Összefoglaló. Bevezetés: A térdízületnek ultrafriss osteochondralis allograft segítségével történő részleges ortopédiai rekonstrukciója képalkotó vizsgálatokon alapuló pontos tervezést igényel, mely folyamatban a morfológia felismerésére képes mesterséges intelligencia nagy segítséget jelenthet. Célkitűzés: Jelen kutatásunk célja a porc morfológiájának MR-felvételen történő felismerésére alkalmas mesterséges intelligencia kifejlesztése volt. Módszer: A feladatra legalkalmasabb MR-szekvencia meghatározása és 180 térd-MR-felvétel elkészítése után a mesterséges intelligencia tanításához manuálisan és félautomata szegmentálási módszerrel bejelölt porckontúrokkal tréninghalmazt hoztunk létre. A mély convolutiós neuralis hálózaton alapuló mesterséges intelligenciát ezekkel az adatokkal tanítottuk be. Eredmények: Munkánk eredménye, hogy a mesterséges intelligencia képes a meghatározott szekvenciájú MR-felvételen a porcnak a műtéti tervezéshez szükséges pontosságú bejelölésére, mely az első lépés a gép által végzett műtéti tervezés felé. Következtetés: A választott technológia – a mesterséges intelligencia – alkalmasnak tűnik a porc geometriájával kapcsolatos feladatok megoldására, ami széles körű alkalmazási lehetőséget teremt az ízületi terápiában. Orv Hetil. 2021; 162(9): 352–360. Summary. Introduction: The partial orthopedic reconstruction of the knee joint with an osteochondral allograft requires precise planning based on medical imaging reliant; an artificial intelligence capable of determining the morphology of the cartilage tissue can be of great help in such a planning. Objective: We aimed to develop and train an artificial intelligence capable of determining the cartilage morphology in a knee joint based on an MR image. Method: After having determined the most appropriate MR sequence to use for this project and having acquired 180 knee MR images, we created the training set for the artificial intelligence by manually and semi-automatically segmenting the contours of the cartilage in the images. We then trained the neural network with this dataset. Results: As a result of our work, the artificial intelligence is capable to determine the morphology of the cartilage tissue in the MR image to a level of accuracy that is sufficient for surgery planning, therefore we have made the first step towards machine-planned surgeries. Conclusion: The selected technology – artificial intelligence – seems capable of solving tasks related to cartilage geometry, creating a wide range of application opportunities in joint therapy. Orv Hetil. 2021; 162(9): 352–360.

In the last two decades extensive study has been carried out on the isolation, identification and biosynthesis of the "endogenous digitalis-like compounds" whose physiological and pathophysiological functions are only starting to be understood. Besides ouabain (strophanthin) and digoxin, four further endogenous cardiac glycosides were isolated and identified so far. These compounds are found in almost all mammalian tissues, including blood plasma and urine, but with the highest concentrations in the adrenal gland, pituitary and hypothalamus. De novo biosynthesis of these glycosides occurs in zona fasciculata cells of adrenal glands, precursors such as progesterone, pregnenolone, and rhamnose increase the synthesis of the ouabain-like immunoreactive material. The secretion of these compounds from the adrenocortical cells are controlled by adrenerg mechanisms, as well as via the renin-angiotensin system. The hydrophobic cardiac glycosides are transported in blood as complexes bound to specific binding globulins. The identified endogenous cardiac glycosides fulfill all the postulated criterions of the hormones, so they represent a new class of steroid hormones. The cardiac glycosides influence the active sodium pump, indirectly the intracellular free calcium concentration and therefore exert a positive inotropic effect on cardiac muscle. Furthermore, in physiological concentrations they can regulate the cell growth and protein synthesis inducing activation of intracellular signal pathways. Under pathological conditions, however, when the concentration of these steroids are high, they play a crucial role in the development of different serious illnesses such as essential hypertension as well as congestive heart failure. Further intensive investigations are needed to clarify some contradictory details accumulated during the last few years in this field.

The activity of acetylcholinesterase molecular forms were examined after separation on sucrose gradients during notexin-induced necrosis and the following regeneration in rat extensor digitorum longus (EDL) and soleus (SOL) muscles. All forms dropped rapidly in both muscles in the first few days after single notexin injection. After a delay small globular forms (G1 + G2) started to regenerate from day 7 and larger forms (G4 and A 12) from day 10 in EDL. The A8 form which cannot be detected in normal EDL was present between day 7 and day 28. In SOL the recovery of AChE forms begun already on day 3. The small globular forms displayed a more rapid increase between day 3 and day 7 then the other forms. In SOL we observed a temporary overshooting peak at day 7 in the activity of all molecular forms. Both muscles recovered their normal AChE pattern by that time when muscle fibres regained their normal diameter (day 28). Most of the events of regeneration of AChE forms resembled those of normal myogenesis.

The 90 kDa heat shock protein (HSP90) is an ATP-binding molecular chaperone with an associated ATPase activity having nucleoplasmin and HSP70-binding homology domains and containing Ca-binding EF-hands and a nuclear localization signal. Here we characterize the HSP90-associated ATPase and show that it is (i) a P-type ATPase inhibited by molybdate and vanadate, (ii) able to hydrolyze methylfluorescein phosphate with a 5–6-fold higher affinity, (iii) a 3-times better GTPase than ATPase in the presence of calcium and (iv) HSP27 and F-actin, but not HSP10 can “convert” the HSP90-associated ATPase activity to HSP90 autokinase activity. The HSP90-associated ATP/GTPase may participate in the regulation of complex formation of HSP90 with other proteins, such as F-actin, tubulin and heat shock proteins.