The STRO-1+ fraction of adult human bone marrow contains the osteogenic precursors

The monoclonal antibody STRO-1 identifies clonogenic bone marrow stromal cell progenitors (fibroblast colony-forming units [CFU-F]) in adult human bone marrow. These STRO-1+ CFU-F have previously been shown to give rise to cells with the phenotype of fibroblasts, adipocytes, and smooth muscle cells. In this study, the osteogenic potential of CFU- F derived from the STRO-1+ fraction of adult human bone marrow was determined. CFU-F were isolated from normal bone marrow aspirates by fluorescence activated cell sorting, based on their expression of the STRO-1 antigen. Osteogenic differentiation was assessed by the induction of alkaline phosphatase expression, by the formation of a mineralized matrix (hydroxyapatite), and by the production of the bone- specific protein osteocalcin. STRO-1+ cells were cultured in the presence of dexamethasone (DEX; 10(-8) mol/L), ascorbic acid 2- phosphate (ASC-2P; 100 mumol/L), and inorganic phosphate (PO4i; 2.9 mmol/L). After 2 weeks of culture, greater than 90% of the cells in each CFU-F colony stained positive for alkaline phosphatase using a monoclonal antibody specific for bone and liver alkaline phosphatase. Alkaline phosphatase activity was confirmed by histochemistry. A mineralized matrix developed in the CFU-F cultures, after 4 weeks of culture in the presence of DEX, ASC-2P, and PO4i. Mineralization was confirmed by both light and electron microscopy. The mineral was identified as hydroxyapatite by electron dispersive x-ray microanalysis and by x-ray diffraction analysis. In replicate cultures, osteocalcin release was shown after exposure of the cells to 1,25-dihydroxyvitamin D3 (10(-7) mol/L) both by radioimmunoassay and Northern blot analysis. This work provides direct evidence that adult human bone marrow-derived CFU-F are capable of differentiating into functional osteoblasts and that osteoprogenitors are present in the STRO-1+ population.     

Performance characteristics of contemporary hemodialysis and venovenous hemofiltration in acute renal failure.

Modality choice in the treatment of acute renal failure (ARF) should be based on the match between individual patient needs and the characteristics of available therapies. Considerations include access, risk of bleeding, hemodynamic instability, and ability to remove excess volume. We prospectively studied 547 consecutive treatments for ARF in 110 patients to determine the performance features of modalities based on single-vessel venous access: hemodialysis (HD) and venovenous hemofiltration (VVH). All treatments were performed in an 18-month period at a single center. Patients' ages ranged from 16 to 84 years; 26 were trauma cases; 69 patients expired during their hospitalization. Mean number of treatments per patient was 4.97. Mean treatment duration was 197 min. Heparin was used unless active bleeding was present or felt to be a high risk; mean dose required was 2628 units. Pressor therapy was in progress prior to initiation of 260 (48%) of treatments. Results: pretreatment and posttreatment mean systolic and diastolic BP were unchanged for the group. Forty-three (7.9%) treatments were terminated prematurely; of these only 27 (4.9%) were due to hypotension. No patient developed clinically apparent bleeding during any treatment. Contemporary equipment and techniques allow for provision of high-quality intermittent therapy for ARF, with excellent hemodynamic stability. Shorter, single-vein access treatments are advantageous for severely ill or injured patients who often undergo invasive monitoring and multiple studies or procedures.     

Scintigraphy with In-111-labeled monoclonal antitumor antibodies: kinetics, biodistribution, and tumor detection

The purpose of this study was to evaluate and compare the kinetics, biodistribution, and tumor-depicting properties of three intact indium-111-labeled murine monoclonal antibodies (MoAb) and to determine if use of In-111-labeled F(ab')2 fragments of one of them had advantages over its intact counterpart for immunoscintigraphy. Ten patients with prostate cancer were studied with an anti-prostatic acid phosphatase MoAb (PAY-276), with a resultant tumor detection rate of 15%. Twenty-eight patients with melanoma were studied with ZME-018, a MoAb that targets the KD-240 melanoma antigen. Forty-three percent of the known lesions were detected. Forty patients with carcinoembryonic antigen (CEA)-producing tumors were studied, 24 with intact ZCE-025, and anti-CEA MoAb, and 16 with its F(ab')2 fragment. With use of intact ZCE-025, 34% of known lesions were detected versus 83% with its F(ab')2 fragment. The distribution of each MoAb appears unique unto itself with regard to kinetics, normal tissue distribution, and response to MoAb mass.     

Distal esophageal ballooning following Heller myotomy

Eccentric ballooning of the distal esophagus was observed radiographically in 11 of 23 patients (48%) who underwent Heller myotomy for achalasia. While, to the authors' knowledge, ballooning at the site of myotomy incision has not been described previously in the radiologic literature, it should be recognized as a normal and frequent postoperative finding. Radiologists should be aware of this finding so that it is not mistaken for postoperative abnormalities following esophagomyotomy or an epiphrenic diverticulum.     

Complex fractures of the clivus: diagnosis with CT and clinical outcome in 11 patients

During a 20-month period, fractures of the clivus occurring after craniocerebral trauma were diagnosed with computed tomography (CT) in 11 patients. Five patients had longitudinally oriented fractures; these were fatal in four patients due to either vertebral-basilar artery occlusion, brain stem trauma, or both. Six other patients had transversely oriented fractures that extended through the carotid canal and petrous temporal bone. While less frequently contributing directly to mortality, transverse fractures were also associated with cerebrospinal fluid leaks (two patients) and a cavernous sinus-carotid fistula (one patient). They were not as frequently associated with Horner syndrome or cranial nerve deficits as suggested in the current literature. This retrospective evaluation reveals two distinct injury patterns that demonstrate a difference in related morbidity and mortality.