Biomedical subjects
Publications and source records attributed to L H Thomas.
A modified naso-pharyngeal swab with nylon bristles had certain advantages for sampling the bovine upper respiratory tract for viruses. The titre of parainfluenza virus type 3 recovered was greatest when this type of swab was used compared with two other methods of sampling.
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The inhibition by Mycoplasma dispar of ciliary activity of organ cultures of bovine fetal trachea was found to be dependent on the presence of serum in the maintenance medium. Inhibitory activity was unaffected by catalase and no toxic substance was demonstrated in organ culture supernatant fluid.
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The passage of a single pulse of relativistic electrons through a plasma is considered, and the total current in the axial direction it induces in the plasma is calculated. This calculation is valid for an injected beam current density that has arbitrary functional dependence on the radial and azimuthal coordinates. For the special case of a beam current density that is uniform in the radial direction out to the beam radius a, these results agree with results of others published previously.This calculation is simple because the equation for the variation with time of the plasma charge density at any point, independent of what happens at other points, is only slightly more complicated than the familiar equation for an ohmic conduction.
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Two dialysis sacs each containing 50 ml dextran sulphate solution were implanted into the peritoneal cavities of five three month-old calves. One sac was inoculated with Pasteurella haemolytica or Streptococcus uberis and the second sac served as an uninoculated control. Samples of sac fluid removed after 0, four, six, eight, 15, 24, 36 and 48 hours and then at 24 hour intervals after inoculation revealed bacterial growth up to 9.0 log10 cfu ml-1 by two to three days after inoculation. Concentrations of 25 to 48 ng ml-1 of the inflammatory mediator prostaglandin E2 (PGE2) were detected six to 96 hours after inoculation, similar amounts being generated in sacs inoculated with either bacterium, but the concentrations in control sacs remained below 10 ng ml-4 over the seven day experiment. Post mortem, a tissue cast invested each of the inoculated sacs. Histologically, the reaction was an acute inflammatory response similar to that evoked by each bacterium in the target organ.
Previous reports demonstrate that synthetic peptides corresponding to the amino acid region 174-187 of G glycoprotein from subgroups A and B human respiratory syncytial virus (HRSV), containing a Cys-->Ser substitution at position 186, confer complete resistance to immunized BALB/c mice against infection with the respective virus. In this report, we show that a Cys186-->Ser substituted peptide (BG/174-187) representing the corresponding region of the bovine (B) RSV G glycoprotein conferred complete protection of mice against BRSV challenge, suggesting that the 174-187 region of RSV G glycoproteins constitutes a dominant protective epitope which has been maintained throughout evolution. Furthermore, immunization of calves with peptide BG/174-187 efficiently induced the production of antibodies capable of recognizing both the parental G glycoprotein and peptide BG/174-187. Following challenge with live BRSV, although none of the animals were protected from upper respiratory tract disease, there were little or no gross pneumonic lesions in the four peptide-immunized calves. In contrast, moderate to extensive pneumonic lesions were observed in 2 out of 3 calves in the control group. Our results thus suggest that peptide BG/174-187 efficiently prevented BRSV-associated pneumonia in the natural host. The use of this system as a model is quite promising with regard to the development of a human synthetic vaccine.
The interaction of cells with surfaces or components of the extracellular matrix alters cell responses and is regulated by integrins on the cell surface. We have used monoclonal antibodies to CD29 and CD49d followed by an F(ab)2 fragment of rabbit anti-mouse IgG1 to cross-link the integrins on the surface of human lung mast cells and basophils. We found that cross-linking either CD29 or CD49d failed to initiate mediator release from the basophils of non-atopic and atopic donors [histamine release (HR) = 1 +/- 0.5% for CD29 and 1 +/- 0.5% for CD49d, n = 10, NS]. In contrast we found that clustering CD29 caused significant HR from the basophils of asthmatic donors (HR = 21 +/- 5%, n = 10, p < 0.005). Clustering of CD49d also caused significant degranulation in the same donors (HR = 9 +/- 3%, n = 10, p < 0.11). Incubating the basophils of these asthmatic donors with a synthetic RGD peptide significantly reduced CD29- and CD49d-induced histamine release. CS-1 peptide was also found to inhibit CD29-induced histamine release but had no significant effect on CD49d-induced histamine release. The tyrosine kinase inhibitors, genistein and piceatannol, completely ablated CD29- and CD49d-induced degranulation. In summary, we have shown that cross-linking integrins can initiate mediator release from the basophils of asthmatic patients and that this appears to involve recognition of RGD and activation of tyrosine kinase.
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This paper describes the contribution of nursing auxiliaries (NAs) compared with qualified nurses (QNs) in terms of activities performed. It also examines how this was affected by three organisational types, namely primary, team and functional nursing. Twelve QNs and 12 NAs were chosen randomly in each organisational type. Data were collected using non-participant observation and a computerised event recorder. The most interesting findings were found across organisational type, with QNs and NAs within each type engaging in similar patterns of work. Both grades of nursing staff in primary wards spent a greater amount of time in direct patient care but less time in supplementary patient care and staff activities. Team and functional nursing staff spent more time with patients in domestic and administrative activities. The implications of these findings for the employment of NAs in care of the elderly wards are discussed.