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J R Gordon

Publications and source records attributed to J R Gordon.

At least 73 records · Page 4Linked to original sources
PubMed1987

Isolation and characterization of salivary antigens from the female tick, Dermacentor andersoni.

The salivary glands of ixodid ticks are complex organs which are known to contain the antigens responsible for tick resistance in animals. We have identified a large number of proteins from salivary gland extracts (SGE), at least some of which are immunologically recognized by tick resistant animals and which are therefore presumed to be secreted salivary components. During the 6 to 10 day feeding process, a number of these antigens alter in concentration according to individual kinetics, and some of these changes correlate with the kinetics of skin test reactivity of SGE obtained at different times throughout the feeding period. By use of immunoaffinity chromatography we have isolated large quantities of many of the salivary antigens (SGA) contained in SGE, and found that they contain several esterase activities. SGA stimulates both immediate and delayed skin reactions in tick resistant guinea-pigs, and these reactions are about 200-fold more intense, per unit protein, than those elicited by SGE. The skin reactions to SGA are basophil-mediated and have many features in common with the cutaneous basophil hypersensitivity reactions of tick resistant animals. The demonstrated antigenic complexity of the glands may have profound implications for attempts to develop anti-tick vaccines, as it may eventually be found that candidate vaccines will have to incorporate more than one tick antigen in order to be effective.

Animals↗
PubMed1987

Immunity to schistosomiasis mansoni in guinea-pigs vaccinated with radiation-attenuated cercariae: I. Humoral responses against skin-stage schistosomula.

The anti-schistosomular humoral responses of guinea-pigs vaccinated with radiation-attenuated cercariae of Schistosoma mansoni have been investigated in vitro. The sera of vaccinated animals contain schistosomulicidal complement-fixing antibodies which peak in titre at week 5 after vaccination and predominantly consist of IgG2 and IgM antibodies. The ability of the serum to arm macrophages from normal animals to bind to schistosomula, also peaks in titre at week 5 and is associated with IgG2 antibodies. Basophils from normal animals can be sensitized in vitro by vaccine serum to degranulate in the presence of schistosomular antigens. This anaphylactic antibody activity is associated with IgG1 but not IgE antibodies, and peaks in titre at week 10. Three antigens (14 kD, 20 kD and 43 kD) are specifically and transiently detected by vaccine serum on Western blots of schistosomular proteins; these antigens are first discernible at week 4, but were virtually undetectable at week 12.

Animals↗
PubMed1986

Early spontaneous metastasis in the human epidermoid carcinoma HEp3/chick embryo model: contribution of incidental colonization.

In the experimental model system where human tumor cells (HEp3) are implanted on the chorioallantoic membrane (CAM) of the chick embryo, metastasis of HEp3 cells to the embryonic lung occurs within a few days. Such rapidity in tumor dissemination makes this an attractive and potentially useful model for studying the metastatic process. The model, however, involves microvascular trauma at the site of implantation and thus tumor cells may accidentally enter the circulation during implantation or shortly thereafter. If these cells are the cause of the lung metastasis subsequently measured, the model would be in effect a colonization system and not a true, spontaneous metastasis system. The possible contribution of accidental lung colonization to secondary tumor growth was therefore critically examined in this model. In standard metastasis assays, HEp3 was inoculated onto the CAMs of 10-day embryos, which were then incubated for various periods of time. The embryos' lungs were passaged to a second group of CAMs, incubated for 7 days to allow expansion of any HEp3 cells present, and then assayed for HEp3 cells by both microscopy and measurement of human plasminogen activator (PA) activity. Metastasis was evidenced by PA values above background (30 mU/mg protein). Morphological analysis of HEp3 cells in the embryonic lung correlated closely with PA values. To focus on the early stages of tumor dissemination when colonization might occur, the primary tumor was surgically excised from 38 embryos at various intervals after tumor inoculation, and after the operation embryos were allowed to develop to day 17. This procedure increased estimated assay sensitivity down to the level of 1 to 10 cells per lung in embryos operated on within 2 days of inoculation. Median PA values in the transplanted lungs were 13, 3, 37, 1,290 and 3,765 mU/mg protein in the groups operated on at 4 hr, 1, 2, 3 and 4 days after inoculation, respectively. Thus very few or no HEp3 cells arrest and grow in the lungs during the first 24 to 48 hr, but extensive metastasis occurs by 72-96 hr. Accidental colonization therefore plays no major part in the rapid pulmonary spread of HEp3 in this model.

Animals↗
PubMed1983

Tularaemia transmitted by ticks (Dermacentor andersoni) in Saskatchewan.

Common wood ticks (Dermacentor andersoni) collected from Saskatchewan Landing Provincial Park, Saskatchewan in the spring of 1982 transmitted a lethal tularaemia infection to four of six rabbits. Francisella tularensis organisms were isolated from tissues taken from the dead rabbits and identified from subcultures using an indirect immunofluorescent antibody assay. One human associated with the animals developed symptoms of tularaemia and, after successful therapy, had a significant increase in titre of specific antibodies to F. tularensis. This is the first time tick-transmitted tularaemia has been reported in Saskatchewan in more than 25 years.

Animals↗
PubMed1982

Lecithin and memory training in suspected Alzheimer's disease.

Ten patients diagnosed clinically as having Alzheimer's disease (age range 54 to 73 years) were given 35 g/day of a 53% lecithin mixture for two weeks, in a double-blind crossover design. Patients received memory training during the lecithin condition and "placebo training" during the placebo drug condition. Repeated assessment with Buschke's Selective Reminding Procedure provided no evidence of a therapeutic lecithin effect either during the two week clinical trial or during longer follow-up trials. Noninvasive measurement of regional cerebral blood flow (nr CBF) by the 133Xe-inhalation method, and repeated EEG's also failed to demonstrate a therapeutic effect. These latter indices reflected a decline in cerebral function over the course of the study, a finding which paralleled clinical impressions in four of the patients. Follow-up trials of memory training under placebo and lecithin conditions provided some suggestion that memory training may lead to some immediate improvement in list-learning ability, but the improvement was not well maintained overtime.

Aged↗
PubMed1980

Percutaneous cervical central venous line placement: a comparison of the internal and external jugular vein routes.

To compare the rate of success and incidence of complications associated with two currently popular routes of percutaneous central venous cannulation, we studied 167 patient in whom either internal or external jugular vein catheterization was attempted. Internal jugular vein (IJV) catheterization (125 patients) was successful in 91%; an intrathoracic location was achieved in 100%; complications occurred in 12.8%. Complications included one case of catheter malposition, one case of tension pneumothorax, and 12 instances of inadvertent carotid artery puncture, one resulting in a paratracheal hematoma and phrenic nerve compression. The success rate of IJV cannulation was higher and carotid artery puncture less frequent when an 18-gauge thin-walled needle and a straight guide-wire were used than when IJV cannulation was performed by bind puncture with a larger over-the-needle catheter. Delayed vein perforation occurred twice. External jugular vein cannulation (42 patients), using a "J" wire technique, yielded a 76% success rate: 93.7% of catheter tips reached an intrathoracic location. No complications occurred. We conclude that IJV cannulation is a more reliable means of percutaneous central venous line placement but is associated with a significant incidence of complications which can be reduced if a technique employing a scout needle and guide-wire is used.

Adolescent↗
PubMed1979

The basophil response in blood and bone marrow of tick-infested guinea pigs.

The concentrations of basophils in blood and bone marrow were monitored in guinea pigs subjected to primary and secondary infestations with larvae of Dermacentor andersoni. In these guinea pigs a significant increase of basophils was evident in peripheral blood. The response following the secondary infestation was more rapid and more intense than that following the primary infestation. Similar changes were also shown to occur in bone marrow. The possible significance of these responses in relation to acquired tick resistance in guinea pigs is discussed.

Animals↗
PubMed1978

Identification of Trypanosoma theileri as a contaminant in primary cultures of bovine retina.

T. theileri has been isolated from primary cultures of bovine retina and subcultered successfully for 2 passages in sub-confluent cultures. When cultures reached confluency no trypomastigotes or epimastigotes could be detected and attempts to recover trypanosomes from these cultures were unsuccessful. The presence of intracellular forms could not formally be excluded.

Animals↗
PubMedDate not supplied

Expression of transforming growth factor beta(1), beta(3), and basic fibroblast growth factor in full-thickness skin wounds of equine limbs and thorax.

OBJECTIVE: To map the expression of transforming growth factor (TGF)-beta(1), TGF-beta(3), and basic fibroblast growth factor (bFGF) in full-thickness skin wounds of the horse. To determine whether their expression differs between limbs and thorax, to understand the pathogenesis of exuberant granulation tissue. STUDY DESIGN: Six wounds were created on one lateral metacarpal area and one midthoracic area of each horse. Sequential wound biopsies allowed comparison of the temporal expression of growth factors between limb and thoracic wounds. ANIMALS: Four 2- to 4-year-old horses. METHODS: Wounds were assessed grossly and histologically at 12 and 24 hours, and 2, 5, 10, and 14 days postoperatively. ELISAs were used to measure the growth factor concentrations of homogenates of wound biopsies taken at the same timepoints. RESULTS: TGF-beta(1) peaked at 24 hours in both locations and returned to baseline in thoracic wounds by 14 days but remained elevated in limb wounds for the duration of the study. Expression kinetics of TGF-beta(3) differed from those of TGF-beta(1). TGF-beta(3) concentrations gradually increased over time, showing a trend toward an earlier and higher peak in thoracic compared with limb wounds. bFGF expression kinetics resembled those of TGF-beta(1), but no statistically significant differences existed between limb and thoracic wounds. CONCLUSIONS: Growth factor expression is up-regulated during normal equine wound repair. TGF-beta(1) and TGF-beta(3) show a reciprocal temporal regulation. Statistically significant differences exist between limb and thoracic wounds with respect to TGF-beta(1) expression. CLINICAL RELEVANCE: The persistence of TGF-beta(1) expression in leg wounds may be related to the development of exuberant granulation tissue in this location, because TGF-beta(1) is profibrotic.

Animals↗
PubMedDate not supplied

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