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At least 649 records · Page 36Linked to original sources
PubMed2002

Association of ulcerative colitis with the inflammatory bowel disease susceptibility locus IBD2 in non-Jewish Caucasians and evidence of genetic heterogeneity among racial and ethnic populations with Crohn disease.

Genomewide scanning has been used to identify chromosomal regions encoding susceptibility loci to inflammatory bowel disease (IBD). The greatest evidence for linkage to IBD has been reported for a region of chromosome 12q14 surrounding the microsatellite marker D12S83, with a logarithm of odds score of 5.47 and a positive transmission disequilibrium test, and which was subsequently named IBD2. We wished to confirm this locus by genotyping the highly polymorphic microsatellites D12S1022, D12S1056, and D12S83, spanning a continuous region on chromosome 12 of 342 kb, in a cohort of nonrelated individuals with ulcerative colitis (89 patients), Crohn disease (121 patients), and population-based control subjects (100 patients). In non-Jewish Caucasians, one D12S1022 allele, one D12S1056 genotype, and three D12S83 alleles were found to have statistically significant differences in distribution between the two disease groups and the control population. These data support a significant association of IBD with the IBD2 locus in close vicinity to the three markers studied. The replication of genetic risk loci in a case control association study may indicate susceptibility genes in this region and may facilitate identification of candidate genes for IBD. Subgroup analysis revealed a notable difference in genotype distribution among Jewish Caucasian and African American patients affected with Crohn disease when compared with similarly affected non-Jewish Caucasians. Using Fisher exact test, statistically significant distribution differences were observed for D12S1022 and D12S83. These data indicate that there may be significant genetic heterogeneity between different ethnic and racial IBD populations or may simply reflect differences in marker allele frequencies among populations.

Adolescent↗
PubMed2004

Prognostic importance of renal function in patients with early heart failure and mild left ventricular dysfunction.

We evaluated the prognostic value of renal function in an initially "untreated" population with mild heart failure and compared the prognosis of this population with a matched controlled population. During a follow-up of 13 years (mean 11.7), 90 patients (56%) died. Mortality was higher compared with a matched controlled population. Multivariate Cox regression analysis demonstrated that beside the well-established risk markers of left ventricular ejection fraction and heart rate, renal function (estimated glomerular filtration rate, hazard ratio 1.16/10 ml/min/1.73 m(2), p = 0.003) was the only additional independent predictor of cardiovascular mortality in patients with early heart failure.

Aged↗
PubMed1985

[Etiologic factors of fetal hypotrophy. Apropos of 600 cases].

The authors have studied 600 cases histories of fetal growth retardation over a period of 11 years from 1970 to 1981. The incidence of growth retardation was 600 cases in 24,906 deliveries from October 1970 to the end of 1981. This gives an incidence of 2.41%. This figure tends to get less progressively, going from 2.5% at the beginning of our study to a little more than 2% in the last years. 1,498 babies were born weighing less than 2,500 g: 600 of them were really true intra-uterine growth retardations (40%) and 898 were babies born prematurely with normal weight for their gestational age. 227 of the 600 small for date babies were born before the 38th week of pregnancy (37.8%). Girls represented 55% of the cases of growth retardation. There was no significant difference in the distribution of age groups of the mothers of small for date babies and the control population. 57% of the women were primiparas whereas only 38% were primiparas in the control population. There is a close relationship between primiparity and young maternal age. 80% of mothers who were under 25 years of age were primiparas. The height of the mother, less than 1,50 m, in our study was significantly less than in the control population (11.9% as against 2.5%). 24% of the mothers weighed less than 45 kg as compared with 7.1% in the general population. The weight gain was not significantly different from that in the control population, if it is not taken in account of mothers who had toxaemia of pregnancy. 158 cases out of the 600, which represents 26% of the mothers, had toxaemia of pregnancy and this confirms how important this aetiological factor is in intra-uterine growth retardation. 113 placentas (18.8%) were studied. They showed histological abnormalities such as infarcts (47 cases) and ischaemic necrosis (18 cases). These features are often associated with toxaemia of pregnancy and/or heavy maternal smoking in 58% of cases. There were abnormalities of the umbilical cords. These were variable so that one could not say that any one was an important cause of intra-uterine growth retardation. A single umbilical artery was found in 8 cases (1.33%). We only speak of recurrent fetal growth retardation, excluding cases of toxaemia, when three or more small for date babies have been born without any particular aetiological reason.(ABSTRACT TRUNCATED AT 400 WORDS)

Body Weight↗
PubMedDate not supplied

Dental problems in patients with diabetes mellitus (II): gingival index and periodontal disease.

UNLABELLED: Among the late complications associated to the diabetes mellitus, periodontal disease has been highlighted, and it can be more severe and refractory to treatment than in healthy subjects. OBJECTIVES: Determine the prevalence of gingivitis and periodontitis as well as the Community Periodontal Index of Need of Treatment (CPITN) in diabetic population compared with a control one. Analyze the histological characteristics in the gingiva of diabetic patients. STUDY DESIGN: The study sample was made up of 74 control subjects and 70 diabetics. We evaluated the following parameters: gingival status according to the Löe and Silness criterion, probe depth, loss of insertion, gingival recession and Community Periodontal Index of Need of Treatment. We also performed gingival biopsies in 42 diabetic patients and 29 controls for histological studies. RESULTS: We found a statistically higher gingivitis index, loss of insertion and gingival recession in diabetic patients compared to the control population, the same not occurring with the probe depth. We did not find significant differences in the CPITN according to the type of diabetes mellitus, metabolic control or disease duration. The biopsy study did not show significant changes in the gingiva of the diabetic patients compared to the control population. CONCLUSIONS: The gingivitis index was higher in the diabetic population. After examination of the treatment needs, we observed how the diabetic patients required more complex treatment.

Adolescent↗
PubMed2004

Fitness cost of resistance to cadmium in the least killifish (Heterandria formosa).

Fitness costs constrain the evolution of resistance to environmental stress in populations. We earlier reported on a rapid response to laboratory selection for cadmium resistance in the least killifish (Heterandria formosa). By the sixth generation, the three selection populations were threefold more resistant to cadmium than the control populations. Here, we report the fitness costs and trade-offs associated with this evolution of resistance. In the F3 and F4 generations, the selection populations produced smaller-sized offspring than the control populations. A comprehensive life-history traits study in the F7 generation showed that the selection populations had, on average, an 18% decrease in fecundity. The selection populations also had a smaller brood size, longer time to first reproduction, and shorter female life expectancy than the control populations. Our results strongly suggest that fitness costs and trade-offs were associated with the evolution of resistance to cadmium in the least killifish. The fitness costs and trade-offs may result from maintenance of the underlying resistance mechanisms, leading to changes in resource allocation in the cadmium-adapted fish.

Adaptation, Physiological↗
PubMed1992

A model of the transmission of dengue fever with an evaluation of the impact of ultra-low volume (ULV) insecticide applications on dengue epidemics.

We have developed a deterministic susceptible, exposed, infectious, resistant or removed (SEIR) model of dengue fever transmission that enables us to explore the behavior of an epidemic, and to experiment with vector control practices. Populations of both host and vector are divided into compartments representing disease status (susceptible, exposed, infectious, and, for humans, resistant), and the flow between compartments is described by differential equations. Examination of the equilibrium points leads to a formulation of the basic reproduction rate (Z0) of the disease. With a base set of parameters, Z0 = 1.9 and the model realistically reproduces epidemic transmission in an immunologically naive population. Control of adult mosquitoes by ultra-low volume (ULV) aerosols is simulated by an abrupt decrease in vector densities, followed by gradual recovery of the vector population. The model indicates that ULV has little impact on disease incidence, even when multiple applications are made, although the peak of the epidemic may be delayed. Decreasing the carrying capacity of the environment for mosquitoes, and thus the basic reproduction rate of the disease, by source reduction or other means, is more effective in reducing transmission.

Animals↗
PubMed1997

Screening for neuroblastoma is ineffective in reducing the incidence of unfavourable advanced stage disease in older children.

Neuroblastoma exhibits many characteristics which would suggest that preclinical detection may improve outcome. The Quebec Neuroblastoma Screening Project was initiated to determine whether mass screening could reduce mortality in a large cohort of infants. All 476,603 children born in the province of Quebec during a 5-year period of time (1 May 1989 to 30 April 1994) were eligible for determinations of urinary catecholamine metabolites at 3 weeks and 6 months of age. Children with positive screening were referred to one of four paediatric cancer centres in Quebec for uniform evaluation and treatment. Standardised incidence ratios (SIRs) were calculated for neuroblastoma in Quebec and two comparable population-based controls during the same period of time using similar ascertainment procedures. Compliance with screening in Quebec was 91% at 3 weeks (n = 425,816) and 74% at 6 months (n = 349,706). Up to 31 July 1995 with a follow-up of the birth cohort of 15-75 months, 118 cases of neuroblastoma were diagnosed, 43 detected preclinically by screening, 20 detected clinically prior to screening at 3 weeks of age and 55 detected clinically after 3 weeks of age having normal screens (n = 52) or never screened (n = 3). Based on data from concurrent control populations, 54.5 cases of neuroblastoma would have been expected in Quebec during the study period for an SIR of 2.17 (95% CI 1.79-2.57, P < 0.0001). For the two control groups, the overall SIR was 1.00 (NS). SIRs for Quebec by age at diagnosis in yearly intervals show a marked increased incidence under 1 year of age (SIR = 2.85, 95% CI 2.26-3.50), with no reduction in incidence in subsequent years. We conclude that screening for neuroblastoma markedly increases the incidence in infants without decreasing the incidence of unfavourable advanced stage disease in older children. It is unlikely that screening for neuroblastoma in infants will reduce the mortality of this disease.

Canada↗
PubMed1976

Evolution of experimental "mutator" populations of Drosophila melanogaster.

The theory of evolution predicts that the rate of adaptation of a population is a function of the amount of genetic variation present in the population. This has been experimentally demonstrated in Drosophila populations in which genetic variability was increased either by mass hybridization of two gene pools, or by X-irradiation.--Mutator genes increase the spontaneous mutation rates of their carriers. We have now studied the effects of a third-chromosome mutator gene, mt, on the rate of adaptation of laboratory populations. Initially, experimental and control populations had similar genetic constitutions except for the presence of absence of the mt gene. The populations were maintained for 20-25 generations by "serial transfer" under conditions of very intense selection.--The number of flies produced per unit time remained constant throughout the experiment in the experimental as well as in the control populations. However, in the mutator-carring populations the average longevity of the flies (and consequently the average population size) gradually decreased. Under the experimental conditions natural selection is unable to counteract completely the increased input of deleterious mutations due to the mt gene.

Animals↗
PubMed1989

Optimal birth control of population dynamics.

The authors studied optimal birth control policies for an age-structured population of McKendrick type which is a distributed parameter system involving 1st order partial differential equations with nonlocal bilinear boundary control. The functional analytic approach of Dubovitskii and Milyutin is adopted in the investigation. Maximum principles for problems with a free end condition and fixed final horizon are developed, and the time optimal control problems, the problem with target sets, and infinite planning horizon case are investigated.

Demography↗
PubMed2004

Factors associated with colorectal cancer screening in a population-based study: the impact of gender, health care source, and time.

INTRODUCTION: The effectiveness of colorectal cancer screening in reducing incident colorectal cancer and the risk of death has been shown. Despite campaigns to promote the benefits of and use of colorectal cancer screening, most people are not participating in screening. In this paper, we examine factors associated with screening behavior over time, by health care provider, and by gender and report associations between screening and development of colorectal cancer after adjusting for diet and lifestyle factors. METHODS: Data from two population-based case-control studies of colorectal cancer were used to examine risk associations with nonparticipation in colorectal cancer screening. Study participants were identified for the first study between 1991 and 1994 (N = 1,346 cases and 1,544 controls) and for the second between 1997 and 2001 (N = 952 cases and 1,205 controls) and were asked to complete a detailed in-person interviewer-administered diet and lifestyle questionnaire. The control population is used to examine changes in screening behavior and associations with screening over time. RESULTS: Significantly, fewer people reported fecal occult blood test (FOBT) in 1997-2001 than in 1991-1994 (62.5% in 1991-1994 vs. 47.2% in 1997-2001); a slight nonsignificant increase in sigmoidoscopy screening was reported for these periods among controls (33.9% vs. 36.6%). In the control population, during these periods, there was a statistically significant increase in the number of people who reported having had a sigmoidoscopy for screening rather than for problems (72.6% in 1997-2001 vs. 63.8% in 1991-1994). There were differences in factors associated with screening behavior by time, by sex, and by health care provider, although having a family history of colorectal cancer, having more education, and being male was associated with more screening in all settings. After adjusting for diet and lifestyle factors, we observed that non-sigmoidoscopy screening significantly influenced risk of incident cancer (rectal OR: 2.9; 95% CI, 2.3-3.7; distal tumor OR: 1.8; 95% CI, 1.4-2.3); proximal tumor: 1.4; 95% CI, 1.1-1.8). Nonuse of FOBT also was associated significantly with tumors in the rectal (OR: 1.6; 95% CI, 1.3-1.9) and distal (OR: 1.4; 95% CI, 1.1-1.8) sites. SUMMARY: These data reinforce the importance of screening to reduce risk of colorectal cancer development. However, flexible sigmoidoscopy screening is increasing only modestly over time, and primarily in settings where a significant investment in screening has been made. FOBT screening, which is effective for rectal cancer prevention, is actually decreasing.

Aged↗
PubMed2005

PPARgamma, energy balance, and associations with colon and rectal cancer.

Peroxisome proliferator-activated receptor-gamma (PPARgamma) has been hypothesized as being involved in colorectal cancer given its role in adipocyte development and insulin resistance. In this study we evaluated the association between the Pro12Ala (P12A) PPARgamma polymorphism and body mass index (BMI), waist-to-hip ratio (WHR), physical activity level, and energy intake and risk of colorectal cancer using data from a population-based, case-control study of colon cancer (1,577 cases and 1,971 controls) and rectal cancer (794 cases and 1,001 controls). We further evaluated how the P12A PPARgamma polymorphism is associated with obesity and fat pattern in the control population. The odd ratio for PPARgamma PA or AA genotype relative to the PP genotype for colon cancer was 0.9 (95% confidence interval, CI=0.8-1.0) and for rectal cancer was 1.2 (95% CI=1.0-1.5) adjusting for race, age, and sex. P12A PPARgamma did not significantly interact with BMI, WHR, energy intake, and energy expenditure to alter risk of colon or rectal cancer. Furthermore, the P12A PPARgamma polymorphism was not associated with obesity or WHR in the control population; it did not interact with energy intake or energy expenditure to alter risk of obesity or large WHR. These data do not support the hypothesis that the P12A PPARgamma polymorphism is associated with colon or rectal cancer through regulation of energy balance.

Aged↗
PubMed1983

Factors preceding the onset of meningococcal disease, with special emphasis on passive smoking, symptoms of ill health.

In a prospective study of 115 patients with systemic meningococcal disease, 61 control patients and 293 population controls, environmental and other factors which preceded the illness and which might have influenced the acquisition and case fatality rate of the meningococcal disease were investigated. Passive smoking in children under 12 year of age, stressful events, and symptoms and signs of preceding illness within the last two weeks were significantly more frequent in meningococcal patients than among the population controls. In contrast, those patients who had been exposed to stressful events, or who had symptoms or signs of ill-health preceding the meningococcal disease, had significantly reduced case fatality rates as compared to those who had not had any such experiences. Passive smoking remains a factor of great interest for further studies and intervention.

Adolescent↗
PubMed2004

Analysis of genes implicated in iron regulation in individuals presenting with primary iron overload.

Extensive investigation into the molecular basis of iron overload disorders has provided new insights into the complexity of iron metabolism and related cellular pathways. The possible involvement of genes affecting iron homeostasis, including HFE, SLC40A1, HAMP and CYBRD1, was investigated in individuals who were referred for confirmation or exclusion of a diagnosis of haemochromatosis, but who tested negative or were heterozygous for the causative HFE mutation, C282Y. Denaturing high performance liquid chromatography analysis of these genes revealed a unique spectrum of mutations in the South African study population, including 67 unrelated patients and 70 population-matched controls. Two novel CYBRD1 gene mutations, R226H and IVS1-4C-->G, were identified in 11% of South African Caucasian patient referrals. We identified a novel D270V mutation in the SLC40A1 gene in a Black South African female with iron overload. These mutations were absent in the control population. In Africans with iron overload not related to the HFE gene, the possible involvement of the SLC40A1 and CYBRD1 genes was demonstrated for the first time. This study confirms the genetic heterogeneity of haemochromatosis and highlights the significance of CYBRD1 mutations in relation to iron overload.

Adult↗
PubMedDate not supplied

A plasminogen activator inhibitor-1 promoter polymorphism and idiopathic interstitial pneumonia.

The normal fibrinolytic activity within the alveolar space is suppressed in fibrotic lung diseases in part because of increased levels of plasminogen activator inhibitor-1 (PAI-1). Studies with animals have shown that inhibition of the plasminogen system by PAI-1 increases the generation of pulmonary fibrosis. To determine if a similar relationship occurs in human fibrotic lung diseases, we took advantage of a polymorphism (4G/5G) that occurs in the promoter region of the human PAI-1 gene and influences the expression of PAI-1. We hypothesized that the 4G/4G genotype, because of its association with higher levels of PAI-1, would occur in patients with idiopathic interstitial pneumonia more frequently than in a control population. PAI-1 promoter genotype was determined in 88 well-characterized patients with idiopathic interstitial pneumonia consisting of 62 patients with usual interstitial pneumonia and 26 with nonspecific interstitial pneumonia. DNA was extracted from paraffin-embedded biopsy tissue and the genotype identified by polymerase chain reaction and restriction endonuclease digestion. We found that the distribution of PAI-1 genotypes in the idiopathic interstitial pneumonia population was similar to that of a large control population. However, subgroup analysis showed that patients with nonspecific interstitial pneumonia were more likely than the control population to have the promoter genotype (4G/4G) that is associated with higher levels of PAI-1. A similar pattern in PAI-1 polymorphism was not seen in the usual interstitial pneumonia subgroup. The results of this study support the conclusion that PAl-1 expression influences the development of nonspecific interstitial pneumonia in a similar manner to what occurs in animal models of pulmonary fibrosis. Patients with usual interstitial pneumonia did not show the same relationship with PAl-1 genotype.

Female↗
PubMed1991

Smoking cessation and nonsmoking intervals: effect of different smoking patterns on lung cancer risk.

A case-control study of lung cancer was conducted in northwestern Germany in 1985-86. The study included 194 lung cancer cases and the same number of hospital controls and population controls who were matched to the cases by sex and age. Personal interviews were conducted by trained interviewers. We report here the effect of different smoking patterns--such as nonsmoking intervals, and time since quitting smoking--on lung cancer risk. Both quitting smoking and having a nonsmoking interval are seen to reduce lung cancer risk significantly. For a nonsmoking interval of three years or more, relative risk (RR) = 0.21, 95 percent confidence interval (CI) = 0.08-0.52; for quitting smoking for 10 years or more, RR = 0.23, CI = 0.11-0.48). A dose-response relationship was estimated for cigarette dose, length of nonsmoking interval, and time since stopped smoking.

Adult↗
PubMed1995

Effects of warfarin therapy on plasma fibrinogen, von Willebrand factor, and fibrin D-dimer in left ventricular dysfunction secondary to coronary artery disease with and without aneurysms.

Cardiac impairment in patients is associated with intracardiac thrombus formation and thromboembolism. A high prothrombotic state may exist in such patients, and abnormalities in plasma markers of thrombogenesis may be indicative of such a state. The aim of this study was to determine the associations of left ventricular (LV) aneurysm formation and dysfunction with plasma fibrinogen, von Willebrand factor, and fibrin D-dimer, which are markers associated with thrombus formation (thrombogenesis) and to investigate the effects of warfarin given to patients with LV aneurysms on fibrinogen and D-dimer levels. A cross-sectional study of 112 patients with coronary artery disease was initially performed: 34 patients had normal LV function (group 1); 30 had LV dysfunction without aneurysm formation (group 2); 29 had LV aneurysms without anticoagulation (group 3a); and 19 patients had LV aneurysms with warfarin therapy (group 3b). Results were compared with 158 population controls from a random population sample. A longitudinal study of 10 patients given warfarin was also performed. In group 1, plasma fibrinogen (median difference 0.36 g/L; p = 0.0009) and von Willebrand factor (median difference 17 IU/dl; p = 0.04) were elevated, whereas plasma D-dimer levels (median difference 23.0 ng/ml; p = 0.001) were lower than those in population control subjects. There were no significant differences in plasma fibrinogen, von Willebrand factor, or D-dimer levels between groups 1 and 2. In group 3a, plasma fibrinogen was elevated when compared with group 1 (median difference 0.6 g/L; p = 0.0001), with a trend toward high von Willebrand factor levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1977

Association between leucocyte group-5a antigen and acute lymphoblastic leukaemia.

Leucocyte group 5 has two dominant alleles (5a and 5b) which segregate independently of the major histocompatibility complex. The group-5 system was studied in a Caucasian population of controls and patients with acute lymphoblastic leukaemia. The 5a gene frequency was 0-09 in 72 controls and 0-38 in 39 patients with acute lymphoblastic leukaemia (p less than 0-001). 15 patients with acute myelogenous leukaemia and 12 patients with aplastic anaemia had 5a and 5b frequencies similar to those seen in the control population. It is concluded that 5a or a closely linked gene is involved in susceptibility to acute lymphoblastic leukaemia.

Alleles↗
PubMed1989

Hearing threshold in patients with diabetes mellitus.

Hearing threshold of 30 diabetic patients and 30 healthy controls attending the medical outpatient department were determined using pure tone audiometry (Arphi Digital 900). All subjects were less than 50 years old. Subjects with otological and other metabolic diseases were excluded from the study. The patients were categorized into groups according to age, duration of disease, complications and control of diabetes. These observations were compared with those from the control subjects using appropriate statistical methods. It was found that diabetics had a poorer hearing threshold than the non-diabetics; all age groups with diabetes showed a significant high frequency hearing loss, as compared to the control population; poorly controlled and complicated diabetics have significant, high frequency hearing loss as compared to those who were well controlled and uncomplicated; there was no relationship between duration of the diabetes and the level of hearing loss.

Adolescent↗