Recent techniques of image analysis brought the possibility to recognize subjects based on discriminative image features. We performed a magnetic resonance imaging (MRI)-based classification study to assess its usefulness for outcome prediction of first-episode schizophrenia patients (FES). We included 39 FES patients and 39 healthy controls (HC) and performed the maximum-uncertainty linear discrimination analysis (MLDA) of MRI brain intensity images. The classification accuracy index (CA) was correlated with the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning scale (GAF) at 1-year follow-up. The rate of correct classifications of patients with poor and good outcomes was analyzed using chi-square tests. MLDA classification was significantly better than classification by chance. Leave-one-out accuracy was 72%. CA correlated significantly with PANSS and GAF scores at the 1-year follow-up. Moreover, significantly more patients with poor outcome than those with good outcome were classified correctly. MLDA of brain MR intensity features is, therefore, able to correctly classify a significant number of FES patients, and the discriminative features are clinically relevant for clinical presentation 1 year after the first episode of schizophrenia. The accuracy of the current approach is, however, insufficient to be used in clinical practice immediately. Several methodological issues need to be addressed to increase the usefulness of this classification approach.

• MeSH
• diskriminační analýza MeSH
• dospělí MeSH
• lidé MeSH
• lineární modely * MeSH
• magnetická rezonanční tomografie metody   MeSH
• mapování mozku * MeSH
• mladý dospělý MeSH
• mozek patologie   MeSH
• počítačové zpracování obrazu metody   MeSH
• psychiatrické posuzovací škály MeSH
• schizofrenie diagnóza   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

In the present paper the role of linear discriminant analysis is delimitated all along with a range of problems which could be solved using this method in appropriate conditions. The analysis is given of possibilities on how to involve the decrease in number of variables in a model, and how to predict probability of incorrect classification. As an example of application, the prediction of dog survival is calculated in radiobiological experiment on the basis of biochemical and hematological values which were obtained by the 2nd day after the irradiation as well as an error probability was determined.

• MeSH
• diskriminační analýza * MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

The hyoid bone is characterized by sexually dimorphic features, enabling it to occasionally be used in the sex determination aspect of establishing the biological profile in skeletal remains. Based on a sample of 298 fused and non-fused hyoid bones, the present paper compares several methodological approaches to sexing human hyoid bones in order to test the legitimacy of osteometrics-based linear discriminant equations and to explore the potentials of symbolic regression and methods of geometric morphometrics. In addition, two sets of published predictive models, one of which originated in an indigenous population, were validated on the studied sample. The results showed that the hyoid shape itself is a moderate sex predictor and a combination of linear measurements is a better representation of sex-related differences. The symbolic regression was shown to exceed the predictive powers of linear discriminant function analysis when two models based on a logistic and step regression reached 96% of correctly classified cases. There was a positive correlation between discriminant scores and an individual's age as the sex assessment was highly skewed in favour of males. This suggests that the human hyoid undergoes age-related modifications which facilitates determination of male bones and complicates determination of females in older individuals. The validation of discriminant equations by Komenda and Černý (1990) and Kindschud et al. (2010) revealed that there are marked inter-population and inter-sample differences which lessened the power to correctly determine female hyoid bones.

• Klíčová slova
• Geometric morphometrics, Hyoid bone, Linear discriminant function analysis, Sex determination, Symbolic regression,
• MeSH
• analýza rozptylu MeSH
• diskriminační analýza MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• mladý dospělý MeSH
• multivariační analýza MeSH
• odchylka pozorovatele MeSH
• os hyoideum anatomie a histologie   MeSH
• reprodukovatelnost výsledků MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• software MeSH
• soudní antropologie MeSH
• určení pohlaví podle kostry metody   MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sex diagnosis of skeletal remains represents one of the main problems in the forensic osteological practice. The purpose of the paper was to apply discriminant analysis as the method of its solution--in the set of measurements carried out on the hyoid bone. Classical procedure by R. A. Fisher yielded the set of linear discriminant functions applicable also in cases of injured bones, which is the relatively frequent situation. Information efficiency of the method proved to be quite satisfactory--in case of complete set of all six measurement level of misclassification should not reach over four per cent of the items to diagnose.

• MeSH
• analýza určování pohlaví * MeSH
• lidé MeSH
• os hyoideum anatomie a histologie   MeSH
• soudní lékařství metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

We investigated a combination of three classification algorithms, namely the modified maximum uncertainty linear discriminant analysis (mMLDA), the centroid method, and the average linkage, with three types of features extracted from three-dimensional T1-weighted magnetic resonance (MR) brain images, specifically MR intensities, grey matter densities, and local deformations for distinguishing 49 first episode schizophrenia male patients from 49 healthy male subjects. The feature sets were reduced using intersubject principal component analysis before classification. By combining the classifiers, we were able to obtain slightly improved results when compared with single classifiers. The best classification performance (81.6% accuracy, 75.5% sensitivity, and 87.8% specificity) was significantly better than classification by chance. We also showed that classifiers based on features calculated using more computation-intensive image preprocessing perform better; mMLDA with classification boundary calculated as weighted mean discriminative scores of the groups had improved sensitivity but similar accuracy compared to the original MLDA; reducing a number of eigenvectors during data reduction did not always lead to higher classification accuracy, since noise as well as the signal important for classification were removed. Our findings provide important information for schizophrenia research and may improve accuracy of computer-aided diagnostics of neuropsychiatric diseases.

• Klíčová slova
• Average linkage, Centroid method, Classification, Computational neuroanatomy, Intersubject principal component analysis (isPCA), Modified maximum uncertainty linear discriminant analysis (mMLDA),
• MeSH
• algoritmy MeSH
• diagnóza počítačová metody   MeSH
• diskriminační analýza MeSH
• dospělí MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• schizofrenie diagnóza   MeSH
• senzitivita a specificita MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In the present paper the prediction method using the logistic regression is explained, and the range of problems for its use is deliminated. The example is presented of mentioned method's application on how to predict the dog survival in a radiolobiological experiment. The obtained results are compared with the prediction of outcome using the linear discriminant function. Both models are identic in a proportion of erroneously classified subjects. This method may be diagnostically supportive in ranging individuals to one of two groups delimitated previously.

• MeSH
• regresní analýza * MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

BACKGROUND: There is initial evidence suggesting that biomarker neurogranin (Ng) may distinguish Alzheimer's disease (AD) from other neurodegenerative diseases. Therefore, we assessed (a) the discriminant ability of cerebrospinal fluid (CSF) Ng levels to distinguish between AD and frontotemporal lobar degeneration (FTLD) pathology and between different stages within the same disease, (b) the relationship between Ng levels and cognitive performance in both AD and FTLD pathology, and (c) whether CSF Ng levels vary by apolipoprotein E (APOE) polymorphism in the AD continuum. METHODS: Participants with subjective cognitive decline (SCD) (n = 33), amnestic mild cognitive impairment (aMCI) due to AD (n = 109), AD dementia (n = 67), MCI due to FTLD (n = 25), and FTLD dementia (n = 29) were recruited from the Czech Brain Aging Study. One-way analysis of covariance (ANCOVA) assessed Ng levels in diagnostic subgroups. Linear regressions evaluated the relationship between CSF Ng levels, memory scores, and APOE polymorphism. RESULTS: Ng levels were higher in aMCI-AD patients compared to MCI-FTLD (F[1, 134] = 15.16, p < .001), and in AD-dementia compared to FTLD-dementia (F[1, 96] = 4.60, p = .029). Additionally, Ng levels were higher in FTLD-dementia patients compared to MCI-FTLD (F[1, 54]= 4.35, p = .034), lower in SCD participants compared to aMCI-AD (F[1, 142] = 10.72, p = .001) and AD-dementia (F[1, 100] = 20.90, p < .001), and did not differ between SCD participants and MCI-FTLD (F[1, 58]= 1.02, p = .491) or FTLD-dementia (F[1, 62]= 2.27, p = .051). The main effect of diagnosis across the diagnostic subgroups on Aβ1-42/Ng ratio was significant too (F[4, 263]=, p < .001). We found a non-significant association between Ng levels and memory scores overall (β=-0.25, p = .154) or in AD diagnostic subgroups, and non-significant differences in this association between overall AD APOE ε4 carriers and non-carriers (β=-0.32, p = .358). CONCLUSIONS: In this first study to-date to assess MCI and dementia due to AD or FTLD within one study, elevated CSF Ng appears to be an early biomarker of AD-related impairment, but its role as a biomarker appears to diminish after dementia diagnosis, whereby dementia-related underlying processes in AD and FTLD may begin to merge. The Aβ1-42/Ng ratio discriminated AD from FTLD patients better than Ng alone. CSF Ng levels were not related to memory in AD or FTLD, suggesting that Ng may be a marker of the biological signs of disease state rather than cognitive deficits.

• Klíčová slova
• APOE, Alzheimer’s disease, Frontotemporal lobar degeneration, Memory, Neurogranin,
• MeSH
• Alzheimerova nemoc * mozkomíšní mok   diagnóza   MeSH
• amyloidní beta-protein mozkomíšní mok   MeSH
• apolipoproteiny E genetika   mozkomíšní mok   MeSH
• biologické markery * mozkomíšní mok   MeSH
• frontotemporální lobární degenerace * mozkomíšní mok   diagnóza   MeSH
• kognitivní dysfunkce * mozkomíšní mok   diagnóza   MeSH
• lidé středního věku MeSH
• lidé MeSH
• neurogranin * mozkomíšní mok   MeSH
• neuropsychologické testy MeSH
• průřezové studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amyloidní beta-protein MeSH
• apolipoproteiny E MeSH
• biologické markery * MeSH
• neurogranin * MeSH
• NRGN protein, human MeSH Prohlížeč

INTRODUCTION: In a recent publication, the phasegram, a bifurcation diagram over time, has been introduced as an intuitive visualization tool for assessing the vibratory states of oscillating systems. Here, this nonlinear dynamics approach is augmented with quantitative analysis parameters, and it is applied to clinical laryngeal high-speed video (HSV) endoscopic recordings of healthy and pathological phonations. METHODS: HSV data from a total of 73 females diagnosed as healthy (n = 42), or with functional dysphonia (n = 15) or with unilateral vocal fold paralysis (n = 16), were quantitatively analyzed. Glottal area waveforms (GAW) and left and right hemi-GAWs (hGAW) were extracted from the HSV recordings. Based on Poincaré sections through phase space-embedded signals, two novel quantitative parameters were computed: the phasegram entropy (PE) and the phasegram complexity estimate (PCE), inspired by signal entropy and correlation dimension computation, respectively. RESULTS: Both PE and PCE assumed higher average values (suggesting more irregular vibrations) for the pathological as compared with the healthy participants, thus significantly discriminating healthy group from the paralysis group (P = 0.02 for both PE and PCE). Comparisons of individual PE or PCE data for the left and the right hGAW within each subject resulted in asymmetry measures for the regularity of vocal fold vibration. The PCE-based asymmetry measure revealed significant differences between the healthy group and the paralysis group (P = 0.03). CONCLUSIONS: Quantitative phasegram analysis of GAW and hGAW data is a promising tool for the automated processing of HSV data in research and in clinical practice.

• Klíčová slova
• glottal area waveform, high-speed video endoscopy, nonlinear analysis, periodicity, phasegram,
• MeSH
• audiovizuální záznam metody   MeSH
• automatizace MeSH
• biomechanika MeSH
• časové faktory MeSH
• dospělí MeSH
• dysfonie diagnóza   patofyziologie   MeSH
• entropie MeSH
• fonace * MeSH
• hlasové řasy patofyziologie   MeSH
• interpretace obrazu počítačem metody   MeSH
• kvalita hlasu * MeSH
• laryngoskopie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nelineární dynamika MeSH
• ochrnutí hlasivek diagnóza   patofyziologie   MeSH
• periodicita MeSH
• prediktivní hodnota testů MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• vibrace MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• audiovizuální média MeSH
• časopisecké články MeSH

The authors evaluated in 82 patients 228 findings of renal functions. Twenty-nine patients with a total number of 113 findings died. In those who died frequently the values of renal functional parameters were beyond the reference limits, indicating various failures (high serum creatinine, high serum urea, elevated fractional osmolal and water excretion, reduced creatinine clearance). In those who died tubular osmotic diuresis was more frequent, while overflow osmotic diuresis was found mostly in the surviving patients. By means of linear discrimination analysis vectors of parameters were assessed suitable for evaluation of the relationship of renal functions and the prognosis and functional shapes of so-called renal prognostic indicators. In the calculation of renal prognostic parameters the following ones prove useful: serum creatinine (SKrea), creatinine clearance (CKrea), serum osmolality (SOsm), osmolality of urine (UOsm), sodium cation in serum (SNa), fractional excretion of water (FeH2o), of potassium (FeK), osmolal (FeOsm), urinary excretion per 24 hours of creatinine (DuKrea), sodium (DuNa) and potassium (DuK). The best prognostic effectiveness was obtained from the calculation of the renal prognostic indicator (RPU) according to the following equation: RPU = SOsm.0.0178--CKrea.0.944 + FeK.0.854 + + DuKrea.0.0665--DuNa.0.0022 + DuK.0.0047--4.931. The RPU value rises with the deteriorating prognosis of the patients; in those who died it reaches more frequently positive values, in surviving patients the values are negative. By reclassification, using this prognostic index, 82% of the patients with a favourable prognosis and 68% with a poor prognosis (those who died) were correctly classified, i. e. a total of 74% patients.

• MeSH
• diuréza MeSH
• lidé MeSH
• péče o pacienty v kritickém stavu * MeSH
• prognóza MeSH
• vyšetření funkce ledvin * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH

The problems of contamination of many products by nitroso compounds have been discussed since 1970's and have been partially solved, namely, the contamination by carcinogenic volatile N-nitrosamines. However, there is still a gap in knowing non-volatile nitroso compounds in terms of both the determination of these compounds and the description of their toxicity. Therefore, a procedure for their detailed non-targeted study is necessary to be developed. Based on these facts, a new method permitting the detection and the classification of nitroso compound groups, such as N-nitroso, C-nitroso, and interfering substances in the nitrosamine specific chemiluminescence detection after previous gas chromatographic separation, was developed. The method is based on signal profiling of chromatographic peaks recorded by a chemiluminescence detector at different pyrolytic temperatures and subsequent multivariate chemometric classification. The resulting classification function by linear discriminant analysis shows good performance with total accuracy of 96.12% after the method validation. The method was successfully applied and demonstrated on a non-targeted beer sample analysis. Nitroso compounds detected by the method were selected for detailed structural analysis by GC-MS/MS. The combination of the presented method with the MS/MS instrumentation provides a really powerful analytical tool for the identification of unknown nitroso compounds in complex samples. This study represents a valuable contribution to the protocols of identification of organic compounds with the nitrogen functional groups - toxicologically and analytically important nitroso compounds.

• Klíčová slova
• Chemiluminescence detection, Discrimination analysis, Gas chromatography, Nitrosamines,
• MeSH
• kontaminace potravin analýza   MeSH
• luminiscenční měření metody   MeSH
• nitrosaminy analýza   MeSH
• pivo analýza   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí metody   MeSH
• pyrolýza MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nitrosaminy MeSH