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Biomedical subjects

R Evans

Publications and source records attributed to R Evans.

At least 397 records · Page 22Linked to original sources
PubMed1981

The diagnosis of hymenoptera hypersensitivity.

Venom skin testing was performed in 216 patients with histories of systemic or local reactions following insect stings. Seventy-six percent of the patients with histories of systemic reactions and 77% of the patients with histories of local reactions had positive skin tests up to 1 mcg/ml. The majority of vespid sensitive patients had positive skin tests to all the vespid species. Significant (p less than .001) cross-reactivity is suggested by regression analysis. This study confirms the value and safety of venom skin testing in hymenoptera hypersensitivity. The implications for venom immunotherapy of the findings are also discussed.

Adult↗
PubMed1981

Adverse reactions to venom immunotherapy.

The authors treated 22 adults patients with histories of systemic hypersensitivity to hymenoptera with venom extracts using a traditional approach to immunotherapy. Patients had an immunological response consisting of an increase in venom specific IgE and IgG. Twelve patients underwent an uneventful in-hospital insect sting challenge. Injections of venom extract elicited large reactions in 50% of the patients for which subsequent venom dosages were adjusted proportionately to the local reaction. Using this approach, the investigators observed no systemic reactions to venom therapy. They conclude that systemic reactions to venom immunotherapy may be lessened by the adjustment of venom dose after local reactions to therapy without a loss of efficacy.

Antibodies↗
PubMed1980

Macrophage content and immunogenicity of C57BL/6J and BALB/cByJ methylcholanthrene-induced sarcomas.

A total of 33 methylcholanthrene-induced sarcomas, growing in C57BL/6J or BALB/cByJ mice, were tested for their immunogenicity and for their relative macrophage content. No relationship was demonstrated between these two characteristics. These results suggest that the direct correlation between macrophage content and immunogenicity demonstrated in rat tumor model systems may not hold for other systems.

Animals↗
PubMed1980

Macrophage accumulation in primary and transplanted tumors growing in C5-deficient B10.D2/oSn mice.

The hypothesis was tested that the fifth component of complement (C5) was required for the accumulation of macrophages at the site of tumor growth. This was based on the assumption that the cleavage product of C5, C5a, attracts peripheral blood monocytes along a chemotactic gradient. Methylcholanthrene-induced primary and transplanted tumors were grown in the genetically C5-deficient B10.D2/oSn strain and the C5-positive B10.D2/oSn strain and their macrophage content assessed after enzymic disaggregation of the tumors. The overall data indicated that there were no significant differences in the two strains since macrophages accumulated in the tumors irrespective of the presence of C5 or its cleavage product C5a.

Animals↗
PubMed1980

Protein synthesis and the presence of absence of a measurable G1 in cultured Chinese hamster cells.

V79-8 cells lack a measurable G1 interval under normal growth conditions. We found that partial inhibition of protein synthesis using low levels of cycloheximide (0.05 mu/ml) could induce a measurable G1 in these cells without any significant effects on S, G2, or M. In view of these findings, recessive mutants selected from the V79-8 cell line, which each express G1, were analyzed for their rates of protein synthesis and degradation/loss. Three of the four mutants showed a decreased rate of protein synthesis sufficient to account for their G1 lengths. A fourth mutant, however, showed parental rates of both protein synthesis and degradation/loss. These results suggest not only that a G1 interval can be expressed as a result of a decreased rate of protein synthesis, but that other alterations (mutations) other than those simply affecting overall protein synthesis can result in the expression of a measureable G1 interval.

Animals↗
PubMed1980

The role of cyproheptadine in the treatment of cold urticaria.

Histamine release in cold urticaria was studied before and after therapy with cyproheptadine to determine whether any effect upon histamine release could be distinguished from end-organ receptor-site blockade. Patients were asymptomatic while taking cyproheptadine, their ice cube test reverted to normal, and only one of six patients had any swelling upon ice-water submersion of one hand for 5 min. Histamine-release curves were obtained following ice-water submersion before and after cyproheptadine therapy. All patients had significant histamine release and in five of six patients there was no evident difference in the magnitude of histamine release before or after therapy. A single patient did have diminished histamine release after therapy, but could not be restudied to be sure this was not a spurious result. Our data demonstrated that cyproheptadine is extremely effective in ameliorating the symptoms and signs of cold urticaria and that its principal effect is that of an H1 receptor antagonist, thereby blocking the effects of histamine. These data further suggest that a sufficient dose of any standard antihistamine should be similarly effective and that patients who do not tolerate cyproheptadine or do not appear to respond to it should be tried on other antihistamines of the H1 type.

Cold Temperature↗
PubMed1980

Sire effect on fatty acid composition of ovine adipose tissue.

The fatty acid composition of perirenal adipose tissue from 255 purebred and crossbred sheep was examined to determine the genetic effects of sire on each of five fatty acids. The sheep, all rams, were the progeny of 30 Dorset Horn sires. The animals were grazed on pasture and slaughtered at an average age of 21 months, when their mean carcass weight was 30 kilograms. The fatty acids studied and their mean percentage compositions were: stearic, 38%; oleic, 31%; palmitic, 20%; palmitoleic, 2%, and linoleic, 2%. These amounted to over 90% by weight of the tissue sample fatty acids. In addition, numerical functions were constructed as ratios for two pairs of fatty acids, ratio 1 (palmitoleic to palmitic) and ratio 2 (oleic to stearic), for estimation of the desaturase enzyme activity in the tissue samples studied. A Softness Index, expressed as a ratio between monounsaturated and saturated acids, was also included in the analysis. Significant birth year and maternal breed effects were found for all the traits studied. This was in contrast to the regression on slaughter age, which with two exceptions was not a significant source of variation in the data. The sire effect, based on 27 degrees of freedom, was highly significant or significant for all traits except stearic or linoleic acid and ratio 2. These results are discussed with reference to utilization of genetic variation between sites in selective breeding programs to modify fatty acid composition of ovine adipose tissue.

Adipose Tissue↗