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OBJECTIVE: To evaluate the changes over time (trend) in sign and magnitude for SSVO2 and SVO2 during and after cardiac surgery. PATIENTS AND METHODS: A prospective and observational study was conducted on 34 cardiac surgery patients. Venous blood samples were taken simultaneously from the introductor (SVCO2) and distal (SVO2) port of the pulmonary artery catheter at predefined intervals. Systemic and pulmonary hemodynamic variables were measured at the same time. The trend was calculated as the difference between 2 consecutive measurements (tSO2). Data were processed with ANOVA for multiple comparisons, Pearson correlation coefficient and Bland-Altman analysis. RESULTS: There was a significant correlation between SVCO2 and tSVO2 (R(2)=0.55), the mean of the differences was 0.36±7.75%, and the limits of agreement ranged from -15.1 to 15.9%. The sign of the trend was similar in 85.1% of the paired data. However, the magnitude of the changes in tSVCO2 and tSVO2 were not always equivalent. Between 0 and 5% of the change in the tSVCO2 was coincident with only 44.7% of the tSVO2. A wide variation was found between both trends when the signs and magnitudes of the changes were taken into account. CONCLUSIONS: When considering the sign and magnitude, the change over time of central venous O2 saturations were not interchangeable in cardiac surgery patients. Clinical decisions based exclusively on tSVCO2 monitoring should be taken with caution.

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Este trabalho teve como objetivo investigar a composição química, estabelecer a dose letal média (DL50) e avaliar os potenciais efeitos mutagênicos do extrato hidroalcoólico de folhas e inflorescências de Erythrina mulungu Mart. ex Benth por meio do teste de micronúcleo em medula óssea de camundongos. Os ensaios fitoquímicos foram realizados através de reações preliminares com mudança de coloração e/ou formação de precipitado; a DL50, por meio da administração intraperitoneal de três concentrações dos extratos, avaliando-se o número de óbitos após 48 horas e o teste de micronúcleo foi feito por meio do método do esfregaço, após exposição dos animais a cinco dias de tratamento. Os resultados fitoquímicos demonstraram presença de açúcares redutores, fenóis e taninos, proteínas e aminoácidos, flavonóides, alcalóides, depsídeos e depsidonas e derivados de cumarina em ambos os órgãos; saponinas espumídicas e esteróides e triterpenóides nas folhas e glicosídeos cardiotônicos e antraquinônicos e alcalóides nas inflorescências. Para a DL50 a folha demonstrou-se atóxica e a inflorescência moderadamente tóxica. Para o teste de micronúcleo, os resultados indicaram ausência de citotoxicidade e genotoxicidade dose-dependente para as folhas e independente da dose para as inflorescências. Assim, esses resultados sugerem que a planta, nas condições analisadas, possui potencial para induzir danos ao DNA.

This study aimed to investigate the chemical composition, to establish the mean lethal dose (LD50) and to assess the potential mutagenic effects of hydroalcoholic extract of leaves and inflorescences of Erythrina mulungu Mart. ex Benth by using micronucleus test in bone marrow of mice. Phytochemical assays were carried out through preliminary reactions with color change and/or precipitate formation; the LD50 was obtained by intraperitoneal administration of three concentrations of the extracts, assessing the number of deaths after 48 hours, and the micronucleus test was done by the smear method, after exposure of animals to five days of treatment. Phytochemical results showed the presence of reducing sugars, phenols and tannins, proteins and amino acids, flavonoids, alkaloids, depsides, depsidones and coumarin derivatives in both organs; foaming and steroidal saponins and triterpenes in the leaves and cardiotonic and anthraquinonic glycosides and alkaloids in the inflorescences. Considering the LD50, the leaf was atoxic and the inflorescence was moderately toxic. As regards the micronucleus test, results indicated absence of cytotoxicity while genotoxicity was dose-dependent for leaves and dose-independent for inflorescences. Thus, these results suggest that the plant, under the tested conditions, has the potential to induce damages to the DNA.

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It is generally accepted that halothane reduces airway and tissue resistance in lungs with preexisting airway tone. However, under conditions of resting airway tone, pulmonary resistance remains unaltered. In this study, we have determined the effects of halothane on respiratory system, pulmonary and chest wall resistive, elastic and viscoelastic mechanical properties, and related the results to findings from lung histology in intact normal rats. Sixteen adult male Wistar rats were allocated randomly to one of two groups (n = 8 in each group): control or halothane group. In the control group, animals were sedated with diazepam 5 mg i.p. and anaesthetized with pentobarbital 20 mg kg-1 i.p. In the halothane group, the anaesthetic was administered at an end-tidal concentration of I MAC throughout the study. Rats were paralysed and underwent mechanical ventilation. Halothane decreased airway resistance but increased the tissue component of resistance (caused by viscoelastic elements and lung inhomogeneity). Static and dynamic elastance also increased with halothane anaesthesia. Pulmonary resistance remained unchanged. Lung histopathology demonstrated airway dilatation and a greater degree of lung collapse and hyperinflation in the halothane group. We conclude that halothane anaesthesia acts both on airway and lung tissue. In airway tissue, dilatation occurs but the lung periphery stiffens. Consequently, these opposing effects result in no overall apparent change in mechanical properties, although changes are observed during halothane anaesthesia in normal animal and subjects.

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