CRISPR-Cas-amplified urinary biomarkers for multiplexed and portable cancer diagnostics

Synthetic biomarkers, bioengineered sensors that generate molecular reporters in diseased microenvironments, represent an emerging paradigm in precision diagnostics. Despite the utility of DNA barcodes as a multiplexing tool, their susceptibility to nucleases in vivo has limited their utility. Here we exploit chemically stabilized nucleic acids to multiplex synthetic biomarkers and produce diagnostic signals in biofluids that can be 'read out' via CRISPR nucleases. The strategy relies on microenvironmental endopeptidase to trigger the release of nucleic acid barcodes and polymerase-amplification-free, CRISPR-Cas-mediated barcode detection in unprocessed urine. Our data suggest that DNA-encoded nanosensors can non-invasively detect and differentiate disease states in transplanted and autochthonous murine cancer models. We also demonstrate that CRISPR-Cas amplification can be harnessed to convert the readout to a point-of-care paper diagnostic tool. Finally, we employ a microfluidic platform for densely multiplexed, CRISPR-mediated DNA barcode readout that can potentially evaluate complex human diseases rapidly and guide therapeutic decisions.

Laparoscopic total extra-peritoneal (TEP) inguinal hernia repair under local anesthesia by topical lidocaine injection

PURPOSE

Laparoscopic total extra-peritoneal (TEP) inguinal hernia repair is usually performed under general anesthesia (GA) for muscle relaxation. However, TEP hernia repair may be reluctant in high-risk patients of GA. The aim of this study was to compare the outcomes of the TEP under GA and local anesthesia (LA).

METHODS

We retrospectively analyzed patients with inguinal hernia who underwent TEP under GA or LA in a single center from December 2016 to May 2018. The outcomes, such as demographics, duration of surgery, length of hospital stay, visual analog scale (VAS), and postoperative complications, were compared in each group.

RESULTS

Seventy-six patients with inguinal hernia underwent TEP under GA (n = 52) or LA (n = 24). Total operation time (mean ± standard deviation; GA, 111.6 ± 23.0 min; LA, 76.3 ± 18.0 min; p < 0.001) and length of hospital stay (GA, 38.3 ± 11.6 min; LA, 30.3 ± 15.6 min; p < 0.014) were shorter in LA group compared to GA group. There were no significant differences in postoperative VAS (1 h, p = 0.247; 4 h, p = 0.086; 12 h, p = 0.469; 24 h, p = 0.411), postoperative adverse effects (vomiting, p = 0.570; urinary retention, p = 0.214; headache, p = 0.494), and postoperative complications (seroma, p = 0.348; scrotal edema, p = 0.178; recurrence, p = 0.822) between LA group and GA group.

CONCLUSION

Compared with GA, there were no differences in postoperative pain and complications in patients who underwent TEP hernia repair under LA. Furthermore, in LA group, total operation time and length of hospital stay were shortened.

Host protease activity classifies pneumonia etiology

Community-acquired pneumonia (CAP) has been brought to the forefront of global health priorities due to the COVID-19 pandemic. However, classification of viral versus bacterial pneumonia etiology remains a significant clinical challenge. To this end, we have engineered a panel of activity-based nanosensors that detect the dysregulated activity of pulmonary host proteases implicated in the response to pneumonia-causing pathogens and produce a urinary readout of disease. The nanosensor targets were selected based on a human protease transcriptomic signature for pneumonia etiology generated from 33 unique publicly available study cohorts. Five mouse models of bacterial or viral CAP were developed to assess the ability of the nanosensors to produce etiology-specific urinary signatures. Machine learning algorithms were used to train diagnostic classifiers that could distinguish infected mice from healthy controls and differentiate those with bacterial versus viral pneumonia with high accuracy. This proof-of-concept diagnostic approach demonstrates a way to distinguish pneumonia etiology based solely on the host proteolytic response to infection.

A214 SIMPLIFICATION OF CARE FOR HCV IS EFFECTIVE DURING THE COVID PANDEMIC: A RETROSPECTIVE STUDY OF HCV TREATMENT UTILIZING THE BRITISH COLUMBIA HEPATITIS C NETWORK

Background

The COVID-19 pandemic has impacted healthcare access, including to curative treatment for hepatitis C (HCV) infection in the form of direct-acting antivirals (DAAs). A 49% decrease in DAA dispensations in Canada during the pandemic has been reported, but little is known about these treated populations.

Aims

To explore the patient characteristics and treatment patterns in those who were treated for HCV during the COVID pandemic.

Methods

A retrospective chart review was conducted at one site of utilizing the British Columbia Hepatitis C Network. Only patients included into the database were analyzed. Patients started on treatment between 03/17/2020-03/16/2021 were included as the “pandemic group” and patients from the 03/17/2019-03/16/2020 were included as a comparison “pre-pandemic group”. Data were extracted for clinicodemographic variables, laboratory investigations, treatment start date, regimen, and sustained virologic response at 12 weeks (SVR12).

Results

97 patients were treated during the pandemic compared to 143 patients the year prior, representing a 32% decline. Patients treated during the pandemic were predominantly new referrals (n=70, 72% vs n=64, 45% pre-pandemic, p&lt;0.01) and had fewer total appointments (median 2 per patient vs 4 per patient pre-pandemic, p&lt;0.01). There was a median of 1 in-person visit and 1 telehealth appointment per patient during the pandemic (vs median 2 per patient of each type pre-pandemic).

Pandemic patients were younger (mean age 56.0 years vs 59.6 pre-pandemic, p=0.04), and a greater proportion were on opioid agonist therapy (28% vs 13% pre-pandemic, p&lt;0.01). Less transient elastography (TE) was performed during the pandemic (69% vs 89% pre-pandemic). Amongst those with TE scores, a lower proportion of those treated during the pandemic were cirrhotic (13% vs 21% pre-pandemic).

During the pandemic, treatment patterns shifted towards more prescriptions for glecaprevir/pibrentasvir (56% of all prescriptions vs 44% pre-pandemic) and sofosbuvir/velpatasvir (37% vs 29% pre-pandemic). There was slightly less use of sofosbuvir/velpatasvir/voxilaprevir at (2% vs 4% pre-pandemic).

The proportion of patients who completed lab work for SVR was similar during the pandemic (n=83/97, 85.6%) compared to pre-pandemic (n=120/143, 83.9%). Similarly, SVR12 remained high during the pandemic at 98.7% (vs 99.3% pre-pandemic). Of all 97 patients prescribed DAAs during the pandemic, 92 (94.8%) completed treatment.

Conclusions

Less persons were treated during the COVID pandemic, which may deter progress towards HCV elimination targets. Very high SVR12 and treatment completion rates during the pandemic suggest that patients can be effectively treated with less pre-treatment investigations and fewer appointments.

Funding Agencies

None

Microenvironment-triggered multimodal precision diagnostics

Therapeutic outcomes in oncology may be aided by precision diagnostics that offer early detection, localization and the opportunity to monitor response to therapy. Here, we report a multimodal nanosensor engineered to target tumours through acidosis, respond to proteases in the microenvironment to release urinary reporters and (optionally) carry positron emission tomography probes to enable localization of primary and metastatic cancers in mouse models of colorectal cancer. We present a paradigm wherein this multimodal sensor can be employed longitudinally to assess burden of disease non-invasively, including tumour progression and response to chemotherapy. Specifically, we showed that acidosis-mediated tumour insertion enhanced on-target release of matrix metalloproteinase-responsive reporters in urine. Subsequent on-demand loading of the radiotracer ⁶⁴Cu allowed pH-dependent tumour visualization, enabling enriched microenvironmental characterization when compared with the conventional metabolic tracer ¹⁸F-fluorodeoxyglucose. Through tailored target specificities, this modular platform has the capacity to be engineered as a pan-cancer test that may guide treatment decisions for numerous tumour types.

A164 PATTERNS IN MEDICAL THERAPY AND CLINICAL OUTCOMES IN PATIENTS WITH CONCOMITANT INFLAMMATORY BOWEL DISEASE AND PRIMARY SCLEROSING CHOLANGITIS: A SINGLE CENTRE RETROSPECTIVE ANALYSIS

Background

Inflammatory bowel disease (IBD) in patients with primary sclerosing cholangitis (PSC) is characterized by pancolitis with rectal sparing and is associated with an increased risk of colorectal and biliary malignancies. Currently, pharmacologic management of IBD in the setting of PSC is the same as in IBD alone.

Aims

To assess patterns in medical therapy, and incidence of adverse outcomes in patients with concomitant IBD and PSC.

Methods

A retrospective review was conducted on all PSC-IBD patients followed between January 2010 and June 2018. The Endoscopic Mayo Score was used to grade IBD severity in PSC-ulcerative colitis (UC).

Results

69 patients were identified, 44 (63.8%) were male. The mean ages of IBD and PSC diagnosis were 28.6 (SD 14.9) and 37.0 (SD 18.9) years, respectively. The median length of follow up was 12 (range 2–49) years. 52 (75.4%) patients had UC, and 17 (24.6%) had Crohn’s disease (CD). 28 (87.5%) PSC-UC patients had pancolitis, and 4 (12.5 %) had proctitis. Among those with pancolitis, 8 (28.6%) had relative rectal sparing. 4 (14.3%) patients had more severe inflammation proximally, whereas only 1 (3.6%) had more severe distal inflammation. 23 (82.1%) patients had the same degree of inflammation throughout. 14 (93.3%) PSC-CD patients had colitis/ileocolitis and 1 (6.7%) had ileitis. Among those with PSC-UC, 16 (50.0%), 12 (37.5%), and 4 (12.5%) patients had grade 1, 2, and 3 disease, respectively. 62 (89.9%) PSC-IBD patients were treated with aminosalicylates, and 26 (37.7%) with biologics at some point in their IBD course. 26 (37.7%) were treated with aminosalicylates alone. 4 (5.8%) did not require any IBD therapy. Cholangiocarcinoma, colorectal cancer, and gallbladder cancer developed in 8 (11.6%), 1 (1.4%), and 1 (1.4%) PSC-IBD patients, respectively. 16 (23.2%) patients required partial or total colectomy. Indication for surgery was inflammation or stenosis, dysplasia, and neoplasia in 13 (81.3%), 2 (12.5%), and 1 (6.3%) patients, respectively.

Conclusions

The majority of this cohort had UC with mild disease activity. Pancolitis was common, with frequent rectal sparing and more severe right-sided inflammation. Despite the predominance of low-grade colitis, a large portion of patients required treatment with biologics. The incidence of adverse outcomes underscores the need for strict adherence to recommended surveillance practices. Low grade endoscopic activity, typical of the quiescent IBD course in PSC-IBD, may mask low grade histologic inflammation, which in turn may contribute to the increased risk of colonic neoplasia. Further studies are needed to determine the best management strategy for IBD in patients with PSC.

Funding Agencies

None

A208 PREDICTORS OF OUTCOMES IN PSC: RETROSPECTIVE ANALYSIS OF TWO TERTIARY CARE CENTERS IN BC

Background

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disorder of the bile ducts. PSC can rapidly progress to cholangiocarcinoma and death. Many clinical features of PSC, as well as its relationship with diseases such as IBD, remain ill-defined. These features are important for disease modeling and clinical trial design.

Aims

To identify features of PSC that may aid in disease modeling and outcomes prediction.

Methods

Patients with a diagnosis of PSC with visits between 2012 and 2018 were identified and data were extracted. Survival analysis was performed, with time defined as time of PSC diagnosis to time at clinical endpoint. The clinical endpoint for survival analysis was defined as development of cholangiocarcinoma, liver transplantation or death. Univariate and multivariate Cox-regression was then performed.

Results

169 patients (99 male, 70 female) were identified. Of these, 102 (60.4%) had a diagnosis of IBD (84 UC). 138 were Caucasian, 9 East Asian, 9 South Asian and 13 Middle East. Mean age at PSC diagnosis was 39.3, IBD diagnosis 29.3 years. Mean time to next diagnosis in those with PSC-IBD was 7.7 years. Of those with PSC-IBD, IBD preceded the diagnosis of PSC in 69 (67.6%) patients. 22 (13.0%) had concurrent liver disease, including 14 AIH and 1 PBC overlap. In those with UC, disease was most often pancolitis (57.8%), with noticeable rate of backwash ileitis (23.3%). There were 26 patients with current or prior use of Infliximab, 14 with Humira, and 6 with Vedolizumab. 28 (16.6%) patients had a partial or total colectomy. 35 (20.7%) patients had diagnoses of cancer, including 16 cholangiocarcinoma, 2 gall bladder carcinoma, and 4 colorectal. 33 (19.5%) patients received liver transplant, and 31 (18.3%) died. Most frequent cause of death was cholangiocarcinoma (12, 38.7%). Univariate analysis identified increased age at PSC diagnosis, presence of IBD, increased age at IBD diagnosis, diagnosis of IBD prior to PSC, increased time from diagnosis of IBD to PSC, diagnosis of UC as opposed to Crohn’s, and lack of Infliximab use as significant predictors of our clinical endpoints (p&lt;0.05). Multivariate analysis only identified increased age at PSC diagnosis, presence of IBD, and diagnosis of IBD prior to PSC as predictors.

Conclusions

PSC affects persons of various ethnic backgrounds. Diagnosis of IBD appears to precede PSC in most PSC-IBD cases, and the temporal relationship may impact outcomes, possibly due to delayed diagnosis of PSC. UC has a worse disease course than Crohn’s. Cholangiocarcinoma still accounts for a large burden of overall death in PSC, and strategies for early diagnosis should be explored. More studies are required to delineate the relationship between biologic use and PSC outcomes. The major limitation of our study is the smaller sample size that may have limited statistical power.

Funding Agencies

NoneNone

Uniform spatial pooling explains topographic organization and deviation from receptive-field scale invariance in primate V1

Receptive field (RF) size and preferred spatial frequency (SF) vary greatly across the primary visual cortex (V1), increasing in a scale invariant fashion with eccentricity. Recent studies reveal that preferred SF also forms a fine-scale periodic map. A fundamental open question is how local variability in preferred SF is tied to the overall spatial RF. Here, we use two-photon imaging to simultaneously measure maps of RF size, phase selectivity, SF bandwidth, and orientation bandwidth—all of which were found to be topographically organized and correlate with preferred SF. Each of these newly characterized inter-map relationships strongly deviate from scale invariance, yet reveal a common motif—they are all accounted for by a model with uniform spatial pooling from scale invariant inputs. Our results and model provide novel and quantitative understanding of the output from V1 to downstream circuits.

Two-photon imaging in macaque V1 captured maps of tuning selectivity for four spatial parameters, all of which correlated with peak spatial frequency. These inter-map relationships reveal a common motif—they are described by uniform spatial pooling from a family of scale invariant Gabor receptive fields.

Peptide Spiders: Peptide-Polymer Conjugates to Traffic Nucleic Acids

Therapeutic nucleic acids hold great promise for the treatment of genetic diseases, yet the delivery of this highly charged macromolecular drug remains a challenge in the field. Peptides are promising agents to mediate nucleic acid delivery because they can encode a biological function to overcome the trafficking barriers. Electrostatic nanocomplexes of nucleic acid and peptides can achieve effective delivery, but the balance between their stability and biological function must be finely tuned. In this work, we explore two peptide building blocks that have been studied in the literature: targeting ligands and intracellular trafficking peptides. We grafted these peptides on a polyethylene glycol (PEG) backbone with eight sites for substitution to create so-called "peptide spiders". These conjugates achieve stability via the well-known hydrophilic shielding effect of PEG. In addition, the coordination of peptide building blocks into multimers may create new biological properties, such as the well-known phenomena of increased binding avidity with multivalent ligands. In this work, we linked two trafficking peptides to the PEG backbone using either nonreducible or reducible chemistries and investigated the ability of these materials to carry silencing RNAs into mammalian cells. We then investigated these nanomaterials for their pharmacokinetic properties and silencing of undruggable targets in a mouse model of cancer. While reducible linkages were more potent at silencing in vitro, this effect was reversed when applied in the context of living animals. This work offers an insight into peptide-based delivery materials and investigates peptide-polymer linkages.

A136 PREDICTIVE FACTORS OF CIRRHOSIS IN HCV PATIENTS WITH LOW PRE-TREATMENT APRI AND/OR FIB-4 SCORES

Background

It is essential to evaluate the stage of hepatic fibrosis prior to the initiation of HCV therapy. In addition to being a major prognostic factor, the presence of cirrhosis requires monitoring for hepatocellular carcinoma (HCC), esophageal varices, and decompensated liver disease. In some cases the presence of cirrhosis may affect the choice of therapy. In tertiary hepatology clinics, transient elastography (TE) is routinely used to assess fibrosis; however access to TE is limited. Fibrosis-4 (FIB4) and AST-to-platelet ratio index (APRI) are simple, easily available non-invasive methods of fibrosis measurement based on routine serum biomarkers. Studies evaluating HCV treatment pathways have reported that the use of FIB4 and APRI are cost-effective strategies for excluding cirrhosis thereby reducing the need for TE prior to treatment. Although the NPV of these tests are well described, a minority of patients will have advanced fibrosis despite low APRI and/or FIB4 scores.

Aims

To investigate predictive factors of cirrhosis in HCV patients with low pre-treatment APRI and/or FIB-4 scores.

Methods

Retrospective observational study with data obtained from the Pacific Gastroenterology Associates (PGA), a tertiary care outpatient Gastroenterology clinic located in Vancouver, British Columbia. Inclusions: Chronic HCV patients treated between Jan 2015 to 2019, pre-treatment TE values ≥12.5 kPa, FIB-4 &lt;1.45 and/or APRI &lt;0.7. Exclusions: those without cirrhosis, or incomplete evaluation prior to HCV treatment. Cirrhosis was defined as those with TE ≥12.5 kPa with clinical, radiographic, or pathologic features of cirrhosis.

Results

52 patients were identified. 11 patients did not have clinical, radiographic, or pathologic features of cirrhosis and 3 patients were excluded for insufficient data. Thus, 39 patients were included in multivariate analysis. The mean age was 59 years and 66% (25/38) were male gender. 10% (4/38) were Genotype 3 (G3). Presence of G3 was not included in the multivariate analysis due to low number of observations.

Conclusions

Generally, an APRI &lt;0.7 and FIB-4 &lt;1.45 have good test characteristics for excluding fibrosis. Our study demonstrates that patients with obesity, dyslipidemia, excessive alcohol use, or known steatosis on ultrasound may have cirrhosis despite low serum biomarker scores. Co-existence of other liver diseases such as alcohol related or non-alcoholic fatty liver disease (NAFLD) should prompt further evaluation for fibrosis assessment beyond biomarkers as these persons may have more advanced liver disease.

Funding Agencies

None

A186 HEPATIC STEATOSIS PREDICTS FIBROSIS IN LONG-TERM METHOTREXATE USE

Background

Methotrexate (MTX) is effective for dermatologic and rheumatologic conditions such as psoriasis (Ps), psoriatic arthritis (PsO) and rheumatoid arthritis (RA). Long-term MTX use may be complicated by hepatic fibrosis, although patient, disease factors and the mechanism remain unclear. Transient elastography (TE) is a non-invasive measure of hepatic fibrosis that is often used as surveillance in this patient population.

Patients with Ps and PsO have higher rates of non-alcoholic fatty liver disease. The controlled attenuation parameter (CAP) measurement is a non-invasive test that correlates with histologic degree of steatosis. To our knowledge, no studies have evaluated hepatic steatosis via CAP scores in MTX use.

Aims

To determine the prevalence of steatosis and significant fibrosis (F≥stage 2) in persons on MTX therapy and to determine the predictive factors for these events.

Methods

A single centred retrospective cohort study was performed. Patients on &gt;6 months of MTX for a dermatologic or rheumatologic disease who had undergone TE from January 2015 to September 2019 were included. Demographic variables, laboratory investigations, TE and CAP scores were collected. Multivariate analysis was performed to determine predictors of steatosis and fibrosis.

Results

A total of 177 patients on methotrexate were included. Ps was the most frequent diagnosis (n=52) followed by RA (n=50) and PsO (n=38). Steatosis (CAP≥245 dB/m) was present in 73.9% of patients. Patients with steatosis had significantly more fibrosis and a higher BMI than those without steatosis (CAP&lt;245 dB/m). Higher CAP score was correlated with increased lifetime dose of methotrexate by Pearson correlation analysis (r=0.48, p=0.001) (n=85 patients). Multivariate regression analysis revealed that diabetes mellitus (OR 10.5, 95% CI 1.38–80.60), hypertension (OR 4.97, 95% CI 1.66–14.84), and BMI&gt; 30 (OR 10.1, 95% CI 1.88–37.14) were predictors of steatosis (CAP≥245 dB/m). Predictors of METAVIR≥F2 (TE≥8.0 kPa) by multivariate regression analysis included CAP score of ≥270 (OR 8.36, 95% CI 1.88–37.14), diabetes mellitus (OR 2.85, 95% CI 1.09–7.48), hypertension (OR 5.4, 95% CI 2.23–13.0), dyslipidemia (OR 3.71, 95% CI 1.50–9.18) and alcohol use (OR 3.06, 95% CI 1.2–7.49).

Conclusions

In patients on MTX for rheumatologic and dermatologic diseases, hepatic steatosis was common and predicted significant fibrosis. Additionally, increasing MTX exposure is correlated with steatosis. Features of the metabolic syndrome including diabetes, hypertension or obesity were predictors of both steatosis and fibrosis (F≥2). Further study is needed to evaluate if steatosis is a mechanism by which fibrosis occurs in patients on MTX, or if it due to other patient factors.

Funding Agencies

None

Twelve-day medium pumping into tubular cell-laden scaffold using a lab-made PDMS connector

In the current study, a method is proposed to supply culture medium into a two-layered cell-laden tubular scaffold in order to enhance cell proliferation, confluence, and viability. The two-layered cell-laden tubular scaffold was made of calcium-alginate mixed with fibroblast cells (NIH/3T3) using a lab-made double- coaxial laminar-flow generator. Afterwards, the tubular scaffold was connected to a syringe pump system using a polydimethylsiloxane (PDMS) micro-connector for long-term cell culture. Three medium pumping conditions were applied and compared: a heart-beat-mimicking pumping (20 µL/s, 1 s period, and 50 % pulse width), a continuous pumping (20 µL/s) and a non-pumping. Non-leaky connections between the tubular scaffolds and the micro-connector outlet were sustained for 13.5 ± 0.83 d in heartbeat-mimicking pumping and 11.8 ± 0.33 d in continuous pumping condition, due to the elasticity of the tubular scaffolds. Importantly, the two pumping conditions resulted in more cell proliferation, confluence, and viability than the non-pumping condition. Furthermore, analysis of newly-produced type-I collagen matrix indicated that the cells under the two pumping conditions formed a tissue-like structure. The proposed technique could further be applied to vascular co-culturing for vascular engineered tissue.

Bioinks and bioprinting technologies to make heterogeneous and biomimetic tissue constructs

The native tissues are complex structures consisting of different cell types, extracellular matrix materials, and biomolecules. Traditional tissue engineering strategies have not been able to fully reproduce biomimetic and heterogeneous tissue constructs because of the lack of appropriate biomaterials and technologies. However, recently developed three-dimensional bioprinting techniques can be leveraged to produce biomimetic and complex tissue structures. To achieve this, multicomponent bioinks composed of multiple biomaterials (natural, synthetic, or hybrid natural-synthetic biomaterials), different types of cells, and soluble factors have been developed. In addition, advanced bioprinting technologies have enabled us to print multimaterial bioinks with spatial and microscale resolution in a rapid and continuous manner, aiming to reproduce the complex architecture of the native tissues. This review highlights important advances in heterogeneous bioinks and bioprinting technologies to fabricate biomimetic tissue constructs. Opportunities and challenges to further accelerate this research area are also described.

Risk-reducing mastectomy for the prevention of primary breast cancer

BACKGROUND

Recent progress in understanding the genetic basis of breast cancer and widely publicized reports of celebrities undergoing risk-reducing mastectomy (RRM) have increased interest in RRM as a method of preventing breast cancer. This is an update of a Cochrane Review first published in 2004 and previously updated in 2006 and 2010.

OBJECTIVES

(i) To determine whether risk-reducing mastectomy reduces death rates from any cause in women who have never had breast cancer and in women who have a history of breast cancer in one breast, and (ii) to examine the effect of risk-reducing mastectomy on other endpoints, including breast cancer incidence, breast cancer mortality, disease-free survival, physical morbidity, and psychosocial outcomes.

SEARCH METHODS

For this Review update, we searched Cochrane Breast Cancer's Specialized Register, MEDLINE, Embase and the WHO International Clinical Trials Registry Platform (ICTRP) on 9 July 2016. We included studies in English.

SELECTION CRITERIA

Participants included women at risk for breast cancer in at least one breast. Interventions included all types of mastectomy performed for the purpose of preventing breast cancer.

DATA COLLECTION AND ANALYSIS

At least two review authors independently abstracted data from each report. We summarized data descriptively; quantitative meta-analysis was not feasible due to heterogeneity of study designs and insufficient reporting. We analyzed data separately for bilateral risk-reducing mastectomy (BRRM) and contralateral risk-reducing mastectomy (CRRM). Four review authors assessed the methodological quality to determine whether or not the methods used sufficiently minimized selection bias, performance bias, detection bias, and attrition bias.

MAIN RESULTS

All 61 included studies were observational studies with some methodological limitations; randomized trials were absent. The studies presented data on 15,077 women with a wide range of risk factors for breast cancer, who underwent RRM.Twenty-one BRRM studies looking at the incidence of breast cancer or disease-specific mortality, or both, reported reductions after BRRM, particularly for those women with BRCA1/2 mutations. Twenty-six CRRM studies consistently reported reductions in incidence of contralateral breast cancer but were inconsistent about improvements in disease-specific survival. Seven studies attempted to control for multiple differences between intervention groups and showed no overall survival advantage for CRRM. Another study showed significantly improved survival following CRRM, but after adjusting for bilateral risk-reducing salpingo-oophorectomy (BRRSO), the CRRM effect on all-cause mortality was no longer significant.Twenty studies assessed psychosocial measures; most reported high levels of satisfaction with the decision to have RRM but greater variation in satisfaction with cosmetic results. Worry over breast cancer was significantly reduced after BRRM when compared both to baseline worry levels and to the groups who opted for surveillance rather than BRRM, but there was diminished satisfaction with body image and sexual feelings.Seventeen case series reporting on adverse events from RRM with or without reconstruction reported rates of unanticipated reoperations from 4% in those without reconstruction to 64% in participants with reconstruction.In women who have had cancer in one breast, removing the other breast may reduce the incidence of cancer in that other breast, but there is insufficient evidence that this improves survival because of the continuing risk of recurrence or metastases from the original cancer. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention, when considering RRM.

AUTHORS' CONCLUSIONS

While published observational studies demonstrated that BRRM was effective in reducing both the incidence of, and death from, breast cancer, more rigorous prospective studies are suggested. BRRM should be considered only among those at high risk of disease, for example, BRCA1/2 carriers. CRRM was shown to reduce the incidence of contralateral breast cancer, but there is insufficient evidence that CRRM improves survival, and studies that control for multiple confounding variables are recommended. It is possible that selection bias in terms of healthier, younger women being recommended for or choosing CRRM produces better overall survival numbers for CRRM. Given the number of women who may be over-treated with BRRM/CRRM, it is critical that women and clinicians understand the true risk for each individual woman before considering surgery. Additionally, thought should be given to other options to reduce breast cancer risk, such as BRRSO and chemoprevention when considering RRM.

Water-adaptive and repeatable self-healing polymers bearing bulky urea bonds

A crosslinked copolymer having a reversible covalent bond between a bulky amine and an isocyanate presents reshapable, repeatable, and water-adaptive self-healing properties.

A micropatterned elastomeric surface with enhanced frictional properties under wet conditions and its application

Engineered surfaces that have high friction under wet or lubricated conditions are important in many practical applications. However, it is not easy to achieve stable high friction under wet conditions because a layer of fluid prevents direct solid-solid contact. Here, we report a micropatterned elastomeric surface with superior wet friction. The surface has unique arch-shaped microstructures arrayed in a circle on the surface to provide high friction on wet or flooded surfaces. The arch-shaped micropatterned surface exhibits remarkably enhanced and stable friction under wet conditions, surpassing even the performance of the hexagonal patterns of tree frogs, owing to the large contact surface and the optimal shape of drainage channels. Robotic substrate transportation systems equipped with the micropatterned surfaces can manipulate a delicate wet substrate without any sliding in a highly stable and reproducible manner, demonstrating the superior frictional capabilities of the surface under wet conditions.

A systematic review of performance-enhancing pharmacologicals and biotechnologies in the Army

INTRODUCTION

In 2015, the Australian Army commissioned a systematic review to assess the evidence on effectiveness and safety of pharmacological and biotechnological products for cognitive enhancement specifically in Army personnel.

METHODS

Searches for studies examining biotechnological and pharmacological products in Army populations were conducted in December 2015. Cochrane CENTRAL, MEDLINE, EMBASE, CINAHL and PsycINFO were searched without date or language restrictions. WHO's International Clinical Trials Registry Platform and ClinicalTrials.gov were searched to identify ongoing trials. Studies meeting inclusion criteria were evaluated for risk of bias using Cochrane's Risk of Bias tool. Due to heterogeneity of findings, meta-analysis could not be conducted. Findings were synthesised narratively and by vote-counting method.

RESULTS

Sixteen pharmacological enhancement products were evaluated in 22 randomised controlled trials (RCTs), involving 1284 personnel. Only three of the studies were published since 2010. The interventions evaluated were varied, including supplements (eg, carbohydrate), stimulants (eg, caffeine) and hormones (eg, melatonin). Generally, caffeine provided an improvement in performance compared with placebo on 5/7 reported cognitive outcomes, followed by levothyroxine (four cognitive outcomes) and prazosin (three cognitive outcomes). Performance results were mixed (finding an improvement and no effect in comparison to placebo) for caffeine and melatonin on two outcomes. No evidence was found pertaining to biotechnological products. Studies rarely reported safety outcomes (eg, adverse events and addiction).

CONCLUSION

Findings from this review need to be interpreted with considerable caution. Future studies should include outcomes such as acute and long-term adverse events, and should evaluate cognitive performance using cognitive tests that are specific to the Army population.

Sustainability in health care by allocating resources effectively (SHARE) 4: exploring opportunities and methods for consumer engagement in resource allocation in a local healthcare setting

BACKGROUND

This is the fourth in a series of papers reporting a program of Sustainability in Health care by Allocating Resources Effectively (SHARE) in a local healthcare setting. Healthcare decision-makers have sought to improve the effectiveness and efficiency of services through removal or restriction of practices that are unsafe or of little benefit, often referred to as 'disinvestment'. A systematic, integrated, evidence-based program for disinvestment was being established within a large Australian health service network. Consumer engagement was acknowledged as integral to this process. This paper reports the process of developing a model to integrate consumer views and preferences into an organisation-wide approach to resource allocation.

METHODS

A literature search was conducted and interviews and workshops were undertaken with health service consumers and staff. Findings were drafted into a model for consumer engagement in resource allocation which was workshopped and refined.

RESULTS

Although consumer engagement is increasingly becoming a requirement of publicly-funded health services and documented in standards and policies, participation in organisational decision-making is not widespread. Several consistent messages for consumer engagement in this context emerged from the literature and consumer responses. Opportunities, settings and activities for consumer engagement through communication, consultation and participation were identified within the resource allocation process. Sources of information regarding consumer values and perspectives in publications and locally-collected data, and methods to use them in health service decision-making, were identified. A model bringing these elements together was developed.

CONCLUSION

The proposed model presents potential opportunities and activities for consumer engagement in the context of resource allocation.

Reducing cranial computed tomography effective radiation dose by 30% using adaptive iterative dose reduction

Introduction:

The use of computed tomography (CT) imaging as a diagnostic modality is increasing rapidly and CT is the dominant contributor to diagnostic medical radiation exposure. The aim of this project was to reduce the effective radiation dose to patients undergoing cranial CT examination, while maintaining diagnostic image quality.

Methods:

Data from a total of 1003, 132 and 27 patients were examined for three protocols: CT head, CT angiography (CTA), and CT perfusion (CTP), respectively. Following installation of adaptive iterative dose reduction (AIDR) 3D software, tube current was lowered in consecutive cycles, in a stepwise manner and effective radiation doses measured at each step.

Results:

Baseline effective radiation doses for CT head, CTA and CTP were 1.80, 3.60 and 3.96 mSv, at currents of 300, 280 and 130–150 mA, respectively. Using AIDR 3D and final reduced currents of 160, 190 and 70–100 mA for CT head, CTA and CTP gave effective doses of 1.29, 3.18 and 2.76 mSv, respectively.

Conclusion:

We demonstrated that satisfactory reductions in the effective radiation dose for CT head (28.3%), CTA (11.6%) and CTP (30.1%) can be achieved without sacrificing diagnostic image quality. We have also shown that iterative reconstruction techniques such as AIDR 3D can be effectively used to help reduce effective radiation dose. The dose reductions were performed within a short period and can be easily achievable, even in busy departments.

Development and preliminary evaluation of culturally specific web-based intervention for parents of adolescents

WHAT IS KNOWN ON THE SUBJECT?: Problematic parent-child relationships have been identified as one of the main predictors of adolescents' mental health problems, but there are few existing interventions that address this issue. The format and delivery method of existing interventions for parents are relatively inaccessible for parents with full-time jobs and families living in rural areas. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: The newly developed 'Stepping Stone' culturally specific web-based intervention, which is intended to help Korean parents of adolescents to acquire both knowledge and communication and conflict management skills, was found to be feasible and well-accepted by parents. This study enabled us to identify areas for improvement in the content and format of the intervention and strategies. This will potentially increase effect sizes for the outcome variables of parents' perception and behaviours. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This web-based intervention could be delivered across diverse settings, such as schools and community mental health centers, to increase parents' knowledge of adolescent's mental health and allow for early detection of mental health problems. Mental health nurses working in schools may spend a significant amount of time addressing students' mental health issues; thus, this web-based intervention could be a useful resource to share with parents and children. In this way, the mental health nurses could facilitate parental engagement in the intervention and then help them to continue to apply and practice the knowledge and skills obtained through the program.

ABSTRACT

Introduction There is a need for accessible, culturally specific web-based interventions to address parent-child relationships and adolescents' mental health. Aims This study developed and conducted a preliminary evaluation of a 4-week web-based intervention for parents of adolescents aged 11 to 16 years in Korea. Methods We used a two-group, repeated measures, quasi-experimental study design to assess the feasibility of developing and implementing a web-based intervention for parents. Descriptive statistics, chi-square and t tests, and mixed effect modeling were used for data analysis. Results The intervention and 1-month follow-up survey were completed by 47 parents in the intervention group and 46 parents in the attention control (AC) group. The intervention was found to be feasible and well-accepted by parents. Discussion This culturally specific web-based intervention is a useful tool for knowledge dissemination among large numbers of parents. Areas for improvement in the content and format of the intervention and strategies to elicit significant parent-child interactions are provided. Implications for practice and conclusion The intervention could be disseminated in collaboration with mental health nurses working in schools to facilitate parents' participation.

Analysis of the barriers and enablers to implementing lifestyle management practices for women with PCOS in Singapore

BACKGROUND

Polycystic ovary syndrome (PCOS) is a condition that affects women of reproductive age and manifests with adverse reproductive, metabolic and psychological consequences. Evidence-based PCOS guidelines recommend lifestyle management first line for infertility. In Singapore women with PCOS can attend the PCOS Clinic at the Kandang Kerbau Women and Children's Hospital for infertility treatment. However lifestyle integration into infertility management is currently limited and barriers and enablers to progress remain unclear.

METHODS

All PCOS clinic staff undertook semi-structured interviews to investigate perceived barriers for staff and consumers for the integration of lifestyle into infertility management. This study utilised various tools including an 8P Ishikawa diagram model to identify and categorise barriers. A modified Hanlon method was then used to prioritise barriers within the Singaporean context considering organisational, cultural and financial constraints. Propriety, economics, acceptability, resources and legality (PEARL) criteria were also incorporated into this decision-making tool.

RESULTS

In the 8P model, there were five factors contributing to the 'procedure (consultations and referral processes)' barrier, one 'policy (government and hospitals)' factor, five 'place' factors, two 'product (lifestyle management programme)' barriers, two 'people (programme capacity)' factors, four 'process (integration)' factors, three 'promotion' barriers and three 'price' factors. Of the prioritised barriers, two were identified across each of 'procedures', 'place', 'product' and 'people' and four related to 'processes'. There were no barriers identified that for 'policies', 'promotion' and 'price' that can be addressed.

CONCLUSIONS

There is a clear need to integrate lifestyle into infertility management in PCOS, in line with current national and international evidence-based guidelines. The highest priority identified improvement opportunity was to develop a collaborative lifestyle management programme across hospital services. Reductions in variation of delivery and strengthening support within the lifestyle programme are other identified priorities. The strength of this study is that this is the first study to utilise a pragmatic quality improvement method for barriers identification and prioritisation in the area of lifestyle management for women with PCOS. This project identified factors that may provide easy improvements, but also identified some local factors that may be very difficult to change. The major limitation of this study is that it is only looking at the Singapore setting, so may have limited applicability to other countries. However, results from quality improvement projects are meant to be context specific.

In science communication, why does the idea of a public deficit always return? How do the shifting information flows in healthcare affect the deficit model of science communication?

The healthcare field contains a multitude of opportunities for science communication. Given the many stakeholders dancing together in a multidirectional tango of communication, we need to ask how much does the deficit model apply to the health field? History dictates that healthcare professionals are the holders of all knowledge, and the patients and other stakeholders are the ones that need the scientific information communicated to them. This essay argues otherwise, in part due to the rise of shared decision-making and patients and other stakeholders acting as partners in healthcare. The traditional deficit model in health held that: (1) doctors were experts and patients were consumers, (2) it is impossible for the public to grasp the many disciplines of knowledge in medicine, (3) if experts have trouble keeping up with medical research then the public surely can't keep up, and (4) it is safer for healthcare professionals to communicate to the public using a deficit model. However, with the rise of partnerships with patients in healthcare decision-making, the deficit model might be weakening. Examples of public participation in healthcare decision-making include: (1) crowd-sourcing public participation in systematic reviews, (2) public participation in health policy, (3) public collaboration in health research, and (4) health consumer groups acting as producers of health information. With the challenges to the deficit model in science communication in health, caution is needed with the increasing role of technology and social media, and how these may affect the legitimacy of healthcare information flows away from the healthcare professional.

Tunable osteogenic differentiation of hMPCs in tubular perfusion system bioreactor

The use of bioreactors for bone tissue engineering has been widely investigated. While the benefits of shear stress on osteogenic differentiation are well known, the underlying effects of dynamic culture on subpopulations within a bioreactor are less evident. In this work, we explore the influence of applied flow in the tubular perfusion system (TPS) bioreactor on the osteogenic differentiation of human mesenchymal progenitor cells (hMPCs), specifically analyzing the effects of axial position along the growth chamber. TPS bioreactor experiments conducted with unidirectional flow demonstrated enhanced expression of osteogenic markers in cells cultured downstream from the inlet flow. We utilized computational fluid dynamic modeling to confirm uniform shear stress distribution on the surface of the scaffolds and along the length of the growth chamber. The concept of paracrine signaling between cell populations was validated with the use of alternating flow, which diminished the differences in osteogenic differentiation between cells cultured at the inlet and outlet of the growth chamber. After the addition of controlled release of bone morphogenic protein-2 (BMP-2) into the system, osteogenic differentiation among subpopulations along the growth chamber was augmented, yet remained homogenous. These results allow for greater understanding of axial bioreactor cultures, their microenvironment, and how well-established parameters of osteogenic differentiation affect bone tissue development. With this work, we have demonstrated the capability of tuning osteogenic differentiation of hMPCs through the application of fluid flow and the addition of exogenous growth factors. Such precise control allows for the culture of distinct subpopulation within one dynamic system for the use of complex engineered tissue constructs. Biotechnol. Bioeng. 2016;113: 1805-1813. © 2016 Wiley Periodicals, Inc.

Dynamic Bioreactor Culture of High Volume Engineered Bone Tissue

Within the field of tissue engineering and regenerative medicine, the fabrication of tissue grafts of any significant size--much less a whole organ or tissue--remains a major challenge. Currently, tissue-engineered constructs cultured in vitro have been restrained in size primarily due to the diffusion limit of oxygen and nutrients to the center of these grafts. Previously, we developed a novel tubular perfusion system (TPS) bioreactor, which allows the dynamic culture of bead-encapsulated cells and increases the supply of nutrients to the entire cell population. More interestingly, the versatility of TPS bioreactor allows a large range of engineered tissue volumes to be cultured, including large bone grafts. In this study, we utilized alginate-encapsulated human mesenchymal stem cells for the culture of a tissue-engineered bone construct in the size and shape of the superior half of an adult human femur (∼ 200 cm(3)), a 20-fold increase over previously reported volumes of in vitro engineered bone grafts. Dynamic culture in TPS bioreactor not only resulted in high cell viability throughout the femur graft, but also showed early signs of stem cell differentiation through increased expression of osteogenic genes and proteins, consistent with our previous models of smaller bone constructs. This first foray into full-scale bone engineering provides the foundation for future clinical applications of bioengineered bone grafts.

Dietary composition in the treatment of polycystic ovary syndrome: a systematic review to inform evidence-based guidelines

While lifestyle management is recommended as first-line treatment of polycystic ovary syndrome (PCOS), the optimal dietary composition is unclear. The aim of this study was to compare the effect of different diet compositions on anthropometric, reproductive, metabolic, and psychological outcomes in PCOS. A literature search was conducted (Australasian Medical Index, CINAHL, EMBASE, Medline, PsycInfo, and EBM reviews; most recent search was performed January 19, 2012). Inclusion criteria were women with PCOS not taking anti-obesity medications and all weight-loss or maintenance diets comparing different dietary compositions. Studies were assessed for risk of bias. A total of 4,154 articles were retrieved and six articles from five studies met the a priori selection criteria, with 137 women included. A meta-analysis was not performed due to clinical heterogeneity for factors including participants, dietary intervention composition, duration, and outcomes. There were subtle differences between diets, with greater weight loss for a monounsaturated fat-enriched diet; improved menstrual regularity for a low-glycemic index diet; increased free androgen index for a high-carbohydrate diet; greater reductions in insulin resistance, fibrinogen, total, and high-density lipoprotein cholesterol for a low-carbohydrate or low-glycemic index diet; improved quality of life for a low-glycemic index diet; and improved depression and self-esteem for a high-protein diet. Weight loss improved the presentation of PCOS regardless of dietary composition in the majority of studies. Weight loss should be targeted in all overweight women with PCOS through reducing caloric intake in the setting of adequate nutritional intake and healthy food choices irrespective of diet composition.