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Biomedical subjects

L Hellgren

Publications and source records attributed to L Hellgren.

At least 55 records · Page 3Linked to original sources
PubMed1980

Antibodies against extractable components from Propionibacterium acnes in humans with and without acne vulgaris.

Acidic polysaccharides (AP) are released from Propionibacterium acnes I and II during growth. Similar antigens are released from two strains of P. avidum, but in a smaller amount. Furthermore, prostaglandin-like substances (PLS) have been isolated from the lipid fraction of P. acnes. The AP antigens give rise to a precipitation reaction against a large proportion of normal sera. However, significantly higher antibody titre levels towards the AP fraction were found in patients with severe acne vulgaris. No rise of antibodies was found towards PLS. These findings suggest that AP's may contribute to the inflammatory response in acne vulgaris as antigens, whereas PLS, as one of the potential mediators trigger development of the initial lesions.

Acne Vulgaris↗
PubMed1980

Lipolytic activity of some dermatophytes.

The lipolytic activities of four common dermatophytes, Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum, were tested on agar medium supplemented with one or other of several lipids. The lipolytic activity was estimated by comparison of the zone sizes around the colonies. The highest lipolytic activity was demonstrated by M. canis, followed by T. mentagrophytes and E. floccosum; T. rubrum virtually lacked lipolytic activity. The clinical importance of these observations and their application in the identification of dermatophytes is discussed.

Epidermophyton↗
PubMed1980

Topical erythromycin for acne vulgaris.

The clinical response of topical erythromycin (1%) in a new penetrative vehicle was evaluated in a double-blind investigation on 28 patients with severe and moderate acne vulgaris. The verum preparation was superior to the placebo in 21 of the patients, while in 4 the reverse was true and in 3 no differences were seen. It is thus obvious that topical erythromycin in the penetrative vehicle is a potent agent for acne treatment. The risk for development of resistant Propionibacterium acnes strains must, however, be considered in topical as well as in systemic antibiotic therapy of acne vulgaris.

Acne Vulgaris↗
PubMed1979

Prostaglandin-like substances in Propionibacterium acnes. III. Differential contractile effects on smooth muscle layers of the human utero-tubal junction.

The biological activity of a lipid fraction extracted from P. acnes was tested on isolated smooth muscle strips from the human utero-tubal junction. The bioassay experiments support the concept that prostaglandin-like substances (PLS) occur in P. acnes. However, in the bioassay system used, the effect of PLS was different from that of PGF2 alpha and PGI2 but similar, although not identical, to that of arachidonic acid and PGE2.

Epoprostenol↗
PubMed1979

Prostaglandin-like substances in Propionibacterium acnes II. Stimulatory effect on ovarian cyclic AMP.

The prostaglandin-like substances (PLS) from Propionibacterium acnes increased the ovarian tissue levels of cyclic AMP (cAMP) approximately 2-fold. The lipid material extracted from P. acnes thus behaved like PG's of the E-type, and since it is unlikely that other known stimulators of the ovarian cAMP system can be present in the bacterial lipid fraction, these experiments give further evidence in favour of the occurrence of PLS in P. acnes.

Animals↗
PubMed1979

Evaluation of a culture procedure for identification of Neisseria gonorrhoeae.

A new rapid culture technique (Microcult GC) for identification of Neisseria gonorrhoeae was compared with a standard culture procedure in 151 patients (59 males, 92 females) suffering from urethritis and/or cervicitis. In 86.8% of the patients identical results were achieved when the new and the standard culture techniques were compared. In 4% the new culture technique revealed N. gonorrhoeae, confirmed by Bram-stain microscopy, when the standard culture was negative. However in 9.1% the reverse was true. In conclusion the new technique showed a decrease of 5% compared with the standard culture method. None of the methods gave rise to detectable false reactions. The new culture procedure might be a complement in the diagnosis of gonorrhoea because of its ease and rapidity (results are available after 24 h) but the method should not be used as a single diagnostic as it suffers from an unacceptable non-specifity especially in women.

Adolescent↗
PubMed1978

Erythromycin stearate in acne vulgaris: its effect on the skin surface lipids and on the activity of purified pancreatic lipase.

To study the mechanism of action of erythromycin stearate in acne vulgaris, the composition of the skin surface lipids was analyzed before, during and after treatment (500 mg daily for 1 week, 250 mg daily for 2 months) in 17 patients. Quantitative thin-layer chromatography showed that the fatty acid fraction in the skin surface lipids decreased significantly during the treatment period. The clinical effect was good in 14 of 17 patients. Further investigations were performed on the effect of erythromycin stearate on purified pancreatic lipase. The enzyme activity was not inhibited by exposure to the drug.

Acne Vulgaris↗
PubMed1977

Influence of some inflammatory or antiinflammatory substances on skin biopsies investigated with microcalorimetry and respiratory techniques.

Thermal effects were achieved from skin biopsies (epidermis, corium, subcutis) measured by batch-microcalorimetry, after exposure to potent inflammatory or antiinflammatory substances (compound 48/80, histamine, serotonine and hydrocortisone phosphate). Exothermic effects were achieved from 48-80, histamine and hydrocortisone phosphate, when exposed to the skin and lasting for varying time. From serotonine initial endothermic signals were achieved but after about 50 min there was stabilizing of the thermal reaction at the baseline. To analyze the nature of these non-specific thermal effects, determinations of O2 consumption and CO2 production were performed, using Warburg technique on exactly matched tissue pieces exposed to the same substances and run parallely with the microcalorimetrical determinations. An increased respiration, probably as an indicator of increased metabolism was registrated for all test substances acting on the skin. It felt, that the thermal effects reflect an increased metabolism of the tissue exposed to the test substances.

Basal Metabolism↗
PubMed1977

Thermal effects from degranulation of mastcells in cutaneous mastocytosis.

Small bipsies of the skin were taken from patients with papulo-cutaneous mastocytosis. The mast cell tumours were then degranulated with compound 48/80 (250 mug/ml in saline), and with a Sorption microcalorimeter, relatively strong exothermic reactions were measured, whereas normal skin showed only 1/10th the intensity. Disodium chromoglicate (1%) had no inhibitory effect on this thermal reaction.

Calorimetry↗
PubMed1977

Degradation and liquefaction effect of streptokinase-Streptodornase and stabilized trypsin on necroses, crusts of fibrinoid, purulent exudate and clotted blood from leg ulcers.

Necrotic materials most frequently found in leg ulcers, including crusts with fibrinogen, pus and blood clots, were exposed to solutions of streptokinase-streptodornase and stabilized crystalline trypsin respectively. The investigations were performed at the temperatures of 26 degrees and 33 degrees C, representing the extreme values of the temperature range found in leg ulcers (arteriosclerotic ulcers, stasis ulcers) and at the pH corresponding to that of the enzyme preparations in wet dressings. Streptokinase-streptodornase demonstrated in vitro a more potent proteolytic activity than crystalline trypsin on necroses, crusts of fibrinoid and purulent exudate, which were more rapidly and thoroughly broken up. Both enzyme preparations were, however, equally effective on three-day-old blood clots.

Humans↗
PubMed1976

Studies on the biological effects of deuteriated organic compounds. II. Morphological changes of Epidermophyton floccosum exposed to perdeuteriated n-hendecanoic acid studied with interference contrast and scanning electron microscopy.

In order to visualise the morphological changes of Epidermophyton floccosum associated with exposure to perdeuteriated n-hendecanoic acid, the architecture of the dermatophyte was investigated by means of interference contrast and scanning electron microscopy. The morphology of mycelia grown on substrate containing perdeuteriated n-hendecanoic acid, or the unlabelled analogue, was compared. The perdeuteriated n-hendecanoic acid produced a characteristic undulant effect of the hyphae. The characteristic wave-like appearance of the mycelia looked similar to the curling effect occuring after treatment of dermatophytes with griseofulvin, but was not so pronounced. Perdeuteriated n-hendecanoic acid, unlike the unlabelled analogue, also seems to cause a reduction of the number of chlamydospores perforations of the macroconidia. The changes in the morphological structure of Epidermophyton floccosum exposed to pereuteriated n-hendecanoic acid have been investigated. Morphological examination of mycelia exposed to this substance by interference contrast microscopy demonstrated a picture of defect hyphae and macroconidia. By the aid of scanning electron microscopy we have attempted to obtain a better visualization of these changes at ultrastructural level.

Chemical Phenomena↗
PubMed1976

Studies on the biological effects of deuteriated organic compounds. III. Antifungal activity of perdeuteriated fatty acids on dermatophytes in vivo experimental microsporie in guinea pigs.

Investigations on the antimycotic properties of perdeuteriated fatty acids were carried out on Microsporum cains infections in vivo. The study was performed on experimental microsporie in guinea pigs using four different methods, all based on the ability of M. canis to cause alopecia. Perdeuteriated n-hendecanoic acid showed in vivo a statistically significant enhanced antimycotic effect compared to its unlabelled analogue. This is in accordance with our previous observations in vitro conditions. The remaining perdeuteriated fatty acids (C12--C18) showed no statistically significant growth retarding effect on M. canis infections in guinea pigs when compared with their unlabelled analogues. The present study attempts to ascertain if some perdeuteriated fatty acids have any antifungal activity in vivo conditions. Our previous papers (3,4) concerning the evaluation of the antifungal activity of some perdeuteriated fatty acids on dermatophytes in vitro, demonstrated that the perdeuteriation of n-hendecanoic acid, lead to a pronounced antimycotic effect on common dermatophytes as e.g. E. floccosum, T. rubrum, M. canis and T. mentagrophytes. As our previous results indicate a decreasing of fungistasis with an increasing carbon-chain length of the perdeuteriated fatty acids, we have attempted to verify this observation in vivo conditions. A special interest was, of course, focused on the most promising compound, the perdeuteriated n-hendecanoic acid.

Alopecia↗
PubMed1976

Allergic delayed skin reactions from lipid fractions of trichophytin.

Crude trichophytin was fractionated to find out if its lipid fraction could cause inflammatory delayed allergic skin reactions in dermatophyte-sensitized guinea pigs. The following fractions were obtained: polysaccharide-peptide, total lipids, total lipids without free fatty acids and free fatty acids. The crude trichophytin and polysaccharide-peptide fraction gave rise to strong and equal allergic delayed skin reactions after 24 h. The total lipids gave statistically significant weaker, but clearly positive reactions, and of the same degree as the free fatty acid fraction. The total lipids without free fatty acids did not produce reactions in the sensitized animals, indicating that free fatty acids are responsible for the allergic skin reactions. In some cases the free fatty acids showed comparatively intense reactions. It can be concluded that free fatty acids are antigenic substances that are, sometimes, involved in the allergic delayed skin reactions in dermatophytosis.

Animals↗
PubMed1976

Contact sensitizing properties of some fatty acids in dermatophytes.

The predominant fatty acids (C10-C18) of dermatophytes were investigated by the Landsteiner-Draize test to establish their allergenicity. It was demonstrated that fatty acids can give rise to sensitization of delayed type in guinea pigs. The middle-chain fatty acids (C10-C12) showed a high allergenicity compared to the (C13-C18) acids with moderate to weak contact sensitizing properties. The fatty acids may act as contact sensitizers and, at least sometimes, be responsible for the skin lesions in dermatophytosis.

Animals↗
PubMed1976

Spark source mass spectrographic study of metal allergenic substances on the skin.

By spark source mass spectrography it is possible to trace very low concentrations of substances such as chromium, cobalt, and nickel in ethanol extracts of the skin. Chromium could be detected in abnormally high concentrations 3 weeks after one application, while nickel and cobalt reached background levels after 2 to 3 weeks. Touching a door handle containing chromium leads to a significant rise in the chromium content of the skin. Increased chromium content of the skin was evident in one case of wristwatch eczema as well.

Allergens↗