hydrogen activation Dotaz Zobrazit nápovědu
Spoľahlivá stabilizácia lieku a liečiva je stále jednýmz najzávažnejších problémov svetovej farmácie,pretože lieky nie sú neobmedzene stále sústavy. Pacient však musí dostať liek kvalitný, preto otázkestability je venovaná pozornosť nielen pri výskume a vývoji, priemyselnej výrobe, ale i pri distribúcii.Mierou stability je doba použiteľnosti. Zriedený roztok peroxidu vodíka (3% roztok) patrí stálek najpoužívanejším a zároveň k najdostupnejším dezinfekčným prostriedkom.V praxi sa udomácnilnielen na Slovensku, ale i v zahraničí. Používa sa vo viacerých koncentráciách. Jednou z jehonajzávažnejších nevýhod je jeho obmedzená stabilita, ktorá výrazne znižuje jeho dobu použiteľnosti.Predložená práca sa zaoberá sledovaním stability roztokov peroxidu vodíka s bežne používanýmikoncentráciami (3%, 6% a 10%) bez a s obsahom stabilizačnej prísady (fenacetín) pripravenýchpriamo v lekárni a skladovaných za rôznych podmienok počas predpokladanej doby použiteľnosti.Obsah peroxidu vodíka bol stanovený liekopisnoumetódou v 7-dňových časových intervaloch. Zistilosa, že všetky koncentrácie roztokov 3%, 6% a 10% peroxidu vodíka počas sledovanej doby splnilipožiadavky na stabilitu. Ich koncentrácia neklesla pod hranicu 90 % obsahu liečiva, pričom skladovanieza zníženej teploty je vhodnejšie. Uchovávanie roztoku peroxidu vodíka na svetle je neprípustné.Pri dodržiavaní podmienok uchovávania možno od roztoku peroxidu vodíka očakávať žiadanýterapeutický efekt v priebehu 3 mesiacov.
Reliable stabilization of the pharmaceutical preparation and the active ingredient remains one ofthe most important problems of world pharmacy because pharmaceutical preparations are notsystems which are stable without limitation. The patient must receive a quality drug and that iswhy the question of stability is paid grest attention to not only in research and development,industrial manufacture, but also in distribution. The measure of stability is the expiration period.Diluted solution of hydrogen peroxide (3% solution) still belongs to the most widely used and at thesame time the most easily accessible disinfectants. In practice it is common both in Slovakia andabroad. It is used in several concentrations. One of its most important disadvantages is its limitedstability, which markedly decreases its expiration period. The present paper investigates thestability of hydrogen peroxide solutions of routinely used concentrations (3%, 6%, and 10%) withoutand with a stabilizing additive (phenacetin) prepared in the pharmacy and stored under differentconditions for the period of their expected usability. The content of hydrogen peroxide was assayedby the pharmacopoeial method in 7-day time intervals. All concentrations of 3%, 6%, and 10%hydrogen peroxide were found to fulfil the conditions for stability in the period of time under study.Their concentration did not fall below the limit od 90 % of the content of the active ingredient, andstorage under decreased temperature proved to be more suitable. Storage of hydrogen peroxide inthe light is inadmissible.When the conditions of storage are observed, the required therapeutic effectof hydrogen peroxide solution can be expected for the period of three months.
Hydrogen sulfide (H2S), an endogenous “gasotransmitter”, exists in the central nervous system. However, the central cardiovascular effects of endogenous H2S are not fully determined. The present study was designed to investigate the central cardiovascular effects and its possible mechanism in anesthetized rats. Intracerebroventricular (icv) injection of NaHS (0.17~17 μg) produced a significant and dose-dependent decrease in blood pressure (BP) and heart rate (HR) (P<0.05) compared to control. The higher dose of NaHS (17 μg, n=6) decreased BP and HR quickly of rats and 2 of them died of respiratory paralyse. Icv injection of the cystathionine betasynthetase (CBS) activator s-adenosyl-L-methionine (SAM, 26 μg) also produced a significant hypotension and bradycardia, which were similar to the results of icv injection of NaHS. Furthermore, the hypotension and bradycardia induced by icv NaHS were effectively attenuated by pretreatment with the KATP channel blocker glibenclamide but not with the CBS inhibitor hydroxylamine. The present study suggests that icv injection of NaHS produces hypotension and bradycardia, which is dependent on the KATP channel activation.
- MeSH
- bradykardie chemicky indukované patofyziologie MeSH
- gating iontového kanálu účinky léků MeSH
- hypotenze chemicky indukované patofyziologie MeSH
- KATP kanály účinky léků MeSH
- krevní tlak účinky léků MeSH
- krysa rodu rattus MeSH
- mozek patofyziologie účinky léků MeSH
- potkani Sprague-Dawley MeSH
- srdce patofyziologie účinky léků MeSH
- srdeční frekvence účinky léků MeSH
- sulfan aplikace a dávkování metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
Klasické vyšetrovacie metódy respiračného traktu sa rozšírili o biochemickú analýzu vydychovaného vzduchu. Jednou z látok často stanovovaných pri hľadaní markerov pľúcnych chorôb je peroxid vodíka. Táto práca zhŕňa literárne údaje o postavení peroxidu vodíka v metabolizme kyslíkových radikálov, metodických možnostiach detekcie koncentrácie H2O2 vo vydychovanom vzduchu a hodnotách jeho produkcie pri pľúcnych chorobách.
Classical methods of respiratory diagnosis were extended with methods allowing determination of the metabolic products from lung tissue – the biochemical analysis of expired air. Hydrogen peroxide is one of the substances used as markers of pathological processes in the respiratory system. This review describes position of hydrogen peroxide in the metabolic pathway of reactive oxygen species, methods of hydrogen peroxide measurement in expired air and changes in hydrogen peroxide production in lung diseases.
- MeSH
- biologické markery MeSH
- finanční podpora výzkumu jako téma MeSH
- lidé MeSH
- oxidační stres diagnóza etiologie metabolismus MeSH
- peroxid vodíku MeSH
- plicní nemoci diagnóza MeSH
- reaktivní formy kyslíku MeSH
- respirační funkční testy metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
Sulfan je nežádoucí složkou bioplynu z mnoha důvodů – toxicita, inhibice mikrobiální kultury v anaerobních reaktorech, korozivní účinky a produkce SOx ve spalinách. Je proto nutné jej před energetickým využitím bioplynu odstranit. Mezi významné metody odsiřo- vání se v poslední době dostávají stále více metody biologické, u kterých na rozdíl od konvenčních metod chemických a fyzikálně- chemických nevznikají problematické vedlejší produkty a jsou z hlediska investičních a provozních nákladů výhodnější. Biologický způsob odstraňování sulfanu z bioplynu je založen na činnosti sirných bakterií, které jsou schopné oxidovat sulfidickou síru a adaptovat se i na vysoké koncentrace sulfanu. Technologická uspořádání biologické oxidace sulfanu se liší hlavně ve formě použité biomasy – suspenzní nebo imobilizovaná kultura. Účinnost procesu závisí na mnoha faktorech, jako je poměr sulfidů a rozpuštěného kyslíku, teplota či pH, proto je nutné při řízení procesu udržovat technologické parametry v optimálním rozmezí.
Hydrogen-sulfide is an undesirable component of biogas for many reasons – toxicity, inhibition of microbial culture in anaerobic digesters, corrosive effects and production of SOx in the flue gases. Its removal from biogas prior energetic utilization is therefore required. Biological desulfurization methods demand lower investment and operation costs compare to conventional chemical and physical-chemical processes. Methods of biological oxidation of hydrogen sulfide are based on the activity of sulfur bacteria that are able to oxidize sulfides and adapt to high concentrations of them. Technological configurations of the process differ mainly in the form of biomass used – bacterial culture in suspension or immobilized. The process efficiency depends on many factors such as the ratio of sulfides and dissolved oxygen, temperature and pH, consequently it needs proper technological process control.
- Klíčová slova
- biologické odsiřování, sirné bakterie,
- MeSH
- bakterie redukující síru metabolismus růst a vývoj MeSH
- biodegradace MeSH
- biopaliva škodlivé účinky MeSH
- bioreaktory mikrobiologie MeSH
- biotechnologie metody MeSH
- financování organizované MeSH
- nakládání s odpady metody MeSH
- sulfan metabolismus škodlivé účinky MeSH
A variety of decontamination techniques are utilized to remove biological and chemical contaminants from surfaces. Nevertheless, new physical and chemical methods and agents are still being developed. The main reason is toxicity of the common used agents. This review summarizes recent findings on a new promising decontamination agent, hydrogen peroxide vapour (VPHP), with almost ideal properties. Decontamination using VPHP has become the method of choice in pharmacy, biomedical applications and health care. The VPHP method is reliable, rapid, leaves no residues (decomposes into water and oxygen) and can be validated. So far only limited information has been published about decontamination of chemical and biologically active compounds using VPHP. The definitive knowledge of its action and the influence of various factors are yet to be discovered.
SIGNIFICANCE: Redox modifications of thiols serve as a molecular code enabling precise and complex regulation of protein tyrosine phosphatases (PTPs) and other proteins. Particular gasotransmitters and even the redox modifications themselves affect each other, of which a typical example is S-nitrosylation-mediated protection against the further oxidation of protein thiols. RECENT ADVANCES: For a long time, PTPs were considered constitutively active housekeeping enzymes. This view has changed substantially over the last two decades, and the PTP family is now recognized as a group of tightly and flexibly regulated fundamental enzymes. In addition to the conventional ways in which they are regulated, including noncovalent interactions, phosphorylation, and oxidation, the evidence that has accumulated during the past two decades suggests that many of these enzymes are also modulated by gasotransmitters, namely by nitric oxide (NO) and hydrogen sulfide (H2S). CRITICAL ISSUES: The specificity and selectivity of the methods used to detect nitrosylation and sulfhydration remains to be corroborated, because several researchers raised the issue of false-positive results, particularly when using the most widespread biotin switch method. Further development of robust and straightforward proteomic methods is needed to further improve our knowledge of the full extent of the gasotransmitters-mediated changes in PTP activity, selectivity, and specificity. FURTHER DIRECTIONS: Results of the hitherto performed studies on gasotransmitter-mediated PTP signaling await translation into clinical medicine and pharmacotherapeutics. In addition to directly affecting the activity of particular PTPs, the use of reversible S-nitrosylation as a protective mechanism against oxidative stress should be of high interest.
- MeSH
- aktivace enzymů MeSH
- lidé MeSH
- reaktivní formy dusíku metabolismus MeSH
- sulfan metabolismus MeSH
- tyrosinfosfatasy metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Naegleria gruberi is a free-living heterotrophic aerobic amoeba well known for its ability to transform from an amoeba to a flagellate form. The genome of N. gruberi has been recently published, and in silico predictions demonstrated that Naegleria has the capacity for both aerobic respiration and anaerobic biochemistry to produce molecular hydrogen in its mitochondria. This finding was considered to have fundamental implications on the evolution of mitochondrial metabolism and of the last eukaryotic common ancestor. However, no actual experimental data have been shown to support this hypothesis. For this reason, we have decided to investigate the anaerobic metabolism of the mitochondrion of N. gruberi. Using in vivo biochemical assays, we have demonstrated that N. gruberi has indeed a functional [FeFe]-hydrogenase, an enzyme that is attributed to anaerobic organisms. Surprisingly, in contrast to the published predictions, we have demonstrated that hydrogenase is localized exclusively in the cytosol, while no hydrogenase activity was associated with mitochondria of the organism. In addition, cytosolic localization displayed for HydE, a marker component of hydrogenase maturases. Naegleria gruberi, an obligate aerobic organism and one of the earliest eukaryotes, is producing hydrogen, a function that raises questions on the purpose of this pathway for the lifestyle of the organism and potentially on the evolution of eukaryotes.
