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W C Wilson

Publications and source records attributed to W C Wilson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Molecular characterization of the segment 2 gene of epizootic hemorrhagic disease virus serotype 2: gene sequence and genetic diversity.

The complete nucleotide sequence of the gene encoding the major outer capsid protein VP2 from the Alberta isolate of epizootic hemorrhagic disease virus serotype 2 (EHDV-2) was determined. Complementary DNA (cDNA) corresponding to segment 2 was 3002 nucleotides in length with a single open reading frame that encoded a VP2 of 982 amino acids. Although the VP2 from EHDV-2 was only 34% homologous to the cognate protein from EHDV-1, their predicted hydropathic profiles were similar, suggesting that conservation of structure is important biologically to these capsid proteins. Sequence analysis of six North American EHDV-2 field isolates showed a high degree of comparative genetic identity (> 97%). Phylogenetic profiles constructed suggest that regionalization of the viruses within the North American continent has contributed to the genetic diversity.

Amino Acid Sequence↗
PubMed1995

A model for the membrane topology of the NS3 protein as predicted from the sequence of segment 10 of epizootic haemorrhagic disease virus serotype 1.

Segment 10, encoding nonstructural proteins 3 (NS3) and 3a (NS3a) of epizootic haemorrhagic disease virus serotype 1 (EHDV-1) was sequenced. Computer motif recognition programs were used for interpretation of the sequence data to predict a structure for NS3. Integral membrane protein theories were then applied to produce a general topological model for the EHDV-1 NS3 protein. Homology was observed between EHDV-1 NS3 integral membrane motifs and those similarly observed in the cognate proteins of other orbiviruses.

Amino Acid Sequence↗
PubMed1995

Development of polymerase chain reaction for specific identification of epizootic hemorrhagic disease virus serotype 1.

The diagnostic potential of the polymerase chain reaction (PCR) for specific identification of epizootic hemorrhagic disease virus serotype 1 (EHDV-1) in cell culture and clinical specimens was evaluated. Using oligonucleotide primers, selected from genome segment 2 of EHDV-1 (New Jersey strain), the PCR-based assay resulted in a 862 base pair (bp) PCR product. EHDV-1 RNA from United States prototype serotype 1 and a number of EHDV-1 field isolates, propagated in cell cultures, were detected by this PCR based assay. The specific 862 bp PCR products were visualized on ethidium bromide-stained agarose gel. Identity of the PCR product was confirmed by chemiluminescent hybridization with non radiolabelled internal probe. Using chemiluminescent hybridization, the sensitivity of the PCR assay was 1.0 fg of virus RNA (equivalent to 60 virus particles). Amplification product was not detected when the PCR-based assay was applied to RNA from EHDV serotype 2 (EHDV-2); the United States bluetongue virus (BLU) prototypes serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cell; or blood cells from calves and deer that were EHDV-seronegative and virus isolation negative. Application of this EHDV-1 PCR-based assay to clinical samples resulted in detection of EHDV-1 RNA from blood samples, collected from a calf experimentally infected with EHDV-1. The described PCR-based assay provides a simple, rapid, sensitive, specific and inexpensive method for specific identification of EHDV-1 infection in susceptible ruminants.

Animals↗
PubMed1995

Complete nucleotide sequence of RNA segment 3 of bluetongue virus serotype 2 (Ona-A). Phylogenetic analyses reveal the probable origin and relationship with other orbiviruses.

The nucleotide sequence of the RNA segment 3 of bluetongue virus (BTV) serotype 2 (Ona-A) from North America was determined to be 2772 nucleotides containing a single large open reading frame of 2703 nucleotides (901 amino acid). The predicted VP3 protein exhibited general physiochemical properties (including hydropathy profiles) which were very similar to those previously deduced for other BTV VP3 proteins. Partial genome segment 3 sequences, obtained by polymerase chain reaction (PCR) sequencing, of BTV isolates from the Caribbean were compared to those from North America, South Africa, India, Indonesia, Malaysia and Australia, as well as other orbiviruses, to determine the phylogenetic relationships amongst them. Three major BTV topotypes (Gould, A.R. (1987) Virus Res. 7, 169-183) were observed which had nucleotide sequences that differed by approximately 20%. At the molecular level, geographic separation had resulted in significant divergence in the BTV genome segment 3 sequences, consistent with the evolution of distinct viral populations. The close phylogenetic relationship between the BTV serotype 2 (Ona-A strain) from Florida and the BTV serotypes 1, 6 and 12 from Jamaica and Honduras, indicated that the presence of BTV serotype 2 in North America was probably due to an exotic incursion from the Caribbean region as previously proposed by Sellers and Maaroof ((1989) Can. J. Vet. Res. 53, 100-102) based on trajectory analysis. Conversely, nucleotide sequence analysis of Caribbean BTV serotype 17 isolates suggested they arose from incursions which originated in the USA, possibly from a BTV population distinct from those circulating in Wyoming.

Amino Acid Sequence↗
PubMed1995

Geographical genetic variation in the gene encoding VP3 from the Alberta isolate of epizootic hemorrhagic disease virus.

The complete nucleic acid and deduced amino acid sequences of gene segment 3 and the encoded VP3 from the North American, Alberta isolate of epizootic hemorrhagic disease virus serotype 2 (EHDV-2) are reported. Complementary DNA corresponding to segment 3 was 2768 nucleotides in length with an open reading frame of 2697 base pairs which encoded a VP3 polypeptide of 899 amino acid residues. Sequence comparison with genome segment 3 and VP3 from the Australian strain of EHDV-2 indicated genotypic and phenotypic homologies of 79% and 94%, respectively. Two North American field isolates of EHDV-2, as well as EHDV-1 (New Jersey isolate), had virtually identical homology to the Alberta isolate. Sequence analysis delineated North American EHDV strains as members of a genetically homologous and geographically distinct group of orbiviruses (topotype). The data support the hypothesis that geographic isolation between North American and Australian orbiviruses has permitted the viral topotypes to maintain their genetic distinctness.

Alberta↗
PubMed1994

Development of a nested-PCR test based on sequence analysis of epizootic hemorrhagic disease viruses non-structural protein 1 (NS1).

Two orbiviruses, epizootic hemorrhagic disease (EHD) and bluetongue (BTV) viruses, cause disease in domestic and wild ruminant species. The gene that encodes non-structural protein 1 (NS1) of EHD virus, serotype 1, was sequenced and compared to EHD and BTV NS1 sequences. The NS1 gene was found to be more conserved than the VP3 gene, and was selected as a target for polymerase chain reaction (PCR) amplification. The NS1 genes of several BTV viruses and another orbivirus, African horse sickness (AHS), were compared to the EHD NS1 genes. This information was used to develop a capture nested-PCR for detection and differentiation of EHD from BTV viral RNA.

African Horse Sickness Virus↗
PubMed1994

The smallest gene of the orbivirus, epizootic hemorrhagic disease, is expressed in virus-infected cells as two proteins and the expression differs from that of the cognate gene of bluetongue virus.

The smallest gene (S10) of the virus of epizootic hemorrhagic disease of deer (EHD, serotype 2) is expressed as two proteins in virus-infected cells. By contrast, the non-structural proteins (NS3 and NS3A) encoded in the smallest gene of bluetongue (BT) viruses are difficult to detect in virus-infected cells. The nucleotide sequence of S10 of EHDV-2 contains two in-frame initiation codons which allow for translation of proteins of mol. wt. 25503 and 23921 analogous to NS3 and NS3A of BT viruses. The S10 genes of BT viruses are highly conserved (82%-99%); the nucleotide sequence similarity of S10 of EHDV-2 and BT viruses is about 64%. Some structural features of NS3 and NS3A are conserved in the two viruses, despite the divergence in the amino acid sequences of the proteins. The hydrophobic domains of the proteins and the putative transmembrane sequences are conserved, as are potential glycosylation sites in the proteins. A cluster of proline residues, which is conserved at residues 36-50 in all of the published sequences of NS3 of BT viruses, is conserved exactly in the alignment of the sequence of NS3 of EHDV-2 with that of the BT viruses. An explanation for the differences in expression of NS3/NS3A in EHD and BT viruses was not evident in comparing the nucleotide sequences of S10 of the viruses.

Amino Acid Sequence↗
PubMed1994

Sequence analysis of the non-structural protein 2 from epizootic hemorrhagic disease viruses.

The non-structural protein 2 (NS2) of epizootic hemorrhagic disease virus serotype 1 (EHD-1) was cloned and sequenced. The NS2 gene was found to be 1185 bp containing a single open reading frame that encodes a 376 amino acid protein. A 97% nucleic acid identity was found between EHD-1 and a previously published NS2 sequence of EHD-2. Only a 60% nucleic acid identity was found between EHD and the bluetongue virus (BTV) serogroup. Comparison of the deduced amino acid sequences revealed 97% identity within the EHD serogroup, and less than or equal to 43% identity between serogroups.

Amino Acid Sequence↗
PubMed1993

Nested and multiplex polymerase chain reactions for the identification of bluetongue virus infection in the biting midge, Culicoides variipennis.

Two polymerase chain reaction tests for the detection of bluetongue viral (BLU) RNA in the principal North American insect vector, Culicoides variipennis, were developed. The BLU serogroup specific test used the highly expressed non-structural protein 1 gene as the target gene and two amplification steps. First a 1228 base pair product was amplified using an outer primer pair, then a second amplification using a nested or internal primer pair produced a 930 base pair product. This nested PCR test was found to be very sensitive detecting an equivalent to 1 plaque-forming unit of BLU viral RNA extracted from infected biting midges. The serotype specific test used a multiplex PCR approach in which five different primer pairs were used simultaneously. Each pair was based on the variable outer capsid protein VP2 gene of the five US serotypes generating specific product which were easily identified by size difference. The sensitivity of the multiplex PCR was less sensitive than the nested-PCR but sufficient for use with field collected samples. These tests provide valuable tools for epidemiologic studies of BLU disease.

Animals↗
PubMed1993

Bluetongue virus in sheep and cattle and Culicoides variipennis and C. stellifer (Diptera: Ceratopogonidae) in Louisiana.

The transmission of bluetongue virus (BLU) to sheep and cattle relative to Culicoides abundance and infection was studied in two areas of the Louisiana State University Agricultural Center, Baton Rouge, LA. The seroprevalence of BLU in beef cattle was 70.5% in 1989 and 37.0% in 1990; 2 of 37 animals tested in both years became positive, indicating active transmission. The prevalence of BLU in sheep decreased from 52.2% in 1989 to 34% in 1990; seroconversion was not detected. Serotypes of positive sheep were as follows: 13 sheep were positive for BLU-13, 6 for BLU-17, 2 for BLU-2, and 2 for both BLU-13 and BLU-17. The seroprevalence of BLU virus in dairy bulls increased from 15.4% in 1989 to 47.4% in 1990; 0 and 7 seroconversions occurred in 1989 and 1990, respectively. Serotypes of BLU from the bulls were as follows: five bulls for BLU-13; two for BLU-17; one for BLU-13 and BLU-17; and one for BLU-13, BLU-17, and BLU-2. Peaks in the abundance of Culicoides variipennis (Coquillett) and C. stellifer (Coquillett) collected in New Jersey light traps corresponded with the suspected transmission dates during 1990. Bluetongue viral RNA was detected in one of 381 pools (6,072 flies) of C. variipennis; no virus was detected in 125 pools (884 flies) of C. stellifer.

Animals↗
PubMed1993

Reperfusion injury and exhaled hydrogen peroxide.

Reactive oxygen species have been implicated in the pathophysiology of lung injury associated with the sequence of ischemia-reperfusion. To study this, we measured the exhaled breath hydrogen peroxide concentration [H2O2] in human and canine models of reperfusion lung injury. Our models were patients subjected to cardiopulmonary bypass (CPB) (Group 1), patients undergoing pulmonary thromboendarterectomy (Group 2), canine single lung transplant (Group 3), and patients subjected to peripheral ischemia resulting from aortic cross-clamping or tourniquet application (Group 4). In addition, we studied two groups with severe lung injury as positive controls. These consisted of hydrochloric acid (HCl)-induced canine lung injury (Group 5) and patients with adult respiratory distress syndrome (Group 6). The exhaled H2O2 was collected by using a -2 degrees C glass coil and assayed by a spectrophotometric method. In Group 1 samples were collected before and immediately after CPB. Group 2 samples were obtained before CPB, immediately after CPB, 3 h later, and daily until extubation. Samples in Group 3 were collected before lung transplant, and hourly for 3 h beginning immediately afterward. Group 4 samples were collected at the onset of reperfusion. Samples from Group 5 were collected before HCl and after HCl injury, at 0.5-1.5 and 2-3 h. Group 6 samples were collected when criteria for adult respiratory distress syndrome were met. Groups 1, 3, and 4 exhibited no significant increases in exhaled [H2O2] compared to control values. Group 2 had significantly increased [H2O2] (5.59 +/- 3.07 x 10(-7) mol/L, P = 0.028) on postoperative Day 2, but there was no correlation of [H2O2] with physiologic indicators of lung injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Prevalence of bluetongue virus expression in leukocytes from experimentally infected ruminants.

Replication of bluetongue virus (BTV) in leukocytes from the blood of sheep, cattle, elk, and mule deer inoculated with BTV serotype 10 or 17 was assessed by immunocytochemical staining and dot blot northern hybridization to determine if differences in the prevalence of infection in this blood fraction might account for the differences in clinical disease among these species. Viremia was confirmed by virus isolation in all inoculated animals. Analysis of leukocytes with monoclonal antibodies specific for BTV proteins revealed low numbers of infected leukocytes in only 2 sheep 8 days after inoculation with BTV serotype 10. Most of the cells expressing BTV were identified morphologically as monocytes; approximately 10% of infected cells were lymphocytes. Bluetongue virus was not detected by use of dot-blot hybridization on samples of blood. Our results suggest that differential infection of leukocytes does not account for the pronounced differences in clinical signs and pathologic changes among ruminants.

Animals↗
PubMed1992

Ordering and administration of sedatives and analgesics during the withholding and withdrawal of life support from critically ill patients.

OBJECTIVE: To determine why and how sedatives and analgesics are ordered and administered during the withholding and withdrawal of life support from critically ill patients. DESIGN: Prospective case series. SETTING: Medical-surgical intensive care units at a county hospital and a university hospital. PATIENTS: Consecutive 1-year sample of 22 patients from whom life support was withheld or withdrawn in one intensive care unit at a county hospital and a random sample of 22 similar patients in the intensive care unit in the university hospital over the same period. MAIN OUTCOME MEASURES: Physicians and nurses were interviewed to determine their reasons for ordering and administering drugs, and medical records were reviewed to document amounts of drugs ordered and administered. RESULTS: Drugs were given to 75% of patients during withholding and withdrawal of life support. Patients who did not receive medication were comatose and considered incapable of benefiting from sedation and analgesia. The median time until death following the initiation of the withholding or withdrawal of life support was 3.5 hours in the patients who received drugs and 1.3 hours in those patients who did not (P, not significant). Physicians ordered drugs to decrease pain in 88% of patients, to decrease anxiety in 85%, to decrease air hunger in 76%, to comfort families in 82%, and to hasten death in 39%; in no instance was hastening death the only reason cited. The amounts of benzodiazepines and opiates averaged 2.2 mg/h of diazepam and 3.3 mg/h of morphine sulfate in the 24 hours before withholding and withdrawal of life support and 9.8 mg/h and 11.2 mg/h in the 24 hours thereafter (P less than .025 and P less than .001, respectively). CONCLUSIONS: Large doses of sedatives and analgesics were ordered primarily to relieve pain and suffering during the withholding and withdrawal of life support, and death was not hastened by drug administration.

Analgesics↗
PubMed1992

General anesthesia and exhaled breath hydrogen peroxide.

To study the role of free radical formation on the impairment of pulmonary function seen with general anesthesia, we measured the hydrogen peroxide (H2O2) concentration in the exhaled breath condensate of 27 patients. Patients were divided into three study groups: a healthy patient group (group 1, n = 15) consisting of ASA physical status 1 and 2 patients undergoing elective noncardiothoracic surgery; a specific anesthetic event group (group 2, n = 6) composed of patients undergoing cardiopulmonary bypass (CPB); and a positive control group (group 3, n = 6) consisting of patients with the adult respiratory distress syndrome (ARDS). The exhaled breath condensate was collected by diverting exhaled breath through a glass condensation coil submerged in an ice/salt water bath. The exhaled breath condensate samples were then assayed using a spectrophotometric method. In group 1, samples were collected before and after the induction of general anesthesia with intravenous drugs, and before and after the administration of the inhalational anesthetics isoflurane (1.5%) (n = 7) or N2O (70%) (n = 8). In group 2, samples were collected pre- and post-CPB, and in group 3, when specific diagnostic criteria for ARDS were met. There was no significantly detectable H2O2 (not significantly different from zero) in any of the samples from the group 1 patients. Similarly, group 2 patients had exhaled breath H2O2 concentrations near zero except for one patient who was positive for the lupus anticoagulant. Group 3 patients had a mean (+/- SE) exhaled breath H2O2 concentration of 0.55 (+/- 0.08) microM, which was significantly greater than zero (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1991

A RNA virus in cells from Culicoides variipennis.

A virus was detected in cells (designated CuVa) cultured from one laboratory colony of the biting midge, Culicoides variipennis. By electron microscopy (30 nm), nonenveloped, icosahedral virions arranged separately and in crystalline matrix arrays were seen in the cytoplasm but not in the nucleus of CuVa cells. Separation by 10% polyacrylamide gel electrophoresis revealed multiple bands of viral-induced double-stranded RNA. Inoculation of this virus onto different cell lines and intracranially into suckling mice revealed no detectable pathology. Immunoperoxidase staining using polyclonal antibody determined that the virus is infectious to toad cells, bovine endothelial cells, bovine kidney cells, mosquito cells, and cells (designated KC) initiated from another laboratory colony of C. variipennis. KC cells infected with this virus were coinfected with bluetongue virus with no decrease in bluetongue virus titer.

Animals↗
PubMed1991

Molecular comparison of VP3 from bluetongue and epizootic hemorrhagic disease viruses.

The complete nucleic acid sequence of gene 3 from epizootic hemorrhagic disease of deer (EHD) virus serotype 1 was determined. The 2768 bp sequence encodes a single protein that contains 899 amino acids and has a molecular weight of 103 kDa. The predicted protein sequence has 94.7% identity with EHD virus serotype 2 and greater than 77% identity with the related bluetongue viruses serotypes 1, 10 and 17 VP3 proteins. The relevance of these data to studies of recombinant DNA diagnostics and genetic relatedness is discussed.

Amino Acids↗