scholarly journals Evaluation of Anti-Mycobacterial Compounds in a Silkworm Infection Model with Mycobacteroides abscessus

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4971
Author(s):  
Kanji Hosoda ◽  
Nobuhiro Koyama ◽  
Hiroshi Hamamoto ◽  
Akiho Yagi ◽  
Ryuji Uchida ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
In Vitro Assay ◽  
Infection Model ◽  
Therapeutic Effects ◽  
Dependent Manner ◽  
Vitro Assay ◽  
Infection Assay ◽  
Microbial Products ◽  
Dose Dependent

Among four mycobacteria, Mycobacterium avium, M. intracellulare, M. bovis BCG and Mycobacteroides (My.) abscessus, we established a silkworm infection assay with My. abscessus. When silkworms (fifth-instar larvae, n = 5) were infected through the hemolymph with My. abscessus (7.5 × 107 CFU/larva) and bred at 37 °C, they all died around 40 h after injection. Under the conditions, clarithromycin and amikacin, clinically used antimicrobial agents, exhibited therapeutic effects in a dose-dependent manner. Furthermore, five kinds of microbial compounds, lariatin A, nosiheptide, ohmyungsamycins A and B, quinomycin and steffimycin, screened in an in vitro assay to observe anti-My. abscessus activity from 400 microbial products were evaluated in this silkworm infection assay. Lariatin A and nosiheptide exhibited therapeutic efficacy. The silkworm infection model with My. abscessus is useful to screen for therapeutically effective anti-My. abscessus antibiotics.

scholarly journals Mechanisms underlying the antifibrotic properties of noninhibitory PAI-1 (PAI-1R) in experimental nephritis

2009 ◽  
Vol 297 (4) ◽  
pp. F1045-F1054 ◽  
Author(s):  
Yufeng Huang ◽  
Wayne A. Border ◽  
Daniel A. Lawrence ◽  
Nancy A. Noble
Keyword(s):  
Half Life ◽  
Stable Form ◽  
Therapeutic Effects ◽  
Dependent Manner ◽  
Therapeutic Action ◽  
Protease Inhibition ◽  
Ecm Degradation ◽  
Dose Dependent ◽  
Pai 1

Administration of a mutant, noninhibitory PAI-1 (PAI-1R), reduces disease in experimental glomerulonephritis. Here we investigated the importance of vitronectin (Vn) binding, PAI-1 stability and protease binding in this therapeutic effect using a panel of PAI-1 mutants differing in half-life, protease binding, and Vn binding. PAI-1R binds Vn normally but does not inhibit proteases. PAI-1AK has a complete defect in Vn binding but retains full inhibitory activity, with a short half-life similar to wild-type (wt)-PAI-1. Mutant 14-lb is identical to wt-PAI-1 but with a longer half-life. PAI-1K has defective Vn binding, inhibits proteases normally, and has a long half-life. In vitro wt-PAI-1 dramatically inhibited degradation of mesangial cell ECM while the AK mutant had much less effect. Mutants 14-1b and PAI-1K, like wt-PAI-1, inhibited matrix degradation but PAI-1R failed to reverse this inhibition although PAI-1R reversed the wt-PAI-1-induced inhibition of ECM degradation in a plasmin-, time-, and dose-dependent manner. Thus the ability of PAI-1 to inhibit ECM degradation is dependent both on its antiproteinase activity and on maintaining an active conformation achieved either by Vn binding or mutation to a stable form. Administration of these PAI-1 mutants to nephritic rats confirmed the in vitro data; only PAI-1R showed therapeutic effects. PAI-1K did not bind to nephritic kidney, indicating that Vn binding is essential to the therapeutic action of PAI-1R. The ability of PAI-1R to remain bound to Vn even in a high-protease environment is very likely the key to its therapeutic efficacy. Furthermore, because both PAI-1R and 14-1b bound to the nephritic kidney in the same pattern and differ only in their ability to bind proteases, lack of protease inhibition is also keyed to PAI-1R's therapeutic action.

In vitro Assay for the Screening of the Plaque-reducing Activity of Antimicrobial Agents

2011 ◽  
Vol 53 (03) ◽  
pp. 182-187
Author(s):  
Frank-Albert Pitten ◽  
Sven Doering ◽  
Axel Kramer ◽  
Michael Rosin
Keyword(s):  
Antimicrobial Agents ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Reducing Activity

scholarly journals Fgr but not Syk tyrosine kinase is a target for beta2 integrin-induced c-Cbl-mediated ubiquitination in adherent human neutrophils

2003 ◽  
Vol 370 (2) ◽  
pp. 687-694 ◽  
Author(s):  
Fredrik MELANDER ◽  
Tommy ANDERSSON ◽  
Karim DIB
Keyword(s):  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Src Kinase ◽  
E3 Ligase ◽  
In Vitro Assay ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Vitro Assay ◽  
Β2 Integrin

An early and critical event in β2 integrin signalling during neutrophil adhesion is activation of Src tyrosine kinases and Syk. In the present study, we report Src kinase-dependent β2 integrin-induced tyrosine phosphorylation of Cbl occurring in parallel with increased Cbl-associated tyrosine kinase activity. These events concurred with activation of Fgr and, surprisingly, also with dissociation of this Src tyrosine kinase from Cbl. Moreover, the presence of the Src kinase inhibitor PP1 in an in vitro assay had only a limited effect on the Cbl-associated kinase activity. These results suggest that an additional active Src-dependent tyrosine kinase associates with Cbl. The following observations imply that Syk is such a kinase: (i) β2 integrins activated Syk in a Src-dependent manner, (ii) Syk was associated with Cbl much longer than Fgr was, and (iii) the Syk inhibitor piceatannol (3,4,3′,5′-tetrahydroxy-trans-stilbene) abolished the Cbl-associated kinase activity in an in vitro assay. Effects of the mentioned interactions between these two kinases and Cbl may be related to the finding that Cbl is a ubiquitin E3 ligase. Indeed, we detected β2 integrin-induced ubiquitination of Fgr that, similar to the phosphorylation of Cbl, was abolished in cells pretreated with PP1. However, the ubiquitination of Fgr did not cause any apparent degradation of the protein. In contrast with Fgr, Syk was not modified by the E3 ligase. Thus Cbl appears to be essential in β2 integrin signalling, first by serving as a matrix for a subsequent agonist-induced signalling interaction between Fgr and Syk, and then by mediating ubiquitination of Fgr which possibly affects its interaction with Cbl.

scholarly journals Effect of Massoia (Massoia aromatica Becc.) Bark on the Phagocytic Activity of Wistar Rat Macrophages

2018 ◽  
Author(s):  
Triana Hertiani ◽  
Agustinus Yuswanto ◽  
Sylvia Utami Tunjung Pratiwi ◽  
Harlyanti Mashar
Keyword(s):  
Phagocytic Activity ◽  
Wistar Rats ◽  
In Vitro Assay ◽  
Phagocytic Index ◽  
Dependent Manner ◽  
Vitro Assay ◽  
Macrophage Cells ◽  
In Vivo Assay

Massoia (Massoia aromatica Becc., Lauraceae) bark has been widely used as a component of traditional Indonesian medicine. The indigenous people boil or steam the bark for traditional applications. Our preliminary research revealed the potency of Massoia essential oil and its major compound, C-10 Massoialactone as potential immunomodulator in vitro. However, no scientific evidence regarding its in vivo effects is available. Therefore, this study evaluated the potential immunomodulatory effects of Massoia bark infusion on the nonspecific immune response (phagocytosis) of Wistar rats. The aqueous extract of Massoia bark was obtained by boiling pulverized bark in water, and the C-10 massoialactone content of the extract was determined through Thin Layer Chromatography (TLC) densitometry. For the in vitro assay, macrophages were treated with the freeze-dried infusion at the concentrations of 2.5, 5, 10, 20, or 40 μg/mL media. For the in vivo assay, 2-month-old male Wistar rats were divided into 5 groups. The baseline group received distilled water at the dose of 1 mL/100 g BW with the immunostimulant herbal product “X” administered as the positive control at the dose of 0.54 mL/rat. The treatment groups received the infusion at a dose of 100, 300, or 500 mg/100 g BW. Treatments were given orally every day for 14 days. The ability of macrophage cells to phagocyte latex was determined as phagocytic index (PI) and was observed under microscopy with 300 macrophages. The in vitro study revealed that the phagocytic activity of the infusion-treated macrophages significantly increased in comparison with that of the control macrophages in a concentration-dependent manner. Among all treatment concentrations, the concentration of 40 μg/ml provided the highest activity with a PI value of 70.51% ± 1.11%. The results of the in vivo assay confirmed those of the in vitro assay. The results of the present study indicate that Massoia bark can increase the phagocytic activity of rat macrophage cells. Its potential as a naturally derived immunomodulatory agent requires further study.

Epitope specificity and isotype of monoclonal anti-D antibodies dictate their ability to inhibit phagocytosis of opsonized platelets

Blood ◽  
2007 ◽  
Vol 110 (4) ◽  
pp. 1359-1361 ◽  
Author(s):  
Mimi Kjaersgaard ◽  
Rukhsana Aslam ◽  
Michael Kim ◽  
Edwin R. Speck ◽  
John Freedman ◽  
...  
Keyword(s):  
Immune Globulin ◽  
In Vitro Assay ◽  
Dependent Manner ◽  
Hemolytic Disease ◽  
Thrombocytopenic Purpura ◽  
Vitro Assay ◽  
Autoimmune Thrombocytopenic Purpura ◽  
Epitope Specificity ◽  
Primary Indication

Abstract Rh immune globulin (WinRho SDF; Cangene, Mississauga, ON, Canada) is an effective treatment for autoimmune thrombocytopenic purpura; however, maintaining a sustained supply for its use in autoimmune thrombocytopenic purpura and its primary indication, hemolytic disease of the newborn, makes the development of alternative reagents desirable. We compared Rh immune globulin and 6 human monoclonal anti-D antibodies (MoAnti-D) with differing isotypes and specificities for their ability to opsonize erythrocytes and inhibit platelet phagocytosis in an in vitro assay. Results demonstrated that opsonization of erythrocytes with Rh immune globulin significantly (P < .001) reduced phagocytosis of fluorescently labeled opsonized platelets in an Fc-dependent manner. Of the MoAnti-D that shared specificity but differed in isotype, only IgG3 antibodies could significantly (P < .001) inhibit platelet phagocytosis. In contrast, 2 MoAnti-D shared isotypes and differed in specificity; however, only one could significantly (P < .001) inhibit platelet phagocytosis. The results suggest that MoAnti-D epitope specificity and isotypes are critical requirements for optimal inhibition of opsonized platelet phagocytosis.

scholarly journals Synthesis and in vitro assay of 1-[5-(4-chloro-phenyl)-[1,3,4]thiadiazol-2-yl] derivatives as new antimicrobial agents

2021 ◽  
Vol 1853 (1) ◽  
pp. 012041
Author(s):  
N B Ayrim ◽  
A M Abdula ◽  
S M Baker ◽  
G L Mohsen ◽  
W F Rodhan ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
In Vitro Assay ◽  
Vitro Assay

Early mouse endoderm is patterned by soluble factors from adjacent germ layers

Development ◽  
2000 ◽  
Vol 127 (8) ◽  
pp. 1563-1572 ◽  
Author(s):  
J.M. Wells ◽  
D.A. Melton
Keyword(s):  
Primitive Streak ◽  
In Vitro Assay ◽  
Specific Gene ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Germ Layers ◽  
Vitro Assay ◽  
Organ Specific ◽  
Early Mouse

Endoderm that forms the respiratory and digestive tracts is a sheet of approximately 500–1000 cells around the distal cup of an E7.5 mouse embryo. Within 2 days, endoderm folds into a primitive gut tube from which numerous organs will bud. To characterize the signals involved in the developmental specification of this early endoderm, we have employed an in vitro assay using germ layer explants and show that adjacent germ layers provide soluble, temporally specific signals that induce organ-specific gene expression in endoderm. Furthermore, we show that FGF4 expressed in primitive streak-mesoderm can induce the differentiation of endoderm in a concentration-dependent manner. We conclude that the differentiation of gastrulation-stage endoderm is directed by adjacent mesoderm and ectoderm, one of the earliest reported patterning events in formation of the vertebrate gut tube.

scholarly journals The in Vitro Effect of Polyvinylpyrrolidone and Citrate Coated Silver Nanoparticles on Erythrocytic Oxidative Damage and Eryptosis

2018 ◽  
Vol 49 (4) ◽  
pp. 1577-1588 ◽  
Author(s):  
Zannatul Ferdous ◽  
Sumaya Beegam ◽  
Saeed Tariq ◽  
Badreldin H Ali ◽  
Abderrahim Nemmar
Keyword(s):  
Oxidative Stress ◽  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Annexin V ◽  
Drug Carriers ◽  
Cellular Protein ◽  
Dependent Manner ◽  
Vitro Effect ◽  
Dose Dependent

Background/Aims: Silver nanoparticles (AgNPs) are increasingly used as antimicrobial agents and drug carriers in various biomedical fields. AgNPs can encounter erythrocytes either directly following intravenous injection, or indirectly via translocation from the site of administration. However, information regarding the pathophysiological effects and possible mechanism of action of AgNPs on the erythrocytes are still inadequately studied. Thus, the aim of our study was to investigate the mechanism underlying the effect of coating and concentration of AgNPs on mouse erythrocytes in vitro. Methods: We studied the interaction of polyvinylpyrrolidone (PVP) and citrate (CT) coated AgNPs (10 nm) at various concentrations (2.5, 10, 40 µg/ml) with mouse erythrocytes in vitro using various techniques including transmission electron microscopy (TEM), hemolysis, and colorimetric measurement of markers of oxidative stress comprising malondialdehyde (MDA), reduced glutathione (GSH), and catalase (CAT). Intracellular calcium (Ca2+) was determined using Fura 2AM fluorescence. Annexin V was quantified using ELISA and the caspase 3 was determined both flurometrically and by western blot technique. Results: Following incubation of the erythrocytes with AgNPs, both PVP- and CT- AgNPs induced significant and dose - dependent increase in hemolysis. TEM revealed that both PVP- and CT- AgNPs were taken up by erythrocytes. The erythrocyte susceptibility to lipid peroxidation measured by MDA was significantly increased in both PVP-and CT- AgNPs. The concentration of GSH and CAT activity were significantly decreased by both types of AgNPs. Additionally, PVP- and CT- AgNPs significantly increased intracellular Ca2+ in a dose -dependent manner. Likewise, the concentration of the cellular protein annexin V was significantly and dose - dependently enhanced by both types of AgNPs. Furthermore, PVP- and CT- AgNPs induced significant increase in calpain activity in incubated erythrocytes. Conclusion: We conclude that both PVP- and CT- AgNPs causes hemolysis, and are taken up by erythrocytes. Moreover, we demonstrated that AgNPs induces oxidative stress and eryptosis. These findings provide evidence for the potential pathophysiological effect of PVP-and CT- AgNPs on erythrocyte physiology.

scholarly journals Propolis as a potential alternative for the control of Dekkera bruxellensis in bioethanol fermentation

2019 ◽  
Vol 40 (5) ◽  
pp. 2071
Author(s):  
Leticia Andrea Fernandez ◽  
Irene Laura Cibanal ◽  
Anna Livia Paraluppi ◽  
Caroline de Freitas ◽  
Lilliana María Gallez ◽  
...  
Keyword(s):  
Alcoholic Fermentation ◽  
Antimicrobial Agents ◽  
Cell Number ◽  
In Vitro Assay ◽  
Dekkera Bruxellensis ◽  
Vitro Assay ◽  
Good Potential ◽  
Potential Alternative ◽  
Specific Absorbance

Dekkera bruxellensis is one of the most important contaminant yeasts of alcoholic fermentation. The use of propolis, which can selectively target contaminating yeasts without affecting the starter one, Saccharomyces cerevisiae, could be a useful nonconventional strategy for controlling the growth of contaminant yeasts. The objective of this research was to evaluate four samples of propolis produced by Apis mellifera honeybees from different regions of Argentina as antimicrobial agents against the growth of D. bruxellensis and S. cerevisiae. Hydroalcoholic extracts of propolis were prepared with ethanol:water (70:30 v/v), and the specific absorbance and final concentration of the samples were evaluated. A qualitative in vitro assay in solid medium was performed with different propolis concentrations, and the evaluation of yeast growth was based on a qualitative scale. A quantitative in vitro assay in liquid medium was also performed to assess the yeast cell number, using two different propolis concentrations. The cell number of D. bruxellensis decreased 1.52 and 1.85 log cycles with the two propolis extracts utilised at a concentration of 4.5 mg mL-1 while the cell number of S. cerevisiae decreased 0.48 and 0.76 log cycles with the same samples of propolis. The results from both assays demonstrated the selectivity of propolis use on the yeast species, leading to a higher inhibition of D. bruxellensis growth. This indicates a good potential for using propolis at the concentration of 4.5 mg mL-1, as a nonconventional strategy to control the growth of D. bruxellensis without significantly affecting S. cerevisiae, the yeast starter of ethanol fermentation.

Erythropoietin regulates endothelial progenitor cells

Blood ◽  
2004 ◽  
Vol 103 (3) ◽  
pp. 921-926 ◽  
Author(s):  
Ferdinand H. Bahlmann ◽  
Kirsten de Groot ◽  
Jens-Michael Spandau ◽  
Aimee L. Landry ◽  
Barbara Hertel ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Peripheral Blood ◽  
Healthy Subjects ◽  
Tube Formation ◽  
Dependent Manner ◽  
Endothelial Progenitor ◽  
Vitro Assay ◽  
Dose Dependent

AbstractCirculating bone marrow–derived endothelial progenitor cells (EPCs) promote vascular reparative processes and neoangiogenesis, and their number in peripheral blood correlates with endothelial function and cardiovascular risk. We tested the hypothesis that the cytokine erythropoietin (EPO) stimulates EPCs in humans. We studied 11 patients with renal anemia and 4 healthy subjects who received standard doses of recombinant human EPO (rhEPO). Treatment with rhEPO caused a significant mobilization of CD34+/CD45+ circulating progenitor cells in peripheral blood (measured by flow cytometry), and increased the number of functionally active EPCs (measured by in vitro assay) in patients (week 2, 312% ± 31%; week 8, 308% ± 40%; both P &lt; .01 versus baseline) as well as in healthy subjects (week 8, 194% ± 15%; P &lt; .05 versus baseline). The effect on EPCs was already observed with an rhEPO dose of about 30 IU/kg per week. Administration of rhEPO increased the number of functionally active EPCs by differentiation in vitro in a dose-dependent manner, assessed in cell culture and by tube formation assay. Furthermore, rhEPO activates the Akt protein kinase pathway in EPCs. Erythropoietin increases the number of functionally active EPCs in humans. Administration of rhEPO or EPO analogs may open new therapeutic strategies in regenerative cardiovascular medicine.

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