[Reference values for the blood coagulation tests in Mexico: usefulness of the pooled plasma from blood donors]. / Valores de referencia para las pruebas de coagulación en México: utilidad de la mezcla de plasmas de donadores de sangre.

INTRODUCTION: The blood coagulation system maintains the blood in a liquid state and bleeding and thrombosis are the manifestations of its malfunction. Blood coagulation laboratory evaluates the physiology of this system. OBJECTIVE: To establish both, the reference values for several tests performed at the blood coagulation laboratory as well as the utility of the pooled plasma to perform these assays. MATERIAL AND: METHODS: In this descriptive, cross-sectional, randomized study, we collected plasma from Mexican Mestizos. Each pooled plasma was prepared with the plasma from at least 20 blood donors. We performed screening and special tests and the Levey-Jennings graphs were built and interpreted after each pass. Results of the tests were analyzed and their distribution was established using the Kolmogorov-Smirnov test. To establish the reference values we used 95% confidence intervals. RESULTS: We collected 72 pooled plasmas. The distribution for PT, APTT, and TT tests was abnormal. Although the PT test showed a bimodal distribution it was normal for factor VII. The reference values for the hemostatic, anticoagulant, and fibrinolytic factors were different from those suggested by the manufacturers. CONCLUSION: We established the reference values for the blood coagulation tests in the adult Mexican population. We have shown that the pooled plasma must be used for the screening tests. We suggest that each clinical laboratory should establish its own reference values (at least for the screening tests). To reach this objective, we encourage the use of the pooled plasma.

Induction of cellular immune response and anti-Salmonella enterica serovar typhi bactericidal antibodies in healthy volunteers by immunization with a vaccine candidate against typhoid fever.

Typhoid fever remains a serious public health problem. We have developed a vaccine from Salmonella enterica serovar typhi (S. typhi) outer-membrane proteins (OMPs) known as porins. A single subcutaneous dose of 10 microg of porins induced a five-fold (P = 0.05) seroconversion index consisting of IgM and IgG at 7 and 15 days after vaccination as well as the production of IgG1 and IgG2 isotypes. The porins-based vaccine induced a two-fold increase (P = 0.05) in bactericidal titres in volunteers, whom also developed a T-cell response characterized by the production of interferon-gamma (INF-gamma). Side effects after vaccination were mild and transient. The data showed that our S. typhi porins-based candidate vaccine is safe and immunogenic in healthy humans.

[Utility of a pneumatic system to transport erythrocyte concentrates: pilot study]. / Utilidad de un sistema neumático para trasladar concentrados eritrocitarios. Estudio piloto.

BACKGROUND: The transport systems of erythrocyte concentrates should be safe and modern. In this paper we analyzed the safety of one pneumatic system to transport erythrocyte concentrates from blood transfusion service to post-surgical therapy service. METHODS: We analyzed 50 erythrocyte concentrates; a sample of 1.5 mL of blood was drawn previously and after delivering the concentrated erythrocyte. The samples were placed in glass tubes to measure temperature, hemoglobin, hematocrit and extracellular potassium concentration. The average and range as univariate analysis and the Mann-Whitney U test as a bivariate analysis were done for statistical analysis. RESULTS: Statistical differences were not observed in the parameters measured. The temperature was not modified by the pneumatic delivery system. The data indicated no significant differences (p > 0.05) pre and post delivered samples in temperature, hemoglobin concentration, hematocrit level or extracellular potassium concentration. The estimated travel time for each sample was 22.88 seconds. CONCLUSIONS: The transport of erythrocyte concentrates through pneumatic delivery system did not change temperature conditions according to the current regulation. Indeed, the data did not show evidence that the cellular suspension underwent a spontaneous cellular lysis by sending erythrocyte concentrates through a pneumatic delivery system.

INTRODUCCIÓN: los sistemas de transporte de componentes eritrocitarios deben ser seguros y modernos. En este trabajo se analiza la seguridad de un sistema neumático como medio de transporte de concentrados eritrocitarios del servicio de transfusiones al servicio de la terapia posquirúrgica. MÉTODOS: se estudiaron las muestras piloto de 50 concentrados eritrocitarios, previa homogeneización del tubo con pinza rotatoria. Se obtuvieron 1.5 mL de la muestra antes de enviar el concentrado eritrocitario por el sistema neumático y 1.5 mL después de su llegada a su destino. Las muestras fueron colocadas en tubos de cristal para su análisis. También se analizaron la concentración de hemoglobina, el nivel de hematócrito y la concentración de potasio extracelular. RESULTADOS: la información obtenida indicó que no hubo diferencias estadísticamente significativas (p > 0.05) al comparar los valores pre o posentrega respecto a la temperatura, la concentración de hemoglobina, el nivel de hematócrito ni la concentración extracelular de potasio. La estimación del tiempo de transporte a través del sistema neumático fue de 22.88 segundos. CONCLUSIONES: el envío de concentrados eritrocitarios mediante el sistema neumático no produjo cambios en las condiciones óptimas de temperatura indicadas en la normatividad vigente. Tampoco existió evidencia de que la suspensión celular enviada sufriera lisis celular espontánea debido al traslado de los componentes sanguíneos.