LO-Phonon Emission Rate of Hot Electrons from an On-Demand Single-Electron Source in a GaAs/AlGaAs Heterostructure

Using a recent time-of-flight measurement technique with 1 ps time resolution and electron-energy spectroscopy, we develop a method to measure the longitudinal-optical-phonon emission rate of hot electrons traveling along a depleted edge of a quantum Hall bar. Comparison to a single-particle model implies the scattering mechanism involves a two-step process via an intra-Landau-level transition. We show that this can be suppressed by control of the edge potential profile, and a scattering length >1  mm can be achieved, allowing the use of this system for scalable single-electron device applications.

Human Papillomavirus and Oropharyngeal Cancer Among Indigenous Australians: Protocol for a Prevalence Study of Oral-Related Human Papillomavirus and Cost-Effectiveness of Prevention

Background

Oropharyngeal cancer is an important, understudied cancer affecting Aboriginal and Torres Strait Islander Australians. The human papillomavirus (HPV) is a significant risk factor for oropharyngeal cancer. Current generation HPV vaccines are effective against the 2 most common types of high-risk HPVs in cancer (hrHPVs 16/18).

Objectives

This study aims (1) to yield population estimates of oncogenic genotypes of HPV in the mouth and oropharynx of defined Aboriginal and Torres Strait Islander populations; (2) to estimate the proportion of oropharyngeal cancer attributable to HPV among these Australian citizens; (3) to estimate the impact of HPV vaccination as currently implemented on rates of oropharyngeal cancer among Aboriginal and Torres Strait Islander Australians; and (4) taking into account impact on oropharyngeal as well as cervical cancer, to evaluate efficacy and cost-effectiveness of targeted extended HPV vaccination to older ages, among our study population.

Methods

Our study design and operation is straightforward, with minimal impost on participants. It involves testing for carriage of hrHPV in the mouth and oropharynx among 1000 Aboriginal South Australians by simple saliva collection and with follow-up at 12 and 24 months, collection of sexual history at baseline, collection of information for estimating health state (quality-of-life) utilities at baseline, genotyping of viruses, predictive outcome and cost-effectiveness modeling, data interpretation and development of vaccination, and follow-up management strategies driven by the Aboriginal community.

Results

Participant recruitment for this study commenced in February 2018 and enrollment is ongoing. The first results are expected to be submitted for publication in 2019.

Conclusions

The project will have a number of important outcomes. Synthesis of evidence will enable generation of estimates of the burden of oropharyngeal cancer among Aboriginal and Torres Strait Islander Australians and indicate the likely effectiveness and cost-effectiveness of prevention. This will be important for health services planning, and for Aboriginal health worker and patient education. The results will also point to important areas where research efforts should be focused to improve outcomes in Aboriginal and Torres Strait Islander Australians with oropharyngeal cancer. There will be a strong focus on community engagement and accounting for the preferences of individuals and the community in control of HPV-related cancers. The project has international relevance in that it will be the first to systematically evaluate prevention of both cervical and oropharyngeal cancer in a high-risk Indigenous population taking into account all population, testing, and surveillance options.

Registered Report Identifier

RR1-10.2196/10503

Laparoscopic common bile duct exploration; a preferential pathway for elderly patients

Background

Laparoscopic common bile duct exploration (LCBDE) has emerged as a recommended alternative to endoscopic retrograde cholangiopancreatography (ERCP) for the management of choledocholithiasis. However, its use in the elderly has been limited, and evidence of its safety and efficacy in these patients is yet to be established. This study describes our experience of LCBDE in elderly patients, analysing the safety and efficacy of this technique in comparison to younger patients.

Methods

All patients undergoing laparoscopic cholecystectomy (LC) with LCBDE for choledocholithiasis in our unit between January 2015 and January 2017 were included. Data pertaining to patient demographics, comorbidities, investigations, operative technique and outcomes were analysed. Patients were divided into 2 groups based on age (Group A:<65 years vs Group B: >/ = 65 years) for comparative analysis.

Results

124 patients (Group A: 65, Group B: 59) were included. Group B were more co-morbid and had a higher ASA grade than Group A. However, there was no significant difference between groups in rates of conversion to open or complications, including bile leak (3.1% vs 5.1%, p = 0.67), retained stone (4.6% vs 1.7%, p = 0.62), or complications according to Clavien-Dindo classification (p = 0.78). Re-intervention rates were also similar between groups (7.7% vs 3.4%, p = 0.44 and 3.1% vs 3.4%, p = 1.0 respectively), as was length of stay.

Conclusion

Despite higher frequency of comorbidities and ASA grade, LCBDE in elderly patients is safe and effective, and has similar outcomes to younger patients. Therefore elderly patients with choledocholithiasis should be offered LCBDE as an alternative to ERCP.

Low-temperature tolerances of tropical fish with potential transgenic applications in relation to winter water temperatures in Canada

Application of fluorescent protein transgenes in tropical freshwater fish is used in research (e.g., in zebrafish) and in the commercial ornamental aquarium trade. To assess the overwinter potential of such fish in Canada, we examined the minimum temperature tolerance of three wild-type species (zebrafish, Danio rerio (Hamilton, 1822); black tetra, Gymnocorymbus ternetzi (Boulenger, 1895); tiger barb, Puntius tetrazona (Bleeker, 1855)) used as fluorescent models in the aquarium trade, as well as four lines of green fluorescent protein (GFP) transgenic and wild-type zebrafish used in research. Both tetra and barb had lower temperature tolerance limits that were higher than surveyed winter temperatures in Canada, and the lower tolerance limits of zebrafish lines was only within the range of a few surveyed lakes in some years. One line of GFP zebrafish had a lower temperature tolerance limit that was significantly higher than those of other lines, suggesting that some fluorescent transgene constructs may alter tolerance to extreme temperatures. When lines of zebrafish were reared at 8, 10, or 28 °C for 4 months, all lines were capable of producing viable embryos after cold rearing. These results indicate that tropical transgenic fish models used in research and in the aquarium trade are not expected to persist over winter in Canadian water systems.

Abstract P5-20-08: HER2 in-Situ hybridization positive breast cancers with HER2/CEP17 ratio ≥2.0 and average HER2 copy number &lt;4.0 are frequently discordant with HER2 immunohistochemistry results: Implications for potential modification of testing algorithm

Background: The current ASCO/CAP guidelines for the determination of HER2 status indicate that dual-probe in-situ hybridization (ISH) samples demonstrating a HER2/CEP17 ratio ≥ 2.0 and average HER2 copy number &lt;4.0 must be reported as positive. Patients with tumors showing these rare features were included in the first generation adjuvant trastuzumab clinical trials. In the absence of data showing lack of efficacy of HER2-targeted in this small subset of patients, these cases continue to be classified as positive without requiring additional work-up. Given that the HER2/CEP17 ratio is skewed in these cases by complex segmental deletions in chromosome 17, additional work-up may improve the final HER2 classification of these tumors. The objective of this study is to assess the potential impact of integrating HER2 IHC into the testing algorithm for these tumors by correlating the HER2 IHC results with ISH positive breast cancers demonstrating HER2/CEP17 ratio ≥2.0 and average HER2 copy number &lt;4.0.

Methods: All invasive mammary carcinomas demonstrating a HER2/CEP17 ratio ≥2.0 and average HER2 copy number &lt;4.0 were identified from our database for years 2009-2017. All ISH testing was performed using the PathVysion HER2 DNA probe kit (Abbott Molecular). During the study interval, HER2 FISH was the institutional primary testing methodology to determine HER2 status. HER2 IHC (Ventana 4B5) was performed on the same sample for all identified cases and scored using 2013 ASCO/CAP scoring guidelines.

Results: A total of 96 (1.4%) of 6,976 consecutive FISH cases met criteria for inclusion into the study. The majority of cases tested negative (67%) or equivocal (29%) by IHC. HER2 protein overexpression was observed in 4% of cases. The results of HER2 IHC testing are summarized below.

HER2 IHC results for HER2 ISH positive tumors showing ratio≥2.0 and average HER2 copy number &lt;4.0Cases (n)IHC Score 0IHC score 1+IHC score 2+IHC score 3+9612 (13%)52 (54%)28 (29%)4 (4%)

Conclusions: HER2 ISH positive breast cancers demonstrating a HER2/CEP17 ratio ≥2.0 and average HER2 copy number &lt;4.0 are rare (1.4% of cases in this study). HER2 IHC results for these tumors are negative in majority of cases. The observed HER2 protein overexpression rate was only 4% in this study. Integration of HER2 IHC into the testing algorithm for tumors demonstrating these uncommon ISH findings would result in reclassification of HER2 status to negative for most tumors.

Citation Format: Livasy C, Johnson N, Domfeh A. HER2 in-Situ hybridization positive breast cancers with HER2/CEP17 ratio ≥2.0 and average HER2 copy number &lt;4.0 are frequently discordant with HER2 immunohistochemistry results: Implications for potential modification of testing algorithm [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-20-08.

Distribution of the tick Dermacentor reticulatus in the United Kingdom

The recent implication of Dermacentor reticulatus (Ixodida: Ixodidae) in the transmission of canine babesiosis in the U.K. has highlighted the lack of accurate published data on its distribution in this country. This paper aims to collate and appraise historical data for D. reticulatus, to supplement such data with more recent surveillance data and to report on field sampling conducted during 2009-2016. These updated data facilitate better understanding of the current distribution of this tick in the U.K., which will better inform disease risk assessments. There appear to be four known regions of the U.K. in which D. reticulatus currently occurs, including western Wales, North and South Devon, and Essex. The majority of foci are located in coastal sand dunes and maritime grasslands, including grazing marsh. However, more recently the tick has been detected in urban greenspace in Essex. The emergence of this tick as a vector of babesiosis in the U.K. and its recent apparent spread in Essex into urban greenspace highlight the need for continued surveillance and for further research into its status as a vector of human and veterinary pathogens.

The bacteriome and mycobiome associated with oral squamous cell carcinoma: metagenomic analysis of samples from Yemeni and Sri Lankan cohorts

There is increasing interest in the possible role of the oral microbiome in oral squamous cell carcinoma (OSSC). However, studies on the possible association between the oral bacteriome and OSCC remain inconclusive, while the potential role of the “mycobiome” in oral carcinogenesis has never been explored. I hereby present results from our recent studies on the bacteriome and mycobiome associated with OSCC based on analysis of samples from Yemeni and Sri Lankan cohorts. Tissue biopsies were obtained from the cases while deep buccal swabs or fibro-epithelial polyps were collected from the controls. Sequencing of the bacterial V1-V3 region of the 16S rRNA gene and the fungal ITS2 region using Illumina’s 2x300 bp chemistry was employed to study the bacteriome and mycobiome, respectively. Merged reads were classified to species level using a BLASTN-algorithm. Downstream analyses were performed using QIIME, PICRUSt, and LEfSe. Fusobacterium nucleatum subsp. polymorphum, Pseudomonas aeruginosa, Prevotella and Campylobacter spp. were more abundant in OSCC samples while Streptococcus mitis and Rothia spp. were overrepresented in the controls. Functionally, inflammatory bacterial attributes including bacterial mobility, flagellar assembly, bacterial chemotaxis and LPS synthesis were enriched in the tumors. Mycobiome analysis revealed a dysbiotic fungal community dominated by C. albicans in association with OSCC.

Blood-feeding patterns of native mosquitoes and insights into their potential role as pathogen vectors in the Thames estuary region of the United Kingdom

BACKGROUND

The range of vertebrate hosts on which species of mosquito blood-feed is an important parameter for identifying potential vectors and in assessing the risk of incursion and establishment of vector-borne pathogens. In the United Kingdom, studies of mosquito host range have collected relatively few specimens and used techniques that could only broadly identify host species. This study conducted intensive collection and analysis of mosquitoes from a grazing marsh environment in southeast England. This site provides extensive wetland habitat for resident and migratory birds and has abundant human nuisance biting mosquitoes. The aim was to identify the blood-feeding patterns of mosquito species present at the site which could contribute to the transmission of pathogens.

METHODS

Twice-weekly collections of mosquitoes were made from Elmley Nature Reserve, Kent, between June and October 2014. Mosquitoes were collected using resting boxes, by aspiration from man-made structures and using a Mosquito Magnet Pro baited with 1-octen-3-ol. Blood-fed specimens were classified according to the degree of blood meal digestion using the Sella scale and vertebrate origin determined using sequencing of a fragment of the mitochondrial cytochrome C oxidase subunit I gene. Mosquitoes that were morphologically cryptic were identified to species level using multiplex PCR and sequencing methods.

RESULTS

A total of 20,666 mosquitoes of 11 species were collected, and 2,159 (10.4%) were blood-fed (Sella scale II-VI); of these 1,341 blood-fed specimens were selected for blood meal analysis. Vertebrate origin was successfully identified in 964 specimens (72%). Collections of blood-fed individuals were dominated by Anopheles maculipennis complex (73.5%), Culiseta annulata (21.2%) and Culex pipiens form pipiens (10.4%). Nineteen vertebrate hosts comprising five mammals and 14 birds were identified as hosts for mosquitoes, including two migratory bird species. Feeding on birds by Culex modestus and Anopheles atroparvus populations in England was demonstrated.

CONCLUSIONS

This study expands the vertebrate host range of mosquitoes in the Thames estuary region of the UK. Feeding on both resident and migratory bird species by potential arbovirus vectors including Cx. pipiens f. pipiens and Cx. modestus indicates the potential for enzootic transmission of an introduced arbovirus between migratory and local bird species by native mosquito species.

Are radiographic measurements of the displacement of a distal radial fracture reliable and reproducible?

AIMS

The degree of displacement of a fracture of the distal radius is an important factor which can be assessed using simple radiographic measurements. Our aim was to investigate the reliability and reproducibility of these measurements and to determine if they should be used clinically.

PATIENTS AND METHODS

A 10% sample was randomly generated from 3670 consecutive adult patients who had presented to University Hospitals of Leicester NHS Trust between 2007 and 2010 with a fracture of the distal radius. Radiographs of the 367 patients were assessed by two independent reviewers. Four measurements of displacement of the fracture were recorded and the inter-observer correlation assessed using the intra-class correlation coefficient.

RESULTS

Inter-observer correlation was high (> 0.8) for three of the four measurements. Repeat measurements of a further randomly generated 10% sample (37) were made four weeks later to assess intra-observer agreement, which was again high (> 0.8) for the same three parameters (radial height, radial inclination and dorsal/palmar tilt). Correlation was poor for articular step and gap.

CONCLUSION

Radiographic assessment of radial angle, radial inclination and dorsal/palmar tilt is a reliable method of determining the degree of displacement of a fracture of the distal radius. Cite this article: Bone Joint J 2016;98-B:1069-73.

Wrist function in malunion: Is the distal radius designed to retain function in the face of fracture?

Introduction Fractures of the distal radius are the most common fracture in humans and are the sempiternal hazard of 3.5 million years of bipedalism. Despite the antiquity of the injury, one of the most controversial topics in current orthopaedics is the management of distal radius fractures. It has been suggested that radiographic appearances rarely correlate with functional outcomes. As the success of the human species is predicated almost exclusively on its dexterity and intelligence, it is conceivable that the distal radius has evolved to preserve function even in the face of injury. We therefore hypothesise that the distal radius is designed to accommodate the possibility of fracture. Methods We conducted a review of studies comparing fracture pattern and form with function. We also explore the paleoanthropological evidence and comparative studies with other primates. Findings The evidence points to the human distal radius being highly tolerant of post-fracture deformity in terms of preservation of function. In addition, the distal radius appears to have apparently anatomically 'redundant' features that confer this capability. We believe these phenomena to be an evolved trait that developed with bipedalism, increasing the chances of survival for a species whose success depends upon its dexterity.

Does physical activity moderate the association between alcohol drinking and all-cause, cancer and cardiovascular diseases mortality? A pooled analysis of eight British population cohorts

OBJECTIVE

To examine whether physical activity (PA) moderates the association between alcohol intake and all-cause mortality, cancer mortality and cardiovascular diseases (CVDs) mortality.

DESIGN

Prospective study using 8 British population-based surveys, each linked to cause-specific mortality: Health Survey for England (1994, 1998, 1999, 2003, 2004 and 2006) and Scottish Health Survey (1998 and 2003).

PARTICIPANTS

36 370 men and women aged 40 years and over were included with a corresponding 5735 deaths and a mean of 353 049 person-years of follow-up.

EXPOSURES

6 sex-specific categories of alcohol intake (UK units/week) were defined: (1) never drunk; (2) ex-drinkers; (3) occasional drinkers; (4) within guidelines (<14 (women); <21 (men)); (5) hazardous (14-35 (women); 21-49 (men)) and (6) harmful (>35 (women) >49 (men)). PA was categorised as inactive (≤7 MET-hour/week), active at the lower (>7.5 MET-hour/week) and upper (>15 MET-hour/week) of recommended levels.

MAIN OUTCOMES AND MEASURES

Cox proportional-hazard models were used to examine associations between alcohol consumption and all-cause, cancer and CVD mortality risk after adjusting for several confounders. Stratified analyses were performed to evaluate mortality risks within each PA stratum.

RESULTS

We found a direct association between alcohol consumption and cancer mortality risk starting from drinking within guidelines (HR (95% CI) hazardous drinking: 1.40 (1.11 to 1.78)). Stratified analyses showed that the association between alcohol intake and mortality risk was attenuated (all-cause) or nearly nullified (cancer) among individuals who met the PA recommendations (HR (95% CI)).

CONCLUSIONS

Meeting the current PA public health recommendations offsets some of the cancer and all-cause mortality risk associated with alcohol drinking.