We evaluated the accuracy of modern infrared photosensors (IPs) from a photoplethysmography (PPG) machine as flow detector in determining the systolic arterial pressures and ankle/brachial indices (ABIs) in comparison to the traditional continuous wave Doppler (Doppler) method. Pressures were obtained by placing an appropriate pneumatic cuff above the elbow and ankle. The Doppler probe was placed at brachial artery, posterior tibial artery and dorsalis pedis artery, and the IP was placed on the pad of the index finger and great toe. The two techniques were compared in 181 limbs in our non-invasive vascular laboratory, 133 limbs with normal and 48 limbs with abnormal ABIs. The accuracy of absolute ankle pressure measurements was also compared by both methods. We found that IPs from PPG machine have a good correlation (linear regression r=0.96 for normal and r=0.95 for abnormal ankle pressures) with the Doppler method. There was no significant difference (P< or =0.0001) in the ABIs calculated by two methods in either normal or abnormal subjects. The PPG method was easier, quicker and automated as compared with the cumbersome Doppler method. While PPG method does not differentiate between occlusive disease of posterior tibial and anterior tibial/dorsalis pedis arteries, it is better suited for non-compliant patients and is superior to Doppler method in advanced occlusive arterial disease. We recommend that it be used on a routine basis.
Objective:
FTY720, an immunomodulator derived from sphingosine-1-phosphate, has recently demonstrated its immunomodulatory, anti-inflammatory, anti-oxidant, anti-apoptotic and anti-inflammatory properties. Furthermore, FTY720 might be a key pharmacological target for preconditioning. In this preclinical model, we have investigated the effects of FTY720 on myocardium during reperfusion in an experimental model of cardioplegic arrest (CPA) and cardiopulmonary bypass.
Methods:
30 Sprague–Dawley rats (300–350 g) were randomized into two groups: Group-A, treated with FTY720 1 mg/kg
via
intravenous cannulation, and Group-B, as control. After 15 min of treatment, rats underwent CPA for 30 min followed by initiation of extracorporeal life support for 2 h. Support weaning was done, and blood and myocardial tissues were collected for analysis. Hemodynamic parameters, inflammatory mediators, nitro-oxidative stress, neutrophil infiltration, immunoblotting analysis, and immunohistochemical staining were analyzed and compared between groups.
Results:
FTY720 treatment activated the Akt/Erk1/2 signaling pathways, reduced the level of inflammatory mediators, activated antiapoptotic proteins, and inhibited proapoptotic proteins, leading to reduced nitro-oxidative stress and cardiomyocyte apoptosis. Moreover, significant preservation of high-energy phosphates were observed in the FTY720-treated group. This resulted in improved recovery of left ventricular systolic and diastolic functions.
Conclusion:
The cardioprotective mechanism in CPA is associated with activation of prosurvival cell signaling pathways that prevents myocardial damage. FTY720 preserves high-energy phosphates attenuates myocardial inflammation and oxidative stress, and improves cardiac function.
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