Intestine submucosa and polypropylene mesh for abdominal wall repair in dogs.

Continuing investigations of abdominal body wall reconstruction materials suggest that unacceptable implant complications continue and that the ideal material has not yet been found. This pilot study compared xenogeneic (porcine) small intestine submucosa (SIS) with polypropylene mesh (PPM) for repair of created partial-thickness (six dogs) and full-thickness (six dogs) abdominal wall defects. Postoperative clinical evaluation of all dogs showed no evidence of implant failure.

The use of xenogeneic small intestinal submucosa as a biomaterial for Achilles tendon repair in a dog model.

A study was conducted to evaluate the tissue response to a xenogeneic biomaterial when this material was used to repair an experimentally induced Achilles tendon defect in the dog. Twenty dogs had a 1.5 cm segmental defect of the Achilles tendon created surgically which was then repaired with acellular connective tissue derived from porcine small intestinal submucosa (SIS).

Experimental evaluation of small intestinal submucosa as a microvascular graft material.

The evaluation of porcine small intestine submucosa (SIS) in a microsurgical model was conducted using an interpositional graft in the rat femoral artery. The SIS grafts were fabricated from processed porcine material that was wrapped around a glass tube and oversewn longitudinally to produce a tubular structure. Of the 42 animals studied, 7 received grafts of untreated SIS (group I), 7 of the grafts were presoaked (PSH) in heparin (Group II), 7 animals were treated with systemic heparin prior to implantation of PSH-SIS (group III), 7 animals received SIS grafts crosslinked to heparin (group IV), 7 animals received SIS grafts crosslinked to urokinase (group V), and 7 animals received untreated autologous epigastric vein grafts (group VI).

Differential expression of muscle regulatory factor genes in normal and denervated adult rat hindlimb muscles.

Skeletal muscle represents an excellent model system in which to examine regulatory mechanisms that modulate gene expression in the mature adult organism. Individual muscle fibers can be categorized as fast- or slow-twitch based upon several physiological and molecular criteria, including metabolic enzyme activity and contractile protein isoforms. Each property can be influenced by a variety of factors such as changes in motor neuron activity or alterations in hormone levels, although the molecular pathways by which environmental factors affect gene expression remain largely unknown.

Enhancement of the thrombolytic efficacy of prourokinase by lys-plasminogen in a dog model of arterial thrombosis.

Current findings suggest that the efficacy of thrombolytic therapy may be limited by the availability of active forms of plasminogen at the thrombus site. The purpose of this study was to determine if the systemic administration of 0.5 mg kg-1 glu-plasminogen (glu-plg) or 0.

The beneficial effect of lys-plasminogen upon the thrombolytic efficacy of urokinase in a dog model of peripheral arterial thrombosis.

The efficacy of thrombolytic therapy may be limited by local availability of plasminogen near a poorly perfused thrombus. The purpose of this study was to determine if the local (i.e.

The protective effect of heparin in a dog model of rethrombosis following pharmacologic thrombolysis.

Rethrombosis is an important clinical problem for patients who have benefitted from pharmacologic thrombolysis. The present study describes a dog model of arterial thrombosis, which includes endothelial denudation, intimal damage, and stenosis, and is suitable for studying the phenomena of both thrombolysis and subsequent rethrombosis. The model was used to determine the effect of tissue-type plasminogen activator (t-PA), high and low dose heparin, and saline upon the incidence of rethrombosis after t-PA-induced thrombolysis.

Simple electrical model of the circulation to explore design parameters for a skeletal muscle ventricle.

To efficiently investigate a variety of designs for an accessory skeletal muscle ventricle for circulatory assistance, we developed an electrical model of the human circulatory system. Heart and blood vessels were modeled as resistive-capacitive networks, pressures as voltages, blood flow as electric current, and the cardiac valves as diodes. Pumping of blood was simulated by the application of damped rectangular voltage pulses to the capacitances of the cardiac ventricles and the skeletal muscle ventricle.

Bolus dose response characteristics of single chain urokinase plasminogen activator and tissue plasminogen activator in a dog model of arterial thrombosis.

Tissue plasminogen activator (t-PA) and single chain urokinase-plasminogen activator (scu-PA) are relatively "fibrin-specific" thrombolytic drugs with short plasma half lives of 6-8 minutes. Most treatment regimens with these agents utilize a bolus injection followed by continuous drug infusion, usually combined with anticoagulant therapy. The purpose of this study was to establish the dose-response characteristics for scu-PA and t-PA, when given as a single intravenous bolus injection, in a dog model of arterial thrombosis.