MyMedR

Displaying publications 21 - 25 of 25 in total

Abstract:

Sort:

Genetic diversity of Chinese rabies viruses: evidence for the presence of two distinct clades in China

Zhang YZ, Xiong CL, Lin XD, Zhou DJ, Jiang RJ, Xiao QY, et al.

Infect Genet Evol, 2009 Jan;9(1):87-96.
PMID: 19041424 DOI: 10.1016/j.meegid.2008.10.014

There have been three major rabies epidemics in China since the 1950s. To gain more insights into the molecular epidemiology of rabies viruses (RVs) for the third (the current) epidemic, we isolated RV from dogs and humans in major endemic areas, and characterized these isolates genetically by sequencing the entire glycoprotein (G) gene and the G-L non-coding region. These sequences were also compared phylogenetically with RVs isolated in China during previous epidemics and those around the world. Comparison of the entire G genes among the Chinese isolates revealed up to 21.8% divergence at the nucleotide level and 17.8% at the amino acid level. The available Chinese isolates could be divided into two distinct clades, each of which could be further divided into six lineages. Viruses in clade I include most of the Chinese viruses as well as viruses from southeast Asian countries including Indonesia, Malaysia, the Philippines, Thailand, and Vietnam. The viruses in the other clade were found infrequently in China, but are closely related to viruses distributed worldwide among terrestrial animals. Interestingly, most of the viruses isolated during the past 10 years belong to lineage A viruses within clade I whereas most of the viruses isolated before 1996 belong to other lineages within clades I and II. Our results indicated that lineages A viruses have been predominant during the past 10 years and thus are largely responsible for the third and the current epidemic in China. Our results also suggested that the Chinese RV isolates in clade I share a common recent ancestor with those circulating in southeast Asia.
Fulltext The Saffold Virus-Penang 2B and 3C Proteins, but not the L Protein, Induce Apoptosis in HEp-2 and Vero Cells

Xu Y, Victorio CBL, Meng T, Jia Q, Tan YJ, Chua KB

Virol Sin, 2019 Jun;34(3):262-269.
PMID: 31016480 DOI: 10.1007/s12250-019-00116-1

Our previous work has shown that Saffold virus (SAFV) induced several rodent and primate cell lines to undergo apoptosis (Xu et al. in Emerg Microb Infect 3:1-8, 2014), but the essential viral proteins of SAFV involved in apoptotic activity lack study. In this study, we individually transfected the viral proteins of SAFV into HEp-2 and Vero cells to assess their ability to induce apoptosis, and found that the 2B and 3C proteins are proapoptotic. Further investigation indicated the transmembrane domain of the 2B protein is essential for the apoptotic activity and tetramer formation of the 2B protein. Our research provides clues for the possible mechanisms of apoptosis induced by SAFV in different cell lines. It also opens up new directions to study viral proteins (the 2B, 3C protein), and sets the stage for future exploration of any possible link between SAFV, inclusive of its related uncultivable genotypes, and multiple sclerosis.
Fulltext Comparative Transcriptomic and Molecular Pathway Analyses of HL-CZ Human Pro-Monocytic Cells Expressing SARS-CoV-2 Spike S1, S2, NP, NSP15 and NSP16 Genes

Sharma A, Ong JW, Loke MF, Chua EG, Lee JJ, Choi HW, et al.

Microorganisms, 2021 May 31;9(6).
PMID: 34073047 DOI: 10.3390/microorganisms9061193

The ongoing COVID-19 pandemic is a clear and present threat to global public health. Research into how the causative SARS-CoV-2 virus together with its individual constituent genes and proteins interact with target host cells can facilitate the development of improved strategies to manage the acute and long-term complications of COVID-19. In this study, to better understand the biological roles of critical SARS-CoV-2 proteins, we determined and compared the host transcriptomic responses of the HL-CZ human pro-monocytic cell line upon transfection with key viral genes encoding the spike S1 subunit, S2 subunit, nucleocapsid protein (NP), NSP15 (endoribonuclease), and NSP16 (2'-O-ribose-methyltransferase). RNA sequencing followed by gene set enrichment analysis and other bioinformatics tools revealed that host genes associated with topologically incorrect protein, virus receptor activity, heat shock protein binding, endoplasmic reticulum stress, antigen processing and presentation were up-regulated in the presence of viral spike S1 expression. With spike S2 expression, pro-monocytic genes associated with the interferon-gamma-mediated signaling pathway, regulation of phosphatidylinositol 3-kinase activity, adipocytokine signaling pathway, and insulin signaling pathway were down-regulated, whereas those associated with cytokine-mediated signaling were up-regulated. The expression of NSP15 induced the up-regulation of genes associated with neutrophil degranulation, neutrophil-mediated immunity, oxidative phosphorylation, prion disease, and pathways of neurodegeneration. The expression of NSP16 resulted in the down-regulation of genes associated with S-adenosylmethionine-dependent methyltransferase activity. The expression of NP down-regulated genes associated with positive regulation of neurogenesis, nervous system development, and heart development. Taken together, the complex transcriptomic alterations arising from these viral-host gene interactions offer useful insights into host genes and their pathways that potentially contribute to SARS-CoV-2 pathogenesis.
Detection rate of colonic polyp among patients who had undergone colonoscopy at gastroenterology unit of Serdang Hospital, Malaysia

Tan YJ, Wendy T, Chieng JY

Med J Malaysia, 2019 02;74(1):20-24.
PMID: 30846657

OBJECTIVE: The aim of this study was to evaluate the demography, and to determine the detection rate of polyps, and detection rate of adenoma at a Malaysian tertiary hospital.
METHODS: This is a retrospective study of all the patients who had undergone colonoscopy at Gastroenterology endoscopy unit, Serdang Hospital from 1st January 2010 to 31st December 2016. Patients who had a history of colorectal cancer, polyp or inflammatory bowel disease were excluded. Data collected which included patients' demography, indication for colonoscopy, colonoscopy finding, and histopathology results. Data was analysed with SPSS version 16.
RESULTS: Among the 559 patients who had fulfilled the inclusion criteria (68 males, 44 females), 112 patients were found to have at least one polyp giving the polyp detection rate (PDR) of 20% and 168 polypectomies were performed. The PDR among male patients was higher than that of females (22.5% vs 17.1%, p<0.05). The detection rate of polyp was nearly equal in Malays, Chinese, Indians, and Others. The polyps were more common in those of age 40 years old and above (p<0.05), with the mean age of 63.0±1.5 years. The commonest morphology of polyp in our patients was sessile (58%) and majority was medium size (5-9mm). Otherwise, the polyps were commonly found in the distal colon those that in proximal colon (55.3% vs 38.7%, p<0.05). The adenoma detection rate (ADR) was 19.1% (107/559).
CONCLUSION: The detection rate of colonic polyp from colonoscopy is 20% in our centre.
Fulltext Epidemiology and Factors Affecting Functional Outcome of Distal Radial Fracture in an Urban Tertiary Medical Centre in Malaysia

Chao WQ, Azman MZ, Rosdi SA, Tuan-Mustafa T, Tan YJ, Abdullah S, et al.

Malays Orthop J, 2021 Nov;15(3):84-90.
PMID: 34966500 DOI: 10.5704/MOJ.2111.013

Introduction: Distal radial fracture is a commonly encountered fracture. This study aims to study the epidemiology of distal radial fracture and factors affecting the patients' functional outcome one to two years after the injury.
Materials and methods: This is a retrospective cohort study. The records of patients, fulfilling the radiographical diagnosis of distal radial fracture, and aged 18 and above, who presented to our Emergency Department from 1st January 2018 to 31st December 2018 were retrieved. According to AO classification, we grouped our patients into A (extra-articular), B (partial articular) and C (complete articular). Patients with congenital abnormalities were excluded. Epidemiological data and relevant medical history were obtained and tabulated. A Malaysian language translation of Disability of the Arm, Shoulder and Hand (DASH) questionnaire was used to assess the functional outcome.
Results: Out of 168 patients' data retrieved, only 110 patients' data were found complete for purposes of this study. The mean DASH score was 13.7 ± 7.87 approximately one to two years post-injury regardless of treatment method. Increasing age was associated with higher DASH score with r=0.407(p<0.001). Several variables had significantly better functional outcome: male gender (p=0.01), Type A fracture configuration (p=0.007) and non-operational treatment (p=0.03). There was no significant difference between treatment modalities in Type A fracture (p=0.094), but Type B (p=0.043) and Type C (p=0.007) had better outcome without surgery. There was no significant difference between different ethnic groups, open or closed fracture and mechanism of injury.
Conclusion: Better functional outcome after sustaining distal radial fracture was associated with young age, male gender, type A fracture and treated non-operatively. Interestingly, more complex fracture pattern had better functionality were observed without surgery.