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Biomedical subjects

J J Collins

Publications and source records attributed to J J Collins.

At least 235 records · Page 13Linked to original sources
PubMed1984

Giant cell myocarditis after mitral valve replacement: case report and studies of the nature of giant cells.

A 22-year-old man with Marfan's syndrome and a history of antinuclear antibody-positive hepatitis died 25 days after undergoing cardiac valve replacement surgery for mitral valve prolapse. Giant cell myocarditis was found at autopsy. The multinucleated giant cells were shown by immunoperoxidase techniques to contain lysozyme, but not myosin or creatine phosphokinase, suggesting that they were derived from macrophage, rather than myocyte, precursors.

Adult↗
PubMed1984

Repression of nitrogen fixation in Klebsiella pneumoniae at high temperature.

The effect of elevated growth temperature on nif mRNA synthesis, nif protein synthesis, and nitrogenase activity was investigated in wild-type and NifL- strains of Klebsiella pneumoniae. Nitrogenase activity is not affected at 41 degrees C; however, nitrogenase is not synthesized at that temperature. Transcription of three nif operons studied is repressed at 41 degrees C. We show that the nifL protein is not required for repression by high temperature and propose that repression of nif at 41 degrees C results from a reversible inactivation of the nifA gene product.

Acetylene↗
PubMed1984

Efficacy and safety of timolol for prevention of supraventricular tachyarrhythmias after coronary artery bypass surgery.

Forty-one patients undergoing coronary artery bypass grafting were randomly assigned to receive prophylactic timolol or placebo, given in a double-blind fashion. beta-Adrenoceptor-blocking therapy was stopped at least one half-life before surgery. Three to 7 hr after surgery (304 +/- 56 min), 0.5 mg of timolol or placebo was given intravenously twice daily in a double-blind manner. When oral medications were resumed postoperatively, 10 mg of timolol twice daily or placebo was continued orally. Continuous electrocardiograms were recorded for 24 hr before and for 7 days after surgery with a standard cassette recorder. No patient received digoxin. Both groups were comparable for frequency of preoperative supraventricular arrhythmias, left ventricular ejection fraction, duration of cardiopulmonary bypass, aortic cross-clamp time, number of bypass grafts, and total duration of monitoring. Analysis of arrhythmias was done by hand counts, and supraventricular arrhythmias were divided into supraventricular tachycardia and atrial fibrillation and/or flutter. Timolol decreased the frequency of supraventricular tachycardia (581 episodes placebo vs 84 timolol; p less than .05) and of atrial fibrillation and/or flutter (291 episodes placebo vs five timolol; p less than .05). Timolol decreased the number of patients with severe (heart rate greater than 200 beats/min, duration greater than 50 beats) episodes of supraventricular tachycardia (four placebo vs 0 timolol; p less than .05) and also decreased the number of episodes of severe (heart rate greater than 200 beats/min, duration greater than 5 min) atrial fibrillation and/or flutter (16 placebo vs one timolol; p less than .005). There were differences in the durations of supraventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗
PubMed1984

Period and cohort factors in the incidence of malignant melanoma in the state of Connecticut.

The reasons for the increase in both incidence and mortality from malignant melanoma are not clear at this time, although there is an indication of a "generation effect" in the increasing frequency of the disease. The application of an age-period-cohort model to incidence data on malignant melanoma for the State of Connecticut indicate that, unlike mortality, the increase is almost entirely related to period factors. Two explanations are provided to explain this pattern of period factor increase. First, the increase in incidence could be artifically produced by better and earlier diagnosis. Second, a decrease in ozone level in the atmosphere may be responsible for the increase.

Adult↗
PubMed1984

Early and late risk of aortic valve replacement. A 12 year concomitant comparison of the porcine bioprosthetic and tilting disc prosthetic aortic valves.

Aortic valve replacement was performed in 912 consecutive patients from January, 1972, to January, 1983. The 616 male and 296 female patients, whose ages ranged from 16 to 95 years (mean 60.6 years and median 63 years), received 663 bioprosthetic valves and 249 tilting disc valves. A higher incidence of Functional Class IV heart disease and ascending aortic aneurysms was noted in the group receiving the tilting disc valve. Six hundred fifty-seven patients had primarily aortic stenosis and 255 had primarily aortic regurgitation. Associated procedures were done in 308 patients (33%): 233 had coronary bypass grafting, 46 had replacement of ascending aortic aneurysms, and 29 had miscellaneous procedures. The overall operative mortality was 6.4% (59/912). The operative mortality was 4.5% (29/640) for isolated aortic valve replacement, 4.2% (21/233) for valve replacement plus coronary bypass, and 17% (8/46) for valve replacement plus replacement of an ascending aortic aneurysm. The mortality was 4.2% (20/663) for the group receiving bioprostheses and 12.4% (31/249) for those receiving tilting disc valves. The operative mortality for 1983 for all aortic valve replacement procedures was 2.1%; for isolated valve replacement, 1%; for valve replacement plus coronary bypass, 4.4%; and for valve replacement plus aortic aneurysm replacement, 0%. The long-term follow-up was analyzed as of Jan. 1, 1984, so that there was a minimum follow-up of 12 months (mean 55 months and median 51 months). The actuarial survival rate at 108 months for all patients was 67% +/- 2%; for valve replacement alone, 71% +/- 3%; for valve replacement plus coronary bypass, 58% +/- 7%; for valve replacement plus ascending aortic aneurysm replacement, 45% +/- 10%; for aortic stenosis, 70% +/- 3%; for aortic regurgitation, 61% +/- 4%; for Functional Classes I to III, 77% +/- 3%; for Class IV, 53% +/- 4%; for age less than 63 years, 75% +/- 3%; and for age greater than 63 years, 57% +/- 4%. At 108 months, the probability of freedom from thromboembolism was 85% +/- 3% after bioprosthetic valve replacement and 83% +/- 3% after replacement with a tilting disc valve (p = NS). The probability of freedom from hemorrhage at 108 months was 98.6% +/- 7% for the bioprosthetic valve group and 89% +/- 2% for the tilting disc valve group (p less than 0.001). The valve thrombosis rate was 0.34% per patient-year for the tilting disc valves and 0.07% per patient-year for the bioprostheses.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

Use of adoptive transfer and Winn assay procedures in the further analysis of antiviral acquired immunity in mice protected against Friend leukemia virus-induced disease by passive serum therapy.

Previous studies have demonstrated that spleen cells from DBA/2 mice protected against challenge with a leukemogenic dose of Friend leukemia virus (FLV) by passive administration of xenogeneic antiviral or anti-FLV Mr 71,000 viral envelope glycoprotein antisera can adoptively transfer antiviral resistance to unimmunized irradiated syngeneic recipients. In addition, elimination of T-cells by treatment with anti-Thy 1.2 antibodies plus complement had no effect on the ability of spleen cells from serum-protected mice to adoptively transfer antiviral resistance. We now show that similar depletion of B-cells with rabbit anti-mouse immunoglobulin G plus complement or macrophages by adherence to Sephadex G-10 columns also leaves intact the protective capacity of spleen cells from serum-protected mice. That these results reflect the ability of more than one spleen cell population to transfer antiviral resistance rather than the activity of a non-T, non-B, nonmacrophage cell compartment is supported by the finding that purified splenic T- or B-cells alone from serum-protected DBA/2 mice can adoptively transfer antiviral resistance. Given the previously reported effects of sublethal irradiation on FLV leukemogenesis which could potentially complicate the interpretation of adoptive transfer experiments carried out in this system, analogous studies were performed using a Winn-type assay in which putative effector cells were preincubated with virus before inoculation of the mixture in unirradiated mice. These Winn assay experiments yielded identical results in that serum-protected spleen cells again prevented viral leukemogenesis, and the separate elimination of T-cells, B-cells, or macrophages had no effect on their protective activity. In addition, mixed transfer of serum-protected and normal spleen cells also protected irradiated mice against FLV challenge, providing further evidence that this adoptive protection truly reflects the presence of virus-specific effector cells in the spleens of serum-protected mice and not an inability of these spleen cells to replace radiation-sensitive viral target cells in recipient animals, since these should be supplied by the normal spleen cells in the transferred mixture.

Animals↗
PubMed1983

Immunotherapy of murine leukemia. IX. The requirement for the Fc portion of antibody for successful passive serum therapy of Friend leukemia virus-induced disease.

The possible role of an antibody-dependent cellular cytotoxicity (ADCC)-type mechanism in the passive serum therapy of Friend leukemia virus (FLV)-induced erythroleukemia has been investigated by determining whether successful serum protection requires an intact Fc portion on the administered antibody. F(ab')2 fragments of IgG extracted from chimpanzee anti-FLV and goat anti-FLV gp71 antisera were prepared and compared with whole serum and uncleaved IgG for their capacity to protect DBA/2 mice against challenge with leukemogenic dose of FLV. Despite demonstrating in vitro virus neutralizing activity equivalent to that seen with antiviral serum or IgG, the virus-specific F(ab')2 preparations were devoid of protective activity. Given that passively administered F(ab')2 of goat origin have been reported to persist at stable levels in the mouse circulation, the failure of these F(ab')2 preparations to protect against virus challenge cannot be ascribed to rapid clearance from the treated animals. These results indicate that the passive serum therapy of FLV-induced disease is Fc dependent, consistent with the involvement of an ADCC-type mechanism, as well as confirming the previous suggestion that virus neutralization does not represent the sole mechanism of serum protection in this system.

Animals↗
PubMed1983

Long-term failure rate and morphologic correlations in porcine bioprosthetic heart valves.

To ascertain relations among site, incidence, and mechanisms of clinically evident failure of porcine bioprosthetic heart valves, the frequency of failure of 1,110 valves in 1,001 adult operative survivors from January 1972 to January 1982 was reviewed and correlated with the pathologic features of 22 consecutive dysfunctional valves. There were 373 mitral, 519 aortic, and 109 double replacements, yielding for study 482 mitral and 628 aortic valves at risk. Infective endocarditis occurred in 1.9% (8 mitral, 7 aortic, and 4 double). Twenty-three valves (13 mitral and 10 aortic) with documented primary dysfunction were explanted, a mean of 55 months (range 9 to 94) after surgery. The primary dysfunction rate for the 333 valves implanted for greater than or equal to 5 years was 6.8% (11 of 161) for mitral and 4.1% (7 of 172) for aortic valves. Valves implanted for less than 5 years had a failure rate of 0.7%. The actuarially determined freedom from primary valve failure was 98 +/- 1% for mitral and 98 +/- 1% for aortic valves at 5 years and 79 +/- 7% for mitral and 91 +/- 4% for aortic valves at 10 years. Recovered valves (12 mitral and 10 aortic) with detailed morphologic analysis were functioning for a mean duration of 52 months (range 12 to 87). Causes of failure included calcification-related tears in 7 (4 mitral and 3 aortic, mean 66 months), tear without calcium deposits in 4 (4 mitral, mean 44 months), cuspal stiffening without tear but with calcium deposits in 2 (1 mitral and 1 aortic, mean 80 months) and thrombosis in 1 (aortic). Late primary dysfunction was most frequently a result of degenerative processes, especially calcification, often with secondary tears, but cuspal tears in the absence of calcium deposits and thrombosis predominated at shorter intervals.

Adolescent↗
PubMed1983

Coexistent carotid and coronary artery disease. Surgical management.

We performed simultaneous coronary artery bypass grafting (CABG) and carotid endarterectomy (CE) in 42 patients (average age, 61 years). Twenty-nine patients had preoperative transient ischemic attacks. Carotid arteriography showed stenosis (greater than 70%) in 38 subjects and extensive ulcerated lesions in two, and two emergency patients were not studied. Carotid artery dissection and sternotomy were simultaneously performed and the patients were cannulated for cardiopulmonary bypass (CPB). We undertook CE (22 left and 24 right) using EEG monitoring prior to CPB in all but one patient. The average carotid occlusion time was 25 minutes without a shunt in 23 patients and 5.5 minutes with a shunt in 19 patients. After CE, CABG was performed with an average aortic clamp time of 39 minutes and an average CPB time of 87 minutes. The operative mortality was 5% (2/42). There were no strokes or perioperative myocardial infarctions. Neurologic morbidity consisted of postoperative headache in one patient, transient upper-extremity weakness in two patients, and transient facial weakness in one patient. The average length of postoperative hospitalization was ten days. Currently, patients with symptomatic coronary artery disease and concomitant carotid bruits with positive noninvasive testing and arteriography should have simultaneous repair of these lesions.

Aged↗
PubMed1983

In vitro growth inhibition of murine leukemia cells by antibody specific for the major envelope glycoprotein (gp71) of Friend leukemia virus.

An in vitro complement (C')-independent growth cytostasis model is described in which the replication of Friend leukemia virus (FLV)-induced erythroleukemia cells (of the FLC-745 cell line) is inhibited by goat serum directed against the major FLV envelope glycoprotein, gp71. The cytostatic effect is reversible, with the degree of this reversibility dependent on both the concentration and duration of exposure to immune serum. The inhibitory factor in heat-activated goat anti-FLV gp71 (delta G alpha FLV gp71) serum has been identified as virus-specific IgG antibody, and F(ab')2 fragments of this antibody are highly effective in suppressing FLC-745 cell growth. Studies with various murine leukemia and lymphoma cell lines, as well as with a panel of antisera directed against various murine oncornaviruses or viral proteins, have demonstrated that antibodies reactive with the group or type determinants of FLV gp71 are capable of mediating cytostasis. Under conditions of antibody-mediated growth inhibition of FLC-745 cells, specific modulation of gp71 expression is followed by nonspecific modulation of H-2d antigen expression. In addition, considerable cell death occurs in cytostatic cultures which is accompanied by continued division (as measured by DNA synthesis) of a portion of the cell population. Cytofluorimetric analysis of nuclei from growth-inhibited FLC-745 cells demonstrates a diminution in the frequency of cells in the G2/M phase of the cell cycle. It is suggested that antibody-mediate FLC-745 cell growth inhibition operates via a blockade of the cell cycle which prevents most cells in the population from traversing G2/M. While these blocked cells appear to be subject to slow cytolysis by a C'-independent mechanism, a portion of the cells escape this blockade and continue to replicate, thus offsetting the death of the former cells to yield a relatively constant density of viable cells for at least 72-96 h of growth inhibition. The possible relevance of this in vitro phenomenon to in vivo passive therapy against FLV-induced disease with G alpha FLV gp71 and similar antisera is briefly considered.

Animals↗
PubMed1983

Noninvasive assessment of valvular heart disease: surgery without catheterization.

Forty-one patients underwent valve surgery at our institution based solely on clinical, M-mode echocardiographic, phonocardiographic, and external pulse recording findings without preoperative cardiac catheterization. Patients with clinical evidence of coronary artery disease were excluded from the study. Preoperatively, 83% of the patients were New York Heart Association functional class III or IV. In all patients, the noninvasive evaluation was considered sufficiently diagnostic of the nature and severity of valvular heart disease to allow surgery without preoperative catheterization. In 23 of 41 cases (group 1), cardiac catheterization was not performed due to the patients' unstable hemodynamic condition at the time surgery was being considered. In the remaining 18 patients (group 2), the probability of obtaining data at catheterization that would significantly affect management decisions was thought to be low, thus not justifying the cost and potential morbidity of this procedure. In all cases, the noninvasive diagnosis was corroborated at operation; there were no unexpected findings nor deaths related to incomplete or incorrect diagnoses. Over a followup period of 4.5 +/- 1.4 years, no patient experienced signs or symptoms of ischemic heart disease. In selected patients without anginal chest pain syndromes, appropriate and successful valve surgery may be performed on the basis of combined clinical and noninvasive evaluation without the need for cardiac catheterization.

Adolescent↗
PubMed1983

A demographic model for performing site-specific health risk projections.

An extension of an earlier life table model for estimating health risks in occupationally exposed workers is presented. The extension of the earlier methodology incorporates specific fertility assumptions and therefore produces a model that is able to perform health risk projections for populations living in or around sites that release agents with potentially adverse health consequences. Results show that fertility patterns are important for assessing risk, even for short-term projections. The interaction of initial age structure, competing risks from other causes of death, and fertility patterns are all important in determining future levels of excess mortality from various pollutants.

Actuarial Analysis↗
PubMed1983

Legal coercion and retention in drug abuse treatment.

The criminal justice system is increasingly referring offenders who have mental health problems to the community mental health system for treatment. The effects of such referrals on treatment outcome and on the mental health and criminal justice systems are not well understood. Because the length of time an individual remains in a drug abuse treatment program is an important indicator of treatment effectiveness, this paper assesses the impact of court referrals by examining the relationship between a drug abuser's length of stay in treatment and his referral by legal and nonlegal sources. Regression analyses on data for more than 2,200 individuals indicate that clients who are legally induced to seek treatment stay in treatment longer than, and do at least as well as, those who seek treatment voluntarily. The implications of these findings for drug abuse treatment and policy are discussed.

Commitment of Persons with Psychiatric Disorders↗
PubMed1983

Immunotherapy of murine leukemia. VIII. Efficacy of passive serum therapy of Friend leukemia virus-induced disease in immunocompromised mice.

Previous studies have demonstrated that the passive therapy of Friend murine leukemia virus (F-MuLV)-induced disease with chimpanzee anti-F-MuLV serum is accompanied by the development of host antiviral humoral and cellular immunity, the latter measurable in adoptive transfer protocols and by the ability of serum-protected mice to resist virus rechallenge. The present study was designed to further examine the contribution of various compartments of the host immune system to serum therapy itself, as well as to the acquired antiviral immunity that develops in serum-protected mice, through the use of naturally immunocompromised animals [e.g., nude athymic mice and natural killer (NK)-deficient beige mutant mice] or mice treated with immunoabrogating agents such as sublethal irradiation, cyclophosphamide [Cytoxan (Cy)], cortisone, and 89Sr. The studies in nude mice indicate that while mature T-cells are not needed for effective serum therapy, they do appear to be necessary for the long-term resistance of serum-protected mice to virus rechallenge and for the generation of the cell population(s) responsible for adoptive transfer of antiviral immunity. Furthermore, this acquired resistance is not due to virus neutralization by serum antibodies since antibody-negative, Cy-treated, serum-protected mice still reject the secondary virus infection. Lastly, while the immunocompromise systems examined did effect various host antiviral immune responses, none of them, including the NK-deficient beige mutation, significantly diminished the efficacy of the passive serum therapy of F-MuLV-induced disease.

Animals↗
PubMed1983

The reliability of angiography in predicting quality and caliber of the distal coronary artery lumen in preparation for bypass surgery.

To determine whether coronary arteriograms accurately predict the presence of distal coronary lumena that are inadequate for bypass because of diffuse disease and/or small caliber, angiographic grading of distal lumen (DL) caliber was carried out on 867 diseased coronary arteries on which bypass was subsequently attempted. Where the DL was graded as normal, bypasses could be successfully constructed in 96% of cases. Where the general DL caliber was normal but one or more localized distal stenoses were present, bypasses could be successfully constructed in 95.6% of cases. Where the DL caliber was reduced to a mild-moderate degree angiographically, bypasses were successfully constructed in 83.6%. Where the DL had a severely reduced caliber or could not be visualized at all, bypasses were successfully constructed in 73.0%. Thus, even when a severely narrowed or totally occluded DL appears present, bypass can still be performed in almost 75% of cases. The angiographic diagnosis of a nongraftable distal segment is therefore unreliable and patients should not be denied bypass on this basis alone.

Coronary Angiography↗
PubMed1983

Thrombosis associated with a porcine bioprosthesis and ascending aortic graft in a patient with the Marfan syndrome.

A fatal thrombosis originating at the junction of an aortic bioprosthetic heart valve and a Dacron aortic graft was observed in a patient with the Marfan syndrome, who had had replacement of the ascending aorta with a valved conduit 29 months previously. This unique complication raises the question of whether patients with such prostheses should be on a program of full anticoagulation.

Adult↗