Multistate outbreak of Escherichia coli O145 infections associated with romaine lettuce consumption, 2010

Non-O157 Shiga toxin-producing Escherichia coli (STEC) can cause severe illness, including hemolytic uremic syndrome (HUS). STEC O145 is the sixth most commonly reported non-O157 STEC in the United States, although outbreaks have been infrequent. In April and May 2010, we investigated a multistate outbreak of STEC O145 infection. Confirmed cases were STEC O145 infections with isolate pulsed-field gel electrophoresis patterns indistinguishable from those of the outbreak strain. Probable cases were STEC O145 infections or HUS in persons who were epidemiologically linked. Case-control studies were conducted in Michigan and Ohio; food exposures were analyzed at the restaurant, menu, and ingredient level. Environmental inspections were conducted in implicated food establishments, and food samples were collected and tested. To characterize clinical findings associated with infections, we conducted a chart review for case patients who sought medical care. We identified 27 confirmed and 4 probable cases from five states. Of these, 14 (45%) were hospitalized, 3 (10%) developed HUS, and none died. Among two case-control studies conducted, illness was significantly associated with consumption of shredded romaine lettuce in Michigan (odds ratio [OR] = undefined; 95% confidence interval [CI] = 1.6 to undefined) and Ohio (OR = 10.9; 95% CI = 3.1 to 40.5). Samples from an unopened bag of shredded romaine lettuce yielded the predominant outbreak strain. Of 15 case patients included in the chart review, 14 (93%) had diarrhea and abdominal cramps and 11 (73%) developed bloody diarrhea. This report documents the first foodborne outbreak of STEC O145 infections in the United States. Current surveillance efforts focus primarily on E. coli O157 infections; however, non-O157 STEC can cause similar disease and outbreaks, and efforts should be made to identify both O157 and non-O157 STEC infections. Providers should test all patients with bloody diarrhea for both non-O157 and O157 STEC.

Development and assessment of a biophysical dispersal model for sea lice

Salmon aquaculture in Scotland continues to increase; however, one of the potential limitations to its further sustainable growth is the ectoparasitic sea louse Lepeophtheirus salmonis. The industry in Scotland undertakes coordinated management procedures to control the levels of sea lice on farms in designated production areas. We developed a biophysical sea lice dispersal model for Loch Linnhe, one of the largest fjords on the west coast of Scotland, to provide further information to help establish more effective farm management areas. We successfully extend modelling principles previously applied to a small Scottish fjordic system. Modelling scenarios demonstrate heterogeneity in the distribution of sea lice within the system and simulations, suggesting that lice could be transmitted up to 30 km. The scenarios are assessed by comparing model predictions against lice sampled by both planktonic trawls and settlement on sentinel caged fish. The model predicts the ranked abundance of both planktonic and settled lice assuming that the lice input to the system is relative to host biomass. Data collection is ongoing for undertaking and assessing additional scenarios.

A central review of histopathology reports after breast cancer neoadjuvant chemotherapy in the neo-tango trial

Background:

Neo-tAnGo, a National Cancer Research Network (NCRN) multicentre randomised neoadjuvant chemotherapy trial in early breast cancer, enroled 831 patients in the United Kingdom. We report a central review of post-chemotherapy histopathology reports on the surgical specimens, to assess the presence and degree of response.

Methods:

A central independent two-reader review (EP and HME) of histopathology reports from post-treatment surgical specimens was performed. The quality and completeness of pathology reporting across all centres was assessed. The reviews included pathological response to chemotherapy (pathological complete response (pCR); minimal residual disease (MRD); and lesser degrees of response), laterality, the number of axillary metastases and axillary nodes, and the type of surgery. A consensus was reached after discussion.

Results:

In all, 825 surgical reports from 816 patients were available for review. Out of 4125 data items there were 347 discrepant results (8.4% of classifications), which involved 281 patients. These involved grading of breast response (169 but only 9 involving pCR vs MRD); laterality (6); presence of axillary metastasis (35); lymph node counts (108); and type of axillary surgery (29). Excluding cases with pCR, only 45% of reports included any comment regarding response in the breast and 30% in the axillary lymph nodes.

Conclusion:

We found considerable variability in the completeness of reporting of surgical specimens within this national neoadjuvant breast cancer trial. This highlights the need for consensus guidelines among trial groups on histopathology reporting, and the participation of histopathologists throughout the development and analysis of neoadjuvant trials.

Selecting breast cancer patients for chemotherapy: the opening of the UK OPTIMA trial

The mortality from breast cancer has improved steadily over the past two decades, in part because of the increased use of more effective adjuvant therapies. Thousands of women are routinely treated with intensive chemotherapy, which can be unpleasant, is expensive and is occasionally hazardous. Oncologists have long known that some of these women may not need treatment, either because they have a low risk of relapse or because they have tumour biology that makes them less sensitive to chemotherapy and more suitable for early adjuvant endocrine therapy. There is an urgent need to improve patient selection so that chemotherapy is restricted to those patients who will benefit from it. Here we review the emerging technologies that are available for improving patient selection for chemotherapy. We describe the OPTIMA trial, which has just opened to recruitment in the UK, is the latest addition to trials in this area, and is the first to focus on the relative cost-effectiveness of alternate predictive assays.

Housing characteristics and their influence on health-related quality of life in persons living with HIV in Ontario, Canada: results from the positive spaces, healthy places study

Although lack of housing is linked with adverse health outcomes, little is known about the impacts of the qualitative aspects of housing on health. This study examined the association between structural elements of housing, housing affordability, housing satisfaction and health-related quality of life over a 1-year period. Participants were 509 individuals living with HIV in Ontario, Canada. Regression analyses were conducted to examine relationships between housing variables and physical and mental health-related quality of life. We found significant cross-sectional associations between housing and neighborhood variables-including place of residence, housing affordability, housing stability, and satisfaction with material, meaningful and spatial dimensions of housing-and both physical and mental health-related quality of life. Our analyses also revealed longitudinal associations between housing and neighborhood variables and health-related quality of life. Interventions that enhance housing affordability and housing satisfaction may help improve health-related quality of life of people living with HIV.

Time-resolved soft x-ray spectra from laser-produced Cu plasma

The volumetric heating of a thin copper target has been studied with time resolved x-ray spectroscopy. The copper target was heated by a plasma produced using the Lawrence Livermore National Laboratory's Compact Multipulse Terawatt (COMET) laser. A variable spaced grating spectrometer coupled to an x-ray streak camera measured soft x-ray emission (800-1550 eV) from the back of the copper target to characterize the bulk heating of the target. Radiation hydrodynamic simulations were modeled in two-dimensions using the HYDRA code. The target conditions calculated by HYDRA were post-processed with the atomic kinetics code CRETIN to generate synthetic emission spectra. A comparison between the experimental and simulated spectra indicates the presence of specific ionization states of copper and the corresponding electron temperatures and ion densities throughout the laser-heated copper target.

Absolute determination of charge-coupled device quantum detection efficiency using Si K-edge x-ray absorption fine structure

We report a method to determine the quantum detection efficiency and the absorbing layers on a front-illuminated charge-coupled device (CCD). The CCD under study, as part of a crystal spectrometer, measures intense continuum x-ray emission from a picosecond laser-produced plasma and spectrally resolves the Si K-edge x-ray absorption fine structure due to the electrode structure of the device. The CCD response across the Si K-edge shows a large discontinuity as well as a number of oscillations that are identified individually and uniquely from Si, SiO(2), and Si(3)N(4) layers. From the spectral analysis of the structure and K-edge discontinuity, the active layer thickness and the different absorbing layers thickness can be determined precisely. A precise CCD detection model from 0.2 to 10 keV can be deduced from this highly sensitive technique.

Simultaneous high-resolution two-dimensional spatial and one-dimensional picosecond streaked x-ray pinhole imaging

A Kentech x-ray streak camera was run at the LLNL compact multipulse terawatt (COMET) laser to record simultaneous space- and time-resolved measurements of picosecond laser-produced plasmas. Four different x-ray energy channels were monitored using broadband filters to record the time history of Cu targets heated at irradiances of 10(16)-10(19) W∕cm(2). Through the Cu filter channel, a time-resolution below 3 ps was obtained. Additionally, an array of 10 μm diameter pinholes was placed in front of the camera to produce multiple time-resolved x-ray images on the photocathode and time-integrated images on the phosphor with 10 and 15 times magnification, respectively, with spatial resolution of < 13 μm.

Atomic inner-shell X-ray laser at 1.46 nanometres pumped by an X-ray free-electron laser

Since the invention of the laser more than 50 years ago, scientists have striven to achieve amplification on atomic transitions of increasingly shorter wavelength. The introduction of X-ray free-electron lasers makes it possible to pump new atomic X-ray lasers with ultrashort pulse duration, extreme spectral brightness and full temporal coherence. Here we describe the implementation of an X-ray laser in the kiloelectronvolt energy regime, based on atomic population inversion and driven by rapid K-shell photo-ionization using pulses from an X-ray free-electron laser. We established a population inversion of the Kα transition in singly ionized neon at 1.46 nanometres (corresponding to a photon energy of 849 electronvolts) in an elongated plasma column created by irradiation of a gas medium. We observed strong amplified spontaneous emission from the end of the excited plasma. This resulted in femtosecond-duration, high-intensity X-ray pulses of much shorter wavelength and greater brilliance than achieved with previous atomic X-ray lasers. Moreover, this scheme provides greatly increased wavelength stability, monochromaticity and improved temporal coherence by comparison with present-day X-ray free-electron lasers. The atomic X-ray lasers realized here may be useful for high-resolution spectroscopy and nonlinear X-ray studies.

OT1-02-08: The PERSEPHONE Trial: Duration of Trastuzumab with Chemotherapy in Women with HER2 Positive Early Breast Cancer. Changing the Randomisation Point To Address Potential Barriers to Recruitment

Background

Persephone is a phase III randomised controlled trial comparing six months of trastuzumab (9 doses) to the standard 12 month duration (18 doses) in patients with HER2 positive early breast cancer in respect of disease free survival, safety and cost-effectiveness. The trial opened to recruitment in October 2007 but soon showed that meeting recruitment targets was challenging, reaching only 20–30 patients per month. A key issue seemed to be the mandatory requirement to randomise before patients started trastuzumab treatment. Successful accrual of patients in the PHARE trial, a Persephone sister study, run by the National Institute for Cancer, Paris had not incorporated this criteria.

Method: In September 2009, following accrual of 316 patients, this potential barrier to recruitment was addressed by a major protocol amendment which relaxed the eligibility criteria to allow randomisation of patients who had received up to 9 doses of trastuzumab.

Results: To date, 1334 patients have been randomised into PERSEPHONE. After the amendment, monthly recruitment increased to 40–50 patients and, more recently, to 60–70 patients. Of the 1018 patients recruited since September 2009, 450 (44%) patients had received at least 1 dose of trastuzumab pre-randomisation (see Table).

Prognosis by breast cancer subtypes in patients treated with adjuvant chemotherapy in a clinical trial

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Background: Breast cancer can be classified into molecular subtypes that have distinct survival patterns. The purpose of this study was i) to evaluate the prognostic significance of breast cancer subtypes in a cohort of women taking part in the NEAT and BR9601 clinical trials comparing CMF with ECMF, and ii) to evaluate whether the subtypes were predictive of the added benefit of epirubicin in these trials.

Methods: Tumor tissue microarrays were stained and scored for ER, PR, HER2, EGFR and CK5/6. These were used to classify the tumors into six intrinsic subtypes (1). We used Cox regression to compare overall survival (OS), breast cancer specific survival (BSS) and relapse free survival (RFS) in the different subgroups. We also compared the effect of ECMF with CMF by subgroup.

Results: IHC data were available for 1725 cases of whom 805 were Luminal 1-basal negative, 153 were Luminal 1-basal positive, 174 were Luminal 2, 192 were HER2-like, 230 were core basal phenotype and 171 were 5-negative phenotype. Median follow-up time was 7 years. The prognostic effects of the subtypes were similar to those reported for unselected breast cancer cases irrespective of adjuvant therapy (Blows FM, et al. PLoS Med 2010;75:e1000279.). In particular, the luminal 1-basal negative tumors were associated with the best prognosis in five years after surgery and the HER2-like tumors were associated with the poorest prognosis. ECMF has previously shown to be associated with a 33% relative risk reduction for OS compared to CMF (Poole CJ et al. N Engl J Med 2006;35518:1851-62.). There was little evidence for significant heterogeneity of effect by tumor subtype for any end point (OS P= 0.40, BSS P=0.53 RFS P=0.50). However, there was an observed trend towards the largest additional benefit from ECMF being in women with tumors of the 5-negative phenotype (OS HR=0.39 95% CI 0.21-0.73) and the smallest being in Luminal 1-basal negative tumors (OS HR=0.86 95% CI 0.64-1.16).

Conclusions: In a clinical trial in which all patients received chemotherapy, we confirmed that breast cancer subtypes show distinct behaviour with differences in short and long term survival. The benefit of ECMF over CMF was statistically similar in all disease subtypes.