Lipopolysaccharide (LPS/endotoxin) is a potent immunologic stimulant. Many commercial-grade reagents used in research are not screened for LPS contamination. LPS induces a wide spectrum of proinflammatory responses in microglia, the immune cells of the brain. Recent studies have demonstrated that a broad range of endogenous factors including plasma-derived proteins and bioactive phospholipids can also activate microglia. However, few of these studies have reported either the LPS levels found in the preparations used or the effect of LPS inhibitors such as polymyxin B (PMX) on factor-induced responses. Here, we used the Limulus amoebocyte lysate assay to screen a broad range of commercial-and pharmaceutical-grade proteins, peptides, lipids, and inhibitors commonly used in microglia research for contamination with LPS. We then characterized the ability of PMX to alter a representative set of factor-induced microglial activation parameters including surface antigen expression, metabolic activity/proliferation, and NO/cytokine/chemokine release in both the N9 microglial cell line and primary microglia. Significant levels of LPS contamination were detected in a number of commercial-grade plasma/ serum-and nonplasma/serum-derived proteins, phospholipids, and synthetic peptide preparations, but not in pharmaceutical-grade recombinant proteins or pharmacological inhibitors. PMX had a significant inhibitory effect on the microglia-activating potential of a number of commercial-, but not pharmaceutical-grade, protein preparations. Novel PMX-resistant responses to α 2 -macroglobulin and albumin were incidentally observed. Our results indicate that LPS is a frequent and significant contaminant in commercial-grade preparations of previously reported microgliaactivating factors. Careful attention to LPS levels and appropriate controls are necessary for future studies in the neuroinflammation field.

Desmoid tumor, desmoplastic fibroma, periosteal desmoid tumor, osteofibrous dysplasia and fibrous dysplasia are benign mesenchymal lesions arising in soft tissue or bone. Desmoid tumors, also known as aggressive fibromatosis or fibromatosis of soft tissue, may occur in extraabdominal, abdominal, or intra-abdominal locations. Desmoplastic fibroma and periosteal desmoid tumor, identical histologically, differ only by location. Desmoplastic fibroma and periosteal desmoid tumor are considered to represent the bone counterparts of desmoid tumors of soft tissue. A tumor-like proliferation of fibroosseous tissue is characteristic of osteofibrous dysplasia and fibrous dysplasia. The former is distinguished histologically by osteoblastic rimming of the bone trabeculae. Cytogenetic and molecular cytogenetic analyses of desmoid tumors are few and are particularly sparse or are nonexistent for desmoplastic fibroma, periosteal desmoid tumor, osteofibrous dysplasia, and fibrous dysplasia. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] To determine the frequency of trisomy 8 and trisomy 20 in additional desmoid tumor cases and to examine their presence in related fibrous lesions of bone, both standard karyotypic analysis and molecular cytogenetic analysis were performed on 22 representative specimens. Materials and Methods Cytogenetic AnalysisTwenty-two specimens (to include three desmoplastic fibromas, two periosteal desmoid tumors, nine desmoid tumors, four osteofibrous dysplasias, and four fibrous dysplasias) from 19 different patients were examined by traditional cytogenetic and molecular cytogenetic methodologies. A 0.5-to 1.0-cm 3 sample of each specimen was received for cytogenetic analysis. Standard culture and harvesting procedures were used that have been described previously. 4 Briefly, the tissues were disaggregated mechanically and enzymatically and then cultured in RPMI 1640 medium supplemented with 20% fetal bovine serum and 1% penicillin/streptomycin-L-glutamine (Irvine Scientific, Santa Ana, CA) for 3 to 5 days. Two to four hours before harvest, cells were exposed to Colcemid (0.02 g/ml). After hypotonic treatment (0.074 mol/L KCl for 30 minutes for flasks and 0.8% sodium citrate for 25 minutes for coverslips), the preparations were fixed three times with methanol/glacial acetic acid (3:1). Metaphase cells were banded with Giemsa trypsin. The karyotypes were expressed according to the International System for Human Cytogenetic Nomenclature 1995. 18

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Patients undergoing hematopoietic stem cell transplantation (HSCT) are at high risk for hospital-related hyperglycemia due to chemotherapy, corticosteroids, and total parenteral nutrition (TPN). The prevalence of hyperglycemia and its association with complications or length of stay (LOS) is not well studied in this population.A retrospective review of 173 patients admitted for HSCT was conducted. Hospital-related hyperglycemia was consistent with American Diabetes Association criteria: Ն2 fasting blood glucoses Ն126 mg/dL or 1 blood glucose Ն200 mg/dL. End points were as follows: renal, cardiac, or infectious complications; graft versus host disease; LOS; and overall survival. Of the 160 patients without pre-existing diabetes, 71% were hyperglycemic. Fifty-four percent of hyperglycemic and 4% of nonhyperglycemic patients received TPN (P Ͻ0.0001). Among the 61 hyperglycemic patients given TPN, 41% developed hyperglycemia while receiving TPN. Hospital-related hyperglycemia was also associated with increased complications (56% vs. 39%, P ϭ 0.05). Median age was higher among hyperglycemic compared with nonhyperglycemic subjects. LOS was increased among subjects who developed complications, but was not associated with development of hyperglycemia after adjustment for confounding complication and treatment variables.TPN and increasing age are both risk factors for the development of hospital-related hyperglycemia in HSCT patients. Hyperglycemia is associated with increased risk of complications but was not associated with longer LOS.