RESUMEN Introducción: La aflatoxina B1 se encuentra entre las micotoxinas más comunes y venenosas producidas por ciertos hongos que dañan a los animales y los cultivos. Las micotoxinas pueden causar una variedad de efectos adversos para la salud y representar una grave amenaza para la salud de los seres humanos. Los límites máximos de residuos de aflatoxina B1en cereales e ingredientes procesados son de 2 ppb y 5 ppb, respectivamente. Objetivos: Evaluar el estado de contaminación por aflatoxina B1 en arroz, maíz y alimentos básicos producidos en la provincia de Ha Giang, en comparación con los niveles máximos permitidos. Métodos: Se analizaron un total de 210 muestras de arroz y maíz para cuantificar el nivel de aflatoxina B1. El análisis de micotoxinas se realizó mediante cromatografía líquida de alta resolución, utilizando un detector de fluorescencia. Resultados: Se encontró que el arroz, los productos de arroz, el maíz y los productos de maíz tenían un contenido medio de aflatoxin B1, de 1,79 ppb, 2,55 ppb, 2,19 ppb y 6,35 ppb, respectivamente. Los resultados también mostraron que el 71,9 % de las muestras estaban contaminadas con micotoxinas y el 14,28 % de las muestras excedieron el límite máximo permitido. Conclusión: La concentración de aflatoxina B1 en el 14,28 % de las muestras está por encima de los límites permisibles por la norma nacional.

ABSTRACT Introduction: Aflatoxins B1 are among the most common poisonous mycotoxins produced by certain fungi that harm animals and crops. Mycotoxins can cause a variety of adverse health effects and pose a serious health threat to humans. The Maximum Residue Limits of aflatoxin B1 in processed cereals and ingredients are 2 parts per billion (ppb) and 5 ppb, respectively. Objectives: To evaluate the status of aflatoxin B1 contamination in rice, corn and staple food produced in Ha Giang province compared with the maximum permitted levels. Methods: A total of 210 rice and maize samples were analyzed to quantify the level of aflatoxin B1. Analysis of mycotoxins was conducted by High Performance Liquid Chromatography using a fluorescence detector. Results: It was found that rice, rice products, maize, and maize products had a mean aflatoxin B1 content of 1.79 ppb, 2.55 ppb, 2.19 ppb, and 6.35 ppb, respectively. The results also showed that 71.9% of samples were contaminated with mycotoxins, and 14.28% of samples exceeded the maximum allowable limit. Conclusion: The concentration of aflatoxin B1 in 14.28% of the samples are over permissible limits by nationwide regulations.

Resumo Introdução O reestabelecimento da continuidade após a cirurgia de Hartmann é considerado um procedimento cirúrgico de grande porte com altas morbidade e mortalidade. O tempo ideal de intervalo entre a cirurgia de Hartmann e a reversão é controverso. Nosso estudo teve como objetivo avaliar a eficácia da reversão da cirurgia de Hartmann e determinar o momento ideal para a cirurgia. Métodos Todos os pacientes submetidos à reversão laparoscópica da cirurgia de Hartmann entre 2008 e 2019 (11 anos) no Centro Médico Universitário (UMC, na sigla em inglês) na cidade de Ho Chi Minh foram recrutados e divididos em 2 grupos de acordo como tempo de intervalo (≤ 4 ou>4meses). Os resultados pós-operatórios de curto prazo destes grupos foram comparados. Resultados Um total de 66 pacientes foram submetidos à reversão laparoscópica da cirurgia de Hartmann (mediana de idade: 63.2 anos); ~ 77 deles tinha câncer colorretal, e 17% tinham doença diverticular complicada. As taxas de mortalidade, de vazamento, e de complicações em geral foram de 0%, 1,5%, e 13,2%, respectivamente. Cirurgia precoce foi realizada em 36 pacientes, e reversão tardia foi realizada em 28 pacientes. Não houve diferença em mortalidade, vazamento anastomótico, complicações operatórias e duração da internação entre os dois grupos. Conclusão A reversão laparoscópica da cirurgia de Hartmann foi eficaz, com morbidade e mortalidade aceitáveis no UMC. Não foi observado qualquer impacto no tempo de intervalo entre a cirurgia de Hartmann e a reversão laparoscópica nos resultados pós-operatórios de curto prazo.

Abstract Background The reestablishment of continuity after Hartmann operation is considered a major surgical procedure with high morbidity and mortality. The optimal interval time between the Hartman procedure and reversal is controversial. Our study aimed to evaluate the effectiveness of laparoscopic Hartmann reversal and to determine the optimal timing of operation. Methods All patients who underwent laparoscopic Hartmann reversal from 2008 to 2019 (11 years) at the University Medical Center (UMC) in Ho Chi Minh City were recruited and divided into 2 groups according to the interval time (≤ 4 or>4months). The short-term operative outcomes of these groups were compared. Results There were 66 patients who underwent laparoscopic Hartmann reversal (mean age: 63.2 years old); ~ 77% of them had colorectal cancer, and 17% had complicated diverticular disease. Themortality rate, anastomotic leakage rate, and overall complication rate were 0%, 1.5%, and 13.2%, respectively. Early operation was performed in 36 patients, and late reversal in 28 patients. There was no difference in mortality, anastomotic leakage, operative complications, and hospital stay between the two groups. Conclusion Laparoscopic Hartmann reversal was effective with acceptable morbidity and mortality at the UMC. There was no observed impact of the interval time between the Hartmann procedure and laparoscopic Hartmann reversal on the short-term operative outcomes.

Abstract Fluorescent nanodiamond (FND) has been used for long-term cell labeling and in vivo cell tracking because they have good at photostability and biocompatibility. In this study, we evaluate the effect of fluorescent nanodiamond labeling on in vitro culture and differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs) into hepatocyte-like cells (HLCs). For hepatic differentiation of hUCMSCs, cells were induced with human hepatocyte growth factor, nicotinamide and Dexamethasone. FND was supplied in two experimental groups with 20 μg/mL and 100 μg/mL in 2 hours. The cell was assessed for FND uptake by laser scan microscopy and flow cytometry methods. The effect of FND on hUCMSCs was evaluated by the cell viability and growth assays as well as the differentiation throughout of morphology alterations or gene expression of anfa-fetoprotein, albumin, and hepatocyte nuclear factor 4α. The results showed that the labeling of hUCMSCs is efficient and easy and there was significant cellular uptake of FND. We did not observe any negative impacts of FND to the cell viability and growth. FND can be utilized for the long-term labeling and tracking of hUCSCs and HLCs in vivo studies.

Abstract In this research, a novel organic photocatalyst of 10-(Perylene-3-yl-10H-Phenoxazine (PHP) has been synthesized successfully from perylene and phenoxazine via Buchwald-Hartwig C-N coupling. The chemical structure of catalyst was determined via proton nuclear magnetic resonance (1H-NMR) spectrum and optical properties were investigated through UV-Vis spectroscopy. The PHP has been used as the reducing photoredox catalyst for organocatalyzed atom transfer radical polymerization (ATRP) under UV irradiation. The well controlled molecular weight of polymers based on methyl methacrylate monomers have been obtained with monomer conversion up to 77.61% and low polydispersity index under 1.5.

Abstract: Novel biomarkers for screening, diagnosis and monitoring the treatment of nasopharyngeal carcinoma (NPC), one of the most common cancers in Vietnam, are urgently required. Increasing evidence suggests that microRNA-141 (miR-141) is associated with NPC, owing to its ability to affect the expression of genes that modulate tumorigenesis. Unfortunately, research on miR-141 expression in Vietnamese patients is limited. Therefore, the objective of the current study was to evaluate miR-141 expression and assess whether miR-141 might be a potential biomarker for diagnosis of NPC in Vietnamese patients. Total RNA isolated from 40 NPC biopsy samples and 37 non-cancerous samples was analyzed by quantitative reverse-transcription PCR. The miR-141 expression levels were compared between NPC biopsy and non-cancerous samples. The frequency of miR-141 detection was 37.50% and 10.80% in the NPC and non-cancerous samples, respectively (p = 0.0143). The miR-141 expression was 5.27 times higher in tumor samples than non-cancerous samples. Additionally, the RR (Relative risk) and OR (Odds ratio) were 1.83 (95%CI = 1.2576–2.6675, p = 0.0016) and 4.95 (95%CI = 1.4625–16.7541, p = 0.01), respectively. In conclusion, miR-141 was up-regulated in the biopsy samples and thus may be a potential biomarker for NPC in the Vietnamese population.

BACKGROUND: Vascular endothelial growth factor (VEGF) is involved in the growth of new blood vessels that feed tumors and kinesin spindle protein (KSP) plays a critical role in mitosis involving in cell proliferation. Simultaneous silencing of VEGF and KSP, an attractive and viable approach in cancer, leads on restricting cancer progression. The purpose of this study is to examine the therapeutic potential of dual gene targeted siRNA cocktail on human hepatocellular carcinoma Hep3B cells. RESULTS: The predesigned siRNAs could inhibit VEGF and KSP at mRNA level. siRNA cocktail showed a further downregulation on KSP mRNA and protein levels compared to KSP-siRNA or VEGF-siRNA, but not on VEGF expression. It also exhibited greater suppression on cell proliferation as well as cell migration or invasion capabilities and induction of apoptosis in Hep3B cells than single siRNA simultaneously. This could be explained by the significant downregulation of Cyclin D1, Bcl-2 and Survivin. However, no sigificant difference in the mRNA and protein levels of ANG2, involving inhibition of angiogenesis was found in HUVECs cultured with supernatant of Hep3B cells treated with siRNA cocktail, compared to that of VEGF-siRNA. CONCLUSION: Silencing of VEGF and KSP plays a key role in inhibiting cell proliferation, migration, invasion and inducing apoptosis of Hep3B cells. Simultaneous silencing of VEGF and KSP using siRNA cocktail yields promising results for eradicating hepatocellular carcinoma cells, a new direction for liver cancer treatment.

OBJECTIVE: To estimate and analyse the costs for providing the expanded programme on immunization (EPI) in a rural community in the north of Viet Nam in 2005. METHODS: An ingredient approach was used to collect cost data from the perspective of the service providers. FINDINGS: The total annual cost of EPI in Bavi district was US$ 58 460 [purchasing power parity (PPP) 282 076]. Vaccines and supplies were the largest cost category (33%), followed by personnel costs (30.2%). The largest share of the total cost was due to activities at commune level (38%). The average cost per fully vaccinated child (FVC) was US$ 4.81 (PPP 23.21), much lower than the figure of US$ 15 that is generally accepted as the cost-effective threshold for EPI in developing countries. CONCLUSION: This empirical study indicates that EPI has been implemented efficiently in rural Viet Nam, but that opportunities exist to make it even more efficient.

OBJETIVO: Estimar y analizar los costos asociados a la aplicación del programa ampliado de inmunización (PAI) en una comunidad rural del norte de Viet Nam en 2005. MÉTODOS: Se utilizó un sistema de componentes para reunir datos sobre los costos desde la perspectiva de los proveedores de servicios. RESULTADOS: El costo anual total del PAI en el distrito de Bavi fue de US$ 58 460 [en paridad del poder adquisitivo (PPP): 282 076]. Las vacunas y los suministros fueron la principal categoría de costos (33%), seguidos de los gastos de personal (30,2%). El mayor porcentaje del costo total correspondió a las actividades realizadas a nivel comunal (38%). El costo promedio por niño totalmente vacunado fue de US$ 4,81 (PPP 23,21), muy inferior a la cifra de US$ 15 aceptada en general como umbral de costoeficacia para el PAI en los países en desarrollo. CONCLUSIÓN: Este estudio empírico muestra que el PAI se ha aplicado de manera eficiente en el Viet Nam rural, pero hay posibilidades de aumentar aún más esa eficiencia.

OBJECTIF: Estimer et analyser les coûts de délivrance du programme élargi de vaccination (PEV) dans une communauté rurale du nord du Viet Nam en 2005. MÉTHODES: On a fait appel à une approche par composants pour collecter les données relatives aux coûts pour les prestateurs de services. RÉSULTATS: Le coût annuel total du PEV dans le district de Bavi était de US $ 58 460 [parité de pouvoir d'achat (PPA) : 282 076]. Les vaccins et les fournitures représentaient la catégorie de coût la plus importante (33 %), suivie par les coûts de main d'œuvre (30,2 %). Les activités au niveau communal totalisaient la plus grande part (38 %) du coût total. Le coût moyen par enfant complètement vacciné était de US $ 4,81 (PPA : 23,21), soit bien moins que le chiffre de US $ 15, généralement accepté comme seuil de rentabilité du PEV dans les pays en développement. CONCLUSION: Cette étude empirique indique que le PEV est mis en œuvre efficacement dans le Viet Nam rural, mais qu'il existe des possibilités de le rendre encore plus efficace.