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Biomedical subjects

E J Smith

Publications and source records attributed to E J Smith.

At least 91 records · Page 5Linked to original sources
PubMed1991

Association of a chicken repetitive element with the endogenous virus-21 slow-feathering locus.

The DNA sequences of an endogenous virus ev21-cell junction fragment (JFIL-1), and the pristine ev21 unoccupied region were analyzed. Comparisons of 3' proviral sequences of JFIL-1 with comparable regions of ev2, the prototype Rous-associated provirus (RAV-0), revealed minor single-base substitutions in the transmembrane domain of proviral envelope glycoprotein and the long terminal repeat of ev21. In the cell component of the JFIL-1, insertion of a 9-bp direct repeat and deletion of a guanine deoxynucleotide abolished HaeIII and BalI recognition sites that were present in the pristine region. Upstream from the insertion site, a large region was 71 and 75% homologous with dispersed chicken repetitive (CR1) elements associated with vitellogenin and very low density apolipoprotein II genes, respectively. Southern blot hybridizations and comparisons of CR1 motifs such as polypurine tracts, a tandem imperfect octamer, and 6-bp duplications indicated that this sex-linked, CR1 element (CR1ev21) may be the longest member of this family reported thus far.

Animals↗
PubMed1991

Application of a locus-specific DNA hybridization probe in the analysis of the slow-feathering endogenous virus complex of chickens.

To investigate further the sex-linked, slow-feathering (SF) locus, a DNA hybridization probe that flanks the integration site of endogenous virus ev21 was used to probe Southern blots from a variety of commercial SF White Leghorn (WL), broiler, and endangered lines. After HaeIII digestion of DNA from SF WL, the 5' and 3' provirus-cell junction fragments were seen in addition to a 2.5-kb fragment of cell sequences that was homologous with the viral integration region. The latter polymorphism, which appeared to represent sequences duplicated after integration of EV21, was designated unoccupied repeat URa. Among SF broiler crosses, the same provirus-cell junction fragments were found but the pristine region that represented the 1.6-kb proviral URb was also found. Only URb was found among rapid-feathering (RF) chickens, regardless of breed. Although there was marked (greater than 95%), agreement between the presence of ev21-cell; junction fragments and the SF phenotype among both WL and broilers, Southern blots of DNA from a few commercial SF broiler chickens lacked ev21 junction fragments but some RF revertants harbored ev21 junction fragments. These anomalies suggest that ev21 may not be the sole determinant of the SF phenotype.

Animals↗
PubMed1991

Genetic variation in the incidence of pipped eggs in turkeys selected for low and high semen ejaculate volume.

Genetic variation in embryonic mortality, expressed as embryos that pip their eggshell but do not hatch, was investigated in turkeys selected for low and high semen ejaculate volume (SEV). Through five generations (Generations 10 to 14, inclusive) mean heritability estimates for pipped eggs were .21 and .08 in the low- and high-SEV lines, respectively. Estimates of sire, dam, and within-hatch components of variance suggest greater environmental and maternal effects than genetic influences on the incidence of pipped eggs in turkeys.

Animals↗
PubMed1990

Ankle arthrodesis in the rheumatoid patient.

We studied 11 patients with severe rheumatoid arthritis of the ankle joint who underwent arthrodesis employing the Charnley technique. Results of the procedure were assessed using the Fries score and the ankle evaluation grading system of Mazur et al. Four patients (36%) suffered pin-track sepsis. Three patients also showed delayed union, but sound bony fusion was eventually achieved in all patients.

Adult↗
PubMed1990

Interactions between endogenous virus loci ev6 and ev21. 1. Immune response to exogenous avian leukosis virus infection.

The effects of ev6, ev21, sex, and hatch, were studied with respect to avian leukosis virus (ALV) viremia, cloacal shedding, and antibody response among RPL-40 virus-infected White Leghorns that carried ev6 and ev21 in all combinations. Among the four possible ev genotypes, chickens that carried only ev21 were the most immunologically tolerant to RPL-40 infection. Incidence of RPL-40 viremia was lowest among hatchmates that lacked both ev genes. Analysis of variance indicated significant interactions between ev6 and ev21 with respect to all responses. Among ev21+ slow-feathering (SF) chickens, the incidence of viremia and shedding of RPL-40 was reduced in the presence of ev6 when compared with ev6- hatchmates. Conversely, among ev21- rapid-feathering (RF) chickens, ev6 significantly enhanced the incidence of RPL-40 viremia when compared with ev6- hatchmates. The endogenous virus, ev6, markedly reduced recovery of the endogenous virus (EV21) from plasmas of slow-feathering chickens. When both flocks were terminated at 21 wk of age, significantly more ev21+ SF females had died from or developed RPL-40-induced tumors than ev21- hatchmates.

Animals↗
PubMed1990

Interactions between endogenous virus loci ev6 and ev21. 2. Congenital transmission of EV21 viral product to female progency from slow-feathering dams.

The influence of the endogenous virus ev6 on congenital transmission of EV21, the infectious viral product encoded by locus ev21, and the immune response to exogenous avian leukosis virus (ALV) infection was studied in rapid-feathering (RF) female progeny from four classes of slow-feathering (SF) (ev21+ and RF (ev21-) dams with and without ev6. Apart from transmitting infectious EV21 and ev6 to progency, dam ev genotype did not influence the immune response or shedding of RPL-40. The endogenous virus envelope glycoprotein encoded by ev6, however, completely restricted shedding and congenital transmission of infectious endogenous virus EV21, from SF dams. After 19 wk of exposure to ALV strain RPL-40 infected cage mates, only 11% of the congenitally infected female progeny mounted neutralizing antibodies against RPL-40, whereas 73% of their noncongenitally infected sisters seroconverted. More ev6+ female progeny, however, were shedders of RPL-40 and developed tumors than ev6- sisters. Among progeny from the four classes of dams, EV21 congenitally infected hens had the highest incidence (31%) of RPL-40-induced tumors.

Animals↗
PubMed1990

Molecular analysis of endogenous virus ev21-slow feathering complex of chickens. 1. Cloning of proviral-cell junction fragment and unoccupied integration site.

Sex-linked slow-feathering gene, K, is genetically associated with the presence of an avian endogenous retrovirus ev21 in White Leghorns (WL). An EcoRI fragment corresponding to the endogenous virus ev21-cell junction fragment and a fragment homologous to the proviral unoccupied site (US) were cloned, respectively, from genomic DNA libraries of two WL chickens: an ev21-only female and an ev-negative male. A 1.7-kilobase pairs (kbp) fragment cleaved from the cloned proviral US by the HaeIII restriction endonuclease was the most informative probe to molecularly characterize the occupied and unoccupied integration sites of ev21 locus. Restriction fragment length polymorphism analysis of slow-feathering (SF) and rapid-feathering (RF) chickens from various commercial breeds, using the US HaeIII 1.7-kbp probe, indicated that the complete genetic association between ev21 and SF phenotype is common among other lines of SF chickens and was not restricted to WL. It was also shown that there was at least one additional DNA region highly homologous to DNA sequences flanking the EV21 integration site in the chicken genome. In SF birds of either sex this additional repeat was distinguishable from the site occupied by ev21 (OR) and represents an unoccupied repeat (UR). Analysis of DNA from RF revertant females showed novel patterns of reversion. In Type I RF revertants, RF is associated with the complete excision of proviral ev21 DNA sequences. In Type II revertants, the UR homologous to the cell sequences flanking ev21 integration site is excised, but proviral ev21 sequences remain intact. A hypothesis to explain these types of reversion is suggested. It postulates a close association between OR and UR on the Z chromosome.

Animals↗
PubMed1990

Trauma scoring methods.

Trauma scoring methods are recommended for use in the management of trauma patients. Currently used methods are reviewed for their use in triage, the determination of injury severity and the assessment of prognosis and outcome in comparative evaluation of trauma care within or between institutions.

Critical Care↗
PubMed1989

Milk production, weight changes and blood biochemical measurements in dairy cattle receiving recombinant bovine somatotropin.

Fortnightly injections with 500 mg (1.4 ml) of recombinant bovine somatotrophin in 20 dairy cows and heifers at 80 +/- 7 days after calving resulted in increasing milk yields, compared with paired control cows, for three to four days. The advantage was maintained for a further seven to eight days with a decline occurring during the last two to three days before the next injection. The milk yield did not return to the level of the control cows, and the gap between the lactation curves widened as treatment continued, until two to three weeks after the last injection. The cows' response to treatment was greater than the response to heifers. Blood beta-hydroxybutyrate concentrations reflected the higher energy requirements of the treated animals and the weight loss of the treated heifers. Urea-nitrogen concentrations were significantly lower in the treated animals, suggesting that they utilised protein more efficiently. Treated animals had higher inorganic phosphate concentrations, although they remained within the normal ranges. Differences in calcium, magnesium, albumin and globulin concentrations were either statistically or practically not significant.

3-Hydroxybutyric Acid↗
PubMed1989

Monocondylar fractures of the femur: a review of 13 patients.

We reviewed 13 patients with monocondylar fractures of the femur. Undisplaced fractures may require extensive radiological investigation to visualize the fracture. Anatomically reduced fractures may displace when treated non-operatively. Joint line incongruity and resultant callus formation produces an abnormal condylar profile leading to early secondary osteoarthritis. We recommend internal fixation in all patients with monocondylar fractures.

Adolescent↗
PubMed1989

Arthrodesis of the metacarpo-phalangeal joint of the thumb: a review of 42 cases.

42 arthrodeses of the metacarpo-phalangeal joint of the thumb in 34 patients have been reviewed at a mean of 22.5 months after operation. Where bone stock allowed, Omer's chevron arthrodesis was used. 83% of these operations were judged to have been successful by our patients, most of whom were suffering from inflammatory joint disease. Some patients had very poor pinch pressures when reviewed, but only those with persistent instability or pain were disappointed. All arthrodeses were fixed in flexion; although the angle varied, no ideal position was identified.

Adult↗
PubMed1989

Potentiation by the lithium ion of morphogenetic responses to a Xenopus inducing factor.

We have cultured explants of Xenopus blastular animal cap tissue from embryos that had received an earlier treatment with LiCl and from their untreated siblings, in various concentrations of XTC-cell-derived mesoderm-inducing factor (XTC-MIF, Smith, 1987; Smith et al. 1988). The pretreatment with lithium that we used transforms later morphogenesis in the whole embryo to give radialized body forms with anterior/dorsal levels of structure grossly over-represented. In addition, animal caps from 'Li+' embryos were allowed to develop without exposure to in vitro MIF (Li+ controls) and compared with normal uninduced control explants, and explants were made from normal early blastulae but given various initial treatments with LiCl in culture. The results confirm that the lithium ion itself will not induce mesoderm in competent, animal cap tissue of Xenopus. It does, however, enhance the responsiveness of this tissue to XTC-MIF, in a way that parallels its recently reported effect in the case of another mesoderm inducer of different character, bFGF (Slack et al. 1988). The effects observed are sufficient to imply that the altered body pattern that follows lithium treatment, in whole embryos, could be caused by modulation of the responses to an unaltered pattern of in situ inductive stimuli. We also observe evidence that appreciable inductive signals reach animal pole tissue beyond the limits of mesoderm formation in normal development. Relatively low concentrations of MIF prevent the development of an epidermis-specific marker in dissociated blastular animal cap cells (Symes et al. 1988). When such experiments are repeated in relation to the lithium pretreatment of embryos, such treatment is seen to have sensitized the cell population, so that the MIF concentration range that assures complete suppression of the marker is reduced. The results are discussed in relation to induction considered as pattern formation.

Animals↗
PubMed1988

Health, welfare and fertility implications of the use of bovine somatotropin in dairy cattle.

Twenty-two Friesian and Friesian cross Ayrshire cows and 16 first lactation heifers were paired. Twenty were injected subcutaneously with 500 mg recombinant bovine somatotropin (sometribove) and 18 with a placebo at fortnightly intervals, starting 80 (+/- 7) days after calving, through the winter of 1986-87. The cows' weights and changes in condition, milk yields, milk solids, health and fertility were recorded regularly. Compound cake was fed at a fixed stepped rate according to the number of days since the cow calved. Silage was available on an easy-feed basis. Ten cows had their daily silage intake measured. Sometribove treated cows produced on average 27.7 kg of milk per day, 4.5 kg more than the controls. Treated heifers produced 23.5 kg per day, 2.5 kg more than the controls. Milk quality was unchanged. Treated cows gained weight during the trial, but not by as much as the controls. Control heifers also gained weight but the treated heifers lost, on average, 3 kg. Local reactions at the injection site were not felt to be of welfare concern, nor was the general effect of the extra milk production. A small number of treated animals experienced mastitis and had poorer fertility but the differences were mostly not statistically significant. If bovine somatotropin should become licensed for use in Britain it is recommended that clear guidelines should be issued on the management practices necessary for economic success and for the welfare of the treated animals.

Animal Welfare↗
PubMed1988

Cystic pneumatosis in coeliac disease.

This report presents a patient with proximal small bowel cystic pneumatosis associated with poorly controlled coeliac disease and pseudo-obstruction. Cystic pneumatosis is rare in the proximal small bowel and we can find no report of its occurrence in association with coeliac disease.

Aged↗
PubMed1988

The restrictive effect of early exposure to lithium upon body pattern in Xenopus development, studied by quantitative anatomy and immunofluorescence.

We have carried out an anatomical study of Xenopus larval and gastrula stages resulting from treatment of synchronous early blastulae for brief periods with Li+. We confirm the proposal that such treatment causes a particular transformation, and partial elimination, of the normal body pattern. Coordinated restriction of pattern, without appreciable loss of cell number, is seen in all three germ layers. The distortion has been investigated by quantitative study of mesoderms at a standard stage, in relation to the normal fate map for mesoderm, and with the help of immunofluorescence on sections for somitic muscle and for blood. In the extreme syndrome, mesoderm arises from all around the blastula as usual, but is symmetrical and corresponds to that arising near the dorsal/anterior meridian of the normally specified egg or embryo with a large posterior subset of the normal pattern values thus missing. The effect is independent of any inhibition of archenteron formation or mesoderm migration (i.e. the cell mechanics of gastrulation) incurred by the treatment. It is also quite separate from a syndrome caused by more prolonged exposure to Li+ during gastrulation. A small, but distinctive, anterior pattern region is also not expressed and, anomalously in relation to their general nature, these forms differentiate considerable blood tissue. We consider the implications of some details of the pattern restriction for our understanding of interaction in the normal development and propose that the Li+ embryo is likely to be useful as a specific 'differential screen', in relation to the normal, during the search for those gene products that mediate initial regionalization of the body.

Animals↗