[Ischemic cerebral vascular accident and zoster infection]. / Accident vasculaire cérébral ischémique et infection zostérienne.

Herpes zoster is uncommonly followed by cerebral infarction. The pathophysiological mechanism remains uncertain. Outcome is favorable after early specific treatment. We report the case of a 70-year-old woman who developed right hemiparesis with aphasia 15 days after thoracic herpes zoster. The herpes zoster induced cerebral vasculitis was hypothesized as no other etiology could be identified after detailed assessment of the cerebral infarction including brain MRI and cerebrospinal fluid study, and as the clinical course responded to antiviral therapy.

Establishment and characterization of B-like lymphoblastoid cell lines by long-term culture of primary explants from human myasthenic thymus.

Using a simple method of long-term culture, it was possible to obtain B-like lymphoblastoid cell lines (LyCLs) from myasthenic thymuses. Successful cultures were carried out from 14 out of 15 hyperplastic thymuses and in 1 out of 3 myasthenic thymoma, whereas none of the 8 control thymuses, nor the 2 Myasthenia gravis-associated normally involuted thymuses, nor the Myasthenia gravis-associated lymphoma gave rise to LyCL. All the LyCLs secreted immunoglobulins (Ig), either IgG or IgM. None of these Ig reacted with acetylcholine receptor or with other antigens known to be often involved in autoimmune diseases. EBV antigens were found in all the LyCLs as well as in the corresponding donors at the time of thymectomy. HLA characterization of some LyCLs and the corresponding donors showed that class II MHC antigens were expressed normally or with mild differences. However, 86% of the LyCL tested did not express class I MHC antigens.

[Cervical myelopathy disclosing dissection of the extracranial vertebral artery]. / Myélopathie cervicale symptomatique d'une dissection de l'artère vertébrale extracrânienne.

A case of medullary ischaemic accident in C5 symptomatic of extracranial vertebral artery dissection is reported. The facilitating factors of vertebral artery dissection are discussed.

Specific effect of corticoids on acetylcholine receptor expression in rat skeletal muscle cell cultures.

The potential effect of different classes of steroids on the expression of acetylcholine receptors (AChR) was studied in different primary cultures of newborn-rat skeletal muscle cells. Comparison among three techniques for preparing newborn skeletal muscle cells showed that these systems were equivalent to study AChR expression. Only corticoids stimulated myogenesis as a twofold increase in AChR expression indicated. Among the corticoids, the glucocorticoids were the more potent, whereas the mineralocorticoid aldosterone had less marked effect. The sex hormones progesterone and testosterone partially blocked these effects, without inducing any significant effect when given alone. The steroids tested differed in efficacy in correlation with their different chemical structures. Among the glucocorticoids a clear structure-activity relationship could be established. These results emphasize the specificity of corticoid action on muscle cells and suggest an explanation for the effects induced by glucocorticoids used in treating human muscular or neuromuscular diseases.

[Arthrogryposis and maternal myasthenia gravis. Risk of recurrence]. / Arthrogrypose et myasthénie maternelle. Risque de récurrence.

A 26-year old myasthenic woman whose disease had been in remission for more than 4 years gave birth, at the end of 2 induced pregnancies, to 2 stillborn infants with arthrogryposis. The presence of inherited antibodies directed against acetylcholine receptors most probably does not explain the diffuse retractions. This case illustrates the risk of recurrent foetal arthrogryposis after a first abnormal pregnancy in women with myasthenia gravis.

Stimulating effects of prednisolone on acetylcholine receptor expression and myogenesis in primary culture of newborn rat muscle cells.

Prednisolone at concentrations of 10(-5) to 10(-8) mol/l, added to 3-day (day D + 2) tissue cultures of newborn rat myogenic cells at the time myoblasts are beginning to fuse, increases the level of myotube acetylcholine receptor expression at the 8th day (day D + 7) of culture. This effect is associated with increases in the number and size of the formed myotubes, not with a changed affinity of the receptor for its ligand, and is very probably mediated by one or more extracellular proteins the synthesis of which is induced early by the presence of prednisolone.