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1.
Rev Med Chil ; 149(2): 171-177, 2021 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-34479260

RESUMO

BACKGROUND: The number of patients waiting for a lung transplant worldwide greatly exceeds the number of available donors. Ex vivo lung perfusion is a useful tool that allows marginal donor lungs to be evaluated and reconditioned for a successful lung transplantation. AIM: To describe the first Chilean and Latin American experience in ex vivo lung perfusion for marginal donor lungs before transplantation. MATERIAL AND METHODS: Descriptive analysis of all ex vivo lung perfusion conducted for marginal donor lungs at a private clinic, from April 2019 to October 2020. High risk donor lungs and rejected lungs from other transplantation centers were included. The "Toronto Protocol" was used for ex vivo lung perfusion. Donor lung characteristics and recipient outcomes were studied. RESULTS: During the study period, five ex vivo lung perfusions were performed. All lungs were reconditioned and transplanted. No complications were associated. There were no primary graft dysfunctions and only one chronic allograft dysfunction. There was no mortality during the first year. The median arterial oxygen partial pressure/fractional inspired oxygen ratio increased from 266 mm Hg in the donor lung to 419 after 3 hours of ex vivo lung perfusion (p = 0.043). CONCLUSIONS: ex vivo lung perfusion is a safe and useful tool that allows marginal donor lungs to be reconditioned and successfully transplanted.


Assuntos
Transplante de Pulmão , Circulação Extracorpórea , Humanos , América Latina , Pulmão/cirurgia , Perfusão , Doadores de Tecidos
2.
J Environ Manage ; 235: 250-256, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30684810

RESUMO

In the Mediterranean Basin, changes in climate and fire regime (increased recurrence and severity) reduce ecosystem services after wildfires by increasing soil degradation and losses in plant diversity. Our study was a biological approach to relate soil properties to vegetation recovery and burn severity. We focused our study on the natural recovery of the soil-plant interphase in Pinus halepensis Mill. forests located in the SE of Iberian Peninsula, a semiarid climate. We included some chemical properties 3 years after fire (available phosphorus (P) and soil organic carbon (Corg), among others), and biological soil indicators 3 and 5 years after fire (i.e. basal soil respiration (BSR), microbial biomass carbon (Cmic), carbon mineralization coefficient (Cmineral), metabolic quotient (qCO2) and microbial quotient (Cmic:Corg)). We analyzed the activity of three different enzymes: urease (UR), phosphatase (PHP) and ß-glucosidase (GLU). The changes in most chemical properties were ephemeral, but P and Corg showed higher values in burned areas, and the highest were found for low-moderate severity. Plant recovery was the triggering factor for the recovery of Corg and biological soil function. Burn severity and time after fire influenced Cmic and the Cmic:Corg, which were higher for moderate-high severity 3 years later, but were below the unburned values 5 years after fire. The microbial activities of GLU and UR were recovered in burned areas 5 years after fire. The PHP values lowered according to higher burn severity and time after fire. The soil ecological trends obtained by a principal component analysis revealed a relationship linking GLU, BSR and qCO2 that explained soil response to burn severity. PHP, Cmic and Cmic:Corg explained most of the variability related to time after fire. Our results provide insights into how burn severity, in Mediterranean fire-prone Aleppo pine stands, modulated the natural plant recovery linked to soil biochemical and microbiological response to fire. High burn severity limited natural vegetation recovery, and both reduced biological soil functionality. This knowledge can be implemented in post-fire planning to apply post-fire management (for mitigation and restoration) in which the "no intervention" tool should be contemplated. These findings provide information to be applied in adaptive forest management to improve the resilience of vulnerable ecosystems and to reduce burn severity in future fire events.


Assuntos
Incêndios , Pinus , Incêndios Florestais , Ecossistema , Florestas , Solo
3.
J Environ Manage ; 241: 138-148, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30999263

RESUMO

The work aim is to identify the risk areas by exposure to Cr, Cu, Pb and Zn in the Metropolitan Zone of Toluca Valley (MZTV) using the mosses Fabriona cilaris and Leskea angustata as a biomonitors, geostatistical interpolation and multi-criteria evaluation by analytical hierarchy process. The results from the estimation of the enrichment factors (EF) showed that Pb is the heavy metal with the highest values, followed by the Zn, Cu and Cr. The EF obtained for all heavy metals show that there is a moderate to high anthropogenic enrichment. The above indicates that in the MZTV there are emission sources that contribute (significantly) in the amount of Cr, Cu, Pb and Zn accumulated in the biomonitor. Combustion processes, vehicle emissions, biomass burning, brick kiln emissions, agricultural and livestock activities, manufacturing industry and re-deposition by the action of the wind, were identified as the main heavy metals sources in the MZTV. Risk maps showed the high and medium risk areas are located in sites with poor urban vegetation coverage and close to highways and industrial parks. Low risk areas are located in sites with high urban vegetation coverage. The method used for identifying risk areas is a rapid and low-cost evaluation tool can allow local government environmental agencies to define public policies on air pollution control.


Assuntos
Briófitas , Metais Pesados , China , Monitoramento Ambiental , Solo , Emissões de Veículos
4.
J Neuroradiol ; 45(1): 32-40, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28865921

RESUMO

PURPOSE: To assess the diagnostic performance of normalized and non-normalized diffusion kurtosis imaging (DKI) metrics extracted from different tumor volume data for grading glioma according to the integrated approach of the revised 2016 WHO classification. MATERIALS AND METHODS: Sixty patients with histopathologically confirmed glioma, who provided written informed consent, were retrospectively assessed between 01/2013 and 08/2016 from a prospective trial approved by the local institutional review board. Mean kurtosis (MK) and mean diffusivity (MD) metrics from DKI were assessed by two blinded physicians from four different volumes of interest (VOI): whole solid tumor including (VOItu-ed) and excluding perifocal edema (VOItu), infiltrative zone (VOIed), and single slice of solid tumor core (VOIslice). Intra-class correlation coefficient (ICC) was calculated to assess inter-rater agreement. One-way ANOVA was used to compare MK between 2016 CNS WHO tumor grades. Friedman's test compared MK and MD of each VOI. Spearman's correlation coefficient was used to correlate MK with 2016 CNS WHO tumor grades. ROC analysis was performed on MK for significant results. RESULTS: The MK assessment showed excellent inter-rater agreement for each VOI (ICC, 0.906-0.955). MK was significantly lower in IDHmutant astrocytoma (0.40±0.07), than in 1p/19q-confirmed oligodendroglioma (0.54±0.10, P=0.001) or IDHwild-type glioblastoma (0.68±0.13, P<0.001). MK and 2016 WHO tumor grades were strongly and positively correlated (VOItu-ed, r=0.684; VOItu, r=0.734; VOIed, r=0.625; VOIslice, r=0.698; P<0.001). CONCLUSIONS: Non-normalized MK values obtained from VOItu and VOIslice showed the best reproducibility and highest diagnostic performance for stratifying glioma according to the integrated approach of the recent 2016 WHO classification.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Glioma/diagnóstico por imagem , Glioma/patologia , Biópsia , Neoplasias Encefálicas/genética , Meios de Contraste , Estudos de Viabilidade , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento Tridimensional , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Compostos Organometálicos , Estudos Retrospectivos , Organização Mundial da Saúde
5.
Rev Med Chil ; 146(11): 1261-1268, 2018 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-30725039

RESUMO

BACKGROUND: Pulmonary nodules are common, and surgery is the only alternative that allows a diagnostic and therapeutic management in a single procedure. AIM: To report the epidemiological, radiological, surgical and pathological features of excised pulmonary nodules. MATERIAL AND METHODS: Review of medical records of patients in whom a pulmonary nodule was excised between 2014 and 2018. Those with incomplete data or without a pathological study were excluded from analysis. RESULTS: We retrieved 108 records and 8 had to be excluded, therefore 100 patients aged 34 to 82 years (57% females) were analyzed. Sixty percent had a history of smoking. Mean nodule size was 16 mm and the solid type was the most common (65%). Forty five percent of nodules had irregular margins and 55% were in the superior lobes. All patients operated by video-assisted thoracoscopic surgery and 40% underwent a lobectomy. Malignant lesions were observed in 87% of biopsies and a pulmonary adenocarcinoma was found in pathology in 40%. CONCLUSIONS: A multidisciplinary approach of pulmonary nodules, using adapted international guidelines, accomplishes an appropriate management, decreasing unnecessary surgical interventions.


Assuntos
Adenocarcinoma de Pulmão/patologia , Carcinoma/patologia , Neoplasias Pulmonares/patologia , Nódulos Pulmonares Múltiplos/patologia , Adenocarcinoma de Pulmão/epidemiologia , Adenocarcinoma de Pulmão/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/epidemiologia , Carcinoma/cirurgia , Chile/epidemiologia , Feminino , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Nódulos Pulmonares Múltiplos/epidemiologia , Nódulos Pulmonares Múltiplos/cirurgia , Estudos Retrospectivos , Distribuição por Sexo , Cirurgia Torácica Vídeoassistida/métodos , Carga Tumoral
6.
Biochim Biophys Acta ; 1860(5): 868-878, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26476135

RESUMO

BACKGROUND: Conformational changes coupled to ligand binding constitute the structural and energetics basis underlying cooperativity, allostery and, in general, protein regulation. These conformational rearrangements are associated with heat capacity changes. ITC is a unique technique for studying binding interactions because of the simultaneous determination of the binding affinity and enthalpy, and for providing the best estimates of binding heat capacity changes. SCOPE OF REVIEW: Still controversial issues in ligand binding are the discrimination between the "conformational selection model" and the "induced fit model", and whether or not conformational changes lead to temperature dependent apparent binding heat capacities. The assessment of conformational changes associated with ligand binding by ITC is discussed. In addition, the "conformational selection" and "induced fit" models are reconciled, and discussed within the context of intrinsically (partially) unstructured proteins. MAJOR CONCLUSIONS: Conformational equilibrium is a major contribution to binding heat capacity changes. A simple model may explain both conformational selection and induced fit scenarios. A temperature-independent binding heat capacity does not necessarily indicate absence of conformational changes upon ligand binding. ITC provides information on the energetics of conformational changes associated with ligand binding (and other possible additional coupled equilibria). GENERAL SIGNIFICANCE: Preferential ligand binding to certain protein states leads to an equilibrium shift that is reflected in the coupling between ligand binding and additional equilibria. This represents the structural/energetic basis of the widespread dependence of ligand binding parameters on temperature, as well as pH, ionic strength and the concentration of other chemical species.


Assuntos
Proteínas de Bactérias/química , Modelos Químicos , Nucleoplasminas/química , Receptores de LDL/química , Regulação Alostérica , Sítios de Ligação , Flavodoxina/química , Protease de HIV/química , Temperatura Alta , Humanos , Cinética , Ligantes , Ligação Proteica , Conformação Proteica , Termodinâmica , Proteínas não Estruturais Virais/química
7.
Allergy ; 72(10): 1556-1564, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28317175

RESUMO

BACKGROUND: Occupational respiratory diseases in workers of peach tree crops have been reported punctually and have been associated with sensitization to proteins present in both pollen and leaf tree. We report the study of 37 workers with respiratory symptoms related to occupational exposure to peach trees. METHODS: Prick tests and specific IgE determinations were performed with extracts from leaves and branches of peach tree. Immunodetection in leaf extract was realized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis SDS-PAGE-immunoblotting with patient sera and rabbit serum anti-Pru p 3. Immunodetection inhibition was performed with rPru p 3 and pollen profilins. The clinical relevance of sensitization was demonstrated by specific bronchial challenge test (SBCT) with peach leaf extract. RESULTS: Most patients suffered symptoms when peach trees had leaves, specifically during thinning and harvesting fruit (rhinoconjunctivitis: 100% and asthma: 67.5%). Sensitization to leaf extract was demonstrated in 86% of patients. IgE-immunoblotting with peach leaf extract revealed in six patient sera a pair of bands of 10 and 16 kDa, and in nine a 16-kDa band. Those bands could be two isoforms of peach leaf lipid transfer proteins( LTP), so the recognition frequency of some LTP isoform by our patient sera was 42%. 33% of the sera recognized a doubled band of about 14.5 kDa and this recognition was inhibited by nPho d 2. The SBCT with peach leaf extract was positive in the asthmatic sensitized patients tested. CONCLUSIONS: Sensitization to peach leaves was the cause of occupational respiratory symptoms in our patients. Some patient sera revealed IgE-binding proteins matching LTP and/or profilin.


Assuntos
Produtos Agrícolas , Exposição Ocupacional/efeitos adversos , Prunus persica , Hipersensibilidade Respiratória/epidemiologia , Hipersensibilidade Respiratória/imunologia , Adolescente , Adulto , Idoso , Alérgenos/imunologia , Antígenos de Plantas/imunologia , Western Blotting , Testes de Provocação Brônquica , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Masculino , Pessoa de Meia-Idade , Hipersensibilidade Respiratória/diagnóstico , Testes Cutâneos , Adulto Jovem
8.
Eur Cell Mater ; 33: 59-75, 2017 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-28138955

RESUMO

Articular cartilage is a load-bearing tissue that lines the surface of bones in diarthrodial joints. Unfortunately, this avascular tissue has a limited capacity for intrinsic repair. Treatment options for articular cartilage defects include microfracture and arthroplasty; however, these strategies fail to generate tissue that adequately restores damaged cartilage. Limitations of current treatments for cartilage defects have prompted the field of cartilage tissue engineering, which seeks to integrate engineering and biological principles to promote the growth of new cartilage to replace damaged tissue. To date, a wide range of scaffolds and cell sources have emerged with a focus on recapitulating the microenvironments present during development or in adult tissue, in order to induce the formation of cartilaginous constructs with biochemical and mechanical properties of native tissue. Hydrogels have emerged as a promising scaffold due to the wide range of possible properties and the ability to entrap cells within the material. Towards improving cartilage repair, hydrogel design has advanced in recent years to improve their utility. Some of these advances include the development of improved network crosslinking (e.g. double-networks), new techniques to process hydrogels (e.g. 3D printing) and better incorporation of biological signals (e.g. controlled release). This review summarises these innovative approaches to engineer hydrogels towards cartilage repair, with an eye towards eventual clinical translation.


Assuntos
Cartilagem/fisiologia , Hidrogéis/farmacologia , Engenharia Tecidual/métodos , Engenharia Tecidual/tendências , Animais , Cartilagem/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Humanos , Hidrogéis/química , Porosidade , Alicerces Teciduais/química
9.
J Dairy Sci ; 100(8): 6256-6265, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28601449

RESUMO

Chia seed (Salvia hispanica L.) is the greatest known plant source of n-3 α-linolenic acid. The present study evaluated the effects of 3 inclusion levels of chia seed [zero (control); low, 2.7% (CLow); and high, 5.5% (CHigh)] in diets of dairy goats on milk yield and fatty acid profile. Nine Saanen dairy goats in the last third of lactation period, live weight 38 ± 8.7 kg, housed in metabolic cages, were fed iso-proteic and iso-energetic (160 g of crude protein/d and 11 MJ of metabolizable energy/d) diets. Gas chromatography was used to analyze fatty acid profile and total conjugated linoleic acid (CLA). Silver ion HPLC was used to analyze the isomeric profile of CLA. The results were subjected to variance analysis using a Latin square design repeated 3 × 3. The CHigh treatment was higher for dry matter, neutral detergent fiber, and acid detergent fiber intake compared with CLow and control diets. Digestibility was not affected by the inclusion of chia seeds. The CHigh diet improved N intake with respect to the control and CLow diet. Milk yield and chemical composition were not affected by the treatment. The milk fatty acid profile of C18:0, C18:1, C18:2, and C:20 was higher for CHigh than the other treatments. The in vitro gas production (mL of gas/g of dry matter) was lower in CHigh than the control diet. In conclusion, the addition of chia seeds at the CHigh level in dairy goat diets negatively affected in vitro rumen fermentation, but increased the milk fatty acid profile of C18:0, C18:1n-9 cis, and C:20, monounsaturated fatty acids, and polyunsaturated fatty acids. The total CLA content increased from 0.33 to 0.73% with the supplementation of chia to the diet, as well as the isomers cis-9,trans-11, trans-7,cis-9, trans-11,cis-13, and trans-12,trans-14.


Assuntos
Ácidos Graxos/análise , Cabras/metabolismo , Leite/química , Salvia , Animais , Dieta , Feminino , Lactação , Ácidos Linoleicos Conjugados , Rúmen , Sementes
10.
Phys Chem Chem Phys ; 18(16): 11017-41, 2016 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-27047995

RESUMO

Dynamic nuclear polarization (DNP) experiments on samples with several types of magnetic nuclei sometimes exhibit "cross-talk" between the nuclei, such as different nuclei having DNP spectra with similar shapes and enhancements. In this work we demonstrate that while at 20 K the DNP spectra of (1)H and (2)H nuclei, in a sample composed of 50% v/v (1)H2O/DMSO-d6 and containing 40 mM TEMPOL, are different and can be analyzed using the indirect cross effect (iCE) model, at 6 K the DNP spectra of both (1)H and (2)H nuclei become identical. In addition we experimentally demonstrate that there exists an efficient polarization exchange between the two nuclear pools at this temperature. Both of these results are hallmark predictions of the thermal mixing (TM) formalism. However, the origin of these observations cannot, in our case, be explained using the standard TM formalism, as in our sample the electron reservoir cannot be described by a single non-Zeeman spin temperature, which is a prerequisite of TM. This conclusion follows from the analysis of the electron electron double resonance (ELDOR) experiments on our sample and is similar to the previously published results. Consequently, another mechanism must be used in order to explain these "cross-talk" effects. The heteronuclear cross effect (hnCE) DNP mechanism, previously introduced based on the simulations of the spin evolution in small model systems, results in "cross-talk" effects between two types of nuclei that are similar to the experimental ones seen in this work. In particular we show that the hnCE mechanism exhibits polarization transfer between the nuclei and that there exists a clear relationship between the steady state polarizations of the two types of nuclei which may, in the future, be correlated with the phenomenon observed in the two types of bulk nuclear signals in samples during DNP experiments. It is suggested that the hnCE electrons are a possible source for the process that equalizes the bulk enhancements of the (1)H and (2)H nuclei and are responsible for the observed cross-talk effects.

11.
Poult Sci ; 95(3): 676-83, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26628341

RESUMO

While horizontal transmission is a route clearly linked to the spread of Campylobacter at the farm level, few studies support the transmission of Campylobacter spp. from breeder flocks to their offspring. Thus, the present study was carried out to investigate the possibility of vertical transmission. Breeders were monitored from the time of housing day-old chicks, then throughout the laying period (0 to 60 wk) and throughout their progeny (broiler fattening, 1 to 42 d) until slaughter. All samples were analyzed according with official method ISO 10272:2006. Results revealed that on breeder farms, Campylobacter isolation started from wk 16 and reached its peak at wk 26, with 57.0% and 93.2% of positive birds, respectively. After this point, the rate of positive birds decreased slightly to 86.0% at 60 wk. However, in broiler production all day-old chicks were found negative for Campylobacter spp, and the bacteria was first isolated at d 14 of age (5.0%), with a significant increase in detection during the fattening period with 62% of Campylobacter positive animals at the end of the production cycle. Moreover, non-positive sample was determined from environmental sources. These results could be explained because Campylobacter may be in a low concentration or in a non-culturable form, as there were several studies that successfully detected Campylobacter DNA, but failed to culture. This form can survive in the environment and infect successive flocks; consequently, further studies are needed to develop more modern, practical, cost-effective and suitable techniques for routine diagnosis.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter/fisiologia , Galinhas , Doenças das Aves Domésticas/microbiologia , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/transmissão , Feminino , Estudos Longitudinais , Masculino , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/transmissão , Espanha/epidemiologia
12.
Rev Med Chil ; 144(9): 1164-1170, 2016 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-28060978

RESUMO

BACKGROUND: People with psychiatric disorders have higher rates of obesity, diabetes mellitus and dyslipidemia. These comorbidities are associated with the underlying psychopathology and drug therapy. AIM: To determine the quality and quantity of carbohydrates and fatty acids in the diet and their association with anthropometric parameters in subjects with schizophrenia and bipolar disorders. PATIENTS AND METHODS: We studied 30 patients with schizophrenia and bipolar disorders in treatment with atypical antipsychotics or mood stabilizers. Three 24-hour recall dietary surveys were carried out. Glycemic index, intake of carbohydrates and fatty acids (g/day) were calculated, and the ratio of saturated, monounsaturated and polyunsaturated fatty acids was determined. Body mass index, waist circumference (WC) and body fat percentage were evaluated. RESULTS: The average intakes of carbohydrates and fatty acids were 295 ± 111 and 73 ± 38 g/day respectively. The mean glycemic index was 59% ± 5.4, while the ratio of saturated, monounsaturated and polyunsaturated fatty acids was 2: 1.4: 0.6. No association between dietary and anthropometric variables was found. Patients using second-generation antipsychotics had a significantly higher waist circumference than those using mood stabilizing drugs. CONCLUSIONS: We found no association between the amount and quality of carbohydrate or fatty acid dietary intake and anthropometric parameters.


Assuntos
Transtorno Bipolar/fisiopatologia , Carboidratos da Dieta/análise , Gorduras na Dieta/análise , Esquizofrenia/fisiopatologia , Circunferência da Cintura/fisiologia , Adulto , Idoso , Feminino , Índice Glicêmico/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estado Nutricional/fisiologia , Inquéritos e Questionários , Adulto Jovem
13.
Phys Chem Chem Phys ; 17(8): 6053-65, 2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25640165

RESUMO

Dynamic Nuclear Polarization (DNP) experiments on solid dielectrics can be described in terms of the Solid Effect (SE) and Cross Effect (CE) mechanisms. These mechanisms are best understood by following the spin dynamics in electron-nuclear and electron-electron-nuclear model systems, respectively. Recently it was shown that the frequency swept DNP enhancement profiles can be reconstructed by combining basic SE and CE DNP spectra. However, this analysis did not take into account the role of the electron spectral diffusion (eSD), which can result in a dramatic loss of electron polarization along the EPR line. In this paper we extend the analysis of DNP spectra by including the influence of the eSD process on the enhancement profiles. We show for an electron-electron-nuclear model system that the change in nuclear polarization can be caused by direct MW irradiation on the CE electron transitions, resulting in a direct CE (dCE) enhancement, or by the influence of the eSD process on the spin system, resulting in nuclear enhancements via a process we term the indirect CE (iCE). We next derive the dependence of the basic SE, dCE, and iCE DNP spectra on the electron polarization distribution along the EPR line and on the MW irradiation frequency. The electron polarization can be obtained from ELDOR experiments, using a recent model which describes its temporal evolution in real samples. Finally, DNP and ELDOR spectra, recorded for a 40 mM TEMPOL sample at 10-40 K, are analyzed. It is shown that the iCE is the major mechanism responsible for the bulk nuclear enhancement at all temperatures.

14.
Phys Chem Chem Phys ; 17(1): 226-44, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25384575

RESUMO

Dynamic nuclear polarization is typically explained either using microscopic systems, such as in the solid effect and cross effect mechanisms, or using the macroscopic formalism of spin temperature which assumes that the state of the electrons can be described using temperature coefficients, giving rise to the thermal mixing mechanism. The distinction between these mechanisms is typically made by measuring the DNP spectrum - i.e. the nuclear enhancement profile as a function of irradiation frequency. In particular, we have previously used the solid effect and cross effect mechanisms to explain temperature dependent DNP spectra. Our past analysis has however neglected the effect of depolarization of the electrons resulting from the microwave (MW) irradiation. In this work we concentrate on this electron depolarization process and perform electron-electron double resonance (ELDOR) experiments on TEMPOL and trityl frozen solutions, using a 3.34 Tesla magnet and at 2.7-30 K, in order to measure the state of the electron polarization during DNP. The experiments indicate that a significant part of the EPR line is affected by the irradiation due to spectral diffusion. Using a theoretical framework based on rate equations for the polarizations of the different electron spin packets and for those of the nuclei we simulated the various ELDOR line-shapes and reproduced the MW frequency and irradiation time dependence. The obtained electron polarization distribution cannot be described using temperature coefficients as required by the classical thermal mixing mechanism, and therefore the DNP mechanism cannot be described by thermal mixing. Instead, the theoretical framework presented here for the analysis of the ELDOR data forms a basis for future interpretation of DNP spectra in combination with EPR measurements.

15.
Spinal Cord ; 53(11): 791-4, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26078232

RESUMO

STUDY DESIGN: A prospective cohort with acute tetraplegia. OBJECTIVE: The purpose of this study was to investigate acute changes in serum brain-derived neurotrophic factor (BDNF) concentrations in tetraplegic spinal cord-injured (SCI) athletes during a typical training session of wheelchair rugby. SETTINGS: German Sport University Cologne, Cologne, Germany. METHODS: Eleven male SCI (AIS A and B) athletes completed a 90-min training session: The warm-up period included continuous pushing, submaximal increasing sprints and agility drills. The main training section comprised ball handling, passing drills, scrimmage activity and tactical practice. At the end of the training session, the athletes did moderate continuous pushing as a short cool-down. Venous blood samples were taken at rest before exercise, after the warm-up period and immediately following the first part of the main training section. Serum was pipetted after 30 min of blood sample resting and a subsequent centrifugation. BDNF concentrations were measured using an enzyme immunoassay ELISA kit. RESULTS: Heart rate (P < 0.01) and lactate (P = 0.04 and P < 0.01) concentration differed significantly in warm-up and main training part in comparison with basal values at rest. At rest, BDNF concentrations were 33.2 ± 21.6 ng ml(-1), after warm up 31.9 ± 18.9 ng ml(-1) and after the training session 29.9 ± 11 ng ml(-1), without significant differences (P > 0.05). CONCLUSIONS: A typical wheelchair rugby training session does not affect basal serum BDNF concentration in elite SCI athletes. In comparison with concentrations previously reported in healthy subjects, the current values at rest were slightly higher or rather at the upper limit.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Exercício Físico/fisiologia , Quadriplegia/sangue , Adulto , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/metabolismo , Masculino , Pessoa de Meia-Idade , Quadriplegia/etiologia , Quadriplegia/reabilitação , Traumatismos da Medula Espinal/complicações , Cadeiras de Rodas
16.
Poult Sci ; 94(4): 766-71, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25743419

RESUMO

Campylobacter is the most common bacterial cause of human gastrointestinal disease in most developed countries. It is generally accepted that poultry products are a significant source of foodborne Campylobacter infections in humans. Assessing the effectiveness of any potential intervention at farm level requires monitoring of the Campylobacter status of broiler flocks, using appropriate sampling methods. The aim of this study was to assess the influence of the sample type across the rearing period for the detection of Campylobacter spp. at farm level. During this study, 21 commercial broiler farms were intensively sampled. Each farm was visited and sampled at different times during the rearing period (d 1, 7, 14, 21, 28, 35, and 42). On the first day of rearing, the status of the house and the day-old flock was evaluated, and environmental and cecal samples were collected. During rearing, 4 different sample types were collected: feces with sock swabs (sock swabs), feces directly from the litter (feces), cloacal swabs, and cecal content. All samples were analyzed according to ISO 10272-1:2006 (Annex E) and also by direct culture. The results of this study showed that Campylobacter spp. were detected in all of the sample types on d 14 of rearing. From this point on, the detection increased significantly, with a maximum detection rate by the end of rearing, regardless of the sample type. All samples that were negative upon direct culture were also negative after pre-enrichment. At the end of rearing, the percentage of samples positive for Campylobacter spp. was 71.4% for cecal samples, 61.9% for cloacal swabs, 45.2% for sock swabs, and 69.1% for fecal samples. C. jejuni was detected in all the sample types, with positive rates ranging from 67.1 to 76.0% for cecal samples and cloacal content, respectively. Cecal samples, cloacal swabs, and fecal samples cultured by direct plating onto modified charcoal cefoperazone deoxycholate agar (mCCDA) without pre-enrichment have the same sensitivity for detection of Campylobacter spp. in broiler flocks independent of the day of rearing.


Assuntos
Técnicas Bacteriológicas/veterinária , Infecções por Campylobacter/veterinária , Campylobacter/isolamento & purificação , Galinhas , Doenças das Aves Domésticas/epidemiologia , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Ceco/microbiologia , Cloaca/microbiologia , Fezes/microbiologia , Conteúdo Gastrointestinal/microbiologia , Doenças das Aves Domésticas/microbiologia
17.
Rev Med Chil ; 143(2): 147-57, 2015 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-25860356

RESUMO

BACKGROUND: There is a gap between the number of patients requiring a renal allograft and the number of potential deceased donors (DD). One alternative is using allografts from non-related living donors (NRLD). AIM: To compare survival and complications of renal allograft recipients from DD, related living donors (RLD) and NRLD. MATERIAL AND METHODS: Observational study of a cohort of renal allograft recipients. Of 253 transplants performed in a Chilean region between 1981 and 2003, 20 patients received and allograft from a NRLD. Graft and patient survival of these patients were compared with those of 93 patients receiving an allograft from a related living donor and 140 receiving it from a DD. Patients were followed for 10 years or until death or dialysis requirement. RESULTS: No significant differences between groups in graft and patient survival, deaths with a functioning graft or return to dialysis were observed. Receptors of DD had more hospital admissions during the first years after receiving the graft, usually due to infections. Also a delayed graft function was more common among them. Glomerular filtration rate ten years after the graft was similar among the three groups. CONCLUSIONS: No differences in graft or patient survival was observed between patients receiving a renal allograft from NRLD, RLD or DD.


Assuntos
Aloenxertos/estatística & dados numéricos , Sobrevivência de Enxerto/fisiologia , Transplante de Rim/mortalidade , Doadores Vivos , Doadores não Relacionados/estatística & dados numéricos , Adulto , Causas de Morte , Chile/epidemiologia , Feminino , Seguimentos , Taxa de Filtração Glomerular/fisiologia , Hospitalização/estatística & dados numéricos , Humanos , Terapia de Imunossupressão/estatística & dados numéricos , Infecções/complicações , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
18.
Rev Biol Trop ; 63(3): 579-90, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26666116

RESUMO

Changes in land use are mainly a consequence of anthropogenic actions. The current agricultural and urban transformations in Costa Rica have raised questions about the effectiveness of conservation and restoration within protected areas. Herein we analyzed the patterns of land use change between three periods: 1997, 2005 and 2010 in terms of magnitude, direction, and pace through categorical maps generated by the photointerpretation for La Cangreja National Park (LCNP), Rancho Mastatal Wildlife Refuge (RMWR), and their surrounding areas (SA), this last compound of one kilometer radius outside the protected areas' boundaries. The matrix which describes the landscape within the protected areas is natural coverage, composed mainly by forest cover and thickets. We found that the most abundant natural cover for both protected areas was forest cover for all years tested. The stability and large areas of forest cover in LCNP and RMWR for 2005 and 2010, reflected that policies, management actions and vigilance, have a positive impact on the conservation and restoration of natural habitats in these Costa Rican Central Pacific areas. However, the high landscape complexity of the SA in 1997, 2005 and 2010 was an evidence of the anthropogenic pressure on these protected areas, and suggested the ineffectiveness of local governments to monitor and abate land use changes, that could hinder the management, conservation and restoration of species in the protected areas.


Assuntos
Conservação dos Recursos Naturais , Florestas , Agricultura , Costa Rica , Ecossistema , Recuperação e Remediação Ambiental , Sistemas de Informação Geográfica
19.
J Clin Immunol ; 34(1): 119-22, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24292696

RESUMO

PURPOSE: We present a patient with Bruton's disease and bronchiectasis who developed renal AA amyloidosis. CASE REPORT: A 38 year-old man was diagnosed with X-linked agammaglobulinemia (Bruton's disease) when he was 3 years old, and he has been treated with parenteral immunoglobulin since then. Eighteen years later, he was diagnosed with central pulmonary bronchiectasis by computerized tomography (CT). In 2008, he gradually developed anemia, edema of lower limbs, and loss of weight. METHOD AND RESULTS: Laboratory studies revealed deterioration of renal function, normocytic normochromic anemia and nephrotic range proteinuria. Hepatitis B and C and HIV serology were negative. Ultrasound and CT of abdomen were normal. A renal biopsy revealed deposits with positive PAS and Congo red staining in glomeruli, interstitium, and vessel's walls. Immunohistochemistry showed positive staining of the A amyloid. Direct immunofluorescence was positive with thioflavin and showed focal and glomerular mesangial IgG deposits, suggesting renal AA amyloidosis. For 2 years the patient conducted pharmacological treatment and follow-up for the Nephrology department with poor prognosis and progression of renal function impairment. In January 2011 he began dialysis treatment with improvement, and he is currently on the waiting list for renal transplantation. CONCLUSION: We present a patient with Bruton's disease and bronchiectasis who developed renal AA amyloidosis a finding rarely reported.


Assuntos
Agamaglobulinemia/complicações , Amiloidose/etiologia , Bronquiectasia/complicações , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Nefropatias/etiologia , Adulto , Amiloide/metabolismo , Amiloidose/diagnóstico , Biópsia , Humanos , Rim/patologia , Nefropatias/diagnóstico , Masculino
20.
Phys Chem Chem Phys ; 16(36): 19218-28, 2014 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-25096750

RESUMO

The microwave frequency swept DNP enhancement, referred to as the DNP spectrum, is strongly dependent on the EPR spectrum of the polarizing radical and it reveals the underlying DNP mechanisms. Here we focus on two chlorinated trityl radicals that feature axially symmetric powder patterns at 95 GHz, the width of which are narrower than those of TEMPOL or TOTAPOL but broader than that of the trityl derivative OX63. The static DNP lineshapes of these commonly used radicals in DNP, have been recently analyzed in terms of a superposition of basic Solid Effect (SE) and Cross Effect (CE)-DNP lineshapes, with their relative contributions as a fit parameter. To substantiate the generality of this approach and further investigate an earlier suggestion that a (35,37)Cl-(13)C polarization transfer pathway, termed "hetero-nuclear assisted DNP", may be in effect in the chlorinated radicals (C. Gabellieri et al., Angew. Chem., Int. Ed., 2010, 49, 3360-3362), we measured the static (13)C-glycerol DNP spectra of solutions of ca. ∼10 mM of the two chlorinated trityl radicals as a function of temperature (10-50 K) and microwave power. Analysis of the DNP lineshapes was first done in terms of the SE/CE superposition model calculated assuming a direct e-(13)C polarization transfer. The CE was found to prevail at the high temperature range (40-50 K), whereas at the low temperature end (10-20 K) the SE dominates, as was observed earlier for (13)C DNP with OX63 and (1)H DNP with TEMPOL and TOTAPOL, thus indicating that this is rather general behavior. Furthermore, it was found that at low temperatures it is possible to suppress the SE, and increase the CE by merely lowering the microwave power. While this analysis gave a good agreement between experimental and calculated lineshapes when the CE dominates, some significant discrepancies were observed at low temperatures, where the SE dominates. We show that by explicitly taking into account the presence of (35/37)Cl nuclei through a e-(35,37)Cl-(13)C polarization pathway in the SE-DNP lineshape calculations, as proposed earlier, we can improve the fit significantly, thus supporting the existence of the "hetero-nuclear assisted DNP" pathway.


Assuntos
Cloro/química , Compostos de Tritil/química , Isótopos de Carbono , Radicais Livres/química , Isótopos , Espectroscopia de Ressonância Magnética , Micro-Ondas
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