Technique for Rapid Hand Transplant Donor Procurement Through the Elbow

Background: Hand and distal forearm allotransplantation has advanced over the last 20 years from experimental to a viable treatment option for bilateral upper extremity amputation. Despite widespread growth of this field, there are few technical reports that elaborate the details of donor arm procurement. This article details a technique for rapid donor procurement through the elbow for mid to distal forearm-level hand allograft procurement. Methods: Nine arm procurements were performed on deceased tissue-only donors provided by the local organ procurement organization, including two bilateral and five unilateral cases. Technique highlights include using a fishmouth incision through the lateral and medical epicondyles, identification of the neurovascular structures, and disarticulating the elbow joint. Results: Procuring through the elbow provides straightforward anatomy, bypasses the need to cut through bone, and allows tissue allotransplantation teams to achieve procurement, flushing, and packaging within 20 minutes. Conclusions: Procurement through the elbow is a simple procedure that streamlines the process for multi-organ donors by minimizing the time needed for hand allograft procurement. Team coordination and surgical rehearsals are essential for successful hand and upper extremity procurement and allotransplantation.

What faculty write versus what students see? Perspectives on multiple-choice questions using Bloom's taxonomy

BACKGROUND

Using revised Bloom's taxonomy, some medical educators assume they can write multiple choice questions (MCQs) that specifically assess higher (analyze, apply) versus lower-order (recall) learning. The purpose of this study was to determine whether three key stakeholder groups (students, faculty, and education assessment experts) assign MCQs the same higher- or lower-order level.

METHODS

In Phase 1, stakeholders' groups assigned 90 MCQs to Bloom's levels. In Phase 2, faculty wrote 25 MCQs specifically intended as higher- or lower-order. Then, 10 students assigned these questions to Bloom's levels.

RESULTS

In Phase 1, there was low interrater reliability within the student group (Krippendorf's alpha = 0.37), the faculty group (alpha = 0.37), and among three groups (alpha = 0.34) when assigning questions as higher- or lower-order. The assessment team alone had high interrater reliability (alpha = 0.90). In Phase 2, 63% of students agreed with the faculty as to whether the MCQs were higher- or lower-order. There was low agreement between paired faculty and student ratings (Cohen's Kappa range .098-.448, mean .256).

DISCUSSION

For many questions, faculty and students did not agree whether the questions were lower- or higher-order. While faculty may try to target specific levels of knowledge or clinical reasoning, students may approach the questions differently than intended.

Design of a foundational sciences curriculum: Applying the ICAP framework to pharmacology education in integrated medical curricula

Expectations for physicians are rapidly changing, as is the environment in which they will practice. In response, preclerkship medical education curricula are adapting to meet these demands, often by reducing the time for foundational sciences. This descriptive study compares preclerkship pharmacology education curricular practices from seven allopathic medical schools across the United States. We compare factors and practices that affect how pharmacology is integrated into the undergraduate medical education curriculum, including teaching techniques, resources, time allocated to pharmacology teaching, and assessment strategies. We use data from seven medical schools in the United States, along with results from a literature survey, to inform the strengths and weaknesses of various approaches and to raise important questions that can guide future research regarding integration of foundational sciences in medical school and health professions' curricula. In this comparative study, we found that there is significant heterogeneity in the number of hours dedicated to pharmacology in the preclerkship curriculum, whereas there was concordance in the use of active learning pedagogies for content delivery. Applying the ICAP (Interactive, Constructive, Active, Passive) Framework for cognitive engagement, our data showed that pharmacology was presented using more highly engaging pedagogies during sessions that are integrated with other foundational sciences. These findings can serve as a model that can be applied beyond pharmacology to other foundational sciences such as genetics, pathology, microbiology, biochemistry, etc.

Choice of Corticosteroid Solution and Outcome After Injection for Trigger Finger

Background: Many techniques for injection of trigger fingers exist. The purpose of this study was to determine whether the type of steroid or technique used for trigger finger injection altered clinical outcomes. Methods: Six hand surgeons at a single institution were surveyed regarding their injection technique, preferred steroid used, and protocol for repeat injection or indication for surgery for symptomatic trigger finger. A retrospective chart review of patients who underwent trigger finger injections was performed by randomly selecting 35 patients for each surgeon between January 2013 and December 2015. Demographic data at the time of presentation were collected. Outcome data during follow-up appointments were also recorded. Results: A total of 210 patient charts were reviewed. Demographic data and initial presenting grade of triggering were similar among all groups. There was no significant difference in clinical course or eventual outcomes noted with injection technique. There were 70 patients in each steroid cohort. Patients receiving triamcinolone required additional injections compared with those receiving methylprednisolone and dexamethasone. Eventual surgical intervention was significantly higher in those patients receiving methylprednisolone. The methylprednisolone group also underwent operative release significantly earlier. Conclusions: Trigger finger injections with triamcinolone demonstrate a higher rate of additional injections when compared with dexamethasone and methylprednisolone. Patients who underwent methylprednisolone injection had surgical release performed earlier and more frequently than the other 2 groups. The choice of corticosteroid significantly affected clinical outcome in this study population. Clinicians performing steroid injections for trigger finger may wish to consider these results when selecting a specific agent.

Free Deoxycholic Acid Exacerbates Vascular Calcification in CKD through ER Stress-Mediated ATF4 Activation

BACKGROUND

Our metabolome approach found that levels of circulating, free deoxycholic acid (DCA) is associated with the severity of vascular calcification in patients with CKD. However, it is not known whether DCA directly causes vascular calcification in CKD.

METHODS

Using various chemicals and animal and cell culture models, we investigated whether the modulation of DCA levels influences vascular calcification in CKD.

RESULTS

CKD increased levels of DCA in mice and humans by decreasing urinary DCA excretion. Treatment of cultured VSMCs with DCA but no other bile acids (BAs) induced vascular calcification and osteogenic differentiation through endoplasmic reticulum (ER) stress-mediated activating transcription factor-4 (ATF4) activation. Treatment of mice with Farnesoid X receptor (FXR)-specific agonists selectively reduced levels of circulating cholic acid-derived BAs, such as DCA, protecting from CKD-dependent medial calcification and atherosclerotic calcification. Reciprocal FXR deficiency and DCA treatment induced vascular calcification by increasing levels of circulating DCA and activating the ER stress response.

CONCLUSIONS

This study demonstrates that DCA plays a causative role in regulating CKD-dependent vascular diseases through ER stress-mediated ATF4 activation.

Twist1 in T Lymphocytes Augments Kidney Fibrosis after Ureteral Obstruction

Background

Twist1 is a basic helix-loop-helix domain-containing transcription factor that participates in diverse cellular functions, including epithelial-mesenchymal transition and the cellular immune response. Although Twist1 plays critical roles in the initiation and progression of kidney diseases, the effects of Twist1 in the T lymphocyte on the progression of renal fibrosis require elucidation.

Methods

129/SvEv mice with a floxed allele for the gene encoding Twist1 or TNFα were bred with CD4-Cre mice to yield CD4-Cre⁺ Twist1^flox/flox (Twist1-TKO) or CD4-Cre⁺ TNF^flox/flox (TNF-TKO) mice with robust, but selective, deletion of Twist1 or TNFα mRNA in T cells, respectively. Twist1 TKO, TNF TKO, and WT controls underwent UUO with assessment of kidney fibrosis and T-cell phenotype at 14 days.

Results

Compared with WT controls, obstructed kidneys from Twist1 TKO mice had attenuated extracellular matrix deposition. Despite this diminished fibrosis, Twist1 TKO obstructed kidneys contained more CD8⁺ T cells than in WTs. These intrarenal CD8⁺ T cells exhibited greater activation and higher levels of TNFα expression than those from WT obstructed kidneys. Further, we found that selective deletion of TNFα from T cells exaggerated renal scar formation and injury after UUO, highlighting the capacity of T-cell TNF to constrain fibrosis in the kidney.

Conclusions

Twist1 in T cells promotes kidney fibrogenesis, in part, by curtailing the renal accumulation of TNF-elaborating T cells.

A hyaluronan synthesis inhibitor delays the progression of diabetic kidney disease in a mouse experimental model

BACKGROUND

The role of hyaluronan (HA) in the development and progression of diabetic kidney disease (DKD), as well as the precise mechanisms and consequences of HA involvement in this pathology are still to be clarified.

METHODS

In this study, we assayed the effects of the HA synthesis inhibitor 4-methylumbelliferone (4-MU) on the development of DKD. Diabetic type 2 model mice (eNOS^-/- C57BLKS/J^db) were fed artificial diets containing 5% 4-MU or not for 9 weeks. Plasma glucose, glomerular filtration rate (GFR), albumin to creatinine ratio (ACR), and biomarkers of kidney function and systemic inflammation were measured at baseline and after treatment. Diabetic nephropathy was further characterized in treated and control mice by histopathology.

RESULTS

Treated animals consumed a daily dose of approximately 6.2 g of 4-MU per kg of body weight. At the end of the experimental period, the 4-MU supplemented diet resulted in a significant decrease in non-fasting plasma glucose (516 [interquartile range 378-1170] vs. 1149 [875.8-1287] mg/dL, P=0.050) and a trend toward lower HA kidney content (5.6 ± 1.5 vs. 8.8 ± 3.1 ng/mg of kidney weight, P=0.070) compared to the control diet, respectively. Diabetic animals treated with 4-MU showed significantly higher GFR and lower urine ACR and plasma cystatin C levels than diabetic controls. Independent histological assessment of DKD also demonstrated a significant decrease in mesangial expansion score and glomerular injury index in 4-MU-treated mice compared to controls. Plasma glucose showed a strong correlation with kidney HA levels (r=0.66, P=0.0098). Both total hyaluronan (r=0.76, P=0.0071) and low-molecular-weight hyaluronan content (r=0.64, P=0.036) in the kidneys correlated with urine ACR in mice.

CONCLUSION

These results show that the hyaluronan synthesis inhibitor 4-MU effectively slowed the progression of DKD and constitutes a potential new therapeutic approach to treat DKD.

Anterior Interosseous Nerve Palsy After Shoulder Arthroscopy Treated With Surgical Decompression: A Case Series and Systematic Review of the Literature

Background: Anterior interosseous nerve (AIN) palsy is a very uncommon cause of upper extremity pain and weakness that comprises less than 1% of all upper extremity nerve palsies. Rarely reported but also mentioned in the literature is AIN palsy after shoulder arthroscopy. Methods: A systematic review of the literature to date using PubMed was conducted to identify patients who suffered AIN palsy after shoulder arthroscopy procedures. Articles included met the following criteria: (1) published in English; (2) primary presentation of the data; (3) patients had undergone shoulder arthroscopy before developing symptoms of AIN palsy; and (4) diagnosis was confirmed with clinical symptoms of AIN palsy. Measured outcomes included patient demographics, specific shoulder procedure, anesthesia procedure, intra-operative patient positioning, intra-operative compressive dressing, intra-operative traction, surgical versus conservative treatment, abnormal findings during decompression procedure, proposed mechanism of injury, and follow-up. Results: The search yielded 6 articles, of which 4 (13 cases) met inclusion criteria. An additional 2 cases were included in this report totaling 15 cases. The average patient age was 49 years (range: 31-64) with 73% males. At average follow-up of 24 months, 67% of patients experienced complete resolution of symptoms-more than half of which underwent surgical decompression. Patients who failed to progress experienced weakness of the flexor digitorum profundus and flexor pollicis longus muscles. Conclusions: Proposed injury mechanisms for AIN palsy after shoulder arthroscopy range from mechanical trauma, compressive hematoma, and direct anesthetic neurotoxicity. Management should be directed by clinical symptoms, imaging, and patient factors with majority of patients expected to have excellent clinical outcomes.

Effect of Metacarpal Fixation Configuration on Strength and Fracture Gap Displacements in a Cadaveric Model of Externally Fixed Distal Radius Fractures

Background: The purpose of the study was to determine the biomechanical effect of distal pin configuration in unilateral external fixation of distal radius fracture in a cadaveric model. Methods: A standardized 2-part extra-articular distal radius fracture model with dorsal comminution was created in 6 matched pairs of cadaveric upper extremities. Specimens within each matched pair were randomly assigned to either 4 or 6 cortices of distal pin metacarpal fixation. Cyclic, compressive loads were applied to the palmar hand. Results: No significant differences were detected in maximum forces. Six-cortex metacarpal fixation showed significantly lower magnitude of actuator displacement at 100 N cyclic loading. The difference in construct stiffness did not translate to disparities in angular and translational interfragmentary displacement at the fracture gap. Conclusions: Utilizing only 4 cortices and sparing the middle finger metacarpal avoids the need for a more transverse orientation required with 6-cortex fixation, which may otherwise impede thumb motion.

The Sensitivity and Specificity of Nerve Conduction Studies for Diagnosis of Carpal Tunnel Syndrome: A Systematic Review

Background: The utility of nerve conduction studies (NCS) for diagnosis of carpal tunnel syndrome (CTS) has continued to be a subject of debate. Proponents of NCS assume a high sensitivity and specificity; however, many are unaware of the actual literature on this topic and the cutoff values commonly used for diagnosis. The purpose of this systematic review of the literature is to report the sensitivity and specificity of NCS for diagnosis of CTS in various studies. Methods: A literature review of PubMed and EMBASE databases was performed for all articles on NCS for diagnosis of CTS. The outcome of interest was the sensitivity and/or specificity of the NCS distal motor latency (DML) or distal sensory latency (DSL) cutoff value used to diagnose CTS in each study. Results: A total of 3066 total articles were screened and 21 were included in the review after assessment by two independent reviewers. The mean cut-off value for DSL was 3.37 ms (range 2.8-4 ms) and the mean cutoff value for DML was 4.28 ms (range 3.8-4.6 ms). Weighted mean DSL sensitivity was 73.4% and weighted mean DSL specificity was 93.6%. Weighted mean DML sensitivity was 56.2% and weighted mean DML specificity was 95.8%. Conclusions: There is significant variation in the cutoff values used for both DSL and DML. The wide range of cut-off values makes it difficult to interpret the literature, and there is a lack of high-quality studies with control groups using a priori cut-off values for diagnosis.

Podocyte Lipotoxicity in CKD

CKD represents the ninth most common cause of death in the United States but, despite this large health burden, treatment options for affected patients remain limited. To remedy this, several relevant pathways have been identified that may lead to novel therapeutic options. Among them, altered renal lipid metabolism, first described in 1982, has been recognized as a common pathway in clinical and experimental CKD of both metabolic and nonmetabolic origin. This observation has led many researchers to investigate the cause of this renal parenchyma lipid accumulation and its downstream effect on renal structure and function. Among key cellular components of the kidney parenchyma, podocytes are terminally differentiated cells that cannot be easily replaced when lost. Clinical and experimental evidence supports a role of reduced podocyte number in the progression of CKD. Given the importance of the podocytes in the maintenance of the glomerular filtration barrier and the accumulation of TG and cholesterol-rich lipid droplets in the podocyte and glomerulus in kidney diseases that cause CKD, understanding the upstream cause and downstream consequences of lipid accumulation in podocytes may lead to novel therapeutic opportunities. In this review, we hope to consolidate our understanding of the causes and consequences of dysregulated renal lipid metabolism in CKD development and progression, with a major focus on podocytes.

In Vivo Entombment of Bacteria and Fungi during Calcium Oxalate, Brushite, and Struvite Urolithiasis

Background

Human kidney stones form via repeated events of mineral precipitation, partial dissolution, and reprecipitation, which are directly analogous to similar processes in other natural and manmade environments, where resident microbiomes strongly influence biomineralization. High-resolution microscopy and high-fidelity metagenomic (microscopy-to-omics) analyses, applicable to all forms of biomineralization, have been applied to assemble definitive evidence of in vivo microbiome entombment during urolithiasis.

Methods

Stone fragments were collected from a randomly chosen cohort of 20 patients using standard percutaneous nephrolithotomy (PCNL). Fourier transform infrared (FTIR) spectroscopy indicated that 18 of these patients were calcium oxalate (CaOx) stone formers, whereas one patient formed each formed brushite and struvite stones. This apportionment is consistent with global stone mineralogy distributions. Stone fragments from seven of these 20 patients (five CaOx, one brushite, and one struvite) were thin sectioned and analyzed using brightfield (BF), polarization (POL), confocal, super-resolution autofluorescence (SRAF), and Raman techniques. DNA from remaining fragments, grouped according to each of the 20 patients, were analyzed with amplicon sequencing of 16S rRNA gene sequences (V1-V3, V3-V5) and internal transcribed spacer (ITS1, ITS2) regions.

Results

Bulk-entombed DNA was sequenced from stone fragments in 11 of the 18 patients who formed CaOx stones, and the patients who formed brushite and struvite stones. These analyses confirmed the presence of an entombed low-diversity community of bacteria and fungi, including Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Aspergillus niger. Bacterial cells approximately 1 μm in diameter were also optically observed to be entombed and well preserved in amorphous hydroxyapatite spherules and fans of needle-like crystals of brushite and struvite.

Conclusions

These results indicate a microbiome is entombed during in vivo CaOx stone formation. Similar processes are implied for brushite and struvite stones. This evidence lays the groundwork for future in vitro and in vivo experimentation to determine how the microbiome may actively and/or passively influence kidney stone biomineralization.

Progress toward the Clinical Application of Mesenchymal Stromal Cells and Other Disease-Modulating Regenerative Therapies: Examples from the Field of Nephrology

Drawing from basic knowledge of stem-cell biology, embryonic development, wound healing, and aging, regenerative medicine seeks to develop therapeutic strategies that complement or replace conventional treatments by actively repairing diseased tissue or generating new organs and tissues. Among the various clinical-translational strategies within the field of regenerative medicine, several can be broadly described as promoting disease resolution indirectly through local or systemic interactions with a patient's cells, without permanently integrating or directly forming new primary tissue. In this review, we focus on such therapies, which we term disease-modulating regenerative therapies (DMRT), and on the extent to which they have been translated into the clinical arena in four distinct areas of nephrology: renovascular disease (RVD), sepsis-associated AKI (SA-AKI), diabetic kidney disease (DKD), and kidney transplantation (KTx). As we describe, the DMRT that has most consistently progressed to human clinical trials for these indications is mesenchymal stem/stromal cells (MSCs), which potently modulate ischemic, inflammatory, profibrotic, and immune-mediated tissue injury through diverse paracrine mechanisms. In KTx, several early-phase clinical trials have also tested the potential for ex vivo-expanded regulatory immune cell therapies to promote donor-specific tolerance and prevent or resolve allograft injury. Other promising DMRT, including adult stem/progenitor cells, stem cell-derived extracellular vesicles, and implantable hydrogels/biomaterials remain at varying preclinical stages of translation for these renal conditions. To date (2021), no DMRT has gained market approval for use in patients with RVD, SA-AKI, DKD, or KTx, and clinical trials demonstrating definitive, cost-effective patient benefits are needed. Nonetheless, exciting progress in understanding the disease-specific mechanisms of action of MSCs and other DMRT, coupled with increasing knowledge of the pathophysiologic basis for renal-tissue injury and the experience gained from pioneering early-phase clinical trials provide optimism that influential, regenerative treatments for diverse kidney diseases will emerge in the years ahead.

The glenohumeral ligaments: Superior, middle, and inferior: Anatomy, biomechanics, injury, and diagnosis

The three glenohumeral ligaments (superior, middle, and inferior) are discrete thickenings of the glenohumeral joint capsule and are critical to shoulder stability and function. Injuries to this area are a cause of significant musculoskeletal morbidity. A literature search was performed by a review of PubMed, Google Scholar, and OVID for all relevant articles published up until 2020. This study highlights the anatomy, biomechanical function, and injury patterns of the glenohumeral ligaments, which may be relevant to clinical presentation and diagnosis. A detailed understanding of the normal anatomy and biomechanics is a necessary prerequisite to understanding the injury patterns and clinical presentations of disorders involving the glenohumeral ligaments of the shoulder.

Sphingolipids and Kidney Disease: Possible Role of Preeclampsia and Intrauterine Growth Restriction (IUGR)

Sphingolipids are now considered not only as constitutional components of the cellular membrane but also as essential bioactive factors regulating development and physiologic functions. Ceramide is a vital intermediate of sphingolipid metabolism, synthesized by de novo and salvage pathways, producing multiple types of sphingolipids and their metabolites. Although mutations in gene-encoding enzymes regulating sphingolipid synthesis and metabolism cause distinct diseases, an abnormal sphingolipid metabolism contributes to various pathologic conditions, including kidney diseases. Excessive accumulation of glycosphingolipids and promotion of the ceramide salvage and sphingosine-1-phosphate (S1P) pathways are found in the damaged kidney. Acceleration of the sphingosine kinase/S1P/S1P receptor (SphK/S1P/S1PR) axis plays a central role in deteriorating kidney functions. The SphK/S1P/S1PR signaling impairment is also found during pregnancy complications, such as preeclampsia and intrauterine growth restriction (IUGR). This mini-review discusses the current state of knowledge regarding the role of sphingolipid metabolism on kidney diseases, and the possible involvement of preeclampsia and IUGR conditions.

Comparing 3 Suture Techniques After Muscle Laceration Repair

Background: Skeletal muscle lacerations are a relatively common injury. Compared with nonrepaired lacerations, surgically repaired muscle lacerations regenerate faster, develop less scar tissue, have a higher return to baseline strength, and have lower incidence of hematomas. Despite the benefits of repair, the optimal repair technique is still unknown. The purpose of this study was to examine the biomechanical properties of common muscle repair techniques to determine the optimal repair. Methods: Forty-two fusiform porcine muscle specimens were dissected and used for this study. Three suture techniques were used for comparative analysis: Figure-eight, Mason Allen, and Perimeter. Each muscle was transected and then repaired using one of the 3 techniques. Fourteen muscle-tendon specimens were prepared for each group and tested for tensile failure using a material testing system. Biomechanical properties, including peak failure point and stiffness, were compared for differences between the suture groups by 1-way analysis of variance. The average time per repair technique was also recorded. Results: The Perimeter technique showed a statistically significant higher peak failure point than the Mason Allen technique (P = .03). Both the Figure-eight (P = .047) and Perimeter techniques (P < .001) were significantly stiffer than the Mason Allen technique. The repair time was comparable across all 3 techniques. Conclusions: The Figure-eight and Perimeter repairs were found to be similar in peak failure point and stiffness, whereas the Mason Allen technique showed significantly lower stiffness and peak failure point. The Figure-eight was the quickest repair to perform. The Figure-eight technique may be strongly considered for muscle laceration repairs due to its simplicity and efficiency.

From Infancy to Fancy: A Glimpse into the Evolutionary Journey of Podocytes in Culture

Podocytes are critical components of the filtration barrier and responsible for maintaining healthy kidney function. An assault on podocytes is generally associated with progression of chronic glomerular diseases. Therefore, podocyte pathophysiology is a favorite research subject for nephrologists. Despite this, podocyte research has lagged because of the unavailability of techniques for culturing such specialized cells ex vivo in quantities that are adequate for mechanistic studies. In recent years, this problem was circumvented by the efforts of researchers, who successfully developed several in vitro podocyte cell culture model systems that paved the way for incredible discoveries in the field of nephrology. This review sets us on a journey that provides a comprehensive insight into the groundbreaking breakthroughs and novel technologic advances made in the field of podocyte cell culture so far, beginning from its inception, evolution, and progression. In this study, we also describe in detail the pros and cons of different models that are being used to culture podocytes. Our extensive and exhaustive deliberation on the status of podocyte cell culture will facilitate researchers to choose wisely an appropriate model for their own research to avoid potential pitfalls in the future.

Proximal Tubular Oxidative Metabolism in Acute Kidney Injury and the Transition to CKD

The proximal tubule relies on oxidative mitochondrial metabolism to meet its energy needs and has limited capacity for glycolysis, which makes it uniquely susceptible to damage during AKI, especially after ischemia and anoxia. Under these conditions, mitochondrial ATP production is initially decreased by several mechanisms, including fatty acid-induced uncoupling and inhibition of respiration related to changes in the shape and volume of mitochondria. Glycolysis is initially insufficient as a source of ATP to protect the cells and mitochondrial function, but supplementation of tricarboxylic acid cycle intermediates augments anaerobic ATP production, and improves recovery of mitochondrial oxidative metabolism. Incomplete recovery is characterized by defects of respiratory enzymes and lipid metabolism. During the transition to CKD, tubular cells atrophy but maintain high expression of glycolytic enzymes, and there is decreased fatty acid oxidation. These metabolic changes may be amenable to a number of therapeutic interventions.

Polyethylene Glycol Fusion of Nerve Injuries: Review of the Technique and Clinical Applicability

Traumatic peripheral nerve injuries present a particular challenge to hand surgeons as mechanisms of nerve-healing pose serious limitations to achieving complete functional recovery. The loss of distal axonal segments through Wallerian degeneration results in the loss of neuromuscular junctions and irreversible muscle atrophy. Current methods of repair depend on the outgrowth of proximal nerve fibers following direct end-to-end repair or gap repair techniques. Investigational techniques in nerve repair using polyethylene glycol (PEG) nerve fusion have been shown to bypass Wallerian degeneration by immediately restoring nerve axonal continuity, thus resulting in a rapid and more complete functional recovery. The purpose of this article is to review the current literature surrounding this novel technique for traumatic nerve repair, paying particular attention to the underlying physiology of nerve healing and the current applications of PEG fusion in the laboratory and clinical setting. This article also serves to identify areas of future investigation to further establish validity and feasibility and encourage the translation of PEG fusion into clinical use.

Factors Associated With Reoperation After Silicone Metacarpophalangeal Joint Arthroplasty in Patients With Inflammatory Arthritis

Background: Silicone metacarpophalangeal (MCP) joint arthroplasty has a high revision rate. It has been suggested that the preoperative degree of ulnar drift and radial wrist deviation influences the durability of MCP silicone arthroplasties. The goal of this study was to evaluate what factors are associated with reoperation after silicone MCP arthroplasty. Materials and Methods: We retrospectively evaluated all adult patients who underwent MCP silicone arthroplasty between 2002 and 2016 at one institutional system for inflammatory arthritis. After manual chart review, we included 73 patients who underwent 252 arthroplasties. Fingers treated included 66 index, 67 long, 60 ring, and 59 small fingers. Results: The overall reoperation rate was 9.1% (N = 23). Indications for reoperation were implant breakage (n = 11), instability (n = 4), soft tissue complications (n = 4), infections (n = 3), and stiffness (n = 1). There was a trend that patients who underwent single-digit arthroplasty had higher rates of revision (19% vs 3.5%, P = .067). Radiographic follow-up demonstrated joint incongruency in 50% of cases, bone erosion in 58% of cases, and implant breakage in 19% of cases. There was a trend toward higher rates of revision in patients without preoperative MCP joint subluxation (19% vs 6.7%, P = .065) The 1-, 5-, and 10-year implant survival rates were 96%, 92%, and 70%, respectively. Revision surgery occurred at <14 months in 15 patients (65%) and after 5 years in 8 (35%) patients. Conclusions: Revision surgery after silicone MCP arthroplasty appears to be bimodal. Patients with greater hand function preoperatively may be at higher risk of revision surgery.

Overview of the Canadian Clinician Investigator Trainees' research presented at the 2019 CSCI-CITAC Joint Meeting

The 2019 Annual General Meeting and Young Investigators' Forum of the Canadian Society for Clinical Investigation / Société Canadienne de Recherche Clinique (CSCI/SCRC) and Clinician Investigator Trainee Association of Canada / Association des Cliniciens-Chercheurs en Formation du Canada (CITAC/ACCFC) was held in Banff, Alberta on November 8-10th, 2019. The theme was "Positioning Early Career Investigators for Success: Strategy and Resilience". Lectures and workshops provided knowledge and tools to facilitate the attendees' development as clinician investigators. Dr. Jason Berman (President of CSCI/SCRC), Elina Cook (President of CITAC/ACCFC) and Drs. Doreen Rabi and Zelma Kiss (University of Calgary Organizing Co-Chairs) gave opening presentations. The keynote speakers were Dr. William Foulkes (McGill University) (Distinguished Scientist Award winner) and Dr. Andrés Finzi (Université de Montréal) (Joe Doupe Young Investigator Award winner). Dr. Robert Bortolussi (Dalhousie University) received the Distinguished Service Award for his work as the Editor-in-Chief of Clinical and Investigative Medicine and for being instrumental in the development of the Canadian Child Health Clinician Scientist Program. This meeting was the first to host a panel discussion with Drs. Stephen Robbins and Marcello Tonelli from the Canadian Institutes of Health Research. Workshops on communication, career planning and work-life balance were hosted by André Picard and Drs. Todd Anderson, Karen Tang, William Ghali, May Lynn Quan, Alicia Polachek and Shannon Ruzycki. The AGM showcased 90 presentations from clinician investigator trainees from across Canada. Most of the abstracts are summarized in this review. Eight outstanding abstracts were selected for oral presentation at the President's Forum.

Characterization of overnight slow-wave slope changes across development in an age-, amplitude-, and region-dependent manner

STUDY OBJECTIVES

The restorative function of sleep has been linked to a net reduction in synaptic strength. The slope of slow-waves, a major characteristic of non-rapid eye movement (NREM) sleep, has been shown to directly reflect synaptic strength, when accounting for amplitude changes across the night. In this study, we aimed to investigate overnight slope changes in the course of development in an age-, amplitude-, and region-dependent manner.

METHODS

All-night high-density electroencephalography data were analyzed in a cross-sectional population of 60 healthy participants in the age range of 8-29 years. To control for amplitude changes across the night, we matched slow-waves from the first and the last hour of NREM sleep according to their amplitude.

RESULTS

We found a reduction of slow-wave slopes from the first to the last hour of NREM sleep across all investigated ages, amplitudes, and most brain regions. The overnight slope change was largest in children and decreased toward early adulthood. A topographical analysis revealed regional differences in slope change. Specifically, for small amplitude waves the decrease was smallest in an occipital area, whereas for large amplitude waves, the decrease was smallest in a central area.

CONCLUSIONS

The larger slope decrease in children might be indicative of a boosted renormalization of synapses during sleep in childhood, which, in turn, might be related to increased plasticity during brain maturation. Regional differences in the extent of slow-wave slope reduction may reflect a "smart" down-selection process or, alternatively, indicate amplitude-dependent differences in the generation of slow-waves.

Recurrent Schwannomatosis of the Hand

Background: Peripheral nerve sheath tumors (PNSTs) are neoplastic soft tissue masses generated from the abnormal proliferation of Schwann cells. Often, these tumors occur in isolation and are known as schwannomas or neurilemmomas. The presence of multiple schwannomas is known as schwannomatosis. The purpose of this article is 2-fold: (1) to review the relevant literature and describe a unique case of this rare condition; and (2) to emphasize salient clinical considerations in the diagnosis and treatment of schwannomatosis. Methods: In this report, we describe the case of a 52-year-old white man who presented with multiple recurrent soft tissue masses of the right hand. On initial presentation, he described pain across his right hand and index finger, which persisted despite numerous prior operations. The index finger had a flexion contracture around the location of the proximal interphalangeal joint, and there were multiple tender masses along the length of the finger and palm. Results: Segmental excision of the affected radial digital nerve was performed. A pulp flap based on contralateral neurovascular bundle resulted in a sensate, pain-free digit. Tissue pathology confirmed the diagnosis of multiple neurilemmomas. Conclusions: We report the success of a radial digital neurectomy in a patient with widespread neurilemmomas, who had previously excluded that painful digit from use. It was through careful consideration of the preoperative differential diagnosis, by valuing the preoperative imaging, and by considering all surgical options with specific attention paid to skin flap design that this good outcome of a fully sensate, pain-free, mobile index finger was achieved.

Myocardial Strain and Cardiac Output are Preferable Measurements for Cardiac Dysfunction and Can Predict Mortality in Septic Mice

Background

Sepsis is the overwhelming host response to infection leading to shock and multiple organ dysfunction. Cardiovascular complications greatly increase sepsis‐associated mortality. Although murine models are routinely used for preclinical studies, the benefit of using genetically engineered mice in sepsis is countered by discrepancies between human and mouse sepsis pathophysiology. Therefore, recent guidelines have called for standardization of preclinical methods to document organ dysfunction. We investigated the course of cardiac dysfunction and myocardial load in different mouse models of sepsis to identify the optimal measurements for early systolic and diastolic dysfunction.

Methods and Results

We performed speckle‐tracking echocardiography and assessed blood pressure, plasma inflammatory cytokines, lactate, B‐type natriuretic peptide, and survival in mouse models of endotoxemia or polymicrobial infection (cecal ligation and puncture, [CLP]) of moderate and high severity. We observed that myocardial strain and cardiac output were consistently impaired early in both sepsis models. Suppression of cardiac output was associated with systolic dysfunction in endotoxemia or combined systolic dysfunction and reduced preload in the CLP model. We found that cardiac output at 2 hours post‐CLP is a negative prognostic indicator with high sensitivity and specificity that predicts mortality at 48 hours. Using a known antibiotic (ertapenem) treatment, we confirmed that this approach can document recovery.

Conclusions

We propose a non‐invasive approach for assessment of cardiac function in sepsis and myocardial strain and strain rate as preferable measures for monitoring cardiovascular function in sepsis mouse models. We further show that the magnitude of cardiac output suppression 2 hours post‐CLP can be used to predict mortality.

Inclusion in the Pulmonary, Critical Care, and Sleep Medicine Physician-Scientist Workforce. Building with Intention

Physician-scientists comprise an exceedingly small fraction of the physician workforce. As the fields of pulmonary, critical care, and sleep medicine continue to invest in the development of the physician-scientist workforce, recruitment and retention strategies need to consider the temporal trend in the decline in numbers of trainees pursuing basic research, the challenges of trainees from underrepresented groups in medicine, and opportunities for career and scientific advancement of women physician-scientists. In this perspective article, we examine the headwinds in the training and education of physician-scientists and highlight potential solutions to reverse these trends.

Paediatric knee anterolateral capsule does not contain a distinct ligament: analysis of histology, immunohistochemistry and gene expression

OBJECTIVES

The presence of a discrete ligament within the knee anterolateral capsule (ALC) is controversial. Tendons and ligaments have typical collagens, ultrastructure, transcription factors and proteins. However, these characteristics have not been investigated in paediatric ALC. The purpose of this study was to characterise the paediatric ALC in terms of tissue ultrastructure and cellular expression of ligament markers scleraxis (SCX)-a basic helix-loop-helix transcription factor-and the downstream transmembrane glycoprotein tenomodulin (TNMD), as compared with the paediatric lateral collateral ligament (LCL) and paediatric quadriceps tendon (QT). We hypothesised that, in comparison to the LCL and QT, the ALC would possess poor collagen orientation and reduced SCX and TNMD expression.

METHODS

15 paediatric ALCs (age 6.3±3.3 years), 5 paediatric LCLs (age 3.4±1.3 years) and 5 paediatric QTs (age 2.0±1.2 years) from fresh cadaveric knees were used in this study. Fresh-frozen samples from each region were cryosectioned and then stained with H&E to evaluate collagen alignment and cell morphology. Expression of SCX and TNMD was determined by gene expression analysis and immunohistochemistry.

RESULTS

The histological sections of the paediatric LCL and QT showed well-organised, dense collagenous tissue fibres with elongated fibroblasts, while the ALC showed more random collagen orientation without clear cellular directionality. The aspect ratio of cells in the ALC was significantly lower than that of the LCL and QT (p<0.0001 and p<0.0001, respectively). The normalised distribution curve of the inclination angles of the nuclei in the ALC was more broadly distributed than that of the LCL or QT, indicating random cell alignment in the ALC. SCX immunostaining was apparent in the paediatric LCL within regions of aligned fibres, while the comparatively disorganised structure of the ALC was negative for SCX. The paediatric LCL also stained positive for TNMD, while the ALC was only sparsely positive for this tendon/ligament cell-surface molecule. Relative gene expression of SCX and TNMD were higher in the LCL and QT than in the ALC.

CONCLUSION

In this study, a distinct ligament could not be discerned in the ALC based on histology, immunohistochemistry and gene expression analysis.

LEVEL OF EVIDENCE

Controlled laboratory study.

From bedside to bench: an evaluation of expectations and challenges encountered by young surgeons facing basic science

Background: The evolution of surgical practice may lead to increasing difficulties for surgeons to perform fundamental research. The aim of this study was to evaluate the expectations and the challenges encountered by young surgeons when starting basic science.Methods: A qualitative study was conducted in France. A written questionnaire was anonymously filled by the participants attending to the Master Degree in surgical science.Results: The study included 47 participants (median age: 28 years, 59.6% of men); 37 (78.7%) participants had applied for a grant for their salary and 32 (68.1%) had obtained it. Nine (19.1%) participants had planned to keep their usual clinical activity. The main motivations were the perspective to embark on an academic career (55.3%) and improvement of knowledge in science (38.3%). The main barriers encountered were the lack of time (70.2%), the lack of interest (27.7%), the lack of financial support (23.4%) and administrative difficulties (12.8%).Conclusion: This study identified main barriers that young surgeons have to face when getting involved in basic science underlining the need to improve institutional and financial support to ensure involvement of new generations of surgeons in surgical research.

Social Constructivism in Medical School Where Students Become Patients with Dietary Restrictions

BACKGROUND

Experiential vertical integration of basic science with clinical concepts remains a challenge in medical school curricula. In addition, training physicians in nutritional competency that translates into patient care is a challenging endeavor ranging from biochemical mechanisms to socioeconomic challenges.

METHODS

Employing a social constructivism paradigm, we implemented a collaborative cook-off competition in a basic science course where 140 first-year medical students per year translated their studies of inborn errors of metabolism, energy metabolism, micronutrients and immunology into edible creations intended for people with disorders requiring dietary management. After learning about the disorders in lecture, problem-based learning, team-based learning and through patient interviews, four problem-based learning groups (7 students per group) were assigned to prepare food dishes for one of the five assigned disorders. Together, students researched the dietary requirements, shopped, paid for, prepared, presented and shared their food. To the class, faculty and re-invited patients, the groups explained the dietary restrictions, the chosen ingredients, how they prepared the food, and why their dish was suitable for the disorder. Each category was judged and awarded a first-place food prize with a grand prize at the end. At the completion of the course, student feedback was elicited via anonymous evaluations. Over 3 years, 380 comments were collected. We used grounded theory to generate a codebook that was then analyzed by the authors for overarching themes.

RESULTS

Qualitative results described three major themes: increased relevance of basic science to real life, increased empathy towards complying with dietary restrictions, and increased student group cohesiveness.

CONCLUSION

The patient-centered cook-off competition taught students the relevance of basic science but in addition, it taught empathy towards the patient experience. We also discovered that the process of food preparation was a bonding experience that promoted collaboration, cohesiveness and friendship within the student class.

Neurobehavioral Deficits After Subarachnoid Hemorrhage in Mice: Sensitivity Analysis and Development of a New Composite Score

Background

Because of the failure of numerous clinical trials, various recommendations have been made to improve the usefulness of preclinical studies. Specifically, the STAIR (Stroke Therapy Academic Industry Roundtable) recommendations highlighted functional outcome as a critical measure. Recent reviews of experimental subarachnoid hemorrhage (SAH) studies have brought to light the numerous neurobehavioral scoring systems that are used in preclinical SAH studies. To gain insight into the utility of these scoring systems, as well as to identify a scoring system that best captures the deficits caused by SAH in mice, we designed the current study.

Methods and Results

Adult male C57BL/6J mice were used. One cohort of mice was randomly allocated to either sham or SAH and had functional testing performed on days 1 to 3 post‐SAH using the modified Bederson Score, Katz Score, Garcia Neuroscore, and Parra Neuroscore, as well as 21 individual subtests. A new composite neuroscore was developed using the 8 most diagnostically accurate subtests. To validate the use of the developed composite neuroscore, another cohort of mice was randomly assigned to either the sham or SAH group and neurobehavior was evaluated on days 1 to 3, 5, and 7 after injury. Receiver operating characteristic curves were used to analyze the diagnostic accuracy of each scoring system, as well as the subtests. Of the 4 published scoring systems, the Parra Neuroscore was diagnostically accurate for SAH injury in mice versus the modified Bederson and Katz Scores, but not the Garcia Neuroscore. However, the newly developed composite neuroscore was found to be statistically more diagnostically accurate than even the Parra Neuroscore.

Conclusions

The findings of this study promote use of the newly developed composite neuroscore for experimental SAH studies in mice.

Distal Digital Nerve Repair Using Nerve Allograft With a Dermal Substitute: A Case Report

Background: Distal digital nerve repairs can present unique challenges for hand surgeons due to their sensitive location and ongoing difficulty obtaining soft tissue coverage in this region. Although autografts and nerve conduits have been shown to be of benefit with nerve gaps, they can have morbidities associated with their use. Nerve allografts have become a viable option over the past decade as their use has increased and data are now showing similar outcomes, particularly in short gap segments. Flaps and skin grafts are traditional coverage options for full thickness wounds but can pose challenges with multiple digit involvement, depth of wound, and critical structures exposed. Methods: We present a case where nerve allograft was used for distal digital nerve repair. Due to the distal nature of the nerve repair in the index digit distal to the trifurcation, the distal end of the nerve graft was connected to multiple small nerve ends. Dermal substitute was placed to achieve distal coverage of the affected digits. Results: At 6-month follow-up, the patient demonstrated improved strength, normal sensation, and full return of digital function. Conclusion: Nerve allograft can be used in combination with dermal skin substitute to achieve normal sensation and return of digital function following distal digital nerve injuries.

Shaping Our Understanding of Medulloblastoma: A Bibliometric Analysis of the 100 Most Cited Articles

The clinical management of medulloblastoma has undergone significant transformation since the recent dawn of the molecular era. The aim of this analysis was to evaluate citation and other bibliometric characteristics of the 100 most cited medulloblastoma articles in the literature to better understand the current state of our research efforts into this diagnosis. Elsevier's Scopus database was searched for the 100 most cited articles that focused on medulloblastoma. Articles were dichotomized as either primarily basic science (BSc) or clinical (CL) articles. Various bibliometric parameters were summarized and compared between BSc and CL articles using Pearson's Chi-square and Mann Whitney U tests. Of the 100 most cited articles, 52 were characterized as BSc articles and 48 as CL articles. Overall median (range) values were as follows: citation count 252 (164-1,270); citation rate per year 17.5 (2.5-110); number of authors 11 (1-135); and publication year 2005 (1925-2014). Articles were published in a total of 40 different journals, and the majority originated in the US (n = 60). When compared to CL articles, BSc articles reported significantly greater citation rates per year (P < 0.01), and more recent years of publication (P < 0.01). In summary, although similar in overall proportion, BSc articles demonstrated significantly increased bibliometric parameters of impact in this field by the successful clustering molecular subtypes. Moving forward, it will be of great interest to see how the findings from these impactful BSc articles will translate into future clinical initiatives and subsequently high-impact CL articles.

Highlights from the 2019 European Congress on Treatment and Research in Multiple Sclerosis (ECTRIMS 2019)

The 2019 ECTRIMS Congress, in Stockholm, has had record-breaking figures for both attendance and scientific production. There were 9361 participants from 100 different countries for a total of 1541 abstracts. Upon invitation of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) executive committee, the authors of this meeting report assessed abstracts from all poster and oral presentations for novelty, scientific quality and relevance for basic and clinical multiple sclerosis (MS) research. The objective of this report is to highlight a selection of basic, translational and clinical studies out of the many outstanding projects that were presented. Abstracts and references cited in our report were chosen at the discretion of the authors and all co-authors and the ECTRIMS executive committee agreed on the selection. In the event of discrepancies between the abstract and the uploaded poster or presentation, we aimed to present data derived from the poster or presentation. All abstracts are accessible through the ECTRIMS online library ( https://onlinelibrary.ectrimscongress.eu/ectrims/#!*menu=36*browseby=3*sortby=2*ce_id=160 ) and also published in this journal (Volume 25 Issue 2_suppl, September 2019; https://journals.sagepub.com/toc/msja/25/2_suppl ). A few additional references from the literature were added but were restricted to the ones that authors considered as absolutely required for an optimized understanding of the topics highlighted.

Differential effects of anesthetics on resting state functional connectivity in the mouse

Blood oxygen level-dependent (BOLD) functional MRI (fMRI) is a standard approach to examine resting state functional connectivity (RSFC), but fMRI in animal models is challenging. Recently, functional optical intrinsic signal imaging-which relies on the same hemodynamic signal underlying BOLD fMRI-has been developed as a complementary approach to assess RSFC in mice. Since it is difficult to ensure that an animal is in a truly resting state while awake, RSFC measurements under anesthesia remain an important approach. Therefore, we systematically examined measures of RSFC using non-invasive, widefield optical intrinsic signal imaging under five different anesthetics in male C57BL/6J mice. We find excellent seed-based, global, and interhemispheric connectivity using tribromoethanol (Avertin) and ketamine-xylazine, comparable to results in the literature including awake animals. Urethane anesthesia yielded intermediate results, while chloral hydrate and isoflurane were both associated with poor RSFC. Furthermore, we found a correspondence between the strength of RSFC and the power of low-frequency hemodynamic fluctuations. In conclusion, Avertin and ketamine-xylazine provide robust and reproducible measures of RSFC in mice, whereas chloral hydrate and isoflurane do not.

Profiling APOL1 Nephropathy Risk Variants in Genome-Edited Kidney Organoids with Single-Cell Transcriptomics

BACKGROUND

DNA variants in APOL1 associate with kidney disease, but the pathophysiologic mechanisms remain incompletely understood. Model organisms lack the APOL1 gene, limiting the degree to which disease states can be recapitulated. Here we present single-cell RNA sequencing (scRNA-seq) of genome-edited human kidney organoids as a platform for profiling effects of APOL1 risk variants in diverse nephron cell types.

METHODS

We performed footprint-free CRISPR-Cas9 genome editing of human induced pluripotent stem cells (iPSCs) to knock in APOL1 high-risk G1 variants at the native genomic locus. iPSCs were differentiated into kidney organoids, treated with vehicle, IFN-γ, or the combination of IFN-γ and tunicamycin, and analyzed with scRNA-seq to profile cell-specific changes in differential gene expression patterns, compared with isogenic G0 controls.

RESULTS

Both G0 and G1 iPSCs differentiated into kidney organoids containing nephron-like structures with glomerular epithelial cells, proximal tubules, distal tubules, and endothelial cells. Organoids expressed detectable APOL1 only after exposure to IFN-γ. scRNA-seq revealed cell type-specific differences in G1 organoid response to APOL1 induction. Additional stress of tunicamycin exposure led to increased glomerular epithelial cell dedifferentiation in G1 organoids.

CONCLUSIONS

Single-cell transcriptomic profiling of human genome-edited kidney organoids expressing APOL1 risk variants provides a novel platform for studying the pathophysiology of APOL1-mediated kidney disease.

Sensory Outcomes in Digital Nerve Repair Techniques: An Updated Meta-analysis and Systematic Review

Background: Injuries to digital nerves are common with trauma to the hand, often requiring surgery. Surgical management of these injuries can be performed using several techniques: direct repair (neurorrhaphy), autograft, allograft, and conduit repair. In light of increasing the availability and use of various digital nerve repair techniques, a new systematic review and meta-analysis was undertaken to comparatively review the available evidence to determine any differences in outcomes to better guide treatment in cases with digital nerve gaps. Methods: Current literature on sensory outcomes of various digital nerve repair techniques was reviewed using static 2-point discrimination (S2PD), moving 2-point discrimination (M2PD), Semmes-Weinstein monofilament testing (SWMF), and complication rates as outcomes of interest. After inclusion and exclusion criteria were applied, 15 articles were reviewed and 625 nerve repairs were analyzed. Results: The average gap length for allograft repair, autograft repair, and conduit repair was 15.4, 24.7, and 13.4 mm, respectively. For S2PD outcomes, autograft repair was statistically superior to all other forms of repair. Allograft trended higher than neurorrhaphy and conduit repair, but results were not statistically significant. For SWMF outcomes, autograft repair was statistically superior to conduit repair and neurorrhaphy; it was statistically comparable with allograft repair. Allograft performed statistically superior to conduit repair relative to M2PD. Conclusions: Based on the current updated meta-analysis using newer data and techniques, we found that all available techniques have reasonable outcomes. Yet when managing a digital nerve injury with a gap, thereby excluding direct neurorrhaphy, both autograft and allograft performed comparably and were superior to conduit repair.

Development of a Small Animal Ankle Arthrodesis Model

BACKGROUND

Our understanding of the biology of ankle arthrodesis is based largely on work in spine and long bone animal models. However, the local soft tissue and vascular anatomy of the foot and ankle is different from that of the spine. Accordingly, the objective of this study was to develop a small animal ankle arthrodesis model.

METHODS

A total of 12 Lewis rats successfully underwent ankle arthrodesis with stabilization consisting of a single Kirschner wire across the prepared tibiotalar joint. Based on high nonunion rates with this initial procedure, a modification was made consisting of a second pin crossing the joint. A total of 6 rats underwent the second procedure. Radiographs were taken postoperatively and in 2-week intervals up to 10 weeks. Micro computed tomography (µCT) and histological analysis was conducted at 10 weeks to assess the fusion mass. Osseous bridging of greater than 50% across the tibiotalar joint was deemed a successful fusion.

RESULTS

µCT analysis determined that 11 of the 12 rats in the single-pin cohort developed nonunions (8.3% fusion rate). In the dual-pin cohort, all 6 animals successfully fused (100% fusion rate). Histological analysis supported the radiographic imaging conclusions.

CONCLUSION

While the initial procedure had a high nonunion rate, enhancing the stability of the fixation greatly increased the union rate.

CLINICAL RELEVANCE

The present work demonstrates the first reliable small animal ankle arthrodesis model. We believe that this model can be used in the development of novel therapies aimed at decreasing complications and increasing fusion rates.

The difference between a clinical technician and clinical practitioner is in the scope of practice: the need for a bioscience understanding in paramedicine

"Only teach me what I need to know!" This commonly heard refrain is often spoken by allied health students while studying preclinical sciences (physiology, anatomy, pharmacology). Here we use a clinical scenario undertaken by second-year Bachelor of Paramedic Practice students of acute coronary syndrome to demonstrate the difference in clinical decision making when using a clinical reasoning approach to treatment rather than relying exclusively on a practice guidelines approach. We hope to demonstrate that understanding basic bioscience concepts, such as the Frank-Starling mechanism and the anatomy and physiology of the autonomic nervous system, are key to providing good clinical care in response to ambiguous patient symptoms. Students who understand these concepts underlying their patient care guideline will make better clinical decisions and better provide quality of care than students who follow the guideline exclusively. We aim this as a practical demonstration of the value of detailed understanding of human bioscience in allied health education. As health care providers transition from "technician" to "practitioner," the key distinguishing feature of the role is the ability to practice independently, using "best judgment" rather than clinical guidelines (alone). Evidence suggests that complex case management requires detailed bioscience understanding.

Simple water-based tacrolimus enemas for refractory proctitis

Background and Aims

Rectal ulcerative colitis (UC) and Crohn's disease (CD) often do not respond to conventional therapies. Oral and suppository tacrolimus are effective but often poorly tolerated or are complex to formulate. Tacrolimus is topically active, water soluble, and has minimal systemic toxicity when administered rectally; we therefore tested a simple tap water‐based enema formulation.

Methods

Tacrolimus powder from 1 mg capsules and tap water in a 60 mL syringe were delivered rectally. The primary end‐point was endoscopic response (UC: MAYO score reduction by one point; CD: improvement in ulcer number and severity). Secondary end‐points included endoscopic remission, clinical response, stool frequency, and rectal bleeding.

Results

Seventeen patients [12 UC, five CD, nine female, median age 31 years] with refractory rectal disease were treated. The majority of patients had failed immunosuppressive therapy [88% thiopurine; 71% biologic therapy]. Initial enemas included 1–4 mg tacrolimus daily and 1–3 mg tacrolimus maintenance three times a week for a median of 20 weeks (range 3–204). Concomitant thiopurine or biologic therapy continued. 94% tolerated therapy. Of 12 UC patients, eight (67%) achieved endoscopic remission, one further patient achieved endoscopic response, and median partial MAYO scores decreased (pre:4 vs. post:2; P = 0.010). Of five CD patients, three (60%) achieved endoscopic response, two (40%) endoscopic remission, and three (60%) clinical response. Stool frequency, rectal bleeding, and C‐reactive protein levels improved. Strictures became endoscopically passable in all four affected patients. No major adverse events were reported, and four patients had disease flare.

Conclusions

Tacrolimus enemas are easy to prepare, well tolerated, effective, and safe. They should be included in the treatment armamentarium for inflammatory bowel disease‐related refractory proctitis.

Focusing on global health and medicine

Focusing on the theme of global health and medicine, at the beginning of the new era (Reiwa) in Japan, we are pleased and honored to launch Global Health & Medicine, an international, open-access, peer-reviewed journal, published by the National Center for Global Health and Medicine (NCGM), which is a national research and development agency in Japan that covers advanced general medicine, basic science, clinical science, and international medical collaboration. The journal is dedicated to publishing high-quality original research that contributes to advancing global health and medicine, with the goal of creating a global information network for global health, basic science as well as clinical science oriented for clinical application. We aspire to identify, attract, and publish original research that supports advances of knowledge in critical areas of global health and medicine.

Multimedia-aided instruction in teaching basic life support to undergraduate nursing students

Basic life support (BLS) knowledge is a necessity for nursing students, as they have to deal with cardiac arrest events during their professional career. Existing studies indicate poor BLS knowledge among health science students, including nursing students. Learning BLS requires an understanding of basic sciences, such as anatomy, physiology, and biochemistry, subjects perceived to be difficult, resulting in misconceptions. Hence, a multimedia-aided instruction on BLS, supplemented with cooperating learning groups, was developed to assist nursing students in gaining correct BLS knowledge. A pretest-posttest designed for single cooperating groups was employed to evaluate students' achievements. Sixty-five undergraduate nursing students took the pretest and posttest that consisted of 10 open-ended questions, each designed to evaluate an aspect of their BLS knowledge. The results show significantly more students (60 vs. 20%) answered more questions correctly on the posttest compared with the pretest (P value <0.05, Wilcoxon signed-rank test). Thus the multimedia-aided instruction package enhanced undergraduate nursing students' understanding of BLS and also assisted to generate a positive perception of multimedia-aided instructions, supplemented with a cooperating learning group.

Longitudinal interprofessional education in a graduate physiology course

The primary purpose of conducting two interprofessional education (IPE) experiences during a multidisciplinary physiology graduate-level course was to provide basic science, physical therapy, and physician assistant graduate students opportunities to work as a team in the diagnosis, treatment, and collaborative care when presented with a patient case focused on acute kidney injury (first case) and female athlete triad (second case). The secondary purpose was to apply basic physiology principles to patient case presentations of pathophysiology. The overall purpose was to assess the longitudinal effects and the value of IPE integrated within a basic science course. The following Interprofessional Education Collaborative subcompetencies were targeted: roles/responsibilities (RR1, RR4). Students were given a pre- and postsurvey to assess their IPE perceptions and knowledge of professional roles. There were statistically significant increases from the presurvey renal IPE experience to the presurvey endocrine IPE experience for two perception questions regarding the ability to explain the roles and responsibilities of a physical therapist (PT) and physician assistant using a Likert scale. In addition, student knowledge of the role of a PT increased significantly when comparing the renal IPE presurvey to the endocrine IPE presurvey results to open-ended questions. Students' perceptions of their knowledge as well as their ability to express, in writing, their newly learned knowledge of the role of a PT was sustained over time. Incorporating multiple IPE experiences into multidisciplinary health science courses represents an appropriate venue to have students learn and apply interprofessional competencies.

Why Content and Cognition Matter: Integrating Conceptual Knowledge to Support Simulation-Based Procedural Skills Transfer

BACKGROUND

Curricular constraints require being selective about the type of content trainees practice in their formal training. Teaching trainees procedural knowledge about "how" to perform steps of a skill along with conceptual knowledge about "why" each step is performed can support skill retention and transfer (i.e., the ability to adapt knowledge to novel problems). However, how best to organize how and why content for procedural skills training is unknown.

OBJECTIVES

We examined the impact of different approaches to integrating why and how content on trainees' skill retention and transfer of simulation-based lumbar puncture (LP).

DESIGN AND PARTICIPANTS

We randomized medical students (N = 66) to practice LP for 1 h using one of three videos. One video presented only the how content for LP (Procedural Only). Two other videos presented how and why content (e.g., anatomy) in two ways: Integrated in Sequence, with why content followed by how content, or Integrated for Causation, with how and why content integrated throughout.

MAIN MEASURES

Pairs of blinded raters scored participants' retention and transfer LP performances on a global rating scale (GRS), and written tests assessed participants' procedural and conceptual knowledge.

KEY RESULTS

Simple mediation regression analyses showed that participants receiving an integrated instructional video performed significantly better on transfer through their intervention's positive impact on conceptual knowledge (all p < 0.01). Further, the Integrated for Causation group performed significantly better on transfer than the Integrated in Sequence group (p < 0.01), again mediated by improved conceptual knowledge. We observed no mediation of participants' skill retention (all p > 0.01).

CONCLUSIONS

When teaching supports cognitive integration of how and why content, trainees are able to transfer learning to new problems because of their improved conceptual understanding. Instructional designs for procedural skills that integrate how and why content can help educators optimize what trainees learn from each repetition of practice.

Assessing time-of-flight signal-to-noise ratio gains within the myocardium and subsequent reductions in administered activity in cardiac PET studies

BACKGROUND

Time-of-flight (TOF) is known to increase signal-to-noise ratio (SNR) and facilitate reductions in administered activity. Established measures of SNR gain are derived from areas of uniform uptake, which is not applicable to the heterogeneous uptake in cardiac PET images using fluoro-deoxyglucose (FDG). This study aimed to develop a technique to quantify SNR gains within the myocardium due to TOF.

METHODS

Reference TOF SNR gains were measured in 88 FDG oncology patients. Phantom data were used to translate reference SNR gains and validate a method of quantifying SNR gains within the myocardium from parametric images produced from multiple replicate images. This technique was applied to 13 FDG cardiac viability patients.

RESULTS

Reference TOF SNR gains of +23% ± 8.5% were measured in oncology patients. Measurements of SNR gain from the phantom data were in agreement and showed the parametric image technique to be sufficiently robust. SNR gains within the myocardium in the viability patients were +21% ± 2.8%.

CONCLUSION

A method to quantify SNR gains from TOF within the myocardium has been developed and evaluated. SNR gains within the myocardium are comparable to those observed by established methods. This allows guidance for protocol optimization for TOF systems in cardiac PET.