Mesenchymal Stromal Cell-Derived Extracellular Vesicles in Wound Healing

The well-orchestrated process of wound healing may be negatively impacted from interrupted or incomplete tissue regenerative processes. The healing potential is further compromised in patients with diabetes mellitus, chronic venous insufficiency, critical limb ischemia, and immunocompromised conditions, with a high health care burden and expenditure. Stem cell-based therapy has shown promising results in clinical studies. Mesenchymal stem cell-derived exosomes (MSC Exos) may favorably impact intercellular signaling and immunomodulation, promoting neoangiogenesis, collagen synthesis, and neoepithelization. This article gives an outline of the biogenesis and mechanism of extracellular vesicles (EVs), particularly exosomes, in the process of tissue regeneration and discusses the use of preconditioned exosomes, platelet-rich plasma-derived exosomes, and engineered exosomes in three-dimensional bioscaffolds such as hydrogels (collagen and chitosan) to prolong the contact time of exosomes at the recipient site within the target tissue. An appropriate antibiotic therapy based on culture-specific guidance coupled with the knowledge of biopolymers helps to fabricate nanotherapeutic materials loaded with MSC Exos to effectively deliver drugs locally and promote novel approaches for the management of chronic wounds.

Monkeypox: An Emerging Global Public Health Emergency

The virus causing monkeypox, a rare zoonotic viral disease, belongs to the Poxviridae family and the Orthopoxvirus genus. On 23 July 2022, the World Health Organization (WHO) declared the monkeypox outbreak as a Public Health Emergency of International Concern (PHEIC). From May to July 2022, a multi-country outbreak of monkeypox was reported in both endemic and non-endemic regions. Major goals of managing monkeypox are to identify the suspected cases, detect generic orthopoxvirus DNA at a state or commercial laboratory, and establish the Centers for Disease Control and Prevention real-time polymerase chain reaction testing. Currently, there are no approved treatments for monkeypox virus infection. However, a variety of antiviral medications originally designed for the treatment of smallpox and other viral infections could be considered. Pre-exposure prophylaxis for laboratory and health care employees and post-exposure prophylaxis for individuals with high-risk or intermediate-risk exposures are to be considered. The CDC Emergency Operations Center is available for advice on the appropriate use of medical countermeasures, and can help in obtaining antiviral drugs and vaccines from the National Strategic Stockpile. This review gives an overview of the global scenario, clinical presentation, and management of monkeypox in the light of a global public health emergency.

Awareness of lipid guideline recommendations for high-risk patients amongst primary care physicians in Canada

Background

Lipid guidelines for cardiovascular (CV) risk reduction have evolved in recent years, particularly since the introduction of PCSK9 inhibitors. In many jurisdictions, CV risk management is provided by primary care physicians (PCPs). We surveyed Canadian PCPs regarding their awareness and implementation of the 2021 Canadian Cardiovascular Society (CCS) lipid guideline recommendations for patients following an acute coronary syndrome (ACS) or for those with diabetes but without CV disease.

Methods and results

From a national database of PCPs with interest and/or experience in CV medicine, we invited PCPs to complete a survey regarding lipid management in high-risk patients. A committee of PCPs and specialists with lipid expertise including several co-authors of the 2021 CCS lipid guidelines had designed the survey to probe awareness and practice patterns. A total of 203 PCPs from across Canada completed the survey between January and March 2022. 23.6% of respondents had previously prescribed a PCSK9 inhibitor. Almost all (96.5%) PCPs concurred that a post-ACS patient should be seen by their PCP within 4 weeks of hospital discharge (79.3% within 2 weeks). Almost half (45.3%) responded that discharge summaries provided inadequate information relevant for PCPs, and 43% felt that lipid management post-ACS was the primary responsibility of specialists. More than half (56%) articulated challenges when seeing a post-ACS patient, related to inadequate discharge information, complexities of polypharmacy and duration of therapies, and managing perceived or real statin intolerance. 62% correctly identified the LDL-C intensification threshold of 1.8 mmol/L in post-ACS patients, while 79% considered that PCSK9 inhibitors were indicated only for those patients who were already receiving statins plus ezetimibe or had substantially elevated LDL-C levels. 55.2% were able to correctly identify clinical features associated with greatest absolute benefit of PCSK9 inhibitors in post-ACS patients. For patients with diabetes but without ASCVD, 80% of PCPs incorrectly believed that PCSK9 inhibitors were indicated for LDL-C levels above threshold despite statin therapy, and only 42% correctly identified the LDL-C threshold for treatment intensification of 2.0 mmol/L.

Conclusion

While PCPs are aware of the urgency regarding lipid management in post-ACS patients, many encounter challenges after hospital discharge, frequently deferring lipid management to specialists. Thus, almost one year following publication of the 2021 CCS lipid guidelines, substantial knowledge gaps remain regarding intensification thresholds and treatment options for patients post-ACS or for those with diabetes. Innovative and effective knowledge translation programs are urgently required.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen Canada

Evaluation of Biochemical Recurrence and Correlation with Various Parameters After Robotic-Assisted Radical Prostatectomy: a Single Center Experience

Introduction

Biochemical recurrence (BCR) is widely used as an early end point to assess treatment success and frequently prompts the initiation of secondary therapy after radical prostatectomy. We conducted an observational, ambispective study to evaluate BCR after robotic-assisted radical prostatectomy (RARP) for clinically localized prostate cancer. We also analyzed correlation of BCR with pre-operative PSA level, D'Amico classification, pathological stage, post-operative GS, and positive surgical margins after RARP.

Material and Methods

A total of 90 patients with clinically localized carcinoma prostate (≤ T 2), who underwent RARP between April 2012 and April 2017 at our institute with 3 year of minimum follow-up were included in our study. Patients having locally advanced disease on clinical staging or died of unrelated cause in follow up or lost to follow up were excluded from study. Patients who had persistent detectable PSA (> 0.20 ng/ml) at 6 week with a second confirmatory level of PSA greater than 0.2 ng/ml at 3rd month were excluded from study.

Results

The age of the patient ranges from 46 to 79 years with the mean age of 65.36 ± 6.55 years. The mean PSA was 24.36 ± 26.68 ng/ml with range between 1.8 and 126.6 ng/ml. Nine patients (10%) developed BCR at 1-year follow-up and 81 patients were BCR-free. Thus, 1-year BCRFS and BCR rate were 90% and 10%, respectively in our study. Total 17 patients (18.9%) developed BCR during a 2-year period and 73 patients were free of BCR. Thus, 2-year BCRFS and BCR rate were 81.1% and 18.9%, respectively. A total of 29 patients (32.2%) had BCR and 61 patients were free of BCR at 3 years of follow-up. Thus, overall 3-year BCR rate and 3-year BCRFS rate were 32.2% and 67.8%, respectively. There was significant correlation of BCR with pre-operative PSA level, D'Amico classification, pathological stage, post-operative GS, and positive surgical margins.

Conclusions

There is relative paucity of data regarding the BCR rate after RARP in the Indian scenario. The BCR rate in our study was similar to previously published Western and limited Indian data on RARP series in localized prostate cancer. There was significant correlation of BCR with PSA, post-operative GS, pathological stage, PSM, and D'Amico classification.

Allogenic perinatal tissue for musculoskeletal regenerative medicine applications: a systematic review protocol

Background

Musculoskeletal ailments impact the lives of millions of people, and at times necessitate surgery followed by physiotherapy, drug treatments, or immobilization. Regenerative musculoskeletal medicine has undergone enormous progress over the last few decades. Sources of tissues used for regenerative medicine purposes can be grouped into autologous or allogenic. Although autologous sources are promising, there is a wide range of limitations with the treatment, including the lack of randomized controlled studies for orthopaedic conditions, donor site morbidity, and highly variable outcomes for patients. Allogenic sources bypass some of these shortcomings and are a promising source for orthopaedic regenerative medicine applications.

Methods

A systematic search will be performed using PubMed, Elsevier, ScienceDirect, and Google Scholar databases for articles published in English before May 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and guidelines will be used. Studies will be eligible if they apply to acute and chronic orthopaedic musculoskeletal complications or animal or human disease models. Publications must include the use of MSCs and/or tissue obtained from amniotic/chorionic membrane, amniotic fluid, umbilical cord, and/or umbilical cord-derived Wharton’s jelly as an intervention. Placebos, noninjury models, acute injury models, non-injury models, and gold standard treatments will be compared. The study selection will be performed by two independent reviewers using a dedicated reference management software. Data synthesis and meta-analysis will be performed separately for preclinical and clinical studies.

Discussion

The results will be published in relevant peer-reviewed scientific journals. Investigators will present results at national or international conferences.

Trial registration: The Protocol will be registered on PROSPERO international prospective register of systematic reviews prior to commencement.

Impact of tele rehabilitation on clinical outcomes in patients recovering from COVID-19: a preliminary investigation

Pulmonary rehabilitation has proven to be an effective therapeutic intervention for people with chronic respiratory disease. Considering the highly contagious nature of coronavirus disease (COVID-19), it becomes imperative to develop a method which can effectively improve clinical disease outcomes of these patients without any physical contact. The purpose of the study was to investigate the impact of tele rehabilitation on dyspnoea, endurance and quality-of-life in patients recovering from COVID 19. Thirty-two participants (age: 42.5±13.94, height: 165.8±10.06, weight: 68.5±9.63, body mass index: 25.0±3.61) who are recovering from COVID-19 were recruited as per the eligibility criteria. They were randomly allocated into two groups, Tele rehabilitation (n=16) and Control (n=16) by lottery method. All the selected participants were assessed at baseline for perceived dyspnoea, endurance and quality-of-life. Patients in the Tele rehabilitation group received 14 sessions of rehabilitation on alternate days online via google meet over a period of 28 days. Control group received usual care during the study period. Standard statistical tests were employed to test the study hypothesis. Results suggested a significant improvement in both dyspnoea (P=0.001) and endurance (P<0.001) in response to tele rehabilitation. Domains of quality-of-life such as physical role (P=0.02), vitality (P=0.04), emotional role (P=0.03), mental health (P=0.02) and physical components score (P=0.007) also showed significant improvement with tele rehabilitation in patients recovering from COVID-19. Findings of this preliminary study concludes that tele rehabilitation may be considered a treatment of choice in patients recovering from COVID-19 for improving outcomes of dyspnoea, endurance and quality-of-life.

Interface morphology driven exchange interaction and magnetization reversal in a Gd/Co multilayer

Rare-earth (RE)/transition metal (TM) ferromagnetic heterostructures with competing interfacial coupling and Zeeman energy provide a rich ground to study different phase states as a function of magnetic field and temperature. The interface morphology as a knob in these RE/TM heterostructures provides an excellent opportunity to engineer the macroscopic magnetic response by tuning the interface dependent microscopic interactions between the layers. We have investigated the interface morphology driven structure and magnetic properties of a Gd/Co multilayer. The interface morphology of the multilayer was controlled by annealing the multilayer at a relatively low temperature of 573 K under vacuum conditions. Combining the different experimental techniques and a simple one-dimensional spin-based model calculation, we studied the detailed magnetic structure and magnetization reversal mechanism in this system across compensation temperature (T_comp), which suggested a strong interface dependent coupling in the system. We showed that changes in the interface morphology of the Gd/Co multilayer strongly influence the macroscopic magnetic properties of the system. The calculation also confirms the formation of a helical magnetic structure with a 2π domain wall in this system below T_comp. The experimental finding and the simulation of this technologically important system will help to understand the physics of all-optical switching and related applications.

Optimization of a Flat Die Including Elongational Viscosity Effects

A software package for optimization of polymer extrusion dies is developed. Die geometry is optimized such that a uniform velocity distribution is obtained at the die exit without excessively increasing the pressure drop in the die. The software uses the BFGS optimization algorithm, and employs the adjoint method to obtain the design sensitivities. The optimization software is successfully used to optimize the geometry of a flat die for polymer sheet extrusion such that a uniform velocity distribution is obtained at the die exit, without increasing the pressure drop in the die.

A134 UES MANOMETRIC PARAMETERS IN ESOPHAGEAL MOTILITY DISORDERS

Background

Upper esophageal sphincter (UES) function may be evaluated manometrically using a solid-state high-resolution manometry (HRM) system, which allows for the measurement of manometric parameters specific to the UES. While many of these parameters have yet to be validated for use in clinical practice, there is some suggestion that there may be an association between esophageal motility and UES function.

Aims

We aimed to identify the relationship between UES manometric variables and high-resolution esophageal manometry (HREM) diagnoses.

Methods

A retrospective analysis of HREM studies was performed between 2019 and 2021. Extraction of esophageal and UES manometric variables were performed. UES manometric values of interest included: mean basal pressure (mmHg), mean residual pressure (mmHg), relaxation time-to-nadir (ms), relaxation duration (ms), and recovery time (ms). Relationships between manometric diagnosis (Chicago Classification version 3) and UES manometric variables were explored. All values are expressed a medians and group means were compared with the non-parametric Mann-Whitney U test.

Results

2119 symptomatic patients underwent HREM over the study period. Manometric diagnoses were achalasia (72 patients), esophagogastric junction outflow obstruction (286), absent contractility (108), distal esophageal spasm (53), jackhammer esophagus (32), and ineffective esophageal motility (694). 886 patients had no specific motility disorder; 643 of whom had ≤ 20% ineffective swallows and were considered symptomatic controls.

Patients with achalasia had significantly higher mean basal pressures (63.2 vs. 54.4, p = .001), mean residual pressure (3.8 vs. -1.9, p < .001), relaxation-time-to-nadir (182.0 vs. 142.0, p = .005), relaxation duration (820.5 vs. 708.0, p < .001) and recovery time (623.0 vs. 562, p < .001) compared to control patients. Among patients with achalasia, the presence of panesophageal pressurization correlated weakly with recovery time (R² .3, p = .03). Patients with ineffective esophageal motility had significantly higher mean basal pressures (61.7 vs. 54.0, p < .001).

Among all patients, patients with incomplete bolus clearance (≥ 30%) had significantly higher UES mean basal pressure (58.9 vs. 54.6, p = .004), mean residual pressure (-.62 vs. -2, p < .001), relaxation duration (724.0 vs. 707.0, p = .014) and recovery time (580 vs. 558.0, p < .001).

Conclusions

Patients with achalasia may have higher basal and residual UES pressures, and slower relaxation compared to patients with normal esophageal motility. This may reflect dynamic changes of the UES in response to obstruction at the esophagogastric junction. Elevated UES pressures are also seen in patients with ineffective esophageal motility, potentially reflecting a response to poor bolus clearance. More work needs to be done to validate these parameters in clinical practice.

Funding Agencies

None

Subclinical left and right ventricular dysfunction in COVID-19 recovered patients using speckle tracking echocardiography

Funding Acknowledgements

Type of funding sources: None.

Introduction

Myocardial injury during acute COVID-19 infection is well characterised however, its persistence during recovery is unclear.

Purpose

We assessed left ventricle (LV) global longitudinal strain (GLS) and right ventricular (RV) free wall longitudinal strain and RV global longitudinal strain (RV-GLS) using speckle tracking echocardiography (STE) in COVID-19 recovered patients (30-45 days post recovery) and studied its correlation with various parameters.

Methods

Of the 245 subjects screened, a total of 53 subjects recovered from COVID-19 infection and normal LV ejection fraction were enrolled. Routine blood investigations, inflammatory markers (on admission) and comprehensive echocardiography including STE were done for all.

Results

All the 53 subjects were symptomatic during COVID-19 illness and were categorized as mild: 27 (50.9%), moderate: 20 (37.7%) and severe: 6 (11.4%) COVID-19 illness. Reduced LV GLS was reported in 22 (41.5%), reduced RV-GLS in 23 (43.4%) and reduced RVFWS in 22 (41.5%) patients respectively. LVGLS was significantly lower in patients recovered from severe illness (mild: -20.3 ± 1.7%; moderate: -15.3 ± 3.4%; severe: -10.7 ± 5.1%; P < 0.0001). Similarly, RVGLS (mild: -21.8 ± 2.8%; moderate: -16.8 ± 4.8%; severe: -9.7 ± 4.6%; P < 0.0001) and RVFWS (mild: -23.0 ± 4.1%; moderate: -18.1 ± 5.5%; severe: -9.3 ± 4.4%; P < 0.0001) were significantly lower in subjects with severe COVID-19. Subjects with reduced LVGLS as well as RVGLS and RVFWS had significantly higher interleukin-6, C-reactive protein, lactate dehydrogenase and serum ferritin levels during index admission.

Conclusions

Subclinical LV and RV dysfunction was seen in majority of  COVID-19 recovered patients. Patients with severe disease during index admission had far lower LV and RVGLS as compared to mild and moderate cases. Our study highlights the need for close follow-up of COVID-19 recovered subjects in order to determine the long-term cardiovascular outcomes.

Asymptomatic infection and transmission of COVID-19 among clusters: systematic review and meta-analysis

OBJECTIVES

Countries throughout the world are experiencing COVID-19 viral load in their populations, leading to potential transmission and infectivity of asymptomatic COVID-19 cases. The current systematic review and meta-analysis aims to investigate the role of asymptomatic infection and transmission reported in family clusters, adults, children and health care workers, globally.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

An online literature search of PubMed, Google Scholar, medRixv and BioRixv was performed using standard Boolean operators and included studies published up to 17 August 2021. For the systematic review, case reports, short communications and retrospective studies were included to ensure sufficient asymptomatic COVID-19 transmission data were reported. For the quantitative synthesis (meta-analysis), participant data from a collection of cohort studies focusing on groups of familial clusters, adults, children and health care workers were included. Inconsistency among studies was assessed using I2 statistics. The data synthesis was computed using the STATA 16.0 software.

RESULTS

This study showed asymptomatic transmission among familial clusters, adults, children and health care workers of 15.72%, 29.48%, 24.09% and 0%, respectively. Overall, asymptomatic transmission was 24.51% (95% confidence interval [CI]: 14.38, 36.02) among all studied population groups, with a heterogeneity of I2 = 95.30% (P < 0.001). No heterogeneity was seen in the population subgroups of children and health care workers. The risk of bias in all included studies was assessed using the Newcastle Ottawa Scale.

CONCLUSIONS

For minimising the spread of COVID-19 within the community, this study found that following the screening of asymptomatic cases and their close contacts for chest CT scan (for symptomatic patients), even after negative nucleic acid testing, it is essential to perform a rigorous epidemiological history, early isolation, social distancing and an increased quarantine period (a minimum of 14-28 days). This systematic review and meta-analysis supports the notion of asymptomatic COVID-19 infection and person-to-person transmission and suggests that this is dependent on the varying viral incubation period among individuals. Children, especially those of school age (i.e. <18 years), need to be monitored carefully and follow mitigation strategies (e.g. social distancing, hand hygiene, wearing face masks) to prevent asymptomatic community transmission of COVID-19.

Evaluation of Diameter of Main Hilar Renal Artery to Predict the Presence of Supplementary Renal Artery by Contrast-enhanced MDCT: A Retrospective Study from in Northern India

Introduction: Accessory renal arteries are non anastomotic end arteries that correspond to a single renal artery’s segmental branch. It is the most common anatomic variation of renal artery, with an incidence ranging from 8.7% to 75.7%. Aim: To determine the normal reference range of diameter of the main hilar renal artery in presence or absence of supplementary renal arteries and using contrast-enhanced Multidetector Computerized Tomography (MDCT) in North Indian population. Materials and Methods: This retrospective study was conducted in the Department of Anatomy in collaboration with the Department of Radiodiagnosis at Santosh Medical College and Hospital, Ghaziabad and Dr. O.P Gupta Imaging Centre, Meerut, Uttar Pradesh, India, from April 2019 to October 2021. Data analysis was done from November 2021 to December 2021. Contrast-enhanced MDCT scan images were reviewed for measurement of the diameter of main hilar and supplementary renal artery. A total of 108 patients were recruited through consecutive sampling. The diameter of the main hilar and supplementary renal artery on each side was measured at the site of origin from the abdominal aorta with the help of an electronic calliper in axial view of MDCT images. The mean differences among the groups with and without supplementary renal artery were evaluated using the student’s t-test. Results: The mean diameter of the main hilar renal artery in the absence of the supplementary renal arteries on the right and left side were 5.99±1.13 mm and 6.07±1.25 mm respectively.The mean diameter of the main hilar renal artery with supplementary renal arteries on the right side was 5.11±1.096 mm and on the left was 5.18±1.08. The mean diameter of the main hilar renal artery was smaller in kidneys with a supplementary renal artery than in those without a supplementary renal artery, statistically significant difference was evaluated (p-value<0.001 on the right and left side). Conclusion: The diameter of the main hilar renal artery can indicate whether supplemental renal arteries exist or not.