Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
World J Surg ; 47(2): 469-476, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36264337

RESUMO

INTRODUCTION: Traditional anterior component separation during incisional hernia repair (IHR) is associated with a high rate of postoperative wound morbidity. Because extensive subcutaneous dissection is avoided by endoscopic anterior component separation (eACS) or open transversus abdominis release (TAR), we hypothesized that these techniques did not increase the incidence of surgical site occurrence (SSO) compared to IHR without component separation (CS). MATERIAL AND METHOD: This was a retrospective single-center cohort study of patients undergoing open retromuscular IHR comparing patients with or without the use of CS. Retromuscular mesh repair was performed in all patients, and CS was obtained by eACS or TAR. The primary outcome was 90-day incidence of postoperative SSO. Secondary outcomes included length of stay (LOS), 90-day readmission, 90-day reoperation rate and 3-year recurrence rate. RESULTS: A total of 321 patients underwent retromuscular repair, 168 (52.3%) of whom received either eACS or TAR. The addition of eACS or TAR was associated neither with development of SSO (odds ratio: 1.80, 95% confidence interval: 0.94-3.46, P = 0.077) nor with hernia recurrence (hazard ratio 0.77, 0.26-2.34, P = 0.648). There was no significant difference between the groups regarding the frequencies of 90-day readmission or 90-day reoperation. CONCLUSION: eACS or TAR as adjuncts to open retromuscular IHR were not associated with increased wound morbidity or hernia recurrence.


Assuntos
Hérnia Ventral , Hérnia Incisional , Humanos , Hérnia Ventral/etiologia , Músculos Abdominais/cirurgia , Hérnia Incisional/epidemiologia , Hérnia Incisional/etiologia , Hérnia Incisional/cirurgia , Estudos de Coortes , Estudos Retrospectivos , Resultado do Tratamento , Herniorrafia/efeitos adversos , Herniorrafia/métodos , Telas Cirúrgicas/efeitos adversos , Incidência , Recidiva
2.
BMC Psychiatry ; 22(1): 204, 2022 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-35305587

RESUMO

BACKGROUND: Cognitive behavioural therapy (CBT) is the recommended first-line treatment for children and adolescents with obsessive-compulsive disorder (OCD), but evidence concerning treatment-specific benefits and harms compared with other interventions is limited. Furthermore, high risk-of-bias in most trials prevent firm conclusions regarding the efficacy of CBT. We investigate the benefits and harms of family-based CBT (FCBT) versus family-based psychoeducation and relaxation training (FPRT) in youth with OCD in a trial designed to reduce risk-of-bias. METHODS: This is an investigator-initiated, independently funded, single-centre, parallel group superiority randomised clinical trial (RCT). Outcome assessors, data managers, statisticians, and conclusion drawers are blinded. From child and adolescent mental health services we include patients aged 8-17 years with a primary OCD diagnosis and an entry score of ≥16 on the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). We exclude patients with comorbid illness contraindicating trial participation; intelligence quotient < 70; or treatment with CBT, PRT, antidepressant or antipsychotic medication within the last 6 months prior to trial entry. Participants are randomised 1:1 to the experimental intervention (FCBT) versus the control intervention (FPRT) each consisting of 14 75-min sessions. All therapists deliver both interventions. Follow-up assessments occur in week 4, 8 and 16 (end-of-treatment). The primary outcome is OCD symptom severity assessed with CY-BOCS at end-of-trial. Secondary outcomes are quality-of-life and adverse events. Based on sample size estimation, a minimum of 128 participants (64 in each intervention group) are included. DISCUSSION: In our trial design we aim to reduce risk-of-bias, enhance generalisability, and broaden the outcome measures by: 1) conducting an investigator-initiated, independently funded RCT; 2) blinding investigators; 3) investigating a representative sample of OCD patients; 3) using an active control intervention (FPRT) to tease apart general and specific therapy effects; 4) using equal dosing of interventions and therapist supervision in both intervention groups; 5) having therapists perform both interventions decided by randomisation; 6) rating fidelity of both interventions; 7) assessing a broad range of benefits and harms with repeated measures. The primary study limitations are the risk of missing data and the inability to blind participants and therapists to the intervention. TRIAL REGISTRATION: ClinicalTrials.gov : NCT03595098, registered July 23, 2018.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno Obsessivo-Compulsivo , Adolescente , Criança , Terapia Cognitivo-Comportamental/métodos , Terapia Familiar , Humanos , Transtorno Obsessivo-Compulsivo/psicologia , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto , Terapia de Relaxamento , Resultado do Tratamento
3.
Scand J Clin Lab Invest ; 82(6): 435-438, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36018574

RESUMO

The primary objective of this study was to examine if people with protein C deficiency, which is a natural anticoagulant and also an endogenous acyl ghrelin peptidase, have elevated circulating levels of acyl ghrelin. The clinical trial was conducted in a university hospital setting. People with protein C deficiency were identified and invited to participate by a specialized coagulation outpatient clinic. People with protein C deficiency were examined and compared to age, sex, and body mass index matched healthy controls with regards to acyl ghrelin, unacylated ghrelin, growth hormone (GH) and insulin-like growth-factor I (IGF-I) in a cross-sectional case-control study. Systemic levels of acyl ghrelin, desacyl ghrelin, acyl-to-desacyl ghrelin ratio, GH and IGF-I were similar in people with protein C deficiency and healthy controls. Despite a significant reduction of protein C in people with protein C deficiency, there was no difference in acyl ghrelin or the secondary end points unacylated ghrelin, GH, or IGF-I in people with protein C deficiency.


Assuntos
Hormônio do Crescimento Humano , Insulinas , Deficiência de Proteína C , Anticoagulantes , Estudos de Casos e Controles , Estudos Transversais , Fibrinogênio , Grelina , Hormônio do Crescimento/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Peptídeo Hidrolases , Proteína C
4.
Glob Chang Biol ; 27(9): 1820-1835, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33528056

RESUMO

Boreal peatland forests have relatively low species diversity and thus impacts of climate change on one or more dominant species could shift ecosystem function. Despite abundant soil water availability, shallowly rooted vascular plants within peatlands may not be able to meet foliar demand for water under drought or heat events that increase vapor pressure deficits while reducing near surface water availability, although concurrent increases in atmospheric CO2 could buffer resultant hydraulic stress. We assessed plant water relations of co-occurring shrub (primarily Rhododendron groenlandicum and Chamaedaphne calyculata) and tree (Picea mariana and Larix laricina) species prior to, and in response to whole ecosystem warming (0 to +9°C) and elevated CO2 using 12.8-m diameter open-top enclosures installed within an ombrotrophic bog. Water relations (water potential [Ψ], turgor loss point, foliar and root hydraulic conductivity) were assessed prior to treatment initiation, then Ψ and peak sap flow (trees only) assessed after 1 or 2 years of treatments. Under the higher temperature treatments, L. laricina Ψ exceeded its turgor loss point, increased its peak sap flow, and was not able to recover Ψ overnight. In contrast, P. mariana operated below its turgor loss point and maintained constant Ψ and sap flow across warming treatments. Similarly, C. calyculata Ψ stress increased with temperature while R. groenlandicum Ψ remained at pretreatment levels. The more anisohydric behavior of L. laricina and C. calyculata may provide greater net C uptake with warming, while the more conservative P. mariana and R. groenlandicum maintained greater hydraulic safety. These latter species also responded to elevated CO2 by reduced Ψ stress, which may also help limit hydraulic failure during periods of extreme drought or heat in the future. Along with Sphagnum moss, the species-specific responses of peatland vascular communities to drier or hotter conditions will shape boreal peatland composition and function in the future.


Assuntos
Larix , Picea , Dióxido de Carbono , Ecossistema , Árvores , Água
5.
Child Dev ; 92(4): 1624-1635, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33506965

RESUMO

A double-blind randomized controlled trial of n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation or matching placebo during third trimester of pregnancy was conducted within the COPSAC2010 mother-child cohort consisting of 736 women and their children. The objective was to determine if maternal n-3 LCPUFA pregnancy supplementation affects offspring neurodevelopment until 6 years. Neurodevelopment was evaluated in 654 children assessing age of motor milestone achievement, language development, cognitive development, general neurodevelopment, and emotional and behavioral problems. Maternal n-3 LCPUFA supplementation during pregnancy improved early language development and reduced the impact of emotional and behavioral problems. The n-3 LCPUFA supplementation was in boys associated with the earlier achievement of gross motor milestones, improved cognitive development, and a reduced impact of emotional and behavioral problems.


Assuntos
Ácidos Graxos Ômega-3 , Óleos de Peixe , Cognição , Suplementos Nutricionais , Feminino , Humanos , Desenvolvimento da Linguagem , Masculino , Gravidez
6.
J Community Psychol ; 48(3): 1028-1039, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32027393

RESUMO

MindSpring (MS) is a community group intervention for refugees with the purpose of strengthening the participants' ability to cope with psychosocial problems, thereby preventing that premigration trauma and postmigratory stressors evolve into psychiatric disorders. The aim of the present project was to study the acceptability and impacts of MS. The study was a mixed-methods observational study including 92 Arabic speaking refugees. Participants completed a baseline demographic questionnaire, an outcome questionnaire and the World Health Organization (WHO)-5 well-being questionnaire (which is also validated as a depression screening tool) before and after the intervention. The paired t test showed a highly significant prepost difference on 12.84 points on the WHO-5. Participants' satisfaction was very high with a 98% overall satisfaction rate. The focus groups results supported these findings. The MS programme is an acceptable intervention for refugees. The significant improvement on WHO-5 suggests a positive impact on depressive symptoms and well-being.


Assuntos
Adaptação Psicológica , Refugiados/psicologia , Transtornos de Estresse Pós-Traumáticos/prevenção & controle , Adulto , Dinamarca , Feminino , Grupos Focais , Humanos , Masculino , Avaliação de Programas e Projetos de Saúde , Pesquisa Qualitativa , Inquéritos e Questionários
7.
New Phytol ; 222(2): 768-784, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30597597

RESUMO

The temperature response of photosynthesis is one of the key factors determining predicted responses to warming in global vegetation models (GVMs). The response may vary geographically, owing to genetic adaptation to climate, and temporally, as a result of acclimation to changes in ambient temperature. Our goal was to develop a robust quantitative global model representing acclimation and adaptation of photosynthetic temperature responses. We quantified and modelled key mechanisms responsible for photosynthetic temperature acclimation and adaptation using a global dataset of photosynthetic CO2 response curves, including data from 141 C3 species from tropical rainforest to Arctic tundra. We separated temperature acclimation and adaptation processes by considering seasonal and common-garden datasets, respectively. The observed global variation in the temperature optimum of photosynthesis was primarily explained by biochemical limitations to photosynthesis, rather than stomatal conductance or respiration. We found acclimation to growth temperature to be a stronger driver of this variation than adaptation to temperature at climate of origin. We developed a summary model to represent photosynthetic temperature responses and showed that it predicted the observed global variation in optimal temperatures with high accuracy. This novel algorithm should enable improved prediction of the function of global ecosystems in a warming climate.


Assuntos
Aclimatação/fisiologia , Fotossíntese/fisiologia , Plantas/metabolismo , Temperatura , Aclimatação/efeitos dos fármacos , Dióxido de Carbono/farmacologia , Respiração Celular/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Modelos Lineares , Modelos Biológicos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Plantas/efeitos dos fármacos , Ribulose-Bifosfato Carboxilase/metabolismo
8.
Acta Paediatr ; 108(9): 1632-1641, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30748036

RESUMO

AIM: The objective of this study was to identify possible pre- and postnatal factors influencing neurodevelopment of the young child. METHODS: We used data from the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010 ) mother-child cohort, but excluded those with a neurological diagnosis, born <37 weeks of gestation and birthweights <2500 g, resulting in 650 children analysed. Neurodevelopment was assessed as age of achievement of early milestones, language scores at 1 and 2 years and cognitive score at 2 ½ years of age. RESULTS: Neurodevelopmental scores were not associated with breastfeeding, persistent wheeze, eczema and number of sick days (p > 0.05 in all tests). Early age at milestone achievement was associated with male sex (p = 0.05), lower maternal age (p = 0.02), higher gestational age (p < 0.001) and paternity leave (p = 0.01). A higher 1-year language score was associated with female sex (p = 0.02) and maternal smoking during pregnancy (p = 0.01) and a higher 2-year language score with female sex (p < 0.001) and being first born (p = 0.01). A higher cognitive score was associated with female sex (p = 0.02). CONCLUSION: Neurodevelopmental scores were unrelated to breastfeeding, persistent wheeze, eczema and number of sick days. Neurodevelopment in early childhood was mostly associated with gender.


Assuntos
Asma/psicologia , Aleitamento Materno , Cognição , Desenvolvimento da Linguagem , Efeitos Tardios da Exposição Pré-Natal , Adulto , Ordem de Nascimento , Estudos de Coortes , Feminino , Humanos , Masculino , Idade Materna , Licença Parental , Gravidez , Caracteres Sexuais , Fumar
9.
Proc Natl Acad Sci U S A ; 113(27): E3950-9, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27313205

RESUMO

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are ligand-gated ion channels that mediate the majority of fast excitatory neurotransmission in the central nervous system. Despite recent advances in structural studies of AMPARs, information about the specific conformational changes that underlie receptor function is lacking. Here, we used single and dual insertion of GFP variants at various positions in AMPAR subunits to enable measurements of conformational changes using fluorescence resonance energy transfer (FRET) in live cells. We produced dual CFP/YFP-tagged GluA2 subunit constructs that had normal activity and displayed intrareceptor FRET. We used fluorescence lifetime imaging microscopy (FLIM) in live HEK293 cells to determine distinct steady-state FRET efficiencies in the presence of different ligands, suggesting a dynamic picture of the resting state. Patch-clamp fluorometry of the double- and single-insert constructs showed that both the intracellular C-terminal domain (CTD) and the loop region between the M1 and M2 helices move during activation and the CTD is detached from the membrane. Our time-resolved measurements revealed unexpectedly complex fluorescence changes within these intracellular domains, providing clues as to how posttranslational modifications and receptor function interact.


Assuntos
Receptores de AMPA/metabolismo , Animais , Feminino , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Humanos , Técnicas de Patch-Clamp , Xenopus laevis
11.
Artigo em Inglês | MEDLINE | ID: mdl-28874373

RESUMO

Chronic Pseudomonas aeruginosa lung infection is characterized by the presence of endobronchial antibiotic-tolerant biofilm, which is subject to strong oxygen (O2) depletion due to the activity of surrounding polymorphonuclear leukocytes. The exact mechanisms affecting the antibiotic susceptibility of biofilms remain unclear, but accumulating evidence suggests that the efficacy of several bactericidal antibiotics is enhanced by stimulation of aerobic respiration of pathogens, while lack of O2 increases their tolerance. In fact, the bactericidal effect of several antibiotics depends on active aerobic metabolism activity and the endogenous formation of reactive O2 radicals (ROS). In this study, we aimed to apply hyperbaric oxygen treatment (HBOT) to sensitize anoxic P. aeruginosa agarose biofilms established to mimic situations with intense O2 consumption by the host response in the cystic fibrosis (CF) lung. Application of HBOT resulted in enhanced bactericidal activity of ciprofloxacin at clinically relevant durations and was accompanied by indications of restored aerobic respiration, involvement of endogenous lethal oxidative stress, and increased bacterial growth. The findings highlight that oxygenation by HBOT improves the bactericidal activity of ciprofloxacin on P. aeruginosa biofilm and suggest that bacterial biofilms are sensitized to antibiotics by supplying hyperbaric O2.


Assuntos
Biofilmes/efeitos dos fármacos , Ciprofloxacina/farmacologia , Oxigenoterapia Hiperbárica , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/farmacologia , Oxigênio/farmacologia , Pseudomonas aeruginosa/fisiologia
12.
J Pediatr ; 183: 153-158.e1, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28088397

RESUMO

OBJECTIVES: To study the association between antibiotic intake in pregnancy and the development of otitis media and placement of ventilation tubes (VTs) in the offspring under the hypothesis that antibiotics in pregnancy may alter the offspring's propensity for disease. STUDY DESIGN: Data from the 700 children in the Copenhagen Prospective Studies on Asthma in Childhood 2010 unselected birth cohort study were used. Information on maternal antibiotic use and other exposures during pregnancy was collected prospectively from interviews and validated in national registries. Otitis media episodes were registered in a prospective diary for 3 years. Information regarding children's VTs was obtained from national registries. RESULTS: There were 514 children who had diary information and were included in the analysis regarding otitis media episodes. For VTs analysis, 699 children were included. Thirty-seven percent of the mothers received antibiotics during pregnancy, and this was associated with increased risk of otitis media (adjusted hazard ratio 1.30; 95% CI 1.04-1.63; P = .02). The risk of receiving VTs was especially associated with third trimester antibiotics (adjusted hazard ratio 1.60; 95% CI 1.08-2.36, P = .02). The risk of otitis media increased with increasing number of treatments (per-level adjusted hazard ratio 1.20; 95% CI 1.04-1.40; P = .02), but for VTs this association was not significant after adjustment. CONCLUSION: Maternal use of antibiotics during pregnancy is associated with an increased risk of otitis media and VT insertions in the offspring. Antibiotics late in pregnancy mainly contributed to these effects, pointing toward potential transmission of an unfavorable microbiome from mother to child.


Assuntos
Antibacterianos/efeitos adversos , Exposição Materna/efeitos adversos , Ventilação da Orelha Média/estatística & dados numéricos , Otite Média/etiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Doença Aguda , Distribuição por Idade , Antibacterianos/uso terapêutico , Pré-Escolar , Estudos de Coortes , Intervalos de Confiança , Dinamarca , Feminino , Humanos , Incidência , Lactente , Masculino , Ventilação da Orelha Média/métodos , Otite Média/epidemiologia , Otite Média/cirurgia , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Distribuição por Sexo
13.
New Phytol ; 215(4): 1425-1437, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27870067

RESUMO

Our objective was to analyze and summarize data describing photosynthetic parameters and foliar nutrient concentrations from tropical forests in Panama to inform model representation of phosphorus (P) limitation of tropical forest productivity. Gas exchange and nutrient content data were collected from 144 observations of upper canopy leaves from at least 65 species at two forest sites in Panama, differing in species composition, rainfall and soil fertility. Photosynthetic parameters were derived from analysis of assimilation rate vs internal CO2 concentration curves (A/Ci ), and relationships with foliar nitrogen (N) and P content were developed. The relationships between area-based photosynthetic parameters and nutrients were of similar strength for N and P and robust across diverse species and site conditions. The strongest relationship expressed maximum electron transport rate (Jmax ) as a multivariate function of both N and P, and this relationship was improved with the inclusion of independent data on wood density. Models that estimate photosynthesis from foliar N would be improved only modestly by including additional data on foliar P, but doing so may increase the capability of models to predict future conditions in P-limited tropical forests, especially when combined with data on edaphic conditions and other environmental drivers.


Assuntos
Modelos Biológicos , Nitrogênio/análise , Fósforo/análise , Fotossíntese , Folhas de Planta/química , Clima Tropical , Madeira/química , Dióxido de Carbono/metabolismo , Florestas , Panamá , Análise de Regressão , Ribulose-Bifosfato Carboxilase/metabolismo , Especificidade da Espécie , Árvores/metabolismo
15.
Blood ; 122(25): 4054-67, 2013 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-24174628

RESUMO

A proangiogenic function of tissue-infiltrating monocytes/macrophages has long been attributed to their matrix metalloproteinase-9 zymogen (proMMP-9). Herein, we evaluated the capacity of human monocytes, mature M0 macrophages, and M1- and M2-polarized macrophages to induce proMMP-9-mediated angiogenesis. Only M2 macrophages induced angiogenesis at levels comparable with highly angiogenic neutrophils previously shown to release their proMMP-9 in a unique form, free of tissue inhibitor of metalloproteinases-1 (TIMP-1). Macrophage differentiation was accompanied by induction of low-angiogenic, TIMP-1-encumbered proMMP-9. However, polarization toward the M2, but not the M1 phenotype, caused a substantial downregulation of TIMP-1 expression, resulting in production of angiogenic, TIMP-deficient proMMP-9. Correspondingly, the angiogenic potency of M2 proMMP-9 was lost after its complexing with TIMP-1, whereas TIMP-1 silencing in M0/M1 macrophages rendered them both angiogenic. Similar to human cells, murine bone marrow-derived M2 macrophages also shut down their TIMP-1 expression and produced proMMP-9 unencumbered by TIMP-1. Providing proof that angiogenic capacity of murine M2 macrophages depended on their TIMP-free proMMP-9, Mmp9-null M2 macrophages were nonangiogenic, although their TIMP-1 was severely downregulated. Our study provides a unifying molecular mechanism for high angiogenic capacity of TIMP-free proMMP-9 that would be uniquely produced in a pathophysiological microenvironment by influxing neutrophils and/or M2 polarized macrophages.


Assuntos
Diferenciação Celular/fisiologia , Precursores Enzimáticos/metabolismo , Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Neovascularização Fisiológica/fisiologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Animais , Embrião de Galinha , Regulação para Baixo/fisiologia , Precursores Enzimáticos/genética , Humanos , Macrófagos/citologia , Metaloproteinase 9 da Matriz/genética , Camundongos , Camundongos Mutantes , Neutrófilos/citologia , Neutrófilos/metabolismo , Inibidor Tecidual de Metaloproteinase-1/genética
16.
Ann Bot ; 116(5): 821-32, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26220656

RESUMO

BACKGROUND AND AIMS: The carbon (C) balance of boreal terrestrial ecosystems is sensitive to increasing temperature, but the direction and thresholds of responses are uncertain. Annual C uptake in Picea and other evergreen boreal conifers is dependent on seasonal- and cohort-specific photosynthetic and respiratory temperature response functions, so this study examined the physiological significance of maintaining multiple foliar cohorts for Picea mariana trees within an ombrotrophic bog ecosystem in Minnesota, USA. METHODS: Measurements were taken on multiple cohorts of needles for photosynthetic capacity, foliar respiration (Rd) and leaf biochemistry and morphology of mature trees from April to October over 4 years. The results were applied to a simple model of canopy photosynthesis in order to simulate annual C uptake by cohort age under ambient and elevated temperature scenarios. KEY RESULTS: Temperature responses of key photosynthetic parameters [i.e. light-saturated rate of CO2 assimilation (Asat), rate of Rubisco carboxylation (Vcmax) and electron transport rate (Jmax)] were dependent on season and generally less responsive in the developing current-year (Y0) needles compared with 1-year-old (Y1) or 2-year-old (Y2) foliage. Temperature optimums ranged from 18·7 to 23·7, 31·3 to 38·3 and 28·7 to 36·7 °C for Asat, Vcmax and Jmax, respectively. Foliar cohorts differed in their morphology and photosynthetic capacity, which resulted in 64 % of modelled annual stand C uptake from Y1&2 cohorts (LAI 0·67 m(2 )m(-2)) and just 36 % from Y0 cohorts (LAI 0·52 m(2 )m(-2)). Under warmer climate change scenarios, the contribution of Y0 cohorts was even less; e.g. 31 % of annual C uptake for a modelled 9 °C rise in mean summer temperatures. Results suggest that net annual C uptake by P. mariana could increase under elevated temperature, and become more dependent on older foliar cohorts. CONCLUSIONS: Collectively, this study illustrates the physiological and ecological significance of different foliar cohorts, and indicates the need for seasonal- and cohort-specific model parameterization when estimating C uptake capacity of boreal forest ecosystems under ambient or future temperature scenarios.


Assuntos
Carbono/metabolismo , Fotossíntese , Picea/metabolismo , Estações do Ano , Picea/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
17.
Plant Cell Environ ; 37(4): 978-94, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24117476

RESUMO

Worldwide measurements of nearly 130 C3 species covering all major plant functional types are analysed in conjunction with model simulations to determine the effects of mesophyll conductance (g(m)) on photosynthetic parameters and their relationships estimated from A/Ci curves. We find that an assumption of infinite g(m) results in up to 75% underestimation for maximum carboxylation rate V(cmax), 60% for maximum electron transport rate J(max), and 40% for triose phosphate utilization rate T(u) . V(cmax) is most sensitive, J(max) is less sensitive, and T(u) has the least sensitivity to the variation of g(m). Because of this asymmetrical effect of g(m), the ratios of J(max) to V(cmax), T(u) to V(cmax) and T(u) to J(max) are all overestimated. An infinite g(m) assumption also limits the freedom of variation of estimated parameters and artificially constrains parameter relationships to stronger shapes. These findings suggest the importance of quantifying g(m) for understanding in situ photosynthetic machinery functioning. We show that a nonzero resistance to CO2 movement in chloroplasts has small effects on estimated parameters. A non-linear function with gm as input is developed to convert the parameters estimated under an assumption of infinite gm to proper values. This function will facilitate gm representation in global carbon cycle models.


Assuntos
Gases/metabolismo , Células do Mesofilo/fisiologia , Fotossíntese , Simulação por Computador , Transporte de Elétrons , Cinética , Fosfatos/metabolismo
18.
Blood Press Monit ; 29(2): 82-88, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38299974

RESUMO

The objective of this study was to assess the feasibility of the Arteriograph 24 device to measure 24-hour PWV and central systolic blood pressure (cSBP) in patients with type 2 diabetes (T2DM) and non-diabetic controls and compare daytime and nighttime characteristics in the two groups. Twenty-four-hour PWV and cSBP was measured in 58 patients with T2DM (mean age: 66 ±â€…9 years, 50% women, mean duration of T2DM: 7.8 ±â€…1.5 years) and 62 age- and sex-matched controls. Seventy percent of participants (71% T2DM patients and 69% controls) had sufficient readings to generate an acceptable 24-hour report (≥14 day and ≥7 night readings). Lower nocturnal than daytime PWV and cSBP were observed in both groups. Nocturnal PWV and cSBP dipping were attenuated in T2DM patients compared to controls (PWV: -0.3 ±â€…0.9 vs. -0.7 ±â€…0.9 m/s, P  = 0.04, cSBP: -8 ±â€…14 vs. -18 ±â€…18 mmHg, P  < 0.01). No group differences in PWV or cSBP were observed during daytime (T2D vs. controls, PWV: 9.2 ±â€…1.1 vs. 9.2 ±â€…1.3 m/s, P  = 0.99, cSBP: 133 ±â€…19 vs. 137 ±â€…25 mmHg, P  = 0.42) or nighttime (PWV: 8.9 ±â€…1.3 vs. 8.4 ±â€…1.3 m/s, P  = 0.14, cSBP 124 ±â€…20 vs. 118 ±â€…27 mmHg, P  = 0.26). The study findings indicate that the nocturnal dipping of PWV and cSBP is attenuated in T2DM patients. The significant number of missing measurements raises concerns regarding the clinical utility of the Arteriograph 24 device.


Assuntos
Diabetes Mellitus Tipo 2 , Rigidez Vascular , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Pressão Sanguínea/fisiologia , Análise de Onda de Pulso , Diabetes Mellitus Tipo 2/complicações , Estudos de Viabilidade , Determinação da Pressão Arterial
19.
J Immunother Cancer ; 12(7)2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39060021

RESUMO

BACKGROUND: Androgen deprivation therapy (ADT) is a front-line treatment for prostate cancer. In some men, their tumors can become refractory leading to the development of castration-resistant prostate cancer (CRPC). This causes tumors to regrow and metastasize, despite ongoing treatment, and impacts negatively on patient survival. ADT is known to stimulate the accumulation of immunosuppressive cells like protumoral tumor-associated macrophages (TAMs), myeloid-derived suppressor cells and regulatory T cells in prostate tumors, as well as hypofunctional T cells. Protumoral TAMs have been shown to accumulate around tumor blood vessels during chemotherapy and radiotherapy in other forms of cancer, where they drive tumor relapse. Our aim was to see whether such perivascular (PV) TAMs also accumulate in ADT-treated prostate tumors prior to CRPC, and, if so, whether selectively inducing them to express a potent immunostimulant, interferon beta (IFNß), would stimulate antitumor immunity and delay CRPC. METHODS: We used multiplex immunofluorescence to assess the effects of ADT on the distribution and activation status of TAMs, CD8+T cells, CD4+T cells and NK cells in mouse and/or human prostate tumors. We then used antibody-coated, lipid nanoparticles (LNPs) to selectively target a STING agonist, 2'3'-cGAMP (cGAMP), to PV TAMs in mouse prostate tumors during ADT. RESULTS: TAMs accumulated at high density around blood vessels in response to ADT and expressed markers of a protumoral phenotype including folate receptor-beta (FR-ß), MRC1 (CD206), CD169 and VISTA. Additionally, higher numbers of inactive (PD-1-) CD8+T cells and reduced numbers of active (CD69+) NK cells were present in these PV tumor areas. LNPs coated with an antibody to FR-ß selectively delivered cGAMP to PV TAMs in ADT-treated tumors, where they activated STING and upregulated the expression of IFNß. This resulted in a marked increase in the density of active CD8+T cells (along with CD4+T cells and NK cells) in PV tumor areas, and significantly delayed the onset of CRPC. Antibody depletion of CD8+T cells during LNP administration demonstrated the essential role of these cells in delay in CRPC induced by LNPs. CONCLUSION: Together, our data indicate that targeting a STING agonist to PV TAMs could be used to extend the treatment window for ADT in prostate cancer.


Assuntos
Macrófagos , Proteínas de Membrana , Masculino , Animais , Camundongos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/agonistas , Macrófagos/metabolismo , Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , Antagonistas de Androgênios/uso terapêutico , Antagonistas de Androgênios/farmacologia , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/efeitos dos fármacos , Macrófagos Associados a Tumor/imunologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Resistencia a Medicamentos Antineoplásicos
20.
Front Physiol ; 14: 1249560, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37731544

RESUMO

Introduction: Due to its chemical properties, functional responses to nitric oxide (NO) are often difficult to examine. In the present study, we established a method to produce NO in an aqueous solution and validated its capacity to evoke functional responses in isolated rat bladders. Furthermore, we compared the NO responses to the commonly used NO donor sodium nitroprusside (SNP). We also investigated the impact of ongoing inflammation on the involvement of soluble guanylate cyclase (sGC) dependent signaling in NO relaxation. Methods: A setup to produce an aqueous NO solution was established, allowing the production of an aqueous solution containing a calculated NO concentration of 2 mM. Sixty male Sprague-Dawley rats received either no treatment (controls) or cyclophosphamide (CYP; 100 mg*kg-1 i.p., 60 h prior to the experiment) to induce experimental cystitis. Bladder strip preparations were mounted in organ baths and studied at basal tension or pre-contracted with methacholine (3 µM). Aqueous NO solution (40-400 µL; 2 mM corresponding to 4-40 µM) or SNP (1-1,000 µM) was added cumulatively in increasing concentrations. Relaxation to aqueous NO was also studied in the presence of the sGC inhibitor ODQ (0.25-25 µM). The expression of sGC was investigated by immunohistochemical analysis. Results: The NO solution caused functional relaxations in both controls and inflamed bladder preparations. NO-induced relaxations were significantly greater in inflamed bladder strips at basal tension, whereas no differences were seen in methacholine pre-contracted strips. In the presence of the sGC inhibitor ODQ in a high concentration, the NO-evoked relaxations were abolished in both control and inflamed preparations. At a lower concentration of ODQ, only NO relaxations in inflamed preparations were attenuated. Immunohistochemical analysis showed that sGC was expressed in the detrusor and mucosa, with a significantly lower expression in the inflamed detrusor. Conclusion: In the present study, we found that aqueous NO solution induces relaxation of the rat detrusor by activating soluble guanylate cyclase in both control and inflamed bladder strips. Induction of inflammation conceivably leads to decreased sGC expression in the detrusor, which may explain the different susceptibility towards inhibition of sGC in inflamed versus control tissue. The use of an aqueous NO solution should be further considered as a valuable complement to the pharmacological tools currently used.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA