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PubMed2002

Parental impressions of the benefits (pros) and barriers (cons) of follow-up care after an acute emergency department visit for children with asthma.

OBJECTIVE: Asthma morbidity, with increasing emergency department (ED) visits, is prevalent among low-income, urban children. Follow-up care after ED visits is infrequent. We developed and evaluated an instrument that describes the parental benefits (pros) and barriers (cons) of obtaining follow-up care for interventions to promote follow-up. METHODS: We enrolled a convenience sample of low-income, urban parents who brought their children to the ED for treatment of asthma. These parents rated 41 items about the pros and cons of making a follow-up visit. Principal component analysis was used to identify the underlying structure of the instrument. RESULTS: One hundred forty-seven participants were interviewed in the ED. Principal component analysis retained 24 total items, which were identified by this sample as highly associated with deciding to take their child to a follow-up visit. Two types of pros were identified, informational and attitudinal, including "ask the doctor questions," and " children with asthma are healthier if they see their doctor regularly." Two types of cons were identified, practical and attitudinal, including "I have to find transportation," and "I don't need to see the doctor unless my child is sick." The mean total pro and con scores were 4.05 +/- 0.63 and 1.73 +/- 0.67, respectively. CONCLUSIONS: The pros and cons are not unidimensional. Even among those with infrequent follow-up, pros were endorsed more highly than cons. Programs that target these pros and cons may improve adherence to follow-up and regular care for low-income urban children.

Adult↗
PubMedDate not supplied

Metabolite composition in breast tumors examined by proton nuclear magnetic resonance spectroscopy.

BACKGROUND: In vivo characterisation of breast tumors using protein (1H) MR spectroscopy relies upon in vitro interpretation of tissue samples. The present study has investigated metabolite composition in extracts from breast tumors and non-involved breast tissue. Multivariate data analysis was used to determinate combinations of metabolites important for differentiation. MATERIALS AND METHODS: Tumor and non-involved breast tissue were obtained from 16 patients undergoing surgical treatment. 1H NMR spectra of perchloric acid tissue extracts were obtained at a BRUKER Avance DRX600 spectrometer. The data was analysed using principal component analysis and probabilistic neural networks. RESULTS: Low levels of glucose and high content of choline compounds were dominant findings in the tumor spectra. Principal component loadings demonstrated this strong association. The spectra were correctly classified using neural network analysis. CONCLUSIONS: Large differences in the metabolite composition of breast tumors and surrounding breast tissues have been documented.

Adult↗
PubMedDate not supplied

[The Young Cognitive Schema Questionnaire: translation and preliminary validation].

Young (1990) proposed a clinical scale to assess personality disorders. We translated and used this scale for validation purpose in pathological (n = 113) and control (n = 54) samples. Our results reflected that Young Schema Questionnaire (SQ) has a good discrimination value between patients (Axes I and II of the DSM III-R classification) and controls. Statistical comparisons indicated significant differences between three subgroups-axis I only (n = 53), axes I and II together (n = 60), and controls (n = 54). The SQ score was the highest in the patients with personality disorders, reflecting the sensitivity of the scale to Axis II pathology. Principal component analysis (unrotated factors) showed a first factor, a failure axis (eigenvalue = 7.93), and a second factor, a narcissistic one (eigenvalue = 1.30). These two principal components explained 62% of the variance.

Adult↗
PubMed1994

[An industrial toxicological study on workers who synthesize aminophenol and anisidine from chloronitrobenzene].

Aromatic nitro- and amino-compounds (ANA) are notorious methemoglobin forming substances. From 1987 to 1993, the author surveyed the exposure level to ANA and health status of workers in a chemical industry where they synthetize nitrophenol and anisidine from chloro-nitrobenzene. The ANA exposure indicator was the diazo-reaction positive substance in the worker's urine (Dz) and the biological effect of ANA was monitored through the methemoglobin concentration in the blood (MHb). The following results were obtained from the survey. 1. Both the Dz and MHb values tended to become lower between 1987 and 1993. 2. The MHb levels of the workers were a little higher than the control levels, and the difference between the values was statistically significant (p < 0.01); both levels were, however, within the normal range. 3. The MHb value was estimable from a mathematical model: MHb = (k1-k2/a) x DU x CH, where k1 and k2 were constants and a, DU and CH indicated the activity of glutathione S transferase in erythrocytes (GST), DZ in urine and blood hemoglobin concentration, respectively. The correlation coefficient of the multiple regression was statistically significant (R2 = 0.263, p < 0.01). This model suggests that the biotransformed fraction of ANA in the pulmonary uptake site, the lung, could not penetrate into erythrocytes or act as an MHb former. The model seemed to be consistent and valid when urinary DZ values were less than 1.0 (mg/mg creatinine) and MHb values were less than 2.0 (mg/ml blood). Thus, the upper limit of normal levels for MHb can be considered to be 2.0 (mg/ml blood), or 12-1.6% of total hemoglobin in blood. 4. The significance of the uptake sites, i.e., lung, skin etc., was discussed with reference to the evidence obtained from the longshoremen cases, who were percutaneously exposed to chloronitrobenzene in 1984. 5. Hemolysate solutions from the blood of workers were applied to isoelectric focusing electrophoresis (IEF), and Hb species of different valencies were separated; intermediate MHbs, where the heme iron in one of the components of Hb, i.e., in the alpha or beta chain was oxidized and MHb where both the alpha and beta chain heme iron oxidized and Hb X and Y, were separated and easily discernible. The correlation matrix was calculated using the data relevant to IEF and other indicators; MHb estimated spectrophotometrically, GST activity of erythrocytes, Hb and urinary DZ vale. The statistical procedure of principal component analysis was applied to the matrix, and two major principal components were extracted from the calculation.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2004

Is perception of upper body orientation based on the inertia tensor? Normogravity versus microgravity conditions.

During lateral leg raising, a synergistic inclination of the supporting leg and trunk in the opposite direction to the leg movement is performed in order to preserve equilibrium. As first hypothesized by Pagano and Turvey (J Exp Psychol Hum Percept Perform, 1995, 21:1070-1087), the perception of limb orientation could be based on the orientation of the limb's inertia tensor. The purpose of this study was thus to explore whether the final upper body orientation (trunk inclination relative to vertical) depends on changes in the trunk inertia tensor. We imposed a loading condition, with total mass of 4 kg added to the subject's trunk in either a symmetrical or asymmetrical configuration. This changed the orientation of the trunk inertia tensor while keeping the total trunk mass constant. In order to separate any effects of the inertia tensor from the effects of gravitational torque, the experiment was carried out in normo- and microgravity. The results indicated that in normogravity the same final upper body orientation was maintained irrespective of the loading condition. In microgravity, regardless of loading conditions the same (but different from the normogravity) orientation of the upper body was achieved through different joint organizations: two joints (the hip and ankle joints of the supporting leg) in the asymmetrical loading condition, and one (hip) in the symmetrical loading condition. In order to determine whether the different orientations of the inertia tensor were perceived during the movement, the interjoint coordination was quantified by performing a principal components analysis (PCA) on the supporting and moving hips and on the supporting ankle joints. It was expected that different loading conditions would modify the principal component of the PCA. In normogravity, asymmetrical loading decreased the coupling between joints, while in microgravity a strong coupling was preserved whatever the loading condition. It was concluded that the trunk inertia tensor did not play a role during the lateral leg raising task because in spite of the absence of gravitational torque the final upper body orientation and the interjoint coupling were not influenced.

Adult↗
PubMed2005

Spiritual needs in cancer patients and spiritual care based on logotherapy.

BACKGROUND: The suitability of Frankl's logotherapy for the spiritual care (psychotherapy) of cancer patients in Japan is suggested. Using Functional Assessment of Chronic Illness Therapy-Spiritual (FACIT-Sp, Japanese version), the Purpose in Life test (PIL test, Japanese version), and WHO-Subjective Inventory (WHO-SUBI, Japanese version), we attempted to elucidate the complicated structure of spirituality in cancer patients in order to identify possible approaches to their spiritual care and means of evaluating such care. MATERIALS: Two hundred and ninety-eight cancer patients participated in the study. All three tests were taken at the same time, and the results were evaluated by principal component analysis. RESULTS: It was demonstrated that all the subscales employed in the present study could be represented by a two-dimensional structure (two principal components), and that the FACIT-Sp and PIL tests have similar contents. DISCUSSION: FACIT-Sp (Japanese version) is very similar in conception to the PIL test, which was prepared in accordance with logotherapy. The results suggest that this test can serve as an adequate evaluation scale for measuring the effectiveness of spiritual care based on Frankl's logotherapy.

Adult↗
PubMed1987

Regional variation of selected polyaromatic and chlorinated hydrocarbons over the South Island of New Zealand, as indicated by their content in Pinus radiata needles.

We analysed needles of Pinus radiata along three transects through the South Island of New Zealand for chlorinated hydrocarbons ( alpha- and gamma-HCH, HCB and PCB) and PAH (fluoranthene, 3,4-benzopyrene, benzo(ghi)perylene and indenopyrene). At rural sites we also collected samples of moss (Wijkia extenuata) and lichens (Usnea sp.) in order to compare the pollutant concentrations within these plants. A principal component analysis confirmed findings from moss and snow studies in Europe that the PAH concentrations vary regionally in the same way. The pattern of the principal component loadings of the chlorinated hydrocarbons reflects their heterogeneous immission and their different chemodynamics. The regional pattern indicates an increase of gamma-HCH from remote areas to those used intensively for agriculture and gardening, followed by a decrease towards the inner city of Christchurch. In contrast, PCB and PAH show their highest levels of contamination in the city. The regional distribution of PAH in Christchurch correlates well with traffic density, and particularly with the pattern of smoke from domestic fires. Our study demonstrates that needles of P. radiata can be better monitors of atmospheric pollution in New Zealand than mosses or lichens.

Journal Article↗
PubMed2003

The influence of extrinsic and intrinsic risk factors on the probability of sustaining an injury.

This study was designed to quantify the relative contributions of extrinsic and intrinsic risk factors to the probability of an injury event. A case-control design was used with data collected from injured patients at an emergency department (n=797) and a community sample matched on area of residence and time of injury (n=797). Principal components analysis was used to develop scales for the measurement of 'intrinsic' risk taking tendencies that were slightly modified versions of previously published measures. Two principal components were identified: 'health risk taking' (HRT) and 'adventurous risk taking' (ART). Logistic regression analysis identified variables that significantly predicted membership of the group of injured cases. The main hypothesis was supported by the results: that 'extrinsic' factors such as location, activity, drug and alcohol use and the type of people present at the time of the injury were related to a greater risk of injury than 'intrinsic' variables (health and adventurous risk taking tendencies). The results suggest that injury research and prevention efforts should continue to focus on the identification and modification of situational risk factors for injury rather developing programs that focus on high-risk individuals. High-risk alcohol use, use of prescribed drugs and aspects of work and recreational environments were identified as warranting particular attention.

Alcohol Drinking↗
PubMed1987

Chemometric classification of reversed-phase high-performance liquid chromatography columns.

Cluster analysis and principal components analysis have been used to classify nine octadecyl (C18) high-performance liquid chromatography (HPLC) columns into three general groups displaying similar chromatographic behaviour. Principal components analysis was also able to identify the key test compounds on which the classification was most highly dependent. These identifications agreed with the classification and test compound selection by an HPLC specialist. In addition, the chemometric techniques can easily be extended to many more columns and test measurements than could be conveniently examined by a human expert.

Chemical Phenomena↗
PubMed2000

Complex denoising of MR data via wavelet analysis: application for functional MRI.

A fast post-processing method for noise reduction of MR images, termed complex-denoising, is presented. The method is based on shrinking noisy discrete wavelet transform coefficients via thresholding, and it can be used for any MRI data-set with no need for high power computers. Unlike previous wavelet application to MR images, the denoising algorithm is applied, separately, to the two orthogonal sets of the complex MR image. The norm of the combined data are used to construct the image. With this method, signal-noise decoupling and Gaussian white noise assumptions used in the wavelet noise suppression scheme, are better fulfilled. The performance of the method is tested by carrying out a qualitative and quantitative comparison of a single-average image, complex-denoised image, multiple-average images, and a magnitude-denoised image, of a standard phantom. The comparison shows that the complex-denoising scheme improves the signal-to-noise and contrast-to-noise ratios more than the magnitude-denoising scheme, particularly in low SNR regions. To demonstrate the method strength, it is applied to fMRI data of somatosensory rat stimulation. It is shown that the activation area in a cross-correlation analysis is approximately 63% larger in the complex-denoised versus original data sets when equal threshold value is used. Application of the method of Principal Component Analysis to the complex-denoised, magnitude-denoised, and original data sets results in a similar but higher variance of the first few principal components obtained from the former data set as compared to those obtained from the later two sets.

Algorithms↗
PubMed1998

Separation of steroidal drugs on porous graphitized carbon column.

The retention time of 11 steroidal drugs was determined on a porous graphitized carbon (PGC) column using water tetrahydrofuran mixtures as eluents. Linear correlations were calculated between the logarithm of the capacity factor (k') and the tetrahydrofuran concentration in the eluent. To find the molecular parameters significantly influencing the retention the intercept and slope values of the above relationship were correlated with the physicochemical characteristics of steroidal drugs using principal component analysis (PCA). Both the slope and intercept values show high differences proving that steroidal drugs can be successfully separated on a PGC column. Five principal components explained > 90% of the total variance. Calculations indicated that both electrostatic interactions and sterical conditions can influence the retention of steroidal drugs on PGC column.

Chemistry Techniques, Analytical↗
PubMed1995

Statistical methods and strategies for working with large data bases.

This article describes the statistical methods and strategies to be used in establishing the linkages between processes and structures of care with risk-adjusted outcomes in a large multicenter Veterans Affairs cooperative study in health services of patients undergoing cardiac surgery. The statistical analyses consist of test involving nine specific hypotheses related to the effect of processes and structures of care on risk-adjusted outcomes. From the statistical point of view, the major obstacles of this study are the need for data reduction and imputation of missing data. The former obstacle is addressed through the use of data-reduction techniques, such as principal components and cluster of variables. The latter is addressed through the use of classic and new techniques for imputation of missing data, such as MISSGEN, principal components for qualitative data, and the expectation and maximization algorithm. Data reduction and imputation of missing data are done with clinically derived variable groups called "dimensions" or "subdimensions." The effect of processes and structures of care is assessed by a two-step process. First, outcomes are modeled using only patient risk factors. The selection of risk factors in the modeling process is discussed in detail. Second, these risk-adjusted outcomes are modeled using one of the nine process or structure subhypotheses. The relationship of the processes and structures of care dimensions and/or subdimensions that are linked to risk-adjusted outcomes are identified.

Cardiac Surgical Procedures↗
PubMed1993

Supermarket checker motions and cumulative trauma risk.

The relationship between specific motions and symptoms consistent with upper extremity cumulative trauma disorders (UECTDs) was investigated in 50 supermarket checkers. Each completed a questionnaire concerning UECTD symptoms; four composite symptom indices were derived: any arm symptoms, hand-wrist-lower arm (S-DIST), upper arm, and symptoms specifically associated with carpal tunnel syndrome (S-SPC). Each participant was videotaped on at least two occasions while performing checking work. Analysis of these tapes assigned each subject a composite motion index for each of the following motions: wrist flexion, wrist extension, body (lumbar) flexion, pronation, grip type, and tendency to lift objects. "Positive" symptom status was defined by a score in the upper quartile for the symptom index. Relationships between an individual's motion indices and symptom indices were analyzed by determining the percent of subjects "positive" for symptoms in each quartile of motion index, by rank correlation, and by regression of symptom scores on principal components of motions. Trends toward relationship of wrist flexion and extension, lumbar flexion, and pronation with S-DIST and S-SPC were noted. Principal components regression confirmed that extension and flexion were related to these two symptom outcomes. This study suggests that postural loading can be determined on an individual basis in a meaningful fashion and that interventions that decrease such loading may be beneficial. It supports the role of certain repetitive motions as causes of UECTD symptoms.

Adult↗
PubMed2002

Identifying microcalcifications in benign and malignant breast lesions by probing differences in their chemical composition using Raman spectroscopy.

We have applied Raman spectroscopy to analyze the chemical composition of microcalcifications occurring in benign and malignant lesions in the human breast. Microcalcifications were initially separated into two categories based on their Raman spectrum: type I, calcium oxalate dihydrate, and type II, calcium hydroxyapatite. Type I microcalcifications were diagnosed as benign, whereas type II were subdivided into benign and malignant categories using principal component analysis, a statistical technique. Although type II microcalcifications are primarily composed of calcium hydroxyapatite, they also contain trace amounts of several biological impurities. Using principal component analysis, we were able to highlight subtle chemical differences in type II microcalcifications that correlate with breast disease. On the basis of these results, we believe that type II microcalcifications formed in benign ducts typically contain a larger amount of calcium carbonate and a smaller amount of protein than those formed in malignant ducts. Using this diagnostic strategy, we were able to distinguish microcalcifications occurring in benign and malignant ducts with a sensitivity of 88% and a specificity of 93%. This is a significant improvement over current X-ray mammography techniques, which are unable to reliably differentiate microcalcifications in benign and malignant breast lesions.

Adult↗
PubMedDate not supplied

[Physicochemical quality of drinking water in Southern Algeria: study of excess mineral salts].

The aim of this study was to determine the physicochemical composition of water intended for human consumption in several regions of Southern Algeria. Excess minerals in drinking water, including magnesium, calcium, sulfates and fluorides play a fundamental role in the prevention of urinary calculi, which are formed mainly from calcium oxalate. The ever-increasingly prevalence of this disorder and its recurrence make it a real public health problem in Algeria. The most elementary preventive treatment, recommended to all subjects with lithiasis, is to drink 2 to 3 L water distributed throughout the (24-hour) day. This study began by conducting a physicochemical analysis of the principal components of water from several sources. We will subsequently test it to examine the effects of its mineral salts on the crystallization kinetics of the principal component of calculi (calcium oxalate). The results indicate that 77.5 % of the samples had magnesium concentrations ([Mg 2+] > 50 mg/L), 95 % were sulfated, with sulfate ion concentrations exceeding the standard recommended by WHO ([SO4 2-] > 250 mg/L). Moreover, 57.5 % had excess fluoride levels, [F-] > 1.5 mg/L, and 65 % excessive calcium concentrations, with Ca 2+ > 150 mg/L.

Algeria↗
PubMed2006

Patterns of p73 N-terminal isoform expression and p53 status have prognostic value in gynecological cancers.

The goal of this study was to determine whether patterns of expression profiles of p73 isoforms and of p53 mutational status are useful combinatorial biomarkers for predicting outcome in a gynecological cancer cohort. This is the first such study using matched tumor/normal tissue pairs from each patient. The median follow-up was over two years. The expression of all 5 N-terminal isoforms (TAp73, DeltaNp73, DeltaN'p73, Ex2p73 and Ex2/3p73) was measured by real-time RT-PCR and p53 status was analyzed by immunohistochemistry. TAp73, DeltaNp73 and DeltaN'p73 were significantly upregulated in tumors. Surprisingly, their range of overexpression was age-dependent, with the highest differences delta (tumor-normal) in the youngest age group. Correction of this age effect was important in further survival correlations. We used all 6 variables (five p73 isoform levels plus p53 status) as input into a principal component analysis with Varimax rotation (VrPCA) to filter out noise from non-disease related individual variability of p73 levels. Rationally selected and individually weighted principal components from each patient were then used to train a support vector machine (SVM) algorithm to predict clinical outcome. This SVM algorithm was able to predict correct outcome in 30 of the 35 patients. We use here a mathematical tool for pattern recognition that has been commonly used in e.g. microarray data mining and apply it for the first time in a prognostic model. We find that PCA/SVM is able to test a clinical hypothesis with robust statistics and show that p73 expression profiles and p53 status are useful prognostic biomarkers that differentiate patients with good vs. poor prognosis with gynecological cancers.

Age Factors↗
PubMed2007

A multivariate statistical analysis of surface water chemistry data--the Ankobra Basin, Ghana.

R-mode hierarchical cluster and principal component analysis (PCA) were simultaneously applied to surface water hydrochemical data from three different locations, Ankwaso, Dominase and Prestea, along the Ankobra Basin, Ghana, to extract principal factors corresponding to the different sources of variation in the hydrochemistry, with the objective of defining the main controls on the hydrochemistry at the basin scale. Using the Kaiser criterion, principal components (PC) were extracted from the data and rotated using varimax normalization, for each location. The varimax rotation ensured that variation in the data was maximized for easy interpretation of the results. The analysis reduced 30, 33 and 33 data points, respectively, for Ankwaso, Dominase and Prestea to four, three and four PC representing the sources of variation in the hydrochemistry at the three different locations. Though the PC analysis proved to be more robust at unveiling the sources of variation in the hydrochemistry than the R-mode hierarchical cluster analysis (HCA), the combined use of both techniques resulted in more reliable interpretations of the hydrochemistry. On the basis of these analyses, the hydrochemistry of the basin is controlled largely by the weathering of minerals (silicates, carbonates, gypsum and apatite) from the underlying meta-sediments of the Birimian and Tarkwaian Systems, and the decay of organic matter from the heavily forested regions. Concentrations of the major chemical parameters are within naturally acceptable limits and do not pose threats to the local ecology and humans. There is no strong evidence of high anthropogenic impacts on the major anions and cations used for this research, though there are variations at the different locations studied. The hydrochemistry at Ankwaso is principally controlled by the weathering of silicate minerals, whereas those of Dominase and Prestea are, respectively, influenced by precipitation and domestic wastewaters, and the decay of organic matter.

Bicarbonates↗
PubMed2001

Removal of naphthalene, phenanthrene, and pyrene by sorbents from hot gas.

It is the first time that the removal of polycyclic aromatic hydrocarbons (PAH) containing different aromatic rings number [naphthalene (Np), phenanthrene (Phe), and pyrene (Py)] from combustion hot gas has been carried out. The aim was to relate the sorbents textural characteristics with the adsorption capacity of these 2-4-ring PAH at the conditions emitted at energy generation. The sorbents textural parameters [total micropore volume (VN2), narrow micropore volume (VCO2), mesopore volume (VBJH), and the free active sites] were analyzed trying to correlate them with their Np, Phe, and Py adsorption capacities. To get this aim, single and multiple linear regressions (MLR) were applied to the three PAH. A principal component analysis was performed to generate new and uncorrelated variables. It enabled us to show that the relations between the textural parameters were analyzed using a principal components regression (PCR). The PCR analysis had a good statistical quality, but neither did it allow differentiating free active site types nor did VN2 and VCO2. The correlations were thus set up applying a MLR to the original variables. The regression statistical quality was similar to the PCR analysis, and it could give an easier explanation of the parameters that affected the adsorption. In Np adsorption, the 87% data variance was explained, and the adsorption was positively correlated to VCO2 and the micropore mean diameter (I.). In the Phe regression there was 98% variance explained, and its adsorption was positively correlated to the VN2 and the micropore distribution, n. Finally, in the Py adsorption, the 96% data variance was explained, and this adsorption was positively correlated to VN2 and VBJH. These dependencies were according to the molecular parameters of these compounds (molecular diameter and volatility) because the higher the number of aromatic rings of the PAH, the more favored the adsorbate-adsorbate interactions. Besides, the higher the mean diameter micropores, the lower the diffusional problems showed by Np, Phe, and Py.

Adsorption↗