Stromal Vascular Fraction-based patches generated under perfusion culture enhance cardiac function in rats with chronic myocardial infarction

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Foundation

The development of novel adjuvant angiogenic therapies to restore the low-perfused microvascular network upon myocardial infarction (MI) is crucial to avoid a possible end-stage heart failure. Of the current adult cell-based therapies, human adipose tissue-derived stromal vascular fraction cell (SVF) has vast reparative potential, principally due to: 1) its heterogeneous composition rich in mesenchymal stem cells (MSC), endothelial cells (EC), pericytes and hematopoietic cells, among others. In vitro engineering of SVF-based patches under unidirectional flow, applied by the help of a perfusion-based bioreactor, was found to increase certain cellular SVF subgroups such as pericytes, compared to static culture. In this study, we aimed at studying the potential of SVF-based engineered tissues in a model of chronic MI in nude rats. Human SVF cells were isolated upon liposuction and cultured on 3D collagen sponges (8 mm diameter, 3 mm thickness) either under constant unidirectional perfusion or in static condition for 5 days. Patches were characterized in terms of cellular composition prior to implantation. MI was induced by permanent ligation of the left anterior descending (LAD) coronary artery in male nude rats. Cardiac MRI was performed 4 weeks after MI; prior to the suture of patches and before sacrifice (4 weeks after implantation). Left ventricular ejection fraction (EF) was the surrogate marker and primary end point for cardiac pump function. Controls included untreated MI animals. Following perfusion culture, SVF cells were composed with a statistically superior percentage of pericytes, identified as CD45- CD34- CD146+ compared to static culture (28.06±10.03 and 3.37±2.50, respectively, p<0.0007). The presence of other cell subpopulations was similar in the patches generated in perfusion or static culture. While the percentage of EF at the time of sacrifice resulted to be not statistically different between static and perfusion-based patches, statically generated constructs showed a general trend of decrease in the % EF before and after treatment (rat 1: 61.96 vs 52.90; rat 2: 55.39 vs 53.00; rat 3: 52.34 vs 50.62, respectively). Perfusion-cultured patches, instead, rather improved the cardiac function, measured as % EF (rat 1: 51.82 vs 58.72; rat 2: 51.66 vs 60.45; rat 3: 53.50 vs 52. 36, respectively for 4 weeks following MI and 4 weeks following treatment). When comparing the ratio of the % EF 8 weeks and 4 weeks between static or perfusion-based patches and the untreated controls, rats treated with patches generated under perfusion resulted to show higher levels of % EF, with an almost statistically difference (p=0.0556), compared to the control group. The observed results showed the great potential of human SVF-based patches in the improvement of the heart pump function.

677 UTILITY OF 24 HOUR AMBULATORY BLOOD PRESSURE MONITORING (ABPM) IN PATIENTS WITH ORTHOSTATIC HYPOTENSION (OH) AT SYNCOPE CLINIC

Introduction

OH is a disabling condition resulting from a sustained reduction in blood pressure (>20 systolic or 10 diastolic) within 3 minutes of standing. It is a common cause of syncope. Patients with concurrent hypertension experiencing syncope present a complex management dilemma where a balance must be established between symptom burden and risk of cardiovascular disease. Current guidance on ABPM use in syncope is limited. European society of cardiology syncope guidelines suggest ABPM in patients with ‘autonomic failure’ to assess nocturnal hypertension or drug-induced hypotension. Could this be improved with further explicit criteria on which patients to assess and how to act on results? The objective of this study is to review the use of 24 hour ABPM in OH within a tertiary referral syncope clinic.

Method

A retrospective analysis was performed electronically for patients with a final diagnosis of OH seen in a syncope clinic between March 2017 and May 2019. Data was collected on comorbidities, medication history, physical mobility, clinic blood pressure, ABPM Results: (if performed) and medication changes. Comparisons were made between patients who had ABPM and those who did not. Statistics were calculated using Fisher’s Exact Test (2 tailed).

Results

119 patients had a final diagnosis of OH in the study period. 45 had ABPM, 74 did not. The ABPM group had a significantly higher proportion of diagnosed hypertension (51.1% vs 23% (p = 0.0025)). A similar proportion of patients in both groups had medication changed however the ABPM group were significantly more likely to have antihypertensive therapy added (19.4% vs 1.8% (p = 0.0053)).

Conclusion

Using 24 hour ABPM in OH patients can aid clinical decision making in the sub-group with hypertension. This can guide the need for alteration/addition of antihypertensive therapy to balance optimum BP control with symptom burden.

National population prevalence of antibodies to SARS-CoV-2 among pregnant women in Scotland during the second wave of the COVID-19 pandemic: a prospective national serosurvey

OBJECTIVES

This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic.

STUDY DESIGN

Prospective national serosurvey.

METHODS

We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations.

RESULTS

Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups.

CONCLUSIONS

By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.

A21 ULCERATIVE COLITIS-ASSOCIATED E. COLI PATHOBIONTS POTENTIATE COLITIS IN SUSCEPTIBEL HOSTS

Background

Ulcerative colitis (UC) is a chronic inflammatory condition linked to intestinal microbial dysbiosis, including the expansion of E. coli strains related to extra-intestinal pathogenic E. coli. These “pathobionts” exhibit pathogenic properties, but their potential to promote UC is unclear due to the lack of relevant animal models.

Aims

We explored the potential to establish a mouse model of GI infection by the UC-associated E. coli strain p19A, as well as characterize the pathogenic features of p19A.

Methods

We used a representative UC pathobiont strain (p19A), and mice lacking single immunoglobulin and toll-interleukin 1 receptor domain (SIGIRR), a deficiency increasing susceptibility to gut infections. Vancomycin-pretreated Sigirr-/- mice were subsequently gavaged with the control E. coli DH10B (a derivative of commensal strain K-12) or p19A. One day after infection, mice were exposed to 2.5% dextran sodium sulfate (DSS) in their drinking water for another 4 days.

Results

Strain p19A was found to adhere to the cecal mucosa of Sigirr-/- mice, causing modest inflammation. Moreover, it dramatically worsened DSS-induced colitis. This potentiation was attenuated using a p19A strain lacking α-hemolysin genes, or when we targeted pathobiont adherence using a p19A strain lacking the adhesin FimH, or following treatment with FimH antagonists.

Conclusions

Thus, UC pathobionts adhere to the intestinal mucosa, and worsen the course of colitis in susceptible hosts in a manner dependent on specific virulence factors, including α-hemolysin and FimH.

Funding Agencies

CCC, CIHR

Tailoring the homing capacity of human Tregs for directed migration to sites of Th1-inflammation or intestinal regions

Cell-based therapy with CD4⁺ FOXP3⁺ regulatory T cells (Tregs) is a promising strategy to limit organ rejection and graft-vs-host disease. Ongoing clinical applications have yet to consider how human Tregs could be modified to direct their migration to specific inflammation sites and/or tissues for more targeted immunosuppression. We show here that stable, homing-receptor-tailored human Tregs can be generated from thymic Tregs isolated from pediatric thymus or adult blood. To direct migration to Th1-inflammatory sites, addition of interferon-γ and IL-12 during Treg expansion produced suppressive, epigenetically stable CXCR3⁺ TBET⁺ FOXP3⁺ T helper (Th)1-Tregs. CXCR3 remained expressed after injection in vivo and Th1-Tregs migrated efficiently towards CXCL10 in vitro. To induce tissue-specific migration, addition of retinoic acid (RA) during Treg expansion induced expression of the gut-homing receptors α4β7-integrin and CCR9. FOXP3⁺ RA-Tregs had elevated expression of the functional markers latency-associated peptide and glycoprotein A repetitions predominant, increased suppressive capacity in vitro and migrated efficiently to healthy and inflamed intestine after injection into mice. Homing-receptor-tailored Tregs were epigenetically stable even after long-term exposure to inflammatory conditions, suppressive in vivo and characterized by Th1- or gut-homing-specific transcriptomes. Tailoring human thymic Treg homing during in vitro expansion offers a new and clinically applicable approach to improving the potency and specificity of Treg therapy.

Expanding the reach of probiotics through social enterprises

The rapid rise in microbiome and probiotic science has led to estimates of product creation and sales exceeding $50 billion within five years. However, many people do not have access to affordable products, and regulatory agencies have stifled progress. The objective of a discussion group at the 2017 meeting of the International Scientific Association for Probiotics and Prebiotics was to identify mechanisms to confer the benefits of probiotics to a larger portion of the world’s population. Three initiatives, built around fermented food, were discussed with different methods of targeting populations that face enormous challenges of malnutrition, infectious disease, poverty and violent conflict. As new candidate probiotic strains emerge, and the market diversifies towards more personalised interventions, manufacturing processes will need to evolve. Information dissemination through scientific channels and social media is projected to provide consumers and healthcare providers with rapid access to clinical results, and to identify the nearest location of sites making new and affordable probiotic food and supplements. This rapid translation of science to individual well-being will not only expand the beneficiaries of probiotics, but also fuel new social enterprises and economic business models.

How do probiotics and prebiotics function at distant sites?

The realisation that microbes regarded as beneficial to the host can impart effects at sites distant from their habitat, has raised many possibilities for treatment of diseases. The objective of a workshop hosted in Turku, Finland, by the International Scientific Association for Probiotics and Prebiotics, was to assess the evidence for these effects and the extent to which early life microbiome programming influences how the gut microbiota communicates with distant sites. In addition, we examined how probiotics and prebiotics might affect the skin, airways, heart, brain and metabolism. The growing levels of scientific and clinical evidence showing how microbes influence the physiology of many body sites, leads us to call for more funding to advance a potentially exciting avenue for novel therapies for many chronic diseases.

Post-acquisition filtering of salt cluster artefacts for LC-MS based human metabolomic studies

Liquid chromatography-high resolution mass spectrometry (LC-MS) has emerged as one of the most widely used platforms for untargeted metabolomics due to its unparalleled sensitivity and metabolite coverage. Despite its prevalence of use, the proportion of true metabolites identified in a given experiment compared to background contaminants and ionization-generated artefacts remains poorly understood. Salt clusters are well documented artefacts of electrospray ionization MS, recognized by their characteristically high mass defects (for this work simply generalized as the decimal numbers after the nominal mass). Exploiting this property, we developed a method to identify and remove salt clusters from LC-MS-based human metabolomics data using mass defect filtering. By comparing the complete set of endogenous metabolites in the human metabolome database to actual plasma, urine and stool samples, we demonstrate that up to 28.5 % of detected features are likely salt clusters. These clusters occur irrespective of ionization mode, column type, sweep gas and sample type, but can be easily removed post-acquisition using a set of R functions presented here. Our mass defect filter removes unwanted noise from LC-MS metabolomics datasets, while retaining true metabolites, and requires only a list of m/z and retention time values. Reducing the number of features prior to statistical analyses will result in more accurate multivariate modeling and differential feature selection, as well as decreased reporting of unknowns that often constitute the largest proportion of human metabolomics data.

The case in favour of probiotics before, during and after pregnancy: insights from the first 1,500 days

Successful human reproduction requires microbial homeostasis in the female reproductive tract, and colonisation of the newborn with beneficial microbes. In order to prevent several complications associated with dysbiosis, the administration of probiotics is more often being considered. The objective of the enclosed review was to examine the rationale for probiotic utility before and during pregnancy and in the early phase of infant life. The conclusions emerged from a panel of researchers who met during the International Scientific Association for Probiotics and Prebiotics (ISAPP) workshop held in Washington, DC, USA in 2015. The group concluded based upon the current literature, that a case can be made for the use of a specific sets of probiotic organisms during the first 1,500 days of life, with the goal of a healthy pregnancy to term, and a healthy start to life with lowered risk of infections and inflammatory events. The key to successfully translating these recommendations to practice is that products be made available and affordable to women in developed and developing countries.

Probiotic lactobacilli: a potential prophylactic treatment for reducing pesticide absorption in humans and wildlife

Numerous pesticides are used in agriculture, gardening, and wildlife-control. Despite their intended toxicity to pests, these compounds can also cause harm to wildlife and humans due to their ability to potentially bioaccumulate, leach into soils, and persist in the environment. Humans and animals are commonly exposed to these compounds through agricultural practices and consumption of contaminated foods and water. Pesticides can cause a range of adverse effects in humans ranging from minor irritation, to endocrine or nervous system disruption, cancer, or even death. A convenient and cost-effective method to reduce unavoidable pesticide absorption in humans and wildlife could be the use of probiotic lactobacilli. Lactobacillus is a genus of Gram-positive gut commensal bacteria used in the production of functional foods, such as yoghurt, cheese, sauerkraut and pickles, as well as silage for animal feed. Preliminary in vitro experiments suggested that lactobacilli are able to degrade some pesticides. Probiotic Lactobacillus rhamnosus GR-1-supplemented yoghurt reduced the bioaccumulation of mercury and arsenic in pregnant women and children. A similar study is warranted to test if this approach can reduce pesticide absorption in vivo, given that the lactobacilli can also attenuate reactive oxygen production, enhance gastrointestinal barrier function, reduce inflammation, and modulate host xenobiotic metabolism.

The effect of pulsing movements on the physiological response to common exercises

AIM

There is a paucity of research on responses to exercises using pulsatile movements (PM) compared to using a full range of motion (FM). The purpose of the present study was to compare the physiological responses to PM vs. FM exercises.

METHODS

Eight participants completed two separate exercise sessions, comprised of three sets of 20 repetitions for five different exercises. During the FM trial, all repetitions were performed using a full range of motion. In the PM trial, half of the repetitions were performed using pulsing movements. Average VO2, total VO2, HR and RPE were compared using paired t-tests. Blood lactate [La-] responses were compared using repeated measures analysis of variance.

RESULTS

Average VO2 in the PM trial (1.52±0.38 L min-1) was similar to the FM trial (1.57±0.43 L min-1). However, total VO2 (PM=23.1±6.6 L, FM=27.2±6.9 L), average HR (PM=134.4 ± 10.9, FM=146.2±14.6 beats per min) and RPE (PM=12.2±0.9, FM=13.3±0.9) were significantly (P<0.05) lower for the PM trial. There were no significant differences in blood [La-] response (PM pre=1.7±0.8, post=6.1±0.8 mmol L-1; FM pre=1.6±0.4, post=6.8±0.5 mmol L-1).

CONCLUSION

FM exercises elicit higher HR and RPE responses compared to PM exercises; without corresponding increases in metabolic rate.

Office gel sonovaginography for the prediction of posterior deep infiltrating endometriosis: a multicenter prospective observational study

OBJECTIVE

To use office gel sonovaginography (SVG) to predict posterior deep infiltrating endometriosis (DIE) in women undergoing laparoscopy.

METHODS

This was a multicenter prospective observational study carried out between January 2009 and February 2013. All women were of reproductive age, had a history of chronic pelvic pain and underwent office gel SVG assessment for the prediction of posterior compartment DIE prior to laparoscopic endometriosis surgery. Gel SVG findings were compared with laparoscopic findings to determine the diagnostic accuracy of office gel SVG for the prediction of posterior compartment DIE.

RESULTS

In total, 189 women underwent preoperative gel SVG and laparoscopy for endometriosis. At laparoscopy, 57 (30%) women had posterior DIE and 43 (23%) had rectosigmoid/anterior rectal DIE. For the prediction of rectosigmoid/anterior rectal (i.e. bowel) DIE, gel SVG had an accuracy of 92%, sensitivity of 88%, specificity of 93%, positive predictive value (PPV) of 79%, negative predictive value (NPV) of 97%, positive likelihood ratio (LR+) of 12.9 and negative likelihood ratio (LR-) of 0.12 (P = 3.98E-25); for posterior vaginal wall and rectovaginal septum (RVS) DIE, respectively, the accuracy was 95% and 95%, sensitivity was 18% and 18%, specificity was 99% and 100%, PPV was 67% and 100%, NPV was 95% and 95%, LR+ was 32.4 and infinity and LR- was 0.82 and 0.82 (P = 0.009 and P = 0.003).

CONCLUSIONS

Office gel SVG appears to be an effective outpatient imaging technique for the prediction of bowel DIE, with a higher accuracy for the prediction of rectosigmoid compared with anterior rectal DIE. Although the sensitivity for vaginal and RVS DIE was limited, gel SVG had a high specificity and NPV for all forms of posterior DIE, indicating that a negative gel SVG examination is highly suggestive of the absence of DIE at laparoscopy.

An RNAi-based screen reveals PLK1, CDK1 and NDC80 as potential therapeutic targets in malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive tumour originating in the thoracic mesothelium. Prognosis remains poor with 9- to 12-month median survival, and new targets for treatments are desperately needed.

METHODS

Utilising an RNA interference (RNAi)-based screen of 40 genes overexpressed in tumours, including genes involved in the control of cell cycle, DNA replication and repair, we investigated potential therapeutic targets for MPM. Following in vitro characterisation of the effects of target silencing on MPM cells, candidates were assessed in tumour samples from 154 patients.

RESULTS

Gene knockdown in MPM cell lines identified growth inhibition following knockdown of NDC80, CDK1 and PLK1. Target knockdown induced cell-cycle arrest and increased apoptosis. Using small-molecule inhibitors specific for these three proteins also led to growth inhibition of MPM cell lines, and Roscovitine (inhibitor of CDK1) sensitised cells to cisplatin. Protein expression was also measured in tumour samples, with markedly variable levels of CDK1 and PLK1 noted. PLK1 expression in over 10% of cells correlated significantly with a poor prognosis.

CONCLUSION

These results suggest that RNAi-based screening has utility in identifying new targets for MPM, and that inhibition of NDC80, CDK1 and PLK1 may hold promise for treatment of this disease.

Probiotics and nutrients for the first 1000 days of life in the developing world

Clinically proven probiotics are, for the most part, not available in the developing world and certainly not affordable for the majority of people. This is unconscionable considering these products can alleviate diarrhoea and various infections, which are by far the major cause of death in children and in adults who are HIV positive. Indeed, some of these products have been proven in developing world settings. Distribution networks exist along with pharmacies and clinics that dispense drugs and products that require refrigeration. So, are lack of profit or company resources the problem? Our university has shown that alternative community based kitchen models that produce probiotics can be established. These empower local people, are socially responsible, produce affordable products and deliver benefits to over 3,000 children and adults daily. Surely, other institutions and corporations can multiply this effect and develop social business models across the developing world that are supported by clinical and basic science studies? In this review, we will discuss the application of probiotics and selected nutrients in the first 1000 days of life, a critical timepoint which is particularly challenging in resource disadvantaged countries.

A multicenter evaluation of pandemic influenza A/H1N1 in hematopoietic stem cell transplant recipients

BACKGROUND

Hematopoietic stem cell transplant (HSCT) recipients have increased morbidity from respiratory viral infections. Pandemic influenza A - A(H1N1)/pdm09 - in 2009-2010 was associated with increased severity of illness in patients with underlying co-morbidities including HSCT, but the factors that contribute to severe disease in HSCT patients are not well characterized.

METHODS

We conducted a multicenter review of microbiologically proven influenza A(H1N1)pdm09 in the HSCT population between April 2009 and April 2010 to determine factors that are associated with severe disease.

RESULTS

We identified 37 adult patients (26 allogeneic and 11 autologous HSCT recipients). Median time from transplant to diagnosis was 411 days (range 4 days-14.9 years). Three cases were hospital acquired. Twenty-eight of 37 (75.7%) had confirmed A(H1N1)pdm09. Presumed viral lower respiratory tract infection was present in 12/37 (32.4%) patients. Antiviral therapy was given to 33/37 (89%) patients, primarily oseltamivir (n = 24) and oseltamivir before or after another antiviral (n = 8). Excluding those with nosocomial A(H1N1)pdm09, 18/34 (52.9%) were hospitalized and 6 (33%) required admission to an intensive care unit. Mortality within 30 and 60 days of symptom onset was 7/37 (18.9%) and 11/37 (29.7%), respectively. Factors associated with mortality included nosocomial acquisition (P = 0.023), receipt of mycophenolate mofetil (P = 0.001), or antilymphocyte antibody (P = 0.005) within the past 6 months, reduced-intensity conditioning (P = 0.027), and bacteremia (P = 0.021).

CONCLUSIONS

A(H1N1)pdm09 infection was particularly severe in HSCT recipients, specifically among those receiving augmented immunosuppression for graft-versus-host disease. The high mortality of the nosocomial cases highlights the need for strict infection-control measures in hospitals during influenza outbreaks.

Prediction of pouch of Douglas obliteration in women with suspected endometriosis using a new real-time dynamic transvaginal ultrasound technique: the sliding sign

OBJECTIVE

To evaluate preoperative real-time dynamic transvaginal sonography (TVS) in the prediction of pouch of Douglas (POD) obliteration in women undergoing laparoscopy for suspected endometriosis.

METHODS

This was a multicenter prospective observational study undertaken from January 2009 to November 2011. All women with symptoms suggestive of endometriosis who were scheduled for laparoscopy underwent detailed preoperative TVS, in particular to ascertain whether the POD was obliterated. POD obliteration was assessed using a real-time TVS technique called the 'sliding sign'. Preoperative TVS sliding sign findings were then compared to gold standard laparoscopic POD findings.

RESULTS

One hundred consecutive women with preoperative TVS and laparoscopic outcomes were included in the final analysis. Mean age was 32.8 years and mean age at diagnosis of endometriosis was 27.4 years. At laparoscopy, 84/100 (84%) were found to have some form of endometriosis (73% peritoneal endometriosis, 35% ovarian endometrioma(s), 33% deep infiltrating endometriosis). At laparoscopy, 30/100 (30%) had an obliterated POD and 19/30 (63.3%) of these women also had evidence of bowel endometriosis. The sonographic sliding sign technique had an accuracy of 93.0%, sensitivity of 83.3%, specificity of 97.1%, positive predictive value of 92.6%, negative predictive value of 93.2%, positive likelihood ratio of 29.2 and negative likelihood ratio of 0.17 in the prediction of POD obliteration (P = 1.8E-16).

CONCLUSIONS

Preoperative real-time dynamic TVS evaluation using the sliding sign seems to establish with a high degree of certainty whether the POD is obliterated. Given the increased risk of deep infiltrating endometriosis in women with POD obliteration, the TVS sliding sign technique may also be useful in the identification of women who may be at a higher risk for bowel endometriosis.