[Study of the efficacy and tolerance of the oral administration of a major new analgesic: pentazocine].
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Biomedical subjects
Publications and source records attributed to D Levy.
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BACKGROUND: Elevated serum creatinine (SCr) levels are a predictor of end-stage renal disease, but little is known about the prevalence of elevated SCr levels and their correlates in the community. METHODS: In this cross-sectional, community-based sample, SCr levels were measured in 6233 adults (mean age, 54 years; 54% women) who composed the "broad sample" of this investigation. A subset, consisting of 3241 individuals who were free of known renal disease, cardiovascular disease, hypertension, and diabetes, constituted the healthy reference sample. In this latter sample, sex-specific 95th percentiles for SCr levels (men, 136 micromol/L [1.5 mg/dL]; women, 120 micromol/L [1.4 mg/dL]) were labeled cutpoints. These cutpoints were applied to the broad sample in a logistic regression model to identify prevalence and correlates of elevated SCr levels. RESULTS: The prevalence of elevated SCr levels was 8.9% in men and 8.0% in women. Logistic regression in men identified age, treatment for hypertension (odds ratio [OR], 1.75; 95% confidence interval [CI], 1.27-2.42), and body mass index (OR, 1.08; 95% CI, 1.01-1.15) as correlates of elevated SCr levels. Additionally, men with diabetes who were receiving antihypertensive medication were more likely to have raised SCr values (OR, 2.94; 95% CI, 1.60-5.39). In women, age, use of cardiac medications (OR, 1.58; 95% CI, 1.10-2.96), and treatment for hypertension (OR, 1.42; 95% CI, 1.07-1.87) were associated with elevated SCr levels. CONCLUSIONS: Elevated SCr levels are common in the community and are strongly associated with older age, treatment for hypertension, and diabetes. Longitudinal studies are warranted to determine the clinical outcomes of individuals with elevated levels of SCr and to examine factors related to the progression of renal disease in the community.
OBJECTIVE: To compare the short- and long-term prognosis following a first Q-wave or non-Q-wave myocardial infarction. DESIGN: Cohort study with a mean follow-up period of 5.1 +/- 4.9 years. SETTING: Population-based. PARTICIPANTS: Framingham (Mass) Heart Study subjects with an initial recognized myocardial infarction during a 17-year period were studied, including 227 men and 136 women with a mean age of 67.2 years. Seventy-seven percent of first infarctions were Q-wave infarctions and 23% were non-Q-wave infarctions. MAIN OUTCOME MEASURES: Reinfarction and death from coronary heart disease. RESULTS: During the follow-up period, subjects with non-Q-wave infarctions had a significantly higher rate of reinfarction than subjects in the Q-wave group (P = .02 for the entire follow-up). The 10-year reinfarction rates were 44.8% vs 27.4%. When analyzed separately by age and sex, differences in reinfarction rates were only noted in men and in those under the age of 65 years. There were no differences in coronary heart disease death rates based on Q-wave status, even when examined separately by age and sex. Multivariate analysis revealed a 1.8-fold higher risk of reinfarction in the non-Q-wave group (95% confidence interval, 1.1 to 3.1), and also demonstrated that baseline hypertension was an independent risk factor for predicting reinfarction (relative risk, 1.8; 95% confidence interval, 1.1 to 3.2). There were no differences in the rates of sudden death or all-cause mortality following the two types of myocardial infarction. Additionally, subjects with a first Q-wave infarction had a higher rate of subsequent congestive heart failure, while those with non-Q-wave infarctions had a significantly higher rate of coronary insufficiency (unstable angina with transient ST-T wave abnormalities). CONCLUSIONS: These results confirm and extend findings from prior studies that have identified patients with first non-Q-wave myocardial infarctions as potentially unstable, with greater subsequent morbidity and similar mortality to their counterparts with Q-wave infarctions.
Since considerable expansion of hematopoietic marrow occurs in patients with sickle cell anemia (SCA), magnetic resonance images of 20 hips in 10 patients with known homozygous SCA were reviewed to determine a) if low signal hematopoietic marrow extended into the femoral capital epiphysis and b) if the MR characteristics of avascular necrosis (AVN) differed depending on the type of epiphyseal marrow. Our results revealed variable epiphyseal marrow type; mixed (fatty and hematopoietic) marrow (42%), fatty marrow (32%), hematopoietic marrow (16%) and hemosiderotic marrow (10%). AVN occurred irrespective of the underlying marrow. Segmental areas of low signal intensity in variable shapes (ring, band, crescent or large homogeneous area) was the most consistent MR manifestation of AVN in SCA. A low signal intensity peripheral rim surrounding a central zone, isointense with epiphyseal marrow on T1 and T2 weighted images, was most frequently observed similar to that described in patients without hemoglobinopathy. The notable difference, however, was of segmental areas within the same femoral head that demonstrated variable central zone signal on T2 weighted images. Further, while an increase in hip joint fluid is commonly seen with both early and advanced AVN in patients without hemoglobinopathy; it was increased in only one hip in patients with SCA. The observed differences in MR characteristics may be due to different pathophysiology of AVN in patients with SCA.
For a given TR and TE, image quality changes when the number of spin echoes obtained is varied. To investigate the importance of this in clinical imaging, a total of 4 patients and 9 volunteers had MRI examinations of the abdomen (n = 7) and/or pelvis (n = 8) which included at least 2 sequences with identical TR (2000 or 2500 ms), TE (80 ms) and other parameters, but with a different series of refocusing pulses. Sequences included single-echo (S), asymmetric and symmetric double-echo (AD and SD) and quadruple-echo (Q) techniques. Image contrast and severity of motion-induced artifact was measured via blind examination by 3 independent MRI radiologists and calculation of signal-difference, signal-difference-to-noise ratios and intensity of motion-induced "ghost artifact." The order of decreasing signal differences was S, SD, AD and Q, and all of three liver lesions were better seen with S than with SD techniques. These observations are consistent with signal loss from cumulative inaccuracies from multiple 180 degrees RF pulses. The order of increasing intensity of ghost artifact was Q, SD, AD and S, consistent with the beneficial motion artifact-reducing effects of even-echo rephasing. Knowledge of these effects of multi-echo imaging allows one to make informed decisions about imaging protocols rather than to simply obtain multiple echoes "because they are free."
Ischemic necrosis of bone is believed to occur exclusively in areas of predominantly fatty marrow. Sickle cell disease is unusual in that marrow infarction occurs in areas of active hematopoiesis. MR images of long bone obtained in ten patients with sickle cell anemia (SCA) were analyzed to correlate the distribution and appearance of marrow infarction with the type of marrow. While the hematopoietic marrow predominated in metaphyseal and diaphyseal regions of femurs and tibias, the fatty or mixed marrow was the most common pattern in epiphyses. Infarcts occurred in fatty as well as hematopoietic marrow. Marrow infarcts were isointense or minimally hyperintense on T1 weighted images with the hematopoietic marrow and therefore difficult to detect. On T2 weighted images, the infarcts showed very high signal. T2 weighted images are essential for detection of marrow infarction. Soft tissue changes seen as low signal on T1 and high signal on T2, may be secondary to intramuscular injections of analgesics or muscle ischemia occurring during sickle crisis.
Total cholesterol level is significantly related to risk of coronary heart disease (CHD), adjusting for other risk factors in women 50 to 79 years old and in men aged 50 to 64 years, at P < .001. Determining the levels of lipoproteins such as low-density-lipoprotein (LDL) cholesterol and high-density-lipoprotein (HDL) cholesterol improves the prediction of risk. Triglycerides are independently related in women at all ages but miss statistical significance in the multivariate studies in men. The total cholesterol-HDL cholesterol ratio is another powerful predictor at all ages in women and is the only lipid predictor independently related to CHD in men 65 to 80 years old. Inspection of the age-specific association of cholesterol with risk in men and women also reveals that the absolute rates of disease worsen with age.
The objectives of this study were to develop sex-, age-, and body size-specific nomograms and partition values for upper and lower limits of M-mode echocardiographic aortic root measurements derived from a large population-based cohort. The study sample consisted of 1433 male and 1816 female participants in the Framingham Heart Study and Framingham Offspring Study who were normotensive and free of clinically apparent heart disease at the baseline examination. Aortic root measurements were obtained by M-mode echocardiography by a leading-edge to leading-edge technique. The relations of age and measures of body size with aortic root dimensions were evaluated with sex-specific correlations and multiple stepwise linear regression analyses. Age was the most important determinant of aortic root size in both men and women in the multivariable regression models. Models with age and body surface area yielded R2 values of 0.214 in men and 0.222 in women. Models with age and height yielded lower R2 values of 0.136 in men and 0.181 in women. Thus aortic root dimensions vary widely with the age, sex, and body size of individuals. Sex-specific reference nomograms of aortic root dimensions in relation to age and body size (body surface area or height) are presented to facilitate the detection of abnormalities of aortic root size.
Congestive heart failure increases in prevalence with age. A large number of elderly subjects with heart failure have either normal or slightly reduced left ventricular (LV) systolic function; their symptoms are due to diastolic LV dysfunction. Reference values for Doppler indexes of LV diastolic filling in a large sample of the very elderly (> 70) have not been reported previously. The objective of this study was to generate reference values for Doppler indexes of LV filling in a population of apparently healthy elderly men and women. A total of 1201 surviving original subjects of the Framingham Heart Study were evaluated by Doppler echocardiography. A subset of 114 rigorously selected healthy subjects (26 men and 88 women) aged 70 to 87 years (mean 76) constituted the study group. Measurements of seven commonly used Doppler indexes were obtained. Mean and 2.5, 5, 10, 25, 50, 75, 90, 95, and 97.5 percentile values for Doppler diastolic indexes were generated. Stepwise regression analyses were performed to determine the relation of diastolic LV filling to age group (70 to 74 years, 75 to 79 years, and 80 years and over), sex, and other clinical variables. Reference values for the various Doppler parameters were generated on the basis of this healthy elderly cohort. There was evidence for a slight progressive decline in indexes of LV inflow with age. In 87% of this elderly population the ratio of peak early to late velocities of LV diastolic inflow was less than 1.0.(ABSTRACT TRUNCATED AT 250 WORDS)
A limitation of most air pollution health effects studies is that they rely on monitoring data averaged over one or more ambient monitors to represent daily air pollution exposures for individuals. Such data analyses therefore implicitly require the assumption of a homogeneous spatial distribution for particulate matter (PM). This assumption may be suspected in the Pacific Northwest because of its hilly topography and local variations in wood burning. To examine the bias from substituting regional PM (i.e., the average of three ambient monitor measurements) for individual PM exposure, we conducted an exposure substudy to identify the influence of location factors, specifically urban versus suburban classification and topographic features ("upstream" versus "downstream"), on local ambient measurements. Using nephelometer measurements collected over 1 year in four locations, we developed regression models to predict local PM as a function of regional PM, atmospheric stagnation, temperature, and location. We found a significant interaction between atmospheric stagnation and topography, with the most upstream site having reduced PM levels on high stagnation days after controlling for regional PM. We also found a significant interaction with temperature at one downstream site thought to be heavily exposed to wood smoke in the winter. These results are consistent with the physics of surface radiation inversions. The interactions reordered the index versus referent exposures in a case-crossover analysis of out-of-hospital primary cardiac arrest for subjects living in specific locations, but did not meaningfully change the associations with PM from the analysis using regional PM as the exposure. The lack of change in these results may be due to limitations in the data used to correct the exposure estimates or to the absence of a PM effect among persons without prior heart disease who experienced a primary cardiac arrest.
The presence of marked changes in the neural retina and retinal vessels of Long-Evans pigmented rat following bilateral carotid ligation has been previously documented by serial ophthalmologic examinations. Light and electron microscopic studies of the optic nerve in this experimental animal model revealed advanced optic nerve atrophy in ten of twelve rats examined. There was no significant pathology in either the retina or optic nerve in the remaining two rats after carotid ligation or in the sham-operated controls.
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