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PubMed1992

Comparison of four hearing screening protocols.

This is the second in a series of three papers concerned with the early identification of hearing loss. In the first paper (Turner, 1991), a simple model that permits the calculation of the performance and cost of early identification protocols is presented. In this paper, the model is used to compare four protocols that differ only in their hearing screening strategies. The high-risk register and auditory brainstem response screening are used to construct the four screening protocols. The cost and performance of the four early identification protocols are calculated using base model parameters derived from the clinical literature. The protocols are evaluated separately for the intensive care nursery and the well-baby nursery.

Audiometry↗
PubMed1989

Comparison of serum biochemical profiles of male broilers with female broilers and White Leghorn chickens.

Male broiler chickens were compared to female broiler chickens and male White Leghorns with respect to a 15-parameter serum biochemical profile at 9, 20, 30 and 42 days of age in order to determine which, if any, of the parameters tested might be useful in the identification of birds susceptible to sudden death syndrome. In comparison to female broilers, male broilers had significantly lower (p less than 0.01) total protein levels at 20 days of age and significantly higher (p less than 0.01) cholesterol levels at 30 days of age. Compared to male White Leghorns, in which sudden death syndrome has not been reported, male broilers had significantly lower (p less than 0.01) levels of cholesterol and creatinine at nine days of age, total protein at 9 and 20 days of age and albumin at 20 days of age and significantly higher (p less than 0.01) levels of potassium at nine days, uric acid at 9, 20 and 30 days, lactate dehydrogenase at 20, 30 and 42 days and cholesterol at 30 days of age.

Animals↗
PubMed1987

[Computerized processing, using a Macintosh, of ambulatory arterial pressure measurements collected on a Spacelabs monitor].

UNLABELLED: The use of the Spacelabs blood pressure recorder has given rise to processing programs running on Apple II and IBM PC computers. The authors have written in M.S. BASIC (2.1) a program who take advantage of graphic abilities and easy manipulation on Macintosh. The software was designed to perform three tasks: Communicating between Macintosh and Spacelabs station using serial interface (RS 232) without requesting specific interface card. Editing a report on two pages: The first is the listing of 96 measurements (one by 15 minutes). The second provides: patient identification, height, weight, diagnosis. Graphic representation of measurements Systolic and diastolic blood pressure (BP) repartition histogram for 24 hours, day and night. Standard deviation and mean of pressure and heart rate (HR) for those periods. A third optionally gives hourly chronogram and diagrams for cumulated BP and HR. Creating a file: 550 records can be stored on a 800 K floppy disk. The file handles: data for each patient (excepted identification). Random access and revision of each parameter is possible. SYNTHESIS: comparative reports for group patients and patient by patient analysing data with appropriate statistical test (ANOVA and correlation) are done.

Blood Pressure Determination↗
PubMed1997

Peritoneal dialysis effluent, cytokine levels, and peritoneal mesothelial cell viability in CAPD: a possible relationship.

Recent studies have emphasized the role of peritoneal mesothelial cell (PMC) in peritoneal immune defense mechanisms in continuous ambulatory peritoneal dialysis (CAPD). The aim of this study was to evaluate a possible relationship between peritoneal dialysis effluent (PDE), cytokine (Cy) levels, and PMC viability and their impact on peritonitis morbidity. Fifteen patients initiating CAPD for end-stage renal failure participated in the study. The following parameters were evaluated: (1) the levels of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-6 (IL-6), and interleukin-8 (IL-8) in PDE samples taken 7 days after initiating CAPD, at the end of the first, third, and sixth month of CAPD (determined by a solid phase enzyme amplified sensitivity immunoassay EASIA); (2) peritoneal mesothelial cell viability [determined by the release of lactate dehydrogenase (LDH) and by trypan blue extrusion test] by isolating and culturing peritoneal mesothelial cells at the moment of the placement of the peritoneal catheter and at the sixth month of CAPD; (3) peritonitis incidence during the 24 months after starting CAPD. At the first month of CAPD in all patients there was a slight increase in PDE IL-1 beta and TNF-alpha levels, while other Cy were almost undetectable. Time course studies showed that in 10 patients (Group I) there was a significant increase in PDE levels of IL-6, IL-8, and INF-gamma (p < 0.0005) in comparison to other Cy and a good PMC viability. In the other 5 patients (Group II) there were higher PDE levels of IL-1 beta and TNF-alpha (p < 0.0005). This was associated with a marked reduction in PMC viability determined by the release of LDH and by the trypan blue extrusion test. During the 24 months after starting CAPD, incidence of peritonitis was one episode per 24 patient-months in Group I and one episode per 9.2 patient-months in Group II. Our results show that from the beginning of CAPD there are distinct patterns of Cy in the PDE that correlate with a different PMC viability and peritonitis morbidity. Thus the analysis of the above-mentioned parameters may be useful in the early identification of the risk of peritonitis, thus allowing preventive measures.

Cell Survival↗
PubMed1984

[Variability of morphologic parameters of individual neurons and neuron clusters in the visceral ganglion of the mollusk Lymnaea stagnalis L].

Quantitative investigations on variability of visual morphological parameters in neurons BB1, BB3-5 and clusters BBb have been performed on the ventral side of the visceral ganglion in 20 molluscs Lymnaea stagnalis L. (height of the shell -45.5-1.3 mm, variation coefficient -2.9%) cought in the same pond and on the same day. Statistical analysis of the data obtained is performed by means of the methods applied for analysing small independent samples. A probability character of visual identification and an essential variability are demonstrated for the parameters of the neuron BB1 (diameter, position, colour), of the number of giant and/or large neurons BB3-5 and the cluster BBb neurons. The variation character of the parameters mentioned is asymmetric. It is possible to speak on a greater determinancy of a preferable gradation of the parameters. The interconnection of the variability and the determinancy of the morphological signs with the identificity and functioning of the neuronal elements are discussed. A suggestion is made that identification of the neurons according to both their morphological and functional criteria, as a whole, can have a probability character. The data considered in the work make doubt the invariance of the neurons studied in the mollusc Lymnaea stagnalis L.

Animals↗
PubMed1988

Hearing disabled children--epidemiology and identification.

An investigation of hearing disabled children was performed in the Copenhagen City and County in order to: evaluate the prevalence and incidence of congenital/early acquired hearing disability and delineate any change in these parameters compared to the 1970'ies; evaluate the time of identification of the hearing impaired child; indicate who first suspects the child's hearing disability. It was demonstrated that the prevalence of hearing aid treated children had been reduced with 40-42%, however, the incidence was unchanged 0.13%. An annual variance of 0.06-0.20% was present. No significant difference in the incidence was found between the two geografical areas. The median age at identification was 15-18 months, and only 32-48% of the hearing disabled children had been identified at the age of 1 year, showing an improvement in comparison to the 15-16% identified at the same age in the 1970'ies. Children, who could be registered as auditory at-risk were not identified earlier than the non-at-risk children. In 57-67% of the children the parents were the first to suspect the hearing disability. On the basis of the investigation it is concluded that the incidence of congenital/early acquired hearing disability in children is unchanged over a 10 year period, and that a delayed identification of these children is present although an improvement in the early identification has taken place.

Child, Preschool↗
PubMed2000

Closed-loop identification of carotid sinus baroreflex transfer characteristics using electrical stimulation.

Although random aortic pressure (AOP) perturbation according to a binary white noise sequence enables us to estimate open-loop dynamic characteristics of the carotid sinus baroreflex under closed-loop conditions, the necessity of arterial catheter implantation limits the applicability of this method in freely moving animal experiments. Thus, we explored a closed-loop system identification method using electrical stimulation. In 6 anesthetized and vagotomized rabbits, we stimulated the aortic depressor nerve with a binary white noise sequence (0-10 Hz) under baroreflex closed-loop conditions while measuring cardiac sympathetic nerve activity (SNA) and AOP. We used a closed-loop identification method to estimate the peripheral arc transfer function from SNA to AOP. The peripheral arc transfer function approximated a second-order low-pass filter and its fitted parameters did not differ from those obtained by an open-loop identification method (dynamic gain: 1.16+/-0.32 vs. 1.02+/-0.11; natural frequency: 0.08+/-0.03 vs. 0.09+/-0.03 Hz; damping ratio: 1.53+/-0.15 vs. 1.57+/-0.21). In 6 different rabbits, we applied intermittent rapid pacing (396 beats/min) under baroreflex closed-loop conditions to estimate the neural arc transfer function from AOP to SNA. The neural arc transfer function approximated a first-order high-pass filter and its fitted parameters did not differ from those obtained by an open-loop identification method (dynamic gain: -1.15+/-0.45 vs. -1.06+/-0.05; corner frequency: 0.12+/-0.05 vs. 0.13+/-0.03 Hz). In conclusion, the closed-loop identification method using electrical stimulation is effective to estimate the neural and peripheral arc transfer functions.

Animals↗
PubMed2004

Two-dimensional transcriptome analysis in chemostat cultures. Combinatorial effects of oxygen availability and macronutrient limitation in Saccharomyces cerevisiae.

Genome-wide analysis of transcriptional regulation is generally studied by determining sets of "signature transcripts" that are up- or down-regulated relative to a reference situation when a single culture parameter or genetic modification is changed. This approach is especially relevant for defining small subsets of transcripts for use in high throughput, cost-effective diagnostic analyses. However, this approach may overlook the simultaneous control of transcription by more than one environmental parameter. This study represents the first quantitative assessment of the impact of transcriptional cross-regulation by different environmental parameters. As a model, we compared the response of aerobic as well as anaerobic chemostat cultures of the yeast Saccharomyces cerevisiae to growth limitation by four different macronutrients (carbon, nitrogen, phosphorus, and sulfur). The identity of the growth-limiting nutrient was shown to have a strong impact on the sets of transcripts that responded to oxygen availability and vice versa. We concluded that identification of reliable signature transcripts for specific environmental parameters can be obtained only by combining transcriptome data sets obtained under several sets of reference conditions. Furthermore, the two-dimensional approach to transcriptome analysis is a valuable new tool to study the interaction of different transcriptional regulation systems.

Aerobiosis↗
PubMed1987

Automated gunshot residue particle search and characterization.

The main disadvantage to gunshot residue (GSR) particle analysis utilizing scanning electron microscope/energy dispersive X-ray (SEM/EDX) instrumentation has been the excessive operator time required for search and identification. This study uses an automated particle search and characterization program for unattended GSR search and identification. This system allows for automatic matrix search, particle sizing, chemical typing, and spectral aquisition with subsequent storage of data to disk for later operator review and verification. This work describes various aspects of the program, determines appropriate parameters adequate for both unique and characteristic GSR particle identification, and evaluates the reliability of data obtained. Samples are collected via the tape lift method from test-firings of .38, .32, .25, and .22 caliber handguns at time after firing intervals of 0 to 6 h. Unique GSR particles are consistently and correctly identified by this method on tape lift samples taken up to 4 h after firing. False positive results of unique GSR particles are not encountered on control handblank samples. This technique appears to provide the forensic science community with an operator-free method of reliable GSR particle search and an improved analyst-time-per-case ratio.

Electron Probe Microanalysis↗
PubMedDate not supplied

Added value for tandem mass spectrometry shotgun proteomics data validation through isoelectric focusing of peptides.

A very popular approach in proteomics is the so-called "shotgun LC-MS/MS" strategy. In its mostly used form, a total protein digest is separated by ion exchange fractionation in the first dimension followed by off- or on-line RP LC-MS/MS. We replaced the first dimension by isoelectric focusing in the liquid phase using the Off-Gel device producing 15 fractions. As peptides are separated by their isoelectric point in the first dimension and hydrophobicity in the second, those experimentally derived parameters (pI and R(T)) can be used for the validation of potentially identified peptides. We applied this strategy to a cellular extract of Drosophila Kc167 cells and identified peptides with two different database search engines, namely PHENYX and SEQUEST, with PeptideProphet validation of the SEQUEST results. PHENYX returned 7582 potential peptide identifications and SEQUEST 7629. The SEQUEST results were reduced to 2006 identifications by validation with PeptideProphet. Validation of the PeptideProphet, SEQUEST and PHENYX results by pI and R(T) parameters confirmed 1837 PeptideProphet identifications while in the remainder of the SEQUEST results another 1130 peptides were found to be likely hits. The validation on PHENYX resulted in the fixation of a solid p-value threshold of <1 x 10(-04) that sets by itself the correct identification confidence to >95%, and a final count of 2034 highly confident peptide identifications was achieved after pI and R(T) validation. Although the PeptideProphet and PHENYX datasets have a very high confidence the overlap of common identifications was only at 79.4%, to be explained by the fact that data interpretation was done searching different protein databases with two search engines of different algorithms. The approach used in this study allowed for an automated and improved data validation process for shotgun proteomics projects producing MS/MS peptide identification results of very high confidence.

Algorithms↗
PubMed2005

Essential radiographic evaluation for distal radius fractures.

Fractures of the distal radius can be complex injuries, often generating multiple fragments with distortion of the normal anatomy in all three dimensions. Superficial assessment of the injury on the standard PA and lateral radiographs often can result in incomplete recognition of the injury pattern and a misdirected approach to treatment. In addition, failure to recognize subtle radiographic findings may result in the acceptance of a reduction that has significant residual incongruency and articular surface disruption. Standard radiographs of the distal radius can provide a wealth of information about the topography of the bone if the surgeon knows what to look for. The ability to recognize detailed landmarks and parameters on the radiographic images and convert this information into a three-dimensional visual image is a skill that requires education and training. As more aggressive treatments have emerged for anatomic restoration of the bony and articular anatomy, accurate identification of the pattern of injury has become essential. Parameters such as the tear drop angle, AP distance, and articular separation have been recognized only recently. Because these parameters reflect the congruency of the articular surface,it would be natural to assume that postreduction films in which these parameters are abnormal would compromise clinical outcome. Because nearly all historical studies do not include routine evaluation of these parameters, knowledge of radiographic correlation with clinical outcome is still incomplete. At the same time, previous studies to assess outcome of distal radius fractures may be compromised by the failure to recognize residual deformity and articular incongruency that would have been evident with measurement of these parameters. With careful understanding of the radiographic landmarks, radiographic parameters, and patterns of injury, the surgeon can visualize a more accurate picture of the fracture itself and the reduction. As a result, treatment decisions for distal radius fractures can be based on a more thorough understanding of the anatomy of the injury, and future grading of radiographic results may reflect more accurately the precision of the articular restoration.

Humans↗
PubMed2004

Synthesis and evaluation of 2-amino-8-alkoxy quinolines as MCHr1 antagonists. Part 2.

The continued SAR investigation of 2-amino-8-alkoxy quinolines as melanin concentrating hormone receptor-1 (MCHr1) antagonists is reported. Prior hit-to-lead efforts resulted in the identification of 1 as a robust MCHr1 antagonist. Further delineation of the structural parameters essential for MCHr1-binding affinity of this class of nontraditional GPCR ligands resulted in the identification of compounds such as 33, 34 and 37, which demonstrate single digit nanomolar antagonism of MCHr1-mediated Ca(2+) release. The synthesis and biological evaluation of these compounds are reported.

Animals↗
PubMed1979

The BAER profile: a method for reporting electrophysiologic brainstem examinations in clinical practice.

We present a method for graphically reporting the results of brainstem auditory evoked response examinations on the basis of multiple parameters. The method is based on a transform that normalizes the many latency and amplitude measures obtained from the averaged evoked responses of normal subjects tested under standardized conditions. Among the advantages of the method are the simplicity of its use, the identification of disease profiles, and the isolation of relevant parameters for research and diagnosis.

Adult↗
PubMed2004

Topographical parameters for specifying a three-dimensional surface.

The importance of different surface geometries and thereby the need for versatile surface identification by describing a number of different surface features is emphasized. A set of topographical parameters for the description of the amplitude and spatial and hybrid properties of surfaces was utilized for a versatile three-dimensional surface characterization of sol-gel samples with different topographies. The image data were measured by atomic force microscopy. The results demonstrate the power of the roughness parameters to identify surfaces according to their specific characteristics. An example is also given about how certain surface topographical properties may control the material reactivity.

Letter↗
PubMed2002

Self-selected modular recurrent neural networks with postural and inertial subnetworks applied to complex movements.

It has been shown that dynamic recurrent neural networks are successful in identifying the complex mapping relationship between full-wave-rectified electromyographic (EMG) signals and limb trajectories during complex movements. These connectionist models include two types of adaptive parameters: the interconnection weights between the units and the time constants associated to each neuron-like unit; they are governed by continuous-time equations. Due to their internal structure, these models are particularly appropriate to solve dynamical tasks (with time-varying input and output signals). We show in this paper that the introduction of a modular organization dedicated to different aspects of the dynamical mapping including privileged communication channels can refine the architecture of these recurrent networks. We first divide the initial individual network into two communicating subnetworks. These two modules receive the same EMG signals as input but are involved in different identification tasks related to position and acceleration. We then show that the introduction of an artificial distance in the model (using a Gaussian modulation factor of weights) induces a reduced modular architecture based on a self-elimination of null synaptic weights. Moreover, this self-selected reduced model based on two subnetworks performs the identification task better than the original single network while using fewer free parameters (better learning curve and better identification quality). We also show that this modular network exhibits several features that can be considered as biologically plausible after the learning process: self-selection of a specific inhibitory communicating path between both subnetworks after the learning process, appearance of tonic and phasic neurons, and coherent distribution of the values of the time constants within each subnetwork.

Adult↗
PubMed2004

Defining the parameters necessary for T-cell recognition of ligands that vary in potency.

Identification of the mechanisms by which a T cell is able to sense ligands of varying strength, such as those that mediate tumor growth, viral evasion, and autoimmunity, is a major goal of T-cell activation studies. In recent years, parameters important for T-cell activation by strong ligands (agonists) are beginning to be characterized. Here, we review our current work on the factors that are critical for T-cell activation by ligands that differ in potency, typified by full agonists, weak agonists, partial agonists, and antagonists. Furthermore, we discuss mechanisms contributing to the lack of a full range of effector functions observed in T cells following their stimulation by suboptimal ligands. Finally, we present strategies for the design of peptide-based therapies to control activation of polyclonal, autoreactive T-cell populations.

Intracellular Signaling Peptides and Proteins↗
PubMed2007

The role of echocardiography in the assessment of mechanical dyssynchrony and its importance in predicting response to prognosis after cardiac resynchronization therapy.

The aim of this review is to synthesize the published evidence regarding the benefits of identifying mechanical asynchrony before implantation of biventricular devices, and the role of echocardiography in the identification and quantification of mechanical asynchrony. It summarizes the published studies addressing the several echocardiographic parameters of dyssynchrony that have already proven to predict response to cardiac resynchronization therapy. M-mode echocardiography, Doppler tissue imaging, strain and strain rate imaging, tissue tracking, and 3-dimensional echocardiography parameters of dyssynchrony shown to be able to identify responders are discussed. In addition, the prognostic implication of the identification of mechanical asynchrony before implantation is addressed. A summary of the published evidence of the echocardiographic parameters able to identify patients more likely to derive a prognostic benefit is provided. Finally, it mentions some of the current uncertainties and possible future applications of echocardiographic evaluation of dyssynchrony.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

Gel based isoelectric focusing of peptides and the utility of isoelectric point in protein identification.

Here we present the theoretical and experimental evaluation of peptide isoelectric point as a method to aid in the identification of peptides from complex mixtures. Predicted pI values were found to match closely the experimentally obtained data, resulting in the development of a unique filter that lowers the effective false positive rate for peptide identification. Due to the reduction of the false positive rate, the cross-correlation parameters Xcorr and deltaCn from the SEQUEST program can be lowered resulting in 25% more peptide identifications. This approach was successfully applied to analysis of the soluble fraction of the E. coli proteome, where 417 proteins were identified from 1022 peptides using just 20 microg of material.

Chromatography, High Pressure Liquid↗