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PubMed1991

Quantitative analysis of electroencephalograms: is there chaos in the future?

The history of quantitative, computerized electroencephalogram (EEG) analysis is reviewed. It is shown that, until very recently, the basic approach to EEG analysis involved the assumption that the EEG is stochastic. Consequently, statistical pattern recognition techniques, segmentation procedures, syntactic methods, knowledge-based approaches, and even artificial neural network methods have been developed with different levels of success. A fundamentally different approach to computerized EEG analysis, however, is making its way into the laboratories. The basic idea, inspired by recent advances in the area of non-linear dynamics, and especially the theory of chaos, is to view an EEG as the output of a deterministic system of relatively simple complexity, but containing non-linearities. This suggests that studying the geometrical dynamics of EEGs, and the development of neurophysiologically realistic models of EEG generation may produce more successful automated EEG analysis techniques than the classical, stochastic methods. Evidence supporting the non-linear dynamics paradigm is reviewed, and possible research paths are indicated.

Algorithms↗
PubMed1998

Quantitative analysis of cholesterol and cholesteryl esters in human atherosclerotic plaques using near-infrared Raman spectroscopy.

Raman spectroscopy is a non-destructive analytical technique and previous results have shown that qualitative analysis of the lipid component of human atheromatous arteries is feasible. In this paper, we describe a quantitative analytical method for cholesterol and cholesteryl esters in human atherosclerotic plaques, combined with Raman spectroscopic results, using partial least-squares (PLS) regression, a statistical multivariate method based on factorial analysis. Twenty-nine human atherosclerotic pooled samples were studied and the results of Raman spectroscopy coupled with the PLS method were compared to biochemical results. The standard error of prediction was 16.1, 13.6, 1.9, 3.3 and 3.4 mg/g for total cholesterol, free cholesterol, palmitate cholesteryl, oleate cholesteryl and linoleate cholesteryl, respectively. The repeatability of Raman spectroscopy was found to be excellent. Our results show that Raman spectroscopy is a promising technique to obtain a consistent and non-destructive quantitative analysis of cholesterol and cholesteryl esters in human atherosclerotic lesions. In situ and in vivo analysis is a possibility in the near future.

Aged↗
PubMed1998

Microscopic measurement of cellular infiltration in the rheumatoid arthritis synovial membrane: a comparison of semiquantitative and quantitative analysis.

Microscopic measurement of inflammation in synovial tissue may be important in studies of clinical status, prognosis and response to treatment. The aim of this study was to compare quantitative microscopic analysis of inflammation with a semiquantitative grading system in rheumatoid arthritis (RA) synovial membrane. Knee synovial membrane samples from 16 patients with RA, including paired samples taken before and after treatment in nine patients, were immunostained with anti-CD68 and anti-CD3 monoclonal antibodies using standard techniques. The intensity of macrophage and T-lymphocyte infiltration was measured both by quantitative and semiquantitative techniques, and the results were compared. In a cross-sectional comparison, both methods correlated significantly for lining layer macrophage infiltration, as well as sublining layer macrophage and T-cell infiltration. However, in some patients demonstrating a clinical response to treatment, semiquantitative analysis lacked sensitivity to biologically relevant changes in mononuclear cell infiltration. These observations have important implications for future studies of therapeutic modalities.

Antibodies, Monoclonal↗
PubMed2006

Fluorescence-suppressed Raman technique for quantitative analysis of protein solution using a micro-Raman probe, the shifted excitation method, and partial least squares regression analysis.

A practical Raman analyzing technique with suppression of the strong fluorescent background in order to obtain quantitative information is proposed in the present study. The technique is based on the shifted excitation method and partial least squares regression (PLSR) analysis. The Raman system consists of a single Raman spectrometer, a background-free electrically tunable Ti:Sapphire laser (BF-ETL), and a micro-Raman probe (MRP). The system allows one to obtain reliable shifted excitation Raman spectra with a simple operation. The PLSR analysis successfully provides quantitative information from the obtained spectra with the suppression of random noise including photon shot noise. The present study demonstrates that the technique is effective for extracting quantitative information concealed behind a fluorescent background that is more than 200 times stronger than the Raman signal.

Animals↗
PubMed2006

Quantitative analysis and effect of attenuation correction on lymph node staging of non-small cell lung cancer on SPECT and CT.

OBJECTIVE: The purpose of our study was to assess quantitative indexes and the effect of attenuation correction on the evaluation of lymph node metastasis in the staging of non-small cell lung cancer (NSCLC) using fused thallium-201 SPECT/CT images. MATERIALS AND METHODS: We evaluated 156 lymph nodes (66 metastatic, 90 nonmetastatic) from 29 patients with NSCLC. Using our combined SPECT/CT system, all patients underwent 201Tl SPECT and CT examinations immediately (early images) and 3 hr after (delayed images) the injection of 201Tl. SPECT images were reconstructed with and without attenuation correction. For the quantitative evaluation of lymph node metastasis, we calculated the early ratio, the delayed ratio, and the washout ratio for SPECT images and the short-axis diameter for CT images. Receiver operating characteristic (ROC) analysis was performed in each index for the differentiation between metastatic and nonmetastatic lymph nodes. Visual analysis was also performed by two experienced radiologists. RESULTS: The area under the ROC curve (A(z)) showed that early ratio and delayed ratio were superior to short-axis diameter for the assessment of lymph node metastasis. In addition, early and delayed ratios on attenuation-corrected images were superior to those ratios on images without attenuation correction. However, the A(z) value for washout ratio was smaller than that for short-axis diameter. Early ratio on attenuation-corrected images was the most useful index (A(z) = 0.94). The sensitivity, specificity, and accuracy for early ratio on attenuation-corrected images were 78.8%, 94.4%, and 87.8% for the diagnosis of lymph node metastasis and 84.6%, 100%, and 93.1% for clinical staging (N0-N1 vs N2-N3), respectively. Fused images showed significantly higher diagnostic accuracy than CT images on visual analysis. CONCLUSION: Quantitative assessment using fused SPECT/CT images is useful for the diagnosis of lymph node metastasis in patients with NSCLC.

Adult↗
PubMed2003

Indicators of empowerment and disempowerment in the subjective evaluation of the psychiatric treatment process by persons with severe and persistent mental illness: a qualitative and quantitative analysis.

Empowerment and disempowerment is studied in terms of the way persons with long and persistent schizophrenia evaluate their psychiatric outpatient treatment. One hundred persons with the diagnosis of schizophrenia (ICD-10 F 20.0) were interviewed about their perceptions and evaluation of the treatment process by means of problem-focused interviews. Transcribed interviews were subjected to qualitative content analysis. Relationships among the categories of the qualitative content analysis were analyzed by means of a homogeneity analysis. The latent dimension extracted by the homogeneity analysis could be interpreted as a quantitative measure of an empowered or a disempowered perception of the treatment process. As a result of the qualitative content analysis it was found that a majority of participants tend to describe their treatment as reduced to drug treatment and that they tend to notice only positive medication effects rather than mixed medication effects or positive effects of conversation and that they feel helpless or indifferent rather than actively involved in the treatment process. The impact of socio-demographic, clinical, and treatment characteristics on the participants' location on a latent dimension called "empowerment" was examined by means of multiple regression analysis. General life satisfaction, negative symptoms and getting depot medication were positively associated with a more disempowered perception of the treatment process whereas positive symptoms, getting antidepressant medication and being treated in an outpatient clinic instead of a private practice were associated with a more empowered perception.

Adult↗
PubMed1993

Quantitative analysis of immunoglobulin G subclasses in the rat.

Quantitative ELISAs have been developed for the four immunoglobulin G (IgG) subclasses (IgG1, IgG2a, IgG2b and IgG2c) of the rat. These assays were shown to have excellent sensitivity, reproducibility and adequate specificity for studies of natural IgG and antigen-elicited IgG responses. The sensitivity (working range for each isotype assay) was: IgG1, 1.6 to 200 ng/ml; IgG2a, 8 to 200 ng/ml; IgG2b, 1.6 to 200 ng/ml; and IgG2c, 1.6 to 1000 ng/ml. The isotype sum and the direct assay of total plasma IgG agreed closely. The utility of these assays was demonstrated in a study of the development of total IgG and of the specific IgG response following immunization with tetanus toxoid (TT). For total IgG, the predominant isotype was IgG2b (64% of total IgG) followed by IgG2a (29%), IgG1 (4%) and IgG2c (3%). In contrast, the anti-TT response was mainly of the IgG1 subclass (57% of total anti-TT). These quantitative assays should prove useful for investigating the response to experimental vaccines and the influence of cytokines on class switching in vivo.

Animals↗
PubMed1983

A quantitative analysis of UV-induced cell killing.

A quantitative hypothesis is developed, analogous to a previously developed model for ionising radiation, to describe the induction of eukaryotic cell killing by ultraviolet light. The hypothesis makes use of a recent proposal which suggests that pairs of dimers close to, and on either side of, a replication termination site provide long-lived blocks to replication, by suggesting that these 'paired dimer' lesions are potentially lethal. The hypothesis contains two crucial elements: (i) two dimers form the crucial lesion, and (ii) the paired dimer lesion is only recognised at the DNA-replication subsequent to exposure. Cell survival is predicted to be related to the square of the UV exposure and several sets of data are shown to be in good agreement with this prediction for surviving fractions down to 5% at least. It is shown that making use of a known molecular repair process, excision repair, the hypothesis gives a logical explanation for the unusual effects of UV fractionation reported previously for both exponentially growing cells and also for stationary cells. The hypothesis is amenable to further experimental verification.

Cell Survival↗
PubMed2001

[Addition internal standard method in chromatographic quantitative analysis].

Internal standard method is a conventional chromatographic quantitative method which requires one or several internal standards added. The internal standard component must not be contained in the sample and need a good separation between the internal standard and sample components. In many cases selecting an internal standard is not convenient or even restricted by the seperation of components. In this paper, we try to combine the internal standard method and the addition method to form a new chromatographic quantitation method named addition internal standard method. The principles of addition internal standard method are suitable to not only chromatographic quantitation but also polarography etc. The related theory and foundation of the method are defined. The operation steps and the conditions suitable to the method are discussed. The advantages and disadvantages of this method are explained in detail.

Chromatography↗
PubMedDate not supplied

Prognostic significance of pathological parameters of endomyocardial biopsy in clinical outcome of patients of dilated cardiomyopathy--I. Quantitative morphometric analysis.

Quantitative evaluation of endomyocardial biopsies from cases of dilated cardiomyopathy (DCM) was carried out using IBAS KONTRON image analyser with a view to recognise parameters that may be diagnostic and reflect prognosis of the disease. Mean fibre and nuclear diameter, percentage area occupied by myofibres and mean perimeter of the muscle fibres were assessed. Haemodynamic observations were correlated with morphological findings. Percentage area occupied by myofibres was least in cases of DCM. It appears that the muscle mass in cases of DCM decreases with a corresponding increase of fibrosis within the interstitium. This parameter showed a significant direct correlation with left ventricular ejection fraction and an inverse relationship with left ventricular end diastolic pressure. Thus the percentage area occupied by myofibres indicated the severity of DCM as it correlated well with the haemodynamic parameters. Its prognostic role, however, needs to be further investigated on a larger number of cases and follow up studies.

Adolescent↗
PubMed2005

Confirmatory and quantitative analysis of beta-lactam antibiotics in bovine kidney tissue by dispersive solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A simple, rapid, rugged, sensitive, and specific method for the confirmation and quantitation of 10 beta-lactam antibiotics in fortified and incurred bovine kidney tissue has been developed. The method uses a simple solvent extraction, dispersive solid-phase extraction (dispersive-SPE) cleanup, and liquid chromatography-tandem mass spectrometry (LC/MS/MS) for confirmation and quantitation. Dispersive-SPE greatly simplifies and accelerates sample cleanup and improves overall recoveries compared with conventional SPE cleanup. The beta-lactam antibiotics tested were as follows: deacetylcephapirin (an antimicrobial metabolite of cephapirin), amoxicillin, desfuroylceftiofur cysteine disulfide (DCCD, an antimicrobial metabolite of ceftiofur), ampicillin, cefazolin, penicillin G, oxacillin, cloxacillin, naficillin, and dicloxacillin. Average recoveries of fortified samples were 70% or better for all beta-lactams except DCCD, which had an average recovery of 58%. The LC/MS/MS method was able to demonstrate quantitative recoveries at established tolerance levels and provide confirmatory data for unambiguous analyte identification. The method was also tested on 30 incurred bovine kidney samples obtained from the USDA Food Safety and Inspection Service, which had previously tested the samples using the approved semiquantitative microbial assay. The results from the quantitative LC/MS/MS analysis were in general agreement with the microbial assay for 23 samples although the LC/MS/MS method was superior in that it could specifically identify which beta-lactam was present and quantitate its concentration, whereas the microbial assay could only identify the type of beta-lactam present and report a concentration with respect to the microbial inhibition of a penicillin G standard. In addition, for 6 of the 23 samples, LC/MS/MS analysis detected a penicillin and a cephalosporin beta-lactam, whereas the microbial assay detected only a penicillin beta-lactam. For samples that do not fall into the "general agreement" category, the most serious discrepancy involves two samples where the LC/MS/MS method detected a violative level of a cephalosporin beta-lactam (deacetylcephapirin) in the first sample and a possibly violative level of desfuroylceftiofur in the second, whereas the microbial assay identified the two samples as having only violative levels of a penicillin beta-lactam.

Animals↗
PubMed1998

Quantitative analysis of nitric oxide synthase expressed in developing and differentiating rat cerebellum.

In order to investigate quantitatively the differentiation and maturation process of granule cells in the postnatal development of rat cerebellum, nitric oxide synthase (NOS) activities were determined in the micro-dissected developing cerebellar layers, using our microassay method. NOS activities were increased in the molecular and internal granular layers (IGLs) during development and the activity was measurable in the neuroblastic external granular layers (EGLs). Newly devised micro-immunoblot analysis semi-quantitatively showed more amount of endothelial NOS (eNOS) and non-negligible amount of neuronal NOS (nNOS) in microsamples from EGL, compared with other developing and adult cerebellar layers. nNOS mRNA was also detected using RT-PCR (reverse transcriptase-polymerase chain reaction) in the microsamples from this germinal layer. Intraperitoneal administration of NG-nitro-l-arginine inhibited NOS activity in vivo and disturbed the layer formation in developing cerebellum.

Aging↗
PubMed2003

Quantitative analysis and characterization of DNA immobilized on gold.

We describe the complementary use of X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy to quantitatively characterize the immobilization of thiolated (dT)(25) single-stranded DNA (ssDNA) on gold. When electron attenuation effects are accurately accounted for in the XPS analysis, the relative coverage values obtained by the two methods are in excellent agreement, and the absolute coverage can be calculated on the basis of the XPS data. The evolution of chemically specific spectral signatures during immobilization indicates that at lower coverages much of the DNA lies flat on the surface, with a substantial fraction of the thymine bases chemisorbed. At higher immobilization densities, the (dT)(25) film consists of randomly coiled ssDNA molecules each anchored via the thiol group and at possibly one or two other bases. We use two examples to demonstrate how the quantitative analysis can be applied to practical problems: the effects of different buffer salts on the immobilization efficiency; the immobilization kinetics. Buffers with divalent salts dramatically increase the efficiency of immobilization and result in very high surface densities (>5 x 10(13)/ cm(2)), densities that may only be possible if the divalent counterions induce strong attractive intermolecular interactions. In contrast with previous reports of alkanethiol adsorption kinetics on gold, ssDNA immobilization in 1 M phosphate buffer does not occur with Langmuir kinetics, a result attributable to rearrangement within the film that follows the initial adsorption.

DNA, Single-Stranded↗
PubMed2006

Rapid quantitative analysis using a single molecule counting approach.

Single molecule detection of target molecules specifically bound by paired fluorescently labeled probes has shown great potential for sensitive quantitation of biomolecules. To date, no reports have rigorously evaluated the analytical capabilities of a single molecule detection platform employing this dual-probe approach or the performance of its data analysis methodology. In this paper, we describe a rapid, automated, and sensitive multicolor single molecule detection apparatus and a novel extension of coincident event counting based on detection of fluorescent probes. The approach estimates the number of dual-labeled molecules of interest from the total number of coincident fluorescent events observed by correcting for unbound probes that randomly pass through the interrogation zone simultaneously. Event counting was evaluated on three combinations of distinct fluorescence channels and was demonstrated to outperform conventional spatial cross-correlation in generating a wider linear dynamic response to target molecules. Furthermore, this approach succeeded in detecting subpicomolar concentrations of a model RNA target to which fluorescently labeled oligonucleotide probes were hybridized in a complex background of RNA. These results illustrate that the fluorescent event counting approach described represents a general tool for rapid sensitive quantitative analysis of any sample analyte, including nucleic acids and proteins, for which pairs of specific probes can be developed.

Base Sequence↗
PubMed1992

Quantitative analysis of cyclic beta-turn models.

The beta-turn is a frequently found structural unit in the conformation of globular proteins. Although the circular dichroism (CD) spectra of the alpha-helix and beta-pleated sheet are well defined, there remains some ambiguity concerning the pure component CD spectra of the different types of beta-turns. Recently, it has been reported (Hollósi, M., Kövér, K.E., Holly, S., Radics, L., & Fasman, G.D., 1987, Biopolymers 26, 1527-1572; Perczel, A., Hollósi, M., Foxman, B.M., & Fasman, G.D., 1991a, J. Am. Chem. Soc. 113, 9772-9784) that some pseudohexapeptides (e.g., the cyclo[(delta)Ava-Gly-Pro-Aaa-Gly] where Aaa = Ser, Ser(OtBu), or Gly) in many solvents adopt a conformational mixture of type I and the type II beta-turns, although the X-ray-determined conformation was an ideal type I beta-turn. In addition to these pseudohexapeptides, conformational analysis was also carried out on three pseudotetrapeptides and three pseudooctapeptides. The target of the conformation analysis reported herein was to determine whether the ring stress of the above beta-turn models has an influence on their conformational properties. Quantitative nuclear Overhauser effect (NOE) measurements yielded interproton distances. The conformational average distances so obtained were interpreted utilizing molecular dynamics (MD) simulations to yield the conformational percentages. These conformational ratios were correlated with the conformational weights obtained by quantitative CD analysis of the same compounds. The pure component CD curves of type I and type II beta-turns were also obtained, using a recently developed algorithm (Perczel, A., Tusnády, G., Hollósi, M., & Fasman, G.D., 1991b, Protein Eng. 4(6), 669-679). For the first time the results of a CD deconvolution, based on the CD spectra of 14 beta-turn models, were assigned by quantitative NOE results. The NOE experiments confirmed the ratios of the component curves found for the two major beta-turns by CD analysis. These results can now be used to enhance the conformational determination of globular proteins on the basis of their CD spectra.

Amino Acid Sequence↗
PubMed1986

A quantitative analysis of the human bone marrow granulocytic cell lineage using the SAMBA 200 cell image processor. II. The blast cells in refractory anemia with an excess of blasts.

A quantitative image analysis of bone marrow blast cells from eight patients with refractory anemia with an excess of blast cells was performed using the SAMBA 200 cell image analyzer. A total of 33 parameters was computed on 665 cells visually classified as B1 blasts (agranular cells), B2 blasts (cells containing a few azurophilic granules) and B3 blasts (cells with numerous granules). The continuum of variation of some cytoplasmic parameters (area, hue and standard deviation of the luminance, hue and saturation histograms) and some nuclear parameters (area and convexity degree) from the B1 cells to the B3 cells indicated a concomitant cytoplasmic and nuclear maturation, with the B1 cells being the most immature. An attempt to automatically classify these cells using a stepwise linear discriminant analysis resulted in an average of 68% correctly classified cells at the fifth step. Among the B1 and B2 blast cells considered together, an unsupervised classification method distinguished seven subgroups of blasts, which were principally different in cytoplasmic area, cytoplasmic color and nuclear texture. The percentages of cells belonging to two of these subgroups were highly discriminatory with respect to the prognosis. These two cell types had morphologic, textural and color features that put them very near the normal immature myeloidlike progenitor cells and normal myeloblasts, as demonstrated by means of canonical analysis. All patients having a very low percentage of these two cells among their blast cells died from overt leukemia less than one year after the first diagnosis of their disease.

Anemia, Refractory, with Excess of Blasts↗
PubMedDate not supplied

MR imaging of minamata disease: qualitative and quantitative analysis.

Minamata disease (MD), a result of methylmercury poisoning, is a neurological illness caused by ingestion of contaminated seafood. We evaluated MR findings of patients with MD qualitatively and quantitatively. Magnetic resonance imaging at 1.5 Tesla was performed in seven patients with MD and in eight control subjects. All of our patients showed typical neurological findings like sensory disturbance, constriction of the visual fields, and ataxia. In the quantitative image analysis, inferior and middle parts of the cerebellar vermis and cerebellar hemispheres were significantly atrophic in comparison with the normal controls. There were no significant differences in measurements of the basis pontis, middle cerebellar peduncles, corpus callosum, or cerebral hemispheres between MD and the normal controls. The calcarine sulci and central sulci were significantly dilated, reflecting atrophy of the visual cortex and postcentral cortex, respectively. The lesions located in the calcarine area, cerebellum, and postcentral gyri were related to three characteristic manifestations of this disease, constriction of the visual fields, ataxia, and sensory disturbance, respectively. MR imaging has proved to be useful in evaluating the CNS abnormalities of methylmercury poisoning.

Ataxia↗