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 721 records · Page 40Linked to original sources
PubMed1999

Use of continuous retropleural bupivacaine in postoperative pain management for pediatric thoracotomy.

BACKGROUND/PURPOSE: The aim of this study was to evaluate the use of a continuous bupivacaine infusion into the retropleural space as an adjunct for postoperative pain management in pediatric thoracotomy. METHODS: A retrospective chart review was performed on 13 pediatric patients undergoing thoracotomy over a 3-year period (April 1995 through July 1997). In seven patients, insertion of a retropleural catheter was accomplished before closure of the thoracotomy by placing an epidural catheter posterior to the parietal pleura. This potential space was entered two intercostal levels below the incision and advanced superiorly four intercostal spaces. Bupivacaine (0.125% or 0.25%) was infused at 0.5 mL/kg/h. Postoperative intravenous narcotic requirement was compared between the study population (n = 7) and the control population (n = 6). Statistical analysis was conducted using the "separate" Student's t test. RESULTS: Thirteen pediatric patients (age range, 7 to 18 years) were evaluated for total morphine use after thoracotomy. Seven patients had anterior spinal release and fusion, whereas five had mediastinal operations, and one patient had a lobectomy. The two groups were comparable in age, weight, and type of operation. Infusion through the retropleural catheter continued for an average of 3.8 days (range, 3 to 6 days). The total mean postoperative morphine requirement was 2.32 mg/kg (0.544 mg/kg/day) in the control population and 0.88 mg/kg (0.204 mg/kg/day) for the patients with a retropleural catheter (P<.001). CONCLUSION: A continuous infusion of bupivacaine through a unique retropleural technique decreases the postoperative need for morphine in postoperative pediatric thoracotomy patients.

Adolescent↗
PubMed2003

Life events, difficulties and dilemmas in the onset of chronic fatigue syndrome: a case-control study.

BACKGROUND: The role of stress in the onset of chronic fatigue syndrome is unclear. Our objectives in this study were first, to determine the relation between the onset of chronic fatigue syndrome and stressful life events and difficulties. Secondly, we examined the role of a particular type of problem, dilemmas, in the onset of chronic fatigue syndrome. METHOD: We used a case-control design with 64 consecutive referrals from an Infectious Diseases/ Liaison Psychiatry Fatigue clinic and 64 age- and sex-matched controls from a general practice population control group in Leeds. We had two main outcome measures; the odds ratios of the risk of developing chronic fatigue syndrome after experiencing a severe life event, severe difficulties or both in the year and 3 months preceding onset; and the proportion of subjects in each group who experienced a dilemma prior to onset. RESULTS: Patients with chronic fatigue syndrome were more likely to experience severe events and difficulties in the 3 months (OR = 9, 95% CI 3.2 to 25.1) and year (OR = 4.3, 95% CI 1.8 to 10.2) prior to onset of their illness than population controls. In the 3 months prior to onset 19 of the 64 patients (30%) experienced a dilemma compared to none of the controls. CONCLUSIONS: Chronic fatigue syndrome is associated with stressful events and difficulties prior to onset. Those events and difficulties characterized as being dilemmas seem to be particularly important.

Adult↗
PubMed1990

Reduced stroke incidence with structured hypertension care: the Skaraborg Hypertension Project.

The Skaraborg Hypertension Project is a 5-year trial testing the impact of structured hypertension care implemented in half of the country, the other half serving as control. Population investigations revealed improved blood pressure control in all treated hypertensives in the study area, blood pressure reduction averaging 2-5 mmHg. The primary trial hypothesis of a possible impact on stroke incidence in the community was tested in this study. Cases of fatal and non-fatal stroke were identified from local and national mortality and morbidity registers, and diagnoses were validated against medical records. Of an initial 1169 reported cases, 1097 proved to be true stroke after validation. A statistically significant difference in stroke incidence trends (fatal and non-fatal) between the study and control populations was identified (P = 0.0251). Improved hypertension control in the study area seems the most plausible explanation for the relative decline in stroke incidence in the study area.

Adult↗
PubMed2006

Increased carotid intima-media thickness in the absence of atherosclerotic plaques in an adult population with Fabry disease.

AIM: Fabry disease is considered primarily as a progressive small vessel disease, with ischaemic degenerative lesions involving the kidneys, brain and heart. Macrovascular involvement in male patients includes an accelerated wall hypertrophy of the radial artery and a thickening of the intima-media of the common carotid artery. The aim of this study is to evaluate the prevalence and severity of carotid artery atherosclerosis in hemizygous and heterozygous patients with Fabry disease, compared with a matched control population. METHODS: The common carotid artery intima-media thickness (IMT) of 53 patients with Fabry disease (24 men, 29 women) was measured by high-definition ultrasonography, and the presence or absence of atherosclerotic plaques reported. Results were compared with those of 120 age-matched healthy individuals (83 men, 37 women). RESULTS: The common carotid artery IMT was increased to the same extent in male and female patients with Fabry disease (706+/-211 microm and 749+/-395 microm, respectively) compared with that of the control population (614+/-113 microm). In the Fabry population, IMT did not correlate with either systolic blood pressure or with renal function (plasma creatinine). In the control population, only systolic blood pressure was positively and significantly correlated with IMT. Atherosclerotic plaques in the common carotid artery were not observed in any patient with Fabry disease, whereas 34% of the control population had carotid artery plaques, as evidenced by focal non-homogeneous intima-media thickening greater than 1.2 mm. CONCLUSION: This study presents evidence of a major increase in common carotid artery IMT, both in hemizygous and heterozygous patients with Fabry disease, in the absence of focal atherosclerotic plaques. These results suggest that the conduit arteries may be protected from atherosclerosis in Fabry disease.

Adult↗
PubMed2001

Analysis of tumor necrosis factor-alpha, lymphotoxin-alpha, tumor necrosis factor receptor II, and interleukin-6 polymorphisms in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by chronic inflammation that is associated with structural damage of the lung and fibrosis. Although the etiology of IPF is unknown, it is likely to involve an interaction between environmental and multiple genetic components. Animal models of pulmonary fibrosis have shown that proinflammatory mediators are critical at both the inflammatory and fibrotic stages of the disease. Genetic variants exist in genes encoding proinflammatory mediators, as well as in genes encoding their receptors, which makes these genes candidates for the pathogenesis of IPF. In the present study, we examined 12 biallelic polymorphisms in the genes for tumor necrosis factor (TNF)-alpha (+488[G/A], -238[G/A], -308[G/A]), lymphotoxin (LT)-alpha (+720[C/A], +365[C/G], and +249[A/G], determining haplotypes LT-alpha1 to LT-alpha4), tumor necrosis factor-receptor 2 (TNF-RII) (gb:M32315: 676[T/G], 1663[A/G], 1668[T/G], 1690[C/T]), and interleukin- (IL)-6 (promoter -174[G/C], intron 4[A/G]). We also examined the haplotypes determined by the three biallelic polymorphisms in each of the TNF-alpha and LT-alpha genes. As compared with a normal control population, the IPF group showed no significant deviations in genotype, allele, or haplotype frequencies. Surprisingly, in the IPF population, but not in the control population, an increased frequency of cocarriage of the IL-6 intron 4G and the TNF-RII 1690C alleles was observed, despite the location of the two genes on different chromosomes. Moreover, using impairment of carbon monoxide transfer (DL(CO)) adjusted for duration of dyspnea as a marker of rapidity of disease progression, we found that the IL-6 intron 4GG genotype was the only genotype independently associated with lower DL(CO) levels. These findings, if independently confirmed, will be the first to suggest that disease progression in IPF may be linked to a particular genetic marker or to functional polymorphisms in other genes near that marker.

Antigens, CD↗
PubMed1985

Two-color immunofluorescence and flow cytometry analysis of lymphocytes in long-term renal allotransplant recipients: identification of a major Leu-7+/Leu-3+ subpopulation.

Using two-color immunofluorescence with fluorescein isothiocyanate (FITC)- and phycoerythrin (PE)-labeled monoclonal antibodies to human lymphocyte antigens and flow cytometry, we studied lymphocyte subsets in 16 long-term renal allotransplant recipients at risk for a mean of 78 +/- 15 mo. The absolute number of Leu-1+, Leu-2a+, and Leu-3a+ lymphocytes is significantly decreased compared with a control population, whereas Leu-7+ and Leu-15+ subsets remain unchanged despite standard chronic immunosuppression (azathioprine and prednisone). Within the Leu-7+ subset, we found various phenotypes. Doubly fluorescent lymphocytes Leu-7+/Leu-1+ and Leu-7+/Leu-2a+ are not significantly different in the transplant population compared with a normal control population. The Leu-7+/Leu-3a+ subpopulation is seen to be significantly elevated, and the Leu-7+/Leu-15+ subpopulation decreases significantly. The relationship between the modification of these two phenotypes within the Leu-7 subset may be an important correlate of decreased NK cell activity in long-term renal allotransplant recipients. These Leu-7+/Leu-3a+ cells, normally less than 1% of peripheral blood lymphocytes, have no known functional activity.

Adult↗
PubMed2005

The combination of shared family environment and individual-specific developmental deviance as a cause for treated psychiatric morbidity in children.

OBJECTIVE: There is an incomplete understanding of why some children growing up in the same family are in need of treatment for psychiatric morbidity whilst their siblings are not. The present paper examined the possible role of individual-specific developmental risk factors. METHOD: Three case-control analyses were conducted: i) 80 children referred to the Community Mental Health Centre (cases) and 320 population controls, ii) 68 healthy siblings of cases and 272 population controls, and iii) 80 children and 68 healthy siblings. Measures of development and psychosocial circumstances were obtained from routine, longitudinal, standardized child medical records. RESULTS: Given shared family environments, additional presence of delays in speech and motor development contributed most to differential sibling mental health outcomes. In addition, cases displayed both earlier expression and more severe levels of developmental behavioural deviance than their healthy siblings, who in turn had higher levels of behavioural deviance than population controls. CONCLUSION: In siblings sharing a familial risk environment, development of psychiatric morbidity may be canalized through additional individual-specific developmental exposures.

Adolescent↗
PubMed1992

Optimal chemical control of populations developing drug resistance.

A system of differential equations for the control of the growth of certain populations by the use of chemical treatment is presented. Rather general growth rates and kill rates of drugs, as well as drug resistance, are considered. A class of optimal control problems with a performance criterion depending on a parameter is formulated and shown to admit the same basic optimal strategy. Applications to cycle nonspecific chemotherapy and control of the growth of bacterial populations in cellulose media in paper production plants are described.

Antineoplastic Agents↗
PubMed1983

Mechanisms that control bacterial populations in continuous-flow culture models of mouse large intestinal flora.

A previous study had established that anaerobic continuous-flow (CF) cultures of conventional mouse cecal flora were able to maintain the in vivo ecological balance among the indigenous bacterial species tested. This paper describes experiments designed to determine the mechanisms which control the population sizes of these species in such CF cultures. One strain each of Escherichia coli, Fusobacterium sp., and Eubacterium sp. were studied. Growth of these strains in filtrates of CF cultures was considerably more rapid than in the CF cultures themselves, indicating that the inhibitory activity had been lost in the process of filtration. Growth rates to match those in CF cultures could be obtained, however, by restoring the original levels of H(2)S in the culture filtrates. The inhibitory effect of H(2)S in filtrates and in dialysates of CF cultures could be abolished by adding glucose or pyruvate, but not formate or lactate. The fatty acids present in CF cultures matched those in the cecum of conventional mice in both quality and concentration. These acids could not account for the slow rates of growth of the tested strains in CF cultures, but they did cause a marked increase in the initial lag phase of E. coli growth. The results obtained are compatible with the hypothesis that the populations of most indigenous intestinal bacteria are controlled by one or a few nutritional substrates which a given strain can utilize most efficiently in the presence of H(2)S and at the prevailing conditions of pH and anaerobiosis. This hypothesis consequently implies that the populations of enterobacteria, such as the E. coli strain tested, and those of the predominant anaerobes are controlled by analogous mechanisms.

Anaerobiosis↗
PubMed2002

Reproductive rights and the state in Serbia and Croatia.

The global reproductive rights movement arose in the late 1980s and early 1990s as a challenge to the population control paradigm that has dominated family planning policy for almost half a century. The essence of the challenge is to place women into the center of population discussions as subjects, not objects of policy, and to reorient family planning and health programs toward meeting the broad reproductive health needs of individuals, rather than the narrow population control objectives of states. Reproductive rights advocates argue that the use of family planning programs for developmentalist-oriented population control objectives is illegimate, and inevitably relegates women to the status of depersonalized policy "targets". The cases of Croatia and Serbia, the two dominant partners in the former Federal Republic of Yugoslavia, offer interesting twists on these reproductive rights issues. In Croatia and Serbia, unlike in many nations, the governments are deliberately seeking to increase rather than decrease fertility levels. Moreover, the objective concerns identity politics, more so than development: the governments have encouraged increased fertility to safeguard the survival of their nations and to strengthen national power amidst threatening internal and external environments of ethnic conflict. In this paper, we examine the dynamics of pro-natalist fertility policy in Croatia and Serbia. We do so with a view to explaining why, despite similarities, the two have followed divergent paths. While reproductive rights violations have occurred in both nations, they have been markedly higher in Serbia than Croatia. To explain this divergence we look at a series of sociopolitical factors, including the space available for groups to mobilize in each political system; the degree of nationalistic extremism present in the discourse of central political leaders; and perceptions of threats and opportunities in external geopolitical environments. In conducting this analysis we seek to drive home the point that a nation's reproductive rights situation and prospects cannot be understood divorced from its sociopolitical context. We also raise an additional impetus for promoting the reproductive rights agenda--one largely unexplored in the family planning literature-that emerges from low fertility nations facing identity issues. Women's bodies must be protected not only against those states seeking to use their reproductive capacities for developmentalist-oriented fertility control, but also against those wanting their bodies for nationalistic-oriented fertility promotion.

Authoritarianism↗
PubMedDate not supplied

Cardiovascular response to mental stress in normal adolescents with hypertensive parents. Hemodynamics and mental stress in adolescents.

The hemodynamic response to mental stress (mental arithmetic) was studied in adolscents with varying risk factors for essential hypertension (EH), One group (genetic) consisted of normotensive well adolescents who had at least one parentnt with EH. Another group (labile) consisted of adolescents with labile hypertension each of whom also had at least one pare with EH. The control population consisted of normotensive adolescents with a negative family history of EH. Subjects with labile hypertension demonstrated a sustained increase in systolic and diastolic pressure and heart rate during stress. This response was significantly different than the control population (P less than THE CONTROL POPULATION (P LESS THAN 0.001). The stress response of the normotensive genetic population was qualitatively similar to the group with labile hypertension and significantly different than the controls in diastolic pressure and heart rate (p less than 0.001, less than 0.02). Post-stress plasma catecholamines were higher in the labile hypertensive and genetic groups than in the control group. These findings demonstrate increased central nervous system mediated adrenergic activity and cardiovascular response in labile hypertension and also in some normotensive subjects with a genetic risk for hypertension.

Adolescent↗
PubMed1999

Cancer incidence in eastern Adriatic isolates, Croatia: examples from the islands of Krk, Cres, Losinj, Rab and Pag.

As an extension of previous research this study investigates the incidence of cancer in five genetic isolate island populations of the Eastern Adriatic, Croatia. Thorough anthropological research over the past three decades has established some of those populations as outstanding examples of genetic isolates. A previous study which found higher cancer incidence in 5 Eastern Adriatic islands than in a control population supported a hypothesis that among the founders of these populations there were genetic variants (especially with recessive inheritance) responsible for genetic susceptibility to certain types of cancer. This study sought to investigate cancer incidence in 5 further island populations. All cancer cases in five island populations (Krk, Cres, Losinj, Rab and Pag) over the 20-year period (1971 to 1990) was extracted from the data of the Croatian Cancer Registry. The mainland populations of Istrian and Primorsko-Goranska County, characterized by similar environmental factors but an outbred genetic structure, represented a control population. After standardization by by sex and age, cancer incidence was higher in the island populations than in the control population in both sexes. The cancer sites primarily responsible for the excess incidence were prostate, stomach and pancreatic cancer in males, and ovarian, breast, stomach, bowel, and brain cancer in females. The reasons for the increased cancer incidence are uncertain and may be due to different environmental exposure between the two populations. However, it is possible that genetic isolation and inbreeding are important factors. Further investigations of cancer in these isolate populations are warranted to explore these findings further.

Adult↗
PubMed2002

Screening for androgen deficiency in women: methodological and interpretive issues.

OBJECTIVE: To appreciate the problems in obtaining and interpreting androgen levels in women. DESIGN: Review of the literature to compare various laboratories and methods of analysis of serum androgens. PATIENT(S): Normal control populations culled from the literature to compare with patients previously reported on by us; data from our laboratory quality control compared with data from the literature. RESULT(S): Investigators and laboratories disagree as to the best methods of measuring testosterone (T) levels in women. Measuring DHEAS levels is much less controversial. CONCLUSION(S): Serum T levels should be measured in the morning hours and during the middle third of the menstrual cycle in premenopausal women. DHEAS levels may be measured at any time. Androgens decrease with age, but age-related levels are not accurate because current control populations have never been screened for sexual dysfunction. Such control populations need to be obtained.

Adolescent↗
PubMed1997

Sensitivity to bee and wasp venoms: association with specific IgE responses to the bee and wasp venom and HLA DRB1 and DPB1.

BACKGROUND: Stings from bees and wasps can cause systemic reactions which can be fatal in some individuals. In these venom-sensitive patients, specific IgE to the venom is produced and is considered to participate in the adverse reactions. This immune response requires antigen presentation by human leucocyte antigens (HLA) class II molecules, which includes DR and DP, which are present on antigen presenting cells. OBJECTIVE: To test for associations between HLA class II DRB1 and DPB1 alleles and life-threatening sensitivity to both bee and wasp venoms. To establish further whether any associations are independent of the atopy phenotype. METHODS: A total of 33 bee- and 44 wasp-venom-sensitive patients was studied. DRB1 genotypes were determined by single stranded oligonucleotide (SSO) probing of PCR products, and DPB1 genotypes by amplified fragment length polymorphism (AFLP) analysis. Total and specific IgE were measured using the Pharmacia Immunocap, FEIA. Patients with specific IgE to the venom antigens only were termed monosensitive and those with additional specific IgE to HDM and/or GP were termed polysensitive. RESULTS: Allele frequencies were compared to an unrelated control population. The 33 bee-sensitive patients had a greater prevalence of DRB1*07 alleles than the control subjects, 26% vs 14%, with an odds ratio (OR) of 2.1 (95% CI, 1.2-3.7, P = 0.015, corrected for multiple comparisons, Pc = ns). This association was confined to the 15 monosensitive bee patients, who had a 43% DRB1*07 allele frequency when compared with 11% in the 18 polysensitive bee patients, OR 6.1 (95% CI, 1.73-22, P = 0.004, Pc = 0.05), and when compared with a control group of non-venom subjects, 43% vs 16%, OR 3.9 (95% CI, 1.72-9.0, P = 0.002, Pc = 0.02). The 44 wasp-sensitive patients had an increase in the DRB1*11 allele when compared with the control subjects, 13% vs 6%, with an OR 2.2 (95% CI, 1.0-4.6, P = 0.04, Pc = NS), and a decreased prevalence of DRB1*04 alleles, 10% vs 19%, with an OR 0.33 (95% CI, 0.24-0.99, P = 0.04, Pc = NS), but these were not significant when multiple comparisons were taken into account. The DPB1 alleles were not significantly different between the venom sensitive patients and the controls. CONCLUSION: Patients monosensitive to bee venom had a significantly greater prevalence of DRB1*07 alleles than the non-venom, control population suggesting that IgE responses in these patients may, in part be controlled by immune response HLA class II genes. These results are also suggestive of wasp-sensitive patients having a higher prevalence of DRB1*11 and a lower prevalence of DRB1*04 than the control population.

Adolescent↗
PubMed2006

Relation of atrial shunts to migraine in patients with ischemic stroke and peripheral emboli.

This study investigated whether the increased incidence of stroke in young subjects with migraine is because they have an increased prevalence of atrial right-to-left shunts. The investigators report the prevalence of clinically relevant atrial shunts in those with stroke and migraine compared with those with stroke but without migraine and also in historic control groups of subjects who had migraine with aura but no stroke and in population controls. Of 60 consecutive stroke patients, 42 (70%) had large- or medium-sized atrial shunts. Transcatheter shunt closure was performed in 39 patients, of whom 35 had patent foramen ovales (mean diameter 9.8 +/- 4.1 mm) and 4 had atrial septal defects. If atrial shunts were unrelated to stroke in patients with migraines, shunt prevalence in those with migraine and stroke would be the same as in those with migraine but without stroke. However, a much greater shunt prevalence was found in those with stroke and migraine with aura (84%) than in those with migraine with aura but no stroke (38.1%, p <0.001), population controls (12.2%, p <0.001), and those with stroke but no migraine (55.6%, p <0.05). Shunt prevalence was also significantly greater in patients who had stroke and migraine without aura (75%) than in population controls (p <0.001) and in those with migraine with aura but no stroke (p <0.05). In conclusion, the increased incidence of stroke in subjects with migraine compared with the general population is because they have a higher prevalence of large atrial shunts and hence an increased risk for paradoxic embolism.

Adolescent↗
PubMed2003

Comparison of alpha/beta estimates from homogeneous (individual) and heterogeneous (population) tumor control models for early stage prostate cancer.

Radiobiological parameter estimates for prostate cancer are obtained from both a homogeneous (individual) and heterogeneous (population) tumor control model based on Poisson statistics and the linear quadratic model of cell survival. Parameter estimates for both models are highly correlated: statistically equivalent fits are achievable using either (1) linear quadratic (LQ) parameters with low numbers of radioresistant tumor stem cells, or (2) LQ parameters with corresponding larger number of radiosensitive tumor stem cells. A theoretical framework is developed to explain this correlation. A Monte Carlo error analysis based on binomial statistics is used to estimate confidence intervals for all parameter estimates. It was found that both the homogeneous and heterogeneous models produce approximately equivalent estimates of radiobiological parameters, including the alpha/beta ratio. However, the 95% confidence interval for the alpha/beta ratio derived from the heterogeneous model are considerably larger than those derived from the homogeneous model, which indicate the homogeneous model overestimates the statistical significance of the alpha/beta estimate.

Cell Survival↗
PubMed1993

Characteristics relating to ovarian cancer risk: collaborative analysis of seven U.S. case-control studies. Epithelial ovarian cancer in black women. Collaborative Ovarian Cancer Group.

BACKGROUND: Previous epidemiologic studies of ovarian cancer have focused chiefly on White women, who have a higher incidence of ovarian cancer than Black women. No study has previously examined risk factors for ovarian cancer among Black women. PURPOSE: This study was designed to evaluate the risk of epithelial ovarian cancer in Black women in relation to reproductive characteristics such as pregnancy, oral contraceptive use, and breast-feeding, and to determine whether differences in reproductive factors between Black and White women account for differences in ovarian cancer incidence. METHODS: Combining interview data from seven case-control studies, we compared reproductive characteristics of 110 Black case subjects with a diagnosis of epithelial ovarian cancer between 1971 and 1986 with characteristics of 251 Black population control subjects and 114 Black hospital control subjects. We also compared the prevalence of reproductive factors in 246 Black population control subjects and 4378 White population control subjects and estimated the fraction of Black-White differences in ovarian cancer incidence attributable to racial differences in prevalence of these characteristics. RESULTS: Decreased risks of epithelial ovarian cancer in Black women were associated with parity of four or higher (odds ratio [OR] = 0.53; 95% confidence interval [CI] = 0.25-1.1), breast-feeding for 6 months or longer (OR = 0.85; 95% CI = 0.36-2.0), and use of oral contraceptives for 6 years or longer (OR = 0.62; 95% CI = 0.24-1.6). A greater proportion of Black women (48%) than White women (27%) reported four or more term pregnancies, and Black women (62%) were more likely than White women (53%) to have breast-fed their children. Oral contraceptive use was more common among White women (59%) than Black women (51%). CONCLUSION: Differences in the prevalence of other factors related to ovarian cancer risk or differences in genetic susceptibility must explain most of the Black-White differences in incidence of ovarian cancer.

Adolescent↗