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PubMed1999

[Filmless magnetic resonance tomography. Advantages and disadvantages in comparison with film reports].

At our hospital, an average MRI examination comprises 170 images. These examinations were evaluated exclusively on digital reporting systems with two high-resolution monitors for a period of 1 year. A retrospective analysis of this reporting method in comparison with films on a conventional viewing wall was performed with subjective and objective data. Radiologists and technicians were requested to evaluate the system on a subjective scale from 1 to 5 for seven topics (image analysis, inspection, time for reporting, handling, comparison with previous reports, quality of PC laser prints, training period). Moreover, personal interviews were conducted and protocols taken. Patient and image frequency, film costs, data transfer time and amount of system failures were evaluated as objective data. The most important results were: Two thirds of the film checking radiologists prefer the conventional viewing walls over the computer monitors. However, 70% of the residents prefer using the computer monitor for reporting. Seventy percent of the interviewed radiologists considered comparison with former examinations on film very difficult. Digitizing of former MRI examinations was not a convincing method; printing on a standard PC laser printer was considered to yield insufficient quality. The different acceptance between radiologists and residents seems to be related to different experiences. The reduction in film costs (48.6%) will improve further with complete PACS installation in the whole hospital. Data transfer rates are still poor; further improvement of network performance is necessary for convenient work. One whole MRI examination and report could be stored on CD-ROM for a cost of less than 2 euros. This could be a future means of cheap archiving and documentation suitable for viewing on any PC with DICOM III viewer. Images and reports could stay with the patients as in the past.

Computer Peripherals↗

PubMed2002

Results from interlaboratory comparisons of aldehyde-2,4 dinitrophenylhydrazone analysis.

Within the framework of the SMT "Aldehydes" project (SMT4-CT97-2910) three laboratory comparisons have been organized in which artificial aldehyde hydrazone samples have been distributed among participating laboratories. To these samples potentially interfering compounds have been added to simulate as closely as possible real air or air emission samples.In addition to the "Aldehydes" project partners external EU laboratories have participated. It may, therefore, be assumed that the results of these comparisons reflect the state-of-the-art in the analytical determination of aldehydes in air samples using the 2,4-dinitrophenylhydrazine (DNPH)-method. In this paper several aspects of the organization of these comparisons and the overall results obtained are presented. These demonstrate that results obtained using liquid chromatographic techniques are usually comparable between laboratories within +/-2 times the coefficient of variation (approximately 6-15%), indicating the robustness of the methodology. In addition, laboratory (liquid chromatography) mean results can be made to agree with preparation concentrations at the 95% confidence levels after optimization of separation and integration conditions; these are mainly related to the measurement of formaldehyde in the presence of interferents and the measurement of low concentrations of acrolein and acetone. Some problem areas still remain, however--namely the measurement of glutaraldehyde and the measurement of low levels of acetone.

Journal Article↗

PubMed2004

Posture-based or trajectory-based movement planning: a comparison of direct and indirect pointing movements.

Various models have been proposed in the literature to explain the control of human arm movements. To make a quantitative comparison between the predictions of various models, we tested subjects for movements to targets on a vertical screen in various conditions. Subjects were asked to move directly from one target to another, or to move by a via-point, at various movement velocities and in a condition with a weight of 0.6 kg attached to the forearm. This set of experimental data was used for comparison with the predictions by various posture-based and trajectory-based models on 3-D movement planning and control. Small but significant effects of starting position and path towards the target were found on the torsion of the arm at the end of the movement. No effects of movement velocity and weight attached to the forearm were found. The experimental results differed significantly from the predictions by any of the models considered. Of the models considered, Donders' law best predicts the experimental data. Our data indicate that future tests of models for motor control (1) should compare the predictions of not just one, but several models to a data set, and (2) should include not only planar, but rather 3-D movements in such a comparison.

Acceleration↗

PubMed2002

Comparison of substitution rates in ZFX and ZFY introns of sheep and goat related species supports the hypothesis of male-biased mutation rates.

There is a growing body of evidence that males serve as the major generators of mutations, due to the larger number of cell divisions involved in sperm compared to egg production. In mammals, this hypothesis (referred to as "male-driven evolution") has been tested by comparison of nucleotide substitution rates on the X and Y sex chromosomes in a limited number of taxa, predominantly primates and rodents. This study asks whether male-driven evolution is a more general phenomenon among mammals, by comparison of paralogous ZFX and ZFY intron sequences in sheep and goat species (the tribe Caprini). The male-to-female mutation ratio, alpha(m), was estimated to be between 2.93 (95% CI, 1.51-8.61) and 3.94 (95% CI, 1.25-32.29) when calculated using pairwise distance and branch length, respectively, suggesting that the Caprini are subject to weak, male-driven evolution. Comparison to published values for primates, felids, and rodents implies that there may be some correlation with reproductive life span. However, this is difficult to test with current data because confidence intervals are large and overlapping. Nonindependent evolution of paralogous sequences and/or the presence of selective constraints could lead to inaccurate estimates of alpha(m). No evidence for gene conversion between the ZFX and the ZFY introns was found, and this suggests that they have evolved independently during the radiation of the Caprini. Finally, there was no apparent evidence that these introns are subject to selective constraints, although low levels of intraspecific polymorphism reduce the power of neutrality tests.

Animals↗

PubMed2006

A genomic comparison of faster-sex, faster-X, and faster-male evolution between Drosophila melanogaster and Drosophila pseudoobscura.

A genomic comparison of Drosophila melanogaster and Drosophila pseudoobscura provides a unique opportunity to investigate factors involved in sequence divergence. The chromosomal arrangements of these species include an autosomal segment in D. melanogaster which is homologous to part of the X chromosome in D. pseudoobscura. Using orthologues to calculate rates of nonsynonymous (d(N)) substitutions, we found genes on the X chromosome to be significantly more diverged than those on the autosomes, but it is not true for segment 3L-XR which is autosomal in D. melanogaster (3L) and X-linked in D. pseudoobscura (XR). We also found that the median d(N) values for genes having reproductive functions in either the male, the female, or both sexes are higher than those for sequences without reproductive function and even higher for sequences involved in male-specific function. These estimates of divergence for male sex-related sequences are most likely underestimates, as the very rapidly evolving reproductive genes would tend to lose homology sooner and thus not be included in the comparison of orthologues. We also noticed a high proportion of male reproductive genes among the othologous genes with the highest rates of d(N). Reproductive genes with and without an orthologue in D. pseudoobscura were compared among D. melanogaster, D. simulans, and D. yakuba and it was found that there were in fact higher rates of divergence in the group without a D. pseudoobscura orthologue. These results, from widely separated taxa, bolster the thesis that sexual system genes experience accelerated rates of change in comparison to nonsexual genes in evolution and speciation.

Animals↗

PubMed2006

Sequence of the tomato chloroplast DNA and evolutionary comparison of solanaceous plastid genomes.

Tomato, Solanum lycopersicum (formerly Lycopersicon esculentum), has long been one of the classical model species of plant genetics. More recently, solanaceous species have become a model of evolutionary genomics, with several EST projects and a tomato genome project having been initiated. As a first contribution toward deciphering the genetic information of tomato, we present here the complete sequence of the tomato chloroplast genome (plastome). The size of this circular genome is 155,461 base pairs (bp), with an average AT content of 62.14%. It contains 114 genes and conserved open reading frames (ycfs). Comparison with the previously sequenced plastid DNAs of Nicotiana tabacum and Atropa belladonna reveals patterns of plastid genome evolution in the Solanaceae family and identifies varying degrees of conservation of individual plastid genes. In addition, we discovered several new sites of RNA editing by cytidine-to-uridine conversion. A detailed comparison of editing patterns in the three solanaceous species highlights the dynamics of RNA editing site evolution in chloroplasts. To assess the level of intraspecific plastome variation in tomato, the plastome of a second tomato cultivar was sequenced. Comparison of the two genotypes (IPA-6, bred in South America, and Ailsa Craig, bred in Europe) revealed no nucleotide differences, suggesting that the plastomes of modern tomato cultivars display very little, if any, sequence variation.

Amino Acid Sequence↗

PubMed2000

Phylogeny of the restriction endonuclease-like superfamily inferred from comparison of protein structures.

To date all attempts to derive a phyletic relationship among restriction endonucleases (ENases) from multiple sequence alignments have been limited by extreme divergence of these enzymes. Based on the approach of Johnson et al. (1990), I report for the first time the evolutionary tree of the ENase-like protein superfamily inferred from quantitative comparison of atomic coordinates of structurally characterized enzymes. The results presented are in harmony with previous comparisons obtained by crystallographic analyses. It is shown that lambda-exonuclease initially diverged from the common ancestor and then two "endonucleolytic" families branched out, separating "blunt end cutters" from "5' four-base overhand cutters." These data may contribute to a better understanding of ENases and encourage the use of structure-based methods for inference of phylogenetic relationship among extremely divergent proteins. In addition, the comparison of three-dimensional structures of ENase-like domains provides a platform for further clustering analyses of sequence similarities among different branches of this large protein family, rational choice of homology modeling templates, and targets for protein engineering.

Catalytic Domain↗

PubMed2000

Comparison of embryonic development and metal contamination in several populations of the sea urchin Sphaerechinus granularis (Lamarck) exposed to anthropogenic pollution.

Over the past years the functional deficiencies observed in the sea urchin Sphaerechinus granularis from the Bay of Brest (France) have led us to select several populations within this species to assess water quality in the Bay of Brest. The present study reports on the comparison of the quality of embryonic development and of the level of metal contamination in sea urchin gonads and gut wall in four populations. Three of them lived in the Bay of Brest, and the last one was considered a reference, being settled in the Glénan Archipelago in southern Brittany (France). The sea urchin population living at the mouth of the River Aulne, at the Armorique Point, seemed to be the most affected, for it displayed the highest rate of blockage and the longest delay in embryonic development along with the highest concentrations in heavy metals, i.e., Fe, Cu, Pb, Cd, and Hg, in the gut wall and in the gonads. A comparison with previous data highlighted a degradation of health conditions in the population living at Marloux in the vicinity of Brest harbor. The comparison of the metal levels detected in individuals from these two populations with the data reported in the literature allowed us to conclude for a local contamination of the bay waters by Fe and Hg. In addition, this study also revealed that Zn and Cd concentrations were sometimes higher than the maximum values reported in the literature and evidenced an increase of contamination by Cu and Pb over the period of study; it should be noted, however, that these values were not excess levels. Our investigations also suggest that Zn, Cd, Pb, and Cu levels should be monitored in the future.

Animals↗

PubMed2006

Visualization of intrarenal vessels by 3.0-T MR angiography in comparison with digital subtraction angiography using renal specimens.

BACKGROUND: MRI at 3.0 T enables high-spatial resolution for renal MR angiography. OBJECTIVE: Evaluation of an arterial tree model in animal kidney specimens with comparison of digital subtraction angiography (DSA) and high-field MRI to find out the maximum spatial resolution of intrarenal vessels. It was considered that objective quantitation of angiogram quality could be achieved. MATERIALS AND METHODS: A total of 27 pig kidney specimens were examined by MR angiography (flash 3D) using a 3.0-T scanner (TRIO; Siemens, Erlangen, Germany) with an eight-channel head coil and a voxel size of 0.9x0.9x1.1 mm in the early arterial phase after implantation of a 4F catheter in the renal artery. DSA (Integris, Philips, Best, The Netherlands) was performed immediately after the MRI. With the help of semiautomated segmentation, all vessels were marked for comparison of the vessel trees. The Wilcoxon rank test was used for statistical evaluation of vessel numbers and branching depths. RESULTS: Objective comparison between DSA and MR angiography was achieved. High-field MR angiography had the ability to depict vessels up to the seventh branching on average. Significant differences in vessel delineation and counts were found from the fifth level of intrarenal branching onwards with DSA showing an advantage. CONCLUSION: High-field MRI has great potential in the detection of intrarenal arteries and is comparable to DSA in visualization of the central intrarenal vessel tree.

Angiography, Digital Subtraction↗

PubMed1997

Radiation dose to technicians per nuclear medicine procedure: comparison between technetium-99m, gallium-67, and iodine-131 radiotracers and fluorine-18 fluorodeoxyglucose.

The aim of this study was to determine the non-extremity gamma dose received by a technician while performing an ordinary nuclear medicine procedure or a static (i.e. without blood sampling) fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) study. The dose per patient was measured by means of a commercial electronic pocket Geiger Mueller dosimeter, worn in the upper left pocket of the overalls. This was previously tested by exposure to known point sources of technetium-99m, gallium-67, iodine-131 and fluorine-18 in the air. A further test was performed with 99mTc, 131I and 18F sources inserted in a water phantom to simulate the condition of high scattering degradation of the primary radiation due to the patient's tissues. Subsequently, the dose was measured by two technicians for a total of 314 clinical cases, covering the most common nuclear medicine procedures, including 44 static, two-level FDG PET studies with repositioning of the patient on the couch between the transmission and the emission scan and seven whole-body PET studies. The dose read by the dosimeter was corrected for environmental background and for detector efficiency measured with sources in the air. For a limited subset of cases, the time spent close to patients was also measured. Doses were then estimated by a crude non-absorbing point source approximation and by using experimental dose rates. A comparison between experimental and estimated doses, as well as with previously published data, completed the work. For most of the conventional procedures, the measured dose per procedure proved to be within the range 0.2-0.4 microSv, except for equilibrium angiocardioscintigraphy (1.0+/-0.5 microSv) and 99mTc-sestamibi single-photon emission tomography (1. 7+/-1.0 microSv). Comparison with data published in the last 20 years shows that our values are generally lower. The current more favourable working conditions are a result of technological improvements (for instance two-head gamma cameras capable of whole-body studies), and safer shielding and distance from patients. Two-level PET gave 11.5+/-4.4 microSv and whole-body PET 5.9+/-1.2 microSv. In a subset of patients these values could be subdivided into the separate contributions from each phase of the procedure. They were: 0.11+/-0.04 microSv for daily quality assurance, 2.9+/-3.0 microSv for two transmission scans, 0.3+/-0.1 microSv for syringe preparation, 2.8+/-1.8 microSv for injection and escorting the patient to the waiting room, 1.7+/-1.5 microSv for a whole-body emission scan, 7.7+/-5.2 microSv for two emission scans, and 0.8+/-0. 2 microSv for patient departure. The higher value from PET by comparison with conventional procedures is attributable to the higher specific gamma constant of 18F, as well as the longer time required for accurate positioning.

Fluorine Radioisotopes↗

PubMed1998

Comparison of metabolic and receptor imaging in recurrent medullary thyroid carcinoma with histopathological findings.

Early diagnosis of metastases of medullary thyroid carcinoma (MTC) provides the optimal condition for curative outcome. The aim of this study was to appraise the detection of metastases in patients with recurrent MTC using [111In-DTPA-d-Phe1]-pentetreotide and pentavalent technetium-99m dimercaptosuccinic acid [99mTc(V)-DMSA] in comparison with histopathological findings. Eighteen MTC patients with persistently elevated tumour marker (calcitonin, carcinoembryonic antigen) levels underwent somatostatin receptor scintigraphy using [111In-DTPA-d-Phe1]-pentetreotide (222 MBq) with early (4 h after injection) and delayed (24 h) whole-body scans and single-photon emission tomography (SPET) imaging. Metabolic whole-body and SPET imaging using 500 MBq 99mTc(V)-DMSA was performed 4 h after injection. Metabolic and receptor imaging revealed 51 sites of focal accumulation in the 18 patients investigated. Comparison with histological findings revealed that metabolic and receptor imaging had a sensitivity of 84% for the diagnosis of MTC. Using [111In-DTPA-d-Phe1]-pentetreotide, SPET discovered four lymph node metastases in two patients in whom planar views had previously identified only one lymph node metastasis, and provided no new information in the other 16 patients. In comparison, SPET studies [using 99mTc(V)-DMSA] additionally localized eight lymph node metastases in four patients and confirmed the diagnosis of hepatic metastases (n=5) in another patient in whom conventional imaging modalities and planar views had previously detected only three liver metastases. Overall, lesion detection sensitivities for 99mTc(V)-DMSA and [111In-DTPA-D-Phe1]-pentetreotide were 69% and 29%, respectively. Five surgically removed foci were adjudged false-positive with respect to MTC metastases. False-positve results were caused by lymphadenitis, an enchondroma and a pheochromocytoma (histologically proven). The smallest lesion identified by metabolic imaging was a 6 mm in diameter lymph node metastasis located in the upper mediastinum. Somatostatin receptor scintigraphy only demonstrated tumour sizes more than 1 cm in diameter. These preliminary results suggest that the combination of metabolic [99mTc(V)-DMSA] and receptor ([111In-DTPA-D-Phe1]-pentetreotide) imaging is more sensitive for tumour localization in patients with recurrent MTC than the use of only one radiopharmaceutical. However, neither 99mTc(V)-DMSA nor [111In-DTPA-D-Phe1]-pentetreotide is specific for MTC and false-positive scintigraphic findings have to be considered. Furthermore, somatostatin receptor scintigraphy cannot visualize small tumour sites (<1 cm). Further studies are needed to evaluate the role of combined metabolic and receptor imaging in the management of patients with recurrent MTC.

Carcinoma, Medullary↗

PubMed2007

Adjusted indirect comparison of celecoxib versus rofecoxib on cardiovascular risk.

To compare the magnitude of celecoxib versus rofecoxib on the cardiovascular risk. We performed adjusted indirect comparison of celecoxib versus rofecoxib for cardiovascular events using two data on The Adenomatous Polyp Prevention on Vioxx (APPROVe) trial and Adenoma Prevention with Celecoxib (APC) trial. Baseline characteristics of the patients and placebos were comparable in both trials, in terms of age, sex, hypertension, diabetes mellitus, smoking, and hypercholesterolemia. The overall incidence of cardiovascular events was similar in both groups (rofecoxib 48/1,287 versus celecoxib 48/1,356, p = 0.79). The relative risks (RRs) of all myocardial infarction or sudden death from cardiac causes were increased in both rofecoxib and celecoxib groups [rofecoxib versus placebo; RR 1.35, 95% confidence interval (CI) 1.07-1.69, p = 0.03, celecoxib versus placebo; RR 1.35, 95% CI 1.14-1.51, p = 0.01]. The RRs for cardiovascular events derived from the adjusted indirect comparisons of the two coxibs did not significantly differ from unity (celecoxib versus rofecoxib; RR 0.95, 95% CI 0.76-1.19, p = 0.67). The adjusted indirect comparison analysis shows that celecoxib and rofecoxib may have similarly effect of cardiovascular events when used for 3 years.

Adenoma↗

PubMed2001

Clinical evaluation of a new stationary high strip density antiscatter grid in comparison with a conventional moving grid: influence on image quality and patient radiation dose.

This study aimed to evaluate a new stationary 13/75 antiscatter grid in comparison with a moving 12/40 grid with regard to its influence on image quality and patient radiation dose. One hundred consecutive patients had plain films of the abdomen using a moving 12/40 grid and another 100 patients were examined with a stationary 13/75 grid (tube voltage 73 kV, film size 35 cm x 43 cm, film-screen system speed class 400). As an intraindividual comparison, radiographs of the abdomen with a film size of 18 cm x 43 cm were taken of 27 patients using both grid types for every patient. Patients' weight and dose-area product were recorded. Image quality was evaluated by a multireader study using standardized questionnaires and three- or five-level grading systems. Results showed that use of the 13/75 grid accords with the ALARA principle: measurement of the dose-area product demonstrated a dose saving of 24% for a film size of 35 cm x 43 cm and a saving of 34% for a film size of 18 cm x 43 cm without calling into question the diagnostic image quality. The mean scores of the 12/40 grid were lower for three out of six normal anatomic structures (P<0.05) among the 200 patients, indicating a loss of image quality with the 13/75 grid. Assessment of the intraindividual trial revealed reduced detectability of three out of four anatomical details when the 13/75 grid was employed. At the cost of a minor loss of image quality in comparison with the 12/40 grid, the new stationary grid provides a clear reduction of radiation dose under clinical circumstances.

Aged↗

PubMed2000

Functional characterisation of LKT1, a K+ uptake channel from tomato root hairs, and comparison with the closely related potato inwardly rectifying K+ channel SKT1 after expression in Xenopus oocytes.

A cDNA encoding a novel inwardly rectifying potassium (K+(in)) channel, LKT1, was cloned from a root-hair-specific cDNA library of tomato (Lycopersicon esculentum Mill.). The LKT1 mRNA was shown to be most strongly expressed in root hairs by Northern blot analysis. The LKT1 channel is a member of the AKT family of K+(in) channels previously identified in Arabidopsis thaliana (L.) Heynh. and potato (Solanum tuberosum L.). Moreover, LKT1 is closely related (97% identical amino acids) to potato SKT1. An electrophysiological comparison of the two channels should therefore assist the identification of possible molecular bases for functional differences. For, this comparison, both channels were functionally expressed and electrophysiologically characterised within the same expression system, i.e. Xenopus laevis oocytes. Voltage-clamp measurements identified LKT1 as a K(+)-selective inward rectifier which activates with slow kinetics upon hyperpolarising voltage pulses to potentials more negative than -50 mV. The activation potential of LKT1 is shifted towards positive potentials with respect to SKT1 which might be due to single amino acid exchanges in the rim of the channel's pore region or in the S4 domain. Like SKT1, LKT1 reversibly activated upon shifting the external pH from 6.6 to 5.5, which indicates a physiological role for pH-dependent regulation of AKT-type K+(in) channels. The pharmacological inhibitor Cs+, applied externally, inhibited K+(in) currents mediated by LKT1 and SKT1 half-maximally with a concentration (IC50) of 21 microM and 17 microM, respectively. In conclusion, LKT1 may serve as a low-affinity influx pathway for K+ into root hair cells. Comparison of homologous K+(in) rectifiers from different plant species expressed in the same heterologous system allows conclusions to be drawn in respect to structure-function relationships.

Amino Acid Sequence↗

PubMed2005

Comparison of endoscopic techniques vs Shouldice and other open nonmesh techniques for inguinal hernia repair: a meta-analysis of randomized controlled trials.

BACKGROUND: We performed a scientific evaluation of the efficacy of different surgical techniques for inginual hernia repair and supported our findings by conducting a systematic review of randomized studies comparing endoscopic with open nonmesh suture techniques. METHODS: After an extensive search of the literature, a total of 27 studies (41 publications) with evidence level lb were identified. These studies randomly compared endoscopic with open nonmesh suturing techniques. The quality of data sufficed to enable a quantitative meta-analysis of various parameters using the original software of the Cochrane Collaboration. Due to its superiority in comparison to other open nonmesh suturing techniques, the Shouldice repair technique was analyzed separately. RESULTS: The systematic comparison of endoscopic techniques with the Shouldice repair showed that these techniques had significant advantages in terms of the following parameters: total morbidity, hematoma, nerve injury, and pain-associated parameters such as time to return to work, and chronic groin pain. The Shouldice operation has the advantages of a shorter operating time and a lower incidence of wound seroma. There was no difference regarding the incidence of major complications, wound infection, testicular atrophy, or hernia recurrence. Open non-Shouldice suturing techniques are associated with higher recurrence rates and more wound infections than endoscopic operations. CONCLUSION: In comparison to open nonmesh suture repair techniques, endoscopic repair techniques have significant advantages in terms of pain-associated parameters. For the revaluation of long-term complications such as hernia recurrence and chronic groin pain, further clinical examination of the existing study collectives is needed.

Atrophy↗

PubMed2004

[Comparison of urokinase type plasminogen activators (uPA) and plasminogen activator inhibitors (PAI-1) in primary resection of oral squamous cell carcinoma].

This article examines the distribution and prognostic importance of urinase type plasminogen activators (uPA) and of plasminogen activator inhibitors (PAI-1) in cases of primary oral squamous cell carcinoma. Tissue from the primary tumor was taken from 79 patients. In order to make an intra-individual comparison, tissue from the healthy mucous membrane of the mouth was taken from 50 patients and metastatic tissue from lymph glands in the neck from 16 patients. The content of uPA and PAI-1 was determined using ELISA. After follow-up, 58 patients with primary surgical therapy were included. Statistical evaluation was carried out using the Kruskal-Wallis test, the Mann-Whitney U-test and the Wilcoxon test. Pearson's product moment correlation was used to determine the relationship between uPA and PAI-1 levels. The median uPA value was 3.43 ng/mg in primary tumor, and for PAI-1 47.1 ng/mg ( n=79). There was a significant correlation between uPA and PAI-1 both in the cancerous as well as the healthy tissue ( P<0.01). The intra-individual comparisons showed uPA and PAI-1 differed significantly between cancerous and healthy tissue ( P<0.0001) with the mean uPA and PAI-1 values being nine times higher in the cancerous tissue ( n=58). The correlation for between uPA and PAI-1 in tumors, healthy tissue and metastatic lymph node tissue ( n=16) showed highly significant values in the tumors ( P<0.001). The comparison between cancerous tissue in the primary tumor and the lymph nodes was not significant for PAI-1. For uPA, the values in the lymph nodes were significantly lower ( P<0.049). There were also significantly higher levels in metastatic lymph node tissue compared with healthy mucous membrane ( P=0.005 for uPA and P=0.003 for PAI-1). There was no significant correlation of PAI-1 and uPA ( n=79) with the patient's sex, size of the tumor (T stage), nodal status (N stage), differentiation (grade), or residual tumor status. If the patients were divided into two groups (< or =58 years and >58 years), the older patients had higher uPA ( P<0.017) and PAI-1 ( P<0.02) levels. The was no significant association between tumor localisation and uPA content in the tumor; for PAI-1 the association was significant ( P<0.02) in the individual areas of the mouth. A total of 23 (40%) patients relapsed (local n=13, lymph node n=3, local and lymph node n=1, lymph node and skin n=1, other locations n=5). Such patients had raised uPA ( P=0.012) and PAI-1 ( P=0.014) levels in the primary tumor. The high variability of the normal clinical parameters in tumors only has a limited prognostic value because it is not taken into account in individual cases. Thus determination of the PAI-1 level directly after surgery could provide an indication of the likelihood of a relapse and thus aid in determining the adjuvant therapy. This confirms a trend in that tumor associated proteases can also play a key role in oral squamous cell carcinoma as new, independent, prognostic factors. Whether or not uPA and PAI-1 will play such a role will be determined in additional multicentre clinical studies.

Carcinoma, Squamous Cell↗

PubMed2006

Development and validation of queries using structured query language (SQL) to determine the utilization of comparison imaging in radiology reports stored on PACS.

The purpose of this research was to develop queries that quantify the utilization of comparison imaging in free-text radiology reports. The queries searched for common phrases that indicate whether comparison imaging was utilized, not available, or not mentioned. The queries were iteratively refined and tested on random samples of 100 reports with human review as a reference standard until the precision and recall of the queries did not improve significantly between iterations. Then, query accuracy was assessed on a new random sample of 200 reports. Overall accuracy of the queries was 95.6%. The queries were then applied to a database of 1.8 million reports. Comparisons were made to prior images in 38.69% of the reports (693,955/1,793,754), were unavailable in 18.79% (337,028/1,793,754), and were not mentioned in 42.52% (762,771/1,793,754). The results show that queries of text reports can achieve greater than 95% accuracy in determining the utilization of prior images.

Database Management Systems↗

PubMed1990

Effectiveness of sotalol for therapy of complex ventricular arrhythmias and comparisons with placebo and class I antiarrhythmic drugs.

In new antiarrhythmic drug development, key comparisons include those with placebo, standard (class I) agents and other beta blockers. This review will cover the first 2 comparisons. The effectiveness of 2 doses of sotalol for complex ventricular arrhythmias has been compared with placebo in a 6-week, multicenter study (parallel, double-blind design) in 102 patients. The frequency of ventricular premature complexes (VPCs) was reduced only 10% with placebo, 75% with low-dose sotalol (160 mg administered twice daily) and 88% with high-dose sotalol (320 mg administered twice daily) (both p less than 0.05 vs placebo). The defined efficacy criterion (greater than or equal to 75% VPC suppression) was achieved by 6% of patients taking placebo, 34% of patients taking low- and 71% of patients taking high-dose sotalol. Sotalol was generally well tolerated, especially with the lower dose. Heart rate decreased, and PR and QTc intervals increased modestly. An open, randomized, crossover study compared sotalol with procainamide in 33 patients. A reduction in VPCs of greater than or equal to 75% was achieved in 22 patients (67%) with sotalol and in 13 patients (39%) with procainamide. Quinidine and sotalol have also been compared in a multicenter study in patients with chronic, complex VPCs, with results to be presented in the near future. Thus, sotalol's antiarrhythmic efficacy is well demonstrated by comparisons with placebo, and its effectiveness and tolerance are likely to compare favorably with standard class I drugs, suggesting its potential as a first-line antiarrhythmic agent.

Anti-Arrhythmia Agents↗