Evaluación de la seguridad de una suspensión de fosfato de cromo(III) para uso en radiosinoviortesis / Evaluation of the safety a Chromium (III) Phosphate suspension for radiosynoviorthesis

Objetivo: evaluar la fuga de radiactividad de la cavidad articular después de la administración de suspensiones radiomarcadas de Fosfato de Cromo(III) y la probabilidad de inducción de genotoxicidad. Métodos: las suspensiones se obtuvieron según método reportado. Para la evaluación de la fuga articular las suspensiones marcadas se administraron por vía intraarticular en ratas y conejos. El seguimiento se realizó por medición de la actividad retenida por cámara gamma. En los estudios de genotoxicidad se determinó la frecuencia de formación de micronúcleos en eritrocitos de médula ósea de ratas para 2 dosis y 2 tiempos para cada preparado. Resultados: para las suspensiones radiomarcadas en estudio la fuga fue no significativa durante 3 semanas (< 3 por ciento para la marcada con 51Cr y ~5 por ciento con 32P). Para los preparados con 32P e 90Y se observó poca diferencia en la frecuencia de aparición de micronúcleos para el 1-er tiempo, independientemente de las dosis administradas. A tiempos mayores se produjo un incremento en la formación de micronúcleos para las dosis superiores. Conclusiones: se demostró la posibilidad del uso seguro de una suspensión de Fosfato de Cromo(III) marcada con diferentes radionúclidos, en particular que la fuga articular de la suspensión no fue significativa durante 3 semanas y se comprobó las ventajas de tener un preparado con mayor tamaño de partículas. Para las suspensiones marcadas con 90Y y 32P no se producen incrementos en la frecuencia de formación de micronúcleos para una dosis superior en aproximadamente 40 veces a la prevista a utilizar en la clínica

Objective: to evaluate the leakage of radioactivity after intraarticular administration of radioactive suspensions based on Chromium (III) Phosphate as well as the probability of induction of genotoxic effect. Methods: the suspensions were obtained in line with the published procedure. For the articular leakage evaluation, the radioactive suspensions were intraarticulary administered in rats and rabbits. The radioactivity retention was measured by gamma chamber. A comparison with commercial radiopharmaceutical labeled with 32P was made. The genotoxicity studies determined the frequency of micronuclei formation in the rats´ bone marrow erythrocytes by using 2 doses and 2 time intervals for each preparation. Results: the radiolabeled suspensions under evaluation showed that the leakage was not significant during 3 weeks (<3 percent for the suspension labeled with 51Cr and ~5 percent in the one labeled with 32P) and the advantages of having larger particle preparation were confirmed. For those suspension labeled with 32P and 90Y , no significant difference was seen in the frequency of micronuclei formation for the first time interval, regardless of the administered doses. The micronuclei formation increased for higher doses and at longer time intervals. Conclusions: the results demonstrated the possibility of the safe use of a of Chromium (III) Phosphate suspension labeled with several radionuclides for the treatment of different joints, in particular the leakage was not significant during 3 weeks and the advantages of having a larger particle radiopharmaceutical was confirmed. For the suspensions labeled with 32P and 90Y micronucleus frequency mildly increased with the time and administered doses

Naegleria fowleri Lysate Induces Strong Cytopathic Effects and Pro-inflammatory Cytokine Release in Rat Microglial Cells

Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A 51Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-alpha, IL-6, and IL-1beta, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.

Assessment of the Accuracy and Precision of Cystatin C-based GFR Estimates and Cr-based GFR Estimates in Comparison with Cr51-EDTA GFR / 대한진단검사의학회지

BACKGROUND: Cystatin C (cysC) is said to be an ideal marker for glomerular filtration rate (GFR), independent of external factors such as age, nutrition and inflammation. The authors compared the accuracy and precision of cysC-based and creatinine (Cr)-based GFR estimates using Cr51-EDTA GFR method as a reference. METHODS: Serum concentrations of cysC and Cr were measured in adults over 17 yr (n=170) and children below 17 yr (n=79) who had had GFR estimated by Cr51-EDTA method. CysC-based GFR was estimated by the formula of Thierry [CysC-based GFR estimates (mL/min/1.73 m2)=78 x (1/cysC, in mg/L)+4] and Cr-based GFR by the formula of modified Modification of Diet in Renal Disease [MDRD II, Cr-based GFR estimates (mL/min/1.73 m2)=186 x (Scr)(-1.154) x (Age)(-0.203) x 0.742 (for a female patient) x 1.212 (for a black patient). RESULTS: In comparison with Cr51-EDTA GFR, in children below 17 yr, the bias +/- standard deviation (SD) of cysC-based and Cr-based GFR estimates were 7.5 +/- 6.1 and 106.5 +/- 98.2, respectively, in the range of below 90 of Cr51-EDTA GFR (mL/min/1.73 m2), and 33.7 +/- 33.0 and 174.4 +/- 18.8 in the range of over 90. In adults over 17 yr, the respective figures were 13.1 +/- 11.0 and 17.4 +/- 29.8 in below 90, and 21.2 +/- 20.1 and 83.6 +/- 108.8 in over 90 of Cr51-EDTA GFR. CONCLUSIONS: CysC-based GFR estimates show acceptable ranges of biases over the whole age and GFR ranges. CysC-based GFR estimates is considered to be the marker for GFR, which could be used without limitation of age and GFR ranges.

Braquiterapia del espacio subaracnoideo y ventrículos cerebrales con el radiocoloide fosfato crómic 32p (CROP) / Brachitherapy of subaracnoid space and brain ventricles with radiocoloid phosphate cromic 32p (CROP)

Se desarrolló un método de Braquiterapia del espacio subaracnoideo mediante la introducción de un coloide de FostatoCrómico 32P (CROP) en el LCR. Se usaron 90 conejos y los coloides fueron inyectados por vía cisternal, Se comprobó la distribución uniforme y permanencia del CROP en la pia-aracnoides de todo el espacio subaracnoideo y superficie cortical y en el epéndimo ventricular mediante autorradiografías y cortes histológicos con técnica de stripping film. La distribución del 32P en hígado (10 por ciento ), bazo (7 por ciento ) y médula ósea (2 por ciento) y otros órganos no provoca efectos significativos. Se comprueba la tolerancia neurológica perfecta para los coloides de partículas finas de menos de 100 nm (CROP), y la neurotoxicidad de los coloides de partículas grandes mayores a 100 nm.. Con altas dosis los estudios histológicos demostraron la ausencia de edema o de lesiones en células y tejido nerviosos. Hasta 6 meses de observación ninguno de los animales mostró trastornos neurológicos atribuíbles al CROP, ni con la repetición de sus aplicaciones

Intestinal permeability in strongyloidiasis

The objective of the present study was to assess intestinal permeability in patients with infection caused by Strongyloides stercoralis. Twenty-six patients (16 women and 10 men), mean age 45.9, with a diagnosis of strongyloidiasis were evaluated. For comparison, 25 healthy volunteers (18 women and 7 men), mean age 44.9, without digestive disorders or intestinal parasites served as normal controls. Intestinal permeability was measured on the basis of urinary radioactivity levels during the 24 h following oral administration of chromium-labeled ethylenediaminetetraacetic acid (51Cr-EDTA) expressed as percentage of the ingested dose. The urinary excretion of 51Cr-EDTA was significantly reduced in patients with strongyloidiasis compared to controls (1.60 + or - 0.74 and 3.10 + or - 1.40, respectively, P = 0.0001). Intestinal permeability is diminished in strongyloidiasis. Abnormalities in mucus secretion and intestinal motility and loss of macromolecules could explain the impaired intestinal permeability

Absorçäo de líquido de irrigaçäo na ressecçäo transuretral da próstata em cäes / Irrigating fluid absorption during transurethral resection of the prostate in dogs

Trinta e dois cäes submetidos a entubaçäo do ducto torácico e cateterismo bilateral dos ureteres, foram divididos em 3 grupos: A- 4 cäes inoculados com RISA 131 I ou EDTA 51 Cr por via intravenosa ou peri-prostática; B- controle de 8 cäes submetidos a irrigaçäo vesical e prostática com 8 litros de glicina a 1,2 por cento contendo os marcadores radioativos; C- 8 cäes manejados como em B mas sujeitos à RTU da próstata. Os cäes foram acompanhados por 5 horas. A absorçäo de líquido de irrigaçäo foi calculada pelos métodos volumétrico e radioisotópico. Em 5 horas, 97 por cento da RISA 131 I inoculada via intravenosa permanecia neste espaço enquanto apenas 4,6 por cento da injetada no espaço peri-prostático penetrou no compartimento vascular. Para o EDTA 51 Cr, 63,6 por cento da massa inoculada no espaço peri-prostático foi recuperada na urina após 5 horas. O método volumétrico mostrou absorçäo média de 22,7 ml no grupo B e 276 ml no C, e o radioisotópico de 6,3 ml e 165,4 ml, respectivamente. O modelo experimental tem similaridades com o ser humano

Aumento da permeabilidade intestinal ao 51Cr-EDTA em crianças com diarréia persistente / Increased intestinal permeability to 51Cr-EDTA among children with persistent diarrhea

A diarréia persistente, uma condiçäo altamente prevalente em países em desenvolvimento, ocasiona diferentes alteraçöes morfológicas e funcionais na mucosa do intestino delgado, incluindo aumento da permeabilidade a diversas moléculas de prova. Investiga-se, pela primeira vez, a permeabilidade intestinal ao Cr-EDTA em crianças brasileiras com diarréia persistente. O teste de absorçäo do Cr-EDTA foi realizado em 13 crianças controle e em 14 com diarréia persistente, oferecendo-se 50 µCi da substância teste, por via oral, com posterior detecçäo da radioatividade excretada na urina de 24 horas. Houve diferença estatisticamente significante entre o grupo controle (mediana = 1,26 variaçäo = 0,20-3,31 por cento) e com diarréia persistente (mediana = 4,68; variaçäo = 1,40-10,29 por cento). Estabelecendo como padräo de referência de normalidade para o teste de absorçäo urinária de Cr-EDTA os valores mínimo e máximo encontrados no grupo controle, observaram-se que 61,5 por cento dos pacientes com diarréia persistente apresentaram resultado alterados. Nos pacientes com diarréia persistente, a excreçäo do Cr-EDTA foi significativamente maior no grupo que fez uso de dieta à base de hidrolisado protéico e/ou nutriçäo parenteral total, em comparaçäo com o que näo fez, demonstrando sua possível utilidade como indicador de gravidade. Em quatro pacientes com diarréia persistente, o teste foi realizado após a recuperaçäo clínica, sendo que houve queda nos valores de excreçäo em todos os casos. A partir destes dados, pode-se concluir que: 1) na diarréia persistente deve haver alteraçäo na permeabilidade intestinal, que permitiria a entrada aumentada de antígenos alimentares locais, com subseqüente sensibilizaçäo e enteropatia alérgica, contribuindo para a perpetuaçäo do ciclo de diarréia, má absorçäo e desnutriçäo; 2) o teste do Cr-EDTA pode ser útil como indicador de gravidade na diarréia persistente; 3) a alteraçäo da permeabilidade intestinal é um fenômeno secundário na diarréia persistente e, com a reconstruçäo da barreira intestinal, ocorre normalizaçäo da mesma.

Assessment of glomerular filtration rate utilizing subcutaneously injected Cr-EDTA

1. 51Cr-EDTA injected with lidocaine and epinephrine, as a subcutaneous button, is slowly absorbed, and a plasma level that is relatively stable can be maintained for a time sufficient to permit measurement of the renal clearance of EDTA, which is a measure of glomerular filtration rate (GFR). We studied this procedure in 32 normal volunteers and 24 patients with different glomerulopathies, comparing EDTA and creatinine clearances. In 20 patients these measurements were also compared with inulin clearance. 2. Creatinine clearance overestimates GFR due to tubular secretion of creatinine. This secretion is present even in patients with significantly reduced glomerular filtration rates. As a consequence, the lower the GFR the higher the overestimation will be. 3. A good correlation was obtained between the 51Cr-EDTA and inulin clearance: y(EDTA) = 4.21 + 0.88 x (inulin), r = 0.98. The procedure is simple to perform, and the radiotracer utilized is significantly less expensive than iothalamate

Gastroenteropatias perdedoras de proteínas: comprovaçäo pelo teste de excreçäo fecal da albumina-51 Cr em 50 casos de diferentes etiologias / Protein-losing gastroentheropathis: evidence through fecal excretion test of 51 Cr-albumin in 50 cases of different etiologies

Entre setembro de 1976 e dezembro de 1986, determinou-se a excreçäo fecal de radioatividade após injeçäo intravenosa da albumina Cr, para detecçäo e medida da perda gastrointestinal de proteínas, em 128 testes realizados em um grupo de 116 pacientes. Destes, 20 eram controles, 38 tinham suspeita clínica da gastroenteropatia perdedora de proteínas e 58 apresentavam doenças presumivelmente associadas a perda protéica digestiva. Os resultados obtidos no grupo controle permitiram definir o limite superior de normalidade do exame em 2,6% da radioatividade administrada. Valores anormais foram encontrados em 23 dos 38 casos com evidências clínicas da gastroenteropatioa perdedora de proteínas, em 12 dos quais haviam alteraçöes primárias ou secundárias do sistema linfático. No subgrupo de pacientes com doenças associadas à perda protéica digestiva, valores anormais da excreçäo fecal da albumina Cr foram encontrados em 11 dos 19 pacientes com paracoccidioidomicose, em quatro dos 14 pacientes com hipertensäo portal esquistossomótica, em cinco dos 14 pacientes com insuficiência cardíaca congestiva crônica e em sete dos 11 pacientes com diferentes afecçöes primárias do tubo digestivo. Os resultados do teste da excreçäo fecal da albumina Cr apresentaram boa correlaçäo com os valores da medida do clearance gastrointestinal de proteínas plasmáticas e tiveram compatibilizaçäo satisfatória om outros dados de ordem clínica e laboratorial. Os 50 casos em que se comprovou perda excessiva de proteínas pelo trato gastrointestinal, em seu conjunto, ilustraram a grande diversidade das doenças que causam esta anormalidade, muitas delas sendo muito comuns em nosso meio, bem como evidenciaram a importância das afecçöes que acometem o sistema linfático como causa das gastroenteropatias perdedoras de proteínas

Gastroenteropatia perdedora de proteínas na infância: observaçoës clínicas, laboratoriais e terapêuticas em 13 pacientes / Protein losing gastroenterophaties in children: clinical, laboratory and therapeutic observations in 13 patients

Säo apresentados 13 crianças com gastroenteropatia perdedora de proteínas, comprovada pelo teste de excreçäo fecal de albumina 51Cr. As idades variaram de 3 meses a 12 anos com uma mediana de 6 anos e 11 meses, sendo que em 11 pacientes os sintomas tiveram início entre 3 a 7 anos. Desnutriçäo de I§ e § graus foi detectada em dez casos. A diarréia foi o achado clínico mais freqüente, econtrado em 11 pacientes, seguido de edema periférico, anorexia, palidez verificados em dez: hipotrofia muscular nove; distensäo abdominal em oito: ascite e emagrecimento em sete crianças e vômiotos referidos em apenas cinco casos. Em 12 pacientes, o níve de albumina sérica foi inferior a 2,5 g/100 ml. com mediana de 1,7g/100 ml. A fraçäo gamaglobulina estava abaixo de 1,0 g/100 ml em oito pacientes e a linfocitopenia (linfócitos < 1500/mm**3) foi verificada em cinco casos. As provas de absorçäo mostraram um comprometimento da absorçäo de gordura, uma vez dioidomicose (cinco pacientes), linfangiectasia intestinal primária (um), estrongiloidíase (um), pericardite constrictiva (um), cardite reumática com dupla lesäo mitral (um), doença de Ménétriéer (um), síndrome de má-absorçäo por intestino curto (um), doença celíaca (um) e intolerância às proteínas do leite de vaca (um). Os mecanismos responsáveis pela perda excessiva de proteínas para a luz do tubo digestivo, bem como os aspectos diagnósticos e terapêuticos dos pacientes apresentados, säo comentados. E feito um relato de quatro casos que exemplificam...

Natural Killer Cell Activity in Rheumatoid Arthritis Measured by a Single Cell Cytotoxicity Assay

The natural killer(NK) cell activity of mononuclear cells (MNC) from peripheral blood (PB) and synovial fluid (SF) of 40 rheumatoid arthritis(RA) patients was investigated by employing 51-chromium-(51Cr) release microcytotoxicity and single cell cytotoxicity assays against K562 target cells. It has been revealed that SF-MNC from RA patients showed a significantly lower NK activity than PB-MNC from the same patients and this might be due to an impaired target binding capacity of the effector cells and not due to a deficiency of active NK cells.

Linfagiectasia intestinal secundaria a pericarditis constrictiva / Intestinal lymphangiectasia secondary to constrictive pericarditis

Se presenta un enfermo con linfangiectasia intestinal secundaria a pericarditis constrictiva que consultó por retraso del peso, edema generalizado asimétrico, hipoproteinemia, linfopemia e hipogamaglobulinemia. El diagnóstico se confirmó por la presencia de linfáticos dilatados en las vellosidades intestinales en la biopsia de yeyuno y por el aumento de la excreción fecal de proteínas marcadas con Cr51. La existencia de injurgitación yugular discreta y reflujo hepato yugular positivo insinuaron el diagnóstico de pericarditis constrictiva. Este fue confirmado por la ecocardiografía modo M y bidimensional. Con el tratamiento quirúrgico se logró una rápida remisión clínica, de laboratorio y de la morfología de la mucosa yeyunal

Studies on the glomerular filtration rate and extracellular fluid volume in rhesus monkeys infected with Plasmodium knowlesi.

The glomerular filtration rate (GFR) and the extracellular fluid volume (ECV) were determined in 5 rhesus monkeys infected with P. knowlesi in comparison with 6 control monkeys by using 51Cr-EDTA. As the disappearance curve of the radioactivity showed a close fit to a double exponential equation, the data was therefore analysed by an open 2-compartment system. Results in the present study showed that the GFR was significantly reduced in the infected group. Both V1 and V2 were also slightly but not significantly decreased which resulted in the lower ECV in monkeys infected with P. knowlesi. As the GFR was reduced much more than ECV, therefore the mean transit time of 51Cr-EDTA in the infected group was longer than that of the normal group. All other intercompartment clearance and fractional transfer rate constants were also found to be lower in the infected group. These findings indicated that there was a delay in the distribution of 51Cr-EDTA between these 2 compartments in monkeys infected with P. knowlesi malaria.

Evidence of trapped red cells in the brain of rhesus monkey infected with Plasmodium knowlesi.

59Fe-labelled normal red cells and 51Cr-labelled P. knowlesi infected red cells were used as tracers for a study on the trapped red cells in the brain of rhesus monkeys infected with P. knowlesi. After instantaneous injection into a common carotid artery, blood was sampled from both of the internal jugular veins at various intervals. Results in 6 experiments on 3 infected monkeys showed that about 17% of infected red cells given was trapped in the capillaries of the brain of the infected monkeys. The remainder of the infected red cells travelled on the same flow rate as the normal red cells. As the volume for the flow of the former was less than that of the latter, the mean transit time of the infected red cells (-ty) was therefore shorter than that of the normal red cells (-th). The mean difference in volume was estimated to be 3.4% in the present study. These findings indicated that some of the P. knowlesi infected red cells were trapped in capillaries of the brains of monkeys infected with P. knowlesi.