Discriminant function analysis
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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
Východiska: Rozvoj nádorového onemocnění tlustého střeva je mimo jiné charakterizován abnormalitami v syntéze a metabolizmu lipidů, ovlivňujícími energetickou rovnováhu, strukturu a funkci biologických membrán, produkci specifických mediátorů a buněčné signálování. Změny buněčného lipidového profilu a metabolizmu (lipidomu) zásadně ovlivňují chování buněk i jejich odpověď na terapii. K lepšímu pochopení problematiky na buněčné a molekulární úrovni jsou využívány permanentní linie epiteliálních buněk tlustého střeva různého stupně nádorového rozvoje. Naše práce vycházela z předpokladu, že detailní analýza lipidomu různých buněčných linií tlustého střeva může odhalit takové rozdíly v množství a profilu specifických tříd/typů lipidů, které se mohou podílet na jejich rozdílné odpovědi k různým podnětům. Materiál a metody: Z buněk šesti lidských epiteliálních linií tlustého střeva odvozených z tkáně v různém stupni nádorového rozvoje byly izolovány lipidy a podrobeny LC/MS/MS (kapalinová chromatografie s tandemovou hmotnostní spektrometrií) analýze. Bylo stanoveno množství a hmotnostní profily všech tříd fosfolipidů (PL), lysofosfolipidů (lysoPL) a sfingolipidů. Tato data byla matematicky vyhodnocena (shluková a diskriminační analýza) s ohledem na vzájemné srovnání linií a na významně diskriminující typy lipidů. Výsledky: Výsledky shlukové analýzy seřadily buněčné linie dle stupně jejich nádorové transformace (normální buňky, adenom, karcinom, lymfatická metastáza). Výsledky diskriminačních analýz odhalily nejvíce rozlišující typy lipidů i odlišnosti v poměru PL: lysoPL. Ukázaly se zejména významné korelace zastoupení a profilu některých specifických tříd lysoPL a sfingolipidů se stupněm nádorové transformace buněk. Podobné přístupy jsou nyní aplikovány při srovnání lipidomu střevních epiteliálních buněk izolovaných z nádorové vs. nenádorové tkáně pacientů s nádory tlustého střeva. Závěr: Naše výsledky ukázaly, že a) vybrané buněčné linie jsou vhodným modelem pro lipidomické studie a mohou sloužit jako základ k navazujícímu klinickému výzkumu, b) analýza buněčného lipidomu by mohla přispět k rozlišení nádorových a nenádorových buněk také u klinických vzorků, u nichž by specifické typy lipidů mohly být využity jako biomarkery.
Backgrounds: Colon cancer development is often characterized by abnormalities in lipid synthesis and metabolism, which may influence energetic balance, structure and function of biological membranes, or production of specific mediators and cell signalling. The changes in lipid profile and metabolism (lipidome) may significantly affect cell behaviour and response to therapy. Permanent epithelial cell lines at various stages of cancer development are used for better understanding of this topic on cellular and molecular levels. In our study, we hypothesized that detailed analyses of colon cancer cell line lipidomes may help to identify major alterations in the amount and profile of specific lipid classes/species, which can contribute to their different response to various stimuli. Material and Methods: Cellular lipids were isolated from six human epithelial cell lines derived from tissues at various stages of tumour development. Liquid chromatography coupled with tandem mass spectometry analyses were performed in order to determine amount and mass profiles of all phospholipid (PL), lysophospholipid (lysoPL) and sphingolipid classes. The data was statistically evaluated (cluster and discrimination analyses) with respect to mutual comparison of cell lines and to significantly discriminating lipid types. Results: The results of cluster analysis arranged cell lines in order corresponding to their level of transformation (normal cells, adenoma, carcinoma and lymph node metastasis). The results of discrimination analyses revealed the most discriminating lipid types and distinction in PL: lysoPL ratios. Particularly, significant correlation of the amount and profiles of both specific lysoPL and sphingolipid classes with cell transformation level were observed. Similar approaches are now applied to compare lipidomes of colon epithelial cells isolated from tumour vs. non-tumour samples of colon cancer patients. Conclusion: Our results indicate that a) selected cancer cell lines are suitable model for lipidomic studies that can serve as a basis for subsequent clinical research, b) cellular lipidome analyses may help to discriminate tumour and non-tumour cells in clinical samples, where specific types of lipids could serve as biomarkers.
- MeSH
- adenom patologie metabolismus MeSH
- chromatografie kapalinová MeSH
- diskriminační analýza MeSH
- fosfolipidy metabolismus MeSH
- karcinom patologie metabolismus MeSH
- lidé MeSH
- lymfatické metastázy patologie metabolismus MeSH
- lysofosfolipidy metabolismus MeSH
- metabolismus lipidů * MeSH
- nádorová transformace buněk * MeSH
- nádorové biomarkery MeSH
- nádorové buněčné linie MeSH
- nádory tračníku * metabolismus patologie MeSH
- sfingolipidy metabolismus MeSH
- shluková analýza MeSH
- tandemová hmotnostní spektrometrie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- diskriminační analýza MeSH
- hlodavci anatomie a histologie MeSH
- infarkt myokardu diagnóza patofyziologie MeSH
- krysa rodu rattus anatomie a histologie MeSH
- magnetická rezonanční tomografie metody přístrojové vybavení využití MeSH
- modely u zvířat MeSH
- počítačové zpracování obrazu MeSH
- software MeSH
- teoretické modely MeSH
- Check Tag
- krysa rodu rattus anatomie a histologie MeSH
The p53 tumor suppressor protein is a transcription factor that mediates the cell's response to various kinds of stress by preventing cell division and/or inducing apoptosis. p53 gene mutations have been detected in nearly 50% of human cancers. These gene aberrations are mostly missense point mutations located predominantly in the central DNA-binding domain. In addition to the classical inactivating mutations, there are also dominant-negative, gain-of-function, temperature-sensitive, and cold-sensitive, discriminating, superactive p53 mutations, and some mutations that do not inactivate p53 activity. Several approaches have been developed for detection and analyses of p53 mutations: first, immunochemical methods have been developed to detect p53 protein levels; second, molecular analyses targeting changes in DNA structure are utilized; and third, functional assays are used to explore the biological properties of the p53 protein. Functional analysis of separated alleles in yeast targets the transactivation capability of the p53 protein expressed in yeast cells. This method uses p53 mRNA isolated from cells and tissues to produce a p53 product by RT-PCR. This method has undergone continuous improvement and now serves as a powerful tool for distinguishing various functional types of p53 mutations. Understanding the exact impact of p53 mutation on its function is an important prerequisite for establishment of efficient anti-cancer therapies.
251 patients with coronary heart disease (CHD) and a control group of 32 normal persons were examined with the purpose of establishing the determinants of the left ventricular function and comparing these determinants with the functional significance of coronary stenosis. The subjects were divided into four groups: I--controls; II--patients with normal left ventricular function (EF more than 60%); III--patients with impaired LV function (EF less than 60%) and Group IV--patients with left ventricular aneurysm. Nine parameters were obtained by multivariate discriminant analysis, which characterize and classify the left ventricular function: the ejection fraction (EF), angina pectoris, exercise ECG, left ventricular end-diastolic pressure, mean velocity of circumferential fibre shortening, left ventricular functional index, longitudinal shortening, LV systolic pressure/systolic volume ratio, and coronary index. On the basis of these parameters, all the normal persons, 88% of Group II, 92% of Group III and 72% of Group IV were classified correctly. The study proves that there is a good correlation between the EF and the haemodynamic and angiocardiographic parameters. The complex left ventricular function index facilitates the prognosis of surgical results. Abnormalities in left ventricular function cannot be reliably assessed by the coronary index values alone.
- MeSH
- angina pectoris patofyziologie MeSH
- dospělí MeSH
- koronární nemoc patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- srdce - funkce komor MeSH
- srdce patofyziologie MeSH
- srdeční komory patofyziologie MeSH
- stenóza patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
... revised and updated -- In the twenty years since publication of the first edition of The Statistical Analysis ... ... classic text with these and other current developments in the second edition of The Statistical Analysis ... ... The final chapter on special topics and examples of data analysis has been completely revised and updated ... ... of Recurrent Event Data Analysis of Correlated Failure Time Data -- With its comprehensive survey of ... ... the field and resources tor students and researchers, The Statistical Analysis of Failure Time Data ...
Wiley series in probability and statistics
2nd ed. xiii, 439 s.
- Klíčová slova
- Analýza dat, Analýza statistická, Regrese,
- Konspekt
- Statistika
- NLK Obory
- statistika, zdravotnická statistika
Developing sensitive and reliable methods to distinguish normal and abnormal brain states is a key neuroscientific challenge. Topological Data Analysis, despite its relative novelty, already generated many promising applications, including in neuroscience. We conjecture its prominent tool of persistent homology may benefit from going beyond analysing structural and functional connectivity to effective connectivity graphs capturing the direct causal interactions or information flows. Therefore, we assess the potential of persistent homology to directed brain network analysis by testing its discriminatory power in two distinctive examples of disease-related brain connectivity alterations: epilepsy and schizophrenia. We estimate connectivity from functional magnetic resonance imaging and electrophysiology data, employ Persistent Homology and quantify its ability to distinguish healthy from diseased brain states by applying a support vector machine to features quantifying persistent homology structure. We show how this novel approach compares to classification using standard undirected approaches and original connectivity matrices. In the schizophrenia classification, topological data analysis generally performs close to random, while classifications from raw connectivity perform substantially better; potentially due to topographical, rather than topological, specificity of the differences. In the easier task of seizure discrimination from scalp electroencephalography data, classification based on persistent homology features generally reached comparable performance to using raw connectivity, albeit with typically smaller accuracies obtained for the directed (effective) connectivity compared to the undirected (functional) connectivity. Specific applications for topological data analysis may open when direct comparison of connectivity matrices is unsuitable - such as for intracranial electrophysiology with individual number and location of measurements. While standard homology performed overall better than directed homology, this could be due to notorious technical problems of accurate effective connectivity estimation.
- MeSH
- elektroencefalografie MeSH
- epilepsie diagnostické zobrazování patofyziologie MeSH
- konektom * MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mapování mozku MeSH
- modely neurologické * MeSH
- mozek diagnostické zobrazování patofyziologie MeSH
- nervová síť diagnostické zobrazování patofyziologie MeSH
- schizofrenie diagnostické zobrazování patofyziologie MeSH
- záchvaty diagnostické zobrazování patofyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH