Značaj salivarnih defenzina i katelicidina u proceni rizika za nastanak karijesa kod dece

The study aimed to examine the significance of human α defensin 1 (HNP-1), human β defensin 2 (hBD-2) and human cathelicidin (LL-37) of unstimulated saliva as caries risk biomarkers in childhood. A one-year, prospective study which included preschool children (N=250) and early adolescents (N=213) was conducted. Having interviewed the mothers/guardians of the subjects, socio-demographic data, data on the health status, oral hygiene, and dietary habits of the subjects were collected. The clinical examination recorded the state of oral hygiene and dental health of the subjects. Unstimulated saliva was sampled to determine its pH value, and in 85 preschool children and 85 early adolescents to determine the salivary level of HNP-1, hBD-2 and LL-37 using commercial ELISA kits. After 12 months, a repeated examination recorded the state of the dental health of the subjects, along with the determination of the annual caries increment. A cross-sectional study showed that the concentration of the tested HNP-1, hBD-2, LL-37 correlated with the age of the children, and the salivary pH but not with the caries presence, so the study did not determine their significance as caries risk indicators. In preschool age, this significance was shown by gender (p=0.021), the age of the mother (p=0.028), length of breastfeeding (p=0.042), frequency of carbohydrate intake (p=0,009), and values of the oral hygiene index (p=0.042), that is, the level of education of the mother (p<0.001) and the father (p=0.002), oral hygiene index values (p<0.001), frequency (p=0.029) and length of performing oral hygiene (p<0.001) in early adolescence. The logistic regression analysis showed that the analysed peptides were not recognized as reliable caries predictors in childhood. The multivariate model showed that the most significant caries predictors in preschool children were the oral hygiene index (p=0.005) and the absence of dental visits (p=0.014), compared to gender (p=0.001) and variables related to oral hygiene (p=0.044) in early adolescence. Determining the importance of salivary defensins and cathelicidin as caries risk biomarkers in childhood is complex, since their concentration may be related to certain factors, such as age and salivary pH which the study found, and probably with many salivary components that may interact with these peptides. Therefore, it could be considered justified to use a multimarker approach in determining the importance of defensins and cathelicidin as caries risk biomarkers in children, rather than analyzing their efficacy as a solely risk biomarkers. Based on the results of the study, socio-demographic characteristics and oral-hygiene habits remain important caries risk factors in childhood, suggesting the importance of the mechanical control of dental biofilm as a central caries preventive measure

Direktna metoda za određivanje ukupne alfa/beta aktivnosti u vodama

Monitoring of environmental samples, drinking and surface waters, is continuously carried out, demanding development of methods that are both reliable and accurate on one side, but as simple and fast as possible, on the other. Screening tests such as gross alpha/beta activity measurements in water samples are one liquid scintillation counting (LSC) technique widely used as an efficient tool for radiological assesment and estimation whether water sample needs further analysis or not. In this paper, establishment of rapid gross alpha/beta screening technique in waters has been presented, which assumes modification of conventional ASTM D 7283-06 method, since samples were directly mixed with liquid scintillation cocktail, without any sample pretreatment. Method’s optimization involved sample-to-cocktail ratio determination based on the achieved detection limit and sample’s quench level. Optimal value of Pulse Shape Analysis (PSA) discriminator that considerably improves performance of LSC technique through alpha/beta spectra separation during radiological quality measurements of drinking waters has also been investigated. Results of calibration experiments and method’s validity measurements on spiked samples with 241Am and 90Sr/90Y aqueous standards are presented. Achieved detection limits for 300 minutes of counting are MDAα=0.294(11) Bq l-1 and MDAβ=0.405(5) Bq l-1, in alpha and beta window, respectively. Direct alpha/beta method provides deviations up to 40% from reference values, but it offers advantages over conventional alpha/beta measurements, it is ultra fast, simple and inexpensive test for efficient screening of water samples.Rutinski monitoring pijaćih i površinskih voda sprovodi se kontinuirano i nameće potrebu za razvojem metoda koje su, s jedne strane, pouzdane i tačne, ali istovremeno, jednostavne i brze. Screening testovi radi procene ukupne alfa/beta aktivnosti u uzorcima voda, jedna su od često primenjenih tehnika tečne scintilacione spektroskopije, kojima se efikasno može utvrditi da li uzorak zahteva dalju radiološku analizu ili ne. U radu je predstavljena optimizacija brze direktne metode za ispitivanje ukupne alfa/beta aktivnosti u vodama, uz prikaz i diskusiju postignutih granica detekcije. Ova metoda je modifikacija standardne test metode ASTM D 7283-06 za ispitivanje ukupne alfa i beta aktivnosti i podrazumeva direktno mešanje uzorka vode sa scintilacionim koktelom. Na taj način, uzorak je spreman za merenje bez prethodne pripreme koja, prema standardnim metodama, obično podrazumeva duge procedure poput uparavanja do suvog ostatka. Optimizacija metode sastoji se u određivanju optimalnog odnosa uzorak: scintilacioni koktel na osnovu granica detekcije (MDA) u alfa i beta kanalima, kao i nivoa prigušenja u uzorcima, uzimajući u obzir i maksimalni kapacitet određenog koktela. Podešena je vrednost PSA (Pulse Shape Analysis) diskriminatora u cilju optimalne separacije alfa i beta spektara i redukcije pozadinskih efekata. Kalibracija i validacija metode je izvršena standardnim referentnim materijalima, rastvorima 241Am i 90Sr/90Y. Utvrđeno je da za 300 minuta merenja tečnim scintilacionim brojačem, mogu se izmeriti koncentracije aktivnosti koje premašuju vrednosti MDAα=0,294(11) Bq l-1 i MDAβ=0,405(5) Bq l-1 u alfa i beta kanalima, respektivno. Rezultati validacije metode pokazuju da maksimalna relativna odstupanja mogu iznositi do 40%, što je prihvatljivo, uzimajući u obzir da metod nije predviđen za precizno merenje koncentracija aktivnosti pojedinih radionuklida, već za celokupnu procenu radiološke bezbednosti uzoraka voda.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Direktna metoda za određivanje ukupne alfa/beta aktivnosti u vodama

Monitoring of environmental samples, drinking and surface waters, is continuously carried out, demanding development of methods that are both reliable and accurate on one side, but as simple and fast as possible, on the other. Screening tests such as gross alpha/beta activity measurements in water samples are one liquid scintillation counting (LSC) technique widely used as an efficient tool for radiological assesment and estimation whether water sample needs further analysis or not. In this paper, establishment of rapid gross alpha/beta screening technique in waters has been presented, which assumes modification of conventional ASTM D 7283-06 method, since samples were directly mixed with liquid scintillation cocktail, without any sample pretreatment. Method’s optimization involved sample-to-cocktail ratio determination based on the achieved detection limit and sample’s quench level. Optimal value of Pulse Shape Analysis (PSA) discriminator that considerably improves performance of LSC technique through alpha/beta spectra separation during radiological quality measurements of drinking waters has also been investigated. Results of calibration experiments and method’s validity measurements on spiked samples with 241Am and 90Sr/90Y aqueous standards are presented. Achieved detection limits for 300 minutes of counting are MDAα=0.294(11) Bq l-1 and MDAβ=0.405(5) Bq l-1, in alpha and beta window, respectively. Direct alpha/beta method provides deviations up to 40% from reference values, but it offers advantages over conventional alpha/beta measurements, it is ultra fast, simple and inexpensive test for efficient screening of water samples.Rutinski monitoring pijaćih i površinskih voda sprovodi se kontinuirano i nameće potrebu za razvojem metoda koje su, s jedne strane, pouzdane i tačne, ali istovremeno, jednostavne i brze. Screening testovi radi procene ukupne alfa/beta aktivnosti u uzorcima voda, jedna su od često primenjenih tehnika tečne scintilacione spektroskopije, kojima se efikasno može utvrditi da li uzorak zahteva dalju radiološku analizu ili ne. U radu je predstavljena optimizacija brze direktne metode za ispitivanje ukupne alfa/beta aktivnosti u vodama, uz prikaz i diskusiju postignutih granica detekcije. Ova metoda je modifikacija standardne test metode ASTM D 7283-06 za ispitivanje ukupne alfa i beta aktivnosti i podrazumeva direktno mešanje uzorka vode sa scintilacionim koktelom. Na taj način, uzorak je spreman za merenje bez prethodne pripreme koja, prema standardnim metodama, obično podrazumeva duge procedure poput uparavanja do suvog ostatka. Optimizacija metode sastoji se u određivanju optimalnog odnosa uzorak: scintilacioni koktel na osnovu granica detekcije (MDA) u alfa i beta kanalima, kao i nivoa prigušenja u uzorcima, uzimajući u obzir i maksimalni kapacitet određenog koktela. Podešena je vrednost PSA (Pulse Shape Analysis) diskriminatora u cilju optimalne separacije alfa i beta spektara i redukcije pozadinskih efekata. Kalibracija i validacija metode je izvršena standardnim referentnim materijalima, rastvorima 241Am i 90Sr/90Y. Utvrđeno je da za 300 minuta merenja tečnim scintilacionim brojačem, mogu se izmeriti koncentracije aktivnosti koje premašuju vrednosti MDAα=0,294(11) Bq l-1 i MDAβ=0,405(5) Bq l-1 u alfa i beta kanalima, respektivno. Rezultati validacije metode pokazuju da maksimalna relativna odstupanja mogu iznositi do 40%, što je prihvatljivo, uzimajući u obzir da metod nije predviđen za precizno merenje koncentracija aktivnosti pojedinih radionuklida, već za celokupnu procenu radiološke bezbednosti uzoraka voda.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Dental health care for children with autism spectrum disorders

Introduction: Autism spectrum disorders (ASD) are pervasive disorders beginning in early childhood. The prevalence of these disorders has been on the rise over the last few decades. A disorder of this kind does not have any direct impact on the oral health, but the behavior of the affected children can markedly deteriorate it. Due to a poor compliance to oral hygiene and maintenance of oral health, dental film accumulates in the oral cavity, leading to both caries and its complications, and gingival-periodontal diseases. A high percentage of children with ASD are not sufficiently compliant during dental interventions, being hyperactive, tense, and often highly agitated. Any dental intervention in such children is therefore very complicated or it cannot be performed at all, consequentially broadening the spectrum of indications for dental extractions. In order to preserve the oral health in children with ASD, an individualized approach to each patient is thus necessary. Conclusion: The journey to a healthy oral cavity and teeth in children with ASD is full of twists and turns, but the desired goals can be realized, although requiring considerable patience and perseverance from both the parents and pediatric dentists

Poređenje metoda za određivanje biogene komponente u tečnim gorivima

A method of direct measurement of 14C activity concentration via liquid scintillation counting (LSC) is recognized as good and fast method for determination of biogenic component in liquid fuels. Two laboratories that used this14C technique participated in this survey: Laboratory from University of Novi Sad (UNS), Serbia and Laboratory from Ruđer Bošković Institute (RBI), Croatia. Each laboratory used its own calibration methods on the same set of samples (produced diesel-based bio-fuels and commercially available domestic oils). From the obtained results it can be concluded that each method which uses 14C technique for determination of biogenic component in liquid fuels has its advantages and disadvantages. RBI data evaluation method is based on two calibration curves, for purely biogenic and purely fossil liquids, and the calibration does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP(E) of approximately 690. Below this value the count rates of biogenic and fossil liquids become close to each other or even indistinguishable from one another and the obtained results for biogenic fractions are not reliable. In this intercomparison UNS used two different methods, one for produced bio-diesels and the other one for domestic oils. UNS data evaluation method is very dependent on the composition of the examined fuels, so the obtained results with the "two-step" method were relatively good in the case of diesel mixtures with biogenic component. In the case of biogenic oil samples (bought on market), UNS "two-step" method did not give realistic results, and with the "one-step" method the limitation is large quenching in the samples, so for the samples with SQP(E) less than 700 this method could not give expected results. Samples prepared with liquid fuels are usually colored and the main challenge for determination of biogenic component in both laboratories is handling of highly quenched liquids.Prema preporukama Evropske Unije sa ciljem da se koriste obnovljivi i održivi izvori, do 2020. godine zahteva se da se u svim tečnim gorivima koja se koriste nalazi bar 10% sintetisanog biodizela. Da bi se koncentracija biodizela mogla proveriti, nekoliko laboratorija u svetu je razvilo metode za tačnu, efikasnu i pouzdanu kvantifikaciju sadržaja biogene komponente. Direktno merenje koncentracije aktivnosti 14C tečnim scintilacionim detektorom (LSC), koje podrazumeva određivanje količine 14C u uzorku kao meru prisutnosti biogene komponente u testiranom gorivu, pokazalo se kao dobra i brza metoda. U ovoj interkomparaciji učestvovale su dve laboratorije: Laboratorija sa Univerziteta u Novom Sadu (UNS), Srbija i Laboratorija sa Instituta Ruđer Bošković (RBI), Hrvatska. Svaka laboratorija je koristila sopstveni kalibracioni metod i isti set uzoraka za interkomparaciju (proizvedena bio-goriva bazirana na dizelu i komercijalno dostupna domaća ulja). Iz dobijenih rezultata može se zaključiti da svaki od prikazanih metoda ima svoje prednosti i mane, što zavisi od samog sastava uzorka. RBI metod se zasniva na upotrebi dve kalibracione krive, za čisto biogena i čisto fosilna goriva, i kalibracija nije zavisna od hemijskog sastava analiziranog uzorka. Ograničenje ove metode je SQP(E) vrednost niža od 690. Ispod ove vrednosti odbroji biogene i fosilne komponente postaju veoma bliski jedan drugom i samim tim rezultati koji se dobijaju nisu pouzdani. U ovoj interkomparaciji, UNS je koristila dve različite metode kalibracije, jednu za proizvedene bio-dizele, a drugu za domaća ulja. UNS metod evaluacije izmerenih podataka u mnogome zavisi od sastava ispitivanog goriva, pa su rezultati dobijeni sa "two-step" metodom relativno dobri za smeše dizela sa biogenom komponentom. U slučaju biogenih ulja, UNS "two-step" metod nije dao realistične rezultate, zbog toga je korišćen "one-step" metoda za koji je utvrđeno ograničenje za SQP(E) parametar na 700. Uzorci koji se pripremaju sa tečnim gorivima su najčešće obojeni i najveći problem koji se javlja je korekcija na prigušenje u samom uzorku, koja mora biti detaljno sprovedena kako bi se dobio pouzdan rezultat, pa najveći izazov daljnjeg razvoja ovih metoda postaje postupak merenja biogene komponente u jako prigušenim uzorcima.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Radium in water: detection of bulk samples in well-type NaI detector

Zbog svoje visoke efikasnosti, NaI detektor oblika jame je odličan izbor za detekciju niskih aktivnosti, pogotovo kod uzoraka uzetih iz prirode. No velik prostorni ugao kojeg aktivna zapremina detektora oblika jame zauzima, neminovno dovodi do efekta koincidentnog sumiranja. Na osnovu većeg broja gama spektara rastvora radijuma je ispitan uticaj koincidentnog sumiranja na efikasnost detekcije u cilju razvijanja brzog i pouzdanog metoda za merenje radijuma u pijaćim vodama. Razvijen je i nov “grafički” metod za određivanje praga detekcije koji je ispitan na primeru voluminoznih uzoraka male aktivnosti.Due to its high efficiency, a well-type NaI detector is an excellent choice for low-level activity detection, especially for samples taken from nature. But, the large space angle that active volume of the detector includes, indispicably leads to coincident summing. Based on large number of gamma spectra of radium solutions, the effect of coincident summing was examined for purposes of developing a fast and reliable method for drinking water radium measurements. Also, a new ”graphical”method for determining MDA, based on measurements of small activity voluminous samples was developed.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Radium in water: detection of bulk samples in well-type NaI detector

Zbog svoje visoke efikasnosti, NaI detektor oblika jame je odličan izbor za detekciju niskih aktivnosti, pogotovo kod uzoraka uzetih iz prirode. No velik prostorni ugao kojeg aktivna zapremina detektora oblika jame zauzima, neminovno dovodi do efekta koincidentnog sumiranja. Na osnovu većeg broja gama spektara rastvora radijuma je ispitan uticaj koincidentnog sumiranja na efikasnost detekcije u cilju razvijanja brzog i pouzdanog metoda za merenje radijuma u pijaćim vodama. Razvijen je i nov “grafički” metod za određivanje praga detekcije koji je ispitan na primeru voluminoznih uzoraka male aktivnosti.Due to its high efficiency, a well-type NaI detector is an excellent choice for low-level activity detection, especially for samples taken from nature. But, the large space angle that active volume of the detector includes, indispicably leads to coincident summing. Based on large number of gamma spectra of radium solutions, the effect of coincident summing was examined for purposes of developing a fast and reliable method for drinking water radium measurements. Also, a new ”graphical”method for determining MDA, based on measurements of small activity voluminous samples was developed.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Poređenje metoda za određivanje biogene komponente u tečnim gorivima

A method of direct measurement of 14C activity concentration via liquid scintillation counting (LSC) is recognized as good and fast method for determination of biogenic component in liquid fuels. Two laboratories that used this14C technique participated in this survey: Laboratory from University of Novi Sad (UNS), Serbia and Laboratory from Ruđer Bošković Institute (RBI), Croatia. Each laboratory used its own calibration methods on the same set of samples (produced diesel-based bio-fuels and commercially available domestic oils). From the obtained results it can be concluded that each method which uses 14C technique for determination of biogenic component in liquid fuels has its advantages and disadvantages. RBI data evaluation method is based on two calibration curves, for purely biogenic and purely fossil liquids, and the calibration does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP(E) of approximately 690. Below this value the count rates of biogenic and fossil liquids become close to each other or even indistinguishable from one another and the obtained results for biogenic fractions are not reliable. In this intercomparison UNS used two different methods, one for produced bio-diesels and the other one for domestic oils. UNS data evaluation method is very dependent on the composition of the examined fuels, so the obtained results with the "two-step" method were relatively good in the case of diesel mixtures with biogenic component. In the case of biogenic oil samples (bought on market), UNS "two-step" method did not give realistic results, and with the "one-step" method the limitation is large quenching in the samples, so for the samples with SQP(E) less than 700 this method could not give expected results. Samples prepared with liquid fuels are usually colored and the main challenge for determination of biogenic component in both laboratories is handling of highly quenched liquids.Prema preporukama Evropske Unije sa ciljem da se koriste obnovljivi i održivi izvori, do 2020. godine zahteva se da se u svim tečnim gorivima koja se koriste nalazi bar 10% sintetisanog biodizela. Da bi se koncentracija biodizela mogla proveriti, nekoliko laboratorija u svetu je razvilo metode za tačnu, efikasnu i pouzdanu kvantifikaciju sadržaja biogene komponente. Direktno merenje koncentracije aktivnosti 14C tečnim scintilacionim detektorom (LSC), koje podrazumeva određivanje količine 14C u uzorku kao meru prisutnosti biogene komponente u testiranom gorivu, pokazalo se kao dobra i brza metoda. U ovoj interkomparaciji učestvovale su dve laboratorije: Laboratorija sa Univerziteta u Novom Sadu (UNS), Srbija i Laboratorija sa Instituta Ruđer Bošković (RBI), Hrvatska. Svaka laboratorija je koristila sopstveni kalibracioni metod i isti set uzoraka za interkomparaciju (proizvedena bio-goriva bazirana na dizelu i komercijalno dostupna domaća ulja). Iz dobijenih rezultata može se zaključiti da svaki od prikazanih metoda ima svoje prednosti i mane, što zavisi od samog sastava uzorka. RBI metod se zasniva na upotrebi dve kalibracione krive, za čisto biogena i čisto fosilna goriva, i kalibracija nije zavisna od hemijskog sastava analiziranog uzorka. Ograničenje ove metode je SQP(E) vrednost niža od 690. Ispod ove vrednosti odbroji biogene i fosilne komponente postaju veoma bliski jedan drugom i samim tim rezultati koji se dobijaju nisu pouzdani. U ovoj interkomparaciji, UNS je koristila dve različite metode kalibracije, jednu za proizvedene bio-dizele, a drugu za domaća ulja. UNS metod evaluacije izmerenih podataka u mnogome zavisi od sastava ispitivanog goriva, pa su rezultati dobijeni sa "two-step" metodom relativno dobri za smeše dizela sa biogenom komponentom. U slučaju biogenih ulja, UNS "two-step" metod nije dao realistične rezultate, zbog toga je korišćen "one-step" metoda za koji je utvrđeno ograničenje za SQP(E) parametar na 700. Uzorci koji se pripremaju sa tečnim gorivima su najčešće obojeni i najveći problem koji se javlja je korekcija na prigušenje u samom uzorku, koja mora biti detaljno sprovedena kako bi se dobio pouzdan rezultat, pa najveći izazov daljnjeg razvoja ovih metoda postaje postupak merenja biogene komponente u jako prigušenim uzorcima.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин