scholarly journals Transmission to Eels, Portals of Entry, and Putative Reservoirs of Vibrio vulnificus Serovar E (Biotype 2)

2001 ◽  
Vol 67 (10) ◽  
pp. 4717-4725 ◽  
Author(s):  
Ester Marco-Noales ◽  
Miguel Milán ◽  
Belén Fouz ◽  
Eva Sanjuán ◽  
Carmen Amaro
Keyword(s):  
Disease Transmission ◽  
Field Experiments ◽  
Vibrio Vulnificus ◽  
Skin Surface ◽  
Etiologic Agent ◽  
In Vitro Assays ◽  
First Time ◽  
Natural Outbreak ◽  
Tank Water

ABSTRACT Vibrio vulnificus serovar E (formerly biotype 2) is the etiologic agent that is responsible for the main infectious disease affecting farmed eels. Although the pathogen can theoretically use water as a vehicle for disease transmission, it has not been isolated from tank water during epizootics to date. In this work, the mode of transmission of the disease to healthy eels, the portals of entry of the pathogen into fish, and their putative reservoirs have been investigated by means of laboratory and field experiments. Results of the experiments of direct and indirect host-to-host transmission, patch contact challenges, and oral-anal intubations suggest that water is the prime vehicle for disease transmission and that gills are the main portals of entry into the eel body. The pathogen mixed with food can also come into the fish through the gastrointestinal tract and develop the disease. These conclusions were supported by field data obtained during a natural outbreak in which we were able to isolate this microorganism from tank water for the first time. The examination of some survivors from experimental infections by indirect immunofluorescence and scanning electron microscopy showed thatV. vulnificus serovar E formed a biofilm-like structure on the eel skin surface. In vitro assays demonstrated that the ability of the pathogen to colonize both hydrophilic and hydrophobic surfaces was inhibited by glucose. The capacity to form biofilms on eel surface could constitute a strategy for surviving between epizootics or outbreaks, and coated survivors could act as reservoirs for the disease.

scholarly journals Pharmacologic Activities¬ of 3’-Hydroxypterostilbene: Cytotoxic, Anti-Oxidant, Anti-Adipogenic, Anti-Inflammatory, Histone Deacetylase and Sirtuin 1 Inhibitory Activity

2015 ◽  
Vol 18 (4) ◽  
pp. 713 ◽  
Author(s):  
Jody K Takemoto ◽  
Connie M. Remsberg ◽  
Neal M. Davies
Keyword(s):  
Histone Deacetylase ◽  
Inhibitory Activity ◽  
Sirtuin 1 ◽  
In Vitro Assays ◽  
Naturally Occurring ◽  
Anti Oxidant ◽  
Anti Inflammatory ◽  
First Time ◽  
Stilbene Compounds

Purpose: Delineate the selected pharmacodynamics of a naturally occurring stilbene 3’-Hydroxypterostilbene. Objective: Characterize for the first time the pharmacodynamics bioactivity in several in-vitro assays with relevant roles in heart disease, inflammation, cancer, and diabetes etiology and pathophysiology. Methods: 3’-Hydroxypterostilbene was studied in in-vitro assays to identify possible bioactivity. Results: 3’-Hydroxypterostilbene demonstrated anti-oxidant, anti-inflammatory, cytotoxic, anti-adipogenic, histone deacetylase, and sirtuin-1 inhibitory activity. Conclusions: The importance of understanding individual stilbene pharmacologic activities were delineated.  Small changes in chemical structure of stilbene compounds result in significant pharmacodynamic differences. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Relationship Between Fungicide Sensitivity and Control of Gummy Stem Blight of Watermelon Under Field Conditions

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1780-1784 ◽  
Author(s):  
A. Thomas ◽  
D. B. Langston ◽  
H. F. Sanders ◽  
K. L. Stevenson
Keyword(s):  
Fungicide Resistance ◽  
Field Experiments ◽  
In Vitro Assays ◽  
Didymella Bryoniae ◽  
Fungicide Sensitivity ◽  
Thiophanate Methyl ◽  
Stem Blight ◽  
Gummy Stem Blight ◽  
And Control

Gummy stem blight (GSB), caused by the fungus Didymella bryoniae, is the most destructive disease of watermelon and is managed primarily with fungicides. D. bryoniae has developed resistance to many fungicides that were once very effective, including azoxystrobin, boscalid, and thiophanate-methyl. Field experiments were conducted in Tifton (TN) and Reidsville (RV), GA in 2009 and 2010 to establish a relationship between frequency of resistance to a fungicide based on in vitro assays and its efficacy in the management of GSB. Frequency of resistance to boscalid, thiophanate-methyl, and azoxystrobin was >0.80 in isolates collected from nontreated plots in both locations and years. All isolates collected after six applications of boscalid, thiophanate-methyl, or azoxystrobin were resistant to the respective fungicide. All isolates collected from treated and nontreated plots were sensitive to tebuconazole and difenoconazole. GSB severity was assessed on a weekly basis from 63 days after planting. GSB severity in plots treated with boscalid, thiophanate-methyl, or azoxystrobin was not significantly different from that in the nontreated plots (39%, TN-2009; 45%, TN-2010; and 16%, RV-2010). GSB severity in tebuconazole-treated plots (27%, TN-2009; 14%, TN-2010; and 4%, RV-2010) was significantly lower than all other treatments and the nontreated control. There was a consistent negative association between frequency of fungicide resistance and disease control in the field. Thus, knowledge of the frequency of fungicide resistance in the pathogen population will be helpful in selecting the most effective fungicides for the management of GSB in watermelon fields.

scholarly journals Mangiferin Rich Products from Aphloia theiformis (Vahl) Benn Leaves: Extraction, Fractionation, Phytochemical Characterization, and Antioxidant Properties

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2081
Author(s):  
Dovilė Grauzdytė ◽  
Audrius Pukalskas ◽  
Chaker El Kalamouni ◽  
Petras Rimantas Venskutonis
Keyword(s):  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Natural Antioxidants ◽  
Liquid Extraction ◽  
In Vitro Assays ◽  
Synthetic Antioxidant ◽  
Liquid Liquid Extraction ◽  
Extraction Solvents ◽  
First Time

Aphloia theiformis is traditionally used in Mauritius, Madagascar, and Reunion Island for treating several diseases. In this study, various extraction solvents and schemes were applied for the recovery of antioxidant rich fractions from the leaves of A. theiformis. The products were evaluated for their antioxidant capacity using well known in vitro assays. Major compounds were characterized by UPLC–QTOF–MS. Hydrophilic extracts of A. theiformis demonstrated strong antioxidant properties, which are comparable with the synthetic antioxidant Trolox. UPLC analysis confirmed mangiferin as the main secondary metabolite of A. theiformis. Tormentic and hydroxytormentic acids as well as their isomers were also abundant in A. theiformis extracts and fractions, while their amounts were determined for the first time. The most potential extract was further separated into the fractions by liquid-liquid extraction and by precipitation at low temperature. Antioxidant capacity and composition of secondary metabolites of derived fractions were determined. Some of the fractions possessed remarkable antioxidant capacity, comparable to pure mangiferin. The results obtained reveal high potential of A. theiformis for recovery of natural antioxidants and other bioactive phytochemicals, particularly mangiferin.

scholarly journals Synergistic AML Cell Death Induction by Marine Cytotoxin (+)-1(R), 6(S), 1’(R), 6’(S), 11(R), 17(S)-Fistularin-3 and Bcl-2 Inhibitor Venetoclax

Marine Drugs ◽  
2018 ◽  
Vol 16 (12) ◽  
pp. 518 ◽  
Author(s):  
Cristina Florean ◽  
Kyung Kim ◽  
Michael Schnekenburger ◽  
Hyun-Jung Kim ◽  
Céline Moriou ◽  
...  
Keyword(s):  
Marine Sponge ◽  
Myeloid Leukemia ◽  
Dna Methyltransferase ◽  
Myeloid Cell ◽  
B Cell Lymphoma ◽  
Docking Studies ◽  
In Vitro Assays ◽  
Dna Methyltransferase 1 ◽  
First Time

Treatment of acute myeloid leukemia (AML) patients is still hindered by resistance and relapse, resulting in an overall poor survival rate. Recently, combining specific B-cell lymphoma (Bcl)-2 inhibitors with compounds downregulating myeloid cell leukemia (Mcl)-1 has been proposed as a new effective strategy to eradicate resistant AML cells. We show here that 1(R), 6(S), 1’(R), 6’(S), 11(R), 17(S)-fistularin-3, a bromotyrosine compound of the fistularin family, isolated from the marine sponge Suberea clavata, synergizes with Bcl-2 inhibitor ABT-199 to efficiently kill Mcl-1/Bcl-2-positive AML cell lines, associated with Mcl-1 downregulation and endoplasmic reticulum stress induction. The absolute configuration of carbons 11 and 17 of the fistularin-3 stereoisomer was fully resolved in this study for the first time, showing that the fistularin we isolated from the marine sponge Subarea clavata is in fact the (+)-11(R), 17(S)-fistularin-3 stereoisomer keeping the known configuration 1(R), 6(S), 1’(R), and 6’(S) for the verongidoic acid part. Docking studies and in vitro assays confirm the potential of this family of molecules to inhibit DNA methyltransferase 1 activity.

Cellular Alterations Induced by Candida albicans RC Nosodes: an in vitro Study

2021 ◽  
Vol 11 (40) ◽  
pp. 209-210
Author(s):  
Fortune Homsani ◽  
Gleyce Moreno ◽  
Camila Siqueira ◽  
Juliana Grechi ◽  
André Luis Santos ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Cell Viability ◽  
Cell Model ◽  
Etiologic Agent ◽  
Yeast Cells ◽  
In Vitro Assays ◽  
Mitochondrial Activity ◽  
No Production ◽  
Cellular Alterations

Introduction: Candidiasis is an opportunist infection, caused by yeast of the genus Candida, which emerges as one of the main causes of systemic infections in hospitalized patients. Candida albicans is the most common causing agent of these infections. According to the Brazilian Homeopathic Pharmacopeia[1], nosodes are medicines compounded from chemically undefined biological products. Living nosodes are prepared using the etiologic agent of an illness in its infective form, were first developed by Brazilian physician Roberto Costa (RC). Roberto Costa’s research indicated that living nosodes present a higher capability to stimulate the host’s immunological system [2]. Aim: This study aims to evaluate cellular alterations induced in C. albicans yeasts and RAW 264-7 macrophages by Candida albicans RC. Methodology: To prepare Candida albicans RC, one part of C. albicans infective yeast suspension (108 cell/ml) was diluted in 9 parts of sterile distilled water and submitted to 100 mechanical succussions. This process was successively repeated to the potencies of 12x and 30x1. Water 30x was prepared by the same technique, as control. The cell viability of C. albicans previously treated with nosodes in both potencies and respective controls was evaluated using the samples at the concentration of 10% (V/V), in a volume of 1ml, distributed in 1-3 days. The viability of the yeast cells was analyzed by MTT (3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolic) (5mg/ml) assay [3] and by Propidium Iodide (PI) incorporation methods. Additionally, using macrophages RAW 264-7 as a cell model, Nitric Oxide (NO) production and cell viability were also evaluated. For this, the following protocol of cell treatment was employed: on each experimental day, RAW 264-7 cells were treated 4 times (4 stimuli) with RC nosode 30x at the concentration of 10% (V/V). Results: The nosodes (12x and 30x) did not present cytotoxic effects on macrophage cells (n=1), or on C. albicans yeasts (n=2), as detected by MTT and PI methods. Moreover, no statistically significant differences on NO production were detected among the experimental groups (n=6). Conclusion: Preliminary results of in vitro assays indicate that nosodes (12x and 30x) do not alter mitochondrial activity or cell viability of C. albicans. Similarly, treatment by RC nosodes does not seem to alter NO release and mitochondrial activity of RAW macrophages. New experiments are being performed to confirm these preliminary data.

Response of a Chlorsulfuron-Resistant Biotype ofKochia scopariato Sulfonylurea and Alternative Herbicides

Weed Science ◽  
1993 ◽  
Vol 41 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Lyle F. Friesen ◽  
Ian N. Morrison ◽  
Abdur Rashid ◽  
Malcolm D. Devine
Keyword(s):  
Field Experiments ◽  
Good Control ◽  
Acetolactate Synthase ◽  
In Vitro Assays ◽  
Shoot Biomass ◽  
Wheat Crop ◽  
Enzyme Assays ◽  
Dry Matter Accumulation ◽  
Severe Stunting

Kochia growing on an industrial site where chlorsulfuron was applied repeatedly over several seasons was confirmed to be resistant to chlorsulfuron and several other acetolactate synthase (ALS) -inhibiting herbicides. In growth room experiments, resistant (R) plants were 2 to >180 times more resistant to five sulfonylurea herbicides and one imidazolinone herbicide (imazethapyr) than susceptible (S) plants, as measured by the ratio of dosages required to inhibit shoot dry matter accumulation by 50% (GR50R/S). Similarly, in vitro assays of ALS activity indicated that from 3 to 30 times more herbicide was required to inhibit the enzyme from R plants than from S plants. Results of ALS enzyme assays indicated that R kochia was approximately equally resistant to metsulfuron, triasulfuron, and thifensulfuron, and 2.5 times more resistant to tribenuron than thifensulfuron. However, the response of R kochia growing in a spring wheat crop in the field was not consistent with results of the ALS enzyme assays. In field experiments, thifensulfuron at 32 g ai ha−1had little effect on R kochia. In contrast, metsulfuron, triasulfuron, and tribenuron at 8 g ha−1did not reduce R kochia seedling densities, but caused severe stunting such that 2 mo after treatment the shoot biomass of plants in untreated plots was four times greater than in sprayed plots. Herbicides with alternative modes of action including fluroxypyr, bromoxynil/MCPA ester, dichlorprop/2,4-D ester, and 2,4-D ester provided good control of R kochia in the field. Quinclorac did not reduce kochia densities, but surviving plants were stunted. To delay or avoid development of ALS inhibitor-resistant kochia populations, these alternative herbicides applied alone or in tank mixtures could be incorporated into a herbicide rotation.

scholarly journals Pre-Clinical Pharmacokinetic and Pharmacodynamic Characterization of Selected Chiral Flavonoids: Pinocembrin and Pinostrobin

2015 ◽  
Vol 18 (4) ◽  
pp. 368 ◽  
Author(s):  
Casey L. Sayre ◽  
Samaa Alrushaid ◽  
Stephanie E. Martinez ◽  
Hope D. Anderson ◽  
Neal M. Davies
Keyword(s):  
Chemical Structure ◽  
In Vitro Assays ◽  
Pharmacokinetic Parameters ◽  
Sprague Dawley ◽  
Pharmacokinetics And Pharmacodynamics ◽  
Sprague Dawley Rats ◽  
Stereoselective Pharmacokinetics ◽  
First Time

Purpose: Delineate the stereospecific pharmacokinetics and pharmacodynamics of the chiral flavonoids pinocembrin and pinostrobin. Objective: Characterize for the first time the stereoselective pharmacokinetics of two flavonoids, pinocembrin and pinostrobin and their bioactivity in several in vitro assays with relevant roles in heart disease, colon cancer, and diabetes etiology and pathophysiology. Methods: Chiral flavonoids were intravenously and orally administered to male Sprague-Dawley rats. Concentrations in serum and urine were characterized via stereospecific HPLC or LC/MS. Pure enantiomeric forms of each flavonoid were tested, where possible, to identify the stereospecific contribution to bioactivity in comparision to their racemates. Results:  Short half-lives (0.2-6 h) in serum were observed, while a better estimation of half-life (3-26 h) and other pharmacokinetic parameters were observed using urinary data. The flavonoids are predominantly excreted via non-renal routes (fe values of 0.3-4.6 %), and undergo rapid and extensive phase II metabolism. Chiral differences in the chemical structure of these compounds result in significant pharmacodynamic differences. Conclusion: The importance of understanding the stereospecific pharmacokinetics and pharmacodynamics of two chiral flavonoids were delineated.This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Development of an In Vitro Membrane Model to Study the Function of EsxAB Heterodimer and Establish the Role of EsxB in Membrane Permeabilizing Activity of Mycobacterium tuberculosis

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1015
Author(s):  
Salvador Vazquez Reyes ◽  
Supriyo Ray ◽  
Javier Aguilera ◽  
Jianjun Sun
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lipid Membranes ◽  
Effect Of Temperature ◽  
In Vitro Assays ◽  
Vitro Model ◽  
First Time ◽  
Dose Dependent Increase ◽  
Dose Dependent

EsxA and EsxB are secreted as a heterodimer and have been shown to play critical roles in phagosome rupture and translocation of Mycobacterium tuberculosis into the cytosol. Recent in vitro studies have suggested that the EsxAB heterodimer is dissociated upon acidification, which might allow EsxA insertion into lipid membranes. While the membrane permeabilizing activity (MPA) of EsxA has been well characterized in liposomes composed of di-oleoyl-phosphatidylcholine (DOPC), the MPA of EsxAB heterodimer has not been detected through in vitro assays due to its negligible activity with DOPC liposomes. In this study, we established a new in vitro membrane assay to test the MPA activity of N-terminal acetylated EsxA (N-EsxA). We established that a dose-dependent increase in anionic charged lipids enhances the MPA of N-EsxA. The MPA of both N-EsxA and EsxAB were significantly increased with this new liposome system and made it possible to characterize the MPA of EsxAB in more physiologically-relevant conditions. We tested, for the first time, the effect of temperature on the MPA of N-EsxA and EsxAB in this new system. Interestingly, the MPA of N-EsxA was lower at 37 °C than at RT, and on the contrary, the MPA of EsxAB was higher at 37 °C than at RT. Surprisingly, after incubation at 37 °C, the MPA of N-EsxA continuously decreased over time, while MPA of EsxAB remained stable, suggesting EsxB plays a key role in stabilizing N-EsxA to preserve its MPA at 37 °C. In summary, this study established a new in vitro model system that characterizes the MPA of EsxAB and the role of EsxB at physiological-relevant conditions.

scholarly journals Evidence for an Intramacrophage Growth Phase of Mycobacterium ulcerans

2006 ◽  
Vol 75 (2) ◽  
pp. 977-987 ◽  
Author(s):  
Egídio Torrado ◽  
Alexandra G. Fraga ◽  
António G. Castro ◽  
Pieter Stragier ◽  
Wayne M. Meyers ◽  
...  
Keyword(s):  
Buruli Ulcer ◽  
Etiologic Agent ◽  
Mycobacterium Ulcerans ◽  
Host Cells ◽  
Delayed Type Hypersensitivity ◽  
In Vitro Assays ◽  
Mouse Macrophages ◽  
Inflammatory Infiltrates ◽  
Extracellular Location

ABSTRACT Mycobacterium ulcerans is the etiologic agent of Buruli ulcer (BU), an emerging tropical skin disease. Virulent M. ulcerans secretes mycolactone, a cytotoxic exotoxin with a key pathogenic role. M. ulcerans in biopsy specimens has been described as an extracellular bacillus. In vitro assays have suggested a mycolactone-induced inhibition of M. ulcerans uptake by macrophages in which its proliferation has not been demonstrated. Therefore, and uniquely for a mycobacterium, M. ulcerans has been classified as an extracellular pathogen. In specimens from patients and in mouse footpad lesions, extracellular bacilli were concentrated in central necrotic acellular areas; however, we found bacilli within macrophages in surrounding inflammatory infiltrates. We demonstrated that mycolactone-producing M. ulcerans isolates are efficiently phagocytosed by murine macrophages, indicating that the extracellular location of M. ulcerans is not a result of inhibition of phagocytosis. Additionally, we found that M. ulcerans multiplies inside cultured mouse macrophages when low multiplicities of infection are used to prevent early mycolactone-associated cytotoxicity. Following the proliferation phase within macrophages, M. ulcerans induces the lysis of the infected host cells, becoming extracellular. Our data show that M. ulcerans, like M. tuberculosis, is an intracellular parasite with phases of intramacrophage and extracellular multiplication. The occurrence of an intramacrophage phase is in accordance with the development of cell-mediated and delayed-type hypersensitivity responses in BU patients.

scholarly journals Inhibition of CYP21A2 Enzyme Activity Caused by Novel Missense Mutations Identified in Brazilian and Scandinavian Patients

2008 ◽  
Vol 93 (6) ◽  
pp. 2416-2420 ◽  
Author(s):  
F. C. Soardi ◽  
M. Barbaro ◽  
I. F. Lau ◽  
S. H. V. Lemos-Marini ◽  
M. T. M. Baptista ◽  
...  
Keyword(s):  
Binding Capacity ◽  
In Vitro Assays ◽  
Missense Mutations ◽  
Hydroxylase Deficiency ◽  
Rare Mutations ◽  
17 Hydroxyprogesterone ◽  
21 Hydroxylase Deficiency ◽  
First Time

Abstract Background: Most patients with 21-hydroxylase deficiency carry CYP21A1P-derived mutations, but an increasing number of novel and rare mutations have been reported in disease-causing alleles. Objective: Functional effects of three novel (p.G56R, p.L107R, p.L142P) and one recurrent (p.R408C) CYP21A2 mutations were investigated. The degree of enzyme impairment caused by p.H62L alone or combined to p.P453S was also analyzed. Design: The study included 10 Brazilian and two Scandinavian patients. To determine the deleterious role of each mutant protein, in vitro assays were performed in transiently transfected COS-1 cells. For a correct genotype-phenotype correlation, the enzymatic activities were evaluated toward the two natural substrates, 17-hydroxyprogesterone and progesterone. Results: Low levels of residual activities obtained for p.G56R, p.L107R, p.L142P, and p.R408C mutants classified them as classical congenital adrenal hyperplasia mutations, whereas the p.H62L showed an activity within the range of nonclassical mutations. Apparent kinetic constants for p.H62L confirmed the nonclassical classification as the substrate binding capacity was within the same magnitude for mutant and normal enzymes. A synergistic effect was observed for the allele bearing the p.H62L+p.P453S combination because it caused a significant reduction in the enzymatic activity. Conclusions: We describe the functional analysis of five rare missense mutations identified in Brazilian and Scandinavian patients. The p.G56R, p.L107R, and p.L142P are reported for the first time. Most probably these novel mutations are closer to null than the p.I172N, but for the p.G56R, that might not be the case, and the p.H62L is definitely a nonclassical mutation.

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