Search PubMed⌕ Search

Biomedical subjects

M W Greaves

Publications and source records attributed to M W Greaves.

At least 289 records · Page 16Linked to original sources
PubMed1979

Diisopropylfluorophosphate-evoked inhibition of anaphylactic histamine release from human skin: decrease of the inhibition by storing the skin specimens.

Antigen-induced histamine release from human skin slices passively sensitized with reaginic serum in vitro was inhibited by DFP, suggesting involvement of serine esterase activation in the reaction. The magnitude of DFP-evoked inhibition of the histamine release was not the same in each skin sample and no correlationship was observed between the magnitude of the DFP-evoked inhibition of the histamine release and that of the histamine release in the absence of DFP. The magnitude of the histamine release in the presence of DFP was smaller in the fresh skin than in the stored skin, whereas that in the absence of DFP was greater in the former than in the latter. The inhibitory effect of cytochalasin B on the anaphylactic histamine release from fresh and stored human skin was the reverse of the effect of DFP. The present results indicate that the magnitude of anaphylactic histamine release from human skin does not match that of the activation of serine esterase in the reaction, suggesting the possibility that there may be some factor modulating the activation of serine esterase in the anaphylactic reaction in human skin.

Antigens↗
PubMed1978

Does ultraviolet-evoked prostaglandin formation protect skin from actinic cancer?

The role of increased prostaglandin activity which results from exposure of human skin to ultraviolet light is uncertain. Evidence from the effects of prostaglandins on epithelial cells in vitro suggests that prostaglandin E reduces proliferative activity in the epidermis, probably through a cyclic-A.M.P.-dependent mechanism, thus reducing the vulnerability of epidermis to the mutagenic effects of ultraviolet exposure.

Cell Division↗
PubMed1978

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Child↗
PubMed1978

Irradiation of human skin by short wavelength ultraviolet radiation (100--290 nm) (u.v.C): increased concentrations of arachidonic acid and prostaglandines E2 and F2alpha.

1. Human abdominal skin was irradiated with six times the minimal erythema dose of ultraviolet C (100--290 nm) radiation. Erythema appeared at 3 h, was of moderate degree by 6 h and was maximal at 12--24 h. It was reduced at 48 h and by 72 h had disappeared. 2. A suction bulla technique was used for the recovery of exudate from normal and inflamed skin at 6, 18, 24 and 48 h after irradiation. 3. Prostaglandin-like activity, estimated by bioassay, showed maximum increase at 18 h, when erythema was also maximum. PGF 2alpha, measured by both radioimmunoassay and by combined gas-liquid chromatography--gas spectrometry, followed a similar time course then fell to normal, or near normal, levels at 48 h. 4. Prostaglandin E2 and arachidonic acid concentrations, measured by gas chromatography--mass spectrometry, were maximally raised at 18--24 h. At 48 h, when some erythema was still present, though reduced, prostaglandin E2 concentrations were still raised above control values. 5. The results provide direct evidence in support of the view that the erythma following irradiation of human skin by u.v.C involves activation of arachidonic acid metabolism. However, the relationship between the erythema and increased prostaglandin activity is not fully understood.

Arachidonic Acids↗
PubMed1978

The effects of indomethacin on arachidonic acid and prostaglandins e2 and f2alpha levels in human skin 24 h after u.v.B and u.v.C irradiation.

1 Clinically normal human abdominal skin was irradiated with either three times its minimal erythema dose (MED) of ultraviolet B (u.v.B) or six MEDs of ultraviolet C (u.v.C) radiation. In both instances erythema was maximal at 24 h. 2 Exudate was recovered by a suction bulla technique from normal and irradiated skin at 24 h after irradiation. 3 Arachidonic acid, prostaglandins E2 and FSalpha, as measured by GC--MS, were significantly elevated at 24 h. Radioimmunoassay also showed increased PGF2alpha-like concentrations. 4 Oral indomethacin only partially reduced the erythema resulting from both types of radiation but totally suppressed the elevation of PGE 2 and F2alpha concentrations. 5 Topical indomethacin also suppressed u.v.B-induced increases in prostaglandins E2 and F2alpha. Unexpectedly, the vehicle alone produced a similar suppressive effect on prostaglandins although erythema appeared unaltered. 6 Most of the arachidonic acid metabolized by indomethacin-sensitive pathways is not converted to prostaglandins E2 and F2alpha in human skin.

Adolescent↗
PubMed1978

Tests to establish the diagnosis in cholinergic urticaria.

Methods for establishing the diagnosis in cholinergic urticaria are reviewed and compared. Provocation by exercise or hot bath is more effective than local provocation by intradermal tests. Of the intradermal tests, responses to nicotine acid tartrate and acetyl beta methylcholine chloride are positive only in patients with the more severe, readily induced eruptions. Furthermore, intradermal testing is not always reproducible in the same patient. In our patients, exercise proved the simplest, most effective diagnostic test.

Adolescent↗