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At least 19 recordsLinked to original sources
PubMed1991

[Implantable devices for permanent venous access. A single-center prospective study comparing an AIDS population with a control population (80 cases)].

Although the tolerance of indwelling catheters in AIDS patients has been evaluated, the complications of implanted devices in this population are unknown. This encouraged us to compare in a prospective unicenter trial, dealing with 80 consecutive implanted devices, the complications of this kind of system in 20 AIDS patients, versus a control population. The follow-up was 10,658 days. No patient was excluded or lost to follow-up. In the control population, the infection rate was 5% (0.036 per 100 catheter days). We observed 3 thromboses (5%). In the AIDS group, the infection rate was 25% (0.21 per 100 catheter days). We observed 1 thrombosis (5%). This trial shows that implanted devices are more frequently infected in AIDS patients (p less than 0.05) than in a control population; it suggests that the infection rate in AIDS patients is not superior to the indwelling catheter rate, as reported in the literature. The precision of bacteriological tests and use of antibiotic therapy adapted to the clinical context should help to determine, in the presence of suspected infection, whether the implanted device can be maintained or should be removed in this high risk population.

Acquired Immunodeficiency Syndrome↗
PubMed1978

Chronic gastric ulcer and stress. A comparison of an ulcer population with a control population regarding stressful events over a lifetime.

Stress was measured by the frequency of 31 major life events with consequent change and distress scores in 50 patients with chronic gastric ulcer and 50 control subjects, matched for age, sex and place of residence. The gastric ulcer population did not differ from the control population regarding the number of events experienced and the associated change and distress scores. However, when analysed according to social grade, the ulcer patients in the lower status suburbs experienced more events and more change than their controls, but the stress scores were similar. In the higher status suburbs, no difference was present between the patients and controls. Change and distress scores rose progressively with age, but there was no significant difference in the number of events experienced between the three age groups. Both men patients and their controls experienced significantly more events and higher change scores than women patients and their controls.

Adult↗
PubMed1992

Characteristics of the infant thermal environment in the control population of a case-control study of SIDS.

This report examines the thermal environment during last sleep of a control population to investigate how the thermal environment of the infant's bedroom varies by season, external temperature and by certain maternal and infant characteristics. Two age-matched control infants were chosen for each case, one of which was also matched on birthweight. The home visits were not pre-arranged and were matched on climatic conditions, time of year and time period of day for the index case. The initial response rate for controls (n = 108) was 86%. Although there was a large amount of variation in the infant thermal environment, thermal insulation correlated with room temperature (r = -0.44, P = 0.0001) and external temperature (r = -0.30, P = 0.002). The thermal environment of the infant, as defined by excess thermal insulation for room temperature, did not vary by indoor or outdoor temperature, but higher average values were observed in teenage mothers (mean difference = 2.7 tog [95% Cl = 0.3, 5.2]), infants who slept in an adult bed (mean difference = 2.6 tog [-0.1, 5.4]) and infants with an illness (mean difference = 0.8 tog [-0.3, 1.9]). There was a tendency for the thermal environment of infants to be higher and more variable during winter, supporting previous hypotheses that paradoxical overheating may occur in some infants during winter. Further work is required to provide a set of recommendations on the optimal thermal conditions for post-neonatal infants.

Bedding and Linens↗
PubMed1988

Cytogenetic monitoring of industrial populations potentially exposed to genotoxic chemicals and of control populations.

Currently the most applied technique for monitoring biological effects of exposure to genotoxic chemicals in industrial workers is the measurement of chromosome aberrations in peripheral blood lymphocytes. In the Shell petrochemical complex in The Netherlands cytogenetic monitoring studies have been carried out from 1976 till 1981 inclusive, in workers potentially exposed to a variety of genotoxic chemicals, i.e. vinyl chloride, ethylene oxide, benzene, epichlorohydrin, epoxy resins. Average exposure levels to these chemicals were well below the occupational exposure limits. Results of these studies indicate that no biologically significant increase in the frequencies of chromosome aberrations in the exposed populations occurred compared with control populations. Our experience with this methodology has shown that the results of chromosome analyses are difficult to interpret, due to the variable and high background levels of chromosome aberrations in control populations and in individuals. It is concluded that the method is not sufficiently sensitive for routine monitoring of cytogenetic effects in workers exposed to the low levels of genotoxic compounds.

Chromosome Aberrations↗
PubMed1987

Spontaneous and induced interferon production by peripheral blood leucocytes from control population and patients with herpes genitalis.

The spontaneous and PHA induced levels of interferon were measured in peripheral blood leucocyte cultures of twenty-eight individuals diagnosed as positive for herpes genitalis, and in a group of control subjects. As reported by Cunningham and Merigan [1983] for herpes labialis, leucocytes from individuals with herpes genitalis produced low levels of interferon spontaneously; however, similar results were found for individuals within the control population. No statistically significant difference could be found for PHA induced interferon levels, antigen induced interferon levels, or helper/suppressor cell ratios between the herpes genitalis population and control population. Our results indicate that interferon does not play a major role in the latency or recurrence of herpes genitalis.

Antigens, Viral↗
PubMed1976

Socio-cultural modalities in population control.

Overpopulation with its identifiable and noxious results, is probably the most ominous and potentially destructive condition existing in current world society. The etiology of this problem includes the failure of mankind to develop compatible interrelationships between members of his own family, clan, society, and world population. The author predicts that all efforts to achieve world population control will be essentially ineffective unless the insights of the holistically oriented science of social psychiatry are refined into principles and rules which direct population control endeavors. This paper reviews the extent and severity of the problem and stresses the need for the operational implementation of the value systems and methodologies of social psychiatry. The author believes that effective population control is possible if the actions of world leaders are directed toward efforts to achieve satisfaction of the basic (Ur) needs of all individuals and groups for physical survival, socialization, and transcendence.

Community Psychiatry↗
PubMed1978

Field independence and attitudes toward population control.

The hypothesis that differences between field independence and dependence would lead to different attitudes about population control activities was tested using 37 students as subjects. The Hidden Figures Test was used to measure field independence while an author-developed scale assessed attitudes. Expected relationships were found; field-independent persons were more independent of the opinions of others, agreed with active population control measures, and were in favor of smaller family size.

Adult↗
PubMed1990

[Survival and causes of secondary mortality in patients undergoing coronary bypass. Comparison with a same age control population].

During 10 years, 867 patients in whom the same surgical team had performed coronary bypass were followed up regularly without any of them being lost sight of. Moreover, the cause of all deaths in this group could be determined fairly accurately. A comparison of mortality between these patients and an age-matched control population studied longitudinally, year after year, showed that the mortality rate in the surgical group was slightly higher than in the control group (84 vs 77). Conversely, when the operative mortality was discounted, it appeared that the patients who survived coronary bypass had a much better survival than the control population (47 vs 77). Without any doubt, the prognosis for life is improved by surgery. In particular, patients with three-vessel disease (58 per cent), tight stenosis of the common coronary artery (10-25 per cent) or altered ventricular ejection fraction (about 30 per cent) would probably have died without myocardial revascularization. However, this study produced a rather astonishing result: compared with the control population, the decrease of long-term mortality in patients who survived coronary bypass was due not only to the decrease of cardiovascular deaths (16 vs 24) but also of deaths due to cancer (15 vs 27) or to other causes (16 vs 26). This suggests that a more hygienic life and a correct medical follow-up contribute to a large extent to the long-term survival of these surgical patients.

Actuarial Analysis↗
PubMed1977

Parallel studies of HLA antigens in patients with rheumatic heart disease and scleritis: comparisons with three control populations.

Parallel studies were carried out on HLA antigens in patients with rheumatic heart disease and scleritis. Comparison with one control population showed a significant excess of BW15 in both disease samples, while a comparison with two other control populations, showed the excess not to be significant. Possible reasons for this discrepancy are discussed, together with the effect on statistical significance of a small percentage of false antigen assignments in one of the samples. A small systematic serological false assignment of an antigen can, by itself, produce a significant result more easily if the frequency of the antigen being detected is low than if it is high. It is suggested that this effect may contribute to the discrepant significant results obtained by different workers in some HLA and disease studies.

Eye Diseases↗
PubMed1976

Casual, basal and supplemental blood pressures in 519 first-degree relatives of substantial hypertensive patients and in 350 population controls.

1. The casual blood pressure is the sum of the relatively stable basal pressure taken under defined conditions of rest and the labile supplemental pressure (casual minus basal), which represents the response to the current degree of physical, mental and probably metabolic stimulation. 2. The basal and supplemental blood pressures behave differently and it seems likely that different factors are involved in their pathogenesis. 3. The 5 and 8 years follow-up mortality is closely related to the basal pressure but not to the supplemental pressure. 4. The rise with age in the basal blood pressure is greater in the relatives of substantial hypertensive patients than in population control subjects. 5. Above the age group 30-39 years there is an increase in the rate of rise of the mean basal blood pressure with age among the first-degree relatives of hypertensive patients. In a population control group an acceleration in the rate of rise of the mean basal blood pressure with age also occurs but a decade or more later than in the relatives of hypertensive patients. 6. In males the mean supplemental pressures (systolic and diastolic) do not rise appreciably with age and the mean supplemental pressures of first-degree relatives and control subjects do not differ appreciably. 7. In females the mean supplemental pressures rise with age but, except after age 60 years, the pressure rise in first-degree relatives is only a little greater than in control subjects. 8. When hypertensive patients with similar casual blood pressures are compared the basal blood pressures are higher in patients with glomerulonephritis than in essential hypertensive patients. 9. In the first-degree relatives of substantial hypertensive patients high-ranking basal blood pressures occur much more frequently than in general population control subjects. 10. The close resemblance of the blood pressures in like twins indicates that genetic or familial factors have an important influence on blood pressure, and on the occurrence of frank hypertension.

Adolescent↗
PubMed1986

Estimation of response to selection and utilization of control populations for additional information and accuracy.

Problems associated with testing and estimation of response to selection are examined. An alternative procedure with increased power for testing hypotheses is given. The increased power results from a more precise method of estimating the variance about response. The new method is based on a Satterthwaite approximation which combines variance components estimated more precisely by other sources of variation in the analysis of variance. The expected variance about response and expected mean squares for the analysis of variance, used in the Satterthwaite procedure, are given. When intergeneration environmental trends cannot be ruled out, a control population must be used to estimate response to selection. However, if the experimental and control populations do not respond in the same direction and with the same magnitude to common environmental effects, then the usual method of estimating response by deviating the experimental values from the control will result in biased estimates. An alternative procedure, using the control as a covariate to adjust for environmental trends, gives relatively unbiased estimates of response in this situation. Some bias results from measurement error associated with the control. However, this bias is usually minimal.

Analysis of Variance↗