Galektin-3 u patogenezi gojaznosti i tip 2 Diabetes melliitus-a

Patogeneza tip 2 Diabetes mellitus-a indukovanog gojaznošću je bazirana na inflamaciji generisanoj u ekspandirajućem visceralnom adipoznom tkivu i infiltraciji makrofaga u pankreasna ostrvca. Metabolička inflamacija („metaflamacija“) je hronična inflamacija niskog stepena (engl. low-grade inflammation) indukovana brojnim štetnim metabolitima nastalim u uslovima povećanog energetskog unosa i predisponira nastanak insulinske rezistencije i tip 2 Diabetes mellitus-a. Galektin-3 je multifunkcionalni β-galaktozid-vezujući lektin eksprimiran u različitim ćelijama kako imunskog sistema, tako i ćelijama drugih tkiva i organa. U zavisnosti od svoje ćelijske lokalizacije (citoplazmatska, nuklearna, membranska ili ekstraćelijska) učestvuje u regulaciji brojnih funkcija adaptivnog i urođenog imunskog odgovora. Galektin-3 igra važnu imunoregulatornu ulogu u patogenezi autoimunskih, inflamatornih i malignih bolesti i verovatno različitim procesima regulacije metaboličke homeostaze. Glavni cilj studije je bio da ispita ulogu galektina-3 u patogenezi gojaznosti i tip 2 Diabetes mellitus-a u mišjem modelu gojaznosti indukovane primenom dijete sa visokim sadržajem masti. U studiju su uključeni miševi kojima je ciljano uklonjen gen za galektin-3 (LGALS3-/-), kao i odgovarajući galektin-3 pozitivni miševi (LGALS3+/+) soja C57BL/6. Ablacija gena za galektin-3 ubrzava nastanak gojaznosti i tip 2 Diabetes mellitus-a što se manifestuje uvećanjem telesne mase i količine visceralnog adipoznog tkiva, hiperglikemijom, hiperinsulinemijom, uvećanjem glikoziliranog hemoglobina (HbA1c), HOMA-IR (engl. homeostasis model assessment of insulin resistance) i sistemskih markera inflamacije u miševa na ishrani sa visokim sadržajem masti. U visceralnom adipoznom tkivu gojaznih LGALS3-/- miševa je povećana infiltracija tip 1 T i NKT limfocita i pro-inflamatornih M1 makrofaga, dok je zastupljenost regulatornih CD4+CD25+FoxP3+ T limfocita i alternativno aktiviranih M2 makrofaga značajno snižena u poređenju sa Galektin-3 u patogenezi gojaznosti i tip 2 Diabetes mellitus-a 178 LGALS3+/+ miševima na istoj vrsti dijete. U pankreasnim ostrvcima LGALS3-/- miševa na ishrani sa visokim sadržajem masti dokumentovana je povećana infiltracija mononuklearnih ćelija, povećana ekspresija NLRP3 inflamazoma i interleukina-1β (IL-1β) u infiltrišućim makrofagima i pojačano deponovanje metabolita AGE (engl. advanced glycation end products) i receptora za AGE (RAGE), što je praćeno povećanom ekspresijom fosforilisanog nuklearnog faktora-κB (NF-κB) r65 i aktivne kaspaze-1 u visceralnom adipoznom tkivu i pankreasnim ostrvcima. In vitro stimulacija peritonealnih makrofaga LGALS3-/- miševa lipopolisaharidom (LPS) i/ili zasićenom masnom kiselinom palmitatom indukuje pojačanu kaspaza-1 zavisnu produkciju IL-1β i fosforilaciju NF-κB r65 u poređenju sa LGALS3+/+ miševima. Isključivanje gena za NLRP3 inflamazom u peritonealnim makrofagima LGALS3-/- miševa metodom transfekcije siRNA (engl. small interfering RNA) atenuira produkciju IL-1β u odgovoru na stimulaciju palmitatom i LPS-om. Ubrzana i pojačana inflamacija u visceralnom adipoznom tkivu i pankreasnim ostrvcima galektin-3 deficijentnih miševa ukazuje na važnu protektivnu ulogu galektina-3 u gojaznosti i tip 2 Diabetes mellitus-u što bi u budućnosti moglo imati terapijske implikacije.Obesity-induced type 2 Diabetes mellitus is associated with inflammation originated in expanding visceral adipose tissue and macrophage infiltration of pancreatic islets. Metabolic inflammation, “metaflammation,” is a chronic, low-grade adipose tissue inflammation triggered by various metabolic “danger” signals during obesity that precedes the development of insulin resistance and type 2 Diabetes mellitus. Galectin-3 is a multifunctional β-galactoside–binding lectin expressed by a variety of cell types. Depending on it's cellular localization (cytoplasmic, nuclear, membrane-bound or extracellular), Galectin-3 regulates various T-cell functions and innate immune responses. Galectin-3 plays an important immunoregulatory role in pathogenesis of autoimmune, inflammatory and malignant diseases, but also in metabolic abnormalities. The aim of this study was to investigate the role of Galectin-3 in high-fat diet (HFD)– induced obesity and associated metabolic abnormalities by using mice lacking galectin-3 (LGALS3-/-) on a C57BL/6 background. Ablation of galectin-3 accelerates high-fat diet–induced obesity and diabetes. Obese LGALS3-/- mice have increased body weight, amount of total visceral adipose tissue, fasting blood glucose and insulin levels, homeostasis model assessment of insulin resistance (HOMA-IR), glycated haemoglobin (HbA1c) and markers of systemic inflammation compared with diet-matched wild-type (LGALS3+/+) animals. Visceral adipose tissue of obese LGALS3-/- mice exhibited increased incidence of type 1 T and NKT lymphocytes and proinflammatory М1 macrophages and decreased CD4+CD25+FoxP3+ regulatory T cells and M2 macrophages. Pronounced mononuclear cell infiltrate, increased expression of NLRP3 inflammasome and interleukin-1β (IL-1β) in macrophages, and increased accumulation of advanced glycation end products (AGEs) and receptor for AGE (RAGE) expression were present in pancreatic islets of obese LGALS3-/- animals accompanied with elevated phosphorylated nuclear factor-kB (NF-kB) p65 and mature caspase-1 protein expression in pancreatic tissue and visceral adipose tissue. In vitro stimulation of LGALS3-/- peritoneal macrophages with lipopolysaccharide Галектин-3 у патогенези гојазности и тип 2 Diabetes mellitus-а 183 (LPS) and saturated fatty acid palmitate caused increased caspase-1–dependent IL-1β production and increased phosphorylation of NF-kB p65 compared with LGALS3+/+ cells. Transfection of LGALS3-/- macrophages with NLRP3 small interfering RNA attenuated IL-1β production in response to palmitate and LPS plus palmitate. Collectively, the amplified obesity-induced inflammation in adipose tissue and pancreatic islets in LGALS3-/- mice suggest a protective role for Gal-3 in obesity and type 2 diabetes, which could be of therapeutic relevance

ELECTROCHEMICAL BEHAVIOR AND DIFFERENTIAL PULSE VOLTAMMETRIC DETREMINATION OF CEFTAZIDIME, CEFUROXIME-AXETIL AND CEFTRIAXONE

The voltammetric behavior of ceftazidime, cefuroxime-axetil and ceftriaxone has been examined in pH range 2.0-8.0 by cyclic and differential pulse voltammetry using hanging mercury drop electrode. The effect of the pH and scan rate on the peak currents and potentials was examined. The nature of the electrode reduction process in acid solution was found to be diffusion controlled for ceftazidime and cefuroxime-axetil, but strongly influenced by the adsorption in the case of ceftriaxone reduction. Ceftriaxone adsorption decreased with the increase of pH, and at pH>7 the reduction process became diffusion controlled. Based on this study, DPV method was developed, validated and suggested for determination of ceftazidime at pH 2.0, cefuroxime-axetil at pH 3.5 and for ceftriaxone at pH 8.0. Linear concentration ranges, LOD and LOQ were determined. The method was applied for determination of cephalosporins in pharmaceutical dosage forms: Ceftazidime powder, Ceroxim tablets and Longaceph powder for injection solution

Synthesis, optical and magnetic properties studies of multiferroic BiFeO3

Nanosized bismuth ferrite powder has a potential application in the production of lead free piezoelectric materials for actuators as well as magnetoelectric sensors. The simple, low-costing and energy-saving hydrothermal method has advantages over the conventional methods. BiFeO3 powders were made using Bi(NO3)35H2O and Fe(NO3)3 9H2O as starting material and 8 M KOH as mineralizer. The particle size and morphology were analyzed using scanning electron microscopy (SEM). The phase composition of obtained samples was determined by X-ray diffraction (XRD) analysis. It revealed that synthesized material crystallize in space group R3c with cell parameters a = b = 5.5780(10) Å and c = 13,863(3) Å. IR and Raman spectroscopy have been performed on the synthesized bismuth ferrite (BFO) powders in order to confirm the formation of pure and well-crystallized BFO nanocrystallites. 57Fe Mössbauer spectroscopy was performed in order to provide information on Fe cation arrangement in the BiFeO3 phase. The magnetic and optical properties of properties of BFO samples were characterized by SQUID magnetometry, and ultraviolet–visible spectroscopy. Temperature dependence of magnetization shows antiferromagnetic-paramagnetic phase transition at TN = 220 K, while below this temperature weak ferromagnetic ordering is detected

Oxidation and erosion behaviour of SiC-HfC multilayered composite

The fabrication of SiC-HfC ceramic composite via self-propagating high-temperature synthesis and simultaneous consolidation was investigated. Dense composite consisting of alternating layers of SiC and HfC was obtained by spark plasma sintering of stack of SiC cloths covered by electrophoretically deposited HfO2. The deposited HfO2 was converted into HfC during sintering. The obtained ceramics was characterized in terms of microstructure, cavitation resistance and oxidation resistance. It was shown that spark plasma sintering is effective way to preserve fibre-like mikrostructure of SiC. The obtained material showed good erosion resistance. The surface layer of HfC transformed to HfO2 during oxidation of samples and protected SiC from further oxidation

Uloga Paecilomyces lilacinus (Thom) Samson i drugih vrsta gljiva u biodegradaciji ohratoksina A

Nine isolates of fungi of genera Aspergillus, Fusarium, Paecilomyces and Penicillium were cultured on the modified Vogel's medium with the addition of crude ochratoxin A (OTA) extract. This crude OTA extract was derived from a natural solid substrate on which Aspergillus ochraceus strain CBS 108.08 was cultivated. OTA was isolated, partially purified, dried by evaporating and dissolved in ethanol (1 mg ml-1), and added to the test medium up to the final concentration of 10 μg ml-1. The presence of OTA residues was determined after 7 and 14 day cultivation of fungi in the test medium at 27±1°C. The Paecilomyces lilacinus isolate (Inf. 2/A), which completely degraded OTA (150 μg) after only seven days, was selected for further studies. Wet sterile rice grains (50 g + 25 ml distilled water) were inoculated with individual isolates of fungi A. ochraceus (strain CBS 108.08) and P. lilacinus (isolate Inf. 2/A), and with their combination. In the case of P. lilacinus monoculture, 0.9 mg of crude OTA was also added into cultivation substrate. Each test was done in three replications. After the four week cultivation of individual and combined fungi at 27±1°C, inoculated rice grains were dried to the constant weight and pulverized. OTA was determined in these samples by the application of standard TLC method for fodder analysis. OTA in the amount of 61.310 μg kg-1 dry matter (DM) was determined only in the samples inoculated with a producer of ochratoxin A (A. ochraceus, strain CBS 108.08). On the other hand, a much smaller amount of OTA (80 μg kg-1 DM) was detected in samples inoculated with combined cultures of A. ochraceus and P. lilacinus isolates. Gained results indicate that P. lilacinus degraded, on average, 99.8% of OTA. After four week cultivation, the same fungal isolate in the samples of wet sterile rice kernels with the addition of 0.9 mg of crude OTA, completely degraded added crude OTA ( lt 8 μg kg-1).Devet izolata gljiva iz rodova Aspergillus, Fusarium, Paecilomyces i Penicillium gajeno je na modifikovanoj Vogelovoj podlozi sa dodatkom sirovog ekstrakta ohratoksina A (OTA). Sirovi ekstrakt OTA je dobijen iz čvrstog prirodnog supstrata na kojem je gajen soj Aspergillus ochraceus CBS 108.08. Izolovan i delimično prečišćen OTA, uparen do suvog ostatka i rastvoren u etanolu (1 mg ml-1), dodat je u test podlogu do finalne koncentracije 10 μg ml-1. Nakon sedam i 14 dana gajenja kultura gljiva u test podlozi na 27 ± 1°C de terminisano je prisustvo rezidua OTA primenom modifikovane metode Filtenborg-a i sar. (1983). Od devet testiranih izolata za dalja ispitivanja je odabran izolat Paecilomyces lilacinus (Inf. 2/A), koji je već posle sedam dana u potpunosti razgradio inicijalnu količinu OTA (150 μg). U drugom delu eksperimenta vlažno sterilno zrno pirinča (50 g + 25 ml destilovane vode) zasejano je sa pojedinačnim izolatima A. ochraceus (CBS 108.08) i P. lilacinus (Inf. 2-A), kao i kombinacijom oba izolata. U slučaju mono-kulture P. lilacinus u podlogu je dodat i sirovi OTA (0,9 mg). Svaki od testova je urađen u 3 ponavljanja. Nakon četiri nedelje gajenja monokultura i mešanih kul tura gljiva na 27±1°C, inokulisana zrna su osušena do konstantne težine i sa mlevena do finog praha. U ovim uzorcima izvršena je determinacija OTA primenom standardne metode tankoslojne hromatografije za analizu stočne hrane. U uzorcima koji su bili zasejani samo sa producentom OTA (A. ochraceus, soj CBS 108.08) detektovan je OTA u prosečnoj količini od 61.310 μg kg-1 suvog ostatka. U uzorcima koji su bili zasejani kombinovanim kulturama izolata A. ochraceus i P. lilacinus utvrđena je znatno manja prosečna količina OTA (80 μg kg-1). Ovi rezultati ukazuju da je izolat P. lilacinus razgradio prosečno 99,8% OTA prisutnog u podlozi za kultivaciju. U uzorcima vlažnog sterilnog zrna pirinča sa dodatkom 0,9 mg sirovog OTA isti gljivični izolat je posle četiri nedelje kultivacije kompletno biorazgradio dodat sirovi OTA ( lt 8 μg kg-1)

In vitro degradacija diacetoksiscirpenola i T-2 toksina posredstvom izolata Mucor racemosus fresen. f. racemosus

Under controlled in vitro conditions the capacity of the Mucor racemosus f. racemosus 1215/09 isolate to degrade type A trichothecenes (diacetoxyscirpenol - DAS and T-2 toxin) was observed in the liquid nutritive medium. According to previously performed experiments it was proved that the selected isolate, originating from sunflower meal, had the ability to degrade these fusariotoxins when growing on the modified Vogel's agar supplemented with crude extracts of DAS and T-2 toxin. In order to determine biodegradation of fusariotoxins, the liquid nutritive medium - SPY (5% sucrose + 0.1% peptone + 0.1% yeast extract, pH 6.2) was simultaneously inoculated with the isolate M. racemosus f. racemosus 1215/09 and: a) Fusarium semitectum SL-B (DAS producer) or b) F. sporotrichioides R-2301 (T-2 toxin producer). The SPY media, inoculated with single fungal isolates, were used as a control of toxin biosynthesis. The cultures were incubated at room temperature (21-26ºC) on the rotary shaker (175 rpm). After the 3-5-day incubation, the filtration of liquid cultures and the extraction of fusariotoxins from filtrates with ethyl-acetate were performed. Determinations of DAS and T-2 toxin were done by thin layer chromatography using silica gel G. Depending on the incubation duration, M. racemosus f. racemosus in the mixed culture with F. semitectum degraded from 90.0 to 99.97% of DAS present in the medium (40,000- 120,000 µg l-1), while in the mixed culture with F. sporotrichioides it degraded from 95.0 to 96.7% of T-2 toxin present in the medium (240,000 µg l-1). Sterile filtrates of mixed cultures and single culture of M. racemosus f. racemosus, obtained by passing liquid cultures through the 0.45-µm membrane filter and added to the SPY medium, did not affect degradation of type A trichothecenes that had been biosynthesised by isolates F. semitectum SL-B and F. sporotrichioides R-2301 in the liquid medium.U kontrolisanim in vitro uslovima proučavana je sposobnost izolata Mucor racemosus f. racemosus 1215/09 da degraduje trihotecene tipa A (diacetoksiscirpenol - DAS i T-2 toksin) u tečnoj hranljivoj podlozi. Prethodnim eksperimentima je dokazano da odabrani izolat, poreklom sa suncokretove sačme, poseduje sposobnost razgradnje navedenih fuzariotoksina, koji su kao sirovi ekstrakti dodati u modifikovanu Vogelovu podlogu. U cilju utvrđivanja biodegradacije fuzariotoksina tečna hranljiva podloga SPK (5% saharoza + 0,1% pepton + 0,1% ekstrakt kvasca, pH 6,2) je zasejana u isto vreme izolatom M. racemosus f. racemosus 1215/09 i: a) Fusarium semitectum SL-B (proizvođač DAS-a) ili b) F. sporotrichioides R-2301 (proizvođač T-2 toksina). Kao kontrola biosinteze toksina korišćena je SPK podloga inokulisana pojedinačnim izolatima gljiva. Kulture su inkubirane na rotacionoj tresilici (175 o/min) tokom 3-5 dana na sobnoj temperaturi (21-26ºC). Nakon 3 do 5 dana inkubacije vršeno je filtriranje tečnih kultura i ekstrakcija fuzariotoksina iz filtrata etil-acetatom. Determinacija DAS-a i T-2 toksina je rađena tankoslojnom hromatografijom na silika gelu G. Zavisno od dužine inkubacije, M. racemosus f. racemosus je u združenoj kulturi sa F. semitectum degradovala 90,0-99,97% DAS-a prisutnog u podlozi (40.000-120.000 µg l-1), dok je u združenoj kulturi sa F. sporotrichioides razgradila 95,0-96,7% T-2 toksina prisutnog u podlozi (240.000 µg l-1). Sterilni filtrati mešanih kultura i pojedinačne kulture M. racemosus f. racemosus, dobijeni propuštanjem tečnih kultura kroz 0,45 µm membranski filter i dodati SPK podlozi, nisu uticali na razgradnju trihotecena tipa A koje su biosintetisali izolati F. semitectum SL-B i F. sporotrichioides R-2301 u tečnoj podlozi

Synthesis and characterization of spider silk calcite composite

Spider silk poses excellent mechanical properties, tenacity and elasticity and it has been used as a template for calcite mineralization to improve load bearing strength of osteoconductive calcite. The samples were obtained by mimicking biomineralization for five days in order to follow formation and growth of calcite on the surface of spider silk. Crystal phase was detected by XRD and FTIR spectroscopy. Microstructure, crystal size and its morphology were studied by means of FESEM. After two days of processing, pure calcite phase was obtained, and a size of the formed crystals increased with prolongation of biomineralization

A novel reduction-oxidation synthetic route for hafnia

Amorphous hafnia (HfO2) powders were synthesized through a novel reduction oxidation route, in which, metal hafnium was reduced from hafnium tetrachloride (HfCl4) by sodium borohydride (NaBH4), and then oxidized in ambient atmosphere. Upon calcinations, the powder crystallized to nanometric size HfO2 powder with monoclinic structure. Powder properties such as lattice parameters, crystallite and particle size were studied. X-ray diffraction analysis (XRD) was used to characterize structure and phase evolution in synthesized samples. Calculation of the average crystallite size (D) was performed on the basis of the full width at half maximum intensity (FWHM) of the XRD peaks. Williamson-Hall plots were used to separate the effect of the size and strain in the nanocrystals. The morphologies of powders calcinated at higher temperatures were followed by Scanning electron microscopy (SEM). (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Synthesis and characterization of tungsten carbide fine powders

Fine tungsten carbide (WC) powder was prepared by solid state reaction between tungsten powder (W) and activated carbon cloth as a new carbon (C) source. The effect of temperature and time of heat treatment as well as the effect of C/W ratio on WC phase formation was studied. The results obtained by X-ray powder diffraction (XRPD) show that obtained powder is single WC. Microstructure and morphology was determinate by means of scanning electron microscopy (SEM). Brunauer-Emmett-Teller (BET) method was used for examining specific surface area and texture of obtained powders. It was found that WC powder was successfully synthesized in excess carbon after eight-hour heat treatment at relatively low temperature (1000 degrees C). (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Synthesis and Characterization of Biomorphic Ceo2 Obtained By Using Egg Shell Membrane as Template

Porous CeO2 was obtained by bio-inspired route using egg shell membranes (ESM) as a template. ESM extracted from the fresh chicken eggs were washed with distilled water and immersed in solution of Ce(NO3)(3) x 6 H2O for seven days. Samples were subsequently thermally treated at temperature ranging from 600 to 1200 degrees C in argon and air.To study the crystallization process, samples were heated to temperature ranging from 600 to 1200 degrees C, in air, at different temperatures (600, 800, 1000 and 1200 degrees C). Samples were characterized by nitrogen adsorption measurements, X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD of samples revealed that well crystallized CeO2 is obtained even at temperature as low as 600 degrees C. SEM images confirmed that morphology of obtained CeO2 is a replica of the morphology of the original ESM.International Conference ModTech Proceedings, 16th International Conference on Modern Technologies, Quality and Innovation, May 24-26, 2012, Sinaia, Romani