RNA editing

Uređivanje RNA opisuje molekularne procese koji uključuju post-transkripcijsku promjenu nukleotida molekule RNA u odnosu na kodirajuću DNA što je često nužno za uspostavljanje biološke funkcije. Odvija se u svim domenama života osim kod prokariota, te kod nekih RNA-virusa. Uređivanjem su zahvaćeni jezgrini, mitohondrijski te plastidni transkripti RNA, a uređivana RNA ne mora nužno kodirati za proteine. Uređivanje RNA se može svrstati u dvije skupine – supstitucijsko, u kojem dolazi do zamjene nukleotida te insercijsko ili delecijsko koje mijenja broj nukleotida u uređivanom transkriptu. Glavni predstavnici supstitucijskih uređivanja kod sisavaca jesu proteinski kompleksi APOBEC i ADAR. Protein APOBEC je citidinska deaminaza te provodi deaminaciju C→U, dok je protein ADAR adenozinska deaminaza te mijenja A→I. Kod praživotinja uređuje se mitohondrijska RNA. Za Trypanosoma karakteristična je insercija tj. delecija uridina kod gena koji kodiraju za proteine. Kod amebe Acanthoamoebe castelanii se uređuje molekula tRNA na 5'-kraju akceptorske petlje. Uređivanje kod biljaka najčešće se odnosi na modifikaciju C→U koja se odvija na mitohondrijskim i plastidnim transkriptima. RNA-virusi kao Ebolavirus i virus hepatitisa delta također bivaju podvrgnuti uređivanju RNA, pomoću vlastitih ili domaćinskih proteina, što ima značajan utjecaj na njihovu virulentnost. Uređivanje RNA je vrlo kompleksan i energetski skup proces te se postavlja pitanje kako je uopće došlo do njegove široke rasprostranjenosti. Model neutralne konstruktivne evolucije pokušava dati zadovoljavajući odgovor na to pitanje gledajući na postojanje sustava uređivanja RNA kao na sustav koji preuzima dio odgovornosti u procesu ispravljanja grešaka u DNA. Pri tome se štetne mutacije ispravljaju ne na razini DNA, već na razini RNA.RNA editing describes molecular processes that include posttranscriptional changes in RNA nucleotide sequence compared to coding DNA sequence and may be necessary for their biological function. It is spread in eukaryotes, and it also occurs in some RNA viruses. Nucleus, mitochondria and plastids are cellular compartments in which RNA editing occurs. Also transcripts to be edited are not necessarily protein coding. There are two main groups of RNA editing – editing by substitution of nucleotides and insertions or deletions in which number of nucleotides in RNA transcripts is changed. For substitution editing, there are two main protein systems in mammals – APOBEC and ADAR. APOBEC has cytidine deaminase activity and conducts C to U deamination whereas ADARs are adenosine deaminases and they change A→I. Protozan RNA editing includes editing of mitochondrial RNA transcripts. Typical editing for trypanosomatid protozoans involves insertion as well as deletion of U in protein coding RNA transcripts. RNA editing in protoza Acanthoamoebe castelanii includes editing of 5’-end of tRNA acceptor stem. In plants C to U editing is the most common type of modification. Mitochondrial and plastids RNAs are targeted for editing in this case. RNA of viruses, like Ebolavirus and hepatitis delta virus, can also undergo editing using its own or host protein complexes. It can largely affect their virulence. RNA editing is complex and energetically expensive process so there is open question why did it even arose. Constructive neutral evolution model tries to give satisfying answer. It proposes that RNA editing system emerged after allowing mutations to happen. RNA editing allows corrections of DNA mutations on RNA level and therefore it permits DNA-encoded information to degenerate progressively

Environmental and occupational exposures associated with male infertility

Porast slučajeva muške neplodnosti tijekom posljednja dva desetljeća, vjerojatno i zbog izloženosti okolišnim čimbenicima, izazvao je značajan interes. Izvješća klinika za neplodnost pokazala su da kronične bolesti i nasljedni čimbenici ili neke zdravstvene smetnje mogu samo djelomično objasniti trenutačnu incidenciju muške neplodnosti. Životni okoliš i radna okolina mogu imati značajnu ulogu u izlaganju složenim smjesama spojeva s endokrinim djelovanjem (ED), koji su povezani s raznim poremećajima plodnosti. Cilj je ovoga preglednog rada dati uvid u trenutačno znanje o tipovima izloženosti koji mogu biti povezani s muškom neplodnošću. Naše se istraživanje oslanjalo na sustavnu pretragu PubMeda, Scopusa i Web of Sciencea za članke objavljene od siječnja 2000. do rujna 2020. Rezultati su pokazali da je za neke čimbenike dobro dokumentirana povezanost s muškom neplodnošću, što uključuje pušenje, neke fiziološke poremećaje te kronične bolesti poput pretilosti i dijabetesa, koji sami po sebi mogu odražavati životne navike i izloženost okolišu, posebice spojevima s ED-om poput ftalata, bisfenola, pesticida i protupožarnih zaštita. Međutim, broj studija o etiologiji muške neplodnosti još je uvijek premalen u usporedbi s veličinom zahvaćene populacije. Medicina rada tijekom sistematskih pregleda ne prikuplja podatke o muškoj neplodnosti premda su spojevi s ED-om prisutni u mnogim tehnološkim procesima.The upsurge in male infertility over the last two decades, possibly due to environmental exposure, has raised significant interest, particularly boosted by reports from fertility clinics, which showed that chronic diseases and hereditary or other medical conditions might only partially explain current incidence of male infertility. Both environmental and occupational settings may have a significant role in exposure to complex mixtures of endocrine disruptors (ED), which play a major role in fertility disorders. The aim of this review is to give an insight into the current knowledge on exposure settings which may be associated with male infertility. Our study relied on a systematic search of PubMed, Scopus, and Web of Science for articles published between January 2000 and September 2020. It showed that some well documented factors associated with male infertility include smoking, and physiological disturbances or chronic diseases such as obesity and diabetes, which in turn, may also reflect lifestyle choices and environmental exposures, especially to EDs such as phthalates, bisphenols, pesticides, and flame retardants. However, the number of studies on the aetiology of male infertility is still too low in comparison with the size of affected population. Occupational health follow-ups and medical surveillance do not collect any data on male infertility, even though ED chemicals are part of many technological processes

Regionalna usporedba poduzetničkih osobina i poduzetničkog ekosustava u Hrvatskoj

Entrepreneurs have a key role in building a sustainable and competitive society. Although their success largely depends on themselves and their competencies, the environment in which they find themselves also plays a significant role in their activities. The more developed and stimulating the entrepreneurial ecosystem, the greater the chances that their ideas will also have a positive impact on the quality of life in their community. This paper answers two main research questions: a) whether all entrepreneurs have the same entrepreneurial traits and b) whether entrepreneurial efficiency depends on the development of the environment (region) in which entrepreneurs operate. The paper is based on a comparison of entrepreneurial traits and entrepreneurial environment in Osijek - Baranja and Dubrovnik - Neretva counties. Data obtained by the primary research on a sample of 25 entrepreneurs from Osijek - Baranja and 25 entrepreneurs from Dubrovnik - Neretva County who operate in activities related to tourism were analysed in the empirical section. Based on the conducted analysis, conclusions were made on the impact of entrepreneurial traits and business environment on the efficient business operation of entrepreneurs. The results of this research can serve as a basis for conducting more extensive research by collecting a larger representative sample, but also for new research that will focus on the impact of the degree of regional development on the growth and development of entrepreneurial ventures.Poduzetnici imaju ključnu ulogu u izgradnji održivog i konkurentnog društva. Iako velikim dijelom njihov uspjeh ovisi o njima samima i njihovim kompetencijama, značajnu ulogu u njihovu djelovanju ima i okruženje u kojem se nalaze. Što je poduzetnički ekosustav razvijeniji i poticajniji, veće su mogućnosti da će svojim idejama imati pozitivan utjecaj na kvalitetu života i u svojoj zajednici. Ovaj rad odgovara na dva glavna istraživačka pitanja: a) Posjeduju li poduzetnici iste poduzetničke osobine? i b) Ovisi li poduzetnička efikasnost o razvijenosti okruženja (regije) u kojoj poduzetnici djeluju? Rad se temelji na usporedbi poduzetničkih osobina i poduzetničkog okruženja u Osječko-baranjskoj i Dubrovačko-neretvanskoj županiji. U empirijskom dijelu analizirani su podaci dobiveni primarnim istraživanjem na uzorku od 25 poduzetnika iz Osječko-baranjske te 25 poduzetnika iz Dubrovačko-neretvanske županije koji posluju u djelatnostima vezanim uz turizam. Na temelju provedene analize, doneseni su zaključci o utjecaju poduzetničkih osobina i poslovnog okruženja na učinkovito poslovanje poduzetnika. Rezultati ovoga istraživanja mogu poslužiti kao temelj za provođenje opsežnijeg istraživanja prikupljanjem većega reprezentativnog uzorka, ali i za nova istraživanja koja tematiziraju utjecaj stupnja regionalne razvijenosti na rast i razvoj poduzetničkih pothvata

Zanimljivi dodaci flori doline rijeke Neretve ( južna Hrvatska) s naglaskom na vodene biljke

While working on several projects dealing with the flora of Neretva River delta in south Croatia, interesting floristic discoveries were made. During fieldtrips, freshwater habitats (rivers, channels and lakes) were in the focus of the survey, and were studied in detail both from the boat and from the mainland. Altogether 69 plant taxa were recorded and are presented in the results, out of which 25 taxa associated with aquatic habitats (hydrophytes, helophytes and species of riparian habitats) were discussed in more detail. These taxa are rare, threatened, invasive, newly found or otherwise seen as important for the studied area and their distribution maps are also presented.Tijekom rada na nekoliko različitih projekata koji uključuju istraživanje flore u dolini rijeke Neretve na jugu Hrvatske, zabilježeni su neki zanimljivi floristički nalazi. Tijekom terenskih izlazaka, u fokusu su bila slatkovodna staništa (rijeke, kanali i jezera) koja su bila detaljno istražena čamcima i s kopna. Zabilježeno je ukupno 69 biljnih svojti koje su prikazane u rezultatima, dok je 25 svojti prikazano i diskutirano detaljnije, a radi se o svojtama koje su u određenoj mjeri vezane za vodena staništa (hidrofiti, helofiti i vrste vlažnih staništa). Odabrane svojte su rijetke, ugrožene, invazivne, novo zabilježene ili su njihovi nalazi na drugi način zanimljivi za ovo područje, a prikazane su i njihove karte rasprostranjenost

Determination of Phenolic Content and DPPH Radical Scavenging Activity of Functional Fruit Juices Fortified with Thymus serpyllum L. and Salvia officinalis L. Extracts

The objective of this study was to spectrophotometric determinate the total phenolic, flavonoid, hydroxycinnamic acid, and flavonol content of orange, pineapple, and apple juices fortified with wild thyme (Thymus serpyllum L.), Dalmatian sage (Salvia officinalis L.), and wild thyme-Dalmatian sage (3 : 1, v / v) extracts, and to evaluate their DPPH radical scavenging activity as a contribution to the development of a new functional beverage. The plant extracts addition increased the amount of phenolic compounds in fruit juices and improved their antioxidant properties. The highest concentrations of bioactive compounds and the greatest DPPH radical activity were obtained by adding Dalmatian sage extract to orange juice. Our study provides the novelty of fortifying fruit juices with wild thyme and Dalmatian sage extracts and offers significant potential for the creation of functional beverages

Diterpenes and Phenolic Compounds from Salvia brachyodon Vandas

Salvia brachyodon, the short-tooth sage, is one of the rarest plant species and endemic in the Adriatic area of the Balkan Peninsula. As aside from its essential oil, only limited information on its phytochemical composition is known, a more detailed study of the leaves was undertaken. From its leaves two diterpenes, agastanol (2), and a new natural compound 1, i.e., 3-methyl-4-methylen-11,12,14-trihydroxy-8,11,13-abietatrien-7-one, were isolated and identified by NMR spectroscopy and mass spectrometry. In addition, caffeic acid, isoquercitrin, luteolin 7-O-glucoside and rosmarinic acid were identfied by comparison with reference compounds. The fraction containg the diterpenes as well as the isolated compound 1 showed significant antimycobacterial activity against Mycobacterium smegmatis. The diterpenes of S. brachyodon represent promising antimycobacterial substances for further evaluation. Due to the endangered nature of the plant, the wide use of S. brachyodon and its bioactive compounds could be achieved by growing the plants in culture

Determination of naphthoquinones in invasive alien plants Impatiens glandulifera Royle and I. balfourii Hook.f. from Croatia

The study aimed to develop an HPLC method for a simultaneous determination of 2-hydroxy-1,4-naphthoquinone (2-HNQ) and 2-methoxy-1,4-naphthoquinone (2-MNQ) in plant material. The method was implemented to determine naphthoquinones (NQs) in leaves and flowers of the invasive alien species Impatiens glandulifera and I. balfourii collected in Croatia. Two NQs extraction methods from plant material were compared: decoction and ultrasonic extraction. Validation parameters indicate that the developed method is reliable for the simultaneous determination of 2-HNQ and 2-MNQ in plant material. The decoction extraction obtained a higher NQs yield than ultrasonic extraction. In the leaves and flowers of I. glandulifera and I. balfourii only 2-MNQ was detected. Both, I. glandulifera and I. balfourii, had higher 2-MNQ concentrations in flowers than in leaves. A significantly higher 2-MNQ concentration was found in I. glandulifera compared to I. balfourii. Therefore, I. glandulifera can be considered a rich source of 2-MNQ whose antitumor potential is established

Insights into the life strategy of the common marine diatom Chaetoceros peruvianus Brightwell

Chaetoceros peruvianus is a marine diatom species with circumglobal distribution. While frequently observed, it appears never to dominate the marine phytoplankton community hence it can be characterized as a rather opportunistic, generalistic species. Here we present ecological interpretations from a long-term data set on marine microphytoplankton in the northern Adriatic Sea, where the abundancies and relative contributions of C. peruvianus were observed along a set of steep ecological gradients. Limited supply of dissolved inorganic phosphate was identified as the driving ecological factor for this ecosystem. In parallel C. peruvianus was cultivated in monoclonal cultures and its morphological and physiological reaction to replete and phosphorus depleted medium was analysed. C. peruvianus reacted to phosphorus depletion by an increase in cell height and length as well as thickness and length of setae. This morphological reaction included an increase in cellular volume and calculated carbon content. Additionally, it represents the transition between two described morphological varieties, C. peruvianus and C. peruvianus var. robusta. C. peruvianus showed a significant induction of extracellular alkaline phosphatase activity if grown in phosphate depleted medium. Microscopical analysis demonstrated this activity to be located exclusively on the setae of the cells