Primjena kulture stanica prednjeg režnja hipofize u toksikološkim istraživanjima

High density plating procedure was used to evaluate the effect of atrazine on anterior pituitary cells of rats in monolayer culture. Collagenase-dispersed pituitary cells plated in suspension with medium-199 and 10% foetal calf serum attached quantitatively to plastic surfaces within 24 hours. Electron microscopy showed subpopulations of different cell types. After prolonged cultivation, most cells established small colonies with extensive contacts among them. Cell-to-cell formation of aggregates was significant and the colonies manifested morphological changes. The cells retained their enzymatic activity, converting testosterone into 5alfa-dihydrotestosterone by enzyme 5alfa-reductase. Immunohistochemical techniques facilitated differentiation of gonadotrophs producing follicle stimulating (FSH) and luteinising hormones (LH). Atrazine in concentrations of 5 to 50 µg/ml of medium was associated with a significant reduction in the number of viable cells within 72 hours. The results suggest that the pituitary cell culture may prove useful in toxicological testing of various toxic compounds and reduce or replace in vivo animal experiments.Atrazin, selektivni s-triazinski herbicid, danas se rabi u velikim količinama za zaštitu kukuruznih polja, a zbog svoje liposolubilnosti i perzistentnosti u okolišu ulazi u hranidbeni lanac. In vitro sustavi tkiva i organa sisavaca uz in vivo pokuse još i danas su pretežite tehnike u toksikologiji koje se pouzdano primjenjuju. Potrebe za smanjenjem broja pokusa na životinjama dovele su do intenzivna razvoja tehnika sa životinjskim stanicama, bilo da se radi o primarnim kulturama ili o staničnim linijama. Primarne kulture stanica središnjega živčanog sustava nisu do danas doživjele punu primjenu. Primjena životinjskih stanica mnogo je jeftinija tehnika koja omogućuje provođenje istodobnog ispitivanja na velikom broju uzoraka. Cilj istraživanja bio je ispitati toksičnost atrazina u in vitro uvjetima na modelu kulture stanica hipofize, koje su odgovorne za normalno funkcioniranje reprodukcijskog procesa. U radu se dobrom izolacijskom metodom i visokim stupnjem uspješnog uspostavljanja kulture stanica, mogao pratiti utjecaj atrazina na razini staničnih promjena. Stanice raspršene kolagenazom u suspenziji s medijem 199 i 10%-tnim telećim serumom prihvatile su se za plastičnu podlogu unutar 24 sata. Elektronskom mikroskopijom nađeni su različiti tipovi stanica. Nakon produljene kultivacije, najveći broj stanica stvorio je male kolonije s uočljivim vezama između stanica. Stanice su pokazale dobru enzimsku aktivnost pri pretvorbi testosterona u aktivni metabolit 5alfa-dihidrotestosteron. Imunohistokemijskim metodama utvrđene su stanice koje sintetiziraju hormone što stimuliraju razvoj folikula (FSH) i hormone luteinizacije (LH). Atrazin je dodan kulturi stanica hipofize u koncentracijama 5–50 µg/ml medija koji je sadržavao 3x105 stanica. Tijekom 24, 48 i 72 sata nađena su značajna smanjenja broja živih stanica, od 36 do 46%. Učinci su ovisili o dozi atrazina. Rezultati upućuju na to da se kulture stanica adenohipofize mogu uspješno rabiti u budućim istraživanjima toksičnosti različitih tvari radi smanjenja ili zamjene in vivo pokusa na životinjama

Potential Application of Yeast β-Glucans in Food Industry

Different β-glucans are found in a variety of natural sources such as bacteria, yeast, algae, mushrooms, barley and oat. They have potential use in medicine and pharmacy, food, cosmetic and chemical industries, in veterinary medicine and feed production. The use of different β-glucans in food industry and their main characteristics important for food production are described in this paper. This review focuses on beneficial properties and application of β-glucans isolated from different yeasts, especially those that are considered as waste from brewing industry. Spent brewer’s yeast, a by-product of beer production, could be used as a raw-material for isolation of β-glucan. In spite of the fact that large quantities of brewer’s yeast are used as a feedstuff , certain quantities are still treated as a liquid waste. β-Glucan is one of the compounds that can achieve a greater commercial value than the brewer’s yeast itself and maximize the total profitability of the brewing process. β-Glucan isolated from spent brewer’s yeast possesses properties that are benefi cial for food production. Therefore, the use of spent brewer’s yeast for isolation of β-glucan intended for food industry would represent a payable technological and economical choice for breweries

ESEM Comparative Studies of Hop (Humulus lupulus L.) Peltate and Bulbous Glandular Trichomes Structure

Hop glandular trichomes are developing on the epidermis of hop cones bracts. The anticline cross cut of hop peltate glandular trichomes in Environment Scanning Electron Microscopy (ESEM) observations confirmed spheroid shape of cells. In our research, length of internal peltate glandular trichomes cells varied from 16.00 to 21.47 μm, width from 4.21 to 4.70 μm and volume from 1.19 × 10-6 to 1.99 × 10-6 mm3. The diameter of cell walls varied from 2.11 to 2.94 μm. Volume of observed peltate glandular trichomes varied from 1.65 × 10-2 to 1.95 × 10-2 mm3. The cell structure of bulbous glandular trichomes in anticline cross cut was not observed. According to 121 observations, bulbs formation was visible on the surface of peltate glandular trichomes in the last phase of morphogenesis. Biosynthesis of hop secondary metabolites and activation of their genetic mechanisms are the most intensive at the end of technological maturity of hop cones of hop cultivar Aurora. It is possible that bulbous glandular trichomes represent the final stage of peltate glandular trichome morphogenesis, instead of being separate morphological formations. During biosynthesis of hops secondary metabolites partial pressures of liquids and gasses increase causing breakage of cell walls, which withdraw towards tunica and form papillary texture

Application of Different Drying Methods on β-Glucan Isolated from Spent Brewer’s Yeast Using Alkaline Procedure

Water-insoluble (particulate) β-glucan was isolated from the cell walls of spent brewer’s yeast using a single-step alkaline treatment. To stabilize β-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused β-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal β-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried β-glucan particles was minimal even after resuspending in water

Karakterizacija β-glukana izoliranih iz pivskoga kvasca te osušenih različitim metodama

Two different procedures have been used for isolation of water-insoluble ß-glucans from brewer’s yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained ß-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. ß-Glucan preparations obtained by AA and AAM isolations had similar values of dry mass, total polysaccharides, proteins and organic elemental microanalysis. The mass fractions of ß-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1→3)-ß-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in ß-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi β-glukani izolirani su iz pivskoga kvasca primjenom dvaju različitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci β-glukana osušeni su na zraku, liofilizacijom i raspršivanjem uz prethodnu obradu ultrazvukom. Takvi su pripravci, dobiveni AK i AKM postupcima, imali približno iste vrijednosti suhe tvari, ukupnih polisaharida i proteina, te udjele ugljika, dušika i kisika određene organskom mikroanalizom. Na udio β-glukana u ukupnim polisaharidima bitno su utjecali različiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipičan za (1→3)-β-D-glukan. Sušenjem na zraku i liofilizacijom došlo je do značajnih promjena strukture čestica i aglomeracije ß-glukana. Sušenje raspršivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina čestica kao ni do znatnih promjena njihove strukture

Karakterizacija β-glukana izoliranih iz pivskoga kvasca te osušenih različitim metodama

Two different procedures have been used for isolation of water-insoluble ß-glucans from brewer’s yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained ß-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. ß-Glucan preparations obtained by AA and AAM isolations had similar values of dry mass, total polysaccharides, proteins and organic elemental microanalysis. The mass fractions of ß-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1→3)-ß-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in ß-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi β-glukani izolirani su iz pivskoga kvasca primjenom dvaju različitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci β-glukana osušeni su na zraku, liofilizacijom i raspršivanjem uz prethodnu obradu ultrazvukom. Takvi su pripravci, dobiveni AK i AKM postupcima, imali približno iste vrijednosti suhe tvari, ukupnih polisaharida i proteina, te udjele ugljika, dušika i kisika određene organskom mikroanalizom. Na udio β-glukana u ukupnim polisaharidima bitno su utjecali različiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipičan za (1→3)-β-D-glukan. Sušenjem na zraku i liofilizacijom došlo je do značajnih promjena strukture čestica i aglomeracije ß-glukana. Sušenje raspršivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina čestica kao ni do znatnih promjena njihove strukture

Application of Different Drying Methods on β-Glucan Isolated from Spent Brewer’s Yeast Using Alkaline Procedure

Water-insoluble (particulate) β-glucan was isolated from the cell walls of spent brewer’s yeast using a single-step alkaline treatment. To stabilize β-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused β-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal β-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried β-glucan particles was minimal even after resuspending in water

Physico-chemical analysis of the Rhine Riesling wines produced in Plešivica-Okić wine region during three consecutive years

Analizirani uzorci vina sorte Rajnski rizling iz vinogorja Plešivica-Okić proizvedeni su tijekom tri uzastopne godine (2009., 2010. i 2011.) na jednom obiteljskom gospodarstvu. Koncentracije alkohola, ukupnih i hlapljivih kiselina, ukupnog SO2 , glicerola i reducirajučih šećera u analiziranim vinima u skladu su sa zakonskim propisima. Uočen je izražen utjecaj klimatskih uvjeta na kemijski sastav analiziranih vina.The analyzed samples of Rhine Riesling wine from the Plešivica-Okić wine region were produced during three consecutive years (2009, 2010 and 2011) in one family winery. Concentrations of alcohol, total and volatile acidity, total SO2 , glycerol and residual sugar in the analyzed wines were in accordance with legal requirements. A pronounced influence of climatic conditions on the chemical composition of the analyzed wines was observed

Importance of Medical Effects of Xanthohumol, Hop (Humulus lupulus L.) Bioflavonoid in Restructuring of World Hop Industry

Nowadays, the world hop industry is faced with one of the biggest crisis in the history. Permanent decrease of hopping rates in the world beer industry during last 20 years caused many problems to hop producers all around the world. It resulted in the huge surpluses of hop stocks between years 2008 and 2010, the ages known as “years of famine” for hop farmers. The hop contains some compounds having medical, pharmaceutical or biological activities, and xanthohumol is one of them. Xanthohumol is a bioflavonoid whose positive effect is confirmed both in vitro and in vivo experiments. It is successfully used in medical treatment of patients having diseases such as prostate and breasts cancer, osteoporosis, menopausal problems, and even HIV. However, such attributes of hop are strong argument to consider the restructuring of the world hop industry and forming a new supply chain, primarily oriented to the pharmaceutical industry

Odabrani biotehnološki čimbenici koji utječu na alkoholnu fermentaciju pri proizvodnji vina

Odstupanja od normalnog tijeka fermentacije predstavljaju veliki problem u proizvodnji vina. Važno je poznavati čimbenike koji utječu na tijek fermentacije kako bi se izbjeglo usporavanje i/ili zastoj fermentacije te spriječilo ekonomske gubitke. Brojna istraživanja pokazala su da odstupanja od normalnog tijeka fermentacije mogu imati više uzroka. U ovom radu su ukratko objašnjeni najvažniji čimbenici koji utječu na tijek fermentacije u proizvodnji vina, a mogu se grupirati u tri skupine - nedostatak nutrijenata, prisutnost spojeva koji inhibiraju alkoholnu fermentaciju te utjecaj enoloških postupaka. Pored zasebnih učinaka pojedinih čimbenika, moguće je i smanjenje brzine fermentacije zbog njihovog sinergističkog djelovanja, što fermentacijske probleme čini još složenijima