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Excessive daytime sleepiness (EDS) has not been investigated using objective tests in myasthenia gravis (MG). We investigated whether objective measurements of somnolence better detected abnormalities compared with sleepiness questionnaires in MG, and determine if MG patients have EDS. Eight patients with mild-to-moderate MG were recruited. Patients completed maintenance of wakefulness, overnight polysomnography, multiple sleep latency tests, Epworth Sleepiness Scale, and fatigue questionnaires. Seven patients demonstrated EDS on objective testing, while Epworth scores were abnormal in two, and the measures showed poor correlation. Our findings highlight that the ESS may be inadequate to diagnose EDS and lead to under-reporting of daytime somnolence in patients with MG.

Objective: To evaluate whether patients with inclusion body myositis (IBM) can have tubuloreticular inclusions present in muscle endothelial cells., Material and Methods: Light microscopy with histochemical staining and electron microscopy of a right quadriceps muscle biopsy were used to identify the pathological features in an 83-year-old patient with a clinical diagnosis of IBM., Results: Light microscopy showed rimmed vacuoles. Immunostaining for HLA-1 revealed widespread membrane labeling and for TDP-43 multiple areas of subsarcolemmal and sarcoplasmic staining. Electron microscopy revealed tubuloreticular inclusions in the cytoplasm of endothelial cells. Electron microscopy also showed the presence of myeloid bodies and aggregates of tubolo filaments in the nucleus and cytoplasm of myocytes which confirmed the diagnosis of inclusion body myositis., Conclusion: Tubuloreticular inclusions may be found in the muscle endothelial cells of patients with a clinical and pathological diagnosis of IBM.

Pulmonary epithelial Na+ channels (ENaC), composed of three distinct subunits (alpha, beta, and gamma), play a critical role in the regulation of fluid reabsorption from airspaces of late-gestation fetal lung. We studied the expression of ENaC subunit genes in cultured human fetal lung. All three mRNAs were expressed at low levels in second trimester lung (13-32% of adult values at 24 wk gestation). There was a spontaneous increase of approximately threefold over preculture values of all three subunits within 24 h of explant culture in serum-free Waymouth's medium. Dexamethasone (Dex) induced all three mRNAs by two- to threefold. Maximal induction was noted by 8 h with 30-100 nM Dex and half-maximal stimulation with 3-10 nM Dex. Cycloheximide decreased basal expression of all three subunits by 8 h but did not alter the response to Dex. Actinomycin D and 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), inhibitors of RNA polymerase II, decreased the basal and the Dex-induced expression of all three subunits with a more marked effect on human hENaC-gamma than on hENaC-alpha or hENaC-beta. Under conditions where transcription was blocked by actinomycin D or DRB, Dex did not alter the stability of the three mRNAs. Triiodothyronine (T3) at low (2 nM) or high (100 nM) concentrations had no effect on the expression of the three subunits in the presence or absence of low (10 nM) or high (100 nM) concentrations of Dex for 8 or 24 h. Similarly, 8-bromoadenosine 3',5'-cyclic monophosphate (2 microM) had no effect on basal or Dex-induced increase in the three subunits. We conclude that the three Na+ channel subunit genes are expressed in second trimester human fetal lung and are coordinately upregulated by glucocorticoid hormones but not by T3 or adenosine 3',5'-cyclic monophosphate. Glucocorticoid induction is receptor mediated, is primarily transcriptional, and does not require the induction of an intermediate protein for transcriptional enhancement. We speculate that induction of lung ENaC may contribute to the beneficial effects of antenatal glucocorticoids in premature babies.