Biomedical subjects
R Lower
Publications and source records attributed to R Lower.
Canadian beef quality audit.
A study was conducted in 4 Canadian processing plants in 1995-96 to determine the prevalence of quality defects in Canadian cattle. One percent of the annual number of cattle processed in Canada were evaluated on the processing floor and 0.1% were graded in the cooler. Brands were observed on 37% and multiple brands on 6% of the cattle. Forty percent of the cattle had horns, 20% of which were scurs, 33% were stubs, 10% were tipped, and 37% were full length. Tag (mud and manure on the hide) was observed on 34% of the cattle. Bruises were found on 78% of the carcasses, 81% of which were minor in severity. Fifteen percent of the bruises were located on the round, 29% on the loin, 40% on the rib, 16% on the chuck, and 0.02% on the brisket. Grubs were observed in 0.02% of the steers, and injection sites were observed in 1.3% of whole hanging carcasses. Seventy percent of the livers were passed for human food and 14% for pet food; 16% were condemned. Approximately 71% of the liver condemnations were due to liver abscesses. Four percent of the heads, 6% of the tongues, and 0.2% of whole carcasses were condemned. The pregnancy rate in female cattle was approximately 6.7%. The average hot carcass weight was 357 kg (s = 40) in steers, 325 kg (s = 41) in heifers, 305 kg (s = 53) in cows, 388 kg (s = 62) in virgin bulls and 340 kg (s = 39) in mature bulls. The average ribeye area in all cattle was 84 cm2 (s = 12); range 29 cm2 to 128 cm2. Grade fat was highly variable and averaged 9 mm (s = 4) for steers and heifers, 6 mm (s = 6) for cows, 5 mm (s = 1) for virgin bulls, and 4 mm (s = 0.5) for mature bulls. The average lean meat yield was 59.7% in cattle (s = 3.4); range 39% to 67%. One percent of the carcasses were devoid of marbling, 1% were dark cutters, and 0.05% of the steer carcasses were staggy. Six percent of the carcasses had poor conformation, 3.7% were underfinished, and 0.7% were overfinished. Yellow fat was observed in 4% of the carcasses; 10% of carcasses were aged. Based on January 1996 prices, the economic analysis showed that the Canadian beef industry lost $70.52 per head or $189.6 million annually from quality nonconformities. Methods identified to reduce these nonconformities included improvements in management, animal identification, handling, genetic selection, marketing, grading, and information transfer.
Late results of free-muscle flaps and delayed bone grafting in the secondary treatment of open distal tibial fractures.
Since no current studies reflect the long-term function of patients accurately categorized and uniformly managed for the same degree and location of tibial injury, seven individuals with type IIIB open distal tibial fractures were studied prospectively for 2 to 4 years after debridement, free-muscle transfer, and delayed autologous bone grafting. Lymphedema, transient drainage, poor ankle motion, limb shortening, nonunion, and delayed union were all significant problems. On average, the patients endured over six operations, 2 months of hospitalization, and a year's course of physical rehabilitation. The study indicates that, although popular, such a regimen is not without important shortcomings. This experience has influenced our selection of and counseling for patients in whom we are contemplating such management.
Applications of percutaneous transluminal coronary angioplasty in cardiac transplantation. Preliminary results in five patients.
Atherosclerotic coronary artery disease is the major cause of late cardiac transplant failure secondary to silent ischemia and infarction. To increase the longevity of cardiac homografts, we performed percutaneous transluminal coronary angioplasty (PTCA) in five male patients (aged 45 +/- 7 years, mean +/- SEM); 17 lesions were dilated during eight procedures 83 +/- 11 months after cardiac transplant. PTCA was successful (greater than or equal to 20% change in vessel diameter) in 13 of 17 (76%) lesions (the degree of prePTCA stenosis was 84% +/- 3% vs. 40% +/- 4% postPTCA; p less than or equal to 0.01). Multiple PTCA procedures were performed for progressive coronary artery disease in two patients; in one patient, two procedures were 13 months apart, and, in the second patient, another three procedures were 2 and 6 months apart. Indications for PTCA included reversible thallium perfusion defects, segmental left ventricular wall-motion abnormalities, or both in the distribution of proximal coronary artery stenoses. No deterioration occurred in the four unsuccessful PTCA attempts (two patients with initial total occlusion, and two patients in whom the lesion could not be crossed with a guidewire). Noninvasive evidence of ischemia was improved immediately after PTCA in all cases. Three patients remain alive 5, 7, and 11 months, respectively, after PTCA without evidence of new ischemia. One patient died 39 months after his first PTCA, while another patient was retransplanted 8 months after the first PTCA. Thus, PTCA can be performed in cardiac transplant patients with proximal major vessel coronary artery disease and may prolong cardiac homograft function.(ABSTRACT TRUNCATED AT 250 WORDS)
Intracellular myocardial pH measured in vivo with sustained and reperfused coronary occlusion.
Intracellular pH provides an important measure of the adequacy of local tissue perfusion. The purpose of this study was to measure regional intracellular myocardial pH (impH) in the ischemic zone in vivo during experimental canine coronary occlusion, with and without coronary reperfusion. Twenty adult dogs were studied. Ten dogs underwent permanent ligation of the proximal anterior left descending coronary artery (group L), five dogs had coronary reperfusion after 1 hour of total coronary occlusion (group R), and five dogs did not undergo ligation and served as controls (group C). Intracellular myocardial pH was measured by 31phosphorus nuclear magnetic resonance spectroscopy at baseline and then at 15-minute intervals for 6 hours after coronary occlusion (or after sham occlusion in group C). Baseline impH did not differ among groups (group C, 7.22 +/- 0.12 mean +/- standard error of mean; group L, 7.17 +/- 0.07; group R, 7.22 +/- 0.09). During hour 1 of total occlusion, the impH of both groups L (6.58 +/- 0.05) and R (6.55 +/- 0.08) was significantly reduced as compared with the impH of group C (7.3 +/- 0.12; p less than 0.05). At 0 to 1, 1 to 3, and 3 to 5 hours of reperfusion, the impH of group R (7.34 +/- 0.08, 7.27 +/- 0.07, and 7.29 +/- 0.06, respectively for these times) did not differ from group C (7.26 +/- 0.11, 7.21 +/- 0.07, and 7.25 +/- 0.10). At these same times, the impH of group L (6.47 +/- 0.05, 6.57 +/- 0.04, and 6.75 +/- 0.04) was significantly reduced as compared with both groups R and C (p less than 0.05). Thus a severe, persistent regional intracellular myocardial acidosis occurs in the ischemic zone with coronary occlusion but is rapidly corrected by reperfusion within 1 hour.
Orthotopic cardiac transplantation in a Veterans Administration hospital.
Of 57 patients referred to the McGuire Veterans Administration Medical Center, Richmond, Va, for evaluation for cardiac transplantation, 18 received allografts. The overall graft survival rate was 67% from two to 24 months after transplantation. In 15 recipients receiving immunosuppression with rabbit anti-human thymocyte globulin, prednisone, and azathioprine, previous transfusion and HLA-DR matching resulted in improved graft survival. In three patients receiving cyclosporin and prednisone, hypertension, nephrotoxicity, and hepatotoxicity were seen. All surviving recipients were in functional New York Heart Association class 1 or 2. The cost to the Medical Center was $23,275 per transplant. The results achieved at the center suggested that a regionalized cardiac transplant program can be established within the VA health care system with acceptable clinical results and significant financial savings.
Daily monitoring of T cell subpopulations in renal allograft recipients: high-resolution measurement of T cell kinetics and their relevance to clinical course.
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Cefamandole kinetics during cardiopulmonary bypass.
The kinetics of cefamandole during cardiac surgery was studied in 16 adult patients given a single intravenous infusion of 20 mg/kg at the time of anesthesia induction. Five normal volunteers who received the same dose served as controls. Cardiopulmonary bypass (CPB) was found to signficantly increase the half-life (t 1/2) of cefamandole. The mean t 1/2 during CPB (113.2 min) was longer than the terminal t 1/2 in normal volunteers (52.0 min; p less than 0.005). Throughout CPB (maximum, 3,7 hr), cefamandole plasma levels were maintained above the minimum inhibitory concentration for those organisms most likely to cause postoperative infections. We conclude that if 20 mg/kg of cefamandole is given within an hour of the beginning of cardiovascular surgery, a supplemental dose is not needed until the patient has been on CPB for at least four hours.
Comparison of cephalothin and cefamandole prophylaxis during insertion of prosthetic heart valves.
Cefamandole nafate (CM) and cephalothin sodium (CP) were administered as prophylaxis in a randomized, prospective study to 30 consecutive patients undergoing prosthetic cardiac valve insertion. A single dose of 20 mg/kg was given intramuscularly during anesthesia induction, and serial plasma antibiotic concentrations, atrial muscle and cardiac valve tissue antibiotic levels, plasma bactericidal activity against pathogenic staphylococci, and infectious complications were determined and compared for the two drugs. Both antibiotics produced high plasma levels (>20 mug/ml 30 min after injection) which fell less than 25% during the period of cardiopulmonary bypass. However, CM levels were significantly higher at most time periods (P<0.05) than CP levels. CP levels were undetectable in atrial muscle from 14 of 15 patients and in valves from 10 of 15 patients. In contrast, CM bioactivity was found in all tissues. Differences in tissue antibiotic concentration could not be accounted for by differences in plasma concentrations or by CP tissue binding and were assumed to be caused by differences in penetration. Plasma bactericidal activity against staphylococci was equal for the two drugs (median titer, 1:16). No infections were seen in either group. CM appeared to be an effective and perhaps preferable prophylactic antibiotic for use during cardiac surgery.
Effective monitoring and modulation of recipient immune reactivity to prevent rejection in early posttransplant period.
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Individualization of recipient immunosuppression by use of in vitro monitoring parameters.
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Differential effects of immunosuppressive drugs on human T, B, and K lymphocytes.
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Some pitfalls in the assessment of analyzability in a psychoanalytic clinic.
We have described some of the problems encountered in an analyzability committee's evolving approach to the assessment of applicants to a psychoanalytic clinic. A primary error was to think in terms of the level of drive development--equating pathology at an oedipal level with analyzability. Recognition that the more important issue for assessment purposes was the presence or absence of those ego capacities and personality characteristics necessary for success in analysis has led to a reorientation of our approach.
Antibodies and human transplant rejection.
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Isolated tricuspid insufficiency. Report of a case with valve replacement.
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Bronchial dynamics and the reconstitution of bronchial artery supply in the autotransplanted lung.
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Hypercholesterolemia in long-term survivors of heart transplantation: an early marker of accelerated coronary artery disease.
Coronary artery disease remains a significant long-term problem for survival after heart transplantation. Hyperlipidemia is a known risk factor for coronary artery disease in the general population, but the role of hyperlipidemia in cardiac allograft recipients has not been elucidated. To study this problem, we retrospectively reviewed 38 heart transplant recipients who survived more than 3 years after surgery and looked at age, development of diabetes, drug protocol, and development of hypercholesterolemia for a possible correlative or predictive value to the development of early coronary artery disease after heart transplantation. Eleven patients were identified as having coronary disease by the third year after transplantation. High-risk cholesterol values (in milligrams per deciliter) at 6 months after heart transplantation were defined as follows: for ages 10 to 20, 190; 20 to 30, 220; 30 to 40, 240; 40+, 260. We found a strong predictive value with high-risk lipid profiles (p less than 0.01) for the development of coronary artery disease by the third year. No significance was found for a low-risk value, the development of diabetes, or hypertension. All patients below the age of 20 years had coronary artery disease by the third year after transplantation. We conclude that a high-risk cholesterol value at 6 months after transplantation is a strong predictor for development of accelerated coronary artery disease and early graft failure. This has major implications for management of hyperlipidemia in the cardiac allograft recipient.