The root is the below-ground organ of a plant, and it has evolved multiple signaling pathways that allow adaptation of architecture, growth rate, and direction to an ever-changing environment. Roots grow along the gravitropic vector towards beneficial areas in the soil to provide the plant with proper nutrients to ensure its survival and productivity. In addition, roots have developed escape mechanisms to avoid adverse environments, which include direct illumination. Standard laboratory growth conditions for basic research of plant development and stress adaptation include growing seedlings in Petri dishes on medium with roots exposed to light. Several studies have shown that direct illumination of roots alters their morphology, cellular and biochemical responses, which results in reduced nutrient uptake and adaptability upon additive stress stimuli. In this review, we summarize recent methods that allow the study of shaded roots under controlled laboratory conditions and discuss the observed changes in the results depending on the root illumination status.

• MeSH
• fyziologická adaptace * MeSH
• kořeny rostlin metabolismus   účinky záření   MeSH
• regulace genové exprese u rostlin účinky záření   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• rostliny metabolismus   účinky záření   MeSH
• semenáček metabolismus   účinky záření   MeSH
• světlo * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Plants can plastically respond to light competition in three strategies, comprising vertical growth, which promotes competitive dominance; shade tolerance, which maximises performance under shade; or lateral growth, which offers avoidance of competition. Here, we test the hypothesis that plants can 'choose' between these responses, according to their abilities to competitively overcome their neighbours. We study this hypothesis in the clonal plant Potentilla reptans using an experimental setup that simulates both the height and density of neighbours, thus presenting plants with different light-competition scenarios. Potentilla reptans ramets exhibit the highest vertical growth under simulated short-dense neighbours, highest specific leaf area (leaf area/dry mass) under tall-dense neighbours, and tend to increase total stolon length under tall-sparse neighbours. These responses suggest shifts between 'confrontational' vertical growth, shade tolerance and lateral-avoidance, respectively, and provide evidence that plants adopt one of several alternative plastic responses in a way that optimally corresponds to prevailing light-competition scenarios.

• MeSH
• listy rostlin MeSH
• Potentilla růst a vývoj   MeSH
• rozhodování MeSH
• světlo * MeSH
• životní prostředí MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Many plant species respond to unfavorable high ambient temperatures by adjusting their vegetative body plan to facilitate cooling. This process is known as thermomorphogenesis and is induced by the phytohormone auxin. Here, we demonstrate that the chromatin-modifying enzyme HISTONE DEACETYLASE 9 (HDA9) mediates thermomorphogenesis but does not interfere with hypocotyl elongation during shade avoidance. HDA9 is stabilized in response to high temperature and mediates histone deacetylation at the YUCCA8 locus, a rate-limiting enzyme in auxin biosynthesis, at warm temperatures. We show that HDA9 permits net eviction of the H2A.Z histone variant from nucleosomes associated with YUCCA8, allowing binding and transcriptional activation by PHYTOCHROME INTERACTING FACTOR 4, followed by auxin accumulation and thermomorphogenesis.

• MeSH
• Arabidopsis enzymologie   genetika   fyziologie   MeSH
• histondeacetylasy genetika   metabolismus   MeSH
• histony genetika   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• oxygenasy se smíšenou funkcí genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• vazba proteinů MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE OF THE STUDY: Leukocyte esterase is an enzyme in neutrophils from which it is released into exudate; its detection by colorimetric test strips indicates the presence of neutrophils. This is a rapid method to find whether exudate is of infectious or non-infectious aetiology. The aim of the study was to determine the sensitivity and specificity of leukocyte esterase testing with use of AUTION Sticks (Arkray) for examination of exudates obtained in inflammatory diseases of the skeletal system. MATERIAL AND METHODS: Exudates associated with skeletal system diseases were collected from 45 patients in the period from July 1st to December 31 st , 2012. Aspirates obtained under sterile conditions were examined for leukocyte esterase; cytological and microbiological examinations were also carried out. For the detection of leukocyte esterase, a drop of aspirate was placed on the reagent zone of a test strip and the resulting colour reaction was read after 90 minutes. Changes in colour were compared with a reference strip provided by the manufacturer. The results were assessed on a five-shade scale as follows: 0, no colour change; 1 to 4, gradual change from light pink to deep purple. The results were compared with those of cytological and microbiological examinations. Shade 4 on the strip corresponded to a positive cytological finding of bacterial infection, and shades 3 and 4 correlated with a positive microbial finding. The sensitivity and specificity of leukocyte esterase testing were statistically evaluated for both comparisons. RESULTS: Based on the results of cytological and microbiological examinations, an infectious aetiology of exudate was diagnosed in 21 (44.4%) and non-infectious aetiology in 24 (63.6%) patients. With leukocyte esterase reagent strips when shade 4 was taken as a positive result, the sensitivity and specificity of examination was assessed as 0.6190 and 0.9583, respectively. When taking both shade 3 and shade 4 for a positive result, sensitivity and specificity were 0.8571 and 0.8750, respectively. Shades 0 and 1 corresponded to the number of leukocytes in exudate that was no higher than 2 x 10⁹/ml. DISCUSSION: The detection of leukocyte esterase is a quick and easy examination. It is useful for readily excluding or confirming an infectious aetiology of exudate and can, to some extent, substitute a cytological examination. It can also help to make a quick decision whether one- or two-stage joint reimplantation should be performed and thus eliminate the need of intra-operative histological examination of frozen tissue samples. A drawback of the method was that exudate samples contaminated with blood interfered with an assessment of colour shades. However, this can be avoided by centrifugation of the sample and use of a supernatant free from erythrocytes. CONCLUSIONS: Diagnosing infectious aetiology of joint exudate or exudate from an abscess using leukocyte esterase reagent strips appears, according to our results, to be a promising, semi-quantitative method with high specificity and sensitivity which is rapid, simple and affordable. It can be useful particularly in out-patient institutions for a quick diagnosis of arthritis; intraoperatively, it can serve as an additional method to other exudate examinations.

• MeSH
• absces diagnóza   mikrobiologie   MeSH
• artritida diagnóza   mikrobiologie   MeSH
• bakteriální infekce diagnóza   MeSH
• cytodiagnostika MeSH
• exsudáty a transsudáty enzymologie   MeSH
• karboxylesterhydrolasy analýza   MeSH
• lidé MeSH
• nemoci kostí diagnóza   mikrobiologie   MeSH
• neutrofily enzymologie   MeSH
• reagenční papírky * MeSH
• senzitivita a specificita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• srovnávací studie MeSH

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
• lidé MeSH
• melanom prevence a kontrola   etiologie   epidemiologie   MeSH
• nádory kůže * prevence a kontrola   etiologie   epidemiologie   MeSH
• nádory vyvolané zářením prevence a kontrola   etiologie   epidemiologie   MeSH
• pigmentace kůže účinky záření   MeSH
• přípravky chránící proti slunci terapeutické užití   MeSH
• rizikové faktory MeSH
• ultrafialové záření * škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• MeSH
• fyzikální vyšetření MeSH
• klinické lékařství MeSH
• muskuloskeletální nemoci diagnóza   MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Ortopedie. Chirurgie. Oftalmologie
• NLK Obory
• ortopedie