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Assessment and correlation between clinical patterns, disability and health-related quality of life in patients with low back pain.

AIM: Low back pain (LBP) is the main symptom of most lumbar spine diseases. This symptom, due to physical, psychological and social factors, is correlated to a real disability which can affect the quality of life (QoL.) The aim of this study is to evaluate the QoL and the disability in patients with LBP and to correlate them to clinical patterns. METHODS: In this prospective multidimensional study, 108 patients underwent the following protocol: 1. collection of patient-oriented and disability data with the use of SF-36 and North American Spine Society (NASS); 2. collection of clinical, anamnestic and instrumental data (MRI, CT) with the use of DOVAC files; 3. assessment of disability with the use of Barthel index (BI) and deambulation index (DI). RESULTS: A significant correlation was found between the BI and the physical composite score (PCS), but no significant correlation was noticed between BI and the mental composite score (MCS). DI was not correlated to the SF-36. A positive Lasegue and the absence of the osteo-tendinous reflexes are significantly correlated to the disability and QoL. CONCLUSIONS: This study shows that there is no simple, linear correlation between QoL and disability.

Acute Disease↗

Correlations between two plaque indices in assessment of toothbrush effectiveness.

BACKGROUND: The Rustogi et al. Modified Navy (RMNPI) and Turesky et al Modification of the Quigley Hein (TQHPI) plaque indices are commonly used to measure plaque removal. This study evaluated the possible correlations of both indices using data relative to a single use assessment of plaque removal using commercially available toothbrushes. METHODS: Single use crossover study designs have been previously reported. Disclosed plaque was scored pre- and post-brushing using both the RMNPI and the TQHPI. Sixty subjects, with an initial mean RMNPI score of 0.6 or greater, were enrolled and completed the study. No minimum score was required for TQHPI. After the initial scoring, the order for each index was randomized so that each subject was scored with either RMNPI followed by TQHPI or vice versa. Two manual toothbrushes [Oral-B CrossAction (CA) and Colgate Navigator (NA)] and one battery-powered brush (Crest SpinBrush Pro) (SBP) were evaluated in the trial. One examiner performed all clinical measurements. Pearson correlations were performed on whole mouth, buccal, and lingual plaque scores for the CA toothbrush. RESULTS: Strong positive correlations were found between the two plaque indices for pre- and post-brushing scores for the whole mouth and on lingual and buccal surfaces, where Pearson correlation coefficients ranged between 0.963 and 0.995. There was no correlation between the pre-brushing plaque score and the amount of plaque removed by brushing indicating that higher plaque levels before brushing do not necessarily predict that greater amounts of plaque will be removed during toothbrushing. Each toothbrush was found to be safe and significantly reduced plaque levels after a single brushing (t-test, p=0.0001). Significantly greater plaque reductions were found with the CA than the NA and SBP toothbrushes at whole mouth, lingual, and approximal surfaces for both indices (analysis of variance (ANOVA), p < or = 0.0002 for all comparisons). CONCLUSIONS: Strong positive correlations were found between two plaque indices (the RMNPI and TQHPI) for pre- and post-brushing scores at whole mouth, lingual, and buccal surfaces as assessed using data from a single use assessment of plaque removal. Efficacy data from this study demonstrated the CA toothbrush provided superior cleaning when compared to the NA manual toothbrush and SBP battery toothbrush. CLINICAL IMPLICATIONS: Two commonly used indices for assessing plaque removal in clinical studies are RMNPI and TQHPI. However, each index differs in the way plaque is scored. This study used both indices to assess comparative toothbrush efficacy and showed a strong correlation between indices for both pre- and post- brushing plaque scores. The result suggests that both indices demonstrate sufficient sensitivity to differentiate toothbrush efficacy.

Adolescent↗

[Evaluation of the determination of seminal ACP and gamma-GT activities and correlation between seminal ACP or gamma-GT activity and semen parameters].

OBJECTIVE: To evaluate the determination of seminal acid phosphatase (ACP) and gamma-glutamyltranspeptidase (gamma-GT) activity, and analyze the correlation between seminal ACP or gamma-GT and semen parameters. METHODS: ACP and gamma-GT activities in 133 samples of seminal plasma were measured. Two of the samples were randomly selected for intra-assay, one for the detection of ACP activity and the other for gamma-GT activity. And another four were selected the same way for the same purpose, two for the detection of ACP activity and the other two for gamma-GT activity. The semen volume, pH, sperm concentration, motility, and grade-a and -b motility were analyzed by CASA system and so were the correlation between seminal ACP or gamma-GT activity and semen parameters. RESULTS: There was significant positive correlation between ACP and gamma-GT activities (r = 0.570, P = 0.000). The intra-CV of ACP was 13.72%, and inter-CVs of ACP were 13.80% and 15.49%. The intra-CV of gamma-GT was 7.68%, and inter-CVs of gamma-GT were 7.76% and 9.73%. Both seminal ACP and gamma-GT activities had significant negative correlation with pH (r = -0.330, P = 0.000 vs r = - 0. 388, P = 0.000). There was obvious correlation between gamma-GT activity and sperm concentration (r = 0.165, P = 0.045), but not between ACP activity and sperm concentration (r = 0.048, P = 0.546). Neither of seminal ACP and gamma-GT activity was correlated with sperm motility, grade-a and -b motility, semen volume, abstinence time and age. CONCLUSION: The precision of the measurement of gamma-GT activity in seminal plasma was higher than that of ACP. The correlation between seminal gamma-GT activity and semen parameters was similar to that between seminal ACP activity and semen parameters. Thus, the determination of gamma-GT activity was a more reliable marker than that of ACP activity for the evaluation of prostate function.

Acid Phosphatase↗

Correlation of tests for detection of Borrelia burgdorferi sensu lato infection in patients with diagnosed borreliosis.

A group of 180 patients with diagnosed Lyme borreliosis were examined for the presence of infection with Borrelia burgdorferi sensu lato (B. burgdorferi s.l.) by serologic tests with B. burgdorferi s.l. antigens (IgM-ELISA, IgG-ELISA, IgM-immunoblot, IgG-immunoblot) and by polymerase chain reaction (PCR, nested-PCR) for detection of B. burgdorferi s.l. DNA in peripheral blood. A total of 61.7 %, 53.9 %, 62.2 %, and 59.4 % of the examined patients' sera showed positive or borderline results in the serologic tests IgM-ELISA, IgG-ELISA, IgM-immunoblot, and IgG immunoblot, respectively. The results of the tests IgM-ELISA and IgM-immunoblot were significantly correlated (p < 0.001). A higher degree of the correlation (p < 0.000001) was found at the comparison of results obtained with IgG-ELISA and IgG-immunoblot. The correlation between the positive findings in the IgM-ELISA and detection with IgM-immunoblot the diagnostically important B. burgdorferi s.l. OspC surface protein was relatively low but statistically significant (0.01 < p < 0.05). Much higher correlation was found between the positive findings in the IgG-ELISA and detection with IgG-immunoblot other diagnostically important B. burgdorferi s.l. antigen, the VlsE protein (p < 0.000001). The presence of B. burgdorferi s.l. DNA was found by PCR in 20 out 180 examined blood samples (11.1 %). No correlation was found to exist between the PCR results and the results of any of the serologic tests for detection of anti B. burgdorferi s.l. antibodies of IgM class. PCR results correlated significantly at a relatively low level (0.01 < p < 0.05) with the results of IgG-ELISA, but not with the results of IgG-immunoblot with regard to total reactions (0.2 < p < 0.1). By contrast, a distinctly significant correlation was found between the PCR results and detection of the VlsE protein with IgG-immunoblot (0.001 < p < 0.01). In conclusion, the results of the present study suggest that antibodies of IgG class are the most reliable marker in laboratory diagnostics of Lyme borreliosis, in particular those directed against VlsE surface protein of Borrelia burgdorferi sensu lato.

Adult↗

Serial changes of pulse wave velocity and correlations with hemodynamic parameters during general anesthesia.

BACKGROUND: Increased pulse wave velocity (PWV) is a marker of increased arterial stiffness and is correlated with cardiovascular mortality and mortality of all causes in the elderly and in patients with essential hypertension and type 2 diabetes. There is also a positive correlation between PWV and arterial blood pressure. The changes of PWV in response to general anesthesia and surgical stimulation remain unclear. The aim of this study was to continuously monitor the PWV, blood pressure and heart rate, and to assess their correlations during general anesthesia in women receiving gynecologic surgery. METHODS: The values of PWV were obtained from calculation of the finger-to-toe distance divided by the transit time using dual-channel photoplethysmography system. The values of PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were recorded before anesthesia induction, 5 min before incision, at incision, in continuation for at least 30 min thereafter, and 5 min after discontinuation of sevoflurane. The correlations between PWV and SBP, DBP and heart rate during the general anesthesia were analyzed using Pearson's correlation test. RESULTS: The serial records of PWV and hemodynamic parameters showed that PWV, SBP, DBP, and heart rate decreased after induction of anesthesia. SBP and DBP increased after surgical incision. There was a trend of progressively declining of PWV and DBP during the general anesthesia but SBP and heart rate remained stationary. All the values of PWV, SBP, DBP, and heart rate increased after discontinuation of anesthesia. There were significant correlations between PWV and SBP (r = 0.4558, P < 0.0001), between PWV and DBP (r = 0.2719, P < 0.0001), between PWV and pulse pressure (r = 0.2067, P < 0.0001), and between PWV and mean arterial pressure (r = 0.3969, P < 0.0001). CONCLUSIONS: We could evaluate the serial changes of PWV in response to general anesthesia and surgical stimulation using a simple and noninvasive dual-channel photoplethysmography system. The value of PWV, an index of arterial stiffness, has significant correlation with arterial blood pressure.

Adult↗

Correlates of external research support among respondents to the 1990 American Federation for Clinical Research survey.

To identify correlates of external funding for research, a mail survey of the membership of the American Federation for Clinical Research was conducted. Data were collected from 2,642 respondents on research training environment, current work environment, current sources and amounts of external research support, and probability of remaining in research. Respondents reported that they worked 62.4 +/- 20.4 hours per week, and that their dominant activities were research (37% of time), clinical responsibilities (20%), teaching (15%), and administration (13%). Nearly two-thirds reported some external research funding, including 1,371 (52%) individuals who received support as principal investigators from federal agencies. In multivariate analyses, the probability of having federal or nonprofit foundation support was positively correlated with the number of hours per week devoted to research, the number of grants submitted in the previous two years, the amount of research training during fellowship, and the presence of PhD degree recipients in the research training environment; and negatively correlated with the number of hours per week of clinical, teaching, and administrative activities, and having a PhD degree. In contrast, corporate support was positively correlated with the number of hours of total work per week, but negatively correlated with the amount of time currently devoted to research. Respondents who reported that their probability of remaining in research was decreasing had fewer months of research training, greater clinical responsibilities, and less external research support. We conclude that federal and nonprofit foundation support but not corporate support are positively correlated with the adequacy of research training and the amount of time currently devoted to research, and negatively correlated with clinical responsibilities.

Data Collection↗

[Clinical methods for evaluating infarct size and its anatomic correlations. Study carried out in 193 cases. III. Comparison of data on the evaluation of the infarct size using the QRS score and a method of maximal creatine kinase determination in the serum].

AIMS: To compare two methods concerning the clinical evaluation of infarct size--one using a QRS score, the other based on peak Ck values--applied to the same population. CONCEPT AND PLACE OF THE STUDY: to determine--based on previously established correlations between a QRS score and the anatomic total infarct size on one hand, and between the peak CK values and the anatomic recent infarct size on the other hand--which myocardial infarction subgroup constitutes the best indication for each method. The study took place in a Coronary Care Unit of a Central Hospital. MATERIAL AND METHODS: 193 patients who died successively of acute myocardial infarction through out 4 years were studied. After establishing the exclusion critéria, the QRS score was calculated according to the method of Selvester modified by Wagner, and peak CK values were evaluated. Infarct size, either recent or old, was determined by means of an anatomical method developed by the authors and based on Hackel's and Alonso's previous works. Correlations were established between data from each clinical method and those from the anatomical method. Several myocardial infarction subgroups were considered for comparison of the correlations found in each subset. RESULTS AND CONCLUSIONS: As long as QRS score was regarded, significant correlations were found between the evaluation by QRS score and anatomical infarct size in the subgroups of patients with severe pump failure, prior myocardial infarction, or total loss of ventricular muscle mass of at least 20 percent; however, a significant correlation was missing when the whole myocardial infarction group was taken into consideration. When peak CK value were considered, a weak significant correlation was found between the evaluation by enzyme determination and anatomical infarct size in the whole group of patients, but a stronger correlation was present in the subgroups of patients with survival longer than 24 hours, anterior wall myocardial infarction, free wall cardiac rupture, or first acute myocardial infarction. In conclusion the choice of the method to be used in the clinical evaluation of infarct size should take into account the type of population beeing studied, and follow the results obtained in different myocardial infarction subgroups as mentioned above.

Creatine Kinase↗

Correlative investigations of craniospinal anatomy and pathology with computed tomography, magnetic resonance imaging and cryomicrotomy.

A correlative computed tomographic-anatomic method was applied to multiplanar anatomic studies. The method was particularly valuable for comparative anatomic investigations of complex regions of the central nervous system. The description of CT and MR anatomy in this thesis is based either on direct CT-anatomic correlation of the same specimen, or on indirect MR-anatomic correlation with cryosectional images from cadavers. In sagittal partial saturation MR images with short repetition times, the pituitary fossa in 41 normal volunteers appeared inhomogeneous. A postero-inferiorly located high intensity signal correlated with an intrasellar fat pad in sagittal cryosectional images. The height of the pituitary gland in 38 normal volunteers was usually less than 8 mm and its upper surface was flat or concave. The cavernous sinus anatomy was studied in coronal and axial MR planes in seven normal volunteers and 15 patients in correlation with cryosectional images. The intracavernous cranial nerves were best shown in the coronal plane, in partial saturation and inversion recovery sequences and displayed as foci of high signals intensity. MR signs of a parasellar mass included obliteration of intracavernous venous spaces, displacement of the intracavernous portion of the internal carotid artery and bulging of the lateral wall of the cavernous sinus. The topographic anatomy of the cervical neuroforamina was investigated in axial, sagittal, coronal and oblique planes in a correlative CT-anatomic investigation in 19 specimens. In four normal volunteers, the surface coil MR images of the cervical neuroforamina were correlated with cryosectional images. Surface coil MR images in a plane perpendicular to the cervical nerve roots allowed to determine their relationship to intraforaminal structures and the boundaries of the foramen. The dorsal and ventral nerve roots were demonstrated with both CT and MRI. They were located in the lower half of the foramen at and below the intervertebral disc space. The dorsal nerve roots were in contact with the superior articular process. The ventral nerve roots abutted the uncinate process and the inferior portion of the foramen. In a biomechanical cervical spinal trauma study, experimental fractures were studied with CT in axial and sagittal planes. Sagittal anatomic images showed the fractures and soft tissue injuries. Non-displaced and horizontal fractures were generally difficult to detect on axial CT scans alone. In two pathologic spine specimens CT scans in axial, sagittal and coronal planes were compared with reformatted scans and cryosectional images. Direct CT images revealed four cervical spinal fractures whereas the reformatted images only showed one displaced pedicle fracture.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

On the properties of maximum likelihood estimators of familial correlations under variable sibship size.

Selected distributional properties of the maximum likelihood estimator and its z-transformation of three familial correlations (parental, parent-offspring, filial) were investigated numerically for the case of nuclear families with variable sibship size. This investigation was based on six different sets of the three correlations, and four different sample sizes, defining 24 sampling conditions, which were replicated 1,000 times each. It was found that the distributional properties of the correlation estimator are affected by the magnitude of the correlations even in large samples although approximate normality is achieved locally. Fisher's z-transformation, here used only in its interclass form, achieves reduction of skewness, stabilization of variance, and approach to normality already in small samples, except for the filial correlation (where it may be deemed inappropriate) in smaller samples. For both the correlation estimator and its z-transformation, the (estimated) relative efficiency was shown to be high (better than 90% in most sampling conditions), suggesting that the estimated minimum variance bound is a satisfactory estimator of the sampling variance. It is concluded that the maximum likelihood estimation of familial correlations under variable sibship size is feasible and, when prudently applied, especially in the form of their z-transformations, provides an appropriate method in analyses of family studies.

Family Characteristics↗

[Correlations between masticatory performance in chewing gum method and occlusion as well as dento-facial morphology].

In order to examine the characteristics of the chewing gum masticatory test, the amount of sugar elution, the chewing time and the amount of sugar elution per second were measured in 109 young adults (93 males and 16 females), after 70 strokes of mastication. Their sex differences, differences among various occlusions, correlations with occlusal areas of the buccal teeth and correlations with roentgen cephalometrics were analyzed. 1. There was no sex difference in the amount of sugar elution. However, chewing time was shorter and the amount of sugar elution per second was higher in males than in females. 2. Compared with the normal occlusion group, the amount of sugar elution was significantly lower in the crowding and anterior cross bite groups (Inoue's classification), and in the Class III malocclusion group (Angle's classification) in males. The amount of sugar elution per second was also significantly lower in the crowding and anterior cross bite groups. However, significant differences could not be found for chewing time. 3. The amount of sugar elution per second was significantly correlated with occlusal areas in males and total samples. 4. The amount of sugar elution was significantly correlated with less than ANB and less than L 1 to MP in males, with less than L 1 to MP in total samples. The chewing time was significantly correlated with S-N, N-Me, N-ANS, S'-Ptm' in females. The amount of sugar elution per second was significantly correlated with less than SNA and less than L 1 to MP in males, and with A'-Ptm', Cd-Go, Go-Pog', Cd-Gn, less than SNA, less than L 1 to MP, less than MP-SN and gonial angle in total samples. 5. It is concluded that the chewing gum masticatory test is highly correlated with occlusion and dento-facial morphology. In particular, amount of sugar elution per second was thought to be a useful measure for masticatory performance in clinical orthodontics.

Chewing Gum↗

Correlations between cytochrome P-450 and oxidative metabolism of benzo[a]pyrene and 7-ethoxycoumarin in human liver in vitro and antipyrine elimination in vivo.

Cytochrome P-450 content was correlated to aryl hydrocarbon hydroxylase and 7-ethoxycoumarin O-de-ethylase activities in human liver biopsy samples in vitro. Antipyrine half-life and clearance were measured in the same patients in vivo. The results were compared with data obtained in rat liver in vitro. The correlation of cytochrome P-450 content with aryl hydrocarbon hydroxylase activity in human liver biopsy samples was relatively good (r = 0.75, p < 0.001), but that with 7-ethoxycoumarin O-de-ethylase activity was much poorer (r = 0.42, p < 0.001). The good correlation between cytochrome P-450 content and aryl hydrocarbon hydroxylase activity in biopsy samples from patients with widely varying hepatic disease processes, exposure to inducers, history of cigarette smoking, etc., is in contrast with the data obtained in the rat, where the corresponding correlation in a population treated with different inducers and inhibitors was rather poor (r = 0.37, p < 0.01). This poor correlation was caused mainly by the nonequal effects of polycyclic aromatic hydrocarbons on cytochrome P-450 and aryl hydrocarbon hydroxylase. Cigarette smoking was not found to induce human liver drug or carcinogen metabolism. Aryl hydrocarbon hydroxylase activity in vitro and antipyrine half-life or clearance in vivo were correlated (r = 0.36, p < 0.01 and r = 0.35, p < 0.01, respectively), indicating a weak, but statistically significant association between these parameters. This study suggests that correlations between in vitro and in vivo measurements of drug metabolism are not strong enough for the tests to be used as predictive tests in experimental or clinical research.

7-Alkoxycoumarin O-Dealkylase↗

[Limits and problems in structural and functional analyses in biomedicine by means of correlation of stereologic-biochemical data].

Several examples of correlated stereological and biochemical investigations of the inner membrane of rat liver mitochondria under different physiological and pathological conditions are presented and critically discussed. In the case of liver lobuli a good quantitative correlation between morphological substrate (cristae or inner boundary membrane) and biochemical substrate (succinate dehydrogenase or glycerol phosphate dehydrogenase respectively) was demonstrated. The situation was more complex when cristae biogenesis was induced by low doses of thyroid hormone for up to 15 days. There was not always a good correlation between membrane biogenesis measured by electron microscopy and the corresponding biochemical parameter. Cardiolipin seemed to be a good parameter reflecting both membrane growth and reduction. The usefulness of a correlated stereological and biochemical work is demonstrated in a diagram showing 7 different biological explanations for a biochemically measured increase of a membrane-bound enzyme. One can conclude that correlations between results of quantitative electron microscopy by stereological means and biochemical results are possible. The correlations do not always occur in a quantitative way. This is especially the case when drastic physiological or pathological alterations are investigated. However, under stable metabolic conditions one can find quantitative correlations.

Biochemical Phenomena↗

Correlations between blood lead concentrations and some blood protein levels in children residing in lead-polluted and control areas.

Ninety children residing in a highly Pb-polluted area near a lead foundry (group E), and 61 children from the control area (group C) were examined and compared. In group E children there were detected significantly increased blood Pb concentrations (girls: 31.6 +/- 16 microgram/100 ml; boys: 38.7 +/- 15.8 microgram/100 ml) in comparison with the control group C children (about 20 microgram/100 ml for both sexes). Regression analysis revealed significantly positive correlation of Pb concentrations in blood with the level of total blood proteins and ALAD, the correlation with A-1AT, alpha-2-M, TRF, and CPL was much less pronounced. Also the correlation of Ca2+ concentrations in blood with blood protein levels was not too marked. On the other hand, the age factor turned out to be very influencing in girls. Remarkable was the change of Pb and Ca correlation positivity in group C children to correlation negativity in group E (ALAD, total proteins, CPL), or of correlation negativity to correlation positivity (A-1AT, TRF). The observed changes are discussed from the aspect of multifactorial action of Pb in the organism.

Adolescent↗

On the problem of nonsense correlations in allergological tests after routine extraction.

The influence of extraction procedures and culturing methods of material used for the preparation of allergenic extracts on correlation patterns found in allergological testing (skin test and RAST) was investigated. In our laboratory a short extraction procedure performed at O degrees C was used for Aspergillus repens. A. penicilloides, Wallemia sebi, their rearing media and non-inoculated medium. For the commercially available extracts from house dust, house-dust mite, pollen of Dactylus glomerata and A. penicilloides a longer procedure (several days) performed at room temperature was used. Statistical analysis showed a separation of all test results into two clusters, each cluster being composed of correlations between extracts from only one the manufacturers did not show any correlation. The correlations found between the short time incubated extracts of the xerophilic fungi and their rearing media could be explained by genetical and biochemical relationships between these fungi depending on ecological conditions. However, while the correlation found between house dust and house-dust mite is understandable, correlations found between long time incubated extracts from house-dust mite and D. glomerata or A. penicilloides may be nonsense correlations, that do not adequately describe the in vivo situation. The similarity of these extracts is presumably artificially created during extraction.

Allergens↗

[A study of the correlation between the stromal reaction to the primary lesion and immunological parameters in patients with cervical cancer (author's transl)].

A correlation between the stromal reaction to the primary lesion and the clinical immunoparameters, such as, the depth of primary lesion, regional lymph node metastasis, delayed hypersensitivity reactions (DNCB, PPD and PHA skin reaction), peripheral lymphocyte count, peripheral monocyte count, peripheral lymphocyte blastogenesis to PHA and prognosis were studied in patients with cervical cancer (stage Ib, II). All patients were treated with curative operation. The degree of stromal reaction was classified to 3 groups, that is, marked stromal reaction group, moderate stromal reaction group and slight stromal reaction group and the following results were obtained. 1) There was a significant correlation between the degree of stromal reaction and the depth of primary lesion, regional lymph node metastasis (p less than 0.05). 2) The degree of stromal reaction was correlated with the positive rate of DNCB skin reaction (p less than 0.05), but there was no significant correlation between the degree of stromal reaction and the positive rate of PPD and PHA skin reaction. 3) The degree of stromal reaction was not correlated with the count of peripheral lymphocyte, monocyte and the ability of lymphocyte blastoid transformation. 4) The recurrence rate in marked stromal reaction group was 13.6%; 22.2% in moderate group and 28. 6% in slight group. There was no significant correlation in the group. 5) Five-years-survival rate in marked stromal reaction group ws 86.4%; 81.5% in moderate group and 71.4% in slight group. There was also no significant correlation in the group.

Carcinoma, Squamous Cell↗

Correlation technique and its application in the His bundle electrocardiogram.

In literature, the HBE has been displayed by application of the averaging method. In this paper, correlation analysis technique was used and the body-surface HBE was displayed in a special-purpose electronic computer. The correlation coefficients of the P-A, A-H, H-V intervals and the H-wave width of both methods are almost equivalent and one can be substituted by the other. Compared with the averaging method, the S/N ratio of the correlation method is greater and the residual noise is nearly absent. Furthermore, the effects of the integrating time T and delay time delta tau on the S/N ratio, the measuring resolution and the analytical time have been studied. Correlation analysis technique is a method based on the cybernetic and information theory. With this technique, by using correlation function, the dependence (auto-correlation function) of the value at one instant upon that of the other during the same random process, or the interdependence between sets of data from 2 random processes can be described. Up to the present, there has been no report on the activities of the ventricular conductive system with the S/N ratio smaller than 1, detected on the body surface by correlation analysis technique[1 - 3]. However, using this technique, the author successfully detected the body surface HBE with a special-purpose mini-computer in 1977.

Bundle of His↗

A generalized estimating equations approach for spatially correlated binary data: applications to the analysis of neuroimaging data.

This paper proposes a generalized estimating equations approach for the analysis of spatially correlated binary data when there are large numbers of spatially correlated observations on a moderate number of subjects. This approach is useful when the scientific focus is on modeling the marginal mean structure. Proper modeling of the spatial correlation structure is shown to provide large efficiency gains along with precise standard error estimates for inference on mean structure parameters. Generalized estimating equations for estimating the parameters of both the mean and spatial correlation structure are proposed. The use of semivariogram models for parameterizing the correlation structure is discussed, and estimation of the sample semivariogram is proposed as a technique for choosing parametric models and starting values for generalized estimating equations estimation. The methodology is illustrated with neuroimaging data collected as part of the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Data Bank. A simulation study demonstrates the importance of accurate modeling of the spatial correlation structure in data with large numbers of spatially correlated observations such as those found in neuroimaging studies.

Brain↗

[Results of radionuclide ventriculography and correlation with echocardiography and angiography].

In a group of 24 patients with coronary artery diseases, correlations of left ventricle end-diastolic volume (EDV), end-systolic volume (ESV), systolic volume (SV), and ejection fraction (EF) measurement results were assessed. Compared results were obtained with radiological angiography (RTG), echocardiography (USG), and radionuclide ventriculography (RNVG). In RNVG, the left ventricle volume was calculated using a geometrical method (GEO), a sample method with measurement of left ventricle position depth from a scintigraphic image (VZ1), and a sample method with assessment of left ventricle position depth from body height and body weight (VZ2). Interpersonal variability of RNVG evaluation was assessed simultaneously. Compared with RTG, the best correlation of EDV measurement was attained with GEO (r = 0.83) and VZ2 (r = 0.82). These methods correlate best also in ESV measurement (r = 0.91). The best correlation of EF values was obtained with USG, while r = 0.85 when using GEO and VZ2. A very low correlation was found in SV (r values from 0.39 to 0.50). The studied methods usually overestimate low values and underestimate higher values. To the EF value of 50 per cent corresponds in USG the value 48 per cent, in GEO and VZ2 the value 42 per cent. The values of EDV, ESV, and SV obtained with USG and RNVG correlate well with RTG, while the values of SV are, due to a low correlation, practically useless. Interpersonal variability of RNVG methods evaluation is minimal. (Tab. 6, Ref. 30.)

Coronary Angiography↗