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PubMed2005

Whole-genome association studies on alcoholism comparing different phenotypes using single-nucleotide polymorphisms and microsatellites.

Alcoholism is a complex disease. As with other common diseases, genetic variants underlying alcoholism have been illusive, possibly due to the small effect from each individual susceptible variant, gene x environment and gene x gene interactions and complications in phenotype definition. We conducted association tests, the family-based association tests (FBAT) and the backward haplotype transmission association (BHTA), on the Collaborative Study of the Genetics of Alcoholism (COGA) data provided by Genetic Analysis Workshop (GAW) 14. Efron's local false discovery rate method was applied to control the proportion of false discoveries. For FBAT, we compared the results based on different types of genetic markers (single-nucleotide polymorphisms (SNPs) versus microsatellites) and different phenotype definitions (clinical diagnoses versus electrophysiological phenotypes). Significant association results were found only between SNPs and clinical diagnoses. In contrast, significant results were found only between microsatellites and electrophysiological phenotypes. In addition, we obtained the association results for SNPs and microsatellites using COGA diagnosis as phenotype based on BHTA. In this case, the results for SNPs and microsatellites are more consistent. Compared to FBAT, more significant markers are detected with BHTA.

Alcoholism↗
PubMed2000

A simple test of association for contingency tables with multiple column responses.

Loughin and Scherer (1998, Biometrics 54, 630-637) investigated tests of association in two-way tables when one of the categorical variables allows for multiple-category responses from individual respondents. Standard chi-squared tests are invalid in this case, and they developed a bootstrap test procedure that provides good control of test levels under the null hypothesis. This procedure and some others that have been proposed are computationally involved and are based on techniques that are relatively unfamiliar to many practitioners. In this paper, the methods introduced by Rao and Scott (1981, Journal of the American Statistical Association 76, 221-230) for analyzing complex survey data are used to develop a simple test based on a corrected chi-squared statistic.

Agriculture↗
PubMed2000

Hyperinsulinemia during oral glucose tolerance test is associated with increased neointimal tissue proliferation after coronary stent implantation in nondiabetic patients: a serial intravascular ultrasound study.

OBJECTIVES: The purpose of this study was to determine whether hyperinsulinemia during the oral glucose tolerance test is associated with increased neointimal tissue proliferation after coronary stent implantation in nondiabetic patients. BACKGROUND: Although hyperinsulinemia induces increased vascular smooth muscle cell proliferation in experimental models, it has not been determined whether hyperinsulinemia is associated with increased neointimal tissue proliferation after coronary stent implantation. METHODS: Serial (postintervention and six-month follow-up) intravascular ultrasound (IVUS) was used to study 67 lesions treated with Palmaz-Schatz stents in 55 nondiabetic patients. Cross-sectional images within stents were taken at every 1 mm, using an automatic pullback, and a neointimal index was calculated as the ratio between the averaged neointimal area and averaged stent area. All patients underwent a 75-g oral glucose tolerance test. Plasma glucose (PG) and immunoreactive insulin (IRI) levels were measured at baseline and 1 and 2 h after the glucose load. The sum of PGs (sigmaPG) and the sum of IRIs (sigmaIRI) were calculated. Body mass index (BMI), lipid levels, and glycosylated hemoglobin levels were measured. RESULTS: There were 27 patients with normal glucose tolerance, and 28 patients with impaired glucose tolerance (IGT). The neointimal index in patients with IGT was greater than that in patients with normal glucose tolerance (42.9 +/- 14% vs. 24.9 +/- 8.3%, respectively, p < 0.0001). Linear regression analysis showed that the neointimal index at follow-up correlated well with sigmaPG (p < 0.0001), fasting IRI (p < 0.0001), sigmaIRI (p < 0.0001), triglyceride level (p = 0.018), and BMI (p < 0.0001). Multiple regression analysis revealed that sigmaIRI (p = 0.0002) and sigmaPG (p = 0.0034) were the best predictors of the greater neointimal index at follow-up. CONCLUSIONS: Serial IVUS assessment shows that hyperinsulinemia during an oral glucose tolerance test is associated with increased neointimal tissue proliferation after coronary stent implantation in nondiabetic patients.

Aged↗
PubMed2004

Testing the association between thyroid dysfunction and psychiatric diagnostic group in an iodine-deficient area.

OBJECTIVE: To test the association between thyroid dysfunction and psychiatric diagnostic group in a large sample of consecutive patients, while controlling for the effects of age, sex, medication and concomitant medical conditions. METHODS: We compared the distribution of psychiatric diagnostic groups according to the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10), and of selected psychopathological symptoms in 100 newly admitted psychiatric patients who had genuine thyroid disease and 92 psychiatric patients who had nonspecific alterations of thyroid function with the corresponding items for the whole group of admitted patients (n = 1134) during the observation period. This analysis was then repeated using an age-matched and sex-matched comparison group selected from all admitted patients in a random order. RESULTS: When all admitted patients were considered, the presence of a genuine thyroid disorder was associated with the diagnosis of a mood disorder (ICD-10 category F3). This effect was no longer detectable when the age-matched and sex-matched comparison group was used, indicating a simple effect of these 2 variables. Nonspecific alterations of thyroid-stimulating hormone (TSH) were associated with the ICD-10 diagnostic group F4 (neurotic, stress-related and somatoform disorders), with demographic variables being similar in this subgroup to those of all admitted patients. These patients also tended to display more symptoms of a mild depressive syndrome. When only patients with nonspecifically decreased TSH concentrations were tested, these findings could not be reproduced. Nonspecifically decreased concentrations of thyroxine and free thyroxine index were found significantly more often in the diagnosis group F1 (mental disorder due to substance use), reflecting results for alcohol-dependent patients. This result could not be replicated using an age-matched and sex-matched control group. CONCLUSION: In newly admitted psychiatric patients with genuine thyroid disease, there was no notable association of thyroid disease and major psychiatric diagnostic groups according to ICD-10, especially depression. This argues against the hypothesis of thyroid disorders being a major risk factor for psychiatric illnesses. Nonspecific alterations of TSH were more frequently seen in patients of diagnostic group F4 and with mild depressive syndromes, possibly representing an altered influence of stress-regulating systems on thyroid function.

Adolescent↗
PubMed1979

Dimensions of Picture Identification Test need associations.

To find a simple and more general structure for need association matrices obtained from Picture Identification Test (PIT) results, PIT need association matrices of eight college student groups were analyzed by INDSCAL, a multidimensional scaling technique. A common three dimensional structure was found. Based on the scale locations of the 22 needs, the dimensions were labeled the Combative, the Personal, and the Competitive dimensions. The INDSCAL model was used as a target for six other comparison groups including male and female English college students, male addicts and controls, and male delinquents and controls. There was enough similarity between the dimensional structure of the need associations of the comparison and target groups to assume that all groups shared the same basic structure of need associations. There were enough differences, however, to suggest that personality characteristics of groups may be related to deviations in the associative structure of their motivation systems. Applications of the techniques to clinical and personality evaluations of groups and individuals were discussed.

Journal Article↗
PubMed2005

Genetic variation of infant reduced folate carrier (A80G) and risk of orofacial defects and congenital heart defects in China.

PURPOSE: This study was designed to investigate whether the risks of congenital heart defects (CHD) and orofacial defects were influenced by a polymorphism of the offspring's RFC1 or by an interaction between the RFC1 gene and maternal periconceptional use of folic acid. METHODS: A case-control study was conducted. A total of 82 families with a child affected by cleft lip with or without cleft palate (CLP), 67 families with a child-affected by CHD, and 100 nonmalformed control families were genotyped using PCR-RFLP. RFC1 G allele was tested through family-based association test. RESULTS: Among mothers who did not use folic acid, the risks of 4.03 (95% CI = 1.33-12.77) for the G80/G80 genotype and 4.14 (95% CI = 1.06-16.82) for the G80/A80 genotype were observed relative to the A80/A80 genotype for CHD offspring. In family-based association tests (FBAT), offspring carrying the G allele for RFC1 is at increased risk for CHD (Z = 2.140, p < .05). No significant association was found between either RFC1 genotype or maternal folic acid supplementation and the risks of CLP. CONCLUSIONS: Our findings suggest that the RFC1 G allele is likely to be an important candidate gene in folate transport and to be associated with risk for CHD. This study found modest evidence for a gene-nutrient interaction between offspring RFC1 genotype and periconceptional intake of folic acid on the risk of congenital heart defects.

Case-Control Studies↗
PubMed1982

Associative thinking in schizophrenia: a contextualist approach.

Explored the question of whether responses that appeared to be highly pathological on the basis of the word association test did indeed reflect an underlying aberrant associative process or whether the associations actually had a greater degree of meaning than was evident from the test (N = 60). Utilizing contextualist techniques designed by the authors, which were analogous to the word association test but yet measured schizophrenic associative thinking in specific contexts that more closely approximated natural language situations, the quality and purposiveness of the schizophrenics' associations were examined. The word association test technique was judged to be inadequate by itself to account for underlying associative processes involved in schizophrenic associative thought disorder. A majority of responses (70% schizophrenic, 81% nonschizophrenic) judged to be pathological on the basis of the word association test alone became meaningful in the context of a sentence created by the Ss to explain purposively their associations. The schizophrenics' experience of a stimulus word and consequent associations to that word became clearer when placed within an appropriate context (i.e., a sentence), rather than examined as isolated semantic features (as in the word association test).

Adult↗
PubMed2001

Factors associated with testing for hepatitis C in an internet-recruited sample of men who have sex with men.

BACKGROUND: Nearly 4 million individuals in the United States (1.8%) have been infected with hepatitis C virus, yet few are aware of their infection. GOAL: To identify correlates associated with hepatitis C virus testing among a sample of men who have sex with men. STUDY DESIGN: Internet communications were used for solicitation and collection of data, using a 31-question survey. RESULTS: When the study was restricted to men who have sex with men in the United States (n = 381), 95% of the respondents (n = 361) reported at least one risk factor for hepatitis C virus transmission, 39% of these respondents (n = 140) reported having been tested for hepatitis C virus. Testing was associated with a history of nonsexual risk behavior, increased knowledge of the hepatitis C virus, and healthcare provider communication. CONCLUSION: A significant proportion of at-risk respondents had not been tested. Interventions are needed to increase hepatitis C virus knowledge in the community of men who have sex with men, and to encourage providers to communicate about hepatitis to the men in this group who screen as high risk on the basis of their risk behaviors.

Adolescent↗
PubMed2003

Use of max and min scores for trend tests for association when the genetic model is unknown.

In case-control studies, the Cochran-Armitage (CA) trend test is powerful for detection of an association between a risk allele and a marker. To apply this test, a score should be assigned to the genotypes based on the genetic model. When the underlying genetic model is unknown, the trend test statistic is a function of the score. In this paper, simple procedures are given to obtain two scores (max and min), which respectively maximize and minimize the CA trend test statistics for genetic associations. These two scores can be used to examine the effect of the choice of scores on the test of no association. When the CA trend test statistic with the max (or min) score is less (or greater) than a prespecified value, the conclusion is clear: we will accept (or reject) the null hypothesis of no association for any scores used. When this value is less than the CA trend test statistic with the max score but greater than the one with the min score, the decision of whether or not to reject the null hypothesis depends on the choice of scores. In this situation, the CA trend test with a prespecified score cannot be used without careful scientific justification of the choice of scores. The use of max and min scoring schemes is applied to a real data set.

Case-Control Studies↗
PubMedDate not supplied

A modification of the relocation test: arthroscopic findings associated with a positive test.

Thirteen overhand-throwing athletes who failed at least 3 months of physical therapy while restricted from throwing and who demonstrated a positive modified relocation test at 90 degrees, 110 degrees, and/or 120 degrees were clinically and arthroscopically examined. On arthroscopic examination, all patients demonstrated articular surface pathology. Eleven patients had fraying of the undersurface of the rotator cuff, and 10 patients had fraying of the posterosuperior labrum. With 90 degrees shoulder abduction, 8 patients had rotator cuff contact with the posterosuperior labrum. When the shoulder was abducted to 110 degrees, all patients demonstrated such contact. At 120 degrees of abduction, 12 patients revealed contact. The presence or absence of pain during the modified relocation test correlated with the presence or absence of cuff contact with the posterosuperior labrum 79% of the time. Six patients had a positive modified relocation test at all levels of abduction. These patients included 2 with SLAP lesions, 1 with a Bankart lesion, and 1 with a complete tear of the rotator cuff.

Adult↗
PubMed1997

[Semantic dimensions of vocabulary for emotional concepts].

The present paper analyzes the semantic features of positive and negative emotion names. In a pretest the 12 most typical positive rated emotion names were selected by means of a free listing of 70 Ss. These 12 items were presented to 42 Ss as stimulus words for a free association test. From this association data overlap coefficients were computed and analyzed by means of nonmetric multidimensional scaling. It was possible to fit the features "Soziale Nähe-Soziale Distanz" (social distance) und "Körperhaftigkeit" (Quality of body feeling) in the two-dimensional euclidian solution. In the same way as described above, an experiment was carried out with 11 negative emotion names. In this case it was possible to fit in the same two features and the feature "Aktivation" (activation).

Adult↗
PubMed2000

Removing the sampling restrictions from family-based tests of association for a quantitative-trait locus.

One strategy for localization of a quantitative-trait locus (QTL) is to test whether the distribution of a quantitative trait depends on the number of copies of a specific genetic-marker allele that an individual possesses. This approach tests for association between alleles at the marker and the QTL, and it assumes that association is a consequence of the marker being physically close to the QTL. However, problems can occur when data are not from a homogeneous population, since associations can arise irrespective of a genetic marker being in physical proximity to the QTL-that is, no information is gained regarding localization. Methods to address this problem have recently been proposed. These proposed methods use family data for indirect stratification of a population, thereby removing the effect of associations that are due to unknown population substructure. They are, however, restricted in terms of the number of children per family that can be used in the analysis. Here we introduce tests that can be used on family data with parent and child genotypes, with child genotypes only, or with a combination of these types of families, without size restrictions. Furthermore, equations that allow one to determine the sample size needed to achieve desired power are derived. By means of simulation, we demonstrate that the existing tests have an elevated false-positive rate when the size restrictions are not followed and that a good deal of information is lost as a result of adherence to the size restrictions. Finally, we introduce permutation procedures that are recommended for small samples but that can also be used for extensions of the tests to multiallelic markers and to the simultaneous use of more than one marker.

Alleles↗
PubMed1981

A Mantel-Haenszel statistic for testing the association between a polychotomous exposure and a rare outcome.

The Mantel-Haenszel statistic has been designed to test the association between two dichotomous variables using information from several 2 x 2 tables. This statistic is extended here for incidence data on a rare outcome arising at two or more levels of an exposure variable. When there are only two levels of exposure the statistic is reduced to the one suggested earlier by Miettinen. The relationship between degree of urbanization and female laryngeal cancer is studied as an example.

Epidemiologic Methods↗
PubMed2004

Cytokine gene polymorphisms in ischaemic heart disease: investigation using family-based tests of association.

Atherosclerosis has an inflammatory basis, with cytokines, cellular adhesion molecules and pro-inflammatory cells having important roles in the initiation and progression of this process. Interleukin (IL) 6, IL-10 and transforming growth factor (TGF) beta1 have been proposed as important modulators of the atherosclerotic process, with IL-6 having a pro-inflammatory, atherogenic effect and IL-10 and TGF-beta1 having anti-inflammatory, protective roles. The possible role of functional polymorphisms in the promoter regions of the IL-6, IL-10 and TGF-beta1 genes in the susceptibility to ischaemic heart disease (IHD) was investigated in a well-defined Irish population using two recently described family-based tests of association. We genotyped 1,012 individuals from 386 families with at least one member prematurely affected with IHD. Using the combined transmission disequilibrium test (TDT)/sib-TDT and the pedigree disequilibrium test, no association between any of the IL-6 -174G/C, IL-10 -1082G/A and TGF-beta1 -509C/T polymorphisms and IHD was found. Our data demonstrate that, in an Irish population, these polymorphisms are not associated with IHD.

Cytokines↗
PubMed1991

Using log-linear models to test for associations among congenital malformations.

Log-linear models can be used to test for pairwise associations and higher order interactions among anatomically distinct birth defects or congenital malformations. A log-linear model, including terms for every possible pairwise association among seven severe and easily detectable congenital malformations, was examined using data on 16,217 infants registered in the Metropolitan Atlanta Congenital Defects Program between 1968 and 1986. The resulting model showed clear patterns of strong association between some congenital malformations and not others, and the presence of 3-way interaction terms where the association between two malformations depended on the presence of a third. Examining a more parsimonious log-linear model showed overlapping patterns of pairwise association involving anal-rectal atresia and omphalocele, anal-rectal atresia and limb deficiency, and anal-rectal atresia and tracheaesophageal fistula. A second common pattern involved a triangular cluster with a hierarchical relationship among the three malformations (where there was a strong association between the first and second malformations and between the first and third malformations, but the association between the second and third was only seen in the absence of the first). Three such overlapping triangular clusters were identified from these data: neural tube defects, oral clefts, and omphalocele; neural tube defects, oral clefts, and limb deficiency; and limb deficiency, diaphragmatic hernia, and neural tube defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed2006

Visual association memory test in differentiating early stage of Alzheimer's disease from vascular dementia.

We studied the results of the Visual Association Memory Test (VAMT) in differentiating Alzheimer's disease (AD) and vascular dementia (VaD). In addition, other basic neuropsychological tests, including the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR) were also used. Generally, with the VAMT, AD patients had a worse performance than VaD patients. Particularly among patients with a CDR = 0.5, the AD patients had statistically significantly lower VAMT scores (score less than 3) (p = 0.026) compared to those of VaD patients. However, the VAMT could not predict clinical severity or disease progression. The VAMT, as revealed in this study, is a brief, simply administered, and less biased test, and may offer a diagnostic adjunct to differentiate AD from VaD especially in an early dementia state.

Aged↗
PubMed1994

A serological survey for bovine immunodeficiency-like virus in Ontario dairy cattle and associations between test results, production records and management practices.

A chemiluminescence Western blot analysis (WBA) for detecting antibovine immunodeficiency-like virus (BIV) antibodies, had good repeatability. The test was subsequently applied to a bank of serum samples from 928 adult cows from 265 herds in Ontario; the number of cows sampled within each herd ranged from 1 to 13. The overall prevalence of anti-BIV antibodies among cows was 5.5% with a 95% confidence interval of 4.2% to 7.2%. In contrast, 18.1% of herds had at least one reactor among cows tested, resulting in a herd-prevalence confidence interval of 13.8% to 23.4%. These estimates of prevalence were in the same range as previous reports from the US and Europe. Bovine immunodeficiency-like virus may have a worldwide distribution. Unfortunately, BIV test sensitivity and specificity are difficult to estimate because virus isolation is inefficient. Therefore, the apparent prevalences could not be adjusted for test sensitivity and specificity, to estimate the true prevalence of infection. The serum samples had previously been tested for antibodies to bovine leukemia virus (BLV). There were no significant associations between BIV and BLV test results. Least squares regression was used to investigate potential associations between BIV test results and selected production indices.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Husbandry↗