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Useful Parameter (useful + parameter)
Selected AbstractsUseful parameters for distinguishing nonalcoholic steatohepatitis with mild steatosis from cryptogenic chronic hepatitis in the Japanese populationLIVER INTERNATIONAL, Issue 8 2006Naoki Tanaka Abstract: Background/Aims: As detecting mild steatosis is difficult by abdominal ultrasonography (US), nonalcoholic steatohepatitis (NASH) with mild steatosis may sometimes be confused with cryptogenic chronic hepatitis. We aimed to test this possibility and to isolate factors that may indicate NASH. Methods: First, 53 Japanese patients diagnosed as having cryptogenic chronic hepatitis by laboratory examination and US were enrolled. These patients were histologically divided into NASH and non-NASH groups, and their clinical features were compared. Second, the diagnostic accuracy of predictors of NASH was examined prospectively. Results: Fifteen patients (28%) were histologically diagnosed as having NASH with mild steatosis. Multivariable analysis revealed that body mass index (BMI) and serum ferritin level were independent predictors of NASH. The best cutoff values to detect NASH were assessed by using receiver-operating characteristic curves: BMI>25.2 kg/m2 and serum ferritin level >142 ng/ml. When both markers were concomitantly negative, the negative predictive value to detect NASH was 100%. Conclusions: In cases of mild steatosis, US is not a perfect tool for the accurate diagnosis of NASH. BMI and serum ferritin level are useful discriminators of NASH from cryptogenic chronic hepatitis, and might be helpful markers for diagnosing NASH more accurately in Japanese patients. [source] Spatial Autocorrelation Analysis and the Identification of Operational Units for Conservation in Continuous PopulationsCONSERVATION BIOLOGY, Issue 4 2002José Alexandre Felizola Diniz-Filho We show that spatial autocorrelation analysis, applied to phenotypic or molecular data, can be used to describe the geographic structure and therefore can help define optimum strategies for conserving genetic variability within species. We propose that the intercept of a spatial correlogram can be an indication of the minimum distance between samples that can conserve and assess genetic diversity with maximum efficiency at lower costs. This parameter can be used both to define units and to establish sampling strategies for conservation programs. We illustrate the utility of this approach by autocorrelation analyses applied to three data sets: isozyme variability among Eugenia dysenterica populations in Brazilian Cerrado and within populations of Adenophora glandiflora in Korea, and microsatellite variation among Ursus arctos populations in North America. Our results suggest that the intercept of spatial correlograms is a useful parameter for establishing operational units for intraspecific conservation in continuous populations, based on overall genetic or phenotypic variability, by defining the minimum geographic distance at which samples are independent. Resumen: A pesar de los avances recientes en la identificación de la estructura genética poblacional mediante la tecnología de marcadores moleculares, la definición de las unidades intraespecíficas para la conservación es aún problemática. Esto sucede particularmente cuando la variación genética y fenotípica se encuentra distribuida de manera continua en un espacio geográfico. Demostramos que el análisis de autocorrelación espacial, aplicado a los datos fenotípicos o moleculares puede ser usado para describir la estructura geográfica y, por lo tanto, puede ayudar a definir estrategias óptimas para la conservación de la variabilidad genética en las especies. Proponemos que el intercepto de un correlograma espacial puede ser un indicador de la distancia mínima entre muestras que pueden conservar y evaluar la diversidad genética con mayor eficiencia a un costo más bajo. Este parámetro puede ser usado tanto para definir unidades como para establecer estrategias de muestreo para los programas de conservación. Ejemplificamos la utilidad de este método mediante la aplicación de análisis de autocorrelación a tres grupos de datos: variabilidad de isozomas entre poblaciones de Adenophora dysenterica en el cerrado brasileño, dentro de poblaciones de Adenophora glandiflora en Korea y variación microsatélite entre poblaciones de Ursus arctos en América del Norte. Nuestros resultados sugieren que el intercepto de los correlogramas espaciales son un parámetro útil que puede establecer unidades operacionales para conservación intraespecífica en poblaciones continuas, en base a la variabilidad general genética o fenótipica, al definir la distancia geográfica mínima a la cual las muestras son independientes. [source] Role of computerized morphometric analysis in diagnosis of effusion specimensDIAGNOSTIC CYTOPATHOLOGY, Issue 10 2006B. Arora M.D. Abstract The present study was undertaken to compare morphometric analysis of cells in 100 effusion samples, with unaided cytological diagnosis. All the cases in the form of Leishman's stained smears were subjected to computerized-interactive morphometry (CIM) by usage of Image analysis software. On routine cytological examination, 44 cases were benign, 26 were malignant, and 30 cases were placed in "atypical" category. On morphometry, values for mean nuclear area (MNA) and mean cytoplasmic area (MCA) in benign cases were found to be 58.39 ± 12.22 ,m2 and 185.70 ± 43.69 ,m2, while for malignant cases were 120.12 ± 16.28 ,m2 and 274.65 ± 61.01 ,m2, respectively (P < 0.001, P < 0.001, highly significant). Significant differences were also noted among benign, atypical, and malignant cases for MNA (P < 0.001). The differences between atypical and malignant cases for N/C (nuclear/cytoplasmic) ratio were also found to be statistically significant (P < 0.001). Finally, 46 cases were found to be benign, 39 malignant, and 15 in the category of atypical cases. CIM helps in better and quicker sorting for malignant cells. MNA and N/C ratio are the most significant parameters in differentiating various cells in effusions. MCA constitutes as another useful parameter. Salient features of CIM, including their applications in the light of current study, are discussed. Diagn. Cytopathol. 2006;34:670,675. © 2006 Wiley-Liss, Inc. [source] Anaemia after renal transplantationEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005M. Lorenz Abstract Anaemia is a frequent complication among long-term renal transplant recipients. A prevalence of approximately 40% has been reported in several studies. If renal function declines to stage 5 kidney disease, the prevalence of anaemia in kidney transplants is even higher. A positive correlation between haemoglobin concentration and creatinine clearance has been reported, which is a function of endogenous erythropoietin production by the functioning graft. Inflammation related to a retained kidney graft may cause hypo-responsiveness to erythropoietic agents once kidney transplant recipients return to dialysis. Furthermore, the use of azathioprine, mycophenolate mofetil and sirolimus may be associated with post-transplant anaemia. Along with erythropoietin deficiency, depletion of iron stores is one of the major reasons for anaemia in the kidney transplant population. The proportion of hypochromic red blood cells appears to be a useful parameter to measure iron supply and utilization as well as to estimate mortality risks in kidney transplant recipients. While anaemia is an important cardiovascular risk-factor after transplantation, our data suggest that anaemia is not associated with mortality and graft loss. Nevertheless, inadequate attention is paid so far to the management of anaemia after renal transplantation. A promising future aspect for risk reduction of cardiovascular disease includes the effect of erythropoietic agents on endothelial progenitor cells. [source] Characterization and chemometric study of crude and refined oils from table olive by-productsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 6 2008M. Victoria Ruiz-Méndez Abstract Table olive processing produces defective fruits and the conditioning operations give rise to solid by-products which are processed to obtain oil. In this study, the most relevant characteristics of crude oils extracted from table olive by-products were high average acidity values (4.5%, green olives; 8.1%, ripe olives), ECN42 values of 0.34 (green olives) and 0.10 (ripe olives), while 2-mono-palmitin averaged 0.92%. The overall content of sterols was 2257,mg/kg (green olives) and 1746,mg/kg (ripe olives), while the concentration of cholesterol was 36,mg/kg (green olives) and 19,mg/kg (ripe olives). The effect of refining was mainly reflected by a decrease in acidity and sterols. Although most characteristics were in agreement with the established regulation for olive oil, the overall trans fatty acid content, the low apparent ,-sitosterol content, and the relatively high cholesterol content prevented their inclusion into classes of crude or refined lampante or pomace olive oils, not even into the vegetable oil category. Therefore, the oils analyzed should be considered for non-edible purposes. The physicochemical characteristics used for chemometric discrimination permitted discrimination among types of oils (crude, 100%; physically refined, 90%; chemically refined, 100%), elaboration styles (green and ripe olives, 100%) and cultivars (Gordal, Manzanilla, Hojiblanca and Cacereña, 100%), with the sterol composition being the most useful parameter for discrimination. [source] P- and S-wave velocities of consolidated sediments from a seafloor seismic survey in the North Celtic Sea Basin, offshore IrelandGEOPHYSICAL PROSPECTING, Issue 2 2008Donna J. Shillington ABSTRACT A geophysical survey was conducted over a hydrocarbon prospect in the North Celtic Sea Basin using a small array of ocean-bottom seismographs (OBSs). The purpose of this study was to determine the ratio of compressional (P)- to shear (S)-wave velocity of consolidated sedimentary rocks in order to constrain possible subsurface variations in pore-fluid content. The ratio of VP and VS is known to be particularly sensitive to lithology, porosity and pore-fluid content, making it a useful parameter for evaluating hydrocarbon prospects. OBSs offer a relatively cheap and time-effective means of acquiring multi-component data compared with ocean-bottom cables. In this contribution, we demonstrate the ability of an OBS survey comprising three pairs of two OBSs spaced at 1.6 km to recover lateral variations in the VP/VS ratio. A key requirement of this type of study is that S waves will be generated by mode conversions in the subsurface, since they cannot be generated in nor travel through fluids. In this survey, the contrast in physical properties of the hard seabed of the North Celtic Sea Basin provided a means of generating converted S waves. Two-dimensional ray-tracing and forward modelling was used to create both VP and VS models along a profile crossing the Blackrock prospect in the North Celtic Sea Basin. These models comprise four layers and extend to a maximum depth of 1.1 km. The observed northward decrease in the VP/VS ratio at depths of 500,1000 m below the seafloor in the study area is interpreted to represent lateral variation in the amount of gas present in the pore space of Upper Cretaceous chalks and shales overlying the prospective reservoir. [source] Usefulness of MRI volumetric evaluation in patients with squamous cell cancer of the head and neck treated with neoadjuvant chemotherapyHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2007Mehran Baghi MD Abstract Background. The purpose was to evaluate the efficacy of tumor volumetry on MRI as predictive of response to treatment with induction chemotherapy, comparing the results with endoscopy. Methods: Fifty patients with advanced squamous cell carcinoma of the head and neck (SSCHN) who underwent MRI volumetry before and after neoadjuvant chemotherapy consisting of docetaxel, cisplatin, and 5-fluorouracil (TPF) were included in this study. The tumor volume was calculated by a slice-by-slice evaluation. With the standard software of a workstation, the area of the tumor was measured slice by slice using manual segmentation. To evaluate the efficacy of MRI volumetry, pretreatment volume was compared with pretreatment remission status as evaluated with endoscopy. Results. Forty-five (90%) patients demonstrated a tumor downstaging after chemotherapy. Fourteen (28%) patients showed a complete histologic remission (CR), 31 (62%) patients showed a partial remission (PR). Pretreatment tumor volume was significantly different between patients whose tumor completely responded (CR) and those whose tumor did not completely respond or whose disease was stable or was progressive (p = .00023). We defined a threshold for the pretreatment tumor volume in patients with CR, which was equal to 29.71 cc. Conclusion. We propose that MRI tumor volume analyses can be a useful parameter to predict the response to neoadjuvant chemotherapy in SCCHN. © 2006 Wiley Periodicals, Inc. Head Neck, 2007 [source] A seven-gene signature (cirrhosis risk score) predicts liver fibrosis progression in patients with initially mild chronic hepatitis C,HEPATOLOGY, Issue 4 2009Moira Marcolongo Fibrosis progression is the main determinant of liver disease outcome in chronic hepatitis C, being influenced by environmental and host factors. Recently, a cirrhosis risk score (CRS) based on seven single-nucleotide polymorphisms was proposed as genetic predictor of cirrhosis in hepatitis C. To assess the role of CRS in predicting fibrosis progression in patients with initially no or minimal to moderate fibrosis, we investigated 271 untreated patients with chronic hepatitis C having initial liver biopsy showing METAVIR stage F0 (n = 104), F1 (n = 101), or F2 (n = 59) who had been followed up without antiviral therapies for at least 60 months (mean 108.5 ± 71.5 months) and had a liver biopsy at the end of this observation period. Of these, 24.4% showed no histologic progression, 75.6% progressed by at least one stage, 45.0% progressed by at least two stages, and 10.3% progressed by more than two stages. The mean CRS was significantly higher (P = 0.005) in patients with fibrosis progression compared with those without progression, and this difference was particularly evident (P = 0.002) with F0 on initial biopsy. Mean CRS scores were not associated with degree of fibrosis progression. The relative risk of fibrosis progression increased with increasing CRS values. This association was significant in males but not in females and was most evident in males with F0 at initial biopsy (odds ratio 16.5, 95% confidence interval 1.6,166; P= 0.02) in the presence of high CRS. Multivariate analysis confirmed the significant association of CRS score with fibrosis progression. The predictive value of CRS was confirmed in hepatitis C virus patients admitting significant alcohol intake. Conclusion: Host genetics defined by CRS predict fibrosis progression in males with initially mild chronic hepatitis C and may become a useful parameter for prognostic evaluation and treatment decision. (HEPATOLOGY 2009.) [source] Usefulness of Interatrial Conduction Time to Distinguish Between Focal Atrial Tachyarrhythmias Originating from the Superior Vena Cava and the Right Superior Pulmonary VeinJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2008KUAN-CHENG CHANG M.D. Objective: Differentiation of the tachycardia originating from the superior vena cava (SVC) or the right superior pulmonary vein (RSPV) is limited by the similar surface P-wave morphology and intraatrial activation pattern during tachycardia. We sought to find a simple method to distinguish between the two tachycardias by analyzing the interatrial conduction time. Methods: Sixteen consecutive patients consisting of 8 with SVC tachycardia and the other 8 with RSPV tachycardia were studied. The interatrial conduction time from the high right atrium (HRA) to the distal coronary sinus (DCS) and the intraatrial conduction time from the HRA to the atrial electrogram at the His bundle region (HIS) were measured during the sinus beat (SR) and during the tachycardia-triggering ectopic atrial premature beat (APB). The differences of interatrial (,[HRA-DCS]SR-APB) and intraatrial (,[HRA-HIS]SR-APB) conduction time between SR and APB were then obtained. Results: The mean ,[HRA-DCS]SR-APB was 1.0 ± 5.2 ms (95% confident interval [CI],3.3,5.3 ms) in SVC tachycardia and 38.5 ± 8.8 ms (95% CI 31.1,45.9 ms) in RSPV tachycardia. The mean ,[HRA-HIS]SR-APB was 1.5 ± 5.3 ms (95% CI ,2.9,5.9 ms) in SVC tachycardia and 19.9 ± 12.0 ms (95% CI 9.9,29.9 ms) in RSPV tachycardia. The difference of ,[HRA-DCS]SR-APB between SVC and RSPV tachycardias was wider than that of ,[HRA-HIS]SR-APB (37.5 ± 9.3 ms vs. 18.4 ± 15.4 ms, P < 0.01). Conclusions: The wide difference of the interatrial conduction time ,[HRA-DCS]SR-APB between SVC and RSPV tachycardias is a useful parameter to distinguish the two tachycardias and may avoid unnecessary atrial transseptal puncture. [source] Age Determination of Ballpoint Pen Ink by Thermal Desorption and Gas Chromatography,Mass Spectrometry,JOURNAL OF FORENSIC SCIENCES, Issue 4 2008Jürgen H. Bügler Ph.D. Abstract:, Two main approaches can be used for determining the age of an ink: indirect dating and direct dating. Indirect dating is based on the chemical analysis of an ink followed by comparison with known samples in a reference collection. The collection should contain information about the inks including the market introduction dates. This approach may allow for an anachronism to be detected. The second concept is based on measuring ink components that change with age. The analysis of solvents in ballpoint inks may be a useful parameter for determining the age of ink on paper. In a previous study, the authors demonstrated that thermal desorption of ink directly from paper, followed by chemical analysis using gas chromatography,mass spectrometry (GC,MS), is a promising procedure for characterizing ink-binder resins and solvents. Preliminary tests showed that monitoring the evaporation of ink solvent from ink on paper is not a suitable method for ink dating. Thermal analysis of ink on paper in two steps revealed that fresh ink releases a relative amount of solvent at a certain low temperature in a defined period of time, which decreases as the ink ages. As a consequence, this relative amount of solvent released at a certain low temperature, and its decrease with time, can be used to estimate ink age. This age-dependent parameter was studied in 85 different inks ranging in age from 1 week to 1.5 years. It was found that some inks showed a significant decrease of this parameter up to an age of several months, and that the aging process can be monitored within this period. For other inks, however, the age-dependent parameter decreases relatively fast, e.g., within a few days, to a constant level, which can be too fast for casework. Based on these results, a general procedure for assessing the age of ballpoint pen inks on paper was developed. [source] Investigation of proton density for measuring tissue temperature,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2006Jing Chen MS Abstract Purpose To examine the temperature dependence of the proton density (PD) in both adipose and muscle tissues, and the application of the PD as a thermometry parameter in breast tissues. Materials and Methods Porcine fat samples and bovine muscle samples were successively heated to temperatures ranging from 30°C to 76°C and then cooled. They were then imaged with a dual-echo spin-echo sequence. T1 and T2 effects were carefully corrected from the images. The apparent PD (APD) in regions of interest (ROIs) and the sum of the APD in all pixels (Sum_APD) were measured and analyzed by linear regression. Results APD in adipose tissue is linear and reversible, and changes with a 0.3%/°C to 0.45%/°C temperature variation. The temperature coefficient of Sum_APD in adipose tissue is approximately 0.29%/°C, as predicted from the Boltzmann distribution. However, the results in muscle tissue are more variable. There is an offset in both APD and Sum_APD between heating and cooling phases, as well as different temperature coefficients between these two phases. Conclusion The Sum_APD in adipose tissue validates the 1/T dependence on temperature. The APD is a potentially useful parameter for fat thermometry; however, its application in muscle tissue requires further investigation. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Levels of HSP70 in HIV+ patients in different viroimmunological statesJOURNAL OF MEDICAL VIROLOGY, Issue 3 2006E. Espigares Abstract The aim of the study was to establish an association between the viroimmunological status of HIV positive patients and their levels of the 70-kD heat shock protein (Hsp70). The longitudinal retrospective case study involved 61 patients at the University Hospital in Granada (Spain) from 1999 to 2002. Twenty-five patients were viroimmunologically stable, while the other 36 patients had suffered virological failure. A minimum of three blood samples were taken at intervals of at least 3 months for the patients who were stable virologically and immunologically, whereas four samples were taken for the virological failure group: two previous to the onset of virological failure, a third corresponding to the time of virological failure, and a fourth at least 3 months after remission of virological failure. Blood samples were also obtained from 20 healthy control subjects; Hsp70 levels in all were determined by enzyme immunoassay. The mean concentration of Hsp70 was 145.4 ng/ml in the HIV-infected patients as opposed to 72.1 ng/ml in the controls. While the viroimmunologically stable group showed levels similar to those of the controls (66.5 ng/ml), the mean value of Hsp70 in the virological failure group was nearly four times as high (249.1 ng/ml), yet this difference was not statistically significant. The patients treated with reverse transcriptase inhibitors were found to have significantly higher levels of Hsp70 than the other subjects. The transformed variable Hsp70/CD4+ presents less variability than the Hsp70 value itself, giving a higher degree of statistical significance, and may be considered a useful parameter for diagnostic, prognostic, and therapeutic management of HIV positive patients. J. Med. Virol. 78:318,323, 2006. © 2006 Wiley-Liss, Inc. [source] Parameters related to lipid metabolism as markers of myelination in mouse brainJOURNAL OF NEUROCHEMISTRY, Issue 1 2001Evan D. Muse Myelination, during both normal development and with respect to disorders of myelination, is commonly studied by morphological and/or biochemical techniques that assay as their end-points the extent of myelination. The rate of myelination is potentially a more useful parameter, but it is difficult and time-consuming to establish, requiring a complete developmental study with labor-intensive methodology. We report herein development of methodology to assay the absolute rate of myelination at any desired time during development. This involves intraperitoneal injection of 3H2O to label body water pools, followed by determination of label in the myelin-specific lipid, cerebroside. The absolute amount of cerebroside synthesized can then be calculated from the specific radioactivity of body water and knowledge of the number of hydrogens from water incorporated into cerebroside. During development, the rate of cerebroside synthesis correlated well with the rate of accumulation of the myelin-specific components, myelin basic protein and cerebroside. For purposes of control, we also tested other putative, albeit less quantitative, indices of the rate of myelination. Levels of mRNA for ceramide galactosyltransferase (rate-limiting enzyme in cerebroside synthesis) and for myelin basic protein did not closely correlate with myelination at all times. Cholesterol synthesis closely matched the rate of cholesterol accumulation but did not track well with myelination. Synthesis of fatty acids did not correlate well with accumulation of either fatty acids (phospholipids) or myelin markers. We conclude that measurement of cerebroside synthesis rates provides a good measure of the rate of myelination. This approach may be useful as an additional parameter for examining the effects of environmental or genetic alterations on the rate of myelination. [source] Wide-ranging molecular mobilities of water in active pharmaceutical ingredient (API) hydrates as determined by NMR relaxation timesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2008Sumie Yoshioka Abstract In order to examine the possibility of determining the molecular mobility of hydration water in active pharmaceutical ingredient (API) hydrates by NMR relaxation measurement, spin,spin relaxation and spin,lattice relaxation were measured for the 11 API hydrates listed in the Japanese Pharmacopeia using pulsed 1H-NMR. For hydration water that has relatively high mobility and shows Lorentzian decay, molecular mobility as determined by spin,spin relaxation time (T2) was correlated with ease of evaporation under both nonisothermal and isothermal conditions, as determined by DSC and water vapor sorption isotherm analysis, respectively. Thus, T2 may be considered a useful parameter which indicates the molecular mobility of hydration water. In contrast, for hydration water that has low mobility and shows Gaussian decay, T2 was found not to correlate with ease of evaporation under nonisothermal conditions, which suggests that in this case, the molecular mobility of hydration water was too low to be determined by T2. A wide range of water mobilities was found among API hydrates, from low mobility that could not be evaluated by NMR relaxation time, such as that of the water molecules in pipemidic acid hydrate, to high mobility that could be evaluated by this method, such as that of the water molecules in ceftazidime hydrate. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4258,4268, 2008 [source] Determination of corneal volume from anterior topography and topographic pachymetry: application to healthy and keratoconic eyesOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2009Alejandro Cerviño Abstract Purpose:, To describe a method to measure corneal volume from topography and pachymetry, and test its clinical use on a sample of healthy human subjects and a case of circumscribed posterior keratoconus. Methods:, Corneal curvature (PCT 200® corneal topography system; Optopol Technology SA, Zawiercie, Poland) and ultrasonic topographic pachometry on 25 points (Ophthasonic® A-Scan/Pachometer III; Teknar Inc., St Louis, MO, USA) were measured on each of 12 young healthy corneas and one cornea suffering from circumscribed posterior keratoconus. Topography and pachymetry data were used to calculate the coordinates for the corresponding points on the posterior surface of the cornea. TableCurve 3D software (Systat Software Inc., Chicago, IL, USA) was used to fit a surface to those points measured. Integration of the surface fitted to the data points, corresponding to the anterior and posterior corneal surfaces, was used to calculate the volume underneath each of them. Subtraction of volumes underneath anterior and posterior surfaces, taking into account an axial offset equal to the central corneal thickness, rendered corneal volume for the central 6 mm of the cornea. Results:, Central corneal thickness ranged from 520 to 630 ,m for the healthy corneas. Corneal volumes for this sample analyzed averaged 18.66 ± 1.15 mm3 (range 17.25,20.53 mm3). For the posterior keratoconic cornea, the affected area was located at about 1.5,2 mm from the corneal center on the 135° hemimeridian of the right eye, observed through topographic pachymetry. Calculated corneal volume for the central 6 mm was 16.072 mm3, noticeably lower than those found in the sample without pathology, but within the range for corneas presenting with keratoconus. Conclusions:, Corneal volume is a useful parameter for characterising dystrophic corneas and can aid in the detection of rare anomalies which are hardly detected with corneal topography and/or central corneal thickness evaluation. A potentially useful measure of corneal volume can be calculated from anterior corneal topography and topographic pachymetry data. Values obtained are in good agreement with previous studies using corneal tomography techniques. The methodology has been shown to have potential for retrospective analysis of data, or where no access is available to tomographical techniques. [source] Composition influence on positron annihilation parameters in ZnO-based nanocrystal semiconductor powdersPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2007L. C. Damonte Abstract Zn1,xMgxO powders at various compositions were obtained by mechanical milling from the binary oxides. The progressive incorporation of Mg atoms into the ZnO lattice was monitored by X-ray diffraction (XRD). The evolution of annihilation parameters with milling time and composition were analyzed and related to the possible types of mechanical and substitutional induced defect present. It was concluded that the average lifetime constitute a useful parameter to sense the complete cation substitution in the wurtzite structure. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] DNA Status on Thawed Semen from Fighting Bull: A Comparison Between the SCD and the SCSA TestsREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009F Martínez-Pastor Contents The assessment of sperm chromatin status is compulsory in a complete spermiogram. Here we applied the sperm chromatin structure assay (SCSA) and the sperm chromatin dispersion (SCD) test to assess the chromatin status of three fighting bulls. Cryopreserved semen (two straws/bull) were analysed by duplicate after thawing and after 6 h at 37°C with and without oxidative stress (1 mm FE2+). Results (SCD: percentage of spermatozoa with halo; SCSA: SD-DFI, %DFI and HDS) were analysed for differences between bulls and treatments, sensitivity and specificity (receiver operating characteristic curves) and repeatability (repeatability coefficients as 2SD of duplicate differences).%DFI for the three bulls was below 2% at 0 h, indicating no risk for fertility according to previous reports. It increased slightly for two of the bulls after FE2+ treatment (%DFI < 5%) and more pronouncedly for the other bull (C, %DFI,10%), which merits further investigation. SCD rendered higher percentage of halos for bull C, but could not discriminate between samples with and without oxidizing treatment (AUC: 0.52). SCSA (%DFI) showed a high discriminating ability between treatments (AUC: 0.96). The repeatability coefficient was also higher for SCD (5.9) than for %DFI (1.8), indicating lower repeatability for SCD. Overall, %DFI might be the most useful parameter for assessing sperm chromatin on fighting bull. SCD might yield different information than SCSA, hence further research is warranted. [source] Prediction of lymphatic invasion by peritumoral lymphatic vessel density in prostate biopsy coresTHE PROSTATE, Issue 10 2008Kenji Kuroda Abstract BACKGROUND Lymphatic invasion in radical prostatectomy specimens has been suggested to be an unfavorable prognostic factor in clinically localized prostate cancer. Lymphangiogenesis detected by antibodies specific for lymphatic endothelial cells has been associated with lymphatic invasion and lymph node metastasis in prostate cancer. This study was designed to examine whether lymphangiogenesis in prostate biopsy could predict lymphatic spread in radical prostatectomy specimens. METHODS Paraffin-embedded positive biopsy cores obtained from 99 patients who underwent radical prostatectomy at our institution were immunostained with D2-40 monoclonal antibody, which specifically recognizes lymphatic endothelium. The association between lymphatic parameters in prostate biopsy and pathological parameters in radical prostatectomy specimens was analyzed. RESULTS Peritumoral and intratumoral lymphatic (ITL) vessels were observed in 90 (90.9%) and 23 cases (23.2%). Average and maximal peritumoral lymphatic vessel density (PTLD) and the presence of ITL in positive biopsy cores were significantly associated with positive biopsy core rates (P,=,0.0015 for average PTLD, P,<,0.0001 for maximal PTLD, and P,=,0.0038 for ITL) and lymphatic vessel invasion (P,<,0.0001 for average PTLD, P,<,0.0001 for maximal PTLD, and P,=,0.0322 for ITL). Among preoperative parameters, the biopsy Gleason score (P,=,0.0092, HR,=,6.108) and average PTLD (P,=,0.0034, HR,=,1.860) were significant predictors of lymphatic invasion in radical prostatectomy specimens in multivariate analysis. CONCLUSIONS PTLD in prostate biopsy specimens assessed by immunohistochemistry using D2-40 antibody could be a useful parameter for predicting lymphatic spread of clinically localized prostate cancer. Prostate 68:1057,1063, 2008. © 2008 Wiley-Liss, Inc. [source] Strain-Encoded Cardiac Magnetic Resonance for the Evaluation of Chronic Allograft Vasculopathy in Transplant RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 11 2009G. Korosoglou The aim of our study was to investigate the ability of Strain-Encoded magnetic resonance imaging (MRI) to detect cardiac allograft vasculopathy (CAV) in heart transplantation (HTx)-recipients. In consecutive subjects (n = 69), who underwent cardiac catheterization, MRI was performed for quantification of myocardial strain and perfusion reserve. Based on angiographic findings subjects were classified: group A including patients with normal vessels; group B, patients with stenosis <50%; and group C, patients with severe CAV (stenosis , 50%). Significant correlations were observed between myocardial perfusion reserve with peak systolic strain (r =,0.53, p < 0.001) and with mean diastolic strain rate (r = 0.82, p < 0.001). Peak systolic strain and strain rate were significantly reduced only in group C, while mean diastolic strain rate and myocardial perfusion reserve were already reduced in group B and A. Myocardial perfusion reserve and mean diastolic strain rate had higher accuracy for the detection of CAV (AUC = 0.95, 95% CI = 0.87,0.99 and AUC = 0.93, 95% CI = 0.84,0.98, respectively) and followed peak systolic strain and strain rate (AUC = 0.80, 95% CI = 0.69,0.89 and AUC = 0.78, 95% CI = 0.67,0.87, respectively). Besides the quantification of myocardial perfusion, the estimation of the diastolic strain rate is a useful parameter for CAV assessment. In combination with the clinical evaluation, these parameters may be effective tools for the routine surveillance of HTx-recipients. [source] Significance of CT Attenuation Value in Liver Grafts Following Right Lobe Living-Donor Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2005Taku Iida In adult living-donor liver transplantation (LDLT), the assessment of the allograft functional reserve is important for adequate graft regeneration. From March 2002 to December 2003, 30 adult recipients underwent right lobe LDLT. Mean CT attenuation values (CT-AVs) in the graft were measured on unenhanced CT for 6 months after LDLT. The histological features of the graft parenchyma were evaluated with post-operative liver biopsy specimens. Mean CT-AVs after LDLT were decreased significantly from the pre-operative values, recovered to over 60 HU within 6 months. There was a positive linear correlation between the CT-AVs and the receptor index (LHL15) in technetium-99m-diethylenetriaminepenta-acetic acid-galactosyl-human serum albumin (99mTc-GSA) liver scintigraphy (r = 0.803, p = 0.005). The recipients were divided into two groups according to the CT-AV at one post-operative week (group H; ,55HU, group L; <55HU). The low CT-AVs, under 55 HU, in group L were prolonged for 3 months compared with those in group H (p < 0.05). The 1-year cumulative survival rate was 94.7% and 45.5% in groups H and L, respectively (p = 0.014). Histological findings revealed that the parenchymal damage was severe in the grafts with low CT-AVs. The CT-AVs in the grafts may be a useful parameter for assessing the allograft functional reserve. [source] Bond analyses of borates from the Inorganic Crystal Structure DatabaseACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2006Daqiu Yu Various fundamental building blocks (FBBs) are observed in the crystallographic structures of oxoborates available in the Inorganic Crystal Structure Database, Version 1.3.3 (2004); the occurrence of borate groups with low complexity is dominant. Bond-valence parameters d0 of B,O bonds in 758 oxoborates with various FBBs have been calculated using the bond-valence sum model. Some discrepancies in the d0 values obviously occur if the detailed configurations of FBBs in borate crystals are considered; d0 is sensitive to the chemical bonding structure of B atoms in the crystallographic framework. Moreover, d0 values are affected by the existence of interstitial atoms and the substitution of other anionic groups. In addition, the d0 parameters for B,N, B,S, B,P and B,F bonds are also calculated statistically. Some suitable d0 data for various borate FBBs are recommended according to their particular configurations, especially for those with low complexity. On the basis of the proposed linear relationship between calculated nonlinear optical (NLO) coefficients of borates and the current d0 values for various FBBs, it is found that the d0 values may be regarded as a useful parameter for pre-investigating the NLO properties of borates, leading to an efficient structural evaluation and design of novel borates. [source] The Construction Process of the Angkor Monuments Elucidated by the Magnetic Susceptibility of Sandstone,ARCHAEOMETRY, Issue 2 2003E. Uchida The Angkor monuments in Cambodia are mainly constructed of grey to yellowish-brown sandstones. No differences in the constituent minerals and in the chemical composition of the sandstones have been confirmed among the monuments. However, we have found their magnetic susceptibility a useful parameter by which to distinguish them. The principal monuments of Angkor Wat, Ta Prohm, Preah Khan, Banteay Kdei and Bayon, constructed from the Angkor Wat period to the Bayon period (from the beginning of the 12th century to the beginning of the 13th century ad), were investigated in detail using a portable magnetic susceptibility meter. We succeeded in dividing the periods of construction into stages. This elucidated the enlargement process of the monuments and correlated their construction stages. [source] Pattern of carcinoembryonic antigen drop after laparoscopic radiofrequency ablation of liver metastasis from colorectal carcinomaCANCER, Issue 1 2006Mohammed Ghanamah M.D. Abstract BACKGROUND Laparoscopic radiofrequency ablation (RFA) is being increasingly used for local control of hepatic metastasis from colorectal carcinoma (CRC). After surgical resection of colorectal liver metastasis, carcinoembryonic antigen (CEA) values fall within 2 weeks, making this a useful parameter to follow shortly after surgery. Little is known, however, about the expected pattern of the CEA drop after RFA. METHODS From September 1998 to October 2002, RFA to CRC liver metastasis was performed on 144 patients. A subset of 17 patients were studied who had no evidence of extrahepatic disease preoperatively, had all detectable tumor ablated intraoperatively, and who on long-term follow-up (up to 15 months) had no evidence of recurrent disease. Serum CEA was determined preoperatively, on the first postoperative day, at 1 week, and every 3 months afterwards. A computed tomography (CT) scan of the abdomen and pelvis was obtained every 3 months postoperatively. RESULTS Ten (58.8%) patients showed an increase in CEA on postoperative Day 1, averaging 38.3% compared with the preoperative value. CEA then fell to 50% of the preoperative value, on average, on Day 7 postoperatively and only reached its nadir at 3 months. CONCLUSIONS Unlike resection patients, those undergoing ablation show an initial rise in CEA, probably due to release from the ablated tissue. Although heating of RFA would be expected to destroy CEA, the initial rise and slow drop postoperatively argue for a release of immunoreactive CEA from the ablated zone. This slow decline in CEA indicates that several months should pass before assessing the extent of potential residual disease. Cancer 2006. © 2006 American Cancer Society. [source] Neuroprotein s-100B , a useful parameter in paediatric patients with mild traumatic brain injury?ACTA PAEDIATRICA, Issue 10 2009C Castellani Abstract Aims:, To examine the correlation of S-100B to cranial computerized tomography (CCT) scan results in children after mild traumatic brain injury (MTBI). Methods:, One hundred and nine paediatric patients (0,18 years) with MTBI were included in this prospective single-centre study. Serum was collected within 6 h of trauma for determination of serum S-100B. The upper reference of S-100B was set to 0.16 ,g/L. A CCT scan was performed in all patients and the results were correlated to the S-100B values. Results:, Computerized tomography was abnormal in 36 patients showing intracerebral haemorrhages and/or skull fractures. Serum S-100B level was significantly higher in patients with a pathological condition as shown in CT scan results (p = 0.003). There were no false negative, but 42 false positive test results for S-100B. This resulted in a sensitivity of 1.00, specificity of 0.42, positive predictive value of 0.46 and negative predictive value of 1.00. An area under the receiver operating curve of 0.68 was calculated. Conclusion:, S-100B is a valuable tool to rule out patients with pathological CCT findings in a collective of paediatric patients with MTBI. Elevations of S-100B do not necessarily lead to a pathological finding in the CT scan, but values below the cut-off safely rule out the evidence of intracranial lesions. [source] A quantitative approach to probe the dependence and correlation of food-effect with aqueous solubility, dose/solubility ratio, and partition coefficient (Log P) for orally active drugs administered as immediate-release formulationsDRUG DEVELOPMENT RESEARCH, Issue 2 2005Brahma N. Singh Abstract The purpose of the present review was to systematically evaluate if aqueous solubility, dose/solubility ratio, and partition coefficient (Log P) could be used as useful parameters to quantitatively probe the dependence and correlation of in vivo food effects with these physicochemical properties of orally active drugs administered as immediate-release (IR) formulations. Mean AUC data obtained under fasted and fed states of over 100 structurally diverse orally active drugs with different physicochemical properties were obtained from the primary literature. Correlations of AUC ratio (Fed/Fasted) with aqueous solubility, dose/solubility ratio, and Log P were derived and statistically evaluated by Pearson's correlation test (two-tailed). A negative correlation was obtained between the logarithm of the aqueous solubility and the AUC ratio (r=,0.5982, N=93), whereas a positive correlation existed between AUC ratio and Log P (r=0.5147, N=110) and between AUC ratio and dose/solubility ratio (r=0.5511, N=87). All these correlations were significant (P<0.0001). Based on this study, the estimated range within which a drug is not expected to be significantly affected by food falls between 0.148,89.39 mg/ml for aqueous solubility and between 0.23,624 ml for the dose:solubility ratio. The corresponding range of Log P for expecting a lack of food-effect lies between ,1.13 and 2.98. Quantitatively, the effect of food was most pronounced for lipophilic, poorly water-soluble drugs (with only a few exceptions), irrespective of whether the drug is acidic, basic, or neutral. It is concluded that aqueous solubility, dose/solubility ratio, and partition coefficient can be used as useful parameters to probe the dependence and correlation of food-effect with these physicochemical parameters for immediate-release formulations. Drug Dev. Res. 65:55,75, 2005. © 2005 Wiley-Liss, Inc. [source] Study of order and dynamic processes in tendon by NMR and MRIJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2007G. Navon PhD Abstract Tendons are composed of a parallel arrangement of densely packed collagen fibrils that results in unique biomechanical properties of strength and flexibility. In the present review we discuss several advanced magnetic resonance spectroscopy (MRS) and imaging (MRI) techniques that have allowed us to better understand the biophysical properties of tendons and ligaments. The methods include multiple quantum and T2 filtering combined with NMR and MRI techniques. It is shown in detail how these techniques can be used to extract a number of useful parameters: 1) the 1H- 1H and 1H- 2H dipolar interactions; 2) the proton exchange rates between water and collagen, and between water molecules; 3) the distribution of fibril orientations; and 4) the anisotropy of diffusion. It is shown that relaxation data as a function of angular dependence can be obtained in vivo using mobile NMR sensors. Finally, this article describes how double quantum filtered (DQF) MRI can be used to image and monitor the healing process in injured tendons. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc. [source] Immunohistochemical analysis for histopathological subtypes in pediatric medulloblastomasPATHOLOGY INTERNATIONAL, Issue 2 2003Eun-Ik Son Medulloblastomas occurring in children represent a histological spectrum of varying anaplasia and nodularity. In order to determine whether immunohistochemical markers might be useful parameters in subclassifying these tumors, 17 pediatric medulloblastomas, including nine diffuse/non-anaplastic, four diffuse/anaplastic, three nodular/non-anaplastic and one nodular/anaplastic subtypes, were studied. In the present report, we investigate the expression of neural cell adhesion molecule (NCAM), nerve growth factor receptor (NGFR), neurofilament (NF), synaptophysin (SYN), glial fibrillary acidic protein (GFAP), S100, Bcl-2, and Ki-67 by using the immunohistochemistry against specific antibodies. This study showed that NGFR, NF, GFAP and S100 were not detected in anaplastic subtypes of medulloblastomas (0/5), while non-anaplastic subtypes were mainly expressed within the nodules. All 17 tumors were reactive for NCAM, SYN and Bcl-2. In addition, Ki-67 labeling indices for anaplastic subtypes (39.0 ± 7.42%) were significantly higher than that of non-anaplastic medulloblastomas (11.4 ± 8.04%; P < 0.0001). These results suggest that immunohistochemical markers are a useful adjunct in characterizing subtypes of pediatric medulloblastomas. [source] Variance of Vestibular-Evoked Myogenic Potentials,THE LARYNGOSCOPE, Issue 3 2001Kentaro Ochi MD Abstract Objectives/Hypothesis Vestibular-evoked myogenic potential (VEMP) has been thought to originate from sacculus. The variance of this potential and the effectiveness of the adjustments of pInII amplitudes using average muscle tonus of ipsilateral sternocleidomastoid muscle were evaluated. In addition, clinical application of VEMP was examined in patients with acoustic tumors (ATs) and vestibular neurolabyrinthitis (VNL). Study Design Prospective evaluation of the VEMP in 18 normal volunteers and 6 patients. Methods Variance and left,right difference of each parameter, including pI latency, nII latency, pInII amplitude, and threshold, was analyzed. Input, output function of pInII amplitude was evaluated. Average muscle tonus was calculated in 20 ears and applied for adjustment of pInII amplitude. Sensitivity of each parameter of VEMP was examined in 3 patients with ATs and 3 patients with VNL. Results VEMP was present in all 36 ears of 18 control subjects. Thresholds of VEMP for normal subjects were 80 to 95 dB normal hearing level (nHL). The muscle tonus affected pInII amplitude significantly; however, no statistically significant improvement was observed in test,retest investigation after adjustment using muscle tonus. The threshold of the affected side was elevated compared with the non-affected side in all patients with ATs, whereas 2 of 3 patients showed normal pInII-ratio. One patient with VNL presented normal VEMP, whereas 2 patients presented no VEMP to the highest stimulus intensity. Conclusions Interaural difference of thresholds might be the most useful parameters. Adjustment using average muscle tonus is not necessary when the subject is able to get sufficient muscle tonus. [source] | ||||||||||||||||||||||||||||