Safety and early effectiveness of robot-assisted partial nephrectomy for large angiomyolipomas.

OBJECTIVE: To evaluate a multicentre series of robot-assisted partial nephrectomy (RAPN) performed for the treatment of large angiomyolipomas (AMLs). PATIENTS AND METHODS: Between 2005 and 2016, 40 patients with large or symptomatic AMLs underwent RAPN at five academic centres in the USA. Patient demographics, AML characteristics, operative and postoperative clinical outcomes were recorded and analysed. Surgical outcomes were compared between patients who underwent selective arterial embolisation (SAE) before RAPN and patients who did not undergo pre-RAPN SAE. RESULTS: The median (interquartile range [IQR]) tumour diameter was 7.2 (5-8.5) cm, and the median (IQR) nephrometry score was 9 (7-10). Six patients (15%) had a history of tuberous sclerosis and 11 (28%) had previously undergone SAE. The median (IQR) operative time and warm ischaemia time was 207 (180-231) and 22.5 (16-28) min, respectively. A non-clamping technique was used in eight (20%) patients. The median (IQR) estimated blood loss was 200 (100-245) mL, and four patients (10%) received blood transfusion postoperatively. One intraoperative complication occurred (2.5%), and seven postoperative complications occurred in six patients (15%). During a median (IQR) follow-up of 8 (1-15) months, none of the patients developed AML-related symptoms. The median estimated glomerular filtration rate preservation rate was 95%. There were no differences in operative or perioperative outcomes between patients who underwent SAE before RAPN and those who did not. CONCLUSIONS: Robot-assisted partial nephrectomy appears to be a safe primary or secondary (post-SAE) treatment for large AMLs, with a favourable perioperative morbidity profile and excellent functional preservation. Longer follow-up is required to fully evaluate therapeutic efficacy.

Racial Disparities in Histology and Short-Term Renal Functional Outcomes Following Robotic Nephron-Sparing Surgery.

PURPOSE: To identify variations in renal function and histology between Caucasian Americans (CA) and African Americans (AA) undergoing robotic nephron-sparing surgery (NSS). METHODS: A retrospective chart review was performed on patients who underwent NSS. Multivariate analysis identified factors affecting postoperative estimated glomerular filtration rate (eGFR). Histology was re-reviewed by pathology to confirm papillary type. RESULTS: A total of 331 patients underwent NSS: CA (n = 212), AA (n = 105), Hispanic (n = 10), and other (n = 4). AA average age (60.1 years) was lower than CA (62.3 years) (P < .001), with a higher proportion of AA women (46%) than CA (37%) (P = .021). AA had a higher incidence of diabetes (58.2%) and hypertension (93.9%). Preoperative average eGFR was similar: 70.35 mL/min for AA versus 69.06 mL/min for CA. Average postoperative eGFR was 50.59 mL/min for AA and 57.85 mL/min for CA. Postoperative creatinine increased more in AA (0.44 mg/dL) versus CA (0.33 mg/dL) (P < .001) even when stratified by pathological stage. Clear cell renal cell carcinoma (RCC) was the most common histology with AA (45%) and CA (60%). A greater than 2-fold higher incidence of papillary RCC was observed in AA (31%) versus CA (13%). AA exhibited a greater proportion of high-grade or type 2 papillary RCC (40% and 30%) versus CA (25% and 13%). CONCLUSIONS: AA patients were treated at a younger age, with a larger proportion of women. Postoperatively, AA experienced a greater increase in serum creatinine. Final histology demonstrated greater papillary RCC incidence in AA and increased likelihood for type 2 papillary RCC, a more aggressive histology.

Technology Based Treatment for UreteroPelvic Junction Obstruction.

Surgical management of ureteropelvic junction obstruction (UPJO) has historically been performed with open pyeloplasty. With the advent of endourology, laparoscopy, and robotics, minimally-invasive techniques have been described and accepted as alternatives to open surgery. Each of these approaches has its own advantages and disadvantages, equipment needs, degree of invasiveness, and experience of the treating urologist. Advocates and critics have their own say as to their preferred technique. In this article, we review the chronological evolution of these techniques and discuss their current role in the management of UPJO.

Nanotechnology combined therapy: tyrosine kinase-bound gold nanorod and laser thermal ablation produce a synergistic higher treatment response of renal cell carcinoma in a murine model.

OBJECTIVE: To investigate tyrosine kinase inhibitors (TKI) and gold nanorods (AuNRs) paired with photothermal ablation in a human metastatic clear cell renal cell carcinoma (RCC) mouse model. Nanoparticles have been successful as a platform for targeted drug delivery in the treatment of urological cancers. Likewise, the use of nanoparticles in photothermal tumour ablation, although early in its development, has provided promising results. Our previous in vitro studies of nanoparticles loaded with both TKI and AuNRs and activated with photothermal ablation have shown significant synergistic cell kill greater than each individual arm alone. This study is a translation of our initial findings to an in vivo model. MATERIALS AND METHODS: Immunologically naïve nude mice (athymic nude-Foxn1nu ) were injected subcutaneously bilaterally in both flanks (n = 36) with 2.5 × 106 cells of a human metastatic renal cell carcinoma cell line (RCC 786-O). Subcutaneous xenograft tumours developed into 1-cm palpable nodules. AuNRs encapsulated in human serum albumin protein (HSA) nanoparticles were synthesised with or without a TKI and injected directly into the tumour nodule. Irradiation was administered with an 808-nm light-emitting diode laser for 6 min. Mice were humanely killed 14 days after irradiation; tumours were excised, formalin fixed, paraffin embedded, and evaluated for size and the percentage of necrosis by a genitourinary pathologist. The untreated contralateral flank tumours were used as controls. RESULTS: In mice that did not receive irradiation, TKI alone yielded 4.2% tumour necrosis on the injected side and administration of HSA-AuNR-TKI alone yielded 11.1% necrosis. In the laser-ablation models, laser ablation alone yielded 62% necrosis and when paired with HSA-AuNR there was 63.4% necrosis. The combination of laser irradiation and HSA-AuNR-TKI had cell kill rate of 100%. CONCLUSIONS: In the absence of laser irradiation, TKI treatment alone or when delivered via nanoparticles produced moderate necrosis. Irradiation with and without gold particles alone also improves tumour necrosis. However, when irradiation is paired with gold particles and drug-loaded nanoparticles, the combined therapy showed the most significant and synergistic complete tumour necrosis of 100% (P < 0.05). This study illustrates the potential of combination nanotechnology as a new approach in the treatment of urological cancers.

Nondestructive Diagnosis of Kidney Cancer on 18-gauge Core Needle Renal Biopsy Using Dual-color Fluorescence Structured Illumination Microscopy.

OBJECTIVE: To present a novel imaging technique used for rapid, nondestructive histological assessment of renal neoplasias using a dual-component fluorescence stain and structured illumination microscopy (SIM). MATERIALS AND METHODS: After Institutional Review Board approval, 65 total biopsies were obtained from 19 patients undergoing partial or radical nephrectomy. Biopsies were stained with a dual-component fluorescent, and optically sectioned SIM images were obtained from the surface of the intact biopsies. Specimens were subsequently fixed and analyzed using hematoxylin and eosin (H&E) histopathologic methods and compared with SIM images. A single, board-certified pathologist blinded to specimens reviewed all SIM images and H&E slides, and determined the presence or absence of neoplasias. Results of blinded diagnosis of SIM were validated against traditional pathology. RESULTS: Of the 19 patients, 15 underwent robotic partial nephrectomies and 4 underwent laparoscopic nephrectomies. Indications included clinical suspicion of renal cell carcinoma. In total, 65 biopsy specimens were available for review. Twenty-one specimens were determined to be neoplastic on H&E, whereas 41 represented benign renal tissue. The final sensitivity and specificity of our study were 79.2% and 95.1%, respectively. CONCLUSION: SIM is a promising technology for rapid, near-patient, ex vivo renal biopsy assessment. By improving the ability to rapidly assess sufficiency of biopsy specimens and enabling immediate diagnostic capability, SIM aids in more effective biopsy performance, tissue triage, and patient counseling regarding management options. Additionally, because tissue is preserved, effective utilization of downstream diagnostic tests and molecular assessments are possible.

Gigapixel surface imaging of radical prostatectomy specimens for comprehensive detection of cancer-positive surgical margins using structured illumination microscopy.

Achieving cancer-free surgical margins in oncologic surgery is critical to reduce the need for additional adjuvant treatments and minimize tumor recurrence; however, there is a delicate balance between completeness of tumor removal and preservation of adjacent tissues critical for normal post-operative function. We sought to establish the feasibility of video-rate structured illumination microscopy (VR-SIM) of the intact removed tumor surface as a practical and non-destructive alternative to intra-operative frozen section pathology, using prostate cancer as an initial target. We present the first images of the intact human prostate surface obtained with pathologically-relevant contrast and subcellular detail, obtained in 24 radical prostatectomy specimens immediately after excision. We demonstrate that it is feasible to routinely image the full prostate circumference, generating gigapixel panorama images of the surface that are readily interpreted by pathologists. VR-SIM confirmed detection of positive surgical margins in 3 out of 4 prostates with pathology-confirmed adenocarcinoma at the circumferential surgical margin, and furthermore detected extensive residual cancer at the circumferential margin in a case post-operatively classified by histopathology as having negative surgical margins. Our results suggest that the increased surface coverage of VR-SIM could also provide added value for detection and characterization of positive surgical margins over traditional histopathology.

Accelerometer Measurement of Head Movement During Laparoscopic Surgery as a Tool to Evaluate Skill Development of Surgeons.

OBJECTIVE: To detect and measure surgeons' head movement during laparoscopic simulator performance to determine whether expert surgeons have economy of motion in their head movement, including change of direction, compared with intermediate and novice surgeons. We investigated head movement as an objective tool for assessment of laparoscopic surgical skill and its potential use for assessing novice surgeons' progress on the learning curve. DESIGN: After obtaining institutional review board approval, medical students, urology residents, and attending staff surgeons from an academic institution were recruited. Participants were grouped by level of experience and performed tasks on the Electronic Data Generation for Evaluation laparoscopic simulator. Surgeons wore a commercially available wireless electroencephalogram monitor as a flexible, adjustable, and lightweight headband with 7 sensors-2 forehead sensors, 2 ear sensors, and 3 reference sensors. The headband incorporates a 3-axis accelerometer enabling head movement quantification. A variance analysis was used to compare the average head movement acceleration data between each group. SETTING: Tulane University Medical Center, New Orleans, LA, an academic medical center and the principal teaching hospital for Tulane University School of Medicine. PARTICIPANTS: A total of following 19 participants were recruited for the study and stratified by surgical experience into novice (n = 6), intermediate (n = 9), and expert (n = 4) laparoscopy groups: 6 medical students, 9 urology residents (postgraduate years 1 to5), and 4 attending urologists, respectively. RESULTS: Analysis of the average acceleration rate of head movement showed statistically significant differences among groups on both the vertical axis (p = 0.006) and horizontal axis (p = 0.018) in the laparoscopic suturing task. This demonstrated the ability to distinguish between experts and novice laparoscopic surgeons. The average acceleration among groups did not demonstrate statistical significance on the vertical axis (p = 0.078) and horizontal axis (p = 0.077) in the peg transfer task. This may be in response to the ease of the task. The analysis of the forward-backward axis or depth perception also showed no significant differences between groups. CONCLUSION: Accelerometer-based motion analysis of head movement appears to be a useful tool to evaluate laparoscopic skill development of surgeons in terms of their economy of motion, and it could potentially be used for ergonomic assessment of training in the future, and progression on the learning curve.

Techniques to resect the distal ureter in robotic/laparoscopic nephroureterectomy.

Treatment of clinically-organ confined high grade urothelial carcinoma of the upper tract has historically comprised open nephroureterectomy, with the distal ureter and bladder cuff mobilized through a separate open pelvic incision. To decrease morbidity, urologists have increasingly adopted laparoscopy and robotics in performing nephroureterectomy. In many published series of laparoscopic nephroureterectomy, the distal ureter and bladder cuff are detached from the bladder endoscopically by a variation of the "pluck" technique, with the resulting bladder defect left to heal by prolonged indwelling urethral catheter drainage. While the distal ureter and bladder cuff can be excised laparoscopically, it does require advanced laparoscopic skills. With the wrist articulation and stereoscopic vision in robotic surgery, robotic nephroureterectomy (RNU) and bladder cuff excision can be performed in antegrade fashion to mimic the open technique together with the ability to intracorporeally close the bladder defect in a watertight, mucosa to mucosa fashion after excising the bladder cuff. In this review, we discuss the published minimally invasive techniques in resecting the distal ureter and bladder cuff during laparoscopic and RNU.

Integration of heterogeneous expression data sets extends the role of the retinol pathway in diabetes and insulin resistance.

MOTIVATION: Type 2 diabetes is a chronic metabolic disease that involves both environmental and genetic factors. To understand the genetics of type 2 diabetes and insulin resistance, the DIabetes Genome Anatomy Project (DGAP) was launched to profile gene expression in a variety of related animal models and human subjects. We asked whether these heterogeneous models can be integrated to provide consistent and robust biological insights into the biology of insulin resistance. RESULTS: We perform integrative analysis of the 16 DGAP data sets that span multiple tissues, conditions, array types, laboratories, species, genetic backgrounds and study designs. For each data set, we identify differentially expressed genes compared with control. Then, for the combined data, we rank genes according to the frequency with which they were found to be statistically significant across data sets. This analysis reveals RetSat as a widely shared component of mechanisms involved in insulin resistance and sensitivity and adds to the growing importance of the retinol pathway in diabetes, adipogenesis and insulin resistance. Top candidates obtained from our analysis have been confirmed in recent laboratory studies.

Differential H3K4 methylation identifies developmentally poised hematopoietic genes.

Throughout development, cell fate decisions are converted into epigenetic information that determines cellular identity. Covalent histone modifications are heritable epigenetic marks and are hypothesized to play a central role in this process. In this report, we assess the concordance of histone H3 lysine 4 dimethylation (H3K4me2) and trimethylation (H3K4me3) on a genome-wide scale in erythroid development by analyzing pluripotent, multipotent, and unipotent cell types. Although H3K4me2 and H3K4me3 are concordant at most genes, multipotential hematopoietic cells have a subset of genes that are differentially methylated (H3K4me2+/me3-). These genes are transcriptionally silent, highly enriched in lineage-specific hematopoietic genes, and uniquely susceptible to differentiation-induced H3K4 demethylation. Self-renewing embryonic stem cells, which restrict H3K4 methylation to genes that contain CpG islands (CGIs), lack H3K4me2+/me3- genes. These data reveal distinct epigenetic regulation of CGI and non-CGI genes during development and indicate an interactive relationship between DNA sequence and differential H3K4 methylation in lineage-specific differentiation.

CGHweb: a tool for comparing DNA copy number segmentations from multiple algorithms.

UNLABELLED: Accurate estimation of DNA copy numbers from array comparative genomic hybridization (CGH) data is important for characterizing the cancer genome. An important part of this process is the segmentation of the log-ratios between the sample and control DNA along the chromosome into regions of different copy numbers. However, multiple algorithms are available in the literature for this procedure and the results can vary substantially among these. Thus, a visualization tool that can display the segmented profiles from a number of methods can be helpful to the biologist or the clinician to ascertain that a feature of interest did not arise as an artifact of the algorithm. Such a tool also allows the methodologist to easily contrast his method against others. We developed a web-based tool that applies a number of popular algorithms to a single array CGH profile entered by the user. It generates a heatmap panel of the segmented profiles for each method as well as a consensus profile. The clickable heatmap can be moved along the chromosome and zoomed in or out. It also displays the time that each algorithm took and provides numerical values of the segmented profiles for download. The web interface calls algorithms written in the statistical language R. We encourage developers of new algorithms to submit their routines to be incorporated into the website. AVAILABILITY: http://compbio.med.harvard.edu/CGHweb.

Pathway analysis of primary central nervous system lymphoma.

Primary central nervous system (CNS) lymphoma (PCNSL) is a diffuse large B-cell lymphoma (DLBCL) confined to the CNS. A genome-wide gene expression comparison between PCNSL and non-CNS DLBCL was performed, the latter consisting of both nodal and extranodal DLBCL (nDLBCL and enDLBCL), to identify a "CNS signature." Pathway analysis with the program SigPathway revealed that PCNSL is characterized notably by significant differential expression of multiple extracellular matrix (ECM) and adhesion-related pathways. The most significantly up-regulated gene is the ECM-related osteopontin (SPP1). Expression at the protein level of ECM-related SPP1 and CHI3L1 in PCNSL cells was demonstrated by immunohistochemistry. The alterations in gene expression can be interpreted within several biologic contexts with implications for PCNSL, including CNS tropism (ECM and adhesion-related pathways, SPP1, DDR1), B-cell migration (CXCL13, SPP1), activated B-cell subtype (MUM1), lymphoproliferation (SPP1, TCL1A, CHI3L1), aggressive clinical behavior (SPP1, CHI3L1, MUM1), and aggressive metastatic cancer phenotype (SPP1, CHI3L1). The gene expression signature discovered in our study may represent a true "CNS signature" because we contrasted PCNSL with wide-spectrum non-CNS DLBCL on a genomic scale and performed an in-depth bioinformatic analysis.

Aging elevates metabolic gene expression in brain cholinergic neurons.

The basal forebrain (BF) cholinergic system is selectively vulnerable in human brain diseases, while the cholinergic groups in the upper pons of the brainstem (BS) resist neurodegeneration. Cholinergic neurons (200 per region per animal) were laser-microdissected from five young (8 months) and five aged (24 months) F344 rats from the BF and the BS pontine lateral dorsal tegmental/pedunculopontine nuclei (LDTN/PPN) and their expression profiles were obtained. The bioinformatics program SigPathway was used to identify gene groups and pathways that were selectively affected by aging. In the BF cholinergic system, aging most significantly altered genes involved with a variety of metabolic functions. In contrast, BS cholinergic neuronal age effects included gene groupings related to neuronal plasticity and a broad range of normal cellular functions. Transcription factor GA-binding protein alpha (GABPalpha), which controls expression of nuclear genes encoding mitochondrial proteins, was more strongly upregulated in the BF cholinergic neurons (+107%) than in the BS cholinergic population (+40%). The results suggest that aging elicits elevates metabolic activity in cholinergic populations and that this occurs to a much greater degree in the BF group than in the BS group.

Network-based analysis of affected biological processes in type 2 diabetes models.

Type 2 diabetes mellitus is a complex disorder associated with multiple genetic, epigenetic, developmental, and environmental factors. Animal models of type 2 diabetes differ based on diet, drug treatment, and gene knockouts, and yet all display the clinical hallmarks of hyperglycemia and insulin resistance in peripheral tissue. The recent advances in gene-expression microarray technologies present an unprecedented opportunity to study type 2 diabetes mellitus at a genome-wide scale and across different models. To date, a key challenge has been to identify the biological processes or signaling pathways that play significant roles in the disorder. Here, using a network-based analysis methodology, we identified two sets of genes, associated with insulin signaling and a network of nuclear receptors, which are recurrent in a statistically significant number of diabetes and insulin resistance models and transcriptionally altered across diverse tissue types. We additionally identified a network of protein-protein interactions between members from the two gene sets that may facilitate signaling between them. Taken together, the results illustrate the benefits of integrating high-throughput microarray studies, together with protein-protein interaction networks, in elucidating the underlying biological processes associated with a complex disorder.

A genome-wide screen reveals functional gene clusters in the cancer genome and identifies EphA2 as a mitogen in glioblastoma.

A novel genome-wide screen that combines patient outcome analysis with array comparative genomic hybridization and mRNA expression profiling was developed to identify genes with copy number alterations, aberrant mRNA expression, and relevance to survival in glioblastoma. The method led to the discovery of physical gene clusters within the cancer genome with boundaries defined by physical proximity, correlated mRNA expression patterns, and survival relatedness. These boundaries delineate a novel genomic interval called the functional common region (FCR). Many FCRs contained genes of high biological relevance to cancer and were used to pinpoint functionally significant DNA alterations that were too small or infrequent to be reliably identified using standard algorithms. One such FCR contained the EphA2 receptor tyrosine kinase. Validation experiments showed that EphA2 mRNA overexpression correlated inversely with patient survival in a panel of 21 glioblastomas, and ligand-mediated EphA2 receptor activation increased glioblastoma proliferation and tumor growth via a mitogen-activated protein kinase-dependent pathway. This novel genome-wide approach greatly expanded the list of target genes in glioblastoma and represents a powerful new strategy to identify the upstream determinants of tumor phenotype in a range of human cancers.

High-resolution ChIP-chip analysis reveals that the Drosophila MSL complex selectively identifies active genes on the male X chromosome.

X-chromosome dosage compensation in Drosophila requires the male-specific lethal (MSL) complex, which up-regulates gene expression from the single male X chromosome. Here, we define X-chromosome-specific MSL binding at high resolution in two male cell lines and in late-stage embryos. We find that the MSL complex is highly enriched over most expressed genes, with binding biased toward the 3' end of transcription units. The binding patterns are largely similar in the distinct cell types, with approximately 600 genes clearly bound in all three cases. Genes identified as clearly bound in one cell type and not in another indicate that attraction of MSL complex correlates with expression state. Thus, sequence alone is not sufficient to explain MSL targeting. We propose that the MSL complex recognizes most X-linked genes, but only in the context of chromatin factors or modifications indicative of active transcription. Distinguishing expressed genes from the bulk of the genome is likely to be an important function common to many chromatin organizing and modifying activities.

Comparative analysis of algorithms for identifying amplifications and deletions in array CGH data.

MOTIVATION: Array Comparative Genomic Hybridization (CGH) can reveal chromosomal aberrations in the genomic DNA. These amplifications and deletions at the DNA level are important in the pathogenesis of cancer and other diseases. While a large number of approaches have been proposed for analyzing the large array CGH datasets, the relative merits of these methods in practice are not clear. RESULTS: We compare 11 different algorithms for analyzing array CGH data. These include both segment detection methods and smoothing methods, based on diverse techniques such as mixture models, Hidden Markov Models, maximum likelihood, regression, wavelets and genetic algorithms. We compute the Receiver Operating Characteristic (ROC) curves using simulated data to quantify sensitivity and specificity for various levels of signal-to-noise ratio and different sizes of abnormalities. We also characterize their performance on chromosomal regions of interest in a real dataset obtained from patients with Glioblastoma Multiforme. While comparisons of this type are difficult due to possibly sub-optimal choice of parameters in the methods, they nevertheless reveal general characteristics that are helpful to the biological investigator.