Úvod: Srdeční resynchronizační léčba (SRL) hraje významnou úlohu v terapii srdečního selhání u pacientů s nízkou ejekční frakcí. Nicméně, signifikantní část pacientů se po implantaci SRL přístroje nezlepší. Optimalizace atrioventrikulárního a interventrikulárního intervalu může pomoct zlepšit klinický stav pacientů. Cíl: Cílem práce je porovnat optimalizaci atrioventrikulárního a interventrikulárního intervalu pomocí neinvazivního měření plochy pod křivkou transaortálního průtoku (aortic VTI) a pomocí invazivního měření maximální hodnoty první derivace tlaku v levé komoře (LVdP/dtmax) a pomocí algoritmu QuickOpt. Metodika: Patnáct non-responderů bylo optimalizováno neinvazivně – pomocí aortic VTI v porovnání s metodou QuickOpt. Kontrolní vyšetření bylo provedeno za tři měsíce: klinické a echokardiografické vyšetření. Deset non-responderů bylo optimalizováno invazivně – pomocí LVdP/dtmax v porovnání s metodou QuickOpt. Kontrolní vyšetření bylo provedeno za tři měsíce: klinické a echokardiografické vyšetření. Výsledky: Ve skupině s neinvazivní optimalizací (věk 74,3 roku [65,3; 84,3], 83,4 % mužů, etiologie: 66 % ischemická choroba srdeční, třída NYHA před optimalizací III v 66,7 %, III–IV ve 33,3 %, ejekční frakce levé komory 23,0 % [15,0; 32,0]) jsme nepotvrdili korelaci optimálního atrioventrikulárního a interventrikulárního intervalu zjištěného pomocí obou metod. Optimalizace měla vliv na zkrácení komplexu QRS. Po třech měsících sledování nebyla nalezena statisticky signifikantní změna v ejekční frakci a jiných parametrech ultrazvukového vyšetření či třídy NYHA. Ve skupině pacientů s invazivní optimalizací (věk 76,7 roku [66,6; 82,4], 90 % mužů, etiologie: 60 % ischemická choroba srdeční, třída NYHA před optimalizací III v 50 %, III–IV v 50 %, ejekční frakce levé komory 29,5 % [10,0; 35,0]) jsme nepotvrdili korelaci optimálního atrioventrikulárního a interventrikulárního intervalu zjištěného pomocí obou metod. Optimalizace měla vliv na zkrácení komplexu QRS. Po třech měsících jsme zjistili zlepšení ejekční frakce levé komory, ale ostatní echokardiografické parametry či třída NYHA zůstaly nezměněny. Závěr: Použití měření plochy pod křivkou transaortálního průtoku při optimalizaci srdeční resynchronizační léčby nepřineslo pacientům non-responderům užitek – echokardiografické parametry ani třída NYHA se při tříměsíčním sledování nezměnily. Použití invazivního měření maximální hodnoty první derivace tlaku v levé komoře vedlo ke zlepšení ejekční frakce, třída NYHA však zůstala nezměněna.

Background: Cardiac resynchronization therapy plays important role in treatment of heart failure patients with low left ventricular ejection fraction. However, a significant number of patients do not improve after implantation. Optimization of atrioventricular and interventricular delay could improve clinical status of these patients. Objectives: The purpose of this study was to compare optimization of atrioventricular (AV) and interventricular (VV) delays with aortic velocity-time integral (VTI) and with maximal value of the first derivative of a left ventricular pressure signal (LVdP/dtmax). Methods: Fifteen non-responders were optimized with aortic VTI method and QuickOpt. After 3 months the follow up echocardiography and clinical evaluation were done. Ten non-responders were optimized with LVdP/dtmax and QuickOpt. After 3 month follow up echocardiography and clinical evaluation were done. Results: In the first group of patients (age 74.3 years [65.3, 84.3], 83.4% male, etiology: 66% ischemic heart disease, NYHA class before optimization III 66.7%, III–IV 33.3%, LVEF 23.0% [15.0; 32.0]), no correlation between AV and VV delays setting obtained from aortic VTI and QuickOpt was found. Optimization generated shorter QRS complex. After 3 months of follow up, there was no change in echo parameters or NYHA class. In the second group of patients (age 76.7 years [66.6, 82.4], 90% male, etiology: 60% ischemic heart disease, NYHA class before optimization III 50%, III–IV 50%, LVEF 29.5% [10.0; 35.0]), no correlation between AV and VV delays setting obtained from LVdP/dtmax and QuickOpt was found. Optimization in this group of patients also generated shorter QRS complex. After 3 months, increase in LVEF was observed, but other echo parameters and NYHA class remained unchanged. Conclusion: Using aortic VTI guided optimization in CRT devices did not bring any profit for non-responder patients. Echocardiography parameters and NYHA status did not change in 3 month follow up. Using invasive LVdP/dtmax leads to a change in left ventricular ejection fraction, but NYHA class remains unchanged.

• MeSH
• Algorithms MeSH
• Diagnostic Techniques, Cardiovascular MeSH
• Echocardiography MeSH
• Electrocardiography MeSH
• Myocardial Ischemia MeSH
• Cardiac Pacing, Artificial * MeSH
• Ventricular Pressure * MeSH
• Middle Aged MeSH
• Humans MeSH
• Cardiac Output MeSH
• Aged MeSH
• Heart Failure * physiopathology   therapy   MeSH
• Heart Atria physiopathology   MeSH
• Statistics as Topic MeSH
• Ultrasonography, Doppler MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

U osob s chronickým srdečním selháním při významné systolické dysfunkci levé komory a prodlouženém komplexu QRS slouží srdeční resynchronizační léčba (SRL) k nápravě synchronicity depolarizace myokardu. Míra zlepšení klinického stavu a echokardiografického nálezu po jejím zavedení však závisí na různých parametrech – strukturálních změnách myokardu, poruchách nitrokomorového vedení a umístění stimulačních elektrod. K individualizaci léčby lze na implantovaných SRL přístrojích nastavit různé parametry, z nichž nejdůležitější jsou AV a VV intervaly. Ačkoliv jejich optimalizace byla předmětem rozsáhlých klinických studií, nepochybný důkaz o prospěšnosti optimalizace těchto intervalů stále chybí. Nejčastěji se k hodnocení optimalizace používá echokardiografie a metody založené na intrakardiální elektrokardiografii. Kvůli nedostatkům ve statistickém zpracování však nelze označit některou z metod jako referenční nebo použitelnou v každodenní klinické praxi. Echokardiografie je zatížena značnou variabilitou výsledků, jejichž kvalita je navíc silně závislá na zkušenosti vyšetřujícího. Optimalizace na podkladě intrakardiálních elektrokardiogramů zatím neprokázala jasně lepší výsledky než empirické nastavení přístroje. Slibnější metodou se zatím jeví hodnocení hemodynamiky prstovou pletysmografií, neboť získaná data jsou vysoce reproducibilní a nezávislá na erudici vyšetřujícího. Zatím však chybějí randomizované multicentrické dvojitě zaslepené studie s prstovou pletysmografií, které by zhodnotily význam této metody v optimalizaci SRL. Měření informačního obsahu jakýchkoliv dat týkajících se optimalizace SRL, analýza jejich reproducibility a všeobecné používání konfidenčních intervalů by mohly též pomoci nalézt další použitelné metody. Při hodnocení výsledků je často nezbytná úzká spolupráce se statistikem.

In patients with heart failure, left ventricular systolic dysfunction and prolonged QRS complex, cardiac resynchronization therapy (CRT) is a treatment method aimed at restoration of myocardial depolarization synchronicity. However, the extent of clinical and echocardiographic improvement depends on anatomical relations in individual patients, on structural changes in the heart, on intrinsic electrical activation, and on the position of pacing leads. Many parameters of CRT devices may be changed in order to tailor the function of CRT to the needs of a particular patient; the most important among them is AV and VV interval. The largest trials studying CRT used various methods for optimization of these intervals but unequivocal proof of the benefit brought by optimization is still lacking. Many methods were evaluated, most frequently based on echocardiography and intracardiac electrogram interval measurement. However, drawbacks in statistics make the studies of limited value for establishing a reference method or guidance for daily practice. Echocardiography has inherent variability of results and is highly operator dependent. Optimization based on intracardiac electrogram intervals has not proved yet to be of clear benefit above arbitrary AV interval. The most promising method is finger plethysmography. Measured data are highly reproducible and operator-independent. A randomized multicenter double-blind study using finger plethysmography is needed to prove the value of this method and of CRT optimization in general. The measurement of information content in any data suitable for CRT optimization, analysis of reproducibility and general usage of confidence intervals may show other methods appropriate for it, too. The cooperation with a statistician is oftentimes a necessity.

• MeSH
• Algorithms MeSH
• Ventricular Dysfunction, Left diagnosis   etiology   therapy   MeSH
• Echocardiography methods   utilization   MeSH
• Hemodynamics MeSH
• Cardiac Pacing, Artificial * methods   utilization   MeSH
• Humans MeSH
• Meta-Analysis as Topic MeSH
• Plethysmography methods   utilization   MeSH
• Signal Processing, Computer-Assisted MeSH
• Arrhythmias, Cardiac diagnosis   complications   therapy   MeSH
• Cardiac Resynchronization Therapy * methods   trends   utilization   MeSH
• Heart Failure * MeSH
• Statistics as Topic MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Úvod: Tato práce prezentuje výsledky optimalizace rekonstrukčních parametrů, konkrétně počet iterací a počet subsetů OSEM algoritmu. Materiál a metody: Optimalizace byla založena na měření kontrastu a poměru signálu k šumu na tomografických rekonstrukcích NEMA Body Fantomu. Byla provedena akvizice čtyř sad projekčních dat se dvěma různými objemovými aktivitami na dvou různých kamerách. Pro nalezení optimálních hodnot byl proskenován parametrický prostor s použitím více než 500 rekonstrukcí s různými korekcemi a resolution recovery algoritmem (RR). Výsledky a závěr: S přihlédnutím k výpočetnímu času a opakované nestabilitě software byly jako nejlepší kombinace vyhodnoceny 4 iterace a 10 subsetů bez RR a 5 iterací a 10 subsetů s RR v matici 128 x 128, 3 iterace a 12 subsetů bez RR a 4 iterace a 12 subsetů s RR v matici 256 x 256.

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• Keywords
• optimalizace rekonstrukčníchparametrů pro SPECT a SPECT/CT,
• MeSH
• Algorithms MeSH
• Artifacts MeSH
• Phantoms, Imaging standards   utilization   MeSH
• Tomography, Emission-Computed, Single-Photon * methods   instrumentation   utilization   MeSH
• Humans MeSH
• Tomography, X-Ray Computed * methods   instrumentation   utilization   MeSH
• Computing Methodologies MeSH
• Image Processing, Computer-Assisted methods   utilization   MeSH
• Statistics as Topic MeSH
• Software Validation * MeSH
• Image Enhancement methods   standards   MeSH
• Check Tag
• Humans MeSH

Plasma cells (PCs) enrichment from bone marrow samples of multiple myeloma (MM) patients is frequently performed by immunomagnetic separation (magnetic activated cell sorting, MACS) using anti-CD138 MicroBeads. The aim of our work was to find optimal strategy for immunomagnetic separation of PCs and determine optimal algorithm of separation techniques for samples with various percentage of neoplastic cells. From 2007 to 2008, selection of PCs using separation programs Possels and Posseld(2) was carried out on 234 bone marrow samples obtained from 208 MM patients. In 2008, an optimal algorithm for separation programs was introduced based on the analysis of the previous experiments. The Possels program is applicable for samples with >10% PCs in the mononuclear fraction, while the Posseld(2) program is used for samples with 5-10% PCs in the mononuclear fraction. Median purity of 92.6% for the positive fraction of cells (range 14.5-99.6%) and median recovery of 60.4% (range 25.7-99.5%) were obtained when the Possels program was applied (n = 45). A total of 80% (36/45) of processed samples had purity of >70%. Median purity for the positive fraction of 83.7% (range 14.3-99.7%) and median recovery of 14.3% (range 3.6-50.0%) were achieved using the Posseld(2) program (n = 99). A total of 68% (67/99) of processed samples reached >70% purity. This separation strategy enabled us to obtain sufficient amounts of highly purified PCs required for subsequent research purposes. The MACS method has been unsuccessful if the percentage of PCs in the initial sample was <5%. These samples were processed by fluorescence activated cell sorting (FACS).

• MeSH
• Algorithms MeSH
• Immunomagnetic Separation methods   standards   MeSH
• Bone Marrow pathology   MeSH
• Humans MeSH
• Methods MeSH
• Multiple Myeloma pathology   MeSH
• Software standards   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

PURPOSE: To verify the technical feasibility of low contrast volume (40 mL) run-off CT angiography (run-off CTA) with the individual scan time optimization based on double-level test bolus technique. MATERIALS AND METHODS: A prospective study of 92 consecutive patients who underwent run-off CTA performed with 40 mL of contrast medium (injection rate of 6 mL/s) and optimized scan times on a second generation of dual-source CT. Individual optimized scan times were calculated from aortopopliteal transit times obtained on the basis of double-level test bolus technique--the single injection of 10 mL test bolus and dynamic acquisitions in two levels (abdominal aorta and popliteal arteries). Intraluminal attenuation (HU) was measured in 6 levels (aorta, iliac, femoral and popliteal arteries, middle and distal lower-legs) and subjective quality (3-point score) was assessed. Relations of image quality, test bolus parameters and arterial circulation involvement were analyzed. RESULTS: High mean attenuation (HU) values (468; 437; 442; 440; 342; 274) and quality score in all monitored levels was achieved. In 91 patients (0.99) the sufficient diagnostic quality (score 1-2) in aorta, iliac and femoral arteries was determined. A total of 6 patients (0.07) were not evaluable in distal lower-legs. Only the weak indirect correlation of image quality and test-bolus parameters was proved in iliac, femoral and popliteal levels (r values: -0.263, -0.298 and -0.254). The statistically significant difference of the test-bolus parameters and image quality was proved in patients with occlusive and aneurysmal disease. CONCLUSION: We proved the technical feasibility and sufficient quality of run-off CTA with low volume of contrast medium and optimized scan time according to aortopopliteal transit time calculated from double-level test bolus.

• MeSH
• Algorithms * MeSH
• Angiography methods   MeSH
• Injections, Intra-Arterial MeSH
• Image Interpretation, Computer-Assisted methods   MeSH
• Contrast Media administration & dosage   diagnostic use   MeSH
• Middle Aged MeSH
• Humans MeSH
• Peripheral Arterial Disease radiography   MeSH
• Tomography, X-Ray Computed methods   MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Feasibility Studies MeSH
• Image Enhancement methods   MeSH
• Dose-Response Relationship, Drug MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH

Taking advantage of surface-enhanced Raman scattering (SERS) methodology with its unique ability to collect abundant intrinsic fingerprint information and noninvasive data acquisition we set up a SERS-based approach for recognition of physically induced DNA damage with further incorporation of artificial neural network (ANN). As a proof-of-concept application, we used the DNA molecules, where the one oligonucleotide (OND) was grafted to the plasmonic surface while complimentary OND was exposed to UV illumination with various exposure doses and further hybridized with the grafted counterpart. All SERS spectra of entrapped DNA were collected by several operators using the portable spectrometer, without any optimization of measurements procedure (e.g., optimization of acquisition time, laser intensity, finding of optimal place on substrate, manual baseline correction, etc.) which usually takes a significant amount of operator's time. The SERS spectra were employed as input data for ANN training, and the performance of the system was verified by predicting the class labels for SERS validation data, using a spectra dataset, which has not been involved in the training process. During that phase, accuracy higher than 98% was achieved with a level of confidence exceeding 95%. It should be noted that utilization of the proposed functional-SERS/ANN approach allows identifying even the minor DNA damage, almost invisible by control measurements, performed with common analytical procedures. Moreover, we introduce the advanced ANN design, which allows not only classifying the samples but also providing the ANN analysis feedback, which associates the spectral changes and chemical transformations of DNA structure.

• MeSH
• Biosensing Techniques * MeSH
• DNA chemistry   isolation & purification   MeSH
• Metal Nanoparticles chemistry   MeSH
• Neural Networks, Computer MeSH
• Oligonucleotides chemistry   MeSH
• DNA Damage * MeSH
• Spectrum Analysis, Raman * MeSH
• Gold chemistry   MeSH
• Publication type
• Journal Article MeSH

Náhodně objevené ložiskové léze nadledvin jsou častým problémem v běžné klinické praxi, neméně důležitou oblastí je pátrání po klinicky manifestních nádorech nadledvin. Hlavním účelem zobrazování nadledvin je odlišit benigní léze od maligních, což je možné mimo jiné průkazem přítomnosti tukové složky. Nejčastěji se hodnotí expanze nadledvin na CT, kde je kromě měření průměrné nativní denzity možné nativně provádět také histogramovou analýzu. V posledních letech se objevují první pokusy o využití techniky s dvojí energií v diagnostice nadledvin. MR vyšetření nadledvin je obvykle metodou druhé volby, nicméně představuje vhodnou alternativu. V navrhovaném projektu plánujeme vyšetření na fantomech simulujících tkáň nadledvin, dále retrospektivní zhodnocení CT nálezů u již verifikovaných nádorů nadledvin a také sestavení prospektivního souboru pacientů, u nichž budeme korelovat CT a MR nálezy s histologickým vyšetřením a biochemickou analýzou vzorků nádorové tkáně. U pacientů bude také sledován vliv zobrazovacích metod na volbu operační strategie u pacientů indikovaných k adrenalektomii.; Incidentally discovered adrenal masses are a common problem in routine clinical practice, an equally important area is detection of clinically manifest adrenal tumors. The main role of adrenal imaging is to distinguish benign from malignant lesions, which can be done e.g. by presence of fat component. CT is the most common technique used to image adrenal glands allowing measuring non-enhanced average density and performing histogram analysis. Recently, there have been attempts to use dual-energy technique in adrenal evaluation. MRI of the adrenal glands is usually the method of second choice, however, it is a suitable alternative. In the project we intent to test CT and MRI on phantoms simulating adrenal tissue, then we plan retrospective evaluation of CT findings in already verified tumors and we plan prospectively recruit group of patients to correlate CT and MRI with histological examination and biochemical analysis of tumor tissue samples. We will also evaluate the influence of imaging methods on the selection of surgical strategy in patients indicated for adrenalectomy.

• MeSH
• Adrenalectomy MeSH
• Algorithms MeSH
• Early Detection of Cancer methods   MeSH
• Humans MeSH
• Magnetic Resonance Imaging methods   MeSH
• Biomarkers, Tumor analysis   MeSH
• Adrenal Gland Neoplasms diagnostic imaging   MeSH
• Tomography, X-Ray Computed methods   MeSH
• Prospective Studies MeSH
• Retrospective Studies MeSH
• Check Tag
• Humans MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• nefrologie
• onkologie
• NML Publication type
• závěrečné zprávy o řešení grantu AZV MZ ČR

Blind inversion of a linear and instantaneous mixture of source signals is a problem often encountered in many signal processing applications. Efficient fastICA (EFICA) offers an asymptotically optimal solution to this problem when all of the sources obey a generalized Gaussian distribution, at most one of them is Gaussian, and each is independent and identically distributed (i.i.d.) in time. Likewise, weights-adjusted second-order blind identification (WASOBI) is asymptotically optimal when all the sources are Gaussian and can be modeled as autoregressive (AR) processes with distinct spectra. Nevertheless, real-life mixtures are likely to contain both Gaussian AR and non-Gaussian i.i.d. sources, rendering WASOBI and EFICA severely suboptimal. In this paper, we propose a novel scheme for combining the strengths of EFICA and WASOBI in order to deal with such hybrid mixtures. Simulations show that our approach outperforms competing algorithms designed for separating similar mixtures.

• MeSH
• Algorithms MeSH
• Time MeSH
• Financing, Organized MeSH
• Humans MeSH
• Neural Networks, Computer MeSH
• Signal Processing, Computer-Assisted MeSH
• Models, Statistical MeSH
• Check Tag
• Humans MeSH

Six population-based methods for real-valued black box optimization are thoroughly compared in this article. One of them, Nelder-Mead simplex search, is rather old, but still a popular technique of direct search. The remaining five (POEMS, G3PCX, Cauchy EDA, BIPOP-CMA-ES, and CMA-ES) are more recent and came from the evolutionary computation community. The recently proposed comparing continuous optimizers (COCO) methodology was adopted as the basis for the comparison. The results show that BIPOP-CMA-ES reaches the highest success rates and is often also quite fast. The results of the remaining algorithms are mixed, but Cauchy EDA and POEMS are usually slow.

• MeSH
• Algorithms * MeSH
• Benchmarking methods   MeSH
• Humans MeSH
• Numerical Analysis, Computer-Assisted MeSH
• Models, Theoretical * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

BACKGROUND: An acute inguinal hernia remains a common emergency surgical condition worldwide. While emergency surgery has a major role to play in treatment of acute hernias, not all patients are fit for emergency surgery, nor are facilities for such surgery always available. Taxis is the manual reduction of incarcerated tissues from the hernia sack to its natural compartment, and can help delay the need for surgery from days to months. The aim of this study was to prepare a safe algorithm for performing manual reduction of incarcerated inguinal hernias in adults. METHODS: Medline, Scopus, Ovid and Embase were searched for papers related to emergency inguinal hernias and manual reduction. In addition, the British National Formulary and Safe Sedation Practice for Healthcare Procedures: Standards and Guidance were reviewed. RESULTS: A safe technique of manual reduction of an acute inguinal hernia, called GPS (Gentle, Prepared and Safe) Taxis, is described. It should be performed within 24 h from the onset of a painful irreducible lump in groin, and when concomitant symptoms and signs of bowel strangulation are absent. Conscious sedation guidelines should be followed. The most popular drug combination is of intravenous morphine and short-acting benzodiazepine, both titrated carefully for optimal and safe effect. The dose of drugs must be individualised, and the smallest effective dosage should be used to avoid oversedation. Following successful taxis, the patient should undergo a short period of observation. Urgent surgery can be undertaken during the same admission or up to several weeks later. CONCLUSIONS: Taxis is a benign/non-invasive method for patients with an acute, non-strangulated inguinal hernias. It likely reduces the risk and complications of anaesthesia and surgery in the emergency settings. GPS Taxis should be considered as first line treatment in the majority of patients presenting with an acute inguinal hernia when existing bowel infarction is unlikely.

• MeSH
• Algorithms MeSH
• Adult MeSH
• Hernia, Inguinal * surgery   MeSH
• Humans MeSH
• Emergencies MeSH
• Herniorrhaphy adverse effects   MeSH
• Groin MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH