Oxidation of methionine — is it limiting the diagnostic properties of 99mTc-labeled Exendin-4, a Glucagon-Like Peptide-1 receptor agonist?

BACKGROUND: Preliminary clinical evaluation of 99mTc-EDDA/HYNIC-Met14-Exendin-4 showed that the complex offers new diagnostic possibilities for insulinoma and MTC. Exendin-4 contains methionine at position 14 in the amino acid chain, which may be oxidized to methionine sulfoxide and, from the pharmaceutical point of view, the oxidized moiety becomes an undesired impurity in the final radioactive preparation. Therefore, the aim of this study was to investigate the influence of commonly used methods to eliminate the effect of methionine oxidation in peptides, i.e. the replacement of methionine by norleucine (Nle) and the addition of L-methionine, on the in vitro stability and the biodistribution. MATERIAL AND METHODS: 99mTc-EDDA/HYNIC-Met14-Exendin-4, 99mTc-EDDA/HYNIC-Nle14-Exendin-4, 99mTc-EDDA/HYNIC-Met14-Ex­endin-4 with the addition of L-methionine and an oxidized form of Exendin-4, i.e. 99mTc-EDDA/HYNIC-Met14(ox)-Exendin-4 were compared in vivo with 68Ga-NODAGA-Nle14-Exendin-4 in normal Wistar rats. The stability and lipophilicity were determined in vitro. RESULTS: Biodistribution studies confirmed the specific uptake of all tested complexes in the GLP-1 positive organs: lungs, pancreas and stomach. The uptake of 99mTc-EDDA/HYNIC-Met14-Exendin-4 with the addition of L-methionine and for 68Ga-NODAGA-Nle14-Exendin-4 at 1h p.i. was around 2-fold higher than that of 99mTc-EDDA/HYNIC-Met14-Exendin-4 and 99mTc-EDDA/HYNIC-Nle14-Exendin-4. CONCLUSION: Although the substitution of methionine by norleucine in the HYNIC-Exendin-4 did not result in improved bio­distribution, the use of L-methionine, as the excipient that inhibits the oxidation of methionine in the peptide chain resulted in higher lung/blood and stomach/blood uptake ratios. Our results confirmed that methionine at position 14 of amino acid chain of Exendin-4 plays an important role in the interaction with GLP-1 receptor positive tissue

^{99m}Tc labeled glucagon-like peptide-1-analogue (^{99m}Tc-GLP1) scintigraphy in the management of patients with occult insulinoma

INTRODUCTION: The aim of this study was to assess the utility of [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4 scintigraphy in the management of patients with hypoglycemia, particularly in the detection of occult insulinoma. MATERIALS AND METHODS: Forty patients with hypoglycemia and increased/confusing results of serum insulin and C-peptide concentration and negative/inconclusive results of other imaging examinations were enrolled in the study. In all patients GLP-1 receptor imaging was performed to localise potential pancreatic lesions. RESULTS: Positive results of GLP-1 scintigraphy were observed in 28 patients. In 18 patients postsurgical histopathological examination confirmed diagnosis of insulinoma. Two patients had contraindications to the surgery, one patient did not want to be operated. One patient, who presented with postprandial hypoglycemia, with positive result of GLP-1 imaging was not qualified for surgery and is in the observational group. Eight patients were lost for follow up, among them 6 patients with positive GLP-1 scintigraphy result. One patient with negative scintigraphy was diagnosed with malignant insulinoma. In two patients with negative scintigraphy Munchausen syndrome was diagnosed (patients were taking insulin). Other seven patients with negative results of (99m)TcGLP-1 scintigraphy and postprandial hypoglycemia with C-peptide and insulin levels within the limits of normal ranges are in the observational group. We would like to mention that (99m)Tc-GLP1-SPECT/CT was also performed in 3 pts with nesidioblastosis (revealing diffuse tracer uptake in two and a focal lesion in one case) and in two patients with malignant insulinoma (with the a focal uptake in the localization of a removed pancreatic headin one case and negative GLP-1 1 scintigraphy in the other patient). CONCLUSIONS: (99m)Tc-GLP1-SPECT/CT could be helpful examination in the management of patients with hypoglycemia enabling proper localization of the pancreatic lesion and effective surgical treatment. This imaging technique may eliminate the need to perform invasive procedures in case of occult insulinoma

Glucagon-like peptide-1 receptor imaging with [Lys^{40}(Ahx-HYNIC-^{99m}Tc/EDDA)NH_2]-exendin-4 for the detection of insulinoma

PURPOSE: The objective of this article is to present a new method for the diagnosis of insulinoma with the use of [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4. METHODS: Studies were performed in 11 patients with negative results of all available non-isotopic diagnostic methods (8 with symptoms of insulinoma, 2 with malignant insulinoma and 1 with nesidioblastosis). In all patients glucagon-like peptide-1 (GLP-1) receptor imaging (whole-body and single photon emission computed tomography/CT examinations) after the injection of 740 MBq of the tracer was performed. RESULTS: Both sensitivity and specificity of GLP-1 receptor imaging were assessed to be 100 % in patients with benign insulinoma. In all eight cases with suspicion of insulinoma a focal uptake in the pancreas was found. In six patients surgical excision of the tumour was performed (type G1 tumours were confirmed histopathologically). In one patient surgical treatment is planned. One patient was disqualified from surgery. In one case with malignant insulinoma pathological accumulation of the tracer was found only in the region of local recurrence. The GLP-1 study was negative in the other malignant insulinoma patient. In one case with suspicion of nesidioblastosis, a focal accumulation of the tracer was observed and histopathology revealed coexistence of insulinoma and nesidioblastosis. CONCLUSION: [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4 seems to be a promising diagnostic tool in the localization of small insulinoma tumours, but requires verification in a larger series of patients

B of Hermann \u27 s tortoise Testudo hermanni on the island Pag

V diplomskem delu smo se posvetili problematiki taksonomije na otoku Pagu živečih (pod)vrst grške kornjače, Testudo hermanni. Želeli smo predstaviti problematiko, morfološke taksonomske znake in lastne rezultate, do katerih smo prišli s terenskim delom na otoku Pagu julija 2009 in aprila 2010. Beležili smo več podatkov, saj smo opazovali tudi dnevno aktivnost, izbiro habitatov in poškodbe oklepov. Najprej smo opisali osnovno vrsto in povzeli morfološke določevalne znake, ki naj bi določali dalmatinsko kornjačo. Nadalje smo se posvetili poškodbam in drugim nepravilnostim oklepa. Sledijo rezultati našega terenskega dela in razprava. Najdene značilnosti smo poskusili podkrepiti in osvetliti s fotografijami najdenih osebkov. Glede na podane morfološke določevalne znake in na naše rezultate se strinjamo s Fritz-em (2001), ki dalmatinske kornjače, Testudo hermanni hercegovinensis ne opisuje kot samostojno podvrsto. Zaradi drugih najdenih morfoloških lastnosti dopuščamo možnost, da je dalmatinska kornjača varieteta podvrste Testudo hermanni boettgeri, torej Testudo hermanni boettgeri var. hercegovinensis. V kolikor gre za podvrsto, jo verjetno določajo druge lastnosti, ki niso nujno morfološke. Želve so najbolj aktivne v dopoldanskem in popoldanskem času. Veliko odraslih osebkov ima poškodbe na oklepu, predvsem na hrbtnem delu.This diploma thesis is devoted to the problem of taxonomy of (sub) species of Greek tortoise, Testudo hermanni, that live on the island of Pag. We wanted to present the problem, morphological taxonomic signs, and our own results, to which we have come with the fieldwork on the island of Pag in July 2009 and April 2010. We were recording several data, as we were also observing daily activities, the choice of habitat, and shell injuries. First, we described the specie and summarized morphological identification signs that should determine the Dalmatian tortoise. Then, we focused on injuries and other irregularities on the shell. Furthermore, the results of our fieldwork and discussion are given. We tried to substantiate and highlight the found characteristics with photographs of the found specimens. According to the given morphological identification signs our results we agree with Fritz (2001) who does not describe the Dalmatian tortoise, Testudo hermanni hercegovinensis, as an independent subspecies. For other found characteristics, we allow the possibility that it is the locality of subspecies Testudo hermanni boettgeri. Turtles are the most active in the morning and afternoon. Many adult specimens have shell injuries, especially at the back part

The Influence of Diet and Its Components on the Development and Prevention of Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is diagnosed annually in nearly a million people worldwide, with approximately half of them being diagnosed at an advanced stage of the disease. Non-infectious risk factors for the development of HCC include an unbalanced lifestyle, including poor dietary choices characterized by a low intake of antioxidants, such as vitamins E and C, selenium, and polyphenols, as well as an excessive consumption of energy and harmful substances. Repeated bad dietary choices that contribute to an unbalanced lifestyle lead to the accumulation of fatty substances in the liver and to it entering an inflammatory state, which, without intervention, results in cirrhosis, the main cause of HCC. This review of the English language literature aims to present the food components that, when included in the daily diet, reduce the risk of developing HCC, as well as identifying foods that may have a carcinogenic effect on liver cells

The effects of the ester derivative of phenytoin on leukemic cell

Hydantoina i jej pochodne stanowią ważną grupę związków chemicznych o dużym spektrum aktywności biologicznej. Fenytoina jest analogiem hydantoiny stosowanym jako lek przeciwdrgawkowy w leczeniu epilepsji i zaburzeń rytmu serca. Nieliczne doniesienia wskazują na przeciwnowotworowe działanie pochodnych hydantoiny. Celem pracy było określenie potencjału przeciwnowotworowego estrowej pochodnej 5,5-difenyloimidazolidyno-2,4-dionu z podstawnikiem bromoalkilowym (BrF). Badania przeprowadzono na komórkach dwóch ludzkich linii leukemicznych promielocytarnej HL-60 oraz monocytarnej U-937. BrF zastosowano w dawkach 25 μM, 50 μM, 100 μM i 200 μM. Analizy wykonywano po upływie 24, 48 i 72 godz. od potraktowania komórek leukemicznych BrF. Czasowe zmiany liczebności i objętości komórek analizowano przy użyciu licznika Beckman Coulter Z2, a zmiany w aktywności metabolicznej przy zastosowaniu testu MTT. Stwierdzono cytotoksyczny wpływ estrowej pochodnej fenytoiny na ludzkie komórki leukemiczne HL-60 oraz U-937. Efekt cytotoksyczny zależał od zastosowanej dawki BrF, okresu czasu upływającego od podania pochodnej fenytoiny oraz od linii komórek leukemicznych. Zaobserwowano spadek liczebności i objętości komórek oraz obniżenie ich aktywności metabolicznej. Wykazano większą wrażliwość komórek U-937 na działanie BrF niż komórek HL-60.Hydantoin and its derivatives are an important group of chemical compounds with a large spectrum of biological activity. Phenytoin is a hydantoin analogue used as an anticonvulsant compound in the treatment of epilepsy and cardiac arrhythmias. However available information on anticancer activity of hydantoin deritaves is scant. Thus the aim of present study was undertaken to determine the anticancer activity of the ester derivative of 5,5-diphenylhydantoin substituted bromine alkyl (BrF) in two human leukemia HL-60 and U-937. The analyses were performed at 24, 48 and 72 h after the leukemic cell exposure to the action of BrF at a dose of 25 μM, 50 μM 100 μM and 200 μM. The temporary changes in the cell count and volume, and were determined using Beckman Coulter counter Z2. The metabolic activity of HL-60 and U-937 cellswere analyzed using MTT assay.The present study demonstrated the influence of BrF on human leukemic cell. Temporary changes in the HL-60 and U-937 cell number and volume, and in the metabolic acticity, were found. The cytotoxic effects were dependent on dose of the BrF, the in time the intervals after its application and leukemic cell line. A decrease in the cell number and volume, and a reduction in metabolic activity were found. The greater sensitivity of U-937 than HL-60 cells to the action of BrF was shown

Lifestyle of Families with Children Aged 4–8 Years before and during Lockdown Due to COVID-19 Pandemic in Poland

The aim of the study was to evaluate the lifestyle changes of families with children aged 4–8 years during lockdown compared to the time before the COVID-19 pandemic. The study was conducted among 1098 parents during the first lockdown in Poland. An originally developed questionnaire was used as the research tool. The Wilcoxon test was used to determine the frequency of differences in the lifestyle of parents and children before the pandemic and during lockdown. Differences were found in the frequency of healthy habits in the periods under investigation, both in the lifestyle of parents and children. A moderately healthy lifestyle was predominant among families with children aged 4–8 years during lockdown. The families’ lifestyle significantly changed in relation to the time before the pandemic. There is a need for lifestyle education for families with children to prevent the development of bad habits during and after the pandemic and isolation time