PubMed Health⌕ Search

Biomedical subjects

S P Azen

Publications and source records attributed to S P Azen.

18 recordsLinked to original sources
PubMed1992

The Monitored Atherosclerosis Regression Study (MARS). Design, methods and baseline results.

OBJECTIVE: The Monitored Atherosclerosis Regression Study (MARS) was designed to evaluate the effect of cholesterol lowering by monotherapy with an HMG-CoA reductase inhibitor on progression/regression of atherosclerosis in subjects with angiographically documented coronary artery disease. The purpose of this paper is to present the design, methods, and baseline results of MARS. DESIGN: MARS is a prospective, randomized, double-blind, placebo-controlled trial with baseline, 2-year, and 4-year coronary angiography as well as carotid, brachial, and popliteal ultrasonography. SETTING: Outpatient clinics at the University of Southern California School of Medicine and the University of Wisconsin School of Medicine. SUBJECTS: Two hundred seventy participants of both sexes were recruited directly from the cardiac catheterization laboratory or by chart review of patients having undergone cardiac catheterization in the past. Subjects were considered eligible if they had angiographically demonstrable atherosclerosis in 2 or more coronary artery segments, unaltered by angioplasty, with at least 1 lesion > or = 50% but < 100% diameter stenosis (%S). The inclusion range for total cholesterol (TC) was between 190 and 295 mg/dL. Exclusion factors were: triglycerides > or = 500 mg/dL; premenopausal females; uncontrolled hypertension; diabetes mellitus; untreated thyroid disease; liver dysfunction; renal insufficiency; congestive heart failure; major arrhythmia; left ventricular conduction defects; or any life-threatening disease. INTERVENTION: Subjects were placed on a low-fat, low-cholesterol diet and either 40 mg b.i.d. lovastatin (Mevacor) or placebo. Randomization was stratified by sex, smoking status, and TC. MAIN OUTCOME MEASURES: Per-subject average change in %S as determined by quantitative coronary angiography (QCA) is the primary angiographic endpoint. Secondary endpoints are: categorical analyses of the proportion of subjects with progression; human panel reading of coronary angiograms; and change in minimum lumen diameter (MLD) in mm by QCA. Carotid, brachial, and popliteal ultrasonography is also being performed. RESULTS: The subjects randomized into MARS are 91.5% male with an age range of 37 to 67 years (mean age 57.9 years). For the cohort, baseline lipids are (mean +/- SD): TC, 231 +/- 24 mg/dL; low-density lipoprotein cholesterol (LDL-C) by ultracentrifugation, 153 +/- 24 mg/dL; LDL-C, by calculation, 157 +/- 23 mg/dL; high-density lipoprotein cholesterol (HDL-C), 43 +/- 10 mg/dL; and triglycerides, 160 +/- 73 mg/dL. There were no significant differences between treatment groups in baseline lipid levels or baseline angiographic characteristics. CONCLUSIONS: MARS baseline data show adequacy of randomization with comparability of lovastatin and placebo groups in demographic, lipid, and angiographic characteristics.

Adult↗
PubMed1979

A user's experience with a standard non-linear regression program (BMDP3R).

A study was made to test and compare the behavior of a standard non-linear regression program (BMDP3R) in fitting data from six classical least-squares problems. The use of three program control parameters is discussed and four measures of regression failure are utilized to give a quantitative reference of success. Recommendations are given to aid the user of packaged programs in the parameter estimation of non-linear regression models.

Computers↗
PubMed1979

Multifactorial probit analysis of mortality in burned patients.

Burn mortality statistics may be misleading unless they account properly for the many factors which may influence outcome. In reviewing such factors in our patients, we identified age, total burn area, third degree burn area, prior bronchopulmonary disease, abnormal Pao2, and airway edema as the factors present on admission which best distinguished survivors from nonsurvivors. Using multifactorial probit analysis, we then calculated the contribution of each to the probability of fatal outcome. The resultant six-factor model significantly improved estimation of the probability of fatal outcome when compared to probit analysis based only on the traditional factors of age and total burn area. It also revealed a spectrum of mortality probabilities varying with the additional factors present. Although crucial in comparing different approaches to burn care, consideration of such prognostic factors will not eliminate the need for randomized treatment trials, because other factors, some of which are obscure, may also influence mortality rates in burned patients.

Adult↗
PubMed1979

A comparison of three methods for the measurement of corneal thickness.

Four subjects who had never worn contact lenses underwent measurement of their corneal thickness by each of three measurement methods: Haag-Streit pachometer with/and without Mishima-Hedby attachment and the Syber specular microscope. Data were collected on three separate sessions, and at each session triplicate measurement trials were made for each method. The resulting 108 measurements were analyzed statistically. Significant differences were found among the measurement methods. Two of the methods were found to be consistent from session to session. In addition, the specular microscope was found to be the most precise method within a session. It was concluded that the specular microscope, which highly trained technicians can utilize to make the measurements, offers a valuable alternative to the measurement of corneal thickness in long-term prospective studies.

Adult↗
PubMed1979

Normal range of motion of joints in male subjects.

With a clinical goniometer, we measured the arcs of active motion of the shoulder, elbow, forearm, wrist, hip, knee, ankle, and foot in 109 normal male subjects ranging in age from eighteen months to fifty-four years old. The normal limits were determined for subjects who were one to nineteen years old and for those who were twenty to fifty-four years old. Significant differences were found between the two age groups for most motions. The data were compared with estimations in the handbook of The American Academy of Orthopaedic Surgeons as the standard reference. The data constitute a more detailed set of measurements, based on a sample described according to height and age, than has been available hitherto.

Adolescent↗
PubMed1978

Reliability of goniometric measurements.

This study determined the intratester and intertester variability and reliability of goniometric measurements taken by four physical therapists on upper and lower extremity motions of normal male subjects. The same subjects were measured once weekly for four weeks by testers with varied experience in goniometry. Data were analyzed by analyses of variance with repeated measures. Intratester variation for all measurements was less than intertester variation. Further, intertester variation was less for the three upper extremity motions than for those of the lower extremity. These findings indicate the necessity for using the same tester when effects of treatment are evaluated. When the same tester measures the same movement, increases in joint motion of at least three to four degrees determine improvement for either the upper or lower extremity. When more than one tester, however, measures the same movement, increases in joint motion should exceed five degrees for the upper extremity and six degrees for the lower extremity to determine improvement.

Adult↗
PubMed1978

A comparison of two developmental instruments in evaluating children with Down's syndrome.

Twenty-one children with Down's syndrome were given both the Bayley Scales of Infant Development and the Gesell Developmental Schedules. Mental and motor developmental lags measured on the Bayley Scale were found to be significantly larger than comparable lags measured on the Gesell Schedules. Further, developmental lags for the mental and motor portions of the Bayley were not significantly different. For the Gesell, however, mental lag was significantly larger than motor lag. Finally, mental and motor lags increased with chronologic age on the Bayley, but only mental lag increased with age on the Gesell. These discrepancies indicate that for this population of infants the Bayley and the Gesell are not interchangeable assessments because they do not yield the same developmental patterns.

Age Factors↗
PubMed1978

A factor analytic approach to an effective lung function screening protocol.

Interrelationships among simple indices of pulmonary function derived from flow-volume curves and single-breath nitrogen tests were investigated by performing a factor analysis on data obtained from a generally healthy office working population (n = 388). Smoking was regarded as the major contribution to pulmonary dysfunction. Delta nitrogen was largely independent of all other measures, while flow-volume measures, including flow rates at high and low lung volumes, were highly intercorrelated but largely independent of closing volume and closing capacity. Delta nitrogen was most affected by smoking in both sexes. Scores derived from flow-volume measurements and from closing-volume measurements were significantly different, on the average, between male smokers and male nonsmokers. The methods and results presented prove to be useful in the design of protocols for effective pulmonary testing of large populations.

Adult↗
PubMed1978

A comparison of operant and sensory integrative methods on developmental parameters in profoundly retarded adults.

The expertise of speech pathologists and occupational therapists was combined to compare the relative effectiveness of an operant approach, a modified sensory integrative approach, and a combination of both methods in eliciting vocalization on other developmental skills on a sample of 27 profoundly retarded, minimally vocal, institutionalized adults. The combined results indicated that the therapy programs promoted significant gains in frequency of eye contact, frequency of vocalization, and quality of postural adaptation. There were no differences in the effects of the respective therapies. The fact that the more controversial sensory integrative procedures elicited comparable gains when compared with the more widely recognized operant method lends credence to the viability of sensory integrative methods.

Adult↗
PubMed1977

A new procedure for the statistical evaluation of intrauterine contraception.

An improved statistical method for assessing the efficacy of intrauterine contraception is presented. This method, called the log-rank method, is based on a daily life table, which yields the best estimates of the cumulative net termination probabilities. It provides a sensitive chi-square test statistic to detect differences among these probabilities for two or more contraceptive devices. When three or more devices are compared, the chi-square statistic may be partitioned into additive components representing comparisons among groups of devices. The log-rank method also permits adjusting for differences among subgroups by controlling for factors such as parity or age. Although calculations may be performed on a desk calculator, a FORTRAN-IV computer program is made available to interested researchers.

Computers↗
PubMed1977

Abnormal serum lipid patterns in primary renal allograft recipients.

The blood lipids profile was determined in 59 patients with successful primary renal allografts, who were followed for an average period of 31.8 months (range, 6 to 80 months). Elevated levels of cholesterol (greater than 250 mg/100 ml) were found in 51% of the patients, elevated levels of triglycerides were found in 56%, and elevated levels of phospholipids in all but one of the patients who were studied (45 of 46). Correlation analysis revealed significant relationships among the systolic blood pressure with total cholesterol (r equals 0.36, P less than 0.01), triglycerides (r equals 0.56, p is less than 0.001), and phospholipids (r equals 0.40, P is less than 0.001). No significant correlations were found between the lipid levels and daily prednisone dosage or with the duration of the period following transplantation. The most significant finding in our study was an elevation of serum phospholipid level--a pattern unreported previously in transplant recipients but which has been reported to be associated with hepatic derangement in nontransplant population. Of 32 patients who had elevated levels of serum phospholipids, the liver function tests were abnormal in 22 patients (69%).

ABO Blood-Group System↗
PubMed1975

Personality patterns of white, black, and Mexican-American patrolmen as measured by the sixteen personality factor questionnaire.

The Sixteen Personality Factor Questionnaire was administered to 461 Los Angeles patrolmen to abtain a normative police profile. Multivariate analysis revealed that the average patrolman appeared brighter, more reserved, dominant, and tough-minded (p less than .001) than the average male. Comparisons were made for 29 black, 33 Mexican-American, and 399 white officers. Mexican-American officers emerged as more conservative and relaxed than whites, while black officers appeared more experimental, analytical, and group-oriented. A comparison with an idependent police sample revealed common traits of self-assurance and conservatism. Results were compared with a social workers' profile and discussed in relation to police officers' actual job activities and community needs.

Black or African American↗
PubMed1975

Mechanism of NaCl reabsorption by hamster thin ascending limbs of Henle's loop.

Two models of ypertonic urine formation in the inner medulla were tested. The active model asserts that thin ascending limbs of Henle's loop (ALH) reasorb NaCl hypertonically by active transport; the passive model suggests the reabsorption is by diffusion down a concentration gradient. Using (Na+) in ascending vasa recta (AVR) as a measure of interstitial (Na+), we found no concentration difference between loop tubular fluid and AVR, when the comparison was made at the bend of the loop, or at an ALH sampling site 1 mm from the bend; the results were the same in antidiuresis and saline diuresis. In saline diuresis with flow of tubular fluid to the ALH slowed by simultaneous collection at the bend of the loop,ALH (Na+) fell below AVR levels, a result consistent with active transport, but not with a purely passive mechanism. Although contragradient transport was shown only with flow slowed and the corticomedullary gradient reduced, a model suggests the active component contributes almost half the observed Na+ flux in antidiuresis.

Animals↗
PubMed1975

Scoliosis: A prospective epidemiological study.

A two and a half-year prospective study was carried out to determine incidence rates and distributions of various parameters associated with idiopathic scoliosis. Data were also collected on the progression curves detected at the initial screening. The results showed: (1) that the incidence rate was 13.6 per cent with a female-to-male ratio of 1.2:1, (2) that the most common type of curve was thoracolumbar, and (3) that spontaneous improvement occurred in approximately 22 per cent of those patients followed for an average of one year.

Adolescent↗