1. Introduction of a spectrophotometric method for salivary iodine determination on microplate based on Sandell-Kolthoff reactionAdrijana Oblak, Jernej Imperl, Mitja Kolar, Gregor Marolt, Blaž Krhin, Katja Zaletel, Simona Gaberšček, 2024, original scientific article Abstract: Background. Iodine is an essential element for the synthesis of thyroid hormones. Therefore, a reliable marker of iodine supply is important. Iodine is predominantly excreted via kidneys, but also via salivary glands. Our aim was to introduce a new and simple method for determination of salivary iodine concentration (SLIC). Materials and methods. Self-prepared chemicals and standards for Sandell-Kolthoff reaction on microplate with ammonium peroxydisulfate (AP) in the range 0−400 µg/L were used. Suitability of water-based standards (WBS) and artificial saliva-based standards (ASS) for standard curve were tested. We followed standards for method validation, defined concentration of used AP and compared our results with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results. WBS gave more reliable results than ASS as an underestimation of iodine concentration was found for ASS. LoB was 6.5 µg/L, LoD 12.0 µg/L, therefore analytical range was 12−400 µg/L. Intra- and inter-assay imprecisions at iodine concentrations, namely 20, 100, 165, and 350 µg/L were 18.4, 5.1, 5.7, and 2.8%, respectively, and 20.7, 6.7, 5.1, and 4.3%, respectively. Suitable molarity of AP was 1.0 mol/L and showed no difference to 1.5 mol/L (P values for samples with concentration 40, 100, and 150 µg/L, were 0.761, 0.085, and 0.275, respectively), whereas there was a significant change using 0.5 mol/L (P<0.001). Saliva samples could be diluted up to 1:8. There was no interference of thiocyanate and caffeine up to 193.5 mg/L. Our original method was comparable to ICP-MS. Spaerman coefficient was 0.989 (95% CI: 0.984−0.993). Conclusions. The new method for SLIC determination is in excellent agreement with ICP-MS and easy-to-use.
Keywords: iodine, salivary iodine concentration, Sandell-Kolthoff reaction
Published in DiRROS: 26.06.2026; Views: 190; Downloads: 132
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2. Interpreting urinary iodine concentration : effects of urine dilution and collection timingAdrijana Oblak, Maša Hribar, Hristo Hristov, Matej Gregorič, Urška Blaznik, Joško Osredkar, Anita Kušar, Katja Žmitek, Živa Lavriša, Tjaša Zaletel, Blaž Krhin, Igor Pravst, Simona Gaberšček, Katja Zaletel, 2024, original scientific article Abstract: OBJECTIVES: In population studies, iodine intake estimation relies on median urinary iodine concentration (UIC). However, interpreting UIC measurements can be challenging. METHODS: In our study, we included 772 adult participants from three groups: nationally representative gender-mixed, women of reproductive age, and pregnant women. We measured UIC and urinary creatinine (U-Cr) to calculate the iodine-to- creatinine ratio (I/Cr). U-Cr cut-off value of 0.226 g/L was used for differentiation between diluted and undiluted urine samples. After excluding samples below this cut-off, new median UIC and I/Cr ratios were calculated. We additionally evaluated the influence of urine sample collection time on UIC. RESULTS: Median UICs were 91.8 μg/L for nationally representative group, 58.3 μg/L for women of reproductive age, and 74.9 μg/L for pregnant women, while I/Cr ratios were 91.7, 102.0, and 159.2 μg/g, respectively. After implementing U-Cr cut-off and excluding all data where U-Cr was below cut-off, new median values were 93.4, 76.3, and 95.4 μg/L for UICs, and 88.6, 88.8, and 128.7 μg/g for I/Cr ratios, respectively. In women of reproductive age, median UIC was significantly lower in urine samples collected after 9:30 and after 12:00 as compared to samples collected before 9.30 (53.4, 57.8, and 97.3 μg/L, respectively). CONCLUSIONS: UIC results should be interpreted with caution, considering urine dilution and sample collection timing. U-Cr measurement should be included in population-based iodine intake studies, with corrections applied especially for pregnant women and younger adults, for whom morning is best for single-spot samples.
Keywords: urine dilution, urinary iodine concentration
Published in DiRROS: 07.11.2025; Views: 876; Downloads: 382
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3. Functional polymorphisms in antioxidant genes in Hurthle cell thyroid neoplasm - an association of GPX1 polymorphism and recurrent Hurthle cell thyroid carcinomaBlaž Krhin, Katja Goričar, Barbara Gazić, Vita Dolžan, Nikola Bešić, 2016, original scientific article Abstract: Hurthle cells of the thyroid gland are very rich in mitochondria and oxidative enzymes. As a high level oxidative metabolism may lead to higher level of oxidative stress and can be associated with an increased risk for cancer, we investigated whether common functional polymorphisms in antioxidant genes (SOD2, CAT, GPX, GSTP1, GSTM1 and GSTT1) are associated with the development or clinical course of Hurthle cell thyroid carcinoma (HCTC). Methods. A retrospective study was performed in 139 patients treated by thyroid surgery for a Hurthle cell neoplasm. HCTC, Hurthle cell thyroid adenoma (HCTA) or Hurthle cell thyroid nodule (HCTN) were diagnosed by pathomorphology. DNA was extracted from cores of histologically confirmed normal tissue obtained from formalin-fixed paraffinembedded specimens and genotyped for investigated polymorphisms. Logistic regression was used to compare genotype distributions between patient groups. Results. HCTC, HCTA and HCTN were diagnosed in 53, 47 and 21 patients, respectively. Metastatic disease and recurrence of HCTC were diagnosed in 20 and 16 HCTC patients, respectively. Genotypes and allele frequencies of investigated polymorphisms did not deviate from Hardy-Weinberg equilibrium in patients with HCTC, HCTA and HCTN. Under the dominant genetic model we observed no differences in the genotype frequency distribution of the investigated polymorphisms when the HCTA and HCTN group was compared to the HCTC group for diagnosis of HCTC or for the presence of metastatic disease. However, GPX1 polymorphism was associated with the occurrence of recurrent disease (p = 0.040). Conclusions. GPX1 polymorphism may influence the risk for recurrent disease in HCTC.
Keywords: Hurthle cell thyroid carcinoma, Hurthle cell neoplasm, thyroid, oxidative stress
Published in DiRROS: 30.04.2024; Views: 1477; Downloads: 508
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4. Effectiveness of L-thyroxine treatment on TSH suppression during pregnancy in patients with a history of thyroid carcinoma after total thyroidectomy and radioiodine ablationBlaž Krhin, Nikola Bešić, 2012, original scientific article Abstract: Introduction. There are scarce data about the optimal increase of L-thyroxine dose during pregnancy in patients with a history of thyroid carcinoma. The first aim of the study was to find out if routine therapeutic measures enable adequate TSH suppression in pregnancy. The other aim was to find out the optimal dose of L-thyroxine for TSH suppression in pregnant women. Patients and methods. In this retrospective observational study, we analysed 36 pregnancies of 32 women with a history of thyroid carcinoma. Before pregnancy, all of them underwent total thyroidectomy and radioiodine ablation of thyroid remnant, and they were on suppressive doses of L-thyroxine. Thyroid function tests were obtained before, during and after pregnancy. Results. Mean L-thyroxine dose before pregnancy, in the first, second and, third trimester and after delivery was 149, 147, 155, 165 and 158 micrograms daily, respectively. TSH concentration remained suppressed in 9 pregnancies, it was within normal range in 22 and elevated in 5 pregnancies. The mean dose of L-thyroxine in patients with suppressed TSH before pregnancy, in the first, second and, third trimester and after delivery was 154, 154, 164, 160 and 161 micrograms daily, respectively. When the dose had to be changed, the mean increase of the dose was 31.5 micrograms daily. Conclusions. The range of changes in TSH concentration during pregnancy in the patients who have been on suppressive L-thyroxine therapy before conception is quite wide. TSH was adequately suppressed in only 25% of pregnancies. The dose of L-thyroxine in patients with suppressed TSH in the first, second and third trimester was 154, 164 and 160 micrograms daily, respectively.
Published in DiRROS: 21.03.2024; Views: 1367; Downloads: 388
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5. Posodobljena priporočila diagnostike in zdravljenja diferenciranega raka ščitniceNikola Bešić, Alenka Grošel, Andraž Perhavec, Andrej Doma, Andreja A. Schwarzbartl-Pevec, Andreja Klevišar Ivančič, Andrej Vogrin, Barbara Vidergar-Kralj, Barbara Gazić, Barbara Perić, Blaž Krhin, Cvetka Grašič-Kuhar, Edvard Pirnat, Ivana Žagar, Jerca Blazina, Katarina Zevnik, Katica Bajuk-Studen, Katja Zaletel, Margareta Strojan Fležar, Marko Hočevar, Marko Kokalj, Marta Dremelj, Nebojša Glumac, Olga Blatnik, Simona Gaberšček, Snežana Đokić, Ulrika Klopčič, Veronika Kloboves-Prevodnik, Zorica Čekić, 2022, professional article Keywords: rak ščitnice, diferencirani rak, zdravljenje, smernice
Published in DiRROS: 01.07.2022; Views: 2724; Downloads: 813
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6. Posodobljena priporočila diagnostike in zdravljenja diferenciranega raka ščitniceAlenka Grošel, Andraž Perhavec, Andrej Doma, Andreja A. Schwarzbartl-Pevec, Andreja Klevišar Ivančič, Andrej Vogrin, Barbara Vidergar-Kralj, Barbara Gazić, Barbara Perić, Blaž Krhin, Cvetka Grašič-Kuhar, Edvard Pirnat, Ivana Žagar, Jerca Blazina, Katica Bajuk-Studen, Katja Zaletel, Margareta Strojan Fležar, Marko Hočevar, Marko Kokalj, Marta Dremelj, Nebojša Glumac, Nikola Bešić, Olga Blatnik, Simona Gaberšček, Snežana Đokić, Ulrika Klopčič, Veronika Kloboves-Prevodnik, Zorica Čekić, 2020, dictionary, encyclopaedia, lexicon, manual, atlas, map Keywords: rak ščitnice, diferencirani rak, zdravljenje, smernice
Published in DiRROS: 12.03.2021; Views: 3060; Downloads: 1033
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7. Smernice diagnostike in zdravljenja diferenciranega raka ščitniceNikola Bešić, Andreja A. Schwarzbartl-Pevec, Andreja Klevišar Ivančič, Barbara Vidergar-Kralj, Barbara Gazić, Blaž Krhin, Branko Zakotnik, Cvetka Grašič-Kuhar, Damijan Bergant, Edvard Pirnat, Helena Gutnik, Ivana Žagar, Jerca Blazina, Katja Zaletel, Margareta Strojan Fležar, Marko Hočevar, Marta Dremelj, Nebojša Glumac, Olga Blatnik, Simona Gaberšček, Snežana Đokić, Ulrika Klopčič, Veronika Kloboves-Prevodnik, Živa Pohar-Marinšek, 2017, dictionary, encyclopaedia, lexicon, manual, atlas, map Keywords: rak ščitnice, diferencirani rak, zdravljenje, smernice
Published in DiRROS: 27.05.2020; Views: 3965; Downloads: 1238
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8. Laboratorijski vodnik za pacienteAlenka Grošel, Blaž Krhin, Katarina Lenart, Barbara Možina, 2016, dictionary, encyclopaedia, lexicon, manual, atlas, map Abstract: V pričujoči knjižici smo na enem mestu zbrali vse pomembne informacije v zvezi z odvzemom različnih bioloških vzorcev na Oddelku za laboratorijske dejavnosti Onkološkega inštituta Ljubljana.
Upamo, da boste našli uporabne informacije tudi v drugem delu knjižice, kjer so na kratko predstavljene vse laboratorijske preiskave, ki jih na oddelku izvajamo ter njihov pomen za onkološke paciente.
Keywords: laboratorijske preiskave, laboratorijska medicina, Onkološki inštitut Ljubljana
Published in DiRROS: 08.09.2016; Views: 8972; Downloads: 1537
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