5-Ethynyl-l-o-D-ribofuranosylimidazole-4-carboxamide (EICAR) and 6'-(R)-6'-C-methylneplanocin A (TJ13025) are two novel antiviral agents which are targeted against IMP dehydrogenase and S-adenosylhomocysteine hydrolase, respectively. These compounds have been examined for their activities against various strains of orthomyxoviruses (influenza virus) and paramyxoviruses (parainfluenza virus, mumps virus, measles virus, and respiratory syncytial virus) in vitro. EICAR was 10-to 59-fold more active than ribavirin and TJ13025 was 32-to 330-fold more active than ribavirin against parainfluenza virus (types 2 and 3), mumps virus, and measles virus. EICAR was also more active than ribavirin against respiratory syncytial virus and influenza virus, whereas TJ13025 was virtually inactive against these viruses. The 50% virus-inhibitory concentrations of EICAR and TJ13025 were generally within the 0.1-to 1-,ug/ml range. Although the compounds did not prove cytotoxic to stationary host cells (HeLa, Vero, MDCK, and LLCMK2) at a concentration of 200 ,ug/ml, concentrations of 4 to 13 ,ug/ml inhibited the growth of dividing cells. EICAR and TJ13025 should be further pursued as candidate drugs for the treatment of ortho-and paramyxovirus infections.Ribavirin has been licensed for clinical use (as an aerosol) in the treatment of respiratory syncytial virus (RSV) infections. Inhalation of aerosolized ribavirin by infants with RSV pneumonia or college students with influenza A leads to an improvement of the clinical symptoms in these patients (7,19,20). The mechanism of action of ribavirin and its metabolism by cells have been investigated (5,6,17,18,21); the main targets for the antiviral action of ribavirin and its phosphorylated form appear to be IMP dehydrogenase, viral mRNA cap formation, and viral RNA transcriptase or polymerase.Recently, we have reported two novel nucleoside analogs, 5 -ethynyl -1-, -D -ribofuranosylimidazole -4 -carboxamide (EICAR) and 6'-(R)-6'-C-methylneplanocin A (TJ13025), as broad-spectrum antiviral agents active against a wide variety of pox-, toga-, reo-, myxo-, rhabdo-, and arenaviruses in vitro (3,16). In this study, we have evaluated the inhibitory effects of EICAR and TJ13025 in comparison with those of ribavirin on the in vitro replication of several ortho-and paramyxoviruses. MATERIALS AND METHODSCompounds. The sources of the three compounds used in this study were as follows: ribavirin, ICN Pharmaceuticals,

Our results suggested that the repeated EV71 outbreaks might be the result of the worldwide transmission of the newly introduced genetically divergent EV71 strains.

Coxsackievirus A16 (CV-A16) and human enterovirus 71 (HEV71) are both major etiologic agents of hand, foot, and mouth disease (HFMD). The surveillance data indicate that CV-A16 and HEV71 infections independently cause large outbreaks and then become quiescent for a period of a few years (6).HEV71-related illness is more severe, with a significantly greater frequency of serious complications and fatality, than illness caused by CV-A16 (2). In 1997, deaths associated with epidemics of HEV71-associated HFMD in Sarawak, Malaysia, followed by outbreaks with high mortality in Taiwan in 1998 and 2000, raised considerable public concern about the virulence of this virus. Since then, several groups have attempted to describe the molecular epidemiology of HEV71 in the AsiaPacific region and have reported the relationships of HEV71 epidemics with the genetic diversity of HEV71 strains (1, 5, 10). The results indicate that HEV71 strains causing HFMD outbreaks were genetically changed.On the other hand, the molecular epidemiology of CV-A16 associated with HFMD epidemics has not been fully described (9). In the present study, we evaluated the relationship between the chronologic CV-A16 epidemics in a restricted area, i.e., Fukushima Prefecture, Japan, and the genetic diversity of the CV-A16 strains. We also examined the geographic genetic relationship between the CV-A16 strains isolated in Fukushima and those isolated in other areas of Japan and China, using phylogenetic analyses constructed using the neighborjoining method on the basis of the VP4 and VP1 sequences. MATERIALS AND METHODSVirus strains. Pharyngeal swab samples were collected from patients with HFMD in the Fukushima Prefecture for virus surveillance and transferred to the Fukushima Institute for Public Health for virus isolation. HEp-2, Vero, and RD-18 cells were used for the isolation of enteroviruses. Confluent cell cultures were seeded in microplate wells and inoculated with 100 l of maintenance medium and 50 l of pharyngeal swab samples. The cell cultures were then incubated at 34°C in 5% CO 2 -95% air and observed for 7 days to check for cytopathic effects. A blind passage was performed once if no cytopathic effect was observed by the end of the observation period. Virus isolates were identified by a neutralization test using anti-CV-A16 polyclonal antibodies provided from the National Institute of Infectious Diseases in Japan. A total of 322 CV-A16 strains were isolated and identified from 1983 to 2003. Those isolates were stored at Ϫ80°C.PCR and sequence determination of VP4 gene. Randomly selected isolates (63 of 241 strains) from 1983 to 1999 and all isolates (69 strains) from 2000 to 2003 were used for further genetic analysis. A total of 132 strains were isolated from patients with HFMD.

ABSTRACT. Objective. To clarify the relationship between enteroviral infection and febrile seizures.Study Design. Cerebrospinal fluid (CSF), serum, throat swab, and rectal swab samples were collected for virologic examination from 67 children with febrile seizures from April 1997 to March 1999. Those samples were examined for the presence of enterovirus using cell culture and 2 polymerase chain reaction (PCR) methods.Results. No enterovirus was isolated from cell culture of CSF, throat swab, or rectal swab samples. All samples were screened for the presence of enteroviral sequences using a sensitive PCR method (PCR-Fukushima). We obtained positive results from 14 of 67 CSF samples, 10 of 62 serum samples, 12 of 64 throat swab samples, and 13 of 64 rectal swab samples. Of 21 patients in whom febrile seizures had developed during the summer months (June through August), 13 (61.9%) had positive PCR results in the CSF. Forty-seven of the 49 samples with a positive result using PCR-Fukushima were reexamined independently for the presence of the enteroviral genome using another PCR method (PCR-Mitsubishi). PCR-Mitsubishi had slightly lower sensitivity than PCR-Fukushima but identified genotypes of enterovirus by subsequent sequence analysis of the PCR products. The presence of the enteroviral genome was confirmed in 39 of the samples (83.0%). In 8 of the 9 enteroviruses detected in the CSF and/or serum samples using PCR-Mitsubishi, the genotypes were identified as coxsackieviruses group A, which are usually difficult to isolate using cell culture methods.Conclusions. These findings proved that the causative agents of febrile illness associated with seizures in summer were primarily enteroviruses, especially coxsackieviruses group A, and that febrile seizures might be caused by enteroviral infection in the central nervous system. Pediatrics 2001;107(1). URL: http://www. pediatrics.org/cgi/content/full/107/1/e12; enterovirus, coxsackievirus group A, febrile seizures, polymerase chain reaction.ABBREVIATIONS. CNS, central nervous system; CSF, cerebrospinal fluid; PCR, polymerase chain reaction; bp, base pair. E nteroviruses-polioviruses, echoviruses, coxsackieviruses group A and group B, and enteroviruses-are responsible for significant and frequent human illness, including various neurologic manifestations. The most common neurologic illness is aseptic meningitis. Encephalitis and other manifestations, such as paralysis, Guillain-Barré syndrome, transverse myelitis, cerebellar ataxia, and peripheral neuritis, also occur. 1 The association of enteroviral infection in the central nervous system (CNS) with febrile seizures, however, has not been demonstrated. In general, the causative agent of the infection is not detected in the CNS of patients with febrile seizures using standard techniques.We previously reported that the enteroviral genome was detected in cerebrospinal fluid (CSF) samples collected from some children with transient neurologic complications, such as seizures and altered states of consciousness associated ...

The inflammatory process observed in human enteroviral meningitis is comparable with that observed in animal models: 1) infection induces proinflammatory cytokine production, followed by infiltration of white blood cells into the infected area, and 2) inflammation is terminated by the anti-inflammatory cytokines that are produced when pathogens are eliminated.

No abstract

Cerebrospinal fluid samples collected from 23 children with neurologic symptoms, such as febrile seizures, status epilepticus, and transient altered states of consciousness, associated with acute febrile illness, were examined for infectious virus by cell culture. Enteroviruses (echovirus type 9 and coxsackievirus B3) were isolated from 2 of the cerebrospinal fluid samples. The samples were also examined for enterovirus by use of the polymerase chain reaction, which could detect nearly the whole human enterovirus group: Enteroviral RNA was detected in 9 of the 23 samples. The findings suggest that transient neurologic complications during the febrile phase of acute febrile illness are caused, in part, by enteroviral infection of the central nervous system.

NAI treatment was effective for inhibiting viral replication during the early days of illness and did not decrease viral susceptibility to NAIs in patients with influenza B virus infection.