogous antecedent and coincident climate conditions associated with the mangrove dieback event were identified in this compilation. However, rising sea level-a key antecedent condition-over the three decades prior to the mangrove dieback is unprecedented in the past 220 years. Similarly, dieback in inland forests and savannas was associated with a multi-decadal wetting trend followed by the longest and most intense drought conditions of the past 250 years, coupled with rising temperatures. While many ecological communities may have experienced CCEs in past centuries, the addition of new environmental stressors associated with varying aspects of global change may exceed their thresholds of resilience. Palaeoclimate compilations provide the much-needed longer term context to better assess frequency and changes in some types of CCEs and their environmental impacts.
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Congenital heart disease (CHD) poses a significant global health and economic burden-despite advances in treating CHD reducing the mortality risk, globally CHD accounts for approximately 300,000 deaths yearly. Children with CHD experience both acute and chronic cardiac complications, and though treatment options have improved, some remain extremely invasive. A challenge in addressing these morbidity and mortality risks is that little is known regarding the cause of many CHDs and current evidence suggests a multifactorial etiology. Some studies implicate an immune contribution to CHD development; however, the role of the immune system is not well-understood. Defining the role of the immune and inflammatory responses in CHD therefore holds promise in elucidating mechanisms underlying these disorders and improving upon current diagnostic and treatment options. In this review, we address the current knowledge coinciding CHDs with immune and inflammatory associations, emphasizing conditions where this understanding would provide clinical benefit, and challenges in studying these mechanisms.
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Malignant mesothelioma (MM) is an incurable cancer. MM is often misdiagnosed, with a poor 5-year survival and limited treatment options. The discovery of endogenous volatile organic compounds (VOCs) is required in order to accelerate the development of a breath test as an alternative to conventional MM diagnosis. For the first time, this study used solid-phase microextraction and gas chromatography-mass spectrometry to identify VOCs released directly from the biphasic MM cell line MSTO-211H and the epithelioid MM cell line NCI-H28 as well as the non-malignant mesothelial cell line MET-5A. Multivariate statistical analysis showed separation between MSTO-211H, NCI-H28 and MET-5A results. 2-ethyl-1-hexanol was significantly increased in both MSTO-211H and NCI-H28 cells compared to MET-5A controls. In addition, ethyl propionate and cyclohexanol were significantly increased in MSTO-211H cells and dodecane was significantly increased in NCI-H28 cells. This is the first study reporting headspace analysis of these MM cell lines and the first to consider the effects of mesothelioma sub-type on VOC profile. Current results further highlight the potential for a diagnostic mesothelioma breath test as well as providing proof of concept for the differentiation between biphasic and epithelioid mesothelioma based on VOC profiles.
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Cromatografia Gasosa-Espectrometria de Massas , Mesotelioma/diagnóstico , Mesotelioma/patologia , Testes Respiratórios , Contagem de Células , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Análise dos Mínimos Quadrados , Análise de Componente Principal , Compostos Orgânicos Voláteis/análiseRESUMO
Bioprosthetic heart valve implants are beset by calcification and failure due to the interactions between the body and the transplant. Hydrogels can be used as biological blank slates that may help to shield implants from these interactions; however, traditional light-based hydrogel polymerization is impeded by tissue opacity and topography. Therefore, new methods must be created to bind hydrogel to implant tissues. To address these complications, a two-step surface-coating method for bioprosthetic valves was developed. A previously developed bioprosthetic valve model (VM) was used to investigate and optimize the coating method. Generally, this coating is achieved by first reacting surface amine groups with an NHS-PEG-acrylate while also allowing glucose to absorb into the bulk. Then, glucose oxidase, poly(ethylene glycol) diacrylate (PEGDA), and iron ions are added to the system to initiate free-radical polymerization that bonds the PEGDA hydrogel to the acrylates sites on the surface. Results showed a thin (â¼8 µm), continuous coating on VM samples that is capable of repelling protein adhesion (2% surface fouling versus 20% on uncoated samples) and does not significantly affect the surface mechanical properties. Based on this success, the coating method was translated to glutaraldehyde-fixed valve tissue samples. Results showed noncontinuous but evident coating on the surface, which was further improved by adjusting the coating solution. These results demonstrate the feasibility of the proposed two-step surface coating method for modifying the surface of bioprosthetic valve replacements.
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OBJECTIVE: Abnormal pulmonary vasculature directly affects the development and progression of congenital diaphragmatic hernia (CDH)-associated pulmonary hypertension (PH). Though overarching structural and cellular changes in CDH-affected pulmonary arteries have been documented, the precise role of the extracellular matrix (ECM) in the pulmonary artery (PA) pathophysiology remains undefined. Here, we quantify the structural, compositional, and mechanical CDH-induced changes in the main and distal PA ECM and investigate the efficacy of mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) as a therapy to ameliorate pathological vascular ECM changes. METHODS: Pregnant Sprague-Dawley rodents were administered nitrofen to induce CDH-affected pulmonary vasculature in the offspring. A portion of CDH-affected pups was treated with intravenous infusion of MSC-EVs (1 × 1010 /mL) upon birth. A suite of histological, mechanical, and transmission electron microscopic analyses were utilized to characterize the PA ECM. RESULTS: The CDH model main PA presented significantly altered characteristics-including greater vessel thickness, greater lysyl oxidase (LOX) expression, and a relatively lower ultimate tensile strength of 13.6 MPa compared to control tissue (25.1 MPa), suggesting that CDH incurs ECM structural disorganization. MSC-EV treatment demonstrated the potential to reverse CDH-related changes, particularly through rapid inhibition of ECM remodeling enzymes (LOX and MMP-9). Additionally, MSC-EV treatment bolstered structural aspects of the PA ECM and mitigated pathological disorganization as exhibited by increased medial wall thickness and stiffness that, while not significantly altered, trends away from CDH-affected tissue. CONCLUSIONS: These data demonstrate notable ECM remodeling in the CDH pulmonary vasculature, along with the capacity of MSC-EVs to attenuate pathological ECM remodeling, identifying MSC-EVs as a potentially efficacious therapeutic for CDH-associated pulmonary hypertension.