The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform
James L. Hardy - One of the best experts on this subject based on the ideXlab platform.
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Adsorptive endocytosis of California Encephalitis virus into mosquito and mammalian cells: a role for G1.
Virology, 1997Co-Authors: Jill K. Hacker, James L. HardyAbstract:The G1 glycoprotein of California Encephalitis (CE) virus plays a critical role in the infection of mosquito and mammalian cells. We found that CE virus enters baby hamster kidney (BHK-21) and Aedes albopictus (C6/36) cells by the endocytic pathway. Ammonium chloride, a lysosomotropic amine that prevents release of virus from endosomes, inhibited infection of both cell types when added within 10 min after viral adsorption. In addition, infected cells formed polykaryons when the extracellular pH was lowered to 6.3; optimal fusion occurred at pH 5.8 and 6.0 (C6/36 and BHK-21 cells, respectively). Two neutralizing G1 MAba, 6D5.5 and 7D4.5, inhibited low pH-induced syncytia formation without affecting viral attachment, suggesting a role for G1 in viral entry. Since viral fusion proteins have been demonstrated to undergo conformational changes at low pH, acid-induced changes in G1 and G2 were assessed. While both G1 and G2 demonstrated low pH-induced alterations in detergent binding, only G1 displayed an altered protease cleavage pattern at the fusion pH. These results indicate that the G1 protein of CE virus undergoes conformational changes necessary for low pH-mediated entry into both mosquito and mammalian cells.
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Determination and comparative analysis of the small RNA genomic sequences of California Encephalitis, Jamestown Canyon, Jerry Slough, Melao, Keystone and Trivittatus viruses (Bunyaviridae, genus Bunyavirus, California serogroup).
Journal of General Virology, 1995Co-Authors: Michael D. Bowen, Andrew O. Jackson, Thomas D. Bruns, David L. Hacker, James L. HardyAbstract:The nucleotide sequences of the small (S) genomic RNAs of six California (CAL) serogroup bunyaviruses (Bunyaviridae: genus Bunyavirus) were determined. The S RNAs of two California Encephalitis virus strains, two Jamestown Canyon virus strains, Jerry Slough virus, Melao virus, Keystone virus and Trivittatus virus contained the overlapping nucleocapsid (N) and nonstructural (NSs) protein open reading frames (ORFs) as described previously for the S RNAs of other CAL serogroup viruses. All N protein ORFs were 708 nucleotides in length and encoded a putative 235 amino acid gene product. The NSs ORFs were found to be of two lengths, 279 and 294 nucleotides, which potentially encode 92 and 97 amino acid proteins, respectively. The complementary termini and a purine-rich sequence in the 3′ non-coding region (genome-complementary sense) were highly conserved amongst CAL serogroup bunya-virus S RNAs. Phylogenetic analyses of N ORF sequences indicate that the CAL serogroup bunyaviruses can be divided into three monophyletic lineages corresponding to three of the complexes previously derived by serological classification. The truncated version of the NSs protein, which is found in five CAL serogroup bunyaviruses, appears to have arisen twice during virus evolution.
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Requirement for the G1 protein of California Encephalitis virus in infection in vitro and in vivo.
Virology, 1995Co-Authors: Jill K. Hacker, Loy E. Volkman, James L. HardyAbstract:Abstract A role for the large glycoprotein (G1) of California Encephalitis (CE) virus was examined in the infection of baby hamster kidney (BHK-21) and Aedes albopictus (C6/36) cell lines and the mosquito Ae. dorsalis using G1 monoclonal antibodies (MAbs) and selective protein cleavage. Five MAbs neutralized CE viral infectivity in both cell lines. One MAb, 7D45, efficiently neutralized the peroral infection of Ae. dorsalis females fed CE virus in artificial bloodmeals. To determine if MAbs to G1 neutralized CE virus by sterically hindering the small glycoprotein (G2), portions of G1 were trypsinized, and viral infectivity was assayed in vivo and in vitro. Cleavage of G1 resulted in a complete loss of infectivity both in mosquitoes and in culture, even though a significant amount of G2 remained intact. The loss of infectivity by both neutralization with G1 MAbs and trypsinization indicates that the G1 protein of CE virus is required for infection of mosquito and mammalian cells in vitro and of mosquitoes by the peroral route.
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Vector competence of California mosquitoes for California Encephalitis and California Encephalitis-like viruses.
The American journal of tropical medicine and hygiene, 1992Co-Authors: Laura D. Kramer, William C. Reeves, James L. Hardy, S. B. Presser, Bruce F. Eldridge, Michael D. BowenAbstract:Abstract Mosquitoes collected from coastal, inland valley, and alpine locations in California were evaluated for their experimental vector competence for two viruses in the California serogroup (Bunyaviridae: Bunyavirus). Aedes squamiger, a coastal salt marsh mosquito, was an efficient vector of a California Encephalitis (CE)-like virus isolated from its habitat (89% of the pledget-fed females became infected and 61% transmitted virus). Aedes dorsalis, a coastal mosquito, and Ae. melanimon, an inland valley mosquito, were competent vectors of prototype CE virus (98% and 100% of the pledget-fed females became infected and 56% and 30%, respectively, transmitted virus). Aedes squamiger and Ae. dorsalis transmitted both viruses vertically to one or more of 20 of their progeny. Culiseta inornata was susceptible to infection with both viruses, but 5% or less transmitted virus perorally. Alpine mosquitoes, Ae. cataphylla, Ae. increpitus, and Ae. tahoensis, became infected with both CE and CE-like viruses, but 3% or less transmitted virus. All species of mosquitoes were more efficient vectors of both viruses following intrathoracic inoculation than following pledget feeding, suggesting the presence of mesenteronal barriers.
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Occurrence and evolutionary significance of a California Encephalitis-like virus in Aedes squamiger (Diptera: Culicidae).
Journal of medical entomology, 1991Co-Authors: Bruce F. Eldridge, William C. Reeves, Gregory C. Lanzaro, Grant L. Campbell, James L. HardyAbstract:More than 12,000 Aedes increpitus Dyar and 4,600 Aedes squamiger (Coquillett) were tested for the presence of arboviruses to test the hypothesis that there is a coevolutionary relationship between Aedes (Ochlerotatus) mosquitoes and California serogroup viruses. Five strains of a California Encephalitis-like virus were isolated from adults reared from larvae of Ae. squamiger collected in January 1989 from a coastal salt marsh at Morro Bay, San Luis Obispo County, California. Viruses were isolated in Vero cell cultures and serotyped by cross-neutralization tests. These isolates represent the first arboviruses isolated from this species. On the basis of morphology, Aedes squamiger has been included in the Aedes stimulans group of the subgenus Ochlerotatus. Other species within the Ae. stimulans group are vectors of California (CAL) serogroup viruses elsewhere in North America. Analysis of isozyme variability supports the inclusion of Ae. squamiger in the Ae. stimulans group and suggests that coastal populations of Ae. increpitus are the closest California relatives of Ae. squamiger. Recovery of virus from Ae. squamiger reinforces the relationship between CAL serogroup viruses and Aedes (Ocherlotatus) mosquitoes. However, the failure to isolate virus from large samples of Ae. increpitus from coastal and low elevation inland habitats suggests a complex evolutionary history involving both vertical and horizontal transmission mechanisms.
Carol A Glaser - One of the best experts on this subject based on the ideXlab platform.
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Anti-N-Methyl-d-Aspartate Receptor Encephalitis Appearing as a New-Onset Psychosis: Disease Course in Children and Adolescents Within the California Encephalitis Project
Pediatric neurology, 2017Co-Authors: Mary Gable, Carol A GlaserAbstract:Abstract Background Given that psychiatric symptoms are common, not only during the course of the illness but also on presentation, in children and adolescents with anti- N -methyl-d-aspartate receptor Encephalitis, it is important that practitioners possess an adequate understanding of the clinical features and potential treatment of this disease. We describe the clinical characteristics of 24 patients who presented to the California Encephalitis Project. Methods Patients were referred by physicians, and standardized forms were used to gather demographic, clinical, and laboratory data. Results Twenty-four patients between ages two and 18 years were identified. Psychosis was a primary presenting symptom in two thirds of patients, and just over 20% of these were admitted to an inpatient psychiatric facility. Ultimately, all patients developed psychiatric symptoms during the course of the illness. There was a characteristic progression of symptoms that was consistent with that noted in other studies, with prominent psychiatric symptoms initially, which then progressed to seizures and autonomic instability in most patients. All of those examined developed movement abnormalities, which included primarily orofacial dyskinesias and choreiform movements. Conclusions Anti- N -methyl-d-aspartate receptor Encephalitis, unlike other paraneoplastic or autoimmune encephalitides, affects those 18 years and under an estimated 40% of the time based on prior studies. Recognizing the signs and symptoms of this condition is essential to making a diagnosis and initiating timely treatment. Child psychiatrists have an important role in this disorder.
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Acute Pediatric Encephalitis Neuroimaging: Single-Institution Series as Part of the California Encephalitis Project
Pediatric neurology, 2015Co-Authors: Julie Bykowski, Heather Sheriff, Carol A Glaser, Peter Kruk, Jeffrey J. Gold, John R. CrawfordAbstract:Abstract Purpose Diagnosing pediatric Encephalitis is challenging because of varied clinical presentation, nonspecific neuroimaging features, and rare confirmation of causality. We reviewed acute neuroimaging of children with clinically suspected Encephalitis to identify findings that may correlate with etiology and length of stay. Methods Imaging of 141 children with clinically suspected Encephalitis as part of The California Encephalitis Project from 2005 to 2012 at a single institution was reviewed to compare the extent of neuroimaging abnormalities to patient age, gender, length of stay, and unknown, possible, or confirmed pathogen. Scan review was blinded and categorized by extent and distribution of abnormal findings. Results Abnormal findings were evident on 23% (22/94) of computed tomography and 50% (67/134) of magnetic resonance imaging studies in the acute setting. Twenty children with normal admission computed tomography had abnormal findings on magnetic resonance imaging performed within 2 days. Length of stay was significantly longer among children with abnormal acute magnetic resonance imaging ( P P P = 0.8). Conclusion Abnormal magnetic resonance imaging findings are more common than abnormal computed tomography findings in pediatric Encephalitis. Increasing complexity of magnetic resonance imaging findings correlated with disease severity as evidenced by longer length of stay, but were not specific for an identifiable pathogen using a standardized diagnostic Encephalitis panel.
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Insights into Pediatric Herpes Simplex Encephalitis From a Cohort of 21 Children From the California Encephalitis Project, 1998–2011
The Pediatric infectious disease journal, 2014Co-Authors: Ariane Soldatos, Heather Sheriff, D. Scott Schmid, Natasha Espinosa, Giorgio Cosentino, Christopher P. Preas, Carol A GlaserAbstract:Twenty-one children with confirmed herpes simplex Encephalitis were identified in the California Encephalitis Project. Noteworthy features included 6 (29%) patients with an initial negative herpes simplex virus cerebrospinal fluid polymerase chain reaction test and 13 (59%) patients with extratempor
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the frequency of autoimmune n methyl d aspartate receptor Encephalitis surpasses that of individual viral etiologies in young individuals enrolled in the California Encephalitis project
Clinical Infectious Diseases, 2012Co-Authors: Mary S Gable, Drake H Tilley, Josep Dalmau, Heather Sheriff, Carol A GlaserAbstract:Background. In 2007, the California Encephalitis Project (CEP), which was established to study the epidemiology of Encephalitis, began identifying cases of anti-N-methyl-D-aspartate receptor (anti-NMDAR) Encephalitis. Increasing numbers of anti-NMDAR Encephalitis cases have been identified at the CEP, and this form rivals commonly known viral etiologies as a causal agent. We report here the relative frequency and differences among encephalitides caused by anti-NMDAR and viral etiologies within the CEP experience. Methods. Demographic, frequency, and clinical data from patients with anti-NMDAR Encephalitis are compared with those with viral encephalitic agents: enterovirus, herpes simplex virus type 1 (HSV-1), varicella-zoster virus (VZV), and West Nile virus (WNV). All examined cases presented to the CEP between September 2007 and February 2011 and are limited to individuals aged #30 years because of the predominance of anti-NMDAR Encephalitis in this group. The diagnostic costs incurred in a single case are also included. Results. Anti-NMDAR Encephalitis was identified .4 times as frequently as HSV-1, WNV, or VZV and was the leading entity identified in our cohort. We found that 65% of anti-NMDAR Encephalitis occurred in patients aged #18 years. This disorder demonstrated a predilection, which was not observed with viral etiologies, for females (P, .01). Seizures, language dysfunction, psychosis, and electroencephalographic abnormalities were significantly more frequent in patients with anti-NMDAR Encephalitis (P , .05), and autonomic instability occurred exclusively in this group. Discussion. Anti-NMDAR Encephalitis rivals viral etiologies as a cause of Encephalitis within the CEP cohort. This entity deserves a prominent place on the encephalitic differential diagnosis to avoid unnecessary diagnostic and treatment costs, and to permit a more timely treatment.
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Enterovirus-Associated Encephalitis in the California Encephalitis Project, 1998–2005
The Journal of infectious diseases, 2008Co-Authors: Ashley Fowlkes, Carol A Glaser, David P. Schnurr, Somayeh Honarmand, Larry J. Anderson, Shigeo Yagi, M. Steven Oberste, Mark A. Pallansch, Nino KhetsurianiAbstract:Background. Encephalitis is a relatively rare presentation of enterovirus (EV) infections. Clinical and epidemiologic characteristics of EV Encephalitis (EVE) have not been well characterized. Methods. Patients with Encephalitis enrolled in the California Encephalitis Project from 1998 to 2005 were tested for a range of pathogens, including EV, using a standardized diagnostic algorithm. EVE was categorized as “confirmed” (EV detected in cerebrospinal fluid [CSF] or brain tissue) or “possible” (EV found in respiratory or fecal specimens or serum EV immunoglobulin [Ig] M detected). We compared clinical and epidemiologic characteristics of EVE with those of other infectious Encephalitis cases. Results. EVE was diagnosed in 73 (4.6%) of 1571 patients (45 confirmed cases, 28 possible cases); 11.1% of cases had other infectious causes. Patients with confirmed EVE were younger, although 27% were adults, who presented with significantly less severe symptoms. Serotypes identified in EVE cases correlated with the predominant serotype for the given year reported to the National Enterovirus Surveillance System at the Centers for Disease Control and Prevention. Two of 4 fatal EVE cases were associated with EV71. Conclusion. EVs are an important cause of Encephalitis cases requiring hospitalization, in both children and adults. Our data suggest that EVE severity varies by serotype, confirm the importance of CSF/brain tissue polymerase chain reaction, and demonstrate that serum IgM findings are of little value in diagnosing EVE. In the United States, Encephalitis causes an estimated 19,000 hospitalizations and up to 1400 deaths each year
Michael D. Bowen - One of the best experts on this subject based on the ideXlab platform.
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Determination and comparative analysis of the small RNA genomic sequences of California Encephalitis, Jamestown Canyon, Jerry Slough, Melao, Keystone and Trivittatus viruses (Bunyaviridae, genus Bunyavirus, California serogroup).
Journal of General Virology, 1995Co-Authors: Michael D. Bowen, Andrew O. Jackson, Thomas D. Bruns, David L. Hacker, James L. HardyAbstract:The nucleotide sequences of the small (S) genomic RNAs of six California (CAL) serogroup bunyaviruses (Bunyaviridae: genus Bunyavirus) were determined. The S RNAs of two California Encephalitis virus strains, two Jamestown Canyon virus strains, Jerry Slough virus, Melao virus, Keystone virus and Trivittatus virus contained the overlapping nucleocapsid (N) and nonstructural (NSs) protein open reading frames (ORFs) as described previously for the S RNAs of other CAL serogroup viruses. All N protein ORFs were 708 nucleotides in length and encoded a putative 235 amino acid gene product. The NSs ORFs were found to be of two lengths, 279 and 294 nucleotides, which potentially encode 92 and 97 amino acid proteins, respectively. The complementary termini and a purine-rich sequence in the 3′ non-coding region (genome-complementary sense) were highly conserved amongst CAL serogroup bunya-virus S RNAs. Phylogenetic analyses of N ORF sequences indicate that the CAL serogroup bunyaviruses can be divided into three monophyletic lineages corresponding to three of the complexes previously derived by serological classification. The truncated version of the NSs protein, which is found in five CAL serogroup bunyaviruses, appears to have arisen twice during virus evolution.
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Vector competence of California mosquitoes for California Encephalitis and California Encephalitis-like viruses.
The American journal of tropical medicine and hygiene, 1992Co-Authors: Laura D. Kramer, William C. Reeves, James L. Hardy, S. B. Presser, Bruce F. Eldridge, Michael D. BowenAbstract:Abstract Mosquitoes collected from coastal, inland valley, and alpine locations in California were evaluated for their experimental vector competence for two viruses in the California serogroup (Bunyaviridae: Bunyavirus). Aedes squamiger, a coastal salt marsh mosquito, was an efficient vector of a California Encephalitis (CE)-like virus isolated from its habitat (89% of the pledget-fed females became infected and 61% transmitted virus). Aedes dorsalis, a coastal mosquito, and Ae. melanimon, an inland valley mosquito, were competent vectors of prototype CE virus (98% and 100% of the pledget-fed females became infected and 56% and 30%, respectively, transmitted virus). Aedes squamiger and Ae. dorsalis transmitted both viruses vertically to one or more of 20 of their progeny. Culiseta inornata was susceptible to infection with both viruses, but 5% or less transmitted virus perorally. Alpine mosquitoes, Ae. cataphylla, Ae. increpitus, and Ae. tahoensis, became infected with both CE and CE-like viruses, but 3% or less transmitted virus. All species of mosquitoes were more efficient vectors of both viruses following intrathoracic inoculation than following pledget feeding, suggesting the presence of mesenteronal barriers.
Bruce F. Eldridge - One of the best experts on this subject based on the ideXlab platform.
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The first reported case of California Encephalitis in more than 50 years.
Emerging infectious diseases, 2001Co-Authors: Bruce F. Eldridge, Carol A Glaser, Robert E. Pedrin, Robert E. ChilesAbstract:A recent case of California Encephalitis, a rare mosquito-borne viral disease, represents only the fourth ever reported and the first since the initial three cases in 1945. This case was diagnosed retrospectively on the basis of a rise in antibody titer between acute- and convalescent-phase serum samples.
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Vector competence of California mosquitoes for California Encephalitis and California Encephalitis-like viruses.
The American journal of tropical medicine and hygiene, 1992Co-Authors: Laura D. Kramer, William C. Reeves, James L. Hardy, S. B. Presser, Bruce F. Eldridge, Michael D. BowenAbstract:Abstract Mosquitoes collected from coastal, inland valley, and alpine locations in California were evaluated for their experimental vector competence for two viruses in the California serogroup (Bunyaviridae: Bunyavirus). Aedes squamiger, a coastal salt marsh mosquito, was an efficient vector of a California Encephalitis (CE)-like virus isolated from its habitat (89% of the pledget-fed females became infected and 61% transmitted virus). Aedes dorsalis, a coastal mosquito, and Ae. melanimon, an inland valley mosquito, were competent vectors of prototype CE virus (98% and 100% of the pledget-fed females became infected and 56% and 30%, respectively, transmitted virus). Aedes squamiger and Ae. dorsalis transmitted both viruses vertically to one or more of 20 of their progeny. Culiseta inornata was susceptible to infection with both viruses, but 5% or less transmitted virus perorally. Alpine mosquitoes, Ae. cataphylla, Ae. increpitus, and Ae. tahoensis, became infected with both CE and CE-like viruses, but 3% or less transmitted virus. All species of mosquitoes were more efficient vectors of both viruses following intrathoracic inoculation than following pledget feeding, suggesting the presence of mesenteronal barriers.
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Occurrence and evolutionary significance of a California Encephalitis-like virus in Aedes squamiger (Diptera: Culicidae).
Journal of medical entomology, 1991Co-Authors: Bruce F. Eldridge, William C. Reeves, Gregory C. Lanzaro, Grant L. Campbell, James L. HardyAbstract:More than 12,000 Aedes increpitus Dyar and 4,600 Aedes squamiger (Coquillett) were tested for the presence of arboviruses to test the hypothesis that there is a coevolutionary relationship between Aedes (Ochlerotatus) mosquitoes and California serogroup viruses. Five strains of a California Encephalitis-like virus were isolated from adults reared from larvae of Ae. squamiger collected in January 1989 from a coastal salt marsh at Morro Bay, San Luis Obispo County, California. Viruses were isolated in Vero cell cultures and serotyped by cross-neutralization tests. These isolates represent the first arboviruses isolated from this species. On the basis of morphology, Aedes squamiger has been included in the Aedes stimulans group of the subgenus Ochlerotatus. Other species within the Ae. stimulans group are vectors of California (CAL) serogroup viruses elsewhere in North America. Analysis of isozyme variability supports the inclusion of Ae. squamiger in the Ae. stimulans group and suggests that coastal populations of Ae. increpitus are the closest California relatives of Ae. squamiger. Recovery of virus from Ae. squamiger reinforces the relationship between CAL serogroup viruses and Aedes (Ocherlotatus) mosquitoes. However, the failure to isolate virus from large samples of Ae. increpitus from coastal and low elevation inland habitats suggests a complex evolutionary history involving both vertical and horizontal transmission mechanisms.
Norbert Nowotny - One of the best experts on this subject based on the ideXlab platform.
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Serological surveillance for Tahyna virus (California Encephalitis orthobunyavirus, Peribunyaviridae) neutralizing antibodies in wild ungulates in Austria, Hungary and Romania.
Zoonoses and Public Health, 2018Co-Authors: Jeremy V. Camp, R. Haider, D. Porea, L. E. Oslobanu, P. Forgách, Norbert NowotnyAbstract:A serosurvey for Tahyna virus (TAHV), a mosquito-borne California Encephalitis orthobunyavirus (Peribunyaviridae) endemic to Europe, was performed to estimate the activity of TAHV on a broad geographic scale. Sera from wild boar (Sus scrofa), roe deer (Capreolus capreolus) and red deer (Cervus elaphus) were collected from Austria, Hungary and Romania. Samples were tested for neutralizing antibodies against TAHV using a virus microneutralization assay. The results demonstrate that TAHV transmission to mammals is widespread in Europe, particularly in the wild boar population where the mean rate of seroconversion is 15.2%.
