60 research outputs found

    Using trace element and halide isotopes to understand salinization mechanisms of groundwaters from an arid aquifer

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    Saline groundwaters are common to inland Australia, yet many aspects of their hydrochemical evolution remain uncertain. The saline groundwaters in the alluvial aquifers of the Darling River have previously been found to exhibit broad similarity in traditional hydrochemical and isotopic tracers. By contrast, trace element isotopes (δ7Li, δ11B and 87Sr/86Sr) and halide isotopes (δ37Cl and δ81Br) provide evidence of more complex hydrogeochemical processes.Hydrochemical evolution was found to be dependent on proximity to theDarling River and depth even though all groundwaters from this aquifer were found to be saline. The differing signatures highlighted the discovery of adeeper palaeo-groundwater system containing heavier trace element and halide isotope values. The measurement of these isotopes has permitted delineation of groundwater end-members and salinization mechanisms that would have otherwise not been identified

    Bioelectrical impedance with different equations versus deuterium oxide dilution method for the inference of body composition in healthy older persons

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    There is no consensus regarding the accuracy of bioimpedance for the determination of body composition in older persons. This study aimed to compare the assessment of lean body mass of healthy older volunteers obtained by the deuterium dilution method (reference) with those obtained by two frequently used bioelectrical impedance formulas and one formula specifically developed for a Latin-American population. A cross-sectional study. Twenty one volunteers were studied, 12 women, with mean age 72 +/- 6.7 years. Urban community, Ribeiro Preto, Brazil. Fat free mass was determined, simultaneously, by the deuterium dilution method and bioelectrical impedance; results were compared. In bioelectrical impedance, body composition was calculated by the formulas of Deuremberg, Lukaski and Bolonchuck and Valencia et al. Lean body mass of the studied volunteers, as determined by bioelectrical impedance was 37.8 +/- 9.2 kg by the application of the Lukaski e Bolonchuk formula, 37.4 +/- 9.3 kg (Deuremberg) and 43.2 +/- 8.9 kg (Valencia et. al.). The results were significantly correlated to those obtained by the deuterium dilution method (41.6 +/- 9.3 Kg), with r=0.963, 0.932 and 0.971, respectively. Lean body mass obtained by the Valencia formula was the most accurate. In this study, lean body mass of older persons obtained by the bioelectrical impedance method showed good correlation with the values obtained by the deuterium dilution method. The formula of Valencia et al., developed for a Latin-American population, showed the best accuracy.FAPESP - Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [98/12696-8]FAEPA - Fundacao de Apoio ao Ensino, PesquisaInternational Atomic Energy Agency [92.696

    Bioelectrical impedance with different equations versus deuterium oxide dilution method for the inference of body composition in healthy older persons

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    There is no consensus regarding the accuracy of bioimpedance for the determination of body composition in older persons. This study aimed to compare the assessment of lean body mass of healthy older volunteers obtained by the deuterium dilution method (reference) with those obtained by two frequently used bioelectrical impedance formulas and one formula specifically developed for a Latin-American population. A cross-sectional study. Twenty one volunteers were studied, 12 women, with mean age 72 +/- 6.7 years. Urban community, Ribeiro Preto, Brazil. Fat free mass was determined, simultaneously, by the deuterium dilution method and bioelectrical impedance; results were compared. In bioelectrical impedance, body composition was calculated by the formulas of Deuremberg, Lukaski and Bolonchuck and Valencia et al. Lean body mass of the studied volunteers, as determined by bioelectrical impedance was 37.8 +/- 9.2 kg by the application of the Lukaski e Bolonchuk formula, 37.4 +/- 9.3 kg (Deuremberg) and 43.2 +/- 8.9 kg (Valencia et. al.). The results were significantly correlated to those obtained by the deuterium dilution method (41.6 +/- 9.3 Kg), with r=0.963, 0.932 and 0.971, respectively. Lean body mass obtained by the Valencia formula was the most accurate. In this study, lean body mass of older persons obtained by the bioelectrical impedance method showed good correlation with the values obtained by the deuterium dilution method. The formula of Valencia et al., developed for a Latin-American population, showed the best accuracy.FAPESP - Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [98/12696-8]FAEPA - Fundacao de Apoio ao Ensino, PesquisaInternational Atomic Energy Agency [92.696

    Manejo das complicações agudas da doença falciforme

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    Anemia falciforme (HbSS) é uma doença autossômica recessiva caracterizada pela herança homozigota da hemoglobina S (HbS). Clinicamente apresenta-se com anemia hemolítica e vaso-oclusão. O termo doença falciforme engloba a anemia falciforme e heterozigozes compostas com hemoglobina S, como S? talassemia e hemoglobinopatia SC, além de outras associações menos comuns. São várias as complicações agudas na doença falciforme: crises vaso-oclusivas, infecções por microorganismos encapsulados, principalmente do trato respiratório e septicemia, síndrome torácica aguda, sequestro esplênico, priapismo, Acidente Vascular Cerebral (AVC) e crise aplástica. O conhecimento das intercorrências na Doença Falciforme é de extrema importância para todos os níveis de atendimento destes pacientes. A detecção precoce das complicações possibilita tratamento adequado e diminuição da morbimortalidade relacionada a elas.Sickle cell anemia (SCA) is an autosomal recessive disease characterized by the presence of hemoglobin S. It presents with hemolytic anemia e vaso-occlusives phenomena. The term sickle cell disease (SCD) includes the SCA and a group of compound heterozygous states in which the person has only one copy of the mutation that causes HbS and one copy of another abnormal haemoglobin allele, like sicklehemoglobin C disease (HbSC), sickle beta-thalassaemia and other rarer combinations. There are many acute complications of SCD: vaso-occlusives crisis, encapsulated organisms infections, mainly of the airways and sepsis, acute chest syndrome, splenic sequestration, priapism, stroke and aplastic crisis.The knowledge of these complications is very important for all grades of medical assistence. The early detection allows appropriate treatment and reduction of the morbidity and mortality associated with the disease

    Avaliação do paciente com artrite

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    Arthritis are clinical manifestations of plenty of diseases. Its etiological classification is many times difficult and depends on careful clinical history and physical examination. Gout and skeptical arthritis presents commonly as acute monoarthritis and reactional arthritis are often polyarticular. Hospitalar admission is a risk factor to the development of reactional arthritis, crisis of gout and septical arthritis.Early diagnosis is imperative to start early treatment, symptom relief and articular function preservation.Synovial fluid aspiration and its analysis are of critical diagnostic importance in cases of acute monoarthritis.Artrites são manifestações clínicas de uma série de doenças. Sua classificação etiológica é muitas vezes difícil e depende de história clínica e exame físico cuidadosos. Artrite séptica e gota se apresentam mais comumente como monoartrite aguda e quadros reacionais são geralmente poliarticulares. A internação hospitalar é fator de risco para o desenvolvimento tanto de artrites reacionais quanto para crises de gota e artrite séptica. O diagnóstico precoce é muito importante a fim de iniciar o tratamento precocemente, alívio dos sintomas e preservação da funcionalidade articular. A punção do líquido sinovial e sua análise são de fundamental importância diagnóstica nos quadros de monoartrite aguda

    Increased peptide YY blood concentrations, not decreased acyl-ghrelin, are associated with reduced hunger and food intake in healthy older women: Preliminary evidence.

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    With ageing there is frequently a loss of appetite, termed anorexia of ageing, which can result in under-nutrition. We do not know how appetite control alters with ageing. The objective of this study was to investigate whether differences in the release of, and response to, gastrointestinal appetite hormones is altered in young compared to old healthy volunteers. We hypothesised that an increase in PYY and GLP-1 or a decrease ghrelin may result in a decreased appetite. A comparative experimental design, using a cross-sectional sample of ages from a healthy population, matched for sex and BMI was used. The study compared total ghrelin, acyl-ghrelin, PYY, GLP-1 and subjective appetite responses to ingestion of a standardised 2781kj (660 kcal) test meal. 31 female volunteers aged between 21 and 92yrs took part. Multiple linear regression showed that both age and sex had an independent effect on energy intake. Subjective appetite scores showed that hunger, pleasantness to eat, and prospective food intake were significantly lower in the older age groups. PYY incremental area under the curve (IAUC) was greater in the oldest old compared to younger ages (f(3,27) = 2.9, p = 0.05. No differences in GLP-1, ghrelin or acyl-ghrelin were observed in the older compared to younger age groups. Our data suggest that there may be increases in postprandial PYY(3-36) levels in female octogenarians, potentially resulting in reduced appetite. There does not appear to be any change in ghrelin or acyl-ghrelin concentrations with ageing

    Effects of Hypothalamic Neurodegeneration on Energy Balance

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    Normal aging in humans and rodents is accompanied by a progressive increase in adiposity. To investigate the role of hypothalamic neuronal circuits in this process, we used a Cre-lox strategy to create mice with specific and progressive degeneration of hypothalamic neurons that express agouti-related protein (Agrp) or proopiomelanocortin (Pomc), neuropeptides that promote positive or negative energy balance, respectively, through their opposing effects on melanocortin receptor signaling. In previous studies, Pomc mutant mice became obese, but Agrp mutant mice were surprisingly normal, suggesting potential compensation by neuronal circuits or genetic redundancy. Here we find that Pomc-ablation mice develop obesity similar to that described for Pomc knockout mice, but also exhibit defects in compensatory hyperphagia similar to what occurs during normal aging. Agrp-ablation female mice exhibit reduced adiposity with normal compensatory hyperphagia, while animals ablated for both Pomc and Agrp neurons exhibit an additive interaction phenotype. These findings provide new insight into the roles of hypothalamic neurons in energy balance regulation, and provide a model for understanding defects in human energy balance associated with neurodegeneration and aging

    Selected isotope ratio measurements of light metallic elements (Li, Mg, Ca, and Cu) by multiple collector ICP-MS

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    The unique capabilities of multiple collector inductively coupled mass spectrometry (MC-ICP-MS) for high precision isotope ratio measurements in light elements as Li, Mg, Ca, and Cu are reviewed in this paper. These elements have been intensively studied at the Geological Survey of Israel (GSI) and other laboratories over the past few years, and the methods used to obtain high precision isotope analyses are discussed in detail. The scientific study of isotopic fractionation of these elements is significant for achieving a better understanding of geochemical and biochemical processes in nature and the environment
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