Decitabine bioproduction using a biocatalyst with improved stability by adding nanocomposites.

A novel IDA-LaNDT derivative was able to reach the highest productivity in the biosynthesis of a well-known antitumoral agent called decitabine. However, the combination of two simple and inexpensive techniques such as ionic absorption and gel entrapment with the incorporation of a bionanocomposite such as bentonite significantly improved the stability of this biocatalyst. These modifications allowed the enhancement of storage stability (for at least 18 months), reusability (400 h of successive batches without significant loss of its initial activity), and thermal and solvent stability with respect to the non-entrapped derivative. Moreover, reaction conditions were optimized by increasing the solubility of 5-aza by dilution with dimethylsulfoxide. Therefore, a scale-up of the bioprocess was assayed using the developed biocatalyst, obtaining 221 mg/L·h of DAC. Finally, green parameters were calculated using the nanostabilized biocatalyst, whose results indicated that it was able to biosynthesize DAC by a smooth, cheap, and environmentally friendly methodology.

Fetal exposure to bisphenol A: Presence of bisphenol A in urine of pregnant women assisted in a hospital in the City of Buenos Aires. Year 2013. / [Exposición fetal a bisfenol A: Presencia de bisfenol A en orina de mujeres gestantes asistidas en un hospital de la Ciudad de Buenos Aires. Año 2013.]

Introduction: Bisphenol A (BPA) is an endocrine disruptor (ED) possibly linked to adverse reproductive and neurodevelopmental effects that is used as an additive in food and beverage containers. There are no data of BPA levels in the Argentine population. The objective of this study was to measure BPA in the urine of pregnant women. Methods: Cross-sectional study. Detection of BPA in pregnant women of the Hospital Italiano de Buenos Aires in 2013, using gas chromatography and mass spectrometry with a limit of quantification of 2 ng / ml and detection of 0.8 ng / ml. The proportion of women exposed to BPA within the 95% confidence interval (IC 95%) is described. Results: 149 pregnant women, average age 32 years (Standard Deviation 5.3), 81% (95% CI 73.9-86.9) workers and 83.7% (95% CI 76.7-89.1) have university or higher education, 66.4% (95% CI 58-74.0) of the urinary samples were quantifiable, with a median BPA of 4.3 ng/mg Cr (RI 3.2-6.7). Conclusions: This study shows that exposure to BPA during the process of embryonic development in a sector of the population of Argentina is widespread. In Argentina, the use of this ED is only regulated in baby bottles.

Introducción: El Bisfenol A (BPA) es un disruptor endócrino (DE) posiblemente vinculado a eventos adversos reproductivos y del desarrollo neurológico que se utiliza como aditivo en envases plásticos de alimentos y bebidas. En la población argentina no existen datos sobre niveles de BPA en orina. El objetivo del estudio fue medir la presencia de BPA en orina de embarazadas. Métodos: Estudio transversal. Detección de BPA en orina de embarazadas atendidas en el Hospital Italiano de Buenos Aires en el año 2013. La técnica utilizada fue cromatografía gaseosa asociada a espectrometría de masa con un límite de cuantificación de 2 ng/ml y de detección de 0,8 ng/ml. Se describe la proporción de mujeres con exposición al BPA con su intervalo de confianza del 95% (IC95%). Resultados: se analizaron 149 muestras de orina de embarazadas de edad promedio 32 años (Desvío Standard 5,3), el 81% (IC95% 73,9-86,9) trabaja y el 83,7% (IC95% 76,7-89,1) posee nivel universitario y/o posgrado.El 66,4% (IC95% 58,2-74,0) de las muestras urinarias presentaron BPA cuantificable, siendo la mediana de BPA de 4,3 ng / mg creatinina (Rango Intercuartilo 3,2-6,7). Conclusiones: Este estudio muestra que la exposición a BPA durante el proceso de formación embrionaria en un sector de la población de Argentina, es generalizada. En Argentina solo está regulado el uso de este DE en mamaderas.

Cardioversión eléctrica de taquicardia ventricular en el embarazo: reporte de un caso / Electrical cardioversion of ventricular tachycardia in pregnancy: case report

Resumen ANTECEDENTES: Las arritmias cardiacas son complicaciones frecuentes durante el embarazo, la mayor parte son benignas y no requieren tratamiento complejo. Las taquicardias ventriculares idiopáticas suelen ser hemodinámicamente estables y se asocian con buen pronóstico. CASO CLÍNICO: Paciente de 22 años, con embarazo de 23 semanas, que inició con mareo y palpitaciones, por lo que acudió al servicio de Urgencias. El electrocardiograma de 12 derivaciones mostró una taquicardia de QRS amplio, con latidos de fusión y disociación auriculoventricular; el ecocardiograma no reportó alteraciones. El diagnóstico definitivo fue taquicardia ventricular fascicular posterior idiopática. El tratamiento inicial consistió en verapamil y amiodarona por 48 horas; sin embargo, persistió la taquicardia, por lo que se decidió realizar una cardioversión eléctrica con 200 Joules, con lo que se obtuvo una reacción satisfactoria. La paciente permaneció asintomática hasta la semana 31 del embarazo, cuando inició nuevamente con palpitaciones; se documentó la misma taquicardia, por lo que se decidió realizar un nuevo procedimiento de cardioversión eléctrica con 200 Joules, que resultó efectiva y sin complicaciones adicionales para la paciente. CONCLUSIONES: La incidencia de taquicardia ventricular idiopática durante el embarazo es relativamente baja. La cardioversión eléctrica es una opción efectiva en pacientes embarazadas con resistencia al tratamiento farmacológico o inestabilidad hemodinámica.

Abstract BACKGROUND: Cardiac arrhythmias are frequent complications in pregnancy, the most of them are benign and don't need specific treatment. Idiopathic ventricular tachycardia usually is hemodynamically stable and associate with a good prognosis. CLINICAL CASE: A 22-year-old woman with a current pregnancy of 23.4 weeks of gestation that began with dizziness and palpitations, she went to the emergency department, a 12-lead electrocardiogram showed a wide QRS tachycardia with fusion beats and atrioventricular dissociation, the echocardiogram was reported normal. Posterior fascicular ventricular idiopathic tachycardia was concluded. Initially, Verapamil and Amiodarone were administered for 48 hours, with tachycardia persisting, so it was decided to perform electrical cardioversion with 200 Joules that was effective. She remained asymptomatic until the 31st week of gestation where she started again with palpitations, the same tachycardia was documented and it was decided to perform again electrical cardioversion with 200 joules, being effective and without complications. CONCLUSIONS: Idiopathic ventricular tachycardia occurs with low frequency in pregnancy. When pharmacological therapy is not effective or there is hemodynamic instability, electrical cardioversion is a viable option in the pregnant patient.

Cuantificación de Bisfenol-A libre en sangre de cordón umbilical humano a nivel de trazas / Quantification of free Bisphenol-A in human umbilical cord blood at trace level / Quantificação de Bisfenol-A livre em sangue de cordão umbilical humano a nível de traços

El Bisfenol-A (BPA) es ampliamente utilizado en la producción de plásticos de policarbonato, por lo que está presente en productos de uso masivo. Es un disruptor endócrino e incide en el desarrollo gonadal y del sistema nervioso central. La exposición de mujeres embarazadas al BPA es particularmente preocupante para el feto en desarrollo, debido a que atraviesa la placenta pasando a la sangre de cordón y al líquido amniótico. Esto se suma a la escasa o nula actividad enzimática fetal para biotransformarlo en BPA-glucurónido inactivo, causando posibles efectos nocivos a la descendencia a dosis muy bajas y sostenidas. Con el propósito de estudiar la exposición al BPA y sus efectos en la población de Argentina se desarrolló y validó un método analítico por cromatografía líquida acoplada a espectrometría de masa, que permite la cuantificación de trazas de BPA libre (forma estrogénica, activa) en plasma de cordón umbilical. La técnica consiste en la precipitación de proteínas de la sangre de cordón por agregado de acetonitrilo y posterior centrifugado e inyección del sobrenadante. Se utilizó una elución isocrática en la cromatografía líquida, y la espectrometría de masa se realizó empleando Electrospray negativo en modo de monitoreo de reacciones múltiples. Los valores de BPA libre cuantificados están en el rango de 1,0 a 12,1 ng/mL, límite de detección: 0,6 ng/mL.

Bisphenol-A (BPA) is widely used in the production of polycarbonate plastics and therefore, it is present in products of massive use. It is known as an endocrine disruptor and has an impact on gonadal and central nervous system development. Exposure of pregnant women to BPA is particularly worrying for the developing fetus because it crosses the placenta into the cord blood and amniotic fluid, coupled with little or no fetal enzymatic activity to biotransform it into inactive BPA-glucuronide, causing possible harmful effects to the offspring at very low and sustained doses. With the aim to study the exposure to BPA and its effects on the population of Argentina, an analytical method was developed and validated by liquid chromatography coupled to mass spectrometry, which allows the quantification of trace amounts of free BPA (estrogenic, active form) in plasma of umbilical cord. The method involves protein precipitation by the addition of acetonitrile and subsequent centrifugation and injection of supernatant. An isocratic elution was used in liquid chromatography, and mass spectrometry was performed using negative Electrospray mode in multiple reaction monitoring. Quantified free BPA values are in the range of 1.0 to 12.1 ng/mL, Detection Limit: 0,6 ng/mL.

O Bisfenol-A (BPA) é amplamente utilizado na produção de plásticos de policarbonato, portanto está presente em produtos de uso massiço. Ele é um disruptor endócrino e tem um impacto no desenvolvimento gonadal e do sistema nervoso central. A exposição de mulheres grávidas ao BPA é particularmente preocupante para o feto em desenvolvimento, visto que atravessa a placenta passando ao sangue do cordão e ao líquido amniótico Isso é adicionado à pouca ou nula atividade enzimática fetal para biotransformá-lo em BPA-glicuronídeo inativo, o que causa possíveis efeitos nocivos aos descendentes em doses muito baixas e sustentadas. Visando a estudar a exposição ao BPA e seus efeitos na população da Argentina, foi desenvolvido e validado um método analítico por cromatografia líquida acoplada à espectrometria de massa, que permitem a quantificação de vestígios de BPA livre (forma estrogênica, livre) em plasma do cordão umbilical. A técnica consiste na precipitação de proteínas do sangue de cordão por adição de acetonitrila e posterior centrifugação e injeção no sobrenadante. Na cromatografia líquida, foi utilizada uma eluição isocrática, e a espectrometria de massa foi realizada utilizando Electrospray negativo em modo de monitoramento de reações múltiplas. Os valores de BPA livre quantificados estão na faixa de 1,0 a 12,1 ng/mL, limite de detecção: 0,6 ng/mL.

Validation of a Reversed-Phase Ultra-High-Performance Liquid Chromatographic Method With Photodiode Array Detection for the Determination of Voriconazole in Human Serum and Its Application to Therapeutic Drug Monitoring.

BACKGROUND: Voriconazole is a broad-spectrum triazole antifungal agent. It is widely used in the treatment of invasive fungal infections in immunocompromised patients. Because the pharmacokinetics of voriconazole demonstrates considerable variability, monitoring its serum levels plays an important role in optimizing therapies against many clinically relevant fungal pathogens. The aim of this study was to validate a simple and rapid U-HPLC-PDA method with minimal sample preparation for routine therapeutic drug monitoring (TDM) of voriconazole. METHODS: After protein precipitation with the internal standard solution (posaconazole 5.0 mg/L in acetonitrile), chromatographic separation was performed in 4 minutes using water and acetonitrile as mobile phases and an Acquity UPLC BEH HSS C18 column (2.1 × 100 mm, 1.7 µm). The temperature was set at 45°C and the flow rate was 0.4 mL/min. Photodiode array detection at 256 nm was used as detection system. The method was validated according international guidelines for linearity, accuracy, precision, selectivity, lower limit of quantitation, carry over, and stability under different conditions. RESULTS: All performance parameters were within acceptance criteria, demonstrating that the validated method is fit for purpose. After assay validation, 115 serum samples collected from 41 patients were analyzed to report the experience of the laboratory in TDM of voriconazole. Results showed a large variability in voriconazole trough levels, suggesting that this drug should be frequently measured in patients under treatment to enhance therapies efficacy and improve safety. CONCLUSIONS: In this study, a reproducible U-HPLC-PDA assay with a short analysis time, requiring only a small amount of serum, good accuracy and reproducibility was validated, which is suitable for routine TDM of voriconazole in serum.

Development of a high efficient biocatalyst by oriented covalent immobilization of a novel recombinant 2'-N-deoxyribosyltransferase from Lactobacillus animalis.

The 2'-N-deoxyribosyltransferases [NDT; EC 2.4.2.6] are a group of enzymes widely used as biocatalysts for nucleoside biosynthesis. In this work, the molecular cloning, expression and purification of a novel NDT from Lactobacillus animalis (LaNDT) have been reported. On the other hand, biocatalyst stability has been significantly enhanced by multipoint covalent immobilization using a hetero-functional support activated with nickel-chelates and glyoxyl groups. The immobilized enzyme could be reused for more than 300 h and stored during almost 3 months without activity loss. Besides, the obtained derivative (Ni2+-Gx-LaNDT) was able to biosynthesize 88 mg floxuridine/g biocatalyst after 1 h of reaction. In this work, a green bioprocess by employing an environmentally friendly methodology was developed, which allowed the obtaining of a compound with proven anti-tumor activity. Therefore, the obtained enzymatic biocatalyst meets the requirements of high activity, stability, and short reaction times needed for low-cost production in a future preparative application.

Comparative bioavailability of two tablet formulations of emtricitabine/tenofovir in healthy, fasting volunteers: a single-dose, randomized-sequence, open-label crossover study.

OBJECTIVE: To evaluate the relative bioavailability of a new formulation of emtricitabine (EMT) 200 mg and tenofovir disoproxil fumarate (TNF) 300 mg and to compare with reference formulation to meet regulatory criteria in Argentina. METHODS: A randomized-sequence, open-label, twoperiod crossover study was conducted on 24 healthy Caucasian volunteers in a fasting state. A single oral dose of T or R formulations was followed by a 7-day washout period. Samples were collected at baseline, 0.25, 0.50, 0.75, 1, 1.25, 1.5, 2, 2.5, 3, 4, 7, 12, 24, and 48 hours after administration. EMT and TNF were determined by LC-MS/MS. RESULTS: Geometric means (90% CI) Cmax for EMT in test and reference were 1,891.22 (1,777.1 - 2,187.31) and 1,830.31 (1,721.19 - 2,134.01) ng/mL, the AUC0-t were 10,283.07 (9,624.29 - 11,566.34) and 10,518.76 (9,942.79 - 11,578.30) ng × h/mL and the AUC0-∞ were 10,615.14 (9,948.56 - 11,866.26) and 10,804.12 (10,221.04 - 11,864.85) ng × h/mL, respectively. For TNF test and reference, Cmax geometric means (CI range) were 202.91 (187.91 - 255.78) and 212.04 (195.98 - 264.87) ng/mL, AUC0-t were 1,429.96 (1,334.63 - 1,680.00) and 1,420.75 (1,326.76 - 1,622.18) ng × h/mL and AUC0-∞ were 1,657.11 (1,551.60 - 1,921.75) and 1,631.84 (1,523.95 - 1,857.97), respectively. No differences were detected between the formulations. The test/reference ratios (90% CI) for Cmax, AUC0-t, and AUC0-∞ were 103.33% (95.7 - 111.6), 97.76% (93.6 - 102.1), and 98.25% (94.3 - 102.4) for EMT, and 95.70% (85.9 - 106.6), 95.20% (83.4 - 108.6) and 91.10% (80.7 - 102.7) for TNF. CONCLUSIONS: In this single-dose study, the EMT/TNF tablets (test formulation) met the standard 90% CI criterion for bioequivalence with the reference formulation.

Prostaglandina tisular y niveles séricos del factor de necrosis tumoral alfa (TNF-α) en un modelo experimental de rectocolitis aguda en ratas

Introducción: en los modelos murinos de inflamación intestinal, de una manera similar a lo que sucede en el hombre, los macrófagos activados producen una potente mezcla de citocinas inflamatorias que influyen al factor de necrosis tumoral alfa (TNF-α). El TNF-α, aumenta el proceso inflamatorio y la destrucción tisular, lo que se manifiesta en la sintomatología de la enfermedad. Los antiinflamatorios no esteroideos (AINES) inhiben la producción de prostaglandinas y han sido reconocidos como inhibidores de la producción del TNF-α. En este estudio, se relaciona la inhibición de las prostaglandinas utilizando el celecoxib con los niveles de TNF-α en ratas con inflamación intestinal y se compara con ratas inflamadas no tratadas. Métodos: se determinaron los niveles de TNF-α en ratas con colitis inducida por ácido acético. El grupo control estuvo representado por 4 ratas instiladas con agua destilada, un grupo de 7 ratas inflamadas sin tratamiento y tres grupos de 7 ratas cada uno medicadas con diferentes concentraciones de celecoxib. Al tercer día se sacrificaron las ratas. A todas se les tomo sangre antes de inflamarlas y de sacrificarlas. Se tomaron muestras de colón para estudio histológico. Los niveles de TNF-α se determinaron por ELISA. Resultados: el edema, la erosión y ulceración es menor en las ratas tratadas que en las inflamadas no tratadas. Los niveles TNF-α obtenidos en los grupos tratados fueron significativamente menores cuando se comparan con el grupo no tratado. Conclusiones: las ratas tratadas con inhibidor de la COX-2 tienen niveles menores de TNF-α y menores lesiones de la mucosa colónica, por lo que podría convertirse en un arma terapéutica importante para la enfermedad inflamatoria intestinal.

Introduction: In murine models of bowel inflammation, in a similar way that occurs in humans, activated macrophages produce a powerful mixture of inflammatory ciytokines that influence the tumor necrosis factor alpha (TNF-α). The TNF-α, increases the inflammatory process and tissue destruction, producing the symptoms of the disease. Non steroidal antiinflamatory drugs (NSAID's) inhibit the production of prostaglandins and have been recognized as inhibitors of the TNF-α production. In this study we correlate prostaglandin inhibition using Celecoxib with TNF-α levels in rats with bowel inflammation comparing results with non treated rats. Methods: The TNF-α levels were determined in rats with induced colitis with acetic acid. The control group was represented by 4 rats administered with distilled water, a group of 7 rats without treatment and three groups of 7 medicated rats each one with different Celecoxib concentrations. At the third day the rats were sacrificed. All rats had blood samples taken before inducing colitis, and after being sacrificed. Histological samples were taken from the colon for pathological study. TNF-α levels were determined by ELISA. Results: Edema, erosion and ulceration were less in the treated rats that in the non treated. TNF-α levels in the treated group were significantly lower when compared with the non treated group. Conclusions: Rats treated with COX-2 inhibitor have lower TNF-α levels and minor injuries to the colonic mucosa, for these reasons it could develop into an important therapeutic weapon for inflammatory bowel disease.

Uso del Lorazepan en la Clínica de Atenas / Use of Lorazepam in the Clinic of Atenas

El Lorazepan es una benzodiazepina ampliamente utilizada con fines ansiolíticos, sedacción, hipnosis, efectos anticonvulsivantes y miorrelajación central. Para este estudio se eligió una muestra de 41 expedientes al azar del total de pacientes que recibieron lorazepam en el mes de febrero del 2003 en la Clínica Central de Atenas, de lo cual se extrajo que una mayoría (73 por ciento) corresponden a mujeres, un 29 por ciento iniciaron el consumo antes de los 40 años, y la mayoría tienen entre 16 y 20 años de consumo.

Bocio multinodular con extensión intratóracica (Reporte de un caso) / Multinodular goiter with intrathoracic extention. (It reports of a case)

El presente caso, es de una paciente quien se le diagnóstico bocio multinodular a los 47 años el cual fue tratado con levotiroxina por 10 años y finalmente fue operado con diagnóstico postoperatorio de bocio multinodular intratorácico. Actualmente el uso de levotiroxina para el tratamiento del bocio multinodular es cuestionado por el riesgo de autonomía de alguno de los nódulos, esta es una de las razones por los que la tiroidectomía total se ha convertido en la opción preferida tanto para bocio multinodular como para bocio intratorácico.

Infecciones del tracto urinario: microbiología y resistencia antibiótica / Urinary tract infections: microbiology and antibiotic resistance

Las infecciones del tracto urinario son la principal causa de morbilidad actualmente, por lo cual a su vez implican el mayor gasto en salud en personas de todas las edades. Nuestro estudio comprendió urocultilvos realizados en la clínica de Atenas del 5-8-02 al 17-12-03, de los cuales; un 78.43 por ciento fueron positivos para E. coli relegando a los demás agentes a una minoría, además la mayoría de las cepas de E. coli son resistentes al Trimetoprim sulfametoxazole (TMP SMX) que es actualmente el medicamento más utilizado. Como segundo agente causal más frecuente encontramos a Kliebsiella sp.