E Bleumink

Vulnerability of the skin to surfactants in different groups of eczema patients and controls as measured by water vapour loss

Healthy unaffected skin of the volar side of the forearm of patients with eczema and of controls was exposed during a period of 48 h to a 100 μl of a 2 g/v% solution of eight surfactants and distilled water by the large Finn chamber method.

Eczematous (irritant and allergic) reactions of the skin and barrier function as determined by water vapour loss

The aim of this study was to compare the influence of irritant and allergic reactions on the barrier function of the skin and to correlate disturbances of barrier function with macroscopically visible changes.

Protease activities in the spicule venom of Euproctis caterpillars.

The spicule venoms of Euproctis chrysorrhoea and Euproctis subflava were investigated for their capacity to hydrolyze chromogenic tripeptide substrates with selective affinities for various serine proteases. Seven substrates were assayed with affinities for trypsin and thrombin, trypsin and urokinase, serine proteases, chymotrypsin, glandular kallikrein, plasma kallikrein and plasmin. Venom material has a broad spectrum of affinities for the substrates with relative high plasma kallikrein activities. In E. chrysorrhoea venom, trypsin-like activities predominated, whereas E. subflava venom hydrolyzed, in preference, substrates with an affinity for chymotrypsin. The venoms were fractionated on Sephadex G-100, leading to three fractions, all having serine protease activity. The ratios of substrate specificities were markedly different, indicating that in both caterpillar venom preparations at least two separate serine proteases are present. In addition, in human plasma, inhibitor activity could be detected to the kallikrein activity of E. chrysorrhoea, but not of E. subflava. The trypsin-like activity was not inhibited by human plasma. These and earlier studies warrant the assumption that serine proteases, particularly kallikrein, are major factors in the elicitation of clinical symptoms observed after contact with caterpillar spicules.

A COMPARATIVE-STUDY OF THE SPICULE VENOM OF EUPROCTIS CATERPILLARS

Caterpillar spicule venoms were extracted and studied for the following activities: arginine ester (BAEE) hydrolase, tyrosine ester (ATEE) hydrolase, protease (casein digestion) and phospholipase A (indirect hemolytic activity). Crude spicule venom of E. chrysorrhoea preferably hydrolyzed BAEE in contrast to E. subflava venom, which hydrolyzed ATEE in preference to BAEE. This difference was confirmed by Sephadex G-100 elution profiles. The esterase activity in E. chrysorrhoea venom was separated into two peaks with average mol. wts. of 96,000 and 44,000. The first peak demonstrated optimal BAEE hydrolysis at pH 8.6 and 37 degrees C, whereas the second peak optimally hydrolyzed both BAEE and ATEE at pH 8.45 and pH 8.6 at 45 degrees C respectively. The esterase activity in E. subflava venom was separated into two peaks with average mol. wts of 63,000 and 32,000 showing optimal hydrolysis of BAEE at pH 8.9 and 37 degrees C, and of ATEE at pH 7.75 and pH 8.5 at 40 degrees C. The column fractions showed comparable proteolytic activity, irrespective of differences between their esterase activities. The presence of phospholipase A (PLA) enzyme in crude spicule venom of both species was evident from their indirect hemolytic activities. The PLA activity eluted with the void volume and seems to be associated with some high molecular weight protein. Under the assay conditions used, E. subflava venom contained 50-100 times less PLA activity than E. chrysorrhoea venom.

IMMUNE REACTIVITY OF WOMEN ON HORMONAL CONTRACEPTIVES - DINITROCHLOROBENZENE SENSITIZATION TEST AND SKIN REACTIVITY TO IRRITANTS

To evaluate the influence of sex steroids on immunity in 87 women on hormonal contraceptives, sensitization tests were performed with the contact allergen, 2,4-dinitrochlorobenzene (DNCB). Forty-five women were taking oral contraceptives of combined oestrogen/progestogen of the same brand (low oestrogenic and middle range progestogenic activity); 27 had received intramuscular injections of medroxyprogesterone acetate and 15 women were using a sequential pill. The results were compared with those of 44 women not taking contraceptive steroids and matched for age. In women on the combined pill and those who had received intramuscular progesterone, the mean DNCB reactivity was significantly increased (0.02 less than p less than 0.05 and 0.001 less than p less than 0.01, respectively), whereas women using a sequential pill proved to show a decreased skin reactivity in the oestrogenic phase of this pill. (p = 0.05). The changes observed proved to be specific, since no statistically significant differences in overall skin reactivity to irritants between the four groups of women could be observed. The clinical implications of these results have been considered.

DOES DNCB THERAPY POTENTIATE EPICUTANEOUS SENSITIZATION TO NON-RELATED CONTACT ALLERGENS

Nineteen patients suffering from alopecia areata were treated weekly with both 2,4‐dinitro‐chlorobenzene (DNCB) and dithranol applied to separate areas on the scalp.

IMMUNE REACTIVITY OF WOMEN ON HORMONAL CONTRACEPTIVES - PHYTOHEMAGGLUTININ AND CONCANAVALIN-A INDUCED LYMPHOCYTE-RESPONSE

To investigate the influence of sex-steroids on the in vitro correlate of cell-mediated immunity (CMI), blood samples from 49 women on hormonal contraceptives were tested on the lymphocyte response to the mitogens phytohemagglutinin (PHA) and concanavalin A (Con-A). Sixteen women were taking oral contraceptives of combined oestrogen/progestogen of the same brand (low oestrogenic and middle range progestogenic activity); 15 had received intramuscular injections of medroxyprogesterone acetate and 18 women were using a sequential pill. The results were compared with those of 18 women not taking contraceptive steroids and matched for age. No significant changes were observed between the different groups. Considering the previously found alterations in dinitrochlorobenzene (DNCB) skin test reactivity by sex steroids, it is hypothesized that sex-steroids have little or no influence on the central proliferative phase of the immune response, but have a profound effect on the efferent phase.

Protease inhibitor deficiencies in patients with angio‐oedema

In 41 patients with recurrent angio‐oedema, studies were undertaken of the plasma protease inhibitor levels, Alpha‐i‐antitrypsin was measured by a Mancini method and the inhibitor levels for C1‐esterase, trypsin, chymotrypsin, urinary kallikrein and plasma kallikrein were determined by enzymatic assays with synthetic esters and chromogenic tripeptides as substrates. The control group consisted of 40 healthy individuals (medical students and department employees).