PURPOSE: The incidence of acute myocardial infarctions (AMI) shows circadian variation typically peaking during morning hours with a decline at night. However, this variation does not occur in patients with diabetes mellitus (DM). The night's decline of AMI may be partially explained by melatonin-related platelet inhibition. Whether this effect is absent in diabetic patients is unknown. The aim was to study the effect of melatonin on in-vitro platelet aggregation in healthy individuals and patients with type 2 DM. METHODS: Platelet aggregation was measured in blood samples from healthy individuals (n = 15) and type 2 DM patients (n = 15) using multiple electrode aggregometry. Adenosine diphosphate (ADP), arachidonic acid (ASPI) and thrombin (TRAP) were used as agonists. Aggregability for each subject was tested after adding melatonin in two concentrations. RESULTS: In healthy individuals, melatonin inhibited platelet aggregation in both higher (10-5 M) and lower concentrations (10-9 M) induced by ADP, ASPI, and TRAP (p < 0.001, p = 0.002, p = 0.029, respectively). In DM patients, melatonin did not affect platelet aggregation in both concentrations induced by ADP, ASPI, and TRAP. Melatonin decreased platelet aggregation induced by ADP, ASPI, and TRAP significantly more in healthy individuals compared to patients with DM. (p = 0.005, p = 0.045 and p = 0.048, respectively). CONCLUSION: Platelet aggregation was inhibited by melatonin in healthy individuals. In-vitro antiplatelet effect of melatonin in type 2 DM patients is significantly attenuated.
- MeSH
- adenosindifosfát farmakologie MeSH
- agregace trombocytů fyziologie MeSH
- diabetes mellitus 2. typu * farmakoterapie MeSH
- infarkt myokardu * MeSH
- inhibitory agregace trombocytů farmakologie terapeutické užití MeSH
- lidé MeSH
- melatonin * farmakologie terapeutické užití MeSH
- trombocyty fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Východiská: Hypoxia lokálne pokročilých karcinómov hlavy a krku je jednou z hlavných príčin ich rádiorezistencie, ktorá sa klinicky manifestuje perzistenciou reziduálnej nádorovej choroby po liečbe rádioterapiou. Detekcia nádorovej hypoxie teda môže byť dôležitým prediktorom efektivity liečby. Karboanhydráza IX (carbonic anhydrase IX – CA IX) je proteín, kódovaný rovnomenným génom, ktorého expresia sa v nádorových tkanivách za hypoxických podmienok zvyšuje. CA IX preto predstavuje endogénny marker nádorovej hypoxie, identifikovateľný v nádorových tkanivách a jeho rozpustnú extracelulárnu doménu je možné detekovať aj v telesných tekutinách pacienta. Primárnym cieľom tejto štúdie bolo zistiť, či existuje korelácia medzi sérovou hladinou CA IX a reziduálnou nádorovou chorobou po liečbe. Sekundárnym cieľom bolo zistiť, ako sa mení sérová hladina CA IX počas frakcionovanej rádioterapie. Materiál a metódy: Táto prospektívna monocentrická klinická štúdia hodnotila súbor 30 pacientov s lokálne pokročilými skvamocelulárnymi karcinómami hlavy a krku, liečených rádioterapiou alebo konkomitantnou chemorádioterapiou s kuratívnym zámerom. Sérová koncentrácia rozpustnej formy CA IX sa vyšetrovala z venóznej krvi pomocou sendvičovej enzýmovej imunoanalýzy (ELISA) pred zahájením rádioterapie, v polovici rádioterapie, pri skončení rádioterapie a šesť týždňov po jej ukončení. Výsledky: Zistili sme výraznú variabilitu nameraných hladín CA IX v sledovanej populácii v rozsahu 0–1 696 pg/ml. Významné zmeny v strednej hodnote koncentrácie CA IX sme v priebehu rádioterapie a po nej nezistili. U 11 pacientov (36,7 %) sa liečbou dosiahla kompletná remisia ochorenia. U týchto pacientov sme zaznamenali v priemere nižšie predliečebné hodnoty CA IX v porovnaní s pacientmi s perzistenciou reziduálnej nádorovej choroby (37,57 vs 77,47; p = 0,154). Záver: Naše výsledky ukazujú, že sérová hladina CA IX sa u pacientov s lokálne pokročilými nádormi hlavy a krku v priebehu frakcionovanej rádioterapie významne nemení. Zistený vzťah medzi sérovou hladinou CA IX a reziduálnou nádorovou chorobou po rádioterapii je potrebné potvrdiť na väčšom súbore pacientov.
Background: Hypoxia of locally advanced head and neck cancers is one of the main causes of their radiation resistance that presents clinically as a persistence of residual tumor disease after radiation therapy. Therefore, detection of tumor hypoxia could be an important predictor of treatment efficacy. Carbonic anhydrase IX (CA IX) is a protein, coded by a homonymous gene, the expression of which increases in tumor tissues at hypoxic conditions. Hence, CA IX represents an endogenic marker of tumor hypoxia, identifiable in tumor tissues, and its soluble extracellular domain can also be detected in body fluids of the patient. The primary endpoint of this study was to explore whether a correlation exists between CA IX serum level and the residual tumor disease after therapy. The secondary endpoint was to find out how the serum concentration of CA IX changes during the course of fractionated radiation therapy. Materials and Methods: The presented prospective monocentric clinical study evaluated a population of 30 patients with locally advanced squamous cell head and neck cancers, treated by radiation therapy or concurrent chemo‑radiation therapy with a curative intent. The serum concentration of the soluble form of CA IX was examined from a venous blood sample, using sandwich enzyme‑linked immunosorbent assay (ELISA). The blood samples were obtained before the treatment initiation, in the middle of radiation therapy, at the time of finishing radiation therapy and six weeks after the treatment completion. Results: We found a substantial variability in the CA IX levels measured in the examined population, ranging 0–1,696 pg/ml. We found no significant changes in the mean value of CA IX concentration during the course of radiation therapy and after the treatment completion. In 11 patients (36.7%), the treatment resulted in complete remission of the disease. In these patients, lower average pre‑treatment levels of CA IX were noted when compared to patients with persistence of residual tumor disease (37.57 vs 77.47; p = 0.154). Conclusion: The results indicate that serum level of CA IX in patients with locally advanced head and neck cancers does not change significantly during the course of fractionated radiation therapy. The relation between CA IX serum level and residual tumor disease after radiation therapy requires verification on a larger population of patients. Key words: head and neck cancer – hypoxia – carbonic anhydrase IX – radiation therapy – residual tumor The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers. Submitted: 10. 2. 2014 Accepted: 4. 3. 2014
- Klíčová slova
- karboanhydráza IX, radiorezistence,
- MeSH
- ELISA MeSH
- frakcionace dávky záření MeSH
- hypoxie buňky * účinky záření MeSH
- karboanhydrasy * krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádorové biomarkery * krev MeSH
- nádorové proteiny * krev MeSH
- nádory hlavy a krku * enzymologie krev metabolismus radioterapie MeSH
- prospektivní studie MeSH
- reziduální nádor krev MeSH
- senioři MeSH
- spinocelulární karcinom enzymologie krev metabolismus radioterapie MeSH
- statistika jako téma MeSH
- transport proteinů MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
