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PubMed2000

Osteometrical skull character in the four species of tree shrew.

The skull size and shape were osteometrically examined in the four species of the tree shrews (Tupaia tana, T. javanica, T. minor and T. dorsalis). We suggest that the skull characters were affected by the species specific behavior and terrestrial, arbo-terrestrial and arboreal life, among the genus Tupaia. The neurocranium was laterally narrower in the braincase area, and the splanchnocranium was longer only on dorsal side in T. tana, and these characters were opposite to T. minor. The principal component analysis confirmed the obviously separated clusters among T. tana, T. javanica and T. minor, affected by the adaptation for each behavior. T. dorsalis was considered as terrestrial species from the results of proportion analysis and the principal component analysis.

Animals↗
PubMed1984

Common femoral artery Doppler wave-forms: a comparison of three methods of objective analysis with direct pressure measurements.

Doppler maximum frequency wave-forms recorded from the femoral arteries of 50 patients with arterial disease have been submitted to three methods of objective analysis in an attempt to quantify the degree of proximal narrowing. The methods were compared with direct femoral artery pressure measurements at rest and during hyperaemia. There was marked overlap between the results of both pulsatility index and Laplace transform damping when compared with pressure assessment. Principal component analysis, however, produced significantly better agreement than Laplace transform damping (chi 2 = 5.8, P less than 0.02) and in addition was found to be sensitive to the presence or absence of disease in the superficial femoral artery. Principal component analysis appears to be the most powerful method of Doppler wave-form analysis so far described and may have a place in the non-invasive assessment of the aorto-iliac segment.

Aorta, Abdominal↗
PubMed2004

Executive processes in Parkinson's disease: FDG-PET and network analysis.

It is assumed widely that the clinical expression of Parkinson's Disease (PD), both motor and cognitive, is subtended by topographically distributed brain networks. However, little is known about the functional neuroanatomy of executive dysfunction in PD. Our objective was to validate further in a PD group the use of network analysis to assess the relationship between executive processes and pathological disorganization of frontostriatal networks. We studied 15 patients with idiopathic PD, and 7 age-matched normal controls, using resting [(18)F]fluorodeoxyglucose (FDG) and high-resolution positron emission tomography (PET). We carried out network analysis on regional metabolic data to identify specific covariation patterns associated with motor and executive dysfunction. We detected two independent patterns relating respectively to the two clinical abnormalities. The first pattern (principal component 1) was topographically similar to that described previously in other PD populations. Subject scores for this pattern discriminated patients from controls and correlated significantly with bradykinesia ratings (P = 0.013, r = 0.655) in PD patients. The second pattern (principal component 2) was characterized by relative ventromedial frontal, hippocampal, and striatal hypometabolism, associated with mediodorsal thalamic hypermetabolism. In the PD group, scores from this pattern correlated with scores on the conditional associative learning (CAL; P = 0.01, r = 0.690) and the Brown Peterson paradigm (BPP; P = 0.017, r = -0.651) tests, respectively assessing strategy and planning, and working memory. According to these findings, the networks subserving bradykinesia and executive dysfunction in PD seems to be topographically distinct and to involve different aspects of subcortico-cortical processing.

Adult↗
PubMed2006

Protein expression in Escherichia coli S17-1 biofilms: impact of indole.

Bacteria undergo significant changes during adherence to surfaces and biofilm development. Cell-to-cell signalling molecules are known to be involved in these phenotypic adaptations to the sessile mode of life. We demonstrated previously that indole can act as an extracellular signal to regulate biofilm formation in E. coli. To identify proteins over- or under-expressed in response to E. coli biofilm formation and indole signalling, we compared the proteomes of the E. coli S17-1 wild-type and 3714 (S17-1 tnaA::Tn5) tryptophanase-negative mutant cells (which don't produce indole) grown as suspensions or biofilms in the presence or absence of exogenous indole. From computer-assisted image analysis, 407 spots were discriminated on two-dimensional electropherograms. Principal component analysis (PCA) of the electropherograms did not discriminate between the proteomes of the wild-type and mutant cells grown as suspensions indicating that indole has a limited impact onto protein expression of planktonic cells. The first principal component extracted by PCA, after standardization of the observations, opposed planktonic and biofilm cells confirming the existence of changes in protein expression during E. coli biofilm formation. Among proteins over- or under-expressed by both sessile wild-type and mutant cells, we identified metabolic enzymes, transporters, proteins involved in the translation and transcription machinery, stress response and regulation, and signalling proteins. The wild-type and mutant strains grown as biofilms in the presence of indole were discriminated by the second component. The role of some proteins whose expression was altered in biofilm bacteria compared to suspended counterparts is discussed.

Amino Acid Sequence↗
PubMed2002

Solute-solvent interactions in micellar electrokinetic chromatography. III. Characterization of the selectivity of micellar electrokinetic chromatography systems.

Several micellar electrokinetic chromatography (MEKC) systems (sodium dodecyl sulfate, lithium dodecyl sulfate, lithium perfluorooctanesulfonate, sodium cholate, sodium deoxycholate, tetradecyltrimethylammonium bromide and hexadecyltrimethylammonium bromide) have been characterized by means of the solvation parameter model. It has been observed that the coefficients of the correlation equations depend strongly on the particular set of compounds analyzed. Principal component analysis has been used to characterize the 2975 compounds with available solute descriptors and to select an appropriate subset of compounds to be analyzed by MEKC. With this set of compounds, the MEKC systems have been characterized. Principal component analysis has also been used to show the similarities and differences between the properties of the surfactants characterized by MEKC.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed2005

Typification of cider brandy on the basis of cider used in its manufacture.

A study of typification of cider brandies on the basis of the origin of the raw material used in their manufacture was conducted using chemometric techniques (principal component analysis, linear discriminant analysis, and Bayesian analysis) together with their composition in volatile compounds, as analyzed by gas chromatography with flame ionization to detect the major volatiles and by mass spectrometric to detect the minor ones. Significant principal components computed by a double cross-validation procedure allowed the structure of the database to be visualized as a function of the raw material, that is, cider made from fresh apple juice versus cider made from apple juice concentrate. Feasible and robust discriminant rules were computed and validated by a cross-validation procedure that allowed the authors to classify fresh and concentrate cider brandies, obtaining classification hits of >92%. The most discriminating variables for typifying cider brandies according to their raw material were 1-butanol and ethyl hexanoate.

Alcoholic Beverages↗
PubMed2026

A genome-wide assessment of the population structure of thirteen admixed and pure Australian beef cattle breeds.

Knowledge of population structure is a key factor for successful multi-breed genomic prediction, especially in single-step analysis when metafounders are considered. In Australia, current assessments mostly focus on single breeds using a single-step genomic prediction method. However, the effective integration of pedigree, phenotypic, and genomic data in a multi-breed framework still requires further research, especially for combined analyses including admixed and multi-breed populations. This study began with 602,952 genotyped individuals with 8K SNPs in common from 13 beef cattle breeds (Alexandria, Angus, Brahman, Brangus, Charolais, Droughtmaster, Hereford, Kynuna, Limousin, Santa Gertrudis, Shorthorn, Speckle Park, and Wagyu). Due to different numbers of animals being genotyped in each breed, a representative subset of animals was chosen by employing a validated sampling strategy using Gaussian Mixture Models (GMM) complemented by Principal Component Analysis (PCA) within each breed. Subsequently, a specific number of animals in each cluster were randomly selected to capture the entire genetic diversity per breed, with a total of 260 animals from each breed. The first three principal components explained 59.89% of the total variation, with PC1 (33.54%) clearly separating Bos indicus from Bos taurus lineages. Admixture analysis identified stable ancestral components and defined the genetic makeup of both pure and composite populations. The results showed extensive genetic diversity in some breeds and highlighted distinct genetic differences between Bos indicus and Bos taurus breeds. In addition, six composite breeds' admixture levels confirmed their origin and breed history, revealing a directional shift in ancestry proportions by a longitudinal increase in Brahman ancestry within tropical composites over time. Thus, the findings pave the way for more effective utilization of genetic diversity both within and across populations and provide a framework for designing multi-breed genetic evaluations and breeding programs to improve productivity and profitability in Australian beef production.

Animals↗
PubMed2002

Phenotyping and genotyping of Sporothrix schenckii isolates according to geographic origin and clinical form of Sporotrichosis.

Sporothrix schenckii isolates of fixed and lymphocutaneous clinical forms from Mexico (MX), Guatemala (GT), and Colombia (CO) as well as environmental isolates from MX were studied by analyzing their phenotypic characteristics (conidial length, thermotolerance by percent growth inhibition [GI] at 35 and 37 degrees C, median lethal dose [LD(50)]) and genotypic characteristics (by random amplified polymorphic DNA [RAPD] analysis-PCR). A significant difference (P < 0.01) in the mean conidial length of S. schenckii clinical isolates from CO ( = 4.03 +/- 1.04 microm) compared with those of clinical isolates from MX ( = 2.06 +/- 0.53 microm) and GT ( = 2.68 +/- 0.83 microm) was observed. The lowest thermotolerance, as determined by measurement of percent GI, was exhibited by isolates from CO at 35 degrees C ( = 50.1% +/- 15.9%) and 37 degrees C ( = 72.7% +/- 10.9%). In general, the highest virulence, as determined by measurement of the LD(50) for mice, was observed for the MX environmental isolates. RAPD analysis-PCR with 10-mer primers OPBG-01, OPBG-14, and OPBG-19 generated 52 reproducible bands. The 44 Sporothrix isolates fell into four major groups by hierarchical cluster analysis. The first group (group I), formed by 25 (of 27) isolates from MX, had two subgroups: subgroup Ia with 10 environmental isolates and subgroup Ib with 14 clinical isolates. The second group (group II) had two subgroups: subgroup IIa, formed by isolates from CO, and subgroup IIb, formed by isolates from GT. Groups III and IV each had only one clinical isolate from MX. A principal-component analysis of the same data yielded three distinct groups, depending on the geographical origins of the isolates, including the isolates in groups III and IV from MX, which were grouped with the isolates from MX by principal-component analysis. This study revealed that isolates from CO had low thermotolerances at 35 and 37 degrees C and could be associated with superficial skin lesions in patients with fixed clinical forms of sporotrichosis, the most frequent form of the disease in CO. Distinct patterns dependent on geographical origins were also revealed by RAPD analysis-PCR, but these had no relation to the clinical form of the disease.

Colombia↗
PubMed2006

Dibenzazecine compounds with a novel dopamine/5HT2A receptor profile and 3D-QSAR analysis.

BACKGROUND: Antipsychotics are divided into typical and atypical compounds based on clinical efficacy and side effects. The purpose of this study was to characterize in vitro a series of novel azecine-type compounds at human dopamine D1-D5 and 5HT2A receptors and to assign them to different classes according to their dopamine/5HT2A receptor profile. RESULTS: Regardless of using affinity data (pKi values at D1-D5 and 5HT2A) or selectivity data (15 log (Ki ratios)), principal component analysis with azecine-type compounds, haloperidol, and clozapine revealed three groups of dopamine/5HT2A ligands: 1) haloperidol; 2) clozapine plus four azecine-type compounds; 3) two hydroxylated dibenzazecines. Reducing the number of Ki ratios used for principal component analysis from 15 to two (the D1/D2 and D2/5HT2A Ki ratios) obtained the same three groups of compounds. The most potent dibenzazecine clustering in the same group as clozapine was the non-hydroxylated LE410 which shows a slightly different D2-like receptor profile (D2L > D3 > D4.4) than clozapine (D4.4 > D2L > D3). The monohydroxylated dibenzacezine LE404 clusters in a separate group from clozapine/LE410 and from haloperidol and shows increased D1 selectivity. CONCLUSION: In conclusion, two compounds with a novel dopamine/5HT2A receptor profile, LE404 and LE410, with some differences in their respective D1/D2 receptor affinities including a validated pharmacophore-based 3D-QSAR model for D1 antagonists are presented.

Animals↗
PubMed2001

Analysis of asymmetry in mammograms via directional filtering with Gabor wavelets.

This paper presents a procedure for the analysis of left-right (bilateral) asymmetry in mammograms. The procedure is based upon the detection of linear directional components by using a multiresolution representation based upon Gabor wavelets. A particular wavelet scheme with two-dimensional Gabor filters as elementary functions with varying tuning frequency and orientation, specifically designed in order to reduce the redundancy in the wavelet-based representation, is applied to the given image. The filter responses for different scales and orientation are analyzed by using the Karhunen-Loève (KL) transform and Otsu's method of thresholding. The KL transform is applied to select the principal components of the filter responses, preserving only the most relevant directional elements appearing at all scales. The selected principal components, thresholded by using Otsu's method, are used to obtain the magnitude and phase of the directional components of the image. Rose diagrams computed from the phase images and statistical measures computed thereof are used for quantitative and qualitative analysis of the oriented patterns. A total of 80 images from 20 normal cases, 14 asymmetric cases, and six architectural distortion cases from the Mini-MIAS (Mammographic Image Analysis Society, London, U.K.) database were used to evaluate the scheme using the leave-one-out methodology. Average classification accuracy rates of up to 74.4% were achieved.

Breast Neoplasms↗
PubMed2003

Quantification of non-protein nitrogen components of infant formulae and follow-up milks: comparison with cows' and human milk.

The composition of fourteen infant formulae and six follow-up milks with regard to their free amino acids (including taurine), free nucleotides, orotic acid, and free and total l-carnitine content was studied. The levels found were compared with the limits established in European legislation and with the composition of human and cows' milk samples. HPLC methodologies, optimized and validated for the matrices under study, were used, except for free and total l-carnitine contents that were quantified using a flow-injection manifold, also optimized and validated for the matrices under study. Global statistical treatment of the results by cluster analysis indicated similarities between the contents of the N compounds under study of infant formulae, follow-up milks and cows' milk and differences with regard to human milk composition. The principal component analysis showed that 60.2 % of the variation in data was due to the first principal component, and the second component represented 23.8 % of the total information. Nucleotide profiles, orotic acid, and free and total l-carnitine contents explain the main differences observed between human milk and the other milks studied (cows' milk, infant formulae and follow-up milks). Cows' milk is distinguished from infant formulae and follow-up milks mainly owing to the different uric acid contents and free amino acids profiles.

Amino Acids↗
PubMed2004

Relationship between hydrocarbon measurements and toxicity to a chironomid, fish larva and daphnid for oils and oil spill chemical treatments in laboratory freshwater marsh microcosms.

This research investigated the extent to which various common hydrocarbon measures can be used to predict toxicity to freshwater aquatic organisms due to fouling by oil. Actual toxicity results, on laboratory freshwater marsh microcosms using two water-column species and a benthic species, were described earlier. The hydrocarbon measures used were TPH(g), TPH(FID), TPH(MS), TTAH (sum of 41 target aromatic hydrocarbons), principal components of 41 TAHs, and each individual TAH. In general, toxicity was more closely related to TPH(MS) levels than to TPH(FID) and (especially) TPH(g) levels. The strongest relationships were found for TTAH levels and for the principal components of the TAHs. Regressions of toxicity on many individual TAHs were also strong, with a single group of compounds explaining as much as 59% of the variation in survival. While the various regressions were highly significant statistically and at times able to accurately predict broad differences in toxicity, the high variation in survival at a specific hydrocarbon concentration indicates that these hydrocarbon measures can not substitute for actual toxicity determinations in accurately ranking the toxicity of samples from oiled freshwater marshes.

Animals↗
PubMed2005

Rapid monitoring of antibiotics using Raman and surface enhanced Raman spectroscopy.

Comparatively few studies have explored the ability of Raman spectroscopy for the quantitative analysis of microbial secondary metabolites in fermentation broths. In this study we investigated the ability of Raman spectroscopy to differentiate between different penicillins and to quantify the level of penicillin in fermentation broths. However, the Raman signal is rather weak, therefore the Raman signal was enhanced using surface enhanced Raman spectroscopy (SERS) employing silver colloids. It was difficult by eye to differentiate between the five different penicillin molecules studied using Raman and SERS spectra, therefore the spectra were analysed by multivariate cluster analysis. Principal components analysis (PCA) clearly showed that SERS rather than the Raman spectra produced reproducible enough spectra to allow for the recovery of each of the different penicillins into their respective five groups. To highlight this further the first five principal components were used to construct a dendrogram using agglomerative clustering, and this again clearly showed that SERS can be used to identify which penicillin molecule was being analysed, despite their molecular similarities. With respect to the quantification of penicillin G it was shown that Raman spectroscopy could be used to quantify the amount of penicillin present in solution when relatively high levels of penicillin were analysed (>50 mM). By contrast, the SERS spectra showed reduced fluorescence, and improved signal to noise ratios from considerably lower concentrations of the antibiotic. This could prove to be advantageous in industry for monitoring low levels of penicillin in the early stages of antibiotic production. In addition, SERS may have advantages for quantifying low levels of high value, low yield, secondary metabolites in microbial processes.

Culture Media↗
PubMed1986

Nonmutagenicity of curcumin and its antimutagenic action versus chili and capsaicin.

Turmeric, which is one of the commonly used spices in Indian cooking, was tested for mutagenicity using the Ames test. The alcoholic extract of fresh or dried turmeric, its principal components, and pyrolyzed turmeric powder and curcumin were tested for mutagenicity in Salmonella typhimurium strains with and without metabolic activation. None of these were mutagenic in all the tester strains. Chilies (which are used with turmeric powder) and their principal alkaloid capsaicin were mutagenic in the TA 98 with S9 mixture. We tested curcumin, which is the principal component of turmeric, for its antimutagenic effect. It showed dose-dependent decreases in mutagenicity of chili extract and capsaicin. Also, we compared the antimutagenicity of curcumin with other known antioxidants, including BHA, vitamins E and C, and vegetable oils. These all showed dose-dependent decreases in mutagenicity of chili extract and capsaicin. These studies show that although there are few mutagenic principles in Indian food, there is still quite a large number of antimutagenic principles in the Indian diet that will modulate the activity of environmental mutagens.

Animals↗
PubMed1994

Rating of medication influences (ROMI) scale in schizophrenia.

Noncompliance with neuroleptic treatment is a major barrier to delivery of effective treatment for schizophrenia outpatients. This article describes the development of a standardized measure for the assessment of attitudinal and behavioral factors influencing patient compliance with neuroleptic treatment. The Rating of Medication Influences (ROMI) scale was developed as part of a longitudinal study of neuroleptic noncompliance in schizophrenia and administered to 115 discharged schizophrenia outpatients. Analyses of the following were conducted to assess the scale's psychometric properties: (1) interrater reliability, (2) internal consistency, (3) principal components, (4) correlation with other subjective measures, and (5) correlation with independent family reports. Most (95%) of the ROMI patient-report items were reliable, whereas rater-judgment items were not reliable. The rater section was dropped. A principal components analysis of the reliable patient-report items yielded three subscales related to compliance (Prevention, Influence of Others, and Medication Affinity) and five subscales related to noncompliance (Denial/Dysphoria, Logistical Problems, Rejection of Label, Family Influence, and Negative Therapeutic Alliance). There were significant correlations between these subscales, and independently obtained family-report ROMI items were significant. The Denial/Dysphoria subscale correlated strongly with two other published measures of dysphoric response to neuroleptics, whereas the other noncompliance subscales did not. The ROMI is a reliable and valid instrument that can be used to assess the patient's subjective reasons for medication compliance and non-compliance. The subscale findings suggest that the ROMI provides a more comprehensive data base for patient-reported compliance attitudes than the other available subjective measures. Indications for use of the ROMI and other subjective measures of neuroleptic response are reviewed.

Adult↗
PubMed1997

Multivariate analysis of muscular fatigue during bicycle ergometer exercise.

The purpose of this study is to estimate the endurance threshold in terms of muscular fatigue during bicycle ergometer exercise. The problems to be solved are induced by dynamic movement and the physiological variation of muscle activity: that is, the progression and impairment of muscle activity occur simultaneously. First of all, we used multichannel recordings of myoelectric (ME) signals to reduce the effect by the movement of a bipolar surface electrode relative to the innervation zones. Second, since even the different types of ME parameters contain redundant information on muscular fatigue, we used the principal component analysis (PCA) to represent the meaningful information by small dimensions. Moreover, we proposed a total evaluation pattern to discriminate muscular fatigue from progression of muscle force at a glance. The total evaluation pattern shows the proportion of first principal component, the components of the first eigenvector, and the correlation coefficients as a function of the work load. The assessment using the total evaluation pattern divided eight subjects into three groups, whereas these subjects were not identified by a specific ME parameter.

Adult↗
PubMed1993

Severity scoring of atopic dermatitis: the SCORAD index. Consensus Report of the European Task Force on Atopic Dermatitis.

BACKGROUND: Assessment methods for atopic dermatitis (AD) are not standardized, and therapeutic studies are difficult to interpret. AIMS: To obtain a consensus on assessment methods in AD and to use a statistical method to develop a composite severity index. METHODS: Consensus definitions were given for items used in the scoring system (extent, intensity, subjective) and illustrated for intensity items. Slides were reviewed to address within- and between-observer variability by a group of 10 trained clinicians, and data were statistically evaluated with a two-way analysis of variance. Two variants of an assessment system were compared in 88 patients at 5 different institutions. Data were analyzed using principal-component analysis. RESULTS: For 5 intensity items studied (erythema, edema/papulation, oozing/crusts, excoriations, lichenification), within- and between-observer variability was good overall, except for edema/papulation which was difficult to assess with slides. In the series of 88 patients, principal-component analysis allowed to extract two unrelated components: the first one accounting for 33% of total variance was interpreted as a 'severity' component; the second one, accounting for 18% of variance, was interpreted as a 'profile' component distinguishing patients with mostly erythema and subjective symptoms and those with mostly lichenification and dryness and lower subjective symptoms. Of the two evaluation systems used, the one using the rule of nine to assess extent was found more workable than the one using a distribution x intensity product. A scoring index (SCORAD) combining extent, severity and subjective symptoms was mathematically derived from the first system and showed a normal distribution of the population studied. CONCLUSION: The final choice for the evaluation system was mostly made based on simplicity and easy routine use in outpatient clinics. Based on mathematical appreciation of weights of the items used in the assessment of AD, extent and subjective symptoms account for around 20% each of the total score, intensity items representing 60%. The so-designed composite index SCORAD needs to be further tested in clinical trials.

Adolescent↗
PubMed1995

Development of a short scale for self-assessment of experiences of hearing loss. The hearing coping assessment.

A short scale for self-assessment of experiences of hearing impairment--the Hearing Coping Assessment (HCA) was developed and administered to 114 consecutive hearing-impaired patients at a Swedish hearing centre. The scale was evaluated in terms of descriptive statistics, reliability, principal components analysis, and validity. The results showed high internal consistency, high split-half correlation, and high item-total correlations. Significant correlations were found between the HCA questionnaire and measures of optimism, depressive syndrome, and audiogram (PTA). The principal component analysis showed two meaningful factors. The first mainly represents disability, and the second emotional reactions due to hearing loss. Aspects of handicap were present in both factors. The subjects in this study were no less optimistic nor did they show more signs of depressive syndrome than comparable norm groups. Still, optimists reported fewer hearing problems as measured by the HCA. The HCA is proposed as a suitable assessment scale in studies on the effects of counselling.

Adaptation, Psychological↗