Heroin-induced leukoencephalopathy: Chasing the imaging findings.

We present a case of a 29-year-old male who was brought into the hospital due to unresponsiveness and found to have heroin inhalational leukoencephalopathy (HLE). HLE is one component of a broad spectrum of opioid encephalopathies that is associated with heroin inhalation and other opioids. There is considerable overlap of HLE with other toxic and hypoxic-ischemic encephalopathies; however, the specific territories of brain involvement help distinguish it from other cerebral insults. The goal of this study is to help elucidate the findings of HLE and compare these findings to other toxic and hypoxic-ischemic encephalopathies.

Structural Characterization and Cytotoxic Activity Evaluation of Ulvan Polysaccharides Extracted from the Green Algae Ulva papenfussii.

Ulvan, a sulfated heteropolysaccharide with structural and functional properties of interest for various uses, was extracted from the green seaweed Ulva papenfussii. U. papenfussii is an unexplored Ulva species found in the South China Sea along the central coast of Vietnam. Based on dry weight, the ulvan yield was ~15% (w/w) and the ulvan had a sulfate content of 13.4 wt%. The compositional constitution encompassed L-Rhamnose (Rhap), D-Xylose (Xylp), D-Glucuronic acid (GlcAp), L-Iduronic acid (IdoAp), D-Galactose (Galp), and D-Glucose (Glcp) with a molar ratio of 1:0.19:0.35:0.52:0.05:0.11, respectively. The structure of ulvan was determined using High-Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Nuclear Magnetic Resonance spectroscopy (NMR) methods. The results showed that the extracted ulvan comprised a mixture of two different structural forms, namely ("A3s") with the repeating disaccharide [→4)-ß-D-GlcAp-(1→4)-α-L-Rhap 3S-(1→]n, and ("B3s") with the repeating disaccharide [→4)-α-L-IdoAp-(1→4)-α-L-Rhap 3S(1→]n. The relative abundance of A3s, and B3s was 1:1.5, respectively. The potential anticarcinogenic attributes of ulvan were evaluated against a trilogy of human cancer cell lineages. Concomitantly, Quantitative Structure-Activity Relationship (QSAR) modeling was also conducted to predict potential adverse reactions stemming from pharmacological interactions. The ulvan showed significant antitumor growth activity against hepatocellular carcinoma (IC50 ≈ 90 µg/mL), human breast cancer cells (IC50 ≈ 85 µg/mL), and cervical cancer cells (IC50 ≈ 67 µg/mL). The QSAR models demonstrated acceptable predictive power, and seven toxicity indications confirmed the safety of ulvan, warranting its candidacy for further in vivo testing and applications as a biologically active pharmaceutical source for human disease treatment.

Efficacy and safety of zero-fluoroscopy ablation of ventricular arrhythmias originating from the right ventricular outflow tract: Comparison with fluoroscopy-guided ablation without a three-dimensional electroanatomic mapping system.

Background: Radiofrequency catheter ablation is the preferred treatment choice for ventricular arrhythmias (VAs) originating from right ventricular outflow tract (RVOT) in symptomatic patients and is usually performed under fluoroscopy guidance. Zero-fluoroscopy (ZF) ablations using 3D mapping system applied for treatment of various types of arrhythmias are trending and practiced in many centers around the world, but rarely done in Vietnam. The objective of this study was to evaluate the efficacy and safety of zero-fluoroscopy ablation of RVOT VAs, compared with fluoroscopy-guided ablation without a 3D electroanatomic mapping (EAM) system. Methods and Results: We conducted a nonrandomized, prospective single-center study including 114 patients with RVOT VAs that had electrocardiographic features of typical left bundle branch block, inferior axis QRS morphology, and a precordial transition ≥ V3, from May 2020 to July 2022. The patients were assigned (without randomization) to two different approaches of either zero-fluoroscopy ablation under the guidance of the Ensite system (ZF group) or fluoroscopy-guided ablation without a 3D EAM (fluoroscopy group) in a 1:1 ratio. After a follow-up time of 5.0 ± 4.9 months and 6.9 ± 9.3 months in the ZF and fluoroscopy groups, respectively, the results showed a higher success rate in the fluoroscopy group than in the complete ZF group (87.3% vs 86.8%), although the difference was not statistically significant. No major complication was noted in both the groups. Conclusion: ZF ablation for RVOT VAs can be done safely and effectively using the 3D electroanatomic mapping system. The results of ZF approach are comparable to that of the fluoroscopy-guided approach without a 3D EAM system.

A new method for synthesis of N,N-diethyl-m-methylbenzamide

RESUMEN Introducción: La N,N-dietil-m-metilbenzamida o N,N-dietil-m-toluamida (DEET), es muy conocida como repelente de insectos. Además, se utiliza para mejorar la administración dérmica y transdérmica de muchos fármacos. Objetivos: Presentar un procedimiento factible para sintetizar DEET a partir de ácido m-toluico y dietilamina. Métodos: El ácido m-toluico fue activado con 1,1'-carbonil-diimidazol, para obtener el producto intermedio 1- (m-toluoil) imidazol que continúa reaccionando con dietilamina, para producir DEET. De este modo, se mejoran los factores que afectan la síntesis de N, N-dietil-m-toluamida. Resultados: Se obtuvo DEET mediante un procedimiento óptimo. Los subproductos de la reacción son solubles en agua; se eliminan fácilmente mediante el método de extracción líquido-líquido con agua y diclorometano. La mayor parte del DEET obtenido tiene gran pureza. Los rendimientos fueron del 94 al 95 %. Conclusiones: Se ha proporcionado una ruta mejorada para una síntesis simple y eficaz de DEET a partir de ácido m-toluico y dietilamina en presencia de 1,1'-carbonil-diimidazol. El procedimiento de síntesis se realizó en un solo reactor y el aislamiento de DEET se logró mediante extracción líquido-líquido. El tiempo total de procedimiento se redujo significativamente. Este método de síntesis es fácilmente escalable y factible industrialmente.

ABSTRACT Introduction: N, N-diethyl-m-methylbenzamide or N, N-diethyl-m-toluamide (DEET), is well known as an insect repellent. In addition, it is used to improve the dermal and transdermal delivery of many drugs. Objectives: To present a feasible procedure to synthesize DEET from m-toluic acid and diethylamine. Methods: The m-toluic acid was activated with 1,1'-carbonyl-diimidazole, to obtain the intermediate product 1- (m-toluoyl) imidazole that continues to react with diethylamine, to produce DEET. In this way, the factors affecting the synthesis of N, N-diethyl-m-toluamide are improved. Results: DEET was obtained through an optimal procedure. The by-products of the reaction are soluble in water; they are easily removed by the liquid-liquid extraction method with water and dichloromethane. Most of the DEET obtained has high purity. The yields were 94 to 95 %. Conclusions: An improved route has been provided for a simple and efficient synthesis of DEET from m-toluic acid and diethylamine in the presence of 1,1'-carbonyl-diimidazole. The synthesis procedure was carried out in one-pot, and the isolation of DEET was achieved by liquid-liquid extraction. The total procedure time was significantly reduced. This synthesis method is easily scalable and industrially feasible.

A novel thermostable prokaryotic fucoidan active sulfatase PsFucS1 with an unusual quaternary hexameric structure.

Fucoidans are sulfated, fucose-rich marine polysaccharides primarily found in cell walls of brown seaweeds (macroalgae). Fucoidans are known to possess beneficial bioactivities depending on their structure and sulfation degree. Here, we report the first functional characterization and the first crystal structure of a prokaryotic sulfatase, PsFucS1, belonging to sulfatase subfamily S1_13, able to release sulfate from fucoidan oligosaccharides. PsFucS1 was identified in the genome of a Pseudoalteromonas sp. isolated from sea cucumber gut. PsFucS1 (57 kDa) is Ca2+ dependent and has an unusually high optimal temperature (68 °C) and thermostability. Further, the PsFucS1 displays a unique quaternary hexameric structure comprising a tight trimeric dimer complex. The structural data imply that this hexamer formation results from an uncommon interaction of each PsFucS1 monomer that is oriented perpendicular to the common dimer interface (~ 1500 Å2) that can be found in analogous sulfatases. The uncommon interaction involves interfacing (1246 Å2) through a bundle of α-helices in the N-terminal domain to form a trimeric ring structure. The high thermostability may be related to this unusual quaternary hexameric structure formation that is suggested to represent a novel protein thermostabilization mechanism.

Underway velocity measurements in the Alderney Race: towards a three-dimensional representation of tidal motions.

The Alderney Race, located northwest of the Cotentin Peninsula (France), is a site with high tidal-stream energy potential. Circulation through the Alderney Race is complex, with current speed exceeding 3 m s-1 at neap tide. Towed acoustic Doppler current profiler (ADCP) measurements and static point velocity measurements were performed in July 2018 focusing on assessment of circulation and vertical structure of tidal currents. Transect surveys revealed peculiar features of local dynamics such as change in location of the tidal jet on ebb and flood flow. The spatial expanse of the tidal jet was quantified and regions with largely sheared or nearly homogeneous velocity distributions were identified on the cross-sections. Velocity profiles acquired along the cross-sections were accurately characterized using a power law. The spatial variability of the power-law exponent α was found to be large and correlated with the tidal conditions. The largest variation in profile shape was observed in the northern sector and assumed to be generated by the current interaction with a bathymetric constriction. The velocity profiles were found to vary from highly sheared on flood flow to nearly homogeneous on ebb flow, with corresponding range of power-law exponent α variation from 6 to 14. In the southern sector, over a relatively smooth bathymetry, the velocity profile shape was accurately approximated using the 1/7 power law with a range of variation of α from 6.5 to 8, with respect to the tidal conditions. To our knowledge, this is the largest field survey done using towed ADCP and the results could represent a significant advance in tidal site characterization and provide advanced information to turbine developers. This article is part of the theme issue 'New insights on tidal dynamics and tidal energy harvesting in the Alderney Race'.

Addressing operational challenges of combatting malaria in a remote forest area of Vietnam using spatial decision support system approaches.

This study examines the development of a spatial decision support system (SDSS) to address operational challenges for combatting malaria in a priority remote forest area of Vietnam including locating active malaria transmission, guiding targeted response, and identifying mobile and high-risk populations. A customized SDSS was developed for three communes in Phu Yen Province, Vietnam. Geographical reconnaissance (GR) was conducted to map and enumerate all households in the study site. During 2015 and 2016, detected malaria cases were reported to the SDSS and georeferenced to household residence. Individual case data were analysed in the SDSS to guide targeted response. Case investigation data, including suspected forest and remote area transmission locations, were also integrated into the SDSS. Surveys and in-depth interviews were conducted to assess utility and user acceptability. In 2015 and 2016, 4,667 households and a population of 17,563 were captured during GR. During the study period, 128 malaria cases were reported and automatically mapped in the SDSS. Targeted response interventions were conducted in 12 villages, testing 1,872 individuals. Intervention and remote-area sleeping site data were mapped and analysed using the SDSS. During follow-up interviews in 2017 the SDSS was found to be highly acceptable to malaria surveillance personnel. Results suggest that an SDSS can provide an effective tool in Vietnam to support the implementation of specialized surveillance, and calls for further research, application and roll-out in the Greater Mekong Subregion.

Detection of antibiotics in chicken eggs obtained from supermarkets in Ho Chi Minh City, Vietnam.

The residual levels of antibiotics in Vietnamese eggs were monitored from 2014 to 2015. A total of 111 egg packages, distributed by 11 different companies, were collected from supermarkets in Ho Chi Minh City and the levels of 28 antibiotics were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening method. Sixteen samples tested positive for antibiotics; a total of eight compounds (enrofloxacin, ciprofloxacin, norfloxacin, sulfadimethoxine, sulfamethazine, sulfamonomethoxine, tilmicosin and trimethoprim) were detected. Enrofloxacin was detected in eight samples, with two samples exhibiting concentrations exceeding 1,000 µg kg-1. Tilmicosin was detected in three samples at a range of 49-568 µg kg-1. We observed that two of the 11 companies frequently sold antibiotic-contaminated eggs (detection rates of 56 and 60%), suggesting that a number of companies do not regulate the use of antibiotics in egg-laying hens. Our findings indicate that livestock farmers require instruction regarding antibiotic use and that continual antibiotic monitoring is essential in Vietnam.

Sonication-Assisted Nanoprecipitation in Drug Delivery.

Sonication-assisted nanoprecipitation provides an effective tool for nanomedicine engineering in therapeutic improvement. In the scope of this review, original works in interdisciplinary areas of using sonication with precipitation method for nanoparticulate drug delivery systems and its applications in management of different diseases are discussed. The use of sonication-assisted nanoprecipitation has been proved to improve drug bioavailability, which attracts tremendous interests as an effective strategy for drug delivery. However, many challenges still remain. To overcome these barriers, different approaches such as precipitation method, rational design, optimization and modification have been investigated. Accordingly, current knowledge of sonication-assisted nanoprecipitation proposes a broad perspective and optimization for the applications of nanotechnology in drug delivery.

An investigation of effects of modification processes on physical properties and mechanism of drug release for sustaining drug release from modified rice.

The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH6.8 at 37±0.5°C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug.

Antibiotic residue monitoring results for pork, chicken, and beef samples in Vietnam in 2012-2013.

A monitoring plan of residual antibiotics in food of animal origin was conducted in Vietnam from 2012 to 2013. Meat samples were collected from slaughterhouses and retail stores in Ho Chi Minh City and Nha Trang. A total of 28 antibiotics were analyzed using a LC-MS/MS screening method. Sulfonamides, fluoroquinolones, and tilmicosin were detected in some of the samples. Sulfaclozine and fluoroquinolones were mainly detected in chicken samples, and sulfamethazine was mainly detected in pork samples. High levels of sulfonamide residues, ranging between 2500 and 2700 µg/kg sulfaclozine and between 1300 and 3600 µg/kg sulfamethazine, were present in two chicken and three pork samples, respectively. Tilmicosin was detected at ranges of 150-450 µg/kg in 10 chicken samples. Positive percentages were 17.3, 8.8, and 7.4% for chicken, pork, and beef, respectively, for an average of 11.9%. The results suggest an appropriate withdrawal period after drug administration had not been observed in some livestock.