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Biomedical subjects

L D Joyce

Publications and source records attributed to L D Joyce.

At least 37 records · Page 2Linked to original sources
PubMed1984

Nutrition for the first Total Artificial Heart patient: implications for future patients.

Since the mid-1960s, millions of dollars in federal funds have been used for research in the development of the Total Artificial Heart (TAH). Significant advances in bio-materials and pump and energy systems, as well as animal experimentations, have led to the clinical reality of the TAH's use in man. On December 2, 1982, Dr. Barney Clark became the first recipient of a permanent TAH. He had been suffering from terminal congestive heart failure secondary to idiopathic cardiomyopathy. No other treatment was available, since, at the age of 61, he was too old for heart transplant. Dr. Clark's 112-day hospitalization was complicated by pulmonary problems, renal insufficiency, seizures, nosebleeds, and a broken heart valve. Dr. Clark appeared malnourished before surgery, and his numerous postoperative complications confounded attempts at nutritional support. Standard nutritional assessment techniques were inadequate or inappropriate in the face of severe edema, renal failure, and multiple transfusions. Although nitrogen balance was achieved intermittently, for the majority of his hospitalization Dr. Clark remained in negative nitrogen balance, due mainly to renal insufficiency. Some of the nutritional complications seen in the first TAH patient might have been preventable with early nutritional assessment and more aggressive support. The Artificial Heart Management Team at the University of Utah now includes a nutritionist, and future protocols outline detailed nutrition monitoring.

Forecasting↗
PubMed1984

Comparison of porcine valve xenografts with mechanical prostheses. A 7 1/2 year experience.

A total of 479 valve replacements were performed in 469 patients for aortic, mitral, and tricuspid disease. A total of 529 valves were implanted (311 Carpentier-Edwards, 118 Hancock, 94 Björk-Shiley, and six other mechanical valves). Of the 479 operations, 51.1% (245) were carried out in male patients and 48.9% (234) were carried out in female patients. The mean age was 57.6 years; however, 28.6% (137) of the operations were performed in patients over 65 years of age. One hundred five patients (21.9%) had had previous cardiac operations of one type or another. Follow-up was 99.6% and the average length of follow-up was 36.2 months. The overall operative mortality was 5.6%. The operative mortality in the isolated aortic valve replacement group was 2.0% and that in the mitral valve replacement group, 4.4%. There was a 5.9% valve explant rate in the Hancock series; however, no valve explants were required because of valve dysfunction in either the Carpentier-Edwards or the Björk-Shiley groups. The thromboembolic rate in the aortic valve position was 2.4, 1.1, and 2.1 emboli per 100 patient-years in the Hancock, Carpentier-Edwards, and Björk-Shiley groups, respectively. The thromboembolic rate in the mitral valve position was 2.8, 2.2, and 1.0 emboli per 100 patient-years in the Hancock, Carpentier-Edwards, and Björk-Shiley groups, respectively.

Aged↗
PubMed1983

Urokinase therapy for thrombosis of tricuspid prosthetic valve.

A 16-month-old child was born with pulmonic stenosis and a hypoplastic right ventricle. After palliative procedures, the patient began having signs of tricuspid insufficiency and stenosis necessitating a tricuspid valve replacement. A St. Jude Medical valve was implanted. While the child was on aspirin therapy, thrombus formation resulted in valve dysfunction. This thrombus was successfully dissolved with urokinase infusion, and normal valve function was restored.

Blood Coagulation Tests↗
PubMed1983

Response of the human body to the first permanent implant of the Jarvik-7 Total Artificial Heart.

The success of the first permanent total artificial heart implant would have been more obvious had the patient been able to be transferred from the hospital to an outlying home care setting. Nevertheless, several major achievements were realized. First, we were able to demonstrate that the total artificial heart will fit within an adult male chest without causing obstruction to inflow or outflow channels. Second, we were able to demonstrate that the total artificial heart would sustain life on a long-term basis (at least up to 112 days) without any evidence of systemic or local infection and without any untoward systemic effects. Third, we were able to demonstrate that the patient was able to tolerate a total artificial heart without complaint of the noise or the bulk of the drive system to which he required permanent attachment and that the patient could be comfortable and totally free of pain. An additional finding, which could not be assessed in the animal experimentations, was the fact that the patient was able to maintain higher CNS activity on an undisturbed basis following the implant of the total artificial heart. It is for these reasons that the entire University of Utah Medical Center staff feel great indebtedness to the patient and his family for demonstrating to the world the feasibility and the necessity for pursuing this device as a new therapy for end-stage heart disease.

Adolescent↗
PubMed1981

Mural thrombosis of the left atrium following replacement of the mitral valve.

The nature and incidence of postoperative mural thrombosis of the septal and/or posterior walls of the left atrium were studied in autopsy specimens of hearts from patients in whom the mitral valve had been replaced by a prosthesis 1 day or longer before death. The cases were divided into length of postoperative period as follows; Group I, 1 to 60 days, 57 cases; Group II, 61 days or longer, 36 cases. In Group I mural thrombus of the septal and/or posterior walls of the left atrium was found in 35 of 57 patients (61%). Thrombi against the septal wall tended to be broad and flat. Thrombi involving the posterior wall tended to be multifocal. In Group II, lesions interpreted as old thrombi of the atrial septum were found in 23 of 36 subjects (64%). Grossly, the old lesions were represented by gray nodularity. Histologically such lesions were consistent with organized thrombi. Superimposed recent thrombosis occurred in some cases. Systemic embolism occurred in each group. In the cases in which left-sided thrombi were restricted to the septal and/or posterior walls of the left atrium, systemic embolism was observed in 10 of 23 cases in Group I (43%) and in two of seven cases in Group II (29%). Obstruction of the mitral prosthesis by bulky mural thrombosis originating at the septal wall of the left atrium was observed in one case. The study suggests that the process of postoperative mural thrombosis of the septal and posterior walls of the left atrium may result from trauma to these structures during the operative procedure.

Adolescent↗
PubMed1980

Resistance to experimental peritonitis induced by local nonspecific stimulation of the reticuloendothelial system.

Zymosan, a yeast cell wall preparation from Saccharomyces cerevisiae, stimulates the reticuloendothelial system (RES) in animals. Pretreatment with zymosan induces resistance to several types of shock. We have shown evidence that zymosan given intraperitoneally (IP) induces greater protection than intravenous (IV) zymosan against E coli peritonitis in the rat. Moreover, IP zymosan has few systemic RES effects, which are commonly associated with IV zymosan. IV and IP zymosan stimulation were compared for effectiveness against experimental fibrinopurulent peritonitis in dogs (a peritonitis model quite similar to clinical peritonitis). Ten dogs received zymosan IV (10 mg/kg), ten dogs received zymosan IP (10 mg/kg), and eight dogs received an equal volume of saline IP on three consecutive days. On day 4, a 7.5 cm length of terminal ileum was isolated and its blood supply ligated to create an infarcted, blind loop of bowel. This loop was left in the peritoneal cavity for five days. Five-day survival was 80% (8/10) for the zymosan IP (P less than 0.05), 60% (6/10) for the zymosan IV and 12.5% (1/8) for the saline controls. All survivors were sacrificed at five days and found to have an intact enteric anastomosis with varying degrees of walled-off abscess at the site of the necrotic loop. Histologic evaluation of intraabdominal organs, peritoneum, and abscess wall was carried out. The IP zymosan had no significant systemic RES effects, whereas the IV zymosan produced a marked increase in liver and spleen weights. These findings reinforce the hypothesis that local nonspecific RES stimulation could have a major role in the preparation of certain high-risk patients for abdominal surgery where the chance of peritoneal soilage is high.

Animals↗
PubMed1979

Enhancement of local immune response in the treatment of experimental peritonitis.

We conclude from these experiments that the host defense in peritoneal infections rests largely on the phagocytic cells attracted into the peritoneal cavity by the offending organism, and that an increase in the number of available phagocytes by pretreatment with chemotactic substances protects against lethal peritoneal infections. There seems to be a direct relationship between the number of available phagocytes in the peritoneal cavity at the time of inoculation and the reduction of mortality in experimental peritonitis (Fig. 1).

Animals↗
PubMed1978

Zymosan-induced resistance to endotoxin and hemorrhagic shock.

Improved surgical techniques and judicial use of available antibiotics have reduced the number of postoperative complications over the past decade. However, septic and hemorrhagic shock occur all too frequently, and each carries with it an appreciable morbidity and mortality. Endotoxins and hemorrhage are both known to suppress the phagocytic activity of the reticuloendothelial system (RES). On the other hand, zymosan, a yeast (Saccharomyces cerevisiae) cell wall preparation administered intravenously, results in temporary RES hyperplasia and increased phagocytic activity. Dogs were pretreated with zymosan to determine the degree of RES stimulation and protection against endotoxin and hemorrhagic shock attainable. Twenty-five dogs received intravenous zymosan (10 mg/kg) on days 1, 2, and 3. Another 24 dogs served as controls. On day four, one-half the animals in each group received E coli endotoxin (1.5 mg/kg) intravenously. The other animals underwent two hours of hemorrhagic shock at a mean blood pressure of 40 mm Hg. Seventy-two hour survival was as follows: Endotoxin treated, 66.7% (8/12); endotoxin control, 27% (3/11); hemorrhagic treated, 53.3% (8/15); and hemorrhagic control, 28.6% (4/14). Hemodynamic, metabolic, and lysosomal enzyme parameters were evaluated. No zymosan toxicity was observed. These findings suggest that an RES stimulant such as zymosan could be incorporated as preoperative adjunctive therapy to induce resistance to these shock syndromes in the elective surgical patient.

Animals↗
PubMed1978

Evaluation of the mechanism of zymosan-induced resistance to experimental peritonitis.

Three injections of intraperiotoneal (IP) zymosan-induced profound resistance to E. coli peritonitis in Sprague-Dawley rats. IP zymosan had minimal effects on organ weights and systemic phagocytic clearance ability, suggesting that this mode of administration had few systemic reticuloendothelial system (RES) effects. Hemoglobin (a known inhibitor of local phagocytosis) reduced the protection induced by zymosan, giving further evidence that IP zymosan acts locally. IP zymosan stimulation results in an initial marked influx of polymorphonuclear cells followed by a greater percentage replacement of mononuclear cells by the third day. Examination of these cells via chemiluminescence studies demonstrated that the phagocytic capacity of zymosan-stimulated peritoneal cells was markedly greater than the control group on a cell-for-cell basis. IP zymosan also gave some protection against intravenous (IV) E. coli, but IV zymosan did not significanly protect against IP E. coli. Possible mechanisms of action are discussed. These findings suggest that a technique of local RES stimulation could have a place in preparation of certain high-risk patients for elective abdominal surgery where peritoneal contamination is likely.

Animals↗
PubMed1978

Reduction of experimental myocardial infarct size by combined treatment with methylprednisolone sodium succinate and betahistine hydrochloride.

This laboratory and others have shown that methylprednisolone sodium succinate and betahistine hydrochloride can each reduce the size of experimental myocardial infarct in dogs at six hours. In light of the fact that these two agents probably act via different mechanisms, a study was carried out to determine if there would be cumulative effects of using these two agents together. Using a left anterior descending coronary artery ligation model to create an experimental myocardial infarction and an intracellular lactic dehydrogenase (LDH) stain to measure the infarct size, 66 dogs were studied. Nineteen dogs served as controls with no therapy; 20 received a continuous intravenous infusion of betahistine hydrochloride (0.24 mg/kg/min) for six hours following ligation; 10 dogs received methylprednisolone sodium succinate intravenously 30 mg/kg at one hour postligation; and 17 other dogs received betahistine hydrochloride intravenously (0.24 mg/kg/min) over six hours following ligation, plus methylprednisolone sodium succinate intravenously (30 mg/kg) at one hour postligation. At six hours, the combined treatment demonstrated no significant improvement over betahistine HCl alone (control, 16.0%; betahistine HCl, 11.4%; combined, 11.2% P less than 0.05). At 24 hours, only the combined treatment group demonstrated a significant infarct size reduction (control, 15.5%; methylprednisolone, 13.1%; betahistine--HCl, 14.2%; combined, 9.7%; P less than 0.0025). Other parameters that were evaluated and analyzed include mean aortic pressure, left atrial pressure, cardiac index, total peripheral resistance, arterial and coronary sinus pH, pCO2, pO2, hematocrit, O2 consumption, O2 content difference, and coronary sinus lactate and creatine phosphokinase (CPK). These results suggest a significant cumulative effect in reducing infarct size over that achieved with one agent alone; however, further studies are needed to determine the appropriate dosage and temporal factors.

Animals↗
PubMed1978

Ball variance and fracture of mitral valve prosthesis causing recurrent thromboemboli.

This report documents the ninth case of ball variance in a Starr-Edwards Model 6000 mitral prosthesis occurring 10 years, 9 months after implantation. It is the fourth case of fracture of a mitral ball of any type. As this case illustrates, the presence of ball variance in the mitral position may be subtle. One must carry a high index of suspicion if the diagnosis is to be made and treatment undertaken before catastrophic events take place. The incidence of ball variance is likely to increase with the length of implantation. We recommend surgical replacement of the defective prosthesis immediately upon confirmation of diagnosis.

Adult↗
PubMed1976

Chylothorax after median sternotomy for intrapericardial cardiac surgery.

Chylothorax following cardiovascular surgery occurs with an incidence of 0.25 to 0.5 per cent. We are aware of only 5 reported cases in the literature following intrapericardial procedures. This report includes the forth documented case following ventricular septal defect closure and the first 4 reported cases following median sternotomy for intrapericardial acquired cardiac disease. The fistula in all cases occurred in the anterior mediastinum in the region of the thymic tissue. This problem can be prevented by surgical ligation of the thymic vascular structures at the time of dissection rather than the use of electrocautery. The treatment recommended is a 2 week trial of conservative therapy with a diet of medium-chain triglycerides and closed-chest suction. If this fails, surgical division of the fistula is recommended.

Adult↗
PubMed1976

Application of contemporary reconstructive techniques in head and neck surgery for anterior oral-facial cancers.

One hundred and seventy-eight patients underwent surgical therapy for oral and cervical cancers from 1964 to 1975. About 25 percent of the patients underwent neck dissection and/or "pull-through" procedures. However, majority of patients required a spectrum of reconstructive techniques extending from marginal mandibulectomy with or without skin flaps (39), partial mandibulectomy with immediate prosthetic mandible reconstruction (36), to extended resections with skin flaps or staged reconstructive procedures (48). The advantages and disadvantages of each reconstructive procedure have been observed and a scheme of graded management has been developed. The therapeutic goal is to maximize functional oral reconstruction without compromising tumor cure. There were two operative deaths--one from myocardial infarction after operation and one from halothane hepatitis. The tumors were grouped according to TNM classification. In the follow-up of the 178 patients, 47 per cent are known to be alive and free of tumor. The better results (greater than 70% free of tumor) are in the group with smaller tumors (less than 2 cm.) and no node involvement, and there are less favorable rates for those patients with larger tumors and nodal metastasis or invasion of adjacent structures. There was a 49 percent 2 year survival rate and 12 of the deaths were from nontumor causes. Ninety percent of these patients smoked more than one pack of cigarettes per day, accounting for the high rate of synchronous or subsequent oroairway cancers (7 percent). Seventy-five percent were considered to be "heavy alcoholics" with evidence of cirrhotic liver disease. These two factors significantly decreased the survival from rate 54 to 47 percent. The series shows that planned primary reconstructive surgery can be done at a low risk, that it can enhance resectability of head and neck cancers, and that it does improve oral function after operation.

Adenocarcinoma↗
PubMed1976

Aberrant left pulmonary artery presenting as a right paratracheal mass in an adult.

Aberrant left pulmonary artery, or pulmonary sling, is a rare variation of the pulmonary vasculature, with only one previous report of the condition being recognized in an adult. In this report a second case recognized de novo in an adult is presented. Both of these adults were evaluated because of right paratracheal masses which required differentiation from pulmonary malignancies. The barium swallow shows a characteristic indentation of the anterior esophageal wall and the lateral tomogram demonstrates absence of the left pulmonary artery from its normal position in the left hilum. The pulmonary arteriogram is diagnostic and allows avoidance of more invasive diagnostic measures.

Airway Obstruction↗