Separation of Poly(styrene-block-t-butyl methacrylate) Copolymers by Various Liquid Chromatography Techniques

The separation of a mixture of three poly(styrene-block-t-butyl methacrylate) copolymers (PS-b-PtBMA), consisting of polystyrene (PS) blocks of similar length and t-butyl methacrylate (PtBMA) blocks of different lengths, was performed using various chromatographic techniques, that is, a gradient liquid chromatography on reversed-phase (C18 and C8) and normal-phase columns, a liquid chromatography under critical conditions for polystyrene as well as a fully automated two-dimensional liquid chromatography that separates block copolymers by chemical composition in the first dimension and by molar mass in the second dimension. The results show that a partial separation of the mixture of PS-b-PtBMA copolymers can be achieved only by gradient liquid chromatography on reversed-phase columns. The coelution of the two block copolymers is ascribed to a much shorter PtBMA block length, compared to the PS block, as well as a small difference in the length of the PtBMA block in two of these copolymers, which was confirmed by SEC-MALS and NMR spectroscopy

Mutacije RET proto-onkogena v slovenski populaciji bolnikov z medularnim rakom ščitnice

Background. Medullary thyroid cancer (MTC) is a rare, endocrine tumour that occurs as part of hereditary cancer syndrome in approximately 25% of cases and develops as a sporadic form in 75%. The aim of the study was to evaluate the frequency and type of RET mutation occurrence in the Slovenian population between 1995 and 2015.Methods. A retrospective analysis of the National Cancer Registry of the Republic of Slovenia and the Registry of Patients with MTC of the Institute of Oncology in Ljubljana between 1995 and 2015 was made. The data of 143 patients with confirmed MTC and 43 healthy relatives referred to genetic counselling and testing was analyzed. Genomic DNA was isolated from peripheral blood leukocytes. Exons 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene were amplified in the polymerase chain reaction (PCR). Point mutations of the RET gene were detected by single strand confirmation analysis (SSCA) and DNA sequencing. Detected mutations were confirmed by restriction enzymes.Results. A germline mutation in the RET proto-oncogene was identified in 51 individuals, 37 among them were patients with MTC, which accounts for 25.9% of all patients with MTC. Eight different germline RET mutations were found. Codons 634 and 618 were the most frequently altered codons, followed by codon 790, codon 804 and codon 918. The average crude incidence rate of MTC (between 1995 and 2015) is 0.34 per 100,000.Conclusions. We estimated that the crude incidence rate of MTC in Slovenia is 0.34 per 100,000. We discovered that 25.9% of Slovenian patients with MTC are RET mutation carriers. The most common mutations were found on codons 634 and 618.Izhodišča. Medularni rak ščitnice (MRŠ) je redek endokrini tumor, ki se v približno 25 % primerov pojavlja v družinski obliki bolezni v sklopu multiple endokrine neoplazije tipa 2, v 75 % pa je bolezen sporadična. Namen dela je bil oceniti incidenco MRŠ ter pogostost in vrsto RET-mutacij v slovenski populaciji bolnikov med letoma 1995 in 2015.Metode. Retrospektivno smo analizirali podatke Registra raka Republike Slovenije in Registra bolnikov z MRŠ Onkološkega Inštituta v Ljubljani, zbrane med letoma 1995 in 2015. Vključili smo 143 bolnikov s potrjenim MRŠ in 43 njihovih zdravih sorodnikov, ki so bili napoteni na genetsko svetovanje in testiranje. Genomsko DNK smo izolirali iz levkocitov periferne krvi. Eksone 10, 11, 13, 14, 15 in 16 RET protoonkogena smo pomnožili z verižno reakcijo s polimerazo. Točkovne mutacije RET protoonkogena smo odkrili z metodo SSCA in DNA-sekvenciranjem. Zaznane mutacije so bile potrjene z restrikcijskimi encimi.Rezultati. Zarodno mutacijo RET protoonkogena smo odkrili pri 51 osebah; med njimi je bilo 37 bolnikov z MRŠ, kar predstavlja 25,9 % vseh bolnikov z MRŠ. Odkrili smo osem različnih mutacij RET protoonkogena. Najpogosteje smo potrdili mutacijo v kodonih 634 in 618, sledili so kodoni 790, 804 in 918. Povprečna groba letna incidenčna stopnja MRŠ v Sloveniji za opazovano obdobje znaša 0,34/100.000 prebivalcev.Zaključek. Ocenjena povprečna groba letna incidenčna stopnja MRŠ v Sloveniji je bila 0,34/100.000. Poleg tega smo ugotovili, da se RET-mutacija pojavlja v naši populaciji bolnikov v 25,9 % ter da najpogosteje prizadene kodona 634 in 618

Evaluation of risk of leukaemias for exposure to low frequency magnetic field in Slovenian children and adolescents

Izhodišča: Raziskave kažejo, da bi lahko nizkofrekvenčno magnetno polje (NF MP) gostote več kot 0,4 µT povečalo tveganje za nastanek otroških levkemij. Raziskali smo to tveganje zaradi izpostavljenosti NF MP zaradi bivanja v bližini daljnovodov in transformatorskih postaj v Sloveniji. Metode: Iz Registra raka Republike Slovenije smo pridobili georeferencirane podatke za vse otroke in mladostnike, stare 0–19 let, zbolele z levkemijo v letih 2005–2016, ter za referenčno populacijo vseh enako starih otrok in mladostnikov. Razdelili smo jih v pet skupin glede na izpostavljenost NF MP v okolici daljnovodov in transformatorskih postaj. Za oceno izpostavljenosti NF MP smo uporabili modelirane vrednosti na drobni prostorski mreži. Relativno tveganje za levkemije smo ocenili s standardiziranim količnikom incidence. Dodatno smo raziskali časovni trend pojavljanja levkemij v obdobju 1967–2016 ter geografsko razporejanje. Rezultati: V letih 1967–2016 je za levkemijami zbolelo 841 otrok in mladostnikov (16 na leto). V letih 2005–2016 je velika večina vseh otrok in mladostnikov (99,5 %) v Sloveniji živela na območjih z NF MP, manjšim od 0,1 μT. Med 195 primeri levkemij se je v 0,1 ≤ NF MP < 0,2 µT blizu daljnovodov razvrstil eden (SKI = 2,4, IZ: 0,1−13,3), v bližini transformatorskih postaj pa pet primerov (SKI = 3,0IZ: 0,97−7,0). V področju gostote NF MP, večje od 0,2 μT, ni bilo zbolelih. Levkemije se niso statistično značilno geografsko razporejale. Zaključki: V Sloveniji nobenega primera levkemij med slovenskimi otroci in mladostniki, starimi do vključno 19 let, ki živijo v okolici daljnovodov in transformatorskih postaj, ne moremo pripisati vplivu izpostavljenosti NF MP

Vloga Bolnišničnega registra raka Onkološkega inštituta Ljubljana

Cancer registries are crucial in collecting and providing data on the cancer burden at both the population and the regional level. Hospital-based cancer registries are engaged in the collection of information on cancer patients treated in a particular hospital. Their main purpose is to contribute to clinical patient care in terms of efficiency, quality and hospital management. Hospital-Based Cancer Registry of the Institute of Oncology Ljubljana was established at the same time as the population-based Cancer Registry of Republic of Slovenia in 1950 and contributes to the Slovenian Cancer Registry one third of all notifications of cancer. The data collected in the hospital-based register are also valuable for the professional and research work of the Institute. One of the tasks of hospital-based cancer registries is the preparation of annual reports for management and other users. Annually at the Institute of Oncology Ljubljana, we treat more than 6000 new cancer patients. The number of patients increased by 16% in the period 2008-2016.Registri raka so ključni pri zbiranju in zagotavljanju podatkov o bremenu raka tako na populacijski kot na regionalni ravni. Bolnišnični registri raka se ukvarjajo z zbiranjem informacij o bolnikih z rakom, ki so obravnavani v določeni bolnišnici. Njihov glavni namen je prispevati h klinični oskrbi bolnikov z vidika učinkovitosti, kakovosti in bolnišničnega upravljanja. Bolnišnični register Onkološkega inštituta Ljubljana je bil osnovan ob ustanovitvi državnega populacijskega registra raka leta 1950 in prispeva v državni register tretjino vseh prijav. Podatki, zbrani v bolnišničnem registru, so dragoceni tudi za strokovno in raziskovalno delo Inštituta. Ena od nalog bolnišničnih registrov raka je priprava letnih poročil za vodstvo in druge uporabnike. Letno na Onkološkem inštitutu Ljubljana sprejmemo več kot 6000 novih onkoloških bolnikov. Število bolnikov se je v obdobju 2008–2016 povečalo za 16 %