Coronavirus motif.
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Biomedical subjects
Publications and source records attributed to P Britton.
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The Spike (S) protein from a virulent British field isolate of porcine transmissible gastroenteritis virus (TGEV) FS772/70 was constructed from cDNA and inserted into the vaccinia virus (VV) thymidine kinase gene locus under the control of the VV early/late gene P7.5k promoter. Recombinant S protein was synthesized as an endo-beta-N-acetylglucosaminidase H (Endo H)-sensitive glycoprotein with high mannose simple oligosaccharides (gp 190) that underwent post-translational modification to an Endo H-resistant glycoprotein with complex oligosaccharides (gp210). Immunofluorescence analysis demonstrated that the majority of recombinant S protein was retained at the Golgi but some S protein was expressed on the plasma membrane. Monoclonal antibodies (mAbs) raised against native S protein reacted with this recombinant S protein; also, mice infected with the recombinant vaccinia virus (rVV) expressing the S protein induced TGEV neutralizing antibodies. A truncated S protein (S delta) was also expressed in rVV-infected cells by introducing a deletion into the S protein cDNA that removed 292 amino acids from the C-terminus. The S delta protein (gp 170) was shown to be antigenically similar to TGEV S protein by immunofluorescence and immunoprecipitation tests but was retained in the endoplasmic reticulum and not expressed on the cell surface.
Porcine transmissible gastroenteritis virus (TGEV) nucleoprotein and integral membrane protein genes were cloned into the vaccinia virus insertion vector, pGS20, in the correct orientation for expression under the control of the vaccinia P7.5K promoter. Recombinant vaccinia viruses were generated by in vivo homologous recombination of the insertion vector with the WR strain of vaccinia virus. Nucleoprotein (N) expressed by both recombinant vaccinia virus and TGEV had a relative molecular mass (Mr) of 47,000 and was susceptible to degradation at the C-terminus yielding discrete breakdown products. The integral membrane protein (M) expressed by a recombinant vaccinia virus and TGEV was sensitive to endoglycosidase H reducing the mature polypeptide of Mr 29,000 to a species of Mr 27,000. Expression of M by recombinant vaccinia virus was inhibited during early infection due to a cryptic vaccinia virus transcriptional termination signal within the TGEV coding sequence. Indirect immunofluorescence showed that both N and M were only localised in the cell cytoplasm of either TGEV or recombinant vaccinia virus immunoprecipitated specific TGEV antigens from lysates of TGEV infected cells but had little significant TGEV neutralising activity in vitro.
Previous analysis of porcine respiratory coronavirus (PRCV) mRNA species showed that mRNAs 2 and 3 were smaller than the corresponding transmissible gastroenteritis virus (TGEV) mRNA species (Page et al. (1991) J. Gen. Virol. 72, 579-587). Sequence analysis showed that mRNA 3 was smaller due to the presence of a new putative RNA-leader binding site upstream of the PRCV ORF-3 gene. However, this observation did not explain the deletion observed in PRCV mRNA 2. Polymerase chain reaction (PCR) was used to generate cDNA from the 3' coding region of the putative polymerase gene to the poly (A) tail of PRCV for comparison to the equivalent region from TGEV. The PRCV S protein was found to consist of 1225 amino acids, which had 98% similarity to the TGEV S protein. However, the PRCV S gene contained a 672 nucleotide deletion, corresponding to 224 amino acids (residues 21 to 245 in TGEV S protein), 59 nucleotides downstream of the S gene initiation codon. The PRCV genome from the ORF-3 gene to the poly (A) tail was sequenced for comparison to TGEV in order to identify other potential differences between the two viruses. Four ORFs were identified that showed 98% similarity to the TGEV ORF-4, M, N and ORF-7 genes. No other deletions or any PRCV specific sequences were identified.
STUDY OBJECTIVE: To determine the efficacy of flexion-extension (F/E) cervical-spine radiographs in detecting acute cervical-spine instability in emergency patients. DESIGN: We retrospectively reviewed the charts of 141 consecutive trauma patients who had F/E views performed after a routine cervical-spine series (three views) was obtained in the emergency department. Interpretations of the routine series were compared with those of the F/E views to determine if additional useful information was provided by the latter. The charts also were reviewed to determine if any variables were associated with an increased use of F/E views, an increased likelihood of these views demonstrating instability, or any neurologic sequelae resulted from these studies. SETTING: An urban Level I adult trauma center. MEASUREMENTS: The interpretations of the routine series were noted to be either normal, abnormal but without demonstrable fracture/dislocation, or demonstrating a fracture/dislocation. The F/E views were categorized as stable, unstable, or uninterpretable. RESULTS: Cervical-spine instability was demonstrated by F/E views in 11 of the 141 patients (8%), four of whom had normal routine cervical-spine films. Three of these four patients required surgical stabilization. Prolonged neck pain (more than 24 hours), an initially abnormal spine series, and a neurosurgical consult were all associated with an increased use of F/E views. Ten of 11 patients with radiographic instability had significant neck pain by history; the remaining patient was intoxicated. No neurologic sequelae resulted from performing F/E studies. There was one false-negative F/E study, which raises concern about the reliability of this procedure in the ED. CONCLUSION: We believe that a large prospective study is required to determine which patients warrant F/E views.
Analysis of porcine transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) mRNA species indicated a deletion in mRNA 3 of PRCV. Polymerase chain reaction (PCR) was used to clone the 5' end of mRNA 3 from PRCV for comparison with the equivalent region in TGEV. Small deletions were observed within and around the PRCV sequence equivalent to the putative open reading frame (ORF) ORF-3a identified in TGEV. The potential RNA polymerase-leader complex binding site (leader RNA binding site), ACTAAAC, found upstream of ORF-3a in TGEV, was absent from the PRCV genome but a potential site was found in the PRCV genome upstream of a gene equivalent to TGEV ORF-3b. PCR analysis, using primers corresponding to sequences within the ORF-3b gene and the leader RNA sequence, confirmed that the leader RNA binding site was upstream of a gene equivalent to TGEV ORF-3b on PRCV mRNA 3 but upstream of ORF-3a on TGEV mRNA 3. The presence of the new leader RNA binding site would be responsible for generating the smaller mRNA 3 species found in PRCV-infected cells.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
The leader RNA sequence was determined for two pig coronaviruses, transmissible gastroenteritis virus (TGEV), and porcine respiratory coronavirus (PRCV). Primer extension, of a synthetic oligonucleotide complementary to the 5' end of the nucleoprotein gene of TGEV was used to produce a single-stranded DNA copy of the leader RNA from the nucleoprotein mRNA species from TGEV and PRCV, the sequences of which were determined by Maxam and Gilbert cleavage. Northern blot analysis, using a synthetic oligonucleotide complementary to the leader RNA, showed that the leader RNA sequence was present on all of the subgenomic mRNA species. The porcine coronavirus leader RNA sequences were compared to each other and to published coronavirus leader RNA sequences. Sequence homologies and secondary structure similarities were identified that may play a role in the biological function of these RNA sequences.
Subgenomic mRNA from a virulent field isolate of porcine transmissible gastroenteritis virus (TGEV), strain FS772/70, was used to produce cDNA. The cDNA from three overlapping clones was sequenced by the chain termination method and two open reading frames (ORFs) were identified. The largest ORF, 4350bp, encoded a polypeptide of 1449 amino acids of relative molecular mass (Mr) 159811, which contained 33 potential N-linked glycosylation sites, a cysteine-rich region, and a potential transmembrane region. The C-terminal half of this ORF showed homology to the S proteins of four other coronaviruses. The other ORF consisted of the 3'-end of a gene with homology to the carboxyl terminus of the F2 subunit of infectious bronchitis virus (IBV) RNA polymerase.
Subgenomic mRNA from a virulent isolate of porcine transmissible gastroenteritis virus (TGEV) was used to produce cDNA clones covering the genome region from the 3' end of the peplomer gene to the start of the integral membrane protein gene. The nucleotide sequence of this area was determined using clone pTG11 and a previously reported cDNA clone pTG22. Three open reading frames (ORFs) were identified encoding putative polypeptides of relative molecular masses (Mr) 6,600, 27,600, and 9,200. The sequence encoding the Mr 9,200 polypeptide was found to be present on the "unique" 5' region of the 3.0 kb mRNA species whereas the other two ORFs mapped on the 3.9 kb mRNA species. Differences between the ORFs from this strain of TGEV and those from a previously reported avirulent strain of TGEV were compared.
Synthetic oligopeptides, corresponding to an amino acid sequence encoded by a potential Mr 9000 product's open reading frame (ORF-4) at the 3' terminus of the transmissible gastroenteritis virus genome, were used to generate rabbit antiserum. These antibodies produced immune complexes with an Mr 14,000 (14K) polypeptide in infected cells. The 14K product was shown by immune fluorescence to become associated with the cell nucleus, correlating with the onset of nuclear vacuolation, and suggesting a role in pathogenesis for the ORF-4 gene.
Subgenomic mRNA from a virulent isolate of porcine transmissible gastroenteritis virus (TGEV) was used to produce cDNA clones. Part of a new clone and a previously reported clone were sequenced and used to construct the viral gene for integral membrane protein. A single open reading frame (ORF) encoding a polypeptide of 262 amino acids, relative molecular mass (Mr) 29,459, was identified. The positive identification of the polypeptide as the integral membrane protein was demonstrated by the production in E. coli of a chimaeric protein comprising most of the ORF encoding the Mr 29,459 polypeptide and beta-galactosidase. The chimaeric protein reacted with a specific monoclonal antibody to viral integral membrane protein and antibodies raised against the chimaeric protein immune precipitated the viral protein. Comparison with the sequence of an avirulent isolate indicates amino acid residues that may be important in pathogenicity.
Subgenomic mRNA from a virulent isolate of porcine transmissible gastroenteritis virus (TGEV) was used to produce cDNA which was sequenced. Two non-overlapping open reading frames (ORFs) were identified. The largest, encoding a polypeptide of 382 amino acids (relative molecular mass (Mr) 43,483), was shown to be the viral nucleoprotein gene. The second ORF, found 3' to the larger ORF, encodes a polypeptide of 78 amino acids (Mr 9068) which has yet to be assigned to a viral product. The nucleoprotein gene was expressed in yeast cells under the control of two types of yeast promoters: the constitutive PGK promoter, and the inducible GAL1 promoter. Yeast cells containing recombinant plasmids, with the nucleoprotein gene in the correct orientation, produced a polypeptide of Mr 47,000, identical to the viral product, that reacted with a specific monoclonal antibody.
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Conceptualizations of 'burnout' vary between authors. Some descriptions of burnout show strong similarities to depression in the work setting, or 'professional depression' as described by Oswin [Children Living in Long Stay Hospitals, 1978. Heinemann, London]. This study supported such a similarity, and demonstrated a considerable extent of depressed mood amongst nursing staff in longstay settings, which was particularly significant amongst male staff. A number of distinct 'burnout' responses were evident amongst staff including not only 'professional depression' and depersonalization but also the avoidance of problems and decisions. Ambiguity about supervisors' expectations and success in meeting such expectations were associated with increased scores on each of these variables. Personality appeared to be related to staff's responses. Staff prone to direct hostility inwards on themselves were more likely to show an avoidance of problems and decisions. Those staff prone to direct hostility outwards were more likely to report an awareness of depersonalization toward others. Both these processes may in different ways affect patient care and relationships with other professionals.
The needs for support of staff in human services work are often stated, but less often is the nature of such support clearly specified. This study attempts to clarify the nature of effective support from a superior, as perceived by qualified nursing staff working in psychiatric, mental handicap and medical settings. 'Personal respect', 'empathic attention' and 'absence of interpersonal defensiveness' appeared to be important components to such support. Staff on the same ward showed a high degree of agreement in judgements of their superior's personal respect and empathic attention, but perceived interpersonal defensiveness appeared more specific to perceptions or interactions between particular staff. Greater degrees of 'personal respect' experienced by staff were associated with reduced role ambiguity and reduced emotional exhaustion ('burnout'). The empathic attention reported as given by ward charge nurses was highly correlated with the personal respect they reported receiving from their own superior. These results support approaches which see respect, empathy and genuineness as important ingredients in helping relationships.