Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| histo-blood group antigen and human milk oligosaccharides: genetic polymorphism and risk of infectious diseases. | abh and lewis antigens are carbohydrates present on gut epithelial cells. these antigens provide diversity within the human population. their biosynthesis largely is controlled by the enzyme products of alleles at the abo, fut2 and fut3 loci. we have shown that norwalk virus (nv) uses structures based on h type 1 as its primary receptor. norwalk virus is the prototype of human caliciviruses, which collectively are responsible for the majority of gastroenteritis outbreaks in people of all ages. i ... | 2004 | 15384573 |
| development of homologous viral internal controls for use in rt-pcr assays of waterborne enteric viruses. | enteric viruses often contaminate water sources causing frequent outbreaks of gastroenteritis. reverse transcription-polymerase chain reaction (rt-pcr) assays are commonly used for detection of human enteric viruses in environmental and drinking water samples. rt-pcr provides a means to rapidly detect low levels of these viruses, but it is sensitive to inhibitors that are present in water samples. inhibitors of rt-pcr are concentrated along with viruses during sample processing. while procedures ... | 2004 | 15350731 |
| nisin-controlled expression of norwalk virus vp60 protein in lactobacillus casei. | a food-grade strain with nisrk stably integrated into the genome, was constructed in order to implement the nisin-controlled expression system (nice) in lactobacillus casei atcc393. expression of beta-glucuronidase (gus) reporter gene was employed to optimize the system, which has been successfully used to produce the main antigenic protein from norwalk virus, opening new perspectives for producing edible vaccines. | 2004 | 15321687 |
| [three kinds of viruses isolated from diarrhea patients of infants and preschool children in fuzhou city]. | 2004 | 15231185 | |
| norovirus disease: changing epidemiology and host susceptibility factors. | noroviruses cause the majority of acute viral gastroenteritis cases that occur worldwide. the increased recognition of noroviruses as the cause of outbreaks and sporadic disease is due to the recent availability of improved norovirus-specific diagnostics. transmission of these viruses is facilitated by their high prevalence in the community, shedding of infectious virus particles from asymptomatic individuals and the high stability of the virus in the environment. currently, the spectrum of clin ... | 2004 | 15165606 |
| inter- and intragenus structural variations in caliciviruses and their functional implications. | the family caliciviridae is divided into four genera and consists of single-stranded rna viruses with hosts ranging from humans to a wide variety of animals. human caliciviruses are the major cause of outbreaks of acute nonbacterial gastroenteritis, whereas animal caliciviruses cause various host-dependent illnesses with a documented potential for zoonoses. to investigate inter- and intragenus structural variations and to provide a better understanding of the structural basis of host specificity ... | 2004 | 15163740 |
| the p domain of norovirus capsid protein forms dimer and binds to histo-blood group antigen receptors. | noroviruses (nvs) are the most important pathogen of epidemic nonbacterial gastroenteritis. the recent finding that nvs recognize human histo-blood group antigens (hbgas) as receptors provided a new approach to study the pathogenesis of nvs. using computational and site-directed mutagenesis approaches, our investigators previously identified a plausible binding pocket in the p domain of the nv capsids. in this study, we further characterize the role of the p domain in the interaction with human ... | 2004 | 15163716 |
| transmission of acute infectious nonbacterial gastroenteritis to volunteers by oral administration of stool filtrates. 1971. | 2004 | 15143483 | |
| norwalk precipitates severe lithium toxicity. | 2004 | 15101507 | |
| norwalk virus n-terminal nonstructural protein is associated with disassembly of the golgi complex in transfected cells. | norwalk virus is the prototype strain for members of the genus norovirus in the family caliciviridae, which are associated with epidemic gastroenteritis in humans. the nonstructural protein encoded in the n-terminal region of the first open reading frame (orf1) of the norwalk virus genome is analogous in gene order to proteins 2a and 2b of the picornaviruses; the latter is known for its membrane-associated activities. confocal microscopy imaging of cells transfected with a vector plasmid that pr ... | 2004 | 15078964 |
| emerging food pathogens and bacterial toxins. | many different foodborne diseases have been described. for example, shigella bacteria, hepatitis a virus and norwalk virus were shown as a unwashed hands microorganisms, but pathogen campylobacter and escherichia coli were named as raw and undercooked meat and poultry or raw milk and untreated water born bacteria. however, two of them: listeria monocytogenes and yersinia enterocolitica are known as growing at refrigerator temperatures. essential virulence determinants of listeria monocytogenes p ... | 2003 | 15058810 |
| [preliminary study of human calicivirus infection in guangzhou]. | to investigate of human calicivirus (hucv) infection in the children of guangzhou, the capital of guangdong province at china, and conduct preliminary study of the prevalence of the virus. | 2004 | 15041544 |
| norovirus capture with histo-blood group antigens reveals novel virus-ligand interactions. | noroviruses are genetically diverse, uncultivable, positive-sense rna viruses and are the most common cause of epidemic acute gastroenteritis in humans in the united states. recent studies of norovirus attachment in vitro by using recombinant virus-like particles (vlps) suggest that various norovirus strains exhibit different patterns of attachment to abh histo-blood group antigens, which are carbohydrate epitopes present in high concentrations on mucosal cell surfaces of the gut. however, attac ... | 2004 | 14990722 |
| prevalence of infection with waterborne pathogens: a seroepidemiologic study in children 6-36 months old in san juan sacatepequez, guatemala. | water and sanitation interventions in developing countries have historically been difficult to evaluate. we conducted a seroepidemiologic study with the following goals: 1) to determine the feasibility of using antibody markers as indicators of waterborne pathogen infection in the evaluation of water and sanitation intervention projects; 2) to characterize the epidemiology of waterborne diarrheal infections in rural guatemala, and 3) to measure the age-specific prevalence of antibodies to waterb ... | 2004 | 14971703 |
| crystal structure of norwalk virus polymerase reveals the carboxyl terminus in the active site cleft. | norwalk virus is a major cause of acute gastroenteritis for which effective treatments are sorely lacking. to provide a basis for the rational design of novel antiviral agents, the main replication enzyme in norwalk virus, the virally encoded rna-dependent rna polymerase (rdrp), has been expressed in an enzymatically active form, and its structure has been crystallographically determined both in the presence and absence of divalent metal cations. although the overall fold of the enzyme is simila ... | 2004 | 14764591 |
| a sybr green, real-time rt-pcr method to detect and quantitate norwalk virus in stools. | a simple, single tube, hot start, real-time reverse transcription-pcr (rt rt-pcr) technique using sybr green fluorescence was developed for the detection of genogroup i, cluster 1 norwalk virus (nv) in stools. sample dilution and heat release of viral rna was effective as an alternative to more complex procedures to extract viruses from stool specimens. real-time rt-pcr was applied to 68 stool isolates from patients participating in a nv volunteer study. first derivative melt curves were used to ... | 2004 | 14715308 |
| in the public's view... vomiting on the high seas. | 2003 | 14702792 | |
| norwalk virus: a need for more awareness. | 2003 | 14700024 | |
| ultrastructure changes induced by dry film formation of a trisodium phosphate blend, antimicrobial solution. | trisodium phosphate (tsp) has been reported to have antimicrobial activity and is approved by the u.s. department of agriculture for use in food processing applications. a novel (u.s. patent 6,184,198), antimicrobial solution containing a blend of tsp, sodium bicarbonate, and sodium carbonate (tsp blend) has demonstrated effective inhibition of microbial contamination in a broad spectrum of applications. this high-resolution cold field emission scanning electron microcopy (lvsem) investigation d ... | 2003 | 14696975 |
| [incidence and prevalent types of norwalk virus, sapporo virus and human astrovirus in pediatric gastroenteritis in hiroshima prefecture]. | the incidence and prevalent types of norwalk virus (nv), sapporo virus (sv), and human astrovirus (hastv) in pediatric gastroenteritis in hiroshima prefecture were investigated in 7 cold seasons, between 1995/96 and 2001/02. the incidences of nv, sv, and hastv were 23.6% ranging from 16.3 to 34.4, 2.5% ranging from 1.5 to 4.7, and 3.2% ranging from 1.5 to 6.0, respectively. the peak of the incidence of nv was found in november and december. no accumulation of monthly incidence in sv or hastv was ... | 2003 | 14672009 |
| simultaneous detection of enteric viruses by multiplex real-time rt-pcr. | a multiplex real-time rt-pcr protocol for the simultaneous detection of noroviruses ("norwalk-like viruses") of genogroups i and ii, human astroviruses and enteroviruses is described. the protocol was developed and evaluated using the lightcycler and corresponding sybr green reagents. new primers were designed within conserved genome regions to optimize the detection range of virus subtypes of each genus. to enable the development of a multiplex pcr assay within one tube (capillary), similar mas ... | 2004 | 14656455 |
| la, ptb, and pab proteins bind to the 3(') untranslated region of norwalk virus genomic rna. | noroviruses are human enteric caliciviruses for which no cell culture is available. consequently, the mechanisms and factors involved in their replication have been difficult to study. in an attempt to analyze the cis- and trans-acting factors that could have a role in nv replication, the 3(')-untranslated region of the genome was studied. use of zuker's mfold-2 software predicted that nv 3(')utr contains a stem-loop structure of 47 nts. proteins from hela cell extracts, such as la and ptb, form ... | 2003 | 14623338 |
| the healthy traveler: cruising past infection. | 2003 | 14619804 | |
| norwalk virus nonstructural protein p48 forms a complex with the snare regulator vap-a and prevents cell surface expression of vesicular stomatitis virus g protein. | norwalk virus (nv), a reference strain of human calicivirus in the norovirus genus of the family caliciviridae, contains a positive-strand rna genome with three open reading frames. orf1 encodes a 1,789-amino-acid polyprotein that is processed into nonstructural proteins that include an ntpase, vpg, protease, and rna-dependent rna polymerase. the n-terminal protein p48 of orf1 shows no significant sequence similarity to viral or cellular proteins, and its function in the human calicivirus replic ... | 2003 | 14557663 |
| the 3' end of norwalk virus mrna contains determinants that regulate the expression and stability of the viral capsid protein vp1: a novel function for the vp2 protein. | norwalk virus (nv) is the prototype strain of a group of noncultivable human caliciviruses responsible for epidemic outbreaks of acute gastroenteritis. the capsid protein vp1 is synthesized from a subgenomic rna that contains two open reading frames (orfs), orf2 and orf3, and the 3' untranslated region (utr). orf2 and orf3 code for the capsid protein (vp1) and a small structural basic protein (vp2), respectively. we discovered that the yields of virus-like particles (vlps) composed of vp1 are si ... | 2003 | 14557646 |
| debugging your travel plans. | 2003 | 14533593 | |
| detection, quantitation, and phylogenetic analysis of noroviruses in japanese oysters. | noroviruses (nvs) cause many cases of oyster- or clam-associated gastroenteritis in various countries. we collected 191 samples from japanese oysters intended for raw consumption that had been harvested from the sea in two different areas between december 2001 and february 2002. to detect, quantitate, and phylogenetically analyze the nv genome in purified concentrates from the stomachs and digestive diverticula of these oysters, we amplified the nv capsid gene by reverse transcription-pcr. phylo ... | 2003 | 14532025 |
| in vitro proteolytic processing of the md145 norovirus orf1 nonstructural polyprotein yields stable precursors and products similar to those detected in calicivirus-infected cells. | the md145-12 strain (gii/4) is a member of the genus norovirus in the caliciviridae and was detected in a patient with acute gastroenteritis in a maryland nursing home. the open reading frame 1 (orf1) (encoding the nonstructural polyprotein) was cloned as a consensus sequence into various expression vectors, and a proteolytic cleavage map was determined. the virus-encoded cysteine proteinase mediated at least five cleavages (q(330)/g(331), q(696)/g(697), e(875)/g(876), e(1008)/a(1009), and e(118 ... | 2003 | 14512545 |
| inhibition of attachment of virions of norwalk virus to mammalian cells by soluble histone molecules. | viral infection is usually initiated by the binding of virus particles to specific receptor molecule(s) on the host cell surface. blocking of this step prevents the following step, penetration into the cell. in the present study, we investigated the virus-cell interactions of virions of norwalk virus (nv), a major etiological agent for viral diarrhea. we found that histone was an extremely strong nv-binding protein. histone h1, a heterologous histone molecule, appeared to be able to interact not ... | 2003 | 14505080 |
| humoral, mucosal, and cellular immune responses to oral norwalk virus-like particles in volunteers. | norwalk virus-like particles (vlps), made from recombinant capsid protein, are a promising vaccine. thirty-six healthy adult volunteers received 250 microg (n = 10), 500 microg (n = 10), or 2000 microg (n = 10) of orally administered vlp or placebo (n = 6). all vaccinees developed significant rises in iga anti-vlp antibody-secreting cells. ninety percent who received 250 microg developed rises in serum anti-vlp igg; neither the rates of seroconversion nor geometric mean titers increased at the h ... | 2003 | 14499247 |
| communicable disease and health protection quarterly review: october to december 2002. | 2003 | 12848412 | |
| reduction of norwalk virus, poliovirus 1, and bacteriophage ms2 by ozone disinfection of water. | norwalk virus and other human caliciviruses (noroviruses) are major agents of gastroenteritis, and water is a major route of their transmission. in an effort to control norwalk virus in drinking water, norwalk virus reduction by bench-scale ozone disinfection was determined using quantitative reverse transcription (rt)-pcr for virus assays. two other enteric viruses, poliovirus 1 and coliphage ms2, were included for comparison, and their reductions were assayed by infectivity assays as well as b ... | 2003 | 12839770 |
| presence of viral genomes in mineral water: a sufficient condition to assume infectious risk? | appropriate interpretation of a positive reverse transcription-pcr is an important issue for virus-related health hazard assessment because viral genomes and infectious viruses exhibit different behavior patterns in water. in this context, using poliovirus 1 and feline calicivirus f9 as examples of enteric viruses, first we demonstrated that the stability of infectious viruses is greatly affected by the temperature of mineral water (10, 20, and 35 degrees c) and that, in contrast, temperature ha ... | 2003 | 12839768 |
| norwalk virus infection and disease is associated with abo histo-blood group type. | 2003 | 12825190 | |
| [outbreaks of viral gastroenteritis, in particular due to the norwalk virus: an underestimated problem]. | 2003 | 12814028 | |
| molecular epidemiology of norwalk-like virus (nlv) outbreaks occurring in kyushu japan between 1988 and 1993. | in nine outbreaks that occurred in the kyushu district between 1988 and 1993, we determined the nucleotide sequences of norwalk-like virus (nlv) gene fragments amplified by rt-pcr and molecular-epidemiologically analyzed the nlv epidemics. it is known that the nlv strains isolated from nine outbreaks of acute gastroenteritis, were divided into five clusters consisting of two genogroups. described by the year of outbreaks, the genogroup-1 (norwalk-like virus group) was prevalent in 1988, 1989, an ... | 2003 | 12803379 |
| studies of epidemiology and seroprevalence of bovine noroviruses in germany. | jena virus (jv) is a bovine enteric calicivirus that causes diarrhea in calves. the virus is approximately 30 nm in diameter and has a surface morphology similar to the human norwalk virus. the genome sequence of jv was recently described, and the virus has been assigned to the genus norovirus of the family caliciviridae: in the present study, the jv capsid gene encoded by open reading frame 2 was cloned into the baculovirus transfer vector pfastbac 1, and this was used to transform escherichia ... | 2003 | 12791840 |
| a multiplex reverse transcription-pcr method for detection of human enteric viruses in groundwater. | untreated groundwater is responsible for about half of the waterborne disease outbreaks in the united states. human enteric viruses are thought to be leading etiological agents of many of these outbreaks, but there is relatively little information on the types and levels of viruses found in groundwater. to address this problem, monthly samples from 29 groundwater sites were analyzed for 1 year for enteroviruses, hepatitis a virus, norwalk virus, reoviruses, and rotaviruses by multiplex reverse t ... | 2003 | 12788711 |
| the genome-linked protein vpg of the norwalk virus binds eif3, suggesting its role in translation initiation complex recruitment. | the positive-strand rna genomes of caliciviruses are not capped, but are instead covalently linked at their 5' ends to a viral protein called vpg. the lack of a cap structure typical of eukaryotic mrna and absence of an internal ribosomal entry site suggest that vpg may function in translation initiation on calicivirus rna. this hypothesis was tested by analyzing binding of norwalk virus vpg to translation initiation factors. the eif3d subunit of eif3 was identified as a binding partner of vpg b ... | 2003 | 12773399 |
| [outbreak of gastroenteritis caused by norwalk virus at a senior citizens assisted living facility in granada, spain]. | the outbreaks of acute gastroenteritis caused by a virus are currently one of the health problems having the greatest impact on those living in senior citizen facilities. the objective of this study is that of investigating the causes of the start and contagion of an outbreak of acute gastroenteritis caused by a norwalk-like virus. | 2003 | 12728663 |
| [norwalk virus infection]. | 2003 | 12722207 | |
| [norwalk virus]. | 2003 | 12718012 | |
| processing of norwalk virus nonstructural proteins by a 3c-like cysteine proteinase. | expression of norwalk virus nonstructural polyprotein precursor in vitro resulted in rapid cotranslational cleavage at specific sites. the cleavage products were similar to those previously identified for southampton virus, a highly related virus. we inactivated the virally encoded proteinase responsible for cleavage of the nonstructural polyprotein by mutation of the putative catalytic cysteine residue, which resulted in production of full-length polyprotein precursor. nv proteinase was express ... | 2003 | 12706072 |
| [nutrition and health--infections caused by food]. | the annual incidence of food-borne infections in the netherlands is estimated to be 250,000 or more; registration, however, is lacking. meat, poultry, milk and eggs are contaminated primarily by intestinal animal commensals (salmonella, campylobacter, e. coli o157:h7, yersinia enterocolitica) or secondarily by animals, humans and the environment during processing (typhoid fever, shigella, listeria, clostridium, hepatitis a virus, norwalk virus, parasites). the guidelines for the prevention of co ... | 2003 | 12701391 |
| human susceptibility and resistance to norwalk virus infection. | infectious diseases have influenced population genetics and the evolution of the structure of the human genome in part by selecting for host susceptibility alleles that modify pathogenesis. norovirus infection is associated with approximately 90% of epidemic non-bacterial acute gastroenteritis worldwide. here, we show that resistance to norwalk virus infection is multifactorial. using a human challenge model, we showed that 29% of our study population was homozygous recessive for the alpha(1,2)f ... | 2003 | 12692541 |
| viruses causing gastroenteritis. | acute gastroenteritis is one of the most common diseases in humans worldwide. viruses are recognized as important causes of this disease, particularly in children. since the norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. rotavirus is the most common cause of severe diarrhea in children under 5 years of age. astrovirus, calicivirus and enteric adenovirus are also important etiologic agents ... | 2003 | 12667234 |
| norwalk or noroviruses. | 2003 | 12649997 | |
| comparative reduction of norwalk virus, poliovirus type 1, f+ rna coliphage ms2 and escherichia coli in miniature soil columns. | norwalk-like viruses (nlvs) are important agents of waterborne illness and have been linked to several groundwater-related outbreaks. the presence of human enteric viruses, in particular the presence of nlvs, is difficult to detect in the environment. consequently, surrogate organisms are typically used as indicators of viruses from faecal contamination. whether traditional bacterial indicators are reliable indicators for viral pathogens remains uncertain. few studies have directly compared mobi ... | 2003 | 12639010 |
| an outbreak of norwalk-like viral gastroenteritis in holidaymakers travelling to andorra, january-february 2002. | a retrospective cohort study was conducted to investigate an outbreak of norwalk-like viral gastroenteritidis that occurred in irish holidaymakers visiting andorra, in january-february 2002. preliminary results showed the risk exposure was higher for tourists who stayed in soldeu and consumed ice cubes in their drinks (or = 2.5, 95% ci [1.3-4.6)], after logistic regression and adjusting for sex and water consumption). | 2003 | 12631977 |
| two nonoverlapping domains on the norwalk virus open reading frame 3 (orf3) protein are involved in the formation of the phosphorylated 35k protein and in orf3-capsid protein interactions. | expression of the norwalk virus open reading frame 3 (orf3) in spodoptera frugiperda (sf9) cells yields two major forms, the predicted 23,000-molecular-weight (23k) form and a larger 35k form. the 23k form is able to interact with the orf2 capsid protein and be incorporated into virus-like particles. in this paper, we provide mass spectrometry evidence that both the 23k and 35k forms are composed only of the orf3 protein. two-dimensional gel electrophoresis and phosphatase treatment showed that ... | 2003 | 12610132 |
| evaluation of a commercial elisa for detecting norwalk-like virus antigen in faeces. | a commercially available enzyme immunoassay, the ideia norwalk-like virus (nlv) enzyme linked immunosorbent assay (elisa; dako cytomation, ely, uk) for detecting nlv antigen in faecal samples and determining the nlv genogroup was evaluated. the performance of the elisa was compared with that of electron microscopy and the reverse transcription polymerase chain reaction by testing a panel of faecal samples collected from patients involved in outbreaks of gastroenteritis. when compared with revers ... | 2003 | 12589841 |
| major incidents. norwalk on the wild side. | an outbreak of the norwalk-like virus at an acute hospital in october affected 147 patients and 200 staff. it was brought under control within two weeks, following the establishment of a team to manage the incident. some day surgery was cancelled, but no inpatient operations were affected. the public was discouraged from visiting the hospital during the outbreak. local gps were co-operative about managing patients with the virus at home. some doctors came to work with symptoms, despite the trust ... | 2003 | 12577823 |
| incidence of enteric viruses in groundwater from household wells in wisconsin. | recent studies on the contamination of groundwater with human enteric viruses have focused on public water systems, whereas little is known about the occurrence of viruses in private household wells. the objective of the present study was to estimate the incidence of viruses in wisconsin household wells located near septage land application sites or in rural subdivisions served by septic systems. fifty wells in seven hydrogeologic districts were sampled four times over a year, once each season. ... | 2003 | 12571044 |
| evaluation of the nuclisens basic kit assay for detection of norwalk virus rna in stool specimens. | norwalk-like viruses (nlvs) are a genetically diverse group of human caliciviruses that are the most common cause of epidemic gastroenteritis and are detected typically in stool by reverse transcription (rt)-pcr or electron microscopy (em). the application of a rapid nucleic acid sequence-based amplification (nasba) assay for the detection of nlv rna in stool is described using the nuclisens basic kit. primers and probes for the nlv basic kit assay were based on the rna polymerase region of the ... | 2003 | 12565163 |
| microbial agents associated with waterborne diseases. | many classes of pathogens excreted in feces are able to initiate waterborne infections. there are bacterial pathogens, including enteric and aquatic bacteria, enteric viruses, and enteric protozoa, which are strongly resistant in the water environment and to most disinfectants. the infection dose of viral and protozoan agents is lower than bacteria, in the range of one to ten infectious units or oocysts. waterborne outbreaks of bacterial origin (particularly typhoid fever) in the developing coun ... | 2002 | 12546197 |
| [evaluation of norwalk virus detection kit by enzyme immunoassay]. | we briefly examined detection kit using the eia method for norwalk virus, and compared the results of the tests using the eia method with those using rt-pcr method. in reproducibility, an amount of variation was observed in data obtained from positive controls and in lower values. the sensitivity obtained from the eia method was about 300 times lower than that obtained from the rt-pcr method. results accordance ratio between eia method and rt-pcr method was 70%. this results discrepancy was pres ... | 2002 | 12542393 |
| a modified cholera holotoxin ct-e29h enhances systemic and mucosal immune responses to recombinant norwalk virus-virus like particle vaccine. | in this study, we evaluated the potential of a genetically modified cholera toxin, ct-e29h as an adjuvant for recombinant norwalk virus like particle (nv-vlp) vaccine. this detoxified mutant, containing e to h substitution at amino acid 29 of the ct-a1 subunit, was administered with a recombinant norwalk virus like particle vaccine to balb/c mice by mucosal routes to monitor the induction of mucosal, humoral and cellular responses. we observed that a low dose of nv-vlp (5 microg) with the adjuva ... | 2003 | 12531635 |
| [outbreaks of viral gastroenteritis, in particular due to the norwalk virus: an underestimated problem]. | in the netherlands about 4 million people (283/1000) suffer from gastroenteritis every year, of which 500,000 cases are caused by 'norwalk-like viruses' (nlvs), formerly known as 'small round-structured viruses'. the reports of two outbreaks illustrate the difficulties in determining the cause and source of the infection. the course is usually mild, but complications may be serious and ought to be documented. vomiting and diarrhoea are the prominent signs and dehydration is the most common compl ... | 2002 | 12518515 |
| norwalk-like viruses: when the runs can slow you down. | 2003 | 12515788 | |
| a feline kidney cell line-based plaque assay for feline calicivirus, a surrogate for norwalk virus. | feline calicivirus (fcv) has been used by researchers as a surrogate for norwalk virus (nv), since they share a similar genomic organization, physicochemical characteristics, and are grouped in the same family, caliciviridae. unlike nv, however, fcv can grow in established cell lines and produce a syncytial form of cytopathic effect. in this report, we describe the development and standardization of a plaque assay for fcv using monolayers of an established line of feline kidney (crfk) cells in 1 ... | 2003 | 12505630 |
| gastrointestinal outbreaks associated with norwalk virus in restaurants in vancouver, british columbia. | 2002 | 12494826 | |
| norwalk virus-like particle hemagglutination by binding to h histo-blood group antigens. | noroviruses are a major cause of epidemic acute nonbacterial gastroenteritis worldwide. here we report our discovery that recombinant norwalk virus virus-like particles (rnv vlps) agglutinate red blood cells (rbcs). since histo-blood group antigens are expressed on gut mucosa as well as rbcs, we used rnv vlp hemagglutination (ha) as a model system for studying nv attachment to cells in order to help identify a potential nv receptor(s). rnv vlp ha is dependent on low temperature (4 degrees c) and ... | 2003 | 12477845 |
| distribution of human virus contamination in shellfish from different growing areas in greece, spain, sweden, and the united kingdom. | viral pollution in shellfish has been analyzed simultaneously across a wide range of geographical regions, with emphasis on the concomitant variations in physicochemical characteristics and social features. the methods for sample treatment and for the detection of human enteric viruses were optimized by the participating laboratories. the second part of this study involves the selection of a protocol for virus detection, which was validated by analyzing the distribution and concentration of huma ... | 2002 | 12450820 |
| binding of norwalk virus-like particles to abh histo-blood group antigens is blocked by antisera from infected human volunteers or experimentally vaccinated mice. | attachment of norwalk (nv), snow mountain (smv), and hawaii (hv) virus-like particles (vlps) to specific abh histo-blood group antigens was investigated by using human saliva and synthetic biotinylated carbohydrates. the three distinct norwalk-like viruses (nlvs) have various capacities for binding abh histo-blood group antigens, suggesting that different mechanisms for nlv attachment likely exist. importantly, antisera from nv-infected human volunteers, as well as from mice inoculated with pack ... | 2002 | 12414974 |
| ultraviolet inactivation of feline calicivirus, human enteric viruses and coliphages. | norwalk and norwalk-like viruses (nlv) are major causes of food- and water-related disease in the united states. there is no host cell line in which the nlv can be tested for infectivity. feline calicivirus (fcv) and nlv both belong to the family caliciviridae. fcv can be assayed for infectivity in the crandell reese feline kidney cell line, so fcv serves as a surrogate for nlv. this study is the first report of uv inactivation of fcv and also of using the plaque technique, in contrast to the 50 ... | 2002 | 12405148 |
| an outbreak of viral gastroenteritis following environmental contamination at a concert hall. | in january 1999, an outbreak of viral gastroenteritis affected more than 300 people who attended a metropolitan concert hall over a 5-day period. norwalk-like virus (nlv) was confirmed in faecal samples by reverse transcription polymerase chain reaction assay. the index case was a concert attendee who vomited in the auditorium and adjacent male toilet. gastrointestinal illness occurred among members of 8/15 school parties who attended the following day. children who sat on the same level of the ... | 2002 | 12403111 |
| zirconium hydroxide effectively immobilizes and concentrates human enteric viruses. | detection of human enteric viruses in foods and environmental samples requires concentration of viruses from complex matrices before application of molecular or cultural methods. previous studies have described the use of zirconium hydroxide to concentrate bacteria from clinical, environmental, and food samples. | 2002 | 12390492 |
| inactivation of hepatitis a virus and a calicivirus by high hydrostatic pressure. | potential application of high hydrostatic pressure processing (hpp) as a method for virus inactivation was evaluated. a 7-log10 pfu/ml hepatitis a virus (hav) stock, in tissue culture medium, was reduced to nondetectable levels after exposure to more than 450 mpa of pressure for 5 min. titers of hav were reduced in a time- and pressure-dependent manner between 300 and 450 mpa. in contrast, poliovirus titer was unaffected by a 5-min treatment at 600 mpa. dilution of hav in seawater increased the ... | 2002 | 12380746 |
| substrate specificity of the norwalk virus 3c-like proteinase. | the norwalk virus (nv) is the prototype strain of human caliciviruses that cause epidemic outbreaks of foodborne and waterborne gastroenteritis. these viruses do not grow in cell culture and the mechanisms of virus replication are obscure. the nv genome is a 7.7 kb ssrna molecule that encodes three open reading frames (orfs). the first orf is a 1789 amino acid polyprotein that is processed into nonstructural proteins by a viral protease similar to the picornavirus 3c protease. primary cleavage s ... | 2002 | 12367748 |
| detection and differentiation of norwalk virus by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. | we have developed a reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay (rt-pcr-elisa), using genetic cluster-specific probes in a microtiter plate format, for the detection and differentiation of norwalk virus (nv) in stool samples. the specificity of the rt-pcr-elisa was confirmed by testing 76 stool specimens and 15 tissue culture fluids derived from growths of unrelated viruses. the sensitivity of the rt-pcr-elisa was compared with conventional pcr and south ... | 2002 | 12210421 |
| viruses detected in the caecum contents of healthy pigs representing a new genetic cluster in genogroup ii of the genus "norwalk-like viruses". | viruses of the genus 'norwalk-like viruses' (nlvs) detected in humans have been genetically classified into two major genetic groups, genogroups i and ii (gi and gii), which together are made up of at least 14 genetic subgroups. however, a comparable classification of nlvs in other species remains to be carried out. we sequenced a 2-kb region from within the rna polymerase gene to the 3' end of open reading frame 2 (orf2) of two nlv strains previously detected in the caecum contents of healthy p ... | 2002 | 12191780 |
| viral causes of diarrhea. | 2002 | 12093939 | |
| concentration and detection of caliciviruses from food contact surfaces. | outbreaks of human norwalk virus (nv) and norwalk-like viruses often originate in food service establishments. no reliable method is available for the detection of these human caliciviruses on food contact surfaces. we describe a simple method for the detection of nv from stainless steel work surfaces using cultivable feline calicivirus (fcv) as a model. stainless steel surfaces were artificially contaminated with known amounts of fcv, followed by its elution in a buffer solution. three methods ... | 2002 | 12092735 |
| cross-reactivity among several recombinant calicivirus virus-like particles (vlps) with monoclonal antibodies obtained from mice immunized orally with one type of vlp. | human caliciviruses (hucvs) are classified into the norwalk-like viruses (nlv) and sapporo-like viruses (slv) as genera within the family caliciviridae: the nlv genus is further classified into genogroups i and ii, based on sequence similarities. to study the antigenic determinants on the hucv capsid protein and develop new diagnostic tools for field samples, we established and characterized monoclonal antibodies (mabs) against baculovirus-expressed recombinant hucv virus-like particles (vlps). ... | 2002 | 12089262 |
| [vaccine development for norwalk virus]. | the rationale for developing a vaccine generally is made on the basis of the clinical and socioeconomical significance of a specific viral disease. the disease burden for rotavirus gastroenteritis in infants is well evaluated and several candidate vaccines for rotavirus has now been developing. an increasing recognition of the clinical significance of norwalk virus causing acute gastroenteritis in humans of all ages, foodborne outbreaks in adults, and relatively severe gastroenteritis in childre ... | 2002 | 12078098 |
| [contamination of oyster sea farm with the norwalk virus: mechanisms and control]. | the norwalk virus(nv) is widely known as a cause of nonbacterial food poisoning, infant diarrhea, and acute gastroenteritis in the winter months between november and march. while it is strongly suspected that nv that is excreted by humans flows into coastal seawaters via rivers and wastewater treatment facilities to contaminate oysters that are grown in farms in the area, light has yet to be shed on the behavior of this virus in the natural environment. we therefore conducted a polymerase chain ... | 2002 | 12078097 |
| [the relationship between epidemic gastroenteritis caused by norwalk viruses (nvs) and acute gastroenteritis in children--based on the history of nvs in japan]. | norwalk viruses(nvs) are well known pathogens that can cause acute nonbacterial epidemic gastroenteritis in adults as well as acute gastroenteritis in children. in food poisoning cases due to raw oysters, nvs is considered as an important pathogen and the molecular epidemiological studies of nvs are the most suitable method to trace these routes of infections in conjunction with oyster supply mechanism. furthermore, the prevalence of genotypes of nvs which are detected from cases of acute gastro ... | 2002 | 12078096 |
| [characteristic of norwalk gastroenteritis and its prevention]. | the application of recently developed molecular technique revealed the important role of the norwalk virus(nv). the major role of the nv as agents of food and water-related outbreaks of gastroenteritis has now been recognized in the world. moreover, a part of nv is also documented as important agents of gastroenteritis in childhood and infancy. a high rate of food-related viral gastroenteritis outbreaks was observed following ingestion of shellfish in japan. specific methods are not available fo ... | 2002 | 12078095 |
| [rapid and efficient detection method of norwalk virus]. | a rapid and efficient rt-pcr with fluorogenic probe(taqman-pcr) was developed for detection of norwalk virus(nv) genomes in clinical specimens. we designed nv genogroup specific primers and fluorogenic probes in the junction of open reading frame (orf)1 and orf2. eighty specimens from patients of gastroenteritis, in which nv-like particles were detected by electron microscopy, were examined by taqman-pcr and rt-pcr using primer sets previously reported; two sets in rdrp region of nv and one set ... | 2002 | 12078092 |
| [identification and genotyping of norwalk virus by stringent microplate hybridization of pcr products]. | there are many genotypes of norwalk virus(nv), and the microplate hybridization method for identification and genotyping of nv requires preparation of many probes. however, the method is simple and the detection sensitivity is high at 10 ng/ml dna, and many samples can be simultaneously examined in an identification test and genotyping of nv. increasing the hybridization temperature increases precision and the homology rate between a probe and dna fragment can be estimated. mixed genotypes of nv ... | 2002 | 12078091 |
| [epidemiology on norwalk virus-related gastroenteritis outbreaks among elderly persons living in nursing homes]. | person-to-person transmission of norwalk virus(nv) is important factor for outbreaks in nursing homes in addition to foodborne and waterbone transmission. nv spread easily among residents and staffs through the care process and highly infectious contamination generated by vomitus and feces remains on the environmental surface. as a result, the outbreak continues for long period(a few weeks) compared with foodborne gastroenteritis outbreak in restaurant. for prevention and control of nv outbreak ... | 2002 | 12078088 |
| [molecular epidemiology of norwalk virus]. | norwalk virus is one of the most important diarrheal viruses. although the virus was discovered in 1970, the genetic analysis has started from 1990. the virus appears in sporadic cases but also in outbreaks in children and adults. the symptoms are vomiting and diarrhea, but rarely are convulsion and others. the molecular epidemiological method is useful to detect the pathogen in environments and hosts. as the results of molecular epidemiology, it was found that the common virus with the identica ... | 2002 | 12078087 |
| [norwalk virus: recent findings]. | acute gastroenteritis due to norwalk virus(nv), a member of the family caliciviridae, is a common illness worldwide. nv is a human pathogen causing food-borne and water-borne diseases that occur in various epidemiological settings. the disease is mild and self-limiting and the symptomatic phase lasts 24 to 72 hours. genetic analyses of the polymerase and the capsid protein indicate that nv is grouped into two clusters, genogroup i and genogroup ii. the development of recombinant virus-like parti ... | 2002 | 12078086 |
| norwalk virus binds to histo-blood group antigens present on gastroduodenal epithelial cells of secretor individuals. | norwalk virus (nv) is a member of the caliciviridae family, which causes acute epidemic gastroenteritis in humans of all ages and its cellular receptors have not yet been characterized. another calicivirus, rabbit hemorrhagic disease virus, attaches to h type 2 histo-blood group oligosaccharide present on rabbit epithelial cells. our aim was to test if, by analogy, recombinant nv-like particles (rnv vlps) use carbohydrates present on human gastroduodenal epithelial cells as ligands. | 2002 | 12055602 |
| virus-like particles of a fish nodavirus display a capsid subunit domain organization different from that of insect nodaviruses. | the structure of recombinant virus-like particles of malabaricus grouper nervous necrosis virus (mgnnv), a fish nodavirus isolated from the grouper epinephelus malabaricus, was determined by electron cryomicroscopy (cryoem) and three-dimensional reconstruction at 23-a resolution. the cryoem structure, sequence comparison, and protein fold recognition analysis indicate that the coat protein of mgnnv has two domains resembling those of tomato bushy stunt virus and norwalk virus, rather than the ex ... | 2002 | 12021370 |
| a norwalk-like virus outbreak on the appalachian trail. | in may and june 1999, an outbreak of acute gastrointestinal illness occurred among long-distance hikers on the appalachian trail between catawba and troutville, virginia. an investigation found that 45 out of 70 hikers had become ill within two days of arriving in catawba, virginia. water samples were collected from a general store frequented by the hikers and from several nearby buildings and a popular all-you-can-eat restaurant. symptoms were consistent with those caused by norwalk-like viruse ... | 2002 | 12004584 |
| norwalk virus infection and disease is associated with abo histo-blood group type. | some people are resistant to norwalk virus (nv) infection; however, the factor(s) responsible for resistance or susceptibility to nv infection has not been identified. this study investigated the relationship between a person's abo histo-blood group type and the risk of nv infection and symptomatic disease after clinical challenge. abo phenotypes were identified by using serum samples from volunteers who participated in an nv challenge study (n=51). individuals with an o phenotype were more like ... | 2002 | 12001052 |
| characterization of norwalk-like virus associated with gastroenteritis in indonesia. | norwalk virus and norwalk-like viruses (nlvs) are reportedly responsible for 2.5-4.0% of nonbacterial acute gastroenteritis (nbag) worldwide. to help clarify the impact of nlvs on nbag in indonesia, stool specimens from 102 patients, 74 with nbag and 28 with bag, were screened for the presence of nlvs, using a reverse transcription-polymerase chain reaction (rt-pcr) assay. the specimens were subtyped using prototype-specific oligonucleotide probes and were sequenced and compared with published n ... | 2002 | 11992587 |
| norwalk-like virus sequences in mineral waters: one-year monitoring of three brands. | in a recent study, rna with nucleotide sequeces specific for "norwalk-like viruses" (nlv) was detected in 11 different brands of european mineral waters. to clarify this finding, a 1-year monitoring study was conducted. samples of three european brands of mineral water without gas were monitored weekly by reverse transcriptase pcr using generic and genogroup-specific oligonucleotides. additional analyses were performed to investigate a possible correlation between nlv sequence contamination and ... | 2002 | 11916714 |
| structural requirements for the assembly of norwalk virus-like particles. | norwalk virus (nv) is the prototype strain of a group of human caliciviruses responsible for epidemic outbreaks of acute gastroenteritis. while these viruses do not grow in tissue culture cells or animal models, expression of the capsid protein in insect cells results in the self-assembly of recombinant nv virus-like particles (rnv vlps) that are morphologically and antigenically similar to native nv. the x-ray structure of the rnv vlps has revealed that the capsid protein folds into two princip ... | 2002 | 11907243 |
| norwalk virus gastroenteritis among israeli soldiers: lack of evidence for flyborne transmission. | paired sera collected from subjects before and after a fly-control intervention trial conducted in the israel defense force (idf) were tested for seroconversion to norwalk virus (nv) to examine the role of nv as a cause of diarrhea in this population and to ascertain whether flies might also be implicated in transmission. | 2002 | 11876512 |
| vectorborne infectious diseases. | 2002 | 11876508 | |
| development of a virus concentration method and its application to detection of enterovirus and norwalk virus from coastal seawater. | we developed a new procedure for concentration of enteric viruses from water using a negatively charged membrane. rinsing the membrane with 0.5 mm h(2)so(4) (ph 3.0) in order to elute cations prior to viral elution with 1 mm naoh (ph 10.5) promoted poliovirus recovery yields from 33 to 95% when applied to pure water and 38 to 89% when applied to natural seawater from tokyo bay, japan, respectively. this method showed average recovery yields of spiked poliovirus of 62% (n = 8) from 1 liter of art ... | 2002 | 11872447 |
| expression and self-assembly of norwalk virus capsid protein from venezuelan equine encephalitis virus replicons. | the norwalk virus (nv) capsid protein was expressed using venezuelan equine encephalitis virus replicon particles (vrp-nv1). vrp-nv1 infection resulted in large numbers of recombinant nv-like particles that were primarily cell associated and were indistinguishable from nv particles produced from baculoviruses. mutations located in the n-terminal and p1 domains of the nv capsid protein ablated capsid self-assembly in mammalian cells. | 2002 | 11861868 |
| baculovirus expression and antigenic characterization of the capsid proteins of three norwalk-like viruses. | human caliciviruses (hucvs) are antigenically diverse. the antigenic relationships among different hucvs have been difficult to study because hucvs cannot be passaged in the laboratory. in this study, we describe cloning, sequencing and expression of the viral capsid proteins of three hucvs that were identified in outbreaks of acute gastroenteritis in virginia in 1997-1998. yields of the capsid proteins similar to previously expressed recombinant norwalk virus were obtained using the baculovirus ... | 2002 | 11855626 |
| [hospital outbreak of viral gastroenteritis attributed to norwalk-like viruses in japan]. | norwalk-like viruses (nlvs), rna viruses in the family of caliciviridae, are known as a pathogen of nonbacterial food-borne gastroenteritis associated with eating raw oysters. nlv can spread from person to person with strong infectivity and can cause large epidemics in communities, schools, nursing homes, and hospitals. here, we describe an outbreak of gastroenteritis associated with nlvs, possibly introduced from outside the hospital, in four different wards on four different occasions between ... | 2002 | 11852472 |
| experimental infection of macaca nemestrina with a toronto norwalk-like virus of epidemic viral gastroenteritis. | norwalk virus (nv) and norwalk-like viruses (nlvs) are common etiologic agents of viral gastroenteritis. viral gastroenteritis is a common disease that is highly transmissible, spreading rapidly through families, institutions, and communities. because methods for in vitro cultivation of norwalk etiologic agents are not available, information regarding this syndrome has come largely from studies in human volunteers. sequential passaging of an nlv through an immunoincompetent newborn pigtail macaq ... | 2002 | 11793394 |
| norwalk-like virus outbreaks at two summer camps--wisconsin, june 2001. | on june 27 and 28, 2001, the wisconsin division of public health was notified by two local health departments of outbreaks of gastroenteritis at two summer recreational camps (camps a and b) in northern wisconsin. this report summarizes the investigation of these outbreaks, which documents person-to-person transmission of "norwalk-like virus" (nlv) and underscores the importance of cleaning environmental surfaces and the availability and use of hand-washing facilities at recreational camps. | 2001 | 11787574 |
| systemic, mucosal, and heterotypic immune induction in mice inoculated with venezuelan equine encephalitis replicons expressing norwalk virus-like particles. | norwalk-like viruses (nlvs) are a diverse group of single-stranded, nonenveloped, positive-polarity rna viruses and are the leading cause of epidemic acute gastroenteritis in the united states. in this study, the major capsid gene of norwalk virus, the prototype nlv, has been cloned and expressed in mammalian cells using a venezuelan equine encephalitis (vee) replicon expression system. upon infection of baby hamster kidney (bhk) cells with vee replicon particles (vrps), the norwalk virus capsid ... | 2002 | 11752163 |
| genogroup-specific pcr primers for detection of norwalk-like viruses. | norwalk-like viruses (nlv) are a major causative agent of nonbacterial gastroenteritis. there are still many nlv strains that are refractory to gene amplification by ordinary reverse transcription-polymerase chain reaction. this is due mainly to the genetic diversity among nlv, especially mismatches in the primer sequences, which limits this technique in clinical utility. in this study, improved primer sets based on the capsid region, to detect both genogroup i and ii nlv by genogroup-specific m ... | 2002 | 11742657 |