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First Determination (first + determination)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

First determination of the incidence of the unique TOR1A gene mutation, c.907delGAG, in a Mediterranean population

MOVEMENT DISORDERS, Issue 6 2007
Mélissa Frédéric MS
Abstract The c.907delGAG mutation in the TOR1A gene (also named DYT1) is the most common cause of early-onset primary dystonia. The mutation frequency and prevalence have so far been only estimated from rare clinical epidemiological reports in some populations. The purpose of this study was to investigate the incidence at birth of the c.907delGAG mutation in a French-representative mixed population of newborn from South-Eastern France. We applied an automated high-throughput genotyping method to dried blood spot samples from 12,000 newborns registered in Hérault between 2004 and 2005. Only one allele was found to carry the mutation, which allows to determine its incidence at birth as 1/12,000 per year in this area. © 2007 Movement Disorder Society [source]

Ultrafast coherent vibronic oscillations in regioregular poly(3-alkylthiophene)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S1 2009
Katsuichi Kanemoto
Abstract Ultrafast degenerate four-wave mixing (DFWM) signals of the regioregular (RR) poly(3-hexylthiophene) (P3HT) film have been investigated by the experiments using sub-20 fs pulses generated from a noncollinear optical parametric amplifier (NOPA) system. Strong DFWM signals were observed owing to a large third-order nonlinear susceptibility ,(3) of the RR-P3HT film. The time profile of the DFWM signals exhibits clear coherent oscillation on a decaying signal. The oscillation turn out to be caused by the C=C stretching mode that gives strong Raman signal. The time profile of the DFWM signal is simulated by a numerical calculation. The result of simulation reveals that decay constants of electronic population and of vibronic oscillation are 200 fs and 210 fs, respectively. This is the first determination of the decay constants for the RR-P3HT film. The obtained result demonstrates that the ,(3) signal of the RR-P3HT film decays very rapidly. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Individual variations of serum testosterone in patients with prostate cancer receiving androgen deprivation therapy

BJU INTERNATIONAL, Issue 3 2009
Juan Morote
OBJECTIVE To analyse individual variations in serum testosterone level, the cumulative rate of ,breakthrough' increases over castrate levels, and to evaluate whether the increases can be predicted. PATIENTS AND METHODS Serum testosterone levels were determined every 6 months over 3 years in 73 consecutive patients with prostate cancer who were medically castrated, prospectively enrolled in a single tertiary academic centre. Patients recruited for this study were being treated with a 3-monthly depot of luteinizing hormone-releasing hormone agonist over 6,48 months. Serum testosterone was measured using a chemiluminescent assay with a lower sensitivity level of 15 ng/dL and interassay coefficient of variation of 25% at low testosterone concentrations. RESULTS Individual variations could not be explained by the interassay variation coefficient in 26% of the patients. The rate of breakthrough increases >50 ng/dL increased from 12.3% at the first determination to 24.7% at the third, then remaining stable. The rate of breakthrough increases of 20,50 ng/dL increased from 27.4% at the first determination to 31.5% at the second, and then remained stable. A first determination of <20 ng/dL provided an 11.4% probability for future increases of >50 ng/dL, with a 5.7% probability if two consecutive determinations were <20 ng/dL and a null probability when three consecutive determinations were <20 ng/dL. CONCLUSIONS Individual variations in serum testosterone level cannot be explained by the coefficient of variation of the assay in a quarter of patients who are medically castrated. Breakthrough increases over castrate levels increase over time and those of >50 ng/dL can be predicted from the previous levels. [source]

Analysis of mean retinal transit time from fluorescein angiography in human eyes: normal values and reproducibility

ACTA OPHTHALMOLOGICA, Issue 6 2002
G. Bjärnhall
ABSTRACT. Objective:, To evaluate three different techniques to quantify retinal blood flow transit times in normal human eyes from fluorescein angiograms. Subjects and Methods:, Fluorescein angiograms were recorded on two different occasions in 18 normal individuals with a scanning laser ophthalmoscope. The angiograms were digitized (5 frames per second) and the images were aligned. Mean transit times (MTT) were analysed with a newly developed technique based on an impulse-response analysis (MTTIR) and again with the conventional technique (MTTSLOPE). Arterio-venous passage times (AVP) were also calculated. Results:, At the first determination, mean values (SD) for MTTIR, MTTSLOPE, and AVP were 3.22 (0.78), 4.88 (1.86), and 1.46 (0.57) seconds, respectively. Detection of an increase of 25% with a power of 80% requires groups of 12, 86 and 17 individuals for the three techniques, respectively. Conclusions:, Mean transit time is a well-defined physiological parameter. The technique based on impulse-response analysis allows for analysis of even badly defined dye curves. We found this technique to be superior to the conventional technique in terms of reproducibility. [source]