The cloning and sequencing of the virion protein genes from a British isolate of porcine respiratory coronavirus: comparison with transmissible gastroenteritis virus genes

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.

Intracellular processing of the porcine coronavirus transmissible gastroenteritis virus spike protein expressed by recombinant vaccinia virus

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.

Sequence comparison of the 5' end of mRNA 3 from transmissible gastroenteritis virus and porcine respiratory coronavirus

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.

Expression and cellular localisation of porcine transmissible gastroenteritis virus N and M proteins by recombinant vaccinia viruses

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.

Sequence of the S gene from a virulent British field isolate of transmissible gastroenteritis virus

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.

Sequence analysis of the leader RNA of two porcine coronaviruses: transmissible gastroenteritis virus and porcine respiratory coronavirus

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.

The polypeptide of Mr 14,000 of porcine transmissible gastroenteritis virus: gene assignment and intracellular location

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.

Sequence of the coding regions from the 3.0 kb and 3.9 kb mRNA. Subgenomic species from a virulent isolate of transmissible gastroenteritis virus

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.

The integral membrane protein from a virulent isolate of transmissible gastroenteritis virus: molecular characterization, sequence and expression in Escherichia coli

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.

Sequence of the nucleoprotein gene from a virulent British field isolate of transmissible gastroenteritis virus and its expression in Saccharomyces cerevisiae

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.

Professional depression, 'burnout' and personality in longstay nursing

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.

Burnout and professional depression: related concepts?

In 1978 Oswin documented a process of 'professional depression' affecting some nursing staff in long-stay hospitals. This study tested the hypothesis that 'professional depression' in long-stay nursing and 'emotional exhaustion' as a component of burnout describe a similar phenomenon. This hypothesis was supported. The results are consistent with Cherniss' characterization of burnout, which appears to show considerable similarities to the concept of depression. In this study professional depression demonstrated a substantial correlation with depressed mood. Personality demonstrated significant relationships with burnout variables, extrapunitive hostility correlating with hardening toward others, intropunitiveness with avoidance as a coping response. These findings, although confined to hospital nurses, support the usefulness of approaches stressing the interaction between the work environment and the individual.

Interpersonal support amongst nurses at work

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.

Cognitive performance of medicated schizophrenics with tardive dyskinesia

Twenty schizophrenic patients with tardive dyskinesia and an equal number of matched controls were tested on a novel cognitive task. The task had two components: cued response and spatial memory. Relative to controls, the dyskinetic subjects showed a superior cued response performance but an equal spatial memory ability. We speculate that this selective facilitation may reflect dopaminergic hyperactivity in the dyskinetic group.

When is a "wen" a "wen"? A diagnostic dilemma

The lay term "wen" has been applied to a wide range of scalp swellings. To help clarify the correct use of the term, we describe three patients recently treated in Leicester, who presented with macroscopically similar but histologically very dissimilar large scalp swellings.