Assessing the Utility of Toe Arm Index and Toe Pressure in Predicting Wound Healing in Patients Undergoing Vascular Intervention.

BACKGROUND: Objective measures of perfusion such as an ankle-brachial index (ABI) and toe pressure remain important in prognosticating wound healing. However, the use of ABI is limited in patients with incompressible vessels and toe pressure may not be comparable across patients. While a toe arm index (TAI) may be of value in this setting, its role as clinical indicator of perfusion for healing in patients with lower-extremity wounds has not been well established. METHODS: A retrospective review was performed of all vascular patients with lower-extremity wounds that underwent peripheral vascular intervention between 2014-2019. Data regarding patient demographics, comorbidities, TAI, ABI, toe pressures, and the wound, ischemia, and foot infection (WIfI) score were collected. Associations between patient variables and wound healing at various time points were evaluated. RESULTS: A total of 173 patients (67.7 ± 10.9 years; 71.1% male) were identified with lower-extremity wounds. Most patients underwent endovascular intervention (77.5%). Patients were followed for a median of 416 (IQR 129-900) days. Mean postoperative TAI was 0.35 ± 0.19 and mean WIfI score was 2.60 ± 1.17. Nine percent (15) of patients healed within 1 month, 44.8% (69) healed within 6 months, and 65.5% (97) healed within 1 year of revascularization without need for major amputation. Those that healed within 1 year without any major amputation did not differ from those that did not heal based on age, gender, race, comorbidities, periprocedural medications, or procedures performed. However, patients that healed without major amputation had a higher postoperative TAI (0.38 vs. 0.30, P = 0.02), higher toe pressure (53 vs. 40 mm Hg, P = 0.004), and lower WIfI score (2.26 vs. 3.12, P < 0.001). Patients that healed with 1 year without requiring any amputation had similar associations with postoperative TAI, toe pressure, and WIfI. Additionally, they were more likely to be White (P = 0.019) and have an open surgical procedure (P < 0.001) and less likely to have chronic kidney disease (P = 0.001) or diabetes (P = 0.008). A Youden index was calculated and identified a TAI value of 0.30 that optimized sensitivity and specificity for wound healing. The area under the curve for TAI as a predictor of wound healing was 0.62. CONCLUSIONS: Higher postoperative TAI is associated with higher odds of wound healing without need for major amputation. Toe arm index is therefore a useful tool to identify patients with adequate arterial perfusion to heal lower-extremity wounds. However, the area under the curve is poor for TAI when used as a sole predictor of wound healing potential suggesting that TAI should be one of multiple factors to considered when prognosticating wound healing potential.

Cyclophosphamide-induced apoptosis in COV434 human granulosa cells involves oxidative stress and glutathione depletion.

The anticancer drug cyclophosphamide induces granulosa cell apoptosis and is detoxified by glutathione (GSH) conjugation. We previously showed that both cyclophosphamide treatment and GSH depletion induced granulosa cell apoptosis in rats, but the role of GSH in apoptosis in human ovarian cells has not been studied. Using the COV434 human granulosa cell line, we tested the hypotheses that (1) GSH depletion or treatment with 4-hydroperoxycyclophosphamide (4HC), a preactivated form of cyclophosphamide, induces apoptosis, (2) GSH depletion potentiates 4HC-induced apoptosis, and (3) 4HC-induced apoptosis is mediated by GSH depletion and oxidative stress. Cells were treated with buthionine sulfoximine (BSO), a specific inhibitor of GSH synthesis, with or without follicle stimulating hormone (FSH) or serum. A significant increase in the number of apoptotic cells, assessed by terminal deoxynucleotidyl transferase-mediated deoxy-uridine triphosphate nick-end labeling (TUNEL) and Hoechst 33342 staining, occurred with BSO treatment. Treatment with 4HC dose-dependently induced apoptosis by TUNEL, Hoechst staining, and caspase 3 activation. Treatment with 4HC caused an increase in reactive oxygen species generation, measured by dichlorofluorescein fluorescence, oxidative DNA damage, measured by 8-hydroxyguanosine immunostaining, and an oxidation of the redox potential for the oxidized glutathione/reduced glutathione couple. Total intracellular GSH declined after 4HC treatment, preceding the onset of cell death. Treatment with antioxidants inhibited 4HC-induced apoptosis. Combined treatment with BSO and 4HC caused greater induction of apoptosis than either treatment alone. These findings are consistent with roles for oxidative stress and GSH depletion in mediating the induction of apoptosis in COV434 cells by cyclophosphamide.