Mentorship in medical education: reflections on the importance of both unofficial and official mentorship programs.

Mentorship, consisting of its official and unofficial forms, transforms medical trainees into competent and well-rounded physicians. In this commentary, we reflected on existing mentorship programs at the McMaster School of Medicine, highlighted lessons from a new peer-based mentorship program, and revisited the benefits of integrating diverse mentorship styles to enhance medical education.

In-Clinic Versus Web-Based Multidisciplinary Exercise-Based Rehabilitation for Treatment of Low Back Pain: Prospective Clinical Trial in an Integrated Practice Unit Model.

BACKGROUND: The recent onset of the COVID-19 pandemic has highlighted the need to reduce barriers to access physical therapy and associated care through the use of web-based programs and telehealth for those seeking treatment for low back pain (LBP). Despite this need, few studies have compared the effectiveness of clinic-based versus web-based or telehealth services. OBJECTIVE: This study aims to compare the clinical outcomes of clinic-based multidisciplinary therapy in an integrated practice unit (C-IPU) model with online integrated multidisciplinary therapy (O-IPU) in individuals undergoing conservative care for LBP. METHODS: A total of 1090 participants were prospectively recruited to participate in a clinical trial registry (NCT04081896) through the SpineZone rehabilitation IPU program. All participants provided informed consent. Participants were allocated to the C-IPU (N=988) or O-IPU (N=102) groups based on their personal preferences. The C-IPU program consisted of a high-intensity machine-based core muscle resistance training program, whereas the O-IPU program consisted of therapist-directed home core strengthening exercises through a web-based platform. Changes in LBP symptom severity (Numeric Pain Rating Scale), disability (Oswestry Disability Index), goal achievement (Patient-Specific Functional Scale), and frequency of opioid use were compared between the C-IPU and O-IPU groups using multivariate linear regression modeling adjusted for age, gender, treatment number, program duration, and baseline pain and disability. RESULTS: Approximately 93.03% (1014/1090) of the participants completed their recommended programs, with no group differences in dropout rates (P=.78). The C-IPU group showed greater pain relief (P<.001) and reductions in disability (P=.002) than the O-IPU group, whereas the O-IPU group reported greater improvements in goal achievement (P<.001). Both programs resulted in reduced opioid use frequency, with 19.0% (188/988) and 21.5% (22/102) of participants reporting cessation of opioid use for C-IPU and O-IPU programs, respectively, leaving only 5.59% (61/1090) of participants reporting opioid use at the end of their treatment. CONCLUSIONS: Both in-clinic and web-based multidisciplinary programs are beneficial in reducing pain, disability, and opioid use and in improving goal achievement. The differences between these self-selected groups shed light on patient characteristics, which require further investigation and could help clinicians optimize these programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04081896; https://clinicaltrials.gov/ct2/show/NCT04081896.

Supervoxel based method for multi-atlas segmentation of brain MR images.

Multi-atlas segmentation has been widely applied to the analysis of brain MR images. However, the state-of-the-art techniques in multi-atlas segmentation, including both patch-based and learning-based methods, are strongly dependent on the pairwise registration or exhibit huge spatial inconsistency. The paper proposes a new segmentation framework based on supervoxels to solve the existing challenges of previous methods. The supervoxel is an aggregation of voxels with similar attributes, which can be used to replace the voxel grid. By formulating the segmentation as a tissue labeling problem associated with a maximum-a-posteriori inference in Markov random field, the problem is solved via a graphical model with supervoxels being considered as the nodes. In addition, a dense labeling scheme is developed to refine the supervoxel labeling results, and the spatial consistency is incorporated in the proposed method. The proposed approach is robust to the pairwise registration errors and of high computational efficiency. Extensive experimental evaluations on three publically available brain MR datasets demonstrate the effectiveness and superior performance of the proposed approach.

Selling blood and gametes during tough economic times: insights from Google search.

INTRODUCTION: To use Google Insights search volume and publicly available economic indicators to test the hypothesis that sperm, egg, and blood donations increase during economic downturns and to demonstrate the feasibility of using Google search volume data to predict national trends in actual sperm, egg, and blood donations rates. MATERIALS AND METHODS: Cross-correlation statistical analysis comparing Google search data for terms relating to blood, egg, and sperm donations with various economic indicators including the S&P 500 closing values, gross domestic product (GDP), the U.S. Index of Leading Indicators (U.S. Leading Index), gross savings rate, mortgage interest rates, unemployment rate, and consumer price index (CPI) from 2004-2011. A secondary analysis determined the Pearson correlation coefficient between Google search data with actual sperm, egg, and blood donation volume in the U.S. as measured by California Cryobank, the National Assisted Reproductive Technology Surveillance System, and the National Blood Collection and Utilization Survey, respectively. Significance of cross-correlation and Pearson correlation analysis as indicated by p value. RESULTS: There were several highly significant cross-correlation relationships between search volume and various economic indicators. Correlation between Google search volume for the term 'sperm donation,' 'egg donation,' and 'blood donation' with actual number of sperm, egg and blood donations in the United States demonstrated Pearson correlation coefficients of 0.2 (p > 0.10), -0.1 (p > 0.10), and 0.07 (p > 0.10), respectively. Temporal analysis showed an improved correlation coefficient of 0.9 (p < 0.05) for blood donation when shifted 12 months later relative to Google search volume. CONCLUSION: Google search volume data for search terms relating to sperm, egg, and blood donation increase during economic downturns. This finding suggests gamete and bodily fluid donations are influenced by market forces like other commodities. Google search may be useful for predicting blood donation trends but is more limited in predicting actual semen and oocyte donation patterns.

Synaptic inputs compete during rapid formation of the calyx of Held: a new model system for neural development.

Hallmark features of neural circuit development include early exuberant innervation followed by competition and pruning to mature innervation topography. Several neural systems, including the neuromuscular junction and climbing fiber innervation of Purkinje cells, are models to study neural development in part because they establish a recognizable endpoint of monoinnervation of their targets and because the presynaptic terminals are large and easily monitored. We demonstrate here that calyx of Held (CH) innervation of its target, which forms a key element of auditory brainstem binaural circuitry, exhibits all of these characteristics. To investigate CH development, we made the first application of serial block-face scanning electron microscopy to neural development with fine temporal resolution and thereby accomplished the first time series for 3D ultrastructural analysis of neural circuit formation. This approach revealed a growth spurt of added apposed surface area (ASA)>200 µm2/d centered on a single age at postnatal day 3 in mice and an initial rapid phase of growth and competition that resolved to monoinnervation in two-thirds of cells within 3 d. This rapid growth occurred in parallel with an increase in action potential threshold, which may mediate selection of the strongest input as the winning competitor. ASAs of competing inputs were segregated on the cell body surface. These data suggest mechanisms to select "winning" inputs by regional reinforcement of postsynaptic membrane to mediate size and strength of competing synaptic inputs.

Flex-DLD: Deep Low-Rank Decomposition Model With Flexible Priors for Hyperspectral Image Denoising and Restoration.

Hyperspectral images (HSIs) are composed of hundreds of contiguous waveband images, offering a wealth of spatial and spectral information. However, the practical use of HSIs is often hindered by the presence of complicated noise caused by various factors such as non-uniform sensor response and dark current. Traditional methods for denoising HSIs rely on constrained optimization approaches, where selecting appropriate prior knowledge is critical for achieving satisfactory results. Nevertheless, these traditional algorithms are limited by hand-crafted priors, leaving room for improvement in their denoising performance. Recently, the supervised deep learning technique has emerged as a promising approach for HSI denoising. However, their requirement for paired training data and poor generalization ability on untrained noise distributions pose challenges in practical applications. In this paper, we design a novel algorithm by the synergism of optimization-based methods and deep learning techniques. Specifically, we introduce a plug-and-play Deep Low-rank Decomposition (DLD) model into the optimization framework. Furthermore, we propose an effective mechanism to incorporate traditional prior knowledge into the DLD model. Finally, we provide a detailed analysis of the optimization process and convergence of the proposed method. Empirical evaluations on various tasks, including hyperspectral image denoising and spectral compressive imaging, demonstrate the superiority of our approach over state-of-the-art methods.

Synchronized wearables for the detection of haemodynamic states via electrocardiography and multispectral photoplethysmography.

Cardiovascular health is typically monitored by measuring blood pressure. Here we describe a wireless on-skin system consisting of synchronized sensors for chest electrocardiography and peripheral multispectral photoplethysmography for the continuous monitoring of metrics related to vascular resistance, cardiac output and blood-pressure regulation. We used data from the sensors to train a support-vector-machine model for the classification of haemodynamic states (resulting from exposure to heat or cold, physical exercise, breath holding, performing the Valsalva manoeuvre or from vasopressor administration during post-operative hypotension) that independently affect blood pressure, cardiac output and vascular resistance. The model classified the haemodynamic states on the basis of an unseen subset of sensor data for 10 healthy individuals, 20 patients with hypertension undergoing haemodynamic stimuli and 15 patients recovering from cardiac surgery, with an average precision of 0.878 and an overall area under the receiver operating characteristic curve of 0.958. The multinodal sensor system may provide clinically actionable insights into haemodynamic states for use in the management of cardiovascular disease.

Injury Patterns in Collegiate Club Quidditch.

BACKGROUND: The purpose of this study is to assess injury patterns in collegiate club quidditch athletes at a single university over three seasons. Injury data were gathered from athletic trainers that provided sideline medical coverage during competitions, the on-site athletic training center where athletes had daily access for evaluation and treatment for acute and chronic injuries, and a sports medicine physician at the on-campus student health center. Athlete exposures were estimated using available previous rosters, practice, and game schedules for the 2014-2017 quidditch seasons. Injuries were evaluated regarding the sex of the athlete, mechanism, body part injuries, and injury type. This is a retrospective descriptive epidemiology study. RESULTS: The overall injury incidence rate (IR) for collegiate club quidditch injuries was 4.55 per 1000 athlete exposures (AEs). Male athletes had an IR = 5.22 (95% CI 3.77, 7.23). Females had an IR = 3.77 (95% CI 2.49, 5.72). The most common mechanism of injury in males was collision with another athlete (36%; IR = 1.88; 95% CI 1.09, 3.24). The most common injuries were lower extremity injuries (foot, ankle, lower leg, knee, thigh, hip/groin) at 57%. The most common injury type in males was sprains at 39% (IR = 2.03; 95% CI 1.20, 3.42). The overall incidence rate for all quidditch athletes for concussions was 1.18 per 1000 AEs. CONCLUSIONS: Quidditch is an increasingly popular mixed-gender collegiate club sport. This study helps identify areas for improvement in education, injury prevention, and care of athletes at the local and national levels. Concussion rates in quidditch are comparable to other contact sports and should encourage discussion to make rule changes to improve the safety of the sport.

An ex vivo physiologic and hyperplastic vessel culture model to study intra-arterial stent therapies.

Conventional in vitro methods for biological evaluation of intra-arterial devices such as stents fail to accurately predict cytotoxicity and remodeling events. An ex vivo flow-tunable vascular bioreactor system (VesselBRx), comprising intra- and extra-luminal monitoring capabilities, addresses these limitations. VesselBRx mimics the in vivo physiological, hyperplastic, and cytocompatibility events of absorbable magnesium (Mg)-based stents in ex vivo stent-treated porcine and human coronary arteries, with in-situ and real-time monitoring of local stent degradation effects. Unlike conventional, static cell culture, the VesselBRx perfusion system eliminates unphysiologically high intracellular Mg2+ concentrations and localized O2 consumption resulting from stent degradation. Whereas static stented arteries exhibited only 20.1% cell viability and upregulated apoptosis, necrosis, metallic ion, and hypoxia-related gene signatures, stented arteries in VesselBRx showed almost identical cell viability to in vivo rabbit models (~94.0%). Hyperplastic intimal remodeling developed in unstented arteries subjected to low shear stress, but was inhibited by Mg-based stents in VesselBRx, similarly to in vivo. VesselBRx represents a critical advance from the current static culture standard of testing absorbable vascular implants.

Nanometric self-assembling peptide layers maintain adult hepatocyte phenotype in sandwich cultures.

BACKGROUND: Isolated hepatocytes removed from their microenvironment soon lose their hepatospecific functions when cultured. Normally hepatocytes are commonly maintained under limited culture medium supply as well as scaffold thickness. Thus, the cells are forced into metabolic stress that degenerate liver specific functions. This study aims to improve hepatospecific activity by creating a platform based on classical collagen sandwich cultures. RESULTS: The modified sandwich cultures replace collagen with self-assembling peptide, RAD16-I, combined with functional peptide motifs such as the integrin-binding sequence RGD and the laminin receptor binding sequence YIG to create a cell-instructive scaffold. In this work, we show that a plasma-deposited coating can be used to obtain a peptide layer thickness in the nanometric range, which in combination with the incorporation of functional peptide motifs have a positive effect on the expression of adult hepatocyte markers including albumin, CYP3A2 and HNF4-alpha. CONCLUSIONS: This study demonstrates the capacity of sandwich cultures with modified instructive self-assembling peptides to promote cell-matrix interaction and the importance of thinner scaffold layers to overcome mass transfer problems. We believe that this bioengineered platform improves the existing hepatocyte culture methods to be used for predictive toxicology and eventually for hepatic assist technologies and future artificial organs.

The Tipping Point: Key Oncologic Imaging Findings Resulting in Critical Changes in the Management of Malignant Tumors of the Gastrointestinal Tract.

OBJECTIVE: The purpose of this article is to review tumor staging systems for gastrointestinal tumors including pancreatic adenocarcinoma, hepatocellular carcinoma, cholangiocarcinoma, gastric adenocarcinoma, small bowel adenocarcinoma, rectal carcinoma, and anal carcinoma and identify the key imaging findings ("tipping points"), which change patient management based on changes in tumor staging. CONCLUSION: For all malignant gastrointestinal tumors, there are key imaging findings ("tipping points") including tumor size, tumor extension, lymphadenopathy, vascular invasion, and distant metastasis that dictate patient management and prognosis, based on changes in tumor stage. In interpreting these imaging studies, radiologists should be cognizant of these "tipping points" to guide patient management.

The impact of levodopa therapy-induced complications on quality of life in Parkinson's disease patients in Singapore.

The objective of this study was to investigate the impact of levodopa therapy-induced complications on the quality of life (QoL) of Parkinson's disease (PD) patients in Singapore over a 1-year follow-up period. 274 PD patients were prospectively recruited, of which 78 patients completed the follow-up. Patients were evaluated on: (1) motor symptoms, (2) non-motor symptoms, (3) levodopa therapy-induced complications and (4) QoL. Levodopa-induced complications including dyskinesia and OFF symptoms occurred in 13.5% and 55.9% of the study population, respectively. In patients who completed the 1-year follow-up, there was a trend suggestive of increasing dyskinesia duration, more disabling dyskinesia as well as longer, more sudden and unpredictable OFF periods. There was a significant decline in the overall QoL at follow-up, in particular, activities of daily living, emotional well-being, cognition and communication domains were the most affected. The multivariable analysis demonstrated that worsening of UPDRS IV total score over 1-year interval was associated with worsening in PDQ-Summary Index score (d = 0.671, p = 0.014). In conclusion, levodopa-induced complications had significant adverse impacts on QoL. This study substantiates the importance for clinicians to closely monitor and promptly manage levodopa therapy-induced complications that may arise in patients.

Simultaneous transrectal ultrasound and photoacoustic human prostate imaging.

Imaging technologies that simultaneously provide anatomical, functional, and molecular information are emerging as an attractive choice for disease screening and management. Since the 1980s, transrectal ultrasound (TRUS) has been routinely used to visualize prostatic anatomy and guide needle biopsy, despite limited specificity. Photoacoustic imaging (PAI) provides functional and molecular information at ultrasonic resolution based on optical absorption. Combining the strengths of TRUS and PAI approaches, we report the development and bench-to-bedside translation of an integrated TRUS and photoacoustic (TRUSPA) device. TRUSPA uses a miniaturized capacitive micromachined ultrasonic transducer array for simultaneous imaging of anatomical and molecular optical contrasts [intrinsic: hemoglobin; extrinsic: intravenous indocyanine green (ICG)] of the human prostate. Hemoglobin absorption mapped vascularity of the prostate and surroundings, whereas ICG absorption enhanced the intraprostatic photoacoustic contrast. Future work using the TRUSPA device for biomarker-specific molecular imaging may enable a fundamentally new approach to prostate cancer diagnosis, prognostication, and therapeutic monitoring.

Severity of congenital heart defects associated with assisted reproductive technologies: Case series and review of the literature.

OBJECTIVE: Assisted reproductive technology (ART) has been associated with a higher incidence of congenital anomalies, including a specific increase in the rate of congenital heart defects (CHD). In this study, the rate of CHD in pregnancies resulting from ART at a single high-risk pregnancy referral center are compared to the published literature. METHODS: Pregnancies were screened by fetal echocardiography for the indication of ART over a 2-year period. CHD were classified as either mild or severe based on the need for postnatal surgical intervention. Results were compared to findings from a literature review of studies examining CHD in pregnancies resulting from ART since 1980. RESULTS: Over the course of two years, 363 fetuses in 264 pregnancies from our cohort were screened for CHD. The incidence of mild CHD in fetuses from ART pregnancies was 2.75% (10 out of 363 fetuses). None of the affected fetuses had severe CHD. Review of the literature yielded 20 studies since 1980 that examined CHD in pregnancies resulting from ART. Composite data from the studies was described based on characterization of severity of the CHD anomalies. The incidence of mild CHD in ART pregnancies was 2.2%, compared to 1% in non-ART pregnancies (out of 332,157 infants). The incidence of severe CHD in ART pregnancies and naturally conceived pregnancies was 1.4% and 1.2%, respectively (out of 661,455 infants). The incidence of unspecified CHD in ART pregnancies was 1.8%, compared to 1% in naturally conceived pregnancies (out of 1,593,277 infants). CONCLUSION: The greatest increase in risk appears to be for mild CHD (nonsurgical), which may inform counseling of patients prior to use of assisted reproductive technologies.

Genes involved in prostate cancer progression determine MRI visibility.

MRI is used to image prostate cancer and target tumors for biopsy or therapeutic ablation. The objective was to understand the biology of tumors not visible on MRI that may go undiagnosed and untreated. Methods: Prostate cancers visible or invisible on multiparametric MRI were macrodissected and examined by RNAseq. Differentially expressed genes (DEGs) based on MRI visibility status were cross-referenced with publicly available gene expression databases to identify genes associated with disease progression. Genes with potential roles in determining MRI visibility and disease progression were knocked down in murine prostate cancer xenografts, and imaged by MRI. Results: RNAseq identified 1,654 DEGs based on MRI visibility status. Comparison of DEGs based on MRI visibility and tumor characteristics revealed that Gleason score (dissimilarity test, p<0.0001) and tumor size (dissimilarity test, p<0.039) did not completely determine MRI visibility. Genes in previously reported prognostic signatures significantly correlated with MRI visibility suggesting that MRI visibility was prognostic. Cross-referencing DEGs with external datasets identified four genes (PHYHD1, CENPF, ALDH2, GDF15) that predict MRI visibility, progression free survival and metastatic deposits. Genetic modification of a human prostate cancer cell line to induce miR-101 and suppress CENPF decreased cell migration and invasion. As prostate cancer xenografts in mice, these cells had decreased visibility on diffusion weighted MRI and decreased perfusion, which correlated with immunostaining showing decreased cell density and proliferation. Conclusions: Genes involved in prostate cancer prognosis and metastasis determine MRI visibility, indicating that MRI visibility has prognostic significance. MRI visibility was associated with genetic features linked to poor prognosis.

Efficacy of Implementation of a Chest Pain Center at a Community Hospital.

INTRODUCTION: Chest pain is the second leading cause for emergency department (ED) visits in the United States; however, <20% of the patients have acute coronary syndrome that require immediate attention. The HEART score is designed for rapid risk stratification of ED chest pain patients using the following criteria: history, electrocardiogram, age, risk factors, and troponin. It has been shown to be superior in identifying patients with low (HEART score 0-3) and high (7-10) risk of major adverse cardiac events, who can then be rapidly discharged or admitted for intervention. OBJECTIVE: This retrospective review and assessment sought to evaluate the efficacy of implementation of a Chest Pain Center (CPC) at a predominantly Asian-based community hospital in the United States. Additionally, this assessment sought to evaluate the effectiveness and safety of a HEART protocol in the first 4 months after its adoption. MATERIALS AND METHODS: The facility implemented the CPC, an observation unit, in October 2016. ED physicians risk stratified patients using the HEART score. The guidelines allow ED physicians to stratify patients into 3 categories: to discharge low-risk patients, observe moderate-risk patients in the CPC, and admit high-risk patients. Patients in the CPC received additional diagnostic work-up under the care of ED physicians and cardiologists for less than 24 hours. In addition, CPC patients were followed-up 2 and 30 days after discharge. RESULTS: A total of 172 patients presented at the ED with a chief complaint of chest pain. The majority of the patients were classified into the moderate-risk group (n = 101). Low-risk patients spent significantly less hours in the hospital than the moderate- and high-risk groups, and the high-risk group spent more time in the hospital than the moderate-risk group. The staff followed-up with 74 CPC patients through telephone calls to assess if patients were still experiencing chest pain and if they had followed-up with a cardiologist or primary care physician. The 2- and 30-day survival rates were 100% and 97%, respectively. DISCUSSION: The data showed a significant reduction in total length of stay for all chest pain patients. This retrospective program evaluation demonstrated some evidence in using HEART score to safely risk stratify chest pain patients to the appropriate level of care. As healthcare moves from a fee-for-service environment to value-based purchasing, hospitals need to devise and implement innovative strategies to provide efficient, beneficial, and safe care for the patients.