We investigated hematopoietic capabilities of murine skeletal muscle using methylcellulose culture and transplantation into lethally irradiated mice. Muscle mononuclear cells (MNC) contained colony-forming cells and long-term engrafting cells. Studies using chimeric mice indicated a bone marrow origin of the hematopoietic cells in the muscle. We then separated muscle MNC by FACS sorting into Ly-5-positive cells and Ly-5-negative cells and analyzed their hematopoietic capability in vitro and in vivo. The hematopoietic progenitors and stem cells were present only in the Ly-5-positive fraction.

Animals↗

PubMedDate not supplied

Hematologic response in patients with aplastic anemia after long-term administration of recombinant human granulocyte colony-stimulating factor and erythropoietin.

Twenty patients with aplastic anemia underwent long-term administration (10 weeks) of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses from 50 to 800 micrograms/m2 per day by intravenous infusion or 50 to 100 micrograms/m2 per day by subcutaneous injection and re-combinant human erythropoietin (rhEPO) in doses ranging from 2000 to 8000 IU/m2 per day by intravenous injection three times a week for at least 4 weeks. The goal was to evaluate whether therapy ameliorated pancytopenia in these patients as well as to determine its safety. All assessable patients showed a substantial increase in absolute neutrophil count, with a recovery of myeloid components (granulocyte series) in the bone marrow, after 2 to 10 weeks of treatment. An increase > 1.5 g/dL in hemoglobin (Hb) concentration was observed in 2 patients (10%). A decrease > 50% in red cell transfusion requirement was observed in 2 patients (10%). Seven patients showed recovery of neutropenia, anemia, and platelet count. In addition, there was no serious infection before or during therapy, and side effects were mild. Of the 20 patients, 3 showed a dramatic improvement in severe anemia after 10 weeks of treatment accompanying a recovery of erythroid components in the bone marrow. They no longer require red cell transfusions and have had normal Hb concentrations and normal ferrokinetics. These results indicate that long-term administration of rhG-CSF and rhEPO may benefit some patients with aplastic anemia. Further studies will be necessary to elucidate the mechanism by which rhGCSF and rhEPO stimulate hematopoiesis and improve hematologic abnormalities in these patients.

Adolescent↗

PubMedDate not supplied

[Clinical characteristics of postinfarction left ventricular aneurysm with extensive calcification].

The authors experienced 4 cases of calcified postinfarction aneurysm of the left ventricle. They were all male, aged 55 to 71 (mean 64). Risk factor for coronary artery disease was only smoking in 2 patients, but there was none in the others. They had had acute anteroseptal or extensive anterior infarction at age 41-57 years (mean 49.3), and associated major cardiac events 10-22 years (mean 14.5) after acute myocardial infarction. Ventricular tachycardia, congestive heart failure and systemic thromboembolism were seen in 4, 2 and 1 patients respectively. However, none developed angina pectoris. In the 2 patients in whom signal-averaged electrocardiogram was performed, late potential was detected, so it was suspected that ventricular tachycardia could be due to reentry. Left ventricular end-diastolic pressure was elevated in all patients except one and ranged from 11 to 22 mmHg. Left ventricle was dilated in all cases and the end-diastolic volume index ranged from 143 to 503 ml/m2. The left ventricular ejection fraction ranged from 11 to 24%. However, in 2 of the 4 patients, the cardiac index was within normal limits, and evidence of congestive heart failure was absent. In 2 other patients with associated congestive heart failure, cardiac indices were 2.32, 1.56 l/min/m2 respectively. Coronary arteriogram showed a total occlusion in the left anterior descending (LAD) artery in all cases, and only the LAD artery was affected in 2 patients. In the remaining 2 patients, the right coronary arteries also were significantly stenotic or totally occluded, i.e., they had 2-vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

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