Biomedical subjects
Publications and source records attributed to R W Harris.
Peroperative evaluation of the success of thromboembolectomy is achieved with a technique that employs interrupted horizontal mattress sutures. Angled traction on the sutures functionally closes the transverse arteriotomy while restoration of circulation is assessed. The arteriotomy may be opened for repassing embolectomy catheters by relieving the traction; if circulation is satisfactory the sutures are tied.
In situ saphenous vein bypass grafts were used to revascularize 109 lower extremities in 99 patients during 1984. Of those, 102 were single length grafts carried out in 53 males and 39 females with an average age of 69 and 75 years old, respectively. The expected associated risk factors were observed: smoking in 69 per cent, hypertension in 57 per cent, heart disease in 52 per cent and diabetes in 31 per cent of the patients. Grafts were performed for limb salvage in 71 patients, claudication in 30 and aneurysm in one. Single length grafts originated from the common (47), superficial (27), deep femoral (18) or popliteal (four) arteries or proximal Dacron (polyester) grafts (six); 93 per cent of the grafts were to an infrageniculate target site, while 44 per cent extended to an infrapopliteal artery and 7 per cent to the ankle. Operating time including completion angiography, which was done in every instance, was comparable to that with reversed vein grafts. The patency rate at one year was 96 per cent or 87 per cent when claudication or limb salvage was the indication for operation, and 92 per cent or 86 per cent when the distal anastomosis was to a popliteal or infrapopliteal artery. Limb salvage rates were 97 per cent at one month and 91 per cent at one year. All five amputations occurred in patients receiving infrapopliteal grafts for gangrene. The survival rate was 97 per cent at one month and 85 per cent at one year.
The results of 160 infrainguinal bypasses with arm vein grafts were analyzed. Seventy-three arteriograms were reviewed to identify early and late graft defects; arteriographic findings paralleled those described for saphenous vein grafts. Intimal fibrosis during the first postoperative year, observed in 16 grafts, was the most common defect. Aneurysmosis and elongation were rare, resulting in two graft replacements. Patency and limb salvage rates were calculated for 88 single-length femorodistal bypass grafts; the other 72 were inflow (eight) or outflow (22) jump grafts, sequential (eight) and composite autogenous vein grafts (34). The primary and secondary patency rates for single-length grafts were 74% and 80% at 1 year and 51% and 57% at 5 years, respectively. The limb salvage rate at 5 years was 82%. The survival rate for all patients was 44% at 5 years. These findings reconfirm our use of arm veins as bypass grafts when the saphenous vein is unavailable.
Autogenous veins other than single-length greater saphenous vein were used in 150 operations to revascularize the extremities of 138 patients; three operations were for upper extremity ischemia and four were lower extremity reconstructions with lesser saphenous vein grafts. The remaining 143 bypasses were performed to revascularize lower extremities in 131 patients. Arm vein grafts were used in 102 operations, and 14 different combinations of vein segments were used to construct 41 totally autogenous composite vein grafts. Tissue necrosis or rest pain was the indication for 70% of arm vein bypasses; 52% of these grafts extended to an infrapopliteal artery. The 1-, 3-, and 5-year patency rates were 82%, 69%, and 60%, resulting in limb salvage rates of 93%, 91%, and 81%, respectively. Composite autogenous vein grafts resulted in a 1-year limb salvage rate of 79% in a select group of elderly patients with advanced arterial disease, poor runoff, and profound ischemia. Limb salvage was the indication for 93% of these operations; tissue necrosis was present in 71% while 80% required infrapopliteal reconstructions--37% to a peroneal artery and 29% to the ankle or foot. Successful limb salvage has been accomplished with alternative autogenous veins when the greater saphenous vein is missing or inadequate, dramatically reducing the use of prosthetic conduits in our practice.
Speech discrimination performance utilizing CID W-22 word lists and patient preferences for hearing aids were investigated. Preference judgments were made using the magnitude estimation procedure. 10 experienced hearing aid users served as subjects. Results revealed that speech discrimination using CID W-22 words was unable to differentiate among hearing aids which possessed similar electroacoustic characteristics. In contrast, the magnitude estimation quality judgment procedure was quite effective and reliable at differentiating among the hearing aids. Further, the magnitude estimation quality judgment procedure is able to provide numerous preference judgments about each hearing aid in a relatively short time. In addition, the magnitude estimation procedure has a major advantage over the paired-comparison quality judgment procedure in that the patient is able to actually wear the hearing aid during the magnitude estimation procedure.
Speech discrimination performance was measured in sound field for 10 young normal-hearing subjects, 10 elderly 'normal-hearing' subjects with a mean pure-tone average of 9.9 dB HTL, and 10 elderly hearing-impaired subjects with a mean pure-tone average of 48.5 dB HTL. Speech discrimination abilities were assessed in quiet and noise (S/N = +10 dB) in a sound suite and under two levels of reverberation in a reverberant room (RT = 0.59 and 1.56 s). Results indicated that the elderly 'normal-hearing' and young normal-hearing subjects have similar speech discrimination performance in the sound suite for both the quiet and noise conditions. In addition, performance by these two groups was almost identical under both levels of reverberation in quiet. However, when noise was added to the reverberant conditions, performance by the elderly 'normal-hearing' subjects was significantly poorer than that obtained by the young normal-hearing subjects. The elderly hearing-impaired subjects yielded speech discrimination scores that were significantly poorer than the elderly 'normal-hearing' subjects and the young normal-hearing subjects for all of the listening conditions.
A group of five diabetic patients had gangrene or failed limited amputations and palpable foot pulses in a total of seven limbs. Because a failure to heal persisted and gangrene progressed, arteriography was performed and disclosed occlusion of all three infrapopliteal arteries. Tibial bypass grafting resulted in complete healing in four of the five patients. The fifth patient refused surgery and died with progressive sepsis. The incidence of this unusual syndrome is unknown, but presumably it is rare. The mechanism of pulse formation in the foot, despite occlusion of the infrapopliteal vessels, is dependent on good flow to the popliteal artery, collateral flow to the rigid distal tibial-peroneal vessels, compliant ankle arteries, and highly resistive distal foot vessels. Although healing of limited amputations is usual in diabetic patients with foot pulses, it is not universal. We recommend that arteriography be performed routinely if gangrene is present and the foot is salvageable, irrespective of pedal pulse status.
Subclavian and axillary artery occlusive disease resulted in sufficient upper extremity symptoms to necessitate 30 vascular reconstructions in 28 patients over the past ten years. Female patients predominated, with a ratio of 2.5:1. The average age of the patients was 61 years. The incidence of diabetes mellitus was low (7%). Sixteen of 18 proximal subclavian lesions were on the left side, while more distal lesions were equally distributed on the left and right. Extrathoracic bypasses were used in all cases. Dacron grafts were used in 16 of 17 carotid-subclavian bypasses. Autogenous vein grafts were used in 11 of 13 bypasses to the axillary or brachial artery. Concomitant cervicodorsal sympathectomy was done in only four patients. The in-hospital graft patency rate was 93% and the long-term graft patency rate at one year and beyond was 88%.
An indirect enzyme-linked immunosorbent assay was developed to detect specific Bacteroides fragilis antigen(s) in human urine. Specimens collected within 72 hr of a positive culture were centrifuged, dialyzed, and treated with Tween 20, polyethylene glycol, and bovine serum albumin. Goat hyperimmune gamma-globulin to B. fragilis strain ATCC 23745 was added and incubated, and supernatants were tested for antibody activity to polysaccharide-protein antigen of the same organism. Mean +/- SD results, reported as percentage inhibition of control values and interpreted blindly, were as follows: 29 normal subjects, 9.8% +/- 6.0%; 22 patients with Enterobacteriaceae bacteremia, 6.0% +/- 5.1%; six patients with nonbacteremic infections due to B. fragilis, 22.3% +/- 10.3%; and nine patients with B. fragilis bacteremia, 28.7% +/- 10.2%. Three of six nonbacteremic patients and eight of nine bacteremic patients yielded values greater than 2 SD of control values. None of 22 patients with Enterobacteriaceae bacteremia was falsely positive (specificity, 100%).
The antimicrobial activity of latamoxef (moxalactam) was examined against Bacteroides fragilis and Escherichia coli individually and in combination in an intraperitoneal tissue capsule animal model during ten days of therapy given at 40 mg/kg/day. Mean peak serum concentration was 32.8 mg/l. Mean capsular latamoxef concentrations during samplings on days three, seven and ten were 1.8 mg/l for Bact. fragilis, 0.7 mg/l for E. coli, less than 0.5 mg/l for polymicrobial infection and 3.4 mg/l in uninoculated controls. Capsular colony counts for Bact. fragilis and E. coli monomicrobial infections decreased by 2.2 and 4.0 log10 cfu respectively and 1.9 and 3.6 log10 cfu in polymicrobial infections. Latamoxef concentrations necessary to eliminate viable bacteria in both monomicrobial and polymicrobial capsules were not achieved.
Successful long-term limb salvage using cephalic vein bypass grafts was attained in 70 limbs of 67 patients over the past 11 years. The saphenous vein was absent in 76% and inadequate in 24% of the cases. Revascularization for limb salvage was carried out in 83%. Ninety per cent of the grafts were extended to the infrageniculate level while 56% were to a tibial vessel. Patency rates at 1, 3, and 5 years were 85%, 72%, and 68%, respectively. Limb salvage rate was 85% at 5 years and thereafter. There were no operative deaths or upper extremity morbidity. The 5-year survival rate was 50%. The results obtained with cephalic vein were comparable to those reported using saphenous vein but superior to those reported for nonautogenous bypass grafts.
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186 Indochinese refugee schoolchildren were screened for middle ear disease using pure-tone audiometry and an acoustic impedance battery. A control group consisting of 186 American schoolchildren was also screened. The purpose of the investigation was to determine the incidence of ear disease in the Indochinese refugee school population as compared to American classmates. A secondary objective was to establish an effective screening criterion for the refugee population. Results indicated that the incidence of ear pathology in the Indochinese population exceeded that found in the American classmates and in most other studies reported on high-risk populations. Medical evaluation confirmed that low compliance (less than 0.25 cm3) is a sensitive predictor of probable middle ear pathology in Indochinese refugee children.
Repair of failing femorodistal bypass grafts with secondary distal "jump" grafts was performed 34 times in 33 patients. Indication for operation was limb salvage for all distal jump grafts and for 85% of the initial femorodistal bypass grafts. Autogenous vein bypass grafts were used in 28 of 33 initial femorodistal grafts (85%) and in 29 of 34 secondary jump grafts (85%). Sixteen of the 33 initial grafts in jeopardy extended to the infrapopliteal level (48%) and 19 of the jump grafts terminated in foot or ankle arteries (56%). The 12 jump grafts performed in the first 2 months of the initial graft were associated with high rates (9%) of graft thrombosis and amputation. Early loss of viability of initial grafts probably resulted from technical and judgment errors or underestimation of distal disease. Progression of distal disease produced late failure after 1 year of implantation of the initial grafts. The 1-year patency rate of the initial femorodistal grafts was 63% but only 32% of these grafted limbs were viable and were not at risk of amputation. Distal jump grafts produced a 49% improvement in limb viability (to an 81% limb salvage rate) and an 11% increase in the initial graft patency rate (to 74%) at 1 year.
Human intra-abdominal infections frequently yield Bacteroides fragilis and require specific antimicrobial and surgical therapy. Noninvasive immunologic assessment of this organism might allow more optimum therapy. Therefore we raised antisera in goats to Bacteroides fragilis ATCC 23745 and allowed it to react with a solid-phase capsular polysaccharide-protein antigen extracted from the same organism. Preliminary work disclosed that 10 ng/ml antigen could be detected in competition assays in both saline and dialyzed rat urine. Results were manifest by diminution of bound antiglobulin alkaline phosphatase conjugate in an antigen-mediated antibody-inhibition enzyme-linked immunosorbent assay. Rats were then infected intra-abdominally with (1) B. fragilis ATCC 23745; (2) one of eight recent clinical isolates of B. fragilis; or (3) one of nine isolates representative of Enterobacteriaceae. Seventy-two rat urine samples obtained prior to infection disclosed essentially no assay inhibition: 98.3% +/- 10.3 (1 S.D.). Mean values of reagent antibody activity after incubation with urine aliquots from 24 hr samples collected between 24 and 72 hr were (1) strain 23745 (n = 35) 70.9% +/- 2.6 (S.E.); (2) eight isolates of B. fragilis (n = 49) 86.8% +/- 1.9; (3) nine isolates of Enterobacteriaceae (n = 47) 100.9% +/- 1.0; and (4) shams (n = 29) 95.5% +/- 1.55. Ascribing values less than or equal to 77.7% (2 S.D.) as positive, seven of the eight clinical B. fragilis isolates causing infection were detected in at least one 24 hr urine sample (sensitivity = 87% by organism); 12 of 17 infected rats were correctly identified as positive by at least one urine (sensitivity = 70.6% by rat). Specificity, as assessed in the Enterobacteriaceae group, was 89% (by organism) and 94.5% (by rat). Collectively, these results suggest the presence of a potentially specific, soluble antigen excreted in the urine of rats with B. fragilis infection.
The husbands of married women with cervical dysplasia, carcinoma-in-situ, or invasive carcinoma of the cervix who, in an earlier study, had claimed to have had no sexual partner other than their husband, were interviewed to determine whether the risk of cervical epithelial abnormalities in the women could be related to their husband's sexual background. Of 322 women previously studied, 57 were eligible for this study and the husbands of 31 of them were interviewed together with the husbands of a control group, matched for age and age at first intercourse. The number of sexual partners reported by the husband was found to be a significant risk factor, with a relative risk of 7.8 for 15 or more partners outside marriage. The relative risk for women who smoked was 7.0, and this was independent of any of the sexual risk factors. The findings for subgroups of women with invasive carcinoma and with dysplasia or carcinoma-in-situ were similar. The data strongly support the view that an infectious agent is involved in the aetiology of cancer of the cervix and suggest that smoking may have an independent carcinogenic action.
In a case-control study, we investigated 169 women aged 15-49 years with malignant melanoma notified to the Oxford and South Western cancer registries during the years 1971-1976, together with 507 matched controls. Data about medical, reproductive, drug and smoking histories were obtained both by reviewing general practitioner (GP) records and from the women themselves by postal questionnaires. There was no significant evidence of any overall increase in the risk of melanoma in oral contraceptive (OC) users (data from GP records-ever use vs never use, relative risk (RR) 1.34, 95% confidence limits 0.92-1.96; corresponding data from postal questionnaires-RR 1.13, limits 0.73-1.75). However, although not significant, the risk estimated from data in the postal questionnaires was higher in women who had used OCs for 5 years or more (use greater than or equal to 5 years vs never use, RR 1.57, limits 0.83-3.03). Previously demonstrated risk factors for melanoma, such as fair skin, blond or red hair and Celtic origin were found to be commoner in the cases than in the controls. Data from the Oxford/Family Planning Association contraceptive study were also examined. Unexpectedly there was a strong suggestion of a negative association between OC use and melanoma risk, but the analysis was based on only 12 women with the disease.
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