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C W Cole

Publications and source records attributed to C W Cole.

At least 19 recordsLinked to original sources
PubMed1992

Epidemiology of abdominal aortic aneurysm: the effect of differing definitions.

There have been several published definitions for abdominal aortic aneurysm (AAA), however, it is not known how different definitions affect what is reported. This paper presents an evaluation of three definitions taken from the literature on (a) aneurysm frequency, (b) prevalence rate and (c) prevalence ratio from an ongoing case-control study evaluating whether male siblings of patients with known AAA have a higher prevalence of aneurysms compared to a control group. Depending on the definition used, the frequency of AAA could vary from a low of five to a high of 23; the prevalence of AAA in siblings could range from 2.1 to 18.8. Changing definitions alters the prevalence ratio (risk of disease) in both magnitude and direction. On the one hand, male sibling of affected patients are at approximately one and a half times (1.6) greater risk of having an AAA compared to controls, whereas using a different definition they are at less than half the risk (0.3).

Aged↗
PubMed1991

Lymphatic fistula after vascular reconstruction: a case-control study.

A retrospective case-control study was carried out to assess the importance of lymphatic fistulas that develop after vascular reconstruction and to determine the risk factors associated with them. The authors compared 35 patients who had lymphatic fistula after vascular reconstruction with 70 control patients, taken from the same database. They found a significant difference between the two groups only in age and indication for surgery: lymphatic fistulas were more likely to develop in older patients and in patients who underwent aortobifemoral bypass for limb salvage rather than for claudication (p less than 0.05).

Aged↗
PubMed1990

Optimized radiolabelling of pig granulocytes with indium-111 tropolonate.

Standard labelling methods using 111In-tropolonate in plasma resulted in lower labelling efficiency (LE) with pig granulocytes than with human cells. Addition of acid-citrate-dextrose (ACD) to cell-free plasma in a ratio of 1:10 tripled the LE to a value which was not significantly different from that obtained in saline. Under optimized conditions, LE was 67 +/- 2% (mean +/- SE) with pig granulocytes, which remained lower than that obtained with human cells but was adequate for nuclear imaging studies of granulocyte deposition in the pig.

Animals↗
PubMed1990

Heparin-associated thrombocytopenia and thrombosis: optimal therapy with ancrod.

Heparin-associated thrombocytopenia and thrombosis (HATT) is an infrequent occurrence but may have disastrous consequences. Continued therapy with heparin must be avoided and anticoagulation achieved by alternative means. Among the few alternatives to heparin in critically ill patients, the best is ancrod. Depletion of fibrinogen with ancrod results in anticoagulation comparable to therapy with heparin within 12 hours. In a small series, nine patients with HATT were treated with ancrod; one underwent angiographic assessment, angioplasty and subsequent vascular reconstruction. Ancrod therapy was not associated with bleeding complications. It appears to provide optimal therapy for patients suspected of having HATT.

Ancrod↗
PubMed1990

Inflammatory aneurysms of the abdominal aorta.

The treatment of inflammatory aneurysms of the abdominal aorta presents a formidable challenge to the surgeon. The retroperitoneal inflammatory reaction obliterates normal tissue planes, limiting access to the infrarenal aorta. During a 70-month period 25 (6%) of 439 patients operated on for abdominal aortic aneurysms were found to have the inflammatory type. These patients were more likely to be symptomatic than patients with noninflammatory aneurysms and they were more likely to be male. Although surgical repair of the aneurysms required longer aortic occlusion time and more blood replacement, the outcome was similar to that for patients treated for noninflammatory aneurysms.

Aged↗
PubMed1990

Comparison of left ventricular function and myocardial perfusion for evaluating perioperative cardiac risk of abdominal aortic surgery.

The measurement of left ventricular function by gated blood pool scanning and of myocardial perfusion by dipyridamole thallium imaging were compared in a prospective study of patients who had abdominal aortic aneurysm or aortoiliac occlusive disease to determine which measurement was the better predictor of postoperative cardiac complications. Sixty-six men and 19 women (mean age 67 years) underwent both tests before admission for surgery. Fifty-six had repair of an abdominal aortic aneurysm, and 29 had reconstruction for aortoiliac occlusive disease. In 17 patients the left ventricular ejection fraction was less than 50%. Dipyridamole thallium imaging was positive, showing redistribution, in 45 patients. Postoperative cardiac complications occurred in 33 patients. The sensitivity of dipyridamole thallium imaging (91%) was significantly (p less than 0.01) greater than that observed with gated blood pool scanning (27%). However, the specificity of gated blood pool scanning (85%) was similar to that of dipyridamole thallium imaging (71%). Diagnostic accuracy was greatest with dipyridamole thallium imaging (79% versus 62% [p less than 0.02]). Dipyridamole thallium imaging is superior to gated blood pool scanning for perioperative evaluation of vascular surgical patients.

Aged↗
PubMed1989

Highlights of an international workshop on abdominal aortic aneurysms.

There is a growing appreciation of the magnitude of the problem of AAA in all Western countries. The large numbers of subjects needed to answer some of the questions, such as the natural history of small AAAs and risk factor analysis, requires that these studies be carried out by a multicentre group. The advantages of international collaboration, when possible, should ensure more uniform methods and definitions as well as more rapid recruitment of subjects. Granting agencies may find such an approach more attractive, and the results may be more relevant.

Aorta, Abdominal↗
PubMed1989

Popliteal aneurysms: an index of generalized vascular disease.

A review of 59 popliteal aneurysms in 38 patients seen over 10 years revealed that 34 (58%) aneurysms were symptomatic. Symptoms included gangrene (15%), ischemia due to thrombosis (38%) and embolism (5%). Patients with unilateral aneurysms (45%) were a median of 7 years younger than those with bilateral lesions (55%). The latter group had more frequent manifestations of occlusive disease, which included previous myocardial infarction, coronary artery bypass grafting and stroke. They also had more concomitant aneurysms, those of the abdominal aorta and femoral and iliac arteries being the most common. Management consisted of bypass grafting in 34 limbs and immediate amputation in 9; 16 inoperable limbs remained viable. At last follow-up (median 32 months) or time of death, 30 of 34 grafts were patent. Four grafts occluded, one perioperatively and the others at 4, 5, and 32 months respectively, resulting in two amputations. The cumulative patency rate in the asymptomatic group was 94% compared with 81% in the symptomatic group. These data illustrate that patients with popliteal aneurysms may have associated vascular disease, the likelihood of which is increased when aneurysms are bilateral.

Aneurysm↗
PubMed1989

Abdominal aortic aneurysm: consequences of a positive family history.

To assess the prevalence of coexisting abdominal aortic aneurysm (AAA) within certain families, a retrospective review was carried out of patients who had undergone AAA repair over a 5-year period. Contact was made with 305 families (52%) and a positive history of an affected, first-degree relative was obtained in 34 (11%). A known AAA was reported to affect approximately 20% of siblings at risk when the proband had an affected parent or sibling. Siblings of patients with an affected first-degree relative represent a high-risk group that may benefit from a screening program for earlier detection and elective management of AAA.

Aorta, Abdominal↗
PubMed1988

Ancrod: a practical alternative to heparin.

To rapidly start systemic anticoagulation there are few alternatives to heparin; those that may be used are often less effective and are impractical substitutes for various reasons. We report the cases of seven patients in whom anticoagulant therapy was begun with ancrod instead of heparin for one or more of the following reasons: (1) failure to achieve systemic anticoagulation in response to heparin (e.g., antithrombin III deficiency), (2) heparin-associated complications (e.g., thrombocytopenia, thrombosis, or both), and (3) combined anticoagulation and improved blood rheology considered to be potentially more beneficial than anticoagulation alone (e.g., massive thrombosis). In the cases reported, ancrod permitted systemic anticoagulation equal to that of heparin; this was achieved without bleeding complications. In contrast to streptokinase or urokinase, ancrod does not degrade preformed, fully cross-linked thrombin fibrin; consequently hemorrhagic complications are uncommon. Ancrod appears to be an appropriate alternative to heparin and may be preferable to it in certain circumstances.

Adult↗
PubMed1988

A neutrophil derived factor(s) stimulates [3H]thymidine incorporation by vascular smooth muscle cells in vitro.

There is increasing evidence for the involvement of inflammatory cells in the development of intimal hyperplasia. This study examines the effect of human neutrophils on the incorporation of [3H]-thymidine into acid precipitable materials (DNA) in cultured rabbit vascular smooth muscle cells. Co-culture of intact neutrophils and vascular smooth muscle cells caused [3H]-thymidine incorporation by these cells to increase 209 +/- 22% (mean +/- SEM) of control. Sonication of the neutrophils abolished this effect (117 +/- 10%). Neutrophil conditioned medium prepared in the presence or absence of fetal calf serum had a similar effect on [3H]-thymidine incorporation by vascular smooth muscle cells (204 +/- 20% and 172 +/- 17% respectively). Stimulation of neutrophils with either Concanavalin A or serum-activated zymosan failed to increase production of the factor(s). The neutrophil derived factor(s) prepared in minimal essential medium was partially stable at 56 degrees C, but inactivated by boiling. Dialysis (pore size 12,000-14,000) did not remove the factor(s). Cyclooxygenase inhibition with indomethacin did not inhibit production of the factor(s) by neutrophils, but indomethacin caused an increase in [3H]-thymidine incorporation by vascular smooth muscle cells (181 +/- 11%). Indomethacin together with intact neutrophils had an additive effect on [3H]-thymidine incorporation (273 +/- 42%) into cellular DNA. These data show that neutrophils produce a factor(s) that stimulates [3H]-thymidine incorporation into DNA by vascular smooth muscle cells and suggests that vascular smooth muscle proliferation and intimal hyperplasia may be initiated by neutrophils adherent to sites of endothelial injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Association of polymorphonuclear leukocytes with sites of aortic catheter-induced injury in rabbits.

The kinetics of the association of polymorphonuclear leukocytes (PMNs) with arterial balloon catheter-induced injury have been examined. An average of 6 X 10(7) PMNs were isolated from 20 ml of blood and labelled with 111In-oxine for reinfusion into the donor rabbit. The cells remained viable as demonstrated by both in vitro and in vivo tests of cell function. The abdominal aorta of rabbits was denuded of endothelium and immediately, 24 h, or 5 weeks later, exposed to autologous radiolabelled PMNs for 1 h. The presence of PMNs at sites of denudation was demonstrated by detection of the radioactive label and was confirmed by light and electron microscopy after 24 h, but not at 5 weeks. Immediately following denudation radioactivity was 2.44 +/- 0.33 times control (P = 0.006); 2.52 +/- 0.18 at 24 h (P = 0.005); and 1.88 +/- 0.32 times control at 5 weeks (P = 0.045). The presence of PMNs, or their products, 5 weeks after denudation suggests a more complex role of PMNs and possibly a direct involvement in the long term changes resulting from arterial balloon catheter injury.

Animals↗
PubMed1986

The role of aspirin and dipyridamole on vascular DNA synthesis and intimal hyperplasia following deendothelialization.

Platelets are implicated both in acute thrombotic events and, through platelet-derived growth factor, in the development of intimal hyperplasia. We have investigated, in vivo, the influence of aspirin and dipyridamole on vascular smooth muscle cell proliferation and DNA synthesis following balloon catheter injury. Fifty-eight male, New Zealand white rabbits were divided equally into two groups; the test group was fed aspirin (14 mg/kg/day) and dipyridamole (9 mg/kg/day) from 2 days prior to surgery until sacrifice at 1, 2, 3, 4, 7, 14, or 28 days after injury. All animals were sacrificed 1 h after injection of [3H]thymidine and the smooth muscle cell DNA specific activity and total kinetic activity were determined. Intimal hyperplasia was measured by light microscopy and intimal nuclear proliferation was determined by counting nuclei per millimeter of internal elastic lamina. Nuclear proliferation was maximal at 14 days (25 +/- 1.2) but intimal hyperplasia was still increasing at 28 days. DNA specific activity after 24 hr (test: 4 +/- 2 dpm/micrograms DNA; control: 3.3 +/- 3 dpm/micrograms DNA) was similar to basal levels in uninjured rabbits. DNA synthesis peaked in both groups between the second and third day (test: 177 +/- 27 dpm/micrograms DNA; control: 185 +/- 39 dpm/micrograms DNA) and then declined slowly toward baseline values. There was no significant difference between treated and normal rabbits in either [3H]thymidine incorporation, nuclear proliferation, or development of intimal hyperplasia despite 90% inhibition of platelet aggregation and a significant reduction (78%) in [14C]serotonin release following collagen challenge (6 micrograms/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Increased vascular contraction and sensitivity to norepinephrine after endothelial denudation is inhibited by prazosin.

The vasomotor function of rabbit aorta was examined after deendothelialization with a Fogarty balloon catheter and during the subsequent development of intimal hyperplasia. Helical strips of injured lower abdominal aortic tissue showed an increase in norepinephrine-induced contraction when compared with control strips from normal upper abdominal aorta. This increase was 235% +/- 40% of control immediately after injury and 341% +/- 51% at 28 days after injury. Standardized dose-response curves demonstrated that the injured tissue was increasingly sensitive over time to norepinephrine and that this was more marked at physiologic levels of norepinephrine. Contraction was blocked by prazosin hydrochloride but not by yohimbine or propranolol. Furthermore, a single intramuscular dose of prazosin hydrochloride 2 hours before injury significantly (p = 0.001) reduced the maximal contraction and sensitivity. These results imply an increase in vasomotor reactivity after deendothelialization mediated through the alpha 1-adrenergic receptor. These functional changes are related to the pertinent morphologic observations.

Animals↗