Semaphorin 3D autocrine signaling mediates the metastatic role of annexin A2 in pancreatic cancer

Most patients with pancreatic ductal adenocarcinoma (PDA) present with metastatic disease at the time of diagnosis or will recur with metastases after surgical treatment. Semaphorin-plexin signaling mediates the migration of neuronal axons during development and of blood vessels during angiogenesis. The expression of the gene encoding semaphorin 3D (Sema3D) is increased in PDA tumors, and the presence of antibodies against the pleiotropic protein annexin A2 (AnxA2) in the sera of some patients after surgical resection of PDA is associated with longer recurrence-free survival. By knocking out AnxA2 in a transgenic mouse model of PDA (KPC) that recapitulates the progression of human PDA from premalignancy to metastatic disease, we found that AnxA2 promoted metastases in vivo. The expression of AnxA2 promoted the secretion of Sema3D from PDA cells, which coimmunoprecipitated with the co-receptor plexin D1 (PlxnD1) on PDA cells. Mouse PDA cells in which SEMA3D was knocked down or ANXA2-null PDA cells exhibited decreased invasive and metastatic potential in culture and in mice. However, restoring Sema3D in AnxA2-null cells did not entirely rescue metastatic behavior in culture and in vivo, suggesting that AnxA2 mediates additional prometastatic mechanisms. Patients with primary PDA tumors that have abundant Sema3D have widely metastatic disease and decreased survival compared to patients with tumors that have relatively low Sema3D abundance. Thus, AnxA2 and Sema3D may be new therapeutic targets and prognostic markers of metastatic PDA.

Genetic diversity, virulence and fitness evolution in an obligate fungal parasite of bees

Within-host competition is predicted to drive the evolution of virulence in parasites, but the precise outcomes of such interactions are often unpredictable due to many factors including the biology of the host and the parasite, stochastic events and co-evolutionary interactions. Here, we use a serial passage experiment (SPE) with three strains of a heterothallic fungal parasite (Ascosphaera apis) of the Honey bee (Apis mellifera) to assess how evolving under increasing competitive pressure affects parasite virulence and fitness evolution. The results show an increase in virulence after successive generations of selection and consequently faster production of spores. This faster sporulation, however, did not translate into more spores being produced during this longer window of sporulation; rather, it appeared to induce a loss of fitness in terms of total spore production. There was no evidence to suggest that a greater diversity of competing strains was a driver of this increased virulence and subsequent fitness cost, but rather that strain-specific competitive interactions influenced the evolutionary outcomes of mixed infections. It is possible that the parasite may have evolved to avoid competition with multiple strains because of its heterothallic mode of reproduction, which highlights the importance of understanding parasite biology when predicting disease dynamics.

The relationship between serum urea levels and outcome in acute epistaxis

OBJECTIVES

To establish whether, for the patient presenting with epistaxis, there is a relationship between clinical outcome and serum urea levels measured on initial attendance at the accident and emergency (A&E) department.

METHODOLOGY

Records were reviewed from all patients attending a single teaching hospital A&E department between 1st January 2010 and 11st February 2011 with a diagnosis of epistaxis. Patients were analysed according to their admission serum urea and creatinine levels and then grouped according to clinical outcome.

RESULTS

We identified 278 patients (145 males, 133 females), 82 of which required hospital admission. Eleven required blood transfusion, and five required surgical arrest of the haemorrhage. No patients died. Serum urea and creatinine levels were measured in 119/278 patients. The mean serum urea level was significantly higher in patients admitted for further management of epistaxis than in patients who were discharged from the A&E department (9.35 mmol/l vs. 6.74 mmol/l, respectively; p = 0.003). There was no significant difference in mean serum urea levels between patients who were transfused and patients who were not, or between patients who went to the operating theatre and patients who did not.

CONCLUSIONS

Elevated serum urea levels on hospital admission are related to more severe clinical outcome in epistaxis.

A preclinical murine model of hepatic metastases

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, murine pancreatic tumor model of hepatic metastases via a hemispleen injection of syngeneic murine pancreatic tumor cells is described. This model mimics many of the clinical conditions in patients with metastatic disease to the liver. Mice consistently develop metastases in the liver allowing for investigation of the metastatic process, experimental therapy testing, and tumor immunology research.

Bacterial endophyte communities of two wheatgrass varieties following propagation in different growing media

Bacterial endophyte communities of two wheatgrass varieties currently being used in the revegetation of military training ranges were studied. Culturable and direct 16S rDNA PCR amplification techniques were used to describe bacterial communities present in Siberian and slender wheatgrass seeds, leaf tissues, and root tissues following propagation in either sand or a peat-based growing mix. Our hypothesis was that the resulting plant endophytic communities would be distinct, showing not only the presence of endophytes originating from the seed but also the characteristics of growth in the two different growing media. Both culture and culture-independent assays showed the likely translocation of Actinobacteria, Firmicutes, and Gammaproteobacteria from seed to mature plant tissues as well as subsequent colonization by exogenous organisms. Statistical analysis of 16S terminal restriction fragment profiles identified growing media as having a greater significant effect on the formation of the endpoint endophytic communities than either plant tissue or wheatgrass variety. In silico digests of the ribosomal database produced putative identifications indicating an increase in overall species diversity and increased relative abundances of Firmicutes and Cyanobacteria following propagation in sand and Betaproteobacteria following propagation in the peat-based growing mix. Results indicated a substantial translocation of endophytes from seed to mature plant tissues for both growing media and that growing medium was a dominant determinant of the final taxonomy of the endpoint plant endophytic communities.

P1-09-03: Prevalence of Germline TP53 Mutations in Young Women with HER2−Positive Breast Cancer

Background: Li Fraumeni syndrome is a rare inherited cancer susceptibility condition associated with germline mutations in the TP53 gene, in which breast cancer (BC) is the most frequent tumor. The prevalence of TP53 mutations in population-based series of very young onset BC (<30 years at diagnosis) ranges from <1% to approximately 7%1-4. Recent data show that BC in patients carrying a germline TP53 mutation are commonly HER2 amplified (63-83%)5-7. In this study, we assessed the prevalence of germline TP53 mutations in women with HER2 positive BC diagnosed age ≤ 50 years.

Material & Methods: We identified 347 women with invasive HER2 positive BC diagnosed at age ≤ 50 years using the Clinical Operations and Research Information System (CORIS) at the Dana Farber Cancer Institute. Information on age at diagnosis, histology, hormone receptor and HER2 status as well as personal and family cancer history was confirmed from medical records. 129 patients were excluded for various reasons, including a cancer diagnosis prior to the BC and a documented BRCA1/2 mutation. A combination of Exon Grouping Analysis (EGAN) and Sanger sequencing for detection of TP53 mutations in exons 2–11 including surrounding intronic sequence was performed on 218 germline DNA samples. Multiplex Ligation-dependent Probe Amplification (MLPA) analysis for the detection of TP53 deletions or duplications is ongoing.

Results: A germline TP53 mutation was identified in 4 women diagnosed at age ≤ 50 years (1.8%, 95%CI 0.5−4.6). At BC diagnosis, they were 23, 32, 44 and 50 years. Two BC were ER+/PR+, HER2+ and 2 were ER-/PR-, HER2+. Estimate of prevalence of germline TP53 mutations by age at BC diagnosis are: age ≤ 35, 2/41 (4.9%, 95%CI 0.6−16.6), and age ≤ 45 3/168 (1.8%, 95%CI 0.4−5.1). Among the women with germline TP53 mutations, 2 met the Chompret criteria8 and none the classic LFS criteria.

Discussion: TP53 mutations were identified in a cohort of women with HER2+ BC at young age. As expected, the frequency is higher in younger women, but mutations were seen in all age groups that were evaluated. None of these women met classic LFS criteria by family history. Consideration of TP53 testing should be given to women diagnosed below age 35 who are negative for BRCA1/2 mutations regardless of family history. Analysis of other series will be helpful in reaching more stable estimates of the prevalence of mutation carriers among patients with HER2+ BC at young age.

1. Sidransky D et al. Cancer Res. 1992; 52:2984–2986.

2. Borresen AL et al. Cancer Res.1992; 52:3234–3236.

3. Lalloo F et al. Lancet 2003; 361:1101–02

4. Gonzalez KD et al. J Clin Oncol 2009;27(8):1250–6

5. Wilson JR et al. J Med Genet 2010;47(11):771–774.

6. Melhem-Bertrandt A et al: San Antonio Breast Cancer Symposium 2010: P3-12-01.

7. Masciari S et al: J Clin Oncol 29: 2011 (suppl; abstr 1519)

8. Tinat J et al. J Clin Oncol. 2009;27(26):e108–9

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-09-03.

EFFECT OF JOB SKILLS TRAINING ON EMPLOYMENT AND JOB SEEKING BEHAVIORS IN AN AMERICAN INDIAN SUBSTANCE ABUSE TREATMENT SAMPLE

Employment difficulties are common among American Indian individuals in substance abuse treatment. To address this problem, the Southwest Node of NIDA's Clinical Trials Network conducted a single-site adaptation of its national Job Seekers Workshop study in an American Indian treatment program, Na'Nizhoozhi Center (NCI). 102 (80% men, 100% American Indian) participants who were in residential treatment and currently unemployed were randomized to (1) a three session, manualized program (Job seekers workshop: JSW) or (2) a 40-minute Job Interviewing Video: JIV). Outcomes were assessed at 3-month follow up: 1) number of days to a new taxed job or enrollment in a job-training program, and 2) total hours working or enrolled in a job-training program. No significant differences were found between the two groups for time to a new taxed job or enrollment in a job-training program. There were no significant differences between groups in substance use frequency at 3-month follow-up. These results do not support the use of the costly and time-consuming JSW intervention in this population and setting. Despite of the lack of a demonstrable treatment effect, this study established the feasibility of including a rural American Indian site in a rigorous CTN trial through a community-based participatory research approach.

Utility of lipid biomarkers in support of bioremediation efforts at army sites

Lipid biomarker analysis has proven valuable in testing the hypothesis that attributes of the extant microbiota can directly reflect the occurrence of contaminant biodegradation. Two past research efforts have demonstrated this utility and are described here. A 4.5 m vertical core was obtained from a diesel fuel oil contamination plume. Core material was assayed for total petroleum hydrocarbons (TPH) and bacterial membrane phospholipids (PLFA) via a single solvent extraction. Microbial viable biomass and the relative abundance of Gram-negative bacterial PLFA biomarkers were found to be significantly correlated with TPH concentration. The core TPH profile also revealed two distinct areas where the average TPH level of 3,000 microg g(-1) fell to near detection limits. Both areas were characterized by a three-fold decrease in the hexadecane/pristane ratio, indicating alkane biodegradation, and a distinct PLFA profile that showed a close similarity to the uncontaminated surface soil. Low-order, incomplete detonations can deposit hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) into training range surface soils. Since surface soils are exposed to temporal and diurnal moisture cycles, we investigated the effect two very different soil moisture tensions had on the in situ microbiota and RDX biodegradation. Saturated soils were characterized by rapid RDX biodegradation, 4 day half-life, a decrease in number of species detected and increase in PLFA biomarkers for Gram-negative proteobacteria (n16:1omega7c, n18:1omega9c, and n18:1omega7c) and Gram-positive firmicutes (i15:0 and a15:0). Terminal restriction fragment length polymorphism (T-RFLP) profiles of endpoint microbial communities indicated a shift from 18 to 36% firmicutes, the loss of gamma-proteobacteria and the emergence of alpha-proteobacteria. These two past research efforts demonstrated the utility of the lipid biomarker analysis in identifying microbial community characteristics that were associated with two very different soil contaminants. Lipid biomarkers defined areas of TPH biodegradation and identified community shifts as a result of soil conditions that affected explosives fate. Information like this can be used to enhance the predictive power of ecological models such as the Army Training and Testing Area Carrying Capacity for munitions model [ATTACC].

Accurate determinations of alpha(s) from realistic lattice QCD

We obtain a new value for the QCD coupling constant by combining lattice QCD simulations with experimental data for hadron masses. Our lattice analysis is the first to (1) include vacuum polarization effects from all three light-quark flavors (using MILC configurations), (2) include third-order terms in perturbation theory, (3) systematically estimate fourth and higher-order terms, (4) use an unambiguous lattice spacing, and (5) use an [symbol: see text](a2)-accurate QCD action. We use 28 different (but related) short-distance quantities to obtain alpha((5)/(MS))(M(Z)) = 0.1170(12).

A community-based clinical selective in end-of-life care

There is a widespread recognition among medical educators and accreditation organizations that medical students and young physicians lack the competency necessary to care for persons near the end of life. This article describes the institutional and attitudinal barriers to innovation in curriculum design. It then presents and evaluates a 1-month selective for fourth year students that focuses on providing end-of-life care to immigrant populations in community-based home hospice. The selective joined biomedical training in pain management and palliative care, a clinical rotation in home hospice care with an analysis of the way that social and ethnic factors inform and influence end-of-life care.

Earnings Supplements and Job Quality among Former Welfare Recipients

The Self-Sufficiency Project (SSP) offered a generous but time-limited earnings supplement to a randomly assigned group of lone parents—who were also long-term social assistance recipients—if they found full-time work and left social assistance. Employment data was collected for this group over a three-year period following the offer, and for a randomly-assigned control group. This article analyzes the characteristics of the first job that SSP participants found after they left social assistance. The occupations and industries of the first job held are analyzed as is SSP’s impact on hourly wages, weekly hours and job stability. The article finds that SSP increased employment in jobs that were no worse (and no better) than the jobs that participants might have taken in the absence of the program.

Interpretation of atypical patterns encountered when using a flow cytometry-based method to detect residual leukocytes in leukoreduced red blood cell components

BACKGROUND

Universal leukoreduction of blood components is becoming the standard of care. Flow cytometry methods are being used for quality control of the leukoreduction process.

METHODS

We provide an atlas of atypical flow cytograms generated by a commercial LeucoCOUNT assay that was used to enumerate residual leukocytes in leukoreduced red blood cell components. Numeric results are derived from a flow cytogram generated by the assay.

RESULTS

Three types of atypical flow cytogram patterns were observed during process validation or routine quality control of leukoreduced red blood cell components. (a) Fixation artifact: Fixation of control or test samples can alter the staining intensity compared with fresh cells. (b) "Rain" pattern: Flow cytometry methods count slightly damaged leukocytes not removed during leukoreduction. Slightly damaged leukocytes appear on a flow cytogram like "rain" falling from a well-defined "cloud" of intact residual leukocytes. Discrepancies between automated flow cytometry results and subjective manual counting methods can occur. (c) Autofluorescence-debris pattern: Cell debris and age-related changes in the sample can cause shifts in the fluorescence staining pattern, resulting in erroneous test results.

CONCLUSION

Review of flow cytograms is essential for accurate reporting of flow cytometry-based methods for enumerating residual leukocytes in leukoreduced blood components.