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Results for “Correlation analysis”

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PubMed1992

Platelet aggregation in spontaneous hypertension: genetic determination and correlation analysis.

OBJECTIVE: Hyper-responsive platelets are often found in essential hypertension. It has also been suggested that in hypertensive patients platelets may serve as an easily accessible indicator of abnormalities in contractile cell function. To test these suggestions, we analysed the relationship between platelet aggregation and genetic hypertension in the rat. METHODS: Linear regression analysis of mean values of recombinant inbred strains was used to evaluate the relationship between blood pressure and ADP-induced platelet aggregation. RESULTS: ADP-induced platelet aggregation in platelet-rich plasma in spontaneously hypertensive rats (SHR) was significantly decreased compared with in normotensive Brown Norway (BN) rats. However, in recombinant inbred strains, derived from (SHR x BN) F2 hybrids, correlation analysis revealed that platelet aggregation and blood pressure are independent traits. CONCLUSIONS: The present results suggest strongly that spontaneous hypertension and platelet hypo-aggregability in SHR were linked together by chance due to drift during selective inbreeding. The absence of a correlation between the two traits also indicates that alterations in platelet function in essential hypertension, often found in population-based studies, may have to be reaffirmed in genetically better-defined situations, e.g. by pedigree analysis.

Animals↗

PubMed1990

[Correlation analysis of pulmonary shunt after resection the lung].

Thirty-three patients with performed thoracotomy and lung resection were studied by measuring changes in shunting after they had undergone the breathing of 100% O2 for 20 minutes during the operative procedure and the immediate postoperative period. The obtained values of the shunt were compared with those in the preoperative period by making a correlative analysis, with a view to examining whether the shunt values and hypoxemia during the operation and the postoperative period could be foreseen on the basis of data on the preoperative shunt. The shunt was calculated from the following equation: Qs/Qt = CcO2--CaO2/CaO2--CvO2.

Adult↗

PubMed1986

Temporal relationship of the pulsatile fluctuation of luteinizing hormone and progesterone in cattle: a time series cross-correlation analysis.

The temporal relationship between the pulsatile patterns of plasma luteinizing hormone (LH) and progesterone (P4) was studied in mid-luteal (ML) and early-pregnant (EP) dairy cows. Blood samples were collected (via external jugular vein cannulae) at 10-min intervals for 16 h in 5 ML cows (d 10 to 12 of the cycle) and for 10 h in 5 EP cows (d 52 to 56 of gestation). Concentrations of LH and P4 were determined by radioimmunoassays and a time series cross-correlation analysis was utilized to evaluate the temporal relationship between them. A pulsatile pattern was found for both hormones in both groups, and in all animals LH peaks were uniformly followed by P4 peaks. In 80% of the cows in both groups the highest cross-correlation occurred between samples LH(n) and P4 (n + 1) (n = sample number), suggesting that a lag time of about 10 min is necessary for luteal stimulation. Results from both groups demonstrate that P4 is released from the corpus luteum in a pulsatile manner and that its release is at least partially dependent upon the pulsatile pattern of plasma LH. Correlation coefficients between LH and P4 mean level, basal levels, peak frequencies and peak amplitudes obtained in both groups indicate that the conceptus alters the hypothalamic-pituitary-ovarian relationship found in the ML cows, suggesting the existence of another factor(s) acting along with LH to release P4 in EP cows.

Animals↗

PubMed1979

Canonical correlation analysis: potential for environmental health planning.

There is a challenging need to identify the relationships between environmental quality and health status. It may be especially important to be able to isolate key variables which can be consolidated into a few indices of environmental conditions as they are related to health. Such indices might be used to identifying associations among groups of variables, such as specific geographic area. The indices may also provide insights into environmental health relationships which are worthy of further epidemiological investigation. Canonical correlation analysis is a multivariate statistical technique which provides a means of identifying associations among groups of variables, such as health and environmental measures. The technique can produce weighted indices of environmental conditions as they are related to health within a city or region. This paper describes what canonical correlation is, and outlines how it might be used for these purposes. An illustrative application based on data collected for Philadelphia, Pennsylvania is also presented.

Aged↗

PubMed1977

A correlational analysis of the effects of surgical transections of three components of the MFB on ingestive behavior and hypothalamic, striatal, and telencephalic amine concentrations.

A retractable wire knife was used to transect medial or lateral components of the MFB or its lateral projections to the striatum and amygdaloid complex. All cuts produced significant depletions of NE, DA, and 5-HT from telencephalon and striatum but little or no effect on hypothalamic NE or 5-HT. Two of our cuts resulted in aphagia and adipsia, the third in hyperphagia and obesity. A detailed correlational analysis of the magnitude and direction of the behavioral and biochemical consequences of our cuts indicated that the ingestive behavior of all of our experimental animals (including animals which had been aphagic and adipsic after surgery as well as animals which were hyperphagic and obese) was positively correlated with the concentration of DA in striatum and telencephalon and negatively correlated with telencephalic 5-HT. Less consistent evidence for facilitatory noradrenergic influences on food intake was also obtained. Our results suggest that the regulation of food intake may be the result of an interaction between telencephalic serotonergic mechanisms and dopaminergic pathways which exert opposite effects on ingestive behavior.

Animals↗

PubMed1986

Quantitation of staining for amyloid in histological sections: sources of variation, correlation analysis, and interstain reproducibility.

Five pathologists estimated with point counting the amount of amyloid in heart muscle autopsy samples from 19 patients who suffered from amyloidosis. The serial sections had been stained with 5 different methods. The different variation sources involved in a quantitative study on amyloid and the interstain reproducibility between the results given by these 5 stains were analyzed. The volume fractions of amyloid after different stains were subjected to correlation analysis. In our test system about a third (34%) of the variation was due to the point counting method. Sirius red had the lowest and Congo red the highest variation due to point counting, since Sirius red gave the most intense staining and highest volume fractions for amyloid. The volume fractions were lowest in Congo red. About 40% of the total variation was composed of the field variation. This variation includes the variation due to variation between fields, field selection and subjective intraobserver variation. Sirius red showed the smallest field variation in respect to the total variation. Congo red, on the other hand, had the highest variation. The variation caused by pure interobserver variation is presented by the difference between total variation and the calculated field variation. This was largest with Sirius red and smallest with Congo red. The pure interobserver variation accounted for about 26% of the total variation. The high reproducibility with Sirius stain is most probably due to the high volume fractions of positively stained material after this stain, not to low interobserver variation. Congo red seems to have low interobserver variation. The senior pathologists were more reliable in measuring the amyloid deposits than the junior pathologists as suggested by interstain reproducibility and variation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amyloid↗

PubMed1977

Design, synthesis, and correlation analysis of 7-substituted 4-hydroxyquinoline-3-carboxylic acids as inhibitors of cellular respiration.

Fifteen 7-substituted 4-hydroxyquinoline-3-carboxylic acids have been designed to minimize covariance between the physicochemical substituent parameters: pi, MR, and sigmap. The molecules have been synthesized and evaluated for their ability to inhibit the respiration of Ehrlich ascites cells as a whole cell model and for their ability to inhibit malate dehydrogenase as an intracellular target enzyme model. Correlation analysis indicates that ascites cell inhibition is linearly related to pi and that malate dehydrogenase inhibition is linearly related to MR.

Animals↗

PubMed1976

Causal priority of social desirability over self-concept: a cross-lagged correlation analysis.

The study examined the causal relationship between social desirability (SD) and self-concept (SC). Two self-report instruments--Crandall's Children's Social Desirability Scale and the Piers-Harris Children's Self-Concept Scale--were administered before and after a 9-month therapeutic treatment designed to enhance self-concept. Subjects were 57 upper elementary pupils in a laboratory research school. Three hypotheses were proposed: (a) There is a positive correlation between SD and SC; (b) SD is more stable across time than SC; and (c) SD is causally prior to SC. Cross-lagged panel correlation analysis supported all three hypotheses. Discussion centers on a causal explanation of the distorting effect of SD upon SC scores.

Child↗

PubMed1995

Contributions of facial morphology, age, and gender to EMG activity under biting and resting conditions: a canonical correlation analysis.

Theoretical studies suggest that facial morphology may confer a mechanical advantage to particular individuals during force production, but not during rest. However, prior studies on the relationship between facial morphology and EMG suffer from various methodological limitations. We examined the hypothesis that facial morphology variables contribute significantly and meaningfully to the variance in masticatory muscle EMG when subjects produce specific levels of interocclusal force, but not when subjects are at rest. Measures of facial morphology included gonial angle, ramus height, and maxillary height, as determined from lateral cephalograms. EMG data were obtained from surface electrodes placed on masseter and temporalis sites. Subjects (N = 96) sat in a darkened, sound-attenuated room while they watched a seven-minute segment of a movie. EMG activity obtained during the last two minutes was used as a baseline period. Using the central incisors, subjects then provided five different force levels ranging from 6.5 to 48 lb in random order on a bite-force device while EMG data were collected. A canonical correlation analysis, performed on the set of predictor variables (age, gender, and facial morphology measurements) and the set of criterion variables (EMG data), showed a significant canonical correlation between the two variable sets while biting, but not at rest. Age, but not the facial morphology variables, was highly related to the canonical variate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Time-correlation analysis of simulated water motion in flexible and rigid gramicidin channels.

Molecular dynamics simulations have been done on a system consisting of the polypeptide membrane channel former gramicidin, plus water molecules in the channel and caps of waters at the two ends of the channel. In the absence of explicit simulation of the surrounding membrane, the helical form of the channel was maintained by artificial restraints on the peptide motion. The characteristic time constant of the artificial restraint was varied to assess the effect of the restraints on the channel structure and water motions. Time-correlation analysis was done on the motions of individual channel waters and on the motions of the center of mass of the channel waters. It is found that individual water molecules confined in the channel execute higher frequency motions than bulk water, for all degrees of channel peptide restraint. The center-of-mass motion of the chain of channel waters (which is the motion that is critical for transmembrane transport, due to the mandatory single filing of water in the channel) does not exhibit these higher frequency motions. The mobility of the water chain is dramatically reduced by holding the channel rigid. Thus permeation through the channel is not like flow through a rigid pipe; rather permeation is facilitated by peptide motion. For the looser restraints we used, the mobility of the water chain was not very much affected by the degree of restraint. Depending on which set of experiments is considered, the computed mobility of our water chain in the flexible channel is four to twenty times too high to account for the experimentally measured resistance of the gramicidin channel to water flow. From this result it appears likely that the peptide motions of an actual gramicidin channel embedded in a lipid membrane may be more restrained than in our flexible channel model, and that these restraints may be a significant modulator of channel permeability. For the completely rigid channel model the "trapping" of the water molecules in preferred positions throughout the molecular dynamics run precludes a reasonable assessment of mobility, but it seems to be quite low.

Gramicidin↗

PubMed1992

Examination of fungi in domestic interiors by using factor analysis: correlations and associations with home factors.

Factor analysis was utilized to investigate correlations among airborne microorganisms collected with Andersen samplers from homes in Topeka, Kans., during the winter of 1987 to 1988. The factors derived were used to relate microbial concentrations with categorical, questionnaire-derived descriptions of housing conditions. This approach successfully identified groups of common aboveground decay fungi including Cladosporium, Alternaria, Epicoccum, and Aureobasidium spp. The common soil fungi Aspergillus and Penicillium spp. were also separated as a group. These previously known ecological groupings were confirmed with air sampling data by a quantitative evaluation technique. The aboveground decay fungi sampled indoors in winter were present at relatively high concentrations in homes with gas stoves for cooking, suggesting a possible association between these fungi and increased humidity from the combustion process. Elevated concentrations of the soil fungi were significantly (P = 0.05) associated with the dirt floor, crawl-space type of basement. Elevated concentrations of water-requiring fungi, such as Fusarium spp., were shown to be associated with water collection in domestic interiors. Also, elevated mean concentrations for the group of fungi including Cladosporium, Epicoccum, Aureobasidium, and yeast spp. were found to be associated (P = 0.03) with symptoms reported on a health questionnaire. This finding was consistent with our previous study of associations between respiratory health and airborne microorganisms by univariate logistic regression analysis.

Air Microbiology↗

PubMed1992

[Correlation analysis between plasma atrial natriuretic peptide and cardiac function in blood deficiency syndrome].

The function of ANP in the cardiovascular regulation is very similar with the TCM theory of "the Heart governs blood circulation". Using the method of cardiac impedance to check cardiac output and the method of radioimmunoassay (RIA) to check plasma ANP, the result showed that in the status of Blood Deficiency Syndrome, cardiac function was impaired, there were reduced kinemia and stroke volume, as well as markedly raised plasma ANP and peripheral resistance. The above-mentioned indexes were significantly different from those of normal group (P < 0.01). Using multivariate regression analysis, cardiac output was negatively correlated with the plasma ANP (P < 0.05). 23 cases with Blood Deficiency Syndrome showed normal hemoglobin, but an evidently changed cardiac output and plasma ANP were closely related with the level of the Blood Deficiency. Both parameters might serve as the objective basis to reflect the level of Blood Deficiency to facilitate the clinical diagnosis of the patient.

Adult↗

PubMed2025

A generalized higher-order correlation analysis framework for multi-omics network inference.

Multiple -omics (genomics, proteomics, etc.) profiles are commonly generated to gain insight into a disease or physiological system. Constructing multi-omics networks with respect to the trait(s) of interest provides an opportunity to understand relationships between molecular features but integration is challenging due to multiple data sets with high dimensionality. One approach is to use canonical correlation to integrate one or two omics types and a single trait of interest. However, these types of methods may be limited due to (1) not accounting for higher-order correlations existing among features, (2) computational inefficiency when extending to more than two omics data when using a penalty term-based sparsity method, and (3) lack of flexibility for focusing on specific correlations (e.g., omics-to-phenotype correlation versus omics-to-omics correlations). In this work, we have developed a novel multi-omics network analysis pipeline called Sparse Generalized Tensor Canonical Correlation Analysis Network Inference (SGTCCA-Net) that can effectively overcome these limitations. We also introduce an implementation to improve the summarization of networks for downstream analyses. Simulation and real-data experiments demonstrate the effectiveness of our novel method for inferring omics networks and features of interest.

Genomics↗

PubMed1995

[Correlation analysis of lipids and apolipoproteins in plasma HDL, LDL and VLDL of normal subjects and endogenous hypertriglyceridemics].

The linear correlation and multiple stepwise regression analysis of lipids and apolipoproteins in plasma, HDL, LDL and VLDL of 20 normal subjects and 20 patients with endogenous hypertriglyceridemia was made. The result of simple factor analysis showed that there was a positive correlation of TG and VLDL TG with apoC II, C III, E, LDL apoB100 and VLDL apoC II, C III, E, B100; and a negative correlation with HDL apoA I. HDL-C was related positively with apoA I, HDL apoA I, C III and negatively with apoC III, E, LDL apoB100 and VLDL apoB100, C II, C III, E. TC was correlated positively with apoB100 and LDL apoB100. The result of multiple factor analysis showed that apoC III, E, B100/A I, VLDL apoC III and HDL apo C II, E, C II/C III, among 20 factors, were main factors which were related with TG. Apo C III, VLDL apoC III and LDL apoB100 were main factors which affected VLDL TG. ApoB100, and C II were main apolipoproteins which were related with TC; while the main apolipoproteins which affected HDL-C were apoA I, HDL apoA I, C II, VLDL apoE, HDL apoA II, the significance of the results is discussed.

Apolipoproteins↗

PubMed1986

Detection of clonal excess in lymphoproliferative disease by kappa/lambda analysis: correlation with immunoglobulin gene DNA rearrangement.

Previous studies have suggested that analysis of the distribution of surface immunoglobulin light chain isotypes by flow cytometry provides evidence for monoclonality of B cell tumors and may detect populations of circulating tumor cells in patients with lymphoproliferative disease. We have used simultaneous flow cytometry and DNA restriction enzyme analysis on 58 samples of tissue and blood to determine whether lymphocyte populations detected by "kappa/lambda" analysis are indeed monoclonal. In greater than 90% of cases, abnormalities detected by flow cytometry correlated with monoclonal rearrangements of immunoglobulin genes as detected by Southern blot analysis. By analyzing tissue and blood from the same patients, we have also demonstrated that monoclonal circulating cells detected by flow cytometry reflect peripheral circulating tumor cells, since DNA from these cells shows the same immunoglobulin rearrangement as DNA from the original tumors in these patients. Although mixing studies suggested that DNA rearrangement studies were more sensitive than was flow cytometry in detecting minor populations of monoclonal lymphocytes, we found only one case in which this affected the diagnostic accuracy of the kappa/lambda analysis, with one notable exception, that of detection of a monoclonal proliferation of B cells that did not express surface immunoglobulin. The kappa/lambda test thus offers a powerful diagnostic tool in the evaluation of lymphoproliferative disease.

DNA↗

PubMed1979

Correlational analysis of speakers' heights, weights, and temporal speech features.

Correlation coefficients on height, weight, and temporal features were computed separately for 15 female and 15 male speakers. With only one exception, speakers' heights and weights were not significantly correlated with their temporal characteristics. Implications of these findings and suggestions for future research are discussed.

Adolescent↗

PubMedDate not supplied

[A spectral-correlational analysis of the EEG of the neocortex in the rabbit in a state of thirst].

Summate electrical activity of the rabbit neocortex during formation of drinking excitation was studied by means of mathematical analysis. It is shown that the change of the electrical activity depends on the level of drinking excitability created by various duration of water deprivation (24-48 h) and is expressed in a generalized lowering of potentials amplitude without frequency change. Spectro-correlative EEG analysis showed that lowering of spectrum power took place within the whole analyzed frequencies range. Besides, an increase took place of interconnections of the cortical electrical processes, estimated by coherence function. It may by suggested that the manifested reconstruction of spectro-correlative characteristics of the neocortical biopotentials reflects a formation of motivational excitation establishing optimal level of cortex functioning.

Animals↗

PubMed1992

The Rationality/Emotional Defensiveness Scale--II. Convergent and discriminant correlational analysis in males and females with and without cancer.

The psychological correlates of the Rationality/Emotional Defensiveness Scale and its two subscales were examined in 1236 males and 863 females from the Western Collaborative Group Study. An additional 157 males and 164 females with some form of cancer other than of the skin were also included in this analysis. Characteristics measured included self-reported emotional control, anger expression, trait personality, depressive and neurotic symptomatology, Type A behavior, hostility, and social desirability. Results indicate that the Rationality/Emotional Defensiveness Scale is most strongly related to the suppression and control of emotions, especially anger. Scores on this scale also tend to be associated with less Type A behavior and hostility and with more social conformity. Analysis of the component subscale suggests that Antiemotionality, i.e. the extent to which an individual uses reason and logic to avoid interpersonally related emotions, is most strongly marked by the control of anger, while Rationality, i.e. the extent to which an individual uses reason and logic as a general approach to coping with the environment, is related to the control of anxiety and a higher level of trait curiosity. The psychological interpretation of the scale appears to be largely invariant across gender, unaffected by residualization of the total scale score for its association with Social Desirability, and, except for a few minor instances, unrelated to the diagnosis of cancer.

Aged↗