Comparative pathogenesis of tissue culture-adapted and wild-type Cowden porcine enteric calicivirus (PEC) in gnotobiotic pigs and induction of diarrhea by intravenous inoculation of wild-type PEC.

Porcine enteric calicivirus (PEC/Cowden) causes diarrhea in pigs, grows in cell culture, and is morphologically and genetically similar to the Sapporo-like human caliciviruses. Genetic analysis revealed that the tissue culture-adapted (TC) Cowden PEC has one distant and three clustered amino acid substitutions in the capsid region and 2 amino acid changes in the RNA polymerase region compared to wild-type (WT) PEC (M. Guo, K.

Low-grade myxoid renal epithelial neoplasms with distal nephron differentiation.

We report 4 distinctive renal epithelial neoplasms that are essentially identical at the morphologic and immunohistochemical levels and do not fit an accepted category in the existing classification of these lesions. The patients were all females, with ages ranging from 32 to 79 years (mean, 50 years). The tumors were well circumscribed and were composed of uniform, predominantly low cuboidal cells with eosinophilic, focally vacuolated cytoplasm.

Clinical and sensorimotor gating effects of ketamine in normals.

The clinical similarities between PCP psychosis and schizophrenia have contributed importantly to the development of the glutamate hypothesis of schizophrenia. Sensory gating, as measured by prepulse inhibition of the acoustic startle reflex (PPI), is impaired in patients with schizophrenia. In animals, the noncompetitive NMDA antagonists PCP and ketamine disrupt PPI in a way that resembles the defect seen in schizophrenia.

Molecular characterization and pathogenesis of transmissible gastroenteritis coronavirus (TGEV) and porcine respiratory coronavirus (PRCV) field isolates co-circulating in a swine herd.

TGEV replicates in intestinal enterocytes and causes diarrhea in young pigs. PRCV, a spike (S) gene deletion mutant of TGEV with an altered respiratory tissue tropism, causes mild or subclinical respiratory infections. Comparisons of TGEV and PRCV strains suggest that tropism and pathogenicity are influenced by the S gene and ORF3, respectively.

Development of a reverse transcription-nested polymerase chain reaction assay for differential diagnosis of transmissible gastroenteritis virus and porcine respiratory coronavirus from feces and nasal swabs of infected pigs.

Transmissible gastroenteritis virus (TGEV), a coronavirus, replicates in intestinal enterocytes and causes diarrhea in young pigs. Porcine respiratory coronavirus (PRCV), a spike (S) gene natural deletion mutant of TGEV, has a respiratory tissue tropism and causes mild or subclinical respiratory infections. Conventional antigen-based diagnostic tests fail to differentiate TGEV and PRCV, and a blocking ELISA test to serologically differentiate TGEV/PRCV-infected pigs is conducted on convalescent serum retrospectively after disease outbreaks.

Comparative sequence analysis of the VP7 genes of G6, G8 and G10 bovine group A rotarviruses and further characterization of G6 subtypes.

We previously reported the relatively high prevalence (15%) of bovine G6 subtypes (G6s) in the field using RT-PCR and restriction fragment length polymorphism (RFLP) analysis (Chang et al., Arch. Virol.

Impaired prepulse inhibition of acoustic startle in schizophrenia.

Background: Schizophrenics show deficits in sensorimotor gating, as measured by prepulse inhibition of acoustic startle (PPI). The goal of this investigation is to further characterize PPI and habituation deficits in schizophrenia, and to examine whether differing subgroups of schizophrenics would show comparable PPI deficits.

Methods: PPI was measured in 24 male schizophrenic subjects (9 acutely decompensated inpatients and 15 stable outpatients) and in 20 age-matched normal control subjects.

Molecular characterization of a porcine enteric calicivirus genetically related to Sapporo-like human caliciviruses.

Porcine enteric calicivirus (PEC) is associated with diarrhea in pigs, and to date it is the only cultivable enteric calicivirus (tissue culture-adapted [TC] PEC/Cowden). Based on sequence analysis of cDNA clones and reverse transcription-PCR products, TC PEC/Cowden has an RNA genome of 7,320 bp, excluding its 3' poly(A)(+) tail. The genome is organized in two open reading frames (ORFs), similar to the organizations of the human Sapporo-like viruses (SLVs) and the lagoviruses.

Passive immunity to bovine rotavirus in newborn calves fed colostrum supplements from cows immunized with recombinant SA11 rotavirus core-like particle (CLP) or virus-like particle (VLP) vaccines.

Heterotypic passive immunity to IND (P/5/G6) bovine rotavirus (BRV) was evaluated. Three groups of calves (n = 5 per group) were fed 1% pooled colostrum supplements (birth to 7 days of age) from BRV seropositive cows vaccinated with recombinant SA11(P/2/G3) rotavirus-like particles (VLPs), recombinant SA11 rotavirus core-like particles (CLPs), or inactivated SA11 rotavirus (SA11). Control calves (n = 5 per group) received either pooled colostrum from unvaccinated (BRV field exposure seropositive) control cows, or no colostrum.

Detection of group B rotaviruses in fecal samples from diarrheic calves and adult cows and characterization of their VP7 genes.

Groups A, B, and C rotaviruses have been identified in cattle. Group B rotaviruses are associated with sporadic cases of diarrhea in calves and adult cows. From diagnostic submissions to our laboratory, 90 fecal samples from cases of calf diarrhea, 81 fecal samples from cases of adult cow diarrhea (winter dysentery), and 20 fecal samples from case control normal adult cows were tested for group B rotaviruses by polyacrylamide gel electrophoresis (PAGE), and reverse transcription (RT)-PCR (targeting 279 bp of the VP7 gene).

Isotype-specific antibody responses to rotavirus and virus proteins in cows inoculated with subunit vaccines composed of recombinant SA11 rotavirus core-like particles (CLP) or virus-like particles (VLP).

The isotype antibody responses to bovine IND P5, G6 and simian SA11 P2, G3 rotavirus and SA11 rotavirus proteins (VP4, VP6 and VP7) in serum, colostrum and milk were analysed by ELISA in three groups of vaccinated cows and nonvaccinated controls. Pregnant cows were vaccinated intramuscularly and intramammarily with recombinant baculovirus-expressed SA11 rotavirus VLP (triple-layered virus-like particles containing rotavirus VP2, VP4, VP6 and VP7); CLP (double-layered core-like particles containing rotavirus VP2 and VP6); or inactivated SA11 rotavirus, respectively. Rotavirus antigen titers were highest (30-200-fold) in ELISA in the VLP vaccine compared to the inactivated SA11 vaccine.

Identification of group B rotaviruses with short genome electropherotypes from adult cows with diarrhea.

Two field strains (BB-RVLV and KD) of group B rotaviruses from adult dairy cows with diarrhea displayed short genome electropherotypes. Gnotobiotic calves inoculated with fecal filtrates of each group B rotavirus developed diarrhea, and only group B rotaviruses or antigens were detected in the feces by immunoelectron microscopy and in intestinal epithelial cells by immunofluorescent staining, respectively. The feces or intestinal contents of the cows and inoculated calves were negative for group A and C rotaviruses by enzyme-linked immunosorbent assay, immunoelectron microscopy, or cell culture immunofluorescence assays.

Rotavirus subunit vaccines.

We evaluated rotavirus subunit vaccines for use in humans and animals. Insect cells were co-infected with combinations of individual baculovirus recombinants expressing human, bovine or simian rotavirus VP2, VP4, VP6 or VP7 to produce virus-like particles (VLPs). To determine whether immunization with VLPs could induce active protective immunity, VLPs were administered parenterally to rabbits, and the immune response and protection from rabbit ALA rotavirus challenge were evaluated.

The characterization of VP7 (G type) and VP4 (P type) genes of bovine group A rotaviruses from field samples using RT-PCR and RFLP analysis.

Characterization of the VP7 (G type) and VP4 (P type) genes of bovine group A rotaviruses (BRV) from field samples was performed using RT-PCR and RFLP analysis. After RT-PCR amplification of the full length VP7 genes and partial length VP4 genes (nucleotides 1 to 1096), four enzymes, EcoRV, NlaIV, BamHI and HpaII were used for digestion analysis. For VP7, four RFLP profiles were observed after analysis of the digests: they were designated as G6, G6s (subtype, showed about 86% nucleotide and 90% amino acid identity to reference G6 strains), G8 and G10.

Comparative nucleotide and deduced amino acid sequence analysis of VP7 gene of the NCDV Cody (I-801) strain of group A bovine rotavirus.

The prevalent G serotypes of group A bovine rotavirus (BRV) reported are G6, G10, and less commonly, G8. Neonatal Calf Diarrhea Virus (NCDV), Lincoln and Cody strains were first isolated from diarrheic calves in Nebraska. The NCDV Lincoln strain is the currently used U.

A survey of G6 and G10 serotypes of group A bovine rotaviruses from diarrheic beef and dairy calves using monoclonal antibodies in ELISA.

Group A bovine rotaviruses (BRV) have been identified worldwide as a major cause of diarrhea in the young of many species, including humans. Group A rotaviruses are classified into serotypes on the basis of the outer capsid proteins, VP7 (G types) and VP4 (P types). To date, there are 14 G types of group A rotaviruses, with G1, G6, G8, and G10 described for BRV isolates.

Serotypic differentiation of rotaviruses in field samples from diarrheic pigs by using nucleic acid probes specific for porcine VP4 and human and porcine VP7 genes.

Of 216 fecal and intestinal samples collected from nursing or weaned diarrheic pigs in the United States and Canada, 57 were identified as group A rotavirus positive by RNA electrophoresis and silver staining. Fifty-seven and 52 rotavirus-positive samples were analyzed by hybridization with Gottfried and OSU PCR-derived gene 9 and 4 probes, respectively. Only 17 samples were identified with either homologous VP4 (P)- or VP7 (G)-coding genes or both.

Detection of rotavirus serotypes G1, G2, G3, and G11 in feces of diarrheic calves by using polymerase chain reaction-derived cDNA probes.

On the basis of antigenic variability in the VP7 outer capsid glycoprotein, at least 14 G serotypes exist for group A rotaviruses. Serotypic diversity exists among bovine rotaviruses (BRV), with serotypes G1, G6, G8, and G10 reported for cattle. Although G1 and G8 rotaviruses were originally described for humans, the recent isolation of G6 and G10 rotaviruses from humans further emphasizes the serotypic similarity between human and bovine rotaviruses and the possible zoonotic potential of rotaviruses.

Characterization of field strains of group A bovine rotaviruses by using polymerase chain reaction-generated G and P type-specific cDNA probes.

Dot and Northern blot hybridization assays were used to analyze field strains of group A bovine rotaviruses (BRVs) by using nucleic acid probes representing P and G type specificities. The probes were prepared by polymerase chain reaction amplification of hyperdivergent regions of the cloned VP4 (nucleotides 211 to 686) and VP7 (nucleotides 51 to 392) genes from four serotypically distinct (in P or G types) strains of rotaviruses: NCDV (G6, P1), IND (G6, P5), 69M (G8, P10), and Cr (G10, P11). The P and G type cDNA probes were radiolabeled with [32P]dCTP and hybridized with RNA extracted from reference cell culture-passaged rotavirus strains or the field samples.

Single-stranded genomic RNA from turkey enterovirus-like virus.

Previously, we described a disease syndrome in young turkeys caused by an enterovirus-like virus. The virus was designated an enterovirus-like virus based on size, morphology, and intracytoplasmic crystalline arrays of virus. In the present study, further characterization of the virus was performed to ascertain its classification.