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At least 109 records · Page 6Linked to original sources
PubMed1990

The APSAC interventional mortality study (AIMS) trial: mortality data.

The anistreplase (anisoylated plasminogen streptokinase activator complex or APSAC) intervention mortality study was designed as a double-blind, placebo-controlled study to test the effectiveness of anistreplase, 30 U administered intravenously within the first 6 hours of acute myocardial infarction. The primary endpoint of the study was mortality of all causes at 30 days and 1 year. Within 30 days, there were 77 deaths with placebo (17.8%) and 40 deaths (6.5%) with anistreplase, an odds reduction of 50.5% (p = 0.0006). By the end of one year, there had been a total of 113 deaths (17.8%) with placebo and 69 deaths (11.1%) with anistreplase, an odds reduction of 42.7% (p = 0.0007).

Acute Disease↗
PubMed1990

Combined radiologic and retrograde endoscopic and biliary interventions.

Methods of treating complex biliary duct problems by a team composed of an endoscopist and interventional radiologist are described. These procedures are of two types: Those in which all manipulations are performed through the endoscope and those in which an antegrade transhepatic and a retrograde endoscopic approach are combined.

Bile Duct Diseases↗
PubMed1989

The beta-adrenergic receptor-adenylate cyclase complex as a target for therapeutic intervention in heart failure.

In the human heart the beta-adrenergic pathways are the primary means of increasing cardiac performance in response to acute or chronic stress. Control of beta pathway function is achieved by changes in the receptors themselves, and to a lesser degree by adjustments in the inhibitory G protein (Gi). In heart failure myocardial beta-receptor function is substantially reduced, but the beta-receptor pathways are so powerful that they remain capable of supporting inotropic function. Certain therapeutic interventions that improve exercise performance in heart failure can partially restore beta-receptor pathway function to normal; these interventions include beta-blocker therapy and treatment with angiotensin converting enzyme inhibitors. Other types of therapy, such as chronic administration of beta-adrenergic agonists, may produce undesirable effects by increasing beta-receptor subsensitivity; however, the effects of beta-agonists on beta-receptor function are somewhat unpredictable and certain beta-agonists do not appear to produce much desensitization. Finally, the failing human heart is in effect partially denervated due to depletion of neuronal norepinephrine, and consequently in advanced heart failure beta-agonists that possess an indirect component of action will be less effective than exclusively direct-acting agents. These observations indicate that the baseline status and the intervention-associated behaviour of the human myocardial beta-adrenergic receptor systems need to be considered in developing therapeutic strategies in congestive heart failure.

Adenylyl Cyclases↗
PubMed1980

[Immunopathology of arterial diseases (author's transl)].

The clinical manifestations of necrotizing angeiitis are of many types (periarteritis nodosa, Wegener's granulomatosis, hypersensitivity, vasculitis...). Their immunological origin is strongly suggested by their analogy with the experimental models of immune complex diseases, and the presence of many immunological anomalies indicating the presence and intervention of these complexes. Several arguments strongly suggest that immunological factors may be also implicated in the pathogenesis of arterial hypertension and arteriosclerosis.

Antigen-Antibody Complex↗
PubMed1978

Regulation of collagenase. Therapeutic considerations.

Why the cornea ulcerates, in the sense of what goes awry, may be related to the trapping of wound healing in a phase of proteolytic debridement related to a persistent epithelial defect. The initial avascularity of the cornea makes it particularly vulnerable to proteolytic damage. Studies on the biochemistry and cell biology of corneal ulceration have indicated that sequential interactions occur which result in the generation of collagenase activity and the development of ulceration. It is likely that the interactions are susceptible to intervention; and it is thought that eventual, successful treatment of corneal ulceration will require a complex therapy, with interventions at multiple sites of regulation.

Animals↗
PubMed1979

[Relapse symptom complex in rectal cancer after radical surgical interventions].

The analysis of 78 questionnaires of patients with recurrence of rectal cancer was performed which revealed this complication of surgery to occur in 60% of cases within a year after operation. Recurrences of the rectum cancer show a characteristic complex of symptoms with a certain structure of painful sensations as a central criterion.

Anal Canal↗
PubMed1994

Fractal analysis of role of smooth muscle Ca2+ fluxes in genesis of chaotic arterial pressure oscillations.

We have investigated the role of vascular smooth muscle Ca2+ fluxes in the genesis of chaotic pressure oscillations induced by histamine in isolated resistance arteries from the rabbit ear. The responses exhibited distinct "fast" and "slow" components, with periods of 5-20 s and 1-5 min, respectively, which could be dissociated pharmacologically. The fast subsystem involved ion movements at the cell membrane and was inhibited by both low (< 2 mM) and high (> 5 mM) extracellular Ca2+ concentration ([Ca2+]o) by verapamil (which inhibits voltage-dependent Ca2+ influx) and by charybdotoxin (ChTX) and apamin (which block Ca(2+)-activated K+ channels). In contrast, the slow subsystem was intracellular and was selectively attenuated by ryanodine, which inhibits Ca(2+)-induced Ca2+ release from sarcoplasmic reticulum. The effects of these interventions on the complexity of the responses were quantified by calculating their fractal dimension, a parameter that estimates the minimum number of independent variables contributing to an irregular time series. Its mean value was generally > 2 under control conditions but decreased to < 2 in a concentration-dependent fashion in the presence of verapamil, ChTX, apamin, or ryanodine and when [Ca2+]o was outside the range of 2-3 mM. Each intervention thus removed one dimension of complexity from the mechanisms generating the rhythmic activity. We conclude that the interaction of a fast membrane oscillator, which involves Ca2+ influx, Ca(2+)-activated K+ efflux, and therefore presumably changes in membrane potential, and a slow intracellular oscillator involving Ca2+ sequestration and release from stores is responsible for vascular chaos in our model. The coupling between these subsystems is likely to be mediated by cytosolic [Ca2+].

Animals↗
PubMed1991

Vector population responses to control interventions.

In 1981, Kenyan authorities attempted eradication of tsetse (Glossina pallidipes) from the Lambwe valley, by sequential aerial spraying of endosulfan. Fly populations were reduced by over 99.9% in the main habitats, but recovered to their original levels within one year. In 1986, an Argentine research team attempted local elimination of domestic Triatominae (Triatoma infestans) in an area of Santiago del Estero. House infestation rates were reduced to an apparent zero, but recovered to pre-control levels in two years. In Sri Lanka, a combination of mosquito control with active case detection and treatment reduced malaria incidence to just 17 cases in 1964. Interruption of the programme then saw case incidence return to over 500,000 by 1969. These three examples-from African trypanosomiasis, South American Chagas disease and malaria-all illustrate the same process. Vector populations, infestation rates, and rates of disease transmission, can be reduced. The real problem is not in achieving the initial reduction, but in subsequently either driving the disease to extinction or maintaining it below acceptable levels. And this problem takes us beyond the simple analysis of interventions, into the complex realms of population behaviour set in its political, social and economic context. It seems that we have been too rarely concerned to plan and implement the long term surveillance and selective interventions that are required to translate initial gains into real success. In biological terms, we tend to ignore the complexity and robustness of vector populations and disease transmission cycles, especially their varied capacity to recover from interference. Moreover, in socio-political terms, a reduced problem-even one representing potential for future catastrophe-tends to claim less priority than present problems, even though premature redeployment of resources may abnegate gains already achieved. The problem is strongly compounded by methods of economic analysis where the benefits of avoiding future problems are strongly discounted in favour of short-term temporary gains. This paper seeks to open discussion on these long-term planning issues.

Animals↗
PubMed1990

Poverty and early childhood parenting: toward a framework for intervention.

The relationship between poverty and child rearing has been a persistent source of social concern in the United States. Drawing on available literature, this paper seeks to establish a conceptual approach to the interaction of these two complex variables. Appropriate interventions and strategies for their implementation are considered.

Child↗
PubMed1995

Effect of cholesterol lowering on intravascular pools of TFPI and its anticoagulant potential in type II hyperlipoproteinemia.

Tissue factor pathway inhibitor (TFPI) inhibits the extrinsic coagulation system. A major pool of TFPI is associated with the vascular endothelium and can be mobilized into the circulation by heparin. In circulating blood, TFPI is mainly associated with LDL (80%), whereas 10% to 20% is carrier free. In this study, heparin administration caused a 2.2-fold and a 7.5-fold increase in TFPI activity and TFPI antigen, respectively, in 25 patients with phenotypes IIa and IIb hyperbetalipoproteinemia. Because the antigen determination of TFPI almost exclusively measures carrier-free TFPI, more than 90% of the heparin-induced increase in TFPI activity was caused by mobilization of carrier-free TFPI from the vascular endothelium. Therapeutic lowering of total cholesterol (a decrease of 31.1 +/- 11.6%, P < .001) by 40 mg/d lovastatin in 17 patients with hyperbetalipoproteinemia was accompanied by a parallel decrease in TFPI activity (of 27.7 +/- 24.2%, P < .001) because of a reduction in LDL-TFPI complexes. However, drug intervention did not affect carrier-free TFPI or the magnitude of the vascular pool of TFPI that could be mobilized into the circulation by heparin. Moreover, this reduction of LDL-TFPI complexes did not reduce the anticoagulant potency of TFPI in plasma or of the vascular endothelial pool. The results of this study may imply that the anticoagulant potency of TFPI is associated with its carrier-free form in plasma or on the endothelium and that downregulation of LDL affects neither the size nor the anticoagulant potency of the endothelial pool of TFPI.

Adult↗
PubMed1982

A data-based approach to assessing clinical interventions in the setting of chronic disease.

Accurately assessing the effect of a clinical intervention is a complex task based on observing patients and their outcomes. Two strategies, the randomized trial and the observational data bank, represent different approaches toward detecting an outcome gradient across treatments. The observational data base is rooted on prospective data collected on an unselected group of patients with continuous surveillance of outcome events. As such, this approach captures a broad spectrum of patients within which prognostically important factors can be identified. In addition, the ongoing nature of the observational approach provides a means for capturing the dynamics of the disease process as well as the dynamics of the surrounding technology. These factors are particularly useful in the study of chronic illness where time frames of years to decades are encountered. In assessing treatment effects, both the randomized trial and the observational data base are subject to inferential errors due to multiple comparisons. In this paper, we describe some of the complexity associated with the study of chronic illness and demonstrate the multiple comparison problem. We have found multivariate models helpful in attenuating multiple comparison problems, but it still seems that independent confirmatory studies are required to establish confidence in a questionable intervention.

Analysis of Variance↗
PubMed1993

Diarrhoeal disease: current concepts and future challenges. Water, sanitation and diarrhoea: the limits of understanding.

This paper reviews the application of epidemiological understanding of diarrhoeal disease to interventions in water and sanitation. Over the past 20 years, great efforts have been made to elucidate the relationships between water supply, sanitation and diarrhoeal disease. At the outset, it was hoped that improved understanding of these relations could provide a rational framework for the planning of public health engineering interventions. This paper also reviews historical and recent perceptions of water, sanitation, and diarrhoeal disease, and summarizes progress to date. On the one hand, some fundamental ideas about the relative importance of water quality and quantity in the transmission of diarrhoeal disease have changed, and there is increased recognition of the complex interrelationships between interventions, hygiene behaviour and health. On the other hand, our understanding of the impact of interventions is painfully incomplete, and is unlikely to improve dramatically in the near future. While further research can usefully illustrate a variety of interactions in specific contexts, globally applicable planning guidelines and design criteria appear a dangerous will-o'-the-wisp. While we know more than ever before about water, sanitation and diarrhoea, much remains unknown, and is perhaps unknowable.

Child↗
PubMed1988

Management of ventricular arrhythmias.

Left ventricular dysfunction and complex VPCs are independent risk factors for subsequent cardiac death in patients with ischemic or nonischemic heart disease. The use of antiarrhythmic drugs during acute myocardial infarction is discussed. Patients with complex VPCs associated with heart disease should be treated with antiarrhythmic drugs. Drug efficacy should be evaluated by a 24-hour ambulatory ECG recording and by a treadmill exercise stress test. Blood drug levels should be measured at appropriate times. Maintenance doses of the various antiarrhythmic drugs are listed. Electrophysiologic testing with induction of ventricular tachycardia by extrastimulation may predict the clinical efficacy of the antiarrhythmic drug or combination of drugs needed for the long-term treatment of ventricular tachyarrhythmias. Electrophysiologic testing must be used for selecting antiarrhythmic drugs in patients who have experienced sustained ventricular tachycardia or ventricular fibrillation but who are free of VPCs during ambulatory ECG monitoring and exercise stress testing. If patients have life-threatening ventricular tachycardia or fibrillation resistant to antiarrhythmic drugs, surgical intervention is indicated. Complex VPCs in asymptomatic patients without heart disease should not be treated with antiarrhythmic drugs.

Anti-Arrhythmia Agents↗
PubMedDate not supplied

[Australia antigen in rheumatoid arthritis].

Australian antigen (Au Ag) was first described by Blumberg in the serum of an Australian aborigen. Its main clinical significance is based on the fact of its association with the presence of hepatitis B (Okochi, Nurakami, 1968; Prince, 1968) (9). Almeida (1969) outlines the intervention of immune complexes on the production of the referred illness. Later works show the importance of the type of immunologic response created by Au Ag (2). Alpert et al. (1) (1970) state the possibility that immune complexes developed by Au Ag and anti Au Ag antibodies may produce in patients with hepatitis B other allied manifestations including arthritis. On the basis of similar immunopathological findings (illnesses including immunocomplexes on their production), Au Ag investigation in rheumatoid arthritis (RA) has been the object of several works, whose results reveal certain discrepancies. We have investigated the presence of Au Ag on 70 patients whose diagnostic was RA "classical (according to the judgement of the American Rheumatism Association). We used immunoelectrophoresis (counter immunoelectrophoresis-CIEP-) and radioimmunoassay (RIA) techniques. We prepared individual records including clinical, epidemic, biochemical and personal data. Au Ag investigation both through different techniques gave negative results in 70 cases, of which only four referred a possible previous hepatitis B clinic history, not showing during the investigation suggestive clinical data of hepatitis or biochemical alterations. Panus et al. (1970) (5), Desche-Labarte et al. (1972), Trempo (1972), Burrel (1973) (6), Serré et al. (1973) (8), obtained negative results in the matter, with similar or lower casuistics than ours. Notwithstanding Roqués et al. (1975) (7), in 300 cases of RA showed the presence of Au Ag in a significant number of cases (5%) as compared to Au Ag incidence in the French population (estimated in about 0.22%) (6). However, Roqués did not find in their Au Ag positive cases any evidence which enables to think that this antigen has played an important role on the origin and development of the rheumatic illness. These important discrepancies may be due to different reasons: a) Use of different techniques for Au Ag detection. b) The transitory character of the presence of Au Ag in the serum. c) Important differences in the antigen geographic distribution. d) Previous hepatitis B. There are som other factors which have attained importance recently, as a consequence of the broad epidemiological studies carried out. So, Au Ag increased incidence has been found--statistically significant--on groups of persons who have been submitted to several surgical interventions and/or have needed repeated hospitalizations or reiterated blood transfusions (6). These three conditions--especially the first two--are accomplished in an illness with chronic and invalidating characteristics as RA...

Arthritis, Rheumatoid↗
PubMed1993

Dietary strategies for cancer prevention.

BACKGROUND: Two-thirds of cancer cases are associated with two lifestyle practices: 35% with the typical American diet, and 30% with tobacco use. In contrast to the field of tobacco control, research and resources dedicated to the field of nutrition have been limited, in part because dietary change has been considered controversial and requires a more complex set of interventions. METHODS: This series of papers reviews the science base underlying diet as a cancer control strategy, including research about diet-cancer relationships, current nutrition policy recommendations, American dietary trends, models of dietary behavior change, and diet in health care delivery. The history of technology transfer of new knowledge into widespread application will be compared and contrasted with other cancer control measures. RESULTS: There is scientific and policy agreement about three priority dietary goals for the year 2000: increase fruit and vegetable consumption to 5 or more servings every day, increase breads, cereals, and legumes to 6 or more servings daily, and decrease fat to no more than 30% of total calories. Current data do not indicate that these goals will be reached. As yet there is no organized effort, with clearly identified steps, to translate research into practice. The parallel with delays in implementing other cancer control measures, including Papanicolaou testing, mammography, and tobacco intervention, is striking. CONCLUSION: Without resources dedicated to dietary modification in the general population, it is not likely that the potential savings of more than 300,000 new cases, 160,000 deaths, and the $25 billion in associated costs will be realized in the foreseeable future.

American Cancer Society↗
PubMed1990

Current techniques for infrainguinal arterial reconstruction.

Infrainguinal reconstruction for peripheral vascular occlusive disease comprises an increasingly complex array of interventions which provide unparalleled options for the salvage of threatened limbs. Conventional autogenous saphenous vein bypass remains the most durable revascularization with anticipated graft patency rates approaching 80 percent after five years and excellent long term limb salvage. These excellent results are equally applicable to vein grafts carried to infrapopliteal and even inframalleolar levels, possibly reflecting increased utilization of the in situ method. Although 20 per cent of grafts fail within five years, secondary intervention results in sustained limb salvage in the majority of patients. In the absence of autogenous vein, however, prosthetic material performs poorly such that new interventions consisting of percutaneous transluminal angioplasty, rotary atherectomy devices and laser systems are under aggressive development. Although initial results with these devices are encouraging, long term patency rates remain poor largely due to restenosis. Further progress seems to depend primarily on an increased understanding of the natural healing response of the injured artery.

Angioplasty, Laser↗