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PubMed2004

Complete control of population transfer between clusters of degenerate states.

We present an analytic solution to the "degenerate quantum control problem," which enables the transfer of any desired fraction of population between arbitrary initial and final pure wave packets, made up of nearly degenerate energy eigenstates. It consists of two two-photon adiabatic passage steps, in which the population of the initial wave packet is first transferred, via a number of nondegenerate intermediate states, to a single eigenstate and then returned to a different target superposition state. We demonstrate the approach by executing a stepwise isomerization of three Jahn-Teller states of the Al3O molecule, where a proper optical coupling can easily be established.

Journal Article↗
PubMed1977

[The difficulty of choosing a good control group in a retrospective study (author's transl)].

The choice of either hospital or population controls in retrospective studies is guided by rules implying underlying hypotheses. In a study on aesophageal cancer in relation to alcohol and tobacco consumption, two such control groups were available and were compared. It was found that some of the currently accepted assumptions relating to representativeness of cases or controls were verified but many others were not, particularly in hospital controls. These were found to give less correct estimates of drinking and smoking habits than those obtained from population controls. The limitations in the use of either type of controls is discussed, in relation to the purpose of the study concerned.

Adult↗
PubMed1978

An investigation of the immune response of patients suffering from anorexia nervosa.

Patients suffering from anorexia nervosa rarely appear to develop the common cold or influenza. This study examines the immunological response of fifteen female anorexia nervosa patients of both the vomiting and carbohydrate-abstaining type and compares them with a control population matched for age and occupation. Both anorectics and control populations received the admune influenza vaccine. Initially both groups had similar haemagglutination inhibition titres against the three different viral antigens: A/HK; A/PC; A/Eng. However, the anorectics showed over a 2-month period a higher titre of antibody especially to the Hong Kong virus: this was sigignificant. Cellular immune responses were measured using a tuberculin and a macrophage inhibition test, no significant difference between the two groups was obderved. These results which support the clinical findings are discussed.

Adolescent↗
PubMedDate not supplied

The real problem.

I really was dismayed to see the basic cause of all our planet's problems buried in the September/October 96 issue: "...religious zealots might wreck the family planning needs of a billion people...." Let's face hard facts: all these problems would go away if the planet's population were small enough. What we really need to establish is what the population of the earth should be, and then set out to achieve that population as soon as possible. All of our efforts to reduce automobile pollution, the amount of reactor waste, the number of species being obliterated, etc., are just postponing the inevitable. What we need to look at, and keep track of, are those factors that encourage expanding population and discourage population control. For example, most businesses like to see the population expand so they can have a growing customer base. I truly appreciate your efforts. But if we are going to get anywhere we have to clearly identify the real problem. And then we have to break it down into manageable pieces and go to work on them. Otherwise we are going to keep looking at the graphs and wringing our hands as this accumulation of problems builds until it sweeps over us like a giant tsunami.

Conservation of Natural Resources↗
PubMed2003

Association study of the IL13 variant Arg110Gln in atopic diseases and juvenile idiopathic arthritis.

BACKGROUND: It has previously been shown that various inflammatory diseases, such as diabetes mellitus, bronchial asthma, chronic inflammatory bowel diseases, and rheumatoid arthritis, are in some circumstances genetically linked to the same chromosomal regions. Consequently, common genes underlying the pathogenetics of these diseases have been proposed. Chronic inflammatory disorders can be subdivided by their predominant immune response, either TH1 or TH2. For example, juvenile idiopathic arthritis (JIA) is a TH1 disease, and bronchial asthma is a TH2 disease. OBJECTIVES: The present study investigated the polymorphism Arg110Gln within the IL13 gene, a strong TH2 cytokine. We attempted to determine whether it is associated with these 2 diseases and whether this would reflect the TH1/TH2 paradigm. METHODS: Arg110Gln was typed in 4 different populations: asthmatic children, atopic children, children with JIA, and a control population. Statistical analysis was performed by using logistic and linear regression analysis of serum IgE levels and the Armitage trend test. RESULTS: The variant Gln110 was shown to be associated with increased total serum IgE levels in our atopic population (P =.006) and was weakly associated with bronchial asthma (P =.04). There was no association of the variant with JIA when compared with the control population. However, the variant Gln110 was significantly less frequent in children with JIA compared with its presence in children with bronchial asthma (P =.007). CONCLUSION: This is the first study to compare the same gene variant in TH1 and TH2 chronic inflammatory diseases. The results suggest that the same gene variant might protect from one disease and make an individual susceptible to the other.

Adolescent↗
PubMed2000

Quorum sensing and the population-dependent control of virulence.

One crucial feature of almost all bacterial infections is the need for the invading pathogen to reach a critical cell population density sufficient to overcome host defences and establish the infection. Controlling the expression of virulence determinants in concert with cell population density may therefore confer a significant survival advantage on the pathogen such that the host is overwhelmed before a defence response can be fully initiated. Many different bacterial pathogens are now known to regulate diverse physiological processes including virulence in a cell-density-dependent manner through cell-cell communication. This phenomenon, which relies on the interaction of a diffusible signal molecule (e.g. an N-acylhomoserine lactone) with a sensor or transcriptional activator to couple gene expression with cell population density, has become known as 'quorum sensing'. Although the size of the 'quorum' is likely to be highly variable and influenced by the diffusibility of the signal molecule within infected tissues, nevertheless quorum-sensing signal molecules can be detected in vivo in both experimental animal model and human infections. Furthermore, certain quorum-sensing molecules have been shown to possess pharmacological and immunomodulatory activity such that they may function as virulence determinants per se. As a consequence, quorum sensing constitutes a novel therapeutic target for the design of small molecular antagonists capable of attenuating virulence through the blockade of bacterial cell-cell communication.

4-Butyrolactone↗
PubMed1998

The gln-Arg192 polymorphism of human paraoxonase gene is not associated with coronary artery disease in italian patients.

Serum paraoxonase (PON) is an HDL-bound enzyme protecting LDL from oxidation. A common polymorphism of the paraoxonase gene (PON1) involving a Gln-to-Arg interchange at position 192 has been demonstrated to modulate PON activity toward paraoxon, a nonphysiological substrate; Arg192 (allele B) is associated with higher activity than Gln192 (allele A). This polymorphism has been proposed as a genetic marker of risk for coronary artery disease (CAD). However, the relationships between codon 192 PON1 genotypes, coronary atherosclerosis, and the occurrence of myocardial infarction (MI) are still controversial. PON1 genotypes were determined in 472 consecutive subjects (>40 years old) who underwent coronary angiography. CAD (>50% stenosis) was detected in 310 subjects (CAD+); 162 subjects with <10% stenosis served as controls (CAD-). We also evaluated 204 randomly selected individuals as population controls. PON1 genotypes were determined by PCR and AlwI restriction enzyme digestion. Frequencies of alleles A and B were 0. 70 and 0.30 in angiographically assessed subjects and 0.73 and 0.27 in population controls, respectively (chi2=2.0; P<0.3). Distribution of PON1 genotypes in CAD+ were not significantly different from those in CAD- (chi2=2.10; P<0.3). Similarly, no differences were observed in the subgroup of CAD+ with MI nor in that at higher oxidative risk (smokers and/or diabetics). After controlling for other coronary risk factors, no association was found between PON1 alleles and the presence of CAD. PON1 AA genotype was associated with reduced concentration of apolipoprotein B-containing triglyceride-rich lipoproteins. This study did not provide evidence of a significant association between codon 192 PON1 genotypes and coronary atherosclerosis in Italian patients. However, it did confirm that the PON1 low-activity allele is associated with a less atherogenic lipid profile.

Adult↗
PubMed2004

Abnormal glucose tolerance--a common risk factor in patients with acute myocardial infarction in comparison with population-based controls.

BACKGROUND: A high prevalence of newly detected diabetes and impaired glucose tolerance (abnormal glucose tolerance) was recently reported in patients with acute myocardial infarction. It is important to verify whether this finding is specific for the patients or attributable to the population, from which they were recruited. OBJECTIVE: To verify whether abnormal glucose tolerance is more prevalent in patients than in controls chosen from the same population and to compare metabolic characteristics between the two groups. DESIGN AND SUBJECTS: The metabolic state was assessed in patients (n = 181) admitted with acute myocardial infarction and no history of diabetes before discharge and after 3 months. Sex- and age-matched controls (n = 185) without previously known diabetes or cardiovascular disease except hypertension were recruited from the general population. MAIN OUTCOME MEASURES: Oral glucose tolerance test, glucosylated haemoglobin A1c (HbA1c), insulin, proinsulin, lipid profile, fibrinolytic function and inflammatory markers. RESULTS: Abnormal glucose tolerance was more common (number/all classified) in patients at discharge 113/168 (67%) and after 3 months 95/145 (66%) than in controls 65/185 (35%) (P < 0.001). Dyslipidaemia (70% vs. 29%; P < 0.001) and previously treated hypertension (32% vs. 18%; P = 0.028) were more frequent amongst patients whilst obesity (18% vs. 24%) did not differ significantly. Blood glucose, HbA1c, proinsulin, proinsulin/insulin ratio, triglycerides, insulin resistance (by HOMA) and fibrinogen were consistently higher in patients than controls (P < 0.01). CONCLUSIONS: Abnormal glucose tolerance was almost twice as common amongst patients with acute myocardial infarction as in matched controls. Impaired glycaemic control accompanied by insulin resistance, dyslipidaemia, hypertension, together with increased plasma fibrinogen and proinsulin levels were main features characterizing patients.

Acute Disease↗
PubMed2001

Evidence based prevention of acute injuries during physical exercise in a WHO safe community.

OBJECTIVE: To evaluate a community based programme for evidence based prevention of injuries during physical exercise. DESIGN: Quasi-experimental evaluation using an intervention population and a non-random control population. PARTICIPANTS: Study municipality (population 41,000) and control municipality (population 26,000) in Sweden. MAIN OUTCOME MEASURES: Morbidity rate for sports related injuries treated in the health care system; severity classification according to the abbreviated injury scale (AIS). RESULTS: The total morbidity rate for sports related injuries in the study area decreased by 14% from 21 to 18 injuries per 1,000 population years (odds ratio 0.87; 95% confidence interval (CI) 0.79 to 0.96). No tendency towards a decrease was observed in people over 40. The rate of moderately severe injury (AIS 2) decreased to almost half (odds ratio 0.58; 95% CI 0.50 to 0.68), whereas the rate of minor injuries (AIS 1) increased (odds ratio 1.22; 95% CI 1.06 to 1.40). The risk of severe injuries (AIS 3-6) remained constant. The rate of total sports injury in the control area did not change (odds ratio 0.93; 95% CI 0.81 to 1.07), and the trends in the study and control areas were not statistically significantly different. CONCLUSION: An evidence based prevention programme based on local safety rules and educational programmes can reduce the burden of injuries related to physical exercise in a community. Future studies need to look at adjusting the programme to benefit all age groups.

Adolescent↗
PubMed1998

The fractionation experiment: reducing heterogeneity to investigate age-specific mortality in Drosophila.

Age-specific mortality rates decelerate at older ages in both genetically homogenous and heterogeneous populations of Drosophila. One explanation proposed for deceleration is population heterogeneity. This hypothesis suggests that a population consists of sub-populations that differ in mortality characteristics and that the deceleration is the result of selective survival of stronger individuals. Here we describe an experiment that fractionates populations into several sub-populations without changing the physiological characteristics of the post-fractionated populations. Through a careful process of selection of Drosophila eggs, larvae, pupae and adults, we attempt to reduce as much as possible the degree of pre-adult, environmentally induced heterogeneity among individuals of a genetically identical cohort. We then ask whether such cohorts, when compared to non-fractionated populations, exhibit a lesser degree of mortality deceleration at advanced ages. From a total of 106 fractionated and control populations, consisting of 51331 individuals, 101 populations (93% of the fractionated populations and 100% of the control populations) exhibit a significant amount of mortality deceleration late in life. These observations suggest that environmental heterogeneity accrued during larval development is not a major factor contributing to mortality deceleration at older ages.

Aging↗
PubMed2005

Polymorphisms and haplotypes of acid mammalian chitinase are associated with bronchial asthma.

RATIONALE: Chitinases are enzymes that cleave chitin, a polysaccharide contained in many parasites of humans. Recent studies in mouse models of bronchial asthma have shown that acid mammalian chitinase (AMCase) is involved in the pathophysiology of asthma. It acts downstream of interleukin-13; inhibition of AMCase leads to an abrogated T-helper cell 2 inflammation, less bronchial hyperreactivity, and fewer eosinophils. OBJECTIVES: The aim of this study was to identify common genetic variants in human AMCase and to use them to test for association of AMCase with pediatric asthma. METHODS: By sequencing the promotor region and all 11 exons on 30 individuals, 12 high-frequency polymorphisms were identified. Genotyping of six variants in exons and one promotor polymorphism was performed on the following populations by means of restriction fragment length polymorphisms: 322 children with asthma, 270 randomly chosen adult controls, and a pediatric control population consisting of 565 children who, at age 10 yr, had never wheezed and never been diagnosed having asthma. MEASUREMENTS AND MAIN RESULTS: We identified three known and two new amino acid variants. Analyses by the Armitage's trend test using both control populations showed association of the newly identified variant K17R and the nearby noncoding polymorphism rs3818822 with asthma (p = 0.0031 and p = 0.0003, respectively). In addition, haplotype analyses revealed strong association of haplotypes with the disease (asthma population vs. pediatric control subjects, p < 10(-10)). CONCLUSIONS: This newly described association between AMCase polymorphisms and asthma adds further evidence supporting the involvement of AMCase in the development of asthma.

Adolescent↗
PubMed1986

Coronary disease and risk factors in close relatives of Utah women with early coronary death.

Familial aggregation of coronary heart disease (CHD) and specific major risk factors were determined among 639 first-degree relatives of 73 women with confirmed coronary death before age 55. They were compared with 1,151 persons in 141 control families. Of women with early coronary death, 62% had first-degree relatives with early coronary disease compared with 12% of affected control family members. In the proband families, coronary incidence rates were 2.7 times the control population rates for women (P<.001) and 1.6 times the control population rates for men (P<.05). An excess incidence of coronary disease was observed for ages 45 to 74 in both men and women.Smoking, hypertension, diagnosed hyperlipidemia and diabetes were all two to three times more common in the female probands with early coronary death than in healthy controls. Hypertension was more common in all proband relatives (both sexes with and without coronary disease). Smoking was more common among female relatives of probands when compared with the controls. These data suggest that early coronary disease in women is often familial and associated with smoking and hypertension. The familial aggregation seems to be stronger in female relatives of female probands with early CHD than in male relatives. Genetic factors or shared family life-style or both likely account for these observations.

Adult↗
PubMed1994

A population-based, controlled study of the relation between HIV infection and cervical neoplasia.

OBJECTIVE: To study a geographically defined population of women exposed to a drug-related risk for human immunodeficiency virus (HIV), together with carefully matched neighbourhood controls, in order to examine (1) the proportion of different groups having cervical cytopathology screening; (2) the association between HIV infection and cervical intraepithelial neoplasia; (3) the independent effect of CD4+ lymphocyte count and duration of HIV infection; and (4) the correspondence between cervical cytopathology and colposcopically directed biopsy. DESIGN: A population-based study. SUBJECTS: All women domiciled in Lothians with the following characteristics: between 1983 and 1987 they had a history of injection drug use or a seropositive partner with a history of injection drug use; they had a pregnancy after that exposure where their serostatus was known. In addition, neighbourhood controls were identified by computer matching for the following criteria--post-code sector, housing deprivation score, age, parity, pregnancy outcome, ethnic group, year of pregnancy, smoking. MAIN OUTCOME MEASURES: Search was carried out for the cervical smear nearest in time to the index pregnancy end date, providing serostatus was known at that time. All identified smears were assessed by a cytopathologist without knowledge of clinical information, study group or serostatus. RESULTS: Of 376 women, appropriate cervical smears were identified for 336. The proportions screened in the different groups were similar. There were more abnormal smears in the seropositive group than in the drug-related seronegative (P < 0.01) or the neighbourhood control groups (P < 0.001). HIV-infected women with abnormal smears had lower CD4+ lymphocyte counts (P < 0.0005). There was a reasonable correspondence between cytopathological classification and histological grading, and this was of similar strength in cases and controls (weighted kappa 0.72, 0.74). CONCLUSIONS: There is a definite relation between HIV infection and cervical intraepithelial neoplasia. This is related to immune depletion but whether this is the sole mechanism for the association is unclear.

Adult↗
PubMed2004

A functional haplotype of the PADI4 gene associated with rheumatoid arthritis in a Japanese population is not associated in a United Kingdom population.

OBJECTIVE: In the era of postgenomic research, linkage- and association-based strategies are beginning to reveal novel complex disease genes. Using such an approach, a functional haplotype of the peptidylarginine deiminase 4 gene (PADI4) has recently been identified as a gene conferring susceptibility to rheumatoid arthritis (RA) in a Japanese population. In the present study, we investigated the association of single-nucleotide polymorphisms (SNPs) in the PADI4 gene with RA in a UK population. METHODS: Association with 4 exonic SNPs (padi4_89*G/A, padi4_90*T/C, padi4_92*G/C, and padi4_104*T/C), mapping to the PADI4 gene and defining a haplotype previously reported to be associated with RA, was investigated. Genotyping was performed using 5' allelic discrimination assays. Estimated haplotypes were generated using the expectation-maximization algorithm, and frequencies of the SNPs and haplotypes were compared between unrelated Caucasian RA patients from the UK (n = 839) and population controls (n = 481). RESULTS: Allele frequencies for the 4 SNPs in the UK population were similar to those reported in the Japanese control population, but none of these was associated with RA. As in the Japanese population, the SNPs in the UK population defined 2 major haplotypes, but neither was associated with RA (P = 0.79). CONCLUSION: A PADI4 susceptibility haplotype associated with RA in a Japanese population is not associated with RA in a UK population. Other genes involved in the citrullinating pathway remain strong candidate RA-susceptibility genes and require further investigation.

Adult↗
PubMed2000

Service screening with mammography in Sweden--evaluation of effects of screening on breast cancer mortality in age group 40-49 years.

The aim of the study was to develop a model for estimating the effect of the nation-wide service screening program with mammography on breast cancer mortality in Sweden. In 1997, the introduction of population-based service screening had been completed in all 26 counties. In approximately half of the counties suitable for evaluation, the lower age limit for invitation was 40 years (study population) and in the other half the age limit was 50 years (control population). The numbers of females aged 40 49 years for the two populations were 202,152 and 237,279, respectively (1988). The study and control populations were compared for the period 1986-1996 with regard to refined breast cancer mortality. To adjust for geographical differences, the period 1976 1986 was used as reference. With a mean follow-up time of 8 years, the estimated relative risk of breast cancer death in relation to invitation to service screening among women aged 40-49 years at breast cancer diagnosis was 0.91 (95% confidence interval 0.72-1.15). These findings were compatible with those presented in the previous overview of the Swedish randomized studies.

Adult↗
PubMed1992

[Modification of the calculation of risk factors in women, possible carriers of Duchenne muscular dystrophy, based on CPK levels].

We have analyzed the CPK levels in 44 carriers of DMD women, previously diagnosed by using molecular techniques (from a risk population of 133 women), and compare them with the CPK levels of 138 women of a control population. The results obtained show that values higher than the normal level (> 250 mU/ml) are compatible compatible in 99% of the cases with the carrier status (21 women of the carrier population and 1 women of the control population showed values higher than 250 mU/ml). On the other hand, normal values do not distinguish between the healthy and carrier populations (22 women of the carrier population showed normal CPK levels). These results can be very useful in genetic counselling, especially in centers where it is not possible to apply recombinant-DNA techniques.

Creatine Kinase↗
PubMed2002

History of myocardial infarction and stroke among incident end-stage renal disease cases and population-based controls: an analysis of shared risk factors.

BACKGROUND: A history of myocardial infarction (MI) and stroke is more common among incident cases of treated end-stage renal disease (ESRD) than in the general US population. METHODS: Whether this association is the result of shared risk factors or renal dysfunction before ESRD was examined using data from a population-based case-control study of 716 incident patients with ESRD and 361 control subjects of similar age from Maryland, Virginia, West Virginia, and Washington, DC. Medical history including a previous MI and stroke, and dates of these events were obtained by means of a structured telephone interview. RESULTS: After adjustment for age, race, and sex, odds of ESRD were 3.6 (95% confidence interval [CI], 2.0 to 6.5) and 11.1 (95% CI, 4.3 to 28.6) times greater for those with versus without a history of MI and stroke, respectively. Adjustment for long-standing hypertension, diabetes mellitus, and several other potential confounders reduced the odds ratio (OR) of ESRD for those with a history of MI by 77% (OR, 1.6; 95% CI, 0.7 to 3.3) and 39% (OR, 7.2; 95% CI, 2.2 to 23.2) for those with a history of stroke. The OR for ESRD was higher within 5 years of an MI (OR, 2.2; 95% CI, 0.8 to 6.1) or stroke (OR, 14.9; 95% CI, 1.8 to 125) than for more distant MI (OR, 0.8; 95% CI, 0.2 to 2.5) and stroke (OR, 4.5; 95% CI, 1.0 to 19.0) events. CONCLUSION: The high prevalence of a history of MI at ESRD incidence is explained primarily by shared risk factors, but the high prevalence of stroke is not.

Adult↗
PubMed2005

Maternal employment status and isolated orofacial clefts in Hungary.

AIMS: To study the role of maternal employment status as indicator of socioeconomic status in the origin of isolated orofacial clefts (OFC) and in the use of periconceptional folic acid/multivitamin supplementation. METHODS: 1,975 cases with OFC (1,374 cases with cleft lip +/- palate and 601 cases with posterior cleft palate), 38,151 population controls without any defects and 20,868 patient controls with other isolated defects were compared in the population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities (HCCSCA), 1980-1996. RESULTS: The proportion of professionals and managerials was lower, while the proportion of unskilled workers, housewives and others was higher in the mothers of cases with OFC compared with the population control group. However, the comparison of OFC and patient control groups did not show any difference in the employment status of mothers. A lower level of folic acid supplementation occurred in the professional and skilled worker mothers of cases with OFC compared with the population control group. This difference was confirmed by the comparison of folic acid used by mothers of cases with OFC compared with patient controls. An infrequent multivitamin use was displayed in the studied groups. CONCLUSIONS: The prevalence of OFC at birth shows a slightly lower maternal employment status as indicator of socioeconomic status than in the population control group. The higher level of maternal education does not imply a higher rate of folic acid supplementation in the group of OFC.

Case-Control Studies↗