Experimental models of kidney transplantation: Possibilities to explore new approaches

Današnja klinička praksa, ali i istraživanja, temelje se na alo(homo)transplantaciji. Najzastupljeniji organ po broju u transplantacijskoj medicini svakako je bubreg. Transplantacija bubrega uvriježen je, najbolji i najekonomičniji način liječenja kronične renalne insuficijencije. Animalni modeli nužni su za istraživanja na području transplantacije organa. Najčešće korištena životinja u istraživanju transplantacije bubrega je štakor. U modernim istraživanjima transplantacije bubrega uvriježila su se dva dobro poznata animalna modela: štakorski model kronične renalne insuficijencije i štakorski model transplantacije bubrega. Za rad i vršenje operacija na eksperimentalnim životinjama istraživač mora posjedovati međunarodni certifikat. Uzgoj, postupci eutanazije, poslijeoperacijske analgezije, razmnožavanja, držanja životinja (nastambe, temperatura, hrana), kao i odlaganja životinjskih leševa i tkiva su visoko standardizirani. Većina današnjih istraživanja, kao i onih koja će se odvijati tijekom sljedećih nekoliko godina, usmjerena su k rješavanju problema oštećenja bubrežnog parenhima transplantata uzrokovanog toplom i hladnom ishemijom. S ciljem izbjegavanja biopsije transplantiranog bubrega istraživanja su i bit će usmjerena k razvoju metoda kontrastnog ultrazvuka u ranoj detekciji reakcije odbacivanja ili k određivanju serumskog markera za akutno odbacivanje transplantiranog bubrega. Također, sve vrste istraživanja bavit će se uzgojem vijabilnih organa za transplantaciju iz matičnih stanica. Iz svega navedenog jasno je kako će različiti animalni modeli transplantacije bubrega imati važnu ulogu u budućim istraživanjima s ciljem povećanja broja transplantacija, kao i produljenja preživljenja transplantiranog organa.Today’s clinical practice and research are based on alo- (homo) transplantation. The most common organ used in transplant medicine is certainly the kidney. Kidney transplantation is ingrained, the best and most economical way to treat chronic renal failure. Animal models are necessary for research in the field of organ transplantation. The most commonly used animal in the study of kidney transplantation is a rat. In modern studies of kidney transplantation, we have two well-known animal models: the rat model of chronic renal failure and the rat model of kidney transplantation. To operate on experimental animal’s researcher must possess an international certificate. Growing, euthanasia procedures, postoperative analgesia, breeding, animal housing (temperature, food, etc.), as well as the disposal of animal carcasses and tissues are highly standardized. Most of the current researches, as well as those that will take place over the next few years have in focus the damage caused by warm and cold ischemia. To avoid the biopsy of the transplanted kidney studies will be directed towards the development of noninvasive methods for early detection of transplant rejection such as contrast ultrasound or serum markers of acute rejection of the transplanted kidney. In addition, all kinds of investigations will address the cultivation of viable organs for transplantation using stem cells. In conclusion it is clear that different animal models of kidney transplantation will play an important role in future researches in order to increase the number of transplants as well as the prolongation of the survival of transplanted organs

Extracorporeal shock wave lithotripsy

Izvantjelesno mrvljenje kamenaca (ESWL) je novija terapijska metoda u liječenju urolitjaze. Temelji se na uporabi šok-valova koji se stvaraju u generatoru, fokusiraju i usmjeruju na kamenac u tijelu pacijenta. Razbijanje kamenca je posljedica nekoliko različith efekata tih valova na sam konkrement. Razbijanjem nastaju manji fragmenti koji se moraju izmokriti. ESWL se korist u liječenju bubrežnih kao i kamenaca u mokraćovodu. Metoda je izbora za liječenje bubrežnih kamenaca manjih od 2 cm te onih u proksimalnom dijelu mokraćovoda veličine do 1 cm. Komplikacije su rijetke i najčešće klinički beznačajne. Efkasnost ove metode ovisi o veličini kamenca, njegovom sastavu, kanalnom sustavu bubrega te o iskustvu i vještni urologa. Velika prednost ove metode je da nije potrebna anestezija, za razliku od drugih minimalno invazivnih metoda. Tretman ESWL-a može se ponavljati više puta. Do sada nije dokazan štetan učinak na bubrežnu funkciju, a može se koristiti i u dječjoj populaciji.Extracorporeal shock wave lithotripsy (ESWL) is a novel method for the treatment of urolithiasis. It is based on the use of shock waves that are generated in the generator, focused and directed to the stone in the body of the patent. Cracking of the stone is the result of several different effects of these waves. It results with stone fragmentation and spontaneous elimination of fragments. ESWL is used in the treatment of kidney stones and stones in the ureter. These method is the method of choice for treating kidney stones smaller than 2 cm, and those in the proximal part of the ureter up to 1 cm. Complicatons are rare and usually clinically insignificant. The effectiveness of this method depends on the stone size, its compositon, the renal system morphology and the experience and skill of the urologist. The great advantage of this method is that anesthesia is not needed, unlike other minimally-invasive treatements. Also, the ESWL treatment can be repeated several times. There is no proven damaging effect on the renal function and can be used for treatment of stones in the children

Utjecaj izvantjelesnog mrvljenja kamenaca šoknim valovima na bubreg

Extracorporeal shockwave lithotripsy is not a novel therapeutic method in the treatment of urolithiasis. It uses shock waves (SW) created in the generator outside of the body that are then focused and directed on the calculus in the patient’s body. It is the method of choice for the treatment of kidney stones smaller than 20 mm, and those in the proximal part of the ureter (up to 10 mm). Complications are relatively rare and most often clinically insignificant. SW can reversibly damage all parts of the renal parenchyma. The degree of damage depends on the number of SW and the energy level delivered to a particular tissue. Such changes are most often asymptomatic. Microhaematuria is present in virtually all patients, and macrohaematuria occurs in about 1/3 of patients. A rare but serious complication is a kidney rupture that requires surgical care that can sometimes lead to a nephrectomy. The occurrence of perinephric or subcapsular hematoma is rare and usually requires only conservative therapy. Despite the aforementioned negative impact of SW on the renal parenchyma (primarily around the calculus), studies have not shown that treatment with this method leads to significant renal function impairment in either the adult or paediatric population.Izvantjelesno mrvljenje kamenaca (ESWL) novija je terapijska metoda u liječenju urolitijaze. Temelji se na uporabi šok- valova koji se stvaraju u generatoru izvan tijela, fokusiraju i usmjeruju na kamenac u tijelu bolesnika. Metoda je izbora za liječenje bubrežnih kamenaca manjih od 20 mm te onih u proksimalnom dijelu mokraćovoda veličine do 10 mm. Komplikacije su relativno rijetke i najčešće klinički beznačajne. Šok valovi mogu reverzibilno oštetiti sve dijelove bubrežnog parenhima. Stupanj oštećenja ovisi o broju udaraca šok-valovima i energetskom nivou koji je isporučen određenom tkivu. Takve promjene su najčešće asimptomatske. Mikrohematurija je prisutna praktički u svih bolesnika, a makrohematurija se javlja u oko 1/3 bolesnika. Rijetka, ali ozbiljna komplikacija je ruptura bubrega koja zahtijeva operacijsko zbrinjavanje i ponekada nefrektomiju. Pojava perinefritičnog ili subkapsularnog hematoma je rijetka i obično prolazi na konzervativnu terapiju. Unatoč prije spomenutom negativnom utjecaju šok valova na bubrežni parenhim (prvenstveno na onaj u okolici kamenca) studije nisu pokazale da liječenje ovom metodom dovodi do značajnijeg oštećenja bubrežne funkcije niti u odrasloj, niti u pedijatrijskoj populaciji

Semantic Segmentation of Urinary Bladder Cancer Masses From CT Images: A Transfer Learning Approach

Urinary bladder cancer is one of the most common cancers of the urinary tract. This cancer is characterized by its high metastatic potential and recurrence rate. Due to the high metastatic potential and recurrence rate, correct and timely diagnosis is crucial for successful treatment and care. With the aim of increasing diagnosis accuracy, artificial intelligence algorithms are introduced to clinical decision making and diagnostics. One of the standard procedures for bladder cancer diagnosis is computer tomography (CT) scanning. In this research, a transfer learning approach to the semantic segmentation of urinary bladder cancer masses from CT images is presented. The initial data set is divided into three sub-sets according to image planes: frontal (4413 images), axial (4993 images), and sagittal (996 images). First, AlexNet is utilized for the design of a plane recognition system, and it achieved high classification and generalization performances with an AUCmicro of 0.9999 and s(AUCmicro) of 0.0006. Furthermore, by applying the transfer learning approach, significant improvements in both semantic segmentation and generalization performances were achieved. For the case of the frontal plane, the highest performances were achieved if pre-trained ResNet101 architecture was used as a backbone for U-net with DSC up to 0.9587 and s(DSC) of 0.0059. When U-net was used for the semantic segmentation of urinary bladder cancer masses from images in the axial plane, the best results were achieved if pre-trained ResNet50 was used as a backbone, with a DSC up to 0.9372 and s(DSC) of 0.0147. Finally, in the case of images in the sagittal plane, the highest results were achieved with VGG-16 as a backbone. In this case, DSC values up to 0.9660 with a s(DSC) of 0.0486 were achieved. From the listed results, the proposed semantic segmentation system worked with high performance both from the semantic segmentation and generalization standpoints. The presented results indicate that there is the possibility for the utilization of the semantic segmentation system in clinical practice

Urological complications after kidney transplantation – experience from Referral Center in Croatia

Cilj: Prikazati učestalost uroloških komplikacija nakon transplantacije bubrega u našem transplantacijskom centru. Ispitanici i metode: Retrospektivnim istraživanjem bili su obuhvaćeni svi pacijenti u Kliničkom bolničkom centru Rijeka u kojih je između 30. siječnja 1971. godine i 31. prosinca 2018. godine učinjena transplantacija bubrega. Rezultati: U promatranom razdoblju u našem transplantacijskom centru učinjeno je 1160 transplantacija bubrega. Urološke komplikacije imala su ukupno 154 pacijenta (13,3 %). Najčešće komplikacije su bile stenoza uretera u 52 pacijenta (4,5 %), urinarna fistula u 50 pacijenata (4,3 %), retencija urina u 23 pacijenta (1,9 %) te urolitijaza u 8 pacijenata (0,7 %). U većine pacijenata je provedeno kirurško liječenje. U posljednje vrijeme značajno se povećalo rješavanje uroloških komplikacija korištenjem minimalno-invazivnih metoda. U dvoje pacijenata (0,17 %) je zbog uroloških komplikacija došlo do gubitka grafta, a u troje pacijenata (0,25 %) su one dovele do smrtnog ishoda. Zaključak: Urološke komplikacije u našoj transplantacijskoj populaciji nisu česte. U pacijenata u kojih je potrebno kirurško liječenje endourološke metode predstavljaju danas inicijalnu metodu liječenja.Aim: To evaluate the incidence of urological complications after kidney transplantation in our transplant center. Patients and Methods: We retrospectively analyzed all patients with kidney transplantation operated in University Hospital Rijeka from January 30st 1971 to December 31st 2018. Results: In the observed period 1160 kidney transplantations were performed in our transplant center. Urological complications were noticed in the 154 patients (13.3%). The most frequent complications were ureteral stenosis in 52 patients (4.5%), urinary fistula in 50 patients (4.3%), urinary retention in 23 patients (1.9%) and urolithiasis in the 8 patients (0.7%). The majority of the patients underwent surgical treatment. Recently, minimally invasive surgery was the method of choice for treatment of urological complications. In two patients (0,17%) urological complications caused graft loss and in the three patients (0,25%) this complications lead to death. Conclusion: Urological complications are not frequent in our transplant population. In the group of patients that required surgical treatment endourology methods are currently the initial treatment modality