Displaying publications 41 - 60 of 77 in total

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  1. Choong ML, Ton SH, Cheong SK
    Asian Pac J Allergy Immunol, 1996 Jun;14(1):19-24.
    PMID: 8980796
    The percentage of lymphocyte subsets from the peripheral blood of healthy adults and hepatitis B surface antigen (HBsAg) carriers were analyzed by flow cytometry. The five lymphocyte subsets studied were:- T (CD3) cells, B (CD19) cells, CD4 cells, CD8 cells, Natural Killer (CD3- CD16+/CD56+) cells (NK cells) and the CD4/CD8 ratio. The percentage (mean +/- SD) for the five lymphocyte subsets from the healthy adults were (67.5 +/- 8.5)%, (12.4 +/- 4.5)%, (35.5 +/- 7.8)%, (36.8 +/- 8.5)%, (17.9 +/- 8.1)% and 1.1 +/- 0.6, respectively. HBsAg carriers positive for HBV-DNA had a lower CD4/CD8 ratio than the healthy population (P = 0.030). The percentage of CD8 cells in HBsAg carriers increased significantly (r = 0.28; P = 0.019) with an increase in ALT levels but the values remained within normal range. The percentage of NK cells and CD4/CD8 ratio in HBsAg carriers positive for anti-HBe were higher than HBsAg carriers negative for anti-HBe (92% of which are HBeAg positive) (P = 0.045 and P = 0.035, respectively). The CD4/CD8 ratio in HBsAg carriers negative for anti-HBe (92% positive for HBeAg) was also lower than in the healthy population (P = 0.042). HBsAg carriers positive for HBV-DNA, HBeAg and raised ALT levels had a lower CD4/ CD8 ratio than did the healthy population. The lower ratio was due to an increase in the percentage of CD8 cells. This suggests an activated immune response triggered by the infection in an attempt to clear the virus. HBsAg carriers with normal ALT levels and who are negative for HBV-DNA may be in a state of tolerance.
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis*
  2. Mah GK, Yeo A
    Ann Acad Med Singap, 1990 May;19(3):339-43.
    PMID: 2144101
    Blood samples from 1,600 persons who sought immunisation against hepatitis B in private clinics in Singapore in 1988-1989 were screened for two viral markers. Of that total, 4.81% were positive for HBsAg and 17.31% had anti-HBs levels greater than 10 mIU/ml, indicating that about 22.12% of the general population would not benefit from immunisation. Preimmunisation screening will identify persons not requiring the hepatitis B vaccine and thus, avoid wastage. When immunisation has already been performed without screening, recall for post-immunisation screening should be considered in order to detect the infectious hepatitis B carriers. Data in this study indicates that at this point in time, it is important to immunise adolescents and adults, in addition to neonates and children.
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis
  3. Goh CL, Kamarudin A, Chan SH, Rajan VS
    Genitourin Med, 1985 Apr;61(2):127-9.
    PMID: 3980022
    The prevalence of hepatitis B virus markers in 121 men and 239 women prostitutes was studied. Of 33 (9.7%) with hepatitis B surface antigen (HBsAg), nine (27.3%) also had hepatitis Be antigen, which was more prevalent in men than women. Antibodies to HBsAg (anti-HBs) and to hepatitis B core antigen (anti-HBc) were found in about 71% of men and women prostitutes. Hepatitis B virus markers were more prevalent in men than in women prostitutes. Compared with other people, prostitutes had a significantly greater prevalence of hepatitis B virus markers. This study strongly suggested the importance of sexual transmission of infection with hepatitis B virus in a country where infection is endemic.
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis
  4. Morad Z, Suleiman AB, Kong CT
    Transplant Proc, 1989 Feb;21(1 Pt 2):1825-6.
    PMID: 2652593
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis*
  5. Quak SH, Singh R, Oon CJ, Wong HB
    Ann Trop Paediatr, 1982 Jun;2(2):53-6.
    PMID: 6185078
    A study of race-related distribution of hepatitis B markers was conducted in 458 children admitted consecutively to Singapore General Hospital. The positive rates for hepatitis B surface antigen (HBsAg) in Chinese, Malays and Indians were 11.2, 8.0 and 12.2% respectively and the corresponding figures for anti-HBs were 30.2, 12.0 and 14.6%. In Chinese children HBsAg prevalence was shown to be sex-related, being higher in males than females. The percentages of Chinese children positive for anti-HBs and anti-HBc were also higher than those of the Indians. This study confirmed that Singapore children were exposed to hepatitis B infection from early life. All three races were equally susceptible to this infection.
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis*
  6. Lopez CG
    PMID: 524138
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis
  7. Sahlan N, Fadzilah MN, Muslim A, Shaari SA, Abdul Rahman T, Hoh BP
    Med J Malaysia, 2019 08;74(4):320-325.
    PMID: 31424040
    INTRODUCTION: Prevalence of Hepatitis B virus (HBV) infection among the non-indigenous people in Malaysia has been well established and range between 3% and 5%. However, data from the indigenous (Orang Asli) people is still lacking. The Negrito population is the most remotely located Orang Asli tribe with limited access to health care facilities. This study was undertaken to determine the epidemiology and seroprevalence of HBV infection among the Negrito.

    METHODS: Surveys were conducted in five Negrito settlements in Kelantan and Perak states in Malaysia. A total of 150 participants were recruited. Clinical history was taken and physical examination was performed. Five millilitres of whole blood were collected and tested for hepatitis B surface antigen (HBsAg) using electrochemiluminescence immunoassay.

    RESULTS: Participants were mainly from the Bateq (49.3%) and Mendriq (29.4%) sub-tribes. Overall, 13 subjects (8.7 %); nine males and four females were HBsAg positive. Nine of the HBsAg positive subjects were ≥35 years old. All of them had history of home deliver without evidence of antenatal record. Six (46%) of the HBsAg positive subjects had tattoo and body piercing in the past.

    CONCLUSION: The prevalence of HBV infection rate amongst the Negrito tribe is almost three-fold compared to the national rates. The reason for this finding remains unclear. Tattooing, body piercing and vertical transmission could be the main possible routes of transmission of HBV among the Negrito population in Malaysia.

    Matched MeSH terms: Hepatitis B Surface Antigens/blood
  8. Ng KP, Saw TL, Baki A, Rozainah K, Pang KW, Ramanathan M
    Med Microbiol Immunol, 2005 May;194(3):163-8.
    PMID: 15834754
    The implementation of the Expanded Program of Immunization (EPI) in 1989 has dramatic impact on hepatitis B virus (HBV) infection in school children in Malaysia. A cross-sectional seroprevalence study of HBV infection in 190,077 school children aged 7-12 years from 1997 to 2003 showed a steady decline of HBV surface antigen (HBsAg) prevalence rate from 2.5% for children born in 1985 to 0.4% among school children born in 1996. The overall prevalence of HBsAg was 0.6%, 0.7% in males and 0.6% in females. Over 92.7% of school children had been vaccinated with HBV vaccine, in which 93.7% were vaccinated under the EPI and 6.3% on voluntary basis. The school children vaccinated under EPI had a 0.4% HBsAg carrier rate, which was significantly lower than school children vaccinated on a voluntary basis (HBsAg carrier rate 1.3%) and non-vaccinated school children (HBsAg carrier rate 2.7%), suggesting that HBV vaccination of infants was the most effective measure in preventing vertical transmission of HBV in the hyperendemic region.
    Matched MeSH terms: Hepatitis B Surface Antigens/blood
  9. Hong YS, Chang Y, Ryu S, Cainzos-Achirica M, Kwon MJ, Zhang Y, et al.
    Sci Rep, 2017 07 04;7(1):4606.
    PMID: 28676706 DOI: 10.1038/s41598-017-04206-6
    The role of hepatitis virus infection in glucose homeostasis is uncertain. We examined the associations between hepatitis B virus (HBV) or hepatitis C virus (HCV) infection and the development of diabetes in a cohort (N = 439,708) of asymptomatic participants in health screening examinations. In cross-sectional analyses, the multivariable-adjusted odds ratio for prevalent diabetes comparing hepatitis B surface antigen (HBsAg) (+) to HBsAg (-) participants was 1.17 (95% CI 1.06-1.31; P = 0.003). The corresponding odds ratio comparing hepatitis C antibodies (HCV Ab) (+) to HCV Ab (-) participants was 1.43 (95% CI 1.01-2.02, P = 0.043). In prospective analyses, the multivariable-adjusted hazard ratio for incident diabetes comparing HBsAg (+) to HbsAg (-) participants was 1.23 (95% CI 1.08-1.41; P = 0.007). The number of incident cases of diabetes among HCV Ab (+) participants (10 cases) was too small to reliably estimate the prospective association between HCV infection and diabetes. In this large population at low risk of diabetes, HBV and HCV infections were associated with diabetes prevalence and HBV infection with the risk of incident diabetes. Our studies add evidence suggesting that diabetes is an additional metabolic complication of HBV and HCV infection.
    Matched MeSH terms: Hepatitis B Surface Antigens/metabolism*
  10. Cheang HK, Wong HT, Ho SC, Chew KS, Lee WS
    Singapore Med J, 2013 Apr;54(4):224-6.
    PMID: 23624451
    INTRODUCTION: This study aimed to assess the immune response in infants who received the three-shot hepatitis B vaccine in Malaysia.

    METHODS: Consecutive infants born between March 2002 and April 2010 who received three doses of hepatitis B vaccine at a community clinic in Malaysia were enrolled in the study. Screening for hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) was performed after the completion of primary immunisation, at approximately one year of age.

    RESULTS: A total of 572 infants (median age 9.3 ± 2.7 months; range 6.3-48 months) were screened for immune response to hepatitis B vaccination - 553 (96.7%) infants had adequate levels of anti-HBs (≥ 10 IU/L). Of the 440 mothers whose HBsAg status was known, 14 (3.2%) were positive for HBsAg. None of the 14 infants who were born to HBsAg-positive mothers were positive for HBsAg, and all but one infant had anti-HBs level ≥ 10 IU/L. Gender, gestational age and maternal HBsAg status were not found to significantly affect the subsequent immune response in infants following vaccination.

    CONCLUSION: The proportion of Malaysian mothers who are positive for HBsAg remains high. The three-shot hepatitis B vaccine, given as part of universal vaccination against hepatitis B, provides adequate anti-HBs in the vast majority of infants in a community setting in Malaysia.
    Matched MeSH terms: Hepatitis B Surface Antigens/immunology
  11. Candotti D, Lin CK, Belkhiri D, Sakuldamrongpanich T, Biswas S, Lin S, et al.
    Gut, 2012 Dec;61(12):1744-53.
    PMID: 22267593 DOI: 10.1136/gutjnl-2011-301281
    To investigate the molecular basis of occult hepatitis B virus (HBV) infection (OBI) in Asian blood donors.
    Matched MeSH terms: Hepatitis B Surface Antigens/genetics; Hepatitis B Surface Antigens/metabolism
  12. Chen XY, Butt AM, Mohd Amin MCI
    Mol Pharm, 2019 09 03;16(9):3853-3872.
    PMID: 31398038 DOI: 10.1021/acs.molpharmaceut.9b00483
    The development of oral vaccine formulation is crucial to facilitate an effective mass immunization program for various vaccine-preventable diseases. In this work, the efficacy of hepatitis B antigen delivered by bacterial nanocellulose/poly(acrylic acid) composite hydrogel microparticles (MPs) as oral vaccine carriers was assessed to induce both local and systemic immunity. Optimal pH-responsive swelling, mucoadhesiveness, protein drug loading, and drug permeability were characterized by MPs formulated with minimal irradiation doses and acrylic acid concentration. The composite hydrogel materials of bacterial nanocellulose and poly(acrylic acid) showed significantly greater antigen release in simulated intestinal fluid while ensuring the integrity of antigen. In in vivo study, mice orally vaccinated with antigen-loaded hydrogel MPs showed enhanced vaccine immunogenicity with significantly higher secretion of mucosal immunoglobulin A, compared to intramuscular vaccinated control. The splenocytes from the same group demonstrated lymphoproliferation and significant increased secretion of interleukin-2 cytokines upon stimulation with hepatitis B antigen. Expression of CD69 in CD4+ T lymphocytes and CD19+ B lymphocytes in splenocytes from mice orally vaccinated with antigen-loaded hydrogel MPs was comparable to that of the intramuscular vaccinated control, indicating early activation of lymphocytes elicited by our oral vaccine formulation in just two doses. These results demonstrated the potential of antigen-loaded hydrogel MPs as an oral vaccination method for hepatitis B.
    Matched MeSH terms: Hepatitis B Surface Antigens/immunology*; Hepatitis B Surface Antigens/chemistry
  13. Hudu SA, Malik YA, Niazlin MT, Harmal NS, Sekawi Z
    Curr Issues Mol Biol, 2014;16:69-78.
    PMID: 24014801
    Hepatitis B virus infection is a serious health problem worldwide, and more than 350 million people are chronic carriers, constituting a major global threat. Southeast Asia and the Western Pacific have the highest levels of endemicity in the world, with an estimated seroprevalence ranging between 2% and 31%. Mutations in the hepatitis B surface antigen (HBsAg) have been reported in many parts of the world but are most common in Asian infants; such mutants have several clinical effects, such as the development of hepatocellular carcinoma. Diagnostic failures by commercial assays have reduced the diagnostic effectiveness of HBsAg detection. For example the substitution of an amino acid in the major hydrophilic region of the S gene reduces the binding of hepatitis B surface antibodies leading to immune escape. The safety of blood transfusion may be compromised by current screening tests due to escape from being neutralised by antibodies induced by HBsAg mutants, and undetectable levels of viral surface protein. Data on the epidemiology of HBsAg mutation in Asia Pacific are scant; however, this manuscript has reviewed the available information on the epidemiology of HBsAg mutation in Asia Pacific.
    Matched MeSH terms: Hepatitis B Surface Antigens/genetics*; Hepatitis B Surface Antigens/isolation & purification
  14. Lee CE, Sri Ponnampalavanar S, Syed Omar SF, Mahadeva S, Ong LY, Kamarulzaman A
    Ann Acad Med Singap, 2011 Oct;40(10):448-53.
    PMID: 22206053 DOI: 10.47102/annals-acadmedsg.V40N10p448
    INTRODUCTION: Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.

    MATERIALS AND METHODS: A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.

    RESULTS: For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.

    CONCLUSION: DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.
    Matched MeSH terms: Hepatitis B Surface Antigens/blood*; Hepatitis B Surface Antigens/immunology
  15. Azlin AH, Looi LM, Cheah PL
    Asian Pac J Cancer Prev, 2014;15(9):3959-63.
    PMID: 24935581
    The tumour suppressor genes, p53 and pRb, are known to play important roles in neoplastic transformation. While molecular routes to the uncontrolled growth of hepatocytes, leading to primary liver cancer have generated considerable interest, the roles of p53 and pRb mutations in hepatocellular carcinoma (HCC) and hepatoblastoma (HB) remain to be clarified. We examined the immunohistochemical expression of p53 and pRb gene products in 26 HCC and 9 HB, sampled into tissue microarray blocks. 10 (38%) of 26 HCC showed > 10% tumour nuclear staining for p53 protein, 3 of these also being HbsAg positive. Conversely, none of 9 HB expressed nuclear p53 immunopositivity. Some 24 (92%) HCC and 8 (89%) HB showed loss of pRb nuclear expression. Two of the 26 HCC and one of the 9 HB showed >10% tumour nuclear staining for pRb protein. Our results suggest that p53 does not have an important role in the development of HB but may contribute in HCC. There is also loss of pRb expression in the majority of HCC and HB, supporting loss of pRb gene function in the hepatocarcinogenesis pathway. However, a comparison of the staining profiles of p53 and pRb proteins in HCC and HB did not reveal a consistent pattern to differentiate between the two types of tumours immunohistochemically. Hence the use of p53 and pRB protein expression has no contribution in the situation where there is a diagnostic difficulty in deciding between HCC and HB.
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis
  16. Yap SF
    Malays J Pathol, 2004 Jun;26(1):1-12.
    PMID: 16190102
    "Parenteral" or "serum" hepatitis is known to have afflicted man for centuries. However, it was not until the mid-1960s that the causative agent of this infection, the hepatitis B virus, was discovered. Since then, the biology and the replication strategy of the virus, and the clinical features and the epidemiology of the hepatitis B infection have been determined. Knowledge about the virus and the infection it causes led to the development of firstly, a plasma-derived vaccine and later a recombinant vaccine for the prevention of the infection. Integration of the hepatitis B vaccine into newborn vaccination programmes on a worldwide basis represents a major step in the effort to eliminate this infectious disease and its complications. Laboratory tests are available for the diagnosis and monitoring of the disease. Therapies have been developed to halt the progress of the chronic infection in affected individuals. While these developments have resulted in a decrease of the frequency of infection in many countries, particularly those that have implemented universal immunization of newborns, the chronic infection remains a significant global problem. Worldwide, over 300 million individuals are infected and each year, an estimated 1 million persons die from chronic complications of the disease including hepatocellular carcinoma and hepatic failure. The therapies currently available result in elimination of the virus in only a relatively small proportion of subjects and carry with it serious side effects. Geopolitical, economic and other factors hinder the vision of elimination of the infection through immunization programmes. Nevertheless, work continues to clarify further the underlying pathological mechanism of the infection, the host and viral factors that promote elimination or persistence of the virus in the human host. It is hoped that such investigations will reveal viral targets for the design of newer and potentially more effective drugs to treat the infection.
    Matched MeSH terms: Hepatitis B Surface Antigens/immunology*
  17. Ton SH, Iskandar K, Noriah R, Thanaletchimy N
    Scand. J. Infect. Dis., 1996;28(6):543-8.
    PMID: 9060053
    As most published studies on precore mutants have been carried out on isolates from patients with liver diseases, and it is unclear whether HBsAg carriers with viraemia in the absence of HBeAg are also generally infected by such mutants, it was decided to sequence the precore region in some HBV-DNA isolated from HBsAg-positive carriers. Precore sequences of HBV-DNA from 43 HBsAg carriers in Malaysia were studied. Three HBV subtypes were identified according to the nucleotide sequence of the precore region. Most of the carriers were found to be infected by the subtype adr. Mutations were detected in the precore regions. The most common conserved mutation was a silent mutation involving conversion from T to C (CCT to CCC) at position 1858 at codon 15 (proline). It was found that 4/43 (9.3%) had a mutation at the penultimate codon where TGG was changed to TAG. All 4 isolates with the TAG mutation had nt T at position 1858. Of the 4 carriers who were infected by these mutant viruses, 2 were coinfected with the wild type, 1 was infected only by a variant with the mutation at position 1896, while another was infected by a variant with mutations at positions 1896 and 1899. Three of the 4 were anti-HBe positive while 1 was HBeAg positive. Alanine aminotransaminase activities in all 4 carriers were normal. This study therefore demonstrated that variants with stop codons at the penultimate codon could be found in asymptomatic carriers in Malaysia.
    Matched MeSH terms: Hepatitis B Surface Antigens/blood
  18. Ton SH, Yeoh KS, Lim WC, Noriah R, Cheong SK, Thanaletchimy N
    J Trop Med Hyg, 1995 Aug;98(4):277-80.
    PMID: 7636926
    HBV-DNA were analysed in 330 HBsAg-positive carriers in Malaysia by dot-blot hybridization and polymerase chain reaction. Seventy-three (22.12%) were positive for the virus. Of these, 65 (89%) were males and 8 (11%) were females. Statistically, there was no significant difference (P = 0.13). No significant decline in HBV-DNA with age in the Malay and Chinese males was observed (P = 0.2). Prevalence of HBV-DNA was higher in the Chinese carriers than in the Malay carriers for most age groups in both sexes. Sixty-one HBV-DNA-positive carriers were also positive for HBeAg. However, three individuals were positive only for anti-HBe, one was positive for both HBeAg and anti-HBe, and eight were negative for both HBeAg and anti-HBe. Fifty-seven were positive for HBeAg but negative for HBV-DNA. No relation was observed between raised alanine aminotransaminase and aspartate aminotransaminase levels and the presence of HBV-DNA (P = 0.4).
    Matched MeSH terms: Hepatitis B Surface Antigens/blood*
  19. Goh KT
    Ann Acad Med Singap, 1980 Apr;9(2):136-41.
    PMID: 6775577
    257 cases of acute hepatitis B were reported between January 1977 and June 1979. This constituted about one-third of all reported acute viral hepatitis cases in Singapore. The mean annual morbidity and mortality rates per 100,000 was 4.4 and 0.12 respectively. The case-fatality rate was 2.7%. The age-specific morbidity rates were high in the 15-24 and 25-34 years age groups, while the ethnic specific morbidity rate was highest in Indians. The male to female ratio was 4.6: 1. Cases were concentrated in urban and suburban areas with high population density. Three outbreaks, one traced to contaminated needles and syringes, one to contaminated tattoo neeedles, and amongst close contacts, were described. Although parenteral procedures were associated with hepatitis B infection (p < 0.005), non-parenteral or inapparent parenteral mode of transmission probably contributes to a significant extent in the transmission of hepatitis B in Singapore. Studies to determine the role of perinatal transmission, and of vectors, in maintaining the endemicity of the disease, were suggested.
    Matched MeSH terms: Hepatitis B Surface Antigens/isolation & purification
  20. Tan DS, Zaini Rahman M, Fang R, Collett D, Ooi BG
    PMID: 3538435
    Sera were obtained from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the medical wards of the rural and urban hospitals in Malaysia. They were tested for HBsAg, HBeAg, and anti-HBs by enzyme immunoassay. The overall HBsAg carrier rate was 18.0% ranging from 9.6% in children, (10 years and under), to a maximum of 23.5% in the adolescents (11 to 20 years), the rates decreasing subsequently to 16.5% and 20.8% in the adult and middle-age groups, respectively. The Chinese (18.6%) and Malays (19.9%) had similar HBsAg carrier rates but the rate in the Indians (9.0%) was distinctly lower. Similar rates were observed in the males (16.5%) and the females (19.8%). The carrier rate was 17.1% in rural patients compared with 21.4% in the urban ones. The 'e' antigen was found in 14 of the 89 HBsAg carriers (15.7%). The overall prevalence was 14/494 (2.8%) rising sharply from childhood (2.9%) to adolescence (5.3%), subsequently declining with advancing age. The Chinese had the highest rate (6.2%) followed by the Indians (1.5%) and the Malays (1.1%). Males had a rate of 3.3% compared to the females with 2.3%. Anti-HBs was found in 33.8% of the patients, increasing steadily from childhood (18.3%) to middle-age (46.4%). The Chinese had a higher prevalence rate (41.6%) than the Indians (32.8%) and the Malays (29.3%). The rates were similar for the males (35.6%) and the females (31.5%). Rural patients (46.1%) had a higher rate than urban patients (35.7%). Both areas showed rising prevalence with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Hepatitis B Surface Antigens/analysis*
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