The University of Medicine & Pharmacy at Ho Chi Minh City
Ho Chi Minh City, Vietnam
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Hornick A.,University of Innsbruck | Lieb A.,University of Innsbruck | Vo N.P.,The University of Medicine & Pharmacy at Ho Chi Minh City | Rollinger J.M.,University of Innsbruck | And 2 more authors.
Neuroscience | Year: 2011

In a previous study the simple, naturally derived coumarin scopoletin (SCT) was identified as an inhibitor of acetylcholinesterase (AChE), using a pharmacophore-based virtual screening approach. In this study the potential of SCT as procholinergic and cognition-enhancing therapeutic was investigated in a more detailed way, using different experimental approaches like measuring newly synthesized acetylcholine (ACh) in synaptosomes, long-term potentiation (LTP) experiments in hippocampal slices, and behavior studies. SCT enhanced the K +-stimulated release of ACh from rat frontal cortex synaptosomes, showing a bell-shaped dose effect curve (E max: 4 μM). This effect was blocked by the nicotinic ACh receptor (nAChR) antagonists mecamylamine (MEC) and dihydro-β-erythroidine (DHE). The nAChR agonist (and AChE inhibitor) galantamine induced a similar increase in ACh release (E max: 1 μM). SCT potentiated LTP in hippocampal slices of rat brain. The high-frequency stimulation (HFS)-induced, N-methyl-D-aspartate (NMDA) receptor dependent LTP of field excitatory postsynaptic potentials at CA3-CA1 synapses was greatly enhanced by pre-HFS application of SCT (4 μM for 4 min). This effect was mimicked by nicotine (2 μM) and abolished by MEC, suggesting an effect on nAChRs. SCT did not restore the total inhibition of LTP by NMDA receptor antagonist d, l-2-amino-5-phosphonopentanoic acid (AP-5). SCT (2 μg, i.c.v.) increased T-maze alternation and ameliorated novel object recognition of mice with scopolamine-induced cholinergic deficit. It also reduced age-associated deficits in object memory of 15-18-month-old mice (2 mg/kg sc). Our findings suggest that SCT possesses memory-improving properties, which are based on its direct nAChR agonistic activity. Therefore, SCT might be able to rescue impaired cholinergic functions by enhancing nAChR-mediated release of neurotransmitters and promoting neural plasticity in hippocampus. © 2011 IBRO.

Huynh N.C.-N.,The University of Medicine & Pharmacy at Ho Chi Minh City | Everts V.,VU University Amsterdam | Ampornaramveth R.S.,Chulalongkorn University
Bone Reports | Year: 2017

Histone acetylation is an important epigenetic mechanism that controls expression of certain genes. It includes non-sequence-based changes of chromosomal regional structure that can alter the expression of genes. Acetylation of histones is controlled by the activity of two groups of enzymes: the histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs remove acetyl groups from the histone tail, which alters its charge and thus promotes compaction of DNA in the nucleosome. HDACs render the chromatin structure into a more compact form of heterochromatin, which makes the genes inaccessible for transcription. By altering the transcriptional activity of bone-associated genes, HDACs control both osteogenesis and osteoclastogenesis. This review presents an overview of the function of HDACs in the modulation of bone formation. Special attention is paid to the use of HDAC inhibitors in mineralized tissue regeneration from cells of dental origin. © 2017 The Authors

Do T.C.M.V.,University of Innsbruck | Nguyen T.D.,The University of Medicine & Pharmacy at Ho Chi Minh City | Tran H.,The University of Medicine & Pharmacy at Ho Chi Minh City | Stuppner H.,University of Innsbruck | Ganzera M.,University of Innsbruck
Journal of Chromatography A | Year: 2013

Lotus leaves are a popular remedy in Asia to treat obesity, insomnia and mental impairment; alkaloids are considered most relevant for bioactivity. In this study the first CE method for the determination of all major alkaloids ((-)-nuciferine, (-)-nornuciferine, (-)-caaverine, (-)-armepavine, (+)-norarmepavine, (+)-isoliensinine and (+)-pronuciferine) in Nelumbo nucifera leaves was developed. The optimum buffer showed to be a solution of 100. mM ammonium acetate in a mixture of methanol, acetonitrile and water, also containing 0.6% acid acetic. Applied voltage, temperature and detection wavelength were 25. kV, 30 °C and 225 nm; the required analysis time was 15. min. By CE-MS all standard compounds could be assigned in positive ESI mode, and two minor alkaloids were tentatively identified (n-nornuciferine and roemerine). A mixture of water, methanol and acetic acid served as sheath liquid in these experiments. The NACE assay was fully validated and utilized to analyze Lotus leaf samples collected in different parts of Vietnam. Respective results revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all samples (-)-nuciferine (0.34-0.63%), (-)-armepavine (0.13-0.20%), and (+)-isoliensinine (0.06-0.19%) were the most dominant alkaloids. The total alkaloid content varied from 0.72 to 1.41%. © 2013 Elsevier B.V.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: KBBE-2007-2-3-03 | Award Amount: 4.10M | Year: 2008

Functional foods provide a buoyant growth sector and the use of carotenoids is the most dynamic not only as colorants but as food additives. One issue with these products is their instability both on the shelf and upon digestion. Recently, gastric-stable bacterial-derived carotenoid preparations have been discovered by members of this consortium and these 2nd generation carotenoid preparations, and the bacteria that produce them will be studied. Existing prototypes will be developed as potential food additives but an extensive screen for new 2nd generation prototypes will also be made from marine environments. The consortium includes microbiologists, biochemists and food bio-technologists and will determine the identity of new carotenoid preparations and the bacteria that produce them. The nutritional value of these bacteria will be assessed and a risk-benefit assessment made using modern metabolomic technologies as well as traditional toxicology in order to designate the prototypes as QPS (ie, qualified presumption of safety). Bioprocessing of these bacterial carotenoid preparations will eliminate traditional chemical synthesis and the use of organic solvents. Also the delivery system will utilise a synergistic biological matrix making it a sustainable source. The use of these bacteria as colour-nutritional additives will be assessed by process optimisations, colour and texture analysis. The consortium includes 9 partners, including one ICPC and one associated country. Two IND partners, one an SME, will work together to exploit prototypes as additives, colourants and as functional foods. This will include patenting, licensing and the opening of new markets. Both IND partners are looking for new markets in the food additive/functional food sector and this project will enable them to identify new markets. The project will directly impact the food industry by developing new, natural as well as novel food additives and ingredients that can replace synthetic ones.

Thai K.-M.,The University of Medicine & Pharmacy at Ho Chi Minh City | Ngo T.-D.,The University of Medicine & Pharmacy at Ho Chi Minh City | Tran T.-D.,The University of Medicine & Pharmacy at Ho Chi Minh City | Le M.-T.,The University of Medicine & Pharmacy at Ho Chi Minh City
Current Topics in Medicinal Chemistry | Year: 2013

The pharmacophore modeling in modern drug research has been applied for both bioactivity profiling and early stage of risk assessment of potential side effects and toxicity due to interactions of drug candidates with antitargets namely P-glycoprotein, hERG, cytochrome P450 and pregnane X-receptor. In this article, an existing state concerning with pharmacophore modeling applied for promiscuous proteins in drug research were updated and reviewed. In an attempt to create new safe medicines faster, the partial overlap of substrate properties of hERG, P-glycoprotein, pregnane X-receptor and cytochrome P450 has to be considered and drug safety has to be dealt on a system level on the off-targets. © 2013 Bentham Science Publishers.

Tam N.U.T.,The University of Medicine & Pharmacy at Ho Chi Minh City | Thoa L.T.B.,The University of Medicine & Pharmacy at Ho Chi Minh City | Long N.P.,The University of Medicine & Pharmacy at Ho Chi Minh City | Trang N.T.H.,Hue University | And 3 more authors.
Bulletin of the World Health Organization | Year: 2015

Objective To estimate the proportion of participants in clinical trials who understand different components of informed consent. Methods Relevant studies were identified by a systematic review of PubMed, Scopus and Google Scholar and by manually reviewing reference lists for publications up to October 2013. A meta-analysis of study results was performed using a random-effects model to take account of heterogeneity. Findings The analysis included 103 studies evaluating 135 cohorts of participants. The pooled proportion of participants who understood components of informed consent was 75.8% for freedom to withdraw at any time, 74.7% for the nature of study, 74.7% for the voluntary nature of participation, 74.0% for potential benefits, 69.6% for the study’s purpose, 67.0% for potential risks and side-effects, 66.2% for confidentiality, 64.1% for the availability of alternative treatment if withdrawn, 62.9% for knowing that treatments were being compared, 53.3% for placebo and 52.1% for randomization. Most participants, 62.4%, had no therapeutic misconceptions and 54.9% could name at least one risk. Subgroup and meta-regression analyses identified covariates, such as age, educational level, critical illness, the study phase and location, that significantly affected understanding and indicated that the proportion of participants who understood informed consent had not increased over 30 years. Conclusion The proportion of participants in clinical trials who understood different components of informed consent varied from 52.1% to 75.8%. Investigators could do more to help participants achieve a complete understanding. © 2015 World Health Organization. All rights reserved.

Lan V.T.N.,The University of Medicine & Pharmacy at Ho Chi Minh City | Linh N.K.,An Sinh Hospital | Tuong H.M.,Vietnam National University, Ho Chi Minh City | Wong P.C.,National University Hospital Singapore | Howles C.M.,ARIES Consulting
Reproductive BioMedicine Online | Year: 2013

This pilot study compared the efficacy and safety of two simple dosing algorithms, one based on anti-Müllerian Hormone (AMH) and the other on the antral follicle count (AFC), to determine the starting dose of recombinant FSH (rFSH) for ovarian stimulation in 348 women. Patients were randomized to a predefined AMH-or AFC-based algorithm. The proportion of cycles with the desired response was similar when rFSH dose was determined using AMH or AFC (35.2% versus 28.4%). There was a significant difference between the groups in the proportion of cycles with a hyperresponse (8.6% and 17.4%, but the incidence of ovarian hyperstimulation syndrome was similar (1.1% and 4.6%). There were no significant differences between two groups in outcomes, including implantation (19.3% versus 19.0%), clinical pregnancy (38.0% versus 46.9%), multiple pregnancy (16.5% versus 15.2%) and miscarriage (7.0% versus 8.3%). However, statistically significant differences in ovarian response were evident among the AMH and AFC subgroups: for AMH, Desired and Hypo; for AFC, Hypo and Hyper. This pilot study provides information for developing protocols to further validate the use of either AMH or AFC to guide the starting dose of rFSH in ovarian stimulation. © 2013, Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Vuong T.N.L.,The University of Medicine & Pharmacy at Ho Chi Minh City | Phung H.T.,An Sinh Hospital | Ho M.T.,Vietnam National University, Ho Chi Minh City
Human Reproduction | Year: 2015

STUDY QUESTION Does luteinizing hormone (LH) supplementation improve live birth rate after in vitro fertilization (IVF) in patients aged ≥35 years receiving a gonadotrophin-releasing hormone (GnRH) antagonist protocol? SUMMARY ANSWER There was no difference in live birth rate with use of LH during IVF in patients aged ≥35 years undergoing IVF treatment using a GnRH antagonist protocol. WHAT IS KNOWN ALREADY Use of GnRH analogues as part of a controlled ovarian hyperstimulation protocol during IVF treatment cycles decreases the amount of LH available to developing follicles. The role of LH supplementation for improving outcomes in patients undergoing controlled ovarian hyperstimulation as part of assisted reproduction treatments, particularly those involving a GnRH antagonist protocol, is unclear. It has been suggested that higher risk patients (e.g. age ≥35 years, poor ovarian reserve) may benefit from LH supplementation. STUDY DESIGN, SIZE, DURATION This single-centre, randomized controlled trial was conducted from 1 October 2012 to 30 June 2014. A total of 240 women aged ≥35 years undergoing IVF received ovarian stimulation using a GnRH antagonist protocol, with recombinant follicle-stimulating hormone (r-FSH; Gonal-F®) starting from cycle day 2 or 3. GnRH antagonist (Cetrotide®) was administered on Day 5 of r-FSH administration. On Day 6, patients in the LH supplementation group were switched to r-FSH/r-LH (Pergoveris®) 150/75 IU/day. Randomization to study treatments was performed in blocks of 4 via a computer-generated random number list. PARTICIPANTS/MATERIALS, SETTING, METHODS Of the 240 patients randomized to treatment, 120 received r-FSH/r-LH and 120 received r-FSH. Patients were recruited from the IVFAS, An Sinh Hospital, Ho Chi Minh City, Vietnam. MAIN RESULTS AND THE ROLE OF CHANCE Live birth rate did not differ significantly (P > 0.05) between r-FSH/r-LH and r-FSH recipients (16.7 versus 17.5%; between-group difference 0.8, 95% confidence interval [CI] -9.5, 11.2). In addition, there were no significant differences between the r-FSH/r-LH and r-FSH groups with respect to the number of oocytes retrieved, implantation rate, miscarriage rate and clinical pregnancy rate. LIMITATIONS, REASONS FOR CAUTION The open-label design could have introduced bias, and the relatively small sample size may have allowed detection of only the most common adverse events. In addition, the study was likely to be underpowered based on differences between the response rate assumptions used in the sample size calculation and the actual response rate during the study. WIDER IMPLICATIONS OF THE FINDINGS The results of this study found no additional benefit from adding LH supplementation to ovarian stimulation with a GnRH antagonist protocol in women aged ≥35 years, and add to the body of evidence in this area. However, findings across studies are still inconsistent and additional research is needed before any clear recommendations for clinical practice can be made. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

Tran T.D.,The University of Medicine & Pharmacy at Ho Chi Minh City
Molecules (Basel, Switzerland) | Year: 2012

A series of simple heterocyclic chalcone analogues have been synthesized by Claisen Schmidt condensation reactions between substituted benzaldehydes and heteroaryl methyl ketones and evaluated for their antibacterial activity. The structures of the synthesized chalcones were established by IR and 1H-NMR analysis. The biological data shows that compounds p 5, f 6 and t 5 had strong activities against both susceptible and resistant Staphylococcus aureus strains, but not activity against a vancomycin and methicillin resistant Staphylococcus aureus isolated from a human sample. The structure and activity relationships confirmed that compounds f 5, f 6 and t 5 are potential candidates for future drug discovery and development.

Chi C.T.,The University of Medicine & Pharmacy at Ho Chi Minh City
Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences | Year: 2014

We report our experience in treatment of traumatic direct carotid cavernous fistula (CCF) via endovascular intervention. We hereof recommend an additional classification system for type A CCF and suggest respective treatment strategies. Only type A CCF patients (Barrow's classification) would be recruited for the study. Based on the angiographic characteristics of the CCF, we classified type A CCF into three subtypes including small size, medium size and large size fistula depending on whether there was presence of the anterior carotid artery (ACA) and/or middle carotid artery (MCA). Angiograms with opacification of both ACA and MCA were categorized as small size fistula. Angiograms with opacification of either ACA or MCA were categorized as medium size fistula and those without opacification of neither ACA nor MCA were classified as large size fiatula. After the confirm angiogram, endovascular embolization would be performed impromptu using detachable balloon, coils or both. All cases were followed up for complication and effect after the embolization. A total of 172 direct traumatic CCF patients were enrolled. The small size fistula was accountant for 12.8% (22 cases), medium size 35.5% (61 cases) and large size fistula accountant for 51.7% (89 cases). The successful rate of fistula occlusion under endovascular embolization was 94% with preservation of the carotid artery in 70%. For the treatment of each subtype, a total of 21/22 cases of the small size fistulas were successfully treated using coils alone. The other single case of small fistula was defaulted. Most of the medium and large size fistulas were cured using detachable balloons. When the fistula sealing could not be obtained using detachable balloon, coils were added to affirm the embolization of the cavernous sinus via venous access. There were about 2.9% of patient experienced direct carotid artery puncture and 0.6% puncture after carotid artery cut-down exposure. About 30% of cases experienced sacrifice of the parent vessels and it was associated with sizes of the fistula. Total severe complication was about 2.4% which included 1 death (0.6%) due to vagal shock; 1 transient hemiparesis post-sacrifice occlusion of the carotid artery but the patient had recovered after 3 months; 1 acute thrombus embolism and the patient was completely saved with recombinant tissue plaminogen activator (rTPA); 1 balloon dislodgement then got stuck at the anterior communicating artery but the patient was asymptomatic. Endovascular intervention as the treatment of direct traumatic CCF had high cure rate and low complication with its ability to preserve the carotid artery. It also can supply flexible accesses to the fistulous site with various alternative embolic materials. The new classification of type A CCF based on angiographic features was helpful for planning for the embolization. Coil should be considered as the first embolic material for small size fistula meanwhile detachable balloons was suggested as the first-choice embolic agent for the medium and large size fistula.

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