An internal pilot study of a novel rectal mucocellular sampling device to allow next-generation sequencing for colorectal disease

BACKGROUND

The ORI-EGI-02 study was designed to test the hypothesis that rectal mucus collected using a novel rectal sampling device (OriCol™), contains sufficient human deoxyribonucleic acid (DNA) of the required quality for Next Generation Sequencing (NGS), for colorectal disease genetic signature discovery.

METHODS

Using National Institute for Health and Care Research methodology, an internal pilot study was performed in January 2020-May 2021, at four sites in the United Kingdom, to assess the process of recruitment, consent, specimen acquisition and viability for analysis. Following an OriCol™ test, the sample was stabilized with a buffer solution to preserve the material, which was posted to the laboratory. Samples were processed using QIAamp® DNA Blood Midi kit to extract DNA and Quant-iT™ PicoGreen® dsDNA Reagent to quantify the retrieved DNA. DNA integrity was measured by Agilent TapeStation system. 25 ng of human amplifiable DNA was prepared for Next Generation Sequencing (NGS), which was performed on an Illumina NextSeq550 sequencer using the 300-cycle high output kit v2.5.

RESULTS

This study assessed the first 300 patients enrolled to the ORI-EGI-02 Study (n = 800). 290/300 (96.67%) were eligible to undergo OriCol™ sampling procedure and 285/290 (98.27%) had a successful OriCol™ sample taken. After transportation, extraction and quantification of DNA, 96.20% (279/290) of the samples had NGS successfully performed for bioinformatic analysis.

CONCLUSIONS

Our internal pilot study demonstrated that the OriCol™ sampling device can capture rectal mucus from unprepared bowel in subjects who could undergo a digital rectal examination. The technique could be applied irrespective of age, frailty, or co-morbidity. Completion of the study to 800 patients and analysis of NGS data for colorectal cancer mutations will now proceed.

A distinct cognitive profile in individuals with 3q29 deletion syndrome

BACKGROUND

3q29 deletion syndrome is associated with mild to moderate intellectual disability as well as comorbid psychopathology such as ADHD, anxiety, ASD and schizophrenia. A greater understanding of specific profiles that could increase risk for psychopathology is necessary in order to best understand and support individuals with 3q29 deletion syndrome. The goal of this study was to thus carefully outline the strengths and weaknesses of these individuals. A second goal was to ask whether the cognitive impact of the deletion predicted psychopathology in other domains.

METHODS

We systematically evaluated cognitive ability, adaptive behaviour and psychopathology in 32 individuals with the canonical 3q29 deletion using gold-standard instruments and a standardised phenotyping protocol.

RESULTS

Mean full scale IQ was 73 (range 40-99). Verbal subtest score (mean 80, range 31-106) was slightly higher and had a greater range than non-verbal subtest score (mean 75, range 53-98). Spatial ability was evaluated in a subset (n = 24) and was lower than verbal and non-verbal ability (mean 71, range 34-108). There was an average 14-point difference between verbal and non-verbal subset scores; 60% of the time the verbal subset score was higher than the non-verbal subset score. Study subjects with a verbal ability subtest score lower than the non-verbal subtest score were four times more likely to have a diagnosis of intellectual disability (suggestive, P value 0.07). The age at which a child first spoke two-word phrases was strongly associated with measures of verbal ability (P value 2.56e-07). Cognitive ability was correlated with adaptive behaviour measures (correlation 0.42, P value 0.02). However, although group means found equivalent scores, there was, on average, a 10-point gap between these skills (range -33 to 33), in either direction, in about 50% of the sample, suggesting that cognitive measures only partially inform adaptive ability. Cognitive ability scores did not have any significant relationship to cumulative burden of psychopathology nor to individual neurodevelopmental or psychiatric diagnoses.

CONCLUSIONS

Individuals with 3q29 deletion syndrome have a complex pattern of cognitive disability. Two-thirds of individuals with the deletion will exhibit significant strength in verbal ability; this may mask deficits in non-verbal reasoning, leading to an overestimation of overall ability. Deficits in verbal ability may be the driver of intellectual disability diagnosis. Cognitive ability is not a strong indicator of other neurodevelopmental or psychiatric impairment; thus, individuals with 3q29 deletion syndrome who exhibit IQ scores within the normal range should receive all recommended behavioural evaluations.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

The association between area-level residential instability and gray matter volume changes

Introduction

Area-level residential instability (ARI), an index of social fragmentation, has been shown to explain the association between urbanicity and psychosis. Urban upbringing has been shown to be associated with decreased gray matter volumes (GMV)s of brain regions corresponding to the right caudal middle frontal gyrus (CMFG) and rostral anterior cingulate cortex (rACC).

Objectives

We hypothesize that greater ARI will be associated with reduced right posterior CMFG and rACC GMVs.

Methods

Data were collected at baseline as part of the North American Prodrome Longitudinal Study. Counties where participants resided during childhood were geographically coded using the US Censuses to area-level factors. ARI was defined as the percentage of residents living in a different house five years ago. Generalized linear mixed models tested associations between ARI and GMVs.

Results

This study included 29 HC and 64 CHR-P individuals who were aged 12 to 24 years, had remained in their baseline residential area, and had magnetic resonance imaging scans. ARI was associated with reduced right CMFG (adjusted β = -0.258; 95% CI = -0.502 – -0.015) and right rACC volumes (adjusted β = -0.318; 95% CI = -0.612 – -0.023). The interaction terms (ARI X diagnostic group) in the prediction of both brain regions were not significant, indicating that the relationships between ARI and regional brain volumes held for both CHR-P and HCs.

Conclusions

Like urban upbringing, ARI may be an important social environmental characteristic that adversely impacts brain regions related to schizophrenia.

Disclosure

No significant relationships.

P61 Impact of the COVID-19 pandemic on the presentation and management of acute appendicitis: a single-centre analysis

Introduction

The COVID-19 pandemic has influenced the delivery of healthcare. In accordance with the UK Joint Royal Colleges’ advice the management of acute appendicitis (AA) changed with greater consideration for non-operative management (NOM) or open appendicectomy where operative management (OM) s sought. Our aim is to share our experience of the presentation, management and outcomes for patients presenting to our Trust with AA to guide care for future viral pandemics.

Methods

This single-centre retrospective cohort study included patients diagnosed with AA in March to July 2019 compared with March to July 2020. Medical records were used to evaluate demographics, inflammatory markers, imaging, severity, management, histology, length of stay (LOS), complications and 90-day outcomes.

Results

There were 149 and 125 patients in the 2019 and 2020 cohort, respectively. 14 patients (9.4%) had NOM in 2019 versus 31 patients (24.8%) in 2020 (p = 0.001). In the 2019 OM group 125 patients (92.6%) had laparoscopic appendicectomy versus 69 (73.4%) in 2020. 59 patients (39.6%) had a CT in 2019 versus 70 (56%) in 2020. The median LOS was 4 days (interquartile range (IQR) 3 to 6 days) in 2019 and 3 days (IQR 2 to 5 days) in 2020 (p = 0.03). Two patients in each year who received NOM had treatment failure (14.3% in 2019 and 6.5% in 2020). Three patients in 2019 who had OM had treatment failure (2.2%). Of 95 patients tested for COVID-19 all but one was negative.

Conclusion

During the COVID-19 pandemic there was no observed increase in severity of AA, patients had a shorter LOS and were more likely to have imaging. NOM proportionally increased with no observed change in outcomes.

Emerging strains of watermelon mosaic virus in Southeastern France: model-based estimation of the dates and places of introduction

Where and when alien organisms are successfully introduced are central questions to elucidate biotic and abiotic conditions favorable to the introduction, establishment and spread of invasive species. We propose a modelling framework to analyze multiple introductions by several invasive genotypes or genetic variants, in competition with a resident population, when observations provide knowledge on the relative proportions of each variant at some dates and places. This framework is based on a mechanistic-statistical model coupling a reaction–diffusion model with a probabilistic observation model. We apply it to a spatio-temporal dataset reporting the relative proportions of five genetic variants of watermelon mosaic virus (WMV, genus Potyvirus, family Potyviridae) in infections of commercial cucurbit fields. Despite the parsimonious nature of the model, it succeeds in fitting the data well and provides an estimation of the dates and places of successful introduction of each emerging variant as well as a reconstruction of the dynamics of each variant since its introduction.

Development of near-infrared imaging agents for detection of junction adhesion molecule-A protein

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Anti-junctional adhesion molecule-A (JAM-A) monoclonal antibodies (mAb) conjugated with near infra-red fluorescent dye, IR700 – as a JAM-A mAb/IR700 agent was developed.

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An in vivo JAM-A mAb/IR700-specific near infra-red imaging of human-derived prostate and breast cancer xenograft is presented.

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A single injection of the agent is diminished number of mitotic cells in cancerous tissue of mice bearing heterotopic tumors.

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Since, our agent depicts the specific accumulation within the targeted tumors, this agent may be adapted to solid tumor targeted photoimmunotherapy.

Introduction

Prostate and breast cancer are the most prevalent primary malignant human tumors globally. Prostatectomy and breast conservative surgery remain the most common definitive treatment option for the >500,000 men and women newly diagnosed with localized prostate and breast cancer each year only in the US. Morphological examination is the mainstay of diagnosis but margin under-sampling of the excised cancer tissue may lead to local recurrence. In despite of the progress of non-invasive optical imaging, there is still a clinical need for targeted optical imaging probes that could rapidly and globally visualize cancerous tissues.

Methods

Elevated expression of junctional adhesion molecule-A (JAM-A) on tumor cells and its multiple pro-tumorigenic activity make the JAM-A a candidate for molecular imaging. Near-infrared imaging probe, which employed anti-JAM-A monoclonal antibody (mAb) phthalocyanine dye IR700 conjugates (JAM-A mAb/IR700), was synthesized and used to identify and visualize heterotopic human prostate and breast tumor mouse xenografts in vivo.

Results

The intravenously injected JAM-A mAb/IR700 conjugates enabled the non-invasive detection of prostate and breast cancerous tissue by fluorescence imaging. A single dose of JAM-A mAb/IR700 reduced number of mitotic cancer cells in vivo, indicating theranostic ability of this imaging agent. The JAM-A mAb/IR700 conjugates allowed us to image a specific receptor expression in prostate and breast tumors without post-image processing.

Conclusion

This agent demonstrates promise as a method to image the extent of prostate and breast cancer in vivo and could assist with real-time visualization of extracapsular extension of cancerous tissue.

The effects of temperature and frequency dispersion on sound speed in bulk poly (vinyl alcohol) poly (N-isopropylacrylamide) hydrogels caused by the phase transition

Bulk Poly (Vinyl Alcohol) (PVA) Poly (N-isopropyl acrylamide) (PNIPAm) hydrogel, one of the thermally responsive phase transitive hydrogels, is a versatile material due to its sharp volumetric phase transition and anomalous behaviors with facile tunability by thermal stimulation. At the lower critical solution temperature (LCST) of 33 °C, the hydrogels undergo a volumetric phase transition that causes drastic, non-monotonic change in the elastic modulus, viscosity, stiffness, and speed of sound. Here, we report the temperature and frequency dependence of the speed of sound in bulk PVA-PNIPAm hydrogel as measured by means of a planar resonant cavity. The linear response theory is applied for calculation of frequency dependent speed of sound. Comparisons find standard time of flight techniques underestimate the speed of sound by up to 6%, with variation in the frequency dependent speed of sound reaching as high as 200 m/s in the ultrasonic range of 0.2-0.8 MHz. The first characterization of frequency dependent speed of sound in PVA-PNIPAm hydrogel is addressed and delineated into its phase transition behaviors as connected to temperature. The findings can lead to better characterization of mechanical properties using ultrasonic spectroscopy, and higher resolution in ultrasonic imaging applications with dispersive media.

Risk factors, and the neurodevelopmental course of schizophrenia

From birth to two years, preschizophrenic children show much higher rates of neuromotor abnormalities and negative affective displays than their healthy siblings. Retrospectively, parents report that preschizophrenic children show more social and interpersonal problems and more abnormalities of thought. Similar results have been found with adolescents who have schizotypal personality disorder. Adolescence appears to be a critical period for the emergence of psychopathology in general, but especially for psychotic disorders. This may in large part be through the actions of gonadal and adrenal hormones, including cortisol, and in particular their influence on the expression of genes. In the case of schizophrenia, these are presumably the vulnerability genes. Patients with schizophrenia have heightened baseline levels of cortisol, and a heightened cortisol response to some biological challenges. Cortisol levels are positively correlated with symptom severity. In addition, the hippocampus, which modulates the activity of the HPA axis, is abnormal in schizophrenia. The HPA axis and hippocampal complex are modulatory neural systems; in the case of schizophrenia, what they might be modulating is the expression of abnormalities in dopamine neurotransmission. Whilst we assume that schizophrenia has prenatal neurodevelopmental origins, neural maturational processes that occur later in life, especially in adolescence, have significant implications for the expression of the illness. It is likely that preventive interventions for schizophrenia, be they pharmacological or behavioural, will have the best chance of success if they are directed at adolescents who are showing preschizophrenic indicators.

Core outcome set for uncomplicated acute appendicitis in children and young people

Background

Research studies to inform clinical practice and policy in children and young people with appendicitis are hampered by inconsistent selection and reporting of outcomes. The aim of this study was to develop a core outcome set for reporting all studies of uncomplicated acute appendicitis in children and young people.

Methods

Systematic literature reviews, qualitative interviews with parents and patients treated for uncomplicated acute appendicitis, and a Study‐Specific Advisory Group informed a long list of outcomes. Outcomes were then prioritized by stakeholders based in the UK (patients, parents, and paediatric and general surgeons) in an online three‐round Delphi consensus process, followed by face‐to‐face consensus meetings.

Results

A long list of 40 items was scored by 147 key stakeholders in the first Delphi round, of whom 90 completed the two subsequent Delphi rounds. The final core outcome set comprises 14 outcomes: intra‐abdominal abscess, reoperation (including interventional radiology procedure), readmission to hospital, bowel obstruction, wound infection, antibiotic failure, wound complication, negative appendicectomy, recurrent appendicitis, death, patient stress/psychological distress, length of hospital stay, time away from full activity and child's quality of life.

Conclusion

A core outcome set comprising 14 outcomes across five key domains has been developed for reporting studies in children and young people with uncomplicated acute appendicitis. Further work is required to determine how and when to measure these outcomes.

Taurine Analysis in Milk and Infant Formulae by Liquid Chromatography: Collaborative Study

A collaborative study was conducted on a liquid chromatographic (LC) method for determination of taurine in infant formula and milk powders. Twenty laboratories participated in the analysis of 8 blind duplicates over the range of approximately 3–60 mg/100 g sample. The method involved protein removal, conversion to the dansyl-derivative, and isocratic LC separation with UV and/or fluorescence detection. Following outlier treatment, overall mean RSDR has been estimated at 7.00% for sup. plemented products with a HORRAT value of 1.1. The poorer precision at endogenous levels establishes a lower limit of determination of about 5 mg/100 g. An overall mean RSDr:RSDR value of 0.7 for all products demonstrated acceptable performance.

Abstract PD2-11: Ki-67 (30-9) scoring and differentiation in Luminal A and Luminal B breast cancer subtypes

Introduction

Ki-67 labeling index is a powerful prognostic marker in breast cancer (BC). It is especially useful in assessing the risk of recurrence for estrogen receptor-positive (ER+) BC, where it may be considered a surrogate of the molecular assays for distinguishing Luminal A-like from Luminal B-like BCs. We evaluated the performance of the VENTANA anti Ki-67 (30-9) rabbit monoclonal antibody in assessing the risk of distant relapses for a large series of patients with ER+ BC treated and followed up in a single Institution.

Patients and Methods

The initial cohort (9415 patients) comprised all women operated on for early ER+, HER2-negative (HER2-) BC at the European Institute of Oncology (IEO), who did not receive neo-adjuvant treatment1. We subsequently restricted the cohort to 3986 patients operated on between 1998-2002 and for whom long-term follow-up data was available. A case-cohort was built by randomly selecting 17% of the above cohort (679 patients, including 84 with events). Additional 303 patients who developed an event (metastasis in distant organs or death due to BC as primary events) were added to this cohort.

Ki-67 was evaluated using the anti-Ki-67 (30-9) antibody (Ventana Medical Systems, Inc., Tucson, AZ) using OptiView IHC DAB detection on the BenchMark ULTRA advanced staining platform. The stained slides were evaluated using the scoring method described by the International Ki-67 in BC Working Group.

We considered “Luminal A-like” tumors that were ER+, HER2-, with Ki-67 <14% or with Ki-67 14-19% and PgR ≥20%, and “Luminal B-like” ER+, HER2- tumors with Ki-67 14-19% and PgR <20% or with Ki-67 ≥20%1.

The main outcome was distant disease-free survival (DDFS) and was calculated from the date of surgery to the date of any first event or last contact with the patient.

Cumulative incidence curves were drawn for patients in the sub-cohort and differences between BC subtypes were assessed using the log-rank test. Multivariable Cox regression with inverse sub-cohort sampling probability weighting was used to evaluate the risk of metastasis or death from BC across groups.

Results

In the sub-cohort, 400 (58.9%) patients had “luminal A-like” and 279 (41.1%) “luminal B-like” BC. The 10-year cumulative incidence of distant metastasis (or BC related death as first event) in the two groups were respectively 8.2% and 24.5% (log rank P<0.0001)

In the whole case-cohort, multivariable analysis confirmed statistically significant increased risk of events for women with “Luminal B-Like” BC compared to women with “Luminal A-Like “BC (HR=1.97; 95% CI 1.38-2.79), after adjustment for pT, pN, PVI and menopausal status.

Conclusion

Ki-67 evaluated using the VENTANA anti-Ki67 (30-9) antibody, was able to stratify patients with endocrine responsive BC, maximizing the number of those classified as having 'Luminal A-like' intrinsic subtype for whom the use of cytotoxic drugs could be at large avoided.

Funding source: Ventana Medical Systems, Inc.

References

Maisonneuve P, Disalvatore D, Rotmensz N, et al. (2014) Proposed new clinicopathological surrogate definitions of luminal A and luminal B (HER2-negative) intrinsic breast cancer subtypes. Breast Cancer Res 16:R65

Citation Format: Viale G, Hanlon Newell AE, Walker E, Bai I, Russo L, Dell'Orto P, Maisonneuve P. Ki-67 (30-9) scoring and differentiation in Luminal A and Luminal B breast cancer subtypes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD2-11.

Fluctuation, invisibility, fatigue - the barriers to maintaining employment with systemic lupus erythematosus: results of an online survey

Objectives

Systemic lupus erythematosus (SLE) is associated with high levels of workplace disability and unemployment. The objective of this study was to understand the reasons for this and to describe the barriers and facilitators of employment identified by people with SLE to develop appropriate solutions. Unemployment, as well as unsuitable work, has adverse health outcomes.

Methods

Adults with SLE completed a UK-specific online survey, through the LUPUS UK website, designed to find out more about the difficulties and successes that people with SLE have in maintaining employment. The survey was predominantly qualitative, to understand participants’ employment experiences to generate possible solutions.

Results

Three hundred and ninety-three people gave detailed responses to the survey within eight weeks. Every respondent reported a detrimental effect of SLE on their ability to work: 40.45% had left employment because of it. The themes of concern to respondents were unambiguous: (i) the difficulties of working (and career damage) with SLE, (ii) fear and anxiety overshadowing work/family life, (iii) the greater potential to remain in some employment or stay in full employment when modifications of work pattern and support from management and colleagues were available. SLE-related fatigue, its invisibility and fluctuating nature were felt to be the main barriers to maintaining employment. Numerous respondents could work only part-time and anxiety was high regarding their future ability to continue working. Many had taken substantial pay reductions and refused offered promotions to preserve their health. Distress due to loss of work and the benefits it brings were reported by every respondent who had left work.

Conclusion

SLE presents specific difficulties for maintaining employment – fatigue, fluctuation and invisibility – not addressed by current anti-discrimination legislation or currently available ‘reasonable adjustments’. This study demonstrates that (i) employment is an important area of concern for people with SLE, (ii) SLE has significant detrimental effects on individuals’ ability to participate and progress in employment, (iii) legislators and employers need information about SLE as invisibility and fluctuation cause hidden problems, and (iv) more data is needed to inform workplace adjustments if individual distress and societal loss of skills are to be addressed.

Nonreciprocal Linear Transmission of Sound in a Viscous Environment with Broken P Symmetry

Reciprocity is a fundamental property of the wave equation in a linear medium that originates from time-reversal symmetry, or T symmetry. For electromagnetic waves, reciprocity can be violated by an external magnetic field. It is much harder to realize nonreciprocity for acoustic waves. Here we report the first experimental observation of linear nonreciprocal transmission of ultrasound through a water-submerged phononic crystal consisting of asymmetric rods. Viscosity of water is the factor that breaks the T symmetry. Asymmetry, or broken P symmetry along the direction of sound propagation, is the second necessary factor for nonreciprocity. Experimental results are in agreement with numerical simulations based on the Navier-Stokes equation. Our study demonstrates that a medium with broken PT symmetry is acoustically nonreciprocal. The proposed passive nonreciprocal device is cheap, robust, and does not require an energy source.

Assessing the Implementation of Workplace Health Programs Outside of Controlled Environments

The study explored the implementation of workplace health programmes in 14 NHS Trusts (hospitals). It sought to identify different approaches to implementation and measures that could be used to guide future development. The study comprised inter-related elements examining the process of implementing workplace health and the impact on staff. An innovative action research approach was applied to the evaluation. The aims of the evaluation were to generate activity and learning within the organisations which was sustainable (long term) and transferable outside the study organisations. The study is described in terms of the multiple methods and the ways in which these have been brought together in the analysis. The approach has been informed by a shift from an individualistic perspective towards one which sees the health of workers within the broader context of organisational development and management. The research identified a number of dilemmas for workplace health with its focus on the health of the individual. A typology was developed which describes different approaches to workplace health and their impact on sustaining such initiatives. It suggests that for workplace health to be successful it must address the organisational context as well as individual staff needs. Results from a survey of staff in the 14 trusts seems to demonstrate an association between the approaches, described in the typology, and an impact on staff. Workplace health programmes need to shift towards approaches where the individual’s health is seen within the wider context of the organisation.

The Efficiency of Bone Marrow Aspiration for the Harvest of Connective Tissue Progenitors from the Human Iliac Crest

BACKGROUND

The rational design and optimization of tissue engineering strategies for cell-based therapy requires a baseline understanding of the concentration and prevalence of osteogenic progenitor cell populations in the source tissues. The aim of this study was to (1) define the efficiency of, and variation among individuals in, bone marrow aspiration as a means of osteogenic connective tissue progenitor (CTP-O) harvest compared with harvest from iliac cancellous bone, and (2) determine the location of CTP-Os within native cancellous bone and their distribution between the marrow-space and trabecular-surface tissue compartments.

METHODS

Eight 2-mL bone marrow aspiration (BMA) samples and one 7-mm transcortical biopsy sample were obtained from the anterior iliac crest of 33 human subjects. Two cell populations were obtained from the iliac cancellous bone (ICB) sample. The ICB sample was placed into αMEM (alpha-minimal essential medium) with antibiotic-antimycotic and minced into small pieces (1 to 2 mm in diameter) with a sharp osteotome. Cells that could be mechanically disassociated from the ICB sample were defined as marrow-space (IC-MS) cells, and cells that were disassociated only after enzymatic digestion were defined as trabecular-surface (IC-TS) cells. The 3 sources of bone and marrow-derived cells were compared on the basis of cellularity and the concentration and prevalence of CTP-Os through colony-forming unit (CFU) analysis.

RESULTS

Large variation was seen among patients with respect to cell and CTP-O yield from the IC-MS, IC-TS, and BMA samples and in the relative distribution of CTP-Os between the IC-MS and IC-TS fractions. The CTP-O prevalence was highest in the IC-TS fraction, which was 11.4-fold greater than in the IC-MS fraction (p < 0.0001) and 1.7-fold greater than in the BMA fraction. However, the median concentration of CTP-Os in the ICB (combining MS and TS fractions) was only 3.04 ± 1.1-fold greater than that in BMA (4,265 compared with 1,402 CTP/mL; p = 0.00004).

CONCLUSIONS

Bone marrow aspiration of a 2-mL volume at a given needle site is an effective means of harvesting CTP-Os, albeit diluted with peripheral blood. However, the median concentration of CTP-Os is 3-fold less than from native iliac cancellous bone. The distribution of CTP-Os between the IC-MS and IC-TS fractions varies widely among patients.

CLINICAL RELEVANCE

Bone marrow aspiration is an effective means of harvesting CTP-Os but is associated with dilution with peripheral blood. Overall, we found that 63.5% of all CTP-Os within iliac cancellous bone resided on the trabecular surface; however, 48% of the patients had more CTP-Os contributed by the IC-MS than the IC-TS fraction.

Early clinical experience of dolutegravir in an HIV cohort in a larger teaching hospital

Dolutegravir (DTG) is the third HIV integrase inhibitor (INI) available for prescription in Belfast since July 2014. It has shown high virological efficacy in both treatment-naïve and -experienced patients. We carried out a retrospective case chart analysis of HIV-1-positive adults commenced on DTG between July 2014 and September 2015. Patients were identified from records as either treatment-naïve or antiretroviral therapy (ART) experienced. Outcomes included: (1) virological response (HIV-1 RNA viral load at 0, 4, 8 and 12 weeks), (2) immunological response (CD4+ cell count at 0, 4, 8 and 12 weeks) and (3) tolerability (side effects and discontinuation). The main exclusion criteria were patients transferring care already established on DTG from other treatment centres or inadequate follow-up information (defined as attendance at <50% of clinical and serological follow-up visits). One hundred and fifty-seven commenced DTG out of 823 patients on ART; 106 (68%) were switched to DTG from another regimen, and 51 (32%) were ART-naïve. One naïve and 14 treatment-experienced patients were excluded from the analysis due to failure to attend clinical follow-up. Analysis of HIV-1 RNA viral load (HIV-1 VL) was divided into three groups: 50 new starters, 68 suppressed at switch and 24 not suppressed at switch. New starters: Baseline median HIV-1 RNA VL 71,259 copies/mL (19,536_Q25-196,413_Q75); 73% were virally undetectable (HIV-1 RNA VL <70 copies/mL) by week 4. Switching patients: Of those with an HIV-1 RNA undetectable viral load prior to switching, two were detectable with a mean viral load of 443,730 copies/mL after four weeks. Of the 24 patients detectable at switch (median HIV-1 VL 2212 [311_Q25-43,467_Q75]), 10 were detectable after four weeks. For those with a recordable viraemia, the median HIV-1 VL reduced to 376 (220_Q25-1181_Q75). At week 12, four patients were detectable with a median VL of 12,390 (567_Q25-52,285_Q75). Overall, 56 (35%) reported side effects; 40 (25%) reported either difficulty with low mood, anxiety or sleep disturbance. Sixteen (10%) discontinued DTG, with 13 (8%) due to intolerable side effects. DTG is a useful drug in naïve or switch patients. It has the potential to effectively suppress the viral load within the first four weeks of treatment and thus reduces infectiousness. Within the cohort, DTG was generally well tolerated but side effects such as low mood, anxiety and sleep disturbance were high, with 8% of patients discontinuing treatment.

Risk assessment tools validated for patients undergoing emergency laparotomy: a systematic review

Emergency laparotomies are performed commonly throughout the world, but one in six patients die within a month of surgery. Current international initiatives to reduce the considerable associated morbidity and mortality are founded upon delivering individualised perioperative care. However, while the identification of high-risk patients requires the routine assessment of individual risk, no method of doing so has been demonstrated to be practical and reliable across the commonly encountered spectrum of presentations, co-morbidities and operative procedures. A systematic review of Embase and Medline identified 20 validation studies assessing 25 risk assessment tools in patients undergoing emergency laparotomy. The most frequently studied general tools were APACHE II, ASA-PS and P-POSSUM. Comparative, quantitative analysis of tool performance was not feasible due to the heterogeneity of study design, poor reporting and infrequent within-study statistical comparison of tool performance. Reporting of calibration was notably absent in many prognostic tool validation studies. APACHE II demonstrated the most consistent discrimination of individual outcome across a variety of patient groups undergoing emergency laparotomy when used either preoperatively or postoperatively (area under the curve 0.76-0.98). While APACHE systems were designed for use in critical care, the ability of APACHE II to generate individual risk estimates from objective, exclusively preoperative data items may lead to better-informed shared decisions, triage and perioperative management of patients undergoing emergency laparotomy. Future endeavours should include the recalibration of APACHE II and P-POSSUM in contemporary cohorts, modifications to enable prediction of morbidity and assessment of the impact of adoption of these tools on clinical practice and patient outcomes.

Heart rate recovery is an important predictor of outcomes in patients with connective tissue disease-associated pulmonary hypertension

Reduced heart rate recovery (HRR) after exercise is associated with increased mortality in cardiac and pulmonary diseases. We sought to evaluate the association between HRR after the 6-minute walk test (6MWT) and outcomes in patients with connective tissue disease-associated pulmonary hypertension (CTD-PH). Data were obtained by review of the medical records. HRR was defined as the difference in heart rate at the end of the 6MWT and after 1 minute (HRR1), 2 minutes (HRR2), and 3 minutes (HRR3) of rest. All patients with pulmonary hypertension and a diagnosis of systemic sclerosis, systemic lupus erythematosus, or mixed connective tissue disease who underwent the 6MWT between August 1, 2009, and October 30, 2011, were included (n = 66). By Kaplan-Meier analysis, HRR1, HRR2, and HRR3 at different cutoff points were all good predictors, with HRR1 of <16 being the best predictor of time to clinical worsening (log-rank P < 0.0001), hospitalization (log-rank P = 0.0001), and survival (log-rank P < 0.003). By proportional hazards regression, patients with HRR1 of <16 were at increased risk of clinical worsening (hazard ratio [HR]: 6.4 [95% confidence interval (CI): 2.6-19.2]; P < 0.0001], hospitalization (HR: 6.6 [95% CI: 2.4-23]; P < 0.0001), and death (HR: 4.5 [95% CI: 1.6-15.7]; P = 0.003). Patients in the highest tercile (HRR1 of ≥19) were unlikely to have a clinical worsening event (HR: 0.1 [95% CI: 0.04-0.5]; P = 0.001], to be hospitalized (HR: 0.1 [95% CI: 0.02-0.5]; P = 0.001), or to die (HR: 0.3 [95% CI: 0.07-0.9]; P = 0.04]. In conclusion, in patients with CTD-PH, abnormal HRR1 (defined as HRR1 of <16) after the 6MWT is a strong predictor of clinical worsening, time to clinical worsening, survival, and hospitalization.

Pulmonary macrophage alterations associated with aging and SIV infection in rhesus macaques (VIR9P.1155)

Accelerated aging occurs in HIV-infected persons HIV, despite ART, as seen by earlier onset of chronic inflammatory diseases and HIV-associated non-AIDS (HANA) conditions than in non-HIV-infected individuals. In the rhesus macaque SIV model, we reported earlier that increasing monocyte turnover associated with tissue macrophage death predicted onset of terminal disease progression. Here, we hypothesize that macrophage dysregulation contributes to accelerated aging that occurs during SIV infection. We compared macrophage populations of the lung in older and younger uninfected and SIV-infected rhesus macaques. We observed that the ratio of alveolar macrophages (AM) to interstitial macrophages (IM) was significantly lower in chronic SIV-infected younger macaques and older uninfected monkeys compared to uninfected young macaques. The mechanisms differed, however, because the lower ratio in the older uninfected monkeys was due to lower numbers of AM while the shift during SIV infection of younger adults was due to increasing numbers of IM. Functionally, AM of older vs younger uninfected animals exhibited higher levels of pro-inflammatory cytokine secretion (TNFα, IL12) during incubation in medium yet produced lower levels of cytokines after induction with LPS ex vivo. During the acute phase of SIV infection, we observed a higher turnover of monocytes and IM in older compared to younger macaques. This suggests that AM become dysregulated during aging and SIV/HIV infection.

Distinct impact of SIV infection in interstitial and alveolar lung macrophages on the pathogenesis of lung disease in rhesus macaques (VIR9P.1147)

Declining CD4+ T cells during HIV infection contributes to immunodeficiency, but we recently reported that increasing monocyte turnover better predicted onset of terminal disease progression to AIDS in SIV-infected rhesus macaques. Here we describe the kinetics of SIV infection on distinct lung macrophage subsets and on monocyte/macrophage turnover rates in relation to pulmonary disease progression in rhesus macaques. Monocyte and tissue macrophage turnover were monitored by in vivo BrdU injection and cell uptake. Cell-associated SIV DNA in lung tissue was quantified by qPCR and in situ hybridization. Massive SIV infection was associated with increasing death rate of shorter-lived lung interstitial macrophages (IM) with elevated monocyte turnover and progression to AIDS. Conversely, the turnover of alveolar macrophages (AM) and decreasing numbers of CD4+ T cells in lung tissue did not directly correlate with disease progression. SIV DNA levels within IM and AM of the lung increased as monocyte turnover increased, but did not change within lung CD4+ T cells regardless of the stage of disease. These data suggest that SIV infection and concurrent destruction of lung IM contribute to pulmonary pathogenesis during AIDS progression while the longer-lived AM that become infected may contribute to establishing a virus reservoir. Also, bronchoalveolar lavage (BAL) specimens contain AM but not IM, so may be insufficient for fully evaluating macrophage-mediated responses in the lung.

The Effect of Intensive Education On Urinary Incontinence Following Radical Prostatectomy: A Randomized Control Trial

Intense bladder control education failed to improve bladder control among patients who underwent a radical prostatectomy as treatment of their prostate cancer. Despite this educational intervention, participants continued to experience post-operative bladder control problems. Nurses need to develop and implement novel interventions that might enhance bladder control.

Higher working memory predicts slower functional decline in autopsy-confirmed Alzheimer's disease

BACKGROUND

There is heterogeneity in the pattern of early cognitive deficits in Alzheimer's disease (AD). However, whether the severity of initial cognitive deficits relates to different clinical trajectories of AD progression is unclear.

OBJECTIVE

To determine if deficits in specific cognitive domains at the initial visit relate to the rate of progression in clinical trajectories of AD dementia.

METHODS

68 subjects from the National Alzheimer's Coordinating Center database who had autopsy-confirmed AD as the primary diagnosis and at least 3 serial assessments a year apart, with a Mini-Mental State Examination (MMSE) score >15 and a Clinical Dementia Rating Scale-Global (CDR-G) score ≤1 at the initial visit were included. A mixed regression model was used to examine the association between initial neuropsychological performance and rate of change on the MMSE and CDR Sum of Boxes.

RESULTS

Preservation of working memory, but not episodic memory, in the mild cognitive impairment and early dementia stages of AD relates to slower rate of functional decline.

DISCUSSION

These findings are relevant for estimating the rate of decline in AD clinical trials and in counseling patients and families. Improving working memory performance as a possible avenue to decrease the rate of functional decline in AD dementia warrants closer investigation.

Race-ethnicity and poverty after spinal cord injury

Objective

Our objective was to examine the relationship between race-ethnicity and poverty status after spinal cord injury (SCI).

Study Design

Secondary analysis of existing data.

Setting

A large specialty hospital in the southeastern United States (US).

Methods

Participants were 2,043 adults with traumatic SCI in the US. Poverty status was measured using criteria from the US Census Bureau.

Results

Whereas only 14% of non-Hispanic White participants were below the poverty level, 41.3% of non-Hispanic Blacks were in poverty. Logistic regression with three different models identified several significant predictors of poverty including marital status, years of education, level of education, age, and employment status. Non-Hispanic Blacks had 2.75 greater odds of living in poverty after controlling for other factors, including education and employment.

Conclusions

We may need to consider quality of education and employment to better understand the elevated risk of poverty among non-Hispanic Blacks in the US.

The onset of suicidal ideation in childhood and adolescence

Event history analysis is used to address questions about the timing of first suicidal ideation during preadolescence and adolescence. Are suicidal thoughts atypical during development? Does the age trajectory of suicidal thoughts parallel that of suicidal actions? Do factors that moderate the risk of suicidal actions also moderate the risk of suicidal thoughts, and does their influence vary by developmental stage? Based on life history data from 364 college students, results indicate that suicidal thoughts in childhood are typical and that the risk of such thoughts begins to increase by age nine. Risk rates are affected by demographic factors (gender, race) and by the experience of parental absence. However, the influence of these factors depends on developmental stage, with whites being at increased risk only during adolescence, and parental absence having its strongest effect during preadolescence. In sum, this study suggests that many children and adolescents contemplate suicide, that the risk of doing so begins to increase at an early age, and that clear similarities exist between those groups at heightened risk for suicidal thought and those at heightened risk for suicidal action. Moreover, this study illustrates the power of employing an analytic technique suitable for modeling transitions. Finally, it highlights the need to model differential influences on suicidal ideation at different stages in development.

Evaluation of osteoconductive scaffolds in the canine femoral multi-defect model

Treatment of large segmental bone defects remains an unsolved clinical challenge, despite a wide array of existing bone graft materials. This project was designed to rapidly assess and compare promising biodegradable osteoconductive scaffolds for use in the systematic development of new bone regeneration methodologies that combine scaffolds, sources of osteogenic cells, and bioactive scaffold modifications. Promising biomaterials and scaffold fabrication methods were identified in laboratories at Rutgers, MIT, Integra Life Sciences, and Mayo Clinic. Scaffolds were fabricated from various materials, including poly(L-lactide-co-glycolide) (PLGA), poly(L-lactide-co-ɛ-caprolactone) (PLCL), tyrosine-derived polycarbonate (TyrPC), and poly(propylene fumarate) (PPF). Highly porous three-dimensional (3D) scaffolds were fabricated by 3D printing, laser stereolithography, or solvent casting followed by porogen leaching. The canine femoral multi-defect model was used to systematically compare scaffold performance and enable selection of the most promising substrate(s) on which to add cell sourcing options and bioactive surface modifications. Mineralized cancellous allograft (MCA) was used to provide a comparative reference to the current clinical standard for osteoconductive scaffolds. Percent bone volume within the defect was assessed 4 weeks after implantation using both MicroCT and limited histomorphometry. Bone formed at the periphery of all scaffolds with varying levels of radial ingrowth. MCA produced a rapid and advanced stage of bone formation and remodeling throughout the defect in 4 weeks, greatly exceeding the performance of all polymer scaffolds. Two scaffold constructs, TyrPC(PL)/TCP and PPF4(SLA)/HA(PLGA) (Dip), proved to be significantly better than alternative PLGA and PLCL scaffolds, justifying further development. MCA remains the current standard for osteoconductive scaffolds.

PINOT NOIR: pulmonic insufficiency improvement with nitric oxide inhalational response

BACKGROUND

Tetralogy of Fallot (TOF) repair and pulmonary valvotomy for pulmonary stenosis (PS) lead to progressive pulmonary insufficiency (PI), right ventricular enlargement and dysfunction. This study assessed whether pulmonary regurgitant fraction measured by cardiovascular magnetic resonance (CMR) could be reduced with inhaled nitric oxide (iNO).

METHODS

Patients with at least moderate PI by echocardiography undergoing clinically indicated CMR were prospectively enrolled. Patients with residual hemodynamic lesions were excluded. Ventricular volume and blood flow sequences were obtained at baseline and during administration of 40 ppm iNO.

RESULTS

Sixteen patients (11 with repaired TOF and 5 with repaired PS) completed the protocol with adequate data for analysis. The median age [range] was 35 [19-46] years, BMI was 26 ± 5 kg/m(2) (mean ± SD), 50% were women and 75% were in NYHA class I. Right ventricular end diastolic volume index for the cohort was 157 ± 33 mL/m(2), end systolic volume index was 93 ± 20 mL/m(2) and right ventricular ejection fraction was 40 ± 6%. Baseline pulmonary regurgitant volume was 45 ± 25 mL/beat and regurgitant fraction was 35 ± 16%. During administration of iNO, regurgitant volume was reduced by an average of 6 ± 9% (p=0.01) and regurgitant fraction was reduced by an average of 5 ± 8% (p=0.02). No significant changes were observed in ventricular indices for either the left or right ventricle.

CONCLUSION

iNO was successfully administered during CMR acquisition and appears to reduce regurgitant fraction in patients with at least moderate PI suggesting a potential role for selective pulmonary vasodilator therapy in these patients.

TRIALS REGISTRATION

ClinicalTrials.gov, NCT00543933.

Prostate cancer patients older than 70 years treated by radical prostatectomy have higher biochemical recurrence rate than their matched younger counterpart

BACKGROUND

Consensus on prostate cancer (PCA) treatment in older men is currently lacking. We evaluated clinicopathological and oncological outcomes in patients >70-year-old treated with radical prostatectomy (RP).

METHODS

Clinicopathological and follow-up (FU) data for >70-year-old RP men (2000-2011) were recorded. Association between preoperative features, extraprostatic extension (EPE) and biochemical failure (bF), and postoperative features and bF, was explored. Patients >70-year-old were matched with younger (50- to 70-year-old) men with similar RP features to analyze the effect of age on bF.

RESULTS

Two hundred eighteen RP patients were >70-year-old. Clinical stage (cT) was T1 in 74.1%. Biopsy (Bx) Gleason score (GS) was 6 (35.8%), 7 (45.9%), and ≥8 (18.3%); RP GS was 6 (10.1%), 7 (63.3%), and ≥8 (26.6%). Median PSAD was 0.14 (range: 0.01-1.12). Pathologic stage (pT) was pT3 in 45.9%. bF occurred in 14.0%. Best preoperative predictive model for pT3 disease included D'Amico risk, number of Bx positive cores, PSAD, maximum % of PCA per core (P < 0.0001); cT, PSAD and primary Bx Gleason pattern best predicted bF preoperatively (P = 0.0031). Among postoperative features, high RP GS, positive margins, and pT3 were significantly associated with bF. Margin status and pT best predicted bF. Patients >70-year-old had 85% higher odds of bF compared to younger men (P = 0.036).

CONCLUSIONS

PCA detected in >70-year-old men shows adverse pathologic features. Failure rate is significantly higher in older than in matched younger patients.

Abstract TP180: Markedly Elevated High-sensitive C-reactive protein (hsCRP) Predicts Early Mortality Among Stroke Patients

Background: High-sensitive C-Reactive Protein (hsCRP) levels are correlated with risk of vascular disease and cardiovascular mortality. The clinical implications of markedly elevated hsCRP levels in the setting of acute stroke are less understood as they are often excluded from studies.

Objective: To determine the association of very high admission hsCRP levels (> 10mg/L) on all-cause mortality in patients with acute stroke

Methods: We performed a retrospective cohort study of patients admitted to our institution with acute stroke (8/2003- 11/2011) who had at least one hsCRP assay drawn < 7 days of stroke diagnosis. Mortality data was obtained using Social Security Death Index. Differences in survival were determined using Kaplan-Meier curves. Cox proportional analysis was used to determine hazard ratios of death among patients with hsCRP values > 10 mg/L after adjusting for age, sex, race and the following co-morbid conditions: cancer, atrial fibrillation, diabetes, hypertension, myocardial infarction

Results: There were 293 stroke patients identified with hsCRP levels drawn < 7 days of stroke admission. Median age was 65.7 years (SD 15.3), and 55% were male. All-cause mortality was 18% (n=53) with a median follow-up of 2.2 years. Median hsCRP level was 5.5 mg/L, [IQR 1.8 - 14.6] with 31.7% patients having hsCRP > 10 mg/L. Patients with hsCRP > 10 mg/L had a 2.7 times higher risk of mortality than those with hsCRP < 10 mg/L (p=0.004). The increased risk was steepest in the first months after stroke (Figure). The only other significant variable affecting hazard for death was age; each year increased the hazard ratio by 3.3%. Of the cases in which cause of death was known (n=31), stroke was the most common cause (71%)

Conclusion: Very high level of hsCRP (>10 mg/L) at the time of admission is associated with increased early mortality among patients presenting with acute strokes. This finding may help stratify risk of death in stroke.

Reinforced fascia patch limits cyclic gapping of rotator cuff repairs in a human cadaveric model

BACKGROUND

Scaffolds continue to be developed and used for rotator cuff repair augmentation, but clinical or biomechanical data to inform their use are limited. We have developed a reinforced fascia lata patch with mechanical properties to meet the needs of musculoskeletal applications. The objective of this study was to assess the extent to which augmentation of a primary human rotator cuff repair with the reinforced fascia patch can reduce gap formation during in vitro cyclic loading.

MATERIALS AND METHODS

Nine paired human cadaveric shoulders were used to investigate the cyclic gap formation and failure properties of augmented and non-augmented rotator cuff repairs with loading of 5 to 180 N for 1000 cycles.

RESULTS

Augmentation significantly decreased the amount of gap formation at cycles 1, 10, 100, and 1000 compared with non-augmented repairs (P < .01). The mean gap formation of the augmented repairs was 1.8 mm after the first cycle of pull (vs 3.6 mm for non-augmented repairs) and remained less than 5 mm after 1000 cycles of loading (4.7 mm for augmented repairs vs 7.3 mm for non-augmented repairs). Furthermore, all augmented repairs were able to complete the 1000-cycle loading protocol, whereas 3 of 9 non-augmented repairs failed before completing 1000 loading cycles.

CONCLUSIONS

This study supports further investigation of reinforced fascia patches to provide mechanical augmentation, minimize tendon retraction, and possibly reduce the incidence of rotator cuff repair failure. Future investigation in animal and human studies will be necessary to fully define the efficacy of the reinforced fascia device in a biologic healing environment.

Host response to xenograft ECM implantation is not different between the shoulder and body wall sites in the rat model

In the context of tendon and ligament repair, mechanical loading and the presence of joint synovial fluid are known to profoundly influence the form and function of the repair tissue and potentially the host response to biomaterials. Previously, we demonstrated that a xenograft extra cellular matrix (ECM) scaffold implanted in the rat shoulder elicited a unique host response from that seen in the body wall. However, the host response to xenografts implanted in shoulders with a tendon/capsule injury was not different from xenografts implanted in shoulders with no injury. In the current study, we hypothesized that varying clinically relevant surgical and environmental factors would introduce significant differences in host response to xenograft implantation at the shoulder. Contrary to our hypothesis, we found no significant differences in host response between any shoulder implantation conditions or between shoulder and body wall implantation in the rat model. These findings suggest that there is no advantage to using an orthotopic shoulder model to investigate the host response to rotator cuff scaffold materials in the rat model, and due to the insensitivity of its host response to various clinically relevant surgical conditions, may suggest that the rat does not provide a surrogate for directly translating the host response to biomaterials to the human application.

In vivo transplantation of autogenous marrow-derived cells following rapid intraoperative magnetic separation based on hyaluronan to augment bone regeneration

INTRODUCTION

This project was designed to test the hypothesis that rapid intraoperative processing of bone marrow based on hyaluronan (HA) could be used to improve the outcome of local bone regeneration if the concentration and prevalence of marrow-derived connective tissue progenitors (CTPs) could be increased and nonprogenitors depleted before implantation.

METHODS

HA was used as a marker for positive selection of marrow-derived CTPs using magnetic separation (MS) to obtain a population of HA-positive cells with an increased CTP prevalence. Mineralized cancellous allograft (MCA) was used as an osteoconductive carrier scaffold for loading of HA-positive cells. The canine femoral multidefect model was used and four cylindrical defects measuring 10 mm in diameter and 15 mm in length were grafted with MCA combined with unprocessed marrow or with MS processed marrow that was enriched in HA(+) CTPs and depleted in red blood cells and nonprogenitors. Outcome was assessed at 4 weeks using quantitative 3D microcomputed tomography (micro-CT) analysis of bone formation and histomorphological assessment.

RESULTS

Histomorphological assessment showed a significant increase in new bone formation and in the vascular sinus area in the MS-processed defects. Robust bone formation was found throughout the defect area in both groups (defects grafted with unprocessed marrow or with MS processed marrow.) Percent bone volume in the defects, as assessed by micro-CT, was greater in defects engrafted with MS processed cells, but the difference was not statistically significant.

CONCLUSION

Rapid intraoperative MS processing to enrich CTPs based on HA as a surface marker can be used to increase the concentration and prevalence of CTPs. MCA grafts supplemented with heparinized bone marrow or MS processed cells resulted in a robust and advanced stage of bone regeneration at 4 weeks. A greater new bone formation and vascular sinus area was found in defects grafted with MS processed cells. These data suggest that MS processing may be used to enhance the performance of marrow-derived CTPs in clinical bone regeneration procedures. Further assessment in a more stringent bone defect model is proposed.

Effect of pretension and suture needle type on mechanical properties of acellular human dermis patches for rotator cuff repair

BACKGROUND

Dermal grafts are used for rotator cuff repair and augmentation. Although the in vitro biomechanical properties of dermal grafts have been reported previously, clinical questions related to their biomechanical performance as a surgical construct and the effect of surgical variables that could potentially improve repair outcomes have not been studied.

METHODS

This study evaluated the failure and fatigue biomechanics of acellular dermis constructs tested in a clinically relevant size (4 × 4 cm patches) and manner (loaded via sutures) for rotator cuff repair. Also investigated were the effect of 2 surgical variables: (1) the fixation of grafts under varying magnitudes of pretension (0, 10, 20N), and (2) the use of reverse-cutting vs tapered needles for suturing grafts.

RESULTS

Dermis constructs stretched ∼25% before bearing significant loads in the high stiffness region. Although 91% of the patches withstood 2500 cycles of loading to 150 N, the constructs stretched 13 to 19 mm after fatigue loading. This elongation could be reduced by 20% to 32% when reverse-cutting needles were used to prepare constructs or by applying 20 N of in situ circumferential pretension to the constructs before loading.

CONCLUSIONS

Although dermis patches demonstrated robustness for use in rotator cuff repair, the patches underwent significant, substantial, and presumably nonrecoverable elongation, even at low physiologic loads. This study indicates that use of reverse-cutting needles for suture passage, preconditioning (cyclically stretching several times), and/or surgical fixation under at least 20 N of circumferential pretension could be developed as strategies to reduce compliance of dermis for its use for rotator cuff repair.