A randomised double-blind, cross-over trial of 4-aminopyridine for downbeat nystagmus--effects on slowphase eye velocity, postural stability, locomotion and symptoms

Objective The effects of 4-aminopyridine (4-AP) on downbeat nystagmus (DBN) were analysed in terms of slow-phase velocity (SPV), stance, locomotion, visual acuity (VA), patient satisfaction and side effects using standardised questionnaires. Methods Twenty-seven patients with DBN received 5 mg 4-AP four times a day or placebo for 3 days and 10 mg 4-AP four times a day or placebo for 4 days. Recordings were done before the first, 60 min after the first and 60 min after the last drug administration. Results SPV decreased from 2.42 deg/s at baseline to 1.38 deg/s with 5 mg 4-AP and to 2.03 deg/s with 10 mg 4-AP (p<0.05; post hoc: 5 mg 4-AP: p=0.04). The rate of responders was 57%. Increasing age correlated with a 4-AP-related decrease in SPV (p<0.05). Patients improved in the ‘get-up-and-go test’ with 4-AP (p<0.001; post hoc: 5 mg: p=0.025; 10 mg: p<0.001). Tandem-walk time (both p<0.01) and tandem-walk error (4-AP: p=0.054; placebo: p=0.059) improved under 4-AP and placebo. Posturography showed that some patients improved with the 5 mg 4-AP dose, particularly older patients. Near VA increased from 0.59 at baseline to 0.66 with 5 mg 4-AP (p<0.05). Patients with idiopathic DBN had the greatest benefit from 4-AP. There were no differences between 4-AP and placebo regarding patient satisfaction and side effects. Conclusions 4-AP reduced SPV of DBN, improved near VA and some locomotor parameters. 4-AP is a useful medication for DBN syndrome, older patients in particular benefit from the effects of 5 mg 4-AP on nystagmus and postural stability.

Dalfampridine in patients with downbeat nystagmus—an observational study

We investigated the effects of dalfampridine, the sustained-release form of 4-aminopyridine, on slow phase velocity (SPV) and visual acuity (VA) in patients with downbeat nystagmus (DBN) and the side effects of the drug. In this proof-of-principle observational study, ten patients received dalfampridine 10 mg bid for 2 weeks. Recordings were conducted at baseline, 180 min after first administration, after 2 weeks of treatment and after 4 weeks of wash-out. Mean SPV decreased from a baseline of 2.12 deg/s ± 1.72 (mean ± SD) to 0.51 deg/s ± 1.00 180 min after first administration of dalfampridine 10 mg and to 0.89 deg/s ± 0.75 after 2 weeks of treatment with dalfampridine (p < 0.05; post hoc both: p < 0.05). After a wash-out period of 1 week, mean SPV increased to 2.30 deg/s ± 1.6 (p < 0.05; post hoc both: p < 0.05). The VA significantly improved during treatment with dalfampridine. Also, 50 % of patients did not report any side effects. The most common reported side effects were abdominal discomfort and dizziness. Dalfampridine is an effective treatment for DBN in terms of SPV. It was well-tolerated in all patients.

Hauptlehren der mosaischen Religion für den Unterricht der Jugend

verf. unter Aufs. u. Leitung d. Abraham Bing u. anerkannt von angesehenen Rabbinern

Vom jüdischen Wesen : Vortr., geh. im Isr. Humanitätsverein "Bohemia" B'nai B'rith in Prag am 6. Nov. 1915

von Emil Spiegel

Memo has a novel role in S1P signaling and crucial for vascular development

Memo is a conserved protein that was identified as an essential mediator of tumor cell motility induced by receptor tyrosine kinase activation. Here we show that Memo null mouse embryonic fibroblasts (MEFs) are impaired in PDGF-induced migration and this is due to a defect in sphingosine-1-phosphate (S1P) signaling. S1P is a bioactive phospholipid produced in response to multiple stimuli, which regulates many cellular processes. S1P is secreted to the extracellular milieu where it exerts its function by binding a family of G-protein coupled receptors (S1PRs), causing their activation in an autocrine or paracrine manner. The process, termed cell-autonomous S1PR signaling, plays a role in survival and migration. Indeed, PDGF uses cell-autonomous S1PR signaling to promote cell migration; we show here that this S1P pathway requires Memo. Using vascular endothelial cells (HUVECs) with Memo knock-down we show that their survival in conditions of serum-starvation is impaired. Furthermore, Memo loss in HUVECs causes a reduction of junctional VE-cadherin and an increase in sprout formation. Each of these phenotypes is rescued by S1P or S1P agonist addition, showing that Memo also plays an important role in cell-autonomous S1PR signaling in endothelial cells. We also produced conventional and endothelial cell-specific conditional Memo knock-out mouse strains and show that Memo is essential for embryonic development. Starting at E13.5 embryos of both strains display bleeding and other vascular problems, some of the phenotypes that have been described in mouse strains lacking S1PRs. The essential role of Memo in embryonic vascular development may be due in part to alterations in S1P signaling. Taken together our results show that Memo has a novel role in the S1P pathway and that Memo is needed to promote cell-autonomous S1PR activation.

Hyperammonemic encephalopathy in multiple myeloma

HISTORY AND CLINICAL FINDINGS A 54-year old man had suffered from advanced multiple myeloma for two years. After initially good response the myeloma was refractrory to treatment with dexamethasone, cyclophosphamide, bortezomibe, zoledronate and additionally doxorubicine. The patient then complained of dyspnea without clinical signs of cardiopulmonary disease. INVESTIGATIONS Arterial blood gas analysis showed hyperventilation with respiratory alkalosis and normal alveolo-arterial gradient as the reason for the dyspnea. With a normal MRI of the brain and lumbal puncture, a neurological disease could be excluded. Serum calcium, creatinine and serum viscosity were normal. Eventually, serum ammonia levels were found to be substantially elevated (144 µmol/l) and hyperammonemic encephalopathy was diagnosed. TREATMENT AND COURSE Therapy with bortezomib and high dose dexamethason was repeated, and the patient also received bendamustin. Despite this treatment, he lost consciousness and died after two weeks because of aspiration pneumonia. CONCLUSION The existence of respiratory alkalosis and multiple myeloma should prompt a search for hyperammonemia.