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Biomedical subjects

M Doss

Publications and source records attributed to M Doss.

At least 109 records · Page 6Linked to original sources
PubMed1978

[Disorder of porphyrin metabolism in thallium intoxication (author's transl)].

A 19-year old male ingested in suicidal attempt 750 mg of thallium. He developed the characteristic symptoms of thallium intoxication. During the acute phase the urinary excretion of porphyrins and porphyrin precursors was largely increased. The percentage distribution of the individual metabolites of heme synthesis revealed a preponderance of kopro- and uroporphyrin. This constellation (kopro- greater than uro- greater than tricarboxylic porphyrin) differs appreciably from that one in lead intoxication. The observation of increased urinary excretion of porphyrins and their precursors in a possibly particular spectrum in thallium intoxication is of special interest for differential-diagnostic reasoning. In each case of a toxic disorder of porphyrin metabolism thallium intoxication ought to be considered a possible cause.

Adrenergic beta-Antagonists↗
PubMed1978

[Diagnosis of acute intermittent porphyria. Results of neurological, biochemical and genetic studies].

Neurological and biochemical studies have been performed on four AIP families with 21 members. Five patients suffered from manifested AIP (Uroporphyrinogen Synthase defect and characteristic urine findings); among their relatives five persons with latent AIP were detected and eight carriers of the genetic-enzymic defect (Uroporphyrinogen Synthase defect). Internal and neurological symptoms could be interpreted as a panneuropathy. Acute and chronical polyneuropathies could be observed as well as myelopathies and cerebral co-reactions. A frequent symptom dominating the crisis and the latent state of AIP were etiologically abscure 'myalgias.' The character of the course of AIP is various and dubious: beyond the 'classical' courses with its intermittent porphyric crises we observed one case which was characterized by a permanent crisis and a second case marked by a chronical, slow progredient course without any porphyric attacks.

5-Aminolevulinate Synthetase↗
PubMed1978

[Alcohol-induced changes of porphyrin metabolism (author's transl)].

Alcohol is a agenrphyrinogenic agent which may cause disturbances in porphyrin metabolism in healthy persons as well as biochemical and clinical manifestations of acute and chronic hepatic porphyrias. After excessive alcohol infestion in man a secondary hepatic coproporphyrinuria develops transiently, which persists in alcoholic liver disease. The alcohol-liver-porphyrinuria syndrome ranges first among the secondary hepatic disturbances of porphyrin metabolism. In acute hepatic porphyrias (acute intermittent porphyria, porphyria varigata and hereditary coproporphyria) alcohol induces delta-aminolevulinic acid synthase because in these porphyrias the control mechanisms of porphyrinogen and heme synthesis in liver are disturbed ("molecular regulatory diseases"). On the contrary, in chronic hepatic porphyrias, which are already associated with liver damage ("membrane diseases"), alcohol potentiates the disturbance of the decarboxylation of uro- and heptacarboxyporphyrinogen, which is followed by a hepatic accumulation of uro- and heptacarboxyporphyrin and their sometimes extreme urinary excretion. Alcohol may transform a symptomatic coproporphyrinuria into chronic hepatic porphyria. One can deduct from experimental and clinical studies that in liver alcohol inhibits the enzymes coproporphyrinogen oxidase, delta-aminolevulinic acid dehydratase and uroporphyrinogen decarboxylase and induces delta-aminolevulinic acid synthase. Abstinence from alcohol is an important measure in the therapy and prophylaxis of all hepatic porphyrias.

Alcoholism↗
PubMed1978

[Uroporphyrinogen synthase in erythrocytes in acute intermittent porphyria: new pathobiochemical aspects (author's transl)].

Uroporphyrinogen synthase (EC 4.3.1.8) was determined in the erythrocytes of 380 patients, of which 21 showed clinical symptoms of acute intermittent porphyria. The normal range of a random sample was 61 +/- 23 mumol/1.h(x +/- 2s, n=302), including the activity of uroporphyrinogen cosynthase and the subsequent enzymes; when all the latter enzymes were destroyed by heating the haemolysate, the normal range for uroporphyrinogen synthase was 65 +/- 25 mumol/1.h(x +/- 2s, n=274). The respective activity of uroporphyrinogen synthase in patients with acute intermittent porphyria was 35 +/- 12, and 40 +/- 18 mumol/1.h which was significantly lower (p less than 0.001) than the control values. In the 21 cases of acute intermittent porphyria, the diagnosis had already been made from the presence of porphyrin precursors and porphyrin in the urine. In 7 of the 21 cases of acute intermittent porphyria, and in 6 relatives of the patients, the activity of the uroporphyrinogen synthase was in the overlap zone (40-50 mumol/1.h). 32 relatives of 9 of the patients with acute intermittent porphyria were investigated: 22 showed a significant decrease of uroporphyrinogen synthase, and 7 of these showed pathological urinary porphyrin precursors and porphyrin. The relative activity of uroporphyrinogen synthase in patients with acute intermittent porphyria was 57%. A decrease of the uroporphyrinogen synthase activity of greater than 30% compared with the mean of the controls is a sure indicator for the presence of a primary enzymic defect in the gene carrier for acute intermittent porphyria.

Acute Disease↗
PubMed1978

[Uroporphyrinogen decarboxylase in erythrocytes: studies on the primary genetic enzyme defect in chronic hepatic porphyria (author's transl)].

In chronic hepatic porphyria, including the clinical phase, porphyria cutanea tarda, the activity of uroporphyrinogen decarboxylase is decreased not only in the liver, but also in the erythrocytes. The synonomous decrease in the enzymic activity in liver and erythrocytes in both familial and sporadic hepatic porphyria shows that the disturbance of this enzyme is the primary genetic defect of this condition; inheritance of the defect is probably autosomal and dominant. The clinical manifestation of disturbances of porphyrin metabolism are precipitated, however, by additional factors, such as liver damage, alcohol, oestrogens and neoplastic growths. In the absence of these other pathogenic influences, the enzyme defect is compensated and does not result in disturbances of haem or haemoglobin synthesis, either in the liver or the bone marrow.

Carboxy-Lyases↗