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At least 991 records · Page 55Linked to original sources
PubMed1994

[Genetic engineering of human insulin. IV. Development and optimization of an analysis system using reversed phase high pressure liquid chromatography].

The effectiveness of the RP HPLC application for the step-by-step analysis of the recombinant insulin production was studied. Properties of a number of commercial and experimental columns in different chromatographic conditions were considered. A three-dimension optimization of selectivity and resolution versus pH and ion strength was carried out. A mechanism of the resolution and selectivity control is suggested.

Chromatography, High Pressure Liquid↗
PubMed1994

Quantitation of immunogold with an interactive image analysis system. A new, practical approach to antibody-induced modulation, internalization and intracellular transport of surface antigens in viable hematopoietic cells.

This work aimed to evaluate the value of computerized quantitative analysis in ultrastructural studies on internalization and intracellular transport of leukocyte antigens traced with immunogold in viable lymphoid cells. The time of analysis and the results were compared with those obtained with a standard method based on counting gold particles on electron micrographs. A commercially available, personal computer-based, single-screen system was used for capturing and processing the ultrastructural images, counting gold particles and presenting data. The viable lymphoblasts of RAJI and NALM-6 cell lines were labeled with B4 (anti-CD19) murine monoclonal antibody followed by rabbit antimouse immunoglobulins coupled to 12.8-nm colloidal gold, cultured for six hours to allow internalization of CD19 antigen, collected after various periods of time and processed for electron microscopy. Each sample was analyzed by counting the gold particles on 30 randomly chosen, equatorial cell sections. Surface-bound particles and those located within certain intracellular compartments (that is, cytoplasmic vesicles, multivesicular bodies and lysosomes) were counted separately. No significant differences were found between the results obtained using electron micrographs and those yielded by on-screen analysis of digitized images. However, the time of analysis varied considerably--approximately eight and two hours, respectively. Also, using computerized analysis saved the cost of photographic processing. In conclusion, the system provided a reliable, rapid and inexpensive alternative for quantitation of immunogold-labeled leukocyte antigens at the ultrastructural level.

Antibodies↗
PubMed1994

The expression of functional link protein in a baculovirus system: analysis of mutants lacking the A, B and B' domains.

Functional recombinant human link protein has been produced using a baculovirus expression system. In addition to the intact link protein, three mutant forms have also been expressed. Each mutant bears a deletion equivalent to the protein encoded by one exon in the gene. These deletions represent the A domain, which is thought to be responsible for interaction with aggrecan, and the B or B' domains, which are associated with the interaction with hyaluronate. Such deletions split codons spanning exon boundaries, but maintain the reading frame of the protein and result in the correct amino acid being present at the splice junction. All the recombinant proteins appear as two components upon SDS/PAGe, though the abundance of the two forms does vary between preparations, as a result of variable substitution by N-linked oligosaccharides. The recombinant intact link protein was able to interact with both hyaluronate and aggrecan, showing that the baculovirus system is able to produce functional molecules. All of the recombinant mutant link proteins were also able to interact with hyaluronate, indicating that both the B and B' domains can function independently. The recombinant mutant link proteins were also able to interact with aggrecan, with the exception of the mutant lacking the A domain, confirming that this ability resides entirely within this domain.

Aggrecans↗
PubMed2003

Genotyping of measles and mumps virus strains using amplification refractory mutation system analysis combined with enzyme immunoassay: a simple method for outbreak investigations.

A simple method, based on a modification of the amplification refractory mutation system (ARMS), for genotyping outbreak strains of measles and mumps viruses and detecting these in a simple enzyme immunoassay (EIA) is described. Fifty-three measles strains circulating at the time of an outbreak in London in 2000 and 26 strains circulating at the time of a mumps outbreak in Accrington, UK, in 1999 were investigated. All strains were genotyped by direct sequencing. ARMS primers were then designed to amplify the outbreak strain. The ARMS-EIA for measles and mumps detected all 36 measles outbreak strains as genotype D6, and all 15 mumps outbreak strains as genotype F, respectively. The sensitivity and specificity of both the measles D6 and Mumps F genotype ARMS EIA was 100% compared with direct sequencing. The results show that ARMS-EIA can be used as a rapid alternative to genotyping by direct sequence analysis in outbreak situations.

Alleles↗
PubMed1997

Fast on-line flow injection analysis system for IgG monitoring in bioprocesses.

An automated immunoassay, with one affinity component immobilized on a solid surface, has been developed to monitor the production of different immunoglobulins during mammalian cell cultivation processes. The whole analysis device is based on the principle of flow injection analysis (FIA) and a cartridge with the immobilized affinity component is implemented into the FIA system. This cartridge is filled with a carrier material to which protein G is covalently bound. After sample injection, binding of the IgG on the protein G within the cartridge takes place while after a washing step, the IgGs are eluted by a pH shift, and the IgG concentration is monitored via fluorescence. In the automated immunoassay, undiluted cell free samples from the reactor or from down-stream processing can be analyzed directly. Due to the separation the IgG can be detected without interference from other sample components by protein fluorescence. The results are obtained with analysis times below 6 min. Sample volumes of less than 100 microliters may be used. The assay is sensitive to concentrations from 5 up to 500 micrograms ml-1. Using this FIA-System, immunoglobulins G, produced in different media, were successfully monitored. The results of the assay were validated by ELISA.

Biochemistry↗
PubMed2000

[Treatment of children with hyperkinetic disorders (ADHD) based on communications- and systems analysis].

Inquired for a therapeutic mode changing hyperactive behavior without application of drugs or diets we analyzed the patterns of cognition, communication and system behavior related to such disturbed children and their families. Following our observations we created a clinically useful therapy basing on a special view to system- and communication theory. We applied our therapeutic mode generally to as hyperactive identified primary school children and collected in N = 46 cases catamnestic data about five years later. In more than 80% out of the sample we found successful developments after application of in means 8 therapeutic sessions during 9 months. About 53% out of the successful treatment children show a splendid school success. Our results are demanding for an extended discussion of relations and family constellations including hyperactive behavior of one child. Searching for the possibilities of change in the view of system theory it seems to be more appropriate to consider relations but individual behavior.

Attention↗
PubMed1986

System analysis of Phycomyces light-growth response with sum-of-sinusoids test stimuli.

The light-growth response of Phycomyces has been studied with the sum-of-sinusoids method of nonlinear system identification (Victor, J.D., and R.M. Shapley, 1980, Biophys. J., 29:459). This transient response of the sporangiophore has been treated as a black-box system with one input (logarithm of the light intensity, I) and one output (elongation rate). The light intensity was modulated so that log I, as a function of time, was a sum of sinusoids. The log-mean intensity was 10(-4) W m-2 and the wavelength was 477 nm. The first- and second-order frequency kernels, which represent the linear and nonlinear behavior of the system, were obtained from the Fourier transform of the response at the appropriate component and combination frequencies. Although the first-order kernel accounts for most of the response, there remains a significant nonlinearity beyond the logarithmic transducer presumed to occur at the input of the sensory transduction chain. From the analysis of the frequency kernels, we have derived a dynamic nonlinear model of the light-growth response system. The model consists of a nonlinear subsystem followed by a linear subsystem. The model parameters were estimated from a combined nonlinear least-squares fit to the first- and second-order frequency kernels.

Kinetics↗
PubMed2001

Spontaneous microdeletions and microinsertions in a transgenic mouse mutation detection system: analysis of age, tissue, and sequence specificity.

A total of 3497 independent spontaneous mutations were examined using the Big Blue transgenic mouse mutation detection system. Base substitutions predominate, although 16% of somatic and germline mutations are microdeletions, microinsertions, or deletions combined with insertions. The pattern of microdeletions and microinsertions is similar in both the lacI transgene and the human p53 gene. Single-base deletions (D1) and insertions (I1) are evenly distributed in the lacI transgene, whereas microdeletions from 2 to 50 bp are clustered at two regions (bp 129-228 and 529-628). The pattern of microdeletions and microinsertions is similar between young (< or =3 months) and old (25 months) mice. Brain tissue has a paucity of deletions combined with insertions when compared with that of thymus and nine other tissues (P = 0.01). A 16-bp deletion at lacI base position 272 is a tissue-specific hotspot preferentially occurring in brain. Approximately 68 and 93% of D1 and I1, respectively, occur at mononucleotide repeats. The frequencies of D1 and I1 in mononucleotide repeats increase in an exponential manner with the length of the repeat. The lacI transgene shows similarity to the human p53 gene in the pattern of microdeletions and microinsertions and the size distribution of microdeletions.

Age Factors↗
PubMed2001

A stable gas chromatography-mass spectrometry analysis system to characterize Ma Huang products found in health foods and supplements.

Herbal mixtures containing Ma Huang are of significant interest because of their popularity regardless of their potential health hazards. In spite of reports of health problems and even several deaths, these products are still frequently recommended for use. The complex nature of the commercial supplement mixtures has posed a problem in both their qualitative and quantitative analysis. A gas chromatographic procedure has been developed to evaluate authenticity of Ma Huang mixtures. Mass spectrometric identification of the six major alkaloid ephedrine components and application of chi-square evaluation of the chromatographic profile allows a determination to be made regarding the nature of the origin of the mixture. For comparison, a standard mixture was prepared that approximates a typical Ma Huang composition based on average amounts of each alkaloid component reported in the literature. The system is temperature stable and allows simultaneous analysis for caffeine and other components of the commercial supplements. Several samples of commercial herbal products were analyzed by the procedure, and their composition is evaluated and discussed.

Dietary Supplements↗
PubMed2005

Predicting antisocial behavior among latino young adolescents: an ecological systems analysis.

The authors used data from a national sample of 420 Latino young adolescents to examine multiple predictors of antisocial behavior within an ecological systems framework. They found that boys and youths who lived a higher proportion of their life in poverty exhibited higher levels of antisocial behavior, and mothers' acculturation was associated with lower levels. Neighborhood and school environments, exposure to deviant peer pressure, and 3 parenting practices--parent-youth attachment, physical punishment, and mothers' monitoring--were related to Latino youth antisocial behavior. Neighborhood quality and peer pressure explained the relation between poverty and an increased risk for antisocial behavior.

Acculturation↗
PubMedDate not supplied

Clinical experience with a multi-element ultrasonic hyperthermia system: analysis of treatment temperatures.

A summary of tumour temperature data obtained from 31 patients who underwent 147 hyperthermia treatments with the Sonotherm 1000 ultrasonic system is presented. The treatment goal was to achieve a minimum of 42.0 degrees C in tumour for 60 min duration with normal tissues remaining below 43.0 degrees C. In 83% of treatments at least one measured tumour temperature reached or exceeded 42.0 degrees C at some time during the treatment. Nineteen per cent of these treatments had a time- and spatial-averaged temperature (measured in tumour) greater than or equal to 42.0 degrees C. A variety of anatomical sites were treated and these were grouped into four categories: groin/trunk, axilla, breast/chest wall and head/neck. Measured temperatures in tumours located in the groin and trunk sites were significantly higher (22% greater than or equal to 42 degrees C) than other locations. The head and neck treatment temperatures were significantly lower (8% of measured points greater than or equal to 42 degrees C.

Body Temperature↗
PubMed2002

Cross-linked polyacrylamide gel electrophoresis of single-stranded DNA for microfabricated genomic analysis systems.

Microfabricated devices are poised to offer inexpensive self-contained alternatives to conventional benchtop-scale laboratory equipment for performing a variety of important DNA analysis assays. In order to realize the dramatic cost savings possible through photolithographic fabrication techniques, these devices must occupy an extremely compact footprint on the silicon wafer. This requirement implies that electrophoretic separations must be performed over ultrashort distances. Employing cross-linked polyacrylamide gels in place of conventional uncross-linked sieving media offers a convenient strategy to achieve this goal. In this paper, we show how the increased resolving power offered by cross-linked polyacrylamide gels, along with improved sample injection techniques, can be exploited to enhance separation performance in microscale systems. We use these techniques to perform high-resolution gel electrophoresis of single-stranded DNA fragments in microfabricated devices over separation distances of 1.5 cm or less. The results presented here are in agreement with theoretical predictions and suggest that it is possible to perform DNA sequencing on compact microchips. More importantly, the separation performance demonstrated in this work is already more than adequate to perform a number of important genomic assays imposing less stringent resolution requirements than sequencing. Successfully adapting even a few of these assays to the microdevice format has the potential to provide a new generation of inexpensive and portable devices suitable for direct end-user applications.

Acrylic Resins↗
PubMed1999

Dynamical systems analysis of arterial blood pressure signals in relation to heart rate fluctuations in chick embryos.

We attempted a new approach based on a modern dynamical system theory to reconstruct the arterial blood pressure signals in relation to heart rate fluctuations of developing chick embryos. The dynamical systems approach in general is to model a phenomenon that is presented by a single time series record and approximate the dynamical property (e.g. heart rate fluctuations) of a system based only on information contained in a single-variable (arterial blood pressure) of the system. The time-series data of the arterial blood pressure was reconstructed in 3-dimensional space to draw characteristic orbits. Since the reconstructed orbits of the blood pressure should retain information contained in the pressure signals, we attempted to derive instantaneous heart rate (IHR) from the reconstructed orbits. The derived IHR presenting HR fluctuations coincided well with the IHR obtained conventionally from the peak-to-peak time intervals of the maximum blood pressure. Movements of the reconstructed orbits of the arterial blood pressure in 3-dimensional space reflected HR fluctuations (i.e. transient decelerations and accelerations).

Animals↗
PubMed1986

An image analysis system for the determination of tooth dimensions from study casts: comparison with manual measurements of mesio-distal diameter.

A first comparison of an image analysis method with classical hand measurement was made using the mesio-distal diameter data derived by the simplest image analysis method, the jawview mode. Fifty casts of male Hong Kong Chinese dental students, mean age 20.4 years, were examined by both methods. The two techniques gave comparable overall results, the correlation coefficients generally being greater than 0.9. A combination of the buccal and occlusal image analysis views gave the best correlation with hand measurement with a comparable variability for different tooth types. For certain teeth, particularly posteriors, reproducibility was better using hand measurement. Optimal weighting of the data from these two different image analysis views can give an "estimated hand measurement" value. Further development of the method to deal with differing orientations of teeth is possible.

Adult↗
PubMed1989

[Initial experiences with a new kind of computer compatible coding and analysis system for inpatient and ambulatory services].

This paper describes a new concept of an operational database management system including the word processing program "Word Star". The system structure is composed of patients identities and linked MIR's (medical information records) to follow a patient's history in space and time. In- and out-patient's data are collected on a special data sheet with numeric responses from the following areas: demographics including risk factors, diagnosis, surgical procedure, intra- and postoperative morbidity analysis. Data are entered using a DBS-16 concurrent dos system and stored on a 105 Megabytes hard disk. The software program in its compiled version allows for processes like outpatients clinic management, appointments organisation and statistical analysis of different variables thus providing detailed information on patients postoperative morbidity.

Ambulatory Care↗
PubMed2006

A neurobehavioral systems analysis of adult rats exposed to methylazoxymethanol acetate on E17: implications for the neuropathology of schizophrenia.

BACKGROUND: As a test of plausibility for the hypothesis that schizophrenia can result from abnormal brain, especially cerebral cortical, development, these studies examined whether, in the rat, disruption of brain development initiated on embryonic day (E) 17, using the methylating agent methylazoxymethanol acetate (MAM), leads to a schizophrenia-relevant pattern of neural and behavioral pathology. Specifically, we tested whether this manipulation leads to disruptions of frontal and limbic corticostriatal circuit function, while producing schizophrenia-like, region-dependent reductions in gray matter in cortex and thalamus. METHODS: In offspring of rats administered MAM (22 mg/kg) on E17 or earlier (E15), regional size, neuron number and neuron density were determined in multiple brain regions. Spontaneous synaptic activity at prefrontal cortical (PFC) and ventral striatal (vSTR) neurons was recorded in vivio. Finally, cognitive and sensorimotor processes mediated by frontal and limbic corticostriatal circuits were assessed. RESULTS: Adult MAM-E17-exposed offspring showed selective histopathology: size reductions in mediodorsal thalamus, hippocampus, and parahippocampal, prefrontal, and occipital cortices, but not in sensory midbrain, cerebellum, or sensorimotor cortex. The prefrontal, perirhinal, and occipital cortices showed increased neuron density with no neuron loss. The histopathology was accompanied by a disruption of synaptically-driven "bistable membrane states" in PFC and vSTR neurons, and, at the behavioral level, cognitive inflexibility, orofacial dyskinesias, sensorimotor gating deficits and a post-pubertal-emerging hyper-responsiveness to amphetamine. Earlier embryonic MAM exposure led to microcephaly and a motor phenotype. CONCLUSIONS: The "MAM-E17" rodent models key aspects of neuropathology in circuits that are highly relevant to schizophrenia.

Amphetamine↗
PubMedDate not supplied

Postoperative evaluation of Keller's arthroplasty and arthrodesis of the first metatarsophalangeal joint using the EMED gait analysis system.

The authors examined 10 patients who had arthrodesis at the first metatarsophalangeal joint and 10 patients who had Keller's arthroplasty operation. The EMED gait analysis was used to measure the pressure distribution over the sole of the foot during walking. Arthrodesis group had significantly increased maximum pressure in the first and third metatarsal regions. The Keller arthroplasty group had the lowest maximum pressure in the big toe but it was not significant.

Adult↗