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Biomedical subjects

J T Davis

Publications and source records attributed to J T Davis.

At least 91 records · Page 5Linked to original sources
PubMed1983

Coronary artery bypass grafts. Success after selective intracoronary thrombolysis in acute myocardial infarction.

Thirteen of 19 patients undergoing streptokinase infusion within five hours after acute myocardial infarction were deemed satisfactory candidates for bypass surgery. In all cases, operation was performed within less than a week, with no demonstrable ill effects from the enzyme. There was only one pulmonary-related death and only two patients in whom the results have been less than satisfactory. Eleven patients have markedly benefited from the combination of procedures, demonstrating excellent functional myocardial preservation. Radioisotope myocardial scan, exercise ECG, and repeat cardiac catheterizations have been used to assess myocardial status.

Adult↗
PubMed1983

Coronary artery bypass surgery in the septuagenarian.

Analyzed during a 3-year period were 86 patients from 70 to 80 years of age who underwent coronary artery bypass grafting without other cardiac procedures. The series included 57 men (66%) and 29 women (34%). The average follow-up period was 27 months. The early mortality rate for the men was 5.2%, and the overall mortality was 8.7%. This compared with an age-adjusted nationally expected death rate of 12.1% for this age group during this period of time. The early mortality rate for the women was 6.9%, with an overall mortality rate of 13.9%. This compared with an 8.7% age-adjusted nationally expected death rate. Factors which did not affect mortality in this particular series included smoking, hypertension, diabetes, and ejection fraction. Factors which did affect mortality included peripheral vascular disease (29% mortality), and postoperative complications (38% mortality). Of the 86 patients operated on from 1978 through 1980, ages 70 to 80, 88% are alive (76 of 86 patients). Of the patients living, 60.5% have no chest pain, and 26.3% describe their chest pain as significantly improved. When medical treatment alone fails, coronary artery bypass grafting is possible in the older age group to relieve disabling angina and improve the quality of life, with very acceptable mortality rates.

Journal Article↗
PubMed1980

A twenty-year experience with surgical management of carcinoma of the esophagus and gastric cardia.

Twenty years of experience with operative treatment of carcinoma of the esophagus and cardia are reviewed. Of the 513 patients with biopsy-proved malignancy reviewed, 211 (41%) underwent gastroesophagectomy. The hospital mortality rate for the patients operated upon was 12%. The 3 year survival rate was 26% and the 5 year survival rate was 15% for the entire surgical series. Squamous cell carcinomas of the lower third were the most favorable subgroup (25% 5 year survival) and lower third adenocarcinomas the least favorable (8% 5 year survival). Our procedure of choice is a one-stage resection with stomach used to restore continuity. Operative details and perioperative management are reviewed. The single-layer wire technique of anastomosis seems to give acceptably low rates of anastomotic leak (4.2%) and stricture (2.3%). Preoperative radiation was not used in this series.

Adenocarcinoma↗
PubMed1980

Aortoiliac occlusive disease in women.

Seventy-five women with aortoiliac (A-I) occlusive disease requiring vascular reconstruction during the past 4 years were reviewed. They represented a growing proportion (39%) of all patients with A-I disease And presented at the same meAn age (57 years) as males. Standard cardiovascular risk factors were high in this group and cigarette smoking was especially predominate (93%). Women presented with elevated triglyceride levels as opposed to increased cholesterol, with frequent type IV hyperlipoproteinemia. An operative mortality rate of 0%, a 4-year graft limb patency of 94%, and a 4-year life-table survival of 93% were observed. Good or excellent long-term relief of symptoms occurred in 96% of patients despite tandem ((superficial femoral) disease in 42% but only 4% superficial femoral reconstruction. A definition of women with "small vessels" was established by using aortic diameter > 1 SD below the overall mean (> 1 cm diameter at the aortic bifurcation). Women in this subgroup presented at a younger age with less severe symptoms, fewer risk factors, and more localized disease. An emphasis on postoperative reduction of cigarette smoking and dietary modification among hyperlipidemic patients probably contributed to the satisfactory results achieved in this increasing percentage of women with A-I occlusive disease.

Adult↗
PubMed1977

Immersion diuresis in dogs.

The mechanism of diuresis during the 1st h of immersion was investigated using anesthetized dogs. Four different experiments were carried out. First, left atrial transmural pressure was measured before, during, and after immersion. The data suggest that, although the left atrium may or may not be stretched depending on the conditions of immersion, the amount of diuresis is independent of the amount of left atrial stretch, and therefore a causal relationship between diuresis and left atrial stretch could not be established. Second, bilateral cervical vagotomy was carried out. Immersion diuresis sometimes occurred despite this vagotomy, suggesting that the left atrial stretch reflex was not participating in those cases. Third, negative-pressure breathing was carried out to simulate the negative transthoracic pressure associated with uncompensated immersion. The average left atrial transmural pressure did not change. A slight hemodilution and a moderate diuresis occurred. There was no correlation between changes in left atrial transmural pressure and changes in urine ouput. Fourth, blood studies were done on splenectomized dogs subjected to immersion. Hemodilution occurred and was most marked in dogs which had had their kidneys removed. The hemodilution is sufficient to explain the early phase of the immersion diuresis. The data suggest that, in anesthetized dogs, hemodilution is the probable initiator of diuresis upon immersion and that, in dogs, left atrial stretch is unrelated to diuresis during immersion or negative-pressure breathing.

Animals↗
PubMed1977

Judged brightness as a function of dark, intermediate, and light adaptation.

33 subjects were randomly assigned to a dark-, intermediate-, or light-adapted condition. They were then presented with two lighted surfaces of different brightness and asked to adjust the comparison stimulus to apparent equality with that of the standard stimulus. Results showed a significant interaction between adaptation level and stimulus intensity. The dark-adapted group showed greater accuracy at low stimulus intensities than at medium or high, while the intermediate- and light-adapted groups were more accurate in judging brightness at medium and high stimulus intensities. Differences in perceived brightness were cited as contributing to this finding.

Adaptation, Ocular↗