Muscle-tendon interaction and EMG profiles of world class endurance runners during hopping.

The present study examined the muscle-tendon interaction of ten international level Kenyan runners. Ultrasonography and kinematics were applied together with EMG recordings of lower limb muscles during repetitive hopping performed at maximal level. The ten Kenyans had longer gastro Achilles tendon at rest (p < 0.01) as compared with ten control subjects matched in height. Conversely, the stretching and shortening amplitudes of the tendinous tissues of the medial gastrocnemius (MG) muscle were significantly smaller in the Kenyans than in controls during the contact phase of hopping. This applied also to the fascicle length changes, which were smaller and more homogeneous among Kenyans. These limited musculo-tendinous changes resulted in higher maximal hopping height and in larger power despite their reduced body weight. The associated finding of a greater shortening to stretching ratio of the MG tendinous tissues during contact could imply that the Kenyan MG muscle-tendon unit is optimized to favor efficient storage and recoil of elastic energy, while operating at optimal muscle fascicle working range (plateau region).

[Trial of combined cytosine arabinoside with granulocyte colony-stimulating factor therapy or refractory acute myeloid leukemia].

Thirteen cases, including 10 relapse cases, of refractory acute myeloid leukemia (AML) (aged 17-70, median 46) by cytosine arabinoside (Ara-C) combined with granulocyte colony-stimulating factor (G-CSF) simultaneously to enhance the sensitivity to Ara-C. Low dose Ara-C (10-40 mg/day) combined with G-CSF was administered in most of them. Complete (CR) and partial remission (PR) were achieved in 5 and 4 patients, respectively, and response (CR + PR) rate was 69.2%. We obtained 5 CRs and 3 PRs in 10 patients with relapsed AML. However, CR and PR duration was short in all cases. None of the 3 patients with MO, AML transformed from myelodysplastic syndrome (MDS), and de novo AML with trilineage myelodysplasia (TMDS) had any response. There was no leukemic colony formation in the culture medium containing G-CSF in the nonresponding patients. The combination therapy caused severe myelosuppression, and most patients experienced prolonged neutropenia, and suffered from infections. In some patients enhanced chemosensitivity of leukemic cells induced by G-CSF was indicated but, the effect of this approach must be determined by large scale controlled studies.