Search for Lepton Number and Flavor Violation in K

Searches for the lepton number violating K^{+}→π^{-}µ^{+}e^{+} decay and the lepton flavor violating K^{+}→π^{+}µ^{-}e^{+} and π^{0}→µ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K^{+}→π^{-}µ^{+}e^{+})<4.2×10^{-11}, B(K^{+}→π^{+}µ^{-}e^{+})<6.6×10^{-11} and B(π^{0}→µ^{-}e^{+})<3.2×10^{-10}. These results improve by 1 order of magnitude over previous results for these decay modes.

Plasma perfusion in myasthenia gravis.

Seven patients with myasthenia gravis (MG) unresponsive to thymectomy and steroid treatment (Osserman group III) underwent plasma perfusion (PP). All patients showed palpebral ptosis, diplopia, dysphonia, dysphagia, and muscle weakness; five of them had impaired ventilatory function. Separated plasma was perfused onto a column to adsorb anti-AChR-Ab. Each patient received a treatment cycle of six PP sessions. Clinical conditions were assessed before and after the treatment, with evaluation of muscular strength, ventilatory function, and electromyographic testing (RSS). Immunologic markers were tested before and after each PP. Clinical improvement in bulbar symptoms and respiratory function was noted in all patients after one to three PP. Limb muscle strength began to improve later. Serum concentration decreased (mean % +/- SD) after each PP:anti-AChR-Ab 36.47 +/- 17.43; IgA 20.44 +/- 11.26; IgG 21.24 +/- 32.56; IgM 23.22 +/- 11.40; C3 36.78 +/- 10.15; C4 42.69 +/- 14.82. In five of seven patients the improvement continues (follow-up 1 to 10 months). In one patient it lasted only 1 month, and in another a relapse occurred after 10 months of benefit, but was successfully reversed by retreatment.

Reversible bilateral internuclear ophthalmoplegia due to head trauma: a case report.

This case report concerns a patient who developed reversible bilateral internuclear ophthalmoplegia as an immediate consequence of head trauma. To our knowledge, only one case of internuclear ophthalmoplegia related to head trauma has been previously reported in the literature. The mechanism by which trauma can produce a relatively isolated brain stem lesion to the medial longitudinal fasciculus is unclear. Some experimental data on the mechanisms of cerebral concussion would indicate that the biomechanical forces due to impact acceleration of the head exert their predominant effect on the posterior portion of the brain stem. This might account for critical vulnerability of the structures situated in this portion, including the medial longitudinal fasciculus.