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Biomedical subjects

W H Allen

Publications and source records attributed to W H Allen.

16 recordsLinked to original sources

High-density winter brooding in a solar facility.

Broilers were brooded under high-density and low ventilation conditions in a solar facility to 25 days of age and then moved to conventional facilities for growout. Nonstatistical comparisons were made on the performance of these birds to that of broilers grown under conventional conditions starting at day-old. Body weight differences during the brooding phase were primarily due to density with birds in the solar house weighing an average of 10.2% less than those brooded in a conventional house. Growth depression continued during the growing phase but was reduced in magnitude to 3% at Day 46. During the brooding phase no definite trends were seen with regard to effects of ventilation or density on feed conversion. Compared with conventionally-housed birds, feed conversion of the birds in the solar facility was slightly poorer at the end of the brooding period. This trend was reversed in the growing phase due to compensatory growth, giving the solar brooded birds an overall advantage at the end of the study. Mortality during the 46-day study was within the expected range for both the solar-brooded (3.1%) and conventionally-brooded (3.0%) birds. Energy consumption for supplemental heat and ventilation in the solar facility (.76 kWh/bird) was similar to that reported for energy efficient, environmentally-controlled houses and about half that for conventional facilities. Litter moisture in the solar facility was excessive due to the high bird density, low ventilation rates, and the use of a concrete slab floor.

Animal Feed↗

A morphometric analysis of human muscle fibers with relation to fiber types and adaptations to exercise.

Muscle biopsies were obtained from the vastus lateralis of 14 male subjects: 3 long distance runners, 2 world class power lifters and 9 active, although not highly trained, individuals used as controls. The fibers were investigated by electron microscopy and the mitochondrial volume percent, lipid volume percent and Z-line width were analyzed morphometrically. With the combined data a direct correlation was found between mitochondrial volume percent and lipid volume percent, lipid volume percent and Z-line width and mitochondrial volume percent and Z-line width. The muscle fibers were classified as slow-twitch oxidative (SO), fast-twitch-oxidative-glycolytic (FOG) and fast-twitch-glycolytic (FG) based on relationships found in the data and well established properties of muscle fiber types. Although no distinct patterns emerged, a good approximation of fiber type characteristics was obtained, and values for volume percent of central mitochondria, volume percent lipid and Z-line width are reported. The fibers classified as SO were characterized by having wide Z-lines, a high mitochondrial volume percent and high lipid volume percent. The fast-twitch fibers (fibers with narrow Z-lines) were separated into 2 groups, those with high mitochondrial volume percent (FOG) and those with low mitochondrial volume percent (FG). No distinction could be made between the fast-twitch subgroups with regard to Z-line width. The fibers from distance runners differed from those from controls by exhibiting a greater capacity for aerobic activity as evidenced by the increased volume percent of mitochondria and lipid in both slow- and fast-twitch fibers. The high strength, anaerobic activity of the world class power lifters was reflected by the low mitochondrial volume percent of many fast-twitch fibers (FG) and the decreased lipid stores in all fibers.

Acclimatization↗

Five-year follow-up of maximal treadmill stress test in asymptomatic men and women.

A five-year follow-up of 888 asymptomatic men and women without known coronary heart disease (CHD) who had a maximal treadmill stress test (MTST) revealed a CHD incidence of 1.1% per year. In women, exercise duration of 3 minutes or less by the Ellestad protocol correlated with subsequent development of CHD (p less than 0.001), although abnormal ST-segment and R-wave responses did not. In men 40 years of age or younger, the MTST did not correlate with subsequent CHD. In men older than 40 years, ischemic ST response (p less than 0.01), an increase or no change in R wave (p less than 0.01), and an exercise duration of 5 minutes of less (p less than 0.001) all correlated with subsequent development of CHD. Five of five men (100%) who had all three criteria developed CHD within 5 years. When men older than 40 years who had all three criteria either present or absent were considered, specificity was 100%. The sensitivity, specificity, predictive value of an abnormal test, and risk ratio for developing CHD within 5 years for the various MTST criteria alone and in combination are tabulated.

Adult↗

Treadmill exercise testing of mass screening for coronary risk factors.

The prevalence of an abnormal maximal treadmill stress test (MTST) was correlated with coronary risk factors in 1,077 asymptomatic adults (709 men and 368 women) in Long Beach, California. Of 1,077 adults, 113 (10.5%) had a positive MTST. A positive MTST was correlated with sex (p less than 0.001), age (p less than 0.001), a serum cholesterol less than or equal to 200 mg% (p less than 0.02), hypertriglyceridemia (p less than 0.05), cigarette smoking (p less than 0.025), and with the number of coronary risk factors (p less than 0.005) but not with hypertension, cigar or pipe smoking, obesity, or blood sugar.

Adult↗

Mass screening for coronary risk factors in 2,524 asymptomatic adults.

The prevalence of coronary risk factors was assessed in 2,524 asymptomatic adults in Long Beach, California. Hypercholesterolemia (serum cholesterol level greater than 250 mg/100 ml) was present in 725 subjects (28.8 per cent), hypertriglyceridemia (serum triglyceride level greater than or equal to 150 mg/100 ml) in 497 (19.7 per cent), and an abnormal lipoprotein pattern in 813 (32.2 per cent). Of the 2,524 subjects, 233 (9.2 per cent) had a blood pressure above 140/90 mm Hg and 116 (4.6 percent) had a blood pressure above 150/100 mm. There were 1,043 cigarette, cigar, or pipe smokers (41.3 per cent). Fifty subjects (2.0 per cent) had a fasting blood sugar level above 120 mg/100 ml, 48 (1.9 per cent) had abnormal triceps skinfold thickness, and 382 (15.2 per cent) weighed 20 per cent or more above the desirable weight. The electrocardiogram during rest was definitely above the desirable weight. The electrocardiogram during rest was definitely abnormal in 183 subjects (7.3 per cent). On the basis of these data it is evident that in many asymptomatic adults, risk factors predisposing to coronary disease are not being detected or treated.

Adolescent↗

Follow-up of mass screening for coronary risk factors in 1817 adults.

The prevalence of coronary risk factors was assessed in 1,817 asymptomatic adults in Long Beach, California, at the beginning and end of a 10-11 month interval. The risk factors evaluated were hypercholesterolemia, hypertriglyceridemia, hypertension, smoking, hyperglycemia, and marked obesity. The results of the tests were sent to the participants and to their physicians. An educational program aimed at reducing coronary risk factors was offered to the first 1,250 persons screened. Eight hundred and seventy-two of those 1,250 allocated to the education group returned for a second screening. The prevalence of 0, 1, 2, 3, 4, 5, or 6 coronary risk factors did not change significantly between the two screens in either the total group of 1,817 adults or in the 872 adults in the educational program. The Long Beach Heart Association mass screening program for coronary risk factors was ineffective in reducing the number of coronary risk factors.

Adult↗

Response of patients and physicians to mass screening for coronary risk factors.

Qestionnaires were sent to 1,817 adults screened twice for coronary risk factors 10 to 11 months apart and to their physicians. Physician questionnaires returned on 1,764 persons indicated that 359 (20.4%) of the total group and 227 of 1,191 persons (19.1%) with one or more abnormal risk factors during the first screen did not return for follow-up care. Only persons with one or more risk factors were given advice or medication. When the 227 patients that did not return for follow-up are removed from the group with one or more risk factors, the 239 patients who received advice or treatment comprise 24.8% of those who could have been treated. Of the total 1,764 patients, 13.5% recieved treatment or advice. Qestionnaires returned by 1,396 persons who received follow-up care by their physicians confirmed that only those who had one or more risk factors received advice or treatment. Results of the patient questionnaires show that 223 persons received advice or treatment (23.2% of all with risk factors who returned for follow-up; 16.0% of the 1,396 persons). Furthermore, of 116 persons prescribed medication for risk factor control, 60 (51.7%) were not taking this medication. Of 20, persons given advice for reduction of risk factors, 162 (78.9%) were not following this advice. These data indicate physician indifference and patient apathy to reduction of coronary risk factors in asymptomatic individuals.

Attitude to Health↗