Prolonged observations on the liver function tests in infectious hepatitis.
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Alanine Transaminase↗
Biomedical subjects
R A Kronmal
Publications and source records attributed to R A Kronmal.
Epidemiological studies of Mycoplasma pneumoniae infections in civilians.
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Adolescent↗
Pneumonia due to Mycoplasma pneumoniae. Its incidence in the membership of a co-operative medical group.
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Adolescent↗
The relationship between cholesterol level and myocardial infarction or mortality risk in patients with coronary artery disease. A report from the Coronary Artery Surgery Study (CASS) registry.
Using data from the Coronary Artery Surgery Study (CASS) registry, we evaluated the relationship between cholesterol levels measured at enrollment and the following events: all-cause mortality, cardiac death, fatal myocardial infarction (MI), and nonfatal MI. Only patients with a significant coronary artery disease (at least one lesion with stenosis > or = 50%) were considered for this study. Results presented for mortality are for a period of up to 11.5 years and those for MI are for a maximum of 8 years of follow-up. Analyses were performed for each type of event and for each subgroup: women (n = 1861) and men (n = 10,941) under age 65, and women (n = 426) and men (n = 1144) age 65 or older. After adjusting for important covariates, cholesterol level was not associated with cardiac or all-cause mortality. No relationship between cholesterol level and fatal or nonfatal MI could be demonstrated except for men under age 65. However, in this subgroup the risk of MI was highest for those with low or middle cholesterol levels. The data show that in patients with angiographically determined coronary artery disease, cholesterol level is not a statistically significant risk factor for death or MI over the follow-up period in CASS.
Aged↗
Vasectomy and urolithiasis.
The relation between vasectomy and renal disease was examined in the data collection phase of a study of vasectomy and coronary artery disease. The date of onset and type of urological disease was obtained for 11,205 men enrolled in the US Coronary Artery Surgery Study. Urolithiasis was the most common reported urological disease. The relative risk for calculi in men who had had a vasectomy ranged from 2.6 for patients 30-35 years old to 1.3 for those aged 55-65. The age-adjusted relative risk was 1.67 (p less than 0.001).
Adult↗
Physical growth of children treated for phenylketonuria.
The growth of 133 children participating in the Collaborative Study of Children Treated for Phenylketonuria (PKU) was compared to growth data from the National Center for Health Statistics (NCHS) to determine whether the growth patterns of the children with PKU were the same as those of unaffected children. Height and weight by age, and weight by height, were analysed for ages 2-10 years. Head circumference by age was analysed for ages 2-7 years. Median height by age of the PKU children was consistently near the 50th percentile of the NCHS growth curves for males and females. However, for both sexes, median weight by height and by age was between the 50th and 75th percentiles for children over 3 years old. Two-sample t-tests showed mean weight was significantly different (p less than 0.05) between the PKU and NCHS groups at most ages for both sexes. Median head circumference for the PKU children tended to be smaller than NCHS standards; however, the maximum difference at any age was less than 0.5 cm. Polynomial growth curves fitted to the PKU and NCHS growth data showed that, on average, the PKU males and females weighed more than their unaffected counterparts, while height and head circumference for both groups were very close. Including median serum phenylalanine (phe) level (mg/dl) in the growth curves suggested that the weight differences between the PKU and NCHS groups are related to degree of diet adherence. Higher phe levels in the PKU group were associated with higher weight levels, more so for girls (p less than 0.001) than for boys (p = 0.08). No relationship was found between phe level and height or head circumference. We conclude that growth in children treated for PKU differs from national standards for weight by age and weight by height, but not for height by age. We speculate that diet adherence may be an important factor in determining which children have a tendency to become overweight.
Adult↗
Chlamydia pneumoniae strain TWAR antibody and angiographically demonstrated coronary artery disease.
A recent case-control study from Finland reported a strong association between high antibody titers to Chlamydia pneumoniae, strain TWAR, and both chronic coronary heart disease and acute myocardial infarction. The current case-control study investigated the relation between C. pneumoniae immunoglobulin G antibody titers and angiographically diagnosed coronary artery disease. Cases (n = 461) were angiography patients with at least one coronary artery lesion occupying at least 50% of the luminal diameter. Controls (n = 95) were angiography patients with no demonstrable coronary artery disease. After standardization for age and gender, the geometric mean antibody titer was higher for cases than for controls (30.0 versus 24.0, p = 0.04). The estimated risk of coronary artery disease, adjusted for age and gender, was greater among subjects with high (greater than or equal to 1:64) antibody titers than among subjects with low (less than or equal to 1:8) antibody titers (relative risk, 2.0; 95% confidence interval, 1.0-4.0). The risk associated with a high antibody titer was particularly great for coronary artery disease with five or more lesions (relative risk, 2.8; 95% confidence interval, 1.2-7.0). The results of this cross-sectional study support an association between infection with C. pneumoniae and coronary artery disease.
Antibodies, Bacterial↗
Factors affecting the extent and severity of coronary artery disease in patients enrolled in the coronary artery surgery study.
This study was designed to test the relationship between each of nine risk variables and the extent and severity of coronary artery disease in 15,298 patients with coronary artery disease proven by arteriography who were enrolled in the Coronary Artery Surgery Study. The extent and severity of the disease were highly significantly (p less than 0.001), but modestly, correlated with age, sex, cholesterol levels, history of diabetes, and history of hypertension. Interestingly, no positive correlation (indeed, in some subgroups, a negative correlation) occurred between the arteriographic measures of disease and the cigarette smoking history (ever or never, number of pack-years of smoking, duration of cigarette smoking, and peak daily cigarette consumption). These results suggest that the risk factors for presence of disease may differ from those influencing angiographic extent and severity.
Adult↗
Stress fractures in ballet dancers.
We surveyed 54 female dancers in two professional ballet companies. A total of 27 fractures were reported in 17 dancers. Metatarsal fractures were the most common (63%), followed by fractures of the tibia (22%) and spine (7%). Dancers who danced greater than 5 hours per day were significantly more likely to have a stress fracture than those dancing less than 5 hours per day. Dancers in the stress fracture group also had a significantly longer duration of amenorrhea than those in the group with no stress fractures. No significant difference was found between the dancers who had stress fractures and those who did not with regard to any of the other variables examined. These data suggest that prolonged amenorrheic intervals and heavy training schedules may predispose ballet dancers to stress fractures. Of the 17 dancers with stress fractures, only 1 had neither of these risk factors.
Adolescent↗
The temporal pattern of reduction of mortality risk after smoking cessation.
We investigated the excess mortality risks of former smokers according to the number of years since they quit smoking in a cohort of 21,112 men and women evaluated with coronary angiography and included in the Coronary Artery Surgery Study registry. There is a prompt decline in mortality risk within the first year of quitting. Thereafter, former smokers have a sustained, modestly elevated mortality risk for at least 20 years compared with people who never smoked. The pattern is similar in men and women, in 35-54, 55-64, and greater than or equal to 65 age groups, and in subcohorts of those with coronary artery disease and those without coronary artery disease.
Adult↗
Treatment of out-of-hospital cardiac arrest with a low-energy impedance-compensating biphasic waveform automatic external defibrillator. The LIFE Investigators.
Few victims of sudden cardiac arrest survive. A new generation of automatic external defibrillators (AEDs), smaller, lighter, easier to use, and less costly, makes the goal of widespread AED deployment and early defibrillation feasible. A low-energy impedance-compensating biphasic waveform allows AED device characteristics more suitable to the goal of early defibrillation than high-energy waveforms. This study observed the performance of such a biphasic waveform in the out-of-hospital setting on 100 consecutive victims of sudden cardiac arrest treated by a wide range of first-responders. AEDs incorporating 150-J impedance-compensating biphasic waveforms were placed into service of 34 EMS systems. Data were obtained from the AED PC data card-recording system. The first endpoint was to determine the effectiveness of this waveform in terminating ventricular fibrillation (VF). The second endpoint was to determine whether or not the use of such an AED culminated in an organized rhythm at the time of patient transfer to an advanced life support (ALS) team or emergency department (ED). The third endpoint was to assess the efficiency of the human-factors design of the AED by measuring user time intervals. The 34 sites provided data from 286 consecutive AED uses, 100 from SCA victims with VF as their initial rhythm upon attachment of the AED. All 286 patients were correctly identified by the AED as requiring a shock (100% sensitivity for the 100 VF patients) or not (100% specificity to the 186 patients not presenting in VF). Times from emergency call to first shock delivery averaged 9.1 +/- 7.3 minutes. A single 150-J biphasic shock defibrillated the initial VF episode in 86% of patients. For all 450 episodes of VF in these 100 patients, an average of 86% +/- 24% of VF episodes were terminated with a single biphasic shock. Of the 449 VF episodes that received up to three shocks, 97% +/- 11% were terminated with three shocks or fewer. The average number of shocks per VF episode was 1.3 +/- 0.7. The average time from AED power-on and pads attached to first defibrillation was 25 +/- 23 sec. At the time of patient transfer, an organized rhythm was present in 65% of the VF patients; asystole was the result in 25%, and VF was in progress in 10%. It is concluded that low-energy impedance-compensating biphasic waveforms terminate long-duration VF at high rates in out-of-hospital cardiac arrest and provide defibrillation rates exceeding those previously achieved with high-energy shocks. Use of this waveform allows AED device characteristics consistent with widespread AED deployment and early defibrillation.
Automation↗