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Biomedical subjects

J C Mitchell

Publications and source records attributed to J C Mitchell.

35 records · Page 2Linked to original sources
PubMed1976

Contact hypersensitivity to sesquiterpene lactones in Chyrsanthemum dermatitis.

In six persons with contact allergy to chrysanthemum of florists, patch tests were performed with 25 sequiterpene lactones. Positive responses were observed to 15 lactones. The most frequently encountered positive responses were to alantolactone (positive in all cases) and to arbusculin A, 8-deoxycumambrin, ambrosin, damsin and psilostachynin. The findings corroborate the assumption that an alpha-methylene group attached to the gamma-lactone ring is an essential prerequisite for allergenic activity of sesquiterpene lactones. Pyrethrum produced a positive reaction in one of the patients, pyrethrins gave negative reactions in all. Some of the chrysanthemum patients were also hypersensitive to turpentine and colophony and to garlic, primin and tars.

Adult↗
PubMed1976

Disabled counselors: perception of their effectiveness in a therapeutic relationship.

It has not been delineated how a disabled person is viewed when interacting with another person. The present study investigated subject perception of a counselor in a wheelchair who was seen in a video-taped counseling interview. Subject degree of body satisfaction was measured to assess the importance of this variable in the perception. Evaluation of the counselor was by the Barett-Lennard Relationship Inventory that measures four dimensions of a relationship: emphatic understanding, positive regard, unconditional regard and congruence. Results suggest that a counselor in a wheelchair is perceived more favorably than an able-bodied counselor along three of these dimensions and female subjects perceive him more favorably than male subjects do. Degree of body satisfaction does not seem to be a factor in this perception.

Attitude to Health↗
PubMed1976

Serum lipids in chronic renal failure.

The serum lipids and lipoprotein patterns in 100 adult patients with nonnephrotic chronic renal failure were analyzed retrospectively. Hypertriglyceridemia was found in 43% of these patients. Forty-nine of the 100 had a normal lipoprotein pattern, whereas 42 had type IV hyperlipoproteinemia. This abnormal lipoprotein pattern could not be correlated with the degree of renal impairment, the type of renal disease, or with the patient's age, sex, weight, or diet.

Adult↗
PubMed1975

The angry back syndrome: eczema creates eczema.

False positive patch test reactions are common when the skin of the back is hper-reactive. Such reactions can obscure or invalidate observations of multiple specific sensitivity and of cross-sensitivity to contactants. The pathogenesis of the hyper-reactive skin ('angry back') is discussed and a mechanism postulated for the notion that eczema at certain sites can provoke an eczematous tendency at other sites.

Back↗
PubMed1975

Contact hypersensitivity to some perfume materials.

Some recent publications concerning perfume contact sensitivity are briefly reviewed. Japanese workers have identified some perfume sensitizers and have devised an allergen replacement system. Costus absolute of perfumery has been found to sensitize guinea-pig and man; sesquiterpene lactones are responsible for cross-sensitivity with some other plant products. Balsam of Peru is a useful screen for perfume sensitivity; terpenoids of balsams require study.

Animals↗
PubMed1975

Subcellular fractions from dermis and epidermis in contact sensitization of guinea pigs to 1-chloro-2,4-dinitrobenzene.

Subcellular fractions were prepared from the epidermis of guinea pigs which had been painted with 1-chloro-2,4 dinitrobenzene 14 h previously. The microsomal fraction showed less activity than other fractions in the MIF test. Similarly, the microsomal fraction from the dermis of skin irritated with croton oil before DNCB painting was relatively inactive. However, the microsomal fractions from the epidermis and more especially from the dermis of skin painted with DNCB while undergoing allergic contact dermatitis from pentadecylcatechol showed significant MIF activities.

Alkanes↗
PubMed1975

Vegetables, international co-operation and journal space.

Many salad and vegetable plants are allergenic. Screening patch tests are restricted to known allergenic plant families. Aimed patch tests include all environmental plant contactants. Taraxacum (Dandelion) yields a potentially allergenic sesquiterpenelactone. International co-operation in authorship can save journal space.

Dermatitis, Contact↗
PubMedDate not supplied

Ultraviolet-mediated antibiotic activity of species of Compositae caused by polyacetylenic compounds.

A survey of North, Central, and South American composites, and of certain polyacetylenic compounds occurring in them, confirmed that the ultraviolet-mediated antibiotic activity against Candida albicans can be ascribed to the presence of particular polyacetylenes and their thiophene derivatives. Leaves, stems, roots, and achenes were assayed separately. An attempt was made to relate the phototoxic activity of specific compounds to their chemical structures. Most composites tested were not phototoxic against Candida, but many were antibiotic. The antibiotic activity also appears to be caused by polyacetylenes. Of 65 sequiterpene lactones assayed, only a few were found to be antibiotic, and only one, glaucolide G, was phototoxic.

Alkynes↗