SummaryA novel CC chemokine, HCC-1, was isolated from the hemoflhrate of patients with chronic renal failure. HCC-1 has a relative molecular mass of 8,673 and consists of 74 amino acids including four cysteines linked to disulfide bonds. HCC-1 cDNA was cloned from human bone marrow and shown to code for the mature protein plus a putative 19-residue leader sequence. Mature HCC-1 has sequence identity of 46% with macrophage inflammatory protein (MIP)-lc~ and MIP-][3, and 29-37% with the other human CC chemokines. Unlike MIP-I~x and the other CC chemokines, HCC-1 is expressed constitutively in several normal tissues (spleen, liver, skeletal and heart muscle, gut, and bone marrow), and is present at high concentrations (1-80 nM) in plasma. HCC-1 has weak activities on human monocytes and acts via receptors that also recognize MIP-lot. It induced intracellular Ca 2+ changes and enzyme release, but no chemotaxis, at concentrations of 100-1,000 nM, and was inactive on T lymphocytes, neutrophils, and eosinophil leukocytes. In addition, HCC-1 enhanced the proliferation of CD34 + myeloid progenitor ceils. It was as effective as MIP-lci, but about 100-fold less potent.H emofittration is a routine treatment for patients with chronic renal failure to remove substances that are normally cleared by the kidney. A filter membrane with a molecular mass cut-off of 20 kD is used, which virtually excludes plasma proteins (1, 2). Being available in large quantities, the hemoflltrate is an excellent source of biologically active human peptides that circulate in the blood. During the last 5 yr, a peptide bank was established from >200,000 liters of hemofiltrate, and several peptide hormones were purified (1). During the course of a systematic search for novel bioactive factors (3), we have identified a new member of the recently recognized family of chemotactic cytokines (chemokines). HCC-1 is structurally related to macrophage inflammatory protein (MIP)-loc Unlike MIP-lo~ and the other CC chemokines, HCC-1 is highly expressed in normal tissues and is present at high concentrations in human plasma. Materials and MethodsPurification. Peptides were extracted from batches of 2,000 liters of hemofiltrate by precipitation with 660 g/liter ammonium sulfate as described previously (2). The precipitate ("250 g) was dissolved in water (125 mg/ml). The peptides were precipitated again by addition of 4.5 vol of2-propanol, redissolved in 10 mM phosphate buffer, pH 3.0, and fractionated by cation exchange chromatography (Fractogel TSK SP-650 M, 6 • 20 cm; Merck, Darmstadt, Germany) with a 0-1.0-M NaC1 gradient in the same buffer. Fractions eluting at high salt concentrations were collected and further purified by preparative reverse-phase (lkP) HPLC (Parcosil RP C4, 300 ft,, 20-45 b~m, 3 • 12.5 cm; Biotek, Oestringen, Germany) using a gradient generated from 0.01 M HCI and 50% 2-propanol/30% methanol in 0.01 M HCI. Analytical R.P HPLC (Parcosil RP C4, 300 A, 5 btm, 1 • 12.5 cm, Biotek, Oestringen, Germany) was then performed using an acetonitrile/T...

The product of the protooncogene c-kit is the receptor for the hematopoietic cytokine stem cell factor (SCF). C-kit is expressed on leukemic cells of the erythroid, myeloid, and mast-cell lineage and SCF has a proliferative effect on some of these cells. The role of SCF and c-kit in lymphoid malignancies is much less clear. Here we review the role of c-kit in normal lymphopoiesis and summarize its role in lymphoid malignancies. C-kit is expressed in normal lymphopoiesis and its ligand SCF synergizes with IL-7 to enhance the proliferation of B- and T-cell progenitors. In malignant lymphopoiesis, c-kit can also be expressed in B and T-lymphoblastic cells from children with non Hodgkin's lymphoma (NHL) or acute lymphoblastic leukemia (ALL) when analyzed by the highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR). While c-kit receptors were detected by flow cytometric (FCM) analysis on about 40% of fresh T-lymphoblastic biopsy tumor cell preparations or T-lymphoblastic cell lines, no receptors were detected on B-lymphoblastic fresh cells or cell lines from children with B-ALL or Burkitt's lymphoma (BL). Almost all of the lymphoblastic cells expressing c-kit protein responded to recombinant human (rh)SCF with a downregulation of c-kit receptors. A proliferative response was detected only in a minority of these cells. B-ALL or BL cell lines showed no response to rhSCF. Upregulation of c-kit in T-lymphoblastic cells could be demonstrated by the addition of IL-1 beta, TNF-alpha, TGF-beta or A23187, and downregulation by rhSCF or phorbol myristate acetate (PMA). Despite upregulation of c-kit mRNA, protein remained undetectable on B-ALL or BL cells in the presence of A23187. The metabolic state of the cells seemed to influence c-kit expression, since c-kit was upregulated in T-lymphoblastic cells by the addition of new medium. C-kit appears to play a role in the growth of some malignant T-lymphoblastic but not B-lymphoblastic cells.

The cytokine stem cell factor (SCF) synergizes with IL-7 to enhance the proliferation of thymocytes. We therefore investigated the role of the SCF receptor, the protooncogene c-kit, in the pathogenesis of pediatric T-lineage malignancies.

ObjectivesTransfusion of allogeneic blood is still common in orthopedic surgery. This analysis evaluates from the perspective of a German hospital the potential cost savings of Epoetin alfa (EPO) compared to predonated autologous blood transfusions or to a nobloodconservationstrategy (allogeneic blood transfusion strategy)during elective hip and knee replacement surgery.MethodsIndividual patients (N = 50,000) were simulated based on data from controlled trials, the German DRG institute (InEK) and various publications and entered into a stochastic model (Monte-Carlo) of three treatment arms: EPO, preoperative autologous donation and nobloodconservationstrategy. All three strategies lead to a different risk for an allogeneic blood transfusion. The model focused on the costs and events of the three different procedures. The costs were obtained from clinical trial databases, the German DRG system, patient records and medical publications: transfusion (allogeneic red blood cells: €320/unit and autologous red blood cells: €250/unit), pneumonia treatment (€5,000), and length of stay (€300/day). Probabilistic sensitivity analyses were performed to determine which factors had an influence on the model's clinical and cost outcomes.ResultsAt acquisition costs of €200/40,000 IU EPO is cost saving compared to autologous blood donation, and cost-effective compared to a nobloodconservationstrategy. The results were most sensitive to the cost of EPO, blood units and hospital days.ConclusionsEPO might become an attractive blood conservation strategy for anemic patients at reasonable costs due to the reduction in allogeneic blood transfusions, in the modeled incidence of transfusion-associated pneumonia andthe prolongedlength of stay.

The influence of temperature on the shear sensitivity of anchorage-dependent baby hamster kidney (BHK) cells was investigated. The temperature effect in general was compared for stressed and unstressed cells. Both the growth rate as well as the shear sensitivity are temperature-dependent. Decreasing the temperature lowered the growth rate and increased the ability of the BHK cells to withstand shear stress.