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Biomedical subjects

W S Moore

Publications and source records attributed to W S Moore.

At least 181 records · Page 10Linked to original sources
PubMed1983

Cause and noninvasive detection of restenosis after carotid endarterectomy.

The incidence of significant restenosis after carotid endarterectomy was studied with ocular pneumoplethysmography. Of 105 operations, symptomatic restenosis occurred in 4.8 percent and asymptomatic restenosis in 6.6 percent. No preoperative factors were identified to be associated with subsequent recurrence. However, technical problems with the end-point of the endarterectomy were associated with restenosis. Half of the restenoses occurred in the first 6 months of operation. The results focus on the need for special attention to the technical management of end-point problems and the need for early noninvasive follow-up to detect a substantial proportion of early restenoses.

Arterial Occlusive Diseases↗
PubMed1983

Fate of aortic graft removal.

Reoperation to remove an aortic graft was performed in 18 patients. The need for removal was infection in the majority. A changing flora was seen in aortic graft infection with gram-negative organisms predominating. Despite a standardized approach with total graft removal, aortic closure, and extraanatomic reconstruction, amputation and mortality rates remain unacceptably high. A new approach to this problem is needed, and further trials with autogenous reconstruction appear warranted.

Aged↗
PubMed1983

Flagellar adhesion in Chlamydomonas induces synthesis of two high molecular weight cell surface proteins.

Because our previous studies (Snell, W.J., and W.S. Moore, 1980, J. Cell Biol. 84:203- 210) on the mating reaction of chlamydomonas reinhardtii showed that there was an adhesion-induced turnover of proteins whose synthesis is induced during aggregation. Analysis by SDS PAGE and autoradiography showed that proteins of 220,000 M(r) and 165, 000 M(r) (designated A(1) and A(2) respectively) consistently showed a high rate of synthesis only in flagella or flagellar membrane-enriched fractions prepared from aggregating gametes. Since the two proteins were soluble in the non-ionic detergent NP-40 and were removed from intact cells by a brief pronase treatment, it is likely that A(1) and A(2) are membrane proteins expose on the cell surface. A(1) and A(2) were each synthesized by gametes of both mating types (mt(-) and mt(+)) and synthesis of these two proteins could be detected in the normal mating reaction (wild type mt(-) and mt(+)), in mixtures of mt(-) and impotent mt(+) gametes (which could aggregate but not fuse), and in mixtures of gametes of a single mating type with isolated flagella of the opposite mating type. Cells aggregating in tunicamycin, an inhibitor of protein glycosylation, lost their adhesiveness during aggregation and did not synthesize the 220,000 M(r) protein but instead produced a protein (possibly an underglycosylated form of A(1)) of slightly lower mol wt. The 220,000 and 165,000 M(R) proteins appeared to be flagellar proteins and not cell wall proteins because A(1) and A(2) did not co-migrate with previously identified cell wall proteins, and synthesis of the two proteins could not be detected in flagella-less (bald-2) mutant cells. Analysis of the adhesive activity of sucrose gradient fraction of detergent (octyl glucoside)-solubilized flagellar membranes revealed that fractions containing A(1) and A(2) did not have detectable adhesive activity. The possibility remains that A(1) and A(2) are adhesion molecules whose activity could not be measured in the assay we used. Alternatively, the 220,000 and 165,000 M(r) proteins may be inactivated adhesion molecules or else they may be flagellar surface proteins involved only indirectly in the adhesion process.

Adhesiveness↗
PubMed1983

Aortic saddle embolus. A twenty-year experience.

Clinical experience with aortic saddle embolus (ASE) is not extensive due to the relative infrequent lodging of emboli at the aortic bifurcation. During the period 1962-1982, 26 patients (mean age, 56 years) were treated at the UCLA Medical Center for ASE and followed from 2 to 158 months (mean, 45 months). These cases were reviewed in order to identify features of diagnosis, anticoagulation, and operation which impact on results. All 26 patients presented with bilateral lower extremity ischemia with or without extension of clot to the iliac bifurcation. Ninety-six per cent of emboli were of cardiac origin and one-third occurred in patients who had previous symptoms of chronic lower extremity ischemia. Rest pain and motor/sensory deficits were main complaints in 92% of the patients, but did not become manifest until more than 6 hours, unlike more distal emboli which have an earlier presentation. Preoperative angiography, even in the patient with a history of claudication, has a small role in planning the surgical approach to patients with ASE and, although performed in 11 patients, it influenced operation in only two. Operation within the "golden period" of 6 hours after embolization did not significantly influence outcome after ASE, since 20 patients were operated on more than 6 hours after embolization, with results similar to six patients who were operated on less than 6 hours after embolization. Early high-dose heparinization, used in all patients and maintained for a mean of 12 days, may have contributed to this effect. In 22 patients (85%) Forgarty catheter extraction via bilateral groin approaches was used with a mortality of 14%; only one death was directly attributed to the catheter embolectomy. In 15% of patients, a direct approach on the aorta was selected with a zero mortality rate. Postoperative functional result was excellent with an amputation rate of only 2% (one limb). Re-embolization occurred in seven patients (27%) after discharge, five of whom had not been maintained on Coumadin and two who were not anticoagulated adequately. The authors conclude that the keys to successful treatment of ASE include high dose heparin which is maintained through the perioperative period, embolectomy without preoperative angiography, and maintenance of long-term oral anticoagulation.

Adult↗
PubMed1983

Nuclear magnetic resonance imaging of the knee: examples of normal anatomy and pathology.

Nuclear magnetic resonance images of the knee were obtained from three normal volunteers and from two patients. The pathology included an osteosarcoma of the distal femur and a fracture of the tibia. Steady State Free Precession (SSFP) techniques were used with a 0.15 Tesla resistive type magnet. Normal anatomy was well displayed and the size of the osteosarcoma was accurately predicted. Using SSFP techniques, the blood in the knee joint was not visualised, but the underlying tibial fracture was clearly outlined.

Adolescent↗
PubMed1982

Vascular manifestations in patients with Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is clinically and genetically a heterogenous disorder of connective tissue synthesis. Seven clinical types of this disease have been identified and the underlying biochemical defects defined in types IV through VII. Unfortunately, most patients with major vascular complications of EDS have few, if any of the commonly recognized musculoskeletal and cutaneous abnormalities. Recognition of the correct diagnosis and the application of accepted vascular surgical techniques may improve the morbidity and mortality for these patients.

Adult↗
PubMed1982

Natural history of nonstenotic, asymptomatic ulcerative lesions of the carotid artery. A further analysis.

The natural history of 153 asymptomatic, nonstenotic ulcerative lesions of the carotid bifurcation in 141 patients was reviewed. A technique for quantitatively defining small (A), large (B), and compound (C) ulcers was developed. During the course of study, extending up to ten years, 3% of patients with A ulcers, 21% with B ulcers, and 19% with C ulcers had hemispheric strokes without antecedent transient ischemic attacks (TIAs), on the side appropriate to the lesion. The interval annual stroke rate was 4.5% for B ulcers and 7.5% for C ulcers. Because these interval stroke rates are comparable to the 6% annual stroke rate occurring in patients with TIAs, a well-accepted indication for operation, we recommend prophylactic operation for these lesions in good surgical candidates, to be performed by surgeons who have demonstrably low operative stroke rates.

Actuarial Analysis↗
PubMed1982

Femoropopliteal tibial bypass: what price failure?

The consequences of failure in 235 femoropopliteal and femorotibial operations are reviewed and compared with the benefits of success so that an accurate perspective of risk-benefit analysis can be achieved. In 72 operations performed for claudication, 10 grafts thrombosed early. The cost included nine reoperations to achieve eight patent grafts and a 12 day average increase in hospital stay. There were no deaths. The benefit obtained was 70 of 72 (97 percent) asymptomatic limbs. In 163 grafts placed for limb salvage, there were 58 initial thromboses. Reoperation in 28 produced an additional 14 patent grafts. The cost of thrombosis was an increase in mortality from 5.6 to 10.7 percent, a 12 day average increase in hospital stay, and raising of preoperative predicted amputation level from below to above the knee in 11 patients with thrombosed grafts whose distal anastomoses were below the knee. This contrasted with a 73 percent limb salvage rate in 104 patients whose preoperative predicted amputation level was below the knee, and a 54 percent limb salvage and a 12 percent lowering of amputation level in 39 patients whose preoperative amputation level was above the knee. Of patients with patent grafts, 89 percent achieved limb salvage. We conclude that the benefits of success in attempted vascular reconstruction for threatened limb loss far outweigh the risks of failure and that the combined results were far superior to the expected outcome in comparable patients undergoing primary amputation.

Amputation, Surgical↗
PubMed1982

Bilateral extracranial-intracranial bypass before carotid ligation for hemorrhage into a pharyngocutaneous fistula.

In this article we present a discussion of the surgical treatment of a patient with spontaneous hemorrhage of the right carotid artery at the site of a pharyngocutaneous fistula following radiation therapy and radical neck surgery for carcinoma of the tonsil. The patient had an atherosclerotic left common carotid artery occlusion. This is the first reported case of bilateral saphenous vein extracranial-intracranial arterial bypass (EIAB). The rationale and results of the operative procedures performed and the benefits of immediate high-flow bypass graft implanted outside the contaminated surgical field before carotid artery ligation are discussed. EIAB should be considered for patients requiring therapeutic carotid artery ligation who have potentially inadequate collateral cerebral blood flow due to associated extracranial or intracranial vascular occlusions or anomalies.

Arteriosclerosis↗
PubMed1981

Prospective use of xenon Xe 133 clearance for amputation level selection.

Xenon Xe 133 clearance was used to select the most distal amputation level that would allow sufficient blood flow for healing. Capillary blood flow was first measured at the most distal potential amputation level, then at successive proximal levels until an amputation site was found that had a capillary skin blood flow rate greater than or equal to 2.6 mL/min/100 g of tissue. Xenon Xe 133 in saline (100 to 500 mCi) was injected intracutaneously at each level, and flow rates were determined using a gamma camera interfaced with a computer system programmed for the Ketty-Schmidt formula modified for capillary blood flow. There were 45 cases, including one toes, six transmetatarsal, five Syme's, 25 below-knee, four knee disarticulation, three above-knee, and one hip disarticulation amputation. All amputations in patients with flow rates exceeding 2.4 mL/min/100 g of tissue healed, with two exceptions.

Aged↗
PubMed1981

Development of an infection-resistant vascular prosthesis.

To develop an infection-resistant arterial prosthesis, amikacin was bonded to 6-mm, uncrimped, filamentous velour prostheses using a collagen-release system. Infrarenal abdominal aortas were resected in 26 mongrel dogs. Thirteen dogs had their aortas replaced with the antibiotic-bonded grafts and 13 dogs had their aortas replaced with a graft containing collagen without antibiotics. Following closure of the abdominal incision, each dog received an intravenous infusion of 10(8) organisms of Staphylococcus aureus administered over a 30-minute interval. Three weeks after recovery from operation, the grafts were removed under aseptic conditions; all 13 (100%) of the control grafts were infected, but only one of 12 experimental grafts (8%) was infected. There were no adverse healing effects; to the contrary, there appeared to be accelerated development of a cellular neointima and fibroblastic infiltration to the interstices. Antibiotic bonding with a collagen-release system is a promising method for imparting infection resistance to a vascular prosthesis.

Amikacin↗
PubMed1981

Changes in venous endothelial fibrinolytic activity and histology with in vitro venous distention and arterial implantation.

We performed intraoperative pressure monitoring in a clinical setting and demonstrated that the average venous distention pressure observed during preparation of autogenous vein grafts for arterial implantation was 300 to 500 mm Hg and often exceeded 500 mm Hg. Similar data on venous distention pressures were obtained by Ramos et al [4] and by Abbott et al [1]. Although the exact relation between venous distention pressure, venous endothelial fibrinolytic activity and long-term autogenous vein graft patency is unknown, our data suggest that autogenous vein graft distention pressure should be kept under 500 mm Hg during graft procurement and static pressure testing before venous autograft implantation. Ideally, either venous distention pressure should be monitored during vein graft harvesting and preparation, and kept as low as possible, or procured autogenous vein grafts should not be statically distended but rather allowed to gradually enlarge due to pulsatile arterial flow after implantation.

Animals↗