Dijagnostičke performanse i ekonomski aspekti testova za detekciju Chlamydia-e trachomatis

C. trachomatis je najčešća seksualno prenosiva bakterijska infekcija u svetu. Procenjuje se da hlamidija seksualnim putem inficira preko 100 miliona ljudi svake godine širom sveta. Akutne infekcije donjeg genitalnog trakta izazvane C. trachomatis (uretritis kod muškaraca, cervititis i uretritis kod žena) su uglavnom asimptomatske te stoga infekcije najčešće prolaze nedijagnostikovane i nelečene, a kao posledica toga kod 20%-40% slučajeva infekcija se širi u gornji genitalni trakt. U gornjem genitalnom traktu,i pored aktivacije imunoloških mehanizama odbrane, hlamidije uspevaju da opstanuzahvaljujući svojojizuzetnoj sposobnosti izbegavanja imunskog odgovora domaćina, što može dovesti do do ozbiljnih oštećenja i komplikacija vezanih za reproduktivno zdravlje žena. Asimptomatska priroda infekcije kao i specifičan razvojni ciklus hlamidija predstavljaju pravi izazov za postavljanje dijagnoze akutne hlamidijalne infekcije. Za uspešnu dijagnozu hlamidijalnih infekcija neophodno je napraviti dobar odabir testa koji obezbeđuje visoku senzitivnost i specifičnost, ali i brzinu izvođenja testa, što su po preporukama evropskog i američkog centra za kontrolu bolesti svakako testovi amplifikacije nukleinskih kiselina. Danas je dostupan veći broj komercijalnih PCR i RT-PCR testova koje karakteriše visoka senzitivnost i specifičnost. Međutim, visoka cena ekonomskih troškova ovih testova, uz tehničku kompleksnost vezanu za prostor, kadar i opremu, uslovili su da je za većinu dijagnostičkih laboratorija u zemljama sa nižim prihodima ovaj standard nedostižan. Tako je u izboru optimalnog dijagnostičkog pristupa neophodno odabrati test koji ima zadovoljavajuće, ne samo dijagnostičke, već i ekonomske performanse. Osnovni cilj ovog istraživanja jeutvrđivanje dijagnostičke efikasnosti četiri pojedinačnatesta (DIF, BT, IgA i IgG),kao i kombinacije pomenutih testova, u odnosu na RT-PCR metodu koja predstavlja zlatni standard za postavljanje dijagnoze akutne hlamidijalne infekcije. Pored ispitivanja dijagnostičke efikasnosti studija pruža uvid i u ekonomsku analizu pomenutih testova u odnosu na RT-PCR metodu. Rezultati naše studije ukazuju na slabo slaganje rezultata dobijenih pomoću zlatnog standarda (RT-PCR) sa rezultatima dobijenim upotrebom skrining testova (DIF, BT, IgA i IgG). Od svih analiziranih testova najbolje slaganje u odnosu na zlatni standard pokazuje brzi test lateralne hromatografije (VT). Kombinacijom testova pokriterijumu „pozitivna dva ili više testa“ i „pozitivan bilo koji test“ nismo popravili slaganjerezultata u odnosu na pojedinačne skrining testove. Analizirajući dijagnostičku efikasnost pojedinačnih skrining testova utvrdili smo da VT povećini analiziranih parametara pokazuje najboljudijagnostičku efikasnost, doktest direktne imunofluorescencije i serumski nivo IgA i IgG antitela, u odnosu na VT, pokazuju bolje uravnotežen odnos senzitivnosti i specifičnosti. Kombinacijom testova po kriterijumu „pozitivna dva ili više testa“ i „pozitivan bilo koji test“ nismo uspeli da popravimo dijagnostičku efikasnostu odnosu na pojedinačne skrining testove, odnosno BT koji je pojedinačno imao najbolje parametre dijagnostičke efikasnosti. Shodno tome, ove kombinacije testova se ne mogu preporučiti za dijagnozu akutne hlamidijalne infekcije. Ipak, kombinacija DIF/IgA (pozitivan bilo koji test) koja pokazuje dobro izbalansiran odnos senzitivnosti i specifičnosti uz superiornu senzitivnost od 100% te se i pored niske pozitivne prediktivne vrednosti može koristiti u situacijama koje zahtevaju visoku senzitivnost. Interensantan podatak je da smo ROC analizom serumskog nivoa IgA i IgG antitela na hlamidijalni MOMR antigen i određivanjem novih cut–off vrednosti (na osnovu karakteristika ROC krive) popravili dijagnostičku efikasnost ovih testova u odnosu na rezultate dobijene na osnovu cut–offvrednosti preporučenihod strane proizvođača testa. Isto možemo da kažemo i za obe grupe kombinacija IgA+IgG testa (pozitivna oba testa) i kombinacije IgA/IgG (pozitivan bilo koji test). Ekonomska analiza ukazuje da su, za dati scenario, najmanji ukupni troškovi po pacijentu kod korišćenja brzog testa, te je stoga primena ovog testa dominantna ekonomska strategija, a prve alternative su serološke metode. Primena kombinacije testova nije isplativa ekonomska strategija jer su ukupni troškovi po pacijentu veći od troškova primene pojedinačnih testova. Imajući u vidu prethodnu analizu dijagnostičke efikasnosti kombinovanih testova, takvom praksom se jedino uvećavaju troškovi analize, bez bitno unapređenih dijagnostičkih performansi. Iako su dijagnostičke performanse svih testova, kako pojedinačnih, tako i kombinovanih, u odnosu na PCR metodu znatno slabije, njena visoka početna cena, u uslovima troškova nacionalnog zdravstvenog sistema, ne može da se kompenzuje boljim dijagnostičkim rezultatima u ukupnom ekonomskom profilu datog scenarija.C. trachomatis is the most common sexually transmitted bacterial infection in the world. It is estimated that chlamydia sexually infects more than 100 million people every year worldwide.Acute infections of the lower genital tract caused by C. trachomatis (uretritis in men, cervicitis and urethritis in women) are mostly asymptomatic, and therefore infections commonly passed undiagnosed and untreated. As a consequence, in 20% -40% of cases, the infection spreads to the upper genital tract. Despite the activation of immune defense mechanisms in the upper genital tract, chlamydia is able to survive owing to its remarkable ability to avoid the host immune response, which can lead to serious damage and complications related to the reproductive health of women. The asymptomatic nature of the infection as well as the specific developmental cycle of chlamydia is a real challenge for establishing the diagnosis of an acute chlamydial infection. For a successful diagnosis of chlamydial infections it is necessary to make a good selection of the test which provides high sensitivity and specificity, as well as the speed of the test, which, according to the recommendations of the European and American Center for Disease Control, are certainly nucleic acid amplification tests. A number of commercial PCR and RTPCR tests are available today, characterized by high sensitivity and specificity. However, the high price of the economic costs of these tests, with the technical complexity of space, personnel and equipment, has made it uncertain for the most diagnostic laboratories in low-income countries. In the selection of an optimal diagnostic approach, it is necessary to select a test that has satisfactory, not only diagnostic, but also the economic performances. The main objective of this study is to determine the diagnostic efficacy of four individual tests (DIF, BT, IgA and IgG), as well as combinations of these tests in relation to the RT-PCR method, which represents the golden standard for diagnosing an acute chlamydial infection. In addition to testing the diagnostic efficiency, the study provides an insight into the economic analysis of the tests mentioned above in relation to the RT-PCR method. The results of our study indicate poor agreement between the results obtained by using the screening tests (DIF, BT, IgA and IgG) in relation to the golden standard (RT-PCR). Of the all analyzed tests, the best matching in relation to the golden standard shows a rapid test of the lateral chromatography (RT). We did not correct the matching of the results in relation to the individual screening tests by combining the tests with the criteria "positive two or more tests" and "positive any test". Analyzing the diagnostic efficiency of individual screening tests, we have established that RT shows the best diagnostic efficacy in most of the analyzed parameters, while the direct immunofluorescence test and serum IgA and IgG antibody levels in comparison to RT show a more balanced relation of sensitivity and specificity. By combining the tests using the criteria "positive two or moretests" and "positive any test", we were unable to improve the diagnostic efficiency in relation to individual screening tests that is RT, which individually had the best parameters of diagnostic efficiency. Consequently, these test combinations cannot be recommended for the diagnosis of an acute chlamydial infection. However, the combination of DIF/IgA (positive any test) that shows a well balanced sensitivity and specificity ratio with superior sensitivity of 100%, and despite a low positive predictive value, can be used in situations requiring high sensitivity. An interesting fact is that the ROC analysis of the serum IgA and IgG antibody levels to the chlamydial MOMR antigen and the determination of new cut-offs (based on the characteristics of the ROC curve) corrected the diagnostic efficacy of these tests in relation to the results obtained from the cut-off values recommended by the test manufacturers. The same can be said for both groups of combination IgA + IgG test (positive both tests) and IgA / IgG combinations (positive any test). Economic analysis indicates that for the given scenario, the lowest total cost per patient is in the use of a rapid test, and therefore the application of this test is the dominant economic strategy, and the first alternatives are serological methods. Using a combination of tests is not a cost-effective economic strategy because the total cost per patient is greater than the cost of using individual tests. Taking into account the previous analysis of the diagnostic efficiency of combined tests, such practice only increases the cost of analysis, without significantly improved diagnostic performance. Although the diagnostic performances of all the tests, both individual and combined are considerably lower compared to the PCR method, its high starting price, in the terms of costs of the national healthcare system, cannot be compensated for better diagnostic results in the overall economic profile of the given scenario

Factors influencing axillary bud induction on nodal segments of Micromeria pulegium (Rochel) Benth.

Micromeria pulegium (Rochel) Benth.is an endemic species from family Lamiaceae. Plants from this family are characterized by presence of secondary metabolites and antioxidant components. M. pulegium contains pulegone which is a potential bio-insecticide and a bio-pesticide. Natural populations of this species are so small that there is a need for an alternative way of propagate and proliferation of individuals. Method of micropropagation was used with the goal of mass production of plants with the chemical composition of essential oils as similar as possible to that in wild-harvested plants. This paper presents the study on influence of concentration of mineral salts, carbon sources (sucrose and maltose) and nitrogen source (casein hydrolysate) on process of in vitro regeneration of plants through induction of axillary buds on the nodal segments of Micromeria pulegium. The greatest number of axillary buds was formed in explants grown on MS culture medium with 3 % sucrose and 500 mg/L casein hydrolysate

Expression of bacteriocin LsbB is dependent on a transcription terminator

The production of LsbB, leaderless class II bacteriocin, is encoded by genes (lsbB and lmrB) located on plasmid pMN5 in Lactococcus lactis BGMN1-5. Heterologous expression of the lsbB gene using the pAZIL vector (pAZIL-lsbB) in L. lactis subsp. cremoris MG7284 resulted in a significant reduction (more than 30 times) of bacteriocin LsbB expression. Subcloning and deletion experiments with plasmid pMN5 revealed that full expression of LsbB requires the presence of a complete transcription terminator located downstream of the lsbB gene. RNA stability analysis revealed that the presence of a transcription terminator increased the RNA stability by three times and the expression of LsbB by 30 times. The study of the influence of transcription terminator on the expression of other bacteriocin genes (lcnB, for lactococcin B production) indicated that this translational terminator likely functions in a lsbB-specific manner rather than in a general manner

Environmental assessment of green concretes for structural use

This paper presents a comparative environmental assessment of several different green concrete mixes for structural use. Four green concrete mixes were compared with a conventional concrete mix: recycled aggregate concrete with a cement binder, high-volume fly ash concrete with natural and recycled aggregates, and alkali activated fly ash concrete with natural aggregates. All five concrete mixes were designed and experimentally verified to have equal compressive strength and workability. An attributional life cycle assessment, based on the scenario which included construction practice, transport distances, and materials available in Serbia, was performed. When treating fly ash impacts, three allocation procedures were compared: ‘no allocation’, economic, and mass allocation, with mass allocation giving unreasonably high impacts of fly ash. Normalization and aggregation of indicators was performed and the impact of each concrete mix was expressed through a global sustainability indicator. A sensitivity analysis was also performed to evaluate the influence of possibly different carbonation resistance and long-term deformational behavior on the functional unit. In this specific case study, regardless of the choice of the functional unit, the best overall environmental performance was shown by the alkali activated fly ash concrete mix with natural aggregates and the high-volume fly ash recycled aggregate concrete mix. The worst performance was shown by the recycled aggregate concrete mix with a cement binder

Konstrukcijski betoni sa delimičnom ili potpunom zamenom cementa elektrofilterskim pepelom

Building industry is facing with great challenges in directing its activities towards sustainable development. Environmental protection, the use of waste and recycled materials and reduction of the use of non-renewable natural resources has become the focus of current research in building materials. Concrete is the most widely used man-made material in the world, and hence the pressure to reduce its harmful impact on the environment as much as possible. Production of the main component of concrete - cement, is one of the major polluters of the environment. With this in mind, research in the field of concrete materials has focused on the use of alternative binder in concrete with less harmful effects on the environment. In recent decades, concrete made with fly ash as a partial or total replacement of cement attracted a lot of attention. This paper gives an overview of the use of fly ash in concrete, as well as physical and mechanical properties of this type of concrete. High volume fly ash concrete with 50% replacement of cement and geopolymer concrete with alkali activated fly ash have been analyzed. This paper gives an overview of research done in this field in the world and own experimental results of these types of concrete made with fly ash from power plant ‘Nikola Tesla B’ from Obrenovac.Građevinska industrija se suočava sa velikim izazovima prilikom usmeravanja svojih delatnosti na put održivog razvoja. Zaštita životne sredine, korišćenje otpadnih i recikliranih materijala i smanjenje upotrebe prirodnih neobnovljivih resursa postali su fokus aktuelnih istraživanja građevinskih materijala. Beton je danas nesumnjivo najčešće korišćeni veštački materijal u svetu, i stoga je pritisak da se njegov štetni uticaj na okolinu što više smanji. Proizvodnja glavne vezivne komponente betona - cementa, predstavlja jedan od većih zagađivača životne sredine. Imajući ovo u vidu, istraživanja u oblasti betona su fokusirana na korišćenje alterantivnih veziva u betonu koja imaju manje štetnih efekata na životnu sredinu. Poslednjih decenija veliku pažnju privlače betoni sa elektrfilterskim pepelom kao delimičnom ili potpunom zamenom cementa. U ovom radu dat je pregled mogućnosti korišćenja elektrfilterskog pepela u betonima i fizičko-mehaničke karakteristike tih betona. Analizirani su betoni sa velikim sadržajem elektrofilterskog pepela koji imaju 50% zamene cementa i geopolimer betoni u kojima je cement potpuno zamenjen alkalno aktiviranim elektrofilterskim pepelom. Dat je pregled istraživanja iz te oblasti u svetu i rezultati sopstvenih eksperimentalnih istraživanja ovih vrsta betona sa elektrofilterskim pepelom iz termoelektrane “Nikola Tesla B” iz Obrenovca

Next generation sequencing as a tool for pharmacogenomic profiling: Nine novel potential genetic markers for targeted therapy in childhood acute lymphoblastic leukemia

Uvod/Cilj Sekvenciranje nove generacije (SNG) omogućilo je genomsko profilisanje svakog bolesnika. Nova saznanja u oblasti farmakogenomike omogućavaju primenu podataka dobijenih ovom metodom u cilju otkrivanja novih mogućih genetičkih markera za ciljanu terapiju mnogih, posebno malignih bolesti. Cilj ovog istraživanja je bio da se primenom SNG odre- di genetski profil akutne limfoblastne leukemije (ALL) kod dece u cilju procene mogućih molekularnih meta za ciljanu terapiju. Metode Analizirali smo DNK uzorke 17 bolesnika obolelih od ALL dečjeg doba koristeći ciljano SNG. Napredne bioinformatičke metode su korišćene da identifikuju nove mutacije u analiziranim genima i da predvide njihov uticaj i farmakogenomski potencijal. Rezultati Identifikovali smo devet genskih varijanti koje do sada nisu opisane u relevantnim bazama podataka. U navedenim varijantama identifikovane su dve 'besmislene' varijante, ABL1 p.Q252* i AKT1 p.W22*, jedna varijanta koja pomera okvir čitanja, STK11 p.G257fs*28, i šest nesinonimnih varijanti. Kreirali smo trodimenzionalni model za četiri proteina koji bi bili produkt novih nesinonimnih varijanti. Analizirali smo farmakogenomski potencijal svake varijante i otkrili da su dve, STK11 c.1023G gt T/ p.L341F i ERBB2 c.2341C gt T/ p.R781W, mogući kandidati za ciljanu terapiju. Zaključak Nove varijante otkrivene u ovoj studiji pripa- daju uglavnom genima povezanim sa Ras signalnim putem, koji je često zahvaćen mutacijama u ALL kod dece. Farmakogenomsko profilisanje svake dečje ALL biće nezamenljivo za nove terapijske pristupe. Detekcija i inicijalna analiza novih genskih varijanti, koja je predstavljena u ovoj studiji, postaće standardna procedura za dizajniranje i razvoj individualizovane terapije za decu obolelu od ALL.Introduction/Objective Next generation sequencing (NGS) technology has enabled genomic profiling of each patient. Growing knowledge in pharmacogenomics makes it possible to use NGS data for discovery of novel potential genetic markers for targeted therapy of many diseases, especially cancers. The aim of this study was to use targeted NGS to make a genetic profile of childhood acute lymphoblastic leukemia (cALL) in order to evaluate potential molecular targets for targeted therapy. Methods We analyzed DNA samples from 17 cALL patients using NGS targeted sequencing. Advanced bioinformatic analysis was used to identify novel mutations in analyzed genes and to predict their effect and pharmacogenomic potential. Results We identified nine variants that have not been previously reported in relevant databases, including two stop-gain variants, ABL1 p.Q252* and AKT1 p.W22*, one frameshift, STK11 p.G257fs*28, and six missense variants. We created three-dimensional models of four proteins harboring novel missense variants. We analyzed pharmacogenomic potential of each variant and found that two of them, STK11 c.1023G gt T/ p.L341F and ERBB2 c.2341C gt T/ p.R781W, are suitable candidates for targeted therapy. Conclusion Most new variants detected in this study were found in the genes associated with Ras signaling pathway, which is frequently mutated in cALL patients. Pharmacogenomic profiling of each cALL will be indispensable for novel therapy approaches. Detection and initial analysis of novel variants, presented in this study, will become a standard procedure for the design and development of individualized therapies for children with ALL, leading to improved patient outcomes

Skupljanje betona na bazi recikliranog agregata

The application of recycled concrete aggregate in concrete structures is necessary for the achievement of sustainable construction and a reduction in the negative environmental impacts. This paper presents the most significant research into the phenomenon of shrinkage of recycled aggregate concretes. Since the amount of research is still relatively small, this paper presents an attempt to systematize them, present their results and analyze them. It is shown that the shrinkage of recycled aggregate concrete is mostly larger than the shrinkage of the reference natural aggregate concrete and that this difference increases as the percentage of recycled concrete aggregate increases. The effect of the water-to- cement ratio has also been analysed.Primena recikliranog agregata u armirano-betonskim konstrukcijama je nužna ako se želi postići održiva gradnja i smanjenje negativnih uticaja eksploatacije prirodnih resursa na životnu okolinu. U ovom radu su predstavljena značajna istraživanja fenomena skupljanja betona na bazi recikliranog agregata. Istraživanja u ovoj oblasti su i dalje relativno malobrojna. U ovom radu je izvršeno njihovo grupisanje, prezentacija, kao i analiza rezultata. Pokazano je da su skupljanja betona na bazi recikliranog agregata po pravilu veća od uporednih betona na bazi prirodnog agregata i da rastu sa procentom zamene prirodnog agregata recikliranim. Analiziran je i uticaj vodocementnog faktora na skupljanje

Фотодиелектрична карактеризација светлосног погона Au/TiO2 наномотори у течном медију

This article reports on photodielectric properties of hydrocolloids of TiO2 particles and Au/TiO2 hybrid particles of lateral dimension of ∼200 nm. Illumination of the colloids with visible light did not cause measurable changes in their electrical conductivity, while the application of UV (365 nm) light led to photoinduced increase in conductivity of up to 2%. The photogeneration of ions in water, regardless of the presence of the particles, makes a dominant contribution to the photoinduced increase in conductivity of the colloid

Karakteristike betona sa visokim sadržajem letećeg pepela, i njegova uloga u održivom razvoju

Zbornik radova Građevinskog fakultet