Reported Events Associated With Spine Robots: An Analysis of the Food and Drug Administration's Manufacturer and User Facility Device Experience Database.

STUDY DESIGN: Cross-Sectional Analysis. OBJECTIVES: To summarize medical device reports (MDRs) between August 1, 2017 and November 30, 2021 relating to robot-assisted spine systems within the Manufacturer and User Facility Device Experience (MAUDE) database maintained by The Food and Drug Administration (FDA). METHODS: The MAUDE database was abstract for all MDRs relating to each FDA-approved robot-assisted spine system. Event descriptions were reviewed and characterized into specific event types. Outcome measures include specific robot-assisted spine systems and reported events as detailed by the MDRs. All data is de-identified and in compliance with the Health Insurance Portability and Accountability Act (HIPAA). RESULTS: There were 263 MDRs consisting of 265 reported events. Misplaced screws represented 61.5% (n = 163) of reported events. Of the 163 reported events, 57.1% (n = 93) described greater than 1 misplaced screw, 15.3% (n = 25) required return to the operating room, 8.6% (n = 14) resulted in neurologic injury, 4.3% (n = 7) resulted in dural tear, and 1.2% (n = 2) resulted in hemorrhage or bleeding. Reported events other than misplaced screws included system imprecision detected prior to screw placement (58/265, 21.9%), mechanical failure (23/265, 8.7%), and software failure (18/265, 6.8%). CONCLUSIONS: As more robot-assisted spine systems gain FDA approval and the adoption of these systems continues to grow, documenting and understanding the range of reported events associated with each "tool" is imperative to balancing patient safety with surgical innovation. This study of the MAUDE database provides a unique summary of reported events associated with robot-assisted spine systems that is not directly linked to a research setting.

CD44 v5 domain inhibition represses the polarization of Th2 cells by interfering with the IL-4/IL-4R signaling pathway.

The balance between T helper type 1 (Th1) and T helper type 2 (Th2) cells is critical for both innate and acquired immune reactions. However, the precise mechanisms of T helper-cell differentiation remain unclear. As an important T-cell activation molecule, CD44 participates in the differentiation of Th1 and Th2 cells. We demonstrated that CD44 variant exon v5 (CD44 v5) is highly expressed by induced human Th2 cells. To investigate the role of the CD44 v5 domain in Th2 cell differentiation, we treated human CD4+ T cells with anti-CD44v5 antibody and observed that the levels of phosphorylated STAT6 and GATA3 and the secretion of interleukin-4 (IL-4) were significantly decreased after the treatment. We also further found that the inhibition of Th2 differentiation was caused by the degradation of the alpha chain of IL-4 receptor (IL-4Rα), the CD44 v5 domain colocalized with IL-4Rα on cell surface and the degradation of IL-4Rα increased after CD44 v5 domain blocking or ablating. Our results indicated that CD44v5 antibody treatment interrupted the interaction between CD44 v5 domain and IL-4Rα, but the CD44 v5 domain blockage would not spoil the colocalization between IL-4R expression and T-cell receptor and the immunological synapse formation; similar results were also found in CD44v5-deficient CD4+ T cells. In conclusion, we revealed the function of the CD44 v5 domain in Th2 cell differentiation; blocking or ablating the CD44 v5 domain could accelerate IL-4Rα degradation and then induce the Th2 cell inhibition.

Cisplatin-Mediated Upregulation of APE2 Binding to MYH9 Provokes Mitochondrial Fragmentation and Acute Kidney Injury.

Cisplatin chemotherapy is standard care for many cancers but is toxic to the kidneys. How this toxicity occurs is uncertain. In this study, we identified apurinic/apyrimidinic endonuclease 2 (APE2) as a critical molecule upregulated in the proximal tubule cells (PTC) following cisplatin-induced nuclear DNA and mitochondrial DNA damage in cisplatin-treated C57B6J mice. The APE2 transgenic mouse phenotype recapitulated the pathophysiological features of C-AKI (acute kidney injury, AKI) in the absence of cisplatin treatment. APE2 pulldown-MS analysis revealed that APE2 binds myosin heavy-Chain 9 (MYH9) protein in mitochondria after cisplatin treatment. Human MYH9-related disorder is caused by mutations in MYH9 that eventually lead to nephritis, macrothrombocytopenia, and deafness, a constellation of symptoms similar to the toxicity profile of cisplatin. Moreover, cisplatin-induced C-AKI was attenuated in APE2-knockout mice. Taken together, these findings suggest that cisplatin promotes AKI development by upregulating APE2, which leads to subsequent MYH9 dysfunction in PTC mitochondria due to an unrelated role of APE2 in DNA damage repair. This postulated mechanism and the availability of an engineered transgenic mouse model based on the mechanism of C-AKI provides an opportunity to identify novel targets for prophylactic treatment of this serious disease. SIGNIFICANCE: These results reveal and highlight an unexpected role of APE2 via its interaction with MYH9 and suggest that APE2 has the potential to prevent acute kidney injury in patients with cisplatin-treated cancer. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/3/713/F1.large.jpg.

Extensor Carpi Ulnaris Tendon Anatomy May Mimic Tears.

Background: Asymptomatic, incidental extensor carpi ulnaris (ECU) tendon abnormalities are frequently noted on imaging studies of the wrist. The aim of this investigation was to determine if variations in gross tendon anatomy existed that could possibly account for these findings on MRI and ultrasound (US) imaging. Methods: The upper extremities of eleven (6 male and 5 female) formalin preserved cadavers were dissected and examined under loupe magnification with attention to the dorsal-ulnar wrist and hand and the ECU tendon. The tendons were inspected for anatomic variations, degenerative changes, and any other pathologies. The presence of intra-tendinous splits arising within the ECU tendon was noted and measured. The distances of the splits from the distal tendon insertion and the edge of the extensor retinaculum were recorded. Statistical correlations between age and the tendon splits were considered using R-squared to assess a linear regression. Results: 17 ECU tendons were dissected and examined, and 5 ECU tendons were excluded due to poor preservation of that upper extremity; all five were right sided upper extremities. Eleven of the 17 specimens demonstrated at least one split in the distal tendon: Seven had 1 split, 1 had 2 splits, and 3 had 3 splits. The mean length of the tendon split was 3.52 cm. The mean distance of the distal edge of the split to the tendon insertion site was 2.4 cm. A linear regression was calculated and showed no correlation between age and number of tendon splits. Conclusions: 64% of specimens showed a longitudinal split in the distal ECU tendon. The location of these frequent splits corresponds to imaging abnormalities on MRI and US in prior studies.

A clinically relevant in vivo zebrafish model of human multiple myeloma to study preclinical therapeutic efficacy.

Patient-derived multiple myeloma (MM) cells are difficult to establish in culture or propagate in vivo in murine model. Here, we describe a zebrafish xenograft model that permits rapid, reliable growth of human MM cells injected into the perivitelline space of albino zebrafish (Casper) embryos 48 hours postfertilization. MM1S and MM1R MM cell lines and primary CD138(+) MM cells were stained with CM-Dil red fluorescent dye and suspended in Matrigel prior to their injection. The cells grew at the site of injection and disseminated throughout the developing embryos and larvae. Tumor size was quantified by fluorescent microscopy, and cell fate was followed for 4 days. All of the cell line xenografts showed responses similar to those previously observed with in vitro assays. CD138(+) plasma cell xenografts derived from MM patients also grew and were inhibited by the same drugs patients had responded to clinically. Using this technique, we can assess drug sensitivity or resistance with a small number of MM cells in a short period. This raises the possibility that one might be able to assess drug sensitivity in real time with readily obtainable clinical samples.