Utilidad de los marcadores tumorales en el diagnóstico de neoplasia asociada a trombosis venosa profunda idiopática / Usefulness of the tumor markers in the diagnose of idiopathic deep venous thrombosis associated cancer

Objetivo: Valorar la utilidad para el diagnóstico de neoplasia de la determinación de un perfil amplio de marcadores tumorales (MT) junto a la evaluación inicial de los pacientes con trombosis venosa profunda (TVP) idiopática. Material y métodos: Estudio prospectivo de 48 pacientes con diagnóstico de TVP idiopática. Se determinó en suero a todos los pacientes: antígeno carcinoembronario, alfa-fetoprotetína, CA 19.9, CA 125, beta2-microglobulina, antígeno de células escamosas, enolasa neuronal específica, antígeno prostático específico en los varones y CA15.3 en las mujeres. Los pacientes fueron evaluados para neoplasia durante el ingreso y seguidos a los 6 y 12 meses. Resultados: La edad media fue de 65 años. En 23 pacientes (48 por ciento) se detectó al menos un marcador elevado. Se diagnosticaron 8 neoplasias (16 por ciento), 4 en el grupo con marcadores elevados y 4 en el grupo con marcadores normales. No apreciamos diferencias significativas en las incidencias de neoplasia entre ambos grupos. Sin embargo, de los 4 casos de neoplasias diagnosticadas en el grupo con marcadores elevados, solo 1 se consideró verdadero positivo puesto que en las otras el marcador elevado no resultó congruente con la neoplasia. Seis neoplasias se diagnosticaron durante el ingreso hospitalario y dos durante el seguimiento. Se obtuvo una sensibilidad del 12 por ciento, una especificidad del 52 por ciento, un valor predictivo positivo del 5 por ciento y un valor predictivo negativo del 75 por ciento. Conclusiones: La incidencia de neoplasia fue similar a la comunicada por otros autores. Encontramos poca sensibilidad y especificidad, y escaso valor predictivo positivo con numerosos falsos positivos. Sin embargo, el valor predictivo del resultado negativo fue del 75 por ciento, con lo que la mayoría de los pacientes con un perfil completo normal de MT y asintomáticos no tuvieron neoplasia al diagnóstico ni durante el tiempo de seguimiento (AU)

Análisis electroquímico / Electrochemical analisys

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[Usefulness of the tumor markers in the diagnosis of idiopathic deep venous thrombosis associated cancer]. / Utilidad de los marcadores tumorales en el diagnóstico de neoplasia asociada a trombosis venosa profunda idiopática.

OBJECTIVE: To evaluate a wide detection of tumor markers practiced during admission for the diagnosis of cancer in patients with idiopathic deep venous thrombosis. MATERIAL AND METHODS: Prospective study including 48 patients with documented DVT who lacked a predisposing cause to DVT. It was determined in serum: carcinoembryonic antigen, alphafetoprotein, CA 19-9, CA 125, beta-2-microglobulin, SCC (squamous cell antigen), NSE (neuron-specific enolase), PSA (prostate-specific antigen) in the males and CA15-3 in the women. The patients were evaluated for cancer during admission and followed up at 6 and 12 months. RESULTS: The age was 65 years. A positive tumor marker at least was detected in 23 patients (48%). A cancer was diagnosed in 8 patients (16%), 4 in the group with elevated tumor markers and 4 in the group with normal tumor markers. We don't find significant differences in cancer incidence between both groups. However, of the 4 cases of cancer diagnosed in the group with elevated markers only 1 was considered true positive since in the others three cases the elevate tumor marker was not appropriated with the cancer diagnosed. Six tumors were diagnosed during admission and two during follow-up period. According to these results was obtained a sensitivity of 12%, a specificity of 52%, a positive predictive value of 5% and a negative predictive value of 75%. CONCLUSIONS: The cancer incidence is similar to previous series. We have found a poor sensitivity, specificity and positive predictive value. However, the negative predictive value was of 75% and the patients who were normals for results of all tumor markers and was asymptomatic during admission hadn't a subsequent cancer diagnosis.

Pruebas de significación en Bioestadística / Biostatistic significance tests

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Principios de bioestadística / Biostatisc principles

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Tumor glutaminase purification.

Two alternative purification schemes to obtain the glutaminase from Ehrlich tumor cells in a highly purified form have been developed. One experimental approach is based on conventional and high-performance liquid chromatography fractionation techniques, yielding a 37-fold higher purification than has been previously reported. The method comprises: isolation of mitochondria, solubilization with Triton X-100, ion-exchange and hydroxyapatite chromatography, ammonium sulfate precipitation, and hydrophobic interaction chromatography. A second purification schedule has been optimized employing native polyacrylamide gel electrophoresis, in situ activity staining, and electroelution of the protein band. This approach resulted in a simple and rapid isolation of a 10-fold higher purified glutaminase than before, minimizing also the potential for proteolytic inactivation of the enzyme. The apparent molecular weight of the protein in native form was determined by gel filtration and sucrose density gradient ultracentrifugation. Polyclonal antibodies raised against Ehrlich glutaminase were immunopurified against the pig kidney enzyme. Immunoblot analyses employing these antibodies as well as anti-rat kidney glutaminase antibodies revealed the same pattern of bands seen with the purified enzyme.

Native polyacrylamide gel electrophoresis of membrane proteins: glutaminase detection after in situ specific activity staining.

A new procedure for the analysis and detection of phosphate-activated glutaminase (EC 3.5.1.2) by native electrophoresis has been developed. The method is based on the in situ detection of glutaminase activity in two different systems of native polyacrylamide gradient gels, containing 3-(3-cholamidopropyl)-dimethyl-ammonio-1-propane sulfonate (CHAPS) or Triton X-100 as nondenaturant detergents. Crude Triton X-100 extracts of mitochondria were resolved by electrophoresis. The enzyme was specifically revealed by incubation of the gel with glutamine and coupling the oxidation of the glutamate formed to the reduction of a tetrazolium dye, in the presence of glutamate dehydrogenase trapped in a 1% agar solid overlay. Both Ehrlich ascitic cell and mouse kidney glutaminases were resolved by native electrophoresis and specifically detected with the activity staining. Moreover, the redox-cycling staining was tested in solution, showing linearity with the amount of glutamate or glutaminase activity present. The method described could be a useful tool for native polyacrylamide gel electrophoresis of membrane proteins.