Dimitri Barski

Hypermethylation and Transcriptional Downregulation of the TIMP3 Gene is Associated with Allelic Loss on 22q12.3 and Malignancy in Meningiomas

The gene for the tissue inhibitor of metalloproteinase 3 (TIMP3) on 22q12.3 had been reported to be inactivated by promoter methylation in various types of cancers, with controversial findings in meningiomas. We performed direct sodium bisulfite sequencing in a series of 50 meningiomas, including 27 benign meningiomas [World Health Organization (WHO) grade I], 11 atypical meningiomas (WHO grade II) and 12 anaplastic meningiomas (WHO grade III), and found hypermethylation of TIMP3 in 67% of anaplastic meningiomas, but only 22% of atypical and 17% of benign meningiomas. Moreover, TIMP3 methylation scores were significantly inversely correlated with TIMP3 mRNA expression levels (P = 0.0123), and treatment of the meningioma cell line Ben‐Men‐1 with demethylating agents induced an increased TIMP3 mRNA expression. TIMP3 is located in the chromosomal band 22q12, the allelic loss of which occurs early in meningioma tumorigenesis and preferentially targets the NF2 tumor suppressor gene. In our tumor panel, all meningiomas with TIMP3 hypermethylation—except for a single case—exhibited allelic losses on 22q12.3. Thus, TIMP3 inactivation by methylation seems fairly exclusive to meningiomas with allelic losses on 22q12 but—in contrast to NF2 mutation—appears to be involved in meningioma progression as it is associated with a more aggressive, high‐grade meningioma phenotype.

Genotyping NAT2 with only two SNPs (rs1041983 and rs1801280) outperforms the tagging SNP rs1495741 and is equivalent to the conventional 7-SNP NAT2 genotype.

Genotyping N-acetyltransferase 2 (NAT2) is of high relevance for individualized dosing of antituberculosis drugs and bladder cancer epidemiology. In this study we compared a recently published tagging single nucleotide polymorphism (SNP) (rs1495741) to the conventional 7-SNP genotype (G191A, C282T, T341C, C481T, G590A, A803G and G857A haplotype pairs) and systematically analysed if novel SNP combinations outperform the latter. For this purpose, we studied 3177 individuals by PCR and phenotyped 344 individuals by the caffeine test. Although the tagSNP and the 7-SNP genotype showed a high degree of correlation (R=0.933, P<0.0001) the 7-SNP genotype nevertheless outperformed the tagging SNP with respect to specificity (1.0 vs. 0.9444, P=0.0065). Considering all possible SNP combinations in a receiver operating characteristic analysis we identified a 2-SNP genotype (C282T, T341C) that outperformed the tagging SNP and was equivalent to the 7-SNP genotype. The 2-SNP genotype predicted the correct phenotype with a sensitivity of 0.8643 and a specificity of 1.0. In addition, it predicted the 7-SNP genotype with sensitivity and specificity of 0.9993 and 0.9880, respectively. The prediction of the NAT2 genotype by the 2-SNP genotype performed similar in populations of Caucasian, Venezuelan and Pakistani background. A 2-SNP genotype predicts NAT2 phenotypes with similar sensitivity and specificity as the conventional 7-SNP genotype. This procedure represents a facilitation in individualized dosing of NAT2 substrates without losing sensitivity or specificity.

Inflammatory Reaction as Determinant of Foreign Body Reaction Is an Early and Susceptible Event after Mesh Implantation

Purpose. To investigate and relate the ultrashort-term and long-term courses of determinants for foreign body reaction as biocompatibility predictors for meshes in an animal model. Materials and Methods. Three different meshes (TVT, UltraPro, and PVDF) were implanted in sheep. Native and plasma coated meshes were placed bilaterally: (a) interaperitoneally, (b) as fascia onlay, and (c) as muscle onlay (fascia sublay). At 5 min, 20 min, 60 min, and 120 min meshes were explanted and histochemically investigated for inflammatory infiltrate, macrophage infiltration, vessel formation, myofibroblast invasion, and connective tissue accumulation. The results were related to long-term values over 24 months. Results. Macrophage invasion reached highest extents with up to 60% in short-term and decreased within 24 months to about 30%. Inflammatory infiltrate increased within the first 2 hours, the reached levels and the different extents and ranking among the investigated meshes remained stable during long-term follow up. For myofibroblasts, connective tissue, and CD31+ cells, no activity was detected during the first 120 min. Conclusion. The local inflammatory reaction is an early and susceptible event after mesh implantation. It cannot be influenced by prior plasma coating and does not depend on the localisation of implantation.

Evaluation of a Structured Report of Functional Prostate Magnetic Resonance Imaging in Patients with Suspicion for Prostate Cancer or under Active Surveillance

Background: Functional magnetic resonance imaging (MRI) seems to be a useful tool for prostate cancer (PCa) detection in patients with a previous negative biopsy but persistently increased prostate-specific antigen (PSA) values. Additionally, it enables correct cancer localization in patients with known PCa under active surveillance to avoid misclassification on repeat biopsies. Nevertheless, suspicious lesions on MRI findings need verification by biopsy. The aim of the present study was to establish a standardized functional prostate MRI reporting scheme. Methods: Prostate MRI with T2-weighted images, T1-weighted images, diffusion-weighted imaging, and dynamic contrast-enhanced MRI of 56 consecutive patients were performed on a 3-T scanner. Patients with prior negative random transrectal ultrasound (TRUS)-guided biopsy and continuous suspicion for PCa as well as patients under active surveillance were included. The MRI localization report of suspicious lesions followed a standardized scheme. TRUS-guided random biopsy with addition of targeted biopsy cores was performed afterwards based on the structured report. Results: Of the 56 patients, 18 had suspicious MRI findings and subsequently underwent repeat biopsy under guidance of the standardized localization scheme. PCa was documented in 72% (13/18). Conclusions: A standardized reporting scheme of suspicious findings on prostate MRI leads to higher success rates as compared to standard random TRUS-guided biopsy.

Coating with Autologous Plasma Improves Biocompatibility of Mesh Grafts In Vitro: Development Stage of a Surgical Innovation

Purpose. To investigate mesh coating modalities with autologous blood components in a recently developed in vitro test system for biocompatibility assessment of alloplastic materials. Materials and Methods. Seven different mesh types, currently used in various indications, were randomly investigated. Meshes were coated prior to cultivation with autologous peripheral blood mononuclear cells (PBMCs), platelets, and blood plasma. Pretreated meshes were incubated over 6 weeks in a minced tissue assay, representative for fibroblasts, muscle cells, and endothelial cells originating from 10 different patients. Adherence of those tissues on the meshes was microscopically investigated and semiquantitatively assessed using a previously described scoring system. Results. Coating with peripheral blood mononuclear cells did not affect the adherence score, whereas coating with platelets and blood plasma increased the score suggesting improved biocompatibility in vitro. The previous ranking of native meshes remained consistent after coating. Conclusion. Plasma coating of meshes improves their biocompatibility score in a novel in vitro test system.

Management and follow up of extra–adrenal phaeochromocytoma

Introduction The prevalence of phaeochromocytoma (PCC) in patients with hypertension is 0.1–0.6% and about 10% of PCCs are detected in extra–adrenal tissue. The diagnosis and therapy of this rare disease detected as a retroperitoneal tumor mass can be difficult for clinicians. Material and methods A PubMed database was searched for the peer–reviewed articles, the listed articles until Dec 2012 were included. Following key words were used: “extra–adrenal phaeochromocytoma”, “paraganglioma”, “diagnosis”, “therapy”, “surgery”, “genetic analysis”, and “SDH mutation”. Results Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) are first choice imaging tools for PCC (sensitivity 90–100%). For the validation of the diagnosis or follow up, the functional imaging 123I–metaiodobenzylguanidine (MIBG) or Fluorine–18–L–dihydroxyphenylalanine (18F–DOPA) positron emission tomography (excellent specificity and sensitivity of 90–100% in detection of small tumors >1–2 cm) are used. Laparoscopic surgery with complete resection is a safe and a first choice approach. The conversion (about 5%) to direct open operation was needed for large lesions (>8 cm) with the suspicion of malignancy. Currently, there are no histological criteria for distinguishing benign and malignant tumors. The genetic testing (Sanger DNA sequencing) for hereditary syndromes (von Hippel–Lindau, neurofibromatosis, etc.) is used for prediction of malignancy and recurrence. All patients should get individual and risk–adapted genetic analysis and consultation, including family members. The rate of malignancy in ePCC is about 30% (PCC about 5–10%). In patients with proven SDHB germline mutations, higher malignancy rate, multiple PCCs and recurrences are likely. A stringent lifelong clinical follow–up is recommended in these cases. Patients with syndromic hereditary forms should be screened for other often associated neoplasms. Conclusions New imaging tools and genetic analysis are crucial to improve the diagnosis and prognosis of phaeochromocytoma.

Coating of mesh grafts for prolapse and urinary incontinence repair with autologous plasma: exploration stage of a surgical innovation.

Purpose. Optimized biocompatibility is a major requirement for alloplastic materials currently applied for stress urinary incontinence (SUI) and pelvic organ prolapse (POP) repair. In the preliminary studies the mesh modification by coating with autologous plasma resulted in the increased adherence score in vitro and improved biocompatibility in an animal model. The first use of plasma coated meshes in human is presented. Materials and Methods. Between 04/2013 and 05/2014, 20 patients with the indication for SUI and POP repair were selected in a single institution. The applied meshes were modified by autologous plasma coating prior to implantation. A retrospective chart review for peri- and early postoperative complications was performed. Functional outcome and QoL were evaluated pre- and postoperatively. Results. The functional outcome and QoL improved significantly in all groups. Two reoperations (Grade IIIB) with the release of TVT-mesh in anesthesia due to the obstruction were needed. No other severe complications were registered. Conclusion. For the first time we applied a mesh modification in a human setting according to IDEAL criteria of surgical innovations. The procedure of mesh coating with autologous plasma is safe and a prospective randomized trial proving a positive effect of plasma coating on the biocompatibility and morbidity outcome with long-term registry is planned.

A Novel Operative Procedure for Pelvic Organ Prolapse Utilizing a MRI-Visible Mesh Implant: Safety and Outcome of Modified Laparoscopic Bilateral Sacropexy

Introduction. Sacropexy is a generally applied treatment of prolapse, yet there are known possible complications of it. An essential need exists for better alloplastic materials. Methods. Between April 2013 and June 2014, we performed a modified laparoscopic bilateral sacropexy (MLBS) in 10 patients using a MRI-visible PVDF mesh implant. Selected patients had prolapse POP-Q stages II-III and concomitant OAB. We studied surgery-related morbidity, anatomical and functional outcome, and mesh-visibility in MRI. Mean follow-up was 7.4 months. Results. Concomitant colporrhaphy was conducted in 1/10 patients. Anatomical success was defined as POP-Q stage 0-I. Apical success rate was 100% and remained stable. A recurrent cystocele was seen in 1/10 patients during follow-up without need for intervention. Out of 6 (6/10) patients with preoperative SUI, 5/6 were healed and 1/6 persisted. De-novo SUI was seen in 1/10 patients. Complications requiring a relaparoscopy were seen in 2/10 patients. 8/10 patients with OAB were relieved postoperatively. The first in-human magnetic resonance visualization of a prolapse mesh implant was performed and showed good quality of visualization. Conclusion. MLBS is a feasible and safe procedure with favorable anatomical and functional outcome and good concomitant healing rates of SUI and OAB. Prospective data and larger samples are required.

Metastatic penile carcinoma - an update on the current diagnosis and treatment options.

Introduction Penile carcinoma has an incidence of 4,000 cases in Europe. The therapy and prognosis depend decisively on the lymph node status. Lymph node metastases are detected in 23–65% cases depending on the histopathological pattern. Due to improved diagnostic methods an early detection of tumor stage is possible. Multimodal therapeutic concepts can offer curability for a subset of patients, even those suffering from advanced disease. Material and methods Current data on penile cancer based on a selective review of the literature by PubMed and the EAU guidelines 2009. Results Invasive diagnostic tools, such as fine–needle biopsy (FNB) and dynamic sentinel node biopsy (DSNB), improved the diagnosis of lymph node status considerably and reduced the morbidity in specialized centers. The application of 18F–FDG–PET/CT for metastases detection needs further evaluation due to inconsistent results. Inguinal lymphadenectomy is the therapeutic standard in case of metastases proof. It was possible to reduce the complications due to the new modified operation techniques. Patients with extended lymph node and distant metastases have a poor prognosis. Different systemic polychemotherapy regimes are applied currently and are associated with poor outcome (response rates <50%) and high morbidity. Neoadjuvant chemotherapy is recommended in patients with unresectable and relapsing lymph node metastases. Conclusions Currently, inconsistent therapy regimens are applied for metastatic penile cancer. Standardization is urgently needed through the development of high–quality studies and long–term registers in order to lower the morbidity and increase the efficiency of diagnosis and therapy.

UBC®Rapid Test for detection of carcinoma in situ for bladder cancer

UBC® Rapid Test is a test that detects fragments of cytokeratins 8 and 18 in urine. We present results of a multicentre study measuring UBC® Rapid Test in bladder cancer patients and healthy controls with focus on carcinoma in situ (CIS) and high-grade bladder cancer. From our study with N = 452 patients, we made a stratified sub-analysis for carcinoma in situ of the urinary bladder. Clinical urine samples were used from 87 patients with tumours of the urinary bladder (23 carcinoma in situ, 23 non-muscle-invasive low-grade tumours, 21 non-muscle-invasive high-grade tumours and 20 muscle-invasive high-grade tumours) and from 22 healthy controls. The cut-off value was defined at 10.0 µg/L. Urine samples were analysed by the UBC® Rapid Test point-of-care system (concile Omega 100 POC reader). Pathological levels of UBC Rapid Test in urine are higher in patients with bladder cancer in comparison to the control group (p < 0.001). Sensitivity was calculated at 86.9% for carcinoma in situ, 30.4% for non-muscle-invasive low-grade bladder cancer, 71.4% for nonmuscle-invasive high grade bladder cancer and 60% for muscle-invasive high-grade bladder cancer, and specificity was 90.9%. The area under the curve of the quantitative UBC® Rapid Test using the optimal threshold obtained by receiveroperated curve analysis was 0.75. Pathological values of UBC® Rapid Test in urine are higher in patients with high-grade bladder cancer in comparison to low-grade tumours and the healthy control group. UBC® Rapid Test has potential to be more sensitive and specific urinary protein biomarker for accurate detection of high-grade patients and could be added especially in the diagnostics for carcinoma in situ and non-muscle-invasive high-grade tumours of urinary bladder cancer.