The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Synergistic effects of processing parameters on the biochemical and physical properties of tofu made from yellow field pea (Pisum sativum), as determined by response surface methodology

Peas are an underutilized crop that do not require allergen labeling and are rarely genetically modified. Peas contain less protein than soy and vary in protein composition. Because peas contain more starch than soy and less lipids, an alternative procedure for pea tofu production needs to be developed to prevent excessive starch gelatinization while promoting curd development. To accomplish this, a response surface model design was utilized to determine optimal oil addition, cook time, and salt concentration. Treatment ranges were from 0.0% to 4.2% for oil addition, 60-134 min for cook time, and 5.0%-9.2% for MgCl2 addition. Treatments had varying effects on tofu texture. Cook time was directly proportional to the hardness and could be used to match the soft, firm, and extra firm texture targets of conventional soy tofu. Protein secondary structure was not related to gel strength, indicating a system with synergies between multiple components other than protein. This research will help satisfy the growing demand for alternatives to soy-based foods.

Legume proteins are smart carriers to encapsulate hydrophilic and hydrophobic bioactive compounds and probiotic bacteria: A review

Encapsulation is a promising technological process enabling the protection of bioactive compounds against harsh storage, processing, and gastrointestinal tract (GIT) conditions. Legume proteins (LPs) are unique carriers that can efficiently encapsulate these unstable and highly reactive ingredients. Stable LPs-based microcapsules loaded with active ingredients can thus develop to be embedded into processed functional foods. The recent advances in micro- and nanoencapsulation process of an extensive span of bioactive health-promoting probiotics and chemical compounds such as marine and plant fatty acid-rich oils, carotenoid pigments, vitamins, flavors, essential oils, phenolic and anthocyanin-rich extracts, iron, and phytase by LPs as single wall materials were highlighted. A technical summary of the use of single LP-based carriers in designing innovative delivery systems for natural bioactive molecules and probiotics was made. The encapsulation mechanisms, encapsulation efficiency, physicochemical and thermal stability, as well as the release and absorption behavior of bioactives were comprehensively discussed. Protein isolates and concentrates of soy and pea were the most common LPs to encapsulate nutraceuticals and probiotics. The microencapsulation of probiotics using LPs improved bacteria survivability, storage stability, and tolerance in the in vitro GIT conditions. Moreover, homogenization and high-pressure pretreatments as well as enzymatic cross-linking of LPs significantly modify their structure and functionality to better encapsulate the bioactive core materials. LPs can be attractive delivery devices for the controlled release and increased bioaccessibility of the main food-grade bioactives.

Utilization of cardiac MRI for the assessment of suspected rejection with negative biopsy in heart transplant recipients

Background

Heart transplant (HTx) patients can develop graft dysfunction (GD) without biopsy evidence of cell or antibody mediated rejection. Cardiac MRI (CMR) can detect inflammatory or infiltrative causes of cardiomyopathy however CMR findings in HTx recipients with GD have not been previously described.

Purpose

We sought to identify CMR characteristics of HTx patients with GD, and evaluate its additive value in its diagnosis and prognosis.

Methods

CMR has been performed routinely to evaluate GD at our institutions. There were 37 HTx recipients who presented with acute decline in left ventricular ejection fraction (LVEF) of <50% and >10% from baseline, with no biopsy evidence of rejection between 2007 and 2018. Coronary angiogram with IVUS was done to rule out allograft vasculopathy. Treatment of GD was per discretion of the treating clinician. Responders were defined as those with LVEF improvement >10% at 180 days or greater post-presentation. LV and RV indices, the presence and pattern of late gadolinium enhancement (LGE) were determined by CMR.

Results

There were 34% females and mean age at transplant was 49±13 years. Median time from HTx to GD was 1.2 years. Presenting symptoms were heart failure (n=25), cardiogenic shock (n=1) and 11 patients were asymptomatic. Mean LVEF at presentation was 37±12% and donor specific antibodies were detected in 38% patients. Most patients were treated with steroid bolus (n=29), and/or plasmapheresis (n=23). There were no major changes made in immunosuppression in 6 patients. Delayed enhancement MRI was performed with standard inversion-recovery (IR) gradient echo sequences, between 5 and 20 minutes after institutional-standard protocol administration of IV gadolinium contrast. Biventricular LGE was present in 18/37 (49%) patients with GD and was more prevalent in responders (57%, 13 of 23) than non-responders (35%, 5 of 14), although not statistically significant (p=0.21). There were two patterns of LGE noted: 1) Diffuse epicardial (10 patients out which 9 were responders) and 2) Patchy pattern with non-specific distribution (8 patients out of which 4 were responders). Myocardial edema by triple IR sequencing was seen in 6 patients, all having diffuse epicardial pattern of enhancement matching the delayed enhancement pattern. When comparing different treatment groups, among those treated for GD (n=31), 12 of 21 (57%) responders had LGE and 4 of 10 (40%) non-responders had LGE (p=0.37), a pattern similar to the broader population. Among those not treated for GD (n=6), 1 of 2 responders had LGE and 1 of 4 non-responders had LGE (p=0.5).

Conclusion

CMR identified inflammation as a potential cause of GD in approximately 50% of HTx patients. There are 2 distinct patterns of LGE observed in GD, diffuse epicardial (56%) and patchy (44%). Although the presence of LGE in itself is not associated with myocardial recovery, 90% of patients with a diffuse epicardial pattern have recovery of GD.

Funding Acknowledgement

Type of funding source: None