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PubMed1989

Effects of maternal discipline and nurturance on toddler's behavior and affect.

Oppositional behavior problems frequently begin in early childhood and remain stable over time. Correlational data point to the importance of parental discipline and nurturance in their development. This study investigated experimentally some of the hypotheses suggested by these correlational data. The effects of immediate, short, firm reprimands and delayed, long, gentle reprimands on transgressions and appropriate play were examined in the context of either high or low nurturant maternal interaction. Forty children (18-31 months) and their mothers participated. Children exposed to reprimands that were immediate, short, and firm transgressed significantly less often and exhibited more negative affect than those exposed to reprimands that were delayed, long, and gentle. The only effect of nurturance was on children's negative affect, with a high level of nurturance increasing negative affect when immediate, short, firm reprimands were delivered. The results indicate that the manner in which reprimands are delivered is critical in influencing children's misbehavior, but the role of nurturance during disciplinary situations is less clear.

Adult↗

PubMed1999

Altered respiratory epithelial cell cytokine production in cystic fibrosis.

BACKGROUND: Reports that lung inflammation in patients with cystic fibrosis (CF) might precede infection raise the possibility that the excessive inflammatory response in lungs of patients with CF might be directly related to defects in epithelial cell cystic fibrosis transmembrane regulator. OBJECTIVE: We sought to determine the relationship of epithelial cell cytokine production to CF lung disease. METHODS: Immunofluorescence and cultures of freshly obtained bronchial epithelial cells and ELISA for IL-10, IL-8, and IL-6 were used to study alterations in epithelial cell cytokine production. RESULTS: Fresh bronchial epithelial cells from healthy control subjects (HCs) secreted 98 +/- 20 pg/mL of the anti-inflammatory cytokine IL-10 when placed in primary culture in vitro but little or no IL-8 or IL-6. In contrast, fresh epithelial cells from patients with CF did not secrete detectable IL-10 but produced 38 +/- 17 pg/mL IL-8 and 40 +/- 17 pg/mL IL-6. These data correlated very well with the immunofluorescence data. The correlation between the immunofluorescent staining of fresh bronchial epithelial cells from both the HCs and patients with CF and the concentrations of cytokines in epithelial lining fluid suggests a reciprocal relationship between anti-inflammatory (IL-10) and proinflammatory (IL-6 and IL-8) cytokine production by the epithelial cells in HCs versus patients with CF. CONCLUSIONS: Alterations in epithelial cell cytokine production in the lungs of patients with CF may contribute to the excessive local inflammation.

Adolescent↗

PubMed1981

[Correlation of the quantitative ECG and echocardiogram indices in left ventricular hypertrophy according to correlational analysis data].

In 47 patients with arterial hypertension and clinicoroentgenological signs of hypertrophy of the left ventricle the echo- and electrocardiographic study (the McFee-Parungao system) was carried out. Highly significant (p less than 0.001) direct correlation was revealed between the index of the corrected ECG, such as sigma R x,y,z + + sigma S x,y,z and Rx + Sz with echocardiographic indices of mass r = +0.851 and +0.848, respectively, and the thickness of the left ventricle of the myocardium (r = +0.806 and +0.794, respectively). The above electrocardiographic indices do not correlate to the main echocardiographic indices of the contractile function of the left ventricle.

Cardiomegaly↗

PubMed2005

Processing of radical prostatectomy specimens for correlation of data from histopathological, molecular biological, and radiological studies: a new whole organ technique.

AIMS: To develop a method of processing non-formalin fixed prostate specimens removed at radical prostatectomy to obtain fresh tissue for research and for correlating diagnostic and molecular results with preoperative imaging. METHODS/RESULTS: The method involves a prostate slicing apparatus comprising a tissue slicer with a series of juxtaposed planar stainless steel blades linked to a support, and a cradle adapted to grip the tissue sample and receive the blades. The fresh prostate gland is held in the cradle and the blades are moved through the cradle slits to produce multiple 4 mm slices of the gland in a plane perpendicular to its posterior surface. One of the resulting slices is preserved in RNAlater. The areas comprising tumour and normal glands within this preserved slice can be identified by matching it to the haematoxylin and eosin stained sections of the adjacent slices that are formalin fixed and paraffin wax embedded. Intact RNA can be extracted from the identified tumour and normal glands within the RNAlater preserved slice. Preoperative imaging studies are acquired with the angulation of axial images chosen to be similar to the slicing axis, such that stained sections from the formalin fixed, paraffin wax embedded slices match their counterparts on imaging. CONCLUSIONS: A novel method of sampling fresh prostate removed at radical prostatectomy that allows tissue samples to be used both for diagnosis and molecular analysis is described. This method also allows the integration of preoperative imaging data with histopathological and molecular data obtained from the prostate tissue slices.

Biomedical Research↗

PubMed1995

How long can humans live? Lower bound for biological limit of human longevity calculated from Danish twin data using correlated frailty model.

How long can people live? Opinions of the researchers diverge and debates continue. Is there any systematic way to address this question? In this paper, we suggest an approach to the estimation of the biological limit of human longevity using survival data for twins from different zygocity groups. The approach is based on the genetic model of individual frailty. It combines ideas used in demography and survival analysis with methods of quantitative genetics and genetic epidemiology. The association between the life-spans of related individuals is described by the correlated frailty model of bivariate survival. A version of this model is used in order to estimate heritability of the individual frailty and to calculate the lower bound of human longevity. The limitations of this approach and directions of further research are discussed.

Aged↗

PubMed2004

Clinical effects of scaling and root planing in adults infected with Actinobacillus actinomycetemcomitans.

The periodontal pathogen Actinobacillus actinomycetemcomitans can frequently be isolated from subgingival plaque of adults with chronic inflammatory periodontal disease and individuals with plaque-induced gingivitis. Problems with the persistence of the organism after thorough debridement of root surfaces have been reported. In the present study clinical effects of the hygienic phase of periodontal therapy in ten adult patients with moderate or advanced periodontitis harbouring A. actinomycetemcomitans were analysed. Since proper analysis of highly correlated data within a given patient is crucial for appropriate interpretation, a major objective of this study was to compare the results of different models derived from logistic regression of clinical and microbiological factors on gain or loss of clinical attachment under different assumptions. Subgingival samples from every tooth present were obtained before and 6 weeks after thorough subgingival scaling, and selectively cultivated for the organism. A relevant gain of clinical attachment of 2 mm or more was observed at a total of 36% of periodontitis sites after scaling. Overall, loss of attachment of 2 mm or more was observed at 8% sites. Most loss occurred at sites with gingival enlargement (15%), whereas 3% periodontitis sites lost 2 mm or more. In multivariate analyses erroneously assuming either independence of data or correctly considering the correlated structure of observations attachment gain was mainly associated with deep probing depths at the outset. Presence or absence of A. actinomycetemcomitans before or after therapy was not included into the periodontitis models. Also, loss of attachment of 2 mm or more after subgingival scaling was not influenced by the organism. A direct comparison of the results obtained with both approaches of logistic regression may be helpful in the assessment of the influence of the magnitude of correlation of the data on the regression coefficients.

Actinobacillus Infections↗

PubMed2003

Prediction of in vivo tissue distribution from in vitro data. 3. Correlation between in vitro and in vivo tissue distribution of a homologous series of nine 5-n-alkyl-5-ethyl barbituric acids.

PURPOSE: To evaluate the ability to determine accurate in vivo tissue-to-unbound plasma distribution coefficients (Kpue) from in vitro data. METHODS: Fresh pieces of fifteen rat tissues/organs were incubated at 37 degrees C with a homologous series of nine barbiturates covering a wide range of lipophilicity (Log P 0.02 to 4.13). Steady-state in vivo Kpue values were estimated from the tissue and plasma concentrations following simultaneous dosing by constant rate i.v. infusion of all nine barbiturates. Drug concentrations in the tissues and media were determined by HPLC with UV or mass spectrometric detection. RESULTS: The pharmacokinetics of the barbiturate series following constant rate i.v. infusion indicated a range of clearance (0.49 to 30 ml x min(-1) x kg(-1)) and volume of distribution at steady state (0.51 to 1.9 l x kg(-1)) values. Good agreement was observed between the in vitro and in vivo Kpu values, although for the most lipophilic barbiturates the in vitro data underpredicted the in vivo tissue distribution for all tissues. CONCLUSION: The in vitro system for predicting the extent of in vivo tissue distribution works well for compounds of widely differing lipophilicity, although for the most lipophilic drugs it may result in an underprediction of in vivo values.

Animals↗

PubMed2006

The contribution of maximal force production to explosive movement among young collegiate athletes.

Critical to multidimensional sport conditioning is a systematic knowledge of the interactions between fitness components, as well as the transference relationships to performance. The purpose of this investigation was to examine the relationships between lower body muscular strength and several fundamental explosive performance measures. Fifty-four men and women collegiate athletes were tested to determine (a) lower-body muscular strength (1 repetition maximum barbell back squat), (b) countermovement vertical jump height and peak power output, (c) standing broad jump distance, (d) agility (cone T-test time), (e) sprint acceleration (m.s(-2)), and (f) sprint velocity (m.s(-1)). Analyses were performed using Pearson r correlations to examine these relationships. Partial correlations tested for relationships between performance measures while controlling for muscular strength. T-tests were performed to assess the difference between men and women. Correlation data demonstrated that significant (p < 0.01) strong linear relationships were indicated between muscular strength and power, as well as every sport-performance field tests. However, when controlling for strength with partial correlation, each of these relationships appreciably diminished. Significant differences (p < 0.05) were found between men and women for each of the performance tests. Muscular strength, peak power output, vertical jumping ability, standing broad jump, agility, sprint acceleration, and sprint velocity were all shown to be very highly related. Further examination demonstrated that body mass-adjusted muscular strength is more highly related to performance measures than is absolute muscular strength. Current correlation data provide a quantified look at the interaction between muscular fitness components, as well as the transfer relationship to several athletic-specific performance measures.

Adolescent↗

PubMed1992

[Seminal vesicles: echographic findings in 244 subjects. Evaluation of anatomic data and correlations with pathologic prostatic-vesicular parameters].

Over a 2-year period (1989-90), about 400 cases were examined (out of nearly 2,500 US examinations of the prostate), 244 of which had subsequent bioptic, surgical or autoptic confirmation. This paper reports the anatomic, clinical and pathologic data relative to the seminal vesicles of 244 subjects who underwent transrectal US of the prostate for different clinical indications. Our biometric values were slightly different from those reported in literature, the latter being based on autoptic findings. Agenesis and monolateral ectopia were confirmed to be extremely rare: 4 cases only (1.6%) in our series. A typical finding was the nearly perfect symmetry; in size and structure, of the two seminal vesicles in the same subject; as a matter of fact, a loco-regional pathologic condition was detected in all the patients (14) with asymmetry. A hundred per cent agreement was observed between the US patterns of the seminal vesicles and the prostatic patterns in case of acute/subacute prostatic inflammation involving also the 2 glands: this parameter can be used to follow the clinical course of the inflammatory process.

Adult↗

PubMed1988

Significance testing for correlated binary outcome data.

Multiple logistic regression is a commonly used multivariate technique for analyzing data with a binary outcome. One assumption needed for this method of analysis is the independence of outcome for all sample points in a data set. In ophthalmologic data and other types of correlated binary data, this assumption is often grossly violated and the validity of the technique becomes an issue. A technique has been developed (Rosner, 1984) that utilizes a polychotomous logistic regression model to allow one to look at multiple exposure variables in the context of a correlated binary data structure. This model is an extension of the beta-binomial model, which has been widely used to model correlated binary data when no covariates are present. In this paper, a relationship is developed between the two techniques, whereby it is shown that use of ordinary logistic regression in the presence of correlated binary data can result in true significance levels that are considerably larger than nominal levels in frequently encountered situations. This relationship is explored in detail in the case of a single dichotomous exposure variable. In this case, the appropriate test statistic can be expressed as an adjusted chi-square statistic based on the 2 X 2 contingency table relating exposure to outcome. The test statistic is easily computed as a function of the ordinary chi-square statistic and the correlation between eyes (or more generally between cluster members) for outcome and exposure, respectively. This generalizes some previous results obtained by Koval and Donner (1987, in Festschrift for V. M. Joshi, I. B. MacNeill (ed.), Vol. V, 199-224.(ABSTRACT TRUNCATED AT 250 WORDS)

Biometry↗

PubMed1990

Noise correlations in data simultaneously acquired from multiple surface coil arrays.

Multiple images acquired simultaneously from an array of surface coils can be combined to give a composite image with an improved signal-to-noise ratio (SNR) and a large field of view. The composite images' SNR can be optimized by taking advantage of noise correlations between coils and phase shifts induced by surface coil reception. Methods are derived for making optimal composite images with uniform noise or with uniform sensitivity. A simplified model is used to provide an intuitive understanding of the interaction of noise correlation and phase shift phenomena.

Humans↗

PubMed1985

Regression analysis of data with correlated errors: an example from the NHLBI twin study.

Epidemiologic studies often involve genetically related individuals, spouses, or repeat observations on the same individual. When regression analysis is required in such studies, significant correlation of the residuals may affect the estimates of the standard errors of the regression coefficients. Ordinary least squares may not provide the best (minimum variance) estimates of the regression coefficients. Generalized least squares (weighted least squares) is more appropriate when the covariance matrix of the errors is known or can be estimated with some degree of confidence. Data from a twin study of pulmonary function were analyzed by three different regression techniques and comparisons of the coefficients and standard errors are made to illustrate the potential effects of correlated errors.

Age Factors↗

PubMed1999

Robustness of the latent variable model for correlated binary data.

The marginal regression model offers a useful alternative to conditional approaches to analyzing binary data (Liang, Zeger, and Qaqish, 1992, Journal of the Royal Statistical Society, Series B 54, 3-40). Instead of modelling the binary data directly as do Liang and Zeger (1986, Biometrika 73, 13-22), the parametric marginal regression model developed by Qu et al. (1992, Biometrics 48, 1095-1102) assumes that there is an underlying multivariate normal vector that gives rise to the observed correlated binary outcomes. Although this parametric approach provides a flexible way to model different within-cluster correlation structures and does not restrict the parameter space, it is of interest to know how robust the parameter estimates are with respect to choices of the latent distribution. We first extend the latent modelling to include multivariate t-distributed latent vectors and assess the robustness in this class of distributions. Then we show through a simulation that the parameter estimates are robust with respect to the latent distribution even if latent distribution is skewed. In addtion to this empirical evidence for robustness, we show through the iterative algorithm that the robustness of the regression coefficents with respect to misspecifications of covariance structure in Liang and Zeger's model in fact indicates robustness with respect to underlying distributional assumptions of the latent vector in the latent variable model.

Algorithms↗

PubMedDate not supplied

Correlation of Risser sign and bone age determination in adolescent idiopathic scoliosis.

At the present, there appears to be a lack of unanimity in the choice of whether the Risser sign (iliac apophysis maturation) or determination of skeletal maturation by bone age roentgenograms is the more accurate indicator of maturity in adolescent idiopathic scoliosis. In an effort to clarify this issue, the authors correlated data from 111 patients to determine the relationship between accuracy of Risser sign and bone age determinations performed during similar chronologic intervals. Data from bone age determinations were then correlated with Risser sign data, and a regression line statistical determination was made. The iliac crest apophysis maturation was statistically significantly (p less than 0.01) correlated with data retrieved by skeletal age assessment.

Adolescent↗

PubMed1990

Zidovudine sensitivity of human immunodeficiency viruses from high-risk, symptom-free individuals during therapy.

Human immunodeficiency type 1 isolates from 18 initially symptom-free men who were treated with zidovudine for 2 years were investigated for drug sensitivity. At the start all the men had persistent core antigenaemia; the acquired immunodeficiency syndrome developed in 6 during the study. The polymerase chain reaction was used to detect mutations at residue 215 of reverse transcriptase, a mutation associated with reduced drug sensitivity. After 2 years 16/18 isolates were mutant. However, after about 6 months of treatment the mutation was detected in only 7 isolates, 4 from individuals who subsequently had AIDS. Limited direct virus sensitivity data correlated with the genetic data. The rate of appearance of the 215 mutation seemed to correlate with CD4 counts and viral virulence.

CD4 Antigens↗

PubMed1977

[Exercise test after myocardial infarct. Correlations with data of coronary angiography and ventriculography].

The authors have studied the exercise test carried out at least three months (3-6 months: 52 cases; greater than 6 months: 48 cases) after myocardial infarction in the anterior position (50 cases), in the "inferior" position (42 cases), and of a diffuse type (8 cases), in patients who were taking no treatment which might interfere with interpretation of the test. For the anterior infarctions there was a good correlation between ST elevation (J max greater than or equal to 1 mm, or better than the sun of the J greater than or equal to 2 mm) and the presence of severe involvement of the left ventricle. A depressed ST segment beyond the area of necrosis corresponds to a stenosis greater than or equal to 75 p. 100 in 36 p. 100 of cases. In inferior infarctions, the correlation between ST elevation and left ventricular involvement is also specific but less sensitive. ST depression outside the area of necrosis corresponds to a stenosis greater than or equal to 75 p. 100 in 66 p. 100 of cases; it is then lateral, but may extend as far as V2. They also indicate a mirror image, especially when the depressed area slopes upwards, and is localised in V2-V3. The other changes which were found have no practical application.

Adult↗

PubMedDate not supplied

Nutrient conversions by photosynthetic bacteria in a concentrated animal feeding operation lagoon system.

A diurnal examination was conducted to determine the effect of photosynthetic bacteria on nutrient conversions in a two-stage concentrated animal feeding operation (CAFO) lagoon system in west-central Oklahoma. Changes in nutrients, microbial populations, and physical parameters were examined at three depths (0, 1.5, and 3.0 m) every 3 h over a 36-h period. The south lagoon (SL) was anaerobic (dissolved oxygen [DO] = 0.09 +/- 0.12 mg/L) while the north lagoon (NL) was facultative (DO ranged from 4.0-0.1 mg/L over 36-h period). Negative sulfide-sulfate (-0.85) and bacteriochlorophyll a (bchl a)-sulfate (-0.83) correlations, as well as positive bchl a-sulfide (0.87) and light intensity (I)-bchl a (0.89) correlations revealed that the SL was dominated by sulfur conversions driven by the photosynthetic purple sulfur bacteria (PSB). The correlation data was supported by diurnal trends for sulfate, sulfide, and bchl a. Both nitrogen and sulfur conversions played a role in the NL; however, nitrogen conversions appeared to dominate this system because of the activity of cyanobacteria. This was shown by positive chlorophyll a (chl a)-I (0.91) and chl a-nitrate (0.98) correlations and the negative correlation between ammonium and nitrite (-0.88). Correlation data was further supported by diurnal trends observed for chl a, DO, and ammonium. For both lagoons, the dominant photosynthetic microbial species determined which nutrient conversion processes were most important.

Animals↗

PubMed2004

The use of Markov chain Monte Carlo for analysis of correlated binary data: patterns of somatic cells in milk and the risk of clinical mastitis in dairy cows.

Two analytical approaches were used to investigate the relationship between somatic cell concentrations in monthly quarter milk samples and subsequent, naturally occurring clinical mastitis in three dairy herds. Firstly, cows with clinical mastitis were selected and a conventional matched analysis was used to compare affected and unaffected quarters of the same cow. The second analysis included all cows, and in order to overcome potential bias associated with the correlation structure, a hierarchical Bayesian generalised linear mixed model was specified. A Markov chain Monte Carlo (MCMC) approach, that is Gibbs sampling, was used to estimate parameters. The results of both the matched analysis and the hierarchical modelling suggested that quarters with a somatic cell count (SCC) in the range 41,000-100,000 cells/ml had a lower risk of clinical mastitis during the next month than quarters <41,000 cell/ml. Quarters with an SCC >200,000 cells/ml were at the greatest risk of clinical mastitis in the next month. There was a reduced risk of clinical mastitis between 1 and 2 months later in quarters with an SCC of 81,000-150,000 cells/ml compared with quarters below this level. The hierarchical modelling analysis identified a further reduced risk of clinical mastitis between 2 and 3 months later in quarters with an SCC 61,000-150,000 cells/ml, compared to other quarters. We conclude that low concentrations of somatic cells in milk are associated with increased risk of clinical mastitis, and that high concentrations are indicative of pre-existing immunological mobilisation against infection. The variation in risk between quarters of affected cows suggests that local quarter immunological events, rather than solely whole cow factors, have an important influence on the risk of clinical mastitis. MCMC proved a useful tool for estimating parameters in a hierarchical Bernoulli model. Model construction and an approach to assessing goodness of model fit are described.

Animals↗