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Biomedical subjects

J Barry

Publications and source records attributed to J Barry.

At least 91 records · Page 5Linked to original sources
PubMed1991

Effects of asymptomatic ischemia on long-term prognosis in chronic stable coronary disease.

BACKGROUND: Ischemia on ambulatory electrocardiographic monitoring has been shown to adversely affect short-term prognoses in patients with unstable angina, after myocardial infarction, and with chronic stable angina. METHODS AND RESULTS: In this long-term study, we followed 138 patients (mean age, 59 +/- 9 years) with chronic stable angina and positive exercise tests for cardiac events (e.g. death, myocardial infarction, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft surgery). In 105 patients, ambulatory electrocardiographic monitoring was performed after all antianginal medication was withheld for 48 hours. In 26 patients, the diagnostic tests were repeated while on their usual medication. In addition to the 105 patients, 33 patients had their monitoring performed only while on their usual medication. During 37 +/- 17 months of follow-up, there were nine deaths, nine myocardial infarctions, and 35 revascularization procedures. In patients monitored off medication, Cox survival analysis showed that the occurrence of ischemia on electrocardiographic monitoring was the most significant predictor of death and myocardial infarction in the subsequent 2 years (p = 0.02) and all adverse events for 5 years (p = 0.009). Patients who were monitored on medication and did not have ischemia (n = 18) appeared to have more adverse events than patients who had no ischemia while being monitored off medication (n = 43). CONCLUSIONS: Asymptomatic ischemia on ambulatory electrocardiographic monitoring in patients with stable angina predicts death and myocardial infarction for 2 years and all adverse events for 5 years. Monitoring performed while on medication may show no ischemia; however, this may not indicate low risk of future coronary events.

Actuarial Analysis↗
PubMed1991

Laboring to manage care.

What happened at AT&T is an example of the possibilities when labor and management cooperate. Both sides contributed their input, and the result was a health care plan that was acceptable to everyone involved.

Cost Control↗
PubMed1990

Long-term prognosis of myocardial ischemia detected by Holter monitoring in peripheral vascular disease.

To assess the long-term prognostic significance of myocardial ischemia, as measured by ambulatory electrocardiographic monitoring, in patients with occlusive peripheral arterial disease, 176 eligible patients scheduled for elective peripheral arterial surgery at Brigham and Women's Hospital were prospectively studied. All patients were monitored preoperatively without alterations to baseline medications. Prospective follow-up was obtained during routine medical care as provided by blinded, independent physicians and by subsequent telephone contact with the patients. Thirty-two patients (18%) had a total of 75 episodes of myocardial ischemia, 73 (97%) of which were asymptomatic. During a mean follow-up period of 615 days, there were 9 cardiac deaths, 1 occurring in-hospital after peripheral vascular surgery, and 13 nonfatal myocardial infarctions, 4 occurring in-hospital after peripheral vascular surgery. Cardiac events occurred in 12 of 32 patients with ischemia (38%), including 6 cardiac deaths, and in 10 of 144 patients without ischemia (7%), including 3 cardiac deaths (risk ratio 5.4, 95% confidence interval 2.6 to 11.4). The sensitivity of ischemia was 55%, the specificity was 87%, the positive predictive value was 38%, and the negative predictive value was 93%. In a multivariate Cox proportional-hazards model controlling for age, gender, coronary risk factors, history of angina, myocardial infarction, coronary artery disease and antianginal medications, the presence of ischemia was the only independent predictor of outcome. In patients with peripheral arterial disease, who often are unable to perform adequate exercise testing, ambulatory monitoring for myocardial ischemia is a significant independent predictor of 1- to 2-year prognosis.

Adult↗
PubMed1990

Silent ischemia after myocardial infarction. Prognosis, mechanism, and intervention.

Asymptomatic ischemia after myocardial infarction is a common clinical problem. As much as 50% of the postinfarction patient population who have ischemia on exercise testing may have no symptoms at all. In these patients, ischemia detected by either exercise testing or ambulatory electrocardiographic monitoring, with or without symptoms, confers a worse prognosis. The mechanism of silent ischemia in this group of patients may be due to the deprivation of afferent innervations created by critically placed infarctions. The management of these postinfarction patients must be centered on the treatment of ischemia, regardless of symptoms.

Biomechanical Phenomena↗
PubMed1989

Enhancement of bacteriophage T4 late transcription by components of the T4 DNA replication apparatus.

The expression of the late genes in bacteriophage T4 development is closely connected to viral DNA replication. Three T4-encoded DNA polymerase accessory proteins are shown to stimulate transcription at T4 late promoters in an adenosine triphosphate (ATP) hydrolysis-requiring process. The properties of the activation resemble those found for enhancers of eukaryotic transcription. However, the nature of the enhancer of T4 late transcription is novel in that it is a structure--a break in the nontranscribed DNA stand--to which the three replication proteins bind, rather than a sequence. Since the three DNA polymerase accessory proteins are carried on the moving replication fork as part of the replisome, we postulate that viral DNA replication forks act, in vivo, as the mobile enhancers of T4 late gene transcription. Whereas Escherichia coli RNA polymerase bearing the T4 gene 55 protein can selectively recognize T4 late promoters, it is only capable of responding to the transcription-enhancing activity of the three replication proteins on acquiring an additional T4-specific modification.

DNA Replication↗
PubMed1989

Paradoxical elevation of threshold to angina pectoris by cold pressor test in men with significant coronary artery disease.

Patients with coronary artery disease (CAD) have angina pectoris at varying levels of myocardial oxygen demand. Fluctuations in coronary blood supply due to dynamic changes in coronary vasomotor tone are believed to be responsible for this variation in angina threshold. Cutaneous cold application produces an inappropriate increase in coronary vascular resistance in patients with CAD. To assess the effect of a coronary vasoconstrictor stimulus during exercise (when there are competitive stimuli for coronary dilatation), 16 men with documented CAD and angina underwent 2 exercise tolerance tests, 1 performed for control purposes and the other during cold application (hand and forearm immersed in ice). The cold pressor test elicited an increase in systolic blood pressure at rest (134 vs 159 mm Hg, p less than 0.02) at the end of stage I (145 vs 165 mm Hg, p less than 0.02) and at peak exercise (154 vs 166 mm Hg, p less than 0.05). The diastolic pressure was similarly increased during cold pressor exercise test, but the heart rate showed little or no change. Most patients (11 of 16) tolerated equal or greater double products (heart rate X systolic pressure X 10(-3) at angina (17 vs 20, p less than 0.02), 1-mm ST-segment depression (16 vs 18, p less than 0.05) and peak exercise (18 vs 20, p less than 0.08) during cold pressor exercise test as compared with the baseline exercise test, without a reduction in exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Effects of dosing intervals on the development of tolerance to high dose transdermal nitroglycerin.

To investigate the antiischemic efficacy and development of tolerance to transdermal nitroglycerin, 14 patients with chronic, stable angina pectoris were studied using continuous ambulatory electrocardiographic monitoring. Patients demonstrated initial hemodynamic responsiveness to sublingual nitroglycerin and were titrated to a maximally tolerated dose of 30 to 60 mg/24 hours (52 +/- 5 mg). Two crossover phases were use in a randomized, double-blind, placebo-controlled manner: continuous nitroglycerin therapy (patches containing active drug worn for 24 hours) and intermittent nitroglycerin therapy (12-hour active drug followed by a 12-hour nitrate-free period). There were no differences in frequency or duration of ischemic episodes between the placebo days of each phase. A significant effect in frequency of episodes was observed between placebo and treatment days of continuous therapy (p less than 0.05). Nonsignificant reductions in frequency and duration of ischemic episodes also occurred during intermittent therapy. The major antiischemic effect of transdermal nitroglycerin therapy occurred during the first day of treatment but was lost by 48 hours. Reductions in frequency and duration of ischemic episodes (p less than 0.05) were present on day 1 of continuous therapy but ischemic episodes returned to placebo levels by day 2, suggesting the development of tolerance. Intermittent therapy did not prevent the development of tolerance on day 2 of treatment. The results demonstrate that the use of high doses of transdermal nitroglycerin in patients with chronic, stable coronary artery disease produced a beneficial reduction in the frequency and duration of ischemia. However, the antiischemic benefit was lost between 24 nd 48 hours after the onset of continuous and intermittent therapy, presumably due to tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1989

Effect of smoking on the activity of ischemic heart disease.

Cigarette smoking has been causally linked to coronary heart disease. To investigate the effect of smoking on the activity of ischemic heart disease, 65 patients with chronic stable manifestations of coronary disease and a positive exercise tolerance test underwent continuous ambulatory monitoring to quantify the amount of ischemic ST segment depression during daily life. Twenty-four smokers were compared with 41 nonsmokers for frequency and duration of electrocardiographic signs of ischemia during 24 hours. A total of 4,968 hours of ambulatory monitoring were analyzed. The frequency of episodes was three times as often (median) and the duration of ischemia was 12 times longer (median duration, 24 vs 2 min/24 h) in smokers than nonsmokers. This finding remained statistically significant when a number of potentially confounding factors were controlled by means of logistic regression. This study shows that patients with coronary artery disease who smoke have significantly and substantially more active myocardial ischemia during daily life than patients who do not.

Activities of Daily Living↗
PubMed1989

An evaluation of the notification of birth form.

Data on 108 Notification of Birth Forms, from a total of 6 hospitals, have been compared with hospital case notes, for both accuracy and completeness. Items related to socio-demographic features of mothers were reliable. However, certain items related to past obstetric history, such as date of last birth and number of previous live births, were less than 90% reliable. Data on index pregnancy were poorest, with three items, first visit to doctor during pregnancy, first visit to hospital during pregnancy and rubella immune status all less than 75% reliable. Data from one hospital were of poorer quality than others, principally because the information on the form is not obtained directly from the mother. Data on forms related to travellers (N = 29) were also of poorer quality.

Birth Certificates↗
PubMed1989

Pelvic inflammatory disease.

Pelvic inflammatory disease is a major cause of infertility in Australia. Although there is still much to learn about the disease, which can be difficult to diagnose, the general practitioner has an important role in reducing the biological, psychological and social impact of this condition.

Adolescent↗
PubMed1989

[Geographical variations in mortality due to diseases amenable to medical intervention in Europe--Commission of European Communities: atlas of avoidable deaths].

The urgent need to develop measures of the outcome of health-care services has led to the collaboration of 10 countries of the European Community in the production of the European Community atlas of avoidable death (1974-1978). Seventeen disease groups were chosen for which it was considered that death within specified age groups should be either wholly or substantially avoidable when appropriate medical care is sought and provided in good time. Mortality from these causes was compared across 360 health-service administrative areas in the participating countries. For all diseases there was considerable variation in mortality both within and between the countries of the European Community and it is suggested that high levels of mortality from these causes should be viewed by health authorities as warning signals of potential failures of health-care services. Work is in progress on a further edition of the Atlas for the years 1980-1984. Changes in avoidable mortality over time could indicate which health authorities have persistent problems and which authorities are succeeding in reducing avoidable mortality.

Adolescent↗
PubMed1988

Brush border membrane vesicles formed from human duodenal biopsies exhibit Na+-dependent concentrative L-leucine and D-glucose uptake.

The human duodenum actively transports L-leucine and D-glucose under Na+ gradient conditions as demonstrated by uptake studies using brush border membrane vesicles from organ donor duodenum. Brush border membrane vesicles formed from peroral duodenal biopsies likewise demonstrate Na+ dependent concentrative uptake of D-glucose and L-leucine. This is the first demonstration of active transport processes in human duodenum. A simple microvesiculation method to form these vesicles is described as well as its potential application to clinical medicine in studying diseases of defective intestinal transport.

Biological Transport↗
PubMed1988

Frequency of ST-segment depression produced by mental stress in stable angina pectoris from coronary artery disease.

Physical exertion is a well-documented trigger of transient myocardial ischemia in patients with coronary disease. More recently, studies have shown that mental stress may also be a cause of myocardial ischemia. The purpose of this study was to examine the relationship of physical activities and perceived mental states to myocardial ischemia while patients were going about their normal daily activities. Twenty-eight patients with documented coronary artery disease underwent ambulatory monitoring of the electrocardiogram. Physical activity and perceived mental status were recorded by patients in a diary which was then graded according to intensity of the activity. Analyses of the continuous electrocardiographic recordings were done separately from the analysis of the diaries. The time of each episode of ischemia, the duration of each episode in minutes and the number of episodes in each 24-hour period were calculated. A total of 372 episodes of ST-segment depression occurred in 912 hours of monitoring. Ischemic events occurring during usual physical and usual mental activities were most frequent (36%). Twenty-six percent of ischemic episodes occurred during increased physical activity, but usual mental activities. Interestingly, 22% of the ischemic events occurred at high levels of mental stress, but low physical activity. Ten percent of episodes occurred during sleep. Although the majority of events occurred during usual daily activities, when duration of ischemia was normalized for time spent in each category, increasing physical or mental activity was associated with an increasing duration of ischemia per unit (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1988

Early use of OKT3 monoclonal antibody in renal transplantation to prevent rejection.

OKT3 monoclonal anti-T cell antibody was used during the first 2 weeks following cadaveric renal transplantation to prevent rejection. When compared with a control group receiving triple immunosuppression with cyclosporine, azathioprine, and prednisone, the OKT3, azathioprine, and prednisone group had significantly fewer acute rejections during the first month (6% v 50%; P less than 0.01), and the mean time of onset of the first rejection was significantly delayed (day 47 v day 8; P less than 0.01) in the OKT3 prophylaxis group. OKT3 was administered intraoperatively safely and without complications on the day of transplantation. The well-reported first dose reaction to OKT3 was similar in these patients when compared with patients receiving OKT3 for treatment of rejection. Anti-OKT3 antibody development occurred in half of the patients receiving OKT3, and did not prevent the subsequent use of OKT3 in these patients, whose rejections following OKT3 prophylaxis were steroid reversible. There were no deaths among the patients receiving prophylactic OKT3, and during a 15-month follow-up, only three of 34 kidneys were lost for any reason. In addition to its use for primary and steroid-resistant rejection, OKT3 may be useful early after transplantation to prevent rejection.

Antibodies, Anti-Idiotypic↗
PubMed1988

Recovery from immobilization-induced atrophy of rabbit soleus muscles can be accelerated by chronic low-frequency stimulation.

Immobilization of rabbit soleus muscles with an ankle joint angle of 90 degrees led to gross degeneration after 2 weeks. Natural recovery in the subsequent 2 weeks had little effect on the mean area of soleus fibres, although there were signs of regeneration. However chronic low-frequency activation of soleus muscles by nerve stimulation greatly accelerated recovery, producing muscle fibres of normal areas and with characteristics of maturity.

Animals↗