Vitamín B17, známý také jako amygdalin, je přírodní kyanogenní glykosid dostupný jako potravinový doplněk, který je využíván v alternativní medicíně. Amygdalin se v těle hydroxyluje na toxický kyanid, který může způsobit život ohrožující intoxikaci. V kazuistice je prezentována život ohrožující otrava kyanidem po požití potravinového doplňku obsahující amygdalin, která byla úspěšně léčena hydroxocobalaminem. Kazuistika dále obsahuje management přednemocniční neodkladné péče u pacienta s akutní intoxikací.
Vitamin B17, well known as amygdalin, is originally a natural cyanogenic glycoside available as a dietary supplement used in the alternative treatment. Amygdalin hydroxylates to toxic cyanide in the body, which can cause life-threatening intoxication. The case report presents a life-threatening cyanide poisoning after ingesting a dietary supplement containing amygdalin identified in pre-hospital care, which was successfully treated with hydroxocobalamin. The case report also contains the management of pre-hospital care in a patient with acute intoxication.
- MeSH
- amygdalin * aplikace a dávkování metabolismus otrava MeSH
- hydroxokobalamin aplikace a dávkování MeSH
- kyanidy otrava MeSH
- lidé MeSH
- nádory komplikace terapie MeSH
- otrava * diagnóza farmakoterapie patologie terapie MeSH
- potravní doplňky otrava MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
Exercise training (ET) is well established to induce vascular adaptations on the metabolically active muscles. These adaptations include increased function of vascular potassium channels and enhanced endothelium-dependent relaxations. However, the available data on the effect of ET on vasculatures that normally constrict during exercise, such as mesenteric arteries (MA), are scarce and not conclusive. Therefore, this study hypothesized that 10 weeks of moderate-intensity ET would result in adaptations towards more vasoconstriction or/and less vasodilatation of MA. Young Fischer 344 rats were randomly assigned to a sedentary group (SED; n=24) or exercise training group (EXE; n=28). The EXE rats underwent a progressive treadmill ET program for 10 weeks. Isometric tensions of small (SED; 252.9+/-29.5 microm, EXE; 248.6+/-34.4 microm) and large (SED; 397.7+/-85.3 microm, EXE; 414.0+/-86.95 microm) MA were recorded in response to cumulative phenylephrine concentrations (PE; 0-30 microM) in the presence and absence of the BKCa channel blocker, Iberiotoxin (100 nM). In another set of experiments, tensions in response to cumulative concentration-response curves of acetylcholine (ACh) or sodium nitroprusside (SNP) were obtained, and pEC50s were compared. Immunoblotting was performed to measure protein expression levels of the BKCa channel subunits and eNOS. ET did not alter the basal tension of small and large MA but significantly increased their responses to PE, and reduced the effect of BKCa channels in opposing the contractile responses to PE without changes in the protein expression level of BKCa subunits. ET also elicited a size-dependent functional adaptations that involved reduced endothelium-independent and endothelium-dependent relaxations. In large MA the sensitivity to SNP was decreased more than in small MA suggesting impaired nitric oxide (NO)-dependent mechanisms within the vascular smooth muscle cells of ET group. Whereas the shift in pEC50 of ACh-induced relaxation of small MA would suggest more effect on the production of NO within the endothelium, which is not changed in large MA of ET group. However, the eNOS protein expression level was not significantly changed between the ET and SED groups. In conclusion, our results indicate an increase in contraction and reduced relaxation of MA after 10 weeks of ET, an adaptation that may help shunt blood flow to metabolically active tissues during acute exercise.
Syrové fazole obsahují několik toxických látek a mohou vyvolat otravu. To naneštěstí v české populaci není všeobecně známo, běžně se proto vyskytují případy jejich pojídání dětmi i dospělými, což vede k toxickým projevům. Za posledních 10 let Toxikologické informační středisko (TIS) odpovídalo téměř na 500 dotazů laiků i zdravotníků na první pomoc a léčení těchto otrav. Příznaky zpravidla zahrnovaly zvracení, bolest břicha a průjem. Pro první pomoc a inaktivaci fasinu i kyanogenních glykosidů, které se vyskytují především v okrasných a exotických fazolích, je třeba podat aktivní uhlí, zahájit sledování a popřípadě symptomatickou terapii s náhradou tekutin. Od výplachu žaludku i podání laxativ se ustupuje, endoskopické odstranění fazolí se nedoporučuje. Příznaky kyanidové toxicity s nutností podání antidota TIS dosud nezaznamenal, a nejsou ani popsány v publikovaných kazuistikách, nelze je však vyloučit po konzumaci jihoamerických fazolí. Je třeba více informovat veřejnost o toxicitě syrových fazolí a významu jejich původu, neboť podle vzhledu fazolové boby rozlišit nelze.
Raw beans contain several toxic substances and can cause poisoning. Unfortunately, this is not generally known in the Czech population, so there are common cases of ingestions by children and adults, leading to toxic manifestations. Over the last 10 years, the Toxicological Information Center (TIC) has answered almost 500 calls from lay people and healthcare professionals concerning the first aid and treatment of these poisonings. Symptoms usually included vomiting, abdominal pain, and diarrhea. For first aid and inactivation of fasin and cyanogenic glycosides, which occur mainly in decorative and exotic beans, it is necessary to administer activated charcoal and start observation and symptomatic treatment, if needed, including fluid replacement therapy. Gastric lavage and laxative administration are abandoned, and endoscopic removal of beans is not recommended. Symptoms of cyanide toxicity with the need for antidote have not yet been reported to TIC, neither in the published case reports, but cannot be ruled out after consumption of South American beans. There is an urgent need to inform the public about the toxicity of raw beans and the importance of their origin, as they cannot be distinguished according to the appearance of the beans.
- MeSH
- dítě MeSH
- fazol * otrava toxicita MeSH
- jedovaté rostliny otrava toxicita MeSH
- kyanidy otrava toxicita MeSH
- lidé MeSH
- noxy otrava toxicita MeSH
- otrava rostlinami diagnóza terapie MeSH
- semena rostlinná otrava toxicita MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- syrová strava otrava toxicita MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
Inhalační trauma je závažnou komplikací u pacientů s popáleninami, která dramaticky zvyšuje jejich morbiditu a mortalitu. U těchto pacientů je obvykle podezření na inhalační poranění s možnou systémovou intoxikací. Obvykle se setkáváme s intoxikací oxidem uhelnatým, ale je třeba myslet i na možnost otravy jinými produkty hoření. Intoxikace kyanidy jsou méně časté, ale jejich diagnostika a léčba je o to složitější. Diagnóza může být stanovena pouze na základě anamnézy, klinického nálezu a nepřímých laboratorních známek Přímé stanovení plazmatických hladin kyanidů není v běžné klinické praxi použitelné. V současné době je k dispozici několik specifických antidot s různým mechanizmem účinku. Neexistují žádná jasná doporučení ohledně výběru konkrétního antidota, a to z důvodu nedostatku důkazů založených na randomizovaných kontrolovaných studií na lidech. Ve dvou minikazuistikách uvádíme naše zkušenosti s diagnostikou a terapií pacientů s podezřením na otravu kyanidy
Inhalation injury is a serious complication in patients with burns that dramatically increases their morbidity and mortality. These patients are always suspected of having inhalation injury with potential intoxication. We usually encounter carbon monoxide intoxication, but it is necessary to think about the possibility of poisoning by other combustion products. Cyanide intoxications are less common, but their diagnosis and treatment are more complicated. The diagnosis can only be based on the history, clinical findings, and indirect laboratory signs. Direct determination of plasma cyanide levels is not generally adopted in routine clinical practice. Nowadays, several specific antidotes with different mechanisms of action are available. There are no clear guidelines on the antidote of choice, as the evidence base is limited by a lack of randomised controlled trials in humans. In two mini case reports, we present our experience with the diagnosis and therapy of patients with suspected cyanide poisoning.
- MeSH
- antidota MeSH
- hydroxokobalamin MeSH
- kyanidy otrava MeSH
- lidé středního věku MeSH
- lidé MeSH
- popálení inhalací diagnóza MeSH
- popálení * MeSH
- poškození plic * MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- MeSH
- alkaloidy chemie škodlivé účinky MeSH
- bezpečnost potravin MeSH
- fytonutrienty * analýza chemie škodlivé účinky MeSH
- kyanidy chemie škodlivé účinky MeSH
- kyselina fytová chemie škodlivé účinky MeSH
- lektiny chemie škodlivé účinky MeSH
- mykotoxiny chemie škodlivé účinky MeSH
- otrava houbami MeSH
- taniny analýza chemie škodlivé účinky MeSH
- vitaminy antagonisté a inhibitory MeSH
- živiny antagonisté a inhibitory MeSH
- Publikační typ
- přehledy MeSH
Drug discovery efforts largely depend on access to structural diversity. Multicomponent reactions allow for time-efficient chemical transformations and provide advanced intermediates with three or four points of diversification for further expansion to a structural variety of organic molecules. This review is aimed at solid-phase syntheses of small molecules involving isocyanide-based multicomponent reactions. The majority of all reported syntheses employ the Ugi four-component reaction. The review also covers the Passerini and Groebke-Blackburn-Bienaymé reactions. To date, the main advantages of the solid-phase approach are the ability to prepare chemical libraries intended for biological screening and elimination of the isocyanide odor. However, the potential of multicomponent reactions has not been fully exploited. The unexplored avenues of these reactions, including chiral frameworks, DNA-encoded libraries, eco-friendly synthesis, and chiral auxiliary reactions, are briefly outlined.
Being a chilling-sensitive staple crop, rice (Oryza sativa L.) is vulnerable to climate change. The competence of rice to withstand chilling stress should, therefore, be enhanced through technological tools. The present study employed chemical intervention like application of sodium nitroprusside (SNP) as nitric oxide (NO) donor and elucidated the underlying morpho-physiological and biochemical mechanisms of NO-mediated chilling tolerance in rice plants. At germination stage, germination indicators were interrupted by chilling stress (5.0 ± 1.0 °C for 8 h day-1), while pretreatment with 100 μM SNP markedly improved all the indicators. At seedling stage (14-day-old), chilling stress caused stunted growth with visible toxicity along with alteration of biochemical markers, for example, increase in oxidative stress markers (superoxide, hydrogen peroxide, and malondialdehyde) and osmolytes (total soluble sugar; proline and soluble protein content, SPC), and decrease in chlorophyll (Chl), relative water content (RWC), and antioxidants. However, NO application attenuated toxicity symptoms with improving growth attributes which might be related to enhance activities of antioxidants, mineral contents, Chl, RWC and SPC. Furthermore, principal component analysis indicated that water imbalance and increased oxidative damage were the main contributors to chilling injury, whereas NO-mediated mineral homeostasis and antioxidant defense were the critical determinants for chilling tolerance in rice. Collectively, our findings revealed that NO protects against chilling stress through valorizing cellular defense mechanisms, suggesting that exogenous application of NO could be a potential tool to evolve cold tolerance as well as climate resilience in rice.
- MeSH
- donory oxidu dusnatého farmakologie MeSH
- homeostáza účinky léků MeSH
- klíčení účinky léků MeSH
- malondialdehyd metabolismus MeSH
- nitroprusid farmakologie MeSH
- nízká teplota MeSH
- ochrana úrody metody MeSH
- oxid dusnatý metabolismus MeSH
- peroxid vodíku metabolismus MeSH
- peroxidace lipidů účinky léků MeSH
- peroxidasy metabolismus MeSH
- reakce na chladový šok fyziologie MeSH
- rýže (rod) účinky léků MeSH
- semenáček účinky léků MeSH
- superoxidy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The slow kinetic phases of the chlorophyll a fluorescence transient (induction) are valuable tools in studying dynamic regulation of light harvesting, light energy distribution between photosystems, and heat dissipation in photosynthetic organisms. However, the origin of these phases are not yet fully understood. This is especially true in the case of prokaryotic oxygenic photoautotrophs, the cyanobacteria. To understand the origin of the slowest (tens of minutes) kinetic phase, the M-T fluorescence decline, in the context of light acclimation of these globally important microorganisms, we have compared spectrally resolved fluorescence induction data from the wild type Synechocystis sp. PCC 6803 cells, using orange (λ = 593 nm) actinic light, with those of mutants, ΔapcD and ΔOCP, that are unable to perform either state transition or fluorescence quenching by orange carotenoid protein (OCP), respectively. Our results suggest a multiple origin of the M-T decline and reveal a complex interplay of various known regulatory processes in maintaining the redox homeostasis of a cyanobacterial cell. In addition, they lead us to suggest that a new type of regulatory process, operating on the timescale of minutes to hours, is involved in dissipating excess light energy in cyanobacteria.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- chlorofyl chemie genetika metabolismus MeSH
- diuron chemie MeSH
- fluorescence MeSH
- fluorescenční spektrometrie MeSH
- fykobilizomy genetika metabolismus MeSH
- kyanid draselný chemie MeSH
- luminiscenční měření MeSH
- světlo MeSH
- Synechocystis chemie genetika metabolismus MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Nitric oxide (NO) is a major gasotransmitter involved in several physiological processes of male reproduction. There is, nevertheless, little information concerning the role of NO during semen storage. The aim of this study was to evaluate the effect of NO on boar semen stored at 17oC for 72 h. For this purporse, sperm samples were treated with 0.625, 1.25, 2.5, 5, and 10 mM aminoguanidine (AG) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME), a selective and non-selective NO synthase (NOS) inhibitor, respectively. Moreover, sodium nitroprusside (SNP), a NO donor, was used at the dose of 18.75, 37.5, 75, and 150 μM. Sperm motility, membrane integrity, and acrosomal status were evaluated at 0, 4, 24, 48, and 72 h of semen storage. A significant increase of the amplitude of lateral sperm head displacement (ALH), and both curvilinear and straight-line velocity (VCL and VSL, respectively) was observed at 72 h of semen storage in samples treated with 0.625 mM AG, probably because of the antioxidant properties of this NOS inhibitor. Contrarily, 0.625 mM L-NAME showed no effect on boar sperm parameters during the entire period of semen storage. Moreover, AG and L-NAME at 10 mM negatively affected sperm kinetics and acrosome integrity, which may provide further support to the notion that low NO levels are necessary for a normal sperm function. The concentrations of SNP used in this study had mostly no or negative effects on boar sperm parameters during semen storage. In conclusion, the results from this study increase the understanding of the role of NO on boar sperm physiology.
- MeSH
- akrozom účinky léků MeSH
- buněčná membrána účinky léků MeSH
- časové faktory MeSH
- guanidiny farmakologie MeSH
- motilita spermií účinky léků MeSH
- nitroprusid farmakologie MeSH
- oxid dusnatý aplikace a dávkování farmakologie MeSH
- prasata * MeSH
- spermie účinky léků MeSH
- synthasa oxidu dusnatého, typ II antagonisté a inhibitory metabolismus MeSH
- uchování spermatu veterinární MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The endothelial barrier function is tightly controlled by a broad range of signaling cascades including nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. It has been proposed that disturbances in NO and cGMP production could interfere with proper endothelial barrier function. In this study, we assessed the effect of interferon-gamma (IFN-gamma), a pro-inflammatory cytokine, on NO and cGMP levels and examined the mechanisms by which NO and cGMP regulate the IFN-gamma-mediated HUVECs hyperpermeability. The flux of fluorescein isothiocyanate-labeled dextran across cell monolayers was used to study the permeability of endothelial cells. Here, we found that IFN-gamma significantly attenuated basal NO concentration and the increased NO levels supplied by a NO donor, sodium nitroprusside (SNP). Besides, application of IFN-gamma also significantly attenuated both the basal cGMP concentration and the increased cGMP production donated by a cell permeable cGMP analogue, 8-bromo-cyclic GMP (8-Br-cGMP). In addition, exposure of the cell monolayer to IFN-gamma significantly increased HUVECs basal permeability. However, L-NAME pretreatment did not suppress IFN-gamma-induced HUVECs hyperpermeability. L-NAME pretreatment followed by SNP or SNP pretreatment partially reduced IFN-gamma-induced HUVECs hyperpermeability. Pretreatment with a guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY83583), led to a further increase in IFN-gamma-induced HUVECs hyperpermeability. The findings suggest that the mechanism underlying IFN-gamma-induced increased HUVECs permeability is partly related to the inhibition of NO production.
- MeSH
- donory oxidu dusnatého farmakologie MeSH
- endoteliální buňky pupečníkové žíly (lidské) účinky léků metabolismus MeSH
- guanosinmonofosfát cyklický analogy a deriváty metabolismus farmakologie MeSH
- guanylátcyklasa antagonisté a inhibitory MeSH
- inhibitory enzymů farmakologie MeSH
- interferon gama farmakologie MeSH
- kapilární permeabilita účinky léků MeSH
- lidé MeSH
- NG-nitroargininmethylester farmakologie MeSH
- nitroprusid farmakologie MeSH
- oxid dusnatý metabolismus MeSH
- permeabilita buněčné membrány MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
