Potential clinical applications of current and future oral forms of desmopressin (Review).

Desmopressin is a synthetic analogue of vasopressin and a selective vasopressin receptor 2 agonist. It was first synthesised in 1967 and utilised for its antidiuretic properties. It is also used in bleeding disorders to enhance clotting. Other potential uses of the drug have been reported. The present review aims to provide a broad overview of the literature on potential further uses of oral forms of desmopressin. Key therapeutic areas of interest were identified based on known physiological activities/targets of desmopressin or reports of an effect of desmopressin in the literature. The feasibility of adequate dosing with oral forms of the drug was also considered. Systematic literature searches were carried out using the silvi.ai software for the identified areas, and summaries of available papers were included in tables and discussed. The results of the searches showed that desmopressin has been investigated for its efficacy in a number of areas, including bleeding control, renal colic, the central nervous system and oncology. Evidence suggests that oral desmopressin may have the potential to be of clinical benefit for renal colic and bleeding control in particular. However, further research is needed to clarify its effect in these areas, including randomised controlled studies and studies specifically of oral formulations (and doses). Further research may also yield findings for cancer, cognition and overactive bladder.

The Problem With National Institute of Standards and Technology Thermodynamics Tables in Continuum Mechanics.

Thermodynamics is a fundamental topic of continuum mechanics and biomechanics, with a wide range of applications to physiological and biological processes. This study addresses two fundamental limitations of current thermodynamic treatments. First, thermodynamics tables distributed online by the U.S. National Institute of Standards and Technology (NIST) report properties of fluids as a function of absolute temperature T and absolute pressure P. These properties include mass density ρ, specific internal energy u, enthalpy h=u+P/ρ, and entropy s. However, formulations of jump conditions across phase boundaries derived from Newton's second law of motion and the first law of thermodynamics employ the gauge pressure p=P-Pr, where Pr is an arbitrarily selected referential absolute pressure. Interchanging p with P is not innocuous as it alters tabulated NIST values for u while keeping h and s unchanged. Using p for functions of state and governing equations solves the problem with using NIST entries for the specific internal energy u in standard thermodynamics tables and analyses of phase transformation in continuum mechanics. Second, constitutive models for the free energy of fluids, such as water and air, are not typically provided in standard thermodynamics treatments. This study proposes a set of constitutive models and validates them against suitably modified NIST data.

Continuum Growth Mechanics: Reconciling Two Common Frameworks.

The objective of this study was to investigate whether the two most common growth mechanics modeling frameworks, the constrained-mixture growth model and the kinematic growth model, could be reconciled mathematically. The purpose of this effort was to provide practical guidelines for potential users of these modeling frameworks. Results showed that the kinematic growth model is mathematically consistent with a special form of the constrained-mixture growth model, where only one generation of a growing solid exists at any given time, overturning its entire solid mass at each instant of growth in order to adopt the reference configuration dictated by the growth deformation. The thermodynamics of the kinematic growth model, along with the specialized constrained-mixture growth model, requires a cellular supply of chemical energy to allow deposition of solid mass under a stressed state. A back-of-the-envelope calculation shows that the amount of chemical energy required to sustain biological growth under these models is negligibly small, when compared to the amount of energy normally consumed daily by the human body. In conclusion, this study successfully reconciled the two most popular growth theories for biological growth and explained the special circumstances under which the constrained-mixture growth model reduces to the kinematic growth model.

Erratum: "A Numerical Scheme for Anisotropic Reactive Nonlinear Viscoelasticity" [ASME J. Biomech Eng., 2023, 145(1), p. 011004; DOI: 10.1115/1.4054983].

In this erratum, we correct a mistake in a subcomponent of the numerical algorithm proposed in our recent study for modeling anisotropic reactive nonlinear viscoelasticity (doi:10.1115/1.4054983), for the special case where multiple weak bond families may be recruited with loading. This correction overcomes a nonphysical response noted under uni-axial cyclical loading.

"It's Like A Partnership": Exploring the Primary Care Experiences and Patient-Defined Goals of People Who Use Drugs.

BACKGROUND: Primary care is an important yet underutilized resource in addressing the overdose crisis. Previous studies have identified important aspects of primary care for people who use drugs (PWUD) and have found patient involvement in healthcare decisions and goal-setting to be especially critical. However, there has been limited research describing the primary care goals of PWUD. In harm reduction settings, where it is imperative that PWUD set their own goals, this research gap becomes especially relevant. OBJECTIVE: To explore how PWUD navigate primary care with a focus on understanding their primary care goals. DESIGN: A qualitative study using semi-structured interviews. PARTICIPANTS: PWUD currently engaged in primary care at the Respectful and Equitable Access to Comprehensive Healthcare (REACH) Program, a harm reduction-based primary care program in New York City. APPROACH: Between June 2022 and August 2022, we conducted 17 semi-structured interviews. Informed by phenomenology, transcripts were coded using both inductive and deductive codes and themes were developed using thematic analysis approaches. KEY RESULTS: Phenomenological analysis identified four core components that, together, created an experience that participants described as "a partnership" between patient and provider: (1) patient-provider collaboration around patient-defined healthcare goals; (2) support provided by harm reduction-based approaches to primary care anchored in incrementalism and flexibility; (3) care teams' ability to address healthcare system fragmentation; and (4) the creation of social connections through primary care. This holistic partnership fostered positive primary care experiences and supported participants' self-defined care goals, thereby facilitating meaningful care outcomes. CONCLUSIONS: To best meet the primary care goals of PWUD, these findings underscore the importance of primary care providers and programs facilitating such partnerships through organizational-level support anchored in harm reduction. Future research should explore how these experiences in primary care affect patient health outcomes, ultimately shaping best practices in the provision of high-quality primary care for PWUD.

Integration of Febio as an Instructional Tool in the Undergraduate Biomechanics Curriculum.

Computer simulations play an important role in a range of biomedical engineering applications. Thus, it is important that biomedical engineering students engage with modeling in their undergraduate education and establish an understanding of its practice. In addition, computational tools enhance active learning and complement standard pedagogical approaches to promote student understanding of course content. Herein, we describe the development and implementation of learning modules for computational modeling and simulation (CM&S) within an undergraduate biomechanics course. We developed four CM&S learning modules that targeted predefined course goals and learning outcomes within the febio studio software. For each module, students were guided through CM&S tutorials and tasked to construct and analyze more advanced models to assess learning and competency and evaluate module effectiveness. Results showed that students demonstrated an increased interest in CM&S through module progression and that modules promoted the understanding of course content. In addition, students exhibited increased understanding and competency in finite element model development and simulation software use. Lastly, it was evident that students recognized the importance of coupling theory, experiments, and modeling and understood the importance of CM&S in biomedical engineering and its broad application. Our findings suggest that integrating well-designed CM&S modules into undergraduate biomedical engineering education holds much promise in supporting student learning experiences and introducing students to modern engineering tools relevant to professional development.

Prevalence of Sleep CALM nocturia factors in a male veteran population.

INTRODUCTION: Nocturia is a complex and multifactorial condition, associated with several genitourinary abnormalities as well as a host of conditions beyond the urinary tract, and thus often poses a significant diagnostic challenge in real-world practice. Sleep Disorders, Comorbidities, Actions, Lower Urinary Tract Dysfunction, and Medications, the so-called "Sleep C.A.L.M." factors, are five common causes of nocturia requiring judicious evaluation according to current consensus guidelines. This study aims to assess the prevalence of the Sleep C.A.L.M. factors in a nocturia clinical population. METHODS: Retrospective analysis of frequency-volume charts from men with ≥2 nocturnal voids as well as concurrent demographic, clinical, and medical history data to identify patients with each of the Sleep C.A.L.M. FACTORS: Comorbidities and medications were classified as a single group. RESULTS: A total of 213 subjects met the criteria for inclusion (median age 68.0 [63.5-75.5] years). The prevalence of 1) sleep disorders, 2) comorbidities and/or medication use, 3) actions (i.e., modifiable behaviors/lifestyle factors), and 4) lower urinary tract dysfunction was 31%, 31%, 19%, and 41%, respectively. Among included participants, 73% were found to have at least 1 Sleep C.A.L.M. factor, and 33% had multiple Sleep C.A.L.M. FACTORS: Results were similar upon stratification by age and nocturnal polyuria status. CONCLUSIONS: The Sleep C.A.L.M. factors are highly common among nocturia patients in the clinical urology setting. Although many of these factors are strongly associated with advanced age in community-based nocturia study samples, they appear common even among younger men in a nocturia patient population; the differential effect of age and individual Sleep C.A.L.M. factors on nocturia pathophysiology requires further investigation.

Nocturia in Menopausal Women: The Link Between Two Common Problems of the Middle Age.

INTRODUCTION AND HYPOTHESIS: The aim of this review is to discuss the link between menopause and nocturia and to give an overview of the increasing prevalence, risk factors, causative factors, treatment needs and options for nocturia in peri-menopausal women. METHODS: This opinion article is a narrative review based on the expertise and consensus of a variety of key opinion leaders, in combination with an extensive literature review. This literature search included a thorough analysis of potential publications on both the PubMed Database and the Web of Science and was conducted between November 2022 and December 2022. The following key words were used "nocturia" and "menopause" or "nocturnal frequency and menopause." Moreover, key words including "incidence," "prevalence," "insomnia," "estrogen therapy," "metabolic syndrome," and "hot flushes" were used in combination with the aforementioned key words. Last, the reference lists of articles obtained were screened for other relevant literature. RESULTS: The perimenopause can be a trigger for inducing nocturia. Typically, obesity, body mass index (BMI), and waist circumference are risk factors for developing peri-menopausal nocturia. Presumably the development of peri-menopausal nocturia is multifactorial, with interplay among bladder, sleep, and kidney problems due to estrogen depletion after the menopause. First, impaired stimulation of estrogen receptors in the urogenital region leads to vaginal atrophy and reduced bladder capacity. Moreover, menopause is associated with an increased incidence of overactive bladder syndrome. Second, estrogen deficiency can induce salt and water diuresis through blunted circadian rhythms for the secretion of antidiuretic hormone and the activation of the renin-angiotensin-aldosterone system. Additionally, an increased incidence of sleep disorders, including vasomotor symptoms and obstructive sleep apnea signs, is observed. Oral dryness and a consequent higher fluid intake are common peri-menopausal symptoms. Higher insulin resistance and a higher risk of cardiovascular diseases may provoke nocturia. Given the impact of nocturia on general health and quality of life, bothersome nocturia should be treated. Initially, behavioral therapy should be advised. If these modifications are inadequate, specific treatment should be proposed. Systemic hormone replacement is found to have a beneficial effect on nocturia, without influencing sodium and water clearance in patients with nocturnal polyuria. It is presumed that the improvement in nocturia from hormonal treatment is due to an improvement in sleep disorders.

Point-of-Care Ultrasound Aids in the Management of Patient Taking Semaglutide Before Surgery: A Case Report.

Semaglutide, a glucagon-like peptide-1 (GLP-1) analog, has various effects on the gastrointestinal tract. In patients undergoing anesthesia delayed gastric emptying time can have sequelae if not identified preoperatively. Modalities include thorough history regarding the last dose administration of a GLP-1 analog and ultrasound of gastric contents before induction of anesthesia. We present a case in which gastric ultrasound identified a patient at increased risk for aspiration on induction and allowed for appropriate alterations in the anesthetic plan.

Application of the Sleep C.A.L.M. Tool for Assessing Nocturia in a Large Nationally Representative Cohort.

PURPOSE: Nocturia significantly impacts patients' quality of life but remains insufficiently evaluated and treated. The "Sleep C.A.L.M." system categorizes the factors thought to collectively reflect most underlying causes of nocturia (Sleep disorders, Comorbidities, Actions [i.e., modifiable patient behaviors such as excess fluid intake], Lower urinary tract dysfunction, and Medications). The purpose of this study was to assess the association of nocturia with the Sleep C.A.L.M. categories using a nationally representative dataset. METHODS: Retrospective analysis of the National Health and Nutrition Examination Survey from 2013/14-2017/18 cycles was conducted. Pertinent questionnaire, laboratory, dietary, and physical examination data were used to ascertain the presence of Sleep C.A.L.M. categories in adults ≥20 years of age. Nocturia was defined as ≥2 nighttime voids. RESULTS: A total of 12,274 included subjects were included (51.6% female; median age, 49.0 years [interquartile range, 34.0-62.0 years]; 27.6% nocturia). Among subjects with nocturia, the prevalence of 0, ≥1, and ≥2 Sleep C.A.L.M. categories was 3.5% (95% confidence interval [CI], 2.8%-4.4%), 96.5% (95% CI, 95.6%-97.2%), and 81.2% (95% CI, 78.9%-83.3%), respectively. Compared to those with 0-1 Sleep C.A.L.M. categories, the adjusted odds of nocturia in subjects with 2, 3, and 4-5 Sleep C. A.L.M. categories were 1.77 (95% CI, 1.43-2.21), 2.33 (1.89-2.87), and 3.49 (2.81-4.35), respectively (P<0.001). Similar trends were observed for most age and sex subgroups. When assessed individually, each of the 5 Sleep C.A.L.M. categories were independently associated with greater odds of nocturia, which likewise persisted across multiple age and sex subgroups. CONCLUSION: Sleep C.A.L.M. burden is associated with increased odds of nocturia in a dose-dependent fashion, and potentially a relevant means by which to organize the underlying etiologies for nocturia among community-dwelling adults.

Toward the Development of a Tissue Engineered Gradient Utilizing CRISPR-Guided Gene Modulation.

Cellular, compositional, and mechanical gradients are found throughout biological tissues, especially in transition zones between tissue types. Yet, strategies to engineer such gradients have proven difficult due to the complex nature of these tissues. Current strategies for tissue engineering complex gradients often utilize stem cells; however, these multipotent cells require direction from environmental cues, which can be difficult to control both in vitro and in vivo. In this study, we utilize clustered regularly-interspaced short palindromic repeats (CRISPR)-guided gene modulation to direct the differentiation of multipotent adipose-derived stem cells (ASCs) to demonstrate the effectiveness of CRISPR-engineered cells in tissue engineering applications. Specifically, we screen CRISPR-interference (CRISPRi) constructs targeting the promotors of selected osteogenic inhibitors and demonstrate that ASC osteogenic differentiation and mineral deposition can be regulated with CRISPRi targeting of Noggin without the use of exogenous growth factors in tissue engineered constructs. As a proof of concept, we combine three technologies developed out of our laboratories to demonstrate the controlled deposition of these engineered cells in a gradient with CRISPR-activation multiplex-engineered aggrecan/collagen type-II-chondrogenic ASCs on a high density anisotropic type I collagen construct to create a cell and tissue gradient similar to the fibrocartilage-to-mineralized-fibrocartilage gradient in the enthesis. Our results display the promise of CRISPR-engineered ASCs to produce tissue gradients, similar to what is observed in native tissue.

World Trade Center workers with asthma and post-traumatic stress disorder perceive airflow limitation more accurately.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a major risk factor for increased asthma morbidity among World Trade Center (WTC) workers. OBJECTIVE: To investigate whether differences in perception of airflow limitation mediate the association of PTSD with worse asthma control in WTC workers. METHODS: We collected data from WTC workers on asthma control (Asthma Control Questionnaire and Asthma Quality of Life Questionnaire) and daily peak expiratory flow (PEF) measures over 6 weeks. Perception of airway limitation was assessed by comparing guessed vs actual PEF values. Post-traumatic stress disorder was diagnosed using the Structured Clinical Interview. We used unadjusted and adjusted models to compare PEF and perception measures in WTC workers with PTSD with those of workers without PTSD. RESULTS: Overall, 25% of 224 participants had PTSD. Post-traumatic stress disorder was associated with worse Asthma Control Questionnaire (2.2±0.8 vs 1.1±0.9, P < .001) and Asthma Quality of Life Questionnaire (3.9±1.1 vs 5.4±1.1, P < .001) scores. Adjusted analyses showed no significant differences in PEF between WTC workers with (351.9±143.3 L/min) and those without PTSD (364.6±131.6 L/min, P = .55). World Trade Center workers with PTSD vs those without PTSD had increased proportion of accurate perception (67.0±37.2% vs 53.5±38.1%, P = .01) and decreased underperception (23.3.0±32.1% vs 38.9±37.5%, P = .004) of airflow limitation during periods of limitation. Similar results were obtained in adjusted analyses. CONCLUSION: This study indicates that differences in perception of airflow limitation may mediate the relationship of PTSD and increased asthma symptoms, given WTC workers with PTSD have worse self-reported asthma control, an increased proportion of accurate perception, and decreased underperception, despite no differences in daily PEF measures.

Nocturia and Blood Pressure Elevation in Adolescents.

Nocturia has been increasingly recognized as a manifestation of various non-urological conditions including hypertension. In adults, blood pressure (BP) elevation has been identified as a robust correlate of nocturia, but such a relationship has not been studied in pediatric populations where nocturia is often attributed to hormonal, sleep, physiological or psychological disorders. Accordingly, this study aimed to determine the relationship between nocturia and BP elevation in adolescents. We prospectively studied 100 patients, aged 10-18 years, recruited from pediatric clinics at our institution. Nocturia (defined as ≥ 1 voids on voiding diary analysis) was present in 45% of the study sample (range: 1-4 voids/night). 37% of subjects self-reported awakening to urinate, and 34% of subjects had BP elevation according to age-dependent thresholds from current Pediatrics guidelines. On multivariate analyses, BP elevation was strongly associated with nocturia determined by both voiding diary (OR 26.2, 95% CI: 6.5, 106.0) and self-report. Conversely, nocturia was associated with increased odds of elevated BP by diary (26.3, 95% CI: 6.5, 106.4) and self-report (OR 8.1, 95% CI: 3.2, 20.5). In conclusion, nocturia appears to be common and is strongly associated with BP elevation in adolescents. These findings suggest that eliciting a history of nocturia holds promise as a simple method of identifying adolescents at risk for hypertension.

From nocturnal awakenings to nocturnal voiding: the relationship between insomnia and nocturia - a systematic review.

INTRODUCTION: The aim of this study was to systematically evaluate relevant literature regarding 1) the prevalence of nocturia in patients with insomnia; 2) sleep characteristics of insomniacs with and without nocturia; 3) interventions for the treatment of insomnia and their effect on nocturia. EVIDENCE ACQUISITION: A systematic review of literature was performed through EMBASE, MEDLINE, CLINICALTRIALS.GOV and CENTRAL databases up until November 2022 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. From the identified reports, 11 studies were retained, of which 7 were eligible for meta-analysis. Bias assessment was performed using the ROBINS tools as per the Cochrane collaboration guidelines. EVIDENCE SYNTHESIS: A total of 5396 older adults were included in the meta-analysis. The pooled estimate of the OR was 1.958 (95% CI: 1.609-2.384) for nocturia in patients with insomnia based on 7 studies in a random effects model with nonsignificant heterogeneity (I2=50.83%, P=0.06). Wake after sleep onset (WASO) was longer in people with insomnia and nocturia compared to those without and sleep efficiency (SE) declined. Interventions with melatonin, diet and behavioral therapy were beneficial on nocturia frequency in insomniacs. A limiting factor of our analysis was the scarcity of available data, potentially causing an important selection bias. CONCLUSIONS: The overall odds for nocturia in older adults is higher in patients with insomnia than those without and is associated with worse sleep outcomes. Interventions for treating insomnia such as melatonin, behavioral therapy and diet show beneficial results on nocturnal voiding frequency. We advocate for further research in which uniform definitions and questionnaires are used. Routine screening for nocturia in patients with insomnia could be beneficial to maximize sleep quality improvement.

How should we assess the cardiovascular system in patients presenting with bothersome nocturia? ICI-RS 2023.

AIMS: The link between nocturia and cardiovascular disease (CVD) is frequently discussed in literature, yet the precise nature of this relationship remains poorly characterized. The existing literature was reviewed in order to address issues concerning the origin, diagnosis, management, and implications of the co-occurrence of CVD and nocturia. METHODS: This review summarizes literature and recommendations regarding the link between CVD and nocturia discussed during a think-tank meeting held at the 2023 International Consultation on Incontinence-Research Society. RESULTS: Cardiovascular disorders are often underestimated contributors to nocturia, with various potential mechanisms influencing nighttime urination, such as impact on fluid retention, atrial natriuretic peptide, and glomerular filtration rate. The redistribution of fluid from leg edema in supine position can lead nocturnal polyuria (NP). Additionally, sleep disturbances due to nocturia in itself may lead to CVD through an increase in blood pressure, insulin resistance, and inflammation. Disrupted circadian rhythms (e.g., in sleep pattern and urine production) were identified as critical factors in most etiologies of nocturia, and their contribution is deemed imperative in future research and treatment approaches, particularly in the aging population. NP can be detected through a simple bladder diary and can even be used to distinguish cardiac from noncardiac causes of nocturia. For the treatment of NP, desmopressin can be effective in select patients, however, caution and close monitoring is warranted for those with CVD due to increased risk of side effects. CONCLUSIONS: Gaps were identified in the available evidence and clear cut recommendations were put forth for future research. It is essential to gain a deeper understanding of the mechanisms linking nocturia and CVD to develop optimal management strategies.

Spatial Configurations of 3D Extracellular Matrix Collagen Density and Anisotropy Simultaneously Guide Angiogenesis.

Extracellular matrix (ECM) collagen density and fibril anisotropy are thought to affect the development of new vasculatures during pathologic and homeostatic angiogenesis. Computational simulation is emerging as a tool to investigate the role of matrix structural configurations on cell guidance. However, prior computational models have only considered the orientation of collagen as a model input. Recent experimental evidence indicates that cell guidance is simultaneously influenced by the direction and intensity of alignment (i.e., degree of anisotropy) as well as the local collagen density. The objective of this study was to explore the role of ECM collagen anisotropy and density during sprouting angiogenesis through simulation in the AngioFE and FEBio modeling frameworks. AngioFE is a plugin for FEBio (Finite Elements for Biomechanics) that simulates cell-matrix interactions during sprouting angiogenesis. We extended AngioFE to represent ECM collagen as deformable 3D ellipsoidal fibril distributions (EFDs). The rate and direction of microvessel growth were modified to depend simultaneously on the ECM collagen anisotropy (orientation and degree of anisotropy) and density. The sensitivity of growing neovessels to these stimuli was adjusted so that AngioFE could reproduce the growth and guidance observed in experiments where microvessels were cultured in collagen gels of varying anisotropy and density. We then compared outcomes from simulations using EFDs to simulations that used AngioFE's prior vector field representation of collagen anisotropy. We found that EFD simulations were more accurate than vector field simulations in predicting experimentally observed microvessel guidance. Predictive simulations demonstrated the ability of anisotropy gradients to recruit microvessels across short and long distances relevant to wound healing. Further, simulations predicted that collagen alignment could enable microvessels to overcome dense tissue interfaces such as tumor-associated collagen structures (TACS) found in desmoplasia and tumor-stroma interfaces. This approach can be generalized to other mechanobiological relationships during cell guidance phenomena in computational settings.

The role of renal circadian biorhythms in lifelong LUTS.

INTRODUCTION: This article delves into the intricate relationship between kidney function, diuresis, and lower urinary tract symptoms (LUTS) throughout the transitions of the human lifespan. It explores circadian regulation of urine production, maturation of renal function from birth to adulthood, and effects of aging on kidney function and LUTS. The complex connections between these factors are highlighted, offering insights into potential interventions and personalized management strategies. METHODS: An international panel of seven experts engaged in online discussions, focusing on kidney function, diuresis, and LUTS throughout life. This manuscript summarizes expert insights, literature reviews, and findings presented during a webinar and subsequent discussions. RESULTS: Renal function undergoes significant maturation from birth to adulthood, with changes in glomerular filtration rate, diuresis, and tubular function. A circadian rhythm in urine production is established during childhood. Adolescents and young adults can experience persistent enuresis due to lifestyle factors, comorbidities, and complex physiological changes. In older adults, age-related alterations in kidney function disrupt the circadian rhythm of diuresis, contributing to nocturnal polyuria and LUTS. CONCLUSION: The interplay between kidney function, diuresis, and LUTS is crucial in understanding lifelong urinary health. Bridging the gap between pediatric and adult care is essential to address enuresis in adolescents and young adults effectively. For older adults, recognizing the impact of aging on renal function and fluid balance is vital in managing nocturia. This holistic approach provides a foundation for developing innovative interventions and personalized treatments to enhance quality of life for individuals with LUTS across all stages of life.

Early Resistance Rehabilitation Improves Functional Regeneration Following Segmental Bone Defect Injury.

Mechanical loading is integral to bone development and repair. The application of mechanical loads through rehabilitation are regularly prescribed as a clinical aide following severe bone injuries. However, current rehabilitation regimens typically involve long periods of non-loading and rely on subjective patient feedback, leading to muscle atrophy and soft tissue fibrosis. While many pre-clinical studies have focused on unloading, ambulatory loading, or direct mechanical compression, rehabilitation intensity and its impact on the local strain environment and subsequent bone healing have largely not been investigated. This study combines implantable strain sensors and subject-specific finite element models in a pre-clinical rodent model with a defect size on the cusp of critically-sized. Animals were enrolled in either high or low intensity rehabilitation one week post injury to investigate how rehabilitation intensity affects the local mechanical environment and subsequent functional bone regeneration. The high intensity rehabilitation animals were given free access to running wheels with resistance, which increased local strains within the regenerative niche by an average of 44% compared to the low intensity (no-resistance) group. Finite element modeling demonstrated that resistance rehabilitation significantly increased compressive strain by a factor of 2.0 at week 1 and 4.45 after 4 weeks of rehabilitation. The resistance rehabilitation group had significantly increased regenerated bone volume and higher bone bridging rates than its sedentary counterpart (bone volume: 22.00 mm3 ± 4.26 resistance rehabilitation vs 8.00 mm3 ± 2.27 sedentary; bridging rates: 90% resistance rehabilitation vs 50% sedentary). In addition, animals that underwent resistance running had femurs with improved mechanical properties compared to those left in sedentary conditions, with failure torque and torsional stiffness values matching their contralateral, intact femurs (stiffness: 0.036 Nm/deg ± 0.006 resistance rehabilitation vs 0.008 Nm/deg ± 0.006 sedentary). Running on a wheel with no resistance rehabilitation also increased bridging rates (100% no resistance rehabilitation vs 50% sedentary). Analysis of bone volume and von Frey suggest no-resistance rehabilitation may improve bone regeneration and hindlimb functionality. These results demonstrate the potential for early resistance rehabilitation as a rehabilitation regimen to improve bone regeneration and functional recovery.

Changing Answers in Multiple-Choice Exam Questions: Patterns of TOP-Tier Versus BOTTOM-Tier Students in Podiatric Medical School.

OBJECTIVES: Students often express uncertainty regarding changing their answers on multiple choice tests despite multiple studies quantitatively showing the benefits of changing answers. METHODS: Data was collected from 86 first-year podiatric medical students over one semester for the course of Biochemistry, as shown in electronic testing data collected via ExamSoft's® Snapshot Viewer. Quantitative analysis was performed comparing frequency of changing answers and whether students changed their answers from incorrect-to-correct, correct-to-incorrect, or incorrect-to-incorrect. A correlation analysis was performed to assess the relationship between the frequency of each type of answer change and class rank. Independent-sample t-tests were used to assess differences in the pattern of changing answers amongst the top and bottom performing students in the class. RESULTS: The correlation between total changes made from correct-to-incorrect per total answer changes and class rank yielded a positive correlation of r = 0.218 (P = .048). There was also a positive correlation of r = 0.502 (P < .000) observed in the number of incorrect-to-incorrect answer changes per total changes made compared to class rank. A negative correlation of r = -0.382 (P < .000) was observed when comparing class rank and the number of changed answers from incorrect-to-correct. While most of the class benefited from changing answers, a significant positive correlation of r = 0.467 (P < .000) for percent ultimately incorrect (regardless of number of changes) and class rank was observed. CONCLUSION: Analysis revealed that class rank correlated to likelihood of a positive gain from changing answers. Higher ranking students were more likely to gain points from changing their answer compared to lower ranking. Top students changed answers less frequently and changed answers to an ultimately correct answer more often, while bottom students changed answers from an incorrect answer to another incorrect answer more frequently than top students.