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PubMed1975

Children's acquisition of idioms in the English language.

Idiomatic comprehension was studied in four groups of 20 subjects each, ages six, nine, and 12 years, and adult. Each subject was read 10 sentences which could be interpreted literally or idiomatically. Following each sentence, the subject chose the two pictures that were closest in meaning to the sentence heard. This procedure generated 800 pairs of selections for analysis. The results indicated a (1) significant difference between literal and idiomatic choices regardless of the subject's age or the voice of the sentence, (2) significant difference between literal and idiomatic choices as a function of age regardless of the voice of the sentence, and (3) significant voice-by-choice interaction indicating that voice affected the choice of literal or idiomatic picture representations.

Adult↗

PubMed1996

Advantage of monitoring skin vibration as an index of arteriovenous fistular blood flow.

Monitoring of the skin vibration is disturbed little by environmental noise. Therefore, the skin vibration is more relevant than bruit on the skin by means of monitoring the fistular blood flow. Frequency analysis of the skin vibration generated by an internal arteriovenous fistula indicated two peaks of power spectral density (PSD), one in the frequency range of 4-10 Hz and the other from 100-300 Hz. The analysis of the skin vibration generated by an external fistula, however, showed only one peak in the range of 4-10 Hz and a moderate flat PSD level in the range of 100-300 Hz. The PSD level in the range of 100-300 Hz decreased dramatically or disappeared when the fistular blood flow diminshed or ceased. Therefore, the optimal frequency for monitoring skin vibration may be the range of 100-300 Hz.

Arteriovenous Fistula↗

PubMed1994

Understanding the process of quantitative ultrasonic tissue characterization.

Because the human vision system cannot distinguish the broad range of gray values that a computer visual system can, computerized image analysis may be used to obtain quantitative information from ultrasonographic (US) real-time B-mode scans. Most quantitative US involves programming an off-line computer to accept, analyze, and display US image data in a way that enhances the detection of changes in small-scale structures and blood flow that occur with disease. Common image textural features used in quantitative US tissue characterization consist of first-order gray-level statistics (eg, occurrence frequency of gray levels independent of location or spatial relationship) and second-order gray-level statistics dependent on location and spatial relationship, including statistical analysis of gradient distribution, co-occurrence matrix, covariance matrix, run-length histogram, and fractal features. A customized tissue signature software has been developed to analyze image data obtained from clinical US scanners. Means comparison testing and multivariate analysis techniques are used to compare the numbers generated for a particular region of interest. By integrating these techniques into the radiologist's interpretation of the sonogram, the quantitative information gained may lead to earlier detection of lesions difficult to see with the human eye.

Humans↗

PubMed2000

Clinical and genetic study of familial Parkinson's disease in Tunisia.

OBJECTIVE: To determine inheritance patterns and clinical characteristics of familial PD (F-PD) in Tunisia. METHODS: Twenty-one index patients were selected on the basis of typical PD and a family history of PD. The 21 families of the index patients were visited at home, and clinical assessment of all available relatives, a total of 133 individuals, was made. Extensive pedigree data detected 67 additional cases. We ascertained medical history, age, age at onset, first sign at onset, course of the disease, dosage and duration of levodopa (LD) treatment, and associated diseases. One patient from each family was hospitalized to confirm response to LD by evaluation of untreated and treated Unified Parkinson's Disease Rating Scale scores. The sex ratio, transmission pattern, ancestral secondary cases, and segregation ratio (SR) were determined by pedigree analysis. RESULTS: Eighty-eight patients were analyzed (44 men and 44 women; mean age at onset, 39.8 +/- 14.4 years). Pedigree analysis showed 10 single-generation (SG) families (i.e., all affected members belonging to 1 generation) and 11 multigenerational (MG) families (i.e., affected members spanning >1 generation). Parental consanguinity was more frequent in SG families than in MG families. The SR in SG families was 0.23 +/- 0.05, compatible with autosomal recessive (AR) inheritance. Analysis of MG pedigrees showed autosomal dominant (AD) inheritance with reduced penetrance in 9 of 10 families. Age at onset was younger than in sporadic PD. Intrafamilial variability of age at onset, symptom of onset, and clinical course was observed. There was no difference in clinical characteristics between SG and MG families apart from dystonic foot at onset, which was more frequent in SG families. CONCLUSIONS: First, F-PD is clinically similar to sporadic PD apart from younger age at onset. Second, there is intrafamilial and interfamilial variability of all clinical features. Third, F-PD in Tunisia is genetically heterogenous with at least two inheritance patterns: AD and AR.

Adolescent↗

PubMed1991

Is urea kinetic modelling an appropriate tool for guiding ultrashort high-flux dialysis therapy?

High-flux dialysers are frequently used for highly efficient ultrashort treatment schedules. To avoid the risk of inadequately low dialysis dose in this treatment strategy where 'every minute counts', it is often advocated to monitor the treatment quality by means of urea kinetic modelling (UKM). However, careful computational analysis of concentration curves generated by UKM versus more realistic two-pool model curves indicates the risk of substantial overestimation of the protein catabolic rate (PCR). Therefore conventional UKM should not be used to monitor and/or guide treatment schedules with dialyser urea clearance greater than 250 ml/min and dialysis time less than 3 h. Under these conditions, PCR can be overestimated by as much as 20%.

Humans↗

PubMedDate not supplied

[Spectral analysis of the EEG and intracortical connections in the presence of a pathologic focus at different levels of the human brain].

EEG spectral analysis in 68 patients with focal brain lesions has shown that EEG power spectra are characterized by greatest changes in the focal zone, as manifested in the augmenting of the slow component and diminution of the alpha-component. By means of phasic analysis it has been established that the slow component is generated in the focal zone. Analysis of the complex function of EEG coherence detected different variants of changes in the spatial-temporal organization of cortical electrical activity, determined by localization of the focus and the extent of its impact on the brain. The revealed discordance of EEG connections, diminution of coherence in some parts of the hemispheres with simultaneous enhancement in the others, manifested differently in different physiological rhythms ranges, reflects an impairment in the structure of intracortical connections of electrical processes, which is typical of the normal brain.

Brain Neoplasms↗

PubMed1998

[Evidence of new diagnostic and prognostic human astrocytoma tumor markers. Potential therapeutic applications. I].

This paper summarises different studies of our group whose aim to improve the accuracy of prognostic values for patients with astrocytic tumors. Our approach aims to optimise the conventional evaluation of astrocytic tumor malignancy by means of the quantification of conventional morphological criteria, and the production of biological variables related to DNA ploidy level. All these quantitative variables have been generated by means of computer-assisted microscopy and submitted to adapted data analysis methods. A series of 250 astrocytic tumors has been analysed, including 39 astrocytomas (AST), 47 anaplastic astrocytomas (ANA) and 164 glioblastomas (GBM) identified in accordance with the WHO classification. This classification distinguishes between tumor groups with relatively (AST), intermediary (ANA) and unfavorable (GBM) prognoses. However, it does not take into account the high degree of heterogeneity in each tumor group and may thus be poorly for individual case prediction. In this context, our approach has been able to identify new entities in the AST and ANA histological groups. These entities have established some reference points on the biological continuum according to the sequence AST-->ANA-->GBM and enable prognosis evaluation to be improved in astrocytic tumors.

Astrocytoma↗

PubMed1990

[Nervous mechanisms of spontaneous oscillations of systolic blood pressure and heart rate].

The phenomenon of rhythmic fluctuations in cardiovascular variables such as heart rate (HR) or arterial blood pressure (BP) has attracted the attention of workers in both pure and applied research. In recent years, the possibility of quantifying these oscillations by using power spectral analysis has aroused a growing interest. We investigated the fluctuations which underly the spontaneous variability of BP and HR in conscious rats. Intrafemoral pulsatile BP was computed to generate evenly spaced signals (systolic, diastolic, mean BP, HR) at 200 ms intervals. This equidistant sampling allowed a direct spectral analysis using a Fast Fourier Transform algorithm. Systolic Blood Pressure (SBP) and HR exhibited low frequency oscillations (Mayer waves, 20-605 mHz) and a high frequency oscillation related to respiration (1,855 mHz). The respiratory fluctuations in HR were almost abolished by vagal blockade (atropine). HR fluctuations in the low frequency regime were diminished by vagal blockade or cardiac sympathetic blockade (atenolol). The respiratory frequency fluctuations in SBP were markedly increased by alpha sympathetic blockade (prazosin). On the contrary the low frequency oscillations in SBP were reduced by alpha sympathetic blockade. These data indicate that in conscious rats: 1) the HR oscillation with respiration is vagally mediated, 2) the HR fluctuation in the low frequency regime is jointly mediated by beta sympathetic and parasympathetic activities, 3) the respiratory oscillation in SBP depends on fluctuations in cardiac output and is normally counteracted by the sympathetic tone, 4) the low frequency oscillations in SBP reflect the sympathetic activity to the resistance vessels.

Animals↗

PubMed1999

A genetic method for generating Drosophila eyes composed exclusively of mitotic clones of a single genotype.

The genetic analysis of a gene at a late developmental stage can be impeded if the gene is required at an earlier developmental stage. The construction of mosaic animals, particularly in Drosophila, has been a means to overcome this obstacle. However, the phenotypic analysis of mitotic clones is often complicated because standard methods for generating mitotic clones render mosaic tissues that are a composite of both mutant and phenotypically normal cells. We describe here a genetic method (called EGUF/hid) that uses both the GAL4/UAS and FLP/FRT systems to overcome this limitation for the Drosophila eye by producing genetically mosaic flies that are otherwise heterozygous but in which the eye is composed exclusively of cells homozygous for one of the five major chromosome arms. These eyes are nearly wild type in size, morphology, and physiology. Applications of this genetic method include phenotypic analysis of existing mutations and F(1) genetic screens to identify as yet unknown genes involved in the biology of the fly eye. We illustrate the utility of the method by applying it to lethal mutations in the synaptic transmission genes synaptotagmin and syntaxin.

Animals↗

PubMed2006

[Differences in anticipatory postural adjustments between self-generated and triggered gait initiation in 20 healthy subjects].

OBJECTIVE: Preparation of upper-limb movements differs between self-paced and triggered conditions. This study analyzed the anticipatory postural adjustments (APAs) of gait initiation in normal subjects in 2 conditions: self-generated and triggered by a "beep" sound. METHODS: We recorded kinematic, spatiotemporal parameters of the first two steps by means of video motion analysis (6 infrared cameras), and kinetic parameters (using a force platform and the optoelectronic system) in 20 normal subjects. Two conditions: 1) self-generated initiation; and 2) initiation triggered by a "beep" sound were studied to evaluate the APA phase, by recording kinetic data (duration of the APAs, trajectory of the center of pressure, speed and trajectory of the center of mass). Kinematic data (first and second step speed, length and duration) were also recorded. RESULTS: First step speed and length were increased in self-paced gait initiation compared to triggered gait initiation in controls. We found no difference between the 2 conditions in terms of second step kinematic data. It was caused by a significant difference between the 2 conditions for the temporal characteristics of anticipatory postural adjustments (APAs) in the initiation of the first step, which was longer when normal subjects performed self-generated gait initiation. The trajectory of center of pressure and center of mass remained the same in the 2 conditions. CONCLUSION: APAs of gait initiation process are delayed under self-paced condition, although they do not differ qualitatively between reaction time and self-paced condition. Neuphysiological support of self-generated movement could explain these differences.

Acoustic Stimulation↗

PubMed1994

Comparative analysis of six different white cell-reduction filters for packed red cells.

BACKGROUND: The reduction of white cells in blood components before transfusion by filters with at least 3 log10 depletion may prevent adverse transfusion reactions such as HLA alloimmunization, febrile reactions, transmitted infections, and immunomodulation. A new generation of filters with 4 log10 depletion is now available. STUDY DESIGN AND METHODS: The aim of this study is to compare the efficiency of white cell reduction by six commercial filters for packed red cells with 3 and 4 log10 depletion (claimed by manufacturers). The analysis of white cell concentration in the white cell-reduced units was performed by flow cytometry and with a Nageotte chamber. RESULTS: The last generation of filters (BPF4, RC400, R01 Plus) show mean residual white cell numbers of 0.18 +/- 0.14, 0.26 +/- 0.21, and 0.25 +/- 0.15 x 10(6), respectively, by flow cytometric analysis and 0.05 +/- 0.04, 0.18 +/- 0.15, and 0.38 +/- 0.23 x 10(6), respectively, by Nageotte chamber evaluation. The 3 log10 depletion filters (R01, Leucostop-4LT-mono, R200) have mean residual white cell numbers of 1.41 +/- 0.92, 2.4 +/- 1.99, and 1.05 +/- 0.64 x 10(6), respectively, by flow cytometric analysis and 3.56 +/- 1.7, 1.67 +/- 1.3, and 3.21 +/- 4.1 x 10(6), respectively, by Nageotte chamber evaluation. The data show that the BPF4, RC400, and R01 Plus filters are likely to be more efficient by 1 log10 reduction than the R01, Leucostop-4LT-mono, and R200 filters. CONCLUSION: The most recent generation of filters is able to deplete white cells from packed red cells by 4 log10; in particular, with one of the filters, the residual WBC content was less than 0.5 x 10(6) per unit in all experiments, while two other filters reached that level in 9 of 10 experiments.

Blood Component Removal↗

PubMed1991

Chromosome microdissection and cloning in human genome and genetic disease analysis.

A procedure has been described for microdissection and microcloning of human chromosomal DNA sequences in which universal amplification of the dissected fragments by Mbo I linker adaptor and polymerase chain reaction is used. A very large library comprising 700,000 recombinant plasmid microclones from 30 dissected chromosomes of human chromosome 21 was constructed. Colony hybridization showed that 42% of the clones contained repetitive sequences and 58% contained single or low-copy sequences. The insert sizes generated by complete Mbo I cleavage ranged from 50 to 1100 base pairs with a mean of 416 base pairs. Southern blot analysis of microclones from the library confirmed their human origin and chromosome 21 specificity. Some of these clones have also been regionally mapped to specific sites of chromosome 21 by using a regional mapping panel of cell hybrids. This chromosome microtechnology can generate large numbers of microclones with unique sequences from defined chromosomal regions and can be used for processes such as (i) isolating corresponding yeast artificial chromosome clones with large inserts, (ii) screening various cDNA libraries for isolating expressed sequences, and (iii) constructing region-specific libraries of the entire human genome. The studies described here demonstrate the power of this technology for high-resolution genome analysis and explicate their use in an efficient search for disease-associated genes localized to specific chromosomal regions.

Animals↗

PubMed2003

A framework for power analysis using a structural equation modelling procedure.

BACKGROUND: This paper demonstrates how structural equation modelling (SEM) can be used as a tool to aid in carrying out power analyses. For many complex multivariate designs that are increasingly being employed, power analyses can be difficult to carry out, because the software available lacks sufficient flexibility. Satorra and Saris developed a method for estimating the power of the likelihood ratio test for structural equation models. Whilst the Satorra and Saris approach is familiar to researchers who use the structural equation modelling approach, it is less well known amongst other researchers. The SEM approach can be equivalent to other multivariate statistical tests, and therefore the Satorra and Saris approach to power analysis can be used. METHODS: The covariance matrix, along with a vector of means, relating to the alternative hypothesis is generated. This represents the hypothesised population effects. A model (representing the null hypothesis) is then tested in a structural equation model, using the population parameters as input. An analysis based on the chi-square of this model can provide estimates of the sample size required for different levels of power to reject the null hypothesis. CONCLUSIONS: The SEM based power analysis approach may prove useful for researchers designing research in the health and medical spheres.

Analysis of Variance↗

PubMed2004

Reliability analysis of microarray data using fuzzy c-means and normal mixture modeling based classification methods.

MOTIVATION: A serious limitation in microarray analysis is the unreliability of the data generated from low signal intensities. Such data may produce erroneous gene expression ratios and cause unnecessary validation or post-analysis follow-up tasks. Therefore, the elimination of unreliable signal intensities will enhance reproducibility and reliability of gene expression ratios produced from microarray data. In this study, we applied fuzzy c-means (FCM) and normal mixture modeling (NMM) based classification methods to separate microarray data into reliable and unreliable signal intensity populations. RESULTS: We compared the results of FCM classification with those of classification based on NMM. Both approaches were validated against reference sets of biological data consisting of only true positives and true negatives. We observed that both methods performed equally well in terms of sensitivity and specificity. Although a comparison of the computation times indicated that the fuzzy approach is computationally more efficient, other considerations support the use of NMM for the reliability analysis of microarray data. AVAILABILITY: The classification approaches described in this paper and sample microarray data are available as Matlab( TM ) (The MathWorks Inc., Natick, MA) programs (mfiles) and text files, respectively, at http://rc.kfshrc.edu.sa/bssc/staff/MusaAsyali/Downloads.asp. The programs can be run/tested on many different computer platforms where Matlab is available. CONTACT: asyali@kfshrc.edu.sa.

Algorithms↗

PubMed2006

Making sense of qualitative data analysis: an introduction with illustrations from DIPEx (personal experiences of health and illness).

OBJECTIVES: This paper outlines an approach to analysing qualitative textual data from interviews and discusses how to ensure analytic procedures are appropriately rigorous. OVERVIEW: Qualitative data analysis should begin at an early stage in data collection and be highly systematic. It is important to identify issues that emerge during the data collection and analysis as well as those that the researcher may have anticipated (from reading or experience). Analysis is very time-consuming, but careful sampling, the collection of rich material and analytic depth mean that a relatively small number of cases can generate insights that apply well beyond the confines of the study. One particular approach to thematic analysis is introduced with examples from the DIPEx (personal experiences of health and illness) project, which collects video- and audio-taped interviews that are freely accessible through http://www.dipex.org. EVALUATION: Qualitative analysis of patients' perspectives of illness can illuminate numerous issues that are important for medical education, some of which are unlikely to arise in the clinical encounter. Qualitative studies can also cover a much broader range of experiences - of both common and rare disease - than clinicians will see in practice. The DIPEx website is based on qualitative analysis of collections of interviews, illustrated with hundreds of video and audio clips, and is an innovative resource for medical education.

Attitude to Health↗

PubMed1999

Sequential imaging and volumetric analysis of an intracerebral C6 glioma by means of a clinical MRI system.

In this study, using high resolution coils; implanted growing rat brain tumors were imaged sequentially with 3-D volume measurements generated by means of a clinical magnetic resonance imaging system (CMRI) and commercially available wrist coil. Ten female Sprague-Dawley rats were used, eight were implanted with C6 rat glioma cells and two served as controls. The images that were used for the three-dimensional (3-D) measurements were obtained from T1 weighted post contrast sequences. A commercially available computer work station with 3-D image analysis software was used to generate the tumor volumes. In addition to the rat studies a mouse was included to see if the resolution would be adequate for imaging very small brains. Six rats had brain tumor growth after transplantation and two rats did not have any tumor growth, however, their images were similar to the controls animals. Tumor volumes varied widely among the implanted rats. The number of implanted tumor cells had no direct relationship to developing tumor volumes. This study demonstrates that high resolution images of a rat brain tumor can be obtained from a CMRI system using a commercially available wrist coil which is capable of imaging two rats at the same time or even a mouse brain. A commercially available computer work station was able to generate the tumor volumes. The ability to image brain tumor and generate volume measurements over time has potential for animal research.

Animals↗

PubMed1984

Seminal plasma proteins of a line of chickens selected for fertility of frozen-thawed semen and the control line.

The seminal plasma from individual ejaculates of 13 males of a line of chickens selected for increased duration of fertility of frozen-thawed semen for 7 generations and 12 males of the control line were analyzed for proteins. The mean +/- SE total seminal plasma protein of the selected and control lines were 8.74 +/- .55 micrograms and 7.52 +/- .92 micrograms/microliter seminal plasma (P greater than .05). Crossed immunoelectrophoretic analysis of the seminal plasma generated, in general, 11 precipitant peaks in both lines. The protein corresponding to peak 11 of the electrophoretic pattern was significantly (P less than .01) higher in the selected line than in the control line, the mean +/- SE being 1.80 +/- .21 and .85 +/- .19 micrograms/microliter seminal plasma.

Animals↗

PubMed1998

Nucleotide sequencing of S-RNA segment and sequence analysis of the nucleocapsid protein gene of the newly isolated Akabane virus PT-17 strain.

The nucleotide sequences of the S-RNA of Akabane viruses JaGAr-39, OBE-1, Iriki and the newly isolated PT-17 strains and the Aino virus were determined and compared. The results reveal that the S-RNAs of the four Akabane strains share 96.9% homology in nucleotide sequences. Only one amino acid difference out of the 233 amino acids of the nucleocapsid protein (N) and three amino acid differences in the 91 amino acids of the nonstructural protein (NSs) were found among the Akabane viruses. Amino acid sequences of N and NSs proteins of the Aino virus have approximately 80% identity as compared with the Akabane viruses. The results also demonstrate that the four Akabane viruses and the Aino virus can be clearly differentiated by RFLP (restriction fragments length polymorphism) analysis using RT-PCR generated nucleocapsid protein genes and digested with HaeIII and HindIII. The phylogenetic tree based on the UPGMA (Unweighted Pair Group Method with Arithmetic Mean) analysis of the sequences of nucleocapsid protein genes and the S-DNAs revealed that the newly isolated PT-17 strain is most closely related to Iriki strain, than the JaGAr-39 or OBE-1 strains.

Amino Acid Sequence↗