Do PT and APTT sensitivities to factors' deficiencies calculated by the H47-A2 2008 CLSI guideline reflect the deficiencies found in plasmas from patients?

INTRODUCTION: Prothrombin time (PT) and activated partial thromboplastin time (APTT) sensitivity for detecting isolated factor deficiencies varies with different reagents and coagulometers. The Clinical and Laboratory Standards Institute (CLSI) H47A2 guideline proposed a method to calculate these sensitivities, but some inconsistency has been reported. This study aimed to calculate factor sensitivities using CLSI guideline and to compare them with those obtained from single factor-deficient patients' data. METHODS: Different mixtures of normal pooled and deficient plasmas were prepared (<1IU/dL to 100 IU/dL) according to the CLSI H47A2 guideline. PT with rabbit brain (RB) and human recombinant (HR) thromboplastins, APTT and factors' activities were measured in an ACL TOP coagulometer. Sensitivities (maximum factor concentration that produces PT or APTT values out of the reference range) were calculated from mixtures and from patients with single-factor deficiencies: 17 factor FV, 36 FVII, 19 FX, 39 FVIII, 15 FIX 15 FXI and 24 FXII. RESULTS: PT sensitivity with RB was as follows: FV 38 and 59, FVII 35 and 58, FX 56 and 64 IU/dL; PT sensitivity with HR was as follows: FV 39 and 45, FVII 51 and 50, FX 33 and 61 IU/dL; and APTT sensitivity was as follows: FV 39 and 45, FX 32 and 38, FVIII 47 and 60, FIX 35 and 44, FXI 33 and 43, FXII 37 and 46 IU/dL, respectively. CONCLUSIONS: Reagent-coagulometer combination has adequate sensitivities to factor deficiencies according to guideline recommendations (>30 IU/dL). These should not be considered as actual sensitivities because those obtained by analysing patients' plasmas with single-factor deficiencies were higher for most factors and could induce misinterpretation of the basic coagulation test results.

Frequent false-positive results of lupus anticoagulant tests in plasmas of patients receiving the new oral anticoagulants and enoxaparin.

INTRODUCTION: Oral direct thrombin and Xa inhibitors are worldwide distributed for prevention and treatment of thrombosis. It is important to recognize their effects on lupus anticoagulant (LA) testing. The aim of the study is to describe the rate of false-positive results of LA tests on plasmas of patients with previous negative LA tests results that receive dabigatran etexilate (DAB) 110 mg/twice a day, rivaroxaban (RIV) 10 mg/day or 15 mg/twice a day, or enoxaparin 40 mg/day. METHODS: Blood was taken between 1.5 and 4 h post administration. Tests evaluated are as follows: prothrombin time, APTT, dilute Russell viper venom time (DRVVT) screen, APTT, and DRVVT mixing studies, index of circulating anticoagulant (ICA) with normal plasma, screen/confirm normalized ratio (NR) for DRVVT and silica clotting time (SCT). RESULTS: Plasmas from patients taking DAB (n = 22) presented 100% prolonged APTT and DRVVT with ICA above the cutoff point and 81.8% positive screen/confirm NR, 100% prolonged SCT screen, but 4.5% positive confirmatory NR. All patients receiving RIV at 15 mg/twice a day (n = 4) presented positive DRVVT screen, mixing, and confirmatory tests, 75% and 100% prolonged APTT and SCT screen, with negative screen/confirm NR. Those taking RIV 10 mg/day (n = 22) showed 81.8% prolonged DRVVT screen, 82.3% and 76.5% of them with positive mixing and confirmatory studies. Patients receiving enoxaparin also presented high prevalence of APTT and DRVVT false-positive results. CONCLUSION: Dabigatran etexilate, RIV, and enoxaparin affect tests for LA not only in screening and mixing, but also in confirmatory studies. We considered that LA testing should not to be performed when patients are taken these drugs, particularly if blood is collected at peak, in order to avoid false-positive results.

Infection and immunity for human parvovirus B19 in patients with febrile exanthema.

The contribution of parvovirus B19 (B19V) as a causative agent of febrile exanthema (FE) in Cordoba, Argentina, was analysed by detection of viral DNA, and specific IgM and IgG. Serum from 141 patients with FE who were negative for measles and rubella, collected during 2005-2009, plus serum from 31 healthy individuals, were assayed. B19V was the aetiological agent in 14·9% of all FE cases, and in 39·1% in an epidemic year (2007). B19V DNA was detected in 47·6% of IgM-positive FE patients, 30·2% of IgM-negative/IgG-positive FE patients, and 9·7% of healthy controls, indicating B19V long-term infection in ~10% of immunocompetent individuals. Persistent B19V DNA was significantly more frequent in children than adults and in males than females. All patients with acute B19V infection had rash and fever, 85·7% had adenopathy, and only 14·3% had arthropathy. This is the first follow-up study of markers of infection and immunity for B19V infection in Argentina.

Colectomías totalmente laparoscópicas con extracción de la pieza quirúrgica por orificios naturales / Totally laparoscopic colectomy with natural orifice specimen extraction

Objetivo: comunicación de la de la factibilidad de las colectomías totalmente laparoscópicas con extracción de la pieza quirúrgica por orificios naturales. Diseño: Trabajo descriptivo, retrospectivo, observacional. Pacientes y Método: Se incluyó una serie de 6 pacientes en quienes se realizó colectomía totalmente laparoscópica (con anastomosis intracorpórea) y extracción de la pieza quirúrgica por orificio natural. Resultados: Desde enero de 2007 a Agosto de 2011, en el Servicio de Cirugía General del Hospital San Roque, se llevaron a cabo 467 cirugías colorrectales, en 355 pacientes (76%), se realizó abordaje a cielo abierto y en 112 (24%), abordaje videolaparoscopico. En seis de ellos, una neoplasia de sigmoides (T2), y cinco enfermedades diverticulares recurrentes se realizó extracción de la pieza quirúrgica por orificios naturales con anastomosis colorrectal totalmente intracorporea. En 3 pacientes se extrajo la pieza por vía transrectoanal (masculinos) y en los 3 restantes por vía transvaginal. No se presentaron complicaciones intraoperatorias, tampoco postquirúrgicas inmediatas. La recuperación del tránsito intestinal, la ingesta de líquidos y el alta hospitalaria fueron similares a las observadas en las colectomías videoasistidas. Conclusiones: La resección de colon izquierdo por laparoscopía, realizando anastomosis intracorpórea, más extracción de la pieza por oríficios naturales (NOSE), puede ser considerada como una técnica alternativa para pacientes que requieren colectomías electivas, en patología benigna y neoplasias tempranas.

Objective: Communication of totally laparoscopic colectomy with natural orifice specimen extraction. Design: descriptive, retrospective, observational work. Patients and Methods: A series of 6 patients underwent totally laparoscopic colectomy (with intracorporeal anastomosis) and extraction of surgical specimen through natural orifice. Results: From January 2007 to August 2011, 467 colorectal surgeries were performed in the General Surgery Service of the Hospital San Roque. 355 (76%) underwent an open approach and 112 (24%) laparoscopic approach. In six of these cases, a sigmoid tumor (T2), and five recurrent diverticular diseases, we performed totally laparoscopic colectomy, with intracorporeal colorectal anastomosis. In 3 patients, the specimen was removed via transanal (male) and the remaining 3 by transvaginal route. There were no intraoperative or postoperative complications. The recovery of intestinal transit, fluid intake and hospital discharge were similar to those observed in video-assisted colectomy. Conclusions: The left colon resection by a totally laparoscopic technique, with intracorporeal anastomosis and the use of natural orifice specimell extraction (NOSE), can be considered as an alternative for patients requiring elective colectomy in benign disease and early neoplasia.

[Prevalence of anti-rubella and anti-parvovirus B19 antibodies in pregnant women in the city of Córdoba, and in women of fertile age in the city of Villa Mercedes, province of San Luis]. / Prevalencia de anticuerpos antirrubéola y antiparvovirus B19 en embarazadas de la ciudad de Córdoba y en mujeres en edad fértil de la ciudad de Villa Mercedes, San Luis.

We determined the prevalence of anti-rubella antibodies in 100 serum samples from pregnant women who attended routine examination at a private institution in the city of Córdoba, and in 100 serum samples from women of gestational age, 42 of whom were pregnant, attending health centres in the city of Villa Mercedes, province of San Luis. IgG antibodies against parvovirus 819 were also determined in the serum samples from Córdoba. Using the hemmagglutination inhibition test, we found a 98% prevalence of anti-rubella antibodies among pregnant women in Córdoba and of 96% among the women in Villa Mercedes, whereas the prevalence of anti-parvovirus 819 was 66% in the serum samples from Cordoba. These results coincide with those reported for other cities in the world, and establish an interest in continuing similar studies in order to monitor the immunization plan, which in Argentina has been going on since 1997. They also suggest the importance of the determination of IgM anti-parvovirus B19 in pregnant women who are symptomatic but with a negative result for rubella.

Prevalencia de anticuerpos antirrubéola y antiparvovirus B19 en embarazadas de la ciudad de Córdoba y en mujeres en edad fértil de la ciudad de Villa Mercedes, San Luis / Prevalence of anti-rubella and anti-parvovirus B19 antibodies in pregnant women in the city of Córdoba, and in women of fertile age in the city of Villa Mercedes, province of San Luis

Se determinó la prevalencia de anticuerpos contra virus rubéola en 100 muestras de suero de mujeres embarazadas que concurrían a chequeos de rutina en una institución privada de la ciudad de Córdoba y en 100 muestras de suero de mujeres en edad fértil (42 de ellas embarazadas) que concurrían a dispensarios de la ciudad de Villa Mercedes, provincia de San Luis. En las muestras tomadas en la ciudad de Córdoba también se determinaron anticuerpos IgG contra parvovirus B19. Por inhibición de la hemoaglutinación, los resultados de los sueros de Córdoba mostraron una prevalencia de anticuerpos antirrubéola del 98%; en las muestras de Villa Mercedes se observó una prevalencia del 96%. La prevalencia de anticuerpos antiparvovirus B19 en los sueros de Córdoba fue del 66%. Estos datos se asemejan a los de la bibliografía mundial y fundamentan el interés en continuar estudios de este tipo para monitorear el plan de inmunización para rubéola, que en Argentina se lleva a cabo desde 1997, como así también la relevancia de la determinación de IgM antiparvovirus B19 en aquellas embarazadas sintomáticas con resultado negativo para rubéola, a fin de elaborar un diagnóstico diferencial.

We determined the prevalence of anti-rubella antibodies in 100 serum samples from pregnant women who attended routine examination at a private institution in the city of Córdoba, and in 100 serum samples from women of gestational age, 42 of whom were pregnant, attending health centres in the city of Villa Mercedes, province of San Luis. IgG antibodies against parvovirus B19 were also determined in the serum samples from Córdoba. Using the hemmagglutination inhibition test, we found a 98 % prevalence of anti-rubella antibodies among pregnant women in Córdoba and of 96 % among the women in Villa Mercedes, whereas the prevalence of anti-parvovirus B19 was 66% in the serum samples from Córdoba. These results coincide with those reported for other cities in the world, and establish an interest in continuing similar studies in order to monitor the immunization plan, which in Argentina has been going on since 1997. They also suggest the importance of the determination of IgM anti-parvovirus B19 in pregnant women who are symptomatic but with a negative result for rubella.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining.

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47%, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2% at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining.

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47

, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2

at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.

Detection of rubella-virus-induced apoptosis in Vero cell cultures with hematoxylin and eosin staining

In order to facilitate the detection of apoptotic cells (Apo C) in Rubella virus (RV) infected cultures in settings of low resources, we compared hematoxylin and eosin staining (H&E) with the conventional TUNEL technique, and confirmed our findings with DNA electrophoresis and transmission electron microscopy. H&E allowed to distinguish Apo C from non-apoptotic cells. The proportion of Apo C in infected cultures was proportional to the multiplicity of infection (MOI). At a MOI of 10, the percent of Apo C at 3, 4 and 5 days post infection (pi) were 26, 45 and 47

, respectively, which were significantly reduced when the caspase inhibitor z-VAD-fmk was present in the supernatant. By the TUNEL assay, the percent of Apo C in RV-infected cultures were lower (0.8, 1.2 and 1.2

at 3, 4 and 5 days pi, respectively). Our results have shown that H&E staining is an easy, rapid, economic and reproducible method to detect Apo C in RV infected Vero cells cultures. It is possible that H&E makes evident early stages of apoptosis, when an apoptotic cell shows chromatin condensation, nuclear and cytoplasmic contraction (but is still attached to the monolayer), while TUNEL detects later stages of apoptosis because it needs an extensive DNA fragmentation, when apoptotic cells are about to or have already detached from the substratum.