Dissecting polarity formation in the Drosophila oocyte

The polarization of cells is a prerequisite for many fundamental biological processes, such as asymmetric cell division, neuronal polarization, and morphogenesis. In Drosophila melanogaster, both main body axes are established during oogenesis through polarization of the oocyte and as a result of crosstalk between the oocyte and surrounding cells

Optogenetic method for rapid and reversible removal of proteins from the mitotic spindle

Na početku mitoze mikrotubuli i pripadajući proteini formiraju diobeno vreteno, strukturu koja omogućuje točnu raspodjelu kromosoma između dvije stanice kćeri. U ovom radu razvijena je optogenetička metoda koja omogućuje brzu i reverzibilnu translokaciju proteina iz diobenog vretena na mitohondrije korištenjem plavog svjetla. Metoda je primijenjena za proučavanje proteina TACC3 i PRC1 koji sudjeluju u formiranju paralelnih, odnosno antiparalelnih svežnjeva mikrotubula. Translokacija oba proteina događala se na vremenskim skalama od nekoliko minuta. Mijenjanjem koncentracije proteina PRC1 na diobenom vretenu bilo je moguće inducirati raspadanje i ponovno formiranje antiparalelnih svežnjeva mikrotubula što je rezultiralo promjenom oblika diobenog vretena. Dakle, ova metoda predstavlja novi moćni alat za proučavanje proteina diobenog vretena kontrolom njihove lokalizacije u pojedinim fazama mitoze.At the onset of mitosis microtubules and microtubule associated proteins form a spindle, which is responsible for proper segregation of chromosomes between two daughter cells. In this thesis, I have developed optogenetic method for rapid and reversible translocation of proteins from the mitotic spindle to mitochondria using blue light. This method was used for studying TACC3 and PRC1, proteins which are required for formation of parallel and antiparallel microtubule bundles, respectively. Translocation of both proteins occurred at time scales of several minutes. By changing concentration of PRC1 in the mitotic spindle, I was able to induce disassembly and formation of antiparallel microtubule bundles, which resulted in changes in the spindle shape. Thus, this method represents powerful new tool for studying spindle proteins by controlling their localization at specific stages of mitosis

Early childhood caries - challenges and methods of treatment

Karijes rane dječje dobi pojam je koji označava pojavu karijesa u dobi do treće godine, a uzrokovan je skupinom mikroorganizama, Streptococcusa mutansa. Nastaje kao infektivna bolest zbog rane kolonizacije usne šupljine navedenim mikroorganizmima. Najčešće nastaje na mjestima koja inače nisu podložna karijesu, ponajprije na mliječnim gornjim središnjim sjekutićima. Prvo uzrokuju demineralizaciju cakline oko vratova zuba, a onda u potpunosti razara zub. Majka može prenijeti na svoje dijete ove bakterije slinom, preko dude ili kapljično. Toj kolonizaciji pogoduju i loša oralna higijena te karijesogena prehrana. Rani dječji karijes može se prevenirati promjenom načina ishrane, promjenom oralne higijene i preventivnim mjerama u prenatalnom i perinatalnom razdoblju koje uključuju edukaciju majke, a potom i stomatološku intervenciju topikalnim fluoridiranjem, edukacijom o oralnoj higijeni koju će stjecati kod kuće. Ovaj tip karijesa ima puno negativnih utjecaja na psihosocijalni razvoj djeteta te je bolje poraditi na njegovoj prevenciji nego terapiji. Ukoliko je terapija potrebna, ona se može provoditi na više načina ovisno o tome koliko su zubi zahvaćeni karijesom, a kreće se od restauracije malog dijela zuba, koji je destruiran karijesom, preko izrade krunica kod većih destrukcija krune zuba, uz prethodni endodontski tretman, sve do ekstrakcije ukoliko se pojave apscesi.Early childhood caries is a term that indicates the appearance of caries at the age of 0-3 years, and is caused by a group of microorganisms, Streptococcus mutans. It occurs as an infectious disease due to early colonization of the oral cavity of the mentioned microorganisms. It is most commonly found in places that are otherwise not subject to caries, primarily in the primary upper middle incisors. First, they cause the enamel demineralization around a tooth cervix, then completely destroys a tooth. A mother can transmit to her child this bacterium through saliva, via a pacifier or droplets. Such colonization is also favoured by poor oral hygiene and cariogenic diet. Early childhood caries can be prevented by changing diet, changing oral hygiene and preventive measures in prenatal and perinatal period involving mother's education, and then dental intervention by topical fluoridation, education on oral hygiene to be acquired at home. This type of caries has a lot of negative impacts on the psychosocial development of a child and it is better to work on its prevention than on therapy. If it comes to therapy, it can be performed in several ways depending on how much teeth are affected by caries. A therapy can include the restoration of a small part of the tooth, which was destroyed by caries, crowning, in a larger crown destruction, with the previous endodontic treatment, in the larger destruction of the tooth crown and finally, if the abscess occurs, extraction

Early vital indicators of newborn born after medically assisted reproduction

Cilj: Cilj rada bio je ispitati razliku u vitalnim karakteristikama novorođenčadi rođene nakon MPO-a, odnosno prirodnog začeća te u karakteristikama i tijeku trudnoće kod žena koje su začele MPO-om i prirodno. Nacrt studije: trogodišnja studija slučajeva i kontrola Ispitanici i metode: U istraživanje je uključeno 120 majki koje su začele nakon IVF-a i 120 majki koje su začele prirodnim putem od 1. 1. 2014. do 31. 12. 2016. godine, a za dobivanje podataka korištena je medicinska dokumentacija. Razlike među varijablama ispitane su pomoću χ2 testa, Fisherovog egzaktnog testa i Mann-Whitneyjevog U testa, a razina statističke značajnosti prihvaćena je za p < 0,05. Rezultati: Majke iz IVF skupine starije su od majki koje su začele prirodnim putem i uglavnom su prvorotke, dok je većina majki koje su začele prirodnim putem višerotke. Većina trudnoća jednoplodne su (85,00 %), zatim blizanačke (14,17 %), dok je tripleta bilo u dvije trudnoće (0,83 %). Sve su višeplodne trudnoće u IVF skupini. Kao način poroda dominira carski rez, osobito u skupini majki koje su začele nakon IVF-a. Komplikacije u trudnoći češće su u IVF skupini. Prosječna rodna masa i gestacijska dob manji su u skupini IVF-a. Značajno veći udio nedonoščadi prisutan je u IVF skupini, a apgar zbroj jednak je u objema skupinama. Zaključak: Novorođenčad rođena nakon metoda medicinski potpomognute oplodnje ima manju rodnu masu i gestacijsku dob, stoga su ugroženija od djece rođene nakon prirodnog začeća.Medically assisted fertilization is a set of methods used in the treatment of infertility. Objectives: The aim of the study was to examine the difference in the vital properties of newborns born after medically assisted fertilization, apropos natural conception and characteristics and the course of pregnancy in women who conceived with medically assisted fertilization and naturally. Study outline: Three-year case-control study. Participants and methods: The study included 120 mothers who conceived after IVF and 120 mothers who conceived naturally between 1st January 2014 and 31st December 2016. The data were obtained from the medical records. Differences between variables were investigated by χ2 test, Fisher's exact test and Mann-Whitney U test, and the level of statistical significance was accepted at p<0,05. Results: Mothers from the IVF group were older than mothers who conceived naturally and are mostly primiparae, while mothers who conceived naturally were multiparae. Most pregnancies were singleton pregnancies (85.00%), followed by twin pregnancies (14.17%), and triplets present only in two pregnancies (0.83%). All of the multiple pregnancies were from the IVF group.Caesarean section was dominant as a way of delivery, especially in the IVF group. Complications during the pregnancy were more often among the IVF group. Average birth weight and gestation age are lower in the IVF group. A significantly higher proportion of preterm neonates is present in the IVF group, and the Apgar score is the same in both groups. Conclusion: Newborns born after medically assisted reproduction have lower birth weight and gestation age, and are therefore more vulnerable compared to children born after natural conception

Odnos kreativnosti sa shizotipijom i psihoticizmom kod studenata umjetničkih i neumjetničkih usmjerenja

Proučavanje odnosa kreativnosti i kliničkih te supkliničkih psihopatologija važno je zbog toga što otkriva kognitivne i bihevioralne korelate kreativnosti. Utvrđeno je da su za kreativnost najpogodniji blagi oblici psihopatoloških osobina kao što su shizotipija ili psihoticizam. Cilj istraživanja bio je ispitati odnos kreativnosti i shizotipije te psihoticizma u skupinama studenata umjetničkog i drugih usmjerenja. U istraživanju su sudjelovala 104 studenta umjetničkog i 193 studenta drugih usmjerenja. Rezultati pokazuju da između dviju skupina studenata postoji statistički značajna razlika u dvjema dimenzijama shizotipije (neobična iskustva i kognitivna dezorganizacija) i u broju kreativnih interesa i aktivnosti. Studenti umjetničkih usmjerenja su izrazili da doživljavaju više neobičnih iskustava poput halucinacija i deluzija te da imaju više dezorganiziranih misli, oslabljenih konceptualnih granica i poteškoća sa zadržavanjem pažnje nego studenti drugih usmjerenja. Također, studenti umjetničkih usmjerenja su naveli veći broj kreativnih interesa i aktivnosti nego studenti drugih usmjerenja. Nadalje, oni studenti koji su iskazali da doživljavaju više neobičnih iskustava i kojima su raspoloženje i ponašanje (posebice vezano uz socijalne norme i konvencije) češće nestabilni, bave se većim brojem kreativnih aktivnosti. S druge strane, oni studenti koji su iskazali veću sklonost introvertiranom, asocijalnom ponašanju sa smanjenom sposobnošću osjećanja ugode, navode manje kreativnih interesa i aktivnosti. Nije utvrđena značajna povezanost psihoticizma i kreativnosti.The study of the relationships between creativity and clinical and sub-clinical psychopathologies is important, because it provides insight into the cognitive and behavioural correlates of creativity. It is found that milder forms of psychopathological traits, such as schizotypy or psychoticism, may be the most beneficial to creativity. Considering this fact, the aim of this study was to examine the relationship between creativity, schizotypy, and psychoticism in groups of students of artistic and other domains. The study included 104 artistic domain students and 193 nonartistic domain students. The results show a statistically significant difference in two schizotypy dimensions (unusual experiences and cognitive disorganisation) and in the number of creative interests and activities between the two groups of students. Students from artistic colleges experience more unusual experiences such as hallucinations and delusions and have more disorganised thoughts, looser conceptual boundaries and attention deficits compared to nonartistic domain students. Also, artistic domain students reported a greater number of creative interests and activities than nonartistic domain students. Furthermore, students who have more unusual experiences and whose mood and behaviour (especially one connected with social norms and conventions) are unstable more often, have more creative activities. On the other hand, those students who are more prone to introverted, asocial behaviour with reduced ability in experiencing pleasure, have less creative interests and activities. No significant correlation was found between psychoticism and creativity

Pivot-and-bond model explains microtubule bundle formation

During mitosis, microtubules form a spindle, which is responsible for proper segregation of the genetic material. A common structural element in a mitotic spindle is a parallel bundle, consisting of two or more microtubules growing from the same origin and held together by cross-linking proteins. An interesting question is what are the physical principles underlying the formation and stability of such microtubule bundles. Here we show, by introducing the pivot-and-bond model, that random angular movement of microtubules around the spindle pole and forces exerted by cross-linking proteins can explain the formation of microtubule bundles as observed in our experiments. The model predicts that stable parallel bundles can form in the presence of either passive crosslinkers or plus-end directed motors, but not minus-end directed motors. In the cases where bundles form, the time needed for their formation depends mainly on the concentration of cross-linking proteins and the angular diffusion of the microtubule. In conclusion, the angular motion drives the alignment of microtubules, which in turn allows the cross-linking proteins to connect the microtubules into a stable bundle

Early Vital Indicators of Newborns Born After Medically Assisted Reproduction

Aim: In this case-control study we wanted to compare the perinatal outcome of naturally conceived newborns to those born after in vitro fertilization (IVF). Methods: At the University Hospital Centre Osijek, in the period from January 2014 to December 2016, we analysed 120 in vitro fertilization pregnancies and compared to 120 natural conception pregnancies. Characteristics of mothers, birth method, perinatal outcome, and vital characteristics of newborns were analysed. Results: IVF-ET pregnancies included 70.0% singleton pregnancies, 28.3% twin and 1.7% triplet pregnancies, while all naturally conceived pregnancies were singletons. When pregnancies were compared between IVF-ET and naturally conceived groups, the following characteristics of mothers were established: age 34.83 (5.8):30.39 (3.9); previous pregnancy 13.3%:56.7%; complications in pregnancy 50.0%:25.0%; Caesarean section (CS) 69.2%:35.8%. All of these were statistically significant (p < 0.001). Comparison of newborns between those two groups established the following: prematurity 39.5% vs. 12.7%; lowest BW 2,114 vs. 3,000 grams; lowest GA 22.29 vs. 28.71 weeks. In the IVF-ET group, 5.7% of newborns had a gestational age of 22-25 weeks, but there were no newborns of that gestational age among the naturally conceived newborns. These were also statistically significant differences (p < 0.001). Apgar score was 10 for both groups, but the difference was in the interquartile range, the values of which were lower in the IVF-ET group. Conclusion: In vitro fertilization pregnancies are high risk due to the characteristics of both the mother and the infant and, as such, require special attention and care. (Milas AM, Pušeljić S, Arambašić J, Šapina M, Tomac V. Early Vital Indicators of Newborns Born After Medically Assisted Reproduction. SEEMEDJ 2020; 4(2); 88-96

Kreativnost i izvedba Simonova zadatka

The aim of this study was to examine performance in the Simon task regarding individual differences in creative behavior measured by The Inventory of Creative Activities and Achievements (ICAA; Diedrich et al., 2018). The study included 105 students and 57 younger working-age individuals (from 19 to 36 years of age). Three-way analyses of variance were carried out on the reaction time in the Simon task given the congruence of the previous and current trials and below/above average results on creative activities and achievements scales. The reaction time in the Simon task was on average shorter in congruent than in incongruent trials (the Simon effect), as well as in the trials preceded by congruent than in those preceded by incongruent trials. The Simon effect was only present in trials preceded by a congruent trial, while reaction times in the trials preceded by incongruent trials were shorter in incongruent than in congruent trials (the Gratton effect). However, neither the Simon nor the Gratton effect were more pronounced within more or less creative participants, but the participants with an above average result on the scale of creative activities reacted on average more slowly than individuals with below the average score. The correlations between the scores on the creativity measures and the different reaction times and indices of the Simon and Gratton effect were not significant. The expected effects related to the Simon task have been obtained in this study, but further research is needed to try to replicate the findings regarding the flexibility of inhibitory control measured by performance in the Simon task and creative behavior.Cilj je ovoga istraživanja bio ispitati uspješnost u Simonovu zadatku s obzirom na individualne razlike u kreativnome ponašanju mjerene Inventarom kreativnih  aktivnosti i postignuća (ICAA; Diedrich i sur., 2018). U istraživanju je sudjelovalo 105 studenata i 57 mlađih radno sposobnih osoba (u dobi od 19 do 36 godina). Provedene su trosmjerne analize varijance vremena reakcije u Simonovu zadatku s obzirom na podudarnost prethodnih i trenutnih pokušaja te ispodprosječne/iznadprosječne rezultate na ljestvicama kreativnih aktivnosti i postignuća. Vrijeme reakcije u Simonovu zadatku bilo je u prosjeku kraće u kongruentnim nego u nekongruentnim pokušajima (Simonov efekt), kao i u pokušajima kojima su prethodili kongruentni u odnosu na pokušaje kojima su prethodili nekongruentni pokušaji. Simonov efekt bio je prisutan samo u pokušajima kojima je prethodio kongruentni pokušaj, dok su vremena reakcije u pokušajima kojima su prethodili nekongruentni pokušaji bila kraća u nekongruentnim nego u kongruentnim pokušajima (Grattonov efekt). Međutim, ni Simonov ni Grattonov efekt nisu bili izraženiji kod više ili manje kreativnih sudionika, već su sudionici s iznadprosječnim rezultatom na ljestvici kreativnih aktivnosti u prosjeku sporije reagirali od pojedinaca s ispodprosječnim rezultatom. Korelacije između rezultata na mjerama kreativnosti te različitih vremena reakcije i indeksa učinka Simona i Grattona nisu bile značajne. U ovome su istraživanju utvrđeni očekivani efekti povezani sa Simonovim zadatkom, no potrebna su daljnja istraživanja da bi se pokušali replicirati nalazi povezani s fleksibilnošću inhibicijske kontrole mjerene izvedbom Simonova zadatka i kreativnim ponašanjem

Učestalost tromboembolijskih događaja u sistemskom obliku vaskulitisa i lokaliziranom kožnom vaskulitisu

Objectives: Vasculitis is a rare disease characterized by inflammation and necrosis of blood vessels. Inflammationinduced thrombosis is a hallmark of several autoimmune diseases, such as systemic lupus erythematosus (SLE ), rheumatoid arthritis (RA ), Sjögren’s syndrome (SS), and systemic vasculitis. In this study, we aimed to investigate the frequency of thromboembolic (TE) events in the systemic form of vasculitis and cutaneous vasculitis and to determine the possible risk factors for developing thromboembolic events. Methods: In this single-centre retrospective study, the patients diagnosed with systemic vasculitis and cutaneous leukocytoclastic vasculitis were included. Medical records of the patients that were treated at the Division of Rheumatology, Clinical Immunology, and Allergology University Hospital Centre Osijek in the period of 30 months (from November 2016. to June 2019.) were analysed. Results: Out of a total of 46 patients who were included in the study, 30 were diagnosed with systemic vasculitis, and 16 with cutaneous vasculitis. Statistically significant differences in relation to gender were found between the two groups (systemic vasculitis vs cutaneous vasculitis: the female gender 76.67% vs 43.75%; p=0.026), but there was no difference between the groups in relation to the age of disease onset. Thromboembolic events were found to be more frequent in the systemic form of the disease (p=0.0321). In the systemic vasculitis group, TE events were found in patients who suffered from involvement of multiple organ systems and in younger patients. Conclusion: Our research found that patients with systemic vasculitis, who are younger, with high disease activity, and who suffered from the involvement of multiple organ system, have an increased risk for developing TE events. In those patients, special attention should be paid to searching for additional TE risk factors, such as genetics, for the purpose of preventing unwanted events and applying TE prophylaxis on time.Uvod: Vaskulitis je rijetka bolest karakterizirana upalom i nekrozom krvnih žila. Upalom inducirana tromboza smatra se svojstvom nekoliko autoimunosnih bolesti poput sistemskog eritemskog lupusa (SLE ), reumatoidnog artritisa (RA ), Sjögrenova sindroma (SS) te sistemskih vaskulitisa. U ovom istraživanju nastojali smo utvrditi učestalost tromboembolijskih (TE) događaja kod sistemskog oblika vaskulitisa i vaskulitisa ograničenog na kožu te procijeniti koji su mogući rizični čimbenici za razvoj tromboembolijskih (TE) događaja. Ispitanici i metode: U ovoj retrospektivnoj studiji sudjelovali su bolesnici s dijagnozom sistemskog vaskulitisa i vaskulitisa ograničenog na kožu liječenih u Zavodu za reumatologiju, kliničku imunologiju i alergologiju Kliničkoga bolničkog centra Osijek u razdoblju od 30 mjeseci (od studenog 2016. do lipnja 2019. godine). Klinički podatci prikupljeni su pretraživanjem medicinske dokumentacije. Rezultati: U studiju je uključeno ukupno 46 bolesnika, 30 s dijagnozom sistemskog vaskulitisa i 16 s vaskulitisom ograničenim na kožu. Među dvjema skupinama bilo je statistički značajne razlike po spolu (sistemski vaskulitis vs vaskulitis ograničen na kožu – ženski spol 76,67% vs 43,75%; p=0,026), no među grupama nije bilo razlike u dobi pojave bolesti. Tromboembolijski događaji bili su češći u bolesnika sa sistemskim oblikom vaskulitisa (p=0,0321). Pri analizi bolesnika sa sistemskim vaskulitisom kao rizični čimbenici za razvoj TE događaja utvrđeni su zahvaćanje više organskih sustava bolešću te mlađa životna dob. Zaključak: U našem istraživanju pokazali smo da bolesnici sa sistemskim vaskulitisom, mlađe životne dobi, uz visoku aktivnost bolesti i zahvaćanje više organskih sustava imaju povećan rizik za nastanak tromoebolijskih događaja te bi se kod takvih bolesnika trebala posvetiti posebna pozornost u otkrivanju dodatnih rizičnih čimbenika kao što je genetska predispozicija u svrhu sprječavanja neželjenih događaja te primjenu pravovremene TE profilakse