Ultrasound technology as a tool to teach basic concepts of physiology and anatomy in undergraduate and graduate courses: a systematic review.

Many publications describe use of ultrasound imaging in teaching on clinical courses, primarily integrated with clinical applications. More recently there has been increasing numbers of papers describing ultrasound as a tool primarily for teaching basic anatomy and physiology concepts, rather than clinical applications. Of these, many described qualitative analysis with a consensus that its use was viewed very positively by students for aiding learning. Far fewer studies have attempted quantitative analysis to support this belief, and conclusions have been varied. A review of studies was conducted which included those that used ultrasound to teach physiology and anatomy concepts. Studies were excluded if they did not contain quantitative or qualitative assessment of efficacy. Medline and Embase databases were searched (16/11/22) and screened by two independent reviewers. Forty-six studies were included, with data extracted relating to cohort characteristics, ultrasound intervention, quantitative or qualitative assessments and any barriers to implementation. It was confirmed that both student and teacher opinions are extremely favourable in most cases. Although conclusions from quantitative studies were not as clear, there was evidence that ultrasound is at least as effective as more conventional teaching methods and could have significantly better performances in short-term assessments. However, varied methods of teaching intervention, experimental protocols and assessment of learning may have contributed to the lack of clarity. Within this context, some of the problems encountered with implementing ultrasound as an educational tool (such as financial and temporal constraints), and in conducting more definitive studies, are discussed.

Antibiotic use and risk of Clostridioides difficile infection in patients with inflammatory bowel disease.

BACKGROUND AND AIM: Patients with inflammatory bowel disease (IBD) have an increased risk of Clostridioides difficile infection (CDI) compared with those without IBD, which is worsened with antibiotic usage. While prior studies have shown a correlation between CDI development and certain classes of antibiotics, the IBD population has not been well represented. This study evaluates the rates of CDI with outpatient antibiotic use in patients with IBD. METHODS: We conducted a retrospective cohort study composed of patients with IBD and compared the incidence of CDI in patients who received an outpatient prescription for antibiotics (6694 patients) against those without prescriptions (6025 patients) from 2014 to 2020 at our institution. We compared CDI rates based on nine antibiotic classes: penicillins, cephalosporins, sulfonamides, tetracyclines, macrolides, quinolones, clindamycin, metronidazole, and nitrofurantoin. RESULTS: The risk of CDI was low (0.7%) but significantly higher for those with antibiotic exposure (0.9% vs 0.5%, P = 0.005) and had a positive correlation with a smoking history. The increased risk of CDI in the IBD population was attributable to the clindamycin and metronidazole classes (odds ratio = 4.7, 95% confidence interval: 1.9-11.9, P = 0.001; odds ratio = 3.6, 95% confidence interval: 2.1-6.2, P < 0.0001, respectively). CONCLUSIONS: The use of clindamycin or metronidazole prescribed in an outpatient setting was associated with a statistically significant increased risk of CDI in patients with IBD. Although the association between clindamycin and CDI is a well-established and common finding, the association between metronidazole and CDI is unique in this study.

Design, Construction, and Test of Compact, Distributed-Charge, X-Band Accelerator Systems that Enable Image-Guided, VHEE FLASH Radiotherapy.

The design and optimization of laser-Compton x-ray systems based on compact distributed charge accelerator structures can enable micron-scale imaging of disease and the concomitant production of beams of Very High Energy Electrons (VHEEs) capable of producing FLASH-relevant dose rates. The physics of laser-Compton x-ray scattering ensures that the scattered x-rays follow exactly the trajectory of the incident electrons, thus providing a route to image-guided, VHEE FLASH radiotherapy. The keys to a compact architecture capable of producing both laser-Compton x-rays and VHEEs are the use of X-band RF accelerator structures which have been demonstrated to operate with over 100 MeV/m acceleration gradients. The operation of these structures in a distributed charge mode in which each radiofrequency (RF) cycle of the drive RF pulse is filled with a low-charge, high-brightness electron bunch is enabled by the illumination of a high-brightness photogun with a train of UV laser pulses synchronized to the frequency of the underlying accelerator system. The UV pulse trains are created by a patented pulse synthesis approach which utilizes the RF clock of the accelerator to phase and amplitude modulate a narrow band continuous wave (CW) seed laser. In this way it is possible to produce up to 10 µA of average beam current from the accelerator. Such high current from a compact accelerator enables production of sufficient x-rays via laser-Compton scattering for clinical imaging and does so from a machine of "clinical" footprint. At the same time, the production of 1000 or greater individual micro-bunches per RF pulse enables > 10 nC of charge to be produced in a macrobunch of < 100 ns. The design, construction, and test of the 100-MeV class prototype system in Irvine, CA is also presented.

A change in cis-regulatory logic underlying obligate versus facultative muscle multinucleation in chordates.

Vertebrates and tunicates are sister groups that share a common fusogenic factor, Myomaker (Mymk), that drives myoblast fusion and muscle multinucleation. Yet they are divergent in when and where they express Mymk. In vertebrates, all developing skeletal muscles express Mymk and are obligately multinucleated. In tunicates, Mymk is expressed only in post-metamorphic multinucleated muscles, but is absent from mononucleated larval muscles. In this study, we demonstrate that cis-regulatory sequence differences in the promoter region of Mymk underlie the different spatiotemporal patterns of its transcriptional activation in tunicates and vertebrates. Although in vertebrates myogenic regulatory factors (MRFs) such as MyoD1 alone are required and sufficient for Mymk transcription in all skeletal muscles, we show that transcription of Mymk in post-metamorphic muscles of the tunicate Ciona requires the combinatorial activity of MRF, MyoD and Early B-cell Factor (Ebf). This macroevolutionary difference appears to be encoded in cis, likely due to the presence of a putative Ebf-binding site adjacent to predicted MRF binding sites in the Ciona Mymk promoter. We further discuss how Mymk and myoblast fusion might have been regulated in the last common ancestor of tunicates and vertebrates, for which we propose two models.

Virtual Pooled Registry-Cancer Linkage System: an improved method for ascertaining cancer diagnoses.

BACKGROUND: The National Cancer Institute funds many large cohort studies that rely on self-reported cancer data requiring medical record validation. This is labor intensive, costly, and prone to underreporting or misreporting of cancer and disparity-related differential response. US population-based central cancer registries identify incident cancer within their catchment area, yielding all malignant neoplasms and benign brain and central nervous system tumors with standardized data fields. This manuscript describes the development, implementation, and features of a system to facilitate linkage between cohort studies and cancer registries and the release of cancer registry data for matched cohort participants. METHODS: The Virtual Pooled Registry-Cancer Linkage System (VPR-CLS) provides an online system to link cohorts with multiple state cancer registries by 1) securely transmitting a study file to registries, 2) providing an optimized linkage algorithm to generate preliminary match counts, and 3) providing a streamlined process and templated forms for submitting and tracking data requests for cohort participants who matched with registries. RESULTS: In 2022, the VPR-CLS launched with 45 registries, covering 95% of the US state populations and Puerto Rico. Registries have linked with 15 studies having 14 273-10.9 million participants. Except in 1 study, linkage sensitivity ranged from 87.0% to 99.9%. Numerous registries have adopted the VPR-CLS templated institutional review board-registry application (n = 39), templated data use agreement (n = 25), and central institutional review board (n = 16). CONCLUSIONS: The VPR-CLS markedly improves ascertainment of cancer outcomes and is the preferred approach for determination of outcomes from cohort studies, postmarketing surveillance, and clinical trials.

Automation of customizable library preparation for next-generation sequencing into an open microfluidic platform.

Next-generation sequencing (NGS) is becoming more relevant for medical diagnostics, especially for using cell-free DNA to monitor response to therapy in cancer management, as high sensitivity of NGS enables detection of rare events. Sequencing Library preparation is a time-consuming and complex process, and large-scale liquid handlers are often used for automation. However, for smaller labs and low-to-medium throughput samples, these liquid handlers are expensive and need experts for handling. This work presents a proof-of-concept for library preparation on a commercially available and open lab-on-a-chip platform, which provides an alternative automation for low-to-medium throughput requirements. It covers common library preparation steps optimized to a microfluidic environment that include customizable PCR for target enrichment, end-repair, adapter ligation, nucleic acid purification via magnetic beads, and an integrated quantification step. The functionality of the cartridge is demonstrated with reference cfDNA containing different allelic frequencies of seven known mutations. Processing the samples in the cartridge reveals highly comparable results to manual processing (Pearson r = 0.94) based on amplicon sequencing. Summarized, the proposed automated lab-on-a-chip workflow for customizable library preparation could further pave the way for NGS to evolve from a technology used for research purposes to one that is applied in routine cancer management.

Ultrasensitive Dual ELONA/SERS-RPA Multiplex Diagnosis of Antimicrobial Resistance.

Antimicrobial resistance (AMR) is a significant global health threat concern, necessitating healthcare practitioners to accurately prescribe the most effective antimicrobial agents with correct doses to combat resistant infections. This is necessary to improve the therapeutic outcomes for patients and prevent further increase in AMR. Consequently, there is an urgent need to implement rapid and sensitive clinical diagnostic methods to identify resistant pathogenic strains and monitor the efficacy of antimicrobials. In this study, we report a novel proof-of-concept magnetic scaffold-recombinase polymerase amplification (RPA) technique, coupled with an enzyme-linked oligonucleotide assay (ELONA) and surface-enhanced Raman scattering (SERS) detection, aimed at selectively amplifying and detecting the DNA signature of three resistant carbapenemase genes, VIM, KPC, and IMP. To achieve this, streptavidin-coated magnetic beads were functionalized with biotin-modified forward primers. RPA was conducted on the surface of the beads, resulting in an immobilized duplex amplicon featuring a single overhang tail specific to each gene. These tails were subsequently hybridized with recognition HRP probes conjugated to a complementary single-stranded oligonucleotide and detected colorimetrically. Additionally, they underwent hybridization with similar selective SERS probes and were measured using a handheld Raman spectrometer. The resulting quantification limits were at subpicomolar level for both assays, allowing the potential for early diagnosis. Moreover, we demonstrated the platform capability to conduct a multiplex RPA-SERS detection of the three genes in a single tube. Compared to similar approaches like PCR, RPA offers advantages of speed, affordability, and isothermal operation at 37 °C, eliminating the need for a thermal cycler. The whole assay was completed within <2 h. Therefore, this novel magnetic scaffold ELONA/SERS-RPA platform, for DNA detection, demonstrated excellent capability for the rapid monitoring of AMR in point-of-care applications, in terms of sensitivity, portability, and speed of analysis.

Investigation of [11C]carfentanil for mu opioid receptor quantification in the rat brain.

[11C]Carfentanil ([11C]CFN) is the only selective carbon-11 labeled radiotracer currently available for positron emission tomography (PET) imaging of mu opioid receptors (MORs). Though used extensively in clinical research, [11C]CFN has not been thoroughly characterized as a tool for preclinical PET imaging. As we were occasionally observing severe vital sign instability in rat [11C]CFN studies, we set out to investigate physiological effects of CFN mass and to explore its influence on MOR quantification. In anesthetized rats (n = 15), significant dose-dependent PCO2 increases and heart rate decreases were observed at a conventional tracer dose range (IV, > 100 ng/kg). Next, we conducted baseline and retest [11C]CFN PET scans over a wide range of molar activities. Baseline [11C]CFN PET studies (n = 27) found that nondisplaceable binding potential (BPND) in the thalamus was positively correlated to CFN injected mass, demonstrating increase of MOR availability at higher injected CFN mass. Consistently, when CFN injected mass was constrained < 40 ng/kg (~ 10% MOR occupancy in rats), baseline MOR availability was significantly decreased. For test-retest variability (TRTV), better reproducibility was achieved by controlling CFN injected mass to limit the difference between scans. Taken together, we report significant cardiorespiratory depression and a paradoxical influence on baseline MOR availability at conventional tracer doses in rats. Our findings might reflect changes in cerebral blood flow, changes in receptor affinity, or receptor internalization, and merits further mechanistic investigation. In conclusion, rat [11C]CFN PET requires stringent quality assurance of radiotracer synthesis and mass injected to avoid pharmacological effects and limit potential influences on MOR quantification and reproducibility.

Global longitudinal active strain energy density (GLASED): age and sex differences between young and veteran athletes.

BACKGROUND: Global longitudinal active strain energy density (GLASED) is an innovative method for assessing myocardial function and quantifies the work performed per unit volume of the left ventricular myocardium. The GLASED, measured using MRI, is the best prognostic marker currently available. This study aimed to evaluate the feasibility of measuring the GLASED using echocardiography and to investigate potential differences in the GLASED among athletes based on age and sex. METHODS: An echocardiographic study was conducted with male controls, male and female young athletes, and male and female veteran athletes. GLASED was calculated from the myocardial stress and strain. RESULTS: The mean age (in years) of the young athletes was 21.6 for males and 21.4 for females, while the mean age of the veteran athletes was 53.5 for males and 54.2 for females. GLASED was found to be highest in young male athletes (2.40 kJ/m3) and lowest in female veterans (1.96 kJ/m3). Veteran males exhibited lower values (1.96 kJ/m3) than young male athletes did (P < 0.001). Young females demonstrated greater GLASED (2.28 kJ/m3) than did veteran females (P < 0.01). However, no significant difference in the GLASED was observed between male and female veterans. CONCLUSION: Our findings demonstrated the feasibility of measuring GLASED using echocardiography. GLASED values were greater in young male athletes than in female athletes and decreased with age, suggesting possible physiological differences in their myocardium. The sex-related differences observed in GLASED values among young athletes were no longer present in veteran athletes. We postulate that measuring the GLASED may serve as a useful additional screening tool for cardiac diseases in athletes, particularly for those with borderline phenotypes of hypertrophic and dilated cardiomyopathies.

Surgical Nonresponders in Zenker Diverticulum and Lower Esophageal Pathology (POUCH Collaborative).

OBJECTIVE: To identify characteristics of patients who have poor improvement in symptoms following surgical management of Zenker Diverticulum (ZD). METHODS: Prospective, multicenter cohort study of all individuals enrolled in the Prospective OUtcomes of Cricopharyngeus Hypertonicity (POUCH) Collaborative who underwent surgical repair of ZD between August 2017 and January 2024. Patient demographics, esophagrams, and the 10-item Eating Assessment Tool (EAT-10) pre- and post-procedure were obtained from a REDCap database. t-tests, Wilcoxon rank sum tests, Chi-square or Fisher's exact tests were used to compare the characteristics. Patients with <50% improvement in their EAT-10 scores were deemed surgical nonresponders (SNRs). Those with ≥50% improvement in their EAT-10 scores were deemed surgical responders (SRs). RESULTS: A total of 184 patients were prospectively followed after undergoing either open or endoscopic surgical management. Twenty-two patients (12%) were deemed SNRs. Preoperative presence of a hiatal hernia was statistically significant characteristic between the SNRs (63.6%) and SRs (32.1%) (p = 0.004). Size of the ZD and history of previous ZD surgery was not a significant characteristic. The length of stay and complication rate were not statistically different between the groups. CONCLUSION: Coexistent esophageal pathology may lead to poor symptomatic improvement following ZD surgery. Preoperative workup of other esophageal disorders is recommended to detect likely SNRs. For SNRs, further esophageal workup may be necessary to evaluate for other esophageal causes related to poor symptomatic improvement following ZD surgery. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 2024.

Subscapularis Management With Biologic Augmentation in Anatomic Total Shoulder Arthroplasty.

Subscapularis insufficiency continues to be a source of morbidity after anatomic total shoulder arthroplasty (TSA). Biologic augmentation following rotator cuff repair has shown promising results. Here we show the technique for performing subscapularis repair after anatomic TSA using a "peel-tenotomy" and bone marrow aspirate concentrate (BMAC). A standard deltopectoral approach is performed. The peel-tenotomy is performed by leaving 0 to 10 mm of subscapularis attached to the lesser tuberosity and peeling off the remainder of the tendon. A trocar is used to aspirate bone marrow from the humeral head, which is then processed. Prior to placing the humeral stem, drill holes are placed at the bicipital groove and lesser tuberosity. Sutures are placed through each drill hole. After impacting the humeral stem, suture is passed through the subscapularis to perform a secure double row repair. Prior to tying the sutures, BMAC is applied along the margins of the subscapularis repair. After securing the sutures, additional BMAC can be applied to the subscapularis repair. It is hypothesized that this technique could provide a more robust subscapularis repair and decrease the rate of subscapularis insufficiency after TSA without any known risk or morbidity to the patient, although further research is needed to show this.

Multi-institutional beta testing of a novel cervical esophagogastric anastomosis simulator.

Objective: A novel simulator developed to offer hands-on practice for the stapled side-to-side cervical esophagogastric anastomosis was tested previously in a single-center study that supported its value in surgical education. This multi-institutional trial was undertaken to evaluate validity evidence from 6 independent thoracic surgery residency programs. Methods: After a virtual session for simulation leaders, learners viewed a narrated video of the procedure and then alternated as surgeon or first assistant. Using an online survey, perceived value was measured across fidelity domains: physical attributes, realism of materials, realism of experience, value, and relevance. Objective assessment included time, number of sutures tearing, bubble test, and direct inspection. Comparison across programs was performed using the Kruskal-Wallis test. Results: Surveys were completed by 63 participants as surgeons (17 junior and 20 senior residents, 18 fellows, and 8 faculty). For 3 of 5 tasks, mean ratings of 4.35 to 4.44 correlated with "somewhat easy" to "very easy" to perform. The interrupted outer layer of the anastomosis rated lowest, suggesting this task was the most difficult. The simulator was rated as a highly valuable training tool. For the objective measurements of performance, "direct inspection" rated highest followed by "time." A total of 90.5% of participants rated the simulator as ready for use with only minor improvements. Conclusions: Results from this multi-institutional study suggest the cervical esophagogastric anastomosis simulator is a useful adjunct for training and assessment. Further research is needed to determine its value in assessing competence for independent operating and associations between improved measured performance and clinical outcomes.

Photochemical Mechanisms in Atmospherically Relevant Iodine Oxide Clusters.

Atmospheric new particle formation events can be driven by iodine oxides or oxoacids via both neutral and ionic mechanisms. Photolysis of new particles likely plays a significant role in their growth mechanisms, but their spectra and photolysis mechanisms remain difficult to characterize. We recorded ultraviolet (UV) photodissociation spectra of (I2O5)0-3(IO3-) clusters, observing loss of an O atom, I2O4, and (I2O5)1,2 in the atmospherically relevant range of 300-340 nm. With increasing cluster size, the intensity of absorption red shifts and generally increases, suggesting particles photolyze more frequently as they grow. Estimates of the rates indicate that even relatively small clusters are likely to undergo photolysis under high-UV conditions. Vibrational spectra identify the covalent moiety I3O8- as the likely chromophore, not IO3-. The I2O5 loss pathway competes with particle growth, while the slower O loss pathway likely produces 3O + 3(cluster) products that could drive subsequent intraparticle chemistry, particularly with co-adsorbed organic or amine species.

Close outpatient follow-up associated with reduced readmission rates in patients with inflammatory bowel disease.

Background: Few studies have shown the effects of prompt outpatient follow-up in relation to reducing readmission rates in patients hospitalized with inflammatory bowel disease (IBD). Our study evaluated whether postdischarge follow-up was associated with fewer IBD-related readmissions. Methods: This single-center retrospective study included 477 patients with Crohn's disease (CD) or ulcerative colitis (UC) who were readmitted to our tertiary care hospital from January 1, 2016, to June 1, 2022. Rehospitalization admissions were defined as admissions that occurred within 90 days after discharge date. We used a chi-square or Fisher's exact test to test for bivariate comparisons to determine if there was an association in patients readmitted for IBD and primary care or gastroenterology follow-up at 1, 2, 3, and 4 weeks versus no follow-up. Results: In UC patients, there were 118 admissions from 2016 to 2022; 36/118 (31%) and 41/118 (34.7%) of the patients were readmitted at 30 days and 90 days, respectively. In the CD group, there were 101 (36.73%) readmissions among 277 patients, with 174 nonreadmissions (63.27%). Conclusions: Gastroenterology follow-up within 1 month was associated with reduced rates of admission in both groups (P < 0.05). This study highlights the importance of close gastroenterology follow-up for IBD-related hospitalizations.

Specification and survival of post-metamorphic branchiomeric neurons in a non-vertebrate chordate.

Tunicates are the sister group to the vertebrates, yet most species have a life cycle split between swimming larva and sedentary adult phases. During metamorphosis, larval neurons are replaced by adult-specific ones. The regulatory mechanisms underlying this replacement remain largely unknown. Using tissue-specific CRISPR/Cas9-mediated mutagenesis in the tunicate Ciona, we show that orthologs of conserved hindbrain and branchiomeric neuron regulatory factors Pax2/5/8 and Phox2 are required to specify the 'neck', a cellular compartment set aside in the larva to give rise to cranial motor neuron-like neurons post-metamorphosis. Using bulk and single-cell RNA-sequencing analyses, we characterize the transcriptome of the neck downstream of Pax2/5/8. We present evidence that neck-derived adult ciliomotor neurons begin to differentiate in the larva and persist through metamorphosis, contrary to the assumption that the adult nervous system is formed after settlement and the death of larval neurons during metamorphosis. Finally, we show that FGF signaling during the larval phase alters the patterning of the neck and its derivatives. Suppression of FGF converts neck cells into larval neurons that fail to survive metamorphosis, whereas prolonged FGF signaling promotes an adult neural stem cell-like fate.

A single-center, assessor-blinded, randomized controlled clinical trial to test the safety and efficacy of a novel brain-computer interface controlled functional electrical stimulation (BCI-FES) intervention for gait rehabilitation in the chronic stroke population.

BACKGROUND: In the United States, there are over seven million stroke survivors, with many facing gait impairments due to foot drop. This restricts their community ambulation and hinders functional independence, leading to several long-term health complications. Despite the best available physical therapy, gait function is incompletely recovered, and this occurs mainly during the acute phase post-stroke. Therapeutic options are limited currently. Novel therapies based on neurobiological principles have the potential to lead to long-term functional improvements. The Brain-Computer Interface (BCI) controlled Functional Electrical Stimulation (FES) system is one such strategy. It is based on Hebbian principles and has shown promise in early feasibility studies. The current study describes the BCI-FES clinical trial, which examines the safety and efficacy of this system, compared to conventional physical therapy (PT), to improve gait velocity for those with chronic gait impairment post-stroke. The trial also aims to find other secondary factors that may impact or accompany these improvements and establish the potential of Hebbian-based rehabilitation therapies. METHODS: This Phase II clinical trial is a two-arm, randomized, controlled, longitudinal study with 66 stroke participants in the chronic (> 6 months) stage of gait impairment. The participants undergo either BCI-FES paired with PT or dose-matched PT sessions (three times weekly for four weeks). The primary outcome is gait velocity (10-meter walk test), and secondary outcomes include gait endurance, range of motion, strength, sensation, quality of life, and neurophysiological biomarkers. These measures are acquired longitudinally. DISCUSSION: BCI-FES holds promise for gait velocity improvements in stroke patients. This clinical trial will evaluate the safety and efficacy of BCI-FES therapy when compared to dose-matched conventional therapy. The success of this trial will inform the potential utility of a Phase III efficacy trial. TRIAL REGISTRATION: The trial was registered as "BCI-FES Therapy for Stroke Rehabilitation" on February 19, 2020, at clinicaltrials.gov with the identifier NCT04279067.

Population Percentage and Population Size of Men Who Have Sex With Men in the United States, 2017-2021: Meta-Analysis of 5 Population-Based Surveys.

BACKGROUND: Male-to-male sexual transmission continues to account for the greatest proportion of new HIV diagnoses in the United States. However, calculating population-specific surveillance metrics for HIV and other sexually transmitted infections requires regularly updated estimates of the number and proportion of men who have sex with men (MSM) in the United States, which are not collected by census surveys. OBJECTIVE: The purpose of this analysis was to estimate the number and percentage of MSM in the United States from population-based surveys. METHODS: We used data from 5 population-based surveys to calculate weighted estimates of the proportion of MSM in the United States and pooled these estimates using meta-analytic procedures. We estimated the proportion of MSM using sexual behavior-based questions (encompassing anal or oral sex) for 3 recall periods-past 12 months, past 5 years, and lifetime. In addition, we estimated the proportion of MSM using self-reported identity and attraction survey responses. The total number of MSM and non-MSM in the United States were calculated from estimates of the percentage of MSM who reported sex with another man in the past 12 months. RESULTS: The percentage of MSM varied by recall period: 3.3% (95% CI 1.7%-4.9%) indicated sex with another male in the past 12 months, 4.7% (95% CI 0.0%-33.8%) in the past 5 years, and 6.2% (95% CI 2.9%-9.5%) in their lifetime. There were comparable percentages of men who identified as gay or bisexual (3.4%, 95% CI 2.2%-4.6%) or who indicated that they are attracted to other men (4.9%, 95% CI 3.1%-6.7%) based on pooled estimates. Our estimate of the total number of MSM in the United States is 4,230,000 (95% CI 2,179,000-6,281,000) based on the history of recent sexual behavior (sex with another man in the past 12 months). CONCLUSIONS: We calculated the pooled percentage and number of MSM in the United States from a meta-analysis of population-based surveys collected from 2017 to 2021. These estimates update and expand upon those derived from the Centers for Disease Control and Prevention in 2012 by including estimates of the percentage of MSM based on sexual identity and sexual attraction. The percentage and number of MSM in the United States is an important indicator for calculating population-specific disease rates and eligibility for preventive interventions such as pre-exposure prophylaxis.

Fragment-Based Discovery of a Series of Allosteric-Binding Site Modulators of ß-Glucocerebrosidase.

ß-Glucocerebrosidase (GBA/GCase) mutations leading to misfolded protein cause Gaucher's disease and are a major genetic risk factor for Parkinson's disease and dementia with Lewy bodies. The identification of small molecule pharmacological chaperones that can stabilize the misfolded protein and increase delivery of degradation-prone mutant GCase to the lysosome is a strategy under active investigation. Here, we describe the first use of fragment-based drug discovery (FBDD) to identify pharmacological chaperones of GCase. The fragment hits were identified by using X-ray crystallography and biophysical techniques. This work led to the discovery of a series of compounds that bind GCase with nM potency and positively modulate GCase activity in cells.

Giant Ulcerated Colonic Lipoma in an Asymptomatic Patient.

Colonic lipomas are benign masses typically found incidentally during routine screening exams. They rarely grow large enough to become symptomatic. While most colonic lipomas are small and do not lead to complications, giant lipomas can present with symptoms ranging from changes in bowel patterns and mild abdominal pain to bowel obstruction. Ulcerated giant colonic lipomas are even more rare findings on screening colonoscopies. Diagnosis in this context can be challenging, and resection is warranted in most cases. Here, we describe an asymptomatic patient who presented for a screening colonoscopy and was found to have a giant ulcerated colonic lipoma.