The neomycin sensing riboswitch is the smallest biologically functional RNA riboswitch, forming a hairpin capped with a U-turn loop-a well-known RNA motif containing a conserved uracil. It was shown previously that a U→C substitution of the eponymous conserved uracil does not alter the riboswitch structure due to C protonation at N3. Furthermore, cytosine is evolutionary permitted to replace uracil in other U-turns. Here, we use molecular dynamics simulations to study the molecular basis of this substitution in the neomycin sensing riboswitch and show that a structure-stabilizing monovalent cation-binding site in the wild-type RNA is the main reason for its negligible structural effect. We then use NMR spectroscopy to confirm the existence of this cation-binding site and to demonstrate its effects on RNA stability. Lastly, using quantum chemical calculations, we show that the cation-binding site is altering the electronic environment of the wild-type U-turn so that it is more similar to the cytosine mutant. The study reveals an amazingly complex and delicate interplay between various energy contributions shaping up the 3D structure and evolution of nucleic acids.
- MeSH
- cytosin chemie MeSH
- draslík MeSH
- hořčík MeSH
- ionty chemie MeSH
- kationty chemie MeSH
- konformace nukleové kyseliny MeSH
- ligandy MeSH
- mutace MeSH
- neomycin MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- párování bází MeSH
- riboswitch * MeSH
- simulace molekulární dynamiky MeSH
- uracil chemie MeSH
- vazebná místa MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The author, as a reviewer of many international journals, describes his long-standing experiences with incorrect identification of mushroom and fungal species and the resultant incorrect naming of those species that served as experimental models. From his own praxis, he selected several characteristic examples that sometimes ended in a curious situation. Some recommendations to authors of publications and persons responsible for the proper naming of mushrooms under study are summarized.
- MeSH
- Agaricales klasifikace genetika růst a vývoj izolace a purifikace MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- fixní kombinace léků MeSH
- gramicidin dějiny normy MeSH
- houby klasifikace genetika růst a vývoj izolace a purifikace MeSH
- mykologické určovací techniky metody normy MeSH
- neomycin dějiny normy MeSH
- nystatin dějiny normy MeSH
- triamcinolonacetonid dějiny normy MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
BACKGROUND: Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata). The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria. METHODOLOGY AND PRINCIPAL FINDINGS: Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae) and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mg g(-1) of diet) for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor. CONCLUSIONS/SIGNIFICANCE: The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mg g(-1) antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet.
- MeSH
- Acaridae účinky léků růst a vývoj mikrobiologie MeSH
- ampicilin farmakologie MeSH
- antibakteriální látky farmakologie MeSH
- Bacteria genetika MeSH
- hustota populace MeSH
- mikrobiální společenstva účinky léků MeSH
- neomycin farmakologie MeSH
- RNA ribozomální 16S MeSH
- streptomycin farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Celiac disease is a gluten-dependent small intestinal disorder with characteristic, but non-specific histopathological features. A number of disorders may cause similar changes in small intestinal biopsies, but fail to respond to a gluten-free diet. Traditionally, infectious agents, such as giardiasis, were often believed to be responsible, but in many patients with a sprue-like intestinal disorder, other causes were detected. The list continues to expand with the emergence of “new” diseases, including transplant enteropathy, distinct immune deficiency syndromes and postcolectomy enteritis, as well as new treatments. Many medications may cause a sprue-like small intestinal mucosal inflammatory process. Alcohol, antibiotics (eg., neomycin), non-steroidal anti-inflammatory drugs (eg., sulindac), stathmokinetic and chemotherapeutic agents (eg., colchicine, vincristine, methotrexate) and immunosuppressive medications (eg., azathioprine, mycophenolate mofetil) may all cause sprue-like small intestinal mucosal changes. A number of “new” drugs have also been recently recognized to cause a sprue-like intestinal disease. These include pharmaceuticals, such as olmesartan, an angiotensin II receptor antagonist used in treatment of hypertension, and biologicals, specifically ipilimumab, a humanized monoclonal antibody designed to overcome cytotoxic T-lymphocyte antigen-4, used in treatment of some advanced malignancies, including malignant melanoma. Increased physician awareness for medication-related sprue-like intestinal disease is critical as the list of emerging and novel medications expands.
- Klíčová slova
- sprue-like střevní onemocnění, sprue podobné enteropatie, nezařazená sprue, malé střevní onemocnění vyvolané léky, post-colectomy enteritis, biologické léky, olmesartan,
- MeSH
- alkoholické nápoje MeSH
- antibakteriální látky MeSH
- antiflogistika nesteroidní MeSH
- bezlepková dieta MeSH
- celiakie * diagnóza etiologie chemicky indukované imunologie patofyziologie prevence a kontrola MeSH
- imunosupresiva MeSH
- ipilimumab MeSH
- kolchicin MeSH
- lidé MeSH
- methotrexát MeSH
- neomycin MeSH
- vinblastin MeSH
- vinkristin MeSH
- Check Tag
- lidé MeSH
The objective of our study was to determine the prevalence of contact hypersensitivity in asymptomatic Czech schoolchildren. We recruited 236 Prague asymptomatic schoolchildren for epicutaneous tests. The children were tested with European baseline series (25 allergens). A total of 218 children (114 boys and 104 girls) completed the study. Of these, 67 (30.7%) children had one or more positive reactions to tested allergens. Nickel, neomycin and potassium dichromate were the most prevalent allergens detected in our study. Our findings may support the notion that allergic contact sensitization in children is not so rare and children, especially those with chronic dermatitis, should be patch tested regularly.
- MeSH
- alergeny MeSH
- atopická dermatitida epidemiologie MeSH
- dítě MeSH
- dvojchroman draselný MeSH
- kontaktní dermatitida epidemiologie MeSH
- konzervační prostředky farmaceutické MeSH
- lidé MeSH
- mladiství MeSH
- náplasťové testy MeSH
- neomycin MeSH
- nikl MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Neomycin, produced by Streptomyces fradiae, has been widely used for the treatment of bacterial infections in clinical and agricultural applications. In this study, a neomycin nonproducing mutant of S. fradiae was obtained by gene disruption technique for mutational biosynthesis. A crucial gene neoC (neo7) which encodes 2-deoxystreptamine (2-DOS) synthases was disrupted. The mutant could resume producing neomycin in the presence of 2-DOS. Salen derivatives of 2-DOS were synthesized and individually added to cultures of the mutant. Antibacterial activity of the mutasynthesis products against Staphylococcus aureus and four plant pathogenic bacteria (Pseudomonas solanacarum, Erwinia carotovora, Xanthomonas oryzae, and Xanthomonas campestris) was detected quantitatively by Oxford cup method. It is suggested that all 2-DOS derivatives were incorporated by the mutant into new active neomycin analogs except for 2-DOS derivative 2d ((1R,2r,3S,4R,6S)-4,6-bis((E)-3,5-di-tert-butyl-2-hydroxybenzylideneamino)cyclohexane-1,2,3-triol). Neomycin analogs produced by feeding 2-DOS derivative 2a ((1R,2r,3S,4R,6S)-4,6-bis((E)-2 hydroxybenzylideneamino)cyclohexane-1,2,3-triol) to cultures of the mutant displayed a similar antibacterial activity with neomycin produced by wild strain.
- MeSH
- antibakteriální látky biosyntéza chemie MeSH
- bakteriální proteiny genetika metabolismus MeSH
- molekulární struktura MeSH
- mutace MeSH
- neomycin analogy a deriváty biosyntéza MeSH
- Streptomyces enzymologie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Psychiatric symptoms often accompany liver disease. The incidence of liver disease has increased recently among psychiatric patients. Hepatic encephalopathy, defined in broad terms as changes in neurological function resulting from liver disease, encompasses a wide range of neuropsychiatric signs and symptoms that are associated with both chronic and acute liver failure. Hepatic encephalopathy is associated with cognitive dysfunction, impairment of the quality of life, and higher incidence of road accidents. The incidence of viral hepatitis C has been increasing worldwide. It can cause general slowing of psychomotor performance, disorientation, depression or hypomania, personality disorders, or sleep disorders. Severe depression can be caused by treatment of hepatitis C with interferon alpha. Paroxetine and citalopram show the best proven results in a double-blinded placebo-controlled trials of prophylactic treatment for IFN-?–induced depression. Before liver transplantation, anxiety, depression and alexithymia are frequent; post-traumatic stress disorder, psychosis and depression (because of survivor guilt) may appear after liver transplantation. In post-transplantation anxiety, women perceive liver transplantation as a psychosocial stressor more than men do. Women also have a worse quality of life after liver transplantation than men.
- MeSH
- duševní poruchy diagnóza etiologie psychologie MeSH
- farmakoterapie metody využití MeSH
- financování organizované MeSH
- hepatitida C diagnóza komplikace psychologie MeSH
- hepatolentikulární degenerace diagnóza komplikace psychologie MeSH
- imunosupresiva aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- jaterní encefalopatie diagnóza komplikace psychologie MeSH
- lidé MeSH
- medicína založená na důkazech trendy MeSH
- mezioborová komunikace MeSH
- nemoci jater komplikace psychologie MeSH
- neomycin aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- příznaky a symptomy MeSH
- psychopatologie MeSH
- ribavirin aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- rifamyciny aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- transplantace jater psychologie škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Autoři v článku referují o stále častějších případech vědomého sebepoškozování mužského zevního genitálu, jehož příčinou je aplikace cizorodých látek do jeho podkoží z kosmetických důvodů (ke zvětšení objemu). Ve většině případů pacienti přicházejí z důvodů obav a studu až s komplikacemi různého stupně.
- MeSH
- bacitracin škodlivé účinky MeSH
- granulom z cizího tělesa etiologie chirurgie MeSH
- injekce subkutánní škodlivé účinky využití MeSH
- lidé MeSH
- masti aplikace a dávkování škodlivé účinky MeSH
- mužské pohlavní orgány zranění MeSH
- neomycin škodlivé účinky MeSH
- parafín aplikace a dávkování škodlivé účinky MeSH
- sebepoškozování MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
