威廉·比蒙医院

Therapeutic ultrasound (US) holds promise as a potential therapy to treat articular cartilage; however, optimized and targeted US protocols are lacking. This study aimed at determining an appropriate set of US protocols for stimulating human chondrocyte activity. Human chondrocytes were exposed to various US parameters, including different central frequencies, power densities, operation modes, pulse parameters, and durations, either daily or every other day over a three-day period. Temperature was monitored during stimulation. Protocols that showed the greatest potential for increasing chondrocyte metabolic activity and proliferation were further investigated and extended to a seven-day application. Cartilage matrix synthesis was analyzed by immunocytochemistry, qPCR, and glycosaminoglycans staining. Chondrocytes exposed to 250 mW/cm2 at 1.25 MHz (continuous or pulsed, every other day), 0.45 MHz (pulsed, daily), or 2.00 MHz (pulsed, every other day) exhibited significantly higher proliferation and metabolic activity. Immunocytochemistry analyses revealed that those protocols markedly increased COL II expression by up to 2.7-fold and aggrecan up to 1.7-fold compared to non-stimulated chondrocytes. Collagen type II and aggrecan mRNA levels were elevated by up to 2.0-fold and 4.5-fold, respectively. No significant effect on glycosaminoglycan production was detected. US stimulation also played an important role in counteracting chondrocyte phenotype loss, reducing collagen type I protein and mRNA expression by up to 68% and 90%, respectively, compared to untreated chondrocytes. Temperature remained stable during US stimulation. The US protocol 250 mW/cm2 at 2.00 MHz (pulsed, 1 Hz, 50% duty cycle) for 20 min, every other day, appears to be the most effective protocol for eliciting cartilage components synthesis and decelerating the dedifferentiation process in chondrocytes and, thus, it should be further explored to regenerate articular cartilage.

621 Background: Neoadjuvant outcomes are variable in human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (EBC), highlighting the unmet need for predictive biomarkers. The BluePrint (BP) assay classifies tumors by molecular intrinsic subtype, whereas the ImPrint hormone receptor-positive (HR+) and ImPrint triple-negative genomic signatures predicted immune sensitivity in the ISPY2 trial. Because HER2+ EBCs are genomically heterogeneous, and because anti-HER2 has an immunologic mechanism of action, we hypothesized that BP and ImPrint could be used to predict outcomes (pathologic complete response, pCR) following neoadjuvant chemotherapy + anti-HER2 (trastuzumab + pertuzumab, HP). Methods: We evaluated n=252 HER2+ EBCs receiving neoadjuvant chemotherapy + HP in the prospective, observational FLEX study. Tumors were classified by BP subtype (HER2, Luminal A/B, or Basal) and ImPrint (+ or -). Fisher’s exact test was used to compare pCR rates across BP/ImPrint results. Multivariable logistic regression was used to evaluate independent associations with pCR, adjusting for nodal status and tumor size. Results: 72% of HER2+ EBCs were HR+ and 28% were HR–. In HR+/HER2+ EBC, 52% were classified by BP as non-HER2 (Luminal A 6%, Luminal B 44%, Basal 2%), whereas in HR-/HER2+ EBC, 14% were classified genomically as non-HER2, all of which were Basal. In the HR+/HER2+ subgroup, pCR rates differed significantly by BP subtype and ImPrint, with the highest pCR observed in BP-HER2/ImPrint+ tumors (Table). Similar significant differences were observed in HR-/HER2+ EBC. In a multivariable model of the HR+/HER2+ subgroup, BP and ImPrint independently predicted pCR after controlling for node status and tumor size (BP-HER2 odds ratio/OR: 8.23 [95% CI: 3.47–21.44]; p<0.001; ImPrint+ OR: 4.48 [95% CI: 1.48–14.89]; p<0.05). Conclusions: An integrated genomic approach that combines BP and ImPrint maximizes prediction of pCR outcome in this dataset, particularly for the HR+/HER2+ subgroup. Further evaluation is warranted, as these data could be useful for guiding clinical decision-making, including selection of chemotherapy backbone and adjuvant therapy. Importantly, this approach may help identify patients who are overtreated or undertreated with current strategies, including those with exceptional treatment sensitivity who may be candidates for chemotherapy de-escalation. Clinical trial information: NCT03053193 . pCR rates by genomic subtypes within HR+/HER2– EBC (Fisher’s exact test). Biomarker Subtype* N pCR rate (%) p-value BluePrint HER2 87 55 < 0.001 Luminal B 80 20 ImPrint Positive 30 60 0.006 Negative 151 32 BluePrint + ImPrint HER2, ImPrint+ 14 79 < 0.001 HER2, ImPrint- 73 51 Luminal B, ImPrint+ 14 43 Luminal B, ImPrint- 66 15 *Excluded Luminal A and Basal due to small N.

Abstract Background Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune astrocytopathy targeting aquaporin-4 (AQP4) water channels. While optic neuritis and longitudinally extensive transverse myelitis are classical, hypothalamic and brainstem lesions can trigger severe autonomic dysfunction. Cardiac arrhythmias and arrest are exceedingly rare but life-threatening manifestations. Case A 74-year-old woman with a history of coiled posterior cerebral artery aneurysm, cerebrovascular disease, rectal cancer (status post resection/chemoradiation with ileostomy), discoid lupus, chronic bicytopenia, and heart failure with preserved ejection fraction presented with altered mentation, weakness, and recurrent falls after multiple prior hospitalizations for similar episodes. On arrival, she was hypothermic (33 °C), bradycardic (HR 40 bpm), and hypotensive (BP 94/65 mmHg), prompting empiric management for sepsis.MRI brain revealed progressive T2/FLAIR hyperintensities in the bilateral globus pallidus and thalamus with stable pontine changes. Serum AQP4-IgG titer exceeded 10,000, confirming NMOSD; ANA, RNP, and SSA were positive. MRI spine was negative for demyelination. She received IV methylprednisolone (5 days) followed by 7 sessions of plasmapheresis. Despite transient improvement, she developed recurrent bradycardia, hypotension, and gastrointestinal dysmotility consistent with global dysautonomia. Echocardiogram showed EF 60% with mild-to-moderate aortic insufficiency and mid-LV cavity obstruction.Serial EKGs demonstrated progressive PR-interval prolongation (254 → 332 ms), evolving from sinus bradycardia with first-degree AV block to junctional bradycardia and complete heart block. Electrophysiology consultation and pacing were deferred. On hospital day 28, she was found unresponsive with glucose 54 mg/dL. Following dextrose administration, she developed apnea, severe bradycardia, and pulseless arrest. Return of spontaneous circulation was achieved after four CPR cycles, but post-arrest imaging revealed anoxic brain injury. Telemetry showed ectopic atrial and junctional escape rhythms, Mobitz I, and third-degree AV block. She was transitioned to comfort care and expired. Discussion Only three cases of sinus arrest in NMOSD have been reported—all with medullary lesions and recovery after corticosteroids (Ryouhei 2020; Endo 2020; Lin 2023). Our patient uniquely demonstrated fatal autonomic failure without medullary involvement, highlighting systemic rather than focal dysautonomia. Progressive conduction disease despite immunotherapy underscores a possible immune-mediated nodal dysfunction and supports earlier pacing consideration. Conclusion NMOSD can precipitate catastrophic autonomic dysregulation and cardiac arrest even in the absence of medullary lesions. Early recognition of dysautonomia and proactive electrophysiologic evaluation may be lifesaving. Multidisciplinary awareness is essential to prevent this under-recognized “fatal face” of NMOSD. This abstract is funded by: None