Inter-laboratory multiplex bead-based surface protein profiling of MSC-derived EV preparations identifies MSC-EV surface marker signatures.

Mesenchymal stromal cells (MSCs) are promising regenerative therapeutics that primarily exert their effects through secreted extracellular vesicles (EVs). These EVs - being small and non-living - are easier to handle and possess advantages over cellular products. Consequently, the therapeutic potential of MSC-EVs is increasingly investigated. However, due to variations in MSC-EV manufacturing strategies, MSC-EV products should be considered as highly diverse. Moreover, the diverse array of EV characterisation technologies used for MSC-EV characterisation further complicates reliable interlaboratory comparisons of published data. Consequently, this study aimed to establish a common method that can easily be used by various MSC-EV researchers to characterise MSC-EV preparations to facilitate interlaboratory comparisons. To this end, we conducted a comprehensive inter-laboratory assessment using a novel multiplex bead-based EV flow cytometry assay panel. This assessment involved 11 different MSC-EV products from five laboratories with varying MSC sources, culture conditions, and EV preparation methods. Through this assay panel covering a range of mostly MSC-related markers, we identified a set of cell surface markers consistently positive (CD44, CD73 and CD105) or negative (CD11b, CD45 and CD197) on EVs of all explored MSC-EV preparations. Hierarchical clustering analysis revealed distinct surface marker profiles associated with specific preparation processes and laboratory conditions. We propose CD73, CD105 and CD44 as robust positive markers for minimally identifying MSC-derived EVs and CD11b, CD14, CD19, CD45 and CD79 as reliable negative markers. Additionally, we highlight the influence of culture medium components, particularly human platelet lysate, on EV surface marker profiles, underscoring the influence of culture conditions on resulting EV products. This standardisable approach for MSC-EV surface marker profiling offers a tool for routine characterisation of manufactured EV products in pre-clinical and clinical research, enhances the quality control of MSC-EV preparations, and hopefully paves the way for higher consistency and reproducibility in the emerging therapeutic MSC-EV field.

Outcomes of Rituximab-abbs versus Rituximab in Patients with Diffuse Large B-Cell Lymphoma in a Noninferiority Study.

BACKGROUND: Rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is one of the first line treatments for diffuse large B-cell lymphoma (DLBCL). Rituximab comprises most of the treatment cost for this regimen; therefore, biosimilars, such as rituximab-abbs are crucial to provide affordable care. Although rituximab-abbs was studied primarily in follicular lymphoma, the Food and Drug Administration (FDA) approved this drug for all indications of the reference product on the basis of extrapolation. Effectiveness and safety data surrounding the use of rituximab-abbs in DLBCL is lacking. OBJECTIVE: To evaluate the effectiveness and safety of rituximab-abbs and reference product rituximab as R-CHOP treatment for patients with DLBCL. PATIENTS AND METHODS: This noninferiority (NI) study compared the 2-year overall survival (OS), overall response rate (ORR), and incidence of adverse events (AEs) between rituximab-abbs and its reference product (RP) in R-CHOP among adult patients with newly diagnosed DLBCL. The study inclusion period was from 1 January 2019 to 31 December 2020. Analyses were performed on the basis of a noninferiority lower limit of 10% for OS and ORR, and an upper limit of 10% for serious AEs. RESULTS: There were 240 patients who received RP rituximab, while 295 patients received rituximab-abbs. The cohort had a mean age of 63.7±12.2 years and 43% were female. The 2-year OS was 81.0% and 79.6% (NI p < 0.01) while the ORR was 80.0% and 69.6% (NI p < 0.01), among the rituximab-abbs and rituximab groups, respectively. The incidence of infusion reaction AEs (NI p < 0.01) and noninfusion reaction AEs (NI p < 0.01) also met noninferiority. CONCLUSIONS: We demonstrated that rituximab-abbs was noninferior to rituximab in both effectiveness and safety among patients receiving R-CHOP for DLBCL in this study. Long-term follow-up would be needed to confirm these results.

T1 mapping from routine 3D T1-weighted inversion recovery sequences in clinical practice: comparison against reference inversion recovery fast field echo T1 scans and feasibility in multiple sclerosis.

BACKGROUND AND PURPOSE: Quantitative T1 mapping can be an essential tool for assessing tissue injury in multiple sclerosis (MS). We introduce T1-REQUIRE, a method that converts a single high-resolution anatomical 3D T1-weighted Turbo Field Echo (3DT1TFE) scan into a parametric T1 map that could be used for quantitative assessment of tissue damage. We present the accuracy and feasibility of this method in MS. METHODS: 14 subjects with relapsing-remitting MS and 10 healthy subjects were examined. T1 maps were generated from 3DT1TFE images using T1-REQUIRE, which estimates T1 values using MR signal equations and internal tissue reference T1 values. Estimated T1 of lesions, white, and gray matter regions were compared with reference Inversion-Recovery Fast Field Echo T1 values and analyzed via correlation and Bland-Altman (BA) statistics. RESULTS: 159 T1-weighted (T1W) hypointense MS lesions and 288 gray matter regions were examined. T1 values for MS lesions showed a Pearson's correlation of r = 0.81 (p < 0.000), R2 = 0.65, and Bias = 4.18%. BA statistics showed a mean difference of -53.95 ms and limits of agreement (LOA) of -344.20 and 236.30 ms. Non-lesional normal-appearing white matter had a correlation coefficient of r = 0.82 (p < 0.000), R2 = 0.67, Bias = 8.78%, mean difference of 73.87 ms, and LOA of -55.67 and 203.41 ms. CONCLUSIONS: We demonstrate the feasibility of retroactively derived high-resolution T1 maps from routinely acquired anatomical images, which could be used to quantify tissue pathology in MS. The results of this study will set the stage for testing this method in larger clinical studies for examining MS disease activity and progression.

Patient-specific tissue engineered vascular graft for aortic arch reconstruction.

Objectives: The complexity of aortic arch reconstruction due to diverse 3-dimensional geometrical abnormalities is a major challenge. This study introduces 3-dimensional printed tissue-engineered vascular grafts, which can fit patient-specific dimensions, optimize hemodynamics, exhibit antithrombotic and anti-infective properties, and accommodate growth. Methods: We procured cardiac magnetic resonance imaging with 4-dimensional flow for native porcine anatomy (n = 10), from which we designed tissue-engineered vascular grafts for the distal aortic arch, 4 weeks before surgery. An optimal shape of the curved vascular graft was designed using computer-aided design informed by computational fluid dynamics analysis. Grafts were manufactured and implanted into the distal aortic arch of porcine models, and postoperative cardiac magnetic resonance imaging data were collected. Pre- and postimplant hemodynamic data and histology were analyzed. Results: Postoperative magnetic resonance imaging of all pigs with 1:1 ratio of polycaprolactone and poly-L-lactide-co-ε-caprolactone demonstrated no specific dilatation or stenosis of the graft, revealing a positive growth trend in the graft area from the day after surgery to 3 months later, with maintaining a similar shape. The peak wall shear stress of the polycaprolactone/poly-L-lactide-co-ε-caprolactone graft portion did not change significantly between the day after surgery and 3 months later. Immunohistochemistry showed endothelization and smooth muscle layer formation without calcification of the polycaprolactone/poly-L-lactide-co-ε-caprolactone graft. Conclusions: Our patient-specific polycaprolactone/poly-L-lactide-co-ε-caprolactone tissue-engineered vascular grafts demonstrated optimal anatomical fit maintaining ideal hemodynamics and neotissue formation in a porcine model. This study provides a proof of concept of patient-specific tissue-engineered vascular grafts for aortic arch reconstruction.

The blood-testis barrier disruption is a prerequisite for toxicant-induced peritubular macrophage increases in the testis of peripubertal rats.

Peritubular macrophages (PTMφ) are predominantly localized near spermatogonial stem cells in the testis. We previously revealed that exposure of peripubertal male Fischer rats to mono-(2-ethylhexyl) phthalate (MEHP) leads to increased PTMφs in the testis. The mechanisms that trigger increases in PTMφs in the testis are poorly understood. However, MEHP exposure is known to both induce spermatocyte apoptosis and to perturb the blood-testis barrier (BTB). This study aims to elucidate the association between the disruption of BTB and the increases of PTMφs in the testis by comparing the effects observed with MEHP to 2 other testicular toxicants with variable effects on the BTB and subtype of germ cell undergoing apoptosis. Methoxyacetic acid (MAA) acts directly on spermatocytes and does not affect BTB function, whereas cadmium chloride (CdCl2) induces profound injury to BTB. The results indicated that MAA exposure significantly increased spermatocyte apoptosis, whereas no significant changes in the numbers of PTMφs in the testis occurred. In contrast, CdCl2 exposure disrupted BTB function and increased the abundance of PTMφs in the testis. To further investigate whether MEHP-induced changes in BTB integrity accounted for the increase in PTMφs, a plasmid for LG3/4/5, the functional component of laminin-alpha 2, was overexpressed in the testis to stabilize BTB integrity before MEHP exposure. The results showed that LG3/4/5 overexpression substantially reduced the ability of MEHP to compromise BTB integrity and prevented the increase in PTMφ numbers after MEHP exposure. These results indicate that BTB disruption is necessary to increase PTMφs in the testis induced by toxicants.

Identifying Witnessed Suicides in National Violent Death Reporting System Narratives.

There is increasing attention to suicides that occur in view of others, as these deaths can cause significant psychological impact on witnesses. This study illuminates characteristics of witnessed suicides and compares characteristics of these deaths to non-witnessed suicides. We develop a codable definition of what constitutes witnessed (vs. non-witnessed) suicide. Our data include a sample of 1200 suicide descriptions from the 2003-2017 National Violent Death Reporting System (NVDRS). We first developed criteria to identify probable cases of witnessed suicide. The coding scheme achieved 94.5% agreement and identified approximately 10% (n = 125) of suicides as witnessed. Next, we examined differences between witnessed and non-witnessed suicides in demographics, manner of death, and social/environmental factors using bivariate Chi-squared tests, multivariate logistic regression, and ANOVA. Witnessed suicide decedents were significantly more likely than non-witnessed suicide decedents to be male, younger, and members of a sexual minority, and to have died in living spaces by means of a firearm. Two thirds of witnesses were strangers to the decedents, while 23.2% were romantic partners or ex-partners of the decedents. Our coding method offers a reliable approach to identify witnessed suicides. While witnessed suicides are relatively infrequent, these deaths have profound impact on witnesses. Articulating the features of witnessed suicides may contribute to identifying potential risk mitigation strategies.

Complete genomes of Limosilactobacillus portuensis and Limosilactobacillus vaginalis isolated from the urine of postmenopausal women.

There is frequent evidence that Limosilactobacillus vaginalis colonizes female genitourinary tracts but few reports of Limosilactobacillus portuensis. Their role in urinary tract infection (UTI) is unclear. We present the first complete genome of L. portuensis and a complete genome of L. vaginalis isolated from postmenopausal women with varying UTI histories.

Responses of peritubular macrophages and the testis transcriptome profiles of peripubertal and adult rodents exposed to an acute dose of MEHP.

Exposure of rodents to mono-(2-ethylhexyl) phthalate (MEHP) is known to disrupt the blood-testis barrier and cause testicular germ cell apoptosis. Peritubular macrophages (PTMφ) are a newly identified type of testicular macrophage that aggregates near the spermatogonial stem cell niche. We have previously reported that MEHP exposure increased the numbers of PTMφs by 6-fold within the testis of peripubertal rats. The underlying mechanism(s) accounting for this change in PTMφs and its biological significance is unknown. This study investigates if MEHP-induced alterations in PTMφs occur in rodents (PND 75 adult rats and PND 26 peripubertal mice) that are known to be less sensitive to MEHP-induced testicular toxicity. Results show that adult rats have a 2-fold higher basal level of PTMφ numbers than species-matched peripubertal animals, but there was no significant increase in PTMφ numbers after MEHP exposure. Peripubertal mice have a 5-fold higher basal level of PTMφ compared with peripubertal rats but did not exhibit increases in number after MEHP exposure. Further, the interrogation of the testis transcriptome was profiled from both the MEHP-responsive peripubertal rats and the less sensitive rodents via 3' Tag sequencing. Significant changes in gene expression were observed in peripubertal rats after MEHP exposure. However, adult rats showed lesser changes in gene expression, and peripubertal mice showed only minor changes. Collectively, the data show that PTMφ numbers are associated with the sensitivity of rodents to MEHP in an age- and species-dependent manner.

Constructing the public in public perceptions research: A case study of forest genomics.

Contemporary scientific and technological endeavours face public and political pressure to adopt open, transparent and democratically accountable practices of public engagement. Prior research has identified different ways that experts 'imagine publics' - as uninformed, as disengaged, as a risk to science, and as co-producers of knowledge - but there has yet to be a systematic exploration of how these views emerge, interact and evolve. This article introduces a typology of imagined publics to analyse how publics are constructed in the field of forest genomics. We find that deficit views of publics have not been replaced by co-production. Instead, deficit and co-productive approaches to publics co-exist and overlap, informing both how publics are characterized and how public perceptions are studied. We outline an agenda for deepening and expanding research on public perceptions of novel technologies. Specifically, we call for more diverse and complex methodological approaches that account for relational dynamics over time.

Safety, immunogenicity and efficacy of an mRNA-based COVID-19 vaccine, GLB-COV2-043, in preclinical animal models.

Several COVID-19 vaccines, some more efficacious than others, are now available and deployed, including multiple mRNA- and viral vector-based vaccines. With the focus on creating cost-effective solutions that can reach the low- and medium- income world, GreenLight Biosciences has developed an mRNA vaccine candidate, GLB-COV2-043, encoding for the full-length SARS-CoV-2 Wuhan wild-type spike protein. In pre-clinical studies in mice, GLB-COV2-043 induced robust antigen-specific binding and virus-neutralizing antibody responses targeting homologous and heterologous SARS-CoV-2 variants and a TH1-biased immune response. Boosting mice with monovalent or bivalent mRNA-LNPs provided rapid recall and long-lasting neutralizing antibody titers, an increase in antibody avidity and breadth that was held over time and generation of antigen-specific memory B- and T- cells. In hamsters, vaccination with GLB-COV2-043 led to lower viral loads, reduced incidence of SARS-CoV-2-related microscopic findings in lungs, and protection against weight loss after heterologous challenge with Omicron BA.1 live virus. Altogether, these data indicate that GLB-COV2-043 mRNA-LNP vaccine candidate elicits robust protective humoral and cellular immune responses and establishes our mRNA-LNP platform for subsequent clinical evaluations.

A chair-stand time of greater than 15 seconds is associated with an increased risk of death and hospitalization in cirrhosis.

Background: Frailty is a clinical state of increased vulnerability and is common in patients with cirrhosis. The liver frailty index (LFI) is a validated tool to evaluate frailty in cirrhosis, comprising of grip strength, chair stands, and balance tests. The chair-stand test is an easy to conduct frailty subcomponent that does not require specialized equipment and may be valuable to predict adverse clinical outcomes in cirrhosis. The objective of this study was to determine if the chair-stand test is an independent predictor of mortality and hospitalization in cirrhosis. Methods: A retrospective review of 787 patients with cirrhosis was conducted. Chair-stand times were collected at baseline in person and divided into three groups: <10 seconds (n = 276), 10-15 seconds (n = 290), and >15 seconds (n = 221). Fine-Gray proportional hazards regression models were used to evaluate the association between chair-stand times and the outcomes of mortality and non-elective hospitalization. Results: The hazard of mortality (HR 3.21, 95% CI 2.16%-4.78%, p <0.001) and non-elective hospitalization (HR 2.24, 95% CI 1.73%-2.91%, p <0.001) was increased in group 3 in comparison to group 1. A chair-stand test time >15 seconds had increased all-cause mortality (HR 2.78, 95% CI 2.01%-3.83%, p <0.001) and non-elective hospitalizations (HR 1.84, 95% CI 1.48%-2.29%, p <0.001) compared to <15 seconds. Conclusions: A chair-stand test time of >15 seconds is independently associated with mortality and non-elective hospitalizations. This test holds promise as a rapid prognostication tool in cirrhosis. Future work will include external validation and virtual assessment in this population.

Transient susceptibility imaging as a measure of hemodynamic compromise: A pilot study.

BACKGROUND AND PURPOSE: The purpose of this study was to test the hypothesis that hemodynamically compromised brains exhibit transient changes in magnetic susceptibility throughout the cardiac cycle, and to model these changes using Linear System Theory to extract an index that reflects cerebrovascular reserve. MATERIALS AND METHODS: Eleven patients with angiographically-confirmed intracranial atherosclerotic disease with >50% stenosis were imaged with susceptibility weighted, cardiac-gated single shot images of cerebral Oxygen Extraction Fraction (OEF) at different timepoints of the cardiac cycle. Cardiac gating of the OEF acquisition allowed interrogation of oxygenated blood and the detection of changes throughout the cardiac cycle. Independent component analysis (ICA) of raw k-space data across the cardiac phase allowed MRI signal decomposition into dynamic and static components for image reconstruction. An asymmetry index score of the resultant parametric images were compared to test the hypothesis that variation in hemoglobin-induced susceptibility across the cardiac cycle indeed reflects pathophysiology of cerebrovascular disease. A mathematical model was derived to parameterize physiologic changes induced by the presence of a hemodynamically significant stenosis in the brain as a tissue impulse response parameter (ß). RESULTS: OEF was elevated in the affected hemisphere (50.34 ± 12.13% vs 46.93 ± 12.34%), but failed to reach statistical significance (p < .0796). Transient changes in the OEF signal showed significant distinction between healthy and compromised tissue (0.56 ± 0.067 vs 0.44 ± 0.067, p < .019)). The derived tissue impulse response function was found to be significant as well (10.72 ± 3.48 10-3 ms-1, 9.69 ± 3.51 10-3 ms-1; p < .037). CONCLUSION: In this pilot study, we found transient OEF and ß to be significant predictors of hemispheric compromise.

Together We Go Farther: Improving Access to Cancer Screening Through a Multidisciplinary, One-Stop-Shop Approach.

RATIONALE AND OBJECTIVES: Despite significant scientific advances in cancer treatment in recent decades, Black Americans still face marked inequities in cancer screening, diagnosis, and treatment. Redressing these persistent inequities will require innovative strategies for community engagement. Radiologists, as experts in cancer screening and diagnosis for multiple malignancies, including breast, lung, and colon, are ideally suited to lead and implement community-based strategies to address local cancer disparities. MATERIALS AND METHODS: Through an established academic-community partnership in West Philadelphia built over the course of multiple prior community healthcare events, the authors piloted a novel radiology-led multidisciplinary approach to improve access to cancer screening for the predominantly Black, medically-underserved residents. Using a "one-stop-shop" framework to provide a comprehensive suite of screening and ancillary services in the heart of the community, the authors sought to remove as many impediments to screening as possible. RESULTS: Approximately 350 participants attended the health fair, and a total of 232 screening tests or assessments were completed. Data from this event suggest that this inclusive approach, as well as the use of a health fair "passport" to incentivize engagement, can successfully improve access to screening and follow-up in an underserved community. CONCLUSION: This "one-stop-shop" community approach can be replicated by radiology-led teams in other settings as a high-value, scalable opportunity to reduce disparities in access to cancer screening.

Psychometric evaluation of a working memory assessment measure in young children with Down syndrome.

BACKGROUND: Working memory involves the temporary storage and manipulation of information and is frequently an area of challenge for individuals with Down syndrome (DS). Despite the potential benefits of intervention, laboratory assessments of working memory that could capture intervention effects have not undergone rigorous evaluation for use with young children with DS. It is critical to evaluate assessments of working memory in young children with DS to ensure the reliable and accurate measurement of performance. AIM: This study evaluated an adapted laboratory measure of working memory for young children with DS 2-8 years old. METHOD: A self-ordered pointing task, the Garage Game, was administered to 78 children with DS (mean = 5.17 years; SD = 1.49). Adaptations were made to the task to minimize potential DS phenotype-related language and motor confounds. RESULTS: Results indicate that the measure is feasible, scalable, and developmentally sensitive, with minimal floor and practice effects for this population within this chronological and developmental age range. CONCLUSION: These findings demonstrate that the Garage Game is promising for use in studies of early working memory and treatment trials that aim to support the development of this critical dimension of executive functioning for children with DS.

A systematic review of kidney-on-a-chip-based models to study human renal (patho-)physiology.

As kidney diseases affect ∼10% of the world population, understanding the underlying mechanisms and developing therapeutic interventions are of high importance. Although animal models have enhanced knowledge of disease mechanisms, human (patho-)physiology may not be adequately represented in animals. Developments in microfluidics and renal cell biology have enabled the development of dynamic models to study renal (patho-)physiology in vitro. Allowing inclusion of human cells and combining different organ models, such as kidney-on-a-chip (KoC) models, enable the refinement and reduction of animal experiments. We systematically reviewed the methodological quality, applicability and effectiveness of kidney-based (multi-)organ-on-a-chip models, and describe the state-of-the-art, strengths and limitations, and opportunities regarding basic research and implementation of these models. We conclude that KoC models have evolved to complex models capable of mimicking systemic (patho-)physiological processes. Commercial chips and human induced pluripotent stem cells and organoids are important for KoC models to study disease mechanisms and assess drug effects, even in a personalized manner. This contributes to the Reduction, Refinement and Replacement of animal models for kidney research. A lack of reporting of intra- and inter-laboratory reproducibility and translational capacity currently hampers implementation of these models.

Environmental evidence in action: on the science and practice of evidence synthesis and evidence-based decision-making.

In civil society we expect that policy and management decisions will be made using the best available evidence. Yet, it is widely known that there are many barriers that limit the extent to which that occurs. One way to overcome these barriers is via robust, comprehensive, transparent and repeatable evidence syntheses (such as systematic reviews) that attempt to minimize various forms of bias to present a summary of existing knowledge for decision-making purposes. Relative to other disciplines (e.g., health care, education), such evidence-based decision-making remains relatively nascent for environment management despite major threats to humanity, such as the climate, pollution and biodiversity crises demonstrating that human well-being is inextricably linked to the biophysical environment. Fortunately, there are a growing number of environmental evidence syntheses being produced that can be used by decision makers. It is therefore an opportune time to reflect on the science and practice of evidence-based decision-making in environment management to understand the extent to which evidence syntheses are embraced and applied in practice. Here we outline a number of key questions related to the use of environmental evidence that need to be explored in an effort to enhance evidence-based decision-making. There is an urgent need for research involving methods from social science, behavioural sciences, and public policy to understand the basis for patterns and trends in environmental evidence use (or misuse or ignorance). There is also a need for those who commission and produce evidence syntheses, as well as the end users of these syntheses to reflect on their experiences and share them with the broader evidence-based practice community to identify needs and opportunities for advancing the entire process of evidence-based practice. It is our hope that the ideas shared here will serve as a roadmap for additional scholarship that will collectively enhance evidence-based decision-making and ultimately benefit the environment and humanity.

Do female and male patients derive similar benefits from approved systemic oncology therapies? A systematic review and meta-analysis.

PURPOSE: The National Institutes of Health's policy for the inclusion of females in clinical research was a pivotal step towards the consideration of sex as a biological variable, which is of particular importance in oncology, given differential incidence and outcomes of cancer between the sexes, and known pharmacodynamic, pharmacokinetic, and immunological differences. Therefore, we aim to investigate if such biological sex-based differences translate to clinically meaningful outcome differences from recently approved systemic oncology therapies. METHODS: A systematic review of randomized control trials (RCTs) cited in Food and Drug Administration, European Medicines Agency, and Health Canada approvals was conducted. Chemotherapy, targeted agents, and immunotherapy RCTs reporting sex-based sub-group analyses for overall/progression-free survival (OS/PFS) were considered. Hazard ratios (HRs) and 95% confidence intervals (CIs) were utilized. Sensitivity analyses for survival endpoints, drug type, and cancer site were conducted. RESULTS: Ninety-nine RCTs were included, representing 62,384 patients (23,574 (38%) female). Pooled OS HRs [95% CIs] were 0.77 [0.72-0.81] and 0.76 [0.72-0.79] for females and males, respectively (P = 0.73), and 0.51 [0.47-0.56] and 0.57 [0.53-0.61] (P = 0.08) for PFS. Sensitivity analyses yielded similar results. No RCTs reported sex-based toxicity or quality-of-life (QOL) data. CONCLUSION: Female and male patients appear to derive comparable benefits from recently approved systemic oncology therapies. Future RCTs are encouraged to report sex-based toxicity and QOL data.

Exploring a case of incompatibility in a complex regimen containing Plasma-Lyte 148 in the pediatric intensive care.

BACKGROUND: In the local pediatric intensive care unit, precipitation was observed in the intravenous catheter upon co-administration of four drugs together with the buffered electrolyte solution (Plasma-Lyte 148, Baxter). Co-infusion of incompatible combinations represents a safety concern. AIMS: To reproduce the clinical case of precipitation. To further explore and understand the risk of precipitation, different combinations of the components as well as the corresponding electrolyte solution with 5% glucose (Plasma-Lyte 148 with 5% glucose) should be investigated. METHODS: Physical compatibility of fentanyl, ketamine, midazolam, and potassium chloride was tested in combination with the buffered electrolyte solutions. The concentrations and infusion rates representative of children 10-40 kg were used to estimate mixing ratios. Analyses detecting visual particles (Tyndall beam) and sub-visual particles (light obscuration technology) were undertaken. Measured turbidity and pH in mixed samples were compared with unmixed controls. RESULTS: Both midazolam and ketamine showed formation of visual and sub-visual particles upon mixing with Plasma-Lyte 148, respectively. Particle formation was confirmed by increased turbidity and a distinct Tyndall effect. pH in mixed samples mirrored the pH of the buffered electrolyte, suggesting that the solubility limits of midazolam, and in some ratios also ketamine, were exceeded. Midazolam also precipitated in combination with the glucose-containing product that held a lower pH, more favorable for keeping midazolam dissolved. CONCLUSIONS: Replication of the case revealed that both midazolam and ketamine contributed to the precipitation. Midazolam and ketamine were both evaluated as incompatible with the buffered electrolyte solution and midazolam also with the buffered electrolyte-glucose solution and should not be co-administered in the same i.v.-catheter line. Fentanyl and potassium chloride were interpreted as compatible with both buffered electrolytes.

Use of RT-PCR in conjunction with a respiratory pathogen assay to concurrently determine the prevalence of bacteria and SARS-CoV-2 from the nasopharynx of outpatients.

Introduction: COVID-19 has emerged as a highly contagious and debilitating disease caused by the SARS-CoV-2 virus and has claimed the lives of over 7.7 million people worldwide. Bacterial co-infections are one of many co-morbidities that have been suggested to impact the outcome of COVID-19 in patients. The goals of this study are to elucidate the presence of bacteria in the nasopharynx of SARS-CoV-2 positive and negative patients and to describe demographic categories that may be associated with the detection of these organisms during one of the initial waves of the COVID-19 pandemic. Methods: To this end, we investigated SARS-CoV-2 and bacterial co-detection from outpatient RT-PCR testing in Texas. Results: The results indicate that Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae were the most frequently detected bacteria in both SARS-CoV-2 positive and SARS-CoV-2 negative patients and that these bacteria were present in these two patient populations at similar proportions. We also detected Staphylococcus aureus in a significantly larger proportion of males relative to females and people under 65 years of age relative to those 65 and over. Finally, we observed that SARS-CoV-2 was more commonly detected in Hispanics compared to non-Hispanics; however, low disclosure rates make volunteer bias a concern when interpreting the effects of demographic variables. Discussion: This study describes the bacteria present in the nasopharynx of SARS-CoV-2 positive and negative patients, highlights associations between patient demographics and SARS-CoV-2 as well as bacterial co-detection. In addition, this study highlights RT-PCR based molecular testing as a tool to detect bacteria simultaneously when SARS-CoV-2 tests are performed.

A human kidney and liver organoid-based multi-organ-on-a-chip model to study the therapeutic effects and biodistribution of mesenchymal stromal cell-derived extracellular vesicles.

Mesenchymal stromal cell (MSC)-derived small extracellular vesicles (sEVs) show therapeutic potential in multiple disease models, including kidney injury. Clinical translation of sEVs requires further preclinical and regulatory developments, including elucidation of the biodistribution and mode of action (MoA). Biodistribution can be determined using labelled sEVs in animal models which come with ethical concerns, are time-consuming and expensive, and may not well represent human physiology. We hypothesised that, based on developments in microfluidics and human organoid technology, in vitro multi-organ-on-a-chip (MOC) models allow us to study effects of sEVs in modelled human organs like kidney and liver in a semi-systemic manner. Human kidney- and liver organoids combined by microfluidic channels maintained physiological functions, and a kidney injury model was established using hydrogenperoxide. MSC-sEVs were isolated, and their size, density and potential contamination were analysed. These sEVs stimulated recovery of the renal epithelium after injury. Microscopic analysis shows increased accumulation of PKH67-labelled sEVs not only in injured kidney cells, but also in the unharmed liver organoids, compared to healthy control conditions. In conclusion, this new MOC model recapitulates therapeutic efficacy and biodistribution of MSC-sEVs as observed in animal models. Its human background allows for in-depth analysis of the MoA and identification of potential side effects.