PubMed Health⌕ Search

Biomedical subjects

B P Griffith

Publications and source records attributed to B P Griffith.

At least 199 records · Page 11Linked to original sources
PubMed1991

Guinea pig model of transplacental congenital cytomegaloviral infection with analysis for labyrinthitis.

Cytomegalovirus is the most frequently recognized cause of congenital viral infection and of viral induced congenital hearing loss. Histopathologic reports on temporal bones from nine congenitally infected infants have most often demonstrated an endolabyrinthitis. The guinea pig and its specific cytomegaloviruses have been studied extensively as a model of transplacentally acquired infection. However, to date no investigation has been performed on the inner ear of such congenitally infected animals. To determine if a congenital viral labyrinthitis occurs in these guinea pigs, a study was conducted in which pregnant Hartley and Strain 2 guinea pigs were injected intraperitoneally with virulent salivary gland passaged cytomegalovirus during the first, second, or third trimester. Various durations of gestation up to delivery were permitted and selected organs from the products were then studied with routine histologic and immunocytochemical methods and cell cultures to verify the presence of transplacental infection. The temporal bones were studied with routine histopathology as well as immunocytochemical methods to detect cytomegalovirus antigen. Over 190 products of conception studied in this fashion revealed no evidence of teratogenesis or labyrinthine infection. It is not clear why in the presence of viremia, which resulted in cytomegalovirus infection of multiple organs, the inner ears of these animals were apparently spared.

Animals↗
PubMed1991

Cardiac transplantation at the University of Pittsburgh: 1980 to 1991.

When examining survival rates following cardiac transplantation, it is important to examine the risk factors for both early (30-day) and late (greater than 30-day) survival as they may well be different. Factors affecting early survival appear related more to the preoperative condition of the patient (including degree of pulmonary hypertension) as well as advances that have been made in postoperative care. It is not immediately obvious why gender has such a profound effect on early survival and why primary graft failure rates appear higher in this group. Donor organ factors did not appear to relate to this difference. On the other hand, late survival appears to be influenced mainly by immunologic factors such as panel reactive antibody level and immunosuppressive protocol. A less dramatic effect of transpulmonary gradient appears to have a lasting effect on recipients even when they survive the initial 30-day period. Thus, pulmonary hypertension may have prolonged effects on the cardiac allograft which as yet we do not understand completely. The majority of late mortality is still due to graft atherosclerosis, infection, and acute cellular rejection, the latter 2 occurring most frequently within the first year after transplantation whereas death from graft atherosclerosis becomes most prominent beyond 5 years. Despite persistent improvements in 30-day survival, late survival following cardiac transplantation will only improve with the advent of better tissue matching and improved immunosuppression. The results with FK506, for example, are promising.

Adult↗
PubMed1991

Progression of systemic disease and reduced long-term survival in patients with cardiac amyloidosis undergoing heart transplantation. Follow-up results of a multicenter survey.

Amyloid heart disease has been considered a contraindication for cardiac transplant based on the hypothesis that it is a systemic disease and that amyloid deposition would occur in the cardiac allograft. A survey was sent to all of the US centers and a limited number of Canadian and European centers listed with the International Registry. Twenty-four centers responded, and data were ultimately provided for a total of 10 patients (3 men, 7 women, mean age 48 years, range 30-60 years) who were transplanted for cardiac amyloid. The diagnosis of cardiac amyloidosis was made histologically on endomyocardial biopsy and/or examination of the explanted heart. Additional documented organ involvement included liver (two of 10), rectal (three of 10), renal (two of 10), gingiva (two of 10), and tongue (one of 10), although invasive biopsies were not performed in a majority of patients. A specific amyloid protein was identified in eight patients (seven lambda, one kappa immunoglobulin light chain). Although four of the surviving nine patients (one perioperative death) developed recurrent amyloid deposition in the allograft, it was detected solely by electron microscopy in two of these and had no clinical significance. There was, however, a progressive risk of major organ involvement with organ function impairment in this group (22% at 12 months, 50% at 24 months, 66% at 48 months). Although the immediate and early postoperative outcomes were not dissimilar between this group and patients undergoing transplantation for other cardiac diseases, late survival was reduced (39% at 48 months) compared with the larger population, but differences were not statistically significant due to the small amyloid sample size (p = 0.16).(ABSTRACT TRUNCATED AT 250 WORDS)

Amyloidosis↗
PubMed1991

Evolution of human cardiac myocyte dimension during prolonged mechanical support.

In animal models using left ventricular assist systems over long time periods, myocardial cellular atrophy has been reported, raising concern that prolonged clinical use of such systems might lead to deterioration in left ventricular function. At the University of Pittsburgh, long-term clinical use of the Novacor (Baxter Healthcare Corp., Novacor Div., Oakland, Calif.) left ventricular support system for patients awaiting heart transplants has allowed study of the effects of long-term mechanical support on human subjects. This study determined that cardiac myocyte dimension is initially greater in patients with end-stage cardiac disease who require support rather than in patients with the same disease who do not require such support. Although myocyte dimension does decrease within a few days of the inception of support, this decrease merely brings cell size closer to the values usual in patients with chronic end-stage cardiac disease, and no further shrinkage is observed. Thus the Novacor left ventricular assist system does not appear associated with left ventricular atrophy, and its long-term use may not be detrimental to left ventricular function.

Cardiomyopathies↗
PubMed1990

Donor-specific cytotoxicity testing: an advance in detecting pulmonary allograft rejection.

Ten beagle dogs underwent left unilateral lung transplantation and were treated with cyclosporine and azathioprine. After three days, cyclosporine administration was discontinued and azathioprine administration was maintained at a suboptimal dose to allow a graded response to the pulmonary allograft. Dogs were monitored by chest roentgenogram, bronchoalveolar lavage (BAL), and sampling of peripheral blood lymphocytes at weekly intervals. Open lung biopsies also were performed at weekly intervals in 5 of the dogs. Lymphocytes from the BAL and peripheral blood and those grown in culture from open and transbronchial biopsy specimens were tested for donor-specific cytotoxicity (DSC) by testing their responsiveness to lymphocytes from their donor. Rejection was confirmed in all animals. Donor-specific cytotoxicity became detectable in all animals in either the BAL fluid or biopsy specimens. An abnormal chest roentgenogram developed in 9 dogs, but not until after DSC was detected in the BAL in 7. In the open biopsy specimens tested for DSC, all exhibited DSC synchronous with the first changes noted on chest roentgenogram. Donor-specific cytotoxicity was sensitive for detecting rejection in 8 of 9 dogs in the BAL and in 5 of 5 dogs in the open biopsy specimens. Based on these results, 3 additional dogs were maintained on cyclosporine. Two of these dogs did not reject their transplants and had no evidence of DSC. We conclude that donor-specific functional assays provide an advance over less sensitive clinical techniques.

Animals↗
PubMed1990

Experience with univentricular support in mortally ill cardiac transplant candidates.

Between July 1987 and March 1989, 11 patients underwent left ventricular support with the Novacor left ventricular assist system irrespective of apparent degree of right ventricular failure. The first 2 patients died of multisystem organ failure while on support. All the remaining patients survived the support period, and actuarial survival after transplantation was 100% at 6 months and 89% at 1 year. In no patient did bacterial infection develop during support or after transplantation. Right ventricular ejection fraction before implantation of the left ventricular assist system was lower than 15% in 6 of 8 patients, yet it increased twofold during left ventricular support. The need for excessive inotropic support (2 patients) or temporary (four days) mechanical right ventricular support (2 patients) while on the left ventricular support system appeared to be related to elevated pulmonary vascular resistance during support in association with large preimplantation ventricular volumes. It appears that even patients with compromised right ventricular performance can be supported long term with a left ventricular assist device. Patients with elevated pulmonary vascular resistance may require temporary right ventricular support.

Adult↗
PubMed1990

Potential role of dendritic cells in bronchiolitis obliterans in heart-lung transplantation.

Dendritic cells are essential for the activation of the type IV immunological reactions that are intrinsic to rejection of transplanted organs. We evaluated the number of dendritic cells in the recipient and donor portions of the trachea and donor bronchi of 6 heart-lung transplant recipients, 3 of whom had evidence of bronchiolitis obliterans, a presumed manifestation of chronic rejection of the lung. As compared with recipients without bronchiolitis obliterans, patients with it showed a significant increase in the number of S100-protein-positive dendritic cells in the tracheal and bronchial epithelium and submucosa of the donor organs. This finding of increased accessory cells in the transplanted mucosa provides support for the belief that bronchiolitis obliterans is an immunologically mediated form of chronic rejection.

Bronchi↗
PubMed1990

Disruption of the aortic anastomosis after heart-lung transplantation.

Disruption of the aorta at the anastomotic site occurred in 4 of 66 consecutive heart-lung transplant recipients and was associated with a 100% mortality. In 3 of these patients, Candida either was cultured from the suture line or was seen in the wall of the aorta at postmortem examination. In 2 of these 3 patients, cultures of material from the donor trachea taken at the time of explanation grew Candida species. Two patients were seen with sudden massive hemorrhage on postoperative day 26 and postoperative day 28. One patient experienced acute decompensation due to right ventricular outflow tract obstruction on postoperative day 30, and the remaining patient was seen 7 months postoperatively with obstruction of both the left main bronchus and the right pulmonary artery caused by extrinsic compression by an aortic pseudoaneurysm. A high index of suspicion should be maintained when transplanting lungs containing Candida species, as we believe there is substantial evidence of donor transmission of the fungal agents. We now include amphotericin B in our antibiotic prophylactic regimen in an attempt to prevent fungal infection because previous treatment has been uniformly unsuccessful. Furthermore, we wrap both the trachea and the aorta with omentum to lessen the likelihood of mediastinal spread of infection to the aortic suture line.

Adolescent↗
PubMed1990

Clinical experience with the Medtronic-Hall valve prosthesis.

Medtronic-Hall valves were implanted during 204 procedures performed between 1982 and 1988. Mean population age was 54.4 years; 96% of patients were in New York Heart Association functional class III or greater. Emergency operations constituted 16% of the procedures. Rheumatic heart disease was the single most common indication for valve replacement. In 18% of patients, operation was performed to replace a previous prosthetic valve. The mean follow-up was 3.2 years. Overall operative mortality was 10.3%, the highest mortality being for double-valve replacements (24%). Valve-related mortality, by position, was 5.3% for aortic valves, 6.0% for mitral valves, and 4.0% for multiple-valve replacements. Actuarial 5-year freedom from events were: survival, 68%; thromboembolism, 90%; prosthetic valve endocarditis, 98%; paravalvular leak, 95%; and reoperation, 92%. Complications with the highest mortality were thromboembolism (36%) and endocarditis (33%). The complication rates in this series are high but the patients were more severely ill than in other reports, and operative survivors experienced a considerable improvement in New York Heart Association functional class.

Aortic Valve↗
PubMed1990

Cellular localization of cytomegalovirus nucleic acids in guinea pig salivary glands by in situ hybridization.

In situ hybridization with guinea pig cytomegalovirus (CMV) DNA probes was used to detect guinea pig CMV nucleic acid sequences in salivary glands during the course of infection. Optimum conditions for detection of guinea pig CMV gene sequences at the cellular level were determined. The technique of nucleic acid hybridization was compared to antigen detection and histologic examination for cellular localization of guinea pig CMV during acute and chronic infection. Tissue sections fixed for 1 h in 4% paraformaldehyde demonstrated darker specific staining and contained significantly larger numbers of cells positive for guinea pig CMV nucleic acids and antigens than sections fixed longer and in other fixatives. The method of in situ hybridization detected more guinea pig CMV infected cells than did routine histological evaluation. Histologically normal salivary gland duct cells as well as cells bearing typical inclusions were found to contain guinea pig CMV nucleic acids. Guinea pig CMV nucleic acids were also detected although less frequently in cells outside of the ducts. These results suggest that in situ hybridization allows for the detection of histologically inapparent guinea pig CMV infections at the cellular level.

Animals↗
PubMed1990

Propagation of infiltrating lymphocytes and graft coronary disease in cardiac transplant recipients.

The pattern of lymphocyte growth from endomyocardial biopsies in 55 heart transplant recipients was shown to be correlated with the subsequent development of graft coronary disease. Persistent lymphocyte growth was observed in 39 patients, and 15 of these growers (or 41%) developed graft coronary disease. In contrast, only 1 of 15 patients (or 6%) with nongrower biopsies showed subsequent graft coronary disease. Thus, biopsy growth was associated with a higher incidence of subsequent GCD (p = 0.02). A comparison between the group of 15 growers with subsequent graft coronary disease and the 24 growers without subsequent graft coronary disease did not show any differences with respect to patient age, presence of coronary artery disease in the native heart, biopsy histology, donor alloreactivity of biopsy grown lymphocytes, and immunosuppressive drug regimen. On the other hand, the number of treated rejection episodes was significantly lower in the grower group with subsequent graft coronary disease (p = 0.04). These data support the concept that graft coronary disease may involve rejection and that more immunosuppression may lower its incidence. This concept is strengthened by findings showing that alloreactive T cells can be propagated from coronary arteries of cardiac allografts with graft coronary disease.

Biopsy↗