Stavros I. Tyritzis
National and Kapodistrian University of Athens
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Featured researches published by Stavros I. Tyritzis.
Journal of Proteome Research | 2008
Spiros D. Garbis; Stavros I. Tyritzis; Theodoros Roumeliotis; Panagiotis Zerefos; Eugenia G. Giannopoulou; Antonia Vlahou; Sophia Kossida; Jose I. Diaz; Stavros Vourekas; Constantin Tamvakopoulos; Kitty Pavlakis; Despina Sanoudou; Constantinos Constantinides
This study aimed to identify candidate new diagnosis and prognosis markers and medicinal targets of prostate cancer (PCa), using state of the art proteomics. A total of 20 prostate tissue specimens from 10 patients with benign prostatic hyperplasia (BPH) and 10 with PCa (Tumour Node Metastasis [TNM] stage T1-T3) were analyzed by isobaric stable isotope labeling (iTRAQ) and two-dimensional liquid chromatography-tandem mass spectrometry (2DLC-MS/MS) approaches using a hybrid quadrupole time-of-flight system (QqTOF). The study resulted in the reproducible identification of 825 nonredundant gene products (p < or = 0.05) of which 30 exhibited up-regulation (> or =2-fold) and another 35 exhibited down-regulation (< or =0.5-fold) between the BPH and PCa specimens constituting a major contribution toward their global proteomic assessment. Selected findings were confirmed by immunohistochemical analysis of prostate tissue specimens. The proteins determined support existing knowledge and uncover novel and promising PCa biomarkers. The PCa proteome found can serve as a useful aid for the identification of improved diagnostic and prognostic markers and ultimately novel chemopreventive and therapeutic targets.
Analytical Chemistry | 2011
Spiros D. Garbis; Theodoros Roumeliotis; Stavros I. Tyritzis; Kostas M. Zorpas; Kitty Pavlakis; Constantinos Constantinides
The current proof-of-principle study was aimed toward development of a novel multidimensional protein identification technology (MudPIT) approach for the in-depth proteome analysis of human serum derived from patients with benign prostate hyperplasia (BPH) using rational chromatographic design principles. This study constituted an extension of our published work relating to the identification and relative quantification of potential clinical biomarkers in BPH and prostate cancer (PCa) tissue specimens. The proposed MudPIT approach encompassed the use of three distinct yet complementary liquid chromatographic chemistries. High-pressure size-exclusion chromatography (SEC) was used for the prefractionation of serum proteins followed by their dialysis exchange and solution phase trypsin proteolysis. The tryptic peptides were then subjected to offline zwitterion-ion hydrophilic interaction chromatography (ZIC-HILIC) fractionation followed by their online analysis with reversed-phase nano-ultraperformance chromatography (RP-nUPLC) hyphenated to nanoelectrospray ionization-tandem mass spectrometry using an ion trap mass analyzer. For the spectral processing, the sequential use of the SpectrumMill, Scaffold, and InsPecT software tools was applied for the tryptic peptide product ion MS(2) spectral processing, false discovery rate (FDR) assessment, validation, and protein identification. This milestone serum analysis study allowed the confident identification of over 1955 proteins (p ≤ 0.05; FDR ≤ 5%) with a broad spectrum of biological and physicochemical properties including secreted, tissue-specific proteins spanning approximately 12 orders of magnitude as they occur in their native abundance levels in the serum matrix. Also encompassed in this proteome was the confident identification of 375 phosphoproteins (p ≤ 0.05; FDR ≤ 5%) with potential importance to cancer biology. To demonstrate the performance characteristics of this novel MudPIT approach, a comparison was made with the proteomes resulting from the immunodepletion of the high abundant albumin and IgG proteins with offline first dimensional tryptic peptide separation with both ZIC-HILIC and strong cation exchange (SCX) chromatography and their subsequent online RP-nUPLC-nESI-MS(2) analysis.
Journal of Endourology | 2012
Konstantinos Stravodimos; Stefanos Adamis; Stavros I. Tyritzis; Zavos Georgios; Constantinos Constantinides
BACKGROUND AND PURPOSE Renal transplant lithiasis represents a rather uncommon complication. Even rare, it can result in significant morbidity and a devastating loss of renal function if obstruction occurs. We present our experience with graft lithiasis in our series of renal transplantations and review the literature regarding the epidemiology, pathophysiology, and current therapeutic strategies in the management of renal transplant lithiasis. PATIENTS AND METHODS In a retrospective analysis of a consecutive series of 1525 renal transplantations that were performed between January 1983 and March 2007, 7 patients were found to have allograft lithiasis. In five cases, the calculi were localized in the renal unit, and in two cases, in the ureter. A review in the English language was also performed of the Medline and PubMed databases using the keywords renal transplant lithiasis, donor-gifted lithiasis, and urological complications after kidney transplantation. Several retrospective studies regarding the incidence, etiology, as well as predisposing factors for graft lithiasis were reviewed. Data regarding the current therapeutic strategies for graft lithiasis were also evaluated, and outcomes were compared with the results of our series. RESULTS Most studies report a renal transplant lithiasis incidence of 0.4% to 1%. In our series, incidence of graft lithiasis was 0.46% (n=7). Of the seven patients, three were treated via percutaneous nephrolithotripsy (PCNL); in three patients, shockwave lithotripsy (SWL) was performed; and in a single case, spontaneous passage of a urinary calculus was observed. All patients are currently stone free but still remain under close urologic surveillance. CONCLUSION Renal transplant lithiasis requires vigilance, a high index of suspicion, prompt recognition, and management. Treatment protocols should mimic those for solitary kidneys. Minimally invasive techniques are available to remove graft calculi. Long-term follow-up is essential to determine the outcome, as well as to prevent recurrence.
Journal of Endourology | 2015
Stavros I. Tyritzis; N.P. Wiklund
A ureteral stricture is a rather rare urological event defined as a narrowing of the ureter causing a functional obstruction and renal failure, if left untreated. The aim of this review article is to summarize and discuss current knowledge on the incidence, pathogenesis, management, and follow up of proximal, mid, and distal ureteral strictures.
Journal of Endourology | 2012
Stavros I. Tyritzis; Abolfazl Hosseini; Martin Jonsson; Christofer Adding; Andreas Nilsson; N. Peter Wiklund
We are celebrating the 10th anniversary of robot-assisted laparoscopic radical cystectomy (RARC) with urinary diversion (UD), and it seems that this operation is successfully following the footsteps of robot-assisted laparoscopic radical prostatectomy. Until now, approximately 1000 RARCs have been recorded; of them, only 102 were performed totally intracorporeally with a formation of an ileal neobladder. Despite the small numbers, morbidity and functional outcomes seem to be acceptable, when compared with the gold standard-the open procedure. It is imperative that in a challenging procedure such as this, the console surgeon follow a standardized protocol of all surgical steps to ensure the optimal results. In this article, we are sharing Karolinskas experience and discuss all perioperative issues along with ways of dealing with tricky cases.
International Scholarly Research Notices | 2011
Stavros I. Tyritzis; Konstantinos Stravodimos; Ioanna Vasileiou; Georgia Fotopoulou; Georgios Koritsiadis; Vasileios Migdalis; Anastasios Michalakis; Constantinos Constantinides
We compared the analgesic efficacy of spinal and general anaesthesia following transurethral procedures. 97 and 47 patients underwent transurethral bladder tumour resection (TUR-B) and transurethral prostatectomy (TUR-P), respectively. Postoperative pain was recorded using an 11-point visual analogue scale (VAS). VAS score was greatest at discharge from recovery room for general anaesthesia (P = 0.027). The pattern changed significantly at 8 h and 12 h for general anaesthesias efficacy (P = 0.017 and P = 0.007, resp.). A higher VAS score was observed in pT2 patients. Patients with resected tumour volume >10 cm3 exhibited a VAS score >3 at 8 h and 24 h (P = 0.050, P = 0.036, resp.). Multifocality of bladder tumours induced more pain overall. It seems that spinal anaesthesia is more effective during the first 2 postoperative hours, while general prevails at later stages and at larger traumatic surfaces. Finally, we incidentally found that tumour stage plays a significant role in postoperative pain, a point that requires further verification.
Research and Reports in Urology | 2014
Konstantinos Stravodimos; Stilianos Giannakopoulos; Stavros I. Tyritzis; Aristeides Alevizopoulos; Stefanos Papadoukakis; Stavros Touloupidis; Constantinos Constantinides
Introduction Approximately one out of five patients with ureteropelvic junction obstruction (UPJO) present lithiasis in the same setting. We present our outcomes of simultaneous laparoscopic management of UPJO and pelvic or calyceal lithiasis and review the current literature. Methods Thirteen patients, with a mean age of 42.8±13.3 years were diagnosed with UPJO and pelvic or calyceal lithiasis. All patients were subjected to laparoscopic dismembered Hynes–Anderson pyeloplasty along with removal of single or multiple stones, using a combination of laparoscopic graspers, irrigation, and flexible nephroscopy with nitinol baskets. Results The mean operative time was 218.8±66 minutes. In two cases, transposition of the ureter due to crossing vessels was performed. The mean diameter of the largest stone was 0.87±0.25 cm and the mean number of stones retrieved was 8.2 (1–32). Eleven out of 13 patients (84.6%) were rendered stone-free. Complications included prolonged urine output from the drain in one case (Clavien grade I) and urinoma formation requiring drainage in another case (Clavien grade IIIa). The mean postoperative follow-up was 30.2 (7–51) months. No patient has experienced stone or UPJO recurrence. Conclusion Laparoscopy for the management of UPJO along with renal stone removal seems a very appealing treatment, with all the advantages of minimally invasive surgery. Concomitant renal stones do not affect the outcome of laparoscopic pyeloplasty, at least in the midterm. According to our results and the latest literature data, we advocate laparoscopic management as the treatment of choice for these cases.
Journal of Postgenomics Drug & Biomarker Development | 2012
Amalia Papanikolopoulou; Olfert Landt; Martin Reczko; Konstantinos Ntoumas; Stefanos Bolomitis; Stavros I. Tyritzis; Nikolaos Drakoulis; Tib Molbiol; Alexander Fleming
Introduction: Common variants on human chromosome 8q24 were found to be associated with prostate cancer risk with different frequency and incidence among the investigated populations. We examined the effect of smoke on this type of cancer and its relationship with the risk variant rs6983267, located at region 3 of chromosome 8q24, in a prostate cancer case-control study conducted in the Greek population in light, intermediate and heavy smokers. Materials and methods: Samples of total blood from 74 patients with histologically confirmed prostate cancer and 24 healthy individuals were genotyped using real time polymerase chain reaction (PCR). Tumor-node-metastasis (TNM) stage, Gleason score and levels of prostate-specific antigen (PSA) at diagnosis were included in the analysis. Results: Light (Packyears, PY 30) smokers are positive associated with prostate cancer, with an additive risk for the carriers of rs6983267 with positive smoking history (ORadj=21.36, C.L=3.79-120.39) to develop the disease. Conclusions: The SNP, rs6983267, has an independent risk for carriers to develop prostate cancer and in combination with smoke; it confers additive risk for the disease, similarly to others, well established risk factors such as age, family history and ethnicity.
Archivio Italiano di Urologia e Andrologia | 2015
Konstantinos Stravodimos; Ioannis Katafigiotis; Evangelos Fragkiadis; Stavros I. Tyritzis; Constantinos Constantinides
OBJECTIVE Robotic assisted pyeloplasty (RAP) is rapidly adopted by surgeons around the world. We present a unique complication of the technique, consisting of pigtail misplacement, which was endoscopically resolved. We discuss the clinical findings, differential diagnosis and principles of endoscopic treatment. MATERIALS AND METHODS A 41 years old female patients underwent transperitoneal right side RAP with the Hynes-Anderson technique for ureteropelvic junction obstruction. Pigtail was placed intraoperatively in an antegrade fashion. Post operative course appeared normal but Kidney-Ureterer-Bladder(KUB) X-ray, revealed a misplaced pigtail. Patient underwent a semirigid ureterorenoscopy demonstrating that the pigtail was exiting the collecting system in the rear line of suturing between continuous sutures. Pigtail was retrieved with a stone retrieval forceps with short upward motions in the renal pelvis under fluoroscopy and then removed from patient, in order to avoid stressing the anastomosis. No leakage was noted in fluoroscopy, a pigtail was correctly placed and patient recovery was uneventful. RESULTS Retrograde pyelography was the key to accurate diagnosis and endoscopic treatment, because the exact point of exit and anastomosis integrity were established. Retrieval of the pigtail was the most challenging part. Lack of proper visualization and mobilization of the rear part of the anastomosis during surgery, combined with lack of tactile feedback, because of robotic instrumentation, were of critical importance in the manifestation of such a mishap. Endoscopy facilitated case resolve, but proper handling is required to protect the anastomosis. CONCLUSIONS The introduction of novel techniques can carry the burden of novel complications. A surgeon must always keep in mind the complications inherent to the technique and at the same time the limitations of the equipment used, especially the lack of tactile feedback in robotic instrumentation.
Indian Journal of Urology | 2018
Stavros I. Tyritzis; N.P. Wiklund