Rat duodenal motility in vitro: Prokinetic effects of DL-homocysteine thiolactone and modulation of nitric oxide mediated inhibition

Homocysteine is a significant but modifiable risk factor for vascular diseases. As gastrointestinal smooth musculature is similar to blood vessel muscles, we investigated how elevated homocysteine levels affect nitric oxide-mediated neurotransmission in the gut. There is accumulated evidence that a dysfunction of NO neurons in the myenteric plexus may cause various diseases in the gastrointestinal tract such as achalasia, diabetic gastroparesis and infantile hypertrophic pyloric stenosis. In the present study, we aimed to assess the effects of homocysteine on NO-mediated responses in vitro, and to examine the effects of DL-homocysteine thiolactone on the spontaneous motility of rat duodenum and nitrergic neurotransmission. DL-homocysteine thiolactone concentration of 10 μmol/L leads to the immediate increase in tone, amplitude and frequency of spontaneous movements in isolated rat duodenum. L-NAME (30 μmol/L) leads to an increase in basal tone, amplitude and frequency of spontaneous contractions. The relaxations induced by EFS were significantly reduced in duodenal segments incubated in DL-homocysteine thiolactone compared with the control group. EFS-induced relaxations were inhibited by L-NAME in both experimental and control groups. These results suggest that a high level of homocysteine causes an important impairment of non-adrenergic non-cholinergic innervation of the rat duodenum. [Projekat Ministarstva nauke Republike Srbije, br. 175043

Dietary Exposure and Risk Assessment of Aflatoxin M1 for Children Aged 1 to 9 Years Old in Serbia

The present study was conducted to estimate the exposure and characterize the risk for the child population of Serbia to Aflatoxin M1 (AFM1) from milk and milk-based food. A total of 3404 samples comprising milk and different milk-based food samples were collected from various regions of Serbia from 2017 to 2019. Evaluation of AFM1 exposure was carried out using the deterministic method, whereas risk characterization was evaluated using the margin of exposure (MOE) and the risk of hepatocellular carcinoma (HCC). Detection rates for AFM1 in milk and milk-based food samples ranged between 2% and 79%, with the highest incidence (79%) and mean level (22.34 ± 0.018 ng kg−1) of AFM1 being detected in pasteurized and UHT milk. According to the three consumption estimates, the values of estimated daily intake (EDI) were higher for toddlers as compared with children aged 3–9 years. Children aged 1–3 years had the highest risk of exposure to AFM1 in milk, with an estimated daily intake of 0.164 and 0.193 ng kg−1 bw day−1 using lower bound (LB) and upper bound (UB) exposure scenarios, respectively. Such difference could result from the higher consumption to weight in younger children. Based on the estimated daily intake (EDI) found in this study, the risk of AFM1 exposure due to consumption of milk and milk-based food was low since the MOE values obtained were >10,000. In addition, the risk of HCC cases/year/105 individuals of different age groups showed that the value of HCC, using potency estimates of 0.0017 (mean), was maximum (0.00034) in the age group 1–3 years, which indicates no health risk for the evaluated groups. The present study revealed the importance of controlling and preventing AFM1 contamination in milk through continuous monitoring and regular inspection to reduce the risk of AFM1 exposure, especially in children

Supplementary material for the article: Šoštarić, T. D.; Petrović, M. S.; Pastor, F. T.; Lončarević, D. R.; Petrović, J. T.; Milojković, J. V.; Stojanović, M. D. Study of Heavy Metals Biosorption on Native and Alkali-Treated Apricot Shells and Its Application in Wastewater Treatment. Journal of Molecular Liquids 2018, 259, 340–349. https://doi.org/10.1016/j.molliq.2018.03.055

Supplementary material for: [https://doi.org/10.1016/j.molliq.2018.03.055]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2152]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2970

Strong coupling regime of semiconductor quantum dot embedded in the nano-cavity

Photonic lattices represent suitable systems for investigation of wave propagation in periodic structures [1]. However, different unavoidable defects may arise either during their process of fabrication or as result of misusage, accidental damage, etc. Although undesirable in the first place, these imperfections enable the existence of different types of stable, localized defect modes [2]. In this paper, we investigate light propagation through composite photonic lattice composed of two identical linear and lossless lattices. The interface between them represents a geometric defect, while each lattice contains a single nonlinear defect that is placed symmetrically with respect to the interface. Depending on the input light beam parameters (its position, width and transverse tilt), the width of geometric defect, strength and position of the nonlinear defects, different dynamical regimes have been identified. These dynamical regimes are caused by the balance of photonic lattice potentials’ contributions originating from the presence of the geometric and two nonlinear defects. We have found numerically conditions under which dynamically stable bounded modes can exist in the area between nonlinear defects or between a nonlinear and a geometric defect. Various types of localized modes such as: two-hump, multi-hump, one- and multicomponent moving breathers localized at a certain area among defects have been observed. The parameters can be adjusted to capture light and to prevent light launched inside the area among defects to leave it, i.e. this corresponds to the appearance of the modes trapped inside this area. Since the configuration of the lattice prevents transmission of the light through the area confined by defects, these modes can formally be related to Fano resonances and Fano- blockade [3, 4]. When light is launched outside the area among defects, different dynamical regimes have been distinguished: total reflection, single and double partial reflection and full transmission through the area among defects. These numerical findings may lead to interesting applications such as blocking, filtering and transporting light beams through the optical medium. Photonic devices based on resonant tunneling such as waveguides interacting through the area between defects, may be applied as add-drop filters.V International School and Conference on Photonics and COST actions: MP1204, BM1205 and MP1205 and the Second international workshop "Control of light and matter waves propagation and localization in photonic lattices" : PHOTONICA2015 : book of abstracts; August 24-28, 2015; Belgrad

Supplementary material for the article: Mihajlović, M.; Petrović, J.; Maletić, S.; Isakovski, M. K.; Stojanović, M.; Lopičić, Z.; Trifunović, S. Hydrothermal Carbonization of Miscanthus × giganteus: Structural and Fuel Properties of Hydrochars and Organic Profile with the Ecotoxicological Assessment of the Liquid Phase. Energy Convers. Manage. 2018, 159, 254–263. https://doi.org/10.1016/j.enconman.2018.01.003

Supplementary material for: [https://doi.org/10.1016/j.enconman.2018.01.003]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2100

Functional, biochemical and histological changes in rat digestive tract in acute hyperhomocysteinemia or subchronic methionine stimulation

Uvod: Homocistein (Hcy) je semi-esencijalna aminokiselina koja sadrži sumpor dobijen iz metionina. In vitro i in vivo studije na pacovima pokazale su alteraciju parametara oksidativnog stresa nakon primene metionina. Hiperhomocisteinemija (HHC) je uključena u patogenezu brojnih bolesti kako svojim prooksidantnim dejstvom tako i oštećenjem antioksidativne zaštite. L-cistein i N-acetil-L-cistein prepoznati su kao supstance sa antioksidativnim kapacitetom u digestivnom traktu. Jedan od načina na koji HHC menja kontraktilni odgovor creva jeste i modulacija nitrergičke neurotransmisije. Studije sprovedene na pacijentima sa HHC ukazuju na to da povišene vrednosti Hcy u plazmi smanjuju stvaranje azot monoksida (NO) i njegove efekte. Cilj ove studije je da utvrdi da li akutna stimulacija homocisteinom ili subhronično opterećenje metioninom dovodi do pojave oksidativnog stresa, i da li L-cistein i N-acetil-L-cistein kao dokazani antioksidansi mogu modulirati efekte subhronične aplikacije metionina. Takođe cilj ovog rada bio je da ispita efekte najtoksičnijeg metabolita homocisteina, tj. D,L-homocistein tiolaktona na kontraktilnost izolovanog creva pacova. Materijal i metode: Za protokol akutne HHC in vivo životinje su bile podeljene u dve grupe (6 po grupi): 1. 1 ml 0,9% NaCl i.p.; 2. 0,6 μmol/g tm D,L- homocisteina i.p.. Nakon 2 sata boravka u laboratorijskim uslovima, životinje su žrtvovane, a tkiva creva i jetre su pripremljena za određivanje pokazatelja oksidativnog statusa (CAT, GPx, SOD, TAS i indeks lipidne peroksidacije). Radi ispitivanja efekata akutne HHC na izolovana tkiva (in vitro uslovi) parametri oksidativnog stresa su određivani u tkivima creva i jetre inkubiranim u Tirodovom rastvoru i D,L-homocistein tiolaktonu (10 μmol/L) u toku 3 h. U supernatantu su određivani parametri oksidativnog stresa (CAT, TBARS, TAS). Pratio se tonus, amplituda i frekvencija spontanih kontrakcija izolovanog creva u Tirodovom rastvoru i u prisustvu D,L-homocistein tiolaktona i supstanci koje utiču na NO posredovanu neurotransmisiju (L-Arginin-10 μmol/L, L-NAME-30 μmol/L)...Introduction: Homocysteine (Hcy) is semi-essential amino acid which contains sumpor from methionine. In vivo and in vitro studies on rats showed alteration of oxidative stress parameters after methionine administration. Hyperhomocysteinemia (HHC) takes part in pathogenesis of various diseases with its prooxidant capacity, and by damaging antioxidative defence as well. L-cysteine and N-acetyl-L-cysteine are substaces with antioxidative capacity in the gut. One of the pattern by which HHC change the contractile response of the gut is modulation of the nitrergic neurotransmission. Studies included patients with HHC showed that increased plasma Hcy concentrations decreased NO production and its effects. This research aimed to investigate effects of acute Hcy stimulation or subchronic methionine administration on oxidative stress paraneters, and L-cysteine and N-acetyl-L-cysteine modulation of subchronic methionine load effects. Also, the aim was to investigate the effects of the most toxic metabolite of homocysteine, D,L-homocysteine thiolactone, on the contractility of isolated segments of the intestine. Material and methods: For the acute HHC protocol in vivo, animals were divided into two groups (6 per group): 1. 1 ml 0.9% NaCl i.p.; 2. 0.6 μmol/g tm D,L- homocysteine i.p. After 2h in laboratory conditions, animals were sacrified, and gut and liver tissues were taken for further analysis (CAT, GPx, SOD, TAS, index of lipid peroxidation). For investigation of the effects of the acute HHC in vitro, oxidative stress parameters were determined in the gut and the liver incubated in Tyrode solution and D,L-homocysteine thiolactone (10 μmol/L) during 3h. In the tissue supernatant oxidative stress parameters were analyzed (CAT, TBARS, TAS). The tone, amplitude and frequency of the contractions of the isolated intestine segments were measured in Tyrode solution and in the presence of D,L-homocysteine thiolactone and substances which modulates NO transmission (L-Arginin-10 μmol/L, L-NAME-30 μmol/L). For subchronic methionine load animals were divided into four groups (n=6): 1..

Functional, biochemical and histological changes in rat digestive tract in acute hyperhomocysteinemia or subchronic methionine stimulation

Uvod: Homocistein (Hcy) je semi-esencijalna aminokiselina koja sadrži sumpor dobijen iz metionina. In vitro i in vivo studije na pacovima pokazale su alteraciju parametara oksidativnog stresa nakon primene metionina. Hiperhomocisteinemija (HHC) je uključena u patogenezu brojnih bolesti kako svojim prooksidantnim dejstvom tako i oštećenjem antioksidativne zaštite. L-cistein i N-acetil-L-cistein prepoznati su kao supstance sa antioksidativnim kapacitetom u digestivnom traktu. Jedan od načina na koji HHC menja kontraktilni odgovor creva jeste i modulacija nitrergičke neurotransmisije. Studije sprovedene na pacijentima sa HHC ukazuju na to da povišene vrednosti Hcy u plazmi smanjuju stvaranje azot monoksida (NO) i njegove efekte. Cilj ove studije je da utvrdi da li akutna stimulacija homocisteinom ili subhronično opterećenje metioninom dovodi do pojave oksidativnog stresa, i da li L-cistein i N-acetil-L-cistein kao dokazani antioksidansi mogu modulirati efekte subhronične aplikacije metionina. Takođe cilj ovog rada bio je da ispita efekte najtoksičnijeg metabolita homocisteina, tj. D,L-homocistein tiolaktona na kontraktilnost izolovanog creva pacova. Materijal i metode: Za protokol akutne HHC in vivo životinje su bile podeljene u dve grupe (6 po grupi): 1. 1 ml 0,9% NaCl i.p.; 2. 0,6 μmol/g tm D,L- homocisteina i.p.. Nakon 2 sata boravka u laboratorijskim uslovima, životinje su žrtvovane, a tkiva creva i jetre su pripremljena za određivanje pokazatelja oksidativnog statusa (CAT, GPx, SOD, TAS i indeks lipidne peroksidacije). Radi ispitivanja efekata akutne HHC na izolovana tkiva (in vitro uslovi) parametri oksidativnog stresa su određivani u tkivima creva i jetre inkubiranim u Tirodovom rastvoru i D,L-homocistein tiolaktonu (10 μmol/L) u toku 3 h. U supernatantu su određivani parametri oksidativnog stresa (CAT, TBARS, TAS). Pratio se tonus, amplituda i frekvencija spontanih kontrakcija izolovanog creva u Tirodovom rastvoru i u prisustvu D,L-homocistein tiolaktona i supstanci koje utiču na NO posredovanu neurotransmisiju (L-Arginin-10 μmol/L, L-NAME-30 μmol/L)...Introduction: Homocysteine (Hcy) is semi-essential amino acid which contains sumpor from methionine. In vivo and in vitro studies on rats showed alteration of oxidative stress parameters after methionine administration. Hyperhomocysteinemia (HHC) takes part in pathogenesis of various diseases with its prooxidant capacity, and by damaging antioxidative defence as well. L-cysteine and N-acetyl-L-cysteine are substaces with antioxidative capacity in the gut. One of the pattern by which HHC change the contractile response of the gut is modulation of the nitrergic neurotransmission. Studies included patients with HHC showed that increased plasma Hcy concentrations decreased NO production and its effects. This research aimed to investigate effects of acute Hcy stimulation or subchronic methionine administration on oxidative stress paraneters, and L-cysteine and N-acetyl-L-cysteine modulation of subchronic methionine load effects. Also, the aim was to investigate the effects of the most toxic metabolite of homocysteine, D,L-homocysteine thiolactone, on the contractility of isolated segments of the intestine. Material and methods: For the acute HHC protocol in vivo, animals were divided into two groups (6 per group): 1. 1 ml 0.9% NaCl i.p.; 2. 0.6 μmol/g tm D,L- homocysteine i.p. After 2h in laboratory conditions, animals were sacrified, and gut and liver tissues were taken for further analysis (CAT, GPx, SOD, TAS, index of lipid peroxidation). For investigation of the effects of the acute HHC in vitro, oxidative stress parameters were determined in the gut and the liver incubated in Tyrode solution and D,L-homocysteine thiolactone (10 μmol/L) during 3h. In the tissue supernatant oxidative stress parameters were analyzed (CAT, TBARS, TAS). The tone, amplitude and frequency of the contractions of the isolated intestine segments were measured in Tyrode solution and in the presence of D,L-homocysteine thiolactone and substances which modulates NO transmission (L-Arginin-10 μmol/L, L-NAME-30 μmol/L). For subchronic methionine load animals were divided into four groups (n=6): 1..

Functional, biochemical and histological changes in rat digestive tract in acute hyperhomocysteinemia or subchronic methionine stimulation

Uvod: Homocistein (Hcy) je semi-esencijalna aminokiselina koja sadrži sumpor dobijen iz metionina. In vitro i in vivo studije na pacovima pokazale su alteraciju parametara oksidativnog stresa nakon primene metionina. Hiperhomocisteinemija (HHC) je uključena u patogenezu brojnih bolesti kako svojim prooksidantnim dejstvom tako i oštećenjem antioksidativne zaštite. L-cistein i N-acetil-L-cistein prepoznati su kao supstance sa antioksidativnim kapacitetom u digestivnom traktu. Jedan od načina na koji HHC menja kontraktilni odgovor creva jeste i modulacija nitrergičke neurotransmisije. Studije sprovedene na pacijentima sa HHC ukazuju na to da povišene vrednosti Hcy u plazmi smanjuju stvaranje azot monoksida (NO) i njegove efekte. Cilj ove studije je da utvrdi da li akutna stimulacija homocisteinom ili subhronično opterećenje metioninom dovodi do pojave oksidativnog stresa, i da li L-cistein i N-acetil-L-cistein kao dokazani antioksidansi mogu modulirati efekte subhronične aplikacije metionina. Takođe cilj ovog rada bio je da ispita efekte najtoksičnijeg metabolita homocisteina, tj. D,L-homocistein tiolaktona na kontraktilnost izolovanog creva pacova. Materijal i metode: Za protokol akutne HHC in vivo životinje su bile podeljene u dve grupe (6 po grupi): 1. 1 ml 0,9% NaCl i.p.; 2. 0,6 μmol/g tm D,L- homocisteina i.p.. Nakon 2 sata boravka u laboratorijskim uslovima, životinje su žrtvovane, a tkiva creva i jetre su pripremljena za određivanje pokazatelja oksidativnog statusa (CAT, GPx, SOD, TAS i indeks lipidne peroksidacije). Radi ispitivanja efekata akutne HHC na izolovana tkiva (in vitro uslovi) parametri oksidativnog stresa su određivani u tkivima creva i jetre inkubiranim u Tirodovom rastvoru i D,L-homocistein tiolaktonu (10 μmol/L) u toku 3 h. U supernatantu su određivani parametri oksidativnog stresa (CAT, TBARS, TAS). Pratio se tonus, amplituda i frekvencija spontanih kontrakcija izolovanog creva u Tirodovom rastvoru i u prisustvu D,L-homocistein tiolaktona i supstanci koje utiču na NO posredovanu neurotransmisiju (L-Arginin-10 μmol/L, L-NAME-30 μmol/L)...Introduction: Homocysteine (Hcy) is semi-essential amino acid which contains sumpor from methionine. In vivo and in vitro studies on rats showed alteration of oxidative stress parameters after methionine administration. Hyperhomocysteinemia (HHC) takes part in pathogenesis of various diseases with its prooxidant capacity, and by damaging antioxidative defence as well. L-cysteine and N-acetyl-L-cysteine are substaces with antioxidative capacity in the gut. One of the pattern by which HHC change the contractile response of the gut is modulation of the nitrergic neurotransmission. Studies included patients with HHC showed that increased plasma Hcy concentrations decreased NO production and its effects. This research aimed to investigate effects of acute Hcy stimulation or subchronic methionine administration on oxidative stress paraneters, and L-cysteine and N-acetyl-L-cysteine modulation of subchronic methionine load effects. Also, the aim was to investigate the effects of the most toxic metabolite of homocysteine, D,L-homocysteine thiolactone, on the contractility of isolated segments of the intestine. Material and methods: For the acute HHC protocol in vivo, animals were divided into two groups (6 per group): 1. 1 ml 0.9% NaCl i.p.; 2. 0.6 μmol/g tm D,L- homocysteine i.p. After 2h in laboratory conditions, animals were sacrified, and gut and liver tissues were taken for further analysis (CAT, GPx, SOD, TAS, index of lipid peroxidation). For investigation of the effects of the acute HHC in vitro, oxidative stress parameters were determined in the gut and the liver incubated in Tyrode solution and D,L-homocysteine thiolactone (10 μmol/L) during 3h. In the tissue supernatant oxidative stress parameters were analyzed (CAT, TBARS, TAS). The tone, amplitude and frequency of the contractions of the isolated intestine segments were measured in Tyrode solution and in the presence of D,L-homocysteine thiolactone and substances which modulates NO transmission (L-Arginin-10 μmol/L, L-NAME-30 μmol/L). For subchronic methionine load animals were divided into four groups (n=6): 1..

Hydrothermal carbonization of Miscanthus x giganteus: Structural and fuel properties of hydrochars and organic profile with the ecotoxicological assessment of the liquid phase

In this study, hydrothermal carbonization (HTC) was employed for thermochemical conversion of energy crop Miscanthus x gigcuiteus GREEF et DEU. The effect of process temperatures, in the range between 180 and 220 degrees C, on the relevant characteristics of the obtained products, hydrochars and process waters, was investigated. The obtained results showed that the HTC promotes fuel properties and energy density of the solids regarding the feedstock. Furthermore, temperature governs the lowering of the volatiles, ash, and moisture in hydrochars, making its potential use as solid fuels more beneficial than the miscanthus. FT-IR spectroscopy and thermal analysis confirmed degradation of hemicellulose at temperatures above 200 degrees C, and an increase of the total content of cellulose and lignin in the hydrochars. In general, hydrochar obtained at 220 degrees C exhibited the best combustion characteristics and is, therefore, the most suitable for use as a solid biofuel. However, in the residual liquids, some amounts of fluorene, phenanthrene, fluoranthene, and pyrene were detected. The polluting potential, visible through the growth of TOC, COD and BOD values, of the analyzed process waters, increases with the rise in carbonization temperature. The TOC values (5.8-9.9 gC L-1) were on average lower than those reported for organic wastewaters ( gt 10 gC L-1). The proportion of hydrocarbons in the process water increases with the increase in the carbonization temperature from 2.92 to 20.9%. Consequently, bioassays with Vibrio fischeri showed a relatively high toxicity of the liquid phase, where a concentration of about 1% was causing bacteria inhibition of 50%.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/2971

Study of heavy metals biosorption on native and alkali-treated apricot shells and its application in wastewater treatment

Locally available apricot (Prunus armeniaca L.) shells classified as a waste product from fruit processing, were alkali activated in order to develop an efficient heavy metal ions sorbent for water purification. To examine the changes occurred after alkali treatment, raw (SH) and modified apricot shells (SHM) were thoroughly characterized in terms of their chemical composition and surface properties. Chemical analysis revealed that alkaline treatment causes the disintegration of hemicellulose (its content decreased from 19.2 to 3.5%), which was in accordance with FTIR results. SEM micrographs and the mercury intrusion porosimetry revealed a larger surface area and porosity of SHM. Bohem's acid-base titration method indicated that the most of the SHM surface carboxylic groups were in sodium salt form and together with the pH of points of zero charge showed increase of surface alkalinity after modification. Treatment with NaOH enhanced the adsorption capacity by 154, 61 and 90% for Cu2+, Zn2+ and Pb2+, respectively. The amount of cations released from SHM was almost equal to the amount of adsorbed metal ions, suggesting ion exchange mechanism. The pseudo-second order kinetic indicated that the heavy metals cations were bound predominantly by complexation. In order to establish the effectiveness of the biosorbent in real wastewater sample, SHM was employed for cleaning-up of drain water emanating from atomic adsorption spectrophotometer. The SHM showed high removal efficiency towards multiple metal ions. The amounts of Fe, Pb, Cu and Cr ions were reduced by 97, 87, 81 and 80%, respectively, while Ni and Zn amounts were reduced for 33 and 14%. Used biosorbent SHM can be successfully regenerated with HCl (desorption gt 95%) and after regeneration biosorbent can be reused or it can be safely disposed. (C) 2018 Elsevier B.V. All rights reserved.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/2969]Peer-reviewed manuscript: [http://cherry.chem.bg.ac.rs/handle/123456789/2970