Low-cost otolaryngology simulation models for early-stage trainees: a scoping review.

BACKGROUND: Medical simulation is essential for surgical training yet is often too expensive and inaccessible in low- and middle-income countries (LMICs). Furthermore, in otolaryngology-head and neck surgery (OHNS), while simulation training is often focused on senior residents and specialists, there is a critical need to target general practitioners who carry a significant load of OHNS care in countries with limited OHNS providers. This scoping review aims to describe affordable, effective OHNS simulation models for early-stage trainees and non-OHNS specialists in resource-limited settings and discuss gaps in the literature. METHODS: This scoping review followed the five stages of Arksey and O'Malley's Scoping Review Methodology. Seven databases were used to search for articles. Included articles discussed physical models of the ear, nose, or throat described as "low-cost," "cost-effective," or defined as <$150 if explicitly stated; related to the management of common and emergent OHNS conditions; and geared towards undergraduate students, medical, dental, or nursing students, and/or early-level residents. RESULTS: Of the 1706 studies screened, 17 met inclusion criteria. Most studies were conducted in HICs. Most models were low-fidelity (less anatomically realistic) models. The most common simulated skills were peritonsillar abscess aspiration and cricothyrotomy. Information on cost was limited, and locally sourced materials were infrequently mentioned. Simulations were evaluated using questionnaires and direct observation. CONCLUSION: Low-cost simulation models can be beneficial for early medical trainees and students in LMICs, addressing resource constraints and improving skill acquisition. However, there is a notable lack of contextually relevant, locally developed, and cost-effective models. This study summarizes existing low-cost OHNS simulation models for early-stage trainees and highlights the need for additional locally sourced models. Further research is needed to assess the effectiveness and sustainability of these models.

Prostate cancer PET tracers: essentials for the urologist.

INTRODUCTION: In the past, positron emission tomography (PET) has played a relatively limited role in prostate cancer imaging. However, in recent years, several new PET tracers have emerged, offering potential improvements in diagnostic performance for both the detection of prostate cancer metastases at initial staging and the localization of recurrent disease. MATERIALS AND METHODS: We reviewed the literature for prostate cancer PET tracers that are either being used for patient management or being evaluated in clinical research trials. For each tracer, we compiled clinically relevant background information and evidence supporting clinical use, with the intention of providing a high-yield primer for urologists managing patients with prostate cancer. RESULTS: 18F-FDG, 18F-NaF, ¹¹C-choline, and 18F-fluciclovine have all proven useful for prostate cancer imaging, though the utility of each of these tracers is limited to targeted management questions and particular clinical settings. In contrast, the newer prostate-specific membrane antigen (PSMA) agents may prove useful as general purpose PET tracers for prostate cancer imaging. Numerous other novel PET tracers have shown promising results in pre-clinical studies. CONCLUSION: Basic knowledge of these PET tracers, specifically their strengths, weaknesses, and indications for use, is essential to urologists and other physicians caring for patients with prostate cancer.

Compact solar autoclave based on steam generation using broadband light-harvesting nanoparticles.

The lack of readily available sterilization processes for medicine and dentistry practices in the developing world is a major risk factor for the propagation of disease. Modern medical facilities in the developed world often use autoclave systems to sterilize medical instruments and equipment and process waste that could contain harmful contagions. Here, we show the use of broadband light-absorbing nanoparticles as solar photothermal heaters, which generate high-temperature steam for a standalone, efficient solar autoclave useful for sanitation of instruments or materials in resource-limited, remote locations. Sterilization was verified using a standard Geobacillus stearothermophilus-based biological indicator.

Low-Cost Otolaryngology Simulation Models for Early-Stage Trainees: A Scoping Review.

Importance: There is a notable lack of low-cost OHNS simulation models that are relevant for early medical trainees and students. By conducting this study, we will understand the current landscape of low-cost otolaryngology-head and neck surgery simulation for early medical trainees and students. Objectives: Medical simulation is essential for surgical training yet is often too expensive and inaccessible in low- and middle-income countries (LMICs). Furthermore, in otolaryngology-head and neck surgery (OHNS), while simulation training is often focused on senior residents and specialists, there is a critical need to target general practitioners who carry a significant load of OHNS care in countries with limited OHNS providers. This scoping review aims to describe affordable, effective OHNS simulation models for early-stage trainees and non-OHNS specialists in resource-limited settings and discuss gaps in the literature. Evidence Review: This scoping review followed the five stages of Arksey and O'Malley's Scoping Review Methodology. Seven databases were used to search for articles. Included articles discussed physical models of the ear, nose, or throat described as "low-cost," "cost-effective," or defined as <$150 if explicitly stated; related to the management of common and emergent OHNS conditions; and geared towards undergraduate students, medical, dental, or nursing students, and/or early-level residents. Findings: Of the 1706 studies screened, 17 met the inclusion criteria. Most studies were conducted in HICs. Most models were low fidelity (less anatomically realistic) models. The most common simulated skills were peritonsillar abscess aspiration and cricothyrotomy. Information on cost was limited, and locally sourced materials were infrequently mentioned. Simulations were evaluated using questionnaires and direct observation. Conclusion and Relevance: Low-cost simulation models can be beneficial for early medical trainees and students in LMICs, addressing resource constraints and improving skill acquisition. However, there is a notable lack of contextually relevant, locally developed, and cost-effective models. This study summarizes existing low-cost OHNS simulation models for early-stage trainees and highlights the need for additional locally sourced models. Further research is needed to assess the effectiveness and sustainability of these models.

Is there association between severe multispace infections of the oral maxillofacial region and diabetes mellitus?

PURPOSE: This study aims to identify the impact of diabetes on the final outcome (length of hospital stay and development of complications) in patients with severe multispace infections in the head and neck. Furthermore, it intends to characterize significant clinical features of these patients compared with nondiabetics. MATERIALS AND METHODS: A retrospective study was conducted in 117 patients who received treatment for multispace infections of the head and neck region from 2007 through 2010 at the Department of Oral and Maxillofacial Surgery, Shanghai Ninth Hospital. The study identified diabetic patients and compared them with nondiabetic patients. Demographics, etiology of infection, clinical parameters (time from first onset of symptoms to hospital admission, number of spaces affected, and distribution of involved spaces), and laboratory values (bacteriology, admission blood glucose level, admission white blood cell count, and percentage of neutrophils on admission) were analyzed for clinical significance. Statistical analyses of the results between groups were performed using the Student t test, χ(2) test, variance analysis, logistic regression analysis, and linear regression analysis. RESULTS: Admission blood glucose level was the only factor influencing the complications in multispace infections in the oral-maxillofacial region. Compared with nondiabetic patients, diabetics had infections that involved more spaces, longer hospital stays, and more frequent complications. Some diabetic patients died. The disease status (with or without diabetes) was associated with clinical outcomes (length of hospital stay and complications) in the therapy procedures. CONCLUSIONS: This study identifies uncontrolled diabetes mellitus as an important indicator of clinical features and outcomes in treating multispace infections of the oral-maxillofacial region.

Three-dimensional soft tissue analysis of the face following micro-implant-supported maxillary skeletal expansion.

BACKGROUND: Skeletal maxillary expander (MSE) is one of the more recent expander designs being utilized for skeletal expansion by splitting the midpalatal sutures applying forces through palatal micro-implants. Its effects on the soft tissue remain a question asked by both patients and clinicians. The aim of this study was to analyze and quantify soft tissue facial changes induced by MSE. METHODS: 3D facial images (3dMD) were used to capture face scans of 25 patients generating 3D soft tissue meshes before expansion (T0), right after expansion (T1), and 1 year in retention (T2). MATLAB was then used, utilizing non-rigid iterative closest point algorithm, to align all samples in vertex correspondence and generate averages. Surface mapping of each average, along with its variance, allows for quantification of changes between the three pools of samples in 3D space. RESULTS: The generated 3D p-maps between T0 and T1 demonstrate that statistically significant changes (p < 0.05 and p < 0.01) are localized in the circummaxillary area (paranasal, lips, and both cheeks). Vector map shows a mean displacement of 1.5 mm in the paranasal area. The right cheek showing a mean displacement magnitude of 2.5 mm while the left cheek has a mean of 2.9 mm. Direction of vectors are latero-anterior with more dominant anterior direction. CONCLUSIONS: There are significant changes in paranasal, upper lip, and at both cheeks following expansion using MSE with greater magnitude at the cheeks area. Those changes do not relapse after 1 year (p < 0.05).

Nanosensors for the Chemical Imaging of Acetylcholine Using Magnetic Resonance Imaging.

A suite of imaging tools for detecting specific chemicals in the central nervous system could accelerate the understanding of neural signaling events critical to brain function and disease. Here, we introduce a class of nanoparticle sensors for the highly specific detection of acetylcholine in the living brain using magnetic resonance imaging. The nanosensor is composed of acetylcholine-catalyzing enzymes and pH-sensitive gadolinium contrast agents co-localized onto the surface of polymer nanoparticles, which leads to changes in T1 relaxation rate (1/ T1). The mechanism of the sensor involves the enzymatic hydrolysis of acetylcholine leading to a localized decrease in pH which is detected by the pH-sensitive gadolinium chelate. The concomitant change in 1/ T1 in vitro measured a 20% increase from 0 to 10 µM acetylcholine concentration. The applicability of the nanosensors in vivo was demonstrated in the rat medial prefrontal cortex showing distinct changes in 1/ T1 induced by pharmacological stimuli. The highly specific acetylcholine nanosensor we present here offers a promising strategy for detection of cholinergic neurotransmission and will facilitate our understanding of brain function through chemical imaging.

Imaging Sodium Flux during Action Potentials in Neurons with Fluorescent Nanosensors and Transparent Microelectrodes.

Sodium flux plays a pivotal role in neurobiological processes including initiation of action potentials and regulation of neuronal cell excitability. However, unlike the wide range of fluorescent calcium indicators used extensively for cellular studies, the choice of sodium probes remains limited. We have previously demonstrated optode-based nanosensors (OBNs) for detecting sodium ions with advantageous modular properties such as tunable physiological sensing range, full reversibility, and superb selectivity against key physiological interfering ion potassium. (1) Motivated by bridging the gap between the great interest in sodium imaging of neuronal cell activity as an alternative to patch clamp and limited choices of optical sodium indicators, in this Letter we report the application of nanosensors capable of detecting intracellular sodium flux in isolated rat dorsal root ganglion neurons during electrical stimulation using transparent microelectrodes. Taking advantage of the ratiometric detection scheme offered by this fluorescent modular sensing platform, we performed dual color imaging of the sensor to monitor the intracellular sodium currents underlying trains of action potentials in real time. The combination of nanosensors and microelectrodes for monitoring neuronal sodium dynamics is a novel tool for investigating the regulatory role of sodium ions involved during neural activities.

Tantalum Cones in Revision Total Knee Arthroplasty.

The best strategy to address large bony defects in revision total knee arthroplasty has yet to be determined. The relatively recent development of porous tantalum cones and their use to address massive bone loss in knee arthroplasty has shown promising short- and intermediate-term results. The purpose of this review is to present the current literature on: (1) basic science of porous tantalum, (2) classification and treatment for bone loss, (3) clinical results, and (4) evolution of newer generation cones.

Anisotropic poly(ethylene glycol)/polycaprolactone hydrogel-fiber composites for heart valve tissue engineering.

The recapitulation of the material properties and structure of the native aortic valve leaflet, specifically its anisotropy and laminate structure, is a major design goal for scaffolds for heart valve tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are attractive scaffolds for this purpose as they are biocompatible, can be modified for their mechanical and biofunctional properties, and can be laminated. This study investigated augmenting PEG hydrogels with polycaprolactone (PCL) as an analog to the fibrosa to improve strength and introduce anisotropic mechanical behavior. However, due to its hydrophobicity, PCL must be modified prior to embedding within PEG hydrogels. In this study, PCL was electrospun (ePCL) and modified in three different ways, by protein adsorption (pPCL), alkali digestion (hPCL), and acrylation (aPCL). Modified PCL of all types maintained the anisotropic elastic moduli and yield strain of unmodified anisotropic ePCL. Composites of PEG and PCL (PPCs) maintained anisotropic elastic moduli, but aPCL and pPCL had isotropic yield strains. Overall, PPCs of all modifications had elastic moduli of 3.79±0.90 MPa and 0.46±0.21 MPa in the parallel and perpendicular directions, respectively. Valvular interstitial cells seeded atop anisotropic aPCL displayed an actin distribution aligned in the direction of the underlying fibers. The resulting scaffold combines the biocompatibility and tunable fabrication of PEG with the strength and anisotropy of ePCL to form a foundation for future engineered valve scaffolds.

Long-term imaging of Caenorhabditis elegans using nanoparticle-mediated immobilization.

One advantage of the nematode Caenorhabditis elegans as a model organism is its suitability for in vivo optical microscopy. Imaging C. elegans often requires animals to be immobilized to avoid movement-related artifacts. Immobilization has been performed by application of anesthetics or by introducing physical constraints using glue or specialized microfluidic devices. Here we present a method for immobilizing C. elegans using polystyrene nanoparticles and agarose pads. Our technique is technically simple, does not expose the worm to toxic substances, and allows recovery of animals. We evaluate the method and show that the polystyrene beads increase friction between the worm and agarose pad. We use our method to quantify calcium transients and long-term regrowth in single neurons following axotomy by a femtosecond laser.

A comparison of the modified Blalock-Taussig shunt with the right ventricle-to-pulmonary artery conduit.

BACKGROUND: This study compared the modified Blalock-Taussig (MBT) shunt with the right ventricle-to-pulmonary artery (RVPA) conduit with respect to outcome and PA growth. METHODS: PA growth was assessed in 19 MBT patients and in 15 RVPA patients before stage 2 palliation for hypoplastic left heart syndrome. The RVPA was done with a ringed Gore-Tex tube (W. L. Gore and Assoc, Flagstaff, AZ) at each anastomosis. RESULTS: The two cohorts had similar pre-Glenn demographic and hemodynamic data. No patient required transcatheter or surgical intervention on the shunt or PAs after stage 1 palliation. The branch PA growth was better in RVPA (McGoon ratio: MBT, 1.5±0.2 vs RVPA, 2.0±0.6; p<0.003) and was significantly more balanced (right-to-left PA area ratio: MBT, 1.5±0.5 vs RVPA, 0.9±0.6; p=0.002). The Nakata index trended higher in RVPA (MBT, 242A±90 mm2/m2 vs RVPA, 267±95 mm2/m2, p=0.2). After stage 2 palliation, oxygen saturation trended higher in the RVPA (81%±5%) vs MBT cohort (77%±8%, p<0.08). CONCLUSIONS: The Norwood operation using a RVPA nonvalved conduit is associated with improved branch PA growth.