Vloga tiroksina pri karcinogenezi ščitnice

The aimof this study was to test the hypothesis on the protective role of thyroxin administration before and during irradiation on the occurrence of thyroid carcinoma in rats. Application of thyroxin before and during irradiation was expected to decrease production of thyrotropin by the hypophyseal feedback mechanism, caused by radiation damage of thyroid tissue. Stabilizing the thyroid cells in this way during irradiation would thus make them less radiosensitive. In the experiment, we first divided 81 three to fourweek old Wistar strain rats of both sexes into two groups, i.e. thyroxin (T4) and water (H2O). The T4 rats were injected 1% thyroxin solution (0.01 mg/100 g body weight) twice a day for 15 days, while the H2O rats received saline in the same way. After ten days, the two main groups were divided each into two subgroups. The rats from both irradiated subgroups (T4/X and (H2O/X) recieved 10 Gy to the neck area. They were iradiated with a telecobalt machinefor five consecutive days with one direct field. During a two years follow - up, all moribund animals were sacrificed and their thyroid glands taken. The rest of the thyroid glands were taken at the end of the experiment.All glands were pathohistologically analysed. Besides, all suspicious and enlarged extrathyroid organs and tissues were examined and the occurrence of tumors was noted. Pathohistological examination revealed the occurrence of 8 thyroid carcinomas and 7 adenomas in the H2O/X group, and 3 adenomas in the T4/X group. In the iradiated group of rats without thyroxin, significantly (P = 0.01) more thyroid carcinomas occurred than in the irradiated group without thyroxin.Namen študije je bil preveriti hipotezo o zaščitni vlogi dajanja tiroksina podganam pred obsevanjem in po njem, na pojavljanje ščitničnega karcinoma. Dajanje tiroksina pred in med obsevanjem naj bi preko povratne zveze s hipofizo preprečilo povečano izločanje tirotropina, povročeno z radiacijsko okvaro ščitničnega tkiva. Na takšen način stabilizirane celice naj bi bile medobsevanjem manj radiosenzibilne. V poskusu smo 81 podgan seva Wistar obeh spolov, starih 3 do 4 tedne najprej razdelili v dve skupini, v tiroksinsko (T4) in vodno (H2O). Tiroksinski skupini smo 15 dni dvakrat dnevno intraperitonealno injicirali enoodstotno raztopino tiroksina (0.01 mg/100 g telesne teže), vodna skupina pa je na enak način dobivala sterilno fiziološko raztopino. Po 10 dneh smo vsako od osnovnih skupin razdelili v dve podskupinipodgane iz obeh obsevanih podskupin (T4/X in H2O/X) so prejele 10 Gy na področje vratu. Na telekobaltovem aparatu smo jih 5 dni zapored obsevaliz direktnim poljem. Med dveletnim opazovanjem smo sproti žertvovali vse živali v slabem stanju in jim odvzeli ščitnice. Preostale ščitnice smo odvzeli ob koncu poskusa. Vse žleze smo patohistološko analizirali. Poleg tegasmo pregledali vse sumljive in povečane ekstratiroidne organe in tkiva terzabeležili vsa pojavljanja tumorjev. Ugotovili smo, da se je v skupini H2O/X pojavilo 8 ščitničnih karcinomov in 7 adenomov, v skupini T4/X pa trije ščitnični adenomi. V skupini obsevanih podgan brez tiroksina je bila incidencakarcinomov ščitnice statistično signifikantno (P = 0,01) večja kot v obsevani skupini s tiroksinom. Z opisanim poskusom je bila potrjena hipoteza o zaščitni vlogi dajanja tiroksina pred in med obsevanjem pri postiradiacijskiščitnični karcinogenezi pri podganah

Anatomija in histologija dojke

Dojki (mammae) sta parni kožni žlezi. Pri moškem ostaneta rudimentarni vse življenje, pri ženskah pa sta nerazviti pred puberteto, po puberteti rasteta in se diferencirata, najbolj sta razviti v zadnjih mesecih nosečnosti in med laktacijo ter usahneta po menopavzi. Dojka je zgrajena iz žleznega parenhima in vezivne strome ter interlobularnega maščobnega tkiva. Sestavlja jo 15 do 25lobusov. Vsak lobus predstavlja sestavljeno alveolarno žlezo z mlečnim izvodilom. Histološka slika dojke je drugačna v različnih starostnih obdobjih ženske, poleg tega pa se histološka slika spreminja pri ženskah v rodnem obdobju tudi med mesečnim ciklusom. Posebej pomembno za razumevanje zasevanja tumorjev je poznavanje limfne drenaže dojke

Adjuvant TNF-a therapy to electrochemotherapy with intravenous cisplatin in murine sarcoma exerts synergistic antitumor effectiveness

Background. Electrochemotherapy is a tumour ablation modality, based on electroporation of the cell membrane, allowing non-permeant anticancer drugs to enter the cell, thus augmenting their cytotoxicity by orders of magnitude. In preclinical studies, bleomycin and cisplatin proved to be the most suitable for clinical use. Intravenous administration of cisplatin for electrochemotherapy is still not widely accepted in the clinics, presumably due to its lower antitumor effectiveness, but adjuvant therapy by immunomodulatory or vascular-targeting agents could provide a way for its potentiation. Hence, the aim of the present study was to explore the possibility of adjuvant tumour necrosis factor % (TNF-%) therapy to potentiate antitumor effectiveness of electrochemotherapy with intravenous cisplatin administration in murine sarcoma. Materials and methods. In vivo study was designed to evaluate the effect of TNF-% applied before or after the electrochemotherapy and to evaluate the effect of adjuvant TNF-% on electrochemotherapy with different cisplatin doses. Results. A synergistic interaction between TNF-% and electrochemotherapy was observed. Administration of TNF-% before the electrochemotherapy resulted in longer tumour growth delay and increased tumour curability, and was significantly more effective than TNF-% administration after the electrochemotherapy. Tumour analysis revealed increased platinum content in tumours, TNF-% induced blood vessel damage and increased tumour necrosis after combination of TNF-% and electrochemotherapy, indicating an anti-vascular action of TNF-%. In addition, immunomodulatory effect might have contributed to curability rate of the tumours. Conclusion. Adjuvant intratumoural TNF-% therapy synergistically contributes to electrochemotherapy with intravenous cisplatin administration. Due to its potentiation at all doses of cisplatin, the combined treatment is predicted to be effective also in tumours, where the drug concentration is suboptimal or in bigger tumours, where electrochemotherapy with intravenous cisplatin is not expected to be sufficiently effective

Induction of Viable but Non-Culturable State in Clinically Relevant Staphylococci and Their Detection with Bacteriophage K

Prosthetic joint infections are frequently associated with biofilm formation and the presence of viable but non-culturable (VBNC) bacteria. Conventional sample culturing remains the gold standard for microbiological diagnosis. However, VBNC bacteria lack the ability to grow on routine culture medium, leading to culture-negative results. Bacteriophages are viruses that specifically recognize and infect bacteria. In this study, we wanted to determine if bacteriophages could be used to detect VBNC bacteria. Four staphylococcal strains were cultured for biofilm formation and transferred to low-nutrient media with different gentamycin concentrations for VBNC state induction. VBNC bacteria were confirmed with the BacLightTM viability kit staining. Suspensions of live, dead, and VBNC bacteria were incubated with bacteriophage K and assessed in a qPCR for their detection. The VBNC state was successfully induced 8 to 19 days after incubation under stressful conditions. In total, 6.1 to 23.9% of bacteria were confirmed alive while not growing on conventional culturing media. During the qPCR assay, live bacterial suspensions showed a substantial increase in phage DNA. No detection was observed in dead bacteria or phage non-susceptible E. coli suspensions. However, a reduction in phage DNA in VBNC bacterial suspensions was observed, which confirmed the detection was successful based on the adsorption of phages