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Fulltext Nipah encephalitis - an update

Sherrini BA, Chong TT

Med J Malaysia, 2014 Aug;69 Suppl A:103-11.
PMID: 25417957

Between September 1998 to May 1999, Malaysia and Singapore were hit by an outbreak of fatal encephalitis caused by a novel virus from the paramyxovirus family. This virus was subsequently named as Nipah virus, after the Sungei Nipah village in Negeri Sembilan, where the virus was first isolated. The means of transmission was thought to be from bats-topigs and subsequently pigs-to-human. Since 2001, almost yearly outbreak of Nipah encephalitis has been reported from Bangladesh and West Bengal, India. These outbreaks were characterized by direct bats-to-human, and human-to-human spread of infection. Nipah virus shares many similar characteristics to Hendra virus, first isolated in an outbreak of respiratory illness involving horses in Australia in 1994. Because of their homology, a new genus called Henipavirus (Hendra + Nipah) was introduced. Henipavirus infection is a human disease manifesting most often as acute encephalitis (which may be relapsing or late-onset) or pneumonia, with a high mortality rate. Pteropus bats act as reservoir for the virus, which subsequently lead to human spread. Transmission may be from consumption of food contaminated by bats secretion, contact with infected animals, or human-to-human spread. With wide geographical distribution of Pteropus bats, Henipavirus infection has become an important emerging human infection with worldwide implication.
Molecular dynamics simulation of monoalkyl glycoside micelles in aqueous solution: influence of carbohydrate headgroup stereochemistry

Chong TT, Hashim R, Bryce RA

J Phys Chem B, 2006 Mar 16;110(10):4978-84.
PMID: 16526739

Comparative molecular dynamics simulations of n-octyl-beta-D-galactopyranoside (beta-C8Gal) and n-octyl-beta-D-glucopyranoside (beta-C8Glc) micelles in aqueous solution have been performed to explore the influence of carbohydrate stereochemistry on glycolipid properties at the atomic level. In particular, we explore the hypothesis that differences in T(m) and T(c) for beta-C8Gal and beta-C8Glc in lyotropic systems arise from a more extensive hydrogen bonding network between beta-C8Gal headgroups relative to beta-C8Glc, due to the axial 4-OH group in beta-C8Gal. Good agreement of the 13 ns micelle-water simulations with available experimental information is found. The micelles exhibit a similar shape, size, and degree of exposed alkyl chain surface area. We find net inter- and intra-headgroup hydrogen bonding is also similar for beta-C8Gal and beta-C8Glc, although n-octyl-beta-D-galactopyranoside micelles do exhibit a slightly greater degree of inter- and intra-headgroup hydrogen bonding. However, the main distinction in the calculated microscopic behavior of beta-C8Glc and beta-C8Gal micelles lies in solvent interactions, where beta-d-glucosyl headgroups are considerably more solvated (mainly at the equatorial O4 oxygen). These results agree with preceding theoretical and experimental studies of monosaccharides in aqueous solution. A number of long water residence times are found for solvent surrounding both micelle types, the largest of which are associated with surface protrusions involving headgroup clusters. Our simulations, therefore, predict differences in hydrogen bonding for the two headgroup stereochemistries, including a small difference in inter-headgroup interactions, which may contribute to the higher T(m) and T(c) values of beta-C8Gal surfactants relative to beta-C8Glc in lyotropic systems.
Carnosine exhibits significant antiviral activity against Dengue and Zika virus

Rothan HA, Abdulrahman AY, Khazali AS, Nor Rashid N, Chong TT, Yusof R

J. Pept. Sci., 2019 Aug;25(8):e3196.
PMID: 31290226 DOI: 10.1002/psc.3196

Dengue virus (DENV) and Zika virus (ZIKV) are flaviviruses transmitted to humans by their common vector, Aedes mosquitoes. DENV infection represents one of the most widely spread mosquito-borne diseases whereas ZIKV infection occasionally re-emerged in the past causing outbreaks. Although there have been considerable advances in understanding the pathophysiology of these viruses, no effective vaccines or antiviral drugs are currently available. In this study, we evaluated the antiviral activity of carnosine, an endogenous dipeptide (β-alanyl-l-histidine), against DENV serotype 2 (DENV2) and ZIKV infection in human liver cells (Huh7). Computational studies were performed to predict the potential interactions between carnosine and viral proteins. Biochemical and cell-based assays were performed to validate the computational results. Mode-of-inhibition, plaque reduction, and immunostaining assays were performed to determine the antiviral activity of carnosine. Exogenous carnosine showed minimal cytotoxicity in Huh7 cells and rescued the viability of infected cells with EC50 values of 52.3 and 59.5 μM for DENV2 and ZIKV infection, respectively. Based on the mode-of-inhibition assays, carnosine inhibited DENV2 mainly by inhibiting viral genome replication and interfering with virus entry. Carnosine antiviral activity was verified with immunostaining assay where carnosine treatment diminished viral fluorescence signal. In conclusion, carnosine exhibited significant inhibitory effects against DENV2 and ZIKV replication in human liver cells and could be utilized as a lead peptide for the development of effective and safe antiviral agents against DENV and ZIKV.
Utility of paclitaxel-coated balloons for the treatment of infrainguinal disease in the Asian population - 24-month outcome data from the BIOLUX P-III Global Registry 24-month Asian outcomes of BIOLUX P-III

Linn YL, Wang JC, Pua U, Yahaya SA, Choke ET, Chong TT, et al.

Vascular, 2023 Aug;31(4):767-776.
PMID: 35410542 DOI: 10.1177/17085381221081969

BACKGROUND: Results from the BIOLUX P-III registry have demonstrated favourable outcomes of Passeo-18 Lux™ (Biotronik®, Buelach, Switzerland) drug-coated balloon in treating obstructive infrainguinal peripheral artery disease, but it has not been established if Asians would benefit to the same extent as non-Asians.
METHODS: A subgroup analysis was performed on the 24-month data comparing the Asian cohort (AC) to non-Asian cohort (NAC).
RESULTS: AC included 49 patients with 77 lesions. AC was significantly younger (65.6 vs 70.3 years, p < 0.05), had more diabetes (87.8% vs 45.3%, p < 0.05), and was more likely to present with CLTI (73.5% vs 35.3%, p < 0.001) compared to NAC. They had significantly longer mean target lesions (115 vs 86.9 mm, p = 0.006), and received significantly higher paclitaxel doses (10.7 vs 7.2 mg, p = 0.0005). Device, technical and procedural successes were 125/125(100%), 95/97(97.5%) and 45/49(91.8%), respectively. There was no significant difference in target lesion revascularization rates between groups (10.5% vs 12%, p = 0.91). However, the AC had more major adverse events (30.2% vs 16.1%, p = 0.001), amputations (26.3% vs 6.2%, p < 0.05) and mortality (37.9% vs 10.6%, p < 0.05) at 24 months.
CONCLUSION: Passeo-18 Lux™ use was efficacious in Asians, but was associated with higher adverse events, amputations and mortality rates, likely attributable to poorer patient comorbidities and more extensive PAD.
Efficacy and safety of low dose, weight-based subcutaneous enoxaparin protocol in recurrent arteriovenous access thrombosis

Gan CC, Tan RY, Cheong MA, Pang SC, Tng RKA, Tan CW, et al.

J Vasc Access, 2023 Sep 19.
PMID: 37726986 DOI: 10.1177/11297298231194102

BACKGROUND: This study aims to evaluate the safety and efficacy of a short-term, low dose, weight-based subcutaneous enoxaparin protocol (SEP) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis.
METHODS: Prospective follow-up of 25 patients who presented to a tertiary institution with recurrent AV access thrombosis and treated with anticoagulation according to SEP following successful thrombectomy. Patency and safety outcomes of SEP were studied.
RESULTS: The participants were 66.4 ± 10.2 years old and predominantly male (60%) and of Chinese ethnicity (72%). The AV accesses had a median age of 1.4 (0.6, 5.6) years with 60% being non-autogenous arteriovenous access while 40% were autogenous arteriovenous access. Thrombolytic agents (urokinase (72%) or alteplase (28%)) were used in all procedures while adjunct thrombectomy device was used in only four procedures. The mean dose of enoxaparin was 36.0 ± 8.2 mg or 0.64 ± 0.1 mg/kg/day for a mean duration 30.0 days (Interquartile range: 27.5, 31.0). One patient developed minor bleeding episode. Kaplan-Meier analysis demonstrated that the mean thrombosis-free survival pre- versus post-SEP adoption was 27.3 (95% CI 17.9-36.7) versus 183.5 (95% CI 100.1-266.9) days (p
Study protocol for a Prospective, Randomized controlled trial of stEnt graft and Drug-coated bAlloon Treatment for cephalic arch stenOsis in dysfunctional arteRio-venous fistulas (PREDATOR)

Gan CC, Tan RY, Delaney CL, Puckridge PJ, Pang SC, Tng ARK, et al.

J Vasc Access, 2022 Nov 03.
PMID: 36330556 DOI: 10.1177/11297298221130897

BACKGROUND: Treatment of cephalic arch stenosis (CAS) is associated with high risk of failure and complications. Although stent-graft (SG) placement has improved patency rates, stent edge restenosis has been raised as a potential limiting factor for SG usage in CAS. This study aims to evaluate the safety and efficacy of combining stent graft placement with paclitaxel-coated balloon (PCB) angioplasty versus PCB alone in the treatment of CAS.
METHODS: This is an investigator-initiated, prospective, international, multicenter, open-label, randomized control clinical trial that plans to recruit 80 patients, who require fistuloplasty from dysfunctional arteriovenous fistula (AVF) from CAS. Eligible participants are randomly assigned to receive treatment with SG and PCB or PCB alone in a 1:1 ratio post-angioplasty (n = 40 in each arm). Randomization is stratified by de novo or recurrent lesion, and the participants are followed up for 1 year. The primary endpoints of the study are target lesion primary patency (TLPP) and access circuit primary patency (ACPP) rates at 6-months. The secondary endpoints are TLPP and ACPP at 3- and 12-month; target lesion and access circuit assisted primary and secondary patency rates at 3, 6, and 12-months and the total number of interventions; complication rate; and cost-effectiveness.
DISCUSSION: This study will evaluate the clinical efficacy and safety of combination SG and PCB implantation compared to PCB alone in the treatment of CAS for hemodialysis patients.
Fulltext 2020 Asian Pacific Society of Cardiology Consensus Recommendations on Antithrombotic Management for High-risk Chronic Coronary Syndrome

Tan JWC, Chew DP, Brieger D, Eikelboom J, Montalescot G, Ako J, et al.

Eur Cardiol, 2021 Feb;16:e26.
PMID: 34249148 DOI: 10.15420/ecr.2020.45

The unique characteristics of patients with chronic coronary syndrome (CCS) in the Asia-Pacific region, heterogeneous approaches because of differences in accesses and resources and low number of patients from the Asia-Pacific region in pivotal studies, mean that international guidelines cannot be routinely applied to these populations. The Asian Pacific Society of Cardiology developed these consensus recommendations to summarise current evidence on the management of CCS and provide recommendations to assist clinicians treat patients from the region. The consensus recommendations were developed by an expert consensus panel who reviewed and appraised the available literature, with focus on data from patients in Asia-Pacific. Consensus statements were developed then put to an online vote. The resulting recommendations provide guidance on the assessment and management of bleeding and ischaemic risks in Asian CCS patients. Furthermore, the selection of long-term antithrombotic therapy is discussed, including the role of single antiplatelet therapy, dual antiplatelet therapy and dual pathway inhibition therapy.