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PubMedDate not supplied

Feasibility study of a single- and multiple-source near-infrared phase-modulation device for characterizing biologic systems.

Near-infrared (NIR) spectroscopy is an inexpensive and noninvasive optical method to characterize biologic and physiologic systems. Measurements of oxygen saturation in various organs, cytochrome oxidase concentration, and glucose concentration in tissue are examples of NIR spectroscopy applications. This instrument also has potential for diagnostic imaging by comparing the optical properties of a given point in tissue with those of the surrounding areas, e.g., tumor localization, hematoma detection, or deep vein thrombosis detection. Currently, NIR spectroscopy is available in three modalities: time-resolved spectroscopy (TRS), continuous-wave spectroscopy (CWS), and a phase-modulation device. This paper describes a single-source phase-modulation device and a multiple-source (in- and anti-phased) device and their application to system identification. The phase and intensity information for homogeneous systems is correlated with system and instrumental parameters. Phase and intensity changes resulting from the presence of one and two absorbers are illustrated. The sensitivity of in- and anti-phased phase-modulation devices (phased arrays) is demonstrated. The use of amplitude-modulated phased array for heterogeneity detection is described.

Computer Simulation↗
PubMedDate not supplied

[Two-parameter flow fluorescence analysis of human chromosomes. Quantitative processing].

A procedure for the quantitative analysis of the results of fluorimetric studies on human chromosomes in a flow is described. The procedure enables one to simultaneously follow two parameters by using two fluorochromes, one of which is selective to the GC-, and the other, to AT base pairs of DNA. Thus, it becomes possible to derive from the experimentally obtained distributions an information on the relative DNA content in individual chromosomes, differences in DNA content between homologous chromosomes, the relative number of chromosomes of each type in the sample tested, as well as on the percent ratio of AT and GC base pairs in a particular chromosome. In addition, the procedure enables one to assign, with a high degree of accuracy, the peaks on experimental distributions to the objects of analysis chromosomes. The analysis cutting off the extreme combines the method of components with the least square method, as applied to the peaks of the Gaussian shape. The first step involves the filtration of the starting experimental data from contaminating signals from both the parts of degraded chromosomes and stained cytoplasm fragments, and from chromosome aggregates. The procedure is realized as a package of programs for IBM-compatible PC/AT computers (486 and later versions), which permits one to perform a comprehensive analysis of two-parameter distributions of chromosome fluorescence signals to solve a number of problems, such as the identification of chromosome aberrations in cell lines tested, quantitative comparison of distinguishing features of homologous chromosomes and whole chromosome sets.

Chromosomes, Human↗
PubMedDate not supplied

Incidence of apoptosis, cell proliferation and P53 expression in renal cell carcinomas.

BACKGROUND: Given the growing evidence that proliferation indices may be of prognostic significance in renal cell carcinoma and that parameters of cell loss (usually, but not exclusively due to programmed cell death) are biologically relevant, identification and quantitation of apoptosis and possible regulatory factors are of considerable clinical importance. MATERIALS AND METHODS: Apoptotic cells were identified and quantified in a series of 87 curatively-resected (R0) renal cell carcinomas using the in situ end labeling method in combination with morphological criteria. The proliferative activity was determined by immunohistochemical assessment of the MIB-1 (Ki-67)-and proliferating cell nuclear antigen (PCNA). The immunoreactivity of p53 was analysed using the DO7 antibody. Immunostaining of p53 has been linked to the accumulation of mutant p53 protein. The results obtained were compared with UICC pathohistological stage and grade and finally with disease-related survival rate. RESULTS: In each carcinoma examined, we could demonstrate apoptosis of varying degrees with in a range from 1 to 19 and with a median of 5. Immunostaining of p53 suggested the presence of mutant p53 in 24/87 (28%). A reciprocal correlation was found between apoptosis and p53-positivity in terms of significantly less apoptosis in p53-positive tumors. Positive statistical correlations were seen between the tumor grade and MIB-1/PCNA positivity and apoptosis. In univariate survival analysis, stage and grade, MIB-1 and PCNA index and apoptotic index were significantly related to prognosis. Multivariate Cox disease-related survival analysis revealed that stage of disease and MIB-1 were significant independent prognostic factors. CONCLUSIONS: These results indicate that apoptosis and cell proliferation are strongly related in renal cell carcinoma and that the presence of mutant p53 seems to be a negative regulator of apoptosis. In univariant survival analysis, apoptosis was, in addition to other parameters, of prognostic significance. However, multivariate analysis found that only the stage of the disease and MIB-1 were independent prognostic factors.

Apoptosis↗
PubMed2001

Features of Immune Status in Patients with Tetralogy of Fallot during Operative Treatment.

Twenty six patients with tetralogy of Fallot at the age from 1 to 3 years old were examined. All examined patients required surgical correction of heart defect and were operated under conditions of artificial circulation. All patients were in a status of relative compensation or subcompensation. The level of a saturation SaO(2) among patients with tetralogy of Fallot in peripheral arterial blood was equal to 66.27 +/- 7.2%. The purpose of work was to study the dynamics of immunological parameters in patients with tetralogy of Fallot in the postoperative period. The complex dynamic study of immune status was carried out to resolve such a task. Identification of membrane markers of peripheral blood immunocompetent cells was made by flow cytofluometry with the usage of monoclonal antibodies to antigens: CD3, CD4, CD5, CD8, CD11b, CD16, CD22, CD25, CD45 RA, HLA DR, CD95. The parameters were determined in dynamics: before operation, on the 7th, the 30th day and after 3 months after operation. Stabilization of parameters of the immune status among patients with tetralogy of Fallot, has been found in the postoperative period and was maintained within 3 months. Apparently it may be due to normalization of cardiohemodynamics, and as a consequence the stabilization of metabolic processes, undoubtedly, rendering modulating effects on immune system of children. However remaining failure of functional activity of immunocompetent cells is the reason to the usage of immunocorrection therapy with the purpose of faster stabilization of immune disbalance.

Journal Article↗
PubMed2001

The importance of traceability for public health and consumer protection.

Since the 1980s, concerns about the safety and quality of food have increased at both governmental and consumer levels. The importance of traceability of animals and animal products has grown as food production and marketing have been removed from direct consumer control. Product traceability, which requires a transparent chain of custody to maintain credibility and to complete information transfer functions, has two components, namely: a unique identification system, and a credible and verifiable mechanism for identity preservation. Traceability systems can be subdivided into the following four categories: country of origin; retail; processor; and farm-to-retail identity. Although the availability of computers and electronic data devices can enhance the speed and accuracy of data acquisition and manipulation, a common set of developmental criteria exists, irrespective of data-handling processes. As data management technologies become more powerful and less costly, product traceability requirements will multiply. Public and private sectors should seize these opportunities to improve public health and quality parameters, or risk a narrowing of their markets.

Animal Identification Systems↗
PubMed1994

Structure identifiability in metabolic pathways: parameter estimation in models based on the power-law formalism.

An important step in understanding a metabolic pathway is to identify its structure, in terms of the flow of material and information. In pursuing this goal, the available information for a given system is usually obtained from experiments in vitro and comes from different sources. Frequently, the final set of regulatory signals acting in the system in vivo is unclear, and some kind of test is needed on the intact system. Besides defining an appropriate experimental approach, identification of the regulatory pattern needs a theoretical framework in which the different experimental measurements can be evaluated and a final picture can be agreed on. Mathematical approaches based on sensitivity coefficients provide a useful tool for addressing this problem. Within this framework, the appropriate parameters are related to both the structure of the reaction network and the signals that regulate the target system. Thus the identification of the regulatory structure can be related to the estimation of the appropriate set of parameters. In pursuing this goal, we will show the limitations of using steady-state measurements and the usefulness of using dynamic data. We suggest a way to test the regulatory pattern in a given metabolic pathway by combining both kinds of data, and we show, by using a reference system, the potential of the method suggested.

Metabolism↗
PubMed1996

Amino acid analysis of proteins separated by two-dimensional electrophoresis in maize: isoform detection and function identification.

The possibility of using experimentally determined amino acid composition to assess relatedness between 75 proteins separated by two-dimensional electrophoresis (2-DE) and to identify them was tested on maize. Two independent parameters, the relative Euclidean distance and the correlation coefficient between the amino acid compositions, were evaluated and used. Previous sequence information for 31 out of the 75 proteins made it possible to evaluate the method for the detection of isoforms and for identification. However, the extension of the interrogation beyond maize to all plant sequences raised the problem of false positives that could nevertheless be limited by replications and by using additional information. The efficiency of the method to assess relatedness between proteins should make amino acid composition analysis a valuable tool in large protein characterization programs based on 2-DE, by facilitating the transfer of information from one well-documented organ/tissue or genotype to another.

Amino Acids↗
PubMed1995

Identification of the cerebrospinal compensatory mechanisms via computer-controlled drainage of the cerebrospinal fluid.

The constant rate infusion test is still widely used for the diagnosis of hydrocephalus in children. The increased resistance to reabsorption of the cerebrospinal fluid (CSF) is considered the most important factor in the improvement seen after shunting. However, the classic infusion test has some disadvantages: the compensatory model is identified in the conditions of raised intracranial pressure, which may provoke some uncontrolled changes in cerebral blood volume in the mechanism of vasomotor response; also non-linear effects in reabsorption mechanisms may have a significant influence. The controlled drainage of CSF can be considered as a form of pressure-volume testing if the volume of the drained fluid is precisely measured. The main advantage of the method is the possibility of estimating unknown parameters in practically physiological conditions (with only slightly decreased pressure). This paper presents a new method for the identification of an electrical model of cerebrospinal volume compensation. The method has been described theoretically, verified on the simulator and introduced into clinical practice at the Medical Academy in Warsaw and the Children's Health Center in Miedzylesie.

Adolescent↗
PubMed1995

[Electron spin resonance spectroscopy investigations of fresh fruit. Evidence of treatment with ionizing radiation].

This paper describes the development of a method for the identification of irradiated fresh fruits by measurement of the e.p.r. spectra of pips, kernels or stones. Measurement parameters were optimized and the irradiation specific spectrum was assigned to a cellulose radical by comparison with the e.p.r. spectrum of pure cellulose. Several fruits especially different varieties of strawberries were examined giving the following results: Detectable minimum doses were between 0.4 kGy and 0.9 kGy and the intensity of the irradiation specific signals was found to be linear up to doses of 11 kGy. The lifetime of the specific radicals (at room temperature and at deep freezing temperatures) was long enough compared to the storage time of fresh fruits. Additional information about the nature of the unspecific central signal was gained measuring the samples which were stored at different temperatures. The main conclusion of this study is that the e.p.r. method seemes to be well suited for the use in routine control and should be tested in an intercomparison to establish a routine method for the identification of irradiated fresh fruits.

Dose-Response Relationship, Radiation↗
PubMed1998

Generalized linear least squares algorithm for non-uniformly sampled biomedical system identification with possible repeated eigenvalues.

The recently developed generalized linear least squares (GLLS) algorithm has been found very useful in non-uniformly sampled biomedical signal processing and parameter estimation. However, the current version of the algorithm cannot deal with signals and systems containing repeated eigenvalues. In this paper, we extend the algorithm, so that it can be used for non-uniformly sampled signals and systems with/without repeated eigenvalues. The related theory and detailed derivation of the algorithm are given. A case study is presented, which demonstrates that the extended algorithm can provide more choices for system identification and is able to select the most suitable model for the system from the non-uniformly sampled noisy signal.

Algorithms↗
PubMed1995

Flow cytometric DNA analysis and lysosomal cathepsins B and L in locally advanced laryngeal cancer. Relationship with clinicopathologic parameters and prognostic significance.

BACKGROUND: The traditional factors of locally advanced laryngeal squamous cell carcinoma (LSCC) have limited predictive value for the identification of high risk patients. Therefore, it is extremely important to define prognostic factors that identify the more aggressive types. Reliable and reproducible prognostic indicators are being investigated to help clinicians identify high risk groups and address more rational treatment. METHODS: Flow cytometric DNA ploidy and S-phase fraction (SPF) measurements were performed on frozen tumor tissues from a consecutive series of 71 patients with Stage III and IV LSCC: Lysosomal cathepsin B and L activity levels were determined biochemically in matched paired sets of tumor tissue and normal mucosa samples. RESULTS: By univariate analysis, lymph node positivity, poor histologic differentiation, DNA aneuploidy, high SPF, and high tumor/mucosa ratio of cathepsin B activity were significantly related to risk of relapse, whereas only DNA aneuploidy and high SPF proved to be significantly related to risk of death. Multivariate analysis showed that high histologic grade and high SPF values (> 15.1%) were independent prognostic factors related to risk of relapse (relative risk [RR] = 3.54; 95% confidence limits [CL] = 1.05-12.0; and RR = 4.22; CL = 1.54-11.6, respectively), whereas only high SPF was related to risk of death (RR = 3.63; CL = 1.17-11.3). CONCLUSIONS: S-phase fraction is an independent predictor of relapse free and overall survival in patients with locally advanced LSCC. On the basis of these findings, SPF should be used in addition to other established prognostic factors to refine the prognostic assessment of these patients further. More studies are needed for a better evaluation of the prognostic significance of DNA ploidy and that of lysosomal cysteine proteinases in these tumors.

Adult↗
PubMed2003

Identification of honey types.

In order to develop a procedure to identify a type and variety of honeys, basing on the physicochemical parameters of honey quality, two-phase calculations were conducted. A method of discrimination analysis was used. Moreover, a model to use while identifying honeys was proposed.

Carbohydrates↗
PubMed1998

Chronic fatigue syndrome: identification of distinct subgroups on the basis of allergy and psychologic variables.

BACKGROUND: We investigated a role for allergic inflammation and psychologic parameters in the development of chronic fatigue syndrome (CFS). METHODS: The design was a comparison between subjects with CFS and age- and sex-matched control cohorts. Studies were performed on CFS subjects (n = 18) and control cohorts consisting of normal subjects (n = 11), allergic subjects (n = 14), and individuals with primary depression (n = 12). We quantified cytokines at baseline as cell-associated immunoreactive peptides and as transcripts evaluated by means of semiquantitative RNA-based polymerase chain reactions. Psychologic evaluations included administration of the Diagnostic Interview Schedule, the Structured Clinical Interview, and the Symptom Checklist 90-Revised. RESULTS: Increases in tumor necrosis factor (TNF)-alpha were identified in individual subjects with CFS (50.1 +/- 14.4 pg TNF-alpha per 10(7) peripheral blood mononuclear cells [PBMCs]; mean +/- SEM) and allergic subjects (41.6 +/- 7.6) in comparison with normal subjects (13.1 +/- 8.8) (P < .01 and P < .05, respectively). Similar trends were observed for interferon (IFN)-alpha in allergic subjects (3.0 +/- 1.7 pg/10(7) PBMCs) and subjects with CFS (6.4 +/- 3.4) compared with normal subjects (1.9 +/- 1.4). A significant increase (P < .05) in TNF-alpha transcripts was demonstrated between subjects with CFS and depressed subjects. In contrast to these proinflammatory cytokines, both subjects with CFS (2.6 +/- 1.8 pg/10(7) PBMCs) and allergic subjects (3.4 +/- 2.8) were associated with a statistically significant (P < .01) decrease in IL-10 concentrations compared with normal subjects (60.2 +/- 18.2). As shown in other studies, most of our subjects with CFS were allergic (15 of 18) and therefore presumably demonstrated cytokine gene activation on that basis. The seasonal exacerbation of allergy was associated with a further increase in cellular IFN-alpha (from 2.1 +/- 1.2 to 14.2 +/- 4.5 pg/107 PBMCs; P < .05) but no further modulation of TNF-alpha or IL-10. Similarly, self-reported exacerbations of CFS were associated with a further increase in IFN-alpha (from 2.5 +/- 1.0 to 21.9 +/- 7.8; P < .05) and occurred at times of seasonal exposures to allergens. This linkage does not permit making any definitive conclusions regarding a causative influence of either seasonal allergies or the increase in cellular IFN-alpha with the increase in CFS symptoms. The close association between atopy and CFS led us to speculate that CFS may arise from an abnormal psychologic response to the disordered expression of these proinflammatory and antiinflammatory cytokines. Psychologic variables were predictive of immune status within the CFS sample (65.9% of the variance in immune status; F (3,10) = 6.44, P < .05). Specifically, the absence of a personality disorder but greater endorsement of global psychiatric symptoms was predictive of immune activation. CONCLUSIONS: Most of our subjects with CFS were allergic, and the CFS and allergy cohorts were similar in terms of their immune status. However, the CFS subjects could be discriminated by the distinct psychologic profiles among subjects with and without immune activation. We propose that in at least a large subgroup of subjects with CFS who had allergies, the concomitant influences of immune activation brought on by allergic inflammation in an individual with the appropriate psychologic profile may interact to produce the symptoms of CFS. In a psychologically predisposed individual, symptoms associated with allergic inflammation are recognized as illness.

Adult↗
PubMed1995

Identification of the active-site nucleophile in 6-phospho-beta-galactosidase from Staphylococcus aureus by labelling with synthetic inhibitors.

Kinetic parameters for the inactivation of the 6-phospho-beta-galactosidase of Staphylococcus aureus by a series (fluoro, chloro, bromo) of 2,4-dinitrophenyl-2-deoxy-2-halogeno- galactoside-6-phosphates have been determined. These inhibitors function by the formation of a stabilised glycosyl-enzyme intermediate. Inactivation and reactivation studies indicate that the fluoro derivative is formed most rapidly, but is also hydrolysed fastest. The chloro derivative forms the most stable covalent intermediate. HPLC profiles of V8-protease digestion of native and inhibited protein show significant differences, whereas the inhibited 6-phospho-beta-galactosidase and a point mutant of 6-phospho-beta- galactosidase (E375Q) yield the same proteolytic fragments. The suggestion that E375 is derivatised is strengthened by matrix-assisted laser-desorption ionisation mass spectrometry experiments which show that the two peptides, residues 336-375 and 376-383, are not produced, due to the absence of the expected cleavage at residues 375 and 376. The reason for the altered proteolysis pattern of the inhibited protein is blocking of the respective V8 cleavage site due to the chemical reaction of the inhibitor at position 375. Specific modification of the glycosyl bond between the inhibitor and E375 by aminolysis with benzylamine generated a glutamatic-acid-5-benzylamide complex at that position in the peptide. The Edman derivative of the modified E375 appears to be stable and was isolated by Edman degradation of trypsin-digested V8-peptide. It was shown to be identical to an authentic, synthetic sample. From this, it is evident that E375 is the active-site nucleophile of 6-phospho-galactosidase, consistent with previous findings for enzymes in this family.

Amino Acid Sequence↗
PubMed2001

Nonradiochemical DNase I footprinting by capillary electrophoresis.

A new application for DNase I footprinting using capillary electrophoresis (CE) has been developed in order to decrease analysis time and to eliminate the use of radiochemicals. An additional advantage of the new method over the traditional radioactive methods is that the DNA probe can be labeled on both ends with different fluorescein dyes. This provides an internal check of the identification of protein-binding sites on DNA, because the binding region can be observed from both DNA strands. The initial parameters for the CE method were developed using the Promega Core Footprinting Kit for analysis of AP-2 binding sites in the SV40 enhancer sequence. After optimization of the method, the protocol was found to be effective for footprint analysis of the immediate upstream region (bases -1 to -370) of the rat glutathione peroxidase (GPX) and it permitted identification of a previously unknown binding site in the upstream sequence of the GPX gene.

Animals↗
PubMed1995

Evaluation on blood platelets by the image analysis system VIDAS 2.5.

This paper introduces a program written on the image analysis system VIDAS 2.5. It enables the automatic quantification of high numbers of adhesion areas of vital human platelets, thus allowing statistical analysis. These adhesion areas were observed by reflection contrast microscopy (RCM), which generates images of an intense contrast and serves as a prerequisite for an evaluation by image analysis. However, RCM-photographs of the observed platelets have highly varying mean greyvalues and greyranges. These common problems for self-operating identification are excluded by two procedures within the program: 1. calibration of the scanning process for an optimal use of the available greyvalues provided by the negative, camera, and the image analysis system; and 2. relation of the threshold for discrimination of adhesion areas to the statistic parameters of the histogram within each individual digitized image. Images processed according to these prerequisites were transferred to the VIDAS implemented routines for identification and measurement of areas. Thus, image analysis combined with RCM offers a tool for basic and clinical platelet research, which is shown by an example of stimulation and inhibited stimulation of platelet activation.

Blood Platelets↗
PubMedDate not supplied

Performance parameters in children and adolescent athletes.

Success in sports, as measured by competitive performance, is dependent upon a number of significant mental and physical components. Somatotype, motor skills, age, nutritional status, physiology, psychology, training level, genetic endowment, and injury risk are the major independent variables influencing performance. Unfortunately, the data available in this area of sports medicine are not always reliable or allow interstudy comparisons. This article reviews the historical and current information used to predict human performance in sports at the childhood and adolescent level. Although mesomorphy, and to a lesser extent ectomorphy, are positively associated with enhanced performance, successful athletes tend to have or acquire somatotypes characteristic of individuals already successful in a particular sport. For the most part, motor skills are age (chronological) and gender dependent. In general, the efficiency of movement progressively improves throughout childhood and into early adolescence and is highly dependent on environmental influences. A lower anaerobic and aerobic capacity reduces performance in the child and adolescent. Nonetheless, regular training can favourably improve motor skills and physiological fitness parameters. The relationship between endurance performance and aerobic capacity, however, is not strong at any age during childhood. Performance levels are reduced if nutrition is inadequate. A number of mental factors such as aggression, spirit, and self-confidence are also related to sports performance, although their correlation is unclear at present. Performance is influenced by the effect of genetic factors on specific traits in 30 to 85% of cases. Risk factors that negatively impact on performance levels include a history of previous injury, excessive training schedules, decreased fitness endurance, joint looseness or tightness, and certain personality traits. It is suggested that sport performance may be optimised by the early identification of individuals with positive genetic and somatotypic markers and negative risk factors. Motor skill development and physiological parameters can then be maximised by using regular, non-excessive training protocols, sound nutrition patterns, a safe environment and protective gear. Further investigations in this important area of sports medicine are essential in order to more fully characterise those criteria essential for successful sports participation. In particular, such studies should be purely longitudinal and should control for multiple confounding factors operating at different times.

Adolescent↗
PubMed1999

Effect of different frequencies of preventive maintenance treatment on periodontal conditions. 5-Year observations in general dentistry patients.

The protocol for this study was designed to evaluate the effects of supportive recall treatments provided with different frequencies, viz. at 3-, 6-, 12- and 18-month intervals. The subjects for the study were recruited from patients attending a public, general dentistry clinic. Prior to baseline, the subjects were given necessary dental treatments to provide a proper baseline for the study. Baseline, intermittent and final recordings included scores of dental plaque, bleeding on probing, probing depth and probing attachment level. Results were evaluated statistically by intergroup comparisons of changes for the various parameters from baseline to final examination after 5 years. The analyses showed some advantage to shorter recall intervals for plaque and bleeding scores. Although not statistically significant, there was a trend suggesting some rebound of sites > or =6 mm deep at the end of the study for the 18-month group, but not for the other groups. Similarly, there was a trend that the 18-month group showed a higher percentage of buccal/lingual furcation sites with attachment loss > or = 1.0 mm than the other groups. Apart from these trends, the analyses failed to demonstrate differences between the groups for either changes of probing depths or probing attachment levels. The negative observations included identification of individuals with 'disease progression' in the various groups, using a series of arbitrary definitions for this parameter. The results of this trial suggest that recall intervals extended to a year may be acceptable for the purpose of reducing periodontal disease progression in individuals with a history of limited susceptibility to the disease.

Adult↗