Canine blood mononuclear cells mediate contact-dependent impairment of granulocyte-macrophage colony formation by bone marrow cells.

Nonphagocytic, nonadherent mononuclear cells from canine peripheral blood (PBMC) were shown to suppress colony formation in agar of autologous and allogeneic bone marrow granulocyte-macrophage progenitor cells (CFU-GM). Suppression required previous cell-to-cell contact in liquid culture between PBMC and bone marrow cells (BMC) and was time- and dose-dependent and resistant to x-irradiation with 20 Gy. Small BMC were less susceptible than large BMC, whereas day-7 and day-14 CFU-GM were equally suppressed. Cryo-preservation of BMC did not enhance CFU-GM inhibition. Spontaneous inactivation during liquid culture of CFU-GM or accessory cells by PBMC is the likely effector mechanism. Possible recognition structures are different from dog leukocyte antigens A and B. Canine PBMC or subpopulations thereof might participate in the regulation of normal hemopoiesis and in the rejection of hemopoietic stem cell grafts by natural killer cell-like mechanisms as has been suggested for human and murine natural killer cells.

Canine neonatally induced coarctation hypertension in the second year. Variably hyperresponsive plasma renin activity.

In canine neonatally-induced coarctation hypertension, we reported abnormally elevated plasma renin activity (PRA) during sodium restriction in 2-year-old dogs, but found normal PRA responses to sodium restriction +/- furosemide in coarcted dogs studied serially over the first year postaortic banding (PAB). To resolve this apparent discrepancy in PRA response, longitudinal studies were extended to 2 years PAB. In two separately-studied groups, each with three coarcted and three littermate controls, measurements of indirect forelimb blood pressure (BP) at 15 to 18 months, direct brachial arterial BP at 24 months, and serial measurement of PRA and extracellular volume (ECV, as 24Na space) were made over a 15- to 24-month age range during three sodium-volume levels: ad libitum sodium intake (NS), low-sodium diet alone (LS), and low-sodium plus Lasix (LS/Lasix). While PRA in coarcted dogs of both groups was comparable to controls at NS and LS, PRA in Group 1 coarcted dogs significantly exceeded that of littermates during LS/Lasix in both 18- and 24-month studies. In contrast, PRA in Group 2 coarcted dogs was not hyperresponsive to LS/Lasix as compared to simultaneously-studied littermates. The hyperresponsive PRA in Group 1 coarcted dogs could not be attributed to larger absolute or relative ECV deficits. Overall, ECV in coarcted dogs of each group was higher on the average but was not statistically different from controls. Results indicate that the hyperresponsive PRA in this canine model is: 1) a variable feature, developing secondarily in the late established phase; 2) reproducible for a given animal; and 3) not attributed to exaggerated ECV deficits during the LS/Lasix protocol.

The activity of the peroxide-metabolizing system in human colon carcinoma.

The major parameters of the peroxide-metabolizing system were investigated in eight human colon carcinoma excisions and compared with apparently non-neoplastic colon tissue from the same patients. The mean malondialdehyde level as an index of lipid peroxidation was 147 pmol/mg protein in carcinoma compared to 40 pmol/mg in healthy tissue. The following relations of specific activities in carcinoma and healthy tissue were found: superoxide dismutase 3.9 micrograms/mg protein (carcinoma): 2.4 micrograms/mg (healthy), glutathione peroxidase 23 mU/mg:10 mU/mg; GSH-transferase 38 mU/mg:25 mU/mg; catalase 2.3 mK/mg:4.1 mK/mg. The mean selenium concentration in carcinoma was 36 ng/mg protein compared to 24 ng/mg. The difference between carcinoma and normal tissue showed an overall-significance of p < 0.002 for the whole set of data. No significant differences were found in GSH levels (12.6 nmol/mg protein in carcinoma: 9.4 nmol/mg in normal colon), GSSG levels (0.6 nmol/mg:0.7 nmol/mg) and in the protein content (70 +/- 23.5 mg/g wet tissue: 66 +/- 20 mg/g). It is concluded that the enhanced lipid peroxidation in tumor tissue may be due to peroxisomally generated H2O2 in conjunction with a lowered catalase activity.

The clinical significance of Raynaud's syndrome.

This study was performed to determine the frequency of occurrence of associated autoimmune disease in a group of patients presenting with Raynaud's symptoms. A consecutive group of 100 patients presenting with Raynaud's syndrome underwent detailed prospective clinical and immunologic evaluation. Magnificantion hand arteriography was performed in certain patients. Based on current diagnostic criteria, the following autoimmune diseases were diagnosed or were suspected strongly: Raynaud's syndrome with scleroderma or CRST--28 patients; Raynaud's syndrome with lupus erythematosus--ten patients; Raynaud's syndrome with miscellaneous autoimmune disease--43 patients: Raynaud's syndrome without diagnosable autoimmune disease--19 patients. Fourteen of the 19 patients in the latter group had isolated serologic abnormalities. Arteriography showed combined organic arterial obstruction and vasospasm of the palmar and digital arteries in all patients. Patients with severe Raynaud's symptoms had more extensive arterial obstruction than did patients with mild or moderate Raynaud's symptoms. These results suggest that all patients with Raynaud's syndrome should be regarded as at high risk for having an associated autoimmune disease.

Lower-extremity amputations for ischemia.

During the past eight years, we performed 312 lower-extremity amputations for ischemia. Amputation requiring no prosthesis was achieved in 31% of patients, knee joint preservation in 72%, and overall primary amputation healing in 75%. Amputation mortality was 6%. The use of prior arterial reconstruction, careful wound care, and willingness to accept nonhealing of trial amputations were important factors in obtaining the most distal possible healed amputation. An accurate evaluation of the impact of new methods of selecting amputation level and evaluating amputation results can only be achieved by a report of the total institutional amputation experience, not by reports of a single type of amputation.

Precise diagnosis of aortic anastomotic aneurysm by computed tomographic scan.

False aneurysms that involve aortoprosthetic anastomoses may be difficult to diagnose prior to fatal rupture. We report a case in which a false aneurysm that developed six year after aortofemoral-graft insertion was accurately diagnosed by a computed tomographic (CT) scan after both ultrasonography and angiography had failed to make the diagnosis. The ability of CT scanning to demonstrate anastomotic aneurysms and accurately determine the presence of periaortic hemorrhage is discussed.

Extracellular volume expansion and delayed resolution of hypertension after canine aortic coarctectomy.

The hemodynamic changes occurring after surgical correction of thoracic aortic coarctation were studied in two neonatally coarcted dogs at six months of age and compared to sham surgery in two littermate controls. Excision of the tight iatrogenic aortic band with direct aortic reanastomosis abolished pressure gradients. Post-coarctectomy systemic pressure rose, after an early transient fall, to pre-operative proximal levels and was sustained for two to four weeks before decreasing to control normotensive values. Femoral systolic pressure (and renal perfusion pressure) rose by 47-57 mmHg in coarcted dogs (p less than .001). Extracellular volume (ECV) increased in both coarcted animals, peaking 28-32 cc/kg (7.1-7.6% increase) above precoarctectomy levels. Peak ECV expansion coincided with the peak post-coarctectomy blood pressure. Fluid administration, blood losses and plasma renin activity (PRA) were comparable in all animals. Post-coarctectomy tachycardia was also noted in coarcted dogs (p less than .001), whereas neither ECV nor heart rate changes occurred in control animals. We postulate that post-coarctectomy baroreceptor stimulation results in sympathetically-mediated renal sodium retention, not only preventing a pressure diuresis, but resulting in overt volume expansion. Failure of PRA suppression despite increased distal pressure and volume excess may also reflect sympathetic activation. Data are compatible with the view that sympathetic activation and consequent volume expansion transiently sustain hypertension in the post-coarctectomy setting until baroreceptor re-adjustments permit normalization of blood pressure.

Human umbilical cord vein allograft arteriovenous fistula for chemotherapy access.

Seven patients who received chronic chemotherapy and required vascular access underwent construction of an arteriovenous fistula of the leg using gluteraldehyde-tanned human umbilical cord vein allografts. No wound or graft complications have occurred and patient tolerance of the operative procedure and subsequent use of the fisulas for chemotherapy has been excellent. Our preliminary results suggest that the use of umbilical vein allograft arteriovenous fistulas is quite satisfactory for long-term chemotherapy access.

Intra-arterial sympathetic blockade in the treatment of clinical frostbite.

Regional medical sympathectomy achieved by the intra-arterial injection of reserpine appeared to be of benefit in the treatment of five patients with acute or chronic frostbite injuries. Clinical improvement was associated with a significant increase in arteriographically determined regional perfusion.

Arm ischemia secondary to giant cell arteritis.

Six cases of arterial insufficiency of the arm secondary to giant cell arteritis are described, all in elderly white women. The clinical presentation of the occlusive disease ranged from an asymptomatic incidental physical finding to an alarming picture of severe ischemia. All patients were treated with steroids and had subsequent stabilization or improvement of extremity symptoms. Vascular reconstruction was also performed in two patients, one of whom developed rest pain after graft occlusion. Another patient had a cerebral infarction while taking prednisone, despite control of large vessel vasculitis. This study indicates that giant cell arteritis should be considered in cases of occlusive disease of the arms, especially in elderly women. Giant cell arteritis is a seriously morbid and potentially fatal disease which justifies a thorough evaluation when sufficient evidence is present to suggest the diagnosis. The response to steroids is usually adequate to eliminate the need for early surgical intervention.

The role of arteriography in abdominal aortic aneurysm.

The results of arteriography in the management of 100 consecutive patients with abdominal aortic aneurysms are presented. Arteriographic information had substantial influence upon management decisions and performance of surgery in 75 per cent of cases. We found the preoperative knowledge of the precise vascular pathology or anatomic variants not only permitted a more rational recommendation for or against surgery but aided in the selection of the most suitable surgical procedure.

Blood flow in the common femoral artery. Evaluation in a vascular laboratory.

Accurate knowledge of the hemodynamics of the common femoral artery is a critical part of both the preoperative evaluation of patients with peripheral vascular disease and the postoperative follow-up examination. Interrogation of the iliofemoral system with determinations of palpable pulse status, Doppler analog waveforms, and upper thigh pressure ratios has yielded an overall sensitivity of 91 percent and a specificity of 85 percent in the detection of inflow stenosis. This degree of accuracy (89 percent) allows practical surgical decisions to be based on the results of these noninvasive studies.

Treatment of chronic visceral ischemia.

Herein, we have described the surgical management of 23 patients with chronic intestinal ischemia. The patients presented most commonly with postprandial pain and weight loss. Diagnosis was confirmed by angiography, including lateral aortography. Surgery included bypass with Dacron being the most common graft material. As many vessels as possible were revascularized using an infrarenal graft origin. Two patients died postoperatively from acute myocardial infarction. There were two graft failures in this group. At the present time, 19 of the 21 surviving patients are asymptomatic or greatly improved.

Extended profundaplasty. Indications and techniques with results of 46 procedures.

We performed extended profundaplasty 46 times in 36 patients. Twelve procedures were performed for ischemic ulcers, 23 for ischemic rest pain and 10 for short-distance claudication. Fourteen procedures were performed independently, 21 to provide outflow for proximal bypass grafts, and 11 were combined with distal bypass grafts. Four of the 46 procedures failed; the rest have been successful for limb salvage or relief of symptoms at a mean follow-up of 15 months. Technical points emphasized are autogenous patch closure of the entire endarterectomy site and careful attention to end-point detail. The results demonstrate that this procedure provides durable limb revascularization.

Evaluation and management of patients with Raynaud's syndrome.

The wide spectrum of associated disorders, the previous lack of understanding of pathogenesis, and the older, arbitrary terminology in relation to ultimate prognosis have led to confusion in the evaluation and management of Raynaud's syndrome. A unified concept of pathogenesis, in which vasospasm and arterial occlusive disease are the fundamental lesions, is presented herein. The associated disorders found in our 219 patients with continuous follow-up are listed and related to the underlying pathogenetic mechanisms. Our approach to diagnosis led to the discovery of an associated condition in 71 percent of our patients. The evaluation can be done in a cost-effective manner. The emphasis of treatment should be on conservative medical management, with avoidance of cold and tobacco and judicious use of pharmacologic agents remaining the cornerstones of therapy. Cervicothoracic sympathectomy has no role in the treatment of Raynaud's syndrome.

Intraarterial streptokinase infusion for acute popliteal and tibial artery occlusion.

Eight consecutive patients with acute thrombotic or embolic occlusion of the popliteal or tibial artery were treated with low-dose intraarterial streptokinase followed by arterial reconstructive surgery where appropriate. Three patients had acute thrombosis of a popliteal aneurysm with limb-threatening ischemia. All three were relieved of their acute ischemia by streptokinase infusion accompanied by lysis of clots in the popliteal artery outflow tract. Each patient then underwent elective popliteal aneurysm bypass. Four patients had acute embolic popliteal or tibial artery occlusion. Each was relieved of ischemic symptoms. One required surgery to remove residual clot. One patient with thrombosis of the tibioperoneal trunk did not have a decrease in symptoms with streptokinase infusion, but did experience sufficient outflow tract thrombolysis to permit construction of a tibial bypass with resultant restoration of normal circulation. Low-dose intraarterial streptokinase may be the treatment of choice for selected patients who present with thrombosis of a popliteal aneurysm with tibial vessel involvement or with embolic popliteal or tibial artery occlusion.

Percutaneous angiographic embolization: a procedure of increasing usefulness: review of a decade of experience.

During the past decade percutaneous therapeutic vascular occlusion was performed on 152 occasions in 124 patients. The primary indication for vasoocclusive therapy was acute or recurrent bleeding. Upper gastrointestinal bleeding from arterial sources was controlled in 92 percent of patients and acute variceal bleeding in 83 percent. Renal embolization was performed for palliation of severe pain and hematuria from unresectable renal primary or secondary malignancies, to decrease blood loss and facilitate surgery in operable renal tumors, and for ablation of renal function to control chronic protein loss or severe hypertension. Our encouraging experience convinces us that transcatheter embolization is a useful, safe and effective procedure in selected patients. It seems certain that the technique of therapeutic embolization will be improved, its indications extended and its application become commonplace whenever angiographic skills and facilities exist.

Lower extremity amputation for ischemia.

Three hundred-twenty-four amputations of the lower extremity for ischemia at the University of Oregon Health Sciences Center over the past ten years are presented. Striking differences between the first and second five-year periods are noted in level of amputation. The primary healing rate of all patients in the two periods was similar. Diabetics tended to have more distal amputations but primary healing was lower than that of nondiabetics.