The Buford Complex Redefined: A Pathologic Morphology in Sheep's Clothing.

Background: Considered a normal anatomic variant, the Buford complex has not been studied in children. Hypothesis: A Buford complex is not a normal anatomic variant and would, therefore, be present at a lower rate than that seen in the adult population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Measurements were recorded from magnetic resonance imaging performed over 13 years in children aged ≤11 years for various pathologies unrelated to glenohumeral instability. Interrater reliability was determined to identify Buford complexes, sublabral foramens and tears, and normal shoulders via 16 preadolescent and adolescent patients with confirmed arthroscopic correlation. The Buford complex and labral foramen rates were then compared with a published rate in adults using a binomial probability test. Results: A total of 122 children (62 girls; mean age, 6.4 years [age range, 2 months-10.9 years]) were evaluated. Interrater reliability was 0.846 (95% CI, 0.56-1) to identify anterosuperior labral variants. The expected sublabral foramen count was 23 children, but only 1 was identified (P < .001). The expected Buford complex count was 8 children, but none could be identified (P < .001). Conclusion: The absence of Buford complexes and the significant reduction in sublabral foramen abundance in younger children suggest that these anatomic variants are more likely to be developmental than congenital. The distinct possibility that these previously considered normal variants are truly pathologic findings cannot be ignored. Evidence of a Buford complex could potentially signify an underlying, long-term shoulder instability issue to the treating provider that warrants further investigation or management.

Identification and characterization of alternative sites and molecular probes for SARS-CoV-2 target proteins.

Three protein targets from SARS-CoV-2, the viral pathogen that causes COVID-19, are studied: the main protease, the 2'-O-RNA methyltransferase, and the nucleocapsid (N) protein. For the main protease, the nucleophilicity of the catalytic cysteine C145 is enabled by coupling to three histidine residues, H163 and H164 and catalytic dyad partner H41. These electrostatic couplings enable significant population of the deprotonated state of C145. For the RNA methyltransferase, the catalytic lysine K6968 that serves as a Brønsted base has significant population of its deprotonated state via strong coupling with K6844 and Y6845. For the main protease, Partial Order Optimum Likelihood (POOL) predicts two clusters of biochemically active residues; one includes the catalytic H41 and C145 and neighboring residues. The other surrounds a second pocket adjacent to the catalytic site and includes S1 residues F140, L141, H163, E166, and H172 and also S2 residue D187. This secondary recognition site could serve as an alternative target for the design of molecular probes. From in silico screening of library compounds, ligands with predicted affinity for the secondary site are reported. For the NSP16-NSP10 complex that comprises the RNA methyltransferase, three different sites are predicted. One is the catalytic core at the conserved K-D-K-E motif that includes catalytic residues D6928, K6968, and E7001 plus K6844. The second site surrounds the catalytic core and consists of Y6845, C6849, I6866, H6867, F6868, V6894, D6895, D6897, I6926, S6927, Y6930, and K6935. The third is located at the heterodimer interface. Ligands predicted to have high affinity for the first or second sites are reported. Three sites are also predicted for the nucleocapsid protein. This work uncovers key interactions that contribute to the function of the three viral proteins and also suggests alternative sites for ligand design.

Cardiac Arrest After Interscalene Block Before Arthroscopic Shoulder Surgery: A Case Report.

CASE: A 42-year-old previously healthy woman developed profound hypotension, bradycardia, and asystolic cardiac arrest requiring cardiopulmonary resuscitation after an interscalene block before being placed in the beach-chair position for shoulder arthroscopy. CONCLUSION: Activation of the Bezold-Jarisch reflex, a vagally mediated reflex leading to hypotensive bradycardic episodes, is a rare but devastating complication of shoulder arthroscopy when performed with the combination of interscalene blocks and the beach-chair position. Our case shows that the Bezold-Jarisch reflex may occur in patients before placement in the beach-chair position and may even lead to extreme reactions in healthy patients including asystolic cardiac arrest.

A rare presentation of sexsomnia in a military service member.

NONE: Sexsomnias are unconscious sexual behaviors during sleep (parasomnias) that are garnering more attention as they become increasingly evident in forensic cases. Presentations of sexsomnia in active duty service members are seldom described, and often evaluation is clouded by intoxication with substances such as alcohol, sleep deprivation, untreated sleep disturbances, or criminal behavior masquerading as a medical disorder. We present a case of a 40-year-old male soldier evaluated in our sleep clinic for multiple episodes of sleep masturbation occurring over a period of 2 years. The patient was concerned about his suitability for deployment to a combat zone and participation in field training exercises (both require sleeping in groups in an open environment). Video polysomnography confirmed moderate obstructive sleep apnea, and the patient showed improvement with continuous positive airway pressure therapy. The authors also discuss the relevance of this case compared with previously reported sexsomnia cases and expand on parasomnia topics that are more common in military populations.