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Biomedical subjects

J Ring

Publications and source records attributed to J Ring.

At least 37 records · Page 2Linked to original sources
PubMed1991

Atopic eczema, Langerhans cells and allergy.

While the pathomechanisms of respiratory atopy are rather well established, the role of IgE-mediated hypersensitivity in the elicitation and maintenance of eczematous skin lesions in atopic eczema is still controversial. Few diseases are characterized by an equally elevated production of IgE antibodies as atopic eczema. Many authors, however, regard this only as epiphenomenon. On the other hand, there is clearcut clinical evidence for exogenous elicitation of atopic eczema by contact with aero or food allergens. A variety of hypotheses may help to explain the participation of IgE antibodies in the induction of eczema: vasoactive mediators secreted by skin mast cells or basophils after allergen contact may produce itch, contact urticaria or a 'late-phase-reaction' with consequent eczematous skin changes further maintained by scratch responses. Recent investigations stress a possible role of Langerhans cells in the epidermis with a low affinity receptor for IgE with possible function for antigen presentation, mediator release or regulatory interactions. Certain cytokines such as interleukin-4 or gamma-interferon are able to enhance the expression of the IgE-receptor on the surface of Langerhans cells. IL-4 and gamma-interferon act synergistically in this respect on Langerhans cells, contrary to B cells. Furthermore lymphocytes may act directly via certain cytokines (e.g. histamine releasing factor, chemotactic factors etc.) on mast cells or eosinophil granulocytes in a proinflammatory sense. Eosinophils seem also to be involved in the inflammatory response in atopic eczema by releasing products such as major basic protein (MBP) or eosinophil cationic protein (ECP) which has been found to be elevated in severe atopic eczema.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1991

Antiasthmatic effects of Picrorhiza kurroa: androsin prevents allergen- and PAF-induced bronchial obstruction in guinea pigs.

In the Ayurvedic medicine, Picrorhiza kurroa Royle ex Benth. is used for the treatment of liver and lung diseases. Using different chemical and pharmacological methods, we could identify the phenol glycoside androsin as active compound preventing allergen and platelet-activating factor induced bronchial obstruction in guinea pigs in vivo (10 mg/kg p.o.; 1 h prior to the inhalation challenge). Histamine release from human polymorphonuclear leukocytes in vitro was inhibited by other compounds yet to be identified.

Acetates↗
PubMed1991

Stigmata of atopic constitution in patients with atopic eczema or atopic respiratory disease.

In the diagnosis of atopic eczema, minor physical markers (stigmata) frequently provide valuable clues. The prevalence of nine stigmata (dry skin, hyperlinearity of the palms or soles, infraorbital fold, white dermographism, facial pallor, orbital darkening, Hertoghe's sign, low hairline) was evaluated in 34 atopic eczema patients without atopic respiratory disease, in 16 patients with allergic rhinitis and/or asthma without atopic eczema, and in 23 controls without atopic respiratory or eczematous disease, and with negative results at prick testing with three common aeroallergens. Compared with controls, all features except Hertoghe's sign were significantly (p less than 0.01) more frequent in atopic eczema, and, except for Hertoghe's sign, dry skin and white dermographism, they were significantly (low hairline, p less than 0.05; others, p less than 0.01) more frequent also in respiratory disease. The prevalence of most stigmata did not differ significantly (p greater than 0.05) in cutaneous vs. respiratory atopic disease, only dry skin being more frequent in atopic eczema (p less than 0.05). Although not specific, most stigmata are characteristic markers not only of atopic eczema, but of atopy as such.

Adolescent↗
PubMed1991

Photopatch testing with different ultraviolet A sources can yield discrepant test results.

A photopatch test series consisting of 27 substances was tested in 81 patients with suspected photosensitivity disorders. Irradiation was performed using the following light sources: TL-K 40W/09 bulbs (UVA'; lambda max. at 355 nm), UVASUN 5000 (UVA''; lambda max. at 375 nm), and TL 20 W/12 bulbs (UVB; lambda max. at 315 nm). One day after applying 4 sets of the test substances (D1), one test series each was exposed to 10 J/cm2 of UVA' or UVA'', or a combination of 40 mJ/cm2 UVB and 10 J/cm2 UVA''; the fourth series was left nonirradiated (control). Photopatch test reactions (PPTR) were defined as positive if there was at least an indurated erythema on D3 or later between D3 and D21 (late-onset reactions) exclusively at the irradiated, but not at the control site. At least one positive PPTR was found in 35 patients (43%), 7 of whom exhibited late-onset reactions only; in 2 cases the tests could not be read because of skin irritation. On D3, there were 44 positive reactions with UVA', only 10 of which were also demonstrable with UVA''. Twenty-one late-onset PPTR were found with UVA' and 17 with UVA''. Late-onset reactions elicited by UVA' or UVA'' mostly were concordant; divergent positive or negative results were found only in a few cases. Compared with the results obtained with UVA' or UVA'' alone, combined irradiation with UVB and UVA'' occasionally led to divergent positive as well as negative results. When photopatch test results are interpreted, it should be considered that testing with different UVA sources may yield divergent results.

Adolescent↗
PubMed1990

High-performance liquid chromatography for the separation of angiotensin and its metabolites in human plasma and sweat.

A reversed-phase high-performance liquid chromatography (HPLC) method with gradient elution for the separation of angiotensin peptides is described. The highly reproducible method allows the base-line separation of angiotensin peptides with UV detection at 225 nm. This chromatographic methodology in combination with radioimmunoassay (RIA) is used for the characterization of angiotensin peptides in human plasma and sweat.

Acetonitriles↗
PubMed1990

H1- and H2-antagonists in allergic and pseudoallergic diseases.

Although known for more than 80 years, histamine still remains a fascinating substance for allergy research. Histamine antagonists have been in clinical use since 1942. The classical H1-antagonists with sedative side-effects have been more or less replaced by newer non-sedating H1-antagonists; the role of H2-receptors in allergic diseases is still controversial. There, are however, increasing reports of beneficial effects of H2-antagonists, mostly in combination with H1-antagonists, in a variety of allergic and pseudoallergic conditions such as chronic urticaria, anaphylactoid reactions due to colloid volume substitutes, opioid analgesics and radiographic contrast media. The combined use of H1- and H2-antagonists might not only act as specific histamine antagonism but exert a mast cell stabilizing effect, as demonstrated in animal experiments and some clinical studies. Future research will show whether the combined use of H1- and H2-antagonists will become a routine therapeutic procedure in allergy therapy.

Anaphylaxis↗
PubMed1990

Histamine, antihistamines and atopic eczema.

Histamine is known to be a classical inducer of pruritus. In atopic eczema, itch is a prominent feature (regarded by some even as a 'primary lesion'!). One of the most potent chemical mediators of itch is histamine. Histamine, together with other mediators may play a role in the pathophysiology of atopic eczema: the increased release of histamine from basophil leucocytes of atopic patients has been described, as well as elevated histamine levels in plasma and skin during acute exacerbations of eczematous lesions. Therefore, application of H1 antagonists seems to be a rational regime in the symptomatic treatment of atopic eczema. Nevertheless, some controversy exists regarding the clinical efficacy of orally applied H1 antagonists in this disease, especially with regard to the newer non-sedating compounds such as terfenadine, astemizole, loratadine and cetirizine. Review of the literature shows that there are studies demonstrating a clear-cut antipruritic effect of non-sedating H1 antagonists. Thus the sedative action does not seem necessarily to be connected with therapeutic efficacy in treating itch in atopic eczema. Newer studies show that cetirizine exerts an additional inhibitory effect on eosinophils. This may broaden the therapeutic spectrum of this H1 antagonist in diseases with eosinophil involvement.

Dermatitis, Atopic↗
PubMed1990

European multicenter study of TRUE Test, Panel 2.

Panel 2 of the standardized, ready-to-apply patch test, the TRUE Test, has been evaluated on 808 patients with suspected contact dermatitis. The patients were tested with 11 different allergens and the negative control, and compared with corresponding allergens in pet. (or aq.) in Finn Chambers fixed with Scanpor. The TRUE Test, Panel 2 and the control were applied symmetrically on the upper back. Left/right application of the respective test varied at random. Most tests were removed after 48 h and evaluated after 72 or 96 h, according to generally accepted recommendations. There were positive test reactions to all 11 allergens tested in the patient group. The concordance of positive reactions (1+, 2+, 3+) was 63% between TRUE Test, Panel 2 and the control method; 17% of positive reactions occurred only with TRUE Test, Panel 2 and 20% only with the compared method. Approximately 75% of all positive test reactions were explained by the patients' present or past history. Irritant/questionable reactions occurred in the same frequency for the 2 methods. Such reactions were recorded in less than 1% of all patches applied. No late reactions were recorded.

Allergens↗