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Biomedical subjects

B P Griffith

Publications and source records attributed to B P Griffith.

At least 415 records · Page 23Linked to original sources
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LVAS pump performance following initiation of left ventricular assistance.

Prevention of disturbed flow (e.g., flow stasis) and consequent thrombosis in heart pumps is based upon design characteristics determined during laboratory bench tests. These tests employ optimal filling and emptying characteristics, such as the full-fill to complete empty mode in the Novacor left ventricular assist system. Filling characteristics of the Novacor LVAS were examined during the first 48 hours after implantation in 14 patients. Fill volume of the pump was reduced in pathologic states, such as cardiac tamponade, and following the initiation of right ventricular mechanical circulatory support. In addition, multiple regression analysis revealed that right ventricular function measured by the amount of inotropic support required, the right ventricular ejection fraction, and the total pulmonary resistance, significantly predicted left ventricular assist pump fill volume during the first 48 hours of support. Flow visualization simulating these clinical conditions of incomplete filling suggest inadequate valve washing, particularly around the inlet valve and its conduit, which may predispose to thrombus formation.

Cardiac Output↗
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Heart transplantation in patients with malignant disease.

We have traditionally pushed the limits of conservative candidate criteria for heart transplantation. We have been gratified by our results in the aged, the diabetic, and the mortally ill. Our inclusion of patients with malignant disease underscores our philosophy to include patients as candidates for transplantation for whom the procedure has reasonable expectation of success. We report here our early results of heart transplantation in 11 patients with malignant disease. Our survival rate in this group is 100%, and all patients are leading active lives with no evidence of recurrent or metastatic tumor. Immunosuppression protocols were adjusted on an individual basis determined by the chemotherapy dosage, duration, and relation to transplantation. Whenever possible a 1-year disease-free interval after completion of adequate cancer therapy is desired before transplantation.

Adult↗
PubMedDate not supplied

Successful intermediate-term outcome for patients with cardiac amyloidosis undergoing heart transplantation: results of a multicenter survey.

Amyloid heart disease has been considered a contraindication for heart transplant on the basis of the hypothesis that it is a systemic disease and that amyloid deposition would occur in the cardiac allograft. Despite these concerns, several centers have performed heart transplantation for amyloidosis in a limited number of cases. A survey was sent to all of the U.S. centers and a limited number of European centers listed with the Registry of the International Society for Heart Transplantation. Nineteen centers responded, and data were provided for a total of seven patients (three men and four women, with a mean age of 46 years, range, 30 to 60 years) who had transplants for cardiac amyloid. The diagnosis of cardiac amyloidosis was made histologically on endomyocardial biopsy and/or examination of the explanted heart. Additional organ involvement included liver (two cases), rectal (two cases), renal (one case), gingiva (one case), and tongue (one case). A specific amyloid protein was identified in five patients (four lambda, one kappa Ig light chain). Two patients developed recurrent amyloid in their allograft seen by electron microscopy at 3 1/2 and 4 months, respectively. One patient developed progressive diastolic dysfunction, but systolic function was preserved. This patient died 13 months after transplantation as a result of progressive liver infiltration with amyloid. One patient died immediately after operation. Five patients are alive and fully rehabilitated 32 +/- 12 months after transplant. On the basis of this small series, some patients with cardiac amyloidosis can undergo heart transplantation with good intermediate-term results.

Adult↗
PubMedDate not supplied

Differential diagnosis of human retrovirus infections in the laboratory.

Several human retroviruses have been discovered in the past decade, the majority of which have been implicated as etiological agents of severe disease entities. Thus, there is a clear need for accurate identification of human retroviruses in the laboratory. In this review, the classification and general properties of human retroviruses are outlined. Methods for detecting the presence of antibodies are reviewed. In addition, the principles of methods used for isolating and identifying retroviruses are discussed. Finally, techniques which detect the presence of retroviruses directly in clinical specimens without prior amplification in culture are summarized. Clearly, the ability to differentiate and recognize the different types of retrovirus is important for the proper treatment of diseases caused by these viruses.

Antibodies, Viral↗
PubMedDate not supplied

Posttransplantation diabetes mellitus in heart transplant recipients.

This study was undertaken to investigate the impact of diabetes, which develops after heart transplantation, on infection and patient survival. Nondiabetic patients (366) underwent heart transplantation at our institution between June 1, 1980 and January 12, 1988. Of these patients, 29 (8%) developed posttransplantation diabetes (PTD), defined as a continued need for hypoglycemic agents. The PTD group did not differ significantly from the nondiabetic recipients in age, sex, or human leukocyte antigen type. The average age in the PTD group was 49 years. Average length of follow-up was 21 months (range 4 to 46 months). Eighteen patients are maintained on insulin. Eight patients are on oral hypoglycemic agents. Three patients died while on insulin. The average prednisone dosage in this group is 0.23 mg/kg/day. There have been 18 minor infections and four potentially serious nonlethal infections in the 27 PTD recipients. One lethal infection occurred 33 months after heart transplantation. The only other fatality was related to metastatic bladder cancer. This lethal infection rate of 3% compares with a rate of 11% in all nondiabetic recipients who have follow-up for 21 months. The 3-year actuarial survival of the PTD group is 75%, which compares favorably with the survival of nondiabetic patients. PTD cannot be predicted by sex, age, or human leukocyte type before transplantation, and it does not significantly increase the incidence of mortality or serious infection.

Coronary Angiography↗
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Lymphocyte growth from cardiac allograft biopsy specimens with no or minimal cellular infiltrates: association with subsequent rejection episode.

Histologic features of endomyocardial biopsy specimens are essential in the monitoring of heart transplant patients. Significant cellular infiltrates accompanied by myocyte damage are diagnostic of transplant rejection, whereas no or minimal infiltrates (grades 0 and 1) suggest absence of rejection. Biopsy specimens were cultured on the basis of the principle that the allograft is infiltrated by activated lymphocytes, which can be expanded in the presence of interleukin-2, a lymphokine that induces proliferation of activated T cells. Although frequency of cell cultures was proportional to histologic rejection grade, 39% of biopsy specimens with grades 0 and 1 cultured during the first month posttransplantation yielded lymphocyte growth. Cell growth was observed in 28% of biopsy specimens with grades 0 and 1 obtained during the first 10 days posttransplantation. In this group (growers) 73% showed clinical rejection after 9.8 +/- 5.0 days. In contrast, 55% of nongrowers were treated for rejection after 19.1 +/- 13.8 days. For biopsy specimens obtained 11 to 20 days posttransplantation, subsequent rejection episodes were observed in 61% of growers, but in only 33% of nongrowers. For biopsy specimens obtained 21 to 30 days posttransplantation the incidence of clinical rejection was 60% versus 14%, respectively. A sequential analysis of biopsy specimens obtained during the first month posttransplantation enabled us to identify 16 persistent nongrowers; only 6 (37%) experienced clinical rejection during the first 3 months posttransplantation. Most of the persistent nongrowers were found among patients on the immunoprophylactic rabbit antithymocyte globulin protocol. These data suggest that in vitro cultures of biopsy specimens with no detectable or minimal cellular infiltration may be useful in identifying patients at risk of developing rejection.

Adult↗
PubMedDate not supplied

Nine year experience with the clinical use of total artificial hearts as cardiac support devices.

One hundred sixteen total artificial hearts (TAH) were implanted in 113 patients by 29 centers between April 4, 1969 and March 1, 1988. Five were permanent and 111 were temporary implants (3 patients received second implants). Eight different types of TAHs have been used. The ages ranged from 15 to 62 (mean age: permanent 57, temporary 42). Sixty-seven percent (72/108) of patients receiving the TAH for temporary support were transplanted; 6 patients were waiting for a transplant. Forty-seven percent (34/72) were alive after transplantation. Of the 92 patients receiving the Jarvik TAH (the most frequently used device) as a temporary device, 67% (62/92) were transplanted (6 currently supported) and 55% were alive after transplantation; 85% were back to work, with a normal life-style. The thromboembolic rate for patients who received the device as a temporary support was 10%, with 3 patients having residual sequellae. No deaths resulted from mechanical failure. Experience to date suggests that the use of the TAH as a temporary device can be beneficial if patients are carefully selected.

Adolescent↗
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Use of the total artificial heart as an interim device: initial experience in Pittsburgh with four patients.

The experimental use of the total artificial heart as an interim device before heart transplantation has demonstrated its potential usefulness. Once again there has been a reaffirmation of the basic principle in transplantation that careful selection of patients is a prerequisite for a high likelihood of success. Our experience suggests that advanced degrees of renal failure and liver dysfunction are not likely to be associated with a consistently useful interim support. Although our numbers of patients are quite small, we continue to be concerned by what appears to be the tendency for the development of severe thrombocytopenia not resulting from the use of heparin. Studies of platelet kinetics and deposition are planned for the future. Although no recipient has had direct evidence of thromboembolic events, systemic anticoagulation with heparin has been aggressively applied, and bleeding complications have been common. All Jarvik-7 hearts on which autopsies have been performed have demonstrated grossly evident platelet fibrin thrombi, especially around the inlet and outlet valve housings. It has not been our purpose to investigate the relative role for univentricular or biventricular assist. It is likely that a number of our patients might have benefited from left ventricular assistance alone. It would appear that additional patients are needed before strong conclusions can be formed regarding the potential benefits and risks of the current Jarvik-7 device or any total artificial heart as an interim method of support before heart transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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Summary of the world experience with clinical use of total artificial hearts as heart support devices.

A review of the world experience with the implantation of total artificial hearts has been carried out. Thirteen centers throughout the world have implanted 27 total artificial hearts in 26 patients. Eight different types of total artificial hearts have been employed. As of June 1, 1986, five of these individuals have had implants for permanent support. Of the other twenty-one patients, three patients died while on a total artificial heart, seven patients died following transplantation, two patients are waiting for transplant, and nine patients have successfully been transplanted and are presently alive. Various clinical preoperative and postoperative parameters are analyzed in this investigation.

Adult↗
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Prostaglandin E1: an effective treatment of right heart failure after orthotopic heart transplantation.

Three patients are presented who had life-threatening postoperative pulmonary hypertension after orthotopic heart transplantation. This pulmonary hypertension was unresponsive to standard therapy but responded dramatically to treatment with prostaglandin E1. The problem of evaluating and treating heart transplant patients with pulmonary hypertension and the role of prostaglandins are discussed.

Alprostadil↗
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Principles of laboratory isolation and identification of the human immunodeficiency virus (HIV).

Diagnosis of human immunodeficiency virus (HIV) infections has relied most frequently on detecting the presence of HIV antibodies in sera. In many situations, however, patients management can be significantly improved if the presence of HIV can be demonstrated in patients' specimens. In this review, the need and value of HIV isolation for confirming the diagnosis of HIV, for disease staging, and for monitoring the effectiveness of antiviral therapy are discussed. The steps involved in isolation of HIV, the cell systems permissive to HIV growth, and the procedures for virus identification are reviewed. Furthermore, methods available for the direct detection of HIV in patients' specimens are summarized. Although isolation of HIV is presently an elaborate procedure, as easier methods become available, it will play a large role in the management of HIV-infected individuals.

Acquired Immunodeficiency Syndrome↗
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Surgical positioning of the Jarvik-7 artificial heart.

The Jarvik-7 total artificial heart has been implanted in 18 patients at the time of this writing. Eleven patients received the 100 ml heart, and the remaining seven were treated with the 70 ml device. To date, five patients have been implanted for permanent use with an average survival in excess of 9 months, and the longest survival is more than 1 1/2 years following implantation of the heart. Complications related to positioning were a contributing factor in the death of one patient. Thirteen patients have received the Jarvik-7 heart as a bridge to transplant. Three died before transplant, and the remaining ten have been transplanted. To date, all are alive, several are home and in excellent condition, and several are still hospitalized but are expected to be released shortly. Three patients have experienced serious complications after transplantation. One patient rejected her heart transplant, was reimplanted with the artificial heart, and now has been sustained for more than 3 months. At this time she is in good condition awaiting a second donor. Selection of the appropriate size Jarvik-7 artificial heart for the individual patient can best be made based on measurements of thoracic dimensions obtained from a computed tomography scan and calculation of body surface area. The appropriate medial or lateral positioning can be determined and decisions concerning the lengths of the grafts and cuffs, excision or nonexcision of the left pericardium, and air drive line position can be made. The Jarvik-7 heart can be successfully used in patients from 50 kg. However, at the lower size limit in patients from approximately 50 to 65 kg, the risk of fit complications is the greatest and availability of an even smaller model heart would be desirable.

Adult↗