scholarly journals Rapid Biodegradation of the Organophosphorus Insecticide Chlorpyrifos by Cupriavidus nantongensis X1T

2019 ◽  
Vol 16 (23) ◽  
pp. 4593 ◽  
Author(s):  
Shi ◽  
Fang ◽  
Qin ◽  
Chen ◽  
Wu ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Aquatic Organisms ◽  
Organophosphorus Hydrolase ◽  
Organophosphorus Insecticides ◽  
Ph Values ◽  
Qpcr Analysis ◽  
Wide Range ◽  
Degradation Activity ◽  
High Concentrations

Chlorpyrifos was one of the most widely used organophosphorus insecticides and the neurotoxicity and genotoxicity of chlorpyrifos to mammals, aquatic organisms and other non-target organisms have caused much public concern. Cupriavidus nantongensis X1T, a type of strain of the genus Cupriavidus, is capable of efficiently degrading 200 mg/L of chlorpyrifos within 48 h. This is ~100 fold faster than Enterobacter B-14, a well-studied chlorpyrifos-degrading bacterial strain. Strain X1T can tolerate high concentrations (500 mg/L) of chlorpyrifos over a wide range of temperatures (30–42 °C) and pH values (5–9). RT-qPCR analysis showed that the organophosphorus hydrolase (OpdB) in strain X1T was an inducible enzyme, and the crude enzyme isolated in vitro could still maintain 75% degradation activity. Strain X1T can simultaneously degrade chlorpyrifos and its main hydrolysate 3,5,6-trichloro-2-pyridinol. TCP could be further metabolized through stepwise oxidative dechlorination and further opening of the benzene ring to be completely degraded by the tricarboxylic acid cycle. The results provide a potential means for the remediation of chlorpyrifos- contaminated soil and water.

Application of the EYTEX™ System to the Evaluation of Cosmetic Products and their Ingredients

1992 ◽  
Vol 20 (1) ◽  
pp. 146-163
Author(s):  
Francis H. Kruszewski ◽  
Laura H. Hearn ◽  
Kyle T. Smith ◽  
Janice J. Teal ◽  
Virginia C. Gordon ◽  
...  
Keyword(s):  
Double Blind ◽  
Eye Irritation ◽  
Ocular Irritation ◽  
Rabbit Eye ◽  
Wide Range ◽  
High Concentrations ◽  
Alkaline Membrane ◽  
Positive Agreement

465 cosmetic product formulations and raw ingredients were evaluated with the EYTEX™ system to determine the potential of this in vitro alternative for identifying eye irritation potential. The EYTEX™ system is a non-animal, biochemical procedure developed by Ropak Laboratories, Irvine, CA, that was designed to approximate the Draize rabbit eye irritation assay for the evaluation of ocular irritation. Avon Products Inc. provided all the test samples, which included over 30 different product types and represented a wide range of eye irritancy. All the EYTEX™ protocols available at the time of this study were used. Samples were evaluated double-blind with both the membrane partition assay (MPA) and the rapid membrane assay (RMA). When appropriate, the standard assay (STD) and the alkaline membrane assay (AMA) were used, as well as specific, documented protocol modifications. EYTEX™ results were correlated with rabbit eye irritation data which was obtained from the historical records of Avon Products Inc. A positive agreement of EYTEX™ results with the in vivo assay was demonstrated by an overall concordance of 80%. The assay error was 20%, of which 18% was due to an overestimation of sample irritancy (false positives) and 2% was attributed to underestimation (false negatives). Overestimation error in this study was due in part to the inability of the protocols to accurately classify test samples with very low irritation potential. Underestimation of sample irritancy was generally associated with ethoxylated materials and high concentrations of specific types of surfactants. 100% sensitivity and 85% predictability were described by the data, indicating the efficiency of EYTEX™ in identifying known irritants. A specificity rate of 39% showed the EYTEX™ assay to be weak in discerning non-irritants. However, the EYTEX™ protocols used in this study were not designed to identify non-irritants. A compatibility rate of 99% proved the effectiveness of the EYTEX™ assay in accommodating a diversity of product types. The EYTEX™ system protocols, when used appropriately, can provide a conservative means of assessing the irritant potential of most cosmetic formulations and their ingredients.

scholarly journals In Vitro Incorporation of Helicobacter pylori into Candida albicans Caused by Acidic pH Stress

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 489 ◽  
Author(s):  
Kimberly Sánchez-Alonzo ◽  
Cristian Parra-Sepúlveda ◽  
Samuel Vega ◽  
Humberto Bernasconi ◽  
Víctor L. Campos ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Candida Albicans ◽  
Pcr Amplification ◽  
Growth Curves ◽  
Acidic Ph ◽  
Ph Values ◽  
16S Gene ◽  
Wide Range ◽  
H Pylori

Yeasts can adapt to a wide range of pH fluctuations (2 to 10), while Helicobacter pylori, a facultative intracellular bacterium, can adapt to a range from pH 6 to 8. This work analyzed if H. pylori J99 can protect itself from acidic pH by entering into Candida albicans ATCC 90028. Growth curves were determined for H. pylori and C. albicans at pH 3, 4, and 7. Both microorganisms were co-incubated at the same pH values, and the presence of intra-yeast bacteria was evaluated. Intra-yeast bacteria-like bodies were detected using wet mounting, and intra-yeast binding of anti-H. pylori antibodies was detected using immunofluorescence. The presence of the H. pylori rDNA 16S gene in total DNA from yeasts was demonstrated after PCR amplification. H. pylori showed larger death percentages at pH 3 and 4 than at pH 7. On the contrary, the viability of the yeast was not affected by any of the pHs evaluated. H. pylori entered into C. albicans at all the pH values assayed but to a greater extent at unfavorable pH values (pH 3 or 4, p = 0.014 and p = 0.001, respectively). In conclusion, it is possible to suggest that H. pylori can shelter itself within C. albicans under unfavorable pH conditions.

Prostacyclin and cerebral vessel relaxation

1982 ◽  
Vol 57 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Kamal S. Paul ◽  
Eric T. Whalley ◽  
Christine Forster ◽  
Richard Lye ◽  
John Dutton
Keyword(s):  
Angiotensin Ii ◽  
Arterial Spasm ◽  
Cerebral Vessel ◽  
Content Type ◽  
Wide Range ◽  
Potent Vasodilator ◽  
Dose Dependent Fashion ◽  
Basilar Arteries ◽  
High Concentrations

✓ The authors have studied the ability of prostacyclin to reverse contractions of human basilar arteries in vitro that were induced by a wide range of substances implicated in the etiology of cerebral arterial spasm. Prostacyclin (10−10 to 10−6M) caused a dose-related reversal of contractions induced by 5-hydroxytryptamine, noradrenaline, angiotensin II, prostaglandin (PG)F2α, and U-46619 (a thromboxane-A2 mimetic). These agents were tested at concentrations or volumes that produced almost maximum or maximum responses and those that produced approximately 50% of the maximum response. Contractions induced by maximum concentrations of angiotensin II and U-46619 were least affected by prostacyclin. In addition, contractions induced by thromboxane-A2 generated from guinea-pig lung were reversed in a dose-dependent fashion by prostacyclin. This ability of prostacyclin to physiologically antagonize contractions of the human basilar artery in vitro induced by high concentrations of various spasmogenic agents suggests that such a potent vasodilator agent or more stable analogue may be of value in the treatment of such disorders as cerebral arterial spasm following subarachnoid hemorrhage.

Effects of polymethoxylated flavone metabolites on apoB100 secretion and MTP activity in Huh7.5 cells

2021 ◽  
Vol 18 ◽  
Author(s):  
Danielle R. Gonçalves ◽  
Thais B. Cesar ◽  
John A. Manthey ◽  
Paulo I. Costa
Keyword(s):  
Lipid Synthesis ◽  
Dependent Manner ◽  
Transfer Protein ◽  
Low Concentrations ◽  
Wide Range ◽  
Cell Assays ◽  
Polymethoxylated Flavones ◽  
High Concentrations

Background: Citrus polymethoxylated flavones (PMFs) reduce the synthesis of liver lipoproteins in animal and in vitro cell assays, but few studies have evaluated the direct effects of their metabolites on this highly regulated process. Objective: To investigate the effects of representative metabolites of PMF on the secretion of liver lipoproteins using the mammalian cell Huh7.5. Method: In this study, the influences of three PMFs and five previously isolated PMF metabolites on hepatic apoB-100 secretion and microsomal transfer protein (MTP) activity were evaluated. Tangeretin (TAN), nobiletin (NOB) and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), and their glucuronides (TAN-Gluc, NOB-Gluc and HMF-Gluc) and oxidatively demethylated metabolites (TAN-OH, NOB-OH, HMF-OH) were incubated with Huh7.5 cells to measure their inhibitory effects on lipid synthesis. Results: The results showed that TAN, HMF and TAN-OH reduced the secretion of apoB-100 in a dose-dependent manner, while NOB and the other tested metabolites showed no inhibition. MTP activity in the Huh7.5 cells was significantly reduced in the presence of low concentrations of TAN, and in high concentrations of NOB-OH. This study also showed that PMFs and PMF metabolites produced a wide range of effects on apoB-100 secretion and MTP activity. Conclusion: The results suggest that while PMFs and their metabolites control dyslipidemia in vivo, the inhibition of MTP activity cannot be the only pathway influenced by these compounds.

scholarly journals Antibacterial and Antifungal Properties of Composite Polyethylene Materials Reinforced with Neem and Turmeric

2020 ◽  
Author(s):  
Thefye Sunthar ◽  
Elia Marin ◽  
Francesco Boschetto ◽  
Matteo Zanocco ◽  
Hirofumi Sunahara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Food Packaging ◽  
Spectroscopic Characterization ◽  
Fungal Colonization ◽  
Green Technologies ◽  
Reinforcing Particles ◽  
Wide Range ◽  
High Concentrations ◽  
Antibacterial And Antifungal

With the increased scientific interest in green technologies, many researches have been focused on the production of polymeric composites containing naturally occurring reinforcing particles. Apart from increasing mechanical properties, these additions can have a wide range of interesting effects, such as increasing the resistance to bacterial and fungal colonization. In this work, different amounts of two different natural products, namely neem and turmeric, have been added to polyethylene to act as a natural antibacterial and antifungal product for food packaging applications. Microscopic and spectroscopic characterization showed that fractions up to 5% of these products can be dispersed into low-molecular weight polyethylene, while higher amounts could not be properly dispersed and resulted in an inhomogeneous, fragile composite. In vitro testing conducted with Escherichia coli, Staphylococcus aureus and Candida albicans showed a reduced proliferation of pathogens when compared to the polyethylene references. In particular, turmeric, resulted to be more effective against E. coli when compared to neem, while they had similar performances against S. aureus. Against C. albicans, only neem was able to show a good antifungal behavior, at high concentrations. Tensile testing showed that the addition of reinforcing particles reduces the mechanical properties of polyethylene, and, in the case of turmeric, it is further reduced by UV irradiation.

A bioassay for systemic fungicides using axenic cultures of the carnation rust fungus, Uromyces dianthi

1973 ◽  
Vol 51 (10) ◽  
pp. 2004-2006 ◽  
Author(s):  
D. R. Jones
Keyword(s):  
Inhibitory Action ◽  
Agar Medium ◽  
Rust Fungus ◽  
Screening Programs ◽  
Systemic Fungicides ◽  
Low Concentrations ◽  
Wide Range ◽  
Axenic Cultures ◽  
High Concentrations

The inhibitory action of three systemic fungicides (Benlate, Hoe 6053, and Milstem) on the growth of axenic cultures of the carnation rust fungus, Uromyces dianthi, was assessed. The rust- and smut-specific fungicide (Hoe 6053) was found to inhibit growth when present in the agar medium in very low concentrations, while moderate concentrations of the wide range fungicide (Benlate), and high concentrations of the powdery mildew-specific fungicide (Milstem) were needed for inhibition. The results indicated the possible use of U. dianthi in future in vitro fungicide screening programs and mode-of-action studies.

Myotropic actions of angiotensin and noradrenaline in strips of rabbit aortae

1977 ◽  
Vol 55 (5) ◽  
pp. 1056-1069 ◽  
Author(s):  
J. St-Louis ◽  
D. Regoli ◽  
J. Barabé ◽  
W. K. Park
Keyword(s):  
Late Phase ◽  
Active Form ◽  
Rabbit Aorta ◽  
Residual Effects ◽  
Receptor Interaction ◽  
Wide Range ◽  
High Concentrations ◽  
Drug Receptor ◽  
Time Required

The myotropic effects of angiotensin II (ATII), some analogues and fragments of ATII, and noradrenaline (NA) have been studied in rabbit aorta strips, in vitro. Contractions elicited by NA consist of an initial rapid and of a slow late phase, while ATII produces a slow and gradual increase of tension, especially at low concentrations. A good correlation has been shown to exist between the time required to increase tension by 50% and the concentration of ATII or the pD2 values of various angiotensins. These results suggest that the pattern of the contractions produced by NA and ATII is influenced by the different diffusion rates of the two agents. Aortic strips contracted by NA maintain a stable plateau of contraction for more than 20 min, while tension in those stimulated by maximal concentrations of ATII fades. This fade persists in the presence of indomethacin, of high concentrations of extracellular Ca2+, and does not depend on the metabolism of the peptide.Extracellular Ca2+ plays an important role in the stimulation or rabbit aorta strips by ATII and NA, but does not effect the binding of ATII to its specific receptors over a wide range of concentrations, and reduces slightly the binding of NA. The ratio of maximum response (ATII–NA) is influenced by external Ca2+ and corresponds to 0.54 in the presence of low Ca2+ (0.01 mM), and to 0.86 in the presence of 2.5 mM Ca2+. Both agonists maintain a fraction of their myotropic effect in tissues exposed to Ca2+-free medium for short periods (10−20 min) but are almost inactive after 60 min of Ca2+ deprivation. It is concluded that a fraction of the myotropic effect of both NA and ATII is independent of external Ca2+. Readdition of Ca2+ (1.5 mM) at the peak of the residual effects obtained in absence of Ca2+ restores full control response to both agents. When the same intervention is repeated at different times after washout of the drug only the strips treated with ATII show a progressively decreasing contractile response. This indicates that ATII remains in the active form in the proximity of the receptors for several minutes after washing, while NA does not.The administration of the antagonists (8-Gly-ATII for ATII and phentolamine for NA) or the removal of external Ca2+ while maintaining the infusion of the two stimulants is followed by relaxations more rapid than that produced by the washout of ATII, but not of NA. A good correlation has been shown to exist between the rates of the relaxations induced by 8-Gly-ATII and the pD2 values of various angiotensins.The results suggest that the major difference between the actions of ATII and NA in rabbit aortae resides in the duration of the drug−receptor interaction. The drug−receptor complex of the peptide appears to be more stable than that of the catecholamine and this may explain the higher (with respect to NA) affinity of ATII for its aortic receptors.

The in vitro effect of commercially available noble metal nanocolloids on the rainbow trout (Oncorhynchus mykiss) leukocyte and splenocyte activity

2013 ◽  
Vol 16 (1) ◽  
pp. 77-84 ◽  
Author(s):  
J. Małaczewska ◽  
A.K. Siwicki
Keyword(s):  
Rainbow Trout ◽  
Aquatic Organisms ◽  
Respiratory Burst Activity ◽  
The Past ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Low Concentrations ◽  
High Concentrations ◽  
Vitro Effect ◽  
Silver Nanocolloid

Abstract The growing popularity of nanotechnology in the past decade has increased nanomaterial concentrations in the environment and the risk of their toxicity for aquatic organisms. Metal nanoparticles, which are easily absorbed and accumulated by fish, are probably able to interact directly with their immunocompetent cells. The objective of this study was to evaluate the in vitro effect of commercially available silver, gold and copper nanocolloids on the rainbow trout leukocyte and splenocyte activity. At high concentrations, all of the nanocolloids studied had adverse effects on the proliferative response of trout lymphocytes, and the most toxic of them, silver, decreased also the respiratory burst activity of splenocytes. Low concentrations of silver nanocolloid, however, had a stimulating effect on the lymhocyte proliferation.

Ethosomes for Dermal Administration of Natural Active Molecules

2019 ◽  
Vol 25 (21) ◽  
pp. 2338-2348 ◽  
Author(s):  
Hiba Natsheh ◽  
Elisa Vettorato ◽  
Elka Touitou
Keyword(s):  
Fungal Infections ◽  
Acne Vulgaris ◽  
Skin Inflammation ◽  
Wide Range ◽  
High Concentrations ◽  
Main Components ◽  
Dermal Administration ◽  
Fluid Bilayers

: Ethosomes are nanovesicular carriers for dermal administration. Phospholipids, ethanol at relatively high concentrations (up to 50%) and water are their main components. Ethosomes are what we call “soft vesicles” with fluid bilayers due to the presence of ethanol. The composition and structure of the vesicles augment their ability to entrap molecules with various physicochemical properties and deliver them to the deep strata of skin. Since their first design, ethosomal systems have been extensively investigated for a wide range of applications. : This review focuses on work carried out in vitro, in vivo in animal models and in humans in clinical studies, with ethosomal formulations containing natural active molecules for the treatment of skin disorders. Skin bacterial and fungal infections, skin inflammation, acne vulgaris, arthritis, and skin cancer are examples of disorders managed successfully by ethosomal systems. Furthermore, Ethosomes loaded with a number of naturally occurring compounds for cosmetic applications are also reported. The efficient treatments together with a good safety profile and lack of toxicity or irritation paved the way towards the development of new dermal therapies.

scholarly journals Development of a LC-MS/MS Method for the Simultaneous Detection of Tricarboxylic Acid Cycle Intermediates in a Range of Biological Matrices

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Omar Al Kadhi ◽  
Antonietta Melchini ◽  
Richard Mithen ◽  
Shikha Saha
Keyword(s):  
Ex Vivo ◽  
Tricarboxylic Acid Cycle ◽  
Simultaneous Detection ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
In Vivo Studies ◽  
Biological Matrices ◽  
Wide Range ◽  
Tca Cycle Intermediates

It is now well-established that perturbations in the tricarboxylic acid (TCA) cycle play an important role in the metabolic transformation occurring in cancer including that of the prostate. A method for simultaneous qualitative and quantitative analysis of TCA cycle intermediates in body fluids, tissues, and cultured cell lines of human origin was developed using a common C18 reversed-phase column by LC-MS/MS technique. This LC-MS/MS method for profiling TCA cycle intermediates offers significant advantages including simple and fast preparation of a wide range of human biological samples. The analytical method was validated according to the guideline of the Royal Society of Chemistry Analytical Methods Committee. The limits of detection were below 60 nM for most of the TCA intermediates with the exception of lactic and fumaric acids. The calibration curves of all TCA analytes showed linearity with correlation coefficientsr2>0.9998. Recoveries were >95% for all TCA analytes. This method was established taking into consideration problems and limitations of existing techniques. We envisage that its application to different biological matrices will facilitate deeper understanding of the metabolic changes in the TCA cycle from in vitro, ex vivo, and in vivo studies.

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