Search

The development of social media applications such as Facebook, Instagram, Twitter and soon have been adapted in various fields such as education, politics and business. This study aims to identify the level of awareness of the use of social media on security issues among Malaysian and Indonesian students. This study is in the form of a survey using questionnaires and the sample involved is a total of 414 people randomly selected from among students in Malaysia and Indonesia. Data analysis for this study is using Statistical Package for the Social Sciences (SPSS) version 21. The study found that the majority of users have awareness and know about privacy and information security issues when dealing online, especially through social media. Therefore, this study suggests that consumers should be more careful about security and privacy issues when sharing personal information, especially information related to online business.

Ecosystem of a freshwater from river or lake can be extremely fragile. Assessment on flows and quality in water system is critical as fresh water mostly come from rivers and lakes. The used of river drifting buoy is new to estuarial and riverine studies compared to the oceanography. The collected river parameters from the drifters benefits the community in term assessment of water quality, usage and storm water control planning. In this work, the river drifting buoy developed were inspired by water-walking arthropods which is water strider. The design drifting buoy were able to control their heading and have the ability to withstand the impact from a deployment at the river banks under several obstacles. The design introduce power efficiency and agile movements on the water surface for deep or very shallow water surfaces. The performance of the buoy were recorded with real data collected at several local area near Batu Pahat.

Evaluation of acid strength was used to investigate the location of organosulfonic acid groups within mesoporous silica materials. Mesoporous silica functionalized with either propylsulfonic or arenesulfonic acid groups at different surface concentrations were synthesized via the co-condensation technique, and their resulting acid strength was determined in a methanol solution using potentiometric titration with the Gran Plot technique. A decrease in spatial distance between the sulfonic acid groups on the pore surface of the mesostructured materials was found to increase the acid strength of the resulting solid acid catalyst as result of acid site cooperativity. Comparison of these results with the catalytic performance of the organosulfonic acid-functionalized mesoporous silica materials in the methanol esterification of palmitic acid suggested that the reaction performance of these materials is not simply related to the effects induced by spatial location of the acidic sites on the acid solid catalyst. The results demonstrate the potential of intentionally designing the catalytic environments of the organic–inorganic hybrid mesoporous materials at the molecular level.

Organosulfonic acid-functionalized mesoporous silicas were tested for catalytic performance in the esterification of oleic acid with methanol in flowing supercritical carbon dioxide. The energy of activation of the sulfonic acid catalysts was found to be about 42 kJ/mol and was shown to be independent of pore size. The catalytic activity of the functionalized silicas was compared to a standard acidic resin, Amberlyst 15, and to an immobilized lipase, Novozym 435. The most active catalyst was Novozym 435.

Propylsulfonic acid-functionalized mesoporous silica materials were synthesized using a co-condensation technique. The catalytic performance of the resulting acidic mesoporous materials was evaluated in the methanol esterification of free fatty acids in beef tallow as a pretreatment step for alkyl ester production. The multicycle stability of the acid-functionalized mesoporous silica catalysts was studied. Issues concerning impurities in the feedstocks as well as a means of improving performance of the acidic solid catalyst through alternative strategies are discussed. Introduction of a hydrophobic group into the organosulfonic acid-functionalized mesoporous silica catalyst significantly enhanced the catalytic performance of the catalyst. The catalytic activity of the synthesized catalysts was compared to commercially available homogeneous and heterogeneous acidic catalysts.

Natural oils and fats are emerging as a biobased alternative feedstock to conventional crude oil in the production of chemicals and transportation fuel. However, many of these biobased chemicals are not currently cost competitive with petrochemicals because of high raw material and production costs. To improve the economic outlook of the biobased chemicals, the use of suitable catalysts becomes imperative. Recently, the discovery of advanced material synthesis strategies such as supramolecular-assembled mesoporous materials has created new opportunities in tailoring catalyst properties specifically for the conversion challenges encountered with oils and fats. These nanostructured materials have a combination of extremely high surface areas and flexible pore sizes that makes them attractive for catalysis applications. This article reviews the application of this new class of advanced materials for the conversion of oils and fats to biobased chemicals.

Organosulfonic acid mesoporous silicas further functionalized with hydrophobic organic groups were synthesized via postsynthesis grafting and one-step co-condensation methods. The resulting materials were tested in the esterification of fatty acid with methanol to produce methyl esters as a pretreatment step in the production of biodiesel. Incorporation of the hydrophobic group into the organic–inorganic hybrid acid catalyst was found to improve the performance of the resulting catalyst. However, the performance of the multifunctionalized mesoporous materials demonstrated a strong dependence on the incorporation method and on the size of the hydrophobic organic groups. Solution effects within the reaction mixture appeared to influence the catalytic activity of the catalysts. The results indicate the potential for intentional design of the catalytic environment at a molecular level with the use of organic–inorganic mesoporous materials.

Sequences of 234 complete genomes and 631 hepatitis B surface antigen genes were used to assess the worldwide diversity of hepatitis B virus (HBV). Apart from the described two subgenotypes each for A and F, also B, C, and D divided into four subgenotypes each in the analysis of complete genomes supported by significant bootstrap values. The subgenotypes of B and C differed in their geographical distribution, with B1 dominating in Japan, B2 in China and Vietnam, B3 confined to Indonesia, and B4 confined to Vietnam, all strains specifying subtype ayw1. Subgenotype C1 was common in Japan, Korea, and China; C2 in China, South-East Asia, and Bangladesh, and C3 in the Oceania comprising strains specifying adrq–, and C4 specifying ayw3 is encountered in Aborigines from Australia. This pattern of defined geographical distribution was less evident for D1–D4, where the subgenotypes were widely spread in Europe, Africa, and Asia, possibly due to their divergence having occurred a longer time ago than for genotypes B and C, with D4 being the first split and still the dominating subgenotype of D in the Oceania. The genetic diversity of HBV and the geographical distribution of its subgenotypes provide a tool to reconstruct the evolutionary history of HBV and may help to complement genetic data in the understanding of the evolution and past migrations of man.

An Al 2 O 3 sample obtained from Seydi y ehir Eti Aluminyum A. z was treated and characterized for its potential use as a catalyst support. Atomic absorption spectroscopy and flame photometry characterization revealed the presence of 95.52% Al 2 O 3 , 4.44% Na 2 O, and 0.043% Fe 2 O 3 in the original sample. Both n -Al 2 O 3 and f -Al 2 O 3 phases were identified in the crystalline structure by X-ray diffraction analysis. However, f -Al 2 O 3 was found to be the phase in abundance. The BET surface area of the original sample was found to be 40.85 m 2 /g. The original sample was treated in various concentrations of hydrochloric acid to remove Na 2 O impurity. The acid concentration was optimized for the Na 2 O removal efficiency and surface area enhancement. The optimum HCl concentration was found to be 1 M. 1 Pt/Al 2 O 3 catalysts prepared from these supports and a reference support (Johnson Matthey n -Al 2 O 3 ) were tested for CO oxidation reactions. Catalysts prepared fromSeydis¸ehir alumina showed rea...

DNA-based immunization may be of prophylactic and therapeutic value for hepatitis C virus (HCV) infection. In efforts to improve the immunogenicity of a plasmid expressing the second envelope protein (E2) of HCV, we evaluated in mice the role of the antigen localization and demonstrated that membrane-bound and secreted forms induced higher titers of E2-specific antibodies, as well as earlier and higher seroconversion rates, than the intracellular form, but all three forms induced strong CTL. We also investigated whether E2-specific antibody responses could be enhanced by CpG optimization of the plasmid backbone and showed that removal of neutralizing CpG dinucleotides did not have a significant effect but addition of 64 immunostimulatory CpG motifs significantly enhanced anti-E2 titers. These results may have implications for the design and development of HCV DNA vaccines.

A rapid, reverse transcription-polymerase chain reaction (RT-PCR) procedure for the detection of reovirus RNA in cell culture is described. Total nucleic acids are extracted from a small volume of cell culture supernatant and reverse transcribed using random hexamers. An aliquot of cDNA is then utilized in nested PCR. The PCR primers correspond to sequences conserved between prototype reovirus strains type 1 Lang, type 2 Jones, and type 3 Dearing, as well as those of several reovirus field-isolate strains. Reactions are analyzed by agarose gel electrophoresis, and samples showing a band of the appropriate size in the first and second amplification, or in the second amplification alone, are designated as positive. This protocol allows for the rapid and sensitive detection of reovirus in cell culture. The RT-PCR methods described below can easily be adapted to the amplification of reovirus from other media, including preserved tissues, clinical specimens, and water.

Reoviruses infect virtually all mammalian species, and infection of humans is associated with mild gastrointestinal or upper respiratory illnesses. To improve reovirus detection strategies, we developed a reverse transcription-PCR technique to amplify a fragment of the reovirus L1 gene segment. This assay was capable of detecting 44 of 44 reovirus field isolate strains and was sufficiently sensitive to detect nearly a single viral particle (1.16 ± 0.13) per PCR of prototype strain type 3 Dearing. Pairwise comparisons of the 44 partial L1 gene sequences revealed that nucleotide variability ranged from 0 to 24.7%, with most of the nucleotide polymorphism occurring at synonymous positions. Phylogenetic trees generated from amplified L1 gene sequences suggest that multiple alleles of the L1 gene cocirculate in nature and that genetic diversity of the L1 gene is largely independent of the host species, geographic locale, or date of isolation. Phylogenetic trees constructed from the L1 gene sequences are distinct from those constructed from the four reovirus S-class gene segments, which supports the hypothesis that reovirus gene segments reassort in nature. This study establishes a new sensitive and specific technique for the identification of mammalian reoviruses and enhances our understanding of reovirus evolution.

BACKGROUND AND OBJECTIVES: The transmission routes for GB virus-C (GBV-C)/hepatitis G virus (HGV) in blood donors unexposed to hepatitis C virus (HCV) are unknown. We performed a case-control study of risk factors for GBV-C/HGV exposure in blood donors. MATERIALS AND METHODS: After testing stored sera from 458 HCV-negative blood donors for GBV-C/HGV RNA and GBV-C/HGV E2 antibodies, 66 donors with GBV-C/HGV markers and 125 age- and gender-matched controls were interviewed regarding risk factors for viral transmission. RESULTS: Exposure to GBV-C/HGV was strongly associated with previous treatment for a sexually transmitted disease (odds ratio [OR] 4.6; 95% confidence interval [CI] 2.2-9.8), with multiple sexual partners (OR 2.9; 95% CI 1.4-5.7) and with a past history of endoscopy (OR 7.0; 95% CI 3.0-16.4). CONCLUSIONS: In blood donors with GBV-C/HGV markers, sexual contacts and medical procedures appear to be the main transmission routes. (Less)

Hepatitis E virus (HEV) has been identified in 2 Argentine patients with acute hepatitis who reported no history of travel to regions in which HEV is considered endemic. These isolates are the first to be identified in South America. By use of degenerate primers from open reading frames 1 and 2, HEV sequences were obtained from these patients' serum and compared with published HEV sequences. The Argentine isolates are different from all previously identified HEV isolates and are most closely related to each other. The Argentine isolates are distinct from the most geographically related isolate from Mexico as well as isolates from other endemic (China, Southeast Asia, and India) and nonendemic (the United States and Europe) regions. Phylogenetic analysis indicate that the Argentine isolates represent a new genotype of HEV, genotype 8, distinct from the Burmese-like genotype 1, Mexican genotype 2, US genotype 3, Chinese/Taiwan genotype 4, and European genotypes 5-7.

Immune responses to two recombinant envelope 2 (E2) proteins, representing genotypes 1 and 2 of the GB virus C, or the hepatitis G virus (GBV-C/HGV), were studied in mice and in 48 individuals with, or without, chronic, or past GBV-C/HGV infection. Immunised mice developed E2-specific antibodies (mean titres, 1:1,167 to 1:9,360), recognising linear antigenic regions and proliferative and IL-2, IL-6 and γIFN cytokine responses regardless of the viral genotype. Individuals with past GBV-C infection had E2 antibody titres from 1:1,500 to 1:7,500 that did not recognise the E. coli derived E2 protein or linear antigenic regions. Proliferative E2-specific responses were detected in peripheral blood mononuclear cells from 6/22 (27%) persons with, and in none without GBV-C markers (P < 0.05). Thus, E2-specific immune responses are mainly crossreactive between different variants of GBV-C/HGV, although proliferative responses appear to be rare. J. Med. Virol. 62:334–344, 2000. © 2000 Wiley-Liss, Inc.

In areas with low hepatitis B virus (HBV) endemicity such as most parts of Europe and the United States “anti-HBc alone” is found in 10–20% of all individuals with HBV markers, i.e., 1–4% of the population. In about 10% of these individuals HBV DNA is detected by PCR, the proportions varying greatly depending on the population studied, being highest in individuals coinfected with hepatitis C virus (HCV) (above 35%) and HIV (above 85%). A small proportion of individuals with “anti-HBc alone” are in the window phase of an HBV infection or in a stage of late HBV immunity. For the large proportion of these individuals this is not the case and they are thought to have an unresolved HBV-infection or a chronic infection in a late or “low grade” productive state. Currently, limited studies have been performed concerning the clinical aspects of individuals with “anti-HBc alone” and suspected chronic HBV infection. The majority of these individuals seem to be healthy. Some chronic carriers with “anti-HBc alone,” however, do present signs of chronic hepatitis. Individuals with “anti-HBc alone” are potentially infectious. This is exemplified by a few case reports of HBV transmission to sexual contacts, perinatal transmission between mother and newborns and in blood recipients. Recommendations are given in relation to both the diagnostic and therapeutic procedures in the individuals with “anti-HBc alone” and in the blood banking and transplantation services. J. Med. Virol. 62:450–455, 2000. © 2000 Wiley-Liss, Inc.

The increasing use of hepatitis B vaccination has had an overwhelming positive impact on the prevention of hepatitis B viral infection. Mutations in the hepatitis B surface antigen (HBsAg) gene occur as a result of vaccine escape mutants, anti-hepatitis B surface antigen immunotherapy, or in chronic hepatitis B viral infection. These mutants may present a challenge to immunoassay detection. Evaluation of the immunodetection of various HBsAg mutants has been sporadic, as the occurrence of these mutants is not common, and sufficient volume of serum samples is difficult to obtain. To investigate mutant detection, recombinant antigens were constructed to reflect mutations described in the literature occurring throughout the S gene. A limited number of serum samples exhibiting discordant immunoassay reactivity were also used to construct recombinant antigens. The evaluation of 25 HBsAg mutants across nine commercial assays of differing formats is described. Mutations affecting immunoassay performance were characterized as occurring mainly in loop 2 of the “a” determinant of HBsAg. It was determined that reagent epitope recognition was more significant for mutant detection than assay format. J. Med. Virol. 59:19–24, 1999. © 1999 Wiley-Liss, Inc.

A rapid reverse transcription-polymerase chain reaction (RT-PCR) procedure for the detection of Hepatitis E virus (HEV) RNA in serum is described. Total nucleic acids are extracted from a small volume of human serum and reverse transcribed using random hexamers. An aliquot of cDNA is then utilized in nested PCR employing degenerate HEV consensus primers. These primers are designed to sequences conserved between the Burma, Mexico, and US HEV strains, generating amplicons within each of the three open reading frames. Reactions are analyzed by agarose gel electrophoresis and samples showing an ethidium bromide stained band of the appropriate size in the first and second amplification, or in the second amplification only, are designated as positive. This protocol allows for the rapid and sensitive detection of HEV infection in human serum.

Hepatitis E infection is typically associated with areas in which hepatitis E virus (HEV) is endemic. Except for a few cases in Europe and in the United States, acute hepatitis E is usually associated with travel to endemic areas. We set out to determine the etiologic role of HEV in acute non-A-C hepatitis in Italy. The presence of HEV-RNA and antibody was determined in 218 patients diagnosed with acute viral non-A-C hepatitis. Acute hepatitis E infection was defined by the presence of HEV-RNA in sera and positivity for IgM anti-HEV and seroconversion to IgG anti-HEV. Acute hepatitis E was found in 10.1% of the patients with acute non-A-C, with 95.5% exhibiting a benign course. A more severe course was observed in a patient co-infected with HAV and HEV. Most cases were travelers to endemic areas, although 18.2% reported no travel. One patient was from a household with an infected patient. Sequence analyses of the polymerase chain reaction (PCR) product derived from a patient who never visited endemic areas, identified an isolate that is divergent significantly from all reported isolates of HEV (79.5-85.8% nucleotide identity). Evidence from this study suggests that HEV accounts for approximately 10% of acute non-A-C viral hepatitis in Italy, diagnosed generally in travelers returning from endemic areas. However, the identification of a new HEV variant in an individual who never indicated travel or contact with individuals associated with endemic areas, suggests that this virus may be native to Italy.

Hepatitis E infection is associated with areas in which hepatitis E virus (HEV) infection is endemic. Acute infections in industrialized nations are usually linked to travel to endemic areas. Recently, an acute hepatitis infection in a patient from the United States (US), with no recent foreign travel history, was linked to a novel strain of HEV. Although a few additional cases have been reported from patients who have not traveled to endemic areas, the source of these infections has not been determined. The objective of this study was to identify additional HEV isolates from patients with acute infection who had no recent history of travel to areas where HEV is considered endemic, and to determine the genetic relationship between these and other HEV isolates. Viral RNA was isolated from serum and polymerase chain reaction (PCR) was performed using consensus primers based on a number of HEV isolates. HEV sequence in open reading frame (ORF) 1 and ORF2 was identified in three patients from nonendemic areas, one from Italy and two from Greece. Comparative and phylogenetic analyses were performed. The Greek and Italian isolates were significantly divergent from two isolates from the US and isolates identified previously from HEV-endemic regions. The Italian isolate was distinct from the two Greek isolates. In addition, the two Greek isolates were significantly divergent from each other. Phylogenetic analysis indicated that the Italian and two Greek isolates represent three new genotypes of HEV, distinct from the Burmese, Mexican, and US genotypes.

Prior to the recent discovery of the swine hepatitis E virus (swine HEV) in pigs from the midwestern United States, HEV was not considered endemic to this country. Since swine HEV is antigenically and genetically related to human strains of HEV, it was important to characterize this new virus further. The infectivity titer of a pool of swine HEV in pigs was determined in order to prepare a standardized reagent and to evaluate the dose response in pigs. Although the sequence of swine HEV varied extensively from those of most human strains of HEV, it was very closely related to the two strains of human HEV (US-1 and US-2) isolated in the United States. The U.S. strains which were recently recovered from two patients with clinical hepatitis E in the United States shared ≥97% amino acid identity with swine HEV in open reading frames 1 and 2. Phylogenetic analyses of different regions of the genome revealed that swine HEV and the U.S. strains grouped together and formed a distinct branch. These results suggested that swine HEV may infect humans. When we inoculated rhesus monkeys and a chimpanzee, experimental surrogates of humans, with swine HEV, the primates became infected. Furthermore, in a reciprocal experiment, specific-pathogen-free pigs were experimentally infected with the US-2 strain of human HEV that is genetically similar to swine HEV. These results provided experimental evidence for cross-species infection by the swine virus. Thus, humans appear to be at risk of infection with swine HEV or closely related viruses.

Recently, two new flaviviruses, GB virus A (GBV-A) and GB virus B (GBV-B), were identified in the plasma of a tamarin infected with the hepatitis GB agent. A third virus, GB virus C (GBV-C), was subsequently identified in humans. In the current study, representational difference analysis (RDA) was used to search for a new virus in the serum of a chimpanzee that developed acute resolving hepatitis following inoculation with a pool of chimpanzee plasma. The plasma pool originated from serial passages of a human sample containing virus-like particles. Numerous cDNA clones were obtained that exhibited 62–80% identity with GBV-C. With the exception of the extreme 5′ and 3′ ends, the complete viral genome was sequenced, revealing a single large open reading frame encoding a 2833 amino acid polyprotein that contains two envelope proteins, two proteases, a helicase, and an RNA-dependent RNA polymerase. Phylogenetic analysis of the new virus indicates that it is closely related to GBV-C, yet still sufficiently divergent as to be placed in a separate group, tentatively labeled GB virus Ctroglodytes (GBV-Ctro). Numerous human samples were screened by reverse transcriptase-polymerase chain reaction (RT-PCR), but GBV-Ctro sequence was not detected. However, a second chimpanzee inoculated with the same plasma pool was shown to develop a GBV-Ctro infection. Although isolated from an Old World primate with hepatitis, the primary host of GBV-Ctro and any association with disease remains to be determined. J. Med. Virol. 56:44–51, 1998. © 1998 Wiley-Liss, Inc.

The recent isolation of GB viruses A and B from GB agent infected tamarins and their lack of involvement in human hepatitis has sparked interest in the origin of these viruses. Several healthy non-human primate species have been shown to harbour sequences 52-79% identical to the GBV-A 5' nontranslated region. In this paper we report the near genome length sequence of GBV-Amx 70047 and GBV-Atri 1122. These sequences support previous observations about the genomic organization of GBV-A and provide insight into the genomic variability within this virus genus. Although the GBV-A variant polyproteins possess many motifs conserved between other members of the Flaviviridae, they do not encode a basic core-like protein. Amino acid sequence comparisons and phylogenetic analysis demonstrate variability within the GBV-A genus similar to that observed between hepatitis C virus (HCV) types. However, genomic organization and disease association demonstrate a closer evolutionary relationship to GBV-C than to HCV.

Exposure to GB virus C (GBV-C) was determined in several U.S. populations by both reverse-transcription-polymerase chain reaction (RT-PCR) and by an enzyme linked immunosorbent assay (ELISA) for antibodies to mammalian cell-expressed GBV-C envelope protein, E2 (GBV-C E2). Most individuals exposed to GBV-C were either RNA positive/ELISA negative or ELISA positive/RNA negative. Exposure, therefore, was measured as the sum of GBV-C RNA positive and GBV-C E2 antibody positive specimens, and was higher in commercial plasmapheresis donors (40.5%) than in volunteer blood donors (5.5%). In intravenous drug users (IVDUs), GBV-C exposure was 89.2%. Serial bleed specimens tested for GBV-C RNA indicate that some patients remain viremic for at least 3 years and fail to produce detectable antibodies to GBV-C E2. In other exposed individuals who tested negative for GBV-C RNA, antibodies to E2 appear to be similarly long-lived (greater than 3 years) with a fairly constant titer (ranging in reciprocal endpoint dilution from 336 to 21,504). Since the detection of GBV-C RNA and GBV-C E2 antibody are mutually exclusive in most exposed individuals, studies pertaining to incidence and prevalence of GBV-C infection require both antibody and nucleic acid detection.

A 315 amino acid recombinant segment of the GB virus C (GBV-C) E2 envelope glycoprotein (E2-315) was expressed and secreted from CHO cells. E2-315 was purified by affinity chromatography using a monoclonal antibody directed to a FLAG sequence genetically engineered onto the C terminus of the recombinant protein. The secreted protein had a molecular mass of 48-56 kDa and was shown to be N-glycosylated. Amino acid sequencing confirmed the expected N-terminal sequence. Purified E2-315 was used to develop an ELISA for detection of E2 antibodies in human sera. Antibodies to GBV-C E2 appeared to be directed toward conformational epitopes since human sera reactivity was detected in ELISA using native E2-315, but it was extremely weak or non-existent with denatured E2 protein. The use of an ELISA which can detect human GBV-C E2 antibodies will be important in further understanding of the clinical significance and epidemiology of GBV-C.

Background. The cloning of yet another hepatitis virus, GB virus-C (GBV-C), has provided the opportunity to study the prevalence, and clinical and laboratory characteristics, associated with GBV-C infection among cadaver organ donors and recipients of organs from infected donors. Methods. Stored sera from a cohort of cadaver organ donors from eight organ procurement organizations, representing different geographic regions of the United States previously screened for hepatitis C virus (HCV) infection, were tested for GBV-C RNA by polymerase chain reaction using degenerate primers derived from the NS3 helicase and 5′-untranslated regions of the GBV-C genome. Pre- and posttransplantation clinical data, and prevalence of GBV-C RNA among recipients of organs from GBV-C RNA-positive and -negative donors, were studied at one of the organ procurement organizations. Results. Twenty-one of 76 (27.6%) anti-HCV ELISA1-positive donors tested positive for GBV-C RNA compared with 6 of 82 (7.3%) ELISA1-negative donors (P=0.001). The prevalence of GBV-C RNA, extrapolated to all cadaver organ donors, was 8.3% (95% confidence interval [CI]: 5.6-11.1%) and was higher than the prevalence of HCV RNA (2.4%). Among ELISA1-positive donors, GBV-C RNA was present in 13 of 35 (37%) donors with HCV RNA, compared with 8 of 41 (20%) donors without HCV RNA (odds ratio [OR]=2.44, P=0.09). Blood alcohol level of more than 100 mg/dl (OR=9.43, P=0.05) and a positive anti-HCV ELISA2 (OR=4.58, P=0.001) were significantly associated with GBV-C infection. In addition, there was a trend toward an association between history of drug abuse (OR=5.23, P=0.06) and younger age (OR=0.97/year, P=0.06) with GBV-C infection. Organs from four GBV-C-positive donors and 47 GBV-C-negative donors procured by the New England Organ Bank (Newton, MA) were transplanted into 6 and 79 recipients, respectively. Among recipients of organs from GBV-C RNA-positive donors, the posttransplantation prevalence of GBV-C RNA (25%) was not significantly higher than among recipients of organs from GBV-C RNA-negative donors (23%). Among recipients in whom both pre- and posttransplantation sera were available, one of three (33%) recipients of kidneys from GBV-C RNA-positive donors acquired GBV-C RNA after transplantation, compared with 4 of 40 (10%) recipients of kidneys from GBV-C RNA-negative donors. After a median follow up of 6 years, the posttransplantation prevalence of liver disease, and graft and patient survival, were not significantly different between recipients of organs from GBV-C RNA-positive and -negative donors. Conclusions. Although GBV-C could be transmitted by organ transplantation, the results of this study preclude definitive conclusions. Further studies are required to determine the risk of transmission of GBV-C by organ transplantation and its role in posttransplantation liver disease.

An ELISA was developed for detection of antibodies to GB virus C (GBV-C) using a recombinant E2 protein expressed in CHO cells. Seroconversion to anti-E2 positivity was noted among several persons infected with GBV-C RNA-positive blood through transfusion. Of 6 blood recipients infected by GBV-C RNA-positive donors, 4 (67%) became anti-E2 positive and cleared their viremia. Thus, anti-E2 seroconversion is associated with viral clearance. The prevalence of antibodies to E2 was relatively low (3.0%-8.1%) in volunteer blood donors but was higher in several other groups, including plasmapheresis donors (34.0%), intravenous drug users (85.2%), and West African subjects (13.3%), all of whom tested negative by GBV-C reverse-transcription polymerase chain reaction (RT-PCR). These data demonstrate that testing for anti-E2 should greatly extend the ability of RT-PCR to define the epidemiology and clinical significance of GBV-C.

Chronic hepatitis B in patients lacking hepatitis B e antigen has been attributed to a hepatitis B virus variant (G-to-A mutation at nucleotide 1896 in the precore region of the genome). We therefore assessed the frequency and significance of this variant among 43 United States patients (10 with chronic hepatitis B seropositive for e antigen, 19 seronegative for e antigen, and 14 healthy carriers). Sera were tested for HBV DNA by polymerase chain reaction and branched DNA assay. The A1896 variant was detected by direct sequencing and ligase chain reaction. Serum HBV DNA was more frequently found among patients with e antigen-positive than e antigen-negative chronic hepatitis B. Viral titers were generally higher in those with e antigen. None of the e antigen-positive and only 24% of e antigen-negative patients harbored the A1896 variant. Patients infected with the variant were more often Asian, had had hepatitis B for longer and had higher levels of viral DNA than HBeAg-negative patients with the wild-type virus. The A1896 variant was found exclusively in patients infected with HBV genotypes C and D. Thus, the A1896 variant is uncommon in the United States. The activity of liver disease appears to be more closely related to the level of HBV replication than the presence of mutations at nucleotide 1896 in the genome.

A 336-amino-acid segment of the GB virus C second envelope protein (E2) has been produced in BHK-21 cells using the Semliki Forest virus vector system. Secretion of this protein was facilitated by deletion of a hydrophobic region at the C-terminus that may represent the membrane anchoring domain. The E2 protein recovered from the culture supernatant exhibited a molecular mass of approximately 52 kDa, with the increase in size relative to the polyprotein backbone being contributed by N-linked glycosylation. A radioimmunoprecipitation assay using GBV-C E2 was developed to test for the presence of antibodies against this protein in human sera. The prevalence of antibodies to E2 was high among injection drug users and other individuals at risk for acquiring parenterally transmitted agents. There was a much higher percentage of anti-E2 seropositivity in GBV-C RT-PCR negative compared to GBV-C RT-PCR positive samples from these populations. In addition, serial samples from patients transfused with blood containing GBV-C showed seroconversion to anti-E2 positivity and loss of GBV-C viremia as measured by RT-PCR within 11 months of transfusion in five of seven individuals. Thus, this system provided a rapid means to identify GBV-C E2 as a useful antigen for the study of GBV-C exposure.

Among the three recently described GB viruses (GBV-A, GBV-B, and GBV-C), only GBV-C has been linked to cryptogenic hepatitis in man. Because of the limited utility of currently available research tests to determine antibody response to GBV-C proteins, the prevalence of GBV-C RNA in human sera was studied using reverse transcription-polymerase chain reaction (RT-PCR). The prevalence of GBV-C is higher among volunteer blood donors with elevated serum alanine aminotransferase (ALT) levels (3.9%) than among volunteer blood donors with normal ALT levels (0.8%). Higher rates were also noted among commercial blood donors (12.9%) and intravenous drug users (16.0%). GBV-C was frequently detected in residents of West Africa, where the prevalence was > 10% in most age groups. Approximately 20% of patients diagnosed with either acute or chronic hepatitis C virus (HCV) were found to be positive for GBV-C RNA. In addition, GBV-C RNA sequences were detected in individuals diagnosed with non-A-E hepatitis, with clinical courses ranging from mild disease to fulminant hepatitis. Fourteen of sixteen subjects with or without clinically apparent hepatitis were positive for GBV-C RNA more than 1 year after the initial positive result.

The genomes of two novel members of the Flaviviridae associated with GB agent hepatitis (GB viruses A and B) were cloned and sequenced recently. The genome of a third novel virus (GB virus C), related to but distinct from GB viruses A and B, has also been identified and characterized. Overlapping clones encompassing the large open reading frames of these three viruses have been expressed in E. coli as CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase (CKS) fusion proteins. Bacterial lysates were subjected to Western blot analyses using sera from GB agent-infected tamarins and human sera from various individuals with or “at risk” for non-A, non-B, non-C, non-D, non-E hepatitis. Antigenic regions were identified in the putative NS3, NS4, and NS5 proteins from all three viruses. An antigenic region was also identified in the putative core protein of GB virus B. Many of the clones identified originally as encoding antigenic proteins were quite large. To map these regions more narrowly, smaller overlapping clones were generated by polymerase chain reaction (PCR), expressed as recombinant CKS fusion proteins and tested by Western blot. Additionally, a λgt11 expression library was generated from infectious tamarin sera and immunoscreened. These studies have identified at least three epitopes in GB virus A, five epitopes in GB virus B and four epitopes in GB virus C. © 1996 Wiley-Liss, Inc.

The hepatitis E virus (HEV) is a cause of severe liver disease in humans, especially in developing countries. Several assays are available to detect the HEV genome and specific antibodies against HEV (anti-IgG, IgA and IgM). Different serological patterns enable the diagnostician to differentiate remote from recent infections. In order to avoid diagnostic errors based on incomplete serological diagnosis, these patterns are shown with their specific serological marker.

The seroprevalences of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers were evaluated in a random sample of 803 children attending school in Ashanti-Akim North district in Ghana in order to gain a better understanding of transmission patterns of these viruses, particularly horizontal transmission of HBV. This rural district is typical of 70% of the Ghanaian population. The overall seroprevalence of at least one marker of HBV infection was 61.2%, with rates increasing from 48% to 80% between the ages of 6–18 years (P 50% lacked detectable levels of anti-HBs, an unusual pattern of convalescent immune response to HBV. The overall seroprevalence of anti-HCV was 5.4% and did not differ significantly by age or gender. Anti-HCV seroprevalence was not associated with the presence of any HBV marker. A better understanding of the unusually high prevalences of HBV and HCV infections demonstrated in this population is likely to influence vaccination and blood transfusion policies and to stimulate further evaluations of these infections and their vehicles of spread in highly endemic regions such as sub-Saharan Africa. © 1996 Wiley-Liss, Inc.

Recently, sequences from a novel virus, termed GB virus C (GBV-C), were identified in serum from several patients with cryptogenic hepatitis. In the present study, the nucleotide sequence of this virus has been extended to near-genome length. GBV-C encodes a putative single large polyprotein in which the structural proteins are positioned at the N-terminal end, with the non-structural proteins located at the C-terminal end. Amino acid sequence analysis of this large polyprotein reveals the presence of protease, helicase, and replicase motifs. Sequence alignments of the polyprotein followed by phylogenetic analyses suggest that GBV-C is a member of the Flaviviridae, most closely related to the recently described GB virus A.

Two flavivirus-like genomes have recently been cloned from infectious tamarin (Saguinus labiatus) serum, derived from the human viral hepatitis GB strain, which is known to induce hepatitis in tamarins. In order to study the natural history of GB infections, further transmission studies were carried out in tamarins. Reverse-transcription-polymerase chain reaction and enzyme-linked immunosorbant assays were developed for the detection of RNA and antibodies associated with the two agents, GB virus-A and GB virus-B. The infectivity of both of these agents was demonstrated in tamarins to be filterable through a 0.1 micron filter. Two distinct genomes were identified in the serum of eight of the infected tamarins, while in four tamarins, the genomes were detected independently of each other. Although specific antibodies to the GB virus-B epitopes were detected in the serum of animals inoculated with both agents or GB virus-B alone, antibodies to putative epitopes specific to GB virus-A were not detected in any of the animals. All tamarins inoculated with serum containing GB virus-B exhibited an elevation in liver enzyme levels after inoculation. Elevations of serum liver enzyme levels did not occur when GB virus-A was the only agent detected in the serum. Infection with the original infectious tamarin inoculum conferred protection from reinfection with GB virus-B but not with GB virus-A.

A total of 12 patients previously treated for acute hepatitis of unknown aetiology were retrospectively found to be anti-hepatitis E virus (HEV) IgG-positive. Four patients were anti-HEV IgM- and IgG-positive consistent with an acute HEV infection. All 4 had travelled to or were immigrants from HEV-endemic countries. One anti-HEV IgM-negative patient seroconverted from anti-HEV IgG-negative to positive and 3 from anti-HEV IgG-positive to negative in 2 consecutive serum samples. Of the remaining 4 patients without anti-HEV IgM, 3 had a history of recent travel to an HEV-endemic country. Most patients were young adults and all but 1 recovered from the hepatitis. One patient with a fulminant hepatitis was anti-HEV IgG-positive when tested 4 months after a journey to Turkey. She died from her fulminant hepatitis shortly after admission. All the other patients but 1 normalized their serum liver enzymes within 1-2 months after the onset of disease.

A 681 nucleotide fragment of the hepatitis B virus (HBV) genome was sequenced that corresponded to the complete gene for hepatitis B surface antigen (HBsAg) in 80 HBsAg- and hepatitis B e antigen (HBeAg)-positive sera of diverse geographical origins. These and 42 previously published HBV sequences within the S gene were used for the construction of a dendrogram. In this comparison, each of the 122 HBsAg genes was found to be related to one or other of the six previously identified genomic groups of HBV, A to F. The HBV strains within each genomic group showed a characteristic geographical distribution. Group A genomes were represented by 23 strains mainly originating in northern Europe and sub-Saharan Africa. The group B and C genomes, represented by 17 and 28 strains respectively, were confined to populations with origins in eastern Asia and the Far East. The group D genomes, represented by 38 strains, were found worldwide, but were the predominant strains in the Mediterranean area, the Near and Middle East, and in south Asia. Group E genomes, represented by nine strains, were indigenous to western sub-Saharan Africa as far south as Angola. There were indications that the F group, made up of six strains, represented the genomic group of HBV among populations with origins in the New World. Thus, HBV has diverged into genomic groups according to the distribution of mankind in the different continents. As well as giving information on the genetic relationship of HBV strains of different geographical origin, this study also provides information on the primary structure of HBsAg in different regions of the world. Such data might prove valuable in explaining the reported failures to obtain protection with current HBV vaccines.

Sucrose and cesium chloride density gradients were used to fractionate hepatitis C virus (HCV) infectious chimpanzee plasma. The fractionated plasma was then evaluated for HCV RNA sequences using cDNA synthesis and the polymerase chain reaction (cDNA/PCR). cDNA/PCR detectable HCV RNA was identified repeatedly in two regions. One region was at the top of the gradients with a buoyant density of ⩽ 1.03 g/cm3, the other at a density of approximately 1.18–1.21 g/cm3.

Two overlapping sets of TT virus (TTV)-specific polymerase chain reaction primers were used to test for presence of TTV, which was found in approximately 10% of US volunteer blood donors, 13% of commercial blood donors, and 17% of intravenous drug abusers. The rate of TTV infection among US non-A, non-B, non-C, non-D, non-E hepatitis patients was only 2%. Among commercial blood donors and intravenous drug abusers, only 1%-3% of the TTV-positive individuals were coinfected with GB virus C (GBV-C), a parenterally transmitted virus. This suggests that GBV-C and TTV may have different routes of transmission. Comparison of the sensitivities of 2 TTV polymerase chain reaction (PCR) primer sets showed that the majority of samples were detected with only 1 of the 2 sets. Therefore, previous studies in which only a single PCR primer pair was used may have significantly underestimated the true prevalence of TTV.

This study evaluated the antinociceptive effects of the selective and non-peptide CXCR2 antagonist SB225002 in mouse models of pain. As assessed in different tests of spontaneous nociception, intraperitoneal (i.p.) administration of SB225002 caused consistent and dose-related reduction of acetic acid-induced abdominal constrictions, whereas it did not significantly affect the nociception evoked by formalin, capsaicin, glutamate or phorbol ester acetate (PMA). Systemic treatment with SB225002 strikingly reduced the spontaneous nociception induced by 8-bromo-cAMP (8-Br-cAMP), or mechanical hypernociception induced by prostaglandin E(2) (PGE(2)), epinephrine, or the keratinocyte-derived chemokine (KC). In the carrageenan model, SB225002 markedly reduced mechanical hypernociception when administered by i.p., intrathecal (i.t.) or intracerebroventricular (i.c.v.) routes, or even when co-administered with carrageenan into the mouse paw, indicating peripheral and central sites of action for SB225002. In addition, i.p. treatment with SB225002 significantly attenuated the increase in MPO activity or the elevation of IL-1beta, TNFalpha or KC levels following carrageenan injection. In the persistent models of pain evoked by complete Freund's adjuvant (CFA) or by the partial ligation of the sciatic nerve (PLSN), the repeated administration of SB225002 displayed prominent and long-lasting antinociceptive effects. Notably, SB225002 did not evoke unspecific central effects, as evaluated in the open-field and rota-rod tests, or even in the latency responses for thermal stimuli. Our data confirm the previous notion on the critical role exerted by chemokines in pain, indicating that selective CXCR2 antagonists, such as SB225002, might well represent interesting and innovative alternatives for the management of both acute and chronic pain.

Hepatitis E virus (HEV), the sole member of the genus Hepevirus in the family of Hepeviridae, is the major cause of several outbreaks of waterborne hepatitis in tropical and subtropical countries and of sporadic cases of viral hepatitis in endemic and industrialized countries. Transmission of HEV occurs predominantly by the fecal-oral route although parenteral and perinatal routes have been implicated. The overall death rate among young adults and pregnant women is 0.5–3% and 15–20%, respectively. HEV is a small non-enveloped particle that consists of a polyadenylated single-strand RNA molecule containing three discontinuous and partially overlapping open reading frames. There are four major genotypes of HEV and a single serotype. At present, there are approximately 1,600 sequences of HEV that are already available at INSDC of both human and animal isolates. Diagnostic and molecular assays have been described for the accurate differentiation of ongoing from remote infection of HEV. Identification and characterization of swine HEV in the United States, Japan, and many other countries and their close relationship to locally characterized human HEV found in the same geographic areas prove that HEV is indeed a zoonotic virus and that domestic swine, wild deer, and boars are reservoirs of HEV in nature. A cell culture system for the propagation of the virus has been described, and a very successful phase 2 vaccine trial has been completed. This review summarizes the current knowledge on the molecular biology, clinical features, transmission, diagnosis, epidemiology, and prevention of HEV. J. Med. Virol. 80:646–658, 2008. © 2008 Wiley-Liss, Inc.

In the last 30 years, tremendous progress in identifying transfusion-transmitted viruses such as HBV, HCV, and HIV in industrialized countries has been achieved. Currently, the residual risk of transmitting these viruses through transfusion is very low especially after the introduction of "minipool" nucleic acid-amplification tests. Despite these major technical advances, there remains a legitimate concern as to the transmission of other blood-borne infectious agents through blood transfusion. Among these agents are HBV mutants, occult HBV, and HCV infections, malaria, Chagas, West Nile, dengue, and vesiviruses, bacterial infections such as Yersinia enterocolitica, and tick borne diseases such as human monocytic ehrlichiosis, human granulocytic ehrlichiosis, Rocky Mountain spotted fever, and Lyme and prion diseases such as Creutzfeldt and variant Creutzfeldt. Most of these agents are very rarely transmitted by transfusion in industrialized countries. However, an awareness of their possible transmission is essential for the control of spread of these diseases among the public by human-to-human transmission via blood transfusion. This review summarizes the current status of prevalence and diagnosis of these emerging diseases and also updates our knowledge on recently discovered non-pathogenic blood-borne viruses such as GB virus C and Torque Tenoviruses.