20966 research outputs found
Sort by
Ischemic Colitis and Small Bowel Ischemia in a Vaccinated Patient with Mild COVID-19 Infection: A Case Report
No full textINTRODUCTION: COVID-19 infection can cause bowel ischemia, with an incidence ranging from 0.22% to 10.5. The COVID-19 vaccine reduces respiratory symptoms and the need for cardiopulmonary support. However, its effects on other manifestations, such as bowel ischemia, have not been extensively studied. Despite having mild respiratory symptoms and receiving three doses of the COVID-19 vaccine, our patient developed ischemic colitis after her first infection and small bowel ischemia following her second infection.
CASE PRESENTATION: An 86-year-old woman presented to the emergency department (ED) with abdominal pain after a mild COVID-19 infection. She was admitted with ischemic colitis, but conservative treatment failed. In the operating room, her entire colon was found to be ischemic, necessitating a total colectomy with end ileostomy. Nine months later, she returned to the ED with mild respiratory symptoms and severe right upper quadrant pain. Imaging revealed pneumoperitoneum and a mid-abdominal abscess. An emergency laparotomy revealed small bowel perforation, with final histology confirming ischemia. The patient had received three doses of the COVID-19 vaccine and was on therapeutic anticoagulation for a history of pulmonary embolism.
CONCLUSION: COVID-19 may increase the risk of bowel and colon ischemia even after vaccination. Patients presenting to the ED with severe abdominal pain and a recent COVID-19 infection should be carefully evaluated for ischemic events
Race Comparisons in Patients With Cardiac Sarcoidosis: Insights From the Cardiac Sarcoidosis Consortium
No full textBACKGROUND: Differences in cardiac sarcoidosis between racial groups remain understudied. Therefore, this study aims to explore race differences in patients with cardiac sarcoidosis.
METHODS: We analyzed data from the Cardiac Sarcoidosis Consortium, an international registry including over 25 centers. The primary clinical outcome was a composite end point of all-cause mortality, left ventricular assist device implantation, heart transplantation, or implantable cardioverter defibrillator therapy.
RESULTS: A total of 619 patients were included in the study (362 White, 193 Black, and 64 other races). Black patients were diagnosed with cardiac sarcoidosis at a younger age (50.5±11.8 versus 53.7±10.5 years old; P=0.010) compared with White patients. Left ventricular ejection fraction was significantly lower in Black patients (44.6±15.4 versus 48.3±14.0; P=0.008). In addition, extracardiac involvement in the lungs (80.3% versus 72.7%; P=0.046), skin (22.8% versus 12.4%; p=0.002), and eyes (13.5% versus 5.5%; P=0.001) was more prevalent in Black patients. Patients had significantly higher rates of hypertension (69.9% versus 50.6%; P\u3c 0.001), diabetes (37.8% versus 21.0%; P\u3c 0.001), smoking (40.9% versus 26.8%; P\u3c 0.001), chronic obstructive pulmonary disease or emphysema (15.5% versus 4.1%; P\u3c 0.001), and chronic kidney disease (25.9% versus 12.4%; P\u3c 0.001). The treatment patterns including glucocorticoid (71% versus 74.3%; P=0.4), glucocorticoid-sparing (53.4% versus 59.9%; P=0.14), and implantable cardioverter defibrillator or cardiac resynchronization implantation (75.6% versus 73.8%; P=0.63), were similar. No significant differences were found in the primary outcome (29.5% in Black versus 28.5% in White; P=0.79). Subgroup analysis of the primary outcome also revealed no significant differences in both the left ventricular ejection fraction \u3e35% group (24.1% in Black versus 25.9% in White; P=0.72) and the left ventricular ejection fraction ≤35% group (51% versus 42.5%; P=0.35).
CONCLUSIONS: Black patients with cardiac sarcoidosis exhibited significantly higher rates of lung, skin, and eye involvement and comorbidities, but had similar cardiac clinical outcomes and all-cause mortality compared with White patients. Nonetheless, ascertainment bias cannot be excluded
Recommendations for Providing Feedback and Medical Reassurance Following Maximal-Graded Exercise Testing for Exercise Prescription in Cardiac Rehabilitation
No full textRole of Embolic Protection in Percutaneous Coronary Intervention Without Saphenous Venous Graft Lesions in ST-Segment-Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis
No full textINTRODUCTION: Embolic protection devices (EPDs) are catheter-based devices that can be used to capture atherosclerotic remnants released during percutaneous coronary intervention (PCI). We aim to study the efficacy and safety of EPDs in PCIs without saphenous vein grafts (SVGs) in ST-segment-elevation myocardial infarction (MI).
METHODS: Three electronic databases of MEDLINE, Web of Science, and Embase were searched from inception to April 10, 2024, to identify relevant randomized controlled trials that compared outcomes of patients subjected to EPD during PCI with a control group where EPDs were not utilized. The primary outcome was 30-day all-cause mortality. Secondary outcomes were major adverse cardiovascular and cerebrovascular events at 30 days, post-PCI thrombolysis in MI grade 3 flow attainment, ST-segment resolution at 90 minutes post-procedure, and postprocedure angiographically detectable signs of distal embolization. The effect estimates of outcomes were assessed using risk ratio (RR) with a 95% confidence interval (CI). Random-effects meta-analysis was conducted using the restricted maximum likelihood method, given that the interstudy variance was inevitable.
RESULTS: We included 3 randomized controlled trials enrolling 741 patients (age, 61.6 ± 12.15 years; 22% females) undergoing PCI without SVG lesions. As opposed to the control group, the use of EPD did not yield a significant effect on all-cause mortality [RR, 0.76 (95% CI, 0.31-1.86); I 2 = 0%], major adverse cardiovascular and cerebrovascular events [RR, 0.66 (95% CI, 0.34-1.27); I 2 = 0%], post-PCI thrombolysis in MI 3 flow [RR, 1.18 (95% CI, 0.86-1.62); I 2 = 77%], and ST-segment resolution at 90 minutes post-procedure [RR, 1.05 (95% CI, 0.90-1.22); I 2 = 0%]. However, EPD significantly decreased angiographically detectable signs of distal embolization [RR, 0.60 (95% CI, 0.36-0.99); I 2 = 0%].
CONCLUSIONS: EPD significantly reduced angiographically detectable signs of distal embolization in PCI without SVG lesions in ST-segment-elevation MI though there were no clinical signs of improved flow or mortality. Further trials are necessary to thoroughly evaluate the potential benefits and requirements of EPD usage in such procedures
Risk prediction for ALS using semi-competing risk models with applications to the ALS Natural History Consortium dataset
No full textBackground and objectives: Important landmarks in progression of amyotrophic lateral sclerosis (ALS) can occur prior to death. Predictive models for the risk of these events can assist in clinical trial design and personal planning. We propose a predictive model, using a semi-competing risks modeling approach, for five important disease progression landmarks in ALS. Methods: Data on 1508 participants from the ALS Natural History Consortium (ALS NHC) were used, including baseline characteristics and the ALS Functional Rating Scale-Revised (ALSFRS-R) score collected at clinic visits. A semi-competing risks modeling approach was used to study the time to disease progression landmarks, accounting for the possibility of death. Specifically, time to gastrostomy, use of noninvasive ventilation (NIV), continuous use of NIV, loss of speech, and loss of ambulation were chosen and modeled individually. To measure the predictive capabilities of the model, the integrated Brier score was computed for each model using cross-validation for the NHC data. Data from Emory University were used for external validation of the models. Results: We present model results using gastrostomy as the intermediate outcome. Similar trends in disease progression groups were found across all model pathways. Diagnostic delay, age, and site of onset were the most important covariates. Predictive metrics in both internal and external validation are presented across all models and for different pathways. Conclusion: Semi-competing risks modeling is a flexible approach to studying disease progression. The models have good predictive capabilities across different outcomes and pathways. These are replicated in the external validation dataset
Impact of repeated intranasal gentamicin irrigation on structure and function of the vestibular brainstem
No full textGentamicin is an aminoglycoside antibiotic that broadly targets Gram-negative bacteria. While gentamicin is a clinically effective antibiotic, it has significant oto- and nephrotoxicity. In human subjects, repeated exposure to gentamicin results in dizziness, tinnitus, and high frequency hearing loss. Gentamicin has similar effects across animal species and through several different routes of delivery, including injection and direct deposits in the tympanic cavity. Gentamicin can also be administered intranasally to treat sinusitis in humans and this route of delivery is believed to minimize toxic effects. Nonetheless, we hypothesized that intranasal irrigation of gentamicin will result in ototoxicity and impaired auditory and vestibular function similar to systemic delivery. We investigated this hypothesis in Sprague-Dawley rats that received bilateral, intranasal irrigations of a therapeutic dose of gentamicin or saline from postnatal day (P) 21-31. We examined vestibular structure and function in control and gentamicin-exposed rats by assessing performance on a series of sensorimotor tasks, recording vestibular evoked myogenic potentials (VEMPs), and examining number and morphology of neurons in the brainstem vestibular nuclei. Gentamicin-exposed animals had significantly worse performance on sensorimotor tasks, significantly slower VEMPs, and significantly fewer neurons in the vestibular nuclei. Together, our findings indicate that intranasal administration of gentamicin results in impaired auditory and vestibular function consistent with other routes of delivery
Characterization of acute radiation-induced vascular changes in animal model of brain tumors using time frequency analysis of DCE MRI information
No full textBACKGROUND: Recent studies have confirmed the effects of whole-brain radiation therapy (RT) on the blood-brain-barrier and vasculature permeability. Optimal therapeutic targeting of cancer depends on ability to distinguish tumor from normal tissue.
PURPOSE: This study recruits nested model selection (NMS) and time-frequency analyses of the time-trace of contrast agent from dynamic-contrast-enhanced MRI information to characterize the acute (i.e., within hours) RT response of tumor and normal brain tissues in an animal model of brain tumors.
METHODS: Twenty immune-compromised-RNU rats were implanted orthotopically with human U251N glioma cells. Twenty-eight days after the brain implantation, two DCE-MRI studies were performed 24 h apart. 20 Gy stereotactic radiation was delivered 1-6.5 h before the second MRI. NMS-based DCE-MRI analysis was performed to distinguish three different brain regions by model selection using a nested paradigm. Model 1 was characterized by non-leaky vasculature and considered as normal brain tissue. Model 2 was characterized by contrast agent (CA) movement predominantly in one direction, out of the vasculature, and was primarily associated with the tumor boundary. In contrast, Model 3 exhibited contrast agent movement in both directions, into and out of the vasculature, and corresponded to the tumor core. Time-traces of CA concentration from pre- and post-RT DCE-MRI data for the different models were analyzed using wavelet-based coherence and wavelet cross-spectrum phase analyses to characterize and rank the magnitude of RT-induced effects. Four distinct time-direction classes (in-phase/anti-phase with lead/lag time) were introduced to describe the impact of RT on CA concentration profiles, allowing for comparison of RT effects across different model-based zones of rat brains.
RESULTS: The time-frequency analyses revealed both average lag and lead times between the pre- and post-RT CA concentration profiles for the three model regions. The average lag times were 2.882 s (95% CI: 2.606-3.157) for Model 1, 1.546 s (95% CI: 1.401-1.691) for Model 2, and 2.515 s (95% CI: 2.319-2.711) for Model 3, all exhibiting anti-phase oscillation. The average lead times were 1.892 s (95% CI: 1.757-2.028) for Model 1, 2.632 s (95% CI: 2.366-2.898) for Model 2, and 2.160 s (95% CI: 2.021-2.299) for Model 3, also with anti-phase oscillation. Results imply that compared to pre-RT, Model 1, 2, and 3 regions that correspond to normal tissue, periphery, and core of the tumor, show lag-time (2.882 [2.606 3.157] s), lead-time (2.632 [2.366 2.898] s), and lag-time (2.515 [2.319 2.711] s), in their post-RT time-trace of CA concentration, respectively. RT-induced lead/lag time changes were found to be more significant for the lower frequency components of the CA concentration profiles of all the three models. The analysis further revealed that Model 2 (tumor periphery) exhibited the most significant lead time, implying a shorter retainage-time of CA after radiation. Conversely, Model 1, normal tissue, showed the most pronounced lag-time, suggesting longer retainage-time of CA.
CONCLUSIONS: This study demonstrates a novel approach to analyze the time-frequency information of DCE-MRI CA concentration profiles of the animal brain to detect acute changes in tumor and normal tissue physiology in response to RT that has clinical translatability and has potential to improve treatment planning and RT efficacy
Pilot Study: Development and Evaluation of Validity Evidence of a Low-Cost, Low-Fidelity Hand Model to Teach Clinical Assessment of Small Joint Swelling in Inflammatory Arthritis
No full textOBJECTIVE: To create an affordable, easily reproducible, low-fidelity hand model and present a validity argument for its use to support residents\u27 learning to identify inflammatory arthritis.
METHODS: We designed a hand model to simulate small joint swelling and evaluated evidence to support its use using Messick\u27s Framework between April 2023 and April 2024. Rheumatologists nationwide rated our model (content validity). At 2 tertiary institutions, rheumatologists (experts) and internal medicine residents (learners) evaluated 3 sets of models for small joint swelling, and their scores were compared with Mann-Whitney U test (construct validity). Learners applied their skills to 3 patient encounters, and patient versus model scores were compared with Wilcoxon signed rank test (predictive validity).
RESULTS: One set of 2 hand models cost less than US $5 to create. Thirteen rheumatologists rated our model at 7.23 ± 2.52 out of 10 points; 11 of the 13 (84.6%) rheumatologists thought the model was helpful for training learners to examine swollen joints. Median model evaluation scores for 12 experts (98.9%; range, 92.2%-100%) and 32 learners (100%; range, 84.4%-100%) were not significantly different (p = 0.143). The 18 learners who also evaluated patients had a significantly lower median score when evaluating patients versus the hand models (difference 10.0%; range, 5.6-15.6; p \u3c 0.001).
CONCLUSION: Content validity evidence supported our model\u27s use in internal medicine training; however, the model needs improvement for greater construct and predictive validity. Our easily constructed, low-cost hand model may be a promising introductory training tool for rheumatology medical education
Machine learning in dentistry: a scoping review
No full textArtificial intelligence (AI), specifically machine learning (ML), is increasingly applied in decision-making for dental diagnosis, prognosis, and treatment. However, the methodological completeness of published models has not been rigorously assessed. We performed a scoping review of PubMed-indexed articles (English, 1 January 2018 - 31 December 2023) that used ML in any dental specialty. Each study was evaluated with the TRIPOD + AI rubric for key reporting elements such as data preprocessing, model validation, and clinical performance. Out of 1,506 identified studies, 280 met the inclusion criteria. Oral and maxillofacial radiology (27.5%), oral and maxillofacial surgery (15.0%), and general dentistry (14.3%) were the most represented specialties. Sixty-four studies (22.9%) lacked comparison with a clinical reference standard or existing model performing the same task. Most models focused on classification (59.6%), whereas generative applications were relatively rare (1.4%). Key gaps included limited assessment of model bias, poor outlier reporting, scarce calibration evaluation, low reproducibility, and restricted data access. ML could transform dental care, but robust calibration assessment and equity evaluation are critical for real-world adoption. Future research should prioritize error explainability, outlier reporting, reproducibility, fairness, and prospective validation
A Comprehensive Scoping Review of Technology in the Care of Historically Marginalized Populations With Asthma: A Work Group Report of the AAAAI Diversity, Equity, and Inclusion Committee
No full textBACKGROUND: Health care technology strategies are increasingly being used in research and clinical care in asthma. The use of technology in addressing asthma disparities has not been reported.
OBJECTIVE: To determine the effect of technology in historically marginalized racial and ethnic populations with asthma.
METHODS: A comprehensive literature search was conducted to identify studies that included the use of health technology in patients with asthma from historically marginalized populations. Authors reviewed studies to determine study characteristics and intervention efficacy according to predetermined outcome measures. Studies were categorized as generalized, unidirectional, or bidirectional according to the degree to which they used personalized participant data.
RESULTS: A total of 1516 studies were initially identified, with 44 studies included in the final analysis. Most studies included a majority Black population, followed by Latino population. Bidirectional studies that collect patient-specific data and provide tailored recommendations, education, or treatment options were most effective as compared with generalized and unidirectional studies. No specific technology methodology was found to be superior to others, though technology modalities that used personalized participant data and allowed for bidirectional information exchange were more effective than those that relied on generalized data.
CONCLUSION: Health care technology strategies can provide an avenue to decrease asthma disparities in historically marginalized populations