Doubling down on best practices: reflecting on teaching physiology during the COVID-19 pandemic.

As we pass the third anniversary of the World Health Organization's declaration of the SARS-CoV-2 global pandemic, it is beneficial to reflect upon how physiology education adapted to the challenges of the pandemic. At the initial stages of the pandemic, many educators were faced with the challenge of quickly transitioning to emergency remote teaching (ERT), requiring shifts in teaching methodology and laboratory structure to adapt to the pandemic normal. In this review, we provide a broad overview of the efforts made by the community of educators associated with the American Physiological Society during the pandemic to encourage best practices in teaching, maintain course and program goals during ERT, and innovate in physiology education. We also highlight diversity, equality, and inclusion work that was produced as the scientific community recommitted to tackling systemic and structural inequalities exacerbated by the pandemic and brought to the forefront by the Black Lives Matter movement. Finally, we examine the potentially long-lasting effects of the pandemic on education from both the student and faculty standpoints and how doubling down on what we learned can be beneficial to the future of physiology education.NEW & NOTEWORTHY This literature review examines and categorizes the repository of publications in physiology education that occurred during and related to the COVID-19 pandemic.

A Systematic Review of Bystander Interventions for the Prevention of Sexual Violence.

INTRODUCTION: Bystander interventions have been successful in changing bystander attitudes and behaviors to prevent sexual violence. This systematic review was performed to summarize and categorize the characteristics of sexual violence bystander intervention programs and analyze bystander intervention training approaches for the primary prevention of sexual violence and assault. METHOD: From June to July 2017, the authors searched both published and unpublished American and Canadian studies from 2007 to 2017. The published sources included six major electronic databases and the unpublished sources were Google Scholar and the 40 program websites. From the 706 studies that resulted from this initial search, a total of 44 studies (that included a single bystander intervention program and assessments at both pretest and at least one posttest) were included. RESULTS: Thirty-two percent of studies analyzed bystander behavior postintervention, and most found significant beneficial outcomes. The most frequently used training methods were presentation, discussion, and active learning exercises. Bringing in the Bystander and The Men's Program had the most replicated empirical support for effectiveness. DISCUSSION: There has been a substantive increase in quasi-experimental and randomized controlled trial approaches to assessing the effectiveness of this type of intervention since 2014. The training methods shared between these efficacious programs may translate to bystander interventions for other victimization types, such as child abuse. CONCLUSION: The use of in-person bystander training can make positive changes in attitudes and behaviors by increasing awareness of a problem and responsibility to solve it.

Vascular Smooth Muscle Sirtuin-1 Protects Against Diet-Induced Aortic Stiffness.

Arterial stiffness, a major cardiovascular risk factor, develops within 2 months in mice fed a high-fat, high-sucrose (HFHS) diet, serving as a model of human metabolic syndrome, and it is associated with activation of proinflammatory and oxidant pathways in vascular smooth muscle (VSM) cells. Sirtuin-1 (SirT1) is an NAD(+)-dependent deacetylase regulated by the cellular metabolic status. Our goal was to study the effects of VSM SirT1 on arterial stiffness in the context of diet-induced metabolic syndrome. Overnight fasting acutely decreased arterial stiffness, measured in vivo by pulse wave velocity, in mice fed HFHS for 2 or 8 months, but not in mice lacking SirT1 in VSM (SMKO). Similarly, VSM-specific genetic SirT1 overexpression (SMTG) prevented pulse wave velocity increases induced by HFHS feeding, during 8 months. Administration of resveratrol or S17834, 2 polyphenolic compounds known to activate SirT1, prevented HFHS-induced arterial stiffness and were mimicked by global SirT1 overexpression (SirT1 bacterial artificial chromosome overexpressor), without evident metabolic improvements. In addition, HFHS-induced pulse wave velocity increases were reversed by 1-week treatment with a specific, small molecule SirT1 activator (SRT1720). These beneficial effects of pharmacological or genetic SirT1 activation, against HFHS-induced arterial stiffness, were associated with a decrease in nuclear factor kappa light chain enhancer of activated B cells (NFκB) activation and vascular cell adhesion molecule (VCAM-1) and p47phox protein expressions, in aorta and VSM cells. In conclusion, VSM SirT1 activation decreases arterial stiffness in the setting of obesity by stimulating anti-inflammatory and antioxidant pathways in the aorta. SirT1 activators may represent a novel therapeutic approach to prevent arterial stiffness and associated cardiovascular complications in overweight/obese individuals with metabolic syndrome.

Vascular Smooth Muscle Sirtuin-1 Protects Against Aortic Dissection During Angiotensin II-Induced Hypertension.

BACKGROUND: Sirtuin-1 (SirT1), a nicotinamide adenine dinucleotide(+)-dependent deacetylase, is a key enzyme in the cellular response to metabolic, inflammatory, and oxidative stresses; however, the role of endogenous SirT1 in the vasculature has not been fully elucidated. Our goal was to evaluate the role of vascular smooth muscle SirT1 in the physiological response of the aortic wall to angiotensin II, a potent hypertrophic, oxidant, and inflammatory stimulus. METHODS AND RESULTS: Mice lacking SirT1 in vascular smooth muscle (ie, smooth muscle SirT1 knockout) had drastically high mortality (70%) caused by aortic dissection after angiotensin II infusion (1 mg/kg per day) but not after an equipotent dose of norepinephrine, despite comparable blood pressure increases. Smooth muscle SirT1 knockout mice did not show any abnormal aortic morphology or blood pressure compared with wild-type littermates. Nonetheless, in response to angiotensin II, aortas from smooth muscle SirT1 knockout mice had severely disorganized elastic lamellae with frequent elastin breaks, increased oxidant production, and aortic stiffness compared with angiotensin II-treated wild-type mice. Matrix metalloproteinase expression and activity were increased in the aortas of angiotensin II-treated smooth muscle SirT1 knockout mice and were prevented in mice overexpressing SirT1 in vascular smooth muscle or with use of the oxidant scavenger tempol. CONCLUSIONS: Endogenous SirT1 in aortic smooth muscle is required to maintain the structural integrity of the aortic wall in response to oxidant and inflammatory stimuli, at least in part, by suppressing oxidant-induced matrix metalloproteinase activity. SirT1 activators could potentially be a novel therapeutic approach to prevent aortic dissection and rupture in patients at risk, such as those with hypertension or genetic disorders, such as Marfan's syndrome.

A redox-resistant sirtuin-1 mutant protects against hepatic metabolic and oxidant stress.

Sirtuin-1 (SirT1), a member of the NAD(+)-dependent class III histone deacetylase family, is inactivated in vitro by oxidation of critical cysteine thiols. In a model of metabolic syndrome, SirT1 activation attenuated apoptosis of hepatocytes and improved liver function including lipid metabolism. We show in SirT1-overexpressing HepG2 cells that oxidants (nitrosocysteine and hydrogen peroxide) or metabolic stress (high palmitate and high glucose) inactivated SirT1 by reversible oxidative post-translational modifications (OPTMs) on three cysteines. Mutating these oxidation-sensitive cysteines to serine preserved SirT1 activity and abolished reversible OPTMs. Overexpressed mutant SirT1 maintained deacetylase activity and attenuated proapoptotic signaling, whereas overexpressed wild type SirT1 was less protective in metabolically or oxidant-stressed cells. To prove that OPTMs of SirT1 are glutathione (GSH) adducts, glutaredoxin-1 was overexpressed to remove this modification. Glutaredoxin-1 overexpression maintained endogenous SirT1 activity and prevented proapoptotic signaling in metabolically stressed HepG2 cells. The in vivo significance of oxidative inactivation of SirT1 was investigated in livers of high fat diet-fed C57/B6J mice. SirT1 deacetylase activity was decreased in the absence of changes in SirT1 expression and associated with a marked increase in OPTMs. These results indicate that glutathione adducts on specific SirT1 thiols may be responsible for dysfunctional SirT1 associated with liver disease in metabolic syndrome.

Arterial stiffening precedes systolic hypertension in diet-induced obesity.

Stiffening of conduit arteries is a risk factor for cardiovascular morbidity. Aortic wall stiffening increases pulsatile hemodynamic forces that are detrimental to the microcirculation in highly perfused organs, such as the heart, brain, and kidney. Arterial stiffness is associated with hypertension but presumed to be due to an adaptive response to increased hemodynamic load. In contrast, a recent clinical study found that stiffness precedes and may contribute to the development of hypertension although the mechanisms underlying hypertension are unknown. Here, we report that in a diet-induced model of obesity, arterial stiffness, measured in vivo, develops within 1 month of the initiation of the diet and precedes the development of hypertension by 5 months. Diet-induced obese mice recapitulate the metabolic syndrome and are characterized by inflammation in visceral fat and aorta. Normalization of the metabolic state by weight loss resulted in return of arterial stiffness and blood pressure to normal. Our findings support the hypothesis that arterial stiffness is a cause rather than a consequence of hypertension.

Secreted and membrane-bound isoforms of protease ADAM9 have opposing effects on breast cancer cell migration.

Tumor cell migration is mediated by cell-autonomous signaling mechanisms as well as paracrine and autocrine factors secreted by activated stromal cells in the tumor microenvironment. Like other members of the ADAM (a disintegrin and metalloproteinase) family, the integrin-binding metalloproteinase ADAM9 modulates cell-cell and cell-matrix interactions as well as ectodomain shedding of cell surface receptors and ligands, thereby modifying intracellular and extracellular signaling. ADAM9 transcripts are alternatively spliced to express a transmembrane protein (ADAM9-L) and a secreted variant (ADAM9-S). In this study, we show that ADAM9-S promotes breast cancer cell migration in a manner requiring its metalloproteinase activity, whereas ADAM9-L suppresses cell migration independent of its metalloproteinase activity. Suppression of migration by ADAM9-L requires a functional disintegrin domain and integrin binding. Expression analysis revealed that both ADAM9 isoforms are expressed in breast cancer cell lines and tissues. Therefore, relative levels of membrane-tethered and secreted variants of ADAM9 are a key determinant in manifestation of aggressive migratory phenotypes associated with breast cancer progression.

Low-volume resistance exercise attenuates the decline in strength and muscle mass associated with immobilization.

We determined the effectiveness of low-volume resistance exercise (EX) for the attenuation of loss of muscle mass and strength during leg immobilization. Men (N = 5) and women (N = 12, age 24 ± 5 years, body mass index 25.4 ± 3.6 kg/m(2)) were divided into two groups: exercise (EX; n = 12) and control (CON; n = 5). Subjects wore a knee brace on one leg that prevented weight bearing for 14 days. Resistance exercise (EX; 80% of maximal) was performed by the immobilized limb every other day. Immobilization induced a significant reduction (P < 0.05) in muscle fiber and thigh cross-sectional area (CSA), isometric knee extensor, and plantarflexor strength in the CON (P < 0.01) but not in the EX group. There were significant losses in triceps surae CSA in the CON and EX groups (P < 0.05), but the losses were greater in CON subjects (P < 0.01). A minimal volume (140 contractions in 14 days) of resistive exercise is an effective countermeasure against immobilization-induced atrophy of the quadriceps femoris but is only partially effective for the triceps surae.

Transfusion premedication to prevent acute transfusion reactions: a retrospective observational study to assess current practices.

BACKGROUND: The use of premedication to prevent acute transfusion reactions has been estimated to occur in 50% to 80% of transfusions. While this practice has some biologic rationale, few clinical studies have been performed to assess the efficacy of this practice, and the methodologic quality of these studies is variable. The primary objective of this study was to describe current practices regarding transfusion premedication to prevent febrile nonhemolytic transfusion reactions, mild allergic transfusion reactions, and transfusion-associated circulatory overload. STUDY DESIGN AND METHODS: We conducted an observational retrospective chart review of a stratified random sample of 324 transfusions that took place over a 6-month period. Data were abstracted from medical records and then scanned into a database for analysis. We calculated inter- and intraobserver agreement on key abstracted data to estimate assessment error. A two-phase adjudication process was used to determine whether or not medications given before the time of each transfusion were intended as premedications. RESULTS: Of the transfusions sampled, 1.6% (95% confidence interval, 0.4-3.9) were associated with premedication medications to prevent an acute transfusion reaction. Inter- and intraobserver reliability in the abstraction of key data points was good. Good agreement in adjudicator classification of outcomes was achieved only when adjudicators were provided with patient source documents. CONCLUSIONS: Premedication use was infrequent and much less common than previously reported. Improved methods of capturing transfusion premedication, which likely require prospective assessments, are needed for future research studies.

Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men.

BACKGROUND: The anabolic effect of resistance exercise is enhanced by the provision of dietary protein. OBJECTIVES: We aimed to determine the ingested protein dose response of muscle (MPS) and albumin protein synthesis (APS) after resistance exercise. In addition, we measured the phosphorylation of candidate signaling proteins thought to regulate acute changes in MPS. DESIGN: Six healthy young men reported to the laboratory on 5 separate occasions to perform an intense bout of leg-based resistance exercise. After exercise, participants consumed, in a randomized order, drinks containing 0, 5, 10, 20, or 40 g whole egg protein. Protein synthesis and whole-body leucine oxidation were measured over 4 h after exercise by a primed constant infusion of [1-(13)C]leucine. RESULTS: MPS displayed a dose response to dietary protein ingestion and was maximally stimulated at 20 g. The phosphorylation of ribosomal protein S6 kinase (Thr(389)), ribosomal protein S6 (Ser(240/244)), and the epsilon-subunit of eukaryotic initiation factor 2B (Ser(539)) were unaffected by protein ingestion. APS increased in a dose-dependent manner and also reached a plateau at 20 g ingested protein. Leucine oxidation was significantly increased after 20 and 40 g protein were ingested. CONCLUSIONS: Ingestion of 20 g intact protein is sufficient to maximally stimulate MPS and APS after resistance exercise. Phosphorylation of candidate signaling proteins was not enhanced with any dose of protein ingested, which suggested that the stimulation of MPS after resistance exercise may be related to amino acid availability. Finally, dietary protein consumed after exercise in excess of the rate at which it can be incorporated into tissue protein stimulates irreversible oxidation.

Cellular transformation by a FERM domain mutant of the Nf2 tumor suppressor gene.

Mutations in the Nf2 tumor suppressor gene lead to tumor formation in humans and mice and cellular overproliferation phenotypes in Drosophila. The Nf2 encoded protein, merlin, shares close sequence similarity in its amino terminus to members of the band 4.1 family of membrane-cytoskeletal linkers. Similarities between merlin and this family suggest a role for merlin in regulating cytoskeletal function. However, the mechanism of the tumor suppressing activity of merlin is not yet understood. Mutational analysis of Nf2 in flies has led to the identification of a dominant-negative allele, which harbors mutations in the amino terminus of the protein. Here, we report that expression of a murine analog of this amino-terminal mutant of Nf2 leads to complete transformation of NIH3T3 fibroblasts in culture. Cells that express this Nf2 mutant allele display disruptions of the actin cytoskeleton, lack of contact inhibition of growth, and anchorage-independent growth. Finally, fibroblasts that express this mutant Nf2 allele form tumors when injected into nude mice.