• Title/Summary/Keyword: viral population

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Epidemiology of Oral Cancer in Asia in the Past Decade- An Update (2000-2012)

  • Rao, Sree Vidya Krishna;Mejia, Gloria;Roberts-Thomson, Kaye;Logan, Richard
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5567-5577
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    • 2013
  • The prevalence of oral cancers (OC) is high in Asian countries, especially in South and Southeast Asia. Asian distinct cultural practices such as betel-quid chewing, and varying patterns of tobacco and alcohol use are important risk factors that predispose to cancer of the oral cavity. The aim of this review is to provide an update on epidemiology of OC between 2000 and 2012. A literature search for this review was conducted on Medline for articles on OC from Asian countries. Some of the articles were also hand searched using Google. High incidence rates were reported from developing nations like India, Pakistan, Bangladesh, Taiwan and Sri Lanka. While an increasing trend has been observed in Pakistan, Taiwan and Thailand, a decreasing trend is seen in Philippines and Sri Lanka. The mean age of occurrence of cancer in different parts of oral cavity is usually between 51-55 years in most countries. The tongue is the leading site among oral cancers in India. The next most common sites in Asian countries include the buccal mucosa and gingiva. The 5 year survival rate has been low for OC, despite improvements in diagnosis and treatment. Tobacco chewing, smoking and alcohol are the main reasons for the increasing incidence rates. Low socioeconomic status and diet low in nutritional value lacking vegetables and fruits contribute towards the risk. In addition, viral infections, such as HPV and poor oral hygiene, are other important risk factors. Hence, it is important to control OC by screening for early diagnosis and controlling tobacco and alcohol use. It is also necessary to have cancer surveillance at the national-level to collect and utilise data for cancer prevention and control programs.

Viral characteristics of plaque variants of porcine reproductive and respiratory syndrome virus

  • Park, Bong-kyun;Molitor, Thomas W.;Joo, Han-soo
    • Korean Journal of Veterinary Research
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    • v.39 no.4
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    • pp.751-759
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    • 1999
  • Plaque characteristics of porcine reproductive and respiratory syndrome (PRRS) virus isolates were examined using MARC-145 line cells. The plaque morphology of PRRS virus isolates was variable in size and heterogenic in population. Upon serial passages of the PRRS virus isolates on MARC-145 tells, heterogeneity was maintained but numbers of the large plaque size virus were increased with certain isolates. A PRRS virus isolate with variable plaque sizes was subcloned into 2 populations : small plaque ($H_S$) and large plaque ($H_L$) viruses. Growth kinetics of the subclones were then determined in MARC-145 cells, and production of the structural polypeptides was analyzed by SDS-PAGE. In a comparison of the growth kinetics, the $H_S$ virus showed higher infectivity titers during the first 48 hours but slower to reach the peak titier than $H_L$ virus did. In a nucleotide sequence comparison, differences of 4 nucleotides in open reading frames 5-6 gene were found between $H_S$ and $H_L$ viruses. Both the $H_S$ and $H_L$ clones produced 5 polypeptide bands with molecular weights of 15, 19, 26, 36 and 42 kD. The 5 bands were detected at 48 hours postinoculation (PI) with antisera to $H_L$ and another large plaque virus ($W_L$) and at 72 hours PI with $H_S$ virus antiserum. The present results demonstrate differences of biologic and molecular characteristics between the two PRRS virus plaque clones.

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A Study on the Positive Rates of HBsAg and Anti-HBs from Old People's Home and Casual Ward in Daegu, Korea

  • Shin, Hyun Gyu
    • Korean Journal of Clinical Laboratory Science
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    • v.43 no.4
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    • pp.145-149
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    • 2011
  • Serum hepatitis is still recognized as a major public health problem in many countries. The most common etiologies are acute viral hepatitis A and B, and hepatitis B virus (HBV) was known as the pathogen of serum hepatitis. since the HBV causes chronic hepatitis. HBV infection is hyperendemic in Korea. It is known that 8% and 1% of the Korean population is chronic carriers of HBV. The total number of 487 serum specimen (old people's home 190, causal ward-Daegu hope village 297) were collected at the laboratory of Department of Clinical Pathology of Daegu medical center. The laboratory tested the specimen to detect for hepatitis B surface antigen (HBsAg) and anti-HBs using reverse passive hemag-glutination (RPHA) and passive hemagglutination (PHA) method between April, 2011 and June, 2011. In one-step test, HBsAg and anti-HBs of Humasis were used. The positive rate for HBsAg was 6.80% (33/487), and the rate in male was 6.93% (19/274) higher than that of female 6.57% (14/213). In the positive rate of HBsAg by age group, the highest positive rate group was in the group of 40-49 years in male (12.0%), and 50-59 years in female (17.65 %). The overall positive rate for anti-HBs was 42.70% (208/487), showing the higher positive rate of 43.80% in male (120/274) than that of 41.30% (88/213) in female. The highest positive rate of anti-HBs in age group was the 40-49 years group in male (52.00%) and the group of under 29 in female (66.67%).

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Incidence of Active HCV infection amongst Blood Donors of Mardan District, Pakistan

  • Karim, Fawad;Nasar, Abu;Alam, Ibrar;Alam, Iftikhar;Hassan, Said;Gul, Rahmat;Ullah, Sana;Rizwan, Muhammad
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.1
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    • pp.235-238
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    • 2016
  • Hepatitis C is an ailment of liver caused by hepatitis C virus (HCV) infection. About 3% of the world population is infected by this virus. HCV infection is a leading reason for liver cirrhosis and therefore a major source of hepatocellular carcinoma. The study focused on the incidence of active HCV infection in blood donors of Mardan district of KPK, Pakistan. A total of 5318 blood donors were inspected for the presence of anti-HCV antibodies and HCV-RNA using ICT (immune-chromatographic test), ELISA and RT-PCR at Mardan Medical Complex (MMC), Mardan. Out of these, 157 (2.95%) were positive by ICT, 60 (1.12%) by ELISA and 56 (1.05%) for HCV-RNA. The frequency of active HCV infectivity amongst the blood donors from district Mardan, KPK Pakistan was 1.05 %. Application of strict measures during blood donor selection and use of proper screening assays such as ELISA in place of ICT devices can give a more accurate picture so that the incidence of this viral infection in HCV negative blood recipients can be reduced.

Change in Concentrations of Human Norovirus and Male-Specific Coliphage under Various Temperatures, Salinities, and pH Levels in Seawater (해수 중의 수온, 염분 및 pH에 따른 노로바이러스 및 Male-Specific Coliphage 농도변화)

  • Kim, Poong Ho;Park, Yong Soo;Park, Kunbawui;Kwon, Ji Young;Yu, Hong Sik;Lee, Hee Jung;Kim, Ji Hoe;Lee, Tae Seek
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.4
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    • pp.454-459
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    • 2016
  • Pre- or post-harvest processing is required to mitigate the risk of norovirus infection mediated by shellfish or seafood. We investigated the environmental resistance of human norovirus (HuNoV) under various conditions of temperature, salinity, and pH in seawater. Male-specific coliphage (MSC) was as the reference virus for all tests. At 4℃, HuNoV GII4 spiked into seawater was continually detected by RT-PCR for 35 days, regardless of salinity or pH level. It maintained nearly stable concentrations, meaning HuNoV can sustain a viral population in seawater long enough to be accumulated by shellfish and other filter feeders during winter. MSC was also stable at 4℃ although viral infectivity dropped sharply after 28 days. The effects of salinity and pH on MSC were indistinct. At 25℃ the detectable period of HuNoV GII4 by RT-PCR in seawater decreased to about one-third or half of the period at 4℃. High salinity (32 psu) and alkaline pH (8.5) were also unfavorable for sustaining HuNoV abundance at 25℃ in seawater. The resistance patterns of MSC to high temperature, high salinity, and alkaline pH were more dramatic and viral infectivity decreased over time, almost in direct proportion to experimental days. MSC was undetectable after 12 days under all salinities and pH levels at 25℃.

Convulsions with Noroviral Gastroenteritis in Children at a Single Center in Korea (단일 센터에서 경험한 소아에서의 노로바이러스 위장관염과 연관된 양성 경련)

  • Kang, SooYeon;Lee, Hyun Ju;Kim, Shin Hye
    • Journal of the Korean Child Neurology Society
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    • v.26 no.4
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    • pp.233-239
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    • 2018
  • Purpose: Viral gastroenteritis is a common disease in infants and children. Seizures can be associated with viral gastroenteritis as benign convulsions with mild gastroenteritis (CwG). After the development of the rotavirus vaccination, norovirus has become inreasingly significant in children. We retrospectively analyzed the clinical features in a pediatric population presenting with seizures and confirmed enteral viral infections, especially norovirus infections. Methods: We retrospectively reviewed the medical records of pediatric patients aged <15 years admitted due to convulsions and gastroenteritis to the Department of Pediatrics of Myongji Hospital between July 2014 and June 2016. Results: A total of 46 patients (24 male and 22 female) were included. Norovirus was detected in 21 (45.7%) patients, adenovirus in three (6.5%), rotavirus in two (4.3%), astrovirus in one (2.2%), and none of agents were detected in 19 (41.3%) patients. Patients in the norovirus gastroenteritis (NGE) group had a higher incidence of diarrhea than that among in the non-norovirus gastroenteritis (NNGE) group (61.9% vs 28.0%; P<0.05). Twelve patients experienced status epilepticus, including five (23.8%) in the NGE group and seven (33.0%) in the NNGE group (P=0.837). Seizures were effectively terminated by intravenous benzodiazepines in 8 (66.7%) of 12 patients. Additional long-acting antiepileptic drugs such as fosphenytoin or levetiracetam were required in three (25%) of 12 patients. Conclusion: Patients with CwG with and without noroviurs infection did not differ in terms of clinical features. However, status epilepticus was not uncommon among patients with CwG by definition.

Monitoring of viruses in wild walleye pollock (Gadus chalcogrammus) population in Korea (국내 자연산 명태(Gadus chalcogrammus) 집단의 바이러스 모니터링)

  • Seo, Hyun-Joon;Nam, U-Hwa;Kim, Jeong-Ho
    • Journal of fish pathology
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    • v.31 no.2
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    • pp.71-79
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    • 2018
  • Wild walleye pollock were caught from Goseong, The East Sea of Korea and examined for the existence of several fish pathogenic viruses; viral hemorrhagic septicemia virus (VHSV), nervous necrosis virus (NNV) and marine birnavirus (MABV). We collected 1,253 wild walleye pollock in total during February 2015 and August 2018. 324 spleen sample sets and 259 brain sample sets were made, and examined for the existence of the viruses mentioned above by reverse transcriptase polymerase chain reaction (RT-PCR). None of the target viruses were detected by one-step PCR. When some of these samples were further examined by two-step PCR, 19.7% (36/183) of spleen sample sets were positive for VHSV, and 4.4% (8/183) of spleen sample sets and 1.2% (3/259) of brain sample sets were positive for NNV. The target sequences of these viruses were clustered with those previously reported in Korea (Genotype IVa of VHSV, RGNNV genotype of NNV) by phylogenetic analysis. The activity of these viruses are not clear because virus isolation was not attempted, but probably very low because all the positive samples were detected by two-step PCR.

Tumor Necrosis Factor Alpha -308 G/A Single Nucleotide Polymorphism and Susceptibility to Hepatocellular Carcinoma Via Hepatitis B Infection

  • Azar, Saleh Shahbazi;Mansoori, Maryam;Attar, Marzieh;Shahbazi, Majid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3381-3384
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    • 2016
  • Background: Hepatitis B virus (HBV) is a key factor for hepatocellular carcinoma (HCC). About 350 million people are affected by chronic infection which is related to the rapid development of liver diseases as well as hepatitis, cirrhosis and hepatocellular carcinoma. Expression of tumor necrosis factor alpha (TNF-${\alpha}$) in the liver demonstrates a major genetic polymorphism which is involved in resistance or susceptibility to chronic HBV infection. Materials and Methods: In this study, two populations were studied by the sequence specific primer-polymerase chain reaction (SSP-PCR) method: HBV cases (n=409), who were HBS-Ag+, and healthy controls (n=483). Results: The results shown that the frequency of TNF-${\alpha}$ -308 G/G genotype in healthy controls (47.2%) was significantly higher than in HBV infected patients (28%) (CI = 1.29-2.61, OR = 1.83, P = 0.0004). Also TNF-${\alpha}$ -308 A/A and A/G genotype frequencies in the healthy controls were 4.6% and 48.2% and in patient group were 19.5% and 52.5% (CI = 2.23-7.12, p: 0.0001, OR: 3.94) respectively. Conclusions: We found that among Iranian people TNF-${\alpha}$ -308A allele not only has the highest genotype frequency but also it has the highest frequency in the world population. In addition, TNF-${\alpha}$-308 G/G polymorphism was associated with HBV resistance, whereas TNF-${\alpha}$-308A (A/A or A/G) polymorphism appeared to associated with chronic HBV infection. These data suggested that among the Iranian population, the -308 G/G polymorphism of TNF-${\alpha}$ gene promoter region has the potential to influence the susceptibility to HBV infection and it may be responsible for viral antigen clearance.

Variation in the Pathogenicity of Lily Isolates of Cucumber mosaic virus

  • Lee, Jin-A;Choi, Seung-Kook;Yoon, Ju-Yeon;Hong, Jin-Sung;Ryu, Ki-Hyun;Lee, Sang-Yong;Choi, Jang-Kyung
    • The Plant Pathology Journal
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    • v.23 no.4
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    • pp.251-259
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    • 2007
  • Two isolates of Cucumber mosaic virus (CMV) originated from lily plants, named Ly2-CMV and Ly8-CMV, were compared with their pathological features in several host plants. Ly2-CMV and Ly8-CMV could induce systemic mosaic symptom in Nicotiana benthamiana, but Ly2-CMV could not systemically infect tomato and cucumber plants that have been used for CMV-propagative hosts. While Fny-CMV used as a control infected systemically the same host plants, producing typical CMV symptoms. Ly8-CMV could infect systemically two species of tobacco (N. tabacum cv. Xanthi-nc and N. glutinosa) and zucchini squash (Curcubita pepo), but Ly2 failed systemic infection on these plants. As resulted from tissue-print immunoblot assay, different kinetics of systemic movement between Ly2-CMV and Ly8-CMV were crucial for systemic infection in tobacco (cv. Xanthi-nc). Sequence analysis of full-length genome of two lily isolates showed Ly2 and Ly8 belonged to subgroup IA of CMV. The lily isolates shared overall 98 % sequence identity in their genomes. Coat protein, 3a protein, and 2b protein involved in virus movement was highly conserved in genomes of the isolates Ly2 and Ly8. Although there is the low frequency of recombinants and reassortants in natural CMV population, phylogenetic analysis of each viral protein among a number of CMV isolates suggested that genetic variation in a defined population of CMV lily isolates was stochastically produced.

Population Analysis of Iranian Potato virus Y Isolates Using Complete Genome Sequence

  • Pourrahim, Reza;Farzadfar, Shirin
    • The Plant Pathology Journal
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    • v.32 no.1
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    • pp.33-46
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    • 2016
  • In this study, the full-length nucleotide sequences of four Iranian PVY isolates belonging to $PVY^N$ strain were determined. The genome of Iranian PVY isolates were 9,703-9,707 nucleotides long encoding all potyviral cistrons including P1, HC-Pro, P3, 6K1, CI, 6K2, VPg, NIa-Pro, NIb and CP with coding regions of 825, 1,395, 1,095, 156, 1,902, 156, 564, 732, 1,557 and 801 nucleotides in length, respectively. The length of pipo, embedded in the P3 cistron, was 231 nucleotides. Phylogenetic analysis showed that the Iranian isolates clustered with European recombinant NTN isolates in the N lineage. Recombination analysis demonstrated that Iranian $PVY^N$ isolates had a typical European $PVY^{NTN}$ genome having three recombinant junctions while $PVY^N$ and $PVY^O$ were identified as the parents. We used dN/dS methods to detect candidate amino acid positions for positive selection in viral proteins. The mean ${\omega}$ ratio differed among different genes. Using model M0, ${\omega}$ values were 0.267 (P1), 0.085 (HC-Pro), 0.153 (P3), 0.050 (CI), 0.078 (VPg), 0.087 (NIa-pro), 0.079 (NIb) and 0.165 (CP). The analysis showed different sites within P1, P3 and CP were under positive selection pressure, however, the sites varied among PVY populations. To the best of our knowledge, our analysis provides the first demonstration of population structure of $PVY^N$ strain in mid-Eurasia Iran using complete genome sequences and highlights the importance of recombination and selection pressure in the evolution of PVY.