The McGivney hemorrhoidal ligator (MHL), a band designed to cause tissue necrosis, is the preferred experimental tool to create hindlimb ischemia-reperfusion (I/R) injury in rodents. This report defines and compares the ex vivo band tension exerted by MHL and orthodontic rubber bands (ORBs) along with select in vivo characteristics of I/R. As to method, ex vivo band tension was measured over relevant diameters using a tensiometer. In vivo assessment of murine limb perfusion during ischemia with ORB and MHL was compared using laser Doppler imaging and measurement of wet weight-to-dry weight ratio. Neuromuscular scoring and histological extent of muscle fiber injury after I/R with MHL and ORB were also compared. A dose-response curve, between the duration of ORB-induced I/R with both mitochondrial activity (methyl-thiazol-tetrazolium) or tail perfusion [laser Doppler imaging (LDI)], was generated. As a results, ex vivo measurements showed that ORB exerted significantly less force than the MHL. Despite less tension in ORB, in vivo testing of the ORB confirmed complete ischemia by both LDI and wet weight-to-dry weight ratio. After I/R, caused by ORB, there was significantly less neuromuscular dysfunction. Histological assessment confirmed similar degrees of muscle fiber injury after I/R with either the MHL or ORB. Increasing durations of ischemia created by the ORB followed by reperfusion significantly decreased mitochondrial activity and tail perfusion after 24 h of ischemia. In conclusions, ORB produced similar levels of tissue ischemia in murine models of limb I/R with fewer levels of nonspecific injury. ORB may be the preferred model for selected studies of limb I/R.

Polyadenosine diphosphate-ribose polymerase (PARP) has been implicated as a mediator of inflammation and tissue necrosis in murine models of human stroke and myocardial infarction. This study was designed to determine whether PARP modulates skeletal muscle injury and cytokine-growth factor levels during ischemia-reperfusion.

This device is the first to incorporate a microfluidics network in the systemic circulatory system. The microvascular network supported viability and function of liver cells in a short-term ex vivo model. Parenchymal chamber pressure generated in an arteriovenous shunt model is a critical parameter that affects viability and must be considered in future designs. The microfluidics-based vascular network is a promising platform for generating a large-scale medical device capable of augmenting liver function in a clinical setting.

With the rise in prevalence of obesity, most general surgeons will have to face the problem of the obese patient with an abdominal wall defect. Treatment of these bariatric patients raises unique challenges, and at this time there is still no consensus on the best treatment option. This study was performed in a high-volume bariatric and minimally invasive surgery center at a tertiary care facility in the USA. Twenty-eight morbidly obese patients treated at our facility between 2003 and 2008 were separated into four groups according to anatomic features and symptoms. Patients with the following characteristics were classified as having a favorable anatomy: body mass index not exceeding 50 kg/m(2), gynecoid body habitus, reducible hernias found in a central location, abdominal wall thickness less than 4 cm, and the defect's largest diameter not exceeding 8 cm. All other patients were classified as having an unfavorable anatomy. In this study, we report a systematic treatment approach for the morbidly obese patient presenting with a ventral hernia based on whether the hernia is symptomatic or asymptomatic, as well as the distinct characteristics of the hernia and body habitus features. We followed up on these patients postoperatively for at least 2 years, with a mean follow-up period of 30 months. Only a total of three hernia recurrences were observed. Successful treatment of ventral hernias in morbidly obese patients should be individualized based on the patient's symptoms and defined hernia characteristics.

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