Evaluation of Plasma Biomarkers for Causal Association With Peripheral Artery Disease.

BACKGROUND: Hundreds of biomarkers for peripheral artery disease (PAD) have been reported in the literature; however, the observational nature of these studies limits causal inference due to the potential of reverse causality and residual confounding. We sought to evaluate the potential causal impact of putative PAD biomarkers identified in human observational studies through genetic causal inference methods. METHODS: Putative circulating PAD biomarkers were identified from human observational studies through a comprehensive literature search based on terms related to PAD using PubMed, Cochrane, and Embase. Genetic instruments were generated from publicly available genome-wide association studies of circulating biomarkers. Two-sample Mendelian randomization was used to test the association of genetically determined biomarker levels with PAD using summary statistics from a genome-wide association study of 31 307 individuals with and 211 753 individuals without PAD in the Veterans Affairs Million Veteran Program and replicated in data from FinnGen comprised of 11 924 individuals with and 288 638 individuals without PAD. RESULTS: We identified 204 unique circulating biomarkers for PAD from the observational literature, of which 173 were genetically instrumented using genome-wide association study results. After accounting for multiple testing (false discovery rate, <0.05), 10 of 173 (5.8%) biomarkers had significant associations with PAD. These 10 biomarkers represented categories including plasma lipoprotein regulation, lipid homeostasis, and protein-lipid complex remodeling. Observational literature highlighted different pathways including inflammatory response, negative regulation of multicellular organismal processes, and regulation of response to external stimuli. CONCLUSIONS: Integrating human observational studies and genetic causal inference highlights several key pathways in PAD pathophysiology. This work demonstrates that a substantial portion of biomarkers identified in observational studies are not well supported by human genetic evidence and emphasizes the importance of triangulating evidence to understand PAD pathophysiology. Although the identified biomarkers offer insights into atherosclerotic development in the lower limb, their specificity to PAD compared with more widespread atherosclerosis requires further study.

Activity-Induced Cortical Glutamatergic Neuron Nascent Proteins.

Neuronal activity initiates signaling cascades that culminate in diverse outcomes including structural and functional neuronal plasticity, and metabolic changes. While studies have revealed activity-dependent neuronal cell type-specific transcriptional changes, unbiased quantitative analysis of cell-specific activity-induced dynamics in newly synthesized proteins (NSPs) synthesis in vivo has been complicated by cellular heterogeneity and a relatively low abundance of NSPs within the proteome in the brain. Here we combined targeted expression of mutant MetRS (methionine tRNA synthetase) in genetically defined cortical glutamatergic neurons with tight temporal control of treatment with the noncanonical amino acid, azidonorleucine, to biotinylate NSPs within a short period after pharmacologically induced seizure in male and female mice. By purifying peptides tagged with heavy or light biotin-alkynes and using direct tandem mass spectrometry detection of biotinylated peptides, we quantified activity-induced changes in cortical glutamatergic neuron NSPs. Seizure triggered significant changes in ∼300 NSPs, 33% of which were decreased by seizure. Proteins mediating excitatory and inhibitory synaptic plasticity, including SynGAP1, Pak3, GEPH1, Copine-6, and collybistin, and DNA and chromatin remodeling proteins, including Rad21, Smarca2, and Ddb1, are differentially synthesized in response to activity. Proteins likely to play homeostatic roles in response to activity, such as regulators of proteastasis, intracellular ion control, and cytoskeleton remodeling proteins, are activity induced. Conversely, seizure decreased newly synthetized NCAM, among others, suggesting that seizure induced degradation. Overall, we identified quantitative changes in the activity-induced nascent proteome from genetically defined cortical glutamatergic neurons as a strategy to discover downstream mediators of neuronal plasticity and generate hypotheses regarding their function.SIGNIFICANCE STATEMENT Activity-induced neuronal and synaptic plasticity are mediated by changes in the protein landscape, including changes in the activity-induced newly synthesized proteins; however, identifying neuronal cell type-specific nascent proteome dynamics in the intact brain has been technically challenging. We conducted an unbiased proteomic screen from which we identified significant activity-induced changes in ∼300 newly synthesized proteins in genetically defined cortical glutamatergic neurons within 20 h after pharmacologically induced seizure. Bioinformatic analysis of the dynamic nascent proteome indicates that the newly synthesized proteins play diverse roles in excitatory and inhibitory synaptic plasticity, chromatin remodeling, homeostatic mechanisms, and proteasomal and metabolic functions, extending our understanding of the diversity of plasticity mechanisms.

Nanoscale organization of hedgehog is essential for long-range signaling.

Hedgehog (Hh) plays crucial roles in tissue-patterning and activates signaling in Patched (Ptc)-expressing cells. Paracrine signaling requires release and transport over many cell diameters away by a process that requires interaction with heparan sulfate proteoglycans (HSPGs). Here, we examine the organization of functional, fluorescently tagged variants in living cells by using optical imaging, FRET microscopy, and mutational studies guided by bioinformatics prediction. We find that cell-surface Hh forms suboptical oligomers, further concentrated in visible clusters colocalized with HSPGs. Mutation of a conserved Lys in a predicted Hh-protomer interaction interface results in an autocrine signaling-competent Hh isoform--incapable of forming dense nanoscale oligomers, interacting with HSPGs, or paracrine signaling. Thus, Hh exhibits a hierarchical organization from the nanoscale to visible clusters with distinct functions.

Exosomes regulate neurogenesis and circuit assembly.

Exosomes are thought to be released by all cells in the body and to be involved in intercellular communication. We tested whether neural exosomes can regulate the development of neural circuits. We show that exosome treatment increases proliferation in developing neural cultures and in vivo in dentate gyrus of P4 mouse brain. We compared the protein cargo and signaling bioactivity of exosomes released by hiPSC-derived neural cultures lacking MECP2, a model of the neurodevelopmental disorder Rett syndrome, with exosomes released by isogenic rescue control neural cultures. Quantitative proteomic analysis indicates that control exosomes contain multiple functional signaling networks known to be important for neuronal circuit development. Treating MECP2-knockdown human primary neural cultures with control exosomes rescues deficits in neuronal proliferation, differentiation, synaptogenesis, and synchronized firing, whereas exosomes from MECP2-deficient hiPSC neural cultures lack this capability. These data indicate that exosomes carry signaling information required to regulate neural circuit development.

Moderate or severe LUTS is associated with increased recurrence of non - muscle - invasive urothelial carcinoma of the bladder.

PURPOSE: Non - muscle - invasive bladder cancer (NMIBC) can recur despite transurethral resection (TURBT) and adjuvant intravesical therapy. Tobacco products excreted in the urine are hypothesized to cause tumor - promoting effects on urothelial cells through direct contact. We determined if moderate or severe lower urinary tract symptoms (LUTS) (defined as International Prostate Symptom Score [IPSS] ≥ 8) was associated with increased tumor recurrence. MATERIALS AND METHODS: We retrospectively identified 70 consecutive men initially diagnosed with NMIBC at our institution from 2010 - 2016. Means were compared with independent T - test and proportions with chi - square analysis. Multivariate logistic regression was performed to determine independent predictors of recurrence. RESULTS: The majority of patients had Ta disease (58.6%) followed by T1 (28.6%) and Tis (12.9%). Forty - one (58.6%) patients had moderate or severe LUTS upon presentation within 30 days of initial TURBT with mean IPSS of 13.2 vs. 5.2 in the control group (p < 0.01). Biopsy - proven tumor recurrence occurred in 24 (34.3%) patients at mean follow-up of 31.7 months. Mean time to recurrence was 14.6 months. Moderate or severe LUTS was an independent predictor of tumor recurrence (odds ratio [OR]: 19.1, 95% confidence interval [CI]: 2.86 - 127; p = 0.002). Voiding or storage symptoms based on the IPSS did not independently correlate with tumor recurrence (p = 0.08 and p = 0.31, respectively) although total mean IPSS score did (OR: 1.26, 95% CI: 1.07 - 1.47, p = 0.005). CONCLUSIONS: The presence of moderate or severe LUTS may be an important prognostic factor in NMIBC. Patients with significant urinary symptoms could be monitored more aggressively due to higher recurrence risk.

Traumatic vertebral artery injury: a review of the screening criteria, imaging spectrum, mimics, and pitfalls.

PURPOSE: Traumatic vertebral artery injury (TVAI) can have a varied clinical presentation and appearance on imaging. In this review, we present the screening criteria, spectrum of imaging features, grading, and imaging pitfalls of TVAI. Our review focuses on the imaging of TVAI on computed tomography angiography (CTA), magnetic resonance angiography (MRA), and cases of TVAI mimics. IMAGING: The imaging spectrum on CTA can range from either focal or long segment luminal stenosis (the most common findings), smooth or tapered narrowing of lumen, string of pearls appearance, concentric intramural haematoma, intimal flap (the most definite sign), and double lumen of the artery. On time-of-flight MRA, the most common findings include loss of flow void within the vessel due to slow flow, thrombosis or occlusion, and hyperintense signal within the vessel wall due to intramural haematoma on T1 fat-saturated images. CONCLUSION: The reader should be aware of the screening criteria, common and uncommon findings, variant anatomy, artifacts, and mimics of TVAI when evaluating cases of craniocervical trauma, to be competent in calling in or ruling out injury.

Emerging, newly-approved treatments for lower urinary tract symptoms secondary to benign prostatic hypertrophy.

INTRODUCTION: Oral therapy with alpha-blockers or 5-alpha reductase inhibitors remains the most common treatment in men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hypertrophy (BPH). For patients who progress or fail medical therapy, the standard of care surgical treatment continues to be transurethral resection of the prostate (TURP), which has long-studied and durable outcomes. Emerging, minimally invasive options for LUTS secondary to the BPH, however, have been developed over the last decade with promising results and minimal side effects typically associated with TURP, such as retrograde ejaculation and erectile dysfunction. MATERIALS AND METHODS: We performed a literature review on PubMed over the last 10 years using keywords such as 'lower urinary tract symptoms,' 'benign prostatic hypertrophy,' 'minimally invasive,' and 'outpatient.' All relevant studies that reported on important urinary endpoints were included for each newly-approved treatment option. Available literature across varying prostate volumes was presented. RESULTS: Newly-approved therapies for BPH include new thermal energy sources (Rezum, aquablation), mechanical stenting (UroLift), prostate artery embolization, and injectable agents. These emerging techniques could be considered in patients where preservation of sexual function is a priority since they have demonstrated comparable urinary outcomes to medical therapy while causing no significant sexual dysfunction. Only prostate artery embolization has been extensively analyzed and proven efficacious in patients with > 80 g prostates who cannot undergo surgery. CONCLUSION: We have summarized the newly-approved treatment options for men with LUTS secondary to BPH as an alternative to traditional medical or surgical therapy. As more minimally invasive, office-based technologies emerge, physician and patients will have the ability to choose a treatment that is more catered to patient expectations.

Surgical control and margin status after robotic and open cystectomy in high-risk cases: Caution or equivalence?

PURPOSE: The benefits of robotic-assisted radical cystectomy (RARC) are unclear, especially in patients with high-risk disease (pT3/T4). We evaluated pathological and postoperative outcomes of RARC versus open radical cystectomy (ORC) in these patients. METHODS: We identified bladder cancer patients treated with RARC or ORC from January 2010-August 2014. Clinicodemographic factors were examined for potential confounding. Our primary outcome of interest was positive soft-tissue surgical margins (STSMs). Secondary outcomes included post-operative complications and length of stay (LOS). We used logistic regression to define the association between clinical factors with outcomes of interest, focusing on patients with locally advanced disease. RESULTS: We identified 472 patients treated with ORC (407, 86.2 %) or RARC (65, 13.8 %) of which 215 (45.6 %) were high-risk cases based on advanced pathologic stage (pT3/4). RARC patients were more commonly men (96.9 vs. 73.2 %, p < 0.01), had better performance status (ECOG 0, 78.5 vs. 59.7 %, p = 0.031), and received less neoadjuvant chemotherapy (21.5 vs. 39.3 %, p = 0.006). Total (52.3 vs. 59.7 %, p = 0.26) and high-grade complication rates (13.8 vs. 19.7 %, p = 0.27) were similar, but median LOS was shorter after RARC (6 vs. 7 days, p < 0.01). On multivariate analysis, prior pelvic radiation (OR: 4.78, 95 % CI: 2.16-10.57), and advanced tumor stage (OR: 3.06, 95 % CI: 1.56-6.03) were independently associated with positive STSMs in high-risk patients but robotic surgical approach was not (OR: 0.81, 95 % CI: 0.29-2.30; p = 0.69). CONCLUSION: RARC had similar short-term postoperative outcomes compared to ORC and did not compromise oncological control in patients with extravesical disease.

Bilateral benign renal oncocytomas and the role of renal biopsy: single institution review.

BACKGROUND: The goal was to assess the natural history and management of patients with pathologically proven bilateral (synchronous) RO after undergoing initial partial nephrectomy (PN). METHODS: All patients underwent either robotic/laparoscopic or open PN by two experienced genitourinary oncologists from 2005-2013. Final pathology was determined by surgical excision, CT-guided percutaneous core biopsy (CT-biopsy) or fine needle aspiration (FNA). Patient demographics, tumor characteristics (pathologic data, location, size) type of surgery, pre/post estimated glomerular filtration rate (eGFR) and surgical complications were recorded. RESULTS: Twelve patients were identified with bilateral RO. Median age at the time of surgery was 68 years (46-77) (Table 1). The median size of the largest tumor(s) resected was 2.75 cm (1.5-5.5 cm) and second largest tumor(s) was 1.75 cm (1.0-4.0 cm). Four patients underwent bilateral staged PN and one patient underwent simultaneous bilateral PN (horseshoe kidney). Two patients underwent RFA at the time of biopsy of the contralateral mass after PN. Five patients underwent CT-bx/FNA (5/5) of the contralateral mass followed by active surveillance. Mean follow up was 34 months. There was no significant change in median creatinine pre- and post-operatively. One patient was lost to follow up and one patient died of unknown causes 5 years post-operatively. eGFR decreased an average of 16.96% post-operatively, including a single patient whose eGFR increased by 7.8% after surgery and a single patient whose eGFR did not change (Table 2). CONCLUSIONS: Patients with bilateral renal masses and pathologically proven RO can be safely managed with active surveillance after biopsy confirmation of the contralateral mass.

Incorporation of Nitrogen Defects for Efficient Reduction of CO2 via Two-Electron Pathway on Three-Dimensional Graphene Foam.

The practical recycling of carbon dioxide (CO2) by the electrochemical reduction route requires an active, stable, and affordable catalyst system. Although noble metals such as gold and silver have been demonstrated to reduce CO2 into carbon monoxide (CO) efficiently, they suffer from poor durability and scarcity. Here we report three-dimensional (3D) graphene foam incorporated with nitrogen defects as a metal-free catalyst for CO2 reduction. The nitrogen-doped 3D graphene foam requires negligible onset overpotential (-0.19 V) for CO formation, and it exhibits superior activity over Au and Ag, achieving similar maximum Faradaic efficiency for CO production (∼85%) at a lower overpotential (-0.47 V) and better stability for at least 5 h. The dependence of catalytic activity on N-defect structures is unraveled by systematic experimental investigations. Indeed, the density functional theory calculations confirm pyridinic N as the most active site for CO2 reduction, consistent with experimental results.

Caudal Regression Syndrome: A Case Series of a Rare Congenital Anomaly.

BACKGROUND: Caudal regression syndrome is a rare, neural tube defect characterized by an abnormal development of the caudal aspect of the vertebral column and the spinal cord., It results in neurological deficits ranging from bladder and bowel involvement to severe sensory and motor deficits in the lower limbs. Maternal diabetes, genetic factors and some teratogens have been shown to be associated with its pathogenesis. Caudal regression syndrome is usually diagnosed initially by antenatal ultrasound with more definitive diagnosis made by antenatal or postnatal MRI. In this case series, we report four cases of caudal regression syndrome in different age groups including prenatal, infant and adult. CASE REPORT: We are presenting multimodal imaging findings of 4 cases of caudal regression syndrome in 4 different age groups including fetus, infant, early childhood and adult. The pathogenesis, associated risk factors, complications, treatment options and prognosis of caudal regression syndrome are discussed as well. CONCLUSIONS: Caudal regression syndrome is a rare entity, characterized by sacrococcygeal dysgenesis with an abrupt termination of a blunt-ending spinal cord. Ultrasound and fetal MRI can be used to make a prenatal diagnosis, while MRI is the imaging modality of choice in adults. Early detection and prompt treatment is very important to decrease the risk of complications, and thus, to improve the prognosis.

Preoperative Patient Reported Mental Health is Associated with High Grade Complications after Radical Cystectomy.

PURPOSE: Psychological distress has been associated with an impaired immune response and poor wound healing. We hypothesized that preoperative patient reported mental health would be associated with high grade 30-day complications after radical cystectomy. MATERIALS AND METHODS: We retrospectively identified patients who underwent radical cystectomy for bladder cancer who completed Short Form 12 (SF-12) surveys for self-assessment of health status less than 6 months before surgery. Median physical and mental composite scores were calculated. An expert model including known predictors of postoperative high grade complications was developed, and SF-12 physical composite score and mental composite score were added to determine their association with this end point. RESULTS: From January 2010 to August 2014, 472 patients underwent radical cystectomy for bladder cancer, of whom 274 (58.1%) completed preoperative SF-12 questionnaires. Responders were more likely to be white (p=0.024), have higher preoperative albumin (p=0.037), receive neoadjuvant chemotherapy (p=0.002), have pT3/T4 disease (p=0.044) and have positive soft tissue surgical margins (p=0.006). Median SF-12 physical composite score was 43.1 (IQR 33.0-51.5) and mental composite score was 48.5 (IQR 39.5-54.7) in responders. Overall 46 (16.8%) responders experienced a high grade 30-day complication. Patients with a high grade complication had a lower preoperative median SF-12 mental composite score (44.8 vs 49.8, p=0.004) but no difference in physical composite score (39.2 vs 43.8, p=0.06). SF-12 mental composite score was also a significant predictive variable when added to our expert model (p=0.01). CONCLUSIONS: Preoperative patient reported mental health was independently associated with high grade complications after radical cystectomy. Therefore, patient self-assessment of health status before surgery through validated questionnaires may provide additional information useful in predicting short-term postoperative outcomes.

Extent of pelvic lymph node dissection in penile cancer may impact survival.

INTRODUCTION: Current guidelines on management of penile carcinoma (PC) recommend ipsilateral pelvic lymph node dissection (PLND) in patients with inguinal lymph node metastasis (LNM) who meet specific criteria. The aim of this article was to assess outcomes in patients treated with bilateral PLND in the presence of unilateral metastatic pelvic nodes. METHODS: After IRB approval, four international centers contributed to this study. Men with PC and unilateral inguinal LNM and pelvic node metastases were retrospectively analyzed. Estimates of overall survival (OS) and cancer-specific survival were provided by the Kaplan-Meier method. Comparisons between subgroups were made using the log-rank test, and Cox regression analysis was used to adjust comparisons for covariates of interest. RESULTS: From 1978 to 2012, fifty-one men with unilateral inguinal LNM and positive pelvic nodes on PLND were identified. Thirty-eight (75 %) had ipsilateral and 13 (25 %) had bilateral PLND. Except the extent of the PLND, patients were comparable with respect to disease and therapeutic interventions. The Kaplan-Meier estimated median OS was significantly longer in the bilateral PLND patients (21.7 vs. 13.1, p = 0.051). On Cox regression analysis, bilateral PLND [HR 0.25, (95 % CI 0.10-0.64)], multiple pelvic node involvement [HR 2.12 (95 % CI 1.02-4.43)], neoadjuvant chemotherapy [HR 0.01, (95 % CI 0.02-0.44)] and adjuvant therapies [HR 0.16, (95 % CI 0.06-0.45)] (compared to no additional therapy) were independent predictors of OS. CONCLUSIONS: Men with PC and pelvic node metastases may benefit from a bilateral PLND. This hypothesis requires further confirmation.