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1.
J Geriatr Oncol ; 14(1): 101372, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36127284

RESUMO

INTRODUCTION: Standard-dose eribulin mesylate (1.4 mg/m2 d1 + 8) achieves clinical benefit rates of 26%-52% in patients with metastatic breast cancer (mBC). <10% of patients in the registration trial were ≥ 70 years old; dose reductions were common in these older patients. MATERIALS AND METHODS: This single-arm phase II trial explored the efficacy of reduced starting dosing of first-line eribulin at 1 mg/m2 d1 + 8 q3 weeks in patients with mBC aged ≥70 years. The primary endpoint was a disease control rate (DCR) ≥55%. The secondary endpoints were objective response (OR), progression-free survival (PFS), overall survival (OS), and patient-reported neurotoxicity. RESULTS: Overall, 77 patients were accrued; their median age was 76 years and Eastern Cooperative Oncology Group performance status was 0-1 in 90%. The DCR was 40% (90% confidence interval [CI]: 31-50); therefore, the primary endpoint was not reached. The overall response rate was 22% (95%CI: 13-33), median PFS 5.4 months (95%CI: 4.5-7.7), and median OS 16.1 months (95%CI: 13.5-26.9). Dose modifications were necessary in 35% of patients. In nine patients, more than fifteen cycles were given; 48 patients (62%) experienced at least one grade 3 toxicity. Median patient-reported neurotoxicity scores remained stable for at least fifteen cycles. The main reason for treatment discontinuation was disease progression (57%). DISCUSSION: We report the first prospective data on first-line eribulin in older patients. The reduced starting dose of 1.1 mg/m2 was safe, with prolonged treatment and DC achieved in a considerable proportion of patients (but less than the 55% assumed), without cumulative neurotoxicity. The reduced dose was apparently within the range of the minimal effective dose, as shown by the efficacy lack in patients requiring further dose reductions. Thus, our results do not support the approach of a reduced starting dose for older patients.


Assuntos
Neoplasias da Mama , Humanos , Idoso , Feminino , Neoplasias da Mama/tratamento farmacológico , Resultado do Tratamento , Estudos Prospectivos , Furanos/efeitos adversos
2.
Br J Oral Maxillofac Surg ; 60(5): 650-654, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35341605

RESUMO

The aim of this study was to determine the rate of persistent pain following total TMJ replacement and to identify potential predictive risk factors. A retrospective review of case notes treated by a single surgeon in a tertiary unit was performed. For each patient a number of variables were recorded including visual analogue pain scores (0 to 10) and opioid usage pre surgery and at 12 months or last follow up beyond 12 months. Persistent pain scores of 5 to 7 were regarded as moderate and 8 to 10 as severe. The mean pain score at last follow-up was significantly lower than preoperatively (2.1 vs. 6.3, p < 0.001) with a mean follow-up time of 40.1 months (range 12-44). 16.4% of the patients reported moderate to severe pain and 13.7% were still on regular opioids at the last follow-up. Therefore 15 patients (20.5%) suffered from chronic postoperative pain after TMJ replacement surgery. Patients reporting severe preoperative pain scores (p = 0.04), regular opioid use (p = 0.001) or multiple previous open TMJ surgeries (p = 0.03) were more likely to suffer from chronic persistent pain and these should be regarded as predictive risk factors. The identification of these factors allows for better risk stratification of patients, informed consent and the agreement of expected outcomes. Patients with true articular disease and a single failed surgery should be considered for early total TMJ replacement to minimise multifactorial persistent pain.


Assuntos
Artroplastia de Substituição , Prótese Articular , Transtornos da Articulação Temporomandibular , Analgésicos Opioides/uso terapêutico , Artroplastia de Substituição/efeitos adversos , Humanos , Prótese Articular/efeitos adversos , Dor Pós-Operatória/etiologia , Amplitude de Movimento Articular , Estudos Retrospectivos , Fatores de Risco , Articulação Temporomandibular/cirurgia , Transtornos da Articulação Temporomandibular/cirurgia , Resultado do Tratamento
3.
Glob Chang Biol ; 27(22): 5711-5725, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34382301

RESUMO

The impacts of global environmental change on productivity in northern latitudes will be contingent on nitrogen (N) availability. In circumpolar boreal ecosystems, nonvascular plants (i.e., bryophytes) and associated N2 -fixing diazotrophs provide one of the largest known N inputs but are rarely accounted for in Earth system models. Instead, most models link N2 -fixation with the functioning of vascular plants. Neglecting nonvascular N2 -fixation may be contributing toward high uncertainty that currently hinders model predictions in northern latitudes, where nonvascular N2 -fixing plants are more common. Adequately accounting for nonvascular N2 -fixation and its drivers could subsequently improve predictions of future N availability and ultimately, productivity, in northern latitudes. Here, we review empirical evidence of boreal nonvascular N2 -fixation responses to global change factors (elevated CO2 , N deposition, warming, precipitation, and shading by vascular plants), and compare empirical findings with model predictions of N2 -fixation using nine Earth system models. The majority of empirical studies found positive effects of CO2 , warming, precipitation, or light on nonvascular N2 -fixation, but N deposition strongly downregulated N2 -fixation in most empirical studies. Furthermore, we found that the responses of N2 -fixation to elevated CO2 were generally consistent between models and very limited empirical data. In contrast, empirical-model comparisons suggest that all models we assessed, and particularly those that scale N2 -fixation with net primary productivity or evapotranspiration, may be overestimating N2 -fixation under increasing N deposition. Overestimations could generate erroneous predictions of future N stocks in boreal ecosystems unless models adequately account for the drivers of nonvascular N2 -fixation. Based on our comparisons, we recommend that models explicitly treat nonvascular N2 -fixation and that field studies include more targeted measurements to improve model structures and parameterization.


Assuntos
Briófitas , Fixação de Nitrogênio , Planeta Terra , Ecossistema , Nitrogênio
4.
BMC Bioinformatics ; 22(1): 189, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849458

RESUMO

BACKGROUND: Despite the importance of alternative poly-adenylation and 3' UTR length for a variety of biological phenomena, there are limited means of detecting UTR changes from standard transcriptomic data. RESULTS: We present the diffUTR Bioconductor package which streamlines and improves upon differential exon usage (DEU) analyses, and leverages existing DEU tools and alternative poly-adenylation site databases to enable differential 3' UTR usage analysis. We demonstrate the diffUTR features and show that it is more flexible and more accurate than state-of-the-art alternatives, both in simulations and in real data. CONCLUSIONS: diffUTR enables differential 3' UTR analysis and more generally facilitates DEU and the exploration of their results.


Assuntos
Biologia Computacional , Poli A , Regiões 3' não Traduzidas , Processamento Alternativo , Éxons/genética , Transcriptoma
5.
Cell Rep ; 33(6): 108364, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33176132

RESUMO

Understanding the structure and function of neural circuits underlying speech and language is a vital step toward better treatments for diseases of these systems. Songbirds, among the few animal orders that share with humans the ability to learn vocalizations from a conspecific, have provided many insights into the neural mechanisms of vocal development. However, research into vocal learning circuits has been hindered by a lack of tools for rapid genetic targeting of specific neuron populations to meet the quick pace of developmental learning. Here, we present a viral tool that enables fast and efficient retrograde access to projection neuron populations. In zebra finches, Bengalese finches, canaries, and mice, we demonstrate fast retrograde labeling of cortical or dopaminergic neurons. We further demonstrate the suitability of our construct for detailed morphological analysis, for in vivo imaging of calcium activity, and for multi-color brainbow labeling.


Assuntos
Neurônios/fisiologia , Vocalização Animal/fisiologia , Animais , Camundongos , Aves Canoras
6.
Oecologia ; 193(4): 969-980, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32725299

RESUMO

Nutrient homeostasis relates ambient stoichiometric conditions in an environment to the stoichiometry of living entities of that ecosystem. Plant nutrient sequestration in wetland ecosystems is a key process for downstream water quality. However, few studies have examined stoichiometric homeostasis of aquatic vegetation despite the importance of stoichiometry to plant nutrient uptake efficiency. This study investigated stoichiometric homeostasis of dominant emergent and submerged aquatic vegetation (EAV and SAV, respectively) within two treatment flow-ways of Everglades Stormwater Treatment Area 2 (STA-2). These flow-ways encompass a large gradient in plant nutrient availability. This study hypothesizes that wetland vegetation is homeostatic relative to ambient nutrients and consequently nutrient resorption does not vary along the nutrient gradient. We developed a framework to investigate how vegetation uptake and resorption of nutrients contribute separately to homeostasis. Overall, we determined that the wetland vegetation in this study was non-homeostatic with respect to differential uptake of nitrogen (N) versus phosphorus (P). In EAV, P resorption was relatively high and N resorption was moderate, and resorption efficiency did not vary significantly along the gradient. In separating the proportional contribution of resorption and uptake to the degree of homeostasis, resorption did not affect overall homeostatic status in EAV.


Assuntos
Purificação da Água , Áreas Alagadas , Ecossistema , Homeostase , Nitrogênio , Nutrientes , Fósforo , Chuva , Abastecimento de Água
7.
Glob Chang Biol ; 25(2): 640-659, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30414347

RESUMO

Our understanding and quantification of global soil nitrous oxide (N2 O) emissions and the underlying processes remain largely uncertain. Here, we assessed the effects of multiple anthropogenic and natural factors, including nitrogen fertilizer (N) application, atmospheric N deposition, manure N application, land cover change, climate change, and rising atmospheric CO2 concentration, on global soil N2 O emissions for the period 1861-2016 using a standard simulation protocol with seven process-based terrestrial biosphere models. Results suggest global soil N2 O emissions have increased from 6.3 ± 1.1 Tg N2 O-N/year in the preindustrial period (the 1860s) to 10.0 ± 2.0 Tg N2 O-N/year in the recent decade (2007-2016). Cropland soil emissions increased from 0.3 Tg N2 O-N/year to 3.3 Tg N2 O-N/year over the same period, accounting for 82% of the total increase. Regionally, China, South Asia, and Southeast Asia underwent rapid increases in cropland N2 O emissions since the 1970s. However, US cropland N2 O emissions had been relatively flat in magnitude since the 1980s, and EU cropland N2 O emissions appear to have decreased by 14%. Soil N2 O emissions from predominantly natural ecosystems accounted for 67% of the global soil emissions in the recent decade but showed only a relatively small increase of 0.7 ± 0.5 Tg N2 O-N/year (11%) since the 1860s. In the recent decade, N fertilizer application, N deposition, manure N application, and climate change contributed 54%, 26%, 15%, and 24%, respectively, to the total increase. Rising atmospheric CO2 concentration reduced soil N2 O emissions by 10% through the enhanced plant N uptake, while land cover change played a minor role. Our estimation here does not account for indirect emissions from soils and the directed emissions from excreta of grazing livestock. To address uncertainties in estimating regional and global soil N2 O emissions, this study recommends several critical strategies for improving the process-based simulations.


Assuntos
Mudança Climática , Gases de Efeito Estufa/análise , Desenvolvimento Industrial , Óxido Nitroso/análise , Solo/química , Poluentes Atmosféricos/análise , Modelos Teóricos , Fatores de Tempo , Incerteza
8.
Swiss Dent J ; (12): 969-973, 2018 12 10.
Artigo em Francês, Alemão | MEDLINE | ID: mdl-30509016

RESUMO

Lyme borreliosis is a prevalent disease with a wide variety of clinical manifestations. However, only a few pertinent references are found in the dental literature. Considering the diversity of differential diagnoses, borreliosis-associated orofacial pain may be a challenge for treatment providers and patients alike. The aim of this case report is to emphasize the importance of a sound, structured medical history and assessment to identify severe cases early and to start interdisciplinary therapy if indicated.

9.
Glob Chang Biol ; 24(1): e259-e274, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28746792

RESUMO

Temperature sensitivity of anaerobic carbon mineralization in wetlands remains poorly represented in most climate models and is especially unconstrained for warmer subtropical and tropical systems which account for a large proportion of global methane emissions. Several studies of experimental warming have documented thermal acclimation of soil respiration involving adjustments in microbial physiology or carbon use efficiency (CUE), with an initial decline in CUE with warming followed by a partial recovery in CUE at a later stage. The variable CUE implies that the rate of warming may impact microbial acclimation and the rate of carbon-dioxide (CO2 ) and methane (CH4 ) production. Here, we assessed the effects of warming rate on the decomposition of subtropical peats, by applying either a large single-step (10°C within a day) or a slow ramping (0.1°C/day for 100 days) temperature increase. The extent of thermal acclimation was tested by monitoring CO2 and CH4 production, CUE, and microbial biomass. Total gaseous C loss, CUE, and MBC were greater in the slow (ramp) warming treatment. However, greater values of CH4 -C:CO2 -C ratios lead to a greater global warming potential in the fast (step) warming treatment. The effect of gradual warming on decomposition was more pronounced in recalcitrant and nutrient-limited soils. Stable carbon isotopes of CH4 and CO2 further indicated the possibility of different carbon processing pathways under the contrasting warming rates. Different responses in fast vs. slow warming treatment combined with different endpoints may indicate alternate pathways with long-term consequences. Incorporations of experimental results into organic matter decomposition models suggest that parameter uncertainties in CUE and CH4 -C:CO2 -C ratios have a larger impact on long-term soil organic carbon and global warming potential than uncertainty in model structure, and shows that particular rates of warming are central to understand the response of wetland soils to global climate change.


Assuntos
Gases de Efeito Estufa/química , Microbiologia do Solo , Solo/química , Anaerobiose , Biomassa , Carbono/metabolismo , Dióxido de Carbono/análise , Mudança Climática , Aquecimento Global , Metano/análise , Temperatura , Fatores de Tempo , Áreas Alagadas
10.
Nuklearmedizin ; 55(5): 203-8, 2016 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-27440125

RESUMO

AIMS: Vaccination by aerosol inhalation can be used to efficiently deliver antigen against HPV to mucosal tissue, which is particularly useful in developing countries (simplicity of administration, costs, no need for cold chain). For optimal immunological response, vaccine particles should preferentially be delivered to proximal bronchial airways. We aimed at quantifying the deposition of inhaled particles in central airways and peripheral lung, and to assess administration biosafety. Participants, methods: 20 healthy volunteers (13W/7M, aged 24±4y) performed a 10-min free-breathing inhalation of (99m)Tc-stannous chloride colloid aerosol (450 MBq) in a buffer solution without vaccinal particles using an ultrasonic nebulizer (mass median aerodynamic diameter 4.2 µm) and a double mask inside a biosafety cabinet dedicated to assess environmental particle release. SPECT/CT and whole-body planar scintigraphy were acquired to determine whole-body and regional C/P distribution ratio (central-to-peripheral pulmonary deposition counts). Using a phantom, SPECT sensitivity was calibrated to obtain absolute pulmonary activity deposited by inhalation. RESULTS: All participants successfully performed the inhalation that was well tolerated (no change in pulmonary peak expiratory flow rate, p = 0.9). It was environmentally safe (no activity released in the biosafety filter.) 1.3±0.6% (range 0.4-2.6%) of the total nebulizer activity was deposited in the lungs with a C/P distribution ratio of 0.40±0.20 (range 0.15-1.14). CONCLUSION: Quantification and regional distribution of inhaled particles in an aerosolized vaccine model is possible using radioactive particles. This will allow optimizing deposition parameters and determining the particles charge for active-particles vaccination.


Assuntos
Aerossóis/farmacocinética , Brônquios/diagnóstico por imagem , Brônquios/metabolismo , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/farmacocinética , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos , Administração por Inalação , Adulto , Aerossóis/administração & dosagem , Feminino , Humanos , Marcação por Isótopo , Masculino , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/prevenção & controle , Compostos Radiofarmacêuticos/farmacocinética , Tecnécio/farmacocinética , Distribuição Tecidual
11.
Arch Gynecol Obstet ; 293(3): 469-84, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26506926

RESUMO

BACKGROUND: Vaginal infections are responsible for a large proportion of gynaecological outpatient visits. Those are bacterial vaginosis (BV), vulvovaginal candidosis (VVC), aerobic vaginitis (AV) associated with aerobic bacteria, and mixed infections. Usual treatments show similar acceptable short-term efficacy, but frequent recurrences and increasing microbial resistance are unsolved issues. Furthermore, vaginal infections are associated with a variety of serious adverse outcomes in pregnancy and generally have a major impact on quality of life. Identifying the correct therapy can be challenging for the clinician, particularly in mixed infections. FINDINGS: Dequalinium chloride (DQC) is an anti-microbial antiseptic agent with a broad bactericidal and fungicidal activity. Systemic absorption after vaginal application of DQC is very low and systemic effects negligible. Vaginal DQC (Fluomizin vaginal tablets) has been shown to have equal clinical efficacy as clindamycin in the treatment of BV. Its broad antimicrobial activity makes it appropriate for the treatment of mixed vaginal infections and in case of uncertain diagnosis. Moreover, resistance of pathogens is unlikely due to its multiple mode of action, and vaginal DQC provides also a reduced risk for post-treatment vaginal infections. CONCLUSIONS: Vaginal DQC (10 mg) as 6-day therapy offers a safe and effective option for empiric therapy of different vaginal infections in daily practice. This review summarizes the available and relevant pharmacological and clinical data for the therapy of vaginal infections with vaginal DQC and provides the rationale for its use in daily gynaecologic practice.


Assuntos
Antibacterianos/uso terapêutico , Anti-Infecciosos Locais/farmacologia , Bactérias/efeitos dos fármacos , Dequalínio/farmacologia , Cremes, Espumas e Géis Vaginais/uso terapêutico , Doenças Vaginais/microbiologia , Anti-Infecciosos Locais/uso terapêutico , Antifúngicos/farmacologia , Bactérias Aeróbias , Candidíase Vulvovaginal/diagnóstico , Feminino , Humanos , Gravidez , Qualidade de Vida , Doenças Vaginais/tratamento farmacológico , Vaginose Bacteriana/microbiologia
12.
Glob Chang Biol ; 21(5): 1777-93, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25643841

RESUMO

The representation of the nitrogen (N) cycle in Earth system models (ESMs) is strongly motivated by the constraint N poses on the sequestration of anthropogenic carbon (C). Models typically implement a stoichiometric relationship between C and N in which external supply and assimilation by organisms are adjusted to maintain their internal stoichiometry. N limitation of primary productivity thus occurs if the N supply from uptake and fixation cannot keep up with the construction of tissues allowed by C assimilation. This basic approach, however, presents considerable challenges in how to faithfully represent N limitation. Here, we review how N limitation is currently implemented and evaluated in ESMs and highlight challenges and opportunities in their future development. At or near steady state, N limitation is governed by the magnitude of losses from the plant-unavailable pool vs. N fixation and there are considerable differences in how models treat both processes. In nonsteady-state systems, the accumulation of N in pools with slow turnover rates reduces N available for plant uptake and can be challenging to represent when initializing ESM simulations. Transactional N limitation occurs when N is incorporated into various vegetation and soil pools and becomes available to plants only after it is mineralized, the dynamics of which depends on how ESMs represent decomposition processes in soils. Other challenges for ESMs emerge when considering seasonal to interannual climatic oscillations as they create asynchronies between C and N demand, leading to transient alternations between N surplus and deficit. Proper evaluation of N dynamics in ESMs requires conceptual understanding of the main levers that trigger N limitation, and we highlight key measurements and observations that can help constrain these levers. Two of the biggest challenges are the mechanistic representation of plant controls on N availability and turnover, including N fixation and organic matter decomposition processes.


Assuntos
Planeta Terra , Ecossistema , Modelos Teóricos , Ciclo do Nitrogênio/fisiologia , Nitrogênio/análise , Solo/química , Sequestro de Carbono/fisiologia , Nitrogênio/metabolismo
14.
Glob Chang Biol ; 20(9): 2915-26, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24604769

RESUMO

Climate warming is expected to increase respiration rates of tropical forest trees and lianas, which may negatively affect the carbon balance of tropical forests. Thermal acclimation could mitigate the expected respiration increase, but the thermal acclimation potential of tropical forests remains largely unknown. In a tropical forest in Panama, we experimentally increased nighttime temperatures of upper canopy leaves of three tree and two liana species by on average 3 °C for 1 week, and quantified temperature responses of leaf dark respiration. Respiration at 25 °C (R25 ) decreased with increasing leaf temperature, but acclimation did not result in perfect homeostasis of respiration across temperatures. In contrast, Q10 of treatment and control leaves exhibited similarly high values (range 2.5-3.0) without evidence of acclimation. The decrease in R25 was not caused by respiratory substrate depletion, as warming did not reduce leaf carbohydrate concentration. To evaluate the wider implications of our experimental results, we simulated the carbon cycle of tropical latitudes (24°S-24°N) from 2000 to 2100 using a dynamic global vegetation model (LM3VN) modified to account for acclimation. Acclimation reduced the degree to which respiration increases with climate warming in the model relative to a no-acclimation scenario, leading to 21% greater increase in net primary productivity and 18% greater increase in biomass carbon storage over the 21st century. We conclude that leaf respiration of tropical forest plants can acclimate to nighttime warming, thereby reducing the magnitude of the positive feedback between climate change and the carbon cycle.


Assuntos
Aclimatação/fisiologia , Ciclo do Carbono/fisiologia , Florestas , Temperatura Alta , Folhas de Planta/fisiologia , Árvores/fisiologia , Modelos Biológicos , Consumo de Oxigênio/fisiologia , Panamá , Clima Tropical
15.
Am Nat ; 183(3): 418-30, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24561604

RESUMO

Nutrient limitation in terrestrial ecosystems is often accompanied with maintaining a nearly closed vegetation-soil nutrient cycle. The ability to retain nutrients in an ecosystem requires the capacity of the plant-soil system to draw down nutrient levels in soils effectually such that export concentrations in soil solutions remain low. Here we address the physical constraints of plant nutrient uptake that may be limited by the diffusive movement of nutrients in soils, by the uptake at the root/mycorrhizal surface, and from interactions with soil water flow. We derive an analytical framework of soil nutrient transport and uptake and predict levels of plant available nutrient concentration and residence time. Our results, which we evaluate for nitrogen, show that the physical environment permits plants to lower soil solute concentration substantially. Our analysis confirms that plant uptake capacities in soils are considerable, such that water movement in soils is generally too small to significantly erode dissolved plant-available nitrogen. Inorganic nitrogen concentrations in headwater streams are congruent with the prediction of our theoretical framework. Our framework offers a physical-based parameterization of nutrient uptake in ecosystem models and has the potential to serve as an important tool toward scaling biogeochemical cycles from individual roots to landscapes.


Assuntos
Ecossistema , Nitrogênio/metabolismo , Raízes de Plantas/metabolismo , Solo/química , Modelos Biológicos , Micorrizas/metabolismo , Fenômenos Fisiológicos da Nutrição , Fenômenos Fisiológicos Vegetais
17.
J Neurosci ; 33(42): 16698-714, 2013 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-24133272

RESUMO

Synaptic vesicles undergo sequential steps in preparation for neurotransmitter release. Individual SNARE proteins and the SNARE complex itself have been implicated in these processes. However, discrete effects of SNARE proteins on synaptic function have been difficult to assess using complete loss-of-function approaches. We therefore used a genetic titration technique in cultured mouse hippocampal neurons to evaluate the contribution of the neuronal SNARE protein Syntaxin1 (Stx1) in vesicle docking, priming, and release probability. We generated graded reductions of total Stx1 levels by combining two approaches, namely, endogenous hypomorphic expression of the isoform Stx1B and RNAi-mediated knockdown. Proximity of synaptic vesicles to the active zone was not strongly affected. However, overall release efficiency of affected neurons was severely impaired, as demonstrated by a smaller readily releasable pool size, slower refilling rate of primed vesicles, and lower release probability. Interestingly, dose-response fitting of Stx1 levels against readily releasable pool size and vesicular release probability showed similar Kd (dissociation constant) values at 18% and 19% of wild-type Stx1, with cooperativity estimates of 3.4 and 2.5, respectively. This strongly suggests that priming and vesicle fusion share the same molecular stoichiometry, and are governed by highly related mechanisms.


Assuntos
Exocitose/fisiologia , Sinapses/metabolismo , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/metabolismo , Sintaxina 1/metabolismo , Animais , Linhagem Celular , Hipocampo/citologia , Hipocampo/metabolismo , Fusão de Membrana/fisiologia , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Vesículas Sinápticas/genética , Sintaxina 1/genética
18.
Pediatr Pulmonol ; 47(12): 1204-14, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22782699

RESUMO

Mechanical ventilation (MV) is life-saving but potentially harmful for lungs of premature infants. So far, animal models dealt with the acute impact of MV on immature lungs, but less with its delayed effects. We used a newborn rodent model including non-surgical and therefore reversible intubation with moderate ventilation and hypothesized that there might be distinct gene expression patterns after a ventilation-free recovery period compared to acute effects directly after MV. Newborn rat pups were subjected to 8 hr of MV with 60% oxygen (O(2)), 24 hr after injection of lipopolysaccharide (LPS), intended to create a low inflammatory background as often recognized in preterm infants. Animals were separated in controls (CTRL), LPS injection (LPS), or full intervention with LPS and MV with 60% O(2) (LPS + MV + O(2)). Lungs were recovered either directly following (T:0 hr) or 48 hr after MV (T:48 hr). Histologically, signs of ventilator-induced lung injury (VILI) were observed in LPS + MV + O(2) lungs at T:0 hr, while changes appeared similar to those known from patients with chronic lung disease (CLD) with fewer albeit larger gas exchange units, at T:48 hr. At T:0 hr, LPS + MV + O(2) increased gene expression of pro-inflammatory MIP-2. In parallel anti-inflammatory IL-1Ra gene expression was increased in LPS and LPS + MV + O(2) groups. At T:48 hr, pro- and anti-inflammatory genes had returned to their basal expression. MMP-2 gene expression was decreased in LPS and LPS + MV + O(2) groups at T:0 hr, but no longer at T:48 hr. MMP-9 gene expression levels were unchanged directly after MV. However, at T:48 hr, gene and protein expression increased in LPS + MV + O(2) group. In conclusion, this study demonstrates the feasibility of delayed outcome measurements after a ventilation-free period in newborn rats and may help to further understand the time-course of molecular changes following MV. The differences obtained from the two time points could be interpreted as an initial transitory increase of inflammation and a delayed impact of the intervention on structure-related genes.


Assuntos
Citocinas/metabolismo , Pulmão/metabolismo , Metaloproteinases da Matriz/metabolismo , RNA Mensageiro/metabolismo , Respiração Artificial/efeitos adversos , Lesão Pulmonar Induzida por Ventilação Mecânica/metabolismo , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Pulmão/patologia , RNA Mensageiro/análise , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Lesão Pulmonar Induzida por Ventilação Mecânica/patologia
19.
Proc Natl Acad Sci U S A ; 109(9): 3406-11, 2012 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-22331889

RESUMO

Climate exerts a powerful influence on biological processes, but the effects of climate change on ecosystem nutrient flux and cycling are poorly resolved. Although rare, long-term records offer a unique opportunity to disentangle effects of climate from other anthropogenic influences. Here, we examine the longest and most complete record of watershed nutrient and climate dynamics available worldwide, which was collected at the Hubbard Brook Experimental Forest in the northeastern United States. We used empirical analyses and model calculations to distinguish between effects of climate change and past perturbations on the forest nitrogen (N) cycle. We find that climate alone cannot explain the occurrence of a dramatic >90% drop in watershed nitrate export over the past 46 y, despite longer growing seasons and higher soil temperatures. The strongest climate influence was an increase in soil temperature accompanied by a shift in paths of soil water flow within the watershed, but this effect explained, at best, only ∼40% of the nitrate decline. In contrast, at least 50-60% of the observed change in the N export could be explained by the long-lasting effect of forest cutting in the early 1900s on the N cycle of the soil and vegetation pools. Our analysis shows that historic events can obscure the influence of modern day stresses on the N cycle, even when analyses have the advantage of being informed by 0.5-century-long datasets. These findings raise fundamental questions about interpretations of long-term trends as a baseline for understanding how climate change influences complex ecosystems.


Assuntos
Mudança Climática , Ciclo do Nitrogênio , Árvores , Atmosfera , Desnitrificação , Ecossistema , Monitoramento Ambiental , Agricultura Florestal/métodos , Humanos , Estudos Longitudinais , Modelos Biológicos , New Hampshire , Nitratos/análise , Desenvolvimento Vegetal , Raízes de Plantas/metabolismo , Plantas/metabolismo , Solo/química , Microbiologia do Solo , Temperatura , Água/química , Microbiologia da Água
20.
Eur J Obstet Gynecol Reprod Biol ; 160(1): 13-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21982938

RESUMO

OBJECTIVE: To assess the seroprevalence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) IgG antibodies and the seroincidence of HSV-1 and HSV-2 infections in pregnant women attending the maternity clinic of the University Hospital Lausanne. STUDY DESIGN: Blood samples from 1030 women were taken at the usual pregnancy visit in the first trimester to assess the prevalence rate of IgG antibodies against HSV-1 and HSV-2 using a type-specific assay. A second blood sample was taken 6-8 weeks postpartum from returning women who were seronegative for HSV-2 or HSV-1 to assess the incidence of seroconversion (primary infection). RESULTS: The seroprevalence rates were 79.4% (95% CI: 76.9-81.9) for HSV-1 and 21.2% (18.7-23.7) for HSV-2 in women 14-46 years old. Type-specific serostatus patterns were as follows: 17.3% HSV-1/-2: +/+, 62.1% HSV-1/-2: +/-, 3.9% HSV-1/-2: -/+, 16.7% HSV-1/-2: -/-. Two hundred and sixty five women (59 of the 212 seronegative for HSV-1 (27.8%) and 265 of the 812 seronegative for HSV-2 (32.6%)) returned to the outpatient clinic for the post-delivery check and a second blood sample was obtained. One HSV-1 seroconversion was detected (HSV-1 seroconversion rate 2.4%/100 patient × year (95% CI: 0.06-13.4)) in a patient who had symptoms compatible with primary genital herpes. No HSV-2 seroconversion was detected (HSV-2 seroconversion rate: 0/100 patient × year (97.5% one-sided CI: 0-2)). CONCLUSION: Compared to a previous population-based study, our study results suggest a rise in the prevalence of HSV-2 among pregnant women in Switzerland. The low incidence of seroconversion detected during pregnancy is consistent with the very low reported incidence of neonatal herpes in Switzerland. CONDENSATION: This study in a public hospital in Western Switzerland suggests an increasing prevalence of HSV-2, but a low incidence of primary infections in women of childbearing age.


Assuntos
Herpes Genital/epidemiologia , Herpes Simples/epidemiologia , Herpesvirus Humano 1 , Herpesvirus Humano 2 , Complicações Infecciosas na Gravidez/epidemiologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Gravidez , Estudos Soroepidemiológicos , Suíça/epidemiologia
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