Flow cytometry-detected changes in megaloblastic anemia secondary to cobalamin deficiency

Introduction: Megaloblastic anemias secondary to Vitamin B12 deficiency are a group of pathologies produced by defective nuclear DNA synthesis. Objective: To describe the maturation alterations found in hematopoietic precursors of the bone marrow in a series of patients with megaloblastic anemia. Methods: Were included patients attended at the Regional Hospital of Concepción with bone marrow samples sent for the study of cytopenia by flow cytometry whose final diagnosis was megaloblastic anemia. The immunophenotype was performed with CD45, CD34, CD117, HLA-DR, markers of neutrophil (CD13, CD11b, CD10, CD16) and/or erythroblast (CD105, CD71, CD36) maturation. Results: From the flow cytometry laboratory database, 8 patients with megaloblastic anemia were identified, and myelodysplastic syndromes (n=9) and normal or reactive bone marrow (n=10) were used as controls. 44% were men, with a median age of 58 years. Megaloblastic anemia was associated with a higher proportion of size and complexity of erythroid and myeloid progenitors compared to lymphocytes compared to controls. The total percentage of erythroblasts and the proportion of CD34+ myeloid cells associated with erythroid lineage was higher in megaloblastic anemia, associated with a maturation arrest in the CD105+ precursor stage (69% vs 19% and 23%, p<0.001). The heterogeneity of CD36 and CD71 in megaloblastic anemia was similar to myelodysplastic syndromes. Conclusions: Megaloblastic anemia produces a heterogeneous involvement of hematopoiesis, characterized by a greater size and cellular complexity of precursors of the neutrophil and erythroid series and a maturation arrest of the erythroblasts.

Introducción: Anemias megaloblásticas secundarias a la deficiencia de vitamina B12 son patologías producidas por una síntesis defectuosa del ADN nuclear. Objetivo: Describir las alteraciones madurativas encontradas en precursores hematopoyéticos de la médula ósea de una serie de pacientes con anemia megaloblástica. Métodos: Se incluyeron pacientes atendidos en el Hospital Regional de Concepción con muestras de médula ósea enviadas para estudio de citopenias por citometría de flujo cuyo diagnóstico fue anemia megaloblástica. El inmunofenotipo se realizó con CD45, CD34, CD117, HLA-DR, marcadores de maduración de serie de neutrófilo (CD13, CD11b, CD10, CD16) y/o eritroblasto (CD105, CD71, CD36). Resultados: Se identificaron 8 pacientes con anemia megaloblástica y como controles se utilizaron síndromes mielodisplásicos (n=9) y médula ósea normal o reactiva (n=10). El 44% eran hombres, con una mediana de edad de 58 años. La anemia megaloblástica se asoció con una mayor proporción de tamaño y complejidad de progenitores eritroides y mieloides con respecto de los linfocitos en comparación a los controles. El porcentaje total de eritroblastos y la proporción de células mieloides CD34+ comprometidas con el linaje eritroide fue mayor en anemia megaloblástica, asociado a una parada madurativa en la etapa de precursor CD105+ (69% vs 19% y 23%, p <0.001). La heterogeneidad de CD36 y CD71 en anemia megaloblástica fue similar a los síndromes mielodisplásicos. Conclusiones: la anemia megaloblástica produce una afectación heterogénea de la hematopoyesis, caracterizada por un mayor tamaño y complejidad celulares de precursores de la serie neutrófilo y eritroide y una detención madurativa de los eritroblastos.

Intereactions between doripenem and clavulanate ­ Application of minimal inhibitory concentration analysis and cytometry flow for bactericidal studies

Background: In view of the current low efficacy of bacterial infection treatment the common trend towards searching for antibiotic systems exhibiting synergistic action is well justified. Among carbapenem analogues a particularly interesting option is provided by combinations of clavulanic acid with meropenem, which have proven to be especially effective. Results: Determination of the minimal inhibitory concentration (MIC) along with the method based on flow cytometry constitutes an important tool in the identification of bacterial sensitivity to active substances. Within this study the inhibitory effect of doripenem, clavulanic acid and the doripenem-clavulanate acid system was analyzed in relation to such bacteria as Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Clostridium butyricum and Clostridium pasteurianum, Acinetobacter baumannii, Enterobacter aerogenes. The lowest MIC, amounting to 0.03 µg/mL, was observed for the doripenem-clavulanate acid system in the case of E. coli ATCC 25922. In turn, the lowest MIC for doripenem applied alone was recorded for K. pneumoniae ATCC 31488, for which it was 0.1 µg/mL. The strain which proved to be most resistant both to doripenem and the doripenem-clavulanate acid system, was A. baumannii, with MIC of 32 µg/mL (clinical isolate) and 16 µg/mL (reference strain). Cytometric analysis for P. aeruginosa ATCC 27853 and S. aureus ATCC 25923 showed changes in cells following exposure to limiting concentrations of the active substance. Conclusions: Analysis of MIC supplies important information concerning microbial sensitivity to active substances, mainly in terms of limiting concentrations causing mortality or vitality of the tested species, which is essential when selecting appropriate antibiotic therapy.

Citometría de flujo y sexaje de espermatozoides en animales / Flow cytometry and sperm sexing in animals

Actualmente, cientos de crías se han gestado a través de inseminación artificial conespermatozoides sexados en producción animal. Desde 1992 se utiliza la citometría de flujo, técnica que permite diferenciar espermatozoides X e Y según su contenido de ADN. No existe, hasta el momento, ninguna otra técnica práctica para sexar espermatozoides manteniendo la capacidad fecundante. Los objetivos de esta revisión son explicar: (1) por qué los espermatozoides que contienen el cromosoma X o Y son similaresfenotípicamente, pero a la vez mantienen diferencias entre ellos, (2) los principios y procedimientos utiliza-dos para sexar espermatozoides mediante citometría de flujo y sorting (3) la precisión, velocidad y la eficiencia de los procedimientos actuales de sexaje espermático, (4) el daño espermático ocurrido durante el sexaje espermático y consecuentemente los efectos sobre la fecundidad.

Flow cytometry is a useful technology in the sexed sperm, which measures and analyzes simultaneously, multiple physical characteristics of the cell, as they flow in a stream flow, through a lightbeam. The measured properties are the size of a particle, relative internal granularity, relative complexity and relative fluorescence intensity. Currently, hundreds of calves have been gestated through artificial insemination with sexed sperm in animal production. Since 1992, flow cytometry has been used, a technique that allows spermatozoa X and Y differentiation by DNA content. There is no other practical technique forsperm sexing to keep sperm functionality. The objectives of this review are to explain: (1) why the sperm containing the X or Y chromosome are phenotypically similar, but differ among themselves, (2) the principlesand procedures used for sexing sperm by flow cytometry and sorting ( 3) accuracy, speed and efficiency ofcurrent procedure sperm sexing, (4) sperm damage occurred during sperm sexing and consequently the effects on fertility.