The effects of pharmacological doses of dexamethasone on calcium metabolism were evaluated in 4 normal subjects, by stable calcium and phosphorus balances and 47Ca kinetic studies. The radioactivity data were satisfactorily fitted to a model with 2 exchanging compartments. There was a significant increase in urinary calcium excretion rate with higher specific activities. The total faecal calcium did not alter despite changes in its components, i. e. a fall in endogenous faecal calcium and an increase in unabsorbed dietary calcium. The data suggest that dexamethasone inhibits the rate of calcium transfer across the intestinal wall. more intensely from the mucosal cell to the lumen (secretion). From the constants of compartmental analysis, the only significant and consistent change was the increase in bone resorption rate. Bone deposition rate increased in 2 and decreased in the remaining 2 subjects. The results of our studies indicate that dexamethasone has a direct effect on the way calcium is dealt with by the kidney and the gut and that the drug has a direct effect on the skeleton. For comparison a patient with Cushing's syndrome was studied during the active phase and also after clinical and laboratorial remission of the disease.

RESUMOAmostras de sangue de animais infectados com cepa Y de Trypanosoma cruzi foram submetidas, respectivamente, a 200 e 300 krad de radiação gama. Para verificar a eficácia do método na eliminação do parasita, o material foi ino¬ culado em camundongos e os parâmetros utilizados na avaliação foram: para¬ sitemia, cultura, xenodiagnóstico, subinoculação, reinoculação com cepa virulenta e exame anátomo-patológico das vísceras. Os sangues expostos às duas diferentes intensidades de radiação e inoculados em dois períodos após o processo, mostraram-se inócuos quanto a capacidade de produzir infecção nos animais UNITERMOS: Doença de Chagas -Camundongos -Raios Gama I NTRODUGAO O risco da veiculação de agentes parasitá-rios e infecciosos se constitui num dos problemas da hemoterapia. Em nosso meio, o mecanismo transfusional vem se tornando cada vez mais importante como forma alternativa da transmissão de Doença de Chagas 1041. Serviços de hemoterapia têm utilizado recursos vários visando a prevenção da transferência do agente causai, o flagelado Trypanosoma cruzi, através de sangue e seus derivados ou componentes. Com esta finalidade, a seleção rigorosa dos doadores, através quer de inTerrogatório minucioso quanto a dados epidemioldgicos, quer de realização de testes sorológicos específicos nem sempre é viável ou tem-se mostrado eficaz. Assim que, o emprego de tripanossomicidas adicionados ao sangue passa a representar o recurso recomendado e adotado em circunstâncias especiais. A violeta de genciana a 1/4.000 adicionada ao sangue a ser transfundido é o método classícamente utilizado no nosso país s -9 , constituindo recurso útil e válido na maioria das circunstâncias, a despeito de restrições que possa apresentar principalmente na superdosagem, onde os efeitos tóxicos poderiam estar presentes além da inconveniência de alterar a coloração da pele. Tem sido preocupação dos hematologistas, utilizando métodos bioquí-micos modernos, o dimensionamento de possí-veis ações deletéricas, sobre o eritrócito, ocasionados pela adição de substâncias diversas ao sangue, assim como a avaliação do risco da potencial toxicidade para o receptor. Recentemente, a anfotericina B, antibiótico poliênico, mostrou-se eficiente como tripanossomicida 3 tendo sido estudado o efeito de sua adição sobre o sangue armazenado 1 .Voltados para o uso de agentes físicos, a literatura mostra várias iniciativas W 2 -" visando verificar a ação dos mesmos sobre T. cruzi em especial o uso de radiações atendo-se, todavia, no estudo das alterações na infectividade e na ação patogênica do microrganismo,

The objective of this study was to evaluate the performance of the CELL-DYN® 3500 for rat and mouse blood analysis in a routine environment. The WBC (white blood cells), RBC (red blood cells), PLT (platelets) counts and the WBC differential were determined. In addition, the following aspects were studied: within-run precision, day-today precision, biasfree paired difference precision; extended ranges of linearity for RBC, HCT (haematocrit), WBC, PLT; carry-over, the fffect of blood ageing, cell stability with different anticoagulants; and the normal ranges, the out of range flagging and some typical pathology cases. The CELL-DYN® 3500 is a multiparameter flow cytometer which counts and differentiates WBC, based on the principle of multi-angle polarised light scatter separation. RBC and PLT are determined by the impedance method. The WBC count is evaluated by both, optical and impedance methods. Reference methods used were according to the ICSH recommendations on blood cell analysis, including manual counts of WBC and platelets, a centrifugal microhaematocrit method and a haemoglobin measurement by spectrophotometry using the WHO haemoglobin standard. All cell counts were compared with the results obtained by our routine blood cell analyser (Contraves AL820), and the WBC differential was compared with the manual microscopic differentiation of the 400 WBC (200 cells differentiated by two technicians). The following coefficients of variation were obtained: within-run precision was 1.2% and 2.7% for WBC; 1.0% and 1.0% for RBC; 1.3% and 0.9% for haematocrit; 2.1% and 2.7% for platelets (rats and mice respectively). Day-today precision was performed using human trilevel control blood, and the CVs were found to be <1.7% for WBC, <1.4% for RBC, <1.2% for haemoglobin and <6.3% for platelets. The following ranges of measurement were found to be linear in the rat: WBC: 0.10-20.20×103/l; RBC: 0.016-14.3×106/l; haemoglobin: 0.08-26.8 g/dl; haematocrit: 5.0%-77%; platelets: 14.0-1670.0×103/l. Equal ranges were observed for mouse blood. Carry-over in rat blood was found to be 0.12% for WBC, 0.05% for RBC, 0.15% for haemoglobin and 0.46% for platelets. In mice, similar carry-over results were obtained. The correlation coefficients (Pearson, correlation coefficient) between the CELL-DYN® 3500 and Contraves AL 820 using linear regression analysis were as follows: 0.988 and 0.997 for WBC; 0.986 and 0.920 for RBC; 0.995 and 0.984 for haemoglobin; 0.958 and 0.85 for haematocrit; 0.958 and 0.963 for platelets, for rats and mice, respectively. Correlation coefficients between the CELL-DYN® 3500 and the manual differential of NEU (neutrophils) and LYM (lymphocytes) were higher than 0.8 in rats and higher than 0.9 in mice. Due to the relatively low absolute counts of MONO (monocytes), EOS (eosinophils) and BASO (basophils), only moderate correlation of methods was found. The CELL-DYN® 3500 was judged to be reliable, accurate and easy-to-use for counting and identifying normal and most of the pathological blood specimens obtained from mic...

The objective of this study was to evaluate the performance of the CELL-DYN® 3500 for rat and mouse blood analysis in a routine environment. The WBC (white blood cells), RBC (red blood cells), PLT (platelets) counts and the WBC differential were determined. In addition, the following aspects were studied: within-run precision, day-to-day precision, biasfree paired difference precision; extended ranges of linearity for RBC, HCT (haematocrit), WBC, PLT; carry-over, the fffect of blood ageing, cell stability with different anticoagulants; and the normal ranges, the out of range flagging and some typical pathology cases. The CELL-DYN® 3500 is a multiparameter flow cytometer which counts and differentiates WBC, based on the principle of multi-angle polarised light scatter separation. RBC and PLT are determined by the impedance method. The WBC count is evaluated by both, optical and impedance methods. Reference methods used were according to the ICSH recommendations on blood cell analysis, including manual counts of WBC and platelets, a centrifugal microhaematocrit method and a haemoglobin measurement by spectrophotometry using the WHO haemoglobin standard. All cell counts were compared with the results obtained by our routine blood cell analyser (Contraves AL820), and the WBC differential was compared with the manual microscopic differentiation of the 400 WBC (200 cells differentiated by two technicians). The following coefficients of variation were obtained: within-run precision was 1.2% and 2.7% for WBC; 1.0% and 1.0% for RBC; 1.3% and 0.9% for haematocrit; 2.1% and 2.7% for platelets (rats and mice respectively). Day-to-day precision was performed using human trilevel control blood, and the CVs were found to be <1.7% for WBC, <1.4% for RBC, <1.2% for haemoglobin and <6.3% for platelets. The following ranges of measurement were found to be linear in the rat: WBC: 0.10-20.20×103/l; RBC: 0.016-14.3×106/l; haemoglobin: 0.08-26.8 g/dl; haematocrit: 5.0%-77%; platelets: 14.0-1670.0×103/l. Equal ranges were observed for mouse blood. Carry-over in rat blood was found to be 0.12% for WBC, 0.05% for RBC, 0.15% for haemoglobin and 0.46% for platelets. In mice, similar carry-over results were obtained. The correlation coefficients (Pearson, correlation coefficient) between the CELL-DYN® 3500 and Contraves AL 820 using linear regression analysis were as follows: 0.988 and 0.997 for WBC; 0.986 and 0.920 for RBC; 0.995 and 0.984 for haemoglobin; 0.958 and 0.85 for haematocrit; 0.958 and 0.963 for platelets, for rats and mice, respectively. Correlation coefficients between the CELL-DYN® 3500 and the manual differential of NEU (neutrophils) and LYM (lymphocytes) were higher than 0.8 in rats and higher than 0.9 in mice. Due to the relatively low absolute counts of MONO (monocytes), EOS (eosinophils) and BASO (basophils), only moderate correlation of methods was found. The CELL-DYN® 3500 was judged to be reliable, accurate and easy-to-use for counting and identifying normal and most of the pathological blood specimens obtained from m...