Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “parameter identification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed1994

Mechanistic considerations in chemopreventive drug development.

This overview of the potential mechanisms of chemopreventive activity will provide the conceptual groundwork for chemopreventive drug discovery, leading to structure-activity and mechanistic studies that identify and evaluate new agents. Possible mechanisms of chemopreventive activity with examples of promising agents include carcinogen blocking activities such as inhibition of carcinogen uptake (calcium), inhibition of formation or activation of carcinogen (arylalkyl isothiocyanates, DHEA, NSAIDs, polyphenols), deactivation or detoxification of carcinogen (oltipraz, other GSH-enhancing agents), preventing carcinogen binding to DNA (oltipraz, polyphenols), and enhancing the level or fidelity of DNA repair (NAC, protease inhibitors). Chemopreventive antioxidant activities include scavenging reactive electrophiles (GSH-enhancing agents), scavenging oxygen radicals (polyphenols, vitamin E), and inhibiting arachidonic acid metabolism (glycyrrhetinic acid, NAC, NSAIDs, polyphenols, tamoxifen). Antiproliferation/antiprogression activities include modulation of signal transduction (glycyrrhetinic acid, NSAIDs, polyphenols, retinoids, tamoxifen), modulation of hormonal and growth factor activity (NSAIDs, retinoids, tamoxifen), inhibition of aberrant oncogene activity (genistein, NSAIDs, monoterpenes), inhibition of polyamine metabolism (DFMO, retinoids, tamoxifen), induction of terminal differentiation (calcium, retinoids, vitamin D3), restoration of immune response (NSAIDs, selenium, vitamin E), enhancing intercellular communication (carotenoids, retinoids), restoration of tumor suppressor function, induction of programmed cell death (apoptosis) (butyric acid, genistein, retinoids, tamoxifen), correction of DNA methylation imbalances (folic acid), inhibition of angiogenesis (genistein, retinoids, tamoxifen), inhibition of basement membrane degradation (protease inhibitors), and activation of antimetastasis genes. A systematic drug development program for chemopreventive agents is only possible with continuing research into mechanisms of action and thoughtful application of the mechanisms to new drug design and discovery. One approach is to construct pharmacological activity profiles for promising agents. These profiles are compared among the promising agents and with untested compounds to identify similarities. Classical structure-activity studies are used to find optimal agents (high efficacy with low toxicity) based on good lead agents. Studies evaluating tissue-specific and pharmacokinetic parameters are very important. A final approach is design of mechanism-based assays and identification of mechanism-based intermediate biomarkers for evaluation of chemopreventive efficacy.

Animals↗
PubMed1992

Time-varying stiffness of human elbow joint during cyclic voluntary movement.

The objective of this study was to determine the extent to which subjects modulate their elbow joint mechanical properties during ongoing arm movement. Small pseudo-random force disturbances were applied to the wrist with an airjet actuator while subjects executed large (1 rad) elbow joint movements. Using a lumped parameter model of the muscle, tendon and proprioceptive feedback dynamics, a time-varying system identification technique was developed to analyze the phasic changes in the elbow joint's mechanical response. The mechanical properties were found to be time-varying, and well approximated by a quasi-linear second-order model. The stiffness of the arm was found to drop during movement. The arm was always underdamped, with the damping ratio changing during movement. Inertia estimates were constant and consistent with previous measurements. Overall, the moving arm was found to be very compliant, with a peak stiffness value less than the lowest value measured during posture, and a natural frequency of less than 3 Hz. Changing the speed of movement, or the load from gravity, changed the stiffness measured, but not in strict proportion to the change in net muscle torque.

Adult↗
PubMed2003

Growth, body composition and hormonal axes in children and adolescents.

Growth and physical maturation are dynamic processes that encompass a broad range of cellular and somatic changes. Most investigators who study growth have focused on linear growth (change in height over time), but alterations in the relative body proportions, body composition, and the regional distribution of body fat (upper body vs lower body, axial vs appendicular, and sc vs deep visceral) are essential elements for growth and sexual maturation. In fact, cardiovascular risk assessment in the adult relies heavily on the regional distribution of body fat. The antecedents for the adult pattern of fat are clearly present in the adolescent, if not the younger child. Standards for each of these parameters have been developed for multiple ethnic and racial populations and aid materially in the identification of children with normal growth and physical development, variations within the broad normal (physiological) range, and those with clearly pathological growth patterns.

Adipose Tissue↗
PubMed2005

Degenerate coding in neural systems.

When the dimensionality of a neural circuit is substantially larger than the dimensionality of the variable it encodes, many different degenerate network states can produce the same output. In this review I will discuss three different neural systems that are linked by this theme. The pyloric network of the lobster, the song control system of the zebra finch, and the odor encoding system of the locust, while different in design, all contain degeneracies between their internal parameters and the outputs they encode. Indeed, although the dynamics of song generation and odor identification are quite different, computationally, odor recognition can be thought of as running the song generation circuitry backwards. In both of these systems, degeneracy plays a vital role in mapping a sparse neural representation devoid of correlations onto external stimuli (odors or song structure) that are strongly correlated. I argue that degeneracy between input and output states is an inherent feature of many neural systems, which can be exploited as a fault-tolerant method of reliably learning, generating, and discriminating closely related patterns.

Animals↗
PubMed1991

Quality versus quantity: optimizing evaluation of ectomycorrhizae for plants under stress.

Many single environmental conditions or stresses have been evaluated with respect to formation and survival of ectomycorrhizae (EM). Current interests in atmospheric change include plant responses to pollutants such as ozone, sulfur dioxide, and acidic deposition in the presence of additional stress such as water deficit or plant disease. Stresses that result in formation of fewer EM or death of fine roots are evaluated routinely by quantifying EM, and results are often correlated with parameters that describe host physiology and growth. However, effects of stresses may be subtle, or identification of early plant responses may be desired. In such cases, quantification of EM may not reveal changes in EM formation by individual species of fungi if roots are colonized by other species with no net change in total numbers. Differences among frequencies of morphotypes suggest changes in species diversity of EM-forming fungi. Although the relative benefits of individual species to the host are largely unknown, information provided by qualitative assessment of EM may offer insight to define plant responses to stress and suggest additional research related to benefits of individual EM-forming fungi.

Journal Article↗
PubMed1994

Long-latency event-related potentials in rats: effects of task and stimulus parameters.

Animal models of event-related potentials have recently been developed in rats in order to gain further understanding of the psychobiological variables which underlie these waveforms. In the present study, unanesthetized male Wistar rats, chronically implanted with electrodes, were utilized in order to: (i) compare event-related potentials recorded following the presentation of passively presented auditory stimuli from different neocortical, hippocampal and perihippocampal sites; (ii) test the effects of changes in stimulus probability and loudness on event-related potentials recorded from those sites; and (iii) record event-related potentials from rats who were actively performing in a tone discrimination task. The results of these studies showed that in all electrode sites (frontal cortex, parietal cortex, entorhinal cortex, hippocampus) a series of large amplitude potentials in the 10-200 ms latency range could be recorded in response to passively presented stimuli. Late positive potentials in the 300-400 ms range were only identified in recordings from the posterior cortex, entorhinal area, and dorsal hippocampus. Some of these late positive components were also found to be sensitive to changes in stimulus probability. A similar series of waves were detected in a paradigm where rats were required to actively discriminate between two tones; however, the morphologies of the waveforms were found to be more distinct. These studies suggest that rats may be good subjects for the exploration of the neural origins of event-related potentials. These studies demonstrate that rats performing in an auditory discrimination task can generate electrophysiological potentials which are time locked to the onset of a "cognitively relevant" stimulus (event-related potentials). These potentials can be recorded in limbic (hippocampus and amygdala) and cortical (parietal cortex) brain sites. The event-related potentials recorded in rats respond to changes in stimulus parameters in a similar fashion to those previously described in monkeys and human subjects. The identification of a rat model of event-related potentials provides an opportunity to further explore the neural origins of event-related potentials, to estimate the role of genetics in determining individual variation in waveforms, as well as to provide electrophysiological assays of the effects of various drugs on neurosensory and cognitive processing.

Acoustic Stimulation↗
PubMed1993

An evaluation of two methods of anatomical alignment of radiotherapy portal images.

PURPOSE: Two techniques have been developed at our institution to allow anatomical registration of digitized portal images to a simulation film. Accuracy of the portal image alignment methods is tested and single intrauser and multiple interuser variation is examined using each technique. METHODS AND MATERIALS: Method one requires the identification of anatomical fiducial points on a simulation image and its corresponding portal image. The parameters required to align the corresponding points are calculated by a least squares fit algorithm. Method two uses an anatomical template generated from the simulation image and superimposing it upon a portal image. The template is then adjusted by a computer mouse to obtain the best subjective anatomical fit on the portal image. Megavoltage portal images of a skull phantom with various known shifts and eight clinical image files were aligned by each method. Each data set was aligned several times by both a single user and multiple users. RESULTS: Alignment of the anatomical phantom portal images demonstrates an accuracy of less than 0.8 +/- 0.9 mm and 0.7 +/- 1.0 degrees with either method. As out of plane rotation increased from 0 to 5 degrees, simulating out of plane malpositioning, alignment orthogonal to the plane of rotation worsened to 1.5 +/- 1.1 mm with the point method and 2.4 +/- 1.6 mm with the template method. Alignment parallel to the axis of the gantry rotation was insensitive to this change and remained constant as did the rotational alignment parameters. For the clinical image files the magnitude of variation for a single user is typically less than +/- 1 mm or +/- 1 degree. The magnitude of variation of alignment increased when multiple users aligned the same image files. The variation was dependent upon anatomical site and to a lesser degree the method of alignment used. The root mean square deviation of translational shifts range from +/- 0.68 mm when using the template method in the pelvis to as high as +/- 2.94 mm with the template method to align abdominal portal images. In the thorax and pelvis translational alignments along the horizontal axis were more precise than along the vertical axis. Multiple user variability was in part due to poor image quality, user experience, non rigidity of the anatomical features, and the difficulty in locating an exact point on a continuous anatomical structure. CONCLUSION: In well controlled phantom studies both the fiducial point and template method provide similar and adequate results. The phantom studies show that alignment error and variance increase with distortion in anatomical features secondary to out of plane rotations. In clinical situations intrauser variation is small, however, multiple interuser variation is larger. The magnitude of variation is dependent upon the anatomical site aligned.

Computer Simulation↗
PubMed2005

Myocardial dysfunction in mitochondrial diabetes treated with Coenzyme Q10.

Maternally-inherited diabetes and deafness (MIDD) has been related to an A to G transition in the mitochondrial tRNA Leu (UUR) gene at the base pair 3243. Although some previous articles have reported that this mutation may be a cause of cardiomyopathy in diabetes, the degree of cardiac involvement and a specific treatment has not been established. Here, we reported a case of a patient with MIDD who developed congestive heart failure and the therapeutic usefulness of Coenzyme Q10 (CoQ10). In our patient, after the introduction of Coenzyme Q10 150 mg/day, there was a gradual improvement on left ventricular function evaluated by echocardiography. The fractional shortening (FS) and ejection fraction (EF) increased from 26 to 34% and from 49 to 64%, respectively. No side effects were noted. Three months after CoQ10 discontinuation, the parameters of systolic function evaluated by echocardiography decreased, suggesting that CoQ10 had a beneficial effect. Identification of diabetes and cardiomyopathy due to mitochondrial gene mutation may have therapeutic implications and Coenzyme Q10 is a possible adjunctive treatment in such patients.

Adult↗
PubMed2005

Automatic morphometry of synaptic boutons of cultured cells using granulometric analysis of digital images.

Numbers, linear density, and surface area of synaptic boutons can be important parameters in studies on synaptic plasticity in cultured neurons. We present a method for automatic identification and morphometry of boutons based on filtering of digital images using granulometric analysis. Cultures of cortical neurons (DIV8 and DIV21) were fixed and marked with fluorescently labeled antibodies for synapsin I (a marker for synaptic boutons) and MAP-2 (a marker for dendrites). Images were acquired on a confocal microscope and automatically processed. Granulometry, a morphological operator sensitive to the geometry and size of objects, was used to construct a filter passing fuzzy fluorescent grains of a certain size. Next, the filter was overlaid with the original image (masking) and the positive pixels were identified by an integral intensity threshold (thresholding). Disjoint grains, representing individual boutons, were reconstructed from the connected pixels above the threshold, numbered and their area was measured. In total, 1498 boutons with a mean diameter of 1.63 +/- 0.49 microm (S.D.) were measured. Comparisons with manual counts showed that the proposed method was capable of identifying boutons in a systematic manner at the light microscopic level and was a viable alternative to manual bouton counting.

Algorithms↗
PubMed2004

Validation of a cardiac monitor for measuring heart rate variability in adult female pigs: accuracy, artefacts and editing.

Autonomic regulation of cardiac activity during stress has not been clearly defined in farm animals. In part, this is due to the limited availability of affordable ambulatory cardiac monitors capable of accurately monitoring and storing large amounts of data that meet the criteria necessary for heart rate variability analysis. Our objectives were to measure the accuracy of a 24-h Polar RR monitor using gold standard ECG, to examine and categorise any occurring anomalies and to ascertain their impact on the outcome of heart rate variability analysis. Five 1-year-old female pigs (gilts) were socially isolated from their pen mates and cardiac activity was simultaneously measured using two systems, a 24-h Polar RR Recorder and a Telemetric ECG system. The Polar data were manually assessed both against and in isolation of the ECG data to identify anomalous beats, which were then assigned to one of five identified error categories. The anomalies in the Polar data were corrected and statistical comparisons were performed among the three data sets to evaluate the effects of anomalies on heart rate variability analysis. Bland-Altman analysis was used to measure the level of agreement among the ECG, Uncorrected Polar and Corrected Polar data. No anomalies or ectopies were found in the ECG data but 46 anomalies (0.81% of total interbeat intervals [IBI]) were found in the Polar Uncorrected data. Manual identification and editing procedures reduced this error to 0.018%. Most mean heart rate and IBI parameters were unaffected by error (P>.05). Standard deviation (S.D.) and root mean square of successive differences (RMSSD) were 45% and 50% higher when anomalies were present in the data. Artefacts affected the magnitude of the frequency domain indices and overestimated total and parasympathetic activity and underestimated sympathetic activity. The mean difference between ECG and Uncorrected Polar data was 1.36 ms (limits of agreement -69.03 to 71.74 ms). This was greatly improved to 0.36 ms (limits of agreement -5.37 to 6.10 ms) after editing. Overall, even a small proportion of error biased the outcome of heart rate variability analysis. This bias was greatly reduced by correcting the anomalous beats. Bland-Altman analysis demonstrated that when there was error present in the Polar data, it could not be used interchangeably with the ECG data. However, if there were no anomalies present in the data or if they were classified and corrected using the approach in this study, then the two systems could be used interchangeably.

Animals↗
PubMed1975

Observations on the heat stability and electrophoretic pattern of alkaline phosphatases extracted from various tissues.

Various tissues were extracted with either normal saline or heat inactivated serum (HIS) and the heat stability and electrophoretic migration of the alkaline phosphatase enzymes (AP) of the extracts were compared to the heat stability and electrophoretic properties of serum AP. The electrophoretic pattern of HIS extracts of liver and bone differed from that of saline extracts but the pattern was unaffected if HIS was added to the saline extracts. The heat stabilities of the tissue AP also differed depending on whether they were extracted with saline or HIS. However, serum AP heat stability can help differentiate between liver and bone disease. It is concluded that the comparison of serum and tissue AP heat stabilities or the comparison of serum and tissue AP electrophoretic patterns as criteria for identification of the tissue source of the serum enzyme may be misleading since both these parameters vary, depending on the medium used for extracting the tissue and the extract(s) may contain a mixture of enzymes different from that in serum. It is further concluded from the electrophoretic studies on tissue AP that the increased serum AP in patients with hepatobiliary disease was unlikely to be due to regurgitation of bile but due to increased synthesis and release of alpha 1 and alpha 2 AP isoenzymes from liver, bile ducts or gall bladder. In patients with bone disease the increased serum AP is derived from bone. The source of the serum AP of "normal" subjects may be either liver or vascular tissue or both.

Alkaline Phosphatase↗
PubMed2003

Separation and identification of photodegradation products of benzoic acid by capillary zone electrophoresis.

A capillary zone electrophoresis (CZE) method was developed for separation and identification of photodegradation products of benzoic acid under irradiation at a wavelength of 300 nm. Parameters such as run buffer, applied voltage and injection time were optimized for the separation of benzoic acid and its photodegradation products. Linearity, limit of detection, and repeatability of migration time as well as peak area of the method were examined. Four reaction products, including salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and 3,4-dihydroxybenzoic acid have been separated and identified by spiking the known compounds into the irradiated samples using the CZE method developed. The confirmation of the reaction products is one of the key steps for proposing the possible reaction mechanisms involved in the photodegradation of benzoic acid.

Benzoic Acid↗
PubMed1983

Structure of a novel Bence-Jones protein (Rhe) fragment at 1.6 A resolution.

The crystal structure of Rhe, a lambda-type Bence-Jones protein fragment, has been solved and refined to a resolution of 1.6 A. A model fragment consisting of the complete variable domain and the first three residues of the constant domain yields a crystallographic residual RF value of 0.149. The protein exists as a dimer both in solution and in the crystals. Although the "immunoglobulin fold" is generally preserved in the structure, there are significant differences in both the monomer conformation and in the mode of association of monomers into dimers, when compared to other known Bence-Jones proteins or Fab fragments. The variations in conformation within monomers are particularly significant as they involve non-hypervariable residues, which previously were believed to be part of a "structurally invariant" framework common to all immunoglobulin variable domains. The novel mode of dimerization is equally important, as it can result in combining site shapes and sizes unobtainable with the conventional mode of dimerization. A comparison of the structure with other variable domain dimers reveals further that the variations within monomers and between domains in the dimer are coupled. Some possible functional implications revealed by this coupling are greater variability, induced fitting of the combining site to better accommodate antigenic determinants, and a mechanism for relaying binding information from one end of the variable domain dimer to the other. In addition to providing the most accurate atomic parameters for an immunoglobulin domain yet obtained, the high resolution and extensive refinement resulted in identification of several tightly bound water molecules in key structural positions. These water molecules may be regarded as integral components of the protein. Other water molecules appear to be required to stabilize the novel conformation.

Amino Acid Sequence↗
PubMed1997

Epidemiology tools program and selected medical applications.

In epidemiological research the calculation of appropriate measures of disease frequency is the basis for a comparison of populations and, therefore, the identification of disease determinants. Two frequencies being compared can be combined into a single summary parameter that estimates the association between an exposure and a disease. This can be accomplished by calculating either the ratio of the measures of disease frequency for two populations which indicates how much more likely one population is to develop a disease than another, or the difference between the frequencies which indicates how much greater the frequency of a disease is in one population compared with the other. In epidemiology we often need to compute measures of disease frequency mentioned above. We can do that by means of complex statistical software, but sometimes it is not easy or possible to use this software for an analysis of epidemiological data. At the EuroMISE Center of Charles University and Academy of Sciences in the framework of the research supported from grant COPERNICUS JRP-10053 the E. T. program (Epidemiology Tools) was developed. This program can be used for practical analysis of data from retrospective (case-control) studies or prospective (cohort) studies and for standardization. However, the program can be also a useful teaching tool in the epidemiology courses.

Adolescent↗
PubMed2005

Identification of N-(hydroxymethyl) norcotinine as a major product of cytochrome P450 2A6, but not cytochrome P450 2A13-catalyzed cotinine metabolism.

Cotinine formation is the major pathway of nicotine metabolism in smokers, and the primary pathway of cotinine metabolism is trans-3'-hydroxylation. trans-3'-Hydroxycotinine and its glucuronide conjugate account for up to 50% of the nicotine metabolites excreted by smokers. Minor metabolites of cotinine excreted by smokers include norcotinine and cotinine N-oxide, each of which account for <5% of the nicotine dose. It has been reported that P450 2A6 is the catalyst of cotinine metabolism. However, we report here that the major product of P450 2A6-catalyzed cotinine metabolism is N-(hydroxymethyl)norcotinine, a previously unknown human metabolite of cotinine. N-(Hydroxymethyl)norcotinine was chemically synthesized, and its stability under the conditions of the enzyme reactions was confirmed. The products of P450 2A6-catalyzed [5-3H]cotinine metabolism were quantified by radioflow HPLC. The identification of N-(hydroxymethyl)norcotinine as the major metabolite was based on HPLC analysis on three unique systems and coelution with N-(hydroxymethyl)norcotinine standard. 5'-Hydroxycotinine and trans-3'-hydroxycotinine were minor products of P450 2A6-catalyzed cotinine metabolism, accounting for 14 and 8% of the total cotinine metabolites, respectively. N-(Hydroxymethyl)norcotinine was a product of cotinine metabolism by the extrahepatic P450, 2A13, but it was a minor one. The major product of P450 2A13-catalyzed cotinine metabolism was 5'-hydroxycotinine, which was formed at twice the rate of trans-3'-hydroxycotinine. The identification of all cotinine metabolites formed by both enzymes was confirmed by LC/MS/MS analysis. Kinetic parameters for cotinine metabolism were determined for P450 2A6 and P450 2A13. This work has confirmed that the major metabolite of cotinine in smokers, trans-3'-hydroxycotinine, is only a minor metabolite of P450 2A6-catalyzed cotinine metabolism.

Chromatography, High Pressure Liquid↗
PubMed1981

Probing the active site of glyoxalase I from human erythrocytes by use of the strong reversible inhibitor S-p-bromobenzylglutathione and metal substitutions.

Glyoxalase I from human erythrocytes was studied by use of the strong reversible competitive inhibitor S-p-bromobenzylglutathione. Replacements of cobalt, manganese and magnesium for the essential zinc in the enzyme were made by a new procedure involving 10% methanol as a stabilizer of the enzyme. The K(m) value for the adduct of methylglyoxal and glutathione was essentially unchanged by the metal substitutions, whereas the inhibition constant for S-p-bromobenzylglutathione increased from 0.08mum for the Zn-containing enzyme to 1.3, 1.7 and 2.4mum for Co-, Mn- and Mg-glyoxalase I respectively. Binding of the inhibitor to the enzyme caused quenching of the tryptophan fluorescence of the protein, from which the binding parameters could be determined by the use of non-linear regression analysis. The highest dissociation constant was obtained for apoenzyme (6.9mum). The identity of the corresponding kinetic and binding parameters of the native enzyme and the Zn(2+)-re-activated apoenzyme and the clear differences from the parameters of the other metal-substituted enzyme forms give strong support to the previous identification of zinc as the natural metal cofactor of glyoxalase I. Binding to apoenzyme was also shown by the use of S-p-bromobenzylglutathione as a ligand in affinity chromatography and as a protector in chemical modification experiments. The tryptophan-modifying reagent 2-hydroxy-5-nitrobenzyl bromide caused up to 85% inactivation of the enzyme. After blocking of the thiol groups (about 8 per enzyme molecule) 6.1 2-hydroxy-5-nitrobenzyl groups were incorporated. Inclusion of S-p-bromobenzylglutathione with the modifying reagent preserved the catalytic activity of the enzyme completely and decreased the number of modified residues to 4.4 per enzyme molecule. The findings indicate the presence of one tryptophan residue in the active centre of each of the two subunits of the enzyme. Thiol groups appear not to be essential for catalytic activity. The presence of at least two categories of tryptophan residues in the protein was also shown by quenching of the fluorescence by KI.

Binding Sites↗
PubMed2001

Detection of clonal T-cell receptor gamma gene rearrangements using fluorescent-based PCR and automated high-resolution capillary electrophoresis.

BACKGROUND: Analysis of T-cell receptor gamma (TCR gamma) gene rearrangements by PCR is a powerful tool for detecting clonal T-cell populations for the diagnosis of lymphoid neoplasms. We report a method for TCR gamma PCR analysis using capillary electrophoresis (CE). METHODS AND RESULTS: To define the threshold for identification of a predominant monoclonal population within a polyclonal background, we developed a novel objective parameter of the peak height ratio (Rn) of the peak of interest and the average of the two immediate flanking peaks. After evaluation of monoclonal, reactive, and normal T-cell populations, an Rn of 3.0 or greater was determined to be consistent with a monoclonal population, whereas an Rn between 1.9 and 3.0 was considered an intermediate range. This CE method was compared with the standard denaturing gradient gel electrophoresis (DGGE) method using previously evaluated clinical specimens. Eleven of 12 clinical specimens (92%) with a definitive diagnosis of T-cell lymphoma were monoclonal by CE, with 100% concordance with the DGGE method. Of nine specimens morphologically suspicious for T-cell lymphoma, five specimens were positive by CE analysis compared with four specimens by DGGE. In addition, 14 specimens for staging from patients with known T-cell lymphoma were studied using both the CE and DGGE methods, with a concordance of 86%. CONCLUSION: CE is a powerful and efficient method for analysis of clonality by TCR gamma PCR.

Biopsy↗
PubMed1995

[The diagnosis of acute pulmonary embolism: a comparison between spiral CT and DSA in an animal experiment].

PURPOSE: The value of helical computed tomography (CT) for diagnosis of acute pulmonary embolism was assessed and compared with digital subtraction angiography (DSA) as a reference method. MATERIAL AND METHODS: In 11 dogs, lobar, segmental, and subsegmental occlusions of the pulmonary arteries were produced. Subsequent to selective pulmonary angiography, the animals were examined with contrast-enhanced helical CT. RESULTS: In the main and lobar pulmonary arteries there was a complete correlation between CT and DSA in documentation of total and partial embolic occlusions. Identification of segmental and subsegmental pulmonary emboli by CT required a second run with optimized parameters in 7 of 11 cases. Nevertheless, 18% of the peripheral arteries could not be classified. CONCLUSION: Helical CT as less invasive modality is competitive with DSA in demonstration of central pulmonary emboli. However, CT imaging of peripheral pulmonary emboli requires optimal bolus timing.

Acute Disease↗