No abstract

Background: Several studies on clinical practice for Duchenne muscular dystrophy (DMD) have been conducted in Western countries. However, there have been only a few similar studies in Asia and Oceania. Here, we investigate the steroid therapyrelated clinical practice for DMD among the local experts. In 2015, we conducted a DMD expert survey in Asia and Oceania to acquire information regarding patients with DMD and to assess current clinical practice with the cooperation of Asian and Oceanian Myology Centre, a neuromuscular disease research network.Results: We obtained survey responses from 87 out of 148 clinicians (62%) from 13 countries and regions. In China, 1385 DMD patients were followed-up by 5 respondent neurologists, and 84% were between 0 and 9 years of age (15% were 10-19 years, 1% > 19 years). While in Japan, 1032 patients were followed-up by 20 clinicians, and the age distribution was similar between the 3 groups (27% were 0-9 years, 35% were 10-19 years, 38% were >19 years). Most respondent clinicians (91%) were aware of DMD standard of care recommendations. Daily prednisolone/prednisone administration was used most frequently at initiation (N = 45, 64%). Inconsistent opinion on steroid therapy after loss of ambulation and medication for bone protection was observed.Conclusions: Rare disease research infrastructures have been underdeveloped in many of Asian and Oceanian countries. In this situation, our results show the snapshots of current medical situation and clinical practice in DMD. For further epidemiological studies, expansion of DMD registries is necessary.

ATPase activity of erythrocyte membranes was determined in 25 cases of Down's syndrome verified by cytological and psychological examinations. The age range of the patients was 8-25 years; 16 males and 9 females. Thirty healthy male volunteers were selected as the control group. There was a marked reduction of total ATPase, Na', K+-ATPase, Mg' +-ATPase activities and rate of ouabain inhibition in the patients with Down's syndrome. The authors suggest that there might exist transport defects in the red cell membranes in such patients.

Dimethyl-4, 4'-dimethoxy-5, 6, 5'-6'-dimethylenedioxybiphenyl-2, 2'-dicarboxylate (DDB) is a synthetic analogue of Schizandrin C, an active compound isolated from a Chinese herb, Fructus schizandrae. We administered this compound to dystrophic hamsters in vivo for 31 days. This led to a 61% reduction of the calcium content, an 86% reduction of the area of calcium deposits, and a 52% reduction of the area of necrosis of cardiac muscle. However, skeletal muscle necrosis was not significantly improved. No clear change in plasma creatine kinase (CK) was observed. In an in vitro incubation study, the rate of CK release and tetanus tension of the extensor digitorum longus muscle of dystrophic hamsters were not substantially changed by the addition of DDB. This study suggests that DDB has some effect on cardiac necrosis, and that it might be useful for treatment of the cardiac involvement in patients with muscular dystrophy or other conditions with accompaning Ca accumulation.

The rate of release of creatine kinase (CK) from the extensor digitorum longus (EDL) muscle of hamsters was estimated in vitro. In oxygenated Krebs-Ringer solution, the EDL muscle was electrically stimulated to produce continuous twitch response. The rate of CK release gradually increased to the level 6 times higher than the initial value after 3 h of incubation. When dimethylformamide was added to the medium, the rate of CK release was further accelerated. Dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylenedioxy-biphenyl-2,2'-dicarboxylate (DDB), an intermediate product in the process of synthesizing Schizandrin C, suppressed the rate of CK release accelerated by dimethylformamide. The mechanism and significance of the present observation were discussed.