Reduced sulphoxidation capacity in D-penicillamine induced myasthenia gravis.

Myasthenia gravis may be observed due to treatment with penicillamine (D-PA). The sulphoxidation capacity was measured in nine Swedish patients with rheumatoid arthritis (RA) who had developed myasthenia gravis toward D-PA. The results show that in eight of nine patients tested, this parameter was markedly reduced. A patient with poor sulphoxidation capacity has a twelve-fold greater risk of developing this rare side effect. The significance of this is discussed.

[Adrenal functions in patients with generalized myasthenia in the late postoperative period]. / Funktsiia nadnyrkovykh zaloz u khvorykh na heneralizovanu miasteniiu u viddalenomu pisliaoperatsiinomu periodi.

The adrenal gland function was studied in 123 patients with generalized myasthenia before the operative treatment and at the late postoperative period on the basis of measurement of the indices of 24 h urinary excretion of 11-OKS, 17-OKS and catecholamines. A significant decrease in the function of cortical and medullary substance of the adrenal glands in patients before thymectomy was revealed. Normalization of the function of cortical substance was observed only in the second five years after the operation, function of the medullary substance was suppressed at all the periods of examination. Changes in the function of the adrenal glands correlated with clinical status of the patients.

[Clinical results of using Nakom in diseases of the nervous system]. / Klinicheskie rezu'ltaty primeneniia Nakoma pri zabolevaniiakh nervnoi sistemy.

Clinical investigation was performed and dopamine metabolism (renal catecholamine excretion) studied in 29 children and 5 adults with various forms of CP, 5 myasthenic children and 1 child with Strümpel disease treated with Nakom. The therapy was judged expedient in 20% of the cases of pronounced muscular rigidity and dystonia with decreased dopamine excretion. The drug proved ineffective in atonic, astatic, severe hyperkinetic arms, and in cases with severe psycho-organic signs.

Increased rates of myofibrillar protein breakdown in muscle-wasting diseases.

The excretion of endogenous creatinine and 3-methylhistidine by subjects with muscle diseases has been measured in order to assess muscle mass and fractional rates of myofibrillar protein degradation. Increases in the rates of myofibrillar protein breakdown were observed in all subjects with Duchenne, Becker, autosomal recessive Duchenne-like, and limb-girdle muscular dystrophy; dystrophia myotonica; myotonia congenita; peroneal muscular atrophy; myasthenia gravis; and central core disease; in some cases of spinal muscular atrophy; but in no cases of facioscapulohumeral muscular dystrophy of dystonia musculorum deformans. All increases in myofibrillar protein breakdown were associated with reductions in muscle proportion below the normal. Muscle-wasting diseases may respond to therapy directed towards an inhibition of muscle protease activity; the efficacy of such therapy can be monitored by the 3-methylhistidine-to-creatinine excretion ratio.

Renal clearance of pyridostigmine in patients with myasthenia gravis.

The urinary clearance of pyridostigmine was studied in six patients with myasthenia gravis. In three patients on pyridostigmine alone, renal clearance ranged from 349 to 481 ml/min, corresponding to a pyridostigmine:creatinine clearance ratio of 2.64 to 3.46. In a patient on bendrofluazide as well as pyridostigmine, a similar clearance ratio was observed. By contrast, the urinary clearance of pyridostigmine and the pyridostigmine:creatinine clearance ratio was reduced in two myasthenic patients concurrently treated with other basic drugs. It is suggested that these results may reflect competition for renal tubular excretion.

[Adrenocortical function in myasthenia pseudoparalytica]. / Badania nad czynnoscia kory nadnerczy w miastenii rzekomoporaznej

In a group of 31 women with myasthenia the urinary excretion of 17-ketosteroids and their fractions (11-deoxy-17-ketosteroids, dehydroisoandrosterone) and 17-hydroxycorticosterone were determined. A statistically significant decrease was observed in the excretion of these substances. Besides that, the plasma cortisol level was determined in these patients and the results obtained in the whole group were at the lower normal range of the laboratory and in 40% of cases they were significantly lower (p less than 0.01). The obtained results may suggest that adrenocortical hypofunction exists in many cases of myasthenia. The pertinent literature is reviewed.