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PubMed1996

Occurrence of heavy metals, sodium, calcium, and potassium in human hair, teeth, and nails.

Heavy metals in biological samples: nails, teeth, and hair were examined during 1991-1993. Investigations of biological samples (hair n = 249 samples, teeth n = 145, nails n = 80 samples) were provided for inhabitants of selected towns in Beskid Slaski. The towns are small mountain towns in southern Poland: Wista, Szczyrk, Istebna, Koniakow, and Jaworzynka. The analysis of ANOVA and MANOVA variances were used for biological samples in the context of age, sex, and type of samples for 12 elements (Pb, Cd, Cr, Zn, Fe, Cu, Mn, Ni, Co, Ca, Na, and K). The matrix correlation and cluster analysis were applied to explain the behavior of metals in human hair, teeth, and nails.

Adolescent↗

PubMed2000

Age scale for assessing functional fitness in older Japanese ambulatory women.

Our aim was to develop an age scale for the assessment of functional fitness in older women. The subjects were 430 older Japanese ambulatory women. They were divided into three groups: (a) less active (N=373, age 72.5+/-6.7 years); (b) active (N=23, age 71.0+/-5.4 years); and (c) sedentary (N=34, age 72.9+/-4.7 years). The less active group was used for the development of the instrumental activities of daily living (IADL) age equation, while data from active and sedentary groups were utilized for the assessment of the criterion-related validity. Seventeen functional fitness variables were selected as test items related to IADL. IADL were defined as extra activities people engaged in during daily living, such as preparing meals, housecleaning activities, and washing. After applying the first principal component analysis to the correlation matrix among the 17 items, the following IADL age equation was obtained: IADL age = - 0.43X1 - 0.57X2 - 0.32X3 + 0.37X4 + 0.37CA + 61.88, where X1 = arm curl (n / 30 s), X2 = moving beans with chopsticks (n / 30 s), X3 = functional reach (cm), X4 = walking around two cones (s), and CA = chronological age (years). The mean IADL age of the less active group (72.2+/-8.4 years) obtained from this equation was matched with their mean CA. The mean IADL age of the active group (66.0+/-3.2 years) was significantly lower than their mean CA (71.0+/-5.4 years, p<0.05), and the mean IADL age of the sedentary group (79.1+/-6.0 years) was significantly higher than their mean CA (72.9+/-4.7 years, p<0.05). In conclusion, the criterion-related validity of the IADL age equation was clearly demonstrated as a means to assess the functional fitness required for IADL in older Japanese women.

Activities of Daily Living↗

PubMed2002

Origin and distribution of polycyclic aromatic hydrocarbons in surficial sediments from the savannah river.

Surface sediments collected from the Savannah River, located in the southeastern state of Georgia, USA, in June-July 1994 were analyzed for individual polycyclic aromatic hydrocarbons (PAHs). Three subdivisions of the river were identified for the study: upstream from, adjacent to, and downstream from the city of Savannah. There was high spatial variability in the total PAH (SigmaPAH) concentrations that ranged from 29 to 5,375 ng/g with an average concentration of 1,216 +/- 1,161 (SD). Of the three subdivisions, the highest SigmaPAH concentrations were in the middle segment, which was adjacent to urban and industrial areas. To elucidate sources, molecular indices based on indices among phenanthrene versus anthracene and fluoranthene versus pyrene were used to determine pyrogenic and petrogenic sources, respectively. These indices have been used by other authors to differentiate sources. In most cases, PAHs in sediments nearest the city of Savannah were of high temperature and pyrogenic origin. These pyrogenic PAHs were highly associated with toxicity to benthic organisms. The two-ringed naphthalene and substituted naphthalenes, which are petroleum-related PAHs, were significantly higher in the lower section of the river relative to the subdivisions. This river segment receives inputs primarily from shipping and boating traffic. Perylene, which is indicative of nonanthropogenic terrestrial inputs of carbon, had the highest concentration among the individual PAHs measured. High perylene concentrations were found at stations located upstream and adjacent to forested terrain and where salinity level was low. To discriminate pattern differences and similarities of individual PAHs among samples, principal component analysis (PCA) was performed on the more hydrophobic and persistent nonalkylated PAHs. These differences and similarities were used to infer perylene origin. PCA was performed on 14 nonalkylated PAHs that was normalized to the sum of nonalkylated PAHs, using a correlation matrix. Generally, the PAHs were separated into group patterns according to chemical and physical properties associated with log K(OW), except perylene. Perylene, a five-ringed PAH, was distinctly separated from the other five-ringed PAHs. The sources for perylene are likely from biogenic, terrestrial precursors. The collected data show that pyrogenic PAHs were highly associated with biological effects on benthic organisms, based on bioassay results. Perylene, a nonanthropogenic PAH, was found throughout the river and constituted a large percentage of total PAHs in the upper river.

Animals↗

PubMed2003

Molecular dynamics simulations on HIV-1 Tat.

Molecular dynamics simulations are used to investigate dynamics and intramolecular interactions of the HIV-1 transactivator (Tat) in aqueous solution. The calculations are based on the AMBER force field with particle mesh Ewald treatment for long-range electrostatics. The Tat structure exhibits a large flexibility, consistent with its absence of secondary structure elements. From an analysis of the correlation matrix and of electrostatic interactions we suggest that segments expressed by the two exons (amino acids 1-72 and 73-86, respectively) exhibit rather separated dynamic and energetic properties. We also identify intramolecular interactions of importance for structure stabilization. In particular, significant electrostatic interactions are recognized between the N-terminus and the basic domain of the protein, consistent with site-directed mutagenesis performed in this work.

Amino Acid Sequence↗

PubMedDate not supplied

Gluteal region morphology: the effect of the weight gain and aging.

The gluteal region is an important secondary sexual character itself and it has its place in the concept of the beauty in all communities. Interestingly, as far as we know, there is not any previous study addressing gluteal region morphology in an objective way in the aesthetic surgery literature. The aim of this study was to define the changes of the gluteal region morphology with aging and weight gain. Beside body weight, a total of five distances between predetermined anatomic points in gluteal region were measured on randomly selected 115 female volunteers, with their age ranging from 17 to 48 years (mean 22.7). All the records were analyzed by a correlation matrix using computer-based SPSS 7.5 program. As women grow older, the width of the gluteal region decreases and the gluteal sulcus elongates laterally and inferiorly. Contrary to aging, with weight gain the gluteal region becomes wider as the gluteal sulcus gets shorter. Although the subject does not sound new, our study is the first, documenting the changes in morphology of the gluteal region in relation to weight gain and aging in an objective way.

Adolescent↗

PubMed2004

Frontal lobe alterations in schizophrenia: neuroimaging and neuropsychological findings.

Functional neuroimaging and neuropsychological performance indicate a prefrontal dysfunction in schizophrenia patients. Frontal morphological brain abnormalities are also evident in these patients, but the relationship between neuropsychology and neuroimaging findings remains unclear. In this study, thirty patients with schizophrenia and 30 control participants were assessed using a neuropsychological test battery sensitive to fronto-striatal system dysfunction. Computed tomography (CT) scans were used to calculate the distance from the corpus callosum to the frontal pole corrected for brain size (anterioposterior length) in the group of patients and in a group of control participants with negative radiological findings. Schizophrenia patients performed significantly worse than controls in all frontal lobe tests. Corrected length from the corpus callosum to the frontal pole was reduced in patients with schizophrenia. This easy-to-perform measurement has not been used in previous studies, and indicates that schizophrenia patients have structural frontal abnormalities. However, correlations between structural and functional measures fail to show a clear relationship between the prefrontal performance and the main CT measures. As a rule, the trend observed in the correlation matrix pointed towards a relationship between CT parameters and a dysfunction on neuropsychological tests sensitive to frontal lobe damage.

Adult↗

PubMed2000

Serum CYFRA 21-1 in cervical cancer patients treated with radiation therapy.

BACKGROUND: A fragment of cytokeratin 19, referred to as CYFRA 21-1, is abundant in the serum of many patients with malignant tumors and is recognized as one of the established tumor markers, especially for non-small-cell lung cancer. In this study, the clinical usefulness of CYFRA 21-1 was investigated in cervical cancer patients treated with radiation therapy with reference to squamous-cell-carcinoma-related antigen (SCC-Ag), a common tumor marker of cervical squamous cell carcinoma. MATERIALS AND METHODS: The serum levels of CYFRA 21-1 and SCC-Ag of 50 patients with squamous cell carcinoma of the uterine cervix were measured before and after radiation therapy. RESULTS: CYFRA 21-1 was positive in 52% of the patients. The incidence increased with the stage of the cancer, and post-treatment increases were a sign of disease progression. During radiation, serum levels of CYFRA 21-1 decreased significantly and reflected the radiation effect well. In addition, CYFRA 21-1 was negative in all patients without distant metastasis at the end of radiation therapy. Compared with SCC-Ag, patients were less often positive for CYFRA 21-1, but there was a statistically positive correlation between the two markers (correlation matrix=0.69). CONCLUSIONS: CYFRA 21-1 can be used in monitoring the outcome of patients with squamous cell carcinoma of the uterine cervix. It may be particularly useful for patients without SCC-Ag.

Adult↗

PubMed2005

Mercury in surface sediments and benthic organisms from Guaymas Bay, east coast of the Gulf of California.

In order to know the concentration of mercury in surface sediments, macroalgae and clams from Guaymas Bay, Mexico, 20 surface sediment samples and several individuals of Codium amplivesciculatum (3), Enteromorpha clathrata (4), Gracilaria subsecundata (2), Ulva lactuca (2), Chione subrugosa (80) and Crassostrea gigas (40) were collected and their Hg concentration was measured by a cold vapor Hg analyzer, after acid digestion. In addition, granulometric analysis and quantification of total organic carbon, aluminum, iron and manganese contents in sediments were performed. A Pearsons correlation matrix was determined and, the enrichment factor, the geoaccumulation index and the biota-sediment accumulation factor were calculated. Mercury concentrations in sediments ranged from 0.3 to 2.3 microg g(-1), with the central and northern portions showing the highest values. Macroalgae had a content of Hg that oscillated from 0.058 to 0.134 microg g(-1), while the average concentrations of this metal for clams and oysters were 0.063 and 0.230 microg g(-1), respectively. A clear effect of Guaymas City and the anthropogenic activities carried out around the Guaymas Bay has been observed and the enrichment factor and the geochemical index suggest that sediments from this coastal ecosystem are moderately to strongly contaminated with Hg. However, according to the figure of the maximum human consumption of Hg per week recommended by the World Health Organization, people can ingest clams without risk to their health.

Aluminum↗

PubMed2006

Major and trace elements in paddy soil contaminated by Pb-Zn mining: a case study of Kocani Field, Macedonia.

The objective of this study was to assess the bulk chemical composition as well as the extent and severity of heavy metal contamination in the paddy soil of Kocani Field (eastern Macedonia). The results revealed that the paddy soil of the western part of Kocani Field is severely contaminated with Pb, Zn, As and Cd in the vicinity of the Zletovska River due to irrigation with riverine water that is severely affected by acid mine and tailing effluents from the Pb-Zn mine in Zletovo. The detected total concentrations of these metals are far above the threshold values considered to be phytotoxically excessive for surface soil. The paddy soil in the vicinity of the Zletovska River was also found to exhibit elevated levels of Ba, Th, U, V, W, Mo, Cu, Sb, Bi, Ag, Au, Hg and Tl, with concentrations above their generally accepted median concentration values obtained during this study. A correlation matrix revealed that the Mn and Fe oxides/hydroxides are the most important carrier phase for several trace elements, with the exception of rare earth elements (REEs). These also represent a major sink for the observed heavy metal pollution of the soil. REEs are mostly associated with two phases: light (L)REEs are bound to K-Al, while heavy (H)REEs are bound to Mg-bearing minerals. Although there is no direct evidence of a health risk, the paddy soil in the vicinity of Zletovska River needs further investigation and an assessment should be made of its suitability for agricultural use, particularly in view of the highly elevated concentrations of Pb, Zn, As and Cd.

Environmental Monitoring↗

PubMed2006

Chemical composition of atmospheric aerosol (PM10) at a semi-arid urban site: influence of terrestrial sources.

Atmospheric aerosol (PM(10)) measurements were made at a regional representative semi-arid urban site, Tirupati, India over one-year period i.e. from October, 2001 to September, 2002. The samples were collected on polyflex filters, and analyzed for the major water-soluble ions - F, Cl, NO(3), SO(4), Na, NH(4), K, Ca and Mg, employing ion chromatograph. The average mass of PM(10) is found to be 32.75 mug/m(3) with a total water-soluble aerosol load (total anion + total cation) of 13.56 mug/m(3). Composition of aerosol showed higher concentration of SO(4) followed by Na, Ca and NO(3). Very good correlation is observed between crustal ions Ca and Mg (r=0.82) as well as between crustal and acidic ions; Ca and SO(4) (r=0.75) and NO(3) (r=0.67) and Mg and NO(3) (r=0.78) and SO(4) (r=0.73), suggest that the ionic composition was influenced by local terrestrial sources. The presence of SO(4) and NO(3) may be due to re-suspension of soil particles (formation by heterogeneous oxidation). Ca, Mg and Na are mainly soil derived ones. Correlation matrix with meteorological factors, as well as seasonal distribution of PM(10) and its ionic components present a clear trend of higher concentrations during summer due to greater particle release and lowering atmospheric levels during the rainy season due to washout effect. ANOVA results showed the significant variation of composition from season to season. Paired comparisons (DMRT) revealed the occurrence of significant difference in pairs of mean concentration from season to season except within monsoon i.e. between S-W and N-E monsoon.

Aerosols↗

PubMed2006

Sources and distribution of trace metals in the Saricay Stream basin of southwestern Turkey.

Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as mass ratio): Co: 5-476 microg g(-1), Cr: 15-1308 microg g(-1), Cu: 7-128 microg g(-1), Fe: 1120-13210 microg g(-1), Mn: 150-2613 microg g(-1), Ni: 102-390 microg g(-1), Pb: 0.7-31.3 microg g(-1) and Zn: 18-304 microg g(-1), whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5-20.7 microg L(-1), Cr: 20.3-284 microg L(-1), Cu: 170-840 microg L(-1), Fe: 176-1830 microg L(-1), Mn: 29.3-387 microg L(-1), and Ni: 4.3-21.9 microg L(-1). Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA) and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison. The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges.

Geologic Sediments↗

PubMed2006

Improvement of band segmentation in Epo images via column shift transformation with cost functions.

In recent years, the development of methodology and laboratory techniques for doping control (DC) of recombinant erythropoietin (rEpo) has become one of the most important topics pursued by doping control laboratories accredited by World Anti-Doping Agency (WADA). The software system GASepo has been developed within the international WADA project as a support for Epo doping control. Although a great number of functions for automatic image processing have been involved in this software, for Epo images with considerably distorted bands additional effort is required from the user to interactively correct the results of improper band segmentation. In this paper a problem of geometrically distorted bands is addressed from the viewpoint of how to transform the lanes in distorted Epo images in order to reach better band segmentation. A method of band straightening via column shift transformation has been proposed that is formulated as an optimization procedure with cost functions. The method involves several novel approaches: two-stage optimization procedure, four cost functions and selection of relevant columns. The developed band straightening algorithm (BSA) has been tested on real Epo images with distorted bands. Based on the evaluation scheme involving the GASepo software itself a recommendation is made for implementation of the method with the cost function based on correlation matrix. Estimates of computational complexity of the individual steps of BSA are also given.

Algorithms↗

PubMed1988

Co-induction of microsomal cytochrome P-452 and the peroxisomal fatty acid beta-oxidation pathway in the rat by clofibrate and di-(2-ethylhexyl)phthalate. Dose-response studies.

Male Wistar rats have been pretreated with either clofibrate or diethylhexylphthalate and the dose-dependency of induction of the microsomal, cytochrome P-452-driven fatty acid hydroxylase and peroxisomal fatty acid beta-oxidation system investigated. Both clofibrate and DEHP specifically induced (approximately 10-fold) the 12-hydroxylation of lauric acid in a dose-dependent manner and only marginally increased the associated 11-hydroxylase activity. This dose-dependent increase in fatty acid hydroxylase activity was accompanied by a similar ten-fold increase in the specific content of the cytochrome P-452 isoenzyme responsible for this activity, as assessed by an immunochemical-based ELISA method. Similarly, both clofibrate and DEHP induced the peroxisomal fatty acid beta-oxidation pathway in a dose-dependent manner. Furthermore, our results provide evidence that, after oral administration, clofibrate has a higher in vivo potency in inducing the above enzymes of fatty acid metabolism than is exhibited by DEHP. A correlation matrix analysis of the above data indicated a close association between the induction of microsomal cytochrome P-452 (and its associated fatty acid hydroxylase activity) and peroxisomal beta-oxidation enzymes, implicating a mechanistic inter-relationship between changes in fatty acid metabolising enzymes in these two hepatic subcellular organelles.

Animals↗

PubMedDate not supplied

Alexithymia and depression: distinct or overlapping constructs?

Previous research showing moderate to high correlations between the Toronto Alexithymia Scale (TAS) and Beck Depression Inventory (BDI) has generated controversy as to whether alexithymia and depression are distinct or overlapping constructs. The present study addressed this controversy using the statistical method of factor analysis. In a sample of undergraduate university students, a correlation matrix comprising items from both the TAS and BDI yielded a four-factor solution with virtually no overlap of the significant factor loadings for the items from each scale, and with the factors corresponding closely with their respective construct. These results were replicated and cross-validated with a sample of psychiatric outpatients. The findings support the view that alexithymia is a construct that is distinct and separate from depression.

Adult↗

PubMed1995

Automated exploration of two-level interrelations of differently-scaled variables.

The SAS macro EXPLORE is conceived as an exploratory data analysis tool. Its output is an extension to the traditional correlation matrix, allowing the assessment of both categorical and numerical data 'at one look'. Depending on the type of data, appropriate statistics and graphs are produced. An overview of the features of the program and their implementation is given. Program invocation and execution are explained. Potential misuses are discussed.

Algorithms↗

PubMed1978

[EEG spectral analysis in normal children between the ages of 6 to 16. Choice and validation of the most significant parameters].

Numerous parameters have been proposed in order to describe the EEG power spectrum. Within the scope of an EEG study on the normal child between 6 and 16 years of age, the following problem had to be solved: given a group of 19 variables measured on 232 subjects in 5 situations, which of these variables best describe the population under examination. The algorithm proposed to answer this question is based on principal component analysis on the correlation matrix. Only 4 parameters are necessary to describe the EEG of a normal child of 6 to 16 years--these are Hjorth's parameters (activity, mobility and first order complexity) and alpha band power. They allow the observation of individual differences and the quantification for a given subject of the reaction to eyes opening, sensitivity to hyperventilation or even reactions that are difficult to perceive visually such as those resulting from doing arithmetic or vocabulary tests.

Adolescent↗

PubMed1994

Energy migration in allophycocyanin-B trimer with a linker polypeptide: analysis by the principal multi-component spectral estimation (PMSE) method.

Energy migration processes in allophycocyanin-B trimer with a linker polypeptide were analyzed using the principal multi-component spectral estimation (PMSE) method, which does not require assumption of component number, decay function, or the spectral band shape. We determined the number of spectral components showing independent kinetic behavior by the eigen-value of an auto-correlation matrix, and further the spectra of the components and their rise and decay curves. Two decay components were resolved at 20 degrees C: one corresponded to the decay of one type of beta-84 chromophore, and the other to the decay from the thermally equilibrated state between another type of beta-84 chromophore and the alpha-allophycocyanin B chromophore. An additional slow decay process was resolved at -196 degrees C. We also compared the component spectra obtained using the PMSE method with the decay-associated spectra obtained using the global analysis.

Cyanobacteria↗

PubMed1995

Extraction of discriminant features in post-cardiosurgical intensive care units.

A linear transformation, based on the Karhunen-Loève expansion, is applied to 13 physiological variables, measured in 200 surgical patients, in order to extract a limited number of features well representative of the differences between normal and high-risk classes of subjects. This transformation may be considered as a mapping from the primitive 13-dimensional space to a lower dimensional one, without severely reducing class separability. The efficacy of both transformed and primitive variables in the separation of normal and high-risk subjects is compared using the error probability, i.e. the probability that a patient is assigned to the wrong class. In particular, its upper bound is evaluated through the Kullback divergence and its estimate is computed, from the available samples, by applying a quadratic classifier. The results obtained show that only two transformed variables are able to present a divergence better than the most effective set of eight primitive variables. In agreement with the divergence criterion, the classifier provides a recognition error lower than 5% and greater than 13% when using the two best transformed and the two best primitive variables, respectively. Even though the new variables do not have a direct physiological meaning, this limitation has been partially overcome by calculating the correlation matrix between transformed and primitive variables. The results presented show that the first two transformed variables are strongly related to the most discriminant primitive ones (i.e. cardiac index, oxygen delivery and arterio-venous oxygen difference). In conclusion, the transformation of variables proposed appears to be extremely attractive for practical applications, since it allows recognition systems to be designed which exhibit both high performance and great simplicity.

Algorithms↗