Effect of superoxide dismutase plus catalase on Ca2+ transport in ischemic and reperfused skeletal muscle.

Cytotoxic oxygen metabolites may contribute to skeletal muscle damage associated with ischemia and reperfusion. This study utilized a rat hindlimb ischemia model to investigate the effect of pretreatment with oxygen free radical scavengers superoxide dismutase (SOD) and catalase (CAT) on skeletal muscle Ca2+ uptake by sarcoplasmic reticulum (SR) in limbs subjected to periods of ischemia and reperfusion. SOD and CAT were conjugated to polyethylene glycol to prolong their half lives.

The role of endorphins and vasopressin in canine endotoxin shock.

Chemical antagonists were used to assess the role of beta-endorphin and arginine-vasopressin (AVP) in canine endotoxin shock. Fifteen awake dogs were given Escherichia coli endotoxin IV. Within 5 min, CO decreased to 28%, LV dP/dt to 46%, and MAP to 52% baseline.

Prostacyclin treatment of ischemic ulcers and rest pain in unreconstructible peripheral arterial occlusive disease.

The efficacy of prostacyclin (PGI2) treatment was assessed in 26 patients with surgically unreconstructible atherosclerotic arterial occlusive disease of the lower extremity manifested by nonhealing ulcers and rest pain. Patients were randomized to receive a 72-hour intravenous infusion of PGI2 (6 ng/kg/min, n = 13) or placebo (n = 13). Ulcer size was measured by photographic planimetry, and rest pain was graded by blinded objective scoring at monthly intervals for 6 months.

Effect of prolonged intra-arterial prostaglandin E1 infusion on canine arterial graft patency.

This study examined the effect of long-term intra-arterial prostaglandin (PG) E1 infusion on the patency of canine femoral-artery grafts made of polytetrafluoroethylene and measuring 4 X 90 mm (diameter X length). An infusion catheter was placed proximal to one of the bilateral femoral-artery grafts and connected to a subcutaneously implanted infusion pump to continuously infuse PGE1 (1 ng/kg/min) in seven experimental dogs and vehicle alone in seven control dogs. Two-week graft patency was significantly higher in both infused (86%) and noninfused (100%) limbs of PGE1-treated dogs than in control dogs (29%).

Effect of thromboxane synthetase inhibition on canine autogenous vein grafts.

This study examined the effect of an orally active thromboxane (TXA2) synthetase inhibitor (TSI) on the patency, TXA2 production, and platelet accumulation of reversed autogenous vein grafts. Ten dogs received TSI (U-63557A) 10 mg/kg po q8 hr for 6 weeks, beginning 24 hr prior to surgery, while 15 control dogs were untreated. One jugular vein was harvested and stored in 37 degrees C saline for 1 hr to induce mild endothelial injury (stored).

Adrenergic and dopaminergic control of the canine paw microcirculation.

Basal isolated canine paw blood flow was equally distributed between arteriovenous anastomosis (AVA) and capillary circulations. Norepinephrine decreased AVA flow by 92% and capillary flow by 41%. Dopamine significantly reduced AVA flow by 94% compared to baseline with a 37% reduction in capillary flow.

Actuarial analysis of variables associated with rupture of small abdominal aortic aneurysms.

This study identified risk factors associated with rupture of small abdominal aortic aneurysms in patients initially selected for nonoperative management. Sixty-seven patients, 53 men and 14 women, 50 to 91 years of age (mean 72 years) were followed 3 to 99 months (mean 36 months). All patients underwent serial aortic ultrasonography.

Celiac artery aneurysms: historic (1745-1949) versus contemporary (1950-1984) differences in etiology and clinical importance.

Celiac artery aneurysms were encountered in nine patients, ranging in age from 39 to 76 years, at the University of Michigan Medical Center between 1961 and 1983. Developmental defects and atherosclerosis were etiologic factors in six cases. Four patients were without symptoms, whereas five experienced abdominal pain, including one with a ruptured aneurysm.

Nonpenetrating subclavian artery injuries.

Nonpenetrating subclavian artery trauma, a potentially catastrophic injury, has been recognized more frequently with the liberal use of angiography in evaluating blunt cervicothoracic trauma. Six patients, five men and one woman, recently underwent surgical treatment at the University of Michigan Hospital for blunt injury of the subclavian artery. The diagnoses were established by arteriography.

Effect of intravenous glucagon on the survival of rats after acute occlusive mesenteric ischemia.

The purpose of this study was to determine the optimal timing of intravenous glucagon infusion for the treatment of acute occlusive mesenteric ischemia. The superior mesenteric artery (SMA) was occluded for 85 min in 106 Sprague-Dawley anesthetized rats. The animals were divided into 12 treatment groups according to the timing of glucagon and saline administration, and survival was measured to 48 hr.

Brachiocephalic arterial occlusions and stenoses. Manifestations and management of complex lesions.

Complex stenotic and occlusive lesions involving multiple brachiocephalic arteries were encountered in 17 symptomatic patients, 25 to 76 years of age. Symptoms included hemispheric transient ischemic attacks (16), visual symptoms (ten), global cerebral ischemia (11), true syncope (six), upper extremity ischemic symptoms (eight), and frank tissue loss (one). Of 68 brachiocephalic arteries, 53 exhibited hemodynamically significant stenoses, including 21 that were totally occluded.

Reoperation for complications of renal artery reconstructive surgery undertaken for treatment of renovascular hypertension.

Seventy-two secondary operations for complications of prior renal artery reconstructive surgery were undertaken in 58 patients. This experience evolved from the management of 373 patients who underwent 425 primary operations for renovascular hypertension. Secondary operations were performed 10 times in pediatric patients following 42 primary procedures (24%); 44 times in adult fibrodysplastic patients following 199 initial operations (22%); and 18 times in atherosclerotic patients after 184 primary operations (10%).

Effects of glucagon and prostacyclin in acute occlusive and postocclusive canine mesenteric ischemia.

Effects of glucagon and prostacyclin (PGI2) were studied in anesthetized dogs during sequential occlusive and postocclusive mesenteric ischemia induced by 90 min of tourniquet stenosis of the superior mesenteric artery (SMA). After 30 min of SMA stenosis, glucagon (1 microgram/kg/min, n = 7), PGI2 (30 ng/kg/min, n = 7), or saline (1 ml/min, n = 3) was infused intravenously for 30 min, followed by 30 min of continued ischemia. SMA flow and distal SMA pressure ( SMAP ) decreased 76% with SMA stenosis (P less than 0.

Atherosclerotic extracranial carotid artery aneurysms.

Twenty-four atherosclerotic extracranial carotid artery aneurysms were encountered in 21 patients during a 25-year period. These represented 46% of all extracranial carotid artery aneurysms diagnosed at the University of Michigan during this period. Neurologic symptoms including amaurosis fugax, transient ischemic attacks, and stroke were present in 50% of the patients.

Pharmacologic interventions in acute mesenteric ischemia: improved survival with intravenous glucagon, methylprednisolone, and prostacyclin.

An experimental model of acute mesenteric ischemia following 85 minutes of superior mesenteric artery (SMA) occlusion in male Wistar rats was used in this investigation. Untreated control animals had a 48-hour survival rate of 38% (n = 26), whereas sham laparotomy resulted in a 100% 48-hour survival rate (n = 10). Study groups received intravenous infusions of normal saline solution (16.

Intermittent claudication. Current results of nonoperative management.

We reviewed the clinical course of 91 men with mild intermittent claudication who had been followed up for at least six months without operation. During 2.5 years' mean follow-up, 60% of the patients had more severe claudication.

Interaction of hindlimb blood flow, A-V shunting and A-V oxygen difference.

The interactions of blood flow, A-V O2 difference (AVDO2), and A-V shunting were measured in normal hindlimbs of nine anesthetized dogs. An aorto-iliac nonpulsatile perfusion pump was used to change femoral artery blood flow from zero (collateral flow only) to twice its baseline level. Femoral AVDO2 was measured by in-line spectrophotometric O2 analysis.

Early derangements of arteriovenous anastomotic and capillary blood flow in the canine hindlimb induced by supplemental pentobarbital anesthesia.

Vasoactive effects of supplemental pentobarbital anesthesia in the canine hindlimb microcirculation were documented in two groups of animals previously anesthetized with 30 mg/kg pentobarbital: Group I with a 5 mg/kg intravenous (iv) bolus of pentobarbital (n = 8) and Group II with a 5 mg/kg 2-min iv infusion of pentobarbital (n = 7). In Group I, measurements at baseline (BL) and 5, 15, 20, and 30 min (min) following pentobarbital administration included cardiac output, mean arterial pressure, total peripheral vascular resistance, common femoral artery flow (CFAQ) and resistance (CFAR), percentage hindlimb arteriovenous anastomotic shunt (AVA%), absolute shunt flow (AVAQ), and hindlimb nutrient capillary flow (NCQ). In Group II these same measurements were made, but the study was continued until all hindlimb hemodynamic parameters returned to control values.

Aorto-iliac reconstruction with Dacron double velour.

Dacron double velour grafts were evaluated in an animal preparation and utilized in 318 patients undergoing elective aortic reconstruction for aneurysmal and occlusive disease. Dacron double velour forms an adherent inner lining, preclots easily, is soft, pliable and easy to handle and suture. Clinical studies revealed excellent patency with a low incidence of prosthesis related complications.

ABO blood group and serum lipids in female atherosclerosis.

Seventy-three women requiring aortoiliac reconstruction for atherosclerotic occlusive disease were reviewed to determine the frequency of blood groups, lipid status and associated cardiovascular risk factors. These women demonstrated an increased frequency of blood group A (48% versus 36% control, p less than .01), which is comparable to published data for their male counterparts.

Arteriographic measurement of the abdominal aorta, iliac, and femoral arteries in women with atherosclerotic occlusive disease.

Arteriographic measurements were made in 73 consecutive women undergoing arterial reconstruction for aorto-iliac occlusive disease. The anatomical distribution of atherosclerosis was unaffected by arterial size. Women with isolated aorto-iliac atherosclerosis had the same size arteries as those with concomitant outflow disease.

Limb-threatening potential of arteriosclerotic popliteal artery aneurysms.

Eighty-eight popliteal artery aneurysms were diagnosed in 59 men and two women (mean age 67 +/- 10 years). Bilateral aneurysms affected 27 patients (44%). Aneurysm diameter ranged from 1.

The effect of sympathetic innervation on canine muscle and skin blood flow.

Two microsphere techniques were used to measure skin and muscle capillary blood flow, plus blood flow through arteriovenous anastomoses (AVAs), before and after unilateral lumbar sympathectomy in 12 anesthetized dogs. Sympathectomy did not alter capillary flow to tibial muscle, thigh, or lower leg skin, whereas paw skin capillary flow decreased, from 28 to 13 mL/min/100 g. However, total extremity blood flow increased after sympathectomy, because of the rate of AVA flow, which increased from 7 to 30 mL/min.