Biomedical subjects
Publications and source records attributed to D A Lewis.
A case of septic arthritis of the elbow caused by Kingella kingae, a Gram-negative bacillus, is described. The patient had long-standing, severe rheumatoid arthritis and Felty's syndrome. This appears to be the first report from the United Kingdom of Kingella kingae as the aetiological agent of septic arthritis.
Animal tumors of spontaneous origin have consistently been found to be less immunogenic than are tumors induced by chemical carcinogens or oncogenic viruses. Spontaneous tumors rarely demonstrate significant immunogenicity in classical transplantation rejection tests. This study demonstrates a novel approach to the question of tumor immunogenicity using viable tumor cells in diffusion chambers. Classical transplantation rejection was induced to the poorly immunogenic, spontaneous B16 murine melanoma by implantation of diffusion chambers containing viable B16 melanoma tumor cells. Implantation of B16 chambers i.p. for at least 4 weeks induced specific, long-term resistance to subsequent live B16 tumor cell challenge. In contrast, immunization with irradiated tumor cells for the same time interval resulted in a delay of tumor growth but had no effect on survival. These studies demonstrate the possibility that a significant anti-tumor immune response against the B16 melanoma may be induced without the presence and negative regulatory influences of a progressively growing B16 tumor. In addition, the diffusion chamber sensitization technique may detect the antigenicity of some tumors which are not detectable by classical transplantation rejection tests. Thus, the diffusion chamber technique provides another avenue for testing the immunogenicity of tumors, especially those of spontaneous origin.
Explore the source record for details and available documents.
This study examines biochemically the Type I collagen isolated from skin of chickens that develop idiopathic scoliosis. Previous studies indicate a defect in collagen exists in these chickens. Alpha 1 (I) and alpha 2 chains were separated by gel filtration and carboxymethyl cellulose column chromatography and were then subjected to the analytical techniques of sodium dodecyl sulfate gel electrophoresis, Staphylococcus aureus V8 protease digestion, cyanogen bromide peptide mapping and amino acid analyses. In all categories, the scoliotic alpha 1 (I) and alpha 2 chains were identical to alpha chains isolated from normal chickens. These data suggest that the altered properties of collagen solubility and connective tissue stress relaxation seen in these scoliotic chickens are not a manifestation of an altered primary structure of the alpha chains or post-translational modification affecting chromatographic elution profiles or electrophoretic migration patterns.
Explore the source record for details and available documents.
Readmissions to mental hospitals are often cited as evidence of the failure of the contemporary mental health system. This essay proposes a different interpretation of readmission. Building on fieldwork and participant observation methods, the authors argue that the "veteran" patient is less a victim of poor psychiatric care and misdirected reform than he is a citizen with few personal resources, using public services to cope with the exigencies of life. Lacking family, job, and income, the ex-patient incorporates the hospital and other "therapeutic stations" into a resource pool upon which he or she can call when the need arises. The essay also discusses the implications of these findings for assessments of the community mental health movement.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A high molecular weight protein fraction, obtained by column chromatography of saline extracts of the livers of rats that had previously been treated with dimethylnitrosamine, was found to have anti-inflammatory activity against carrageenin induced inflammation in the rat. Evidence was presented that the anti-inflammatory activity may be due to a protein fragment produced by proteolysis of a larger molecule.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The gas chromatography of the heptafluorobutyryl derivatives of carbofuran, 3-ketocarbofuran and 3-hydroxycarbofuran is examined with electrolytic conductivity detection (halogen mode). The reaction consists of heating the compounds with heptafluorobutyric anhydride in the presence of trimethylamine catalyst. Although as little as 200 pg of carbofuran, 400 pg of 3-ketocarbofuran and 100 pg of 3-hydroxycarbofuran can be detected by electrolytic conductivity, the minimum detectable quantities by electron capture are about 20-fold less for each derivative. Application to the analysis of carbofuran and 3-ketocarbofuran in corn, potato, turnip and wheat is carried out. This technique is compared to direct gas chromatography in the nitrogen mode and to direct high-pressure liquid chromatography with UV detection at 254 nm using extracts of field-treated turnips.
Explore the source record for details and available documents.
The stabilizing action of indomethacin on lysosomes and protein in vivtro was studied. The magnitude of the stabilizing action on lysosomes was greater than that of aspirin or oxyphenbutazone, similar to that of phenylbutazone, but less than that of prednisolone. The stabilizing action of indomethacin on lysosomes possibly may contribute to its anti-inflammatory properties.
The influences of various diurnal stomatal opening patterns, spines, and ribs on the stem surface temperature and water economy of a CAM succulent, the barrel cactus Ferocactus acanthodes, were examined using an energy budget model. To incorporate energy exchanges by shortwave and longwave irradiation, latent heat, conduction, and convection as well as the heat storage in the massive stem, the plant was subdivided into over 100 internal and external regions in the model. This enabled the average surface temperature to be predicted within 1 C of the measured temperature for both winter and summer days.Reducing the stem water vapor conductance from the values observed in the field to zero caused the average daily stem surface temperature to increase only 0.7 C for a winter day and 0.3 C for a summer day. Thus, latent heat loss does not substantially reduce stem temperature. Although the surface temperatures averaged 18 C warmer for the summer day than for the winter day for a plant 41 cm tall, the temperature dependence of stomatal opening caused the simulated nighttime water loss rates to be about the same for the 2 days.Spines moderated the amplitude of the diurnal temperature changes of the stem surface, since the daily variation was 17 C for the winter day and 25 C for the summer day with spines compared with 23 C and 41 C, respectively, in their simulated absence. Ribs reduced the daytime temperature rise by providing 54% more area for convective heat loss than for a smooth circumscribing surface. In a simulation where both spines and ribs were eliminated, the daytime average surface temperature rose by 5 C.
Explore the source record for details and available documents.
Protease, antiprotease, and acid phosphatase blood levels of adjuvant arthritic rats were determined. The protease levels appear to vary inversely with the antiprotease levels. Changes in the protease levels correspond closely to changes in the acid phosphatase levels. Thus it is likely that the lysosomes contribute to the proteases present in the blood. Administered cortisol appears to raise blood antiprotease levels in both normal and arthritic rats and this may reflect an anti-inflammatory action by this drug.