Extremity bone tumors: evaluation by P-31 MR spectroscopy

High-resolution P-31 MR spectra were obtained in four patients with bone tumors of their distal extremities. In one case the tumor, a Ewing sarcoma of the tibia, was investigated during clinical remission after radiation therapy and chemotherapy. The other three cases - one low-grade chondrosarcoma of the tibial head, one malignant fibrous histiocytoma of the tibia, and one chondroblastoma of the medial femoral condyle - showed clinically active tumor growth, with corresponding increased metabolism as demonstrated by bone scintigraphy. The spectra of the three active tumors indicated a comparably high adenosine triphosphate content, similar to previously published spectra from animal tumors or human tumors implanted into animals. There were also high resonances of inorganic phosphate and low resonances of phosphocreatine; there were definite peaks in the phosphodiester and phosphomonoester regions, indicating the existence of these metabolites in the tumors. Slight but definite changes in the metabolite content were observed in one tumor after chemotherapy. The spectra of the unaffected leg did not show any well-resolved P-31 signals, which is typical for healthy bone. These are the first P-31 MR spectra of human bone tumors measured in patients to our knowledge.     

Suspected leaking abdominal aortic aneurysm: use of sonography in the emergency room

To determine the value of sonography in the emergent evaluation of suspected leaking abdominal aortic aneurysms, the authors examined 60 patients in the emergency department using sonography and a protocol involving advance radio notification from the ambulance; arrival of sonographic personnel and equipment in the triage room before patient arrival; and, during other triage activities, rapid sonographic evaluation of the aorta for aneurysm and of the paraaortic region for extraluminal blood. Sonographic findings were correlated with surgical results and clinical outcome. When performed under these circumstances, sonography was accurate in demonstrating presence or absence of aneurysm (98%), but its sensitivity for extraluminal blood was poor (4%). A combination of sonographic confirmation of aneurysm, abdominal pain, and unstable hemodynamic condition resulted in the correct decision to perform emergent surgery in 21 of 22 patients (95%). An abbreviated sonographic examination done in the emergency room can provide accurate, useful information about the presence of aneurysm; this procedure does not significantly delay triage of these patients.     

Cyclic hematopoiesis: effects of lithium on colony-forming cells and colony-stimulating activity in grey collie dogs

The cycling of blood cell counts in grey collie dogs with cyclic hematopoiesis can be eliminated by treatment with oral lithium carbonate. To explore the mechanism by which lithium alters this stem cell disorder, studies of bone marrow granulocyte-macrophage progenitor cells (CFU-C), neutrophil colony-forming cells (neutrophilic CFU-C), and colony-stimulating activity (CSA) were performed. In untreated dogs, the proportions of CFU-C were found to fluctuate cyclically, but the cyclic fluctuations in neutrophil colony-forming cells were even more marked, with numbers decreasing to undetectable levels during each period of neutrophilia. Dogs on lithium, however, did not cycle the numbers of total or neutrophilic CFU-C. Tritiated thymidine suicide rates were not altered by treatment with lithium. Serum CSA levels and bone marrow cell elaboration of CSA were not increased by lithium. These studies suggest that lithium corrects cyclic neutropenia by a direct effect on the differentiation and proliferation of CFU-C; normalization of the proportion of CFU-C that enter neutrophilopoiesis appears to be an important effect of the lithium therapy.     

Ex vivo expansion with stem cell factor and interleukin-11 augments both short-term recovery posttransplant and the ability to serially transplant marrow

The characterization of many cytokines involved in the control of hematopoiesis has led to intense investigation into their potential use in ex vivo culture to expand progenitor numbers. We have established the optimum ex vivo culture conditions that allow substantial amplification of transient engrafting murine stem cells and which, simultaneously, augment the ability to sustain serial bone marrow transplantation (BMT). Short-term incubation of unfractionated BM cells in liquid culture with stem cell factor (SCF) and interleukin-11 (IL- 11) produced a 50-fold amplification of clonogenic multipotential progenitors (CFU-A). Following such ex vivo expansion, substantially fewer cells were required to rescue lethally irradiated mice. When transplanted in cell doses above threshold for engraftment, BM cells expanded ex vivo resulted in significantly more rapid hematopoietic recovery. In a serial transplantation model, unmanipulated BM was only able to consistently sustain secondary BMT recipients, but BM expanded ex vivo has sustained quaternary BMT recipients that remain alive and well more than 140 days after 4th degree BMT. These results show augmentation of both short-term recovery posttransplant and the ability to serially transplant marrow by preincubation in culture with SCF and IL-11.