Citations

Abstract To establish a useful laboratory protocol to investigate possible cases of fatal anaphylaxis, we measured mast-cell-derived tryptase levels and allergen-specific immunoglobulin E (IgE) antibody levels in sera obtained prior to or within 24 h after death from 19 anaphylaxis victims. Elevated serum tryptase levels (range = 12 ng/mL to 150 μg/mL) were found in nine of nine Hymenoptera sting fatalities, six of eight food-induced fatalities, and two of two reactions to diagnostic/therapeutic agents. Tryptase levels were normal (<10 ng/mL) in 57 sequential sera obtained postmortem from six control patients. Tryptase could not be measured by pleural or pericardial fluids for technical reasons. Serum IgE antibodies were elevated in five of the nine Hymenoptera sting fatalities and in eight of the eight fatal food reactions; assays were unavailable for the two diagnostic/therapeutic agents. If elevated, the victim's serum IgE antibodies to food could be used to identify allergens in uneaten portions of foods consumed shortly before the anaphylactic event. IgE antibodies were moderately stable during storage in a variety of anticoagulants at room temperature for up to 11 weeks. Elevated mast-cell-derived tryptase levels in postmortem sera reflect antemortem mast cell activation and may be used as a marker for fatal anaphylaxis. If assays are available for IgE antibodies to relevant allergens, such assays provide evidence for antemortem sensitization; these assays may be modified to identify allergens in foods consumed by victims of food-induced anaphylaxis.

Objective Pulmonary hypertension (PH) is associated with increased mortality after surgical or transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS), and when the pulmonary artery pressure is particularly elevated, there may be questions about the clinical benefit of TAVR. We aimed to identify clinical and haemodynamic factors associated with increased mortality after TAVR among those with moderate/severe PH. Methods Among patients with symptomatic AS at high or prohibitive surgical risk receiving TAVR in the Placement of Aortic Transcatheter Valves (PARTNER) I randomised trial or registry, 2180 patients with an invasive measurement of mean pulmonary artery pressure (mPAP) recorded were included, and moderate/severe PH was defined as an mPAP ≥35 mm Hg. Results Increasing severity of PH was associated with progressively worse 1-year all-cause mortality: none (n=785, 18.6%), mild (n=838, 22.7%) and moderate/severe (n=557, 25.0%) (p=0.01). The increased hazard of mortality associated with moderate/severe PH was observed in females, but not males (interaction p=0.03). In adjusted analyses, females with moderate/severe PH had an increased hazard of death at 1 year compared with females without PH (adjusted HR 2.14, 95% CI 1.44 to 3.18), whereas those with mild PH did not. Among males, there was no increased hazard of death associated with any severity of PH. In a multivariable Cox model of patients with moderate/severe PH, oxygen-dependent lung disease, inability to perform a 6 min walk, impaired renal function and lower aortic valve mean gradient were independently associated with increased 1-year mortality (p<0.05 for all), whereas several haemodynamic indices were not. A risk score, including these factors, was able to identify patients with a 15% vs 59% 1-year mortality. Conclusions The relationship between moderate/severe PH and increased mortality after TAVR is altered by sex, and clinical factors appear to be more influential in stratifying risk than haemodynamic indices. These findings may have implications for the evaluation of and treatment decisions for patients referred for TAVR with significant PH. Trial registration NCT00530894.

Abstract Single-positive thymocytes that successfully complete positive and negative selection must still undergo one final step, generally termed T cell maturation, before they gain functional competency and enter the long-lived T cell pool. Maturation initiates after positive selection in single-positive thymocytes and continues in the periphery in recent thymic emigrants, before these newly produced T cells gain functional competency and are ready to participate in the immune response as peripheral naive T cells. Recent work using genetically altered mice demonstrates that T cell maturation is not a single process, but a series of steps that occur independently and sequentially after positive selection. This review focuses on the changes that occur during T cell maturation, as well as the molecules and pathways that are critical at each step.

Abstract The oncogenic EGFR/HER2/K-RAS “pathway” activation is pivotal in driving uncontrolled cell proliferation, aggressive tumor growth and systemic metastasis. Guided by studies in Drosophila, SIAH (seven-in-absentia homologue), the most downstream gatekeeper required for proper RAS signaling and tumor cell survival, was identified as a suitable target for anti-neoplastic therapy. We have shown that anti-SIAH-based therapy leads to the complete blockade of tumorigenesis in highly aggressive pancreatic, lung and breast cancer cells expressing a proteolysis deficient mutant protein, SIAHPD, at the onset of tumor initiation. In this study, we aim to determine if this anti-SIAH strategy is effective against well-established and late-stage pancreatic and triple negative breast (TNBC) tumors in a xenograft mouse model in vivo. We established stable cancer cell lines with doxycycline (DOX)-inducible SIAH2PD expression. One million MiaPaCa-SIAH2PD or MDA-MB-231-SIAH2PD cells were injected subcutaneously bilaterally in the dorsal scapular areas or bilaterally into the mammary fat pads, respectively, in 4-week-old female athymic nude mice. Tumor growth was monitored 3 times per week. Once tumors reached certain volume, SIAH2PD expression was induced via oral DOX treatment. Tumor growth in these mice was compared to control. Immunohistochemical (IHC) and immunofluorescence (IF) staining for endogenous SIAH and FLAG-tagged exogenous SIAH2PD were performed on formalin-fixed, paraffin-embedded sections of tumor tissue. Expression of SIAH2PD blocks oncogenic K-RAS signaling and K-RAS-mediated tumor growth in established pancreatic (MiaPaCa) and triple negative breast (MDA-MB-231) tumors in athymic nude mice. The immunohistochemical (IHC) and immunofluorescent (IF) staining reveals that in control tumors there is high expression of endogenous SIAH and none of SIAH2PD, while in tumors responding to treatment there is pronounced SIAH2PD and diminished endogenous SIAH expression. Oncogenic HER2/EGFR/K-RAS activation promote neoplastic transformation and tumorigenesis. In this study, we have identified a new vulnerability in the oncogenic K-RAS signaling pathway and we have demonstrated a novel and effective way to block K-RAS-driven tumor growth in well-established pancreatic adenocarcinoma and TNBC tumors in a xenograft model. In the follow-up studies, we hope to develop a small molecule inhibitor against SIAH, test their efficacy against patient-derived stage IV and II tumors in our “xenopatient” models. In the future, we aim to translate these exciting findings to the cancer clinics to benefit our cancer patients with metastatic diseases in VA. Citation Format: Minglei Bian, Vasilena Zheleva, Xiaofei Gao, Justin Odanga, Monica Njogu, Zena Urban, Bruce Knudsen, Richard A. Hoefer, Roger R. Perry, Amy H. Tang. Inhibition of late-stage tumor growth of human pancreatic and triple-negative breast cancer by blocking the most downstream “gatekeeper” signaling module, SIAH E3 ligase, in the oncogenic ERBB/ K-RAS signaling pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4366. doi:10.1158/1538-7445.AM2015-4366

Background and Purpose— The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography–based planimetry (CTP). Methods— In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results— In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC ( r 2 =0.93) than with site-ABC ( r 2 =0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm 3 ; CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P <0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots. Conclusions— ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

Abstract Glioblastoma (GBM) is the most common primary tumor of the CNS and carries a dismal prognosis. The aggressive invasion of GBM cells into the surrounding normal brain makes complete resection impossible, significantly increases resistance to the standard therapy regimen, and virtually assures tumor recurrence. Median survival for newly diagnosed GBM is 14.6 months and declines to 8 months for patients with recurrent GBM. New therapeutic strategies that target the molecular drivers of invasion are required for improved clinical outcome. We have demonstrated that TROY (TNFRSF19), a member of the TNFR super-family, plays an important role in GBM invasion and resistance. TROY expression increases with glial tumor grade and inversely correlates with patient survival. TROY stimulates GBM cell invasion and increases resistance to temozolomide (TMZ) and radiation treatment. Conversely, knockdown of TROY expression inhibits GBM cell invasion, increases sensitivity to temozolomide, and prolongs survival in an intracranial xenograft model. Propentofylline (PPF), an atypical synthetic methylxanthine compound, has been extensively studied in Phase II and Phase III clinical trials for Alzheimer's disease and vascular dementia where it has demonstrated blood-brain permeability and minimal adverse side effects. In this study, we demonstrated that PPF decreases TROY protein expression in glioma cells, and subsequently suppress activation downstream signaling effectors including AKT, NF-κB, and Rac1. PPF treatment of glioma cells also suppressed glioma cell migration and invasion, demonstrated by transwell migration assay and reduced membrane ruffling. Finally, PPF treatment increased vulnerability of glioma cells to Temozolomide (TMZ) and radiation. In summary, this study demonstrates that PPF provides a pharmacologic approach to target TROY to inhibit glioma cell invasion and reduce therapeutic resistance to TMZ and radiation. Citation Format: Harshil D. Dhruv, Serdar Tuncali, Alison Roos, Patrick Tomboc, Nathan Jameson, Ashley Chavez, Joseph Loftus, Michael E. Berens, Nhan L. Tran. Propentofylline inhibits TROY/TNFRSF19 signaling to enhance therapeutic efficacy in invasive glioblastoma cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5366. doi:10.1158/1538-7445.AM2015-5366

Abstract Telomeres are complex structures that cap chromosome ends, protecting them from degradation, double strand breaks and end-to-end fusions. Telomeres are maintained by the enzyme telomerase, which is made up of a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. The telomere structure itself is composed of proteins encoded by ACD, ACYP2, BICD1, DKC1, DCLRE1B, MPHOSPH6, NAF1, NOLA1, NOLA2, NOLA3, OBFC1, PIK3C3, POT1, RTEL1, TEP1, TERF1, TERF2, TERF21P, TINF2, TNKS/PINX1, TPP1 and ZNF208. Several single nucleotide polymorphisms (SNPs) in the TERT and adjoining CLPTM1L gene region are associated with multiple cancer types, and some are associated with both increased and decreased risks across different cancer types. We systematically characterized the patterns of association between variants in these 25 telomere structure and maintenance genes and risk across five cancer types in the Genetic Association and Mechanisms in Oncology (GAME-ON) consortium. We performed a subset-based meta-analysis (ASSET) of 209,367 directly measured and imputed SNPs, one megabase up- and downstream of these genes, across genome-wide association studies of colorectal (5,100 cases, 4,831 controls), lung (12,160 cases, 16,838 controls), breast (15,748 cases, 18,084 controls), ovarian (4,369 cases, 9,123 controls) and prostate (14,160 cases, 12,724 controls) cancers. Correlations (r2) between SNPs were examined in Haploview using the 1000 Genomes Project CEU population. A total of 87 TERT, 123 TERC and 26 DCLRE1B SNPs were associated with cancer risk at gene-level Bonferroni-corrected p-values of 4.2-7.8×10−6. Patterns of association were similar for prostate and colorectal cancers in DCLRE1B. Much stronger associations were observed in TERT and TERC, with 63 and 24 SNPs reaching genome-wide significance (p&lt;5.0×10−8), respectively. Of these, 9 TERT and 9 TERC SNPs were correlated at r2&lt;0.75. The most strongly associated SNPs in TERT (rs37004, p = 2.6×10−11) and TERC (rs76925190, p = 1.5×10−15) are in regions containing documented risk loci for lung and prostate cancers, respectively. TERT rs37004 (p = 1.2×10−13) and 6 of the other 9 SNPs in TERT were associated only with lung cancer risk. For the other 2 SNPs, there was a suggestion that patterns of risk were opposite for lung and prostate cancers. While TERC rs76925190 was strongly associated with prostate cancer risk (p = 5.4 x10−17), it was also suggestively associated with colorectal cancer risk (p&lt;0.005). This pattern was similar for another 2 of the 9 SNPs, while for the rest, associations were limited to prostate cancer. The complex patterns of association in telomere structure and maintenance genes observed across cancer types may provide insight about the mechanisms through which telomere dysfunction in different tissues influences cancer risk. Citation Format: Sara Karami, Younghun Han, Fredrick R. Schumacher, Zsofia Kote-Jarai, Sara Lindstrom, John S. Witte, Iona Cheng, Shenying Fang, Jiali Han, Peter Kraft, Fengju Song, Rayjean J. Hung, James McKay, Stephen J. Chanock, Mala Pande, Angela Risch, Hongbing Shen, Christopher A. Haiman, Lisa Boardman, Cornelia M. Ulrich, Graham Casey, Ulrike Peters, Nilanjan Chatterjee, Brandon Pierce, Wei Zheng, Christopher I. Amos, Jennifer A. Doherty. Risk loci in telomere structure and maintenance genes across five cancer types: GAME-ON Consortium. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4609. doi:10.1158/1538-7445.AM2015-4609

ABSTRACT In 2011 a surveillance study for the susceptibility to fidaxomicin and epidemiology of Clostridium difficile isolates in the United States was undertaken in seven geographically dispersed medical centers. This report encompasses baseline surveillance in 2011 and 2012 on 925 isolates. A convenience sample of C. difficile isolates or toxin positive stools from patients were referred to a central laboratory. Antimicrobial susceptibility was determined by agar dilution (CLSI M11-A8). Clinical and Laboratory Standards Institute (CLSI), Food and Drug Administration, or European Union of Clinical Antimicrobial Susceptibility Testing (EUCAST) breakpoints were applied where applicable. Toxin gene profiles were characterized by multiplex PCR on each isolate. A random sample of 322 strains, stratified by institution, underwent restriction endonuclease analysis (REA). The fidaxomicin MIC 90 was 0.5 μg/ml for all isolates regardless of REA type or toxin gene profile, and all isolates were inhibited at ≤1.0 μg/ml. By REA typing, BI strains represented 25.5% of the isolates. The toxin gene profile of tcdA , tcdB , and cdtA/B positive with a tcdC 18-bp deletion correlated with BI REA group. Moxifloxacin and clindamycin resistance was increased among either BI or binary toxin-positive isolates. Metronidazole and vancomycin showed reduced susceptibility (EUCAST criteria) in these isolates. Geographic variations in susceptibility, REA group and binary toxin gene presence were observed. Fidaxomicin activity against C. difficile isolated in a national surveillance study did not change more than 1 year after licensure. This analysis provides baseline results for future comparisons.