Displaying publications 1 - 20 of 36 in total

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  1. Farhadi A, Behzad-Behbahani A, Geramizadeh B, Sekawi Z, Rahsaz M, Sharifzadeh S
    J. Med. Virol., 2014 Jul;86(7):1134-44.
    PMID: 24700118 DOI: 10.1002/jmv.23945
    Limited data exist regarding whether a high-risk human papillomavirus (HR-HPV) infection increases the risk of developing renal cell carcinoma. The aim of this study was to investigate whether HPV infection has a role in the pathogenesis or development of a certain histological subtype of renal cell carcinoma. Formalin-fixed paraffin-embedded (FFPE) specimens of 122 patients with histopathologically proven renal cell carcinoma and their respective peritumoral tissues were examined. The presence of HPV-DNA was determined by a combination of MY/GP+ consensus primers and HPV-16/18 type specific nested PCRs followed by direct sequencing. Catalyzed signal-amplified colorimetric in situ hybridization (CSAC-ISH) technique was applied to determine the physical status of viral genome. The expression of p16INK4a and HPV L1 capsid proteins was evaluated using immunohistochemistry. HPV genome was detected in 37 (30.3%) tumor specimens and their four (4.1%) corresponding peritumoral tissues. HPV-18 was the most common viral type identified followed by HPV-16 and 58. Immunoexpression of p16INK4a was detected in 24 (20.3%) cases. Data analysis showed a significant correlation between p16INK4a expression and the presence of HR-HPV DNA (P 
  2. Ong LY, Razak SN, Lee YM, Sri La Sri Ponnampalavanar S, Syed Omar SF, Azwa RI, et al.
    J. Med. Virol., 2014 Jan;86(1):38-44.
    PMID: 24127302 DOI: 10.1002/jmv.23772
    Expansion of antiretroviral treatment programs have led to the growing concern for the development of antiretroviral drug resistance. The aims were to assess the prevalence of drug resistant HIV-1 variants and to identify circulating subtypes among HAART-naïve patients. Plasma specimens from N = 100 HIV+ HAART-naïve adult were collected between March 2008 and August 2010 and viral RNA were extracted for nested PCR and sequenced. PR-RT sequences were protein aligned and checked for transmitted drug resistance mutations. Phylogenetic reconstruction and recombination analysis were performed to determine the genotypes. Based on the WHO consensus guidelines, none of the recruited patients had any transmitted drug resistance mutations. When analyzed against the Stanford guidelines, 35% of patients had at least one reported mutation that may reduce drug susceptibility to PI (24%), NRTI (5%), and NNRTI (14%). The commonly detected mutation that may affect current first line therapy was V179D (3%), which may lead to reduced susceptibility to NNRTI. The predominant circulating HIV-1 genotypes were CRF01_AE (51%) and CRF33_01B (17%). The prevalence of unique recombinant forms (URF) was 7%; five distinct recombinant structures involving CRF01_AE and subtype B' were observed, among them a cluster of three isolates that could form a novel circulating recombinant form (CRF) candidate. Transmitted drug resistance prevalence among HAART-naïve patients was low in this cohort of patients in Kuala Lumpur despite introduction of HAART 5 years ago. Owing to the high genetic diversity, continued molecular surveillance can identify the persistent emergence of HIV-1 URF and novel CRF with significant epidemiological impact.
  3. Kalaycioglu AT, Baykal A, Guldemir D, Bakkaloglu Z, Korukluoglu G, Coskun A, et al.
    J. Med. Virol., 2013 Dec;85(12):2128-35.
    PMID: 23959542 DOI: 10.1002/jmv.23714
    Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n = 26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus.
  4. Sam IC, Shaw R, Chan YF, Hooi PS, Hurt AC, Barr IG
    J. Med. Virol., 2013 Aug;85(8):1420-5.
    PMID: 23765779 DOI: 10.1002/jmv.23622
    Relatively little is known about the burden of influenza in tropical countries. The seroprevalence of pandemic influenza A (H1N1) 2009, seasonal H1N1 and H3N2 was determined in Kuala Lumpur, Malaysia. Pre- and post-pandemic residual laboratory sera were tested by hemagglutination-inhibition. The seroprevalence of A(H1N1)pdm09 increased from 3.7% pre-pandemic to 21.9% post-pandemic, giving an overall cumulative incidence of 18.1% (95% CI, 13.8-22.5%), mainly due to increases in those <5, 5-17, and 18-29 years old. In contrast with findings from USA, Europe, and Australia, pre-existing seroprevalence to A(H1N1)pdm09 was low at 5.6% in the elderly age group of >55 years. A(H1N1)pdm09 affected almost a third of those <30 years in Kuala Lumpur. Pre-pandemic seroprevalence was 14.7% for seasonal H1N1 and 21.0% for H3N2, and these rates did not change significantly after the pandemic. Seasonal and pandemic influenza cause a considerable burden in tropical Malaysia, particularly in children and young adults.
  5. Cheng WY, Wang HC, Liu MT, Wu HS
    J. Med. Virol., 2013 Apr;85(4):745-53.
    PMID: 23417619 DOI: 10.1002/jmv.23451
    Rubella has been listed as a mandatory notifiable disease in Taiwan since 1988. Because of high coverage rates with an effective vaccine, rubella cases have decreased dramatically in Taiwan since 1994. However, rubella outbreaks still occur due to imported transmission. Five large clusters were detected in Taiwan from 2007 to 2011. In 2007, one cluster was caused by rubella genotype 1E viruses that were imported from Vietnam, whereas another cluster was caused by genotype 2B viruses and was untraceable. In 2008, two clusters were caused by different lineages of genotype 1E viruses that were imported from Malaysia. In 2009, a cluster that was caused by genotype 2B viruses was associated with imported cases from Vietnam. The rubella viruses from 124 confirmed cases from 2005 to 2011 were characterized, and the data revealed that these viruses were distributed in the following four genotypes: 1E (n = 56), 1h (n = 1), 1j (n = 4), and 2B (n = 63). Of these viruses, 93 (75%) were associated with imported cases, and 43 of 56 genotype 1E viruses were associated with imported cases from China, Vietnam, Malaysia, and Indonesia. One genotype 1h virus was imported from Belarus, and three of four genotype 1j viruses were imported from the Philippines. Of 63 rubella genotype 2B viruses, 46 were imported from Vietnam, Thailand, Malaysia, China, Germany, and South Africa. Molecular surveillance allows for the differentiation of circulating rubella viruses and can be used to investigate transmission pathways, which are important to identify the interruption of endemic virus transmission.
  6. Akhtar A, Khan AH, Sulaiman SA, Soo CT, Khan K
    J. Med. Virol., 2016 Mar;88(3):455-60.
    PMID: 26255632 DOI: 10.1002/jmv.24347
    According to WHO, Malaysia has been classified as a concentrated epidemic country due to progression of HIV infection in the population of injecting drug users. The main objectives of current study are to determine the prevalence of HBV among HIV-positive individuals in a tertiary care hospital of Malaysia and to assess the predictors involved in the outcomes of HIV-HBV co-infected patients. A retrospective, cross-sectional study is conducted at Hospital Palau Pinang, Malaysia. The collection of socio-demographic data as well as clinical data is done with the help of data collection form. Data were analyzed after putting the collected values of required data by using statistical software SPSS version 20.0 and P > 0.05 is considered as significant. Results show that the overall prevalence of HBV was 86 (13%) including 495 (74.5%) males and 169 (25.5%) females among a total of 664 HIV-infected patients. It was observed that there is a high prevalence of HIV-HBV co-infection in males 76 (11.4%) as compared to females 10 (1.5%) (P = 0.002). The median age of the study population was 39 years. The statistical significant risk factors involved in the outcomes of HIV-HBV co-infected patients were observed in the variables of gender, age groups, and injecting drug users. The findings of the present study shows that the prevalence of HBV infection among HIV-positive patients was 13% and the risk factors involved in the outcomes of HIV-HBV co-infected patients were gender, age, and intravenous drug users.
  7. Lo Presti A, Cella E, Giovanetti M, Lai A, Angeletti S, Zehender G, et al.
    J. Med. Virol., 2016 Mar;88(3):380-8.
    PMID: 26252523 DOI: 10.1002/jmv.24345
    Nipah virus, member of the Paramyxoviridae family, is classified as a Biosafety Level-4 agent and category C priority pathogen. Nipah virus disease is endemic in south Asia and outbreaks have been reported in Malaysia, Singapore, India, and Bangladesh. Bats of the genus Pteropus appear to be the natural reservoir of this virus. The aim of this study was to investigate the genetic diversity of Nipah virus, to estimate the date of origin and the spread of the infection. The mean value of Nipah virus N gene evolutionary rate, was 6.5 × 10(-4) substitution/site/year (95% HPD: 2.3 × 10(-4)-1.18 × 10(-3)). The time-scaled phylogenetic analysis showed that the root of the tree originated in 1947 (95% HPD: 1888-1988) as the virus entered in south eastern Asiatic regions. The segregation of sequences in two main clades (I and II) indicating that Nipah virus had two different introductions: one in 1995 (95% HPD: 1985-2002) which correspond to clade I, and the other in 1985 (95% HPD: 1971-1996) which correspond to clade II. The phylogeographic reconstruction indicated that the epidemic followed two different routes spreading to the other locations. The trade of infected pigs may have played a role in the spread of the virus. Bats of the Pteropus genus, that are able to travel to long distances, may have contributed to the spread of the infection. Negatively selected sites, statistically supported, could reflect the stability of the viral N protein.
  8. Syed IA, Sulaiman SA, Hassali MA, Syed SH, Shan LH, Lee CK
    J. Med. Virol., 2016 May;88(5):790-7.
    PMID: 26399724 DOI: 10.1002/jmv.24389
    Suboptimal viral suppression and CD4 response to antiretroviral treatment (HAART) is known to cause poor outcomes with the increase cost of treatment. We aimed to assess factors associated with such control among HIV/AIDS patients in Malaysia. Four hundred and six HIV/AIDS patients, using Antiretroviral Therapy (ART) for at least the past three months, treated as outpatients at medication therapy adherence clinics (MTAC) were recruited. CD4 cell counts, viral load readings along with co-variants such as socio-demographic factors, adverse drug reactions, comorbidities, and medication record were obtained. Statistical Package for Social Sciences (SPSS(®) ) version 18 and STATA IC(®) version 12 were used for data analysis. CD4 counts were found highest among those within the age category 41-50 years (390.43 ± 272.28), female (402.64 ± 276.14), other ethnicities (400.20 ± 278.04), and participants with no formal education (414.87 ± 290.90). Patients experiencing adverse effects had a 2.28 (95%CI:1.25-4.18) fold greater risk of poor CD4 control, while patients with comorbidities had 2.46 (95%CI:1.02-5.91) fold greater risk of mild viral suppression. Adverse drug reactions, co-morbidities were found to be significantly associated with poor immunological and virological outcomes in HIV/AIDS patients. However, a comprehensive evaluation is needed to better understand other confounders.
    Study site: Medication therapy adherence clinic, Hospital Sungai Buloh, Selangor, Malaysia
  9. Cheng WY, Wang HC, Wu HS, Liu MT
    J. Med. Virol., 2016 May;88(5):746-53.
    PMID: 26400063 DOI: 10.1002/jmv.24392
    In Taiwan, although the coverage rate of two doses of measles-containing vaccine has been maintained at over 95% since 2001, measles outbreaks occurred in 2002, 2009, and 2011. The present study reports that 43 cases were confirmed by laboratory testing in Taiwan in 2012-2014 and that adults have emerged as one of groups susceptible to measles virus (MV) infection, who may have discrepant humoral immune reactions-indicated by the level of IgM and IgG antibodies compared to a naïve, susceptible measles case. Thirty-seven of 43 cases confirmed by RT-PCR were further characterized by genotyping. In Taiwan, genotype H1 was the major strain in circulation prior to 2010, while D9 was the most frequently detected MV genotype between 2010 and 2011. The genotyping data collected between 2012 and 2014 revealed that H1 rebounded in 2012 after an absence in 2011 and was imported from China and Vietnam. In 2014, genotype B3 first appeared in Taiwan following import from the Philippines and became the most frequently detected strain. Genotype D8, linked to importation from various countries, including India, Indonesia, Thailand, and Vietnam, showed sequence divergence. D9 was imported from Malaysia in 2014. The MV genotypes detected in Taiwan reflected the genotypes of circulating endemic measles strains in neighboring countries. A significant rise in the number of measles cases and in measles with genotypes imported from surrounding countries indicated that measles resurged in Asia in 2014. J. Med. Virol. 88:746-753, 2016. © 2015 Wiley Periodicals, Inc.
  10. Voon K, Tan YF, Leong PP, Teng CL, Gunnasekaran R, Ujang K, et al.
    J. Med. Virol., 2015 Dec;87(12):2149-53.
    PMID: 26106066 DOI: 10.1002/jmv.24304
    This study aims to assess the incidence rate of Pteropine orthreovirus (PRV) infection in patients with acute upper respiratory tract infection (URTI) in a suburban setting in Malaysia, where bats are known to be present in the neighborhood. Using molecular detection of PRVs directly from oropharyngeal swabs, our study demonstrates that PRV is among one of the common causative agents of acute URTI with cough and sore throat as the commonest presenting clinical features. Phylogenetic analysis on partial major outer and inner capsid proteins shows that these PRV strains are closely related to Melaka and Kampar viruses previously isolated in Malaysia. Further study is required to determine the public health significance of PRV infection in Southeast Asia, especially in cases where co-infection with other pathogens may potentially lead to different clinical outcomes.
    Study site: Klinik Kesihatan Rembau, Negeri Sembilan, Malaysia
  11. Jiamsakul A, Chaiwarith R, Durier N, Sirivichayakul S, Kiertiburanakul S, Van Den Eede P, et al.
    J. Med. Virol., 2016 Feb;88(2):234-43.
    PMID: 26147742 DOI: 10.1002/jmv.24320
    HIV drug resistance assessments and interpretations can be obtained from genotyping (GT), virtual phenotyping (VP) and laboratory-based phenotyping (PT). We compared resistance calls obtained from GT and VP with those from PT (GT-PT and VP-PT) among CRF01_AE and subtype B HIV-1 infected patients. GT predictions were obtained from the Stanford HIV database. VP and PT were obtained from Janssen Diagnostics BVBA's vircoType(TM) HIV-1 and Antivirogram®, respectively. With PT assumed as the "gold standard," the area under the curve (AUC) and the Bland-Altman plot were used to assess the level of agreement in resistance interpretations. A total of 80 CRF01_AE samples from Asia and 100 subtype B from Janssen Diagnostics BVBA's database were analysed. CRF01_AE showed discordances ranging from 3 to 27 samples for GT-PT and 1 to 20 samples for VP-PT. The GT-PT and VP-PT AUCs were 0.76-0.97 and 0.81-0.99, respectively. Subtype B showed 3-61 discordances for GT-PT and 2-75 discordances for VP-PT. The AUCs ranged from 0.55 to 0.95 for GT-PT and 0.55 to 0.97 for VP-PT. Didanosine had the highest proportion of discordances and/or AUC in all comparisons. The patient with the largest didanosine FC difference in each subtype harboured Q151M mutation. Overall, GT and VP predictions for CRF01_AE performed significantly better than subtype B for three NRTIs. Although discrepancies exist, GT and VP resistance interpretations in HIV-1 CRF01_AE strains were highly robust in comparison with the gold-standard PT.
  12. Chook JB, Ngeow YF, Khang TF, Ng KP, Tiang YP, Mohamed R
    J. Med. Virol., 2013 Mar;85(3):419-24.
    PMID: 23297244 DOI: 10.1002/jmv.23500
    Infection with the hepatitis B virus (HBV) may lead to an acute or chronic infection. It is generally accepted that the clinical outcome of infection depends on the balance between host immunity and viral survival strategies. In order to persist, the virus needs to have a high rate of replication and some immune-escape capabilities. Hence, HBVs lacking these properties are likely to be eliminated more rapidly by the host, leading to a lower rate of chronicity. To test this hypothesis, 177 HBV genomes from acute non-fulminant cases and 1,149 from chronic cases were retrieved from GenBank for comparative analysis. Selection of candidate nucleotides associated with the disease state was done using random guess cut-off and the Bonferroni correction. Five significant nucleotides were detected using this filtering step. Their predictive values were assessed using the support vector machine classification with five-fold cross-validation. The average prediction accuracy was 61% ± 1%, with a sensitivity of 24% ± 1%, specificity of 98% ± 1%, positive predictive value of 92% ± 4% and negative predictive value of 56% ± 1%. BCP/X, enhancer I and surface/polymerase variants were found to be associated almost exclusively with acute hepatitis. These HBV variants are novel potential markers for non-progression to chronic hepatitis.
  13. Louisirirotchanakul S, Olinger CM, Arunkaewchaemsri P, Poovorawan Y, Kanoksinsombat C, Thongme C, et al.
    J. Med. Virol., 2012 Oct;84(10):1541-7.
    PMID: 22930500 DOI: 10.1002/jmv.23363
    Phylogenetic analysis was performed on hepatitis B virus (HBV) strains obtained from 86 hepatitis B surface antigen (HBsAg) positive donors from Thailand originating throughout the country. Based on the S gene, 87.5% of strains were of genotype C while 10.5% were of genotype B, with all genotype B strains obtained from patients originating from the central or the south Thailand. No genotype B strains were found in the north of Thailand. Surprisingly, one patient was infected with a genotype H strain while another patient was infected with a genotype G strain. Complete genome sequencing and recombination analysis identified the latter as being a genotype G and C2 recombinant with the breakpoint around nucleotide position 700. The origin of the genotype G fragment was not identifiable while the genotype C2 fragment most likely came from strains circulating in Laos or Malaysia. The performance of different HBsAg diagnostic kits and HBV nucleic acid amplification technology (NAT) was evaluated. The genotype H and G/C2 recombination did not interfere with HBV detection.
  14. Ch'ng WC, Stanbridge EJ, Ong KC, Wong KT, Yusoff K, Shafee N
    J. Med. Virol., 2011 Oct;83(10):1783-91.
    PMID: 21837796 DOI: 10.1002/jmv.22198
    Enterovirus 71 (EV71) infection may cause severe neurological complications, particularly in young children. Despite the risks, there are still no commercially available EV71 vaccines. Hence, a candidate vaccine construct, containing recombinant Newcastle disease virus capsids that display an EV71 VP1 fragment (NPt-VP1(1-100) ) protein, was evaluated in a mouse model of EV71 infection. Previously, it was shown that this protein construct provoked a strong immune response in vaccinated adult rabbits. That study, however, did not address the issue of its effectiveness against EV71 infection in young animals. In the present study, EV71 viral challenge in vaccinated newborn mice resulted in more than 40% increase in survival rate. Significantly, half of the surviving mice fully recovered from their paralysis. Histological analysis of all of the surviving mice revealed a complete clearance of EV71 viral antigens from their brains and spinal cords. In hind limb muscles, the amounts of the antigens detected correlated with the degrees of tissue damage and paralysis. Findings from this study provide evidence that immunization with the NPt-VP1(1-100) immunogen in a newborn mouse model confers partial protection against EV71 infection, and also highlights the importance of NPt-VP1(1-100) as a possible candidate vaccine for protection against EV71 infections.
  15. Chook JB, Ngeow YF, Yap SF, Tan TC, Mohamed R
    J. Med. Virol., 2011 Apr;83(4):594-601.
    PMID: 21328372 DOI: 10.1002/jmv.22016
    Hepatitis B virus (HBV) and high liver iron deposits have both been associated with the development of cirrhosis. Among HBV factors, genotype and mutations in the basal core promoter (BCP) and precore regions have been most frequently studied but the evidence for a positive association with cirrhosis has been inconsistent. In this study, sera from persons with chronic HBV infection with and without cirrhosis were used for whole HBV genome analysis and for the estimation of serum iron marker (serum iron or ferritin) levels. Single codon analysis showed that the precore wild-type, TGG (nt 1,895-1,897), gave the highest accuracy (77.5%) for the identification of cirrhosis compared to other codons. When TGG was analyzed together with the precore start codon wild-type, ATG (nt 1,814-1,816), the accuracy was improved to 80.0% (odds ratio=35.29; 95% confidence interval=3.87-321.93; Phi=0.629; P<0.001). When the serum iron marker was included for analysis, it was clear that a combination of a precore wild-type and high serum iron marker gave a better accuracy (90.0%) (odds ratio=107.67; 95% confidence interval=10.21-1,135.59; Phi=0.804; P<0.001) for the identification of cirrhosis than either biomarker alone. It appeared that a combined use of both these biomarkers might help to predict the development of cirrhosis in a person with chronic HBV infection, but longitudinal studies are required to test this hypothesis.
  16. Sivasamugham LA, Cardosa MJ, Tan WS, Yusoff K
    J. Med. Virol., 2006 Aug;78(8):1096-104.
    PMID: 16789020
    The complete VP1 protein of EV71 was truncated into six segments and fused to the C-terminal ends of full-length nucleocapsid protein (NPfl) and truncated NP (NPt; lacks 20% amino acid residues from its C-terminal end) of newcastle disease virus (NDV). Western blot analysis using anti-VP1 rabbit serum showed that the N-terminal region of the VP1 protein contains a major antigenic region. The recombinant proteins carrying the truncated VP1 protein, VP1(1-100), were expressed most efficiently in Escherichia coli as determined by Western blot analysis. Electron microscopic analysis of the purified recombinant protein, NPt-VP(1-100) revealed that it predominantly self-assembled into intact ring-like structures whereas NPfl-VP(1-100) recombinant proteins showed disrupted ring-like formations. Rabbits immunized with the purified NPt-VP(1-100) and NPfl-VP(1-100) exhibited a strong immune response against the complete VP1 protein. The antisera of these recombinant proteins also reacted positively with authentic enterovirus 71 and the closely related Coxsackievirus A16 when analyzed by an immunofluorescence assay suggesting their potential as immunological reagents for the detection of anti-enterovirus 71 antibodies in serum samples.
  17. Chang LY, Ali AR, Hassan SS, AbuBakar S
    J. Med. Virol., 2006 Aug;78(8):1105-12.
    PMID: 16789019
    Nipah virus infection of porcine stable kidney cells (PS), human neuronal cells (SK-N-MC), human lung fibroblasts cells (MRC-5), and human monocytes (THP-1) were examined. Rapid progression of cytopathic effects (CPE) and cell death were noted in PS cell cultures treated with Nipah virus, followed by MRC-5, SK-N-MC, and THP-1 cell cultures, in descending order of rapidity. Significant increase in the intracellular Nipah virus RNA occurred beginning at 24 hr PI in all the infected cells. Whereas, the extracellular release of Nipah virus RNA increased significantly beginning at 48 and 72 hr PI for the infected MRC-5 cells and PS cells, respectively. No significant release of extracellular Nipah virus RNA was detected from the Nipah virus-infected SK-N-MC and THP-1 cells. At its peak, approximately 6.6 log PFU/microl of extracellular Nipah virus RNA was released from the Nipah virus-infected PS cells, with at least a 100-fold less virus RNA was recorded in the Nipah virus-infected SK-N-MC and THP-1. Approximately 15.2% (+/-0.1%) of the released virus from the infected PS cell cultures was infectious in contrast to approximately 5.5% (+/-0.7%) from the infected SK-N-MC cells. The findings suggest that there are no differences in the capacity to support Nipah virus replication between pigs and humans in fully susceptible PS and MRC-5 cells. However, there are differences between these cells and human neuronal cells and monocytes in the ability to support Nipah virus replication and virus release.
  18. Eshaghi M, Tan WS, Yusoff K
    J. Med. Virol., 2005 Jan;75(1):147-52.
    PMID: 15543570
    A random peptide library of heptamers displayed on the surface of M13 bacteriophage was used to identify specific epitopes of antibodies in pooled sera of swine naturally infected by Nipah virus. The selected heptapeptides were aligned with protein sequences of Nipah virus and several putative epitopes were identified within the nucleocapsid protein. A total of 41 of 60 (68%) selected phage clones had inserts resembling a region with the sequence SNRTQGE, located at the C-terminal end (amino acids 503-509) of the nucleocapsid protein. The binding of antibodies in the swine and human antisera to the phage clone was inhibited by a synthetic peptide corresponding to this region. Epitopes identified by phage display are consistent with the predicted antigenic sites for the Nipah virus nucleocapsid protein. The selected phage clone used as a coating antigen discriminated swine and human Nipah virus sera-positive from sera-negative samples exhibiting characteristics, which might be attractive for diagnostic tests.
  19. Tan WS, Ong ST, Eshaghi M, Foo SS, Yusoff K
    J. Med. Virol., 2004 May;73(1):105-12.
    PMID: 15042656
    The nucleocapsid (N) protein of Nipah virus (NiV) can be produced in three Escherichia coli strains [TOP10, BL21(DE3) and SG935] under the control of trc promoter. However, most of the product existed in the form of insoluble inclusion bodies. There was no improvement in the solubility of the product when this protein was placed under the control of T7 promoter. However, the solubility of the N protein was significantly improved by lowering the growth temperature of E. coli BL21(DE3) cell cultures. Solubility analysis of N- and C-terminally deleted mutants revealed that the full-length N protein has the highest solubility. The soluble N protein could be purified efficiently by sucrose gradient centrifugation and nickel affinity chromatography. Electron microscopic analysis of the purified product revealed that the N protein assembled into herringbone-like particles of different lengths. The C-terminal end of the N protein contains the major antigenic region when probed with antisera from humans and pigs infected naturally.
  20. Tan EL, Peh SC, Sam CK
    J. Med. Virol., 2003 Feb;69(2):251-7.
    PMID: 12683415
    Nasopharyngeal carcinoma, a malignancy associated closely with Epstein-Barr virus (EBV), is prevalent among Chinese of Southern China origin. Epidemiological studies indicate a high prevalence of EBV in Asia with viral isolates having typical characteristics of the putative viral oncogene, latent membrane protein 1 (LMP-1), such as the loss of the Xho1 restriction site in Exon 1 and the 30-bp deletion in Exon 3. The EBV LMP-1 gene from throat washings of 120 nasopharyngeal carcinoma patients and 14 healthy individuals were analyzed. Similar analyses were also carried out on 30 and 12 postnasal space biopsies from nasopharyngeal carcinoma patients and healthy individuals, respectively. The 30-bp deletion was detected in 20% of nasopharyngeal carcinoma throat washes and in 100% of nasopharyngeal carcinoma postnasal space biopsies. Interestingly, 16% of the nasopharyngeal carcinoma biopsies possessed both the deleted and the undeleted variants, suggestive of dual infections. The notion of dual infections in nasopharyngeal carcinoma was further supported by the coexistence of both "F" and "f" (BamH1F region) EBV variants in 11% of the nasopharyngeal carcinoma biopsies. All of the throat washes and biopsies from the healthy controls showed the undeleted variant. The loss of the Xho1 restriction site was found with higher frequency both in throat washes and biopsies from patients with nasopharyngeal carcinoma. The discrepancy in the frequency of the 30-bp deletion between throat washes (20%) and postnasal space biopsies (100%) was an indication that this deletion is specific for viral isolates from primary tumour sites.
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