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Biomedical subjects

B A Reitz

Publications and source records attributed to B A Reitz.

At least 145 records · Page 8Linked to original sources
PubMed1987

Histologic predictors of acute cardiac rejection in human endomyocardial biopsies: a multivariate analysis.

To identify specific histologic abnormalities that could predict early cardiac rejection before the development of myocyte necrosis, 167 consecutive endomyocardial biopsy samples from 18 cardiac transplant recipients were retrospectively analyzed and 17 histologic variables were semiquantitatively graded from 0 to 3. Forty-five biopsy samples contained foci of myocyte necrosis and were labeled Rejectors. The two samples immediately preceding Rejector biopsies were labeled Predictors (n = 44). All remaining samples were labeled Others (n = 78). Endocardial and interstitial infiltrates, interstitial mononuclear cells, pyroninophilic mononuclear cells, polymorphonuclear leukocytes and other cells (eosinophils and plasma cells) were significantly increased in graded severity in Rejector biopsy samples as compared with Predictors or Others (p less than 0.001, ANOVA testing). These variables cannot distinguish Predictor biopsy specimens from Others. On the other hand, interstitial edema, perivascular karyorrhexis and perivascular infiltrate with intermyocyte extension are histologic abnormalities that can distinguish Predictor biopsy samples from Others (p less than 0.001, ANOVA testing). Multiple logistic regression analysis indicates that the relative risk of developing myocyte necrosis when a biopsy sample contains interstitial edema is 8.1. With perivascular infiltrate with intermyocyte extension in addition, the relative risk is 41.4. In summary, three histologic abnormalities have been identified that help predict the future development of myocyte necrosis within the next two endomyocardial biopsies. Biopsy specimens with these abnormalities probably represent early cardiac rejection before the development of myocyte necrosis.

Biopsy↗
PubMed1987

Successful extended cardiopulmonary preservation in the autoperfused working heart-lung preparation.

Myocardial and pulmonary preservation can be prolonged in the autoperfused working heart-lung (AWHL) preparation by metabolic substrate enhancement. However, uncontrolled pulmonary hypertension following denervation may result in extensive lung injury and occasional early failure of the preparation. To determine whether cardiopulmonary preservation could be reliably extended without development of pulmonary hypertension, six heart-lung blocks were harvested from calves, placed in a normothermic AWHL circuit, and studied. Continuous infusions of isoproterenol and dextrose/insulin were administered for the duration of the preparation. Thirteen heart-lung preparations received neither isoproterenol nor metabolic substrate and served as controls. Myocardial function was assessed by sonomicrometric techniques and pulmonary preservation was evaluated by extravascular lung water, arterial oxygenation on 100% inspired oxygen, static lung compliance, and pulmonary vascular resistance. Pulmonary hypertension developed in the control group and these animals did not survive beyond 7.5 hours. The addition of isoproterenol and metabolic substrate increased organ survival from 4.8 +/- 0.4 to 18.0 +/- 1.4 hours (p = 0.0001) and significantly reduced postexplant pulmonary vasoconstriction (p less than 0.05). Addition of isoproterenol and metabolic substrate to the AWHL model prolonged support of cardiorespiratory function and provided a reliable method for distant procurement in heart-lung transplantation.

Animals↗
PubMed1987

A no-flush, core-cooling technique for successful cardiopulmonary preservation in heart-lung transplantation.

In order to determine whether a no-flush, core-cooling technique could provide extended heart-lung preservation, we placed donor calves on cardiopulmonary bypass and instituted rapid cooling to 15 degrees C during the continuous infusion of isoproterenol. The heart and lungs were harvested after the administration of a cardioplegic solution through the aortic root. In the control group (N = 5), heart and lungs were orthotopically allotransplanted immediately. In the preserved group (N = 5), heart and lungs were similarly excised but were stored in a normal saline bath at 4 degrees C for approximately 4 hours and then transplanted. Both groups received isoproterenol during reperfusion and were studied for 6 hours after implantation. A load independent analysis of myocardial function was done by determining with a sonomicrometer the ratio of the end-systolic pressure to the end-systolic dimension. Pulmonary preservation was evaluated by measurement of extravascular lung water with a double-indicator dilution method, arterial oxygenation on 100% inspired oxygen, and serial lung biopsies. Myocardial and pulmonary function after 4 hours of static preservation was found to be similar to controls. No-flush, core-cooling with cardiopulmonary bypass provides adequate cardiorespiratory function after acute bovine heart-lung allotransplantation. With the use of this technique, successful extended cold ischemic cardiopulmonary preservation for heart-lung transplantation may be achieved.

Animals↗
PubMed1987

Comparative analysis of mechanical and bioprosthetic valves after aortic valve replacement.

Comparative long-term performance characteristics of Björk-Shiley mechanical and bioprosthetic valves were analyzed for patients undergoing aortic valve replacement between 1976 and 1981. A total of 419 patients received either a standard Björk-Shiley (n = 266) or bioprosthetic (porcine, n = 126, or pericardial, n = 27) aortic valve. Cumulative patient follow-up was 1,705 patient-years; the average patient follow-up was 4.1 +/- 2.7 years. Survival data were obtained for all but 11 patients (97% complete follow-up) up to 9 years after operation. Survival at 5 years was 81% +/- 4% (+/- standard error) for Björk-Shiley and for bioprosthetic valve recipients. Valve failure in the Björk-Shiley group was predominantly due to valve-related mortality and did not result from structural failure. Patients with bioprosthetic valves experienced valve failure as a result of prosthetic valve endocarditis and intrinsic valve degeneration. Although patients with bioprostheses experienced a lower incidence of valve-related morbidity than Björk-Shiley valve recipients (p less than 0.03), no difference could be demonstrated in the incidence of valve-related mortality or valve failure at 5 years between bioprosthetic and Björk-Shiley valves. Mortality rate from valve failure was higher for Björk-Shiley (86%, 12/14) than bioprosthetic valves (36%, 5/14) (p less than 0.01).

Actuarial Analysis↗
PubMed1986

Cardiac papillary fibroelastoma and stroke. Echocardiographic diagnosis and guide to excision.

Cardiac papillary fibroelastomas are rare and have been considered a "benign," incidental finding. With two-dimensional echocardiography, these tumors can now be readily diagnosed. A young male patient who had a stroke due to a mitral valve papillary fibroelastoma is described. In this patient, not only did preoperative echocardiography establish the diagnosis, but intraoperative transesophageal two-dimensional echocardiography was utilized to guide tumor excision.

Adult↗
PubMed1986

Hypothermic preservation of the heart and lungs with Collins solution: effect on cardiorespiratory function following heart-lung allotransplantation in dogs.

The effect of preserving the heart and lungs with hypothermia and Collins solution was studied in 13 mongrel dogs undergoing combined heart-lung transplantation. The five control animals who underwent an immediate transplant following Collins solution perfusion had small increases in extravascular lung water when measured 2.5 hours posttransplant as seen in a previous study. The eight animals who had hypothermic preservation following Collins solution perfusion had significantly higher extravascular lung water than controls (16.3 +/- 1.8 ml/kg in preserved animals; 11.2 +/- 1.7 ml/kg in controls p less than 0.05). The level of lung water reached at 2.5 hours postoperatively was similar to that reached with a previously reported, unacceptable preservation technique. Survival beyond this point was poor due to severe pulmonary edema. We conclude that the use of this solution, given under the experimental conditions which we describe, is not acceptable for hypothermic preservation of the heart and lungs for combined transplantation.

Animals↗
PubMed1986

Organization, development and early results of a heart transplant program. The Johns Hopkins Hospital experience.

Improved survival and quality of life have resulted in a resurgence in cardiac transplantation and the proliferation of centers contemplating initiation of a transplant program. Organization of such a program requires cooperation among several clinical and non-clinical departments of the hospital. Prior to implementation of such a program, a number of issues need to be addressed, including state authorization, an expeditious method for donor organ retrieval, protocols for recipient selection and evaluation, and perioperative and follow-up care of the transplant recipient. Since July of 1983, 35 patients (27 men and eight women) have undergone orthotopic cardiac transplantation. Transplantation was undertaken for cardiomyopathy (30) or end-stage ischemic heart disease (5). The mean age was 38 years (range, 16 to 57 yrs). Distant organ procurement was used for 83 percent of patients; mean ischemic time was 164 min (range, 75 to 250 min). Current immunosuppressive regimen consists of oral cyclosporine (10 mg/kg) and prednisone. Mean follow-up was 10.3 months (range, two weeks to 27 months). Transient renal dysfunction appeared early in 15 patients. Six deaths have occurred: three from rejection, one from infection, one from metastatic prostate carcinoma, and one from pulmonary hemorrhage. All but three recent patients have been rehabilitated. These initial encouraging results are a result of careful planning, institutional commitment, adequate resources and, most importantly, a dedicated transplant team.

Adolescent↗
PubMed1986

Combined heart-lung transplantation for end-stage Eisenmenger's syndrome.

Between May, 1981, and December, 1984, thirteen combined heart-lung transplants were performed in 12 patients for the treatment of Eisenmenger's syndrome. The age range of the recipients was 22 to 42 years. Two patients had undergone previous open cardiac operations; in addition, one had had closure of a persistent ductus arteriosus, one an open lung biopsy, one a pulmonary artery banding, and one patient received a second heart-lung transplant after 3 years. Four recipients died before hospital discharge, one at operation and three at 4, 10, and 33 days after operation. Early symptomatic results and cardiopulmonary function were excellent in all of the survivors. Two patients died 14 and 15 months after transplantation of accelerated graft arteriosclerosis and respiratory failure, respectively, and six remain alive 7 to 44 months after transplantation. Four of these surviving patients and the two patients who died late subsequently had major pulmonary complications. Symptoms included progressive breathlessness, cough (often productive), and fever with physical signs of diffuse crepitations and expiratory rhonchi. Serial pulmonary function tests showed progressive obstructive physiology in all six patients with superimposed restrictive defects in four. Histologic examination of tissue from open lung biopsy or autopsy displayed bronchiolitis obliterans in five of these patients, one of whom required retransplantation. It is possible that these late changes are the result of rejection, since similar changes in one other patient have now been reversed with augmented immunosuppression. Further understanding of the causes and manifestations of late pulmonary deterioration should improve the late functional results of this operation for Eisenmenger's syndrome.

Adult↗
PubMed1986

Anatomic and anesthetic considerations in experimental cardiopulmonary surgery in swine.

We have used immature commercial swine (13-25 kg) successfully in a variety of experimental cardiopulmonary surgical procedures in our laboratories since 1981. Multiple drug anesthetic protocols using barbiturates, narcotics, paralytic and antiarrhythmic agents have been employed in over 400 procedures per year. Complications, including fatal cardiac arrhythmias, have been greatly reduced by anesthetic protocols and surgical procedures developed through experience.

Acepromazine↗
PubMed1986

Technique for removal of renal cell carcinoma with suprahepatic vena caval tumor thrombus.

Hemorrhage and poor visualization of the interior of the vena cava frequently occur with the removal of a renal cell carcinoma with a suprahepatic vena caval tumor thrombus. The use of cardiopulmonary bypass, hypothermia, and temporary cardiac arrest facilitates surgical removal of a suprahepatic vena caval tumor thrombus. This technique provides total control of the circulation of the body and creates a disciplined, well-visualized operative field.

Adult↗
PubMed1986

Five year follow-up after valve replacement with the St. Jude Medical valve in infants and children.

Since 1979, 34 infants and children, 3 weeks to 17 years of age, have undergone cardiac valve replacement with a St. Jude Medical (SJM) prosthesis at our institution. Seventeen children underwent mitral valve replacement (MVR), 16 aortic valve replacement (AVR), and one pulmonary valve replacement. Three hospital deaths were associated with MVR and complex congenital heart disease. All surviving patients were functional in class I. A cumulative 89.1 patient-years of follow-up were analyzed to evaluate valve-related mortality and morbidity. Late complications included thromboembolus (one patient), anticoagulant-related hemorrhage (one patient), and perivalvular leak (one patient). One of six late deaths resulted from mitral valve thrombosis. Actuarial 5 year survival for patients who underwent AVR was 100%, but it was 53% for MVR (p = .03). Freedom from significant morbidity and mortality for up to 5 years after operation was 92 +/- 7% for those who underwent AVR and 45 +/- 16% for those who underwent MVR. Patient-related factors appear to account for an increased rate of complications after MVR. Because of difficulties with achieving anticoagulation with warfarin, aspirin therapy should be used for patients less than 5 years of age, while older patients can be managed with warfarin. The SJM valve is a satisfactory cardiac valve substitute for the pediatric age group.

Adolescent↗
PubMed1985

Value of intraoperative left ventricular microbubbles detected by transesophageal two-dimensional echocardiography in predicting neurologic outcome after cardiac operations.

To determine whether the presence or absence of left ventricular (LV) intracavitary microbubbles during cardiac surgery predicts neurologic sequelae, 82 patients undergoing cardiac surgery were studied using transesophageal 2-dimensional (2-D) echocardiography. Cross-sectional images were recorded just before and immediately after cardiopulmonary bypass and stop frames were reviewed for the presence of microbubbles, rated as: 0 = absent, 1 = fewer than 5/frame, 2 = 10 to 25/frame, 3 = too numerous to count. Microbubbles were detected after cardiopulmonary bypass in 34 patients (41%) and found more often in valvular or other intracardiac manipulations than in coronary revascularization, 30 of 40 vs 4 of 42, respectively (p less than 0.001). When grade 2 or 3 microbubbles were identified (22 of 34 patients), mechanical attempts to eradicate them were not successful. Postoperative follow-up in all patients revealed no new focal neurologic deficits. Prolonged encephalopathy (confusional state more than 72 hours) occurred in 4 of 48 patients with no detectable microbubbles and in 3 of 34 patients with microbubbles (difference not significant). Thus, intracavitary left ventricular microbubbles are often detected during cardiac operations, particularly during valve replacement, but are not predictive of postoperative neurologic complications. This is true even if microbubbles are densely concentrated; attempts to eradicate microbubbles are unsuccessful and may be unnecessary.

Cardiac Surgical Procedures↗
PubMed1985

High-level expression of the bovine growth hormone gene in heterologous mammalian cells.

The gene coding for bovine growth hormone (bGH) was isolated from a lambda-phage library constructed using bovine pituitary DNA partially digested with MboI. Expression of this gene transfected into mouse and monkey cells was studied. CV-1 monkey cells transfected with simian virus 40 (SV40) vectors containing the intact bGH gene, including the putative promoter region, did not express bGH. However, replacement of the bGH promoter with the mouse metallothionein-I (MT) promoter resulted in high-level synthesis and secretion of bGH. These results show that the bGH promoter functions poorly in CV-1 cells but CV-1 cells process and translate the bGH mRNA accurately. The MT-bGH chimeric gene was used to establish permanent bGH-secreting mouse C127 cell lines using the 69% transforming fragment of bovine papilloma virus (BPV) as the vector. One such cell line produced high levels of bGH and secreted it into the medium efficiently. Secreted bGH is processed accurately and is bioactive as judged by its ability to bind to rabbit liver membrane preparations.

Animals↗
PubMed1985

Stroke following coronary artery bypass grafting: a ten-year study.

To identify possible risk factors for the occurrence of stroke during coronary artery bypass grafting (CABG), the cases of 3,279 consecutive patients having isolated CABG from 1974 to 1983 were reviewed. During this period, the risk of death fell from 3.9% to 2.6%. The stroke rate, however, fell initially but then rose from 0.57% in 1979 to 2.4% in 1983. Adjustment of these data for age clearly demonstrated that the risk of stroke has increased largely because of an increase in the mean age of patients undergoing CABG procedures. A case-control study involving all 56 stroke victims and 112 control patients was used to identify those risk factors significantly associated with the development of stroke in univariate analysis: increased age (63 versus 57 years in stroke patients and controls, respectively; p less than 0.0001); preexisting cerebrovascular disease (20% versus 8%; p less than 0.03); severe atherosclerosis of the ascending aorta (14% versus 3%; p less than 0.005); protracted cardiopulmonary bypass time (122 minutes versus 105 minutes; p less than 0.005); and severe perioperative hypotension (23% versus 4%; p less than 0.0001). Other variables not found to correlate with postoperative stroke included previous myocardial infarction, hypertension, diabetes mellitus, lower extremity vascular disease, preoperative left ventricular function, and intraoperative perfusion techniques. Elderly patients who have preexisting cerebrovascular disease or severe atherosclerosis of the ascending aorta or who require extensive revascularization procedures have a significantly increased risk of postoperative stroke.

Age Factors↗