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Biomedical subjects

J J Collins

Publications and source records attributed to J J Collins.

At least 307 records · Page 17Linked to original sources
PubMed1977

Rationale for seeking occult metastases in patients with bronchial carcinoma.

The usefulness of performing diagnostic staging tests on patients thought to have operable bronchial carcinoma was explored by modeling the diagnostic and therapeutic processes for patients with this disease. The availability of appropriate autopsy and survival data allowed this investigation. We analyzed the results of two diagnostic and therapeeutic strategies: a test strategy in which extensive staging tests are performed preoperatively on patients with Stage I or II disease and a no test strategy in which such examinations are not performed. Average survival times are little affected by the choice of the test or no test diagnostic strategy. The chance of an immediate postoperative death, of an unnecessary operation and of a long term cure are affected more. Within the error of measurement, financial costs for the two strategies are probably the same. This investigation is a prototype for estimating the value of diagnostic staging tests and the effects of consequent alternative methods of treatment for patients with known malignant conditions.

Bronchial Neoplasms↗
PubMed1977

A new look at the consultation continuum.

The purpose of this paper is to bring into sharp focus the intricate and vital linkages among the active participants in the consultation process (Figure 1). For too long the profession has been locked into a ritualistic, buck-passing processing frequently resulting in unorganized efforts on behalf of objects rather than subjects. The essential overriding concern then could well be represented by the center diagram (the patient and his family) and the supporting persons - communicating before, during, and after the consultation - completing a process which could bring about improvement in the quality of life for the patient, the referring physician, and the family. Through the added efforts to give feedback to the specialist we could conceivably improve the consultant's quality of life too.

Family Practice↗
PubMed1976

Small vessel replacement with gore-tex (expanded polytetrafluoroethylene).

Conduits of expanded, fibrillated polytetrafluoroethylene (PTFE [Gore-tex]) have been evaluated as small vessel prostheses in dogs during a 6-month period. A configuration of high porosity and low density, long fibril Gore-tex was found to yield the best patency in canine arteries (femoral and carotid) and veins (femoral) as compared with more dense, less porous PTFE with shorter fibrils. Host tissue reaction showed minimal inflammation, excellent infiltration, and formation of a smooth neointima, which suggested satisfactory acceptance of the prosthesis.

Animals↗
PubMed1976

Chromosomally depleted interspecific hybrid cell clones selected with cytotoxic antisera: utilization in the study of control of murine leukemia virus host-range.

A chromosomally stable mouse-Chinese hamster hybrid cell line was subjected to five rounds of selection with cytotoxic antisera raised in rabbits against either the parental mouse 3T3 cells or the parental Chinese hamster Wg-1 cells. Routine karyological analysis of clones isolated at each stage of serum selection revealed that treatment with either serum resulted in a limited loss of chromosomes (compared to the untreated hybrid cell cultured in parallel) and that the pattern of chromosome loss could not be correlated with the particular antiserum used for selection. However, more detailed analysis with the SSC-formamide C-banding technique, which identifies chromosomes containing a mouse centromere region, demonstrated that while large-scale chromosome loss was not achieved as a result of antiserum selection, the limited loss of chromosomes did, in fact, reflect a specific depletion of chromosomes in response to treatment with cytotoxic antiserum. Specific chromosomal elimination was shown to occur as early as the first round of antiserum treatment. Antigenic analysis of the serum-selected clones revealed a quantitative decrease in the expression of the species-specific surface antigens selected against, but no qualitative loss of antigens was detected. The results suggest that treatment with cytotoxic antiserum may select for clones that have lost specific chromosomes bearing genes regulating the expression of species-specific surface antigens, rather than for those demonstrating large-scale depletion of chromosomes bearing the corresponding structural genes. Some of these chromosomally depleted hybrid cell clones have been used (along with pseudotype viruses containing the genome of vesicular stomatitis virus within the envelope of murine leukemia virus, VSV [MuLV]), to study the mechanisms regulating MuLV replication in Chinese hamster cells. The results indicate that the restriction of MuLV replication in Chinese hamster cells operates at two levels: (a) an inability to adsorb to or penetrate Chinese hamster cells; and (b) an additional intracellular block which is dominant in the mouse-Chinese hamster hybrid cell clones examined. This latter block is presently under study.

Antigens↗
PubMed1976

Surgical treatment of congenital unilateral pulmonary arterial stenosis with contralateral pulmonary hypertension.

This report describes the diagnosis and surgical treatment of a 48 year old patient with congenital right pulmonary arterial ostial stenosis, no intra- or extracardiac shunts and systemic levels of pressure in the main and left pulmonary artery with pulmonary vascular obstruction in the left lung. Operation consisted of a bypass graft of 10 mm woven Dacron from the main pulmonary artery to the distal right pulmonary artery producing an immediate 50 percent reduction in mean left pulmonary arterial pressure. Late postoperative evaluation revealed equal perfusion of both lungs, maintenance of the reduced pulmonary arterial pressure and improvement from New York Heart Association functional class IV to class I.

Arterial Occlusive Diseases↗
PubMed1976

Emergency aortic valve replacement.

The aortic valve was replaced as an emergency in twenty-seven patients between July 1970 and December 1974. Twenty-two patients had critical aortic stenosis and five had acute aortic insufficiency. The indications for emergency surgery were cardiac arrest in five patients, low cardiac output in four patients, and medically intractable pulmonary edema in eighteen patients. Cardiac catheterization was not undertaken in ten persons because of their critical condition. The clinical diagnosis in these patients was supported by noninvasive maneuvers. No surgical deaths occurred. Twenty-five patients are well, active and NYHA Class I at five to thirty-three months after surgery. There has been one late death and one patient has some residual exertional dyspnea. One patient required reoperation to relieve a clotted prosthetic valve. These results suggest that the patient with aortic valve disease may be offered a reasonable chance for survival, even when desperately ill.

Adult↗
PubMed1976

Aortic valve replacement with the Hancock porcine xenograft.

The Hancock porcine xenograft stabilized with the glutaraldehyde process was used for isolated aortic valve replacement in 71 patients from March, 1972, to July, 1975. Aortic stenosis was the primary diagnosis in 52 patients and aortic insufficiency in 19. There were 52 men and 19 women ranging in age from 18 to 82 years; 14 patients were older than 70 years. One patient was in Functional Class II, 50 in Class III, and 20 in Class IV preoperatively. Seventy-three patients undergoing Björk-Shiley aortic valve replacement during the same period are presented for comparison. The operative mortality was 3% (2 of the 71 patients); 4 of the remaining 69 patients (6%) died in the late postoperative period. No patient was placed on anticoagulation during the postoperative course, and there was 1 postoperative embolus in a patient with chronic atrial fibrillation (1.4%). With a mean follow-up period of 17 months, 60 patients are now in Functional Class I, 4 in Class II, and 1 in Class III. Seven patients have had transvalvular gradients and effective valve areas measured postoperatively that ranged from 32 to 5 mm Hg and 0.9 to 2.9 cm2 in 21 through 25 mm (OD) sizes.

Adolescent↗
PubMed1976

Actuarial comparison of Hancock porcine and prosthetic disc valves for isolated mitral valve replacement.

From July 1970 through December 1974, 109 patients underwent isolated mitral valve replacement (MVR). A Harken prosthetic disc valve (DVR) was used in 53 patients and glutaraldehyde-preserved Hancock porcine xenograft (PVR) in 56 patients. The functional class, distribution of mitral valve pathology, and incidence of atrial fibrillation were similar in both groups. There were no operative and three (5.5%) late deaths in the PVR group and two (3.8%) operative and ten (19.5%) late deaths in the DVR group. Anticoagulants were not used in the PVR group; there were 3 nonfatal emboli (10%), all occurring in patients with atrial fibrillation and large left atria. Although anticoagulants were used there were 14 emboli (five in patients who died, nine nonfatal) in the DVR group (26.4%). In our experience, there is a significant reduction in morbidity and mortality, primarily from a reduced risk of thromboemboli, if a porcine valve is used for MVR. Anticoagulants should be used in patients with atrial fibrillation and enlarged left atria regardless of the type of valve used.

Adult↗
PubMed1976

Use of the augmented ejection fraction to select patients with left ventricular dysfunction for coronary revascularization.

Thirty-three patients with angina (31 men and 2 women, age 33 to 68 years, 52), as well as signs and symptoms of severe left ventricular dysfunction, were evaluated for coronary revascularization surgery. All had multiple vessel coronary artery disease and at least one prior myocardial infarction. Cardiac catheterization demonstrated abnormally elevated left ventricular end-diastolic pressure (LUEDP), low cardiac output, and depressed resting biplane systolic ejection fraction (SEF) ranging from 18 to 45 per cent (31 per cent). To evaluate potential myocardial function, a premature ventricular contraction was introduced during the ventriculogram and the SEF of the postextrasystolic potentiated (PESP) beat calculated and compared to a sinus beat SEF. Patients were separated into two groups based on the increase in SEF: those with greater than 0.10 augmentation (24 patients) and those with less than 0.10 augmentation (9 patients). Coronary revascularization was carried out with at least two bypass grafts in each patient. The operative mortality in those with more than 0.1 SEF augmentation was 9 per cent (2/24), late mortality rate 5 per cent (1/22), and 20/21 became Class I or II in the follow-up period of 11 to 57 months (25). Operative mortality in those with SEF augmentation of less than 0.1 3/9 33 per cent), late mortality rate 1/6, and only 1/5 achieved Class 1 status during the follow-up period of 10 to 35 months (22) postoperatively. These data suggest that significant augmentation of SEF by a premature ventricular contraction is a simple and useful indicator to aid in selection of patients with left ventricular dysfunction for coronary revascularization.

Adult↗
PubMed1975

Selective depletion of chromosomes in a stable mouse-Chinese hamster hybrid cell line using antisera directed against species-specific cell surface antigens.

A chromosomally-stable mouse-Chinese hamster hybrid cell line was subjected to five rounds of selection with cytotoxic antisera raised in rabbits against either the parental mouse 3T3 cells or the parental Chinese hamster Wg-1 cells. Routine karyological analysis of clones isolated at each stage of serum selection revealed that treatment with either serum resulted in a limited loss of chromosomes (compared to the untreated hybrid cell cultured in parallel) and that the pattern of chromosome loss could not be correlated with the particular antiserum used for selection. However, more detailed analysis with the SSC-formamide C-banding technique, which identifies chromosomes containing a mouse centromere region, demonstrated that while large-scale chromosome loss was not achieved as a result of antiserum selection, the limited loss of chromosomes did, in fact, reflect a specific depletion of chromosomes in response to treatment with cytotoxic antiserum. Specific chromosomal elimination was shown to occur as early asthe first round of antiserum treatment. Antigenic analysis of the serum-selected clones revealed a quantitative decrease in the expression of the species-specific surface antigens selected against, but no qualitative loss of antigens was detected. The results suggest that treatment with cytotoxic antiserum may select for clones that have lost specific chromosomes bearing genes regulating the expression of species-specific surface antigens, rather than for those demonstrating large-scale depletion of chromosomes bearing the corresponding structural genes.

Antigens↗
PubMed1975

Coronary artery anatomy before and after direct revascularization surgery: clinical and cinearteriographic studies in 67 selected patients.

This report relates the postoperative clinical and cineangiographic status of 67 patients selected from a total of 202 patients who underwent coronary artery surgery at the Peter Bent Brigham Hospital from July, 1970, to July, 1972. The mean interval after operation was 12.6 months. Ninety-one per cent of the 67 patients were improved from their preoperative status. Forty-eight patients (71 per cent) were studied to evaluate recurrence of mild to moderate angina or occurrence of interval myocardial infarction, and 19 patients (29 per cent) were entirely asymptomatic. In the 67 patients studied, 112 coronary arteries received a total of 115 grafts. (There were 89 ungrafted coronary arteries.) Total graft patency rate for the 58 patients in whom angina was totally or significantly relieved was 65 per cent. However, one or more grafts were patent in 52 (90 per cent) of these 58 patients. In grafted arteries, progression was found in segments proximal to the graft in 37 per cent of arteries, at the site of anastomosis in 10 per cent, and distal to the site of anastomosis in 17 per cent. The frequency of obstruction distal to the site of anastomosis was not significantly different from the frequency of progression in nongrafted arteries, in contrast to preliminary data from this laboratory. Overall and regional progression in grafted arteries appeared to occur primarily within the first four months after surgery and was found, thereafter, in a constand percentage of vessels studied. Progression in coronary arteries was independent of patency or occlusion of the graft to the vessel. It is hypothesized that while proximal progression is probably a consequence of altered hydraulic factors, distal lesions seem to represent natural progression of atherosclerotic disease.

Angina Pectoris↗