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Biomedical subjects

C D Campbell

Publications and source records attributed to C D Campbell.

At least 19 recordsLinked to original sources
PubMed1999

Characterisation of rhizobia from African acacias and other tropical woody legumes using Biolog and partial 16S rRNA sequencing.

A Biolog (sole carbon source utilisation) user database of tropical and temperature rhizobial strains was created and used in conjunction with the partial 16S rRNA sequencing method to characterise 12 rhizobial isolates from African acacias and other tropical woody legumes. There was close agreement between the two methods but also some significant discrepancies. A high degree of diversity was shown in the relatively small sample of isolates, with 4 out of 5 of the currently proposed rhizobial genera represented. This is the first time Biolog has shown congruence with genotypic fingerprinting using a wide selection of rhizobial reference and test strains.

Acacia↗
PubMed1996

Molecular population genetics of the alcohol dehydrogenase locus in the Hawaiian drosophilid D. mimica.

Sequence variation among 10 alleles of the alcohol dehydrogenase (Adh) gene of the Hawaiian drosophilid D. mimica was analyzed with reference to the evolutionary history of the Hawaiian subgroup as well as to levels and patterns of polymorphism of the Adh gene in continental drosophilid species. The Adh gene of D. mimica is less polymorphic than that of other drosophilid species, and no replacement substitutions were found. Statistical analyses of the Adh alleles suggested the action of balancing selection and revealed significant linkage disequilibrium among three of the variable sites. The effective population size was estimated to be only slightly smaller than that of continental species and, surprisingly, on the same order of magnitude as the actual size.

Alcohol Dehydrogenase↗
PubMed1995

Mental acuity of the normal elderly.

The elderly are persons over age 65, now comprising 12% of our population. The normal elderly function normally both in their self care, and also in their social activities of daily living, which we tabulate. The current terms for the normally functioning elderly who show only mild psychological deficits are age-associated memory impairment and age-related cognitive decline, which we define, criticize and tabulate. The psychological deficits of the elderly consist of mild generalized slowing and inaccuracies compared to normal young persons. These deficits are measured by objective psychological tests which mimic real daily living situations--the name-face test, fire alarm test, two delayed recall tests, misplaced objects test, shopping list test, and digit symbol test, which we describe. A longer early formal education is preventive of mental dulling during normal aging. Treating using overlearning, by cognitive training, is significantly beneficial.

Activities of Daily Living↗
PubMed1992

Comparison of the vasoconstrictive and anesthetic effects of intranasally applied cocaine vs. xylometazoline/lidocaine solution.

Cocaine solution has traditionally been the agent of choice for vasoconstriction and anesthesia when applied topically to the nasal mucosa during nasal operative procedures. Because of the relative scarcity and resulting expense of cocaine, there has arisen an impetus for an alternative intranasal solution for mucosal anesthesia and vasoconstriction. As a logical alternative, we have used a mixed solution of xylometazoline and lidocaine with reasonable results. No clinical studies comparing the efficacy of the two solutions exist, however, and there is presently no such solution commercially available. A double-blind, randomized, placebo-controlled study was undertaken to assess the relative efficacy of the preparations. Both solutions resulted in a marked and roughly equivalent degree of mucosal vasoconstriction (as evidenced by comparable increases in nasal airway cross-sectional area). Subjective pain ratings of mucosal pin-prick decreased a surprisingly small degree after application of both solutions. It appears that xylometazoline/lidocaine solution is comparable to cocaine solution for purposes of vasoconstriction and anesthesia during intranasal operative procedures.

Administration, Intranasal↗
PubMed1989

Experimental aortocoronary artery bypass grafting using a CO2 laser on the dog: acute experiment.

This study was designed to evaluate the feasibility of using laser tissue welding in aortocoronary bypass operation. Simulated aortocoronary bypass operations were performed on 10 dog hearts supported by extracorporeal circulation. Distal anastomoses between internal mammary artery and coronary artery were achieved using the laser technique, which includes four stay sutures of 7-0 polypropylene and tissue welding between the stays by the laser at a power level of 65 mW. Short-term luminal patency was 100% without stenosis by angiography. Microscopy and histology showed that CO2 laser caused medial change resulting in fusion with preservation of normal intimal morphology. The aortocoronary bypass operation using a CO2 laser is technically feasible, and this technique may open up a new method for patients with small peripheral coronary artery obstruction and for pediatric patients with certain conditions (eg, Kawasaki disease).

Anastomosis, Surgical↗
PubMed1989

Surgery for mitral regurgitation associated with ischemic heart disease. Results and strategies.

Analysis of published reports indicates that ischemic mitral insufficiency is associated with higher operative mortality (10-30%) than is nonischemic mitral valve procedures. Probable incremental risk factors include emergency operation, acute myocardial infarction, hemodynamic instability, poor left ventricular function, pulmonary hypertension, advanced age, and renal failure. Early valve repair or replacement with myocardial revascularization improves survival in patients with circulatory insufficiency due to acute postinfarction mitral regurgitation. Although the technique of repair of nonacute ischemic mitral insufficiency is not standardized, repair with revascularization is preferred. Preliminary data suggest that long-term results are primarily related to the severity of left ventricular dysfunction.

Coronary Disease↗
PubMed1989

End-to-side and end-to-end vascular anastomoses with a carbon dioxide laser.

This study was designed to compare anastomoses performed with a carbon dioxide laser and conventional anastomoses performed with 7-0 polypropylene suture. In each of 80 rabbits, the divided left carotid artery was anastomosed by a continuous suture technique and the right carotid was anastomosed with a carbon dioxide laser. In each of 40 additional rabbits, both end-to-end and end-to-side laser anastomoses were performed on the same carotid artery. The laser technique involved the placement of three stay sutures (end-to-end technique) or four stay sutures (end-to-side technique) of 7-0 polypropylene and an everting laser seal at a power level of 65 mW. The 1-year overall patency rate was 98% (78/80) in laser anastomoses, 79% (63/80) in suture anastomoses, and 95% (38/40) in combined end-to-end and end-to-side laser anastomoses. Microscopic findings in laser anastomoses demonstrated degeneration of collagen and protein in the adventitia and media, but much less intimal injury than in suture anastomoses, with reendothelialization beginning earlier (within 7 days after anastomosis as compared with 2 to 4 weeks). The tissue tensile strength at 1 hour was less in laser anastomoses than in suture anastomoses, but the laser anastomoses still withstood an intraluminal pressure load of 380 mm Hg. Laser anastomosis improved the microscopic and histologic appearance of the intimal layer, allowing for rapid early reendothelialization and resulting in excellent patency rates.

Anastomosis, Surgical↗
PubMed1988

Mechanical support for postcardiotomy heart failure.

Cardiac failure remains a life-threatening complication for certain patients undergoing intracardiac repair. Despite improvements in surgical techniques, methods of myocardial protection, and postoperative care, patients are frequently at risk to develop postoperative low output syndrome. Approximately 1% of cardiac surgical patients cannot be weaned from extracorporeal circulation in spite of adequate volume loading, the use of inotropic support, and initiation of intraaortic balloon pumping. In these cases, ventricular assist devices (VAD) can mechanically aid the failing heart and reverse the low output state. The concept of mechanical support for the failing left ventricle was first proposed by Clauss et al. in 1961. By 1968, Kantrowitz and associates had developed and refined the first intraaortic balloon pump (IABP). Through the efforts of Moulopolous and others, this device evolved into the present-day intraaortic balloon pump (IABP). Clinical evidence for the efficacy of left ventricular assist devices (LVAD) remained questionable until 1980, when the National Heart, Blood and Lung Institute evaluated short-term LVADs by comparing various types of mechanical aids. This report focused attention primarily on the failing left ventricle (LV). As the use of inotropic support, intraaortic balloon pumping, and LVADs improved, a small group of patients emerged who could not be separated from extracorporeal circulation due to a failing right ventricle. The failing right ventricle emerged as a unique clinical entity similar to postcardiotomy left ventricular failure that also benefited from mechanical cardiac assistance. Current therapy at major centers incorporating mechanical assist devices is based on the premise that the low output state will allow the failing heart to recover from a reversible injury. The frequent occurrence of postcardiotomy ischemia may be due to several factors such as poor myocardial protection, overdistension of the LV, emboli, coronary spasm or technical problems. Whatever the etiology, the end product of cardiac failure is a demand for oxygen consumption that cannot be met, thus leading to cardiac demise.

Academic Medical Centers↗
PubMed1984

Combined application of heterologous collagen and fibrin sealant for liver injuries.

Hemostasis in complex liver injuries remains a problem despite improvements in operative techniques including debridement, suturing or packing. To evaluate fibrin sealant (FS), a new biodegradable hemostatic agent in combination with porcine collagen for sealing of liver injuries, three series of experiments were performed in 132 rats. In series I, 18 rats had a 10-mm in diameter and 2-mm in depth punch defect to the left lateral lobe. In the FS group (n = 9), bleeding was treated by insertion of an FS-soaked piece of collagen of equal size which was firmly attached to a plastic disk with wire anchor. In the control group (n = 9), collagen alone was inserted. Fifteen minutes after the insertion the lobe was excised and pull-off experiments were performed with simultaneous script chart recording. There was a highly significant difference in the adhesion to the liver surface (85.6 +/- 7.1 in the FS group versus 24.8 +/- 2.6 g/cm2 in the control group, P less than 0.001). In series II, 42 anticoagulated rats (Coumadin, PT 27.5% +/- 1.3) with lobectomy or liver rupture were placed in three groups (n = 14). Group I was treated with FS, group II with FS and collagen, and group III with catgut sutures which served as controls. Fourteen days later 12 rats of group I, 13 of group II, and 7 of group III were alive yielding 85.7, 92.8, and 50% overall survival rates, P less than 0.05 groups I and II versus group III. In series III, 72 non-anticoagulated rats were treated identically to series II and examined morphologically at 1, 7, 28, and 56 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Use of fibrin sealant for reinforcing arterial anastomoses.

Despite improvements in needles, sutures, and technique, hemorrhage remains a problem in cardiovascular surgery. In this study conventional vascular suture lines and suture lines reinforced with fibrin sealant are compared for blood loss and burst strength. Bilateral femoral arteries in 20 dogs were divided at 50% of their circumference and repaired with six 6-0 polypropylene sutures. Ten animals were systemically heparinized (3 mg/kg), and 10 were not on anticoagulants. The right femoral artery anastomosis was treated with fibrin sealant in all animals, and the left suture line served as the control. Three minutes after initiation of the sealing procedure, blood flow was reinstituted in both femoral arteries. After 3 minutes a significant difference in blood loss between the conventional suture technique and fibrin-reinforced anastomoses was noted in both heparinized (12.1 +/- 2.79 vs. 0.13 +/- 0.06 ml/min; p less than 0.01) and nonheparinized dogs (8.45 +/- 1.37 vs. 0.20 +/- 0.08 ml/min; p less than 0.001). After 30 minutes volume inflow and pressure catheters were inserted into snared compartments encompassing the femoral artery anastomosis. Continuous pressure recordings during volume loading with normal saline solution demonstrated increased bursting pressures of the fibrin-sealed suture lines in both the heparinized (317.5 +/- 13.18 vs. 135 +/- 23.17 mm Hg; p less than 0.001) and nonheparinized animals (474.5 +/- 26.82 vs. 311 +/- 29.31 mm Hg; p less than 0.001). Histologic examination revealed no fibrosis or foreign body reaction and complete resorption of the fibrin sealant within 3 weeks. Fibrin sealant, a powerful hemostatic agent produced from human donors not suffering from hepatitis, decreases blood loss and strengthens suture lines.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Evaluation of fibrin sealing for cardiovascular surgery.

Hemorrhage remains a problem in patients undergoing cardiovascular surgery. To evaluate fibrin sealant, a completely biodegradable hemostatic agent, three series of experiments were performed in mongrel dogs. In series I, 18 dogs had a 7 cm interposition of knitted Dacron (water porosity 1500 ml/min/cm2) in the descending aorta. In group A, all prostheses were treated with fibrin sealant and in group B by blood preclotting. Measurements of blood loss demonstrated 1.29 +/- 0.26 ml/min in group A as compared with 30.16 +/- 2.85 ml/min in group B (p less than .001). In series II, six dogs of each group were compared for thrombogenicity and platelet survival by using indium-111-labeled autologous platelets. According to Goldman et al., the thrombogenicity index was calculated. The mean thrombogenicity index for group A was 0.23 +/- 0.02 in contrast to 0.33 +/- 0.05 for group B (p greater than .05). Mean platelet survival was 5.59 +/- 0.23 days in group A in contrast to 5.34 +/- 0.05 days in group B (p greater than .05). In series III, the gluing potential was investigated by creating four types of injuries: four dogs had an aortic stab wound 3 to 5 mm, six dogs received a 10 to 15 mm stab wound to the left ventricle, seven dogs had a 3 cm laceration of the left atrial appendage, and four dogs had bilateral division of their carotid arteries. Wounds of the aorta and left atrial appendage were treated by partial clamping and the sole use of fibrin sealant, the carotid arteries were repaired by four simple sutures and fibrin sealant, and the left ventricular stab wounds were treated by the combined use of heterologous collagen and fibrin sealant without suture.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Functional reassembly of lymphocyte lentil lectin receptor glycoproteins into lipid bilayer vesicles.

Plasma membrane vesicles purified from pig mesenteric lymph nodes were solubilized using the mild, readily-dialyzable detergent dodecyltrimethylammonium bromide, and lentil lectin receptor glycoproteins were isolated by affinity chromatography. The receptor fraction showed 12 major bands on SDS-polyacrylamide gel electrophoresis representing 8-9% of the membrane protein. 5'-Nucleotidase (EC 3.1.3.5) was very effectively solubilized by the detergent and was recovered in high yield in the receptor fraction. Receptor glycoproteins were reassembled into large unilamellar vesicles of phosphatidylcholine/phosphatidylserine (mean diameter 0.235 microm) using a detergent dialysis technique. Sixty to seventy percent of the glycoprotein and most of the 5'-nucleotidase activity is associated with the phospholipid vesicles. 5'-Nucleotidase is reassembled in a symmetrical fashion and is inhibited by binding of concanavalin A, lentil lectin and pea lectin but not by succinyl-concanavalin A. Measured values for Ki and maximal inhibition are similar to those observed with intact plasma membrane vesicles. Hemagglutination inhibition studies showed that the reassembled receptors effectively bind lentil lectin. Thus lymphocyte membrane glycoproteins reassembled into phospholipid vesicles seem to retain at least part of their function in that enzyme activities such as 5'-nucleotidase remain intact and the receptors effectively bind lentil lectin.

Animals↗
PubMed1983

Long-term evaluation of pericardial substitutes.

The development of postoperative pericardial adhesions increases the risk of cardiac reoperations because of the danger of damaging the heart, great vessels, or grafts. Several pericardial substitutes have been tested in the past in an attempt to facilitate reoperation, with inconclusive results. This study evaluated eight different materials as pericardial substitutes: six synthetic materials and two different preparations of bovine pericardium. In 32 dogs a 10 by 5 cm piece of pericardium was excised through a right thoracotomy and the defect closed with a measured patch. Each material tested was implanted in four dogs that were put to death at 3, 6, 9, and 12 months. At autopsy the development of adhesions and epicardial reaction were graded as none, minimal, moderate, and severe. Histologic studies of the patch, the epicardium, and the suture line were performed. Our results suggest that both types of bovine pericardium were an excellent substitute. Although minimal adhesions developed, these were easily dissected. The underlying anatomy was clearly recognizable because of the lack of epicardial reaction. Silicone rubber-coated polyester fabric was an acceptable material for the prevention of adhesions, but a severe fibrous epicardial reaction impeded the recognition of the coronary arteries. Both silicone-filled and high-porosity polytetrafluoroethylene (PTFE) films reduced adhesions but caused a severe epicardial reaction. The other synthetic materials were considered inferior because of severe epicardial reaction and/or structural deterioration.

Animals↗
PubMed1982

TMJ symptoms and referred pain patterns.

The purpose of this study was to determine the relationship between TMJ symptoms, (muscle tenderness, joint noise, deviant jaw opening and closing patterns, and limited jaw opening), and a history of referred pain patterns (earaches, headaches, neck pain, and sinus problems). A questionnaire was completed by 100 subjects regarding histories of the previously mentioned problems. The researcher then examined the subject's TMJs, and their symptoms were recorded as being present or absent. The following relationships were found to be significant: Headaches and lateral pterygoid muscle tenderness, Earache and medial pterygoid muscle tenderness, Neck pain and one or more tender muscles, Sinus problems and one or more tender muscles, Sinus problems and temporal muscle tenderness, Sinus problems and medial pterygoid muscle tenderness. However, r values for the above relationships were between 0.22 and 0.3 indicating that the relationships were not strong. It appears that some normal patients already have patterns of masticatory muscle tenderness and associated referred pain patterns prior to seeking treatment for acute TMJ symptoms.

Adult↗
PubMed1982

Traumatic avulsion of the innominate and left carotid arteries: successful repair.

Traumatic rupture of the aorta or the arch vessels is a rare and frequently fatal injury. This lesion should be considered in all cases of severe chest trauma. Early aortography is essential for accurate diagnosis. Nineteen cases of avulsion of the innominate artery have been previously reported. In only two of them a second aortic arch branch had an associated injury. The case presented here is the first successful repair of a combined avulsion of both the innominate and the carotid arteries from the aortic arch. Cerebral circulation was maintained during the operation with a heparin-coated shunt from the ascending aorta to the right common carotid artery. Reconstruction was accomplished by inserting a bifurcated Dacron prosthesis from the aorta to the innominate and left carotid arteries. The use of a heparin-bonded shunt maintained cerebral perfusion, and greatly simplified the operation and avoided the risk of extracorporeal circulation and systemic anticoagulation in a patient with multiple trauma.

Adult↗