Proteomic analysis identifies key differences in the cardiac interactomes of dystrophin and micro-dystrophin.

ΔR4-R23/ΔCT micro-dystrophin (µDys) is a miniaturized version of dystrophin currently evaluated in a Duchenne muscular dystrophy (DMD) gene therapy trial to treat skeletal and cardiac muscle disease. In pre-clinical studies, µDys efficiently rescues cardiac histopathology, but only partially normalizes cardiac function. To gain insights into factors that may impact the cardiac therapeutic efficacy of µDys, we compared by mass spectrometry the composition of purified dystrophin and µDys protein complexes in the mouse heart. We report that compared to dystrophin, µDys has altered associations with α1- and ß2-syntrophins, as well as cavins, a group of caveolae-associated signaling proteins. In particular, we found that membrane localization of cavin-1 and cavin-4 in cardiomyocytes requires dystrophin and is profoundly disrupted in the heart of mdx5cv mice, a model of DMD. Following cardiac stress/damage, membrane-associated cavin-4 recruits the signaling molecule ERK to caveolae, which activates key cardio-protective responses. Evaluation of ERK signaling revealed a profound inhibition, below physiological baseline, in the mdx5cv mouse heart. Expression of µDys in mdx5cv mice prevented the development of cardiac histopathology but did not rescue membrane localization of cavins nor did it normalize ERK signaling. Our study provides the first comparative analysis of purified protein complexes assembled in vivo by full-length dystrophin and a therapeutic micro-dystrophin construct. This has revealed disruptions in cavins and ERK signaling that may contribute to DMD cardiomyopathy. This new knowledge is important for ongoing efforts to prevent and treat heart disease in DMD patients.

Identification of structures for ion channel kinetic models.

Markov models of ion channel dynamics have evolved as experimental advances have improved our understanding of channel function. Past studies have examined limited sets of various topologies for Markov models of channel dynamics. We present a systematic method for identification of all possible Markov model topologies using experimental data for two types of native voltage-gated ion channel currents: mouse atrial sodium currents and human left ventricular fast transient outward potassium currents. Successful models identified with this approach have certain characteristics in common, suggesting that aspects of the model topology are determined by the experimental data. Incorporating these channel models into cell and tissue simulations to assess model performance within protocols that were not used for training provided validation and further narrowing of the number of acceptable models. The success of this approach suggests a channel model creation pipeline may be feasible where the structure of the model is not specified a priori.

Sweet-cheeks vs. pea-brain: embodiment, valence, and task all influence the emotional salience of language.

Previous research has found that more embodied insults (e.g. numbskull) are identified faster and more accurately than less embodied insults (e.g. idiot). The linguistic processing of embodied compliments has not been well explored. In the present study, participants completed two tasks where they identified insults and compliments, respectively. Half of the stimuli were more embodied than the other half. We examined the late positive potential (LPP) component of event-related potentials in early (400-500 ms), middle (500-600 ms), and late (600-700 ms) time windows. Increased embodiment resulted in improved response accuracy to compliments in both tasks, whereas it only improved accuracy for insults in the compliment detection task. More embodied stimuli elicited a larger LPP than less embodied stimuli in the early time window. Insults generated a larger LPP in the late time window in the insult task; compliments generated a larger LPP in the early window in the compliment task. These results indicate that electrophysiological correlates of emotional language perception are sensitive to both top-down and bottom-up processes.

Preoperative Immunonutrition and Elective Colorectal Resection Outcomes.

BACKGROUND: Randomized controlled trials demonstrate the efficacy of arginine-enriched nutritional supplements (immunonutrition) in reducing complications after surgery. The effectiveness of preoperative immunonutrition has not been evaluated in a community setting. OBJECTIVE: This study aims to determine whether immunonutrition before elective colorectal surgery improves outcomes in the community at large. DESIGN: This is a prospective cohort study with a propensity score-matched comparative effectiveness evaluation. SETTINGS: This study was conducted in Washington State hospitals in the Surgical Care Outcomes Assessment Program from 2012 to 2015. PATIENTS: Adults undergoing elective colorectal surgery were selected. INTERVENTIONS: Surgeons used a preoperative checklist that recommended that patients take oral immunonutrition (237 mL, 3 times daily) for 5 days before elective colorectal resection. MAIN OUTCOME MEASURES: Serious adverse events (infection, anastomotic leak, reoperation, and death) and prolonged length of stay were the primary outcomes measured. RESULTS: Three thousand three hundred seventy-five patients (mean age 59.9 ± 15.2 years, 56% female) underwent elective colorectal surgery. Patients receiving immunonutrition more commonly were in a higher ASA class (III-V, 44% vs 38%; p = 0.01) or required an ostomy (18% vs 14%; p = 0.02). The rate of serious adverse events was 6.8% vs 8.3% (p = 0.25) and the rate of prolonged length of stay was 13.8% vs 17.3% (p = 0.04) in those who did and did not receive immunonutrition. After propensity score matching, covariates were similar among 960 patients. Although differences in serious adverse events were nonsignificant (relative risk, 0.76; 95% CI, 0.49-1.16), prolonged length of stay (relative risk, 0.77; 95% CI, 0.58-1.01 p = 0.05) was lower in those receiving immunonutrition. LIMITATIONS: Patient compliance with the intervention was not measured. Residual confounding, including surgeon-level heterogeneity, may influence estimates of the effect of immunonutrition. CONCLUSIONS: Reductions in prolonged length of stay, likely related to fewer complications, support the use of immunonutrition in quality improvement initiatives related to elective colorectal surgery. This population-based study supports previous trials of immunonutrition, but shows a lower magnitude of benefit, perhaps related to compliance or a lower rate of adverse events, highlighting the value of community-based assessments of comparative effectiveness.

Characterization of SEMA3A-encoded semaphorin as a naturally occurring Kv4.3 protein inhibitor and its contribution to Brugada syndrome.

RATIONALE: Semaphorin 3A (SEMA3A)-encoded semaphorin is a chemorepellent that disrupts neural patterning in the nervous and cardiac systems. In addition, SEMA3A has an amino acid motif that is analogous to hanatoxin, an inhibitor of voltage-gated K(+) channels. SEMA3A-knockout mice exhibit an abnormal ECG pattern and are prone to ventricular arrhythmias and sudden cardiac death. OBJECTIVE: Our aim was to determine whether SEMA3A is a naturally occurring protein inhibitor of Kv4.3 (Ito) channels and its potential contribution to Brugada syndrome. METHODS AND RESULTS: Kv4.3, Nav1.5, Cav1.2, or Kv4.2 were coexpressed or perfused with SEMA3A in HEK293 cells, and electrophysiological properties were examined via whole-cell patch clamp technique. SEMA3A selectively altered Kv4.3 by significantly reducing peak current density without perturbing Kv4.3 cell surface protein expression. SEMA3A also reduced Ito current density in cardiomyocytes derived from human-induced pluripotent stem cells. Disruption of a putative toxin binding domain on Kv4.3 was used to assess physical interactions between SEMA3A and Kv4.3. These findings in combination with coimmunoprecipitations of SEMA3A and Kv4.3 revealed a potential direct binding interaction between these proteins. Comprehensive mutational analysis of SEMA3A was performed on 198 unrelated SCN5A genotype-negative patients with Brugada syndrome, and 2 rare SEMA3A missense mutations were identified. The SEMA3A mutations disrupted SEMA3A's ability to inhibit Kv4.3 channels, resulting in a significant gain of Kv4.3 current compared with wild-type SEMA3A. CONCLUSIONS: This study is the first to demonstrate SEMA3A as a naturally occurring protein that selectively inhibits Kv4.3 and SEMA3A as a possible Brugada syndrome susceptibility gene through a Kv4.3 gain-of-function mechanism.

Fluorescence Angiography in Colorectal Resection.

BACKGROUND: Intraoperative laser fluorescence angiography is a relatively new tool that can be used by colorectal surgeons to ensure adequate perfusion to bowel that remains after resection. It has been used mostly to determine an appropriate point of transection of the proximal bowel, as well as to ensure perfusion after the anastomosis has been constructed. We propose a different use of the technology in complex cases to ensure the ability to safely transect a major vascular pedicle and to ensure that perfusion will remain adequate. OBJECTIVE: The purpose of this article is to describe a new use for fluorescence angiography technology. DESIGN: This is a technical note. SETTINGS: The work was conducted at a tertiary care military medical center. PATIENTS: Patients included individuals requiring oncologic colorectal resection where the status of 1 major vascular pedicle was unknown or impaired. MAIN OUTCOME MEASURES: We assessed perfusion after occlusion of a major vascular pedicle for the short term in hospital outcomes. RESULTS: Adequate studies were obtained, and perfusion was maintained in both patients. Oncologic resections were performed, and short-term outcomes were comparable with any individual undergoing these procedures. LIMITATIONS: This study was limited because it is early experience that was not performed in the setting of a scientific investigation. CONCLUSIONS: Application of intraoperative fluorescence angiography in this setting appears to be safe and may assist the surgeon in estimating reliable vascular perfusion in patients such as these who require oncologic colorectal resection.

Have we progressed in the surgical literature? Thirty-year trends in clinical studies in 3 surgical journals.

BACKGROUND: We practice in an era of evidence-based medicine. In 1993, Solomon and McLeod published an article examining study designs in 3 surgical journals from 1980 and 1990. OBJECTIVE: The purpose of this study was to evaluate subsequent 30-year trends in the quality of selected literature. DESIGN: All of the articles from Diseases of the Colon & Rectum, Surgery, and the British Journal of Surgery during 2000 and 2010 were classified by study design. Nonclinical studies were substratified by animal/laboratory, surgical technique, editorial/review, or miscellaneous articles. Clinical articles were categorized as case or comparative studies, further categorized by study design, and rated on a 10-point scale to determine strength. We compared interobserver reliability using a random sample. SETTING: This study was conducted at 3 North American medical centers. PATIENTS: Patients described in the scope of the literature were included in this study. MAIN OUTCOME MEASURES: Frequency, type, and strength of study design were measured. RESULTS: We evaluated 1911 articles (967 clinical; 17% comparative). There was a significant increase in multicenter clinical studies (from 12% to 27%; p < 0.0001) and mean study population (from 326 to 6775; p < 0.05). Studies using administrative data increased from 14% to 43% (p < 0.0001). Case reports decreased from 16% to 7% of all clinical studies (p < 0.001), whereas the percentage of comparative studies increased from 14% to 21% (p = 0.001). The percentage of randomized controlled trials did not increase significantly (8.5% in 2000; 10.0% in 2010; p = 0.44). The mean 10-point score for comparative studies was 6.7 for both years (p = 0.50). There was good interobserver agreement in the classification of studies (κ = 0.70) and moderate agreement in scoring comparative studies (κ = 0.47). LIMITATIONS: This descriptive study cannot fully account for the reasons behind the identified differences. CONCLUSIONS: Comparative and multicenter studies, mean study population, and the use of administrative data increased from 2000 to 2010. This suggests that increased use of administrative databases has allowed larger populations of patients from more institutions to be studied and may be more generalizable. Researchers should strive toward improving the level of evidence (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A167).

Do the advantages of a minimally invasive approach remain in complex colorectal procedures? A nationwide comparison.

BACKGROUND: Since the introduction of laparoscopic colectomy, experience and technology continue to improve. Although accepted for many colorectal conditions, its use and outcomes in complex procedures are less understood. OBJECTIVE: The purpose of this work was to compare the perioperative outcomes of laparoscopic transverse colectomy and total abdominal colectomy (study group) with an open approach (comparative group) and the more established laparoscopic right, left, and sigmoid colectomies (control group). DESIGN: This was a retrospective review of the Nationwide Inpatient Sample (2008-2011) of all patients undergoing elective right, left, sigmoid, total, or transverse colectomy as identified by International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Risk-adjusted 30-day outcomes were assessed using regression modeling accounting for patient characteristics, comorbidities, and surgical procedures. SETTINGS: The study included a national sample from a population database. PATIENTS: There were 45,771 admissions: 2946 in the study group, 36,949 in the control group, and 5876 in the open comparative group. MAIN OUTCOME MEASURES: Mortality was the primary outcome. Secondary outcomes included in-hospital complications, length of stay, and hospital charges. RESULTS: The patients were predominantly white (73%), had private insurance (64%), and underwent surgery at urban centers (92%). Mortality was similar between the study and control groups (0.42% vs 0.51%; p = 0.52), with a higher complication rate in the study group (19% vs 14%; p < 0.01). The study group was also associated with a lower mortality rate compared with the open group (0.51% vs 2.20%; p < 0.01), which remained consistent after adjusting for covariates (OR, 0.38 [95% CI, 0.20-0.71]; p < 0.01). The study group had fewer complications overall compared with the open group (19% vs 27%; p < 0.01) and a shorter median length of stay (4.6 vs 6.3 days; p < 0.01). LIMITATIONS: This was a retrospective study using an administrative database. CONCLUSIONS: A laparoscopic approach for total abdominal and transverse colectomies has similar mortality rates and slightly higher complications than the more established laparoscopic colectomy procedures and improved perioperative outcomes when compared with an open technique (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A178).

The impact of perianal disease in young patients with inflammatory bowel disease.

BACKGROUND: Perianal disease is a potentially significant source of morbidity for patients with inflammatory bowel disease (IBD). We sought to identify the impact of perianal disease on IBD outcomes in children, adolescents, and young adults. METHODS: We studied 12,465 inpatient admissions for patients ≤20 years old with IBD in 2009 using the Kids' Inpatient Database (KID). Patients were stratified by their principal diagnosis of ulcerative colitis (UC) or Crohn's disease (CD). Perianal disease (perianal abscess, anal fissure, or anal fistula), complex fistulas (rectourethral, rectovaginal, or enterovesical), and growth failure were defined by ICD-9 codes. Logistic regression was performed adjusting for CD or UC, gender, age, need for surgical intervention, fistulas, or growth failure. RESULTS: Of the 511 (4.1%) patients with perianal disease, 480 had CD (94%, p < 0.001). Girls were less likely to suffer perianal disease (OR = 0.63, CI 0.52-0.76, p < 0.001). Those with perianal disease were more likely to suffer complex fistulas (OR = 3.5, CI 1.98-6.20, p < 0.001) but less likely to suffer enteroenteral fistulas (OR = 0.30, CI 0.15-0.63, p = 0.001) than those without perianal disease. Perianal disease did not increase the incidence of growth failure (p = 0.997) but doubled the likelihood of an operation of any type during admission (p < 0.001). Additionally, patients with perianal disease spent on average 1.29 more days in the hospital (7.45 vs. 6.16 days, p < 0.001) and accrued $5838 extra in hospital charges (p = 0.005). CONCLUSIONS: Perianal disease in younger patients is associated with a longer length of stay, higher hospital charges, and increased rates of both perineal and abdominal operative procedures. These data support the notion that, similar to adults, the presence of perianal disease in pediatric Crohn's patients is associated with a more severe course.

Novel operative anoscope for Ferguson hemorrhoidectomy: a feasibility study and comparative cohort analysis.

BACKGROUND: Operative hemorrhoidectomy can result in pain and altered continence from excessive excision of anoderm or surrounding tissue. We assessed a novel low-profile slotted anoscope to determine if the device would promote safe dissection, lessen trauma, and reduce operative times for hemorrhoidectomy. METHODS: Patients requiring hemorrhoidectomy (June 2008 - January 2010) underwent a prospective phase-2 trial evaluating a new operating anoscope (CAD, Ethicon Endosurgery, Cincinnati, OH). Demographics and perioperative end points including bleeding, pain, fecal incontinence, stenosis, and symptom recurrence were analyzed at 4 weeks, 3 months, 6 months, and 1 year postoperatively. We compared these to patients undergoing hemorrhoidectomy (February 2010 - November 2012) with a traditional Hill-Ferguson anoscope (THF). RESULTS: 40 patients (CAD, 20 vs THF, 20) were included. Presenting symptoms were similar, whereas mean duration of symptoms was longer for CAD (41.2 ± 8.4 vs 27 ± 9.5 months; P < .05). Estimated blood loss was lower for CAD [8.3 mL (range = 2-40 mL) vs 11.3 mL THF (range = 5-35 mL; P = .87)]. Mean operative times were lower for the CAD than the THF group (15.6 ± 3.4 vs 26.1 ± 4.1 minutes; P < .05). Visual analog pain scores were non-significantly increased in the THF group at 4 weeks (P = .23). At 3 months, 6 months, and 1 year, there was no difference in continence. CONCLUSION: The CAD anoscope reduced operative times for modified Ferguson (closed) hemorrhoidectomy when compared with traditional retractors. There was no difference in incontinence or pain between groups.

The ZZ domain of dystrophin in DMD: making sense of missense mutations.

Duchenne muscular dystrophy (DMD) is associated with the loss of dystrophin, which plays an important role in myofiber integrity via interactions with ß-dystroglycan and other members of the transmembrane dystrophin-associated protein complex. The ZZ domain, a cysteine-rich zinc-finger domain near the dystrophin C-terminus, is implicated in forming a stable interaction between dystrophin and ß-dystroglycan, but the mechanism of pathogenesis of ZZ missense mutations has remained unclear because not all such mutations have been shown to alter ß-dystroglycan binding in previous experimental systems. We engineered three ZZ mutations (p.Cys3313Phe, p.Asp3335His, and p.Cys3340Tyr) into a short construct similar to the Dp71 dystrophin isoform for in vitro and in vivo studies and delineated their effect on protein expression, folding properties, and binding partners. Our results demonstrate two distinct pathogenic mechanisms for ZZ missense mutations. The cysteine mutations result in diminished or absent subsarcolemmal expression because of protein instability, likely due to misfolding. In contrast, the aspartic acid mutation disrupts binding with ß-dystroglycan despite an almost normal expression at the membrane, confirming a role for the ZZ domain in ß-dystroglycan binding but surprisingly demonstrating that such binding is not required for subsarcolemmal localization of dystrophin, even in the absence of actin binding domains.

Crohn's disease and pregnancy: the impact of perianal disease on delivery methods and complications.

BACKGROUND: The optimal delivery method in patients with Crohn's disease is unknown, and there is no large-scale evidence on which to base decisions. OBJECTIVE: The aim of this study was to compare delivery methods and outcomes in patients with and without Crohn's disease. DESIGN AND PATIENTS: The Nationwide Inpatient Sample and International Classification of Diseases, Ninth Revision codes were used to identify childbirth deliveries. Patients were stratified by the presence or absence of Crohn's disease and perianal disease (anorectal fistula or abscess, rectovaginal fistula, anal fissure, and anal stenosis). SETTINGS: A large population-cohort database was used for the analysis. MAIN OUTCOME MEASURES: The primary outcomes measured were cesarean delivery and perineal lacerations. RESULTS: Of 6,794,787 pregnant women who delivered, 2882 had a diagnosis of Crohn's disease. Rates of cesarean delivery were higher in patients who had Crohn's disease with (83.1%) and without (42.8%) perianal disease in comparison with patients who did not have Crohn's disease with (38.9%) and without (25.6%) perianal disease (p < 0.001). Rates of 4th degree perineal lacerations were similar between patients who had or did not have Crohn's disease without perianal disease (1.4% vs 1.3%), but these rates increased significantly in patients with perianal disease (12.3%, p < 0.001). On multivariate analysis, perianal disease (OR, 10.9; 95% CI, 8.3-4.1; p < 0.001) and smoking (OR, 1.6; 95% CI, 1.5-1.7; p < 0.001) were independently associated with higher rates of 4th degree laceration. Crohn's disease was not independently associated with 4th degree laceration. LIMITATIONS: This was a retrospective study with the inherent limitations of large databases. CONCLUSIONS: Patients with Crohn's disease have higher rates of cesarean delivery. Perianal disease predicts severe perineal laceration independent of the presence of Crohn's disease. In the absence of perianal disease, the method of delivery in women with Crohn's disease should be predicated on obstetric indication.

The impact of age on colorectal cancer incidence, treatment, and outcomes in an equal-access health care system.

BACKGROUND: Inferior outcomes in younger patients with colorectal cancer may be associated with multiple factors, including tumor biology, delayed diagnosis, disparities such as access to care, and/or treatment differences. OBJECTIVE: This study aims to examine age-based colorectal cancer outcomes in an equal-access health care system. DESIGN: This study is a retrospective large multi-institutional database analysis. PATIENTS: Patients with colorectal cancer included in the Department of Defense Automated Central Tumor Registry (January 1993 to December 2008) were stratified by age <40, 40 to 49, 50 to 79, and ≥80 years to determine the effect of age on incidence, treatment, and outcomes. MAIN OUTCOME MEASURES: The primary outcomes measured were the stage at presentation, adjuvant therapy use, 3- and 5-year disease-free survival, and overall survival. RESULTS: Some 7948 patients were identified; most (77%) patients were in the 50- to 79-year age group. Overall, 25% presented with stage III disease. Compared with patients aged 50 to 79 and ≥80 years, patients aged <40 and 40 to 49 years presented more frequently with advanced disease (stage III (35% and 35% vs 28% and 26%) and stage IV (24% and 21% vs 18% and 15%); all p < 0.001). Adjuvant chemotherapy use in stage III patients was 62%; those patients ≥80 and 50 to 79 years had decreased use (p < 0.001). Overall recurrence was 8.1% at 3 years and 9.7% at 5 years, with the highest rates in patients <40 years (11.8%; p = 0.007). Overall survival was worse in patients ≥80 years, whereas the remaining cohorts were similar. For stage III disease, patients 40 to 49 years had the highest survival among all cohorts (p < 0.001). LIMITATIONS: This study was limited by the lack of specific comorbid information and the limitations inherent to large database reviews. CONCLUSIONS: In an equal-access system, young age at presentation (<50 years) was associated with advanced stage and higher recurrence of colorectal cancer, but similar survival in comparison with older patients. Although increased adjuvant therapy use in younger patients may partially account for stage-specific increases in survival, the relative decreased chemotherapy use overall requires further evaluation.

Prophylactic antibiotics for hemorrhoidectomy: are they really needed?

BACKGROUND: Hemorrhoidectomy is considered by many to be a contaminated operation that requires antibiotic prophylaxis to lower the incidence of surgical site infection. In reality, little evidence exists to either support or refute the use of antibiotic prophylaxis in this setting. OBJECTIVE: This study aimed to determine if antibiotic prophylaxis is associated with reduced incidence of postoperative surgical site infection following hemorrhoidectomy. DESIGN: This is a retrospective database review. SETTING: This study was conducted at multiple institutions. PATIENTS: All patients undergoing hemorrhoidectomy with minimum 3-month follow-up were included. MAIN OUTCOME MEASURES: The primary outcome measure was the incidence of postoperative surgical site infection. RESULTS: Eight hundred fifty-two patients met the inclusion criteria (50.1% female; mean age, 50.0 ± 13.7 years). The prevalence of preoperative risk factors for surgical site infection included 7.7% with a smoking history, 2.5% with diabetes mellitus, 0.8% receiving steroids, and 0.2% with Crohn's disease. Surgery was performed predominately for 3-column prolapsed internal and mixed internal/external hemorrhoidal disease. All surgeries performed were closed hemorrhoidectomies. Antibiotic prophylaxis was used in a fewer number of cases (41.3% vs 58.7%). Overall, there were only 12 documented postoperative infections identified, producing an overall incidence of 1.4%. Of those patients who developed postoperative surgical site infections, 9 (75%) did not receive antibiotic prophylaxis (p = 0.25). On multivariate regression analysis, no perioperative risk factor was associated with an increased risk of developing a posthemorrhoidectomy surgical site infection. Conversely, there were no adverse antibiotic-related complications such as Clostridium difficile colitis or antibiotic-associated diarrhea in those receiving antibiotic prophylaxis. LIMITATIONS: This study was limited by the retrospective nature of the analysis. CONCLUSIONS: Postoperative surgical site infection is an exceedingly rare event following hemorrhoidectomy. Antibiotic prophylaxis does not reduce the incidence of postoperative surgical site infection, and its routine use appears unnecessary.