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Biomedical subjects

S E Wright

Publications and source records attributed to S E Wright.

At least 73 records · Page 4Linked to original sources
PubMed1985

Detection and localization of the v-myb(AMV) gene products of avian myeloblastosis virus by a synthetic peptide antiserum.

An antiserum made against a synthetic peptide from an internal region of the predicted amino acid sequence of the avian myeloblastosis virus (AMV) transforming v-myb(AMV) gene identified two products, p46v-myb(AMV) and p32v-myb(AMV), which were localized in the nucleus of AMV-transformed myeloblasts. We propose that these proteins are the in vivo products of the v-myb(AMV) gene and thus the transforming protein(s) of AMV.

Animals↗
PubMed1985

Effect of experimental Ostertagia circumcincta infection on the performance of grazing lambs.

Groups of 10 three-and-a-half-month-old Suffolkcross lambs were infected daily, five times a week, for 12 weeks with either zero, 500, 1500, 3000 or 5000 larvae of Ostertagia circumcincta and grazed together on a series of 'clean' paddocks. All the lambs were moved at seven to 10 day intervals to a fresh paddock to prevent autoinfection and were killed after 14 weeks. Another group was killed at the outset as a control for carcase analysis. Mean O circumcincta populations were 34 (grazing control) and 1224, 473, 1092 and 4331 for the groups receiving 500, 1500, 3000 and 5000 larvae per day respectively. The percentage of fourth stage larvae increased with increasing larval intake. Extensive abomasal damage with mucosal hypertrophy and depletion of parietal cells occurred in the lambs receiving 3000 and 5000 O circumcincta larvae per day. Intakes of 1500 larvae per day and above depressed growth rate by 24 to 37 per cent, reduced the deposition of protein in the carcase by 34 to 52 per cent and lowered calcium/phosphorus deposition by 23 to 48 per cent. Plasma pepsinogen concentrations were consistently elevated in lambs receiving 3000 or 5000 larvae per day and may be a useful aid to recognising abomasal damage sufficient to affect productivity.

Abomasum↗
PubMed1985

Effect of Ostertagia ostertagi on lamb performance and cross resistance to O circumcincta.

Fifteen worm-free lambs (two-and-a-half to three months or four to four-and-a-half months old) were infected with 3500 or 4000 Ostertagia ostertagi larvae on five days each week for six weeks, and their performance compared to that of controls. Eleven lambs were killed after eight weeks and four were challenged with O circumcincta to determine whether any cross resistance had developed. A feature of the O ostertagi infection was the considerable variation in response. Overall liveweight gain was lowered by 24 per cent in the two-and-a-half to three-month-old infected lambs, mainly due to reductions of 27 to 40 per cent in four of the seven lambs. There was no consistent effect in the older lambs. The worm populations consisted mainly of early fourth stage larvae and developing worms, but a small percentage reached sexual maturity and these produced a low faecal egg count (1 to 63 eggs per gram). Numerous intraluminal refractive crystals were present in the gut of both adult worms and developing stages, possibly reflecting degenerative changes. Hypertrophy of the abomasal mucosa with patchy loss of differentiation was a feature of the infection, and in four lambs serum pepsinogen concentrations were elevated. Exposure to O ostertagi did confer some protection against challenge with O circumcincta in that worm counts were reduced to about 60 per cent of those in controls, although no increase was observed in the numbers of arrested larvae. The successful passage of O ostertagi through young lambs could be important in mixed or alternate grazing systems by providing a reservoir of infection for the alternate host.

Animals↗
PubMed1984

Candidate products of avian myeloblastosis virus oncogene region produced by in vitro translation of genomic RNA.

Avian myeloblastosis virus (AMV) genomic RNA was translated in vitro to identify the AMV transforming gene (myb) product(s). Full-length RNA yielded, in addition to the expected Pr76gag, a gag-related product of 92,000 daltons which did not appear to be a gag-oncogene fusion protein. Subgenomic AMV RNA in vitro translation, nonstructural products (specific for AMV) were of 54,000, 49,000 and 34,000 daltons. Based on their sizes and similar peptide maps for the smaller two proteins, it is proposed that they derive from the myb region of AMV.

Avian Leukosis Virus↗
PubMed1984

Electron microscopy in small cell lung carcinomas: clinical correlation.

In order to investigate the relationship of subcellular differentiation of small cell lung carcinomas (SCLC) and clinical response, we reviewed the electron microscopic (EM) features of tumor biopsy specimens from 33 patients with SCLC diagnosed by light microscopy (LM). These tumors were divided by EM into four groups according to the ultrastructural features. Group I (13 patients) had tumors with only neurosecretory granules on EM. Group II (11 patients) had tumors with neurosecretory granules and other subcellular features of non-SCLC. Group III (five patients) had tumors that lacked neurosecretory granules but contained subcellular features of non-SCLC. Group IV (four patients) had tumors that lacked all of these features. The complete and partial response rate to systemic chemotherapy with or without radiation therapy was 88% in the total population studied. The response rates were not statistically different in any of the four groups based on EM findings. The results of this study suggest that the LM diagnosis of SCLC alone adequately identifies lung cancer patients with a high response rate to systemic therapy.

Adult↗
PubMed1983

Comparison of the oligosaccharide moieties of the major envelope glycoproteins of the subgroup A and subgroup B avian myeloblastosis-associated viruses.

The nature of the oligosaccharide chains of the major envelope glycoprotein, gp85, from avian myeloblastosis-associated viruses has been examined for the subgroup A and subgroup B viruses replicated in fibroblasts from the same chicken embryos. Pronase-digested glycopeptides from [3H]mannose- or [3H]glucosamine-labeled viruses were analyzed by the combined techniques of gel filtration, endo-beta-N-acetylglucosaminidase digestion, and concanavalin A affinity chromatography. The gp85 protein from these two viruses, and also from another subgroup A avian leukosis virus replicated in the same cells, contained a diverse array of asparagine-linked oligosaccharides of the acidic type [(sialic acid +/- galactose-N-acetylglucosamine)2-4-(mannose)3-N-acetylglucosamine2(+/- fucose)-asparagine], hybrid type (sialic acid +/- galactose-N-acetylglucosamine-(mannose)5,4-N-acetylglucosamine2-asparagine), and neutral type [(mannose)5-9-N-acetylglucosamine2-asparagine], with the more highly branched (tri or tetraantennary or both) acidic-type structures representing the predominant class of oligosaccharide. Minor differences were observed between the gp85 of the subgroup B versus subgroup A viruses.

Avian Leukosis Virus↗
PubMed1981

Transformation-dependent alterations in the oligosaccharides of Prague C Rous sarcoma virus glycoproteins.

The influence of cell transformation on the glycosylation of viral envelope glycoproteins was examined by high-resolution gel filtration and specific glycosidase digestions of 3H-sugar-labeled glycopeptides from nondefective and transformation-defective Prague C strains of Rous sarcoma virus replicated in fibroblasts from the same chicken embryo. The major difference in glycosylation attributable to the viral transformation of the host cells was an increase in this relative amount of larger acidic-type oligosaccharides containing additional "branch" sugars (NeuNAc-Gal-GlcNAc-) compared with the smaller acidic-type and neutral-type oligosaccharides. There was also a shift in size distribution of neutral-type oligosaccharides toward smaller oligomannosyl cores in the transforming versus nontransforming virus glycopeptides. These alterations were consistent with a transformation-dependent increase in the extent of intracellular processing of a common precursor structure for the asparagine-linked oligosaccharides of Rous sarcoma virus.

Animals↗
PubMed1981

Rous sarcoma virus glycoproteins contain hybrid-type oligosaccharides.

Examination of [3H]mannose-labeled glycopeptides from Prague C Rous sarcoma virus gp85 with gel filtration and sequential glycosidase digestions demonstrated the presence of hybrid-type asparaginyl-oligosaccharides. The major hybrid species had an oligomannosyl core (Man5GlcNAc2-ASN) characteristic of neutral structures, plus "branch" sugars (NeuNAc-Gal-GlcNAc-) characteristic of complex, acidic structures.

Asparagine↗
PubMed1979

Oligosaccharide chains of avian RNA tumor virus glycoproteins contain heterogeneous oligomannosyl cores.

Chicken embryo fibroblasts (C/E phenotype) infected with subgroups B and C of the Prague strain of Rous sarcoma virus were radiolabeled with either [6-(3)H]-glucosamine or [2-(3)H]mannose, and virus was purified from the growth medium. The large envelope glycoprotein, gp85, was the only major radiolabeled component of purified virus. Pronase-digested glycopeptides from purified virus were analyzed by a combination of (i) gel filtration with columns of Sephadex G15/G50 and Bio-Gel P4 and (ii) enzymatic digestion of the oligosaccharide chains with specific exoglycosidases and endo-beta-N-acetylglucosaminidases. The rather broad molecular weight distribution (approximately 2,000 to 4,000) for glycopeptides in these studies and previous studies in other laboratories was shown to represent actual heterogeneity in the carbohydrate moieties: (i) the glycopeptides contained both mannose-rich, neutral chains and complex, acidic chains with terminal sialic acid; and (ii) both classes of asparagine-linked carbohydrate structures exhibited heterogeneity in the size of the oligomannosyl core (a mixture of approximately 5 to 9 mannose units for the neutral structures, and 3 or 5 mannose units for the acidic structures). With the [2-(3)H]mannose-labeled glycopeptides from Rous sarcoma virus, Prague strain subgroup C, most of the oligosaccharide chains were high-molecular-weight, acidic structures, with similar numbers of 3-mannose and 5-mannose core structures.

Acetylglucosaminidase↗
PubMed1976

Experience with second marrow transplants.

This report summarizes the experience with 25 patients who received a second marrow transplant. The marrow donor for the first transplant was an identical twin in four cases and a sibling matched at the major histocompatibility complex in 21 instances. The donor for the second transplant was the same as the first except for three patients whose second donor was another matched sibling. Nine patients with aplastic anemia rejected their first graft. Four of these patients were prepared for the second graft with a regimen of procarbazine and antithymocyte globulin (ATG) followed by cyclophosphamide or total body irradiation and were successfully regrafted. One rejected the second graft, two died of septicemia and one is alive and well 10 months after the second graft. Twelve patients with hematologic malignancy had a recurrence of disease after the first transplant. Despite preparation for the second graft with a variety of intensive chemotherapeutic regimens, the five patients who did not succumb to infection showed an early recurrence of disease. Four patients with hematologic malignancy had a failure of the first graft for unknown reasons, possibly related to the administration of ATG or methotrexate. One patient prepared for the second graft with procarbazine and ATG showed evidence of engraftment but died of infection. Two out of three patients given no additional preparation were successfully grafted. One died of recurrent central nervous system leukemia after 18 months and one is alive and well 26 months after the second graft.

Anemia, Aplastic↗
PubMed1974

Nucleotide sequence relationships of avian RNA tumor viruses: measurement of the deletion in a transformation-defective mutant of Rous sarcoma virus.

Stocks of cloned helper-independent Rous sarcoma virus (RSV) spontaneously segregate transformation-defective (td) mutants that appear to have an RNA genome composed of smaller subunits than those of the patent virus. Differential hybridization and competitive hybridization techniques involving reactions between viral RNA and proviral sequences in host cell DNA (under conditions of initial DNA excess) were used to measure the extent of the deletion in a td mutant of Prague strain (Pr) of RSV (Pr RSV-C). Viral 60 to 70S RNA sequences labeled to 1 to 5 x 10(7) counts per min per mug with (125)I were characterized with respect to their properties in hybridization reactions and used to reinforce data obtained with [(3)H]RNA of lower specific activity. By these techniques, about 13% +/- 3% of the sequences Pr RSV-C that formed hybrids with DNA from virus-induced sarcomas appeared to be deleted from the genome of td Pr RSV-C. Studies comparing hybridization of RNA from Pr RSV-C and td Pr RSV-C with RSV-related sequences in normal cells, and competition experiments with RNA from the endogenous chicken oncornavirus Rous-associated virus type 0 (RAV-0) provided evidence that the majority, if not all, of the RNA sequences of Pr RSV-C deleted from its transformation-defective mutant are not represented in normal chicken DNA. Competition studies with a leukosis virus, RAV-7, indicated this virus also lacks a genome segment of about the same size as the deletion in the td mutant. Finally, the genome of all three "exogenous" viruses was found to lack a small segment (about 12%) of sequences present in the endogenous provirus of RAV-O.

Animals↗