Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Population Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed1985

Studies to evaluate the effectiveness of sex pheromone-impregnated formulations for control of populations of the American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae).

The sex pheromone, 2,6-dichlorophenol, was combined with a pesticide to control populations of the American dog tick, Dermacentor variabilis (Say). This pheromone persisted in the fur of treated dogs for at least 18 days. The mixture of pheromone and pesticide was much more effective in reducing mating among the surviving ticks than the treatments without pheromone. The pheromone-pesticide mixture also killed significantly more ticks than the treatment without pheromone. This increased effectiveness was due almost entirely to the significantly greater kill of male ticks. Combining the sex pheromone with pesticide treatments offers a means of suppressing tick populations by curtailing their mating and subsequent reproductive success. The potential applications of this technique and the benefits to be expected are discussed.

Animals↗
PubMed1999

Asymptotic bias and efficiency in case-control studies of candidate genes and gene-environment interactions: basic family designs.

Case-control designs that use population controls are compared with those that use controls selected from their relatives (i.e., siblings, cousins, or "pseudosibs" based on parental alleles) for estimating the effect of candidate genes and gene-environment interactions. The authors first evaluate the asymptotic bias in relative risk estimates resulting from using population controls when there is confounding due to population stratification. Using siblings or pseudosibs as controls completely addresses this issue, whereas cousins provide only partial protection from population stratification. Next, they show that the conventional conditional likelihood for matched case-control studies can give asymptotically biased effect estimates when applied to the pseudosib approach; the asymptotic bias is toward the null and disappears with disease rarity. They show how to reparameterize the pseudosib likelihood so this approach gives consistent effect estimates. They then show that the designs using population or pseudosib controls are generally the most efficient for estimating the main effect of a candidate gene, followed in efficiency by the design using cousins. Finally, they show that the design using sibling controls can be quite efficient when studying gene-environment interactions. In addition to asymptotic bias and efficiency issues, family-based designs might benefit from a higher motivation to participate among cases' relatives, but these designs have the disadvantage that many potential cases will be excluded from study by having no available controls.

Bias↗
PubMed1984

Random digit dialing in selecting a population-based control group.

Results are described from four epidemiologic studies in the United States which used random digit dialing in over 30,000 households to identify controls from the general population for use in case-control studies. Methods and problems in telephone sampling are discussed. It is concluded that if complete population rosters are unavailable and if the population to be sampled has the high rates of telephone ownership typical of much of the United States, telephone-based sampling can yield a nearly random sample of the individuals in a population, often at much less expense than can dwelling-based sampling.

Adolescent↗
PubMed2001

Costs of care for irritable bowel syndrome patients in a health maintenance organization.

OBJECTIVES: The aims of this study were: 1) to determine the total costs of care and costs related to lower GI-related problems for patients who received a diagnosis of irritable bowel syndrome (IBS), and 2) to compare them to age- and sex-matched population controls and patients treated for inflammatory bowel disease (IBD) or gastroesophageal reflux disease (GERD). METHODS: Use and cost data were obtained through the computerized information systems of a large staff-model health maintenance organization on three groups of patients diagnosed in 1994 or 1995 with IBS, IBD, or GERD; and an age- and sex-matched control group of patients without any of these listed diagnoses. The IBS patient group was compared to the three comparison groups on components of total and IBS-related costs. RESULTS: Total costs of care for IBS patients were 49% higher than population controls during the year starting with the visit at which IBS patients were identified. In the index year, every component of total costs except inpatient care was significantly higher for IBS patients than for population controls. The costs of care for lower GI problems were significantly higher for patients with IBS than for population controls across a range of services. However, only 33% of the difference in total costs of care between IBS patients and population controls was due to lower GI-related services in the index year. In the subsequent years, lower GI-related services accounted for 18% and 20% of the total cost difference between IBS patients and population controls. The total costs of care as well as the components of costs of care were generally higher for IBD patients than for IBS patients, but were comparable for GERD and IBS patients. CONCLUSIONS: Patients with IBS show sustained increases in health care costs relative to population controls for both lower GI services and care unrelated to lower GI problems. However, the majority of the excess in health care costs resulted from medical care not directly related to lower GI problems.

Adolescent↗
PubMed2005

Association of two mutations in the CHEK2 gene with breast cancer.

The 1100delC mutation of the cell cycle checkpoint kinase 2 (CHEK2) gene confers an increased risk for breast cancer, but the clinical impact of other CHEK2 gene variants remains unclear. We determined the frequency of two functionally relevant CHEK2 gene mutations, I157T and IVS2+1G > A, in two large series of breast cancer cases and controls from two independent populations. Our first series consisted of a hospital-based cohort of 996 German breast cancer cases and 486 population controls, and the second series consisted of 424 breast cancer patients and 307 population controls from the Republic of Belarus. The missense substitution I157T was identified in 22/996 cases (2.2%) vs. 3/486 controls (0.6%; OR = 3.6, 95% CI 1.1-12.2, p = 0.044) in the German population and in 24/424 cases (5.7%) vs. 4/307 controls (1.3%; OR = 4.5, 95% CI 1.6-13.2, p = 0.005) in the Byelorussian cohorts. The splicing mutation IVS2+1G > A was infrequent in both populations, being observed in 3/996 German and 4/424 Byelorussian patients (0.3% and 0.9%, respectively) and in 1/486 German controls (0.2%; adjusted OR = 4.0, 95% CI 0.5-30.8, p = 0.273). Heterozygous CHEK2 mutation carriers tended to be diagnosed at an earlier age in both populations, but these differences did not reach statistical significance. Family history of breast cancer did not differ between carriers and noncarriers. Our data indicate that the I157T allele, and possibly the IVS2+1G > A allele, of the CHEK2 gene contribute to inherited breast cancer susceptibility.

Adult↗
PubMedDate not supplied

[Control of population growth in China].

"By way of introduction the study outlines the serious problems caused by the huge mass of population, and the problems associated with the strict birth control introduced by [the] Chinese government. The prevailing administrative methods, previously applied under the conditions of centralised planned economy, have lost much of their effectiveness in the developing market economy. The author analyses what other methods might be applied, in addition to (sometimes instead of) those referred [to] above, being in line with the market and based on the interests of families and communities." (SUMMARY IN ENG)

Asia↗
PubMed2003

Vascular endothelial growth factor and the risk of smoking-related COPD.

STUDY OBJECTIVES: Vascular endothelial growth factor (VEGF) signaling may be required for maintenance of the alveolar structures, and alveolar septal cell apoptosis could contribute to the pathogenesis of COPD presenting emphysematous changes; however, the common mutation at position 936 in the 3' untranslated region of the VEGF gene, a C to T substitution (the C allele was denoted as 1, and the T allele as 2), VEGF936*2, has been reported to be associated with significantly lower VEGF plasma levels. Based on these concepts, we hypothesized that VEGF936*1/2 polymorphism may be linked to the development of COPD. DESIGN: The differences in VEGF936*1/2 allele frequency were examined in 113 patients with smoking-related COPD and two control groups (101 smoker/ex-smoker control subjects and 102 population control subjects) using the polymerase chain reaction-restriction fragment length polymorphism technique. RESULTS: VEGF936*1/2 allele frequencies did not differ among the groups: 0.792/0.208 in COPD patients, 0.822/0.178 in smoker/ex-smoker control subjects, and 0.842/0.152 in population control subjects. CONCLUSION: The 936 C/T polymorphism of the VEGF gene (including both homozygous and heterozygous) was not associated with the development of COPD (odds ratio, 1.23; 95% confidence interval, 0.760 to 1.995).

Aged↗
PubMed1986

Role of abortion in control of global population growth.

No nation desirous of reducing its growth rate to 1% or less can expect to do so without the widespread use of abortion. This observational study, based on the experience of 116 of the world's largest countries, supports the contention that abortion is essential to any national population growth control effort. The principal findings are: Except for a few countries with ageing populations and very high contraceptive prevalence rates, developed countries will need to maintain abortion rates generally in the range of 201-500 abortions per 1000 live births if they are to maintain growth rates at levels below 1%. The current rate in the USA is 426 abortions per 1000 live births. Developing countries, on the other hand, are faced with a different and more difficult set of circumstances that require even greater reliance on abortion. No developing nation wanting to reduce its growth to less than 1% can expect to do so without the widespread use of abortion, generally at a rate greater than 500 abortions per 1000 live births. Widespread availability of abortion is a necessary but not sufficient condition to achieve growth rates below 1%. A high contraceptive prevalence is essential as well in order to achieve growth rates below 1%. A high contraceptive prevalence is a necessary but not sufficient condition to achieve population growth rates below 1%. A high rate of abortion (generally 201-500 or more abortions per 1000 live births in the developed and greater than 500 abortions per 1000 live births in the developing countries) is essential to achieve growth rates below 1%. The different and more difficult set of circumstances faced by developing countries that will necessitate even higher abortion rates than developed countries includes a young population with resultant rapidly growing numbers of young fertile women, poor contraceptive use-effectiveness, low prevalence of contraception, and poor or non-existent systems for providing contraceptives. These data show that high death rates of infants and children can moderate population growth rates--a most undesirable solution. The data in this report suggest that actual alternatives are high death rates of infants and children or widespread use of contraception and abortion. African nations tend to have the very lowest abortion rates and the very highest infant and child death rates. To avoid a world with deteriorating social, economic and political stability, with the concomitant loss of personal and national security, we must ensure that safe abortion is made available to all who wish to use this service.

Abortion, Illegal↗
PubMed1995

Isolated microscopic hematuria in patients with rheumatoid arthritis compared with age and sex matched controls. A population based study.

OBJECTIVE: To evaluate the prevalence and causes of isolated microscopic hematuria in patients with rheumatoid arthritis (RA). METHODS: An unselected population of 1018 patients with RA (810 women, 208 men) were studied prospectively (n = 604) or retrospectively (n = 414), and the results were compared with an age and sex matched control population (n = 457; 352 women, 105 men). Hematuria was defined as a positive dipstick result in 2 urine samples, and was regarded as isolated when no concomitant proteinuria was found (urine protein excretion < or = 0.15 g/24 h). To investigate the urological causes of isolated hematuria, urine cytology, renal ultrasound, and urethrocystoscopy were undertaken. Renal biopsy was performed when no urological lesions were found. RESULTS: There was no difference in the prevalence of isolated hematuria between patients with RA and controls (women 10 and 9%, men 5 and 6%, respectively; total 9% for both). Mild mesangial glomerulopathy was the most common renal biopsy finding in patients with RA with isolated hematuria, found in 13 of 15 adequate renal biopsy specimens. The cause of hematuria remained uncertain or unknown in 52% of the patients with RA and in 61% of controls. CONCLUSION: The prevalence of isolated microscopic hematuria was not significantly more frequent in patients with RA than in age and sex matched controls. This result was independent of the definition or grade of hematuria. Mesangial glomerulopathy was the most common renal biopsy finding in patients with RA with isolated hematuria.

Adult↗
PubMed1997

Anxiety and depression in adolescent cancer: findings in patients and parents at the time of diagnosis.

Adolescent cancer is uncommon and presents an exceptional stress for the young patient and their parents. The emotional needs of adolescents with cancer are a major factor in the recommendation for the establishment of adolescent cancer units in major cancer centres in the U.K. However, there have been no prospective, longitudinal studies assessing the psychological impact of a diagnosis of cancer on the adolescent patient and their family. In 1994 we began a longitudinal study of the emotional impact of the diagnosis of cancer in patients and their families presenting to an adolescent cancer unit and of the coping strategies they employ. This first report presents the results of the study at the time of diagnosis in 42 adolescents, 34 mothers and 27 fathers. The Beck Depression Inventory (BDI) was used to assess depression and anxiety levels were measured using Spielberger's State Trait Anxiety Inventory (STAI). Adolescents and their parents completed the questionnaires on first admission to the adolescent cancer unit. The median time since cancer diagnosis was approximately 3 weeks. To provide normative data for the U.K. adolescent population, control values were obtained from 173 pupils of the same age and background. The results showed that, contrary to expectation, adolescents with cancer were no more anxious or depressed than the control adolescent population. Nevertheless, a substantial minority of patients and controls had elevated anxiety or depression scores. Girls were significantly more anxious (P = 0.011) and depressed (P < 0.0001) than boys. Mothers were the most anxious family members and were significantly more anxious than fathers (P = 0.038). Parental anxiety scores, especially mothers, were much higher than reported norms. There was no significant difference between mothers' and fathers' depression scores. Although at the time of diagnosis adolescent cancer patients are not more anxious or depressed than their healthy peers, many adolescents without cancer are anxious or depressed. Staff on adolescent cancer units should therefore be aware of the frequency of emotional disturbance in this population. Mothers are the most anxious family members. Although the findings are relatively reassuring at the time of diagnosis, follow-up data from this cohort will show whether anxiety and depression change with treatment involving intensive chemotherapy, surgery and radiotherapy and will indicate the coping strategies which patients and their families adopt in dealing with both the disease and its treatment.

Adolescent↗
PubMed2005

Cultivation factors and population size control the uptake of nitrogen by the microalgae Chlorella vulgaris when interacting with the microalgae growth-promoting bacterium Azospirillum brasilense.

Growth of and the capacity to take up nitrogen in the freshwater microalgae Chlorella vulgaris were studied while varying the concentrations of ammonium and nitrate, the pH and the source of carbon in a synthetic wastewater growth medium when co-immobilized in alginate beads with the microalgae growth-promoting bacterium Azospirillum brasilense. Analyses of 29 independent experiments showed that co-immobilization of the microalgae with A. brasilense could result in two independent phenomena directly affected by cultivation factors, such as nitrogen species, pH and presence of a carbon source. First, growth of the microalgal population increased without an increase in the capacity of the single cells to take up nitrogen, or second, the capacity of cells to take up nitrogen increased without an increase of the total microalgal population. These phenomena were dependent on the population density of the microalgae, which was in turn affected by cultivation factors. This supports the conclusion that the size of the microalgal population controls the uptake of nitrogen in C. vulgaris cells - the higher the population (regardless the experimental parameters), the less nitrogen each cell takes up.

Azospirillum brasilense↗
PubMed1991

No association between an allele at the D2 dopamine receptor gene (DRD2) and alcoholism.

OBJECTIVE: --We attempted to replicate a positive allelic association between the A1 allele of DRD2 (the D2 dopamine receptor locus) and alcoholism that has been reported. DESIGN: --We compared allele frequencies at the previously described Taq I restriction fragment length polymorphism system of DRD2 in alcoholics and random population controls. SUBJECTS: --The alcoholic subjects were 44 unrelated white individuals, diagnosed by direct structured interview to have alcohol dependence (by the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, criteria). The subjects in our random population control group (N = 68) were also white. RESULTS: --For the control group, allele frequencies at DRD2 were 0.20 (A1) and 0.80 (A2). For the alcoholic group overall, allele frequencies were 0.23 (A1) and 0.77 (A2). There were no significant differences in allele frequencies at the DRD2 locus between alcoholics and controls. The allele frequencies in both groups agreed closely with those observed in most previously described control populations. Subtyping the alcoholic group according to presence or absence of family history of alcoholism, presence or absence of antisocial personality disorder, age of onset, presence or absence of physical withdrawal symptoms, or recent alcohol consumption (as a measure of severity) did not in any case reveal significant differences in allele frequencies. CONCLUSION: --We were not able to replicate the results previously reported. We conclude that our data do not support an allelic association between the A1 allele at DRD2 and alcoholism.

Adult↗
PubMed1989

Prognostic significance of pregnancy in stage I melanoma.

The clinical course of 66 patients with stage I melanoma, diagnosed during pregnancy, treated in the Division of Surgical Oncology at UCLA, was retrospectively reviewed. These patients were compared with 619 nonpregnant female patients with melanoma. There was no significant difference between the pregnant population and control population with respect to location of the primary tumor, age at diagnosis, Clark's level, mean depth of invasion (pregnant females, 1.24 mm vs control, 1.28 mm), and histologic type. The 5-year survival for the women diagnosed with melanoma during pregnancy and for the entire population was 86% and 87%, respectively. These results demonstrate that women diagnosed with melanoma during pregnancy fare no worse than their nonpregnant counterparts. Criteria other than the theoretical effect of pregnancy on the tumor should be used to counsel patients diagnosed with melanoma during pregnancy.

Adolescent↗
PubMed1984

Is wide availability of abortion essential to national population growth control programs? Experiences of 116 countries.

No nation wanting to reduce its growth rate to less than or equal to 1% can expect to do so without the widespread use of abortion. This study, based on the experience of 116 of the world's largest countries, supports the contention that abortion is essential to any national population growth control effort. Existing circumstances in developed countries have facilitated reduction of growth rates to less than 1%, with abortion rates generally in the range of 200 to 500 per 1000 live births. However, developing countries are faced with a different and more difficult set of circumstances that require even greater reliance on abortion. These obstacles include a young population with resultant rapidly growing numbers of young fertile women, poor contraceptive use-effectiveness, low prevalence of contraception, and poor or nonexistent systems for providing contraceptives. By virtue of their profession, physicians play a critical role in family planning and carry a special responsibility in ensuring that abortion services are available to all women who need them.

Abortion, Induced↗
PubMed2003

Altered dopamine D2 receptor function in fibromyalgia patients: a neuroendocrine study with buspirone in women with fibromyalgia compared to female population based controls.

BACKGROUND: To what extent fibromyalgia belongs to affective spectrum disorders or anxiety spectrum disorders remains disputed. Buspirone induces a hypothermic response, which most likely is due to 5-HT(1A) autoreceptor stimulation, and growth hormone (GH) release, which probably is related to postsynaptic 5-HT(1A) receptor stimulation. The prolactin response to buspirone has been suggested to be mediated through dopamine (DA) antagonistic effects. OBJECTIVES: Based on the assumption that fibromyalgia is more strongly related to stress and anxiety than affective spectrum disorders, we hypothesized that compared to population controls, fibromyalgia patients should demonstrate an increased prolactin response (DA sensitivity) to buspirone challenge test, but no difference in hypothermic response or GH release (5HT sensitivity). METHOD: A 60-mg dose of buspirone was given orally to 22 premenopausal women with fibromyalgia and 14 age and sex matched healthy control subjects. Core body temperature, growth hormone and prolactin levels were analyzed at baseline and after 60, 90, and 150 min. RESULTS: Fibromyalgia patients showed an augmented prolactin response to buspirone compared to controls. Temperature and growth hormone responses did not differ from controls. CONCLUSIONS: Dopaminergic rather than serotonergic neurotransmission is altered in fibromyalgia, suggesting increased sensitivity or density of dopamine D(2) receptors in fibromyalgia patients. Stress and anxiety is an important modulator of dopaminergic neurotransmission. Our results suggest that fibromyalgia is related to anxiety and associated with disturbance in the stress response systems.

Anxiety↗
PubMed2000

Contribution of the cystathionine beta-synthase gene (844ins68) polymorphism to the risk of early-onset venous and arterial occlusive disease and of fasting hyperhomocysteinemia.

The frequency of the heterozygous 844ins68 mutation of the cystathionine beta-synthase (CBS) gene and of its association with the homozygous C677T transition of the methylenetetrahydrofolate reductase (MTHFR) gene, plasma fasting tHcy, folate and vitamin B12 levels were evaluated in 309 consecutive patients with objectively diagnosed early-onset venous (n = 200) or arterial thromboembolic disease (n = 109) recruited over 25 months in Milan (North Italy) and Naples (South Italy). The above gene polymorphisms were also evaluated in a population of 787 unmatched controls, 204 of whom--similar to patients for age- and sex-distribution--had fasting tHcy, vitamins and activated protein C resistance measured in their plasma. Moderate fasting hyperhomocysteinemia was detected in 15.5% of patients and in 5.9% of 204 controls (Mantel-Haenszel OR after stratification for type of occlusive disease and gender: 2.88; 1.48-5.32). The frequencies of the 677TT mutation of the MTHFR gene and of the heterozygous 844ins68 insertion of the CBS gene were not significantly different in the patient (19.4% and 6.9%) and the control population (16.5% and 7.8%), but the association of the two gene polymorphisms found in 3.9% of patients and in 1.1% of controls - was significantly associated with an increased risk of venous or arterial occlusive diseases (RR = 3.63; 1.48-8.91). The MTHFR 677TT mutation (RR: 6.92; 3.86-12.4) and its association with the 844ins68 insertion (RR: 21.9; 8.35-57.4), but not the isolated insertion (RR: 0.71), were more frequent in patients and controls with fasting hyperhomocysteinemia than in normohomocysteinemic subjects, irrespective of the type of occlusive disease (venous or arterial). When adjusted for determinants of hyperhomocysteinemia in the patient and the control populations (generalized linear model), fasting tHcy levels were significantly higher in subjects with association of the two gene abnormalities (24.2+/-3.8 micromol/L) than in subjects with the MTHFR 677TT mutation only (14.0+/-5.8 micromol/L, p = 0.004). Activated protein C resistance was significantly more prevalent in venous patients (9.9%) than in controls (3.9%, OR = 2.69; 1.08-6.88). Six of 21 venous patients with APC-resistance also had hyperhomocysteinemia (RR = 5.04; 0.68-37.6), but isolated fasting hyperhomocysteinemia retained statistical significance for the association with venous occlusive disease (RR = 2.84; 1.34-6.01). Heterozygosity for the 844ins68 mutation of the CBS gene is not per se a risk factor for premature arterial and/or venous occlusive diseases. However, when detected in combination with thermolabile MTHFR, it increases by almost 4-fold the risk of occlusive diseases (arterial and/or venous), by increasing the risk and the degree of fasting hyperhomocysteinemia.

Adult↗
PubMed2000

Relation of Cigarette Smoking, Alcohol Use, and Dietary Habits to Colon Adenomas: A Case-Control Study in Saitama, Japan.

A case-control study of colon adenoma in relation to dietary habits was undertaken in Saitama, Japan. The population included 105 patients with newly diagnosed colon adenoma, 843 general population controls, and 84 hospital controls who had no pathologic lesions at colonoscopy. The adenoma patients and the hospital controls underwent total colonoscopy between November 1992 and March 1994. Information about diet, cigarette smoking and alcohol use were obtained with a self-administered questionnaire. Unconditional logistic regression analysis was used to compare adenoma patients with general population controls and with hospital controls. We found that current cigarette smokers had a higher risk (OR = 2.86, CI = 1.20-6.80) than did nonsmoking hospital controls. Current alcohol use did not affect the risk of colon adenoma. Ex-drinkers had a higher risk (OR = 2.36, CI = 1.02-5.45) than did nondrinking general population controls. The same tendency was observed in comparison with hospital controls. The consumption of raw vegetables was inversely related to the risk of colon adenoma when adenoma patients were compared with general population controls (P for trend = 0.02) or hospital controls (trend P=0.17). Having one bowel movement per day was associated with a lower risk than having less or more frequently bowel movements when adenoma patients were compared with either general population or hospital controls. The present study suggests that the high consumption of raw vegetables is important in the primary prevention of colon adenoma.

Journal Article↗