Učebnice, která se zaměřuje na biostatistiku.; Moderní učebnice statistiky, která představuje statistické nástroje klíčové pro čtenáře z biologických a biologii blízkých oborů.Autoři nejprve představují problémy, které daná statistická metoda řeší, a poté uvádějí princip metody i její nezbytné předpoklady. Podstatnou součást knihy tvoří praktické příklady. Jejich řešení, postup zpracování a podobu výsledků autoři ukazují s použitím dvou statistických programů: \"Statistica\" a \"R\", běžně využívaných v České republice. K praktickým příkladům také doplňují, jak mohou být statistické výsledky prezentovány v anglicky psaných odborných publikacích, i jak v těchto publikacích použité statistické metody popsat.

• Keywords
• Statistica (software), R (software),
• MeSH
• Data Analysis MeSH
• Biostatistics MeSH
• Software MeSH
• Statistics as Topic MeSH
• Publication type
• Textbook MeSH

• Conspectus
• Statistika
• Učební osnovy. Vyučovací předměty. Učebnice
• NML Fields
• statistika, zdravotnická statistika
• biologie

Cancers of the skin are the most commonly occurring cancers in humans. In fair-skinned populations, up to 95% of keratinocyte skin cancers and 70-95% of cutaneous melanomas are caused by ultraviolet radiation and are thus theoretically preventable. Currently, however, there is no comprehensive global advice on practical steps to be taken to reduce the toll of skin cancer. To address this gap, an expert working group comprising clinicians and researchers from Africa, America, Asia, Australia, and Europe, together with learned societies (European Association of Dermato-Oncology, Euromelanoma, Euroskin, European Union of Medical Specialists, and the Melanoma World Society) reviewed the extant evidence and issued the following evidence-based recommendations for photoprotection as a strategy to prevent skin cancer. Fair skinned people, especially children, should minimise their exposure to ultraviolet radiation, and are advised to use protective measures when the UV index is forecast to reach 3 or higher. Protective measures include a combination of seeking shade, physical protection (e.g. clothing, hat, sunglasses), and applying broad-spectrum, SPF 30 + sunscreens to uncovered skin. Intentional exposure to solar ultraviolet radiation for the purpose of sunbathing and tanning is considered an unhealthy behaviour and should be avoided. Similarly, use of solaria and other artificial sources of ultraviolet radiation to encourage tanning should be strongly discouraged, through regulation if necessary. Primary prevention of skin cancer has a positive return on investment. We encourage policymakers to communicate these messages to the general public and promote their wider implementation.

• MeSH
• Humans MeSH
• Melanoma prevention & control   etiology   epidemiology   MeSH
• Skin Neoplasms * prevention & control   etiology   epidemiology   MeSH
• Neoplasms, Radiation-Induced prevention & control   etiology   epidemiology   MeSH
• Skin Pigmentation radiation effects   MeSH
• Sunscreening Agents therapeutic use   MeSH
• Risk Factors MeSH
• Ultraviolet Rays * adverse effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Efficient absorbance detection of a low-volume chromatography peak is a difficult task. In this work, an improved design of the fused silica capillary flow cell for absorbance detection in microcolumn liquid chromatography is described. The cell was fabricated from 0.15 mm I. D. fused silica capillary and silica optical fibres. Optical fibres were fully integrated into the cell design and enabled a convenient and effective connection of the cell with the light source and light detector (265 nm UV LED and photodiode in this work). Manufactured cells covered the range of physical lengths 3.1-9.9 mm (55-175 nL) and were used without any focusing optics and slits. Baseline noise was typically below 0.05 mAU and the effective optical path determined in the experiments was 83-97% of the cell's physical length. The level of stray (parasitic) light indicated by a 1% deviation from linearity at 1.7 AU was 0.08% only. The proposed cell design was found to be moderately susceptible to the refractive index change (20-35 mAU baseline change in 5-95% (v/v) gradient of acetonitrile or methanol in a mixture with water, G index up to 4 AU·s/RIU). Manufactured cells were finally applied for absorbance detection of components of test the mixture eluted off 0.3 mm I. D. microcolumn. 9.9 mm cell (175 nL) with an effective optical path of 8.9 mm exhibited contribution to the broadening of chromatography peak comparable with commercial 6 mm (80 nL) rectangular flow cell.

• MeSH
• Chromatography, Liquid MeSH
• Commerce MeSH
• Optical Fibers * MeSH
• Silicon Dioxide * MeSH
• Water MeSH
• Publication type
• Journal Article MeSH

BACKGROUND AND OBJECTIVES: The severity of multiple sclerosis (MS) varies widely among individuals. Understanding the determinants of this heterogeneity will help clinicians optimize the management of MS. The aim of this study was to investigate the association between latitude of residence, UV B radiation (UVB) exposure, and the severity of MS. METHODS: This observational study used the MSBase registry data. The included patients met the 2005 or 2010 McDonald diagnostic criteria for MS and had a minimum dataset recorded in the registry (date of birth, sex, clinic location, date of MS symptom onset, disease phenotype at baseline and censoring, and ≥1 Expanded Disability Status Scale score recorded). The latitude of each study center and cumulative annualized UVB dose at study center (calculated from National Aeronautics and Space Administration's Total Ozone Mapping Spectrometer) at ages 6 and 18 years and the year of disability assessment were calculated. Disease severity was quantified with Multiple Sclerosis Severity Score (MSSS). Quadratic regression was used to model the associations between latitude, UVB, and MSSS. RESULTS: The 46,128 patients who contributed 453,208 visits and a cumulative follow-up of 351,196 patient-years (70% women, mean age 39.2 ± 12 years, resident between latitudes 19°35' and 56°16') were included in this study. Latitude showed a nonlinear association with MS severity. In latitudes <40°, more severe disease was associated with higher latitudes (β = 0.08, 95% CI 0.04-0.12). For example, this translates into a mean difference of 1.3 points of MSSS between patients living in Madrid and Copenhagen. No such association was observed in latitudes <40° (β = -0.02, 95% CI -0.06 to 0.03). The overall disability accrual was faster in those with a lower level of estimated UVB exposure before the age of 6 years (β = - 0.5, 95% CI -0.6 to 0.4) and 18 years (β = - 0.6, 95% CI -0.7 to 0.4), as well as with lower lifetime UVB exposure at the time of disability assessment (β = -1.0, 95% CI -1.1 to 0.9). DISCUSSION: In temperate zones, MS severity is associated with latitude. This association is mainly, but not exclusively, driven by UVB exposure contributing to both MS susceptibility and severity.

• MeSH
• Humans MeSH
• Disability Evaluation MeSH
• Registries MeSH
• Multiple Sclerosis * diagnosis   epidemiology   MeSH
• Severity of Illness Index MeSH
• Ultraviolet Rays adverse effects   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH

BACKGROUND: The human skin is greatly affected by external factors such as UV radiation (UVR), ambient temperature (T), and air humidity. These factors oscillate during the year giving rise to the seasonal variations in the skin properties. The aim of this study was to evaluate the effect of seasons, environmental T, relative and absolute humidity on the skin parameters of Caucasian women, perform a literature review and discuss the possible factors lying behind the found changes. MATERIALS AND METHODS: We measured stratum corneum (SC) hydration, transepidermal water loss (TEWL), sebum level, erythema index, and elasticity parameters R2 and R7 on the forehead and the cheek of Caucasian women from the Czech Republic throughout the year. We also performed a non-systematic literature review focused on the seasonal variations in these skin parameters. RESULTS: We confirmed a well-documented low SC hydration and sebum production in winter. In spring, we found the lowest TEWL (on the forehead) and the highest SC hydration but also the highest erythema index and the lowest elasticity presumably indicating skin photodamage. For most of the skin parameters, the seasonal variations probably arise due to a complex action of different factors as we extensively discussed. CONCLUSION: The data about the seasonal variations in the skin parameters are still highly inconsistent and further studies are needed for better understanding of the normal skin changes throughout the year.

• MeSH
• Skin Physiological Phenomena * MeSH
• Skin * metabolism   MeSH
• Humans MeSH
• Water Loss, Insensible MeSH
• Seasons MeSH
• Sebum MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Polycyclic aromatic hydrocarbons (PAHs) and ultraviolet radiation (UV) represent genotoxic factors that commonly occur in the living and working environment. The dermal form of exposure represents a significant part of the total load of dangerous chemical and physical environmental factors to which an organism is subjected. However, simultaneous dermal exposures to PAHs (pharmaceutical crude coal tar [CCT]) and UV (UVA and UVB) also have therapeutic uses. A typical example is Goeckerman therapy (GT) for psoriasis. The question of the therapeutic efficacy of GT and the related level of genotoxic danger is still under discussion. The aim of the present study was to compare four GT variants (G1-G4) in terms of efficacy and acceptable genotoxic hazard. Efficacy was expressed by the psoriasis area of severity index (PASI) score, genotoxic hazard by chromosomal aberration in peripheral lymphocytes. The lowest risk of genotoxic hazard and the lowest efficiency was observed in G1 variant (3% of the CCT and UVA + UVB). The efficacy of G2 (4% CCT and UVA + UVB), G3 (4% CCT and UVB), and G4 variants (5% CCT and UVA + UVB) was comparable. The highest risk of genotoxic hazard was found in the G3 variant. In the terms of sufficient efficacy and acceptable genotoxic hazard, a combination of 4% or 5% of CCT and UVA and UVB seems to be acceptable (variants G2 and G4).

• MeSH
• Chromosome Aberrations MeSH
• Coal Tar therapeutic use   MeSH
• Humans MeSH
• Lymphocytes MeSH
• Polycyclic Aromatic Hydrocarbons toxicity   MeSH
• DNA Damage MeSH
• Psoriasis drug therapy   MeSH
• Ultraviolet Rays * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Goeckerman therapy (GT) of psoriasis involves dermal application of crude coal tar containing polycyclic aromatic hydrocarbons (PAHs) and exposure to ultraviolet radiation (UVR). Little is known about GT influence on DNA epigenetics. OBJECTIVE: The study aim was to discover epigenetic mechanisms altered by the exposure related to the GT of psoriasis. METHODS: Observed group of patients with plaque psoriasis (n = 23) was treated by GT with 3 % CCT. Before and after GT, we analyzed the levels of benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA adducts (BPDE-DNA), p53 protein in serum, 5-methylcytosine (5-mC, global DNA methylation), and methylation in selected CpG sites of p53 gene. RESULTS: We found a significant increase in the levels of BPDE-DNA (p < 0.01) and serum levels of p53 protein (p < 0.01) after GT, and an insignificant decrease in the percentage of 5-mC in peripheral blood DNA. Methylation of p53 CpG sites was affected neither by psoriasis nor by GT. The study confirmed good effectiveness of GT (significantly reduced psoriasis area and severity index; p < 0.001). CONCLUSION: Our findings indicate that there is a significantly increased genotoxic hazard related to the exposure of PAHs and UV radiation after GT of psoriasis. However, global DNA methylation and p53 gene methylation evade the effect of GT, as they remained unchanged (Tab. 4, Fig. 3, Ref. 50).

• Keywords
• Goeckermanova terapie,
• MeSH
• 5-Methylcytosine blood   MeSH
• DNA Adducts blood   MeSH
• Coal Tar adverse effects   MeSH
• Adult MeSH
• Genetic Markers drug effects   radiation effects   MeSH
• Humans MeSH
• DNA Methylation drug effects   radiation effects   MeSH
• Tumor Suppressor Protein p53 blood   MeSH
• Polycyclic Aromatic Hydrocarbons * adverse effects   MeSH
• Psoriasis drug therapy   complications   radiotherapy   MeSH
• Ultraviolet Therapy * adverse effects   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Clinical Study MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND AND AIMS: Ultraviolet-B radiation (UV-B) radiation damages the DNA, cells and photosynthetic apparatus of plants. Plants commonly prevent this damage by synthetizing UV-B-protective compounds. Recent laboratory experiments in Arabidopsis and cucumber have indicated that plants can also respond to UV-B stress with endopolyploidy. Here we test the generality of this response in natural plant populations, considering their monocentric or holocentric chromosomal structure. METHODS: We measured the endopolyploidy index (flow cytometry) and the concentration of UV-B-protective compounds in leaves of 12 herbaceous species (1007 individuals) from forest interiors and neighbouring clearings where they were exposed to increased UV-B radiation (103 forest + clearing populations). We then analysed the data using phylogenetic mixed models. KEY RESULTS: The concentration of UV-B protectives increased with UV-B doses estimated from hemispheric photographs of the sky above sample collection sites, but the increase was more rapid in species with monocentric chromosomes. Endopolyploidy index increased with UV-B doses and with concentrations of UV-B-absorbing compounds only in species with monocentric chromosomes, while holocentric species responded negligibly. CONCLUSIONS: Endopolyploidy seems to be a common response to increased UV-B in monocentric plants. Low sensitivity to UV-B in holocentric species might relate to their success in high-UV-stressed habitats and corroborates the hypothesized role of holocentric chromosomes in plant terrestrialization.

• MeSH
• Arabidopsis * MeSH
• Chromosomes * MeSH
• Phylogeny MeSH
• Humans MeSH
• Plant Leaves MeSH
• Ultraviolet Rays MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Vzhledem k širokému terapeutickému indexu jsou b-laktamová antibiotika často využívána při léčbě kriticky nemocných pacientů. Právě u těchto pacientů pozorujeme významnou heterogenitu ve farmakokinetice oproti populačnímu průměru, a to zejména u distribučního objemu, clearance a biologického poločasu, jejichž hodnoty zaznamenávají až dvojnásobný, v případě biologického poločasu až čtyřnásobný nárůst. K významným farmakokinetickým změnám dochází také v případech morbidní obezity, renální insufi­cience a při použití složitých chirurgických technik, jako je mimotělní oběh. Terapeutické monitorování piperacilin/tazobaktamu je způsob, jak personalizovat a optimalizovat terapii pro tyto skupiny pacientů. Preklinická data popisují korelaci mezi pravděpodobností terapeutického úspěchu a koncentracemi volné frakce antibiotika, přesahující minimální inhibiční koncentraci (MIC) po dobu 40–50 % dávkovacího intervalu, avšak u kriticky nemocných může být požadován cíl ještě vyšší, v ideálním případě 100 % fT > 4xMIC. Lepší farmakodynamický profil můžeme získat použitím prodloužené nebo kontinuální infuze. Největší překážkou rutinního TDM u β-laktamů je rychlost kvalitního stanovení vzorku. V současné době je nejvyužívanější metodou stanovení plazmatických koncentrací kapalinová chromatografie s UV nebo MS detekcí.

Given their wide therapeutic index, β-lactam antibiotics are commonly used to treat critically ill patients. It is in these patients that significant heterogeneity in pharmacokinetics was noted, compared to the population average, especially in the volume of distribution, drug clearance and biological half-life, with values increasing as much as two-fold or, in the case of biological half-life, as much as fourfold. Significant pharmacokinetic changes also occur in cases of morbid obesity or renal insufficiency and when complex surgical techniques such as extracorporeal circulation are used. Therapeutic monitoring of piperacillin/tazobactam is a way to personalize and optimize therapy for these groups of patients. Preclinical data show a correlation between the probability of therapeutic success and concentrations of the unbound fraction of an antibiotic exceeding the minimum inhibitory concentration (MIC) for 40–50 % of the dosing interval. This time appears to be the preferred pharmacodynamic target for β-lactam antibiotics. In critically ill patients, however, an even higher target may be required, ideally 100 % fT > 4xMIC. A better pharmacodynamic profile can be obtained using prolonged or continuous infusion. The biggest obstacle to routine TDM in β-lactams is the speed of quality sample determination. Currently, the most widely used method of measuring plasma concentrations is liquid chromatography coupled with UV or MS detection.

OBJECTIVES: This study sought to determine new reference cutoffs for normal unipolar voltage (UV) and bipolar voltage (BV) that would be adjusted for the LV remodeling. BACKGROUND: The definition of "normal" left ventricular (LV) endocardial voltage in patients with post-infarct scar is still lacking. The reference voltage of the noninfarcted myocardium (NIM) may differ between patients depending on LV structural remodeling and the ensuing interstitial fibrosis. METHODS: Electroanatomic voltage mapping was integrated with isotropic late gadolinium-enhanced cardiac magnetic resonance in 15 patients with nonremodeled LV and 12 patients with remodeled LV (end-systolic volume index >50 ml/m2 with ejection fraction <47% assessed by cardiac magnetic resonance). Reference voltages (fifth percentile values) were determined from pooled NIM segments without late gadolinium enhancement. RESULTS: The cutoffs for normal BV and UV were ≥3.0 and ≥6.7 mV for nonremodeled LV and ≥2.1 and ≥6.4 mV for remodeled LV. Endocardial low-voltage area (LVA) defined by the adjusted cutoffs corresponded better to late gadolinium enhancement-detected scar than did LVA defined by uniform cutoffs. In 15 patients who underwent successful ablation of ventricular tachycardia, the LVA contained >97% of targeted evoked delayed potentials. Insights from whole-heart T1 mapping revealed more fibrotic NIM in patients with remodeled LV compared with nonremodeled LV. CONCLUSIONS: This study found substantial differences in endocardial voltage of NIM in post-infarct patients with remodeled versus nonremodeled LV. The new adjusted cutoffs for "normal" BV and UV enable a patient-tailored approach to electroanatomic voltage mapping of LV.

• MeSH
• Electrophysiologic Techniques, Cardiac * MeSH
• Endocardium diagnostic imaging   physiology   physiopathology   MeSH
• Myocardial Infarction complications   physiopathology   MeSH
• Cicatrix diagnostic imaging   etiology   physiopathology   MeSH
• Catheter Ablation MeSH
• Tachycardia, Ventricular etiology   physiopathology   surgery   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Imaging, Cine MeSH
• Magnetic Resonance Imaging MeSH
• Reference Values MeSH
• Ventricular Remodeling physiology   MeSH
• Aged MeSH
• Case-Control Studies MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH