RESUMO
Measurements of net primary productivity (NPP) and litter decomposition from tropical peatlands are severely lacking, limiting our ability to parameterise and validate models of tropical peatland development and thereby make robust predictions of how these systems will respond to future environmental and climatic change. Here, we present total NPP (i.e., above- and below-ground) and decomposition data from two floristically and structurally distinct forested peatland sites within the Pastaza Marañón Foreland Basin, northern Peru, the largest tropical peatland area in Amazonia: (1) a palm (largely Mauritia flexuosa) dominated swamp forest and (2) a hardwood dominated swamp forest (known as 'pole forest', due to the abundance of thin-stemmed trees). Total NPP in the palm forest and hardwood-dominated forest (9.83 ± 1.43 and 7.34 ± 0.84 Mg C ha-1 year-1, respectively) was low compared with values reported for terra firme forest in the region (14.21-15.01 Mg C ha-1 year-1) and for tropical peatlands elsewhere (11.06 and 13.20 Mg C ha-1 year-1). Despite the similar total NPP of the two forest types, there were considerable differences in the distribution of NPP. Fine root NPP was seven times higher in the palm forest (4.56 ± 1.05 Mg C ha-1 year-1) than in the hardwood forest (0.61 ± 0.22 Mg C ha-1 year-1). Above-ground palm NPP, a frequently overlooked component, made large contributions to total NPP in the palm-dominated forest, accounting for 41% (14% in the hardwood-dominated forest). Conversely, Mauritia flexuosa litter decomposition rates were the same in both plots: highest for leaf material, followed by root and then stem material (21%, 77% and 86% of mass remaining after 1 year respectively for both plots). Our results suggest potential differences in these two peatland types' responses to climate and other environmental changes and will assist in future modelling studies of these systems.
Mediciones de la productividad primaria neta (PPN) y la descomposición de materia orgánica de las turberas tropicales son escasas, lo que limita nuestra capacidad para parametrizar y validar modelos de desarrollo de las turberas tropicales y, en consecuencia, realizar predicciones sólidas sobre la respuesta de estos sistemas ante futuros cambios ambientales y climáticos. En este estudio, presentamos datos de PPN total (es decir, biomasa aérea y subterránea) y descomposición de la materia orgánica colectada en dos turberas boscosas con características florísticas y estructurales contrastantes dentro de la cuenca Pastaza Marañón al norte del Perú, el área de turberas tropicales más grande de la Amazonia: (1) un bosque pantanoso dominado por palmeras (principalmente Mauritia flexuosa) y (2) un bosque pantanosos dominado por árboles leñosos de tallo delgado (conocido como 'varillal hidromórfico'). La PPN total en el bosque de palmeras y el varillal hidromórfico (9,83 ± 1,43 y 7,34 ± 0,84 Mg C ha1 año1 respectivamente) fue baja en comparación con los valores reportados para los bosques de tierra firme en la región (14,2115,01 Mg C ha1 año1) y para turberas tropicales en otros lugares (11,06 y 13,20 Mg C ha1 año1). A pesar de que la PPN total fue similar en ambos tipos de bosque, hubo diferencias considerables en la distribución de la PPN. La PPN de las raíces finas fue siete veces mayor en el bosque de palmeras (4,56 ± 1,05 Mg C ha1 año1) que en el varillal hidromórfico (0,61 ± 0,22 Mg C ha1 año1). La PPN de la biomasa aérea de las palmeras, un componente ignorado frecuentemente, contribuyó en gran medida a la PPN total del bosque de palmeras, representando el 41% (14% en el varillal hidromórfico). Por el contrario, la tasa de descomposición de materia orgánica de Mauritia flexuosa fue la misma en ambos sitios: la más alta corresponde a la hojarasca, seguida por las raíces y luego el tallo (21%, 77% y 86% de la masa restante después de un año, respectivamente para ambos sitios). Nuestros resultados sugieren diferencias potenciales en la respuesta de estos dos tipos de turberas al clima y otros cambios ambientales, y ayudarán en futuros estudios de modelamiento de estos sistemas.
Assuntos
Florestas , Peru , Áreas Alagadas , Solo/química , Folhas de Planta/metabolismo , Clima TropicalRESUMO
PURPOSE: Surgery is associated with a post-operative stress response, changes in cardiopulmonary reserve, and metabolic demand. Here recovery after abdominal aortic aneurysm repair is investigated using cardiopulmonary exercise testing and patient-reported questionnaires. MATERIALS AND METHODS: Patients undergoing open (n = 21) or endovascular (n = 21) repair undertook cardiopulmonary exercise tests, activity, and health score questionnaires pre-operatively and, 8 and 16 weeks, post-operatively. Oxygen uptake and ventilatory parameters were measured, and routine blood tests were undertaken. RESULTS: Recovery was characterised by falls in anaerobic threshold, peak oxygen uptake, and oxygen pulse at 8 weeks which appeared to be associated with operative severity; the fall in peak oxygen uptake was greater following open vs. endovascular repair (3.5 vs. 1.6 ml.kg-1.min-1) and anaerobic threshold showed a similar tendency (3.1 vs. 1.7 ml.kg-1.min-1). In the smaller number of patients re-tested these changes resolved by 16 weeks. Reported health and activity did not change. CONCLUSIONS: Aortic repair is associated with falls in the anaerobic threshold, peak oxygen uptake, and oxygen pulse of a magnitude that reflects operative severity and appears to resolve by 16 weeks. Thus, post-operatively patients may be at higher risk of further metabolic insult e.g. infection. This further characterises physiological recovery from aortic surgery and may assist in defining post-operative shielding time.IMPLICATIONS FOR REHABILITATIONAbdominal aortic aneurysm repair is a life-saving operation, the outcome from which is influenced by pre-operative cardiopulmonary reserve; individuals with poor reserve being at greater risk of peri-operative complications and death. However, for this operation, the physiological impact of surgery has not been studied.In a relatively small sample, this study suggests that AAA repair is associated with a significant decline in cardiopulmonary reserve when measured 8 weeks post-operatively and appears to recover by 16 weeks. Moreover, the impact may be greater in endovascular vs. open repair.
Assuntos
Aneurisma da Aorta Abdominal , Procedimentos Endovasculares , Humanos , Teste de Esforço , Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Cirúrgicos Vasculares , Medidas de Resultados Relatados pelo Paciente , Oxigênio , Resultado do Tratamento , Fatores de Risco , Complicações Pós-Operatórias/etiologia , Estudos RetrospectivosRESUMO
Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-destructive measurements of tree form independent of tree size and shape. We show examples of three-dimensional (3D) TLS measurements from various tropical and temperate forests and describe how the resulting TLS point clouds can be used to produce quantitative 3D models of branch and trunk size, shape and distribution. These models can drastically improve estimates of AGB, provide new, improved large-scale ASEs, and deliver insights into a range of fundamental tree properties related to structure. Large quantities of detailed measurements of individual 3D tree structure also have the potential to open new and exciting avenues of research in areas where difficulties of measurement have until now prevented statistical approaches to detecting and understanding underlying patterns of scaling, form and function. We discuss these opportunities and some of the challenges that remain to be overcome to enable wider adoption of TLS methods.
RESUMO
Equine obesity can cause life-threatening secondary chronic conditions, similar to those in humans and other animal species. Equine metabolic syndrome (EMS), primarily characterized by hyperinsulinemia, is often present in obese horses and ponies. Due to clinical similarities to conditions such as pituitary pars intermedia dysfunction (formerly equine Cushing's disease), conclusive diagnosis of EMS often proves challenging. Aside from changes in diet and exercise, few targeted treatments are available for EMS, emphasizing the need for early identification of at-risk individuals to enable implementation of preventative measures. A genomewide association study (GWAS) using Arabian horses with a history of severe laminitis secondary to EMS revealed significant genetic markers near a single candidate gene () that may play a role in cholesterol homeostasis. The best marker, BIEC2-263524 (chr14:69276814 T > C), was correlated with elevated insulin values and increased frequency of laminitis ( = 0.0024 and = 9.663 × 10, respectively). In a second population of Arabian horses, the BIEC2-263524 marker maintained its associations with higher modified insulin-to-glucose ratio (MIRG) values ( = 0.0056) and BCS ( = 0.0063). Screening of the predicted coding regions by sequencing identified a polymorphic guanine homopolymer and 5 haplotypes in the 3' untranslated region (UTR). An 11 guanine (11-G) allele at was correlated with elevated insulin values in the GWAS population ( = 0.0008) and, in the second population, elevated MIRG and increased BCS > 6.5 ( = 0.0055 and = 0.0162, respectively). The BIEC2-263524-C and the 3' UTR -11(G) polymorphisms were correlated at a 98% frequency, indicating strong linkage disequilibrium across this 150-kb haplotype. Assays for these markers could diagnose horses with a genetic predisposition to develop obesity. Additionally, discovery of FAM174A function may improve our understanding of the etiology of this troubling illness in the horse and warrants investigation of this locus for a role in metabolic- and obesity-related disorders of other species.
Assuntos
Estudo de Associação Genômica Ampla , Doenças dos Cavalos/genética , Síndrome Metabólica/veterinária , Obesidade/veterinária , Animais , Predisposição Genética para Doença , Cavalos , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Obesidade/genéticaRESUMO
Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.
Assuntos
Dióxido de Carbono/análise , Sequestro de Carbono , Floresta Úmida , Atmosfera/química , Biomassa , Brasil , Carbono/análise , Carbono/metabolismo , Dióxido de Carbono/metabolismo , Caules de Planta/metabolismo , Árvores/crescimento & desenvolvimento , Árvores/metabolismo , Clima Tropical , Madeira/análiseRESUMO
OBJECTIVE: To use real-time human milk macronutrient analysis to calculate final composition following fortification. STUDY DESIGN: Preterm HM (PHM) and pooled donor human milks (DHM) were analyzed by mid-infrared spectroscopy for protein, fat and lactose. Energy content was calculated from macronutrient results. Three lactation stages were constructed. DHM was compared to PHM. Four milk sample profiles were selected to demonstrate individualized fortification results. RESULTS: Lactose was similar in PHM and DHM. Protein in PHM showed the expected decline as lactation progressed. DHM protein was significantly lower vs. PHM. Fat was highly variable and lowest in DHM. Using standard fortification protocols, not all fortified milks met targets for protein and energy. Individualized fortification resulted in milks closer to target recommendations. CONCLUSIONS: Real-time analysis of HM provides assessment of the macronutrient content of the milk and can guide fortification. Individualized protocols, based on actual milk macronutrient profiles, may need to be considered to avoid unexpected nutrient content.
Assuntos
Alimentos Fortificados/análise , Leite Humano/química , Valor Nutritivo , Gorduras na Dieta/análise , Humanos , Lactose/análise , Proteínas do Leite/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodosRESUMO
We present a GIS method to interpret qualitatively expressed socio-economic scenarios in quantitative map-based terms. (i) We built scenarios using local stakeholders and experts to define how major land cover classes may change under different sets of drivers; (ii) we formalized these as spatially explicit rules, for example agriculture can only occur on certain soil types; (iii) we created a future land cover map which can then be used to model ecosystem services. We illustrate this for carbon storage in the Eastern Arc Mountains of Tanzania using two scenarios: the first based on sustainable development, the second based on 'business as usual' with continued forest-woodland degradation and poor protection of existing forest reserves. Between 2000 and 2025 4% of carbon stocks were lost under the first scenario compared to a loss of 41% of carbon stocks under the second scenario. Quantifying the impacts of differing future scenarios using the method we document here will be important if payments for ecosystem services are to be used to change policy in order to maintain critical ecosystem services.
Assuntos
Ecossistema , Sistemas de Informação Geográfica , Modelos Teóricos , Fatores Socioeconômicos , TanzâniaRESUMO
OBJECTIVE: To evaluate early amino-acid (AA) administration in extremely low birth weight (ELBW) infants over three time periods, beginning with the initiation of this strategy. STUDY DESIGN: This was a retrospective study of ELBW infants between 2000 and 2007. Nutritional intake and laboratory results were monitored during the first 5 days of life. Growth rates and complications were followed until discharge. RESULT: Infants were similar in birth weight (BW), gestational age (GA) and severity of illness. The age at initiation of AA decreased significantly over time. Age at weight nadir, return to BW and percent postnatal weight loss decreased in epoch 3. There were modest increases in blood urea nitrogen (BUN), but no significant metabolic disturbances were observed. Cholestasis was more prevalent in epoch 2. CONCLUSION: AA administration within the first hours of life appears to be safe and beneficial for ELBW infants. Absent signs of renal dysfunction, a modest rise in BUN is consistent with the neonate's utilization of AAs for energy.
Assuntos
Aminoácidos/administração & dosagem , Recém-Nascido de Peso Extremamente Baixo ao Nascer/metabolismo , Recém-Nascido Prematuro/metabolismo , Nutrição Parenteral/métodos , Aumento de Peso , Aminoácidos/metabolismo , Nitrogênio da Ureia Sanguínea , Humanos , Recém-Nascido de Peso Extremamente Baixo ao Nascer/crescimento & desenvolvimento , Recém-Nascido , Recém-Nascido Prematuro/crescimento & desenvolvimento , Estudos RetrospectivosRESUMO
The haematological complications of acquired copper deficiency have been well documented, but the neurological complications have only recently been reported. An illustrative case of copper deficiency myeloneuropathy with pancytopenia is presented and the potential aetiologies and neurological manifestations of this deficiency state discussed.
Assuntos
Cobre/deficiência , Cobre/uso terapêutico , Neurônios/patologia , Pancitopenia/sangue , Pancitopenia/induzido quimicamente , Doenças da Medula Espinal/etiologia , Doenças da Medula Espinal/fisiopatologia , Zinco/efeitos adversos , Zinco/sangue , Cobre/sangue , Overdose de Drogas , Eletromiografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Doenças da Medula Espinal/patologia , Zinco/administração & dosagemRESUMO
Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests.
Assuntos
Biodiversidade , Monitoramento Ambiental , Árvores , Biomassa , Carbono/análise , Geografia , Estudos Longitudinais , Mortalidade , Dinâmica Populacional , Chuva , Reprodução/fisiologia , Solo/análise , América do Sul , Clima TropicalRESUMO
Several widespread changes in the ecology of old-growth tropical forests have recently been documented for the late twentieth century, in particular an increase in stem turnover (pan-tropical), and an increase in above-ground biomass (neotropical). Whether these changes are synchronous and whether changes in growth are also occurring is not known. We analysed stand-level changes within 50 long-term monitoring plots from across South America spanning 1971-2002. We show that: (i) basal area (BA: sum of the cross-sectional areas of all trees in a plot) increased significantly over time (by 0.10 +/- 0.04 m2 ha(-1) yr(-1), mean +/- 95% CI); as did both (ii) stand-level BA growth rates (sum of the increments of BA of surviving trees and BA of new trees that recruited into a plot); and (iii) stand-level BA mortality rates (sum of the cross-sectional areas of all trees that died in a plot). Similar patterns were observed on a per-stem basis: (i) stem density (number of stems per hectare; 1 hectare is 10(4) m2) increased significantly over time (0.94 +/- 0.63 stems ha(-1) yr(-1)); as did both (ii) stem recruitment rates; and (iii) stem mortality rates. In relative terms, the pools of BA and stem density increased by 0.38 +/- 0.15% and 0.18 +/- 0.12% yr(-1), respectively. The fluxes into and out of these pools-stand-level BA growth, stand-level BA mortality, stem recruitment and stem mortality rates-increased, in relative terms, by an order of magnitude more. The gain terms (BA growth, stem recruitment) consistently exceeded the loss terms (BA loss, stem mortality) throughout the period, suggesting that whatever process is driving these changes was already acting before the plot network was established. Large long-term increases in stand-level BA growth and simultaneous increases in stand BA and stem density imply a continent-wide increase in resource availability which is increasing net primary productivity and altering forest dynamics. Continent-wide changes in incoming solar radiation, and increases in atmospheric concentrations of CO2 and air temperatures may have increased resource supply over recent decades, thus causing accelerated growth and increased dynamism across the world's largest tract of tropical forest.
Assuntos
Ecossistema , Monitoramento Ambiental , Modelos Biológicos , Árvores , Clima Tropical , Dióxido de Carbono , Geografia , Estudos Longitudinais , Mortalidade , América do Sul , Luz Solar , TemperaturaRESUMO
Most dance injuries are of the overuse variety. Their gradual onset, coupled with the intense competition for professional positions, often results in injuries being ignored and thus seen late in their course. While treatment of the specific injury is of paramount concern, maintenance of the extremes of flexibility, strength, and conditioning necessary to dance professionally is an equally important treatment element.
Assuntos
Acidentes de Trabalho , Traumatismos em Atletas/etiologia , Dança/lesões , Traumatismos da Perna/etiologia , Doenças Profissionais/etiologia , Acidentes de Trabalho/estatística & dados numéricos , Traumatismos do Tornozelo/etiologia , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/reabilitação , Lesões nas Costas/etiologia , Transtornos Traumáticos Cumulativos/etiologia , Dança/estatística & dados numéricos , Drama , Terapia por Exercício/métodos , Feminino , Traumatismos do Pé/etiologia , Fraturas de Estresse/etiologia , Humanos , Traumatismos do Joelho/etiologia , Traumatismos da Perna/epidemiologia , Traumatismos da Perna/reabilitação , Masculino , Ossos do Metatarso/lesões , Doenças Profissionais/epidemiologia , Doenças Profissionais/reabilitação , Tendinopatia/etiologia , Fraturas da Tíbia/etiologia , Local de TrabalhoRESUMO
The purpose of this study was to identify and prioritize research topics of importance for nephrology nursing and the American Nephrology Nurses' Association (ANNA). This was an explorative survey design using the Delphi technique. Nephrology nurses who are members of ANNA participated in the study. In Round 1 participants included 90 members of the Advanced Practice Special Interest Group. Round 2 participants were 537 nephrology nurses who attended the 28th ANNA National Symposium. Participants in Round 3 were 491 ANNA members who had at least a master's degree in nursing or another field. A three-round Delphi technique was used to solicit, identify, and prioritize problems for nephrology nursing research. In Round 1, 90 nurses identified problems in response to an open-ended question. These responses were analyzed and categorized into a 21-item research survey that was used for subsequent rounds. Round 2 participants rated each research question/topic on the survey on a 1 to 5 scale for level of importance. In addition, they were asked to identify the top-ranked research priorities from the 21 questions. In Round 3, the participants were asked to do the same as in Round 2. In addition, they indicated whether the research priority was primarily a nursing responsibility or a collaborative effort with other health care personnel. Based on 3 rounds of the Delphi study and analysis of both level of importance and rated-research priority, the five areas that were identified as research priorities are (a) nursing interventions to prevent vascular access infections, (b) nursing interventions to maintain vascular access patency, (c) educational needs of patients and families, (d) levels of nursing competence and the effect on patient outcomes, and (e) validation of nursing interventions to achieve patient outcomes. These research priorities provide direction for nephrology nursing research and the ANNA. This Delphi study represents a significant step for ANNA in its commitment to research.
Assuntos
Prioridades em Saúde , Nefrologia , Pesquisa em Enfermagem/organização & administração , Sociedades de Enfermagem , Especialidades de Enfermagem/organização & administração , Adulto , Idoso , Técnica Delphi , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Apoio à Pesquisa como Assunto/organização & administração , Especialidades de Enfermagem/educação , Inquéritos e Questionários , Estados UnidosRESUMO
OBJECTIVE: The purpose of this study was to determine nephrology nurses' perceptions of barriers to research utilization and to identify effective ways to facilitate integration of research findings in nephrology nurses' practice. DESIGN: This was an explorative, descriptive study. SAMPLE/SETTING: Four hundred ninety-eight nephrology nurses participated in the study. The primary areas of clinical practice were hemodialysis (36%), peritoneal dialysis (29%), transplantation (15%), pediatric nephrology (3%), or various combinations (18%). METHODS: Participants completed a demographic data form and the previously validated instrument, Barriers and Facilitators to Using Research in Practice. Descriptive statistics were used to analyze the data. RESULTS: The majority of respondents (52%) were staff nurses. The other respondents included 30% in management, 12% in advanced practice roles, and 6% in education. The barriers to research utilization most frequently identified were insufficient time on the job to implement new ideas and not enough time to read research. The most effective facilitators identified were increased administrative support and encouragement, increased time available for reviewing and implementing research findings, and improved understandability of research reports. CONCLUSIONS: Additional nursing and nonnursing administrative support for research activities and designated time to read research and implement research-based clinical practices may facilitate the development of research-based nephrology nursing practice.
Assuntos
Atitude do Pessoal de Saúde , Difusão de Inovações , Nefrologia , Pesquisa em Enfermagem , Recursos Humanos de Enfermagem/psicologia , Especialidades de Enfermagem , Adulto , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Nefrologia/educação , Recursos Humanos de Enfermagem/educação , Especialidades de Enfermagem/educação , Inquéritos e Questionários , Fatores de Tempo , Carga de TrabalhoRESUMO
The pathophysiology of transient global amnesia (TGA) has been obscure since the definition of this syndrome more than 30 years ago. Current hypotheses include migraine, seizure, or transient cerebral arterial ischaemia. However, none of these potential mechanisms explain both the absence of other neurological signs or symptoms during TGA, and its frequent precipitating activities: many of which would be expected to result in marked increases in venous return from the arms to the superior vena cava. Patients with TGA also commonly have a Valsalva manoeuvre at the onset of attacks. I suggest that a Valsalva manoeuvre, blocking venous return through the superior vena cava, may allow brief retrograde transmission of high venous pressure from the arms to the cerebral venous system, resulting in venous ischaemia to the diencephalon or mesial temporal lobes and to TGA.
Assuntos
Amnésia/etiologia , Amnésia/fisiopatologia , Braço/irrigação sanguínea , Veias Cerebrais/fisiopatologia , Diencéfalo/irrigação sanguínea , Humanos , Ataque Isquêmico Transitório/complicações , Transtornos de Enxaqueca/complicações , Fluxo Sanguíneo Regional/fisiologia , Convulsões/complicações , Lobo Temporal/irrigação sanguínea , Manobra de Valsalva/fisiologia , Veia Cava Superior/fisiopatologia , Pressão Venosa/fisiologiaRESUMO
Lung transplantation has recently offered hope for prolonged survival in patients with cystic fibrosis. Patients with cystic fibrosis have a 7% prevalence of associated liver disease and portal hypertension. These patients have been previously excluded from consideration for lung transplantation. The natural history of cystic fibrosis-associated liver disease suggests a benign and protracted course in most cases. At the University of Washington, 14 of 53 patients (26%) have undergone lung transplantation for cystic fibrosis-related respiratory failure. We report the outcome of double lung transplantation in four of these 14 patients who also had cystic fibrosis-associated liver disease and portal hypertension, all of whom were symptom free from their liver disease. All four patients are alive and well without complications 4 to 31 months after transplantation. We conclude that the presence of cystic fibrosis-associated liver disease with portal hypertension, in the setting of good synthetic function (albumin > 3.0 gm/L and normal prothrombin time), normal serum bilirubin, minimal varices, without ascites or encephalopathy, should not be an absolute contraindication to lung transplantation. We recommend that other transplantation centers also include this patient population in consideration for lung transplantation.
Assuntos
Fibrose Cística/cirurgia , Hipertensão Portal/cirurgia , Cirrose Hepática/cirurgia , Testes de Função Hepática , Transplante de Pulmão/fisiologia , Complicações Pós-Operatórias/diagnóstico , Adulto , Contraindicações , Fibrose Cística/diagnóstico , Fibrose Cística/fisiopatologia , Seguimentos , Volume Expiratório Forçado/fisiologia , Humanos , Hipertensão Portal/diagnóstico , Hipertensão Portal/fisiopatologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/fisiopatologia , Masculino , Complicações Pós-Operatórias/fisiopatologia , Resultado do TratamentoRESUMO
OBJECTIVE: Cellular immune function in peritoneal dialysis patients has been shown to be depressed, but the mechanism of this immunosuppression has not been ascertained. Because calcium is an important mediator of lymphocyte activation, this study was designed to investigate if there was an alteration of calcium metabolism in the lymphocytes of continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Sixteen CAPD patients were studied at the initiation of CAPD and after two months of treatment. Twenty-three normal controls were also enrolled in the study. Cytoplasmic calcium changes were investigated in response to the mitogen phytohemagglutinin (PHA) in peripheral blood and peritoneal lymphocytes, using the intracellular calcium probe indo-1 and flow cytometry. Baseline cytoplasmic calcium levels and changes in cytoplasmic calcium in response to PHA were assessed at the initiation of CAPD and after two months of therapy. RESULTS: Peripheral lymphocytes of patients and controls had similar calcium baseline levels, but the peritoneal lymphocytes had baseline cytoplasmic calcium levels averaging 81% higher than the corresponding calcium levels of the patients' peripheral blood lymphocytes. As compared to peripheral lymphocytes, the response to PHA stimulation was significantly less in the peritoneal lymphocytes, increasing an average of only 46.8% above baseline. Peripheral blood lymphocytes of the patients responded by an average increase of 78.9% over baseline. Control cells increased an average of 66.3% over baseline. Follow-up studies done two months after the initiation of CAPD indicated there were no significant changes (as compared to month 0) that occurred in baseline or stimulated intracellular calcium concentrations. CONCLUSIONS: While the peripheral lymphocytes of CAPD patients respond adequately to PHA, the high baseline calcium levels of the peritoneal lymphocytes suggest that these cells may be in a state of chronic activation and may respond minimally to an antigenic challenge.
Assuntos
Cálcio/metabolismo , Linfócitos/metabolismo , Diálise Peritoneal Ambulatorial Contínua , Peritônio/citologia , Adulto , Idoso , Cálcio/sangue , Cálcio/farmacologia , Feminino , Humanos , Ativação Linfocitária/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do TratamentoRESUMO
Previous studies of changes in immune function in platelet donors have investigated subjects who were undergoing plateletpheresis using older equipment that is no longer in general use. Therefore, the purpose of this study was to determine the effect of long-term platelet donation on lymphocyte numbers and subsets and plasma protein concentrations in platelet donors using newer cell separators. Three groups included in the study were nondonor controls (n = 27), long-term whole blood donors (n = 29), and long-term platelet donors (n = 20). Using a cross-sectional analysis, lymphocyte numbers and subsets were determined and compared among the three groups. Plasma concentrations of total protein, globulin, albumin, and IgG were also compared. Among the three groups there were no significant differences in total white blood cell counts, percentage or absolute number of lymphocytes, or percentage or absolute number of lymphocyte subsets. Serum total protein, globulin, albumin, and IgG concentrations of platelet donors were within normal ranges. These data support the current Food and Drug Administration (FDA) and American Association of Blood Banks' standards for the frequency of platelet donation allowed and monitoring required for plateletpheresis donors. Furthermore, these data indicate that the FDA could eliminate the requirement for the warning in informed consents about lymphocyte depletion in platelet donors.
Assuntos
Doadores de Sangue , Proteínas Sanguíneas , Subpopulações de Linfócitos , Transfusão de Plaquetas , Plaquetoferese/efeitos adversos , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Patients with acute renal failure are at high risk for developing malnutrition. Provision of adequate nutrition support begins with an understanding of the metabolic alterations that occur due to the disease state and renal replacement therapies. Assessment of nutritional requirements and implementation of appropriate feeding modalities can lead to optimal nutritional status and positive patient outcomes. Building collaborative relationships with other health care professionals is crucial to overcoming the barriers that hinder implementation of appropriate nutritional management.