Sebastian Nestler

The unique complexity of the CYP3A4 upstream region suggests a nongenetic explanation of its expression variability.

Objective The individually variable and unpredictable expression of CYP3A4 compromises therapies with 50% of contemporary drugs. Gene variants explain only a fraction of this variability. Methods We investigated the evolution of CYP3A4 transcriptional regulation by nuclear receptors such as the xenobiotics sensors PXR and CAR. Results The combination of a proximal ER6 element with XREM and CLEM represents the original scheme of CYP3A regulation by nuclear receptors in placental mammals. Among human CYP3A genes, this scheme is retained only in CYP3A4, whereas non-CYP3A4 genes lost these elements to a variable extent during primate evolution. In parallel, the number of elements outside XREM and CLEM potentially responsive to PXR and CAR increased in primate CYP3A4 orthologs, which led to enhanced CYP3A4 inducibility. Additions to the other primate CYP3A genes were more restricted and specific, as exemplified by a CYP3A5 DR4 site responsive to CAR, but not to PXR. All these changes resulted in human CYP3A4 having a much more complex upstream regulatory region in comparison to its paralogs. Conclusion Instead of gene variants, the intraindividual CYP3A4 expression variability in humans may be primarily caused by particular sensitivity of this gene to endogenous and exogenous PXR and CAR ligands conferred by the unique complexity of its upstream regulatory region.

Robot-Assisted Transvesical Enucleation of Benign Prostatic Hyperplasia: Lessons from a Single Surgeon’s Learning Curve

Introduction: Open simple prostatectomy is a well‐established and effective operation for prostate volumes greater than 80 gm but also associated with bleeding and urinary incontinence. To benefit from the advances of laparoscopy, robot‐assisted simple prostatectomy was established. We determined the learning curve of this minimally invasive surgery by evaluating the first procedures by an experienced robotic surgeon. Methods: Patients presenting for surgical therapy with prostate volumes greater than 80 gm were considered for the study. Evaluation included validated questionnaires preoperatively, and at 6 and 12 weeks postoperatively. Blood loss, transfusions, operation time and pad use after catheter removal were documented. The experience based on the results from 18 cases treated with robot‐assisted simple prostatectomy by one of us (JWT) is presented. Results: Mean age of the 18 patients was 71.2 years, mean enucleated prostate volume was 91 gm and mean preoperative flow was 9.0 ml/second. I‐PSS and QoL values improved significantly from 25 to 6.1 (p <0.005) and from 5 to 1.1 (p <0.005), respectively, and flow rate increased to 28.2 ml/second (p <0.005) postoperatively. There were no significant changes in sexual performance based on IIEF (p = 0.73). Of the 18 patients 14 had complete continence immediately after catheter removal, and at 6 weeks postoperatively 17 were completely continent. Decreases in operation time from 250 to 150 minutes and blood loss from 400 to 200 ml were noted after 5 procedures. Only minor complications occurred and 1 patient required transfusion postoperatively (Clavien‐Dindo II). Conclusions: Robot‐assisted simple prostatectomy is a safe and effective operation for benign prostatic hyperplasia, which can be learned with good results in a rather short time.

Pancreatic Fistulae after Urologic Surgery - A Single Centre Experience

Introduction: To evaluate incidence, symptoms and management of postoperative pancreatic fistula (POPF) after urologic surgery based on our experience. Material and Methods: Database was searched for clinically evident POPF after urologic surgery between 1998 and 2014. Fistulae were graded using the POPF classification. Clinical course of every POPF patient was evaluated. Results: During this time, 3,200 surgeries for renal, adrenal and retroperitoneal pathologies were performed. Twelve POPF occurred postoperatively in this series. Eight fistulae were POPF grade A, 3 POPF grade B and one POPF grade C. POPF became clinically evident after a median of 3 days (IQR 2-3). In all POPF grade A/B patients, secretion from the pancreatic fistula completely subsided under conservative therapy. In one POPF grade C patient with positive surgical margins of urothelial cancer, conservative treatment failed and the patient died due to POPF-related sepsis. Conclusions: POPF is a rare complication after urologic surgery. Conservative therapy is the first choice of treatment and will be successful in the majority of cases. Pancreatic fistula after surgery of recurrent malignancy may have a poor outcome.

Pregnane X Receptor and Yin Yang 1 Contribute to the Differential Tissue Expression and Induction of CYP3A5 and CYP3A4

The hepato-intestinal induction of the detoxifying enzymes CYP3A4 and CYP3A5 by the xenosensing pregnane X receptor (PXR) constitutes a key adaptive response to oral drugs and dietary xenobiotics. In contrast to CYP3A4, CYP3A5 is additionally expressed in several, mostly steroidogenic organs, which creates potential for induction-driven disturbances of the steroid homeostasis. Using cell lines and mice transgenic for a CYP3A5 promoter we demonstrate that the CYP3A5 expression in these organs is non-inducible and independent from PXR. Instead, it is enabled by the loss of a suppressing yin yang 1 (YY1)-binding site from the CYP3A5 promoter which occurred in haplorrhine primates. This YY1 site is conserved in CYP3A4, but its inhibitory effect can be offset by PXR acting on response elements such as XREM. Taken together, the loss of YY1 binding site from promoters of the CYP3A5 gene lineage during primate evolution may have enabled the utilization of CYP3A5 both in the adaptive hepato-intestinal response to xenobiotics and as a constitutively expressed gene in other organs. Our results thus constitute a first description of uncoupling induction from constitutive expression for a major detoxifying enzyme. They also suggest an explanation for the considerable tissue expression differences between CYP3A5 and CYP3A4.

PNFBA-13 ARE THE CURRENT FOLLOW-UP GUIDELINES AFTER TREATMENT FOR ORGAN CONFINED RENAL CANCER SUFFICIENT?

following genes were queried: VHL, PBRM1, SETD2, BAP1, KDM5C, KIT, NFE2L2, MET, TP53, CDKN2A, FGFR3, PIK3CA, BRAF, MUC4. Criteria for calling mutations included adequate frequency by overall count and percentage of reads, identification in all overlapping sequences, and presence of buffy coat for comparison with <0.5% containing the mutation. RESULTS: Thirty preoperative test patients with RCC and 32 healthy controls were analyzed using the gene panel. Of the 32 patients analyzed in the healthy control cohort, 27 (84%) failed to yield sequence of the genes of interest. Of the pre operative RCC patients, 20/30 (67%) had detectable somatic mutations, resulting in nonsynonymous, frameshift, stopgain, or splice site mutations, compared to 1/32 (3.1%) controls. Mutations were detected in both early and advanced stage disease, including a patient with a 1.1 x 0.7 x 0.5 cm tumor. Mutations were seen in all genes assayed. CONCLUSIONS: These data demonstrate feasibility of genespecific whole exome sequencing of ctDNA for diagnosis of RCC in patients with solid renal tumors. The majority of RCC patients of various stages and histology had ctDNA detected in a single preoperative blood sample. A single control gave a positive test. Non invasive detection of RCC shows promise for not only initial diagnosis but also disease monitoring and guidance of targeted therapies throughout a wide spectrum of disease severity, including small lesions.

Indikationsstellung und Strategien bei BPH: transurethral vs. retropubisch/suprapubisch

Die Indikation zur Operation und die Entscheidung uber den Zugangsweg bei benigner Prostatahyperplasie (BPH) sind multifaktoriell. Grundsatzlich besteht eine Indikation zur operativen Sanierung einer BPH in den Stadien II und III bei ausgepragter Restharnbildung, rezidivierenden Harnwegsinfektionen, Blasensteinbildung und Harnstauungsnieren. Aber auch im Stadium I mit unter Medikation fortbestehenden obstruktiven und/oder irritativen Beschwerden kann eine operative Therapie angezeigt sein. In erster Linie bestimmt die Grose der Prostata die Art des Vorgehens. Bei einem Drusenvolumen bis 80 g ist die transurethrale Elektroresektion Methode der Wahl, jenseits der 80 g die offene Enukleation. Die Enukleation mittels HoLEp oder Thulium-Laser bieten eine inzwischen gut etablierte Alternative, die unabhangig vom Volumen der Druse eingesetzt werden kann. Begleitpathologien wie Blasendivertikel und Blasensteine konnen das Vorgehen verandern und sogar ein zweizeitiges Vorgehen notwendig erscheinen lassen. Letztlich ist die Entscheidung uber das Vorgehen in diesen Fallen aber stets eine Einzelfallentscheidung.

Robotisch assistierte laparoskopische partielle Nephrektomie

BACKGROUND In recent years, small renal masses (SRM) have been increasingly detected as an incidental finding of radiological or ultrasound studies for other indications. Organ-sparing renal tumor resection as open partial nephrectomy (OPN) is the international standard for renal tumors <7 cm. RESULTS Due to technical developments, minimally invasive procedures have emerged as an alternative to OPN. In experienced hands, conventional laparoscopic partial nephrectomy (LPN) has achieved good functional and oncological results comparable to OPN. Robot-assisted laparoscopic partial nephrectomy (RAPN) has been performed since 2004. Compared to LPN, RAPN provides a faster learning curve, better visualization and more versatile instrumentation due to the degrees of freedom of the articulated instruments. After about 30 procedures, a level of experience is reached, which is characterized by good functional results, less blood loss, and shorter warm ischemia time of the kidney as compared to LPN. This can relate to a shorter hospital stay and faster recovery. Complications according to the Clavien classification are mostly grade I and II and are mainly treated conservatively. CONCLUSION Oncological long-term results are not available yet; so that RAPN cannot be considered as an equivalent treatment to LPN and OPN. Until long-term evidence is available, decisions regarding the surgical technique for organ-sparing renal tumor resection will be determined by patients wishes and surgeons preference.

Robotisch assistierte laparoskopische partielle Nephrektomie@@@Robot-assisted laparoscopic partial nephrectomy: Funktionelle und onkologische Ergebnisse@@@Functional and oncological outcomes

BACKGROUND In recent years, small renal masses (SRM) have been increasingly detected as an incidental finding of radiological or ultrasound studies for other indications. Organ-sparing renal tumor resection as open partial nephrectomy (OPN) is the international standard for renal tumors <7 cm. RESULTS Due to technical developments, minimally invasive procedures have emerged as an alternative to OPN. In experienced hands, conventional laparoscopic partial nephrectomy (LPN) has achieved good functional and oncological results comparable to OPN. Robot-assisted laparoscopic partial nephrectomy (RAPN) has been performed since 2004. Compared to LPN, RAPN provides a faster learning curve, better visualization and more versatile instrumentation due to the degrees of freedom of the articulated instruments. After about 30 procedures, a level of experience is reached, which is characterized by good functional results, less blood loss, and shorter warm ischemia time of the kidney as compared to LPN. This can relate to a shorter hospital stay and faster recovery. Complications according to the Clavien classification are mostly grade I and II and are mainly treated conservatively. CONCLUSION Oncological long-term results are not available yet; so that RAPN cannot be considered as an equivalent treatment to LPN and OPN. Until long-term evidence is available, decisions regarding the surgical technique for organ-sparing renal tumor resection will be determined by patients wishes and surgeons preference.

[Robot-assisted laparoscopic partial nephrectomy: functional and oncological outcomes].

BACKGROUND In recent years, small renal masses (SRM) have been increasingly detected as an incidental finding of radiological or ultrasound studies for other indications. Organ-sparing renal tumor resection as open partial nephrectomy (OPN) is the international standard for renal tumors <7 cm. RESULTS Due to technical developments, minimally invasive procedures have emerged as an alternative to OPN. In experienced hands, conventional laparoscopic partial nephrectomy (LPN) has achieved good functional and oncological results comparable to OPN. Robot-assisted laparoscopic partial nephrectomy (RAPN) has been performed since 2004. Compared to LPN, RAPN provides a faster learning curve, better visualization and more versatile instrumentation due to the degrees of freedom of the articulated instruments. After about 30 procedures, a level of experience is reached, which is characterized by good functional results, less blood loss, and shorter warm ischemia time of the kidney as compared to LPN. This can relate to a shorter hospital stay and faster recovery. Complications according to the Clavien classification are mostly grade I and II and are mainly treated conservatively. CONCLUSION Oncological long-term results are not available yet; so that RAPN cannot be considered as an equivalent treatment to LPN and OPN. Until long-term evidence is available, decisions regarding the surgical technique for organ-sparing renal tumor resection will be determined by patients wishes and surgeons preference.