Citations

Single-cell diversity in the brain The cells that make up an organism may all start from one genome, but somatic mutations mean that somewhere along the line of development, an organism's individual cellular genomes diverge. McConnell et al. review the implications and causes of single-cell genomic diversity for brain function. Somatic mutations caused by mobile genetic elements or errors in DNA repair may underlie certain neuropsychiatric disorders. Science , this issue p. eaal1641

Purpose To use a national database to determine (1) the incidence of joint infection after elbow arthroscopy, (2) identify independent patient‐related risk factors for infection, and (3) determine the influence of concomitant intra‐articular corticosteroid injection on infection risk. Methods The 100% Medicare Standard Analytic Files were queried to identify patients who underwent elbow arthroscopy from 2005 to 2012. Postoperative elbow infections occurring within 6 months of surgery were identified using both International Classification of Diseases, 9th Revision codes for postoperative infection and Current Procedural Terminology codes for the surgical treatment of a postoperative infection. Patients were excluded if their initial arthroscopic procedure was performed for infection. A multivariate binomial logistic regression analysis was then used to evaluate patient‐related risk factors for postoperative infection. Results Of the 2,704 elbow arthroscopy cases identified, 42 (1.55%) developed a postoperative infection. The annual incidence of infections did not increase significantly over the course of the study ( P = .374). A number of patient demographics and medical comorbidities significantly increased the risk of infection. The most notable factors included age ≥ 65 years (odds ratio [OR] 2.38, P = .006), body mass index > 40 (OR 1.97, P = .024), tobacco usage (OR 1.80, P = .046), alcohol usage (OR 4.01, P < .001), diabetes mellitus (OR 2.10, P = .015), inflammatory arthritis (OR 2.81, P < .001), hypercoagulable disorder (OR 2.51, P = .015), and intra‐articular corticosteroid injection at the time of arthroscopy (OR 2.79, P = .006). Conclusions The annual number of elbow arthroscopies performed in the United States has increased steadily; however, the postoperative infection rate remained consistently low at 1.55%. There are a number of patient‐specific risk factors that increase this risk with OR ranging from 1.97 to 4.01. Similarly, patients who receive an intra‐articular corticosteroid injection at the time of surgery are nearly 3 times (OR 2.79) more likely to develop a postoperative infection. Level of Evidence Level III, case‐control study.

3 Background: There is a clear need to develop a clinically relevant molecular subtyping approach for prostate cancer. We hypothesized that prostate cancer can be subtyped based on luminal versus basal lineage. Methods: We applied the PAM50 classifier, which is used clinically to identify luminal and basal cancers in breast cancer, to subtype a total of 3,782 prostate cancer samples using a high-density microarray platform run in a CLIA-certified laboratory. We examined the associations of these subtypes and clinical outcomes. Results: We demonstrate that PAM50 segregates prostate cancer into three reproducible subtypes in both retrospective cohorts and on prospective validation: luminal A (33.3%-34.3%), luminal B (28.5%-32.6%), and basal (34.1%-37.1%). Luminal B prostate cancers exhibited the worst clinical prognoses, followed by basal and luminal A subtypes (10-year biochemical recurrence-free survival: 29/39/41%; distant metastasis-free survival: 53/73/73%; prostate cancer-specific survival: 78/86/89%; overall survival: 69/80/82% respectively) on both univariable and multivariable analyses accounting for standard clinicopathologic prognostic factors. Known luminal lineage markers, such as NKX3.1 and KRT18, and the basal lineage CD49f signature, were enriched in luminal- and basal-like cancers respectively, demonstrating the connection between these subtypes and established prostate cancer biology. While both luminal-like subtypes were associated with increased AR expression and signaling, only luminal B prostate cancers were significantly associated with post-operative response to androgen deprivation therapy (ADT) in a subset analysis matching patients based on clinicopathologic variables (interaction p = 0.006, luminal B 10-year metastasis: 33% (treated) vs. 55% (untreated), non-luminal B: 37% (treated) vs. 21% (untreated)). Conclusions: These findings contribute novel insight into the biology of prostate cancer, and provide translatable clinical tools for personalizing post-operative ADT for patients with prostate cancer. Similar to breast cancer, these findings suggest that luminal/basal subtyping may be useful in treatment selection in prostate cancer.

704 Background: Inpatients with gastrointestinal (GI) malignancies are at a high risk for Clostridium difficile infection (CDI) but the impact of CDI on outcomes in these patients needs elucidation. We analyzed the incidence of CDI and its impact on outcomes in GI cancer patients using the National Hospital Discharge Survey (NHDS) database from 2001 - 2010. Methods: NHDS collects clinical information on patients dismissed from non-Federal short-stay United States hospitals. Demographics, diagnoses (GI malignancies, CDI and comorbidities), length of stay (LOS), and dismissal information were abstracted using ICD-9 diagnosis and procedure codes. Weighted analyses were performed using SAS version 9.4. Results: Of an estimated 317.9 million unique hospitalizations; 4.6 million had a diagnosis of a GI malignancy (1.4%); median age 68 years, 46.1% female. CDI was more common in patients with GI malignancies compared to patients with no GI malignancy (1.05% vs 0.69%, aOR 1.16, 95% CI 1.15- 1.17, p < 0.0001). There was a significant increase in CDI incidence in GI cancer patients over the 10-year study period (72.7 in 2001-2002 to 109.1 in 2009-2010, per 10,000 discharges, p < 0001). In multivariable analysis, compared to GI cancer patients without CDI, GI cancer patients with CDI had a longer mean LOS (3.94 more days, 95% CI 3.31-4.56) and dismissal to a care facility (adjusted OR, 1.75; 95% CI, 1.71-1.79), but lower all-cause in-hospital mortality (adjusted OR, 0.76; 95% CI, 0.74-0.79), all p < 0.0001 Conclusions: In this national database of hospitalized patients, an increasing incidence of CDI in patients with GI malignancies was noted over the study period. CDI prolonged hospitalization, and was associated with increased dismissal to a care-facility. Lower rates of in-hospital mortality may represent early diagnosis due to vigilance or a milder form of CDI. Despite increased attention over the last few decades, CDI remained a serious infection in GI cancer patients, and merits appropriate prevention, management and follow-up.

370 Background: The Phase 1 portion of a Phase 1/2 trial of Necuparanib (“Necu”) combined with nab-paclitaxel (nabP) + gemcitabine (gem) in patients with metastatic pancreatic cancer (ClinicalTrials.gov Identifier NCT01621243) showed acceptable safety and tolerability and encouraging signals of activity and established a dose for the randomized, placebo (PBO)-controlled Phase 2 portion. Methods: In Phase 2, patients received daily s.c. injections of either 5 mg/kg Necu daily or PBO, combined with i.v. 125 mg/m2 nabP and 1000 mg/m2 gem (Days 1, 8, 15 of each 28-day cycle). The primary endpoint was overall survival (OS); other endpoints included progression-free survival (PFS), response rates, safety, and CA19.9 levels. An interim futility analysis was conducted in July 2016 once 57 deaths (50% of the target number of 114 events required for trial completion) had occurred. Results: The analysis was conducted on data from 120 randomized patients (62 Necu, 58 PBO). The Z-score for futility was -0.42 (prespecified boundary of -0.148 was crossed as actual score was lower). Median OS was Necu = 10.71 and PBO = 9.99 months; hazard ratio (HR) = 1.12 (favoring PBO); OS curves were intertwined. PFS was Necu = 5.52 and PBO = 6.93 months; HR = 0.97. RECIST response rates were comparable between arms: complete response, Necu = 0%, PBO = 3%; partial response, Necu = 26%, PBO = 26%; stable disease, Necu = 31%, PBO = 34%; disease control rate, Necu = 56%, PBO = 64%. The most common Grade 3+ adverse events (AEs) were neutropenia (Necu = 33%, PBO = 33%), thrombocytopenia (Necu = 27%, PBO = 5%), and anemia (Necu = 22%, PBO = 11%). There were lower rate of serious AEs with Necu (48%) vs. PBO (60%). Modest increases in APTT, AST, and ALT were noted following Necu relative to PBO. 23% of Necu and 5% of PBO patients were IgG positive with an anti-heparin/PF4 antibody titer of ≥ 0.4 at any time. There were no treatment differences for decreases in CA19.9. Conclusions: No new safety signals were observed and the toxicity profile was considered manageable; however, Necu in combination with nabP and gem did not show a sufficient level of efficacy in metastatic pancreatic cancer to warrant continued enrollment. Clinical trial information: NCT01621243.

Background: Obesity as a cause of lower extremity deformity in children has been well established. This deformity is most often seen as tibia vara, however, at our institution we have observed more obese children and adolescents over age 7 years with excessive or progressive idiopathic genu valgum. Our hypothesis is that children with idiopathic genu valgum have high rates of obesity which impact the severity of their disease. Methods: Retrospective review of existing data was performed on 66 consecutive children/112 limbs over age 7 years with idiopathic genu valgum, seen from 2010 to 2013. Children with known metabolic or skeletal disease were excluded. Genu valgum was defined as mechanical axis in zone II or III and mechanical tibiofemoral angle ≥4 degrees on standing anteroposterior radiograph of the lower extremities. Body mass index (BMI) was calculated and classified by Center for Disease Control percentiles. Skeletal maturation was rated by closure of pelvic and peri-genu physes. Severity of genu valgum was also assessed by femoral and tibial mechanical axes and the mechanical axis deviation. Results: Mean patient age was 12.2±2.2 years. 47% of patients had BMI≥30 and 71% were categorized as obese (>95th percentile). No sex differences were identified. Skeletal maturation explained 25% of the variance in the mechanical axis deviation and 22% of the mechanical tibiofemoral angle. BMI predicted 9.8% of the tibial valgus. Because of its skewed distribution, BMI percentile was a less useful parameter for assessment. Conclusions: The 71% obesity rate found in our children with idiopathic genu valgum is significantly higher than the normal population. Higher BMI is associated with more tibial valgum but skeletal maturation was the main predictor of overall valgus severity. This suggests that obesity may play a role in the etiology of idiopathic genu valgum which progresses with skeletal maturation, thereby increasing the risk of osteoarthritis in adulthood. Level of Evidence: Level III.

Alcohol consumption is a well‐established risk factor for the onset and progression of fatty liver disease. An estimated 90% of heavy drinkers are thought to develop significant liver steatosis. For these reasons, an increased understanding of the molecular basis for alcohol‐induced hepatic steatosis is important. It has become clear that autophagy, a catabolic process of intracellular degradation and recycling, plays a key role in hepatic lipid metabolism. We have shown that Rab7, a small guanosine triphosphatase known to regulate membrane trafficking, acts as a key orchestrator of hepatocellular lipophagy, a selective form of autophagy in which lipid droplets (LDs) are specifically targeted for turnover by the autophagic machinery. Nutrient starvation results in Rab7 activation on the surface of the LD and lysosomal compartments, resulting in the mobilization of triglycerides stored within the LDs for energy production. Here, we examine whether the steatotic effects of alcohol exposure are a result of perturbations to the Rab7‐mediated lipophagic pathway. Rats chronically fed an ethanol‐containing diet accumulated significantly higher levels of fat in their hepatocytes. Interestingly, hepatocytes isolated from these ethanol‐fed rats contained juxtanuclear lysosomes that exhibited impaired motility. These changes are similar to those we observed in Rab7‐depleted hepatocytes. Consistent with these defects in the lysosomal compartment, we observed a marked 80% reduction in Rab7 activity in cultured hepatocytes as well as a complete block in starvation‐induced Rab7 activation in primary hepatocytes isolated from chronic ethanol‐fed animals.Conclusion: A mechanism is supported whereby ethanol exposure inhibits Rab7 activity, resulting in the impaired transport, targeting, and fusion of the autophagic machinery with LDs, leading to an accumulation of hepatocellular lipids and hepatic steatosis. (Hepatology Communications2017;1:140‐152)

ObjectiveCompare nasal endoscopy with 3 mm versus conventional 4 mm rigid 30° endoscopes for visualization, patient comfort, and examiner ease.MethodsTen adults with no previous sinus surgery underwent bilateral nasal endoscopy with both 4 mm and 3 mm endoscopes (resulting in 20 paired nasal endoscopies). Visualization, patient discomfort and examiner's difficulty were assessed with every endoscopy. Sino‐nasal structures were checked on a list if visualized satisfactorily. Patients rated discomfort on a standardized numerical pain scale (0–10). Examiners rated difficulty of examination on a scale of 1–5 (1 = easiest).ResultsVisualization with 3 mm endoscope was superior for the sphenoid ostium (P = 0.002), superior turbinate (P = 0.007), spheno‐ethmoid recess (P = 0.006), uncinate process (P = 0.002), cribriform area (P = 0.007), and Valve of Hasner (P = 0.002). Patient discomfort was not significantly different for 3 mm vs. 4 mm endoscopes but correlated with the examiners' assessment of difficulty (r = 0.73). The examiner rated endoscopy with 4 mm endoscopes more difficult (P = 0.027).ConclusionsThe 3 mm endoscope was superior in visualizing the sphenoid ostium, superior turbinate, spheno‐ethmoid recess, uncinate process, cribriform plate, and valve of Hasner. It therefore may be useful in assessment of spheno‐ethmoid recess, nasolacrimal duct, and cribriform area pathologies. Overall, patients tolerated nasal endoscopy well. Though patient discomfort was not significantly different between the endoscopes, most discomfort with 3 mm endoscopes was noted while examining structures difficult to visualize with the 4 mm endoscope. Patients' discomfort correlated with the examiner's assessment of difficulty.