Biomedical subjects

R I Whyte

Publications and source records attributed to R I Whyte.

13 recordsLinked to original sources

PubMed1992

Adjuvant treatment using transfer factor for bronchogenic carcinoma: long-term follow-up.

Transfer factor, a dialyzable lymphocyte extract that may act as an immune stimulator by transferring antigen-specific immunity between genetically dissimilar individuals, was administered in a prospective, randomized study to patients with non-small cell bronchogenic carcinoma. Between 1976 and 1982, 63 patients who underwent pulmonary resection, mediastinal lymph node dissection, and, when indicated by the presence of mediastinal lymph node involvement, mediastinal irradiation were randomized into two groups. Group 1 (n = 28) received 1 mL of pooled transfer factor at 3-month intervals after operation; group 2 (n = 35 ) served as controls and received saline solution. There were no statistically significant differences between the two groups with respect to age, sex, tumor histology, stage of disease, or extent of resection. One patient was lost to follow-up at 96 months; follow-up was complete in all others through July 1990. In patients receiving transfer factor, the 2-, 5-, and 10-year survival rates were 82%, 64%, and 43% respectively, whereas in controls they were 63%, 43%, and 23%. Survival in patients receiving transfer factor was consistently better than in those receiving placebo. Furthermore, survival in patients receiving transfer factor was greater at all stages of disease for both adenocarcinoma and squamous cell carcinoma. Although these long-term results were not statistically significant using survival analysis with covariates (p = 0.08), they confirm our previously reported short-term findings suggesting that administration of transfer factor, either through nonspecific immune stimulation, enhancement of cell-mediated immunity, or an as yet undefined mechanism, can improve survival in patients with bronchogenic carcinoma.

Adenocarcinoma↗

PubMed1992

Binding and neutralization of endotoxin by Limulus antilipopolysaccharide factor.

In order to examine the ability of Limulus antilipopolysaccharide factor (LALF) to bind lipopolysaccharide (LPS), we purified LALF to homogeneity from Limulus amoebocyte lysate and coupled it covalently to agarose beads. LALF-coupled beads captured more tritiated LPS from rough and smooth strains of gram-negative bacteria than did control human serum albumin-coupled beads. Unlabeled homologous and heterologous LPS competed for the binding of 3H-LPS to LALF-coupled beads. LALF bound LPS in a dose-dependent manner as assessed by the precipitation of LPS-LALF complexes with 50% saturated ammonium sulfate. We also studied the ability of LALF to neutralize LPS. LPS preincubated with LALF was less mitogenic for murine splenocytes, was less pyrogenic in the rabbit fever assay, was less lethal in mice which had been sensitized to LPS with actinomycin D, and induced less fever, neutropenia, and pulmonary hypertension when infused into sheep. Our findings extend prior studies which suggested that LALF binds to and neutralizes LPS from multiple strains of gram-negative bacteria.

Animals↗

PubMed1992

Tumor emboli from lung neoplasms involving the pulmonary vein.

Systemic tumor embolization during pulmonary resection for lung neoplasms is an uncommon but potentially catastrophic complication. In recent months, two patients undergoing pulmonary resection for bronchogenic carcinoma were found at operation to have tumor extending into a pulmonary vein. Both patients had systemic tumor embolization, one with a fatal outcome because of occlusion of the superior mesenteric artery. The possibility of systemic tumor embolization should be considered in patients with large, central tumors and particularly those that abut the pulmonary veins. The implications of such pulmonary vein involvement is reviewed, and an algorithm for postoperative evaluation and management of these patients is presented.

Aged↗

PubMed1990

Esophagogastrectomy via left thoracophrenotomy.

Esophagogastrectomy is generally considered to be the treatment of choice for resectable tumors of the esophagus. Although many approaches and techniques have been advocated, since April 1983 we have used a left thoracophrenotomy approach for most lesions of the lower two thirds of the esophagus and gastric cardia. Stapling instruments have been used for mobilization of the stomach and fashioning of the esophagogastric anastomosis. One-hundred fifteen patients undergoing resection of malignant tumors with this technique were retrospectively reviewed. Perioperative mortality was 8.7% (10/115). The rate of anastomotic leakage was 1.7% (2/115), and benign narrowing of the anastomosis requiring dilation developed in 16 patients. The rate of recurrent anastomotic tumor was 4.3%. Eighteen patients had complications, and the mean postoperative hospital stay was 13 days. Survival at 3 years was 22.1%. During the period of study, 22 patients underwent esophageal resection by some other approach; the reasons for this are described. The advantages of the left thoracophrenotomy approach are discussed.

Adult↗

PubMed1989

Clinical and ultrasound results after aortic valve replacement: intermediate-term follow-up with the St. Jude Medical prosthesis.

Mortality, morbidity, quality of life, and left ventricular (LV) function were evaluated in 49 patients after aortic valve replacement with the St. Jude prosthesis. Total follow-up was 2577 patient-months; survivors were followed-up for 4 to 7 years by clinical examination and echocardiography. The actuarial survival rate at 6 years was 79.6%, and there were no valve-related deaths. The linearized rates for thromboembolism and hemorrhage were 0.93% and 3.26% per patient-year, respectively. In 34% of the survivors the quality of life was poor. In the first three postoperative months, patients with aortic stenosis (n = 12) had a significant decrease in the muscle cross-sectional area (p less than 0.01) and patients with aortic regurgitation (n = 11) had decreases in both LV end-diastolic diameter (p less than 0.05) and cross-sectional area (p less than 0.001). All of these results were maintained at 5 years without modification of LV systolic function. Despite the good overall results, six patients deteriorated and had major LV dilatation. Multivariate logistic regression analysis identified two independent preoperative variables associated with a poor outcome defined as death of LV dysfunction (p less than 0.05): age and end-diastolic diameter. Thus meticulous follow-up showed a high incidence of hemorrhage and a poor quality of life in many of the survivors. It was concluded that in high-risk patients (age and end-diastolic diameter) surgery should probably be considered earlier.

Aortic Valve↗

PubMed1989

Recent surgical experience for pulmonary tuberculosis.

Lung resection for pulmonary tuberculosis is unusual today. Over a 10-year-period 31 patients with pulmonary tuberculosis underwent thoracotomy at this Regional Centre. Five of these were for complications of known tuberculosis; two subsequently proved to be complications of pulmonary tuberculosis, and the remainder were for suspected malignancy. The clinical features, radiology, microbiology, and pathology are reviewed and the contemporary role of the surgeon in the management of pulmonary tuberculosis is examined.

Adult↗

PubMed1989

Tolerance to low-dose endotoxin in awake sheep.

Dose response and tolerance to a small intravenous dose of Serratia marcescens lipopolysaccharide (LPS) were studied in awake sheep. Core temperature significantly increased after a dose of 0.002 micrograms/kg; changes in pulmonary arterial pressure, pulmonary vascular resistance, plasma thromboxane B2, and circulating leukocyte concentration occurred after 0.02 micrograms/kg; plasma 6-keto-prostaglandin F1 alpha increased after 0.2 micrograms/kg. Development of acute tolerance was studied by injection of S. marcescens LPS (0.02 micrograms/kg iv) on 3 consecutive days: pulmonary arterial pressure and thromboxane B2 levels were significantly lower than controls after the second dose, whereas fever and the degree of leukopenia were not diminished until the third dose. After intravenous administration of LPS given in increasing doses from 0.1 to 3.2 micrograms/kg three times weekly over 7 wk, there were no measurable changes in any of the above parameters after challenge with S. marcescens LPS (0.02 micrograms/kg) after a 1-wk rest period. In awake sheep, small intravenous doses of LPS can cause physiologically important changes of the pulmonary circulation and can alter the hemodynamic and eicosanoid mediator responses to subsequent challenges with LPS. Large intravenous doses of LPS can ablate the physiological responses to subsequent small doses of LPS.

Animals↗

PubMed1989

Sonomicrometric regional diaphragmatic shortening in awake sheep after thoracic surgery.

Through a right thoracotomy in seven sheep we chronically implanted sonomicrometry crystals and electromyographic electrodes in the costal and crural diaphragmatic regions. Awake sheep were studied during recovery for 4-6 wk, both during quiet breathing (QB) and during CO2 rebreathing. Tidal volume, respiratory frequency, and esophageal and gastric pressures were studied before and after surgery. Normalized resting length (LFRC) was significantly decreased for the costal segment on postoperative day 1 compared with postoperative day 28. Fractional costal shortening both during QB and at 10% end-tidal CO2 (ETCO2) increased significantly from postoperative days 1 to 28, whereas crural shortening did not change during QB but progressively increased at 10% ETCO2. Maximal costal shortening during electrophrenic stimulation was constant at 40% LFRC during recovery, although maximal crural shortening increased from 23 to 32% LFRC. Minute ventilation, tidal volume, and transdiaphragmatic pressure at 10% ETCO2 increased progressively after thoracotomy until postoperative day 28. Our results suggest there is profound diaphragmatic inhibition after thoracotomy and crystal implantation in sheep that requires at least 3-4 wk for stable recovery.

Animals↗

PubMed1989

Cervical thymectomy in the treatment of myasthenia gravis.

Treatment modalities in myasthenia gravis consist of surgery, chemotherapy and plasmapheresis. Thymectomy can be accomplished either through a median sternotomy or through a small, transverse cervical incision. Forty patients who underwent cervical thymectomy for non-thymomatous myasthenia gravis were studied retrospectively. Twenty-six patients (65%) showed a favourable response to thymectomy and there were statistically significant improvements in myasthenic symptoms and reductions in medication requirements. Age, sex, duration of symptoms and thymic histology were not predictive of response to thymectomy. Operative mortality was zero and operative morbidity was minimal. During the last 6 years, only two of 22 patients required admission to the intensive care unit postoperatively. The postoperative hospital stay ranged from 2 to 23 days. Cervical thymectomy does not preclude later sternotomy in those patients who fail to respond favourably. We therefore recommend cervical thymectomy as the initial surgical procedure in the treatment of non-thymomatous myasthenia gravis.

Adolescent↗

PubMed1988

Carcinoma of the bronchus with unsuspected microscopic resection-line involvement.

In a series of 560 pulmonary resections for bronchial carcinoma, unsuspected microscopic tumor was present at the bronchial resection margin in 26 patients (4.5%). Adjuvant chemotherapy or radiotherapy was given in two patients. In follow-up times ranging from 1 to 72 months (mean, 22 months), 58% of patients were alive and free of recurrent disease. Twelve patients underwent periodic surveillance bronchoscopy in an attempt to identify early local recurrence. Eighty-three percent of these patients were alive and disease-free in follow-up times from 4 to 72 months (mean, 29.7 months). Only one choscopies. It was concluded that microscopic residual resection-line tumor does not preclude prolonged survival and that no benefit from surveillance bronchoscopy could be demonstrated in this small patient sample.

Bronchi↗

PubMed1988

Oesophagogastrectomy using stapling instruments.

Oesophagogastrectomy is generally considered to be the treatment of choice for resectable tumours of the oesophagus. We have, since January 1980, used stapling instruments whenever possible for the resection and anastomosis. We have also, since June 1983, employed a left thoracotomy approach for lesions of the gastric cardia and mid- or lower oesophagus. One hundred and sixty four patients underwent oesophagogastrectomy during a seven year period, 75 via left thoracotomy. The overall peri-operative mortality was 7.9%. Complications occurred in 17% of patients with anastomotic leakage in 1.8% and anastomotic strictures in 9.7%. Mean hospital stay was 14 days. In the left thoracotomy sub-group mortality was 5%, the complication rate 23%, leak rate 3%, stricture rate 12% and mean hospital stay 13 days.

Adult↗

PubMed1987

Pulmonary resection using automatic stapling devices.

Between January 1980 and December 1986, 674 patients underwent pulmonary surgery at this institution under the supervision of one surgeon (RJD). Automatic stapling devices were used to close the bronchus in all but 12 patients. Malignant disease was the reason for 85% of resections. The operative mortality was 4.9% (3.2% in patients undergoing lobectomy and 8.3% in those undergoing pneumonectomy). The complication rate was 17.3%. Bronchopleural fistula (BPF) occurred in 11 patients, an incidence of 1.7%. The post-pneumonectomy incidence of BPF was 2.7% within 3 months of surgery and 4.5% overall. Stapled closure of one or more hilar vessels was employed in 153 patients. The role of staplers in pulmonary surgery with particular reference to the incidence of bronchopleural fistula is examined.

Adolescent↗

PubMedDate not supplied

Angiosarcoma of the carotid artery: a case report.

Angiosarcomas are rare tumors, particularly in the head and neck region. A case report of an angiosarcoma arising in the internal carotid artery is described; such an occurrence has not previously been reported. The etiology, pathology, and treatment of this unusual tumor are discussed.

Carotid Artery Diseases↗