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Results for “Correlation analysis”

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At least 91 records · Page 5Linked to original sources

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↗

PubMed1994

Brief interval heart period variability by different methods of analysis correlates highly with 24 h analyses in normals.

Heart period variability (HPV) measured from 24 h ECG recordings predicts mortality following myocardial infarction and may be a measure of cardiovascular health in the general population. Since epidemiologic evaluation of healthy people will require alternatives less intensive than 24 h recording, we investigated the relationship between HPV derived from 24 h and 5 min recordings, using two approaches for obtaining RR intervals. Template-matching (TM) algorithms were applied to 24 h ECG recordings from 41 normal subjects (mean age 35.7 +/- 13 years). Five min of ECG data during this 24 h period also were collected by an on-line microcomputer-based system for peak detection (PD) analysis. Intraclass correlations comparing the TM and PD approaches on the 5 min period were .80 or greater for all measures of HPV. Pearson correlation coefficients between the 5 min (TM) estimates and 24 h data and 5 min (PD) estimates and 24 h data exceeded .60 and .55, respectively, for all but one variable, with all p values < .05. Thus, in healthy adults, TM and PD approaches to HPV estimation from short segments of ECG data are highly consistent and the correlations between HPV obtained from brief intervals and 24 h measures were substantial, suggesting that assessment of HPV as a screening measure of cardiac autonomic control in healthy adults may be feasible.

Adult↗

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↗

PubMedDate not supplied

[Cross-correlation analysis of auditory neuron activity in response to acoustic clicks].

Cross correlation function relating the output spike train and the input puassoneous click trains were obtained for 213 single units located in the auditory midbrain center of the frog (Rana ridibunda). Five types of responses were found: type 1 (29 units) was due to polysynaptic unimodal excitation, type II (73 units) resulted from excitation followed by inhibition, type III (26 units) resulted from inhibition followed by excitation. In the IVth type (36 units) the excitation was preceded and followed by inhibition. The neurons of the Vth type had bimodal or trimodal correlation functions. The cross correlation functions allow to estimate the temporal shape of postsynaptic excitability changes and to reveal the inhibitory stimulus effects even for the units escaping spontaneous impulsation.

Animals↗

PubMed1983

A correlational analysis of symmetry between the arrowhead and featherhead Müller-Lyer illusions.

Correlational methods were used to investigate symmetry of effect for the arrowhead and featherhead versions of the Müller-Lyer figure. Two control figures were compared in the determination of baseline levels for measurement of the illusions: a shaft presented without any inducing context, and a shaft with vertical inducing lines attached. In addition, results based on difference-score measures of the illusions were contrasted with results obtained by partial-correlation techniques. Overall, when one considers the results for either one of the arrowhead or featherhead versions, the evidence favours a common underlying mechanism. However, results across the two versions suggest that the mechanisms for the two versions differ fundamentally. In weighting the different kinds of evidence contributing to this conclusion, methodological issues were raised. By obtaining two judgments for each stimulus figure from a large number of subjects, it was possible to demonstrate not only that conventional difference-score measures of illusions are highly unreliable, but also that they can yield biased results.

Adolescent↗

PubMedDate not supplied

[Cross-correlation analysis of spontaneous spike activity of neurons of the isolated cerebral cortex].

Correlation of neuronal impulse activity was studied in the visual and sensorimotor areas of the intact and chronically isolated rabbit cortex. Summate crosscorrelation function of neurones activity of the isolated cortex possess an a symmetrical bimodal form with positive significant deviations in both branches. Summate crosscorrelation function of cells activity in the intact cortex has a significant deviation only in the right branch. The possibility of transmission of excitation through the isolated and intact cortex is suggested and discussed.

Animals↗

PubMedDate not supplied

Correlative analysis of ethanol-related phenotypes in rat inbred strains.

As a summary presentation of the ethanol-related traits in the rat inbred strains, the responses to ethanol for various traits of the eight strains were analyzed. The intercorrelations among the means of the strains were computed and the interrelationships among the strain correlations were determined further by partial correlation and factor analysis. Sources of data on strain ethanol response included measures from laboratories of Drs. Deitrich, Li, Erickson, Pohorecky, and Tabakoff, who have participated in this joint study on the development of the rat heterogeneous stock (N/Nih). Although there are problems with estimating strain correlations from data collected in different laboratories, some informative associations among the ethanol-related traits were apparent. Genetic variation for behavioral and physiological responses to ethanol was indicated by the inbred strain distribution. The strains clearly differed in response to ethanol, with the mean of the National Institutes of Health stock falling intermediate within the range of the inbred strain distribution. For the ethanol-related traits considered jointly, an association between initial behavioral sensitivity, ethanol intake, and metabolism, as well as an association between development of tolerance, initial sensitivity, and several physiological measures, was suggested. Thus, the rat heterogeneous stock, a systematically outbred population, should provide a useful animal model with which to study the physiological basis for ethanol intake and preference, response to acute ethanol, and the development of tolerance.

Alcohol Drinking↗

PubMed1976

Correlation analysis of muscle spindle responses to single motor unit contractions.

1. Cross-correlation techniques have been used to study the responses of muscle spindle afferents from the soleus muscle of the cat to twitch contractions of single motor units. 2. Cross-correlograms (post-stimulus time histograms) were used to give the frequency of occurrence of a receptor spike at various times following the initiation of a motor unit contraction together with a display of the average twitch tension wave form. 3. The cross-correlograms revealed that the contraction of a single motor unit can be an effective stimulus to a spindle receptor and may induce afferent firing pattern alterations similar to those observed with whole muscle contraction. 4. The cross-correlograms also revealed quantitative differences in the response of a receptor to contraction of different motor units and to contraction of the same motor unit at different lengths. These differences reflect subtle changes in receptor deformation developed by the twitch of a motor unit under different conditions and by the twitches of different motor units. The results are consistent with anatomical data on the number and distribution of motor units and receptor organs in cat soleus. 5. These findings emphasize that rather than simply acting as generalized force or length sensors for the muscle as a whole, each receptor's spike train carries information about the state of a particular set of motor units.

Afferent Pathways↗

PubMed1980

[Correlation analysis of the conjugation tables].

The paper describes a method for determining the correlation of the frequency indices grouped in the conjugation tables. The main stages involve the calculation of Pirson's criterion, determination of confidential probability of the correlation coefficient by comparison of the calculated Pirson's criterion with the standard values, and calculation of the correlation coefficient. The latter may vary within 0-1 and characterizes the correlation strength.

Acute Disease↗

PubMed1981

A two-stage immunocytochemical method for oestrogen receptor analysis: correlation with morphological parameters of breast carcinomas.

An immunocytochemical method for oestrogen receptor (ER) analysis of breast carcinomas is described and compared with the dextran-coated charcoal (DCC) assay and a cytochemical method. The method described is superior to the purely cytochemical, especially in terms of sensitivity, demonstration of nuclear receptors and correlation with the DCC assay. The DCC assay is reliable except in the case of poorly cellular tumours: in these the immunocytochemical method is far superior, being independent of tumor cellularity. With this new method, lobular carcinomas are shown to be ER-rich compared with their ductal counterparts, a conclusion currently disputed, largely because methods employed mostly fail to take account of tumour cellularity. A combination of the DCC assay and the immunocytochemical method here described gives the maximum information about the ER-status of a particular carcinoma.

Adult↗

PubMed1995

Rigid-body motions of sub-units in DNA: a correlation analysis of a 200 ps molecular dynamics simulation.

A 200 ps molecular dynamics simulation of the B-form double stranded self-complementary octanucleotide d(CTGATCAG) is analyzed in terms of correlated motions using the canonical analysis approach. Each nucleotide is decomposed in three sub-units corresponding to the base, the sugar ring and the backbone respectively. The correlation between the full dynamics of two sub-units was found to decrease as their mutual distance increases. The interpretation of the full dynamics of sub-units as the superimposition of rigid-body motions (translation and orientation) and deformation shows that the main source of correlation is rigid-body motions. Correlation between sub-units deformation is weak and practically vanishes for sub-units belonging to non-adjacent nucleotides. It is also shown that the correlation is much more important for sub-units of the same strand than of opposite strands. We conclude that the internal dynamics of the octanucleotide may be well described by rigid-body motions, the sub-units deformation having only local influence whereas sub-units translation and rotation have repercussion to long distances. The results presented in this study suggest how the number of degrees of freedom may be reduced for simulating long-time dynamics of oligonucleotides.

Computer Simulation↗

PubMed1978

Correlation analysis of the physiological factors controlling fundamental voice frequency.

A technique has been developed to obtain a quantitative measure of correlation between electromyographic (EMG) activity of various laryngeal muscles, subglottal air pressure, and the fundamental frequency of vibration of the vocal folds (Fo). Data were collected and analyzed on one subject, a native speaker of American English. The results show that an analysis of this type can provide a useful measure of correlation between the physiological and acoustical events in speech and, furthermore, can yield detailed insights into the organization and nature of the speech production process. In particular, based on these results, a model is suggested of Fo control involving laryngeal state functions that seems to agree with present knowledge of laryngeal control and experimental evidence.

Acoustics↗

PubMed1976

[Correlation analysis in studying the mechanism of action of smooth muscle stimulants].

The presence of correlation between the value of the maximal effects of acetylcholine and other cholinomimetics, as well as serotonin, barium chloride and depolarizing solution was studied on an isolated strip of rat stomach. It was shown that the effect of acetylcholine closely correlated with the effects of other cholinomimetics, to a lesser degree with the effects of barium chloride and depolarizing solution, and least of all with the effect of serotonin. It is proposed to use the degree of this correlation to analyze the point of action of different drugs and processes of coupling the receptor stimulation with the observed effect. It was shown that the point of convergence of the ways of coupling of the three latter influences preceded the convergence of their common way with the way of coupling of the cholinomimetic effects.

Acetylcholine↗

PubMed1981

[Correlation analysis of coagulogram indices in stroke].

With the use of a "Minsk-32" computer correlations between expanded coagulograms taken from 850 patients with ischemic cerebral stroke and 146 patients with cerebral hemorrhage were analyzed. The statistical parameters of the coagulograms and the matrices of their pair correlation quotients were calculated separately in three groups of patients, i. e. under 45, 45 to 59 and 60 years of the age and older. It was found that it was the plasma tolerance of heparin, in combination with the plasma recalcification time, the fibrinogen content, the fibrinolytic activity and the thrombotest that were the most reliable tests for evaluating the hemocoagulation status and its changes in the process of anticoagulant and hemostatic therapy of the stroke. The correlations between the coagulogram parameters varied depending on the stroke type and the patients' age. This should be taken into consideration while instituting individualized therapy.

Age Factors↗

PubMed1986

Cross-correlation analysis of intracellularly recorded synaptic activities: an evaluation of the method through computer simulation.

Cross-correlation of 'spontaneous' synaptic activities intracellularly recorded from pairs of neurons may be used to detect shared synaptic input, which could remain hidden in the raw data by the non-synchronized postsynaptic potentials (PSPs); besides, if a normalized cross-correlation function is adopted, the fraction of synchronized activity may be quantitatively estimated. To evaluate power and limits of this method, computer-simulated synaptic activities of pairs of neurons, in which a given percentage of PSPs were simultaneous, were subjected to this type of analysis. It was shown that percentages of shared activities as low as 4% and in some cases 2% could be revealed, with a conspicuity which was influenced by the types of associated PSPs.

Action Potentials↗

PubMed1985

Cross-correlation analysis of thalamic neurons and EMG activity in parkinsonian tremor.

Bursting activity in cells cross-correlated with electromyographic (EMG) activity during parkinsonian tremor. Statistically significant evidence of cross-correlation was found for 49% of cells located at the lesion target for relief of tremor. Statistically significant correlation was found for 90% of cells having tremor frequency power greater than twice 'average power' at nontremor frequencies. This population of cells may be involved in the generation of parkinsonian tremor.

Electromyography↗