Pruebas de función plaquetaria por el sistema PFA-200 / PFA-200 system for platelet dysfunction analysis

Las pruebas de función plaquetaria realizadas con el analizador PFA-200 (del inglés, Platelet Function Analyzer) han venido reemplazando el tiempo de sangría, una prueba ya obsoleta, de acuerdo con el College of American Pathologists (CAP) y la American Society for Clinical Pathology (ASCP). Este analizador, mediante un sistema que utiliza cartuchos, posee la capacidad de simular in vitro las condiciones hemodinámicas del paciente para el tamizaje rápido, sencillo y automatizado de la disfunción plaquetaria. Las pruebas son de utilidad para evaluar la función plaquetaria en pacientes con alteraciones como enfermedad de von Willebrand y otras trombocitopatías congénitas o adquiridas, y evalúa la disfunción plaquetaria causada por inhibidores de la agregación plaquetaria, como la aspirina. Además, son de gran utilidad para el tamizaje prequirúrgico y en los embarazos de alto riego. Este sistema ofrece con su más reciente prueba, la INNOVANCE® PFA-200 P2Y, la posibilidad de evaluar la respuesta de pacientes que están siendo tratados con antagonistas del receptor plaquetario P2Y12, como son clopidogrel, prasugrel y ticagrelor, determinando el porcentaje de adhesión y agregación plaquetaria, logrando discriminar entre un paciente antiagregado y un paciente resistente al tratamiento

Variation In Branching Pattern Of Femoral Artery

Background: During clinical procedure to prevent damage, anatomical knowledge of the common femoral artery,profunda femoris artery (PFA) and the circumflex arteries is essential.Material and Methods: Present study was done on 40 lower limbs (20 left and 20 right) in Government MedicalCollege and Hospital, Chandigarh. Dissection was done as per the guidelines in Chunighums.Aim: Present study was done to discuss variations in branching pattern of FA, PFA and also their embryologicaland clinical significances.Results: In the present study, we observed that length of FA (Femoral artery) commonly placed “between” 310-350mm in 55% (22 cases in which 14 right & 8 cases on left side) whereas outer circumferential diameter iscommonly placed “between” 16 -20 mm in 52.5% (21 cases) 10 right & 11 left lower limbs and detailed finding arediscussed with literature.Conclusions: This study will be very helpful to the surgeons, radiologist and plastic surgeons to understandpossible variations and also will be very useful in reducing the chances of intra-operative secondary haemorrhageand post-operative complications.

Variations In The Origin Of Medial Circumflex Femoral Artery

Medial circumflex femoral artery(MCFA) usually arises from the Profunda femoris artery(PFA) in the femoral triangle and is the chief source of blood supply to the head of femur. Knowledge about the anatomy of MCFA is essential during orthopedic procedures and interventional surgeries. AIM: To study the variations in the origin of medial circumflex femoral artery MATERIALS AND METHODS:100 lower limbs, by dissection method. RESULTS: MCFA arose from PFA in 65% and from FA(Femoral artery) in 35%.A common stem for PFA and MCFA was found in 15%.A common stem for MCFA, Lateral circumflex femoral artery and PFA was found in 4%.

Platelet Function Analyzer-200 P2Y Results Are Predictive of the Risk of Major Adverse Cardiac Events in Korean Patients Receiving Clopidogrel Therapy Following Acute Coronary Syndrome

BACKGROUND: Clopidogrel is one of the most commonly used anti-platelet agents in cardiovascular diseases. We analyzed the relationship between the platelet function analyzer (PFA)-200 P2Y (INNOVANCE PFA-200 System, Siemens Healthcare, Germany) results and occurrence of major adverse cardiac events (MACEs) in Korean patients with recent-onset acute coronary syndrome (ACS) taking clopidogrel. METHODS: Between August 2013 and June 2016, we prospectively enrolled 106 patients with recent-onset ACS who had been treated with clopidogrel. We obtained blood samples and measured closure time (CT) using the PFA-200 P2Y test. Patients were divided into two groups on the basis of a CT cut-off value of 106 seconds. We compared patient characteristics and various MACEs that occurred during the follow-up period. RESULTS: The CTs for 78 patients exceeded the cut-off value. At the time of these analyses, 11 patients had been diagnosed with MACEs. In the time-to-event analysis, there was a difference between the two groups (P<0.001). After adjusting other variables associated with MACE occurrence, CT value was the strongest predictor of MACEs, with a 7.30-fold occurrence risk (P=0.002). CONCLUSIONS: We found a strong relationship between CT and MACE risk in Korean patients with recent-onset ACS taking clopidogrel. Accordingly, PFA-200 P2Y results could be used as a predictive marker for MACE risk in such patients.

Correlation Between the CYP2C19 Phenotype Status and the Results of Three Different Platelet Function Tests in Cardiovascular Disease Patients Receiving Antiplatelet Therapy: An Emphasis on Newly Introduced Platelet Function Analyzer-200 P2Y Test

BACKGROUND: An association has been reported between CYP2C19 polymorphism and the altered antiplatelet activity of clopidogrel. We investigated this association using the newly introduced platelet function analyzer (PFA)-200 (INNOVANCE PFA-200 System; Siemens Healthcare, Germany) P2Y test. METHODS: Polymorphisms of CYP2C19*2, *3, *17 and the degree of inhibition of platelet function were determined in 83 patients. Three different platelet function tests were used to evaluate the degree of platelet inhibition and to check the association with genotype. RESULTS: The post-procedure PFA-200 values of extensive metabolizers (EM) patients (285.3+/-38.8) were higher than those of intermediate metabolizers (IM) and poor metabolizers (PM) patients (227.7+/-98.3 and 133.7+/-99.2, respectively; P=0.024). Light transmittance aggregometry (LTA) and the VerifyNow system showed that the post-procedure values for EM patients were lower than those of IM and PM patients (LTA: 24.4+/-15.7, 34.1+/-17.6, and 42.2+/-16.9, respectively, P<0.001; VerifyNow: 133.2+/-60.5, 171.5+/-42.6, and 218.7+/-59.3, respectively, P<0.001). The high residual platelet reactivity (HPR) rates were significantly different among the EM, IM, and PM groups using PFA-200 (PM:IM:EM=82.4:40.6:11.8, P<0.001). CONCLUSIONS: Approximately, 59.0% of Korean patients with cardiovascular disease receiving clopidogrel had CYP2C19 loss-of-function genotypes classified as IM or PM, and the frequency was similar to the data from Asian people. The PFA-200, LTA, and VerifyNow platelet function tests revealed evidence of a significant association between the efficacy of clopidogrel and CYP2C19 genotypes.

Réquiem por el tiempo de sangría: una prueba obsoleta: [Editorial] / Requiem for bleeding time: an obsolete test: [Editorial]

El tiempo de sangría, descrito hace más de 100 años [1], fue la única prueba disponible para el estudio de la función plaquetaria, llegando a ser el “estándar de oro” de la hemostasia primaria [2]; hasta que a finales de la década del 90, el Colegio Americano de Patólogos y la Sociedad Americana de Patología Clínica, pusieron de manifiesto sus limitaciones técnicas y su pobre desempeño analítico, representado en falta de reproducibilidad, escasa sensibilidad y en su carácter de prueba invasiva [3]. Como resultado de lo anterior, el tiempo de sangría debería pasar a ser una prueba histórica, al ser reconocido en el contexto de la literatura médica mundial como una prueba obsoleta [4, 5]. A rey muerto, rey puesto. En el caso del tiempo de sangría, la comunidad científica se beneficia de las nuevas pruebas de función plaquetaria, porque no son invasivas y suministran al médico mayor información sobre las alteraciones funcionales de las plaquetas, tanto de origen adquirido como congénito [10, 11]. De las diferentes pruebas para el estudio de la función plaquetaria desarrolladas en las últimas décadas, el PFA-100 representa una excelente opción para tamización de las disfunciones plaquetarias [12, 13]. Con la incorporación del PFA-100 al laboratorio clínico, se abren importantes frentes de trabajo.

Efeitos do Foscarnet sobre a infecção pelos herpesvírus bovino tipos 1 e 5 em coelhos / Effects of Foscarnet on the infection by bovine herpesviruses 1 and 5 in rabbits

O efeito antiviral do Foscarnet (PFA) foi demonstrado anteriormente em células de cultivo infectadas com três herpesvírus bovino (BoHV). No presente estudo, investigaram-se os seus efeitos sobre a infecção e doença causadas pelo BoHV-1 e BoHV-5 em coelhos infectados experimentalmente. Coelhos inoculados com o BoHV-5 pela via intraconjuntival (IC) e tratados com o PFA (100mg/kg/dia) a partir do dia 1 pós-inoculação (pi) apresentaram uma redução nos títulos de vírus excretados entre os dias 2 e 6 pi em comparação com o grupo não-tratado; essa diferença foi significativa no dia 3 pi [F(9,108) = 2,23; P<0,03)]. Os coelhos inoculados com o BoHV-5 e tratados com o PFA apresentaram uma redução significativa nos índices de morbidade e mortalidade (95,4 por cento [21/22] nos controles; 50 por cento [11/22] nos tratados; [P<0,0008]). Em coelhos inoculados com o BoHV-1 pela via IC, o tratamento com o PFA resultou em redução nos títulos de vírus excretados, entre os dias 1 e 4, e 6 e 7 pi. Esses animais apresentaram um período de incubação mais curto e um curso clínico mais longo comparando-se com o grupo controle não tratado (P<0,005 e P<0,04, respectivamente). O PFA também reduziu a freqüência e severidade da doença ocular nos coelhos inoculados com o BoHV-1. Esses resultados demonstram que o PFA possui atividade frente ao BoHV-1 e BoHV-5 in vivo e são promissores para o uso desse fármaco em terapias experimentais das infecções herpéticas dos animais domésticos.

The activity of Foscarnet (PFA) against three bovine herpesviruses (BoHVs) was previously demonstrated in cell culture. Herein we evaluated the effects of PFA on the infection and disease by BoHV-1 and BoHV-5 in a rabbit model. Rabbits inoculated with BoHV-5 in the conjunctival sac (IC) and treated with PFA (100 mg/kg/day) from day 1 to 17 post-inoculation (pi) shed less virus between days 2 and 6 pi comparing to untreated controls; this difference was significant at day 3 pi [F(9,108) = 2,23; P<0.03]. The morbidity and mortality rates of rabbits inoculated with BoHV-5 IC or intranasally (IN) were also significantly reduced in PFA-treated rabbits (50 percent; 11/22) comparing to untreated controls (95.4 percent; 21/22) (P<0.0008). In rabbits inoculated IC with BoHV-1, a reduction in virus shedding was observed in PFA-treated animals between days 1 and 4 pi; 6 and 7 pi. In addition, PFA-treated rabbits presented a longer incubation period and a shorter clinical course comparing to untreated controls (P<0.005 and P<0.04, respectively). The frequency and severity of ocular signs were also reduced in the PFA-treated group. These results demonstrate that PFA is effective against BoHV-1 and BoHV-5 in vivo and open the way towards its use in experimental therapy of herpetic infections in domestic animals.

Vigilancia epidemiológica de las parálisis fláccidas agudas (PFA) en menores de 15 años / Epidemiological surveillance of acute flaccid paralysis (AFP) in children under 15

Hasta el año 2006, las regiones de América, Pacífico Oriental y Europa han sido certificadas libres de la circulación autóctona del virus salvaje de la poliomielitis. En Chile, el último caso ocurrió en 1975, y en la región de las Américas en 1991. Para mantener sistemas de vigilancia eficaces a fin de erradicar la poliomielitis, se realiza la vigilancia sindromática de todo menor de 15 años que presente Parálisis Fláccida Aguda de causa no traumática. En el año 2006 ingresaron 76 casos de Parálisis Fláccida Aguda en menores de 15 años al sistema de vigilancia de poliomielitis en Chile, de los cuales, 75 fueron descartados y 1 fue clasificado como caso compatible. Este artículo, da cuenta de la situación epidemiológica de la PFA en Chile durante el año 2006 y presenta los resultados obtenidos para cada indicador de la vigilancia, tanto a nivel nacional como regional.

Reconfirmation of Preanalytical Variables and Establishment of Reference Intervals of Platelet Function Analyzer-100 Closure Times in Korean Adults / 대한진단검사의학회지

BACKGROUND: Platelet Function Analyzer-100 (PFA-100, Dade-Behring, Germany) is an instrument that simulates in vivo hemostatic plug formation under high shear flow by measuring the time required to occlude aperture. We performed this study to reconfirm preanalytical variables and establish the reference intervals of Korean adults. METHODS: A total of 120 healthy individuals were enrolled. Closure times (CT) with the collagen/ epinephrine (CEPI) and the collagen/ADP (CADP) cartridges were measured. RESULTS: The reference intervals by the central 95th percentile were 82-182 sec for CEPI-CT and 62-109 sec for CADP-CT. Females had significantly longer CEPI- and CADP-CT than males (P=0.034 and 0.022, respectively). Individuals over 40 yr showed shorter CEPI- and CADP-CT compared with younger ones (P=0.002 and 0.003, respectively). CEPI- and CADP-CT values measured in the afternoon were significantly longer than corresponding ones in the morning (P<0.0001 in both conditions). Group O blood groups were related to longer CEPI- and CADP-CT compared with non-O blood groups (P=0.0003 and <0.0001, respectively). CADP-CT was weakly correlated with hematocrit (r=-0.296, P=0.001), but not CEPI-CT. CONCLUSIONS: We reconfirmed the preanalytical variables and established the reference intervals of PFA-100 CT in Korean adults. It is recommended that reference interval of this test should be verified according to age, diurnal variation, and ABO blood groups for optimal utilization.

The Measurement of UVA and UVB Photoprotectiveness and its Influencing Factors / 대한피부과학회지

Recently, exposure to sunlight is increasing due to expanded life time, outdoor leisures, and reduced sun protective ozone layer. Sunlight can produce not only benefit but also various kinds of harmful effect, such as skin carcinogenesis, photoaging and immunologic alterations, These effects can be minimized by sunscreens. This article reviews the methods to measure a suncreens efficacy and factors influencing the measurement. I. Measurement of photoprctective efficacy 1)The sun protective factor(SPF): The SPF is defined as the ratio of the UVB doses required to produce minimal erythema dose(MED) with sunscreen applied to without it. However, the exact procedures are not estabiished and the value is varied by methods. 2)Photoprotective factor A(FFA): In spite of its clinical improtance, evaluation of UVA protection rernains a problem due to its physiologic features. The methods to measure UVA protection are by the use of erythemal, phototoxic and pigmentary rections. 3)Outdoor measurement: It is ideal to measure the photoprotectiveness outdoor but a wide variation in value results from radiance sources and environmental factors. II. Factors influencing the evaluation The radiance sources, individ zal sensitivity to sunlight, product components and various environmental factors can make differences. Conclusion As more sunlight, exposure, he irnportance of photoprotection is increasing. The exact methods to measure the protectiveness of UVA and UVB should be established, especially adjusted to Korean people

Properties of Hepatitis B Virus Associated DNA Polymerase

The nature of hepatitis B virus (HBV) particle associated DNA polymerase was studied in relation to various enzyme inhibitors including antiviral agents. HBV DNA polymerase required high concentration of MgCl2(> 30 mM) and neutral pH for its full activity. p-chloromercuribenzoate was a strong inhibitor (85% inhibition at 1 mM) but N-ethylmaleimide had much less inhibitory effect (20% inhibition at 10 mM). Phosphonoformic acid showed the greatest inhibitory effect on HBV-DNA polymerase (almost complete inhibition at 100 microM) among phosphocompounds tested. Adenine arabinoside triphosphate (ara-ATP) and cytosine arabinoside triphosphate (ara-CTP) were competitive inhibitors with respect to their respective deoxyribonucleoside triphosphate (dATP and dCTP). Ara-CPT was a stronger inhibitor of HBV-DNA polymerase compared to ara-ATP. Ki values for ara-ATP and ara-CTP were 15.0 microM and 11.7 microM , respectively. HBV-DNA polymerase is characteristic in its ionic requirements and susceptibilities to certain inhibitors.