High-titer manufacturing of SARS-CoV-2 Spike-pseudotyped VSV in stirred-tank bioreactors.

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pandemic highlighted the importance of vaccine innovation in public health. Hundreds of vaccines built on numerous technology platforms have been rapidly developed against SARS-CoV-2 since 2020. Like all vaccine platforms, an important bottleneck to viral-vectored vaccine development is manufacturing. Here, we describe a scalable manufacturing protocol for replication-competent SARS-CoV-2 Spike-pseudotyped vesicular stomatitis virus (S-VSV)-vectored vaccines using Vero cells grown on microcarriers in a stirred-tank bioreactor. Using Cytodex 1 microcarriers over 6 days of fed-batch culture, Vero cells grew to a density of 3.95 ± 0.42 ×106 cells/mL in 1-L stirred-tank bioreactors. Ancestral strain S-VSV reached a peak titer of 2.05 ± 0.58 ×108 plaque-forming units (PFUs)/mL at 3 days postinfection. When compared to growth in plate-based cultures, this was a 29-fold increase in virus production, meaning a 1-L bioreactor produces the same amount of virus as 1,284 plates of 15 cm. In addition, the omicron BA.1 S-VSV reached a peak titer of 5.58 ± 0.35 × 106 PFU/mL. Quality control testing showed plate- and bioreactor-produced S-VSV had similar particle-to-PFU ratios and elicited comparable levels of neutralizing antibodies in immunized hamsters. This method should enhance preclinical and clinical development of pseudotyped VSV-vectored vaccines in future pandemics.

Bioprocess development for cord blood mesenchymal stromal cells on microcarriers in Vertical-Wheel bioreactors.

Equine mesenchymal stromal cells (MSCs) have been found to be beneficial for the treatment of many ailments, including orthopedic injuries, due to their superior differentiation potential and immunomodulating properties. Cell therapies require large cell numbers, which are not efficiently generated using conventional static expansion methods. Expansion of equine cord blood-derived MSCs (eCB-MSCs) in bioreactors, using microcarriers as an attachment surface, has the potential to generate large numbers of cells with increased reproducibility and homogeneity compared with static T-flask expansion. This study investigated the development of an expansion process using Vertical-Wheel (VW) bioreactors, a single-use bioreactor technology that incorporates a wheel instead of an impeller. Initially, microcarriers were screened at small scale to assess eCB-MSC attachment and growth and then in bioreactors to assess cell expansion and harvesting. The effect of different donors, serial passaging, and batch versus fed batch were all examined in 0.1 L VW bioreactors. The use of VW bioreactors with an appropriate microcarrier was shown to be able to produce cell densities of up to 1E6 cells/mL, while maintaining cell phenotype and functionality, thus demonstrating great potential for the use of these bioreactors to produce large cell numbers for cell therapies.

Bacterial-Nanocellulose-Based Biointerfaces and Biomimetic Constructs for Blood-Contacting Medical Applications.

Understanding the interaction between biomaterials and blood is critical in the design of novel biomaterials for use in biomedical applications. Depending on the application, biomaterials can be designed to promote hemostasis, slow or stop bleeding in an internal or external wound, or prevent thrombosis for use in permanent or temporary medical implants. Bacterial nanocellulose (BNC) is a natural, biocompatible biopolymer that has recently gained interest for its potential use in blood-contacting biomedical applications (e.g., artificial vascular grafts), due to its high porosity, shapeability, and tissue-like properties. To promote hemostasis, BNC has been modified through oxidation or functionalization with various peptides, proteins, polysaccharides, and minerals that interact with the coagulation cascade. For use as an artificial vascular graft or to promote vascularization, BNC has been extensively researched, with studies investigating different modification techniques to enhance endothelialization such as functionalizing with adhesion peptides or extracellular matrix (ECM) proteins as well as tuning the structural properties of BNC such as surface roughness, pore size, and fiber size. While BNC inherently exhibits comparable mechanical characteristics to endogenous blood vessels, these mechanical properties can be enhanced through chemical functionalization or through altering the fabrication method. In this review, we provide a comprehensive overview of the various modification techniques that have been implemented to enhance the suitability of BNC for blood-contacting biomedical applications and different testing techniques that can be applied to evaluate their performance. Initially, we focused on the modification techniques that have been applied to BNC for hemostatic applications. Subsequently, we outline the different methods used for the production of BNC-based artificial vascular grafts and to generate vasculature in tissue engineered constructs. This sequential organization enables a clear and concise discussion of the various modifications of BNC for different blood-contacting biomedical applications and highlights the diverse and versatile nature of BNC as a natural biomaterial.

Environmental Health Knowledge Does Not Necessarily Translate to Action in Youth.

Environmental challenges pose serious health problems, especially for children, and lay public action is lacking. This study sought to characterize the relationship between environmental health knowledge and behavior in youth. A cross-sectional, descriptive survey with quantitative and qualitative questions was conducted. Open-ended questions were coded to generate themes/subthemes. Subscales' scores were presented as mean ± SD or median and interquartile range (IQR). T- and Mann-Whitney tests were used to compare groups, and correlations were used to evaluate covariation. A total of 452 children were surveyed. Youth verbalized concerns about their environments and their impact on health. Air pollution was the most concerning issue. Participants had moderate knowledge scores. Few described the three health domains; even fewer included environment. Behavior scores were low and weakly correlated with knowledge, but were moderately correlated with attitude and self-efficacy. Participation in environmental classes, activities, and clubs was associated with higher scores. We found variable environmental health knowledge, limited understanding of the local environment's impact on health, and a weak association between youth's knowledge and behavior. Focused formal and non-formal educational experiences were associated with improved scores, indicating the value of targeted youth educational programming to increase environmental health knowledge and action.

The Impact of Underlying Obstructive Sleep Apnea Treatment on Exercise Capacity in Patients With Pulmonary Hypertension Undergoing a Cardiac Rehabilitation Program.

PURPOSE: Obstructive sleep apnea (OSA)-related pulmonary hypertension (PH) can often be reversed with treatment of OSA via continuous positive airway pressure. We hypothesized that treatment of OSA would be associated with a greater improvement in exercise capacity (EC) with cardiac rehabilitation (CR), especially in patients with PH as compared with those who are untreated. METHODS: We reviewed medical records of 315 consecutive patients who participated in CR. Pulmonary hypertension status was assessed on the basis of peak tricuspid regurgitant velocity (>2.8 m/sec) on pre-CR echocardiograms. The OSA status (no, untreated, or treated OSA) was determined on the basis of results from sleep studies, continuous positive airway pressure device data, and physician notes. Exercise capacity was assessed by measuring metabolic equivalents (METs) using a treadmill stress test before and after CR. RESULTS: We included 290 patients who participated in CR with available echocardiographic data: 44 (15%) had PH, and 102 (35%) had known OSA (30 treated and 72 untreated). Patients with OSA versus those with no OSA were more likely to have PH ( P = .06). Patients with PH versus no-PH were associated with significantly lower baseline METs in crude and adjusted analyses ( P ≤. 004). The PH and OSA status in isolation were not associated with changes in METs ( P > .2) with CR. There was a significant interaction between OSA treatment and PH in crude and adjusted analyses ( P ≤.01): treatment vs no treatment of OSA was associated with a clinically and statistically greater improvement in METs in patients who participated in CR with but not without PH. CONCLUSION: Baseline PH was associated with decreased baseline EC but did not attenuate CR-related improvements in METs. However, in the subset of OSA patients with PH, OSA therapy was associated with improved EC after CR.

Challenges and opportunities in downstream separation processes for mesenchymal stromal cells cultured in microcarrier-based stirred suspension bioreactors.

Mesenchymal stromal cells (MSC) are a promising platform for regenerative medicine applications because of their multilineage differentiation abilities and ease of collection, isolation, and growth ex vivo. To meet the demand for clinical applications, large-scale manufacturing will be required using three-dimensional culture platforms in vessels such as stirred suspension bioreactors. As MSCs are an adherent cell type, microcarriers are added to the culture to increase the available surface area for attachment and growth. Although extensive research has been performed on efficiently culturing MSCs using microcarriers, challenges persist in downstream processing, including harvesting, filtration, and volume reduction, which all play a critical role in the translation of cell therapies to the clinic. The objective of this review is to assess the current state of downstream technologies available for microcarrier-based MSC cultures. This includes a review of current research within the three stages: harvesting, filtration, and volume reduction. Using this information, a downstream process for MSCs is proposed, which can be applied to a wide range of applications.

The Pathogenesis of Central and Complex Sleep Apnea.

PURPOSE: The purpose of this article is to review the recent literature on central apnea. Sleep disordered breathing (SDB) is characterized by apneas (cessation in breathing), and hypopneas (reductions in breathing), that occur during sleep. Central sleep apnea (CSA) is sleep disordered breathing in which there is an absence or diminution of respiratory effort during breathing disturbances while asleep. In obstructive sleep apnea (OSA), on the other hand, there is an absence of flow despite ongoing ventilatory effort. RECENT FINDINGS: Central sleep apnea is a heterogeneous disease with multiple clinical manifestations. OSA is by far the more common condition; however, CSA is highly prevalent among certain patient groups. Complex sleep apnea (CompSA) is defined as the occurrence/emergence of CSA upon treatment of OSA. Similarly, there is considerable overlap between CSA and OSA in pathogenesis as well as impacts. Thus, understanding sleep disordered breathing is important for many practicing clinicians.

Evaluation of an Infectious Diseases Elective for Early Clinical Medical Students on Their Internal Medicine Clerkship.

Background: Early medical subspecialty training is an emerging trend in medical education. These electives are still rare for Early Clinical Medical Students (ECMS). We describe the introduction of an Infectious Disease (ID) inpatient consult rotation elective for ECMS. Methods: In addition to seeing patients and rounding with the inpatient ID consult team, we created a supplemental curriculum to provide added support for ECMS that included a checklist of clinical skills learning objectives, self-directed, publicly available mini-lectures on ID topics, and an ID Coach who provided directed and personalized tutoring for students. We surveyed ECMS, ID fellows and attendings on service, and ID Coaches to evaluate the acceptability, feasibility, and effectiveness of this rotation and curriculum. Results: The majority of ECMS reported that the rotation was a useful educational experience and that the ID Coach was one of the most valuable aspects of the rotation. The majority of ID fellows and attendings reported that working with ECMS improved their job satisfaction and well-being. Conclusions: This multifaceted approach to early medical subspecialty training was valuable for ECMS, ID fellows, and faculty. Ongoing improvements in this curriculum will provide a useful tool for medical education.

Identification of sleep fragmentation-induced gut microbiota alteration and prediction of functional impact in Sprague Dawley rats harboring microbiome derived from multiple human donors.

Objectives: Poor quality sleep, including sleep fragmentation (SF), can result in severe health consequences. Gut microbiota symbiotically coexist with the host, making essential contributions to overall well-being. In this study, the effects of both acute (6-day) and chronic (6-week) SF in a humanized rat model were examined to evaluate the impact of SF on this symbiotic relationship. Material and Methods: Human fecal material was transplanted into antibiotic-treated, microbially depleted, Sprague Dawley rats. Animals were subjected to either acute or chronic SF and shifts to gut microbiota were investigated using 16S rRNA sequencing and predictive functional profiles were constructed with PICRUSt. We also investigated SF-induced intestinal microbial adhesion and penetration or increased microbial invasion of selected tissues and organs; as well as changes in crypt/villi architecture. Results: Microbiota profiling indicated that chronic, but not acute, SF significantly decreased the richness of alpha-diversity of distal ileum microbiota, and altered cecum and distal ileum beta-diversity; although both acute and chronic SF significantly changed select populations of microbiota in all three regions. Neither acute nor chronic SF induced changes to microbial adhesion, penetration, or invasion into intestinal tissues or nearby organs. Additionally, we found that chronic SF caused a reduction in villus height in the proximal colon. Discussion: Our study suggests that acute SF alters the gut microbiota in this humanized rat model, while chronic SF produces more pronounced changes to microbiota populations. This study identified potential microbiota targets for the prevention and/or intervention of the adverse effects of S F.

SARS-CoV-2 outbreak in a Canadian suburban tertiary hospital necessitating full facility closure: a descriptive observational study.

BACKGROUND: SARS-CoV-2 can cause outbreaks in community- and hospital-based settings. The aim of this study was to provide a detailed epidemiologic account of a hospital-wide SARS-CoV-2 outbreak and provide a description of case evaluations, transmission networks and the interventions implemented to stem the outbreak. METHODS: We conducted a retrospective descriptive study of a hospital-wide SARS-CoV-2 outbreak at the Misericordia Community Hospital (Edmonton) from June 21 to Aug. 14, 2020. We reviewed hospital chart, public health and occupational health records to determine demographics, case type (community- or hospital-acquired), need for critical care and outcome for each case linked to the outbreak (patients, hospital staff, and community and patient visitors). We developed detailed transmission networks using epidemiologic data to determine what variables may have contributed to transmission. RESULTS: Fifty-eight cases of SARS-CoV-2 infection were linked to this hospital outbreak (31 patients, 25 staff members and 2 visitors; 66% female, age range 19-97 years). One patient required critical care, and 11 deaths were recorded (all among inpatients). Most cases were hospital-acquired (91%), and 28% were asymptomatic at the time of diagnosis. The outbreak was composed of 2 clusters driven by protective equipment breaches, premature removal of precautions, transmission in small staff quarters and infection of a staff member after exposure to a wandering patient with dementia and asymptomatic, undetected SARS-CoV-2 infection. INTERPRETATION: A detailed epidemiologic review of this hospital-wide outbreak shows that a SARS-CoV-2 outbreak can involve complex transmission chains and clusters. Multipronged bundled approaches, aggressive contact tracing, and patient and staff prevalence screening are important to help bring such outbreaks under control, along with ongoing vigilance in detecting delayed cases.

Extensive genome-wide duplications in the eastern oyster (Crassostrea virginica).

Genomic structural variation is an important source of genetic and phenotypic diversity, playing a critical role in evolution. The recent availability of a high-quality reference genome for the eastern oyster, Crassostrea virginica, and whole-genome sequence data of samples from across the species range in the USA, provides an opportunity to explore structural variation across the genome of this species. Our analysis shows significantly greater individual-level duplications of regions across the genome than that of most model vertebrate species. Duplications are widespread across all ten chromosomes with variation in frequency per chromosome. The eastern oyster shows a large interindividual variation in duplications as well as particular chromosomal regions with a higher density of duplications. A high percentage of duplications seen in C. virginica lie completely within genes and exons, suggesting the potential for impacts on gene function. These results support the hypothesis that structural changes may play a significant role in standing genetic variation in C. virginica, and potentially have a role in their adaptive and evolutionary success. Altogether, these results suggest that copy number variation plays an important role in the genomic variation of C. virginica. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.

Reconstructive options for cutaneous dorsal hand defects.

BACKGROUND: Moderate to large dorsal hand defects pose reconstructive challenges owing to the small surface area, immobile adjacent finger tissue, and thin, fragile skin. OBJECTIVE: To present reconstructive options for moderate to large dorsal hand defects. MATERIALS AND METHODS: First, a brief review of dorsal hand reconstructive options is discussed. Then, three approaches to reconstructing dorsal hand defects are presented based on the amount of available underlying tissue and location of the defect on the hand. RESULTS: In the authors' opinion, for larger defects on the mid-distal 1st-3rd metacarpals, the single arm rotation flap is preferable. For medium-sized defects with underlying soft tissue, a Burow's graft is appropriate. The O-Z flap is best for medium- to large-sized defects on the proximal half of the metacarpals. Defects of the digits are excluded. CONCLUSION: The O-Z rotation flap, single arm rotation flap, or Burow's graft can be used to reconstruct the majority of moderate to large dorsal hand defects.

Non-parental Adults and Sexual Health Behaviors Among Young Minority Men: A Qualitative Examination.

Young Black and Latino sexual minority men (YBLSM) exhibit disproportionately high rates of negative sexual health outcomes, including HIV and other sexually transmitted infections, compared to other groups, partly due to relatively higher rates of exposure to a host of socio-structural risk factors (e.g., unstable housing and under-employment). However, an under-studied interpersonal resource exists for many YBLSM, non-parental adults (NPAs, i.e., adults who act as role models and provide social support), who may be able to influence contextual (e.g., unemployment) and individual (e.g., reduced health expectations) factors underlying sexual health disparities. Aims: This study sought to examine the role of NPAs in factors that affect sexual health behaviors and in supporting those health behaviors directly, among YBLSM living in a mid-sized city in the southern United States. A total of n=20 participants, n=10 YBLSM (ages 16 to 22), and n=10 NPAs (ages 26 to 52) were interviewed using semi-structured guides to examine NPA involvement in the lives of YBLSM from both sides of the relationship. The research team used a framework analysis approach to iteratively identify and define meaningful codes and sub-codes. Both YBLSM and NPAs described NPAs helping YBLSM through role modeling and social support in a variety of areas found to affect sexual health behaviors, such as housing instability and psychological distress, as well as in specific behaviors, such as condom use and HIV medication adherence. Given the multiple socio-structural obstacles facing YBLSM and their multifaceted relationships with NPAs, NPAs may be a promising resource to help address these impediments to health. Partnering more intentionally with NPAs is a potentially promising strategy to help reduce HIV-related disparities affecting YBLSM that is worthy of additional empirical attention.

Reconstruction of cutaneous dorsal finger defects.

BACKGROUND: Reconstruction of surgical defects on the dorsal finger can be challenging because of a lack of adjacent tissue reservoirs, poor laxity, and often thin, atrophic skin surrounding the defect. OBJECTIVE: To present reconstructive options for cutaneous dorsal finger defects. METHODS: We describe our five preferred approaches to reconstructing cutaneous dorsal finger defects based on the amount of available underlying tissue and location of the defect on the finger. RESULTS: In the authors' opinion, for smaller defects between and including the metacarpophalangeal joint extending to the proximal interphalangeal joint, a transposition flap or unilateral advancement flap is preferable. For proximal finger defects that are wider, a unilateral rotation flap is appropriate. A Burow full-thickness skin graft can be used for any proximal defect with underlying soft tissue present. For defects with underlying bone or tendon present, a reverse cross-finger interpolation flap can be utilized. CONCLUSIONS: The unilateral advancement flap, unilateral rotation flap, transposition flap, full-thickness skin grafts, or the reverse cross-finger interpolation flap can be used to reconstruct the majority of cutaneous dorsal finger defects.

Use of spironolactone to treat acne in adolescent females.

BACKGROUND/OBJECTIVES: Studies assessing the utility of spironolactone for treating acne in adolescent females are lacking. Thus, we sought to examine spironolactone's role in treating this patient population. METHODS: A retrospective review was performed to determine the efficacy of spironolactone treatment in adolescent females seen at Mayo Clinic in Rochester, Minnesota, from 2007 to 2017. RESULTS: In a cohort of 80 pediatric patients with a median age of 19 years (range, 14-20 years), 64 patients (80%) experienced improvement of acne on treatment with spironolactone (median dose, 100 mg daily) with a favorable side effect profile. Approximately a quarter of patients (22.5%) had a complete response; more than half (58.8%) had a complete response or a partial response greater than 50%. Initial and maximal responses were observed at a median of 3 months and 5 months, respectively. Patients received treatment with spironolactone for a median duration of 7 months (range, 3-45 months) with limited side effects. CONCLUSIONS: Spironolactone demonstrated efficacy in treating acne in adolescent females and is a safe long-term alternative to systemic antibiotics in these patients.

Distribution of Patients at Risk for Complications Related to COVID-19 in the United States: Model Development Study.

BACKGROUND: Coronavirus disease (COVID-19) has spread exponentially across the United States. Older adults with underlying health conditions are at an especially high risk of developing life-threatening complications if infected. Most intensive care unit (ICU) admissions and non-ICU hospitalizations have been among patients with at least one underlying health condition. OBJECTIVE: The aim of this study was to develop a model to estimate the risk status of the patients of a nationwide pharmacy chain in the United States, and to identify the geographic distribution of patients who have the highest risk of severe COVID-19 complications. METHODS: A risk model was developed using a training test split approach to identify patients who are at high risk of developing serious complications from COVID-19. Adult patients (aged ≥18 years) were identified from the Walgreens pharmacy electronic data warehouse. Patients were considered eligible to contribute data to the model if they had at least one prescription filled at a Walgreens location between October 27, 2019, and March 25, 2020. Risk parameters included age, whether the patient is being treated for a serious or chronic condition, and urban density classification. Parameters were differentially weighted based on their association with severe complications, as reported in earlier cases. An at-risk rate per 1000 people was calculated at the county level, and ArcMap was used to depict the rate of patients at high risk for severe complications from COVID-19. Real-time COVID-19 cases captured by the Johns Hopkins University Center for Systems Science and Engineering (CSSE) were layered in the risk map to show where cases exist relative to the high-risk populations. RESULTS: Of the 30,100,826 adults included in this study, the average age is 50 years, 15% have at least one specialty medication, and the average patient has 2 to 3 comorbidities. Nearly 28% of patients have the greatest risk score, and an additional 34.64% of patients are considered high-risk, with scores ranging from 8 to 10. Age accounts for 53% of a patient's total risk, followed by the number of comorbidities (29%); inferred chronic obstructive pulmonary disease, hypertension, or diabetes (15%); and urban density classification (5%). CONCLUSIONS: This risk model utilizes data from approximately 10% of the US population. Currently, this is the most comprehensive US model to estimate and depict the county-level prognosis of COVID-19 infection. This study shows that there are counties across the United States whose residents are at high risk of developing severe complications from COVID-19. Our county-level risk estimates may be used alongside other data sets to improve the accuracy of anticipated health care resource needs. The interactive map can also aid in proactive planning and preparations among employers that are deemed critical, such as pharmacies and grocery stores, to prevent the spread of COVID-19 within their facilities.