Modified comet assay with Giemsa staining: a suitable method for assessing genotoxicity in rats / Ensaio cometa modificado com coloração de Giemsa: um método adequado para avaliar a genotoxicidade em ratos

The present study tested a comet assay that was modified for compatibility with Giemsa staining to assess the drug genotoxicity in the peripheral blood of rats. We analysed the peripheral blood of 16 female Wistar rats (N=8 rats/group) from a control group and from a group that was treated with an intraperitoneal injection of 50mg cyclophosphamide/kg. The comet assay was carried out with modifications of the blood volume and immersion time in the lysing solution and different combinations of electrophoresis conditions (running time, voltage and current), to Giemsa staining. The lysing time and electrophoresis conditions allowed for the expression of all classes of DNA damage during the electrophoresis run, and the comets were efficiently stained with Giemsa. The technique showed high reproducibility for the DNA classes. The results demonstrate that the modified comet assay with Giemsa staining can be standardized for routine laboratory procedures using a 20µL blood sample, 3h and 30min immersions in the lysing solution and electrophoresis runs with 23 to 25 V and 310 and 360mA of electrical current. The modified comet assay with Giemsa staining that was described in the present study was standardized to be applied in the laboratory routine.(AU)

O presente estudo testou um ensaio cometa modificado para a coloração de Giemsa para avaliar a genotoxicidade de fármacos no sangue periférico de ratos. Analisou-se o sangue periférico de 16 ratas Wistar (n=8 ratas/grupo) de um grupo controle e de um grupo que foi tratado com uma injeção intraperitoneal de 50mg/kg pv. de ciclofosfamida. O ensaio cometa foi realizado com modificações do volume sanguíneo e do tempo de imersão na solução de lise, bem como com diferentes combinações de condições de eletroforese (tempo de corrida, tensão e corrente), para coloração de Giemsa. O tempo de lise e as condições de eletroforese permitiram a expressão de todas as classes de danos no DNA durante a corrida de eletroforese, e os cometas foram eficientemente corados com Giemsa. A técnica mostrou alta reprodutibilidade para as classes de DNA. Os resultados demonstram que o ensaio cometa modificado com coloração de Giemsa foi padronizado para procedimentos laboratoriais de rotina usando-se uma amostra de sangue de 20µL, 3h30min de imersão na solução de lise e eletroforese com 23 a 25 V e 310 e 360mA. O ensaio cometa modificado com coloração de Giemsa descrito foi padronizado para ser aplicado na rotina laboratorial.(AU)

Trisomía 9: reporte de un caso / Trisomy 9: a case report

La trisomía 9 es una enfermedad rara, que ha sido descrita por primera vez en 1970, a la fecha existen más de 150 casos reportados, caracterizados por dismorfias faciales, anomalías congénitas y retraso en el desarrollo psicomotor y/o discapacidad intelectual. Este es el primer caso reportado en nuestra población en un infante de sexo masculino con peso y talla bajos, fisura labiopalatina y retraso madurativo en varias áreas del desarrollo, en quien el cariotipo mostró un mosaico cromosómico con el 70% de sus células con la trisomía del cromosoma 9. El asesoramiento genético en estos casos es de vital importancia para orientar a los padres sobre posibles causas y explicar sobre la condición genética, su manejo y establecer pautas de seguimiento para hacer prevención terciaria

Comparative study of metachromatic staining methods in assessing the exfoliative cell types during oestrous cycle in Sprague-Dawley laboratory rats / Estudio comparativo de los métodos de tinción metacromática en la evaluación de los tipos de células exfoliativas durante el ciclo estral en ratas Sprague-Dawley de laboratorio

This study was aimed at comparing the commonly used metachromatic stains viz., Papanicolaou stain, WrightGiemsa, Toluidine blue and Methylene blue in the assessment of cell types of the oestrous cycle in rats. Eight female Sprague-Dawley rats aged 8-9 weeks were used for this assessment. Cotton Swabs were gently inserted in the animals vagina to obtain cells from which they were then transferred to glass slides for staining and evaluation under microscopy. The different cell types were compared for their morphological features and clarity of cellular detail under all four stains. The application, advantages and limitations of all stains were then discussed. It was concluded that the selection of the most effective stain in the assessment of vaginal cytology depends on their application to clinical or research which was based on the cellular detail of interest, time, cost and availability of each staining procedure.

El presente estudio tuvo como objetivo comparar las tinciones metacromáticas comúnmente utilizadas, Wright's-Giemsa, azul de toluidina, azul de metileno y tinción de Papanicolaou, en la evaluación de los tipos de células del ciclo estral en ratas. El estudio se realizó en ocho ratas hembras SpragueDawley, con edades entre 8 y 9 semanas, y se usaron hisopos vaginales de algodón para preparar portaobjetos. Los diferentes tipos de células se compararon por sus características morfológicas y claridad en las cuatro tinciones. La aplicación, ventajas y limitaciones de todas las tinciones fueron discutidas. Se concluye que la selección de la tinción más efectiva en la evaluación de la citología vaginal depende de su uso, es decir, clínico o de investigación, el detalle celular de interés, tiempo, costo y disponibilidad.

Enhancement of quantum efficiency of a dye-sensitized electrochemical cell by using triturated zinc oxide mixed with two organic dyes, azure C and rose bengal

For efficiently utilising solar energy, when suitable nanoparticles are being engineered, triturated zinc oxide an eco-friendly, easily available, low-cost material has been used as an agent for solar energy conversion. Two organic dyes Azure C and Rose bengal having absorption bands in two different spectral regions at 545 nm and 610 nm respectively, were chosen in order to overcome the band absorption limits of each dye and utilise the broad spectrum of solar radiation. The material was mixed with these two dyes in a specially devised electrochemical cell and photovoltage with significant efficiency was generated. The energy conversion efficiency of the cell using three different potencies 6C, 30C and 200C of triturated zinc oxide with the same concentration of two dyes (0.5x10-5 M) in all cases are 0.39%, 0.43% and 0.35% respectively. The efficiency is only 0.15% for the mixed dye under similar conditions.

Respuesta inflamatoria genital en la detección de alteraciones por virus del papiloma humano / The inflammatory genital reaction in the detection of alterations by human papilloma virus / Reagào inflamatoria genital na detecgào de alteragòes por Papilomavírus Humano

Disfunción vaginal (DV) (vaginosis/vaginitis) es el síndrome genérico de mayor prevalencia, alcanzando el 50% de todas las mujeres en edad fértil (sintomáticas y asintomáticas). El virus del Papiloma Humano (HPV) se detecta en 30 a 40% de mujeres en edad fértil (sintomáticas y asintomáticas) y se asocia a alteraciones pre-neoplásicas y a carcinoma invasor del cuello uterino. El diagnóstico sindrómico de DV y alteraciones inducidas por HPV es ineficiente y en la actualidad la morfología (macro y microscópica) es el gold standard, pero requiere ordenamiento. El Estudio del Contenido Vaginal es la prueba de laboratorio bacteriológico de mayor solicitud luego del urocultivo. BACOVA normatiza el diagnóstico de vaginosis/vaginitis y ERIGE aumenta el valor predictivo de células que alertan sobre alteraciones epiteliales. Desde 2007 al presente en los talleres BACOVA ERIGE (tinción de Giemsa) se evaluó la sensibilidad de la detección de células anormales exfoliadas. Un 99% de los participantes coincidió con la detección de koi-locitos. BACOVA/ERIGE no reemplaza al Papanicolaou de ninguna manera, pero puede y debe realizarse en laboratorios periféricos, con lo que además del diagnóstico de vaginosis/vaginitis con 100% de valor predictivo, aumentan la cobertura preventiva de estados proliferativos.

Vaginal dysfunction (DV) (vaginosis/vaginitis) is the generic syndrome of major prevalence, reaching 50% of all women in fertile age (symptomatic and asymptomatic). The Human Papillomavirus (HPV) is detected in 30-40% of women in fertile age (symptomatic and asymptomatic) and is associated to pre-neoplastic lesions and invading carcinoma of the uterine cervix. The diagnosis for the symptoms of DV and the alterations induced by HPV are inefficient and at present, the morphology (macroscopic and microscopic) is the standard gold, but it needs better classification. The Study of the Vaginal Content is the test of major request after urocultives in bacteriological laboratories. BACOVA establishes the procedure for the diagnosis of vaginosis/vaginitis and ERIGE increases the predictive value of cells that give the alarm on epithelial alterations. From 2007 to the present sensitivity in the detection of abnormal exfoliated cells from vagina and uterine cervix was evaluated during the BACOVA - ERIGE, (Giemsa's stain) workshops, 99% of the participants coincided with the detection of koilocytes. BACOVA/ERIGE does not replace the Papanicolaou by any means, but it can and must be performed in peripheral laboratories, where apart from the diagnosis of vaginosis/vaginitis with 100% of predictive value, it is possible to increase the detection of precocious proliferative changes of the squamous epithelium.

Disfungào vaginal (DV) (vaginose / vaginite) é a síndrome mais prevalente genérica, atingindo 50% de todas as mulheres em idade fértil (sintomáticas e assintomáticas). O Papilomavírus Humano (HPV) é detectado em 30-40% das mulheres em idade fértil (sintomáticas e assintomáticas) e está associado a alteragòes pré-neoplásicas e a carcinoma invasivo do colo do útero. O diagnóstico sindrómico de DV e alteragòes induzidas pelo HPV é ineficiente e atualmente a morfologia (macroscópica e microscópica) é o padrào ouro, mas precisa de ordenamento. O Estudo do Conteúdo Vaginal é o exame de laboratòrio bacteriológico mais solicitado, seguido da urocultura. BACOVA normatiza o diagnòstico de vaginose/ vaginite e ERIGE aumenta o valor preditivo de células que alertam a respeito de alteragòes epiteliais. Desde 2007 até hoje, nos workshops BACOVA/ERIGE (coloragào de Giemsa), foi avaliada a sensibili-dade da detecgào de células anormais esfoliadas. 99% dos participantes coincidiram com a detecgào de coilócitos. Bacova/Erige nào substitui o Papanicolaou de forma alguma, mas pode e deve ser feito em laboratórios periféricos, com o qual além do diagnóstico de vaginose / vaginite com 100% de valor preditivo, aumentam a cobertura preventiva de estados proliferativos.

Cultivo de la línea celular HEp-2: doblaje poblacional y coloración con Giemsa Perspectivas para el estudio de la infección con Chlamydia trachomatis / Cultivation of the cell line hep-2: dubbing of population and coloring with Giemsa

Los cultivos celulares se han convertido en herramientas esenciales para la investigación básica. Se aplican en inmunología, virología, biología molecular, ingeniería genética y farmacología, entre otras áreas. Se usan también en procesos industriales farmacéuticos, en técnicas de diagnóstico clínico y para estudio de trasplante de tejidos. En bacteriología, estos cultivos permiten confirmar una infección, evaluar la eficiencia de antimicrobianos, realizar estudios de infectividad, investigar sobre nuevas especies, obtener gran cantidad de microorganismos no cultivables para optimizar técnicas y examinar las relaciones entre la célula huésped y los microorganismos intracelulares (virus, bacterias y parásitos). La línea celular HEp-2 (Human Epidermoid Cancer Cells) es utilizada en estudios de infección con diferentes bacterias, entre ellas Chlamydia trachomatis (CT), con el fin de determinar los mecanismos por los cuales este patógeno sobrevive en la célula huésped. También se emplea para observar la acción de péptidos antimicrobianos y de extractos para combatir la infección causada por dicha bacteria. Para este estudio se realizaron curvas de crecimiento en la línea celular HEp-2 con medios DMEM-F12 y MEM. Se estandarizó, además, la coloración con Giemsa y se calculó el doblaje poblacional con diferentes inóculos para evaluar el desarrollo de la línea celular en cultivo y seleccionar las condiciones óptimas para realizar futuros ensayos de infección con parásitos intracelulares, en particular con CT serovar L2.

Cell cultures have become essential tools for basic research. They are applied in immunology, virology, molecular biology, genetic engineering and pharmacology, among other areas. They are also used in pharmaceutical industrial processes, in techniques of clinical diagnostic, and to study tissue transplantation. In bacteriology, these crops allow us to confirm an infection, assess the efficiency of antimicrobials, carry out studies of infectivity, investigate on new species, obtaining a large number of microorganisms non-arable to optimize techniques, and to examine the relationship between the host cell and intracellular microorganisms (bacteria, viruses, and parasites). The HEp-2 cell line (Human epidermoid cancer cells) is used in studies of infection with different bacteria, including Chlamydia trachomatis (CT), in order to determine the mechanisms by which the pathogen survives in the host cell. It is also used to observe the action of antimicrobial peptides and extracts to combat the infection caused by the bacterium. For this study, growth curves of the HEp-2 cell line were carried out with DMEM-F12 and MEM media. In addition, the staining with Giemsa was standardized, and the population dubbing was calculated with different inocula for assessing the development of the cultured cell line and select the optimal conditions for future tests of infection with intracellular parasites, in particular with CT serovar L2.

Diagnóstico presuntivo de histoplasmosis en un frotis sanguíneo / Presumptive diagnosis of histoplasmosis in a blood smear / Diagnóstico presuntivo de histoplasmose em um esfregaço de sangue

Se comunica el diagnóstico de un caso de histoplasmosis asociada al SIDA a partir de la microscopía de un extendido hemático realizado en oportunidad del procesamiento de una muestra enviada al laboratorio para un estudio hematológico. El extendido, fijado con metanol y teñido con solución de Giemsa al 10% reveló, con objetivo de 100X, estructuras levaduriformes de 2-4 µ de diámetro dentro de las células leucocitarias sanguíneas, con la típica tinción en casquete y la presencia de un halo claro periférico, que caracterizan microscópicamente a Histoplasma capsulatum. Luego, para confirmar el hallazgo micológico, se procedió a teñir el mismo preparado con la técnica de Grocott, la cual puso de manifiesto levaduras de color pardo, dentro de los leucocitos sanguíneos. El paciente, deteriorado clínica e inmunológicamente (<50 linfocitos T CD4+/µL), falleció al día siguiente de efectuado el diagnóstico, a pesar de las medidas terapéuticas tomadas. Este hallazgo pone de manifiesto la necesidad de contar, en un Centro de Referencia de Enfermedades Infecciosas, con operadores entrenados para reconocer estructuras microbianas de importancia diagnóstica en extendidos hemáticos, aún en el Laboratorio General. El diagnóstico inmediato de ésta y otras infecciones graves, como el paludismo, a partir de estas muestras permite instalar un tratamiento etiológico y mejorar las posibilidades de éxito terapéutico.

A case of AIDS-associated histoplasmosis diagnosed by microscopy from a blood smear performed during a hematologic study was reported. The smear, fixed with methanol and stained with 10% Giemsa solution, revealed with a 100X objective, 2-4 µ-diameter yeast - like structures within the leuMicrobiología contakocytes, showing a typical staining in cap and a peripheral clear halo, characteristic of Histoplasma capsulatum. To confirm the mycological finding, the same smear was stained with the Grocott technique, showing brownish yeasts in the leucocytes. The patient, clinically deteriorated and with advanced immunological disorder (<50 T CD4+ lymphocytes/µL), died the next day after the diagnosis was made, in spite of the established treatments. This finding highlights the need to have operators trained in the recognition of microbiological structures of diagnostic importance in hematological smears in a Reference Center of Infectious Diseases, and even in the General Laboratory. The immediate diagnosis of this and other serious infections, as Malaria, enables the etiologic treatment and increases the possibilities of therapeutic success.

Comunica-se o diagnóstico de um caso de histoplasmose associada à AIDS, de uma microscopia de extensão sanguínea realizada por ocasião do processamento de uma amostra enviada ao laboratório para um estudo hematológico. A extensão, fixada com metanol e corada com solução de Giemsa a 10%, revelou com objetivo de 100X, estruturas leveduriformes de 2-4 µ diâmetro dentro de células leucocitárias do sangue, com a típica coloração em tampão e a presença de um halo claro periférico, os quais caracterizam microscopicamente a Histoplasma capsulatum. Em seguida, para confirmar o achado micológico, foi corada a mesma preparação com a técnica de Grocott, que mostrou leveduras de cor parda, dentro dos leucócitos sanguíneos. O paciente clínica e imunologicamente deteriorado (<50 células T CD4+/ µL) morreu um dia após o diagnóstico, apesar das medidas terapêuticas adotadas. Este achado evidencia a necessidade de contar, em um Centro de Referência para Doenças Infecciosas, com operadores treinados para reconhecer estruturas microbianas de importância diagnóstica em extensões sanguíneas, mesmo no Laboratório Geral. O diagnóstico imediato desta e de outras infecções graves como a Malária, a partir de uma extensão sanguínea torna possível instalar um tratamento etiológico e melhorar as chances de êxito terapêutico.

Aporte de la técnica de PCR en el diagnóstico de Mansonella ozzardi en zonas endémicas de la Argentina / Contribution of the PCR assay to the diagnosis of Mansonella ozzardi in endemic areas of Argentina

Mansonella ozzardi es un nematode parásito tisular, agente etiológico de mansonellosis en casi la totalidad de los países latinoamericanos. En Argentina la mansonellosis ha sido descrita a lo largo de la región de las yungas. Su diagnóstico microscópico puede dar resultados falsos negativos en microfilaremias bajas. El objetivo del presente estudio fue optimizar su diagnóstico molecular y comparar los resultados con los obtenidos mediante las pruebas microscópicas de Knott, de gota gruesa y de extendido hemático fino, en 92 muestras de sangre de pacientes de zona endémica. La técnica de PCR seguida de la secuenciación del producto amplificado presentó una sensibilidad del 100 % frente al método de Knott, considerado como referencia, e incluso permitió identificar 7 casos más de la parasitosis.

Mansonella ozzardi is a tissue-dwelling parasitic nematode, the causative agent of mansonelliasis in almost all Latin American countries. It has been described along the Argentine Yungas region. The microscopic diagnosis can yield false-negative test results at low microfilaremia levels. The aim of this study was to optimize the molecular diagnostic technique and compare it with the Knott's method and standard blood smear procedures (thin blood films and thick smears) in 92 blood samples of individuals from an endemic area. The PCR technique followed by the sequencing of the amplified product yielded 100 % sensitivity compared to the Knott's test, which is considered a reference method. Seven more cases of this parasitosis could only be identified with the molecular technique.

Mycoremediation of Congo red dye by filamentous fungi

Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was to study the factors influencing mycoremediation of Congo red. Several basidiomycetes and deuteromycetes species were tested for the decolourisation of Congo red (0.05 g/l) in a semi synthetic broth at static and shaking conditions. Poor decolourisation was observed when the dye acted as the sole source of nitrogen, whereas semi synthetic broth supplemented with fertilizer resulted in better decolourisation. Decolourisation of Congo red was checked in the presence of salts of heavy metals such as mercuric chloride, lead acetate and zinc sulphate. Decolourisation parameters such as temperature, pH, and rpm were optimized and the decolourisation obtained at optimized conditions varied between 29.25- 97.28 percent at static condition and 82.1- 100 percent at shaking condition. Sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis revealed bands with molecular weights ranging between 66.5 to 71 kDa, a characteristic of the fungal laccases. High efficiency decolourisation of Congo red makes these fungal forms a promising choice in biological treatment of waste water containing Congo red.

Donovanose / Granuloma inguinale (Donovanosis)

Os autores apresentam imagens de duas formas clínicas mais frequentes da Donovanose, em ambos sexos. A donovanose é considerada uma doença sexualmente transmissível, endêmica nas regiões tropicais e semitropicais do globo. Apresentam também imagens de duas lâminas: uma da pesquisa direta (corpúsculos de Donovan, dentro de grandes células mononucleadas coradas de vermelho pelo Giemsa) e outra de achados histológicos típicos (formato de alfinete dentro do histiócito).

The authors present images of two of the most common clinical forms of granuloma inguinale (donovanosis) in males and females. Donovanosis is considered a sexually transmitted disease that is endemic in tropical and subtropical regions of the world. Two microscopic images are also shown, one of a direct smear (the presence of Donovan bodies within large mononuclear cells identified using Giemsa stain) and the other of typical histological findings (rod-shaped Donovan bodies within a mononuclear histiocyte).

Avaliação da permeabilidade radicular em dentes com rizogênese incompleta após aplicação de hidróxido de cálcio como medicação intracanal / Root permeability evaluation in immature permanent teeth after calcium hydroxyde application as intra root medication

Introdução - Foi avaliada a possível variação da permeabilidade dentinária radicular, em dentes com rizogênese incompleta, após medicação com hidróxido de cálcio veiculado em solução anestésica. Material e Métodos - Decorrido o prazo experimental, os dentes foram re-preparados com quatro diferentes técnicas de remoção da medicação, avaliando-se quantitativamente o índice de permeabilidade dentinária radicular, através da penetração do corante azul de metileno. Observou-se existir diferença estatisticamente significante quanto à porcentagem de penetração de corante em função do tipo de técnica usada na remoção da medicação. Resultados - O uso do EDTA-T seguido ao seu final pelo creme de Endo-PTC neutralizado pelo hipoclorito de sódio a 1%, foi o que melhor proporcionou um aumento no índice de permeabilidade pós-medicação, devolvendo ao dente a condição prévia de permeabilidade conseguida após o preparo químico-cirúrgico, não havendo diferença estatisticamente significante ao nível de 5% entre o Grupo 2 e 6, nos diferentes terços radiculares. Conclusões - A medicação com hidróxido de cálcio interferiu, de forma decisiva, no índice de permeabilidade dentinária radicular, independente do terço radicular analisado

Comparación de las coloraciones de Giemsa y Grocott en el diagnóstico de la histoplasmosis / Comparison of Giemsa and Grocott stains in the diagnosis of histoplasmosis

El diagnóstico de histoplasmosis se realiza tradicionalmente mediante el reconocimiento de típicas levaduras intracelulares de Histoplasma capsulatum en preparaciones microscópicas teñidas con Giemsa. Se comparó la eficacia de una modificación rápida de la técnica de Grocott (MRG) y la tradicional de Giemsa para el diagnóstico de la histoplasmosis, a partir de la aplicación de ambas a 10 secreciones respiratorias, 8 escarificaciones de lesiones cutáneas y una biopsia ganglionar, pertenecientes todas a pacientes con sospecha clínica de esta micosis. En 15 de las 19 muestras no se encontraron diferencias significativas en la capacidad y rapidez para arribar al diagnóstico, mientras que en las 4 restantes, fueron reconocidas con la MRG estructuras que pasaron desapercibidas con la coloración de Giemsa. La modificación rápida permitió un reconocimiento más rápido del H. capsulatum en materiales donde este hongo se observó en escaso número y permitió además identificar con seguridad otros patógenos fúngicos diferentes de H. capsulatum, como Pneumocystis jiroveci, Paracoccidioides brasiliensis y Cryptococcus neoformans, difíciles de observar con la coloración de Giemsa. Se propone la técnica de Grocott o su modificación rápida para el diagnóstico de la histoplasmosis, especialmente cuando el empleo de la coloración de Giemsa da lugar a resultados negativos o dudosos.

The diagnosis of histoplasmosis is traditionally achieved by recognizing the typical intracellular yeasts of Histoplasma capsulatum, in smears stained with Giemsa stain. The usefulness of a rapid modification of Grocott and of traditional Giemsa stains for the diagnosis of histoplasmosis was compared applying both techniques in 10 respiratory secretions, 8 cutaneous lesions scrapings and 1 adenomegaly biopsy, all of them belonging to patients with clinically suspected histoplasmosis. In 15 out of the 19 evaluated samples, no significant differences were found in the ability or speed to reach the diagnosis with the applied techniques; while in the remaining 4 samples, structures that had not been observed with Giemsa stain were recognized with the rapid modification. The modification enabled quicker recognition of H. capsulatum than Giemsa stain in those clinical samples where the number of these fungal pathogens was scant. Additionally, the rapid modification also enabled the recognition of fungal pathogens other than H. capsulatum, as Pneumocystis jiroveci, Paracoccidioides brasiliensis and Cryptococcus neoformans, difficult to observe with the Giemsa stain. Use of Grocott technique or rapid modification stain is proposed for the diagnosis of histoplasmosis, when the result obtained with the Giemsa stain is doubtful or negative.

Chlamydia trachomatis in the conjunctiva of children living in three rural areas in Mexico

OBJECTIVES: Chlamydia trachomatis infections, in the context of extreme poverty, may trigger trachoma. Because the levels of C. trachomatis eye infections in Mexico are unknown, this study sought to determine if C. trachomatis was present in the conjunctiva of children living in three poor, rural areas of the country. METHODS: Clinical diagnosis of conjunctival follicles in children was conducted during the 2004 visual acuity assessment campaigns in rural areas of the states of Chiapas, Oaxaca, and Zacatecas. C. trachomatis detection was carried out by sampling the children with follicles and examining the specimens after Giemsa or microimmunofluorescence (MIF) staining. RESULTS: A total of 941 children from 6 to 12 years of age were examined in 2004. Of the 484 in Chiapas, 30 percent were found to have follicles; of the 181 in Zacatecas, 22 percent; and of the 276 in Oaxaca, 42 percent. C. trachomatis was detected at levels ranging between 2 percent and 5 percent; positive by Giemsa in 4.5 percent of the children with follicles, and by MIF in 15.5 percent. CONCLUSIONS: Considering that the chlamydiae sampling procedures and detection methods used in this study were not the most sensitive, the results underestimate the chlamydial eye infections and represent a conservative assessment of a potential risk for preventable visual impairment. Because C. trachomatis was detected here at levels similar to those reported for low-endemic trachoma areas, health authorities should be prepared to implement appropriate measures should it be confirmed that the visual health of MexicoÆs children is at risk.

OBJETIVOS: En un contexto de pobreza extrema, la infección por Chlamydia trachomatis puede desencadenar el tracoma. Debido a que se desconocen los niveles de infección ocular con C. trachomatis en México, el objetivo de este estudio fue determinar la presencia de C. trachomatis en la conjuntiva de niños de tres zonas rurales pobres de México. MÉTODOS:El diagnóstico clínico de folículos conjuntivales en los niños se llevó a cabo durante la campaña de evaluación de la agudeza visual en áreas rurales de los estados de Chiapas, Oaxaca y Zacatecas en 2004. Para la detección de C. trachomatis se tomaron muestras de los niños con folículos y se analizaron mediante la tinción de Giemsa o microinmunofluorescencia (MIF). RESULTADOS: En total se examinaron 941 niños de 6 a 12 años de edad en 2004. Se observaron folículos en 30 por ciento de los 484 niños de Chiapas, en 22 por ciento de los 181 de Zacatecas y en 42 por ciento de los 276 niños de Oaxaca. Se detectó C. trachomatis en niveles entre 2 por ciento y 5 por ciento; de los niños con folículos, 4,5 por ciento resultaron positivos por Giemsa y 15,5 por ciento por MIF. CONCLUSIONES: Estos resultados subestiman el nivel de infección ocular por clamidia, ya que los procedimientos de muestreo y los métodos de detección de clamidia empleados en este estudio no eran los más sensibles, por lo que representan una valoración conservadora del riesgo de trastornos visuales prevenibles. Como los niveles de C. trachomatis encontrados son similares a los informados para áreas de baja endemia de tracoma, las autoridades de salud deben estar listas para implementar medidas apropiadas si se confirmaran los riesgos para la salud visual de los niños mexicanos.

Sensitivity and specificity of polymerase chain reaction in Giemsa-stained slides for diagnosis of visceral leishmaniasis in children

The aim of this study was to evaluate the sensitivity and specificity of polymerase chain reaction (PCR) in the detection of Leishmania DNA in archived Giemsa-stained bone marrow slides for diagnosis of visceral leishmaniasis (VL), and to compare PCR with conventional diagnostic techniques, like direct microscopy and parasite culture. Specimens of archived Giemsa-stained bone marrow slides from 91 patients with VL and from 79 controls with other diseases or conditions were studied. PCR showed the highest sensitivity (92.3 percent) and had good specificity (97.5 percent). Direct examination detected 79.1 percent and culture 59 percent of positive samples. In addition, PCR was able to detect VL in 16 of 19 patients (84.2 percent) with negative microscopy. PCR in Giemsa-stained bone marrow slides is a suitable tool for confirming diagnosis in patients with VL and may be useful in the diagnosis of difficult cases. Slide smears are easily stored, do not require special storage conditions such as low temperatures, and can be easily mailed to centers where PCR is available, making it an excellent option for diagnosis in the field.

Theileria electrophorin.sp., a parasite of the electric eel Electrophorus electricus (Osteichthyes: Cypriniformes: Gymnotidae) from Amazonian Brazil

The name Theileria electrophori n.sp. is proposed for a small parasite described in the erythrocytes of the electric eel, Electrophorus electricus, from Amazonian Brazil. Division of the organism in the erythrocyte produces only four bacilliform daughter cells which become scattered in the host cell, without a cruciform or rosette-shaped disposition. Exoerythrocytic meronts producing a large number of merozoites were encountered in Giemsa-stained impression smears of the internal organs, principally in the liver, and are presumably the source of the intraerythrocytic forms of the parasite. This developmental pattern is characteristic of piroplasms within the family Theileriidae, where the author considers the parasite of E. electricus to most appropriately belong. It effectively distinguishes the organism from the dactylosomatid parasites Babesiosoma Jakowska and Nigrelli, 1956 and Dactylosoma Labbé, 1894 also found in fishes. This appears to be the second report of Theileria Bettencourt, Franca and Borges, 1907 in a fish.

Karyotypic studies of Cratylia argentea (Desv.) O. Kuntze and C. mollis Mart. ex Benth. (Fabaceae - Papilionoideae)

Cratylia argentea and C. mollis (Fabaceae-Papilionoideae) are legume shrubs native to the Cerrado and Caatinga, respectively. Both species show great resistance to drought and high nutritive value, which makes them a valuable forage resource in tropical regions. Cytogenetic studies were carried out on accessions of C. argentea and C. mollis from Germplasm Banks of Embrapa Gado de Leite (Juiz de Fora, MG) and Embrapa Semi-Árido (Petrolina, PE), respectively. Root tips were treated with 3 mM 8-hydroxyquinoline and slides were made using the air-dry technique. Karyotype description for each accession took into account the following features: chromosome number; total length, relative length and arm ratio of each chromosome; haploid set length, and degree of asymmetry. Mitotic metaphases in both species showed 2n = 22 chromosomes, where this is the first report of diploid number for C. mollis. Chromosome length was also quite similar for the two species, ranging from 5.08 to 2.50 µm in C. argentea and 5.12 to 2.51 µm in C. mollis, with haploid sets of equal size, measuring 38.10 and 37.85 µm, respectively. However, they did not show the same karyotypic formula, which was 5 m + 4 sm + 2 st for C. argentea and 7 m + 2 sm + 2 st for C. mollis. This indicates the occurrence of rearrangements within chromosomes I and VI. Both karyotypes showed a tendency for asymmetry.

Cytogenetic characterization of Rhamdiaquelen (Siluriformes, Heptapteridae) from the Bodoquena Plateau, Mato Grosso do Sul, Brazil

We made a cytogenetic study of the fish Rhamdia quelen collected from the Bodoquena Plateau, an isolated national park region in Mato Grosso do Sul State, Brazil. The diploid number was 2n = 58, with 36 metacentric + 16 submetacentric + 6 subtelocentric chromosomes. We found one to three B chromosomes, which were metacentric and submetacentric and of medium size, showing both intra- and interindividual variation. The nucleolus organizer region (NOR) was located in the terminal region of the short arm of submetacentric pair 20. Staining with CMA3 fluorochrome revealed the NOR location, while there was no evidence of fluorescent staining with DAPI. C banding revealed heterochromatin mainly in the terminal regions of the chromosome arms, including the NOR pair. In addition, metacentric pair 2 showed three heterochromatic blocks in the terminal portions and in the pericentromeric region. The B chromosomes appeared euchromatic. The CB + CMA3 staining combination demonstrated only one chromosome pair with fluorescence, probably the NOR-bearing one, while CB + DAPI gave various fluorescent signals, including metacentric pair 2, indicating that these heterochromatic regions are AT-rich in this population of R. quelen. The R. quelen population in this isolated region of Brazil is chromosomally distinct from that of other populations that have been studied.

Prevalence of Helicobacter pylori infection in advanced gastric carcinoma

BACKGROUD: There is substantial evidence that infection with Helicobacter pylori plays a role in the development of gastric cancer and that it is rarely found in gastric biopsy of atrophic gastritis and gastric cancer. On advanced gastric tumors, the bacteria can be lost from the stomach. AIMS: To analyze the hypothesis that the prevalence of H.pylori in operated advanced gastric carcinomas and adjacent non-tumor tissues is high, comparing intestinal and diffuse tumors according to Lauren's classification METHODS: A prospective controlled study enrolled 56 patients from "Hospital Universitário", Federal University of Rio Grande do Norte, Natal, RN, Brazil, with advanced gastric cancer, treated from February 2000 to March 2003. Immediately after partial gastrectomy, the resected stomach was opened and several mucosal biopsy samples were taken from the gastric tumor and from the adjacent mucosa within 4 cm distance from the tumor margin. Tissue sections were stained with hematoxylin and eosin. Lauren's classification for gastric cancer was used, to analyse the prevalence of H. pylori in intestinal or diffuse carcinomas assessed by the urease rapid test, IgG by ELISA and Giemsa staining. H. pylori infected patients were treated with omeprazole, clarithromycin and amoxicillin for 7 days. Follow-up endoscopy and serology were performed 6 months after treatment to determine successful eradication of H. pylori in non-tumor tissue. Thereafter, follow-up endoscopies were scheduled annually. Chi-square and MacNemar tests with 0.05 significance were used. RESULTS: Thirty-four tumors (60.7 percent) were intestinal-type and 22 (39.3 percent) diffuse type carcinomas. In adjacent non-tumor gastric mucosa, chronic gastritis were found in 53 cases (94.6 percent) and atrophic mucosa in 36 patients (64.3 percent). All the patients with atrophic mucosa were H. pylori positive. When examined by Giemsa and urease test, H. pylori positive rate in tumor...

RACIONAL: Existe evidência de que a infecção pelo Helicobacter pylori desempenha papel importante na causa do câncer gástrico e que é raramente encontrada em biopsias de gastrite atrófica e em tecido tumoral de câncer do estômago. Com a evolução para câncer gástrico avançado, a bactéria tende a desaparecer do tecido tumoral OBJETIVOS: Analisar a prevalência do H. pylori em peças operatórias de carcinomas gástricos avançados e no tecido adjacente aos tumores, comparando os tumores tipo intestinal e difuso de acordo com a classificação de Lauren MÉTODOS: Estudo prospectivo controlado incluiu 56 pacientes operados no Hospital Universitário da Universidade Federal do Rio Grande do Norte, Natal, RN, com câncer gástrico avançado, entre fevereiro de 2000 e março de 2003. Imediatamente após a gastrectomia, a peça operatória foi aberta e foram feitas várias biopsias do tecido neoplásico e da mucosa adjacente a 4 cm da margem tumoral. Os tecidos formam processados e corados pela hematoxilina-eosina. Foi usada a classificação de Lauren para carcinoma gástrico. A infecção pelo H. pylori foi diagnosticada pelo teste da urease, dosagem de IgG por ELISA e histopatologia com coloração Giemsa. Os pacientes infectados pelo H. pylori foram tratados com omeprazol, claritromicina e amoxicilina por 7 dias. Após 6 meses, 1 ano e 2 anos, foi feito seguimento utilizando endoscopia, dosagem de IgG e teste da urease para avaliar o sucesso da erradicação do H. pylori e recidiva do tumor RESULTADOS: O carcinoma tipo intestinal ocorreu em 34 (60,7 por cento) pacientes e 22 (39,3 por cento) foram acometidos de carcinoma difuso. No tecido adjacente não-tumoral a gastrite crônica foi observada em 53 casos (94,6 por cento) e mucosa atrófica em 36 pacientes (64,3 por cento), todos H. pylori positivos. Exames pelo Giemsa e teste da urease revelaram maior prevalência de H. pylori positivo no tecido tumoral do carcinoma tipo intestinal do que no tipo difuso. Quando foi comparada...

Linfoma B rico en células T / T-Cell rich B-Cell Lymphomas

El linfoma B rico en células T es una proliferación de células grandes B aisladas en medio de una alta proporción de linfocitos. Biológicamente el linfoma B rico en células T es similar al linfoma de grandes células B convencional, pero se lo considera una entidad debido a los problemas que surgen de su diagnóstico diferencial