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Biomedical subjects

H Ippen

Publications and source records attributed to H Ippen.

At least 37 records · Page 2Linked to original sources
PubMed1989

Studies on uroporphyrinogen decarboxylase of etiolated Euglena gracilis Z.

1. A 423-fold purified fraction of uroporphyrinogen decarboxylase (EC 4.1.1.37) showing a specific activity of 770 units/mg protein has been employed in order to study some properties in etiolated Euglena gracilis Z. 2. Uroporphyrinogen decarboxylase has a relative molecular mass of 54,000, an optimum pH of 7.2 and exhibits Michaelis-Menten kinetics, employing both uroporphyrinogen I and uroporphyrinogen III as substrates. 3. Anaerobic conditions seem not to be necessary for uroporphyrinogen decarboxylase activity. Neither EDTA nor cysteine affected enzyme activity, whereas dithiothreitol produced a remarkable activation of coproporphyrinogen formation. 4. Kinetic data employing both substrates showed an accumulation of porphyrinogen (i.e. hexa- and hepta-porphyrin) containing six or seven COOH groups, depending on the uroporphyrinogen concentration used. 5. An unusual elution profile of the intermediates on Sephacryl S-200 was found.

Animals↗
PubMed1988

[Preparations containing sunscreens in West Germany 1988].

The commercial UV-absorbing cosmetics and sunscreens which are currently available in Germany are presented in two tables. In addition to the UV-absorbing and light-reflecting sunscreens, we list other ingredients which may cause skin reactions or have special properties. Our survey provides quick information on potential allergens and photoallergens. Well-tolerated alternative preparations can be chosen on the basis of the listed ingredients. Complete declaration of all ingredients in cosmetics and sun cosmetics is necessary in order to facilitate the diagnosis of allergies and photoallergies and should replace comprehensive surveys, which are rapidly outdated.

Chemical Phenomena↗
PubMed1988

[Photoallergic and allergic contact eczema caused by dibenzoylmethane compounds and other sunscreening agents].

Dibenzoylmethanes are widely used in Europe in UV-A-absorbing sunscreens. We report on 21 patients with (photo)allergic contact dermatitis from 4-isopropyl-dibenzoylmethane. Six subjects revealed, in addition, (photo)allergic reactions to 4-tert.butyl-4'-methoxy-dibenzoylmethane, seven to 3-(4-methylbenzylidene)-camphor, two to 2-phenyl-benzimidazole-5-sulfonic acid and one to 2-phenyl-5-methylbenzoxazole. Allergic contact dermatitis from 2-phenyl-benzimidazole-5-sulfonic acid has not been reported previously. The relevance of sunscreens as a cause of (photo-)allergic contact dermatitis is discussed.

Adolescent↗
PubMed1988

[Sunscreening agents in West Germany 1988].

The commercial UV-absorbing cosmetics and sunscreens which are currently available in Germany are presented in two tables. In addition to the UV-absorbing and light-reflecting sunscreens, we list other ingredients which may cause skin reactions or have special properties. Our survey provides quick information on potential allergens and photoallergens. Well-tolerated alternative preparations can be chosen on the basis of the listed ingredients. Complete declaration of all ingredients in cosmetics and sun cosmetics is necessary in order to facilitate the diagnosis of allergies and photoallergies and should replace comprehensive surveys, which are rapidly outdated.

Chemical Phenomena↗
PubMed1987

[Treatment of acute intermittent porphyria with a new protein-bound lyophilized hematin].

Hematin (iron-III-protoporphyrin 9) has been used for several years in the treatment of acute attacks of inducible porphyrias. Three patients were treated with a new, albumin-bound lyophilized hematin preparation (manufactured by Behringwerke). In all patients it achieved a reduction in the urine of the porphyrin precursors porphobilinogen and 5-aminolevulin acid. In two patients the clinical symptoms were clearly improved, while a third patient died with tetraparesis. Hematin administration proved superior to the preceding glucose treatment. No abnormality of clotting or thrombophlebitis was detectable after hematin infusion.

Acute Disease↗
PubMed1986

Elimination of porphyrins and their precursors in rats pretreated with hexabromobenzene.

The elimination times of porphyrins and their precursors and of hexabromobenzene (HBB) itself were studied in female rats given 15 mg HBB by stomach tube every other day for 4 months. The concentrations of HBB in the blood, liver and adipose tissue were in the ratio 1:1.5:25, 24 hr after the last dose. Two weeks after the end of treatment, HBB was no longer detectable in the tissues. In animals given a single oral dose of 16.6 mg HBB/kg body weight, HBB was no longer detectable in adipose tissue 12 days after dosing. The half-life of HBB in adipose tissue was about 2.5 days in the animals given HBB for 4 months, and at the end of the treatment the concentrations of porphyrin in the liver, urine and faeces were increased to about 1000, 600-700 and 60-70 times the control values. The amounts of delta-aminolaevulinic acid and porphobilinogen in the urine of treated animals were 6-7 times those in controls. After the end of HBB treatment, it took almost 1.5 yr for delta-aminolaevulinic acid and porphobilinogen excretion to return to normal. Nearly 2 yr were needed for complete elimination of the accumulated liver porphyrins.

Adipose Tissue↗
PubMed1986

Pelea anisata.

Explore the source record for details and available documents.

Dermatitis, Contact↗
PubMed1986

Photoallergic and allergic contact dermatitis from dibenzoylmethanes.

Dibenzoylmethanes are widely used in Europe in UVA-absorbing sunscreens. We found that 2 of these, 4-isopropyl-dibenzoylmethane and 4-tert.butyl-4'-methoxy-dibenzoylmethane caused allergic or photoallergic contact dermatitis. This is the first report on allergic and photoallergic reactions caused by dibenzoylmethanes.

Adolescent↗
PubMed1985

[Hypersensitivity phenomena in dialysis patients. Incidence of eosinophilia, raised IgE and ethyleneoxide-induced antibodies].

The hypersensitivity parameters eosinophil count, serum IgE and IgE-type antibodies to ethylene oxide-albumin conjugates (ETO-antibodies), were determined in 182 dialysis patients. Eosinophilia was seen in 21.7% of patients, IgE elevation in 21.4% and ETO-antibodies in 12.4%. A pathological change in at least one of the measured parameters was present in 33.1%. The appearance of ETO-antibodies was frequently associated with severe clinical symptoms, especially asthma and anaphylactic shock. Sensitisation is apparently common in dialysis patients. Since ETO-antibodies are often associated with severe clinical symptoms, their presence should be sought in those dialysis patients showing incompatibility reactions or asthma.

Adult↗
PubMed1985

[Generalized verrucosis in familial T-helper cell deficiency. Treatment with interferon and Tigason].

We report on a 17-year-old patient suffering from generalized verrucosis. This diagnose had been confirmed by means of light microscopy, electron microscopy, and DNA hybridisation (HPV type 2). The study of immunological parameters revealed reduced numbers of T-lymphocytes, especially of helper-T-cells. Skin tests with recall antigens were normal. Three brothers of our patient showed slight reduction of helper-T-cells. Treatment with topical retinoic acid was not effective. Treatment with alpha-interferon i.m. intralesionally was effective in the beginning, but two weeks after onset of therapy no further improvement could be achieved. Discontinuation of therapy was followed by a relapse. Tigason which was given thereafter led to flattening of the warts but failed to bring about complete regression within the following four months.

Adolescent↗