[No Parkinsonian syndrome following acute paraquat poisoning]

Paraquat structurally resembles N-methyl-4-phenyltetrahydropyridine (MPTP) and its metabolite 1-methyl-4-phenylpyridine (MPP+). MPTP and MPP+ are neurotoxic chemicals, which induce in exposed humans and in animal-models a Parkinson's disease. A high correlation between the incidence of Parkinson's disease and herbicide use in Canada led to the assumption that paraquat could give rise to parkinsonism. We have therefore carried out a follow-up study with patients having had dermal contact with paraquat or having swallowed paraquat accidentally or in a suicidal attempt. 7 patients took part in the study. Three of them had dermal contact. One had ingested paraquat by accident and three were survivors from suicidal paraquat intake. It was possible to exclude parkinsonism in all patients. One patient exhibited tardive dykinesia most likely due to a long term therapy with neuroleptic drugs.

[Diagnosis and therapy of mushroom poisoning (II)]

In the second part of this review of mushroom poisonings, the syndromes with intermediate and long lag-times are discussed. They include the coprinus-, phalloides-, gyromitrin- and the orellanus syndrome. The coprinus syndrome occurs whenever alcohol is consumed after a meal containing coprine. The lag-time varies according to the amount and time of alcohol intake. It is very similar to the disulfiram syndrome which is known from the adverse therapy of alcoholism. The lag-time of the phalloides syndrome varies between 7 and 24 hours. It starts with massive gastroenteritis followed by hepatopathia which can lead to hepatic coma and kidney failure. The phalloides syndrome is caused by the amatoxins of the death caps, which inhibit the RNA Polymerase B in the nucleus of the liver cell. The gyromitrin syndrome exhibits also a delayed onset. The hepatotoxicity and the nephrotoxicity are less severe than in the phalloides syndrome. The first metabolite of gyromitrin monomethylhydrazin is responsible for CNS-symptoms such as delirium and convulsions. In contrast to the phalloides syndrome vomiting can be the only leading symptom in gyromitrin poisoning. The orellanus syndrome has the most delayed onset of all mushroom poisonings with 1-3 weeks. It should be thought of in all cases of kidney insufficiency of unknown origin. The orellanines damage the kidney and induce all degrees of kidney insufficiency according to the amount of ingested poison. Terminal kidney failure which requires hemodialysis treatment can occur in severe cases.

[Diagnosis and therapy of mushroom poisoning (1)]

The diagnosis of mushroom poisoning is based on three principles: the description of the mushroom, the toxicological analysis of the mushroom and, most important, the mushroom syndrome. Mushroom poisoning can be classified according to the lag time between the meal and the onset of symptoms. In this paper we will discuss mushroom poisoning with short and intermediate lag time. With short lag time and a predominance of CNS signs and symptoms the diagnosis is either fly-agaric, pantherina or psilocybin syndrome. Parasympathomimetic signs and symptoms indicate the muscarine syndrome. If--with a lag period of up to four hours--vomiting and diarrhea are predominant, we will find a poisoning with one of the many mushrooms which lead to gastroenteritis. Gastroenteritis combined with hemolysis points to a paxillus syndrome.

Metabolic effects of prenalterol in healthy volunteers

The effect of the beta 1-adrenoceptor agonist prenalterol on the metabolic parameters glucose, lactate, free fatty acids and serum-insulin were studied in 8 healthy volunteers. Prenalterol was administered intravenously in geometrically increasing doses from 5 to 80 micrograms/kg. The only metabolic effect of prenalterol that could be proved was a significant dose-dependent rise in FFA-concentration. The stimulating effect of prenalterol on lipolysis was significant not only at the time points of maximal effect following each injection, but also 30 min later. Serum-insulin-concentration and glucose- and lactate-concentration failed, however, to show a significant rise after prenalterol administration. This behaviour is a strong indication of a beta 1-selectivity of prenalterol over the whole dose range given.

[Concentration of C-peptide and insulin in serum of patients with acute virus hepatitis (author's transl)]

Intravenous glucose tolerance tests were performed in 10 patients with acute virus hepatitis. The assimilation coefficient of glucose and the level of insulin and C-peptide in serum were determined before and in the course of the glucose tolerance tests. In comparison to healthy normal weight persons C-peptide concentration in patients with acute hepatitis increased twice as high whereas the pattern of insulin secretion did not differ significantly. The higher levels of C-peptide indicate an increase of the beta-cell secretion in acute hepatitis. One could suppose an increased hepatic destruction of insulin in acute hepatitis, because there is no significant difference among the insulin levels. More likely, there is a reactive increase of secretion of the beta-cell due to a reduction of insulin sensitivity and this is indicated much better by C-peptide- than insulin levels because of the longer half live of the the C-peptide molecule.

[Effects of the beta-adrenergic blocking agent propranolol on the carbohydrate- and lipometabolism (author's transl)]

Intravenous glucose tolerance tests were performed in 17 patients suffering from hyperthyreosis before and after a week of treatment with propranolol. The blood taken until the 125. minute after the glucose load was used for the determination of serum glucose, the free fatty acids (FFA), the free glycerol and the radioimmunologically measurable insulin (IRI). The following results were received: After the treatment with propranolol the glucose tolerance decreased significantly. The insulin secretion was diminished showing a significant difference for the fifth minute after glucose injection. The concentration of the FFA remained unchanged. The levels of the free glycerol were significantly lower after the propranolol treatment than before. Though an inhibition of lipolysis was possible by the propranolol treatment the glucose tolerance did not improve due to the inhibition of insulin secretion under propranolol. Beta-adrenergic blocking agents do not lead to an essential change in the carbohydrate- and lipometobolism. Therefore, their use in hyperthyroidism is mainly justified because of the cardial symptomatology.

[Concentration of C-peptide in correlation to kidney function (author's transl)]

Recently, the radioimmunological determination of C-peptide came into interest because of the jugdement of the remaining function of the islet apparatus in insulin-dependent diabetics. As the degradation of C-peptide preferably takes place in the kidney we performed an intravenous glucose load in 32 patients with kidney diseases. The following results were obtained: 1. In patients with a healthy carbohydrate metabolism a clear correlation exists between the concentration of creatinine on the one hand, the creatinine-clearance and the fasting C-peptide concentration respectively the measured amount of C-peptide on the other hand. 2. The more advanced the renal insufficiency the better is the correlation between the parameter of the kidney function and the C-peptide concentration. 3. In diabetic patients there shows to be no clear correlation between the C-peptide levels and the kidney function. --In insulin-dependent diabetics the amount of C-peptide is only of diagnostic use if the renal function is well known.

[Studies on the question of a possible autoregulation of insulin secretion (author's transl)]

In eight normal weight healthy volunteers it was proved by C-peptide assay whether high concentrations of insulin in serum would suppress the secretion of insulin in an autoregulative manner. Insulin combined with glucose, therefore was given intravenously as a single bolus injection as well as an infusion over a period of two hours. Moreover it was proved whether high levels of insulin would suppress the reactivity of the B-cell to sulphonylurea administration. It was demonstrated that the secretion of the B-cell is regulated only by the concentration of the blood sugar, but not by the level of serum insulin. Likewise the stimulation of the B-cell by sulphonyl-urea administration is not suppressed by high concentrations of insulin.

[Value and relevance of metabolic function tests in the diagnosis of primary hyperparathyroidism (author's transl)]

Calcium, phosphate and alcaline phosphatase levels were determined in the serum of 29 patients with suspected primary hyperparathyroidism. Phosphate clearance according to Kyle, 24 hours urine hydroxyproline excretion during collagen free diet, the excretion of cAMP in the 24 h urine during calcium restricted diet were examined with regard to the diagnostic value and relevance as compared to the consumption of laboratory and staff time. The elevation of the serum calcium levels are not specific and only of minor diagnostic value. It has been found that the highest diagnostic value is given by the Kyle-test using 15 mg Ca ions/kg body weight. No false positive results were recorded. The excretion of hydroxyproline and calcium are only of limited value. Serum alcaline phosphatase and cAMP excretion have no diagnostic significance whereas concentration of serum phosphate may have some value.

[Mechanism of action of gliquidone (author's transl)]

A study of 13 metabolically normal persons, 12 patients with asymptomatic or latent diabetes and 11 with manifest diabetes showed that 30 mg gliquidone orally prevents or delays the blood sugar rise during repeated small carbohydrate meals with simultaneous stimulation of insulin secretion. This effect was less marked in the normal and asymptomatic or latent diabetic subjects than after glibenclamide 5 mg, while there was no difference between the two drugs in those with manifest diabetes.