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PubMed1994

Behavioral profiles of adult rats in a difficult food supply social situation, related to certain early behavioral features.

Behavioral profiles of male rats were defined in nine intralitter groups of six individuals at various stages of their development: (a) at pup stage in individual situations (uncomfortable positions) and social situations (removal away from the mother), and (b) at adult stage in a difficult food supply social situation (complete immersion of the food access way). The male population was split into two sets, both at pup stage (the most and the least swift and efficient of each group to overcome uncomfortable situations), and at adult stage (carriers and noncarriers of food in each group tested). Our results showed an important relation between these pup and adult behavioral profiles: the swiftest and most efficient individuals of a group at pup stage adopted more often a food carrier behavioral profile at adult stage. Assumptions about the predictive value of some behavioral features of a young rat in regard to its adult behavioral profile are discussed.

Aging↗
PubMed1997

Different cytokine profile and antigen-specificity repertoire in Helicobacter pylori-specific T cell clones from the antrum of chronic gastritis patients with or without peptic ulcer.

Helicobacter pylori (Hp) infection almost invariably results in chronic antral gastritis, but only a proportion of patients develop peptic ulcer. Some Hp strains may be more ulcerogenic than others, but some ulcerogenic mechanisms may also depend on the type of the host immune response. In this study, the antigen specificity and the cytokine profile of 53 Hp-specific CD4+ T cell clones derived from the antral mucosa of five patients with Hp-induced uncomplicated chronic gastritis (CG) were assessed and compared with those of 34 Hp-specific CD4+ T cell clones derived from six Hp-infected patients with chronic gastritis and peptic ulcer (CG-PU). The majority (28/34; 82%) of gastric Hp-specific T cell clones from CG-PU patients expressed the Th1 profile and 17 (all Th1) of the 34 clones were specific for cytotoxin-associated protein (CagA). In contrast, 34 (64%) of the 53 Hp-specific gastric T cell clones derived from CG patients were able to secrete both Th1 and Th2 cytokines (Th0 profile) and only 36% expressed a polarized Th1 profile. The majority (85%) of Hp-specific clones from CG patients recognized Hp antigens other than CagA, since 13/53 (25%) were specific for urease, 6 (11%) for VacA, 6 (11%) for HSP and 20 (38%) for other undefined Hp antigens. Results provide evidence that the type of T helper cell response against Hp may vary according to the antigen involved and suggest that a polarized Th1 response may play a role in the genesis of peptic ulcer, whereas a local Th0 response, including interleukin-4 production, may represent an individual host factor which contributes to lower the degree of gastric inflammation and prevent ulcer complication.

Adult↗
PubMed2005

Capillary electrophoresis-mass spectrometry in impurity profiling of pharmaceutical products.

Generally reversed-phase high-performance liquid chromatography (RP-HPLC) methods are extensively applied during quality control of pharmaceutical products. Since capillary electrophoresis (CE) is based on a different separation principle and consequently results in a unique selectivity compared to RP-HPLC, it can advantageously be used as an orthogonal technique. CE equipped with a mass spectrometer detector provides even more information that can be helpful for identification and structural elucidation purposes. CE-MS was recently implemented in the method development approach to support impurity profiling of pharmaceutical products. In this paper the application of CE-electrospray ionization (ESI)-MS/MS to the impurity profiling of galantamine hydrobromide in stressed Reminyl Extended Release (ER) capsules is discussed. Reminyl ER samples were stressed at different storing conditions. The impurity profile of these samples was compared with the current RP-HPLC and chiral CE method, but also with CE-ESI-MS/MS. The combination of these three methods provided valuable data that allowed understanding comprehensively the impurity profile of these samples. Two impurities were detected at concentrations lower than 0.05%, which did not occur in nonstressed samples. Chromatographic data and the fragmentation patterns of galantamine and related compounds were also examined for identification of these two degradation products.

Chromatography, High Pressure Liquid↗
PubMed2005

SELDI-TOF MS profiling of serum for detection of the progression of chronic hepatitis C to hepatocellular carcinoma.

Proteomic profiling of serum is an emerging technique to identify new biomarkers indicative of disease severity and progression. The objective of our study was to assess the use of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) to identify multiple serum protein biomarkers for detection of liver disease progression to hepatocellular carcinoma (HCC). A cohort of 170 serum samples obtained from subjects in the United States with no liver disease (n = 39), liver diseases not associated with cirrhosis (n = 36), cirrhosis (n = 38), or HCC (n = 57) were applied to metal affinity protein chips for protein profiling by SELDI-TOF MS. Across the four test groups, 38 differentially expressed proteins were used to generate multiple decision classification trees to distinguish the known disease states. Analysis of a subset of samples with only hepatitis C virus (HCV)-related disease was emphasized. The serum protein profiles of control patients were readily distinguished from each HCV-associated disease state. Two-way comparisons of chronic hepatitis C, HCV cirrhosis, or HCV-HCC versus healthy had a sensitivity/specificity range of 74% to 95%. For distinguishing chronic HCV from HCV-HCC, a sensitivity of 61% and a specificity of 76% were obtained. However, when the values of known serum markers alpha fetoprotein, des-gamma carboxyprothrombin, and GP73 were combined with the SELDI peak values, the sensitivity and specifity improved to 75% and 92%, respectively. In conclusion, SELDI-TOF MS serum profiling is able to distinguish HCC from liver disease before cirrhosis as well as cirrhosis, especially in patients with HCV infection compared with other etiologies.

Adult↗
PubMed2006

Urinary biomarker profiling in transitional cell carcinoma.

Urinary biomarkers or profiles that allow noninvasive detection of recurrent transitional cell carcinoma (TCC) of the bladder are urgently needed. We obtained duplicate proteomic (SELDI) profiles from 227 subjects (118 TCC, 77 healthy controls and 32 controls with benign urological conditions) and used linear mixed effects models to identify peaks that are differentially expressed between TCC and controls and within TCC subgroups. A Random Forest classifier was trained on 130 profiles to develop an algorithm to predict the presence of TCC in a randomly selected initial test set (n = 54) and an independent validation set (n = 43) several months later. Twenty two peaks were differentially expressed between all TCC and controls (p < 10(-7)). However potential confounding effects of age, sex and analytical run were identified. In an age-matched sub-set, 23 peaks were differentially expressed between TCC and combined benign and healthy controls at the 0.005 significance level. Using the Random Forest classifier, TCC was predicted with 71.7% sensitivity and 62.5% specificity in the initial set and with 78.3% sensitivity and 65.0% specificity in the validation set after 6 months, compared with controls. Several peaks of importance were also identified in the linear mixed effects model. We conclude that SELDI profiling of urine samples can identify patients with TCC with comparable sensitivities and specificities to current tumor marker tests. This is the first time that reproducibility has been demonstrated on an independent test set analyzed several months later. Identification of the relevant peaks may facilitate multiplex marker assay development for detection of recurrent disease.

Adult↗
PubMed2002

Isomers of C(20): an energy profile.

Semiempirical calucaltions, at the PM 3 level, are used to geometrically optimize and determine the absolute energies (heats of formation) of a variety of C(20) isomers. Based on the geometrically optimized Cartesian coordinates of the ring and the bowl isomers, and the subsequent saddle-point calculation, a two-dimensional energy profile between these two isomers is generated. Performing geometry optimization on the Cartesian coordinates that correspond to energy minima within the ring-bowl profile, we have been able to identify several more isomers of C(20) that are predicted to be energitically stable. With these additional stable structures, we have identified pairs of isomers that lie adjacent to one another on the potential energy surface, as is evidenced by the form of their respective energy profiles. These adjacent pairs of isomers establish a step-wise transformation between the ring and the bowl. This process, which extends out over the three-dimensional surface, is predicted to require less energy than that of the direct, two-dimensional transformation predicted in the ring-bowl profile.

Journal Article↗
PubMed2003

The effects of dietary fat and caloric content on the body-size estimates of Anorexic Profile and normal college students.

Anorexic-Profile (AP) and Normal-Profile (NP) college-women's body-size estimates of a fictitious female student (target) consuming a regular diet of high- vs low-fat/calorie foods were compared. Participants initially were divided into four groups based on scores from the Eating-Disorders Inventory (AP and NP) and Body-Mass Index Scores (Low and High Body Mass) and then randomly assigned to one of four dietary conditions. Participants then rated the estimated body size of the target using the Figure-Rating Scale. Significant main effects were found for profile status (AP vs NP), caloric content, and fat content. The significant two-way interaction of profile status and dietary fat revealed a greater increase in body-size estimates for AP vs NP participants as the diet of the target changed from low to high fat. Results highlight the importance given to dietary fat, especially among AP women, when predicting likely effects on body size.

Adult↗
PubMed2005

Using fetal acoustic stimulation to shorten the biophysical profile.

PURPOSE: To determine whether fetal acoustic stimulation can decrease the time required to achieve a reassuring biophysical profile. METHODS: Patients scheduled for a biophysical profile were prospectively assigned to study and control groups. The study group received 3 seconds of acoustic stimulation if fetal breathing, tone, or movement were not present during the first 5 minutes of the study. The biophysical profile was completed in the standard fashion, for both groups. RESULTS: A total of 870 patients were enrolled (458 control, 412 with stimulation). The fetal acoustic stimulation group had decreased testing time (3 minutes) and fewer non-reassuring tests (5%). The fetal acoustic stimulation group had fewer studies without breathing, potentially reducing the need for further testing or intervention. CONCLUSIONS: Fetal acoustic stimulation can be used to decrease the biophysical profile testing time and to reduce the number of non-reassuring tests.

Acoustic Stimulation↗
PubMed2006

Optimizing UV laser focus profiles for improved MALDI performance.

Matrix assisted laser desorption/ionization (MALDI) applications, such as proteomics, genomics, clinical profiling and MALDI imaging, have created a growing demand for faster instrumentation. Since the commonly used nitrogen lasers have throughput and life span limitations, diode-pumped solid-state lasers are an alternative. Unfortunately this type of laser shows clear performance limitations in MALDI in terms of sensitivity, resolution and ease of use, for applications such as thin-layer sample preparations, acceptance of various matrices (e.g. DHB for glycopeptides) and MALDI imaging. While it is obvious that the MALDI process has some dependence on the characteristics of the laser used, it is unclear which features are the most critical in determining laser performance for MALDI. In this paper we show, for the first time, that a spatially structured laser beam profile in lieu of a Gaussian profile is of striking importance. This result enabled us to design diode-pumped Nd : YAG lasers that on various critical applications perform as well for MALDI as the nitrogen lasers and in some respects even better. The modulation of the beam profile appears to be a new parameter for optimizing the MALDI process. In addition, the results trigger new questions directing us to a better understanding of the MALDI process.

Algorithms↗
PubMed2001

An intelligent data acquisition system for simultaneous screening of microsomal stability and metabolite profiling by liquid chromatography/mass spectrometry.

This paper describes the development of a mass spectrometer-based, intelligent, programmable, sample-selection data acquisition system with two unique features. One is that the system allows automatic determination of the mass to charge ratio (m/z) of an unknown compound and the utilization of the molecular ion information to perform selective ion monitoring (SIM) experiments for quantitation. The other is its decision-making capability to select intelligently different samples and perform different experiments during data acquisition. These features were demonstrated by the application of the system to simultaneous screening for the microsomal stability and metabolite profiling of adatanserin. In this application, the data acquisition system continuously calculated the peak areas of adatanserin from SIM analyses of a batch of microsomal incubates stopped at various time points. Once the peak area of adatanserin had dropped to an arbitrarily predefined 60% of the initial value, the system made a decision to perform metabolite profiling of the sample. This decision initiated a series of automated operations, such as selecting a sample for re-analysis, changing the data acquisition time and liquid chromatographic gradient and switching the SIM mode to the data-dependent product ion scanning mode. The completed analysis of the batch of samples provided information both on the microsomal stability and on the metabolic profile of adatanserin. This simultaneous approach to investigating microsomal stability and metabolite profiling significantly increases the throughput for drug discovery support.

Algorithms↗
PubMed1977

Predictive conversion of in vitro drug dissolution data into in vivo drug response versus time profiles exemplified for plasma levels of warfarin.

A mathematical approach to computing the in vivo drug response profiles (such as plasma level, pharmacological response, and urinary recovery versus time curves) corresponding to observed in vitro dissolution of drug dosage form versus time profiles is described. The method is exemplified for warfarin tablets,for which observed in vivo plasma level profiles are compared to corresponding predicted profiles computed from in vitro dissolution data. The potential of the method is demonstrated; approaches to its improvement, as well as its limitations, are discussed.

Computers, Analog↗
PubMed2002

Detection and modeling of non-Gaussian apparent diffusion coefficient profiles in human brain data.

This work details the observation of non-Gaussian apparent diffusion coefficient (ADC) profiles in multi-direction, diffusion-weighted MR data acquired with easily achievable imaging parameters (b approximately 1000 s/mm(2)). A technique is described for modeling the profile of the ADC over the sphere, which can capture non-Gaussian effects that can occur at, for example, intersections of different tissue types or white matter fiber tracts. When these effects are significant, the common diffusion tensor model is inappropriate, since it is based on the assumption of a simple underlying diffusion process, which can be described by a Gaussian probability density function. A sequence of models of increasing complexity is obtained by truncating the spherical harmonic (SH) expansion of the ADC measurements at several orders. Further, a method is described for selection of the most appropriate of these models, in order to describe the data adequately but without overfitting. The combined procedure is used to classify the profile at each voxel as isotropic, anisotropic Gaussian, or non-Gaussian, each with reference to the underlying probability density function of displacement of water molecules. We use it to show that non-Gaussian profiles arise consistently in various regions of the human brain where complex tissue structure is known to exist, and can be observed in data typical of clinical scanners. The performance of the procedure developed is characterized using synthetic data in order to demonstrate that the observed effects are genuine. This characterization validates the use of our method as an indicator of pathology that affects tissue structure, which will tend to reduce the complexity of the selected model.

Brain↗
PubMed1995

Signal profile measurements for evaluation of the volume-selection performance of ISIS.

High-resolution signal profiles obtained with a test phantom were used in this study to evaluate the volume-selection performance of an implementation of ISIS (Image Selected In vivo Spectroscopy). The phantom simulated the brain with regard to volume and loading of coil. A remotely controlled, movable signal source inside the phantom was filled with orthophosphoric acid. Signal profiles of the volume of interest (VOI) were measured in three perpendicular directions. Special interest was focused on the transition zones, the position of the profiles, and the effects of off-resonance and T1 smearing. The transition zones were on average 5.6 mm wide and the full width at half maximum (FWHM) was 35 mm for a VOI of 40 x 40 x 40 mm3. The positions of the centre of the signal profiles were x = 3.2, y = -0.7 and z = 3.3 mm off-centre. The deviation of the volume position could be explained by off-resonance effects during imaging and spectroscopy. These data illustrate the importance of detailed knowledge of the volume-selection performance when attempting precision measurements using image-guided in vivo MRS.

Brain↗
PubMed2005

Protein structure prediction using a variety of profile libraries and 3D verification.

This study is intended to construct a useful method for fold recognition, regardless of whether the proteins to be compared are evolutionarily related. We developed several descendants of our profile-profile comparison method to make use of known structural information for protein structure prediction. Our prediction strategy in CASP6 is simple. For every CASP6 target, we derived target-template alignments from several different versions of profile-profile comparisons. We then constructed and exhaustively evaluated 3D models based on those alignments. Subsequently, we selected proper model(s) among them. We specifically addressed the validation of our simple approach for protein structure prediction through CASP6 because the fold recognition results of CASP5 revealed areas of improvement in the selection of good models. Consequently, we applied a more stringent method for 3D model evaluation this time. All generated models were evaluated based on a structural quality score calculated by both Verify3D and Prosa2003 programs. It turns out that the prediction results of our human group were supported by the results of three servers. The pipeline that we constructed for our human group prediction and human intervention were also greatly effective in improving prediction models, but the efficacy of our scheme for 3D model evaluation was obscure.

Algorithms↗
PubMed2005

Serum protein profiling by miniaturized solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry.

Serum profiling by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) holds promise as a clinical tool for early diagnosis of cancer and other human diseases. Sample preparation is key to achieving reproducible and well-resolved signals in MALDI-MS; a prerequisite for translation of MALDI-MS based diagnostic methods to clinical applications. We have investigated a number of MALDI matrices and several miniaturized solid-phase extraction (SPE) methods for serum protein concentration and desalting with the aim of generating reproducible, high-quality protein profiles by MALDI-MS. We developed a simple protocol for serum profiling that combines a matrix mixture of 2,5-dihydroxybenzoic acid and alpha-cyano-4-hydroxycinnamic acid with miniaturized SPE and MALDI-MS. Functionalized membrane discs with hydrophobic, ion-exchange or chelating properties allowed reproducible MALDI mass spectra (m/z 1000-12,000) to be obtained from serum. In a proof-of-principle application, SPE with chelating material and MALDI-MS identified protein peaks in serum that had been previously reported for distinguishing a person diagnosed with breast cancer from a control. These preliminary results indicate that this simple SPE/MALDI-MS method for serum profiling provides a versatile and scalable platform for clinical proteomics.

Blood Proteins↗
PubMed2002

Evolution of the delta13C signature related to total carbon contents and carbon decomposition rate constants in a soil profile under grassland.

Evolution of the total carbon (C) content and the (13)C enrichment (delta(13)C signature) of soil organic matter (SOM) with increasing depth in a soil profile under permanent grassland (C(3) vegetation) were investigated. The relationship between the total C content and the delta(13)C signature at different depths in the upper 30 cm of the soil profile could be well fitted by the Rayleigh equation (y = -29.8 - 2.3x, R(2) = 0.95, p < 0.001), describing the enrichment in (13)C as resulting from isotopic fractionation associated with C mineralization (isotope enrichment factor epsilon = -2.3 per thousand). Potential C dynamics of SOM in four depth intervals of the profile (0-10, 10-20, 20-30 and 30-40 cm depth) were investigated through an incubation study. The C decomposition rate constants decreased with increasing sampling depth from 0.0479 yr(-1) (0-10 cm sampling depth) to 0.0256 yr(-1) (30-40 cm sampling depth) and were highly correlated (y = 0.02 + 0.13x, R(2) = 0.93, p < 0.05) with the corresponding deltadelta(13)C values (average change of the delta(13)C signature per depth increment). These results suggest that changes of the delta(13)C signature of SOM in undisturbed soil profiles under continuous C(3) vegetation may serve as an indicator of the variation of SOM quality with increasing depth.

Biodegradation, Environmental↗
PubMed2002

Longitudinal profiles of health care providers.

Provider profiling is the activity of collecting, comparing and reporting quality of care measures for individuals, groups, agencies and institutions that provide health care services. Univariate provider profiles, such as hospital-specific mortality rates, have been constructed using cross-sectional data based on posterior summaries or maximum likelihood estimates. As data continue to be collected over time, the construction and interpretation of longitudinal profiles of health care providers will become increasingly important. Longitudinal series can be used to improve the precision of estimates - a feature that is particularly important for providers who treat a small number of patients per year. We extend and apply hierarchical models to examine and classify provider performance over time using two examples, one in the area of cardiology and the other in mental health. Performance is evaluated using the squared Mahalanobis distance and posterior probabilities based on this distance. By comparing providers based on level and temporal trend simultaneously, conservative but comprehensive assessments of performance are possible. Furthermore, the longitudinal profiles developed are easily interpreted and flexible, making them of practical use to policy-makers.

Cardiovascular Diseases↗
PubMedDate not supplied

Analysis of pseudo-profiles in organ pharmacokinetics and toxicokinetics.

In general, the pharmacokinetic model parameters, like rate constants, area under the curve (AUC) etc. are estimated via a two-stage procedure, where the values obtained from concentration-time relationships within one subject (experimental unit) are considered to be functionally related to the drug concentrations measured. In many cases 'mean' estimators and their respective standard errors are calculated afterwards. The determination of drug concentrations in organs as well as in the serum of small animals (mice, rats) in dependence of the time after administration often does not permit the establishment of reasonable profiles within one subject suited for conventional pharmacokinetic analyses and tolerability studies. Frequently, only one experimental value per organ or animal is recorded. The consequence is that most pharmacokinetic parameters are to be estimated on the basis of the mean concentrations rather than via the mean of individual parameter estimates. In all cases of a non-linear relationship between a target item and the concentration, the mean-concentration based estimators and the two-stage profile based estimators need not coincide. In addition, in the former case variance estimators may be either difficult to obtain or not deducible. In order to get variance estimators as well as to enable comparisons between different treatment regimens, in addition to bioequivalence testing as a step towards human dose finding studies, various resampling techniques (parametric and non-parametric bootstrap) were applied to generate pseudo-profiles from independent measurements and compared to their more conventional counterparts where applicable. Simulation studies based on different predefined pharmacokinetic models (first-order elimination after i.v. bolus, first-order elimination after first-order absorption, simple capacity-limited kinetics) revealed that even the non-parametric pseudo-profile stratified 'bootstrap' (resampling with replacement per time point) performs quite satisfactorily.

Administration, Oral↗