Neoplasias sólidas de células redondas en edad pediátrica: correlación entre diagnóstico morfológico e inmunohistoquímica / Solid neoplasm of circle celis in the pediatric age: correlation between morphological and immunohistochemistry diagnóstic

Precisar la importancia de realizar el estudio de inmunohistoquímica y su correlación con el diagnóstico anatomopatológico de rutina para el diagnóstico de los tumores sólidos malignos de células redondas en pacientes pediátricos. Se realizó un estudio transversal, descriptivo, retrospectivo no experimental. Se estudiaron 147 pacientes con diagnóstico de neoplasia de células redondas, de los cuales 96 cumplieron con criterios de inclusión. La mayor frecuencia de casos la obtuvo el linfoma No Hodgkin (20,8%), seguido del linfoma de Hodgkin (15,6%) y tumor de Wilms (17,7%). El grupo etario mayormente afectado fue el escolar (37,5%). El género predominante fue el masculino (60,4%). Las manifestaciones clínicas más frecuentes fueron masa palpable (76,04%), fiebre(44,79%), anemia (41,67%), dolor (41,30%) y pérdida de peso (33,33%). Se evidenció la mayor correlación diagnóstica en el tumor de Wilms (100%), seguido del linfoma No Hodgkin (80%) y el linfoma de Hodgkin (75%); la menor correlación la presentaron el sarcoma de Ewingy el neuroblastoma (41,7%, ambos). La correlación total resultó “considerable” según la fuerza de concordancia del coeficiente de Kappa (k: 0,601. P=0,000). Se requiere la integración del examen histopatológico de rutina como método diagnóstico de pesquisa y del estudio de inmunohistoquímica como método auxiliar diagnóstico, para determinar la histogénesis de las neoplasias, descartar diagnósticos diferenciales, realizar un diseño terapéutico apropiado y precisar el pronóstico.

To precise the state and the importance o fthe study of immunohistochemistry and its correlation with the routine pathological diagnosis to use in diagnosis of malignant solid tumors of round cells in pediatric patients. We was performed a transversal, descriptive and retrospective non-experimental study. We studied 147 patients diagnosed with round cell tumor, 96 of them weremet in inclusion criteria. The highest frequency of the cases was Non-Hodgkin lymphoma (20.8%), followed by the Hodgkin lymphoma (15.6%) and the Wilms tumor(17.7%). The age group most affected was the school(37.5%). The male gender was the predominant (60.4%).The most frequent clinical manifestations were a palpablemass (76.04%), the fever (44.79%), the anemia (41.67%),the pain (41.30%) and the weight loss (33.33%). Evidencedthe highest correlation in the diagnosis of Wilms tumor(100%), followed by Non-Hodgkin lymphoma (80%) and Hodgkin lymphoma (75%); showed the lowest correlation between the Ewing sarcoma and neuroblastoma (41.7%, both). The total correlation is “considerable” accordingto strength of agreement the Kappa coefficient (k: 0.601.P=0.000). It requires the integration of routine histopathological examination as diagnostic method of research and study of immunohistochemistry as an auxiliary diagnostic method to determine the histogenesis of neoplasm and exclude the differential diagnoses, make anappropriate therapeutic design and the determine prognosis of this group of patients.

Seroepidemiología de la infección por toxoplasma gondii en embarazadas / Seroepidemiology of toxoplasa gondii infection in a pregnant women

Se determinó la frecuencia de anticuerpos IgG e IgM anti-Toxoplasma gondii en 61 mujeres embarazadas con edades comprendidas entre 16 y 38 años y diferente edad gestacional. Se utilizaron los métodos de Inmunofluorescencia Indirecta para determinar IgG y Enzimoinmunoensayo para determinar IgM, para el análisis estadístico se utilizó la prueba de Chi cuadrado. 40 de las 61 embarazadas (65,57 por ciento) mostraron títulos de anticuerpos IgG anti.T. gondii iguales o superiores a 1:64; 1 de 61 de las mujeres evaluadas (1,64 por ciento) presentó anticuerpos IgM. De las 40 embarazadas con títulos mayor igual 164, solo 8 (20 por ciento) refirieron antecedentes de aborto, sin encontrar diferencias estadísticamente significativas entre la infección por T. gondii y el antecedente de abortos. También se demostró independencia entre cohabitación con gatos e infección por T. gondii

Trypanosoma cruzi contains major pyrophosphate stores, and its growth in vitro and in vivo is blocked by pyrophosphate analogs.

High field (31)P nuclear magnetic resonance spectroscopy showed that inorganic pyrophosphate (P(2)O(7)(4-)) is more abundant than ATP in Trypanosoma cruzi, the causative agents of Chagas' disease. These results were confirmed by specific analytical assays, which showed that in epimastigotes, the concentrations of inorganic pyrophosphate and ATP were 194.7 +/- 25.9 and 37.6 +/- 5.5 nmol/mg of protein, respectively, and for the amastigote form, the corresponding concentrations were 358.0 +/- 17.0 and 36.0 +/- 1.9 nmol/mg of protein. High performance liquid chromatographic analysis of perchloric acid extracts of epimastigotes labeled for 3 h with (32)P-orthophosphate showed a significant incorporation of the precursor into inorganic pyrophosphate. Inorganic pyrophosphate was not uniformly distributed in T. cruzi but was shown by (31)P-NMR and chemical analysis to be particularly associated with acidocalcisomes, organelles shown previously to contain large amounts of phosphorus and various elements. Electron microscopy analysis of pyrophosphatase-treated permeabilized epimastigotes showed disappearance of the electron density of the acidocalcisomes. Nonmetabolizable analogs of pyrophosphate, currently used for the treatment of bone resorption disorders, selectively inhibited the proliferation of intracellular T. cruzi amastigotes and produced a profound suppression in the number of circulating trypomastigotes in mice with an acute infection of T. cruzi, offering a potentially new route to chemotherapy.

Antiproliferative effects and mechanism of action of SCH 56592 against Trypanosoma (Schizotrypanum) cruzi: in vitro and in vivo studies.

We have investigated the antiproliferative effects of SCH 56592, a new experimental triazole, against Trypanosoma (Schizotrypanum) cruzi, the etiological agent of Chagas' disease in Latin America. SCH 56592 blocked the proliferation of the epimastigote form of the parasite in vitro at 30 nM, a concentration 30- to 100-fold lower than that required with the reference compounds ketoconazole and itraconazole. At that concentration all the parasite's endogenous sterols (ergosterol, 24-ethyl-cholesta-5,7,22-trien-3 beta-ol, and its 22-dihydro analogs), were replaced by methylated sterols (lanosterol and 24-methylene-dihydrolanosterol), as revealed by high-resolution gas chromatography coupled with mass spectrometry. This indicated that the primary mechanism of action of the drug was inhibition of the parasite's sterol C-14 alpha demethylase. Against the clinically relevant intracellular amastigote form, grown in cultured Vero cells at 37 degrees C, the MIC of SCH 56592 was 0.3 nM, again 33- to 100-fold lower than that of ketoconazole or itraconazole. In a murine model of acute Chagas' disease, SCH 56592 given at > or = 10 mg/kg of body weight/day for a total of 43 doses allowed 85 to 100% survival and 90 to 100% cure of the surviving animals, as verified by parasitological, serological, and PCR-based tests, while ketoconazole given at 30 mg/kg day allowed 60% survival but only 20% cure. In a murine model of chronic Chagas' disease, SCH 56592 was again more effective than ketoconazole, providing 75 to 85% protection from death, with 60 to 75% parasitological cures of the surviving animals, while no parasitological cures were observed with ketoconazole. The results indicate that SCH 56592 is the most powerful sterol biosynthesis inhibitor ever tested against T. cruzi and may be useful in the treatment of human Chagas' disease.

Cure of short- and long-term experimental Chagas' disease using D0870.

Chagas' disease, a protozoan infection by the kinetoplastid Trypanosoma cruzi, constitutes a major public health problem in Latin America. With the use of mouse models of both short- and long-term forms of the disease, the efficacy of D0870, a bis-triazole derivative, was tested. D0870 was able to prevent death and induced parasitological cure in 70 to 90 percent of animals, in both the short- and long-term disease. In contrast, currently used drugs such as nifurtimox or ketoconazole prolonged survival but did not induce significant curing effects. D0870 may be useful in the treatment of human long-term Chagas' disease, a condition that is currently incurable.

IgG e IgM anti Chlamydia trachomatis en lactantes con infección respiratoria aguda en tracto inferior / IgG and IgM anti Chlamydia trachomatis in infants with acute respiratory infection in lower tract

A los fines de determinar la incidencia de anticuerpos anti Chlamydia trachomatis en lactates con infecciones respiratorias agudas (IRA) del tracto inferior, se analizaron 64 muestras de suero provenientes de lactantes menores de 6 meses que acudieron al Servicio de Emergencia Pediátrica del Hospital Universitario de los Andes, en la ciudad de Mérida, de los cuales, 32 tenían diagnóstico clínico de IRA del tracto inferior, y 32 otras patologías no respiratorias, como grupo control. Para la determinación de anticuerpos IgG-IgM anti Chlamydia trachomatis, se siguió el método de Inmunofluorescencia indirecta. 14 pacientes (43.7 por ciento) presentaron títulos significativos (>=1:64) para IgM anti Chlamydia trachomatis. Para el grupo control, 16 muestras (50 por ciento) fueron positivas a títulos menores 1:64. Se concluye que el método de inmunofluorescencia indirecta es una alternativa importante para el diagnóstico de IRA del tracto inferior por Chlamydia trachomatis en lactantes menores de 6 meses