Citations

ABSTRACT The Sensititre MycoTB plate (TREK Diagnostic Systems, Cleveland, OH) uses a microtiter plate MIC format for susceptibility testing of Mycobacterium tuberculosis complex isolates against first- and second-line antituberculosis agents. Categorical agreement versus the agar proportion method for 122 M. tuberculosis complex isolates was 94% to 100%.

ABSTRACT Superantigens (SAg), the potent activators of the immune system, are important determinants of Staphylococcus aureus virulence and pathogenicity. Superior response to SAg in human leukocyte antigen (HLA)-DR3 transgenic mice rendered them more susceptible than C57BL/6 mice to pneumonia caused by SAg-producing strains of S. aureus . Linezolid, a bacterial protein synthesis inhibitor, was superior to vancomycin in inhibiting SAg production by S. aureus in vitro and conferred greater protection from pneumonia caused by SAg-producing staphylococci.

Abstract Chronic nasal and skin colonization with superantigen (SAg)-producing Staphylococcus aureus is well documented in humans. Given that trans-mucosal and trans-cutaneous absorption of SAgs can occur, we determined whether chronic exposure to small amounts of SAg per se could activate autoreactive CD4+ and CD8+ T cells and precipitate any autoimmune disease without further external autoantigenic stimulation. Because HLA class II molecules present SAg more efficiently than do mouse MHC class II molecules, HLA-DQ8 transgenic mice were implanted s.c. with mini-osmotic pumps capable of continuously delivering the SAg, staphylococcal enterotoxin B (total of 10 μg/mouse), or PBS over 4 wk. Chronic exposure to staphylococcal enterotoxin B resulted in a multisystem autoimmune inflammatory disease with features similar to systemic lupus erythematosus. The disease was characterized by mononuclear cell infiltration of lungs, liver, and kidneys, accompanied by the production of anti-nuclear Abs and deposition of immune complexes in the renal glomeruli. The inflammatory infiltrates in various organs predominantly consisted of CD4+ T cells bearing TCR Vβ8. The extent of immunopathology was markedly reduced in mice lacking CD4+ T cells and CD28, indicating that the disease is CD4+ T cell mediated and CD28 dependent. The absence of disease in STAT4-deficient, as well as IFN-γ–deficient, HLA-DQ8 mice suggested the pathogenic role of Th1-type cytokines, IL-12 and IFN-γ. In conclusion, our study suggests that chronic exposure to extremely small amounts of bacterial SAg could be an etiological factor for systemic lupus erythematosus.

Neural cells derived from induced pluripotent stem cells from patients with genetic forms of Parkinson’s disease provide insights into disease pathogenesis.

Abstract Pancreatic cancer is the most lethal type of cancer due to its high proliferation, metastasis and resistance to chemotherapy. In pancreatic cancer, pancreatic ductal adenocacinoma (PDAC) is the most common form. Current opinion is that PDAC originates from acinar or centroacinar cells though a process called “acinar-to-ductal metaplasia” (ADM). During ADM, acinar cells undergo a transformation to ductal PanIN (pancreatic intraepithelial neoplasia) cells, which is believed as the first step in PDAC formation. Transforming growth factor α (TGFα) is produced by pancreatic cancer cells and promotes tumor growth. In an ex vivo explant culture system, TGFα transforms murine pancreatic acinar cells into ductal cells. Here we describe a cell signaling pathway that TGFα utilizes to induce acinar-to-ductal transformation. We show that K-ras is downstream of TGFα and is sufficient to drive ADM. We further show the mechanisms that K-ras uses to induce cell structural rearrangement of acinar cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1123. doi:10.1158/1538-7445.AM2011-1123

Abstract Introduction: Androstenedione is a precursor for estrogen biosynthesis catalyzed by aromatase. Plasma androstenedione concentrations in postmenopausal women with early stage breast cancer display large interindividual variation (Ingle et al., Cancer Res. 70:3278–86, 2010). We performed a GWAS to identify single nucleotide polymorphisms (SNPs) associated with plasma levels of androstenedione in 776 postmenopausal women with resected early stage breast cancer. Methods: Plasma androstenedione concentrations were measured by GC-MS/MS. GWAS was performed using Illumina Human610-Quad BeadChips. The GWAS results were controlled for population stratification (PS) by Eigenstrat analyses. Plasma androstenedione concentrations were associated with genotype by using a quasi-likelihood model with adjustment for PS, BMI, age and other clinical variables associated with androstenedione concentrations (p<0.01). Imputation using HapMap2 data was performed within 200 kb on either side of regions containing SNPs with p<E-05. Results: 563,945 SNPs were analyzed, followed by imputation. The genotyped SNP with the lowest p value, rs4736317 (p=4.61E-06), was on chromosome 8 near the CYP11B1 and CYP11B2 genes. This SNP had a multiplicative effect of 1.128 (95% Cl: 1.07, 1.19) and a MAF of 0.40. After imputation, 20 SNPs with apparent p<E-06 were observed in this same region, with the lowest p value for rs9773022 (p=8.1E-08). We then performed functional genomic studies, and observed that two of the SNPs with low p values (rs4736312, p=1.49E-05 and rs4736350, p=6.34E-06) created apparent Oct-1 transcription factor binding sites (TFBS). Differential nuclear protein binding of Oct-1 to probes for these SNPs was verified with EMS and supershift assays using nuclear extract from A549 and NCI-H295R cells. Treatment of these two cell lines with 10 nM androstenedione led to the disruption of Oct-1 binding with the A (wild type) allele on rs4736312. rs4736312 is located in the 3'-UTR of CYP11B1 15 bp distant from response elements for the progesterone receptor and the glucocorticoid receptor. We also demonstrated that CYP11B1 and CYP11B2 were induced by estradiol in U2OS cell lines that express ER receptor and by androstenedione in H295R cells that express the androgen receptor. Transfection of a reporter gene construct with the rs4736312 SNP sequences into COS-1 and H295R cells suppressed reporter gene activity for the variant SNP sequence as compared to wild type, an observation that may correlate with the higher plasma levels of androstenedione in women (549× 328 vs 410×208 mean×SD, M/ml) with the variant allele. Conclusion: We have identified a series of SNPs in a region of chromosome 8 in and around CYP11B1 and CYP11B2 that are associated with elevated plasma androstenedione concentrations in postmenopausal women with resected early stage breast cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C114.

Background Aprotinin is a serine protease inhibitor that reduces blood loss and transfusion requirements when administered prophylactically to cardiac surgical patients. To examine the safety and dose-related efficacy of aprotinin, a prospective, multicenter, placebo-controlled trial was conducted in patients undergoing repeat coronary artery bypass graft (CABG) surgery. Methods and Results Two hundred eighty-seven patients were randomly assigned to receive either high-dose aprotinin, low-dose aprotinin, pump-prime-only aprotinin, or placebo. Drug efficacy was determined by the reduction in donor-blood transfusion up to postoperative day 12 and in postoperative thoracic-drainage volume. The percentage of patients requiring donor–red-blood-cell (RBC) transfusions in the high- and low-dose aprotinin groups was reduced compared with the pump-prime-only and placebo groups (high-dose aprotinin, 54%; low-dose aprotinin, 46%; pump-prime only, 72%; and placebo, 75%; overall P =.001). The number of units of donor RBCs transfused was significantly lower in the aprotinin-treated patients compared with placebo (high-dose aprotinin, 1.6±0.2 U; low-dose aprotinin, 1.6±0.3 U; pump-prime-only, 2.5±0.3 U; and placebo, 3.4±0.5 U; P =.0001). There was also a significant difference in total blood-product exposures among treatment groups (high-dose aprotinin, 2.2±0.4 U; low-dose aprotinin, 3.4±0.9 U; pump-prime-only, 5.1±0.9 U; placebo, 10.3±1.4 U). There were no differences among treatment groups for the incidence of perioperative myocardial infarction (MI). Conclusions This study demonstrates that high- and low-dose aprotinin significantly reduces the requirement for donor-blood transfusion in repeat CABG patients without increasing the risk for perioperative MI.