scholarly journals Physiological Importance of Hydrogen Sulfide: Emerging Potent Neuroprotector and Neuromodulator

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Sandesh Panthi ◽  
Hyung-Joo Chung ◽  
Junyang Jung ◽  
Na Young Jeong
Keyword(s):  
Hydrogen Sulfide ◽  
Human Body ◽  
Defense Mechanism ◽  
Peripheral Nerve Regeneration ◽  
Endocrine System ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Beneficial Effects ◽  
Physiological Importance ◽  
Wide Range

Hydrogen sulfide (H2S) is an emerging neuromodulator that is considered to be a gasotransmitter similar to nitrogen oxide (NO) and carbon monoxide (CO). H2S exerts universal cytoprotective effects and acts as a defense mechanism in organisms ranging from bacteria to mammals. It is produced by the enzymes cystathionineβ-synthase (CBS), cystathionineϒ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (MST), and D-amino acid oxidase (DAO), which are also involved in tissue-specific biochemical pathways for H2S production in the human body. H2S exerts a wide range of pathological and physiological functions in the human body, from endocrine system and cellular longevity to hepatic protection and kidney function. Previous studies have shown that H2S plays important roles in peripheral nerve regeneration and degeneration and has significant value during Schwann cell dedifferentiation and proliferation but it is also associated with axonal degradation and the remyelination of Schwann cells. To date, physiological and toxic levels of H2S in the human body remain unclear and most of the mechanisms of action underlying the effects of H2S have yet to be fully elucidated. The primary purpose of this review was to provide an overview of the role of H2S in the human body and to describe its beneficial effects.

An Automated Detection System for Most L-α-Amino Acids

1969 ◽  
Vol 15 (2) ◽  
pp. 154-161 ◽  
Author(s):  
K Van Dyke ◽  
C Szustkiewicz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Detection System ◽  
Automated System ◽  
Acid Oxidase ◽  
Enzymatic Reactions ◽  
Amino Acid Oxidase ◽  
Automated Method ◽  
Wide Range

Abstract An automated system for the determination of the L-α form of the majority of amino acids is presented. The method is based upon oxidative deamination of the amino acid coupled with oxidation of o-dianisidine by hydrogen peroxide. This procedure can be used comparatively for the determination of a mixture of L-α-amino acids or for the majority of separated L-α-amino acids (especially in conjunction with column separations from urine and blood which give falsely positive identification with ninhydrin detection). The stereospecific nature of the L-α-amino acid oxidase enables the investigator to quantitate the amount of L-α-amino acid in the presence of the D-α form. From an academic viewpoint, the extreme sensitivity and wide range of the detection system make it advantageous for the study of the enzyme itself. This automated method also may be employed to follow enzymatic reactions—e.g., those catalyzed by peptidases or racemases. The methodology is extremely convenient with good reagent stability and is much more sensitive than manometric technics.

scholarly journals Quercetin Improves the Endocrine Function of Rat Testicular Tissue Under in Vitro Conditions

2021 ◽  
Vol 70 (1-2) ◽  
pp. 1-5
Author(s):  
Filip Benko ◽  
Patrik Hrnčiar ◽  
Norbert Lukáč ◽  
Róbert Kirchner ◽  
Eva Tvrdá
Keyword(s):  
Positive Impact ◽  
Endocrine System ◽  
Testicular Tissue ◽  
Endocrine Function ◽  
Enzyme Linked Immunosorbent Assay ◽  
Beneficial Effects ◽  
Wide Range ◽  
Male Hormones ◽  
The Impact

Summary Compounds of natural origin are often used for their beneficial effects on the male endocrine system and the synthesis of steroid biomolecules in testicular tissue. One of such compounds is quercetin (QUE), which belongs to the flavonoid family and is found in a wide range of vegetables, fruits and plant products. The purpose of this study is to evaluate the impact of QUE on the endocrine function of rat testicular fragments under in vitro conditions. Testicular fragments from adult Wistar rats (n=9), cultured in the D-MEM medium with different concentrations of QUE (namely 1, 10 and 100 µmol/L) for 24 h at 37°C (5% CO2), were used in the experiment conducted. Following culture, the medium was separated and the levels of cholesterol (CHOL) and male hormones were measured. CHOL values were quantified spectrophotometrically, whereas the concentrations of androstenedione (ANDRO), dehydropeiandrosterone (DHEA) and testosterone (TEST) were quantified using the enzyme-linked immunosorbent assay (ELISA) commercial kit. The results obtained indicate that 10 µmol/L QUE significantly increased (P<0.001; P<0.05) the concentrations of all the steroid biomolecules considered (CHOL, ANDRO, DHEA and TEST) when compared to the control samples. Accordingly, our findings confirm the positive impact of QUE on the endocrine function and steroidogenesis of rat testicular tissue under in vitro conditions.

Sensitive, colorimetric enzyme amplification cascade for determination of alkaline phosphatase and application of the method to an immunoassay of thyrotropin

1991 ◽  
Vol 37 (9) ◽  
pp. 1513-1518 ◽  
Author(s):  
D M Obzansky ◽  
B R Rabin ◽  
D M Simons ◽  
S Y Tseng ◽  
D M Severino ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Colorimetric Detection ◽  
High Sensitivity ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Highly Sensitive ◽  
Wide Range ◽  
Colored Product ◽  
Enzyme Amplification ◽  
Amplification Cascade

Abstract A highly sensitive flavin adenine dinucleotide-3'-phosphate (FADP)-based enzyme amplification cascade has been developed for determining alkaline phosphatase (ALP; EC 3.1.3.1). The cascade detects ALP via the dephosphorylation of the novel substrate FADP to produce the cofactor FAD, which binds stoichiometrically to inactive apo D-amino acid oxidase (D-AAO). The resulting active holo D-AAO oxidizes D-proline to produce hydrogen peroxide, which is quantified by the horseradish peroxidase-mediated conversion of 3,5-dichloro-2-hydroxybenzenesulfonic acid and 4-aminoantipyrine to a colored product. The FADP-based enzyme amplification cascade has been used in a novel releasable linker immunoassay (RELIA) to quantify thyrotropin (TSH). In the assay, TSH is first captured onto antibody-coated chromium dioxide particles. After formation of an antibody-TSH sandwich with a dethiobiotinylated second antibody, the complex is reacted with a streptavidin-ALP conjugate. Biotin is then used to release the conjugate into solution, and ALP is quantified in an automated version of the FADP-based amplification cascade on the aca discrete clinical analyzer (Du Pont). The sensitivity of the colorimetric RELIA assay for TSH (less than 0.1 milli-int. unit/L) is comparable with that of fluorometric assays. This technology provides a way to adapt to the aca high-sensitivity immunoassays for a wide range of analytes via colorimetric detection.

scholarly journals The Drug Developments of Hydrogen Sulfide on Cardiovascular Disease

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Ya-Dan Wen ◽  
Hong Wang ◽  
Yi-Zhun Zhu
Keyword(s):  
Cardiovascular Disease ◽  
Hydrogen Sulfide ◽  
Molecular Mechanisms ◽  
Pathological Process ◽  
The Other ◽  
Acid Oxidase ◽  
Organosulfur Compounds ◽  
Amino Acid Oxidase ◽  
Mercaptopyruvate Sulfurtransferase ◽  
The One

The recognition of hydrogen sulfide (H2S) has been evolved from a toxic gas to a physiological mediator, exhibiting properties similar to NO and CO. On the one hand, H2S is produced from L-cysteine by enzymes of cystathionineγ-lyase (CSE) and cystathionineβ-synthase (CBS), 3-mercaptopyruvate sulfurtransferase (3MST) in combination with aspartate aminotransferase (AAT) (also called as cysteine aminotransferase, CAT); on the other hand, H2S is produced from D-cysteine by enzymes of D-amino acid oxidase (DAO). Besides sulfide salt, several sulfide-releasing compounds have been synthesized, including organosulfur compounds, Lawesson’s reagent and analogs, and plant-derived natural products. Based on garlic extractions, we synthesized S-propargyl-L-cysteine (SPRC) and its analogs to contribute our endeavors on drug development of sulfide-containing compounds. A multitude of evidences has presented H2S is widely involved in the roles of physiological and pathological process, including hypertension, atherosclerosis, angiogenesis, and myocardial infarcts. This review summarizes current sulfide compounds, available H2S measurements, and potential molecular mechanisms involved in cardioprotections to help researchers develop further applications and therapeutically drugs.

Evidence that d-cysteine protects mice from gastric damage via hydrogen sulfide produced by d-amino acid oxidase

Nitric Oxide ◽  
2017 ◽  
Vol 64 ◽  
pp. 1-6 ◽  
Author(s):  
Luan Kelves M. Souza ◽  
Thiago S.L. Araújo ◽  
Nayara A. Sousa ◽  
Francisca Beatriz M. Sousa ◽  
Kerolayne M. Nogueira ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Amino Acid ◽  
Gastric Damage ◽  
Acid Oxidase ◽  
Amino Acid Oxidase

scholarly journals Crystallization and preliminary X-ray diffraction analysis of anL-amino-acid oxidase fromBothrops jararacussuvenom

2012 ◽  
Vol 68 (2) ◽  
pp. 211-213 ◽  
Author(s):  
Anwar Ullah ◽  
Monika Coronado ◽  
Mário T. Murakami ◽  
Christian Betzel ◽  
Raghuvir K. Arni
Keyword(s):  
Amino Acid ◽  
Acid Oxidase ◽  
X Ray Diffraction ◽  
Structural Determinants ◽  
Amino Acid Oxidase ◽  
Pharmacological Activities ◽  
X Ray ◽  
Cell Parameters ◽  
Wide Range ◽  
Systematic Effects

Snake-venom L-amino-acid oxidases (SV-LAAOs) trigger a wide range of local and systematic effects, including inhibition of platelet aggregation, cytotoxicity, haemolysis, apoptosis and haemorrhage. These effects mainly arise from the uncontrolled release of the hydrogen peroxide that is produced by the redox reaction involving L-amino acids catalyzed by these flavoenzymes. Taking their clinical relevance into account, few SV-LAAOs have been structurally characterized and the structural determinants responsible for their broad direct and indirect pharmacological activities remain unclear. In this work, an LAAO fromBothrops jararacussuvenom (BJu-LAAO) was purified and crystallized. The BJu-LAAO crystals belonged to space groupP21, with unit-cell parametersa = 66.38,b= 72.19,c= 101.53 Å, β = 90.9°. The asymmetric unit contained two molecules and the structure was determined and partially refined at 3.0 Å resolution.

scholarly journals The importance of environmental exposure on selected xenoestrogens in the pathogenesis of breast cancer

2020 ◽  
Vol 74 ◽  
pp. 155-170
Author(s):  
Ewa Sawicka ◽  
Kamila Boszkiewicz ◽  
Martyna Wolniak ◽  
Agnieszka Piwowar
Keyword(s):  
Breast Cancer ◽  
Human Body ◽  
Human Life ◽  
Endocrine System ◽  
The Body ◽  
Human Environment ◽  
Female Sex Hormones ◽  
Wide Range ◽  
Mammary Gland Cancer ◽  
Exogenous Compounds

Breast cancer is one of the most common types of cancer observed in women, and in its pathogenesis, in addition to endogenous estrogens, a significant role is played by xenoestrogens, which are present in the human life environment. It is a large group of exogenous compounds of diverse structure, not produced in the human body, which imitate the action of female sex hormones, especially estrogens, and in consequence affect the hormonal balance of the body. Despite the diverse structure, their common feature is the ability to interact with estrogen receptors. In this way they change the functioning of the endocrine system and, consequently, they can induce negative changes in the human body and effects on the health of both the parental generation and its offspring. Some xenoestrogens may cause tumor growth by stimulating cell proliferation, angiogenesis and metastasis. So far, such properties have been found for organic compounds, but also for some metal ions, referred to as metalloestrogens. For this reason, it is extremely important to know the sources of the presence and mechanisms of xenoestrogens in the pathogenesis of mammary gland cancer. The presented paper discusses the role of selected xenoestrogens, such as: bisphenol A, phthalates, parabens or cadmium, as a metalloestrogen. A wide range of xenoestrogens has been selected for the compounds given above, due to their importance in the pathogenesis of breast cancer and their widespread presence in the human environment, as well as to draw attention to the still-present problem of possible chronic environmental or occupational exposure of humans. The paper also explores the problem of the effect of xenoestrogens on the efficacy of breast cancer treatment, presenting possible xenoestrogen-drug interactions. It also explains how xenoestrogens present in foods (phytoestrogens) can affect the effectiveness of pharmacotherapy of breast cancer.

Purification and Characterization of Lupus Anticoagulant Like Protein from Agkistrodon Halys Brevicaudus Venom

1996 ◽  
Vol 76 (06) ◽  
pp. 0993-0997
Author(s):  
Zhao-Yan Li ◽  
Xiao-Wei Wu ◽  
Tie-Fu Yu ◽  
Eric C-Y Lian
Keyword(s):  
Amino Acid ◽  
Lupus Anticoagulant ◽  
Inhibitory Effect ◽  
Clotting Factor ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Sds Page ◽  
The Individual ◽  
Reducing Condition

SummaryBy means of CM-Sephadex C-25, DEAE-Sephadex A-50, Sephadex G-200, and Sephadex G-75 chromatographies, a lupus anticoagulant like protein (LALP) from Agkistrodon halys brevicaudus was purified. On SDS-PAGE, the purified LALP had a molecular weight of 25,500 daltons under non-reducing condition and 15,000 daltons under reducing condition. The isoelectric point was pH 5.6. Its N terminal amino acid sequencing revealed a mixture of 2 sequences: DCP(P/S)(D/G)WSSYEGH(C/R)Q(Q/K). It was devoid of phospho-lipaseA, fibrino(geno)lytic, 5′-nucleotidase, L-amino acid oxidase, phosphomonoesterase, phosphodiesterase and thrombin-like activities, which were found in crude venom. In the presence of LALP, PT, aPTT, and dRVVT of human plasma were markedly prolonged and its effects were concentration-dependent but time-independent. The inhibitory effect of LALP on the plasma clotting time was enhanced by decreasing phospholipid concentration in TTI test. The individual clotting factor activity was not affected by LALP when higher dilutions of LALP-plasma mixture were used for assay. Russell’s viper venom time was shortened when high phospholipid confirmatory reagent was used. Therefore, the protein has lupus anticoagulant property.

Impairment of Platelet Aggregation by Echis colorata Venom Mediated by L-Amino Acid Oxidase or H2O2

1982 ◽  
Vol 48 (03) ◽  
pp. 277-282 ◽  
Author(s):  
I Nathan ◽  
A Dvilansky ◽  
T Yirmiyahu ◽  
M Aharon ◽  
A Livne
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Platelet Aggregation ◽  
Snake Venom ◽  
Oxidase Activity ◽  
Enzyme Preparation ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Hemostatic Disorders

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.

Transcending Time and Space with Digital Emotional Support

2020 ◽  
Author(s):  
Tyler Colasante ◽  
Lauren Lin ◽  
Kalee DeFrance ◽  
Tom Hollenstein
Keyword(s):  
Emotional Support ◽  
Negative Emotion ◽  
Negative Emotions ◽  
Good News ◽  
Social Avoidance ◽  
Time And Space ◽  
Beneficial Effects ◽  
Digital Devices ◽  
Wide Range ◽  
Socially Isolated

In the current digital age, emotional support is increasingly received through digital devices. However, virtually all studies assessing the benefits of emotional support have focused on in-person support. Using an experience sampling methodology, we assessed participants’ negative emotions, digital and in-person support for those emotions, and success in regulating them three times per day for 14 days, thus covering a wide range of digital support scenarios (N = 164 participants with 6,530 collective measurement occasions). We also considered whether participants were alone versus with others at the time of their negative emotion and higher versus lower in social avoidance as plausible moderators of when digital support was utilized and effective. We expected more pronounced use and efficacy of digital support when participants were alone and higher in trait social avoidance. However, digital support was used and perceived as effective for regulating negative emotions regardless of these factors and its beneficial effects were on par with those of traditional in-person support. The unique benefits of digital support may not be restricted to socially isolated or socially avoidant users. These findings are timely given the widespread anxiety and isolation under the current COVID-19 pandemic. If transcending time and space with digital emotional support is the new norm, the good news is that it seems to be working.

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