scholarly journals Identification of a two-component Class IIb bacteriocin in Streptococcus pyogenes by recombinase-based in vivo expression technology

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Brent D. Armstrong ◽  
Christine A. Herfst ◽  
Nicholas C. Tonial ◽  
Adrienne T. Wakabayashi ◽  
Joseph J. Zeppa ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Two Component ◽  
In Vivo Expression ◽  
Class Iib ◽  
Component Class

A technique for protecting delicate specimens during processing

1989 ◽  
Vol 47 ◽  
pp. 982-983
Author(s):  
R.J. Mount ◽  
R.V. Harrison
Keyword(s):  
Basilar Membrane ◽  
Low Cost ◽  
Organ Of Corti ◽  
Region Of Interest ◽  
Sensory Epithelium ◽  
Physical Damage ◽  
Air Drying ◽  
Specimen Handling ◽  
Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

Ethanol Extract Of Centella Asiatica (L.) Urban Leaves Effectively Inhibit Streptococcus pyogenes and Pseudomonas aeruginosa by Invitro Test

2020 ◽  
Vol 2 (2) ◽  
pp. 69-76
Author(s):  
Dini Aulia Azmi ◽  
Nurlailah Nurlailah ◽  
Ratih Dewi Dwiyanti
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Streptococcus Pyogenes ◽  
Bacterial Infections ◽  
Herbal Medicines ◽  
Centella Asiatica ◽  
Ethanol Extract ◽  
Dilution Method ◽  
Initial Stage ◽  
Independent Variable

Streptococcus pyogenes and Pseudomonas aeruginosa are some of the causes of infectious diseases. Centella asiatica (L.) Urban has many benefits for humans, including overcoming fever, anti-bacterial, and anti-inflammatory. This study aims to determine the inhibition of Centella asiatica (L.) Urban leaves ethanol extract on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. This research is the initial stage of the development of herbal medicines to treat Streptococcus pyogenes and Pseudomonas aeruginosa infections. The independent variable was the concentration of ethanol extract of Centella asiatica (L.) Urban leaves and the dependent variable was the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. The anti-bacterial activity test was carried out by the liquid dilution method. The concentrations used are 20%, 40%, 60%, 80%. 100% The results showed that the minimum inhibitory concentration (MIC) against Streptococcus pyogenes: 40% and Pseudomonas aeruginosa: 40%. Minimum bactericidal concentration (MBC) results for Streptococcus pyogenes: 60% and Pseudomonas aeruginosa: 60%. So it can be concluded that there is inhibition of the ethanol extract of Centella asiatica (L.) Urban leaves on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. Centella Asiatica (L.) Urban extract has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

scholarly journals Identification of a natural soluble neuropilin-1 that binds vascular endothelial growth factor: In vivo expression and antitumor activity

2000 ◽  
Vol 97 (6) ◽  
pp. 2573-2578 ◽  
Author(s):  
M. L. Gagnon ◽  
D. R. Bielenberg ◽  
Z.'e. Gechtman ◽  
H.-Q. Miao ◽  
S. Takashima ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Antitumor Activity ◽  
Vascular Endothelial ◽  
Neuropilin 1 ◽  
In Vivo Expression ◽  
Endothelial Growth Factor

scholarly journals In Vivo Expression of Reprogramming Factor OCT4 Ameliorates Myelination Deficits and Induces Striatal Neuroprotection in Huntington’s Disease

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 712
Author(s):  
Ji-Hea Yu ◽  
Bae-Geun Nam ◽  
Min-Gi Kim ◽  
Soonil Pyo ◽  
Jung-Hwa Seo ◽  
...  
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Cell Fate ◽  
Gabaergic Neurons ◽  
Oligodendrocyte Progenitor Cells ◽  
Adeno Associated Virus ◽  
In Vivo Expression ◽  
Transcription Factor 4 ◽  
Phosphate Buffered Saline

White matter atrophy has been shown to precede the massive loss of striatal GABAergic neurons in Huntington’s disease (HD). This study investigated the effects of in vivo expression of reprogramming factor octamer-binding transcription factor 4 (OCT4) on neural stem cell (NSC) niche activation in the subventricular zone (SVZ) and induction of cell fate specific to the microenvironment of HD. R6/2 mice randomly received adeno-associated virus 9 (AAV9)-OCT4, AAV9-Null, or phosphate-buffered saline into both lateral ventricles at 4 weeks of age. The AAV9-OCT4 group displayed significantly improved behavioral performance compared to the control groups. Following AAV9-OCT4 treatment, the number of newly generated NSCs and oligodendrocyte progenitor cells (OPCs) significantly increased in the SVZ, and the expression of OPC-related genes and glial cell-derived neurotrophic factor (GDNF) significantly increased. Further, amelioration of myelination deficits in the corpus callosum was observed through electron microscopy and magnetic resonance imaging, and striatal DARPP32+ GABAergic neurons significantly increased in the AAV9-OCT4 group. These results suggest that in situ expression of the reprogramming factor OCT4 in the SVZ induces OPC proliferation, thereby attenuating myelination deficits. Particularly, GDNF released by OPCs seems to induce striatal neuroprotection in HD, which explains the behavioral improvement in R6/2 mice overexpressing OCT4.

scholarly journals An In Vivo Predictive Dissolution Methodology (iPD Methodology) with a BCS Class IIb Drug Can Predict the In Vivo Bioequivalence Results: Etoricoxib Products

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 507
Author(s):  
Isabel Gonzalez-Alvarez ◽  
Marival Bermejo ◽  
Yasuhiro Tsume ◽  
Alejandro Ruiz-Picazo ◽  
Marta Gonzalez-Alvarez ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
In Vitro Dissolution ◽  
Case Examples ◽  
Dissolution Studies ◽  
Weak Bases ◽  
Transit Times ◽  
Class Iib ◽  
The Impact

The purpose of this study was to predict in vivo performance of three oral products of Etoricoxib (Arcoxia® as reference and two generic formulations in development) by conducting in vivo predictive dissolution with GIS (Gastro Intestinal Simulator) and computational analysis. Those predictions were compared with the results from previous bioequivalence (BE) human studies. Product dissolution studies were performed using a computer-controlled multicompartmental dissolution device (GIS) equipped with three dissolution chambers, representing stomach, duodenum, and jejunum, with integrated transit times and secretion rates. The measured dissolved amounts were modelled in each compartment with a set of differential equations representing transit, dissolution, and precipitation processes. The observed drug concentration by in vitro dissolution studies were directly convoluted with permeability and disposition parameters from literature to generate the predicted plasma concentrations. The GIS was able to detect the dissolution differences among reference and generic formulations in the gastric chamber where the drug solubility is high (pH 2) while the USP 2 standard dissolution test at pH 2 did not show any difference. Therefore, the current study confirms the importance of multicompartmental dissolution testing for weak bases as observed for other case examples but also the impact of excipients on duodenal and jejunal in vivo behavior.

scholarly journals 1455. Potential Mechanisms of Cefiderocol MIC Increase in Enterobacterales in In Vitro Resistance Acquisition Studies

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S730-S730
Author(s):  
Yoshinori Yamano ◽  
Rio Nakamura ◽  
Miki Takemura ◽  
Roger Echols
Keyword(s):  
Iron Transport ◽  
Resistance Mechanisms ◽  
Altered Expression ◽  
Carbapenem Resistant ◽  
Mueller Hinton ◽  
Two Component ◽  
Mueller Hinton Agar ◽  
Related Proteins

Abstract Background Cefiderocol (CFDC) is a novel siderophore, iron-chelating cephalosporin, which is transported into bacteria via iron transporters. CFDC has potent in vitro and in vivo activity against all aerobic Gram-negative bacteria, including carbapenem-resistant strains. To date, clinical isolates with cefiderocol MIC >4 µg/mL have been found infrequently, in which the presence of a few β-lactamases or altered iron transport was found. We investigated potential new mechanisms causing CFDC MIC increases in non-clinical studies. Methods The mutation positions were determined by whole genome sequencing using four K. pneumoniae mutants including two KPC producers and one NDM producer that had shown CFDC MIC increases in previous in vitro resistance-acquisition studies. The mutant strains were obtained at the frequency of 10-7 to < 10-8 by spreading bacteria on standard Mueller‒Hinton agar medium containing CFDC at concentrations of 10× MIC, with or without apo-transferrin (20 μg/mL). CFDC MIC was determined by broth microdilution using iron-depleted cation-adjusted Mueller-Hinton broth based on Clinical and Laboratory Standards Institute guidelines. The emergence of MIC increase mutants was also assessed by in vitro chemostat models under humanized plasma pharmacokinetic exposures of CFDC. Results The possible resistance mechanisms were investigated. Mutation of baeS or envZ, sensors of two-component regulation systems, were found in three or two mutants among the tested four isolates, respectively, and caused the MIC to increase by 4–32-fold. The altered expression level of specific genes by the baeS or envZ mutation could affect CFDC susceptibility, but the specific genes have not been identified. In addition, the mutation of exbD, an accessory protein related to iron transport, was identified in one case and caused the MIC to increase by >8-fold. In vitro chemostat studies using two isolates (one NDM producer and one KPC producer) showed no resistance acquisition during 24-hour exposure. Table. Overview of mutation emergence in five isolates of K. pneumoniae Conclusion The mutation of two-component regulation systems (BaeSR and OmpR/EnvZ) and iron transport-related proteins were shown to be possible mechanisms causing CFDC MIC increases, but these mutants did not appear under human exposures. Disclosures Yoshinori Yamano, PhD, Shionogi & Co., Ltd. (Employee) Rio Nakamura, BSc, Shionogi & Co., Ltd. (Employee) Miki Takemura, MSc, Shionogi & Co., Ltd. (Employee) Roger Echols, MD, Shionogi Inc. (Consultant)

scholarly journals Intra- and Interspecies Signaling betweenStreptococcus salivarius and Streptococcus pyogenes Mediated by SalA and SalA1 Lantibiotic Peptides

2001 ◽  
Vol 183 (13) ◽  
pp. 3931-3938 ◽  
Author(s):  
M. Upton ◽  
J. R. Tagg ◽  
P. Wescombe ◽  
H. F. Jenkinson
Keyword(s):  
Streptococcus Pyogenes ◽  
Response Regulator ◽  
Genetic Locus ◽  
Two Component System ◽  
Peptide Modification ◽  
Insertional Inactivation ◽  
Two Component ◽  
Genes Encoding ◽  
Dose Dependent

ABSTRACT Streptococcus salivarius 20P3 produces a 22-amino-acid residue lantibiotic, designated salivaricin A (SalA), that inhibits the growth of a range of streptococci, including all strains ofStreptococcus pyogenes. Lantibiotic production is associated with the sal genetic locus comprisingsalA, the lantibiotic structural gene; salBCTXgenes encoding peptide modification and export machinery proteins; andsalYKR genes encoding a putative immunity protein and two-component sensor-regulator system. Insertional inactivation ofsalB in S. salivarius 20P3 resulted in abrogation of SalA peptide production, of immunity to SalA, and ofsalA transcription. Addition of exogenous SalA peptide tosalB mutant cultures induced dose-dependent expression ofsalA mRNA (0.2 kb), demonstrating that SalA production was normally autoregulated. Inactivation of salR encoding the response regulator of the SalKR two-component system led to reduced production of, and immunity to, SalA. The sal genetic locus was also present in S. pyogenes SF370 (M type 1), but because of a deletion across the salBCT genes, the corresponding lantibiotic peptide, designated SalA1, was not produced. However, in S. pyogenes T11 (M type 4) the sallocus gene complement was apparently complete, and active SalA1 peptide was synthesized. Exogenously added SalA1 peptide from S. pyogenes T11 induced salA1 transcription in S. pyogenes SF370 and in an isogenic S. pyogenes T11salB mutant and salA transcription in S. salivarius 20P3 salB. Thus, SalA and SalA1 are examples of streptococcal lantibiotics whose production is autoregulated. These peptides act as intra- and interspecies signaling molecules, modulating lantibiotic production and possibly influencing streptococcal population ecology in the oral cavity.

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