Response surface method
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Response surface methodology was used to evaluate the effect of main variables such as concentration of galactose, yeast extract and wheat bran on alpha-galactosidase production from Aspergillus parasiticus MTCC-2796 under submerged fermentation conditions. A full factorial Central Composite Design was applied to study these main factors that affected alpha-galactosidase production. The experimental results showed that the optimum concentration of galactose, yeast extract and wheat bran were 1.5 %, 0.06 % and 1.5 %, respectively. This method was efficient as only 20 experiments were necessary to asses these conditions, and model adequacy was very satisfactory as the coefficient of determination was 0.9921.
Living organisms interact with various chemical compounds via receptors, which is described by the receptor theory. The affinity of the biologically active compounds toward receptors and their ability to trigger a biological or toxic signal vary substantially. In this work, we describe a new insight into understanding of the mode of action of receptor partial agonists and the receptor theory using a Full Logistic Model (FLM) of mixture toxicology. We describe the hypothesis that the effect of a partial agonist can be mathematically described via separation of agonistic and antagonistic behavior of the partial agonist where the antagonistic effect is described as an action of the compound producing zero effect. In this way, a competitive antagonist can be considered as an agonist with zero effect. This idea is also placed into a context with classical concepts, e.g., Gaddum's equation. Using the assumption that competitive antagonists are agonists with no effect, equations describing the microscopic and macroscopic equilibrium constants have been derived. Accordingly, we show that the constants could be calculated from the measured partial agonistic dose-response curve. As a consequence, we provide a simple mathematical tool for comparison of dose-response curves of drugs according to their affinities and efficacies.
PURPOSE: Obstructive Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease. Meibomian glands at the eyelid secrete lipids that prevent evaporation of the aqueous tear film. The pathogenesis of obstructive MGD is incompletely understood to date. Herein, we aim to investigate the pathogenesis of obstructive MGD using murine and human samples with various forms of ocular surface inflammation. METHOD: The presence of Neutrophil extracellular Traps (NETs) was detected with immunofluorescence analysis of ocular surface discharge and biopsy samples from patients with blepharitis. Tear fluid from patients with MGD and blepharitis were evaluated for the presence of inflammatory mediators using bead based immunoassay. Murine model of allergic eye disease (AED) was performed to investigate the role of NETs in MG occlusion. RESULTS: we show that the ocular discharge from patients with blepharitis contains aggregated neutrophil extracellular traps (aggNETs). Furthermore, the ducts of human Meibomian glands affected by blepharitis were largely congested by aggNETs. Tear fluid from patients with MGD showed elevated neutrophil chemoattractants (C5a, IL6, IL8 and IL18). C5a and IL8 correlated with the degree of deficiency of tear fluid. In the murine model of allergic eye disease (AED), aggNETs accumulated in the MG leading to occlusion of their ducts and the retrograde pent-up of the fluid followed by acinar atrophy. Constraining aggNET formation by genetic or pharmacological inhibition of peptidyl arginine deiminase type 4 (PADI4) effectively reduced MG damage. CONCLUSION: We conclude that aggNETs occlude MG causing MGD after ocular surface inflammation.
- MeSH
- extracelulární pasti * MeSH
- lidé MeSH
- meibomské žlázky MeSH
- myši MeSH
- nemoci očních víček * MeSH
- slzy MeSH
- syndromy suchého oka * MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
L-asparaginase is an essential enzyme used in cancer treatment, but its production faces challenges like low yield, high cost, and immunogenicity. Recombinant production is a promising method to overcome these limitations. In this study, response surface methodology (RSM) was used to optimize the production of L-asparaginase 1 from Saccharomyces cerevisiae in Escherichia coli K-12 BW25113. The Box-Behnken design (BBD) was utilized for the RSM modeling, and a total of 29 experiments were conducted. These experiments aimed to examine the impact of different factors, including the concentration of isopropyl-b-LD-thiogalactopyranoside (IPTG), the cell density prior to induction, the duration of induction, and the temperature, on the expression level of L-asparaginase 1. The results revealed that while the post-induction temperature, cell density at induction time, and post-induction time all had a significant influence on the response, the post-induction time exhibited the greatest effect. The optimized conditions (induction at cell density 0.8 with 0.7 mM IPTG for 4 h at 30 °C) resulted in a significant amount of L-asparaginase with a titer of 93.52 μg/mL, which was consistent with the model-based prediction. The study concluded that RSM optimization effectively increased the production of L-asparaginase 1 in E. coli, which could have the potential for large-scale fermentation. Further research can explore using other host cells, optimizing the fermentation process, and examining the effect of other variables to increase production.
- MeSH
- asparaginasa * genetika biosyntéza metabolismus MeSH
- Escherichia coli K12 genetika enzymologie MeSH
- Escherichia coli genetika metabolismus MeSH
- fermentace MeSH
- isopropylthiogalaktosid farmakologie MeSH
- rekombinantní proteiny * genetika metabolismus MeSH
- Saccharomyces cerevisiae * genetika metabolismus MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Na souboru 23 studentů byla pomocí Moire metody, barogratického vyšetření a EMG vyšetření zkoumaná odezva axiálního systému na uměle navozené typy sedů. Byly zvoleny tři druhy sedů (nekorigovaný sed bez použití pomůcek, sed na sedacím klínu a sed na labilní ploše - míč overball). Doba měření pro každý typ sedu byla 2 minuty. Výsledky ukázaly klíčové postavení pánve. Břišní svaly se nejvíce aktivovaly v poloze na míči. Rozložení tlaku na sedací hrboly se snížilo na sedacím klínu.
By means ot Moire method, barographic examination, and EMG examination the response ot axial system on artiticially evoked types ot sitting positions was investigated in the complex ot 23 students. There were chosen three types ot sitting positions (incorrected sitting position without the use ot aids, sitting position on a sitting wedge, and sitting on an unstable surface - overball). The time ot measuring tor each type ot the sitting position were 2 minutes. Results showed the key position ot pelvis. Abdominal muscles were the most activated in position on the balt. Spread ot the pressures on sitting tubercles was lowered on the sitting wedge.
Cíl: pomocí pokusů in vitro studovat vliv povrchových vlastností vybraných implantačních materiálů na adherenci některých krevních složek (plazma, sérum) a sledovat vliv těchto adsorbovaných proteinů na povrchu implantátu na adhezi i syntetickou aktivitu kultivovaných osteoblastů. Metodika: U zvolených materiálů : titan leptaný (Ti-Etch), titan plazma-sprayovaný (Ti-PlaSpray), titan s hydroxyapatitovou vrstvou (Ti-HA), a uhlíkový kompozit (C/C) byly stanoveny fyzikálně-chemické parametry povrchu (drsnost, smáčivost a volná povrchová energie). Jako kontrola sloužil polystyren kultivačních destiček pro tkáňové kultury (TCPS). Biologická úprava materiálů byla provedena pokrytím jednou ze dvou vybraných krevních komponent–plazma nebo sérum. Na materiálech bez pokrytí i s biologickou úpravou byly kultivovány osteoblasty a následně byla z mitochondriální oxidační aktivity monolayeru buněk (MTT test) vyhodnocena jejich proliferace. V získaném kultivačním médiu byla pomocí enzymoimunosorbentní analýzy (ELISA) stanovena aktivita osteoblastů jako hladina kostní alkalické fosfatázy (BAP) a produkce zánětlivých cytokinů (TNF-?, IL-8). Výsledky: Vysoká drsnost implantátů ovlivnila zvýšenou proliferaci u titanových materiálů (Ti-PlaSpray). Nízká proliferace C/C je přičítána téměř nulové hodnotě polární složky povrchové energie. Potažení materiálů aktivovanou plazmou (fibrinovou sítí) vedlo ke vzniku unifikovaného povrchu jak z hlediska proliferace, tak i z hlediska syntetické aktivity. Oproti tomu při potažení implantátů sérem (albuminem) nebyl pozorován takový stimulační efekt na osteoblasty jaký jsme předpokládali. Závěr: Pokrytí vybraných implantačních materiálů aktivovanou plazmou (tj. fibrinovou sítí) vede k vytvoření povrchu s potřebnou rovnováhou mezi mírou proliferace a syntetickou aktivitou osteoblastů jako modelu imunitní odpovědi organizmu na zavedený implantát.
Aim of the study: To study the impact of surface properties of selected implant materials on adherence of some blood components (plasma, serum), and the impact of these proteins, adsorbed on the implant surface, on the adhesion and synthetic activity of cultured osteoblasts using in vitro experiments. Methods: In selected materials such as etched titanium (Ti-Etch), plasma-sprayed titanium (Ti-PlaSpray), titanium with hydroxyapatite layer (Ti-HA), and carbon composite (C/C), the physiochemical parameters were determined (roughness, wettability, and free surface energy). Tissue culture polystyrene (TCPS) was used as a control. Biological modification of materials was performed by overlaying of one of two selected blood components – plasma or serum. Osteoblasts were cultured on materials without overlay, as well as materials with biological modification, and consequently, the proliferation of osteoblasts was evaluated due to the mitochondrial oxidation activity of monolayer (MTT assay). In the obtained culture medium, the activity of osteoblasts was determined as the level of bone alkaline phosphatase (BAP) and the production of inflammatory cytokines (TNF-?, IL-8) using enzyme-linked immunosorbent assay (ELISA). Results: High roughness of implants affected the increased proliferation in titanium materials (Ti-PlaSpray). A decreased proliferation of C/C is attributed to almost zero value of polar component of surface energy. Overlaying of materials by activated plasma (fibrin network) led to formation of unified surface in terms of both proliferation and synthetic activity. However, overlaying of implants by serum (albumin) did not have the anticipated stimulatory effect on osteoblasts. Conclusion: Overalying of selected implant materials by activated plasma (i.e. fibrin network) leads to formation of a surface with required balance between the proliferation rate and synthetic activity of osteoblasts as a model of organisms’s immune response to an applied implant. Key words:
- MeSH
- adhezivita MeSH
- cytokiny imunologie MeSH
- ELISA metody využití MeSH
- financování organizované MeSH
- krevní buňky metabolismus MeSH
- krevní plazma fyziologie metabolismus MeSH
- lidé MeSH
- osteoblasty metabolismus MeSH
- povrchové napětí MeSH
- povrchové vlastnosti MeSH
- proliferace buněk MeSH
- protézy a implantáty škodlivé účinky MeSH
- sérum fyziologie metabolismus MeSH
- smáčivost MeSH
- Check Tag
- lidé MeSH
BACKGROUND: The main goal of this research was to study the interactions of a fully characterized set of silver nanomaterials (Ag ENMs) with cells in vitro, according to the standards of Good Laboratory Practices (GLP), to assure the quality of nanotoxicology research. We were interested in whether Ag ENMs synthesized by the same method, with the same size distribution, shape and specific surface area, but with different charges and surface compositions could give different biological responses. METHODS: A range of methods and toxicity endpoints were applied to study the impacts of interaction of the Ag ENMs with TK6 cells. As tests of viability, relative growth activity and trypan blue exclusion were applied. Genotoxicity was evaluated by the alkaline comet assay for detection of strand breaks and oxidized purines. The mutagenic potential of Ag ENMs was investigated with the in vitro HPRT gene mutation test on V79-4 cells according to the OECD protocol. Ag ENM agglomeration, dissolution as well as uptake and distribution within the cells were investigated as crucial aspects of Ag ENM toxicity. Ag ENM stabilizers were included in addition to positive and negative controls. RESULTS: Different cytotoxic effects were observed including membrane damage, cell cycle arrest and cell death. Ag ENMs also induced various kinds of DNA damage including strand breaks and DNA oxidation, and caused gene mutation. We found that positive Ag ENMs had greater impact on cyto- and genotoxicity than did Ag ENMs with neutral or negative charge, assumed to be related to their greater uptake into cells and to their presence in the nucleus and mitochondria, implying that Ag ENMs might induce toxicity by both direct and indirect mechanisms. CONCLUSION: We showed that Ag ENMs could be cytotoxic, genotoxic and mutagenic. Our experiments with the HPRT gene mutation assay demonstrated that surface chemical composition plays a significant role in Ag ENM toxicity.
- MeSH
- biologický transport MeSH
- buněčná membrána účinky léků patologie MeSH
- Cricetulus MeSH
- hodnocení rizik MeSH
- hypoxanthinfosforibosyltransferasa genetika MeSH
- kometový test MeSH
- kontrolní body buněčného cyklu účinky léků MeSH
- kovové nanočástice * MeSH
- lidé MeSH
- mutace * MeSH
- mutační analýza DNA MeSH
- nádorové buněčné linie MeSH
- oxidační stres účinky léků MeSH
- poškození DNA * MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- sloučeniny stříbra chemická syntéza metabolismus toxicita MeSH
- tvar buňky účinky léků MeSH
- velikost částic MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
For experiments with dispersed radioactive aerosols in a radon-aerosol chamber (RAC), it is desirable to know the activity of the radioactive aerosols applied in the RAC. A COLIBRI TTC survey metre with an SABG-15+ probe (Canberra, USA) was purchased for this purpose. The probe is designed for surface contamination measurements, and it is intended to measure the activity of aerosols deposited on the filters during experiments in the RAC. Since the probe is calibrated in a different geometry, its response in the authors' experimental geometry was simulated by a Monte Carlo method. The authors present a Monte Carlo model using MCNPX and an experimental verification of this probe model.
- MeSH
- aerosoly analýza MeSH
- alfa částice MeSH
- design vybavení MeSH
- kalibrace MeSH
- metoda Monte Carlo MeSH
- monitorování radiace přístrojové vybavení MeSH
- počítačová simulace MeSH
- radioaktivní látky znečišťující vzduch analýza MeSH
- radiometrie přístrojové vybavení metody MeSH
- radionuklidy analýza MeSH
- teoretické modely MeSH
- záření gama MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
