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56
result(s) for
"Pham, Truong Q"
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SNAP-25, but not SNAP-23, is essential for photoreceptor development, survival, and function in mice
2024
SNARE-mediated vesicular transport is thought to play roles in photoreceptor glutamate exocytosis and photopigment delivery. However, the functions of Synaptosomal-associated protein (SNAP) isoforms in photoreceptors are unknown. Here, we revisit the expression of SNAP-23 and SNAP-25 and generate photoreceptor-specific knockout mice to investigate their roles. Although we find that
SNAP-23
shows weak mRNA expression in photoreceptors, SNAP-23 removal does not affect retinal morphology or vision.
SNAP-25
mRNA is developmentally regulated and undergoes mRNA trafficking to photoreceptor inner segments at postnatal day 9 (P9). SNAP-25 knockout photoreceptors develop normally until P9 but degenerate by P14 resulting in severe retinal thinning. Photoreceptor loss in SNAP-25 knockout mice is associated with abolished electroretinograms and vision loss. We find mistrafficked photopigments, enlarged synaptic vesicles, and abnormal synaptic ribbons which potentially underlie photoreceptor degeneration. Our results conclude that SNAP-25, but not SNAP-23, mediates photopigment delivery and synaptic functioning required for photoreceptor development, survival, and function.
A study using photoreceptor-specific knockout mice finds that SNAP-25, and not SNAP-23, is the isoform crucial for photoreceptor development, survival, and function. Mechanistically, SNAP-25 mediates photopigment trafficking and synaptic functioning.
Journal Article
Homogeneous low-molecular-weight heparins with reversible anticoagulant activity
by
Key, Nigel S
,
Chandarajoti, Kasemsiri
,
Pawlinski, Rafal
in
631/443/592
,
631/92/221
,
631/92/72
2014
Heparin analogs can serve as potent anticoagulants, but heterogeneous structures in some preparations and lack of antidote for others can complicate treatments. A chemoenzymatic method that prevents reversible epimerization now enables reversible application of defined constructs in cells and mice.
Low-molecular-weight heparins (LMWHs) are carbohydrate-based anticoagulants clinically used to treat thrombotic disorders, but impurities, structural heterogeneity or functional irreversibility can limit treatment options. We report a series of synthetic LMWHs prepared by cost-effective chemoenzymatic methods. The high activity of one defined synthetic LMWH against human factor Xa (FXa) was reversible
in vitro
and
in vivo
using protamine, demonstrating that synthetically accessible constructs can have a critical role in the next generation of LMWHs.
Journal Article
SNAP-25, but not SNAP-23, is essential for photoreceptor function and survival in mice
2023
Vesicular transport plays critical roles in photopigment delivery at photoreceptor outer segments and glutamate exocytosis at photoreceptor synapses. Previous studies into the role of photoreceptor SNAP proteins are limited in their characterizations into only gene/protein expression and do not delve further into their functional role. Here, we examine the expression and localization of SNAP-23 and SNAP-25 mRNA and protein. Using SNAP-23 and SNAP-25 conditional knockout mice, we further evaluated the morphological and functional consequences that the absence of these proteins has on vision. Although we found that the ubiquitously expressed SNAP-23 showed weak mRNA expression in photoreceptors, removal of SNAP-23 did not result in any observable phenotype. We found that neuronal SNAP-25 is developmentally regulated and SNAP-25 mRNA undergoes mRNA trafficking to the photoreceptor inner segments coinciding with the development of photoreceptor outer segments. Removal of SNAP-25 in photoreceptor cells led to changes in both outer segment protein trafficking and synaptic integrity, resulting in a complete loss of vision in SNAP-25 cKO mice. Our results conclude that SNAP-25, but not SNAP-23, is the essential isoform for photoreceptor survival and function.
Intracytoplasmic sperm injection versus conventional in-vitro fertilisation in couples with infertility in whom the male partner has normal total sperm count and motility: an open-label, randomised controlled trial
by
Mol, Ben W
,
Pham, Quan T
,
Nguyen, Dung P
in
Adult
,
Embryo transfer
,
Embryo Transfer - methods
2021
The use of intracytoplasmic sperm injection has increased substantially worldwide, primarily in couples with non-male factor infertility. However, there is a paucity of evidence from randomised trials supporting this approach compared with conventional in-vitro fertilisation (IVF). We aimed to investigate whether intracytoplasmic sperm injection would result in a higher livebirth rate compared with conventional IVF.
This open-label, multicentre, randomised trial was done at two IVF centres in Ho Chi Minh City, Vietnam (IVFMD, My Duc Hospital and IVFAS, An Sinh Hospital). Eligible couples were aged at least 18 years and the male partner's sperm count and motility (progressive motility) were normal based on WHO 2010 criteria. Couples had to have undergone two or fewer previous conventional IVF or intracytoplasmic sperm injection attempts, have used an antagonist protocol for ovarian stimulation, and agree to have two or fewer embryos transferred. Couples were randomly assigned (1:1) to undergo either intracytoplasmic sperm injection or conventional IVF, using block randomisation with variable block size of 2, 4, or 8 and a telephone-based central randomisation method. The computer-generated randomisation list was prepared by an independent statistician who had no other involvement in the study. Embryologists and couples were not masked to study groups because of the type of interventions and differences in hospital fees, but clinicians performing embryo transfer were unaware of study group allocation. The primary outcome was livebirth after the first embryo transfer from the initiated cycle. Analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03428919.
Between March 16, 2018, and Aug 12, 2019, we randomly assigned 1064 couples to intracytoplasmic sperm injection (n=532) or conventional IVF (n=532). Livebirth after the first embryo transfer from the initiated cycle occurred in 184 (35%) of 532 couples randomly assigned to intracytoplasmic sperm injection and in 166 (31%) of 532 couples randomly assigned to conventional IVF (absolute difference 3·4%, 95% CI −2·4 to 9·2; risk ratio [RR] 1·11, 95% CI 0·93 to 1·32; p=0·27). 29 (5%) couples in the intracytoplasmic sperm injection group and 34 (6%) couples in the conventional IVF group had fertilisation failure (absolute difference −0·9%, −4·0 to 2·1, RR 0·85, 95% CI 0·53 to 1·38; p=0·60).
In couples with infertility in whom the male partner has a normal total sperm count and motility, intracytoplasmic sperm injection did not improve the livebirth rate compared with conventional IVF. Our results challenge the value of the routine use of intracytoplasmic sperm injection in assisted reproduction techniques for this population.
My Duc Hospital and Merck Sharp and Dohme.
Journal Article
Measuring health literacy in Asia: Validation of the HLS-EU-Q47 survey tool in six Asian countries
by
Pham, Khue M.
,
Baisunova, Gaukhar
,
Huang, Hsiao-Ling
in
Asian health literacy surveys
,
Confirmatory factor analysis
,
Consistency
2017
Health literacy has been increasingly recognized as one of the most important social determinants for health. However, an appropriate and comprehensive assessment tool is not available in many Asian countries. This study validates a comprehensive health literacy survey tool European health literacy questionnaire (HLS-EU-Q47) for the general public in several Asian countries.
A cross-sectional survey based on multistage random sampling in the target countries. A total of 10,024 participants aged ≥15 years were recruited during 2013–2014 in Indonesia, Kazakhstan, Malaysia, Myanmar, Taiwan, and Vietnam. The questionnaire was translated into local languages to measure general health literacy and its three domains. To evaluate the validity of the tool in these countries, data were analyzed by confirmatory factor analysis, internal consistency analysis, and regression analysis.
The questionnaire was shown to have good construct validity, satisfactory goodness-of-fit of the data to the hypothetical model in three health literacy domains, high internal consistency (Cronbach's alpha >0.90), satisfactory item-scale convergent validity (item-scale correlation ≥0.40), and no floor/ceiling effects in these countries. General health literacy index score was significantly associated with level of education (P from <0.001 to 0.011) and perceived social status (P from <0.001 to 0.016), with evidence of known-group validity.
The HLS-EU-Q47 was a satisfactory and comprehensive health literacy survey tool for use in Asia.
•A comprehensive health literacy survey tool was validated in several countries.•Health literacy was significantly associated with education and social status.•The tool was shown to be reliable for public health survey in Asia.
Journal Article
Impact of Preconception Micronutrient Supplementation on Anemia and Iron Status during Pregnancy and Postpartum: A Randomized Controlled Trial in Rural Vietnam
2016
Preconception micronutrient interventions may be a promising approach to reduce anemia and iron deficiency during pregnancy, but currently we have limited data to inform policies. We evaluated whether providing additional pre-pregnancy weekly iron-folic acid (IFA) or multiple micronutrient (MM) supplements compared to only folic acid (FA) improves iron status and anemia during pregnancy and early postpartum.
We conducted a double blind randomized controlled trial in which 5011 Vietnamese women were provided with weekly supplements containing either only 2800 μg FA (control group), IFA (60 mg Fe and 2800 μg FA) or MM (15 micronutrients with similar amounts of IFA). All women who became pregnant (n = 1813) in each of the 3 groups received daily IFA (60 mg Fe and 400 μg FA) through delivery. Hematological indicators were assessed at baseline (pre-pregnancy), during pregnancy, 3 months post-partum, and in cord blood. Adjusted generalized linear models were applied to examine the impact of preconception supplementation on anemia and iron stores, using both intention to treat and per protocol analyses (women consumed supplements ≥ 26 weeks before conception).
At baseline, 20% of women were anemic, but only 14% had low iron stores (ferritin <30 μg/L) and 3% had iron deficiency (ferritin <12 μg/L). The groups were balanced for baseline characteristics. Anemia prevalence increased during pregnancy and post-partum but was similar among intervention groups. In intention to treat analyses, prenatal ferritin was significantly higher among women receiving MM (geometric mean (μg/L) [95% CI]: 93.6 [89.3-98.2]) and IFA (91.9 [87.6-96.3]) compared to control (85.3 [81.5-89.2]). In per protocol analyses, women receiving MM or IFA had higher ferritin 3 months postpartum (MM 118.2 [109.3-127.8]), IFA 117.8 [108.7-127.7] vs control 101.5 [94.0-109.7]) and gave birth to infants with greater iron stores (MM 184.3 [176.1-192.9]), IFA 189.9 [181.6-198.3] vs control 175.1 [167.9-182.6]).
Preconception supplementation with MM or IFA resulted in modest increases in maternal and infant iron stores but did not impact anemia. Further research is needed to characterize the etiology of anemia in this population and identify effective interventions for reducing prenatal anemia.
ClinicalTrials.Gov NCT01665378.
Journal Article
The diagnostic accuracy of umbilical cord procalcitonin in predicting early-onset neonatal infection
by
Pham, Thi Ny
,
Truong, Quang Vinh
,
Thi, Diep Anh Truong
in
Antibiotics
,
Anticoagulants
,
Biology and Life Sciences
2025
To determine the threshold of umbilical cord blood procalcitonin for early-onset neonatal infection diagnosis.
This prospective study was conducted on 126 neonates in the neonatal care unit of Hue University of Medicine and Pharmacy Hospital, Vietnam, from June 01, 2023 to August 31, 2024. All neonates showed signs at birth or risk factors for early-onset infection (EOI) and were divided into two groups: EOI group and non-EOI group. Umbilical cord blood samples were collected for procalcitonin analysis immediately after birth.
The median procalcitonin (PCT) levels in umbilical cord blood were significantly higher in the EOI group (0.154 ng/ml [0.092-0.197]) compared to the non-EOI group (0.097 ng/ml [0.082-0.134]; p < 0.001). Receiver operating characteristic (ROC) curve determined the optimal threshold value of PCT of 0.142 ng/ml with an AUC 0.751 (95% CI: 0.661-0.841, p<0.001) in the total population. At this cut-off, the Se, Sp, PPV, and NPV were 68.2%, 76.8%, 61.2%, and 81.8%, respectively. The optimal cut-off value for preterm neonates was 0.122 ng/ml (AUC: 0.785, 95% CI: 0.658-0.911, p<0.001) corresponding a Se of 79.2%, Sp of 74.1%, PPV of 73.1%, and NPV of 80.0%. In term group, the optimal cut-off value was 0.150 ng/ml (AUC: 0.726, 95% CI: 0.583-0.860, p<0.01), with a Se of 60.0%, Sp of 80.4%, PPV of 52.2%, and NPV of 84.9%.
Umbilical cord blood PCT concentration were elevated in neonates with EOI. PCT could be a valuable marker for the early diagnosis of EOI.
Journal Article
A Randomized, Double-Blind Placebo Controlled Trial of Balapiravir, a Polymerase Inhibitor, in Adult Dengue Patients
by
Nguyen, Quyen Than Ha
,
Hoang, Long Truong
,
Javanbakht, Hassan
in
Administration, Oral
,
Adult
,
Antigens, Viral - blood
2013
Background. Dengue is the most common arboviral infection of humans. There are currently no specific treatments for dengue. Balapiravir is a prodrug of a nucleoside analogue (called R1479) and an inhibitor of hepatitis C virus replication in vivo. Methods. We conducted in vitro experiments to determine the potency of balapiravir against dengue viruses and then an exploratory, dose-escalating, randomized placebo-controlled trial in adult male patients with dengue with <48 hours of fever. Results. The clinical and laboratory adverse event profile in patients receiving balapiravir at doses of 1500 mg (n = 10) or 3000 mg (n = 22) orally for 5 days was similar to that of patients receiving placebo (n = 32), indicating balapiravir was well tolerated. However, twice daily assessment of viremia and daily assessment of NS1 antigenemia indicated balapiravir did not measurably alter the kinetics of these virological markers, nor did it reduce the fever clearance time. The kinetics of plasma cytokine concentrations and the whole blood transcriptional profile were also not attenuated by balapiravir treatment. Conclusions. Although this trial, the first of its kind in dengue, does not support balapiravir as a candidate drug, it does establish a framework for antiviral treatment trials in dengue and provides the field with a clinically evaluated benchmark molecule. Clinical Trials Registration. NCT01096576.
Journal Article
Microbiological profile and risk factors for in-hospital mortality of infective endocarditis in tertiary care hospitals of south Vietnam
2017
We aimed to evaluate the microbiological characteristics and risk factors for mortality of infective endocarditis in two tertiary hospitals in Ho Chi Minh City, south Vietnam.
A retrospective study of 189 patients (120 men, 69 women; mean age 38 ± 18 years) with the diagnosis of probable or definite infective endocarditis (IE) according to the modified Duke Criteria admitted to The Heart Institute or Tam Duc Hospital between January 2005 and December 2014.
IE was related to a native valve in 165 patients (87.3%), and prosthetic valve in 24 (12.7%). Of the 189 patients in our series, the culture positive rate was 70.4%. The most common isolated pathogens were Streptococci (75.2%), Staphylococci (9.8%) followed by gram negative organism (4.5%). The sensitivity rate of Streptococci to ampicillin, ceftriaxone or vancomycin was 100%. The rate of methicillin resistant Staphylococcus aureus was 40%. There was a decrease in penicillin sensitivity for Streptococci over three eras: 2005-2007 (100%), 2008-2010 (94%) and 2010-2014 (84%). The in-hospital mortality rate was 6.9%. Logistic regression analysis found prosthetic valve and NYHA grade 3 or 4 heart failure and vegetation size of more than 15 mm as strong predictors of in-hospital mortality.
Streptococcal species were the major pathogen of IE in the recent years with low rates of antimicrobial resistance. Prosthetic valve involvement, moderate or severe heart failure and vegetation size of more than 15 mm were independent predictors for in-hospital mortality in IE.
Journal Article
Extreme Temperatures Reduce Copepod Performance and Change the Relative Abundance of Internal Microbiota
2024
Copepods are one of the most abundant invertebrate groups in the seas and oceans and are a significant food source for marine animals. Copepods are also particularly sensitive to elevated temperatures. However, it is relatively unknown how the internal microbiome influences copepod susceptibility to warming. We addressed this fundamental knowledge gap by assessing key life history traits (survival, development, and reproduction) and changes in the internal microbiome in the tropical calanoid copepod Acartia sp. in response to warming (26°C, 30°C, and 34°C). Copepod microbiomes were analyzed using high throughput DNA sequencing of V1–V9 of 16S rRNA hypervariable regions. Copepod performance was better at 30°C than at 26°C, as indicated by faster development, a higher growth rate, and fecundity. However, these parameters strongly decreased at 34°C. We recorded 1,262,987 amplicon sequence reads, corresponding to 392 total operational taxonomic units (OTUs) at 97% similarity. Warming did not affect OTU numbers and the biodiversity indices, but it substantially changed the relative abundance of three major phyla: Proteobacteria, Actinobacteria, and Bacteroidota. The thermophilic and opportunistic Proteobacteria and Bacteroidota increased under extreme temperatures (34°C) while Actinobacteria abundance was strongly reduced. Changes in the relative abundance of these bacteria might be related to reduced copepod growth, survival, and reproduction under extreme temperatures. Profiling the functional role of all internal bacterial groups in response to the temperature change will fundamentally advance our mechanistic understanding of the performance of tropical copepods and, more generally, marine invertebrates to a warming climate. Marine heatwaves (MHWs) emerge as a severe stressor in marine ecosystems, yet it is relatively unknown the role of the internal microbiome in shaping copepod susceptibility to MHWs. Our study showed that Acartia copepods decreased survival, growth, and reproduction at 34°C, a typical MHW temperature. The thermophilic and opportunistic Proteobacteria and Bacteroidota increased under extreme temperatures while Actinobacteria abundance was strongly reduced; all might be related to reduced copepod growth, survival, and reproduction.
Journal Article