Citations

Abstract Aims We have previously reported that asymptomatic systolic heart failure (HF) is characterized by an impaired renal response to volume expansion due to lack of activation of urinary cGMP which is corrected by subcutaneous (SQ) BNP. In the current study, we sought to define the cardiorenal response to intravascular volume expansion after 12 weeks of SQ BNP therapy. Methods and results We utilized a double-blinded, placebo-controlled study to compare 12 weeks of twice-daily SQ BNP 10 µg/kg (n = 22) or placebo (n = 12) in asymptomatic systolic HF. Subjects underwent two study visits: baseline and after 12 weeks of therapy. At each study visit, echocardiography, renal, and neurohumoral assessments were performed before and after intravascular volume expansion. The primary endpoint was change in urinary sodium excretion in response to volume expansion at 12 weeks, and we observed a greater increase in urinary sodium excretion [166 (77, 290) vs. 15 (−39, 72) mEq/min; P = 0.02] with SQ BNP treatment vs. placebo. Secondary endpoints included change in urine flow and glomerular filtration rate (GFR) in response to volume expansion at 12 weeks. We observed a significant increase in urine flow (P < 0.01) and trend for differential response in GFR (P = 0.08) with SQ BNP treatment vs. placebo. Conclusion Among patients with asymptomatic systolic HF, twice-daily SQ BNP therapy improved the cardiorenal response to volume expansion at 12-week follow-up. Further studies are warranted to determine if these beneficial physiological observations with chronic natriuretic peptide administration translate into a delay in the progression to symptomatic HF.

Purpose Noninvasive stiffness imaging techniques (elastography) can image myocardial tissue biomechanics in vivo. For cardiac MR elastography (MRE) techniques, the optimal vibration frequency for in vivo experiments is unknown. Furthermore, the accuracy of cardiac MRE has never been evaluated in a geometrically accurate phantom. Therefore, the purpose of this study was to determine the necessary driving frequency to obtain accurate three‐dimensional (3D) cardiac MRE stiffness estimates in a geometrically accurate diastolic cardiac phantom and to determine the optimal vibration frequency that can be introduced in healthy volunteers. Methods The 3D cardiac MRE was performed on eight healthy volunteers using 80 Hz, 100 Hz, 140 Hz, 180 Hz, and 220 Hz vibration frequencies. These frequencies were tested in a geometrically accurate diastolic heart phantom and compared with dynamic mechanical analysis (DMA). Results The 3D Cardiac MRE was shown to be feasible in volunteers at frequencies as high as 180 Hz. MRE and DMA agreed within 5% at frequencies greater than 180 Hz in the cardiac phantom. However, octahedral shear strain signal to noise ratios and myocardial coverage was shown to be highest at a frequency of 140 Hz across all subjects. Conclusion This study motivates future evaluation of high‐frequency 3D MRE in patient populations. Magn Reson Med 77:351–360, 2017. © 2016 Wiley Periodicals, Inc.

Background— Cardiac sarcoidosis is associated with an increased risk of heart failure and sudden death, but its risk in patients with preserved left ventricular ejection fraction is unknown. Using cardiovascular magnetic resonance in patients with extracardiac sarcoidosis and preserved left ventricular ejection fraction, we sought to (1) determine the prevalence of cardiac sarcoidosis or associated myocardial damage, defined by the presence of late gadolinium enhancement (LGE), (2) quantify their risk of death/ventricular tachycardia (VT), and (3) identify imaging-based covariates that predict who is at greatest risk of death/VT. Methods and Results— Parameters of left and right ventricular function and LGE burden were measured in 205 patients with left ventricular ejection fraction >50% and extracardiac sarcoidosis who underwent cardiovascular magnetic resonance for LGE evaluation. The association between covariates and death/VT in the entire group and within the LGE+ group was determined using Cox proportional hazard models and time-dependent receiver–operator curves analysis. Forty-one of 205 patients (20%) had LGE; 12 of 205 (6%) died or had VT during follow-up; of these, 10 (83%) were in the LGE+ group. In the LGE+ group (1) the rate of death/VT per year was >20× higher than LGE− (4.9 versus 0.2%, P <0.01); (2) death/VT were associated with a greater burden of LGE (14±11 versus 5±5%, P <0.01) and right ventricular dysfunction (right ventricular EF 45±12 versus 53±28%, P =0.04). LGE burden was the best predictor of death/VT (area under the receiver-operating characteristics curve, 0.80); for every 1% increase of LGE burden, the hazard of death/VT increased by 8%. Conclusions— Sarcoidosis patients with LGE are at significant risk for death/VT, even with preserved left ventricular ejection fraction. Increased LGE burden and right ventricular dysfunction can identify LGE+ patients at highest risk of death/VT.

Background: There is a paucity of data on the results of reverse (anteverting) periacetabular osteotomy (RPAO) for treatment of femoroacetabular impingement (FAI) secondary to acetabular retroversion. Purpose: To evaluate the midterm outcomes of RPAO for FAI secondary to acetabular retroversion in those with and without hip dysplasia. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review identified RPAOs performed on patients with acetabular retroversion in isolation or in the setting of dysplasia (lateral center-edge angle [LCEA] ≤19°). Acetabular retroversion with FAI was diagnosed clinically and radiographically, with a positive crossover and posterior wall signs on pelvic radiographs. Twenty-three patients (30 hips) met the inclusion criteria; 20 hips with isolated retroversion and 10 hips with retroversion and hip dysplasia. The average age at the time of the procedure was 26 years (range, 13-45 years). The average length of follow-up was 5 years (range, 2-19 years). Harris Hip Score (HHS) and radiographs were evaluated preoperatively and at last follow-up. Results: The mean preoperative LCEA was 31° (range, 22°-49°) in the isolated retroversion group and 9° (range, –4° to 17°) in the dysplastic group. Postoperatively, the LCEA in the dysplastic group increased to 35° (range, 15°-46°) ( P = .0001). The crossover sign corrected in 55% (11/20) of the isolated retroversion group and 80% (8/10) of the dysplastic group. The acetabular index (mean ± SD) improved from 1.3 ± 0.3 to 1.7 ± 0.6 ( P = .0001), indicating improved anteversion. At the latest follow-up, the average HHS in the isolated retroversion group increased from 58 preoperatively (range, 23-77) to 93 (range, 68-100) ( P = .0001); the HHS in the dysplastic group improved from 49 (range, 20-74) to 92 (range, 77-100) ( P < .0001). Complication rates were similar in both groups. Excluding hardware removal, additional surgeries were performed in 13% (4/30). Conclusion: RPAO performed for FAI in the young patient with isolated acetabular retroversion or retroversion in the setting of dysplasia successfully improved clinical and radiographic results at mid- to long-term follow-up.

Recent applications of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system have greatly improved the efficiency of genome editing in pigs. However, in some cases, genetically modified pig models need an additional modification to improve their application. The objective of this experiment was to determine whether a combination of somatic cell NT (SCNT) by using a previously modified donor cell line and subsequent zygote injection with CRISPR/Cas9 guide RNA to target a second gene would result in embryos and offspring successfully containing both modifications. Fibroblast cell lines were collected from fumarylacetoacetate hydrolase deficient (FAH–/–) fetuses and used as the donor cell line. Somatic cell NT was performed by standard technique. A CRISPR guide RNA specific for recombination activating gene 2 (RAG2) was designed and in vitro transcribed from a synthesised gBlock (IDT) containing a T7 promoter sequence, the CRISPR Guide RNA (20 bp), and 85 bp of tracer RNA. The gBlock was PCR amplified with Q5 polymerase (NEB, Ipswich, MA, USA) and in vitro transcribed with the MEGAshortscript™ T7 Transcription Kit (Life Technologies, Grand Island, NY, USA). Guide RNA (20 ng µL–1) and polyadenylated Cas9 (20 ng µL–1, Sigma, St. Louis, MO, USA) were co-injected into the cytoplasm of SCNT zygotes at 14 to 16 h after fusion and activation. Injected SCNT were then cultured in vitro in PZM3 + 1.69 mM arginine medium (MU1) to Day 5. Three embryo transfers were performed surgically into recipient gilts on Day 4 or 5 of oestrus (50, 62, or 70 embryos per pig) to evaluate in vivo development. The remaining embryos were cultured in MU1 to Day 7 and analysed for the presence of modifications to the RAG2 gene. Embryos were classified as modified if they contained an INDEL as measured by both gel electrophoresis and DNA sequencing of PCR amplicons spanning the targeted exon. The RAG2 modification rate was 83.3% (n = 6), of which 50% (n = 3) of the embryos contained biallelic modifications. All control embryos contained a wild-type RAG2 gene (n = 5). Embryo transfer resulted in a 33.3% pregnancy rate (1/3). The combination of SCNT and CRISPR/Cas9 zygote injection can be a highly efficient tool to successfully create pig embryos with an additional modification. This additional technique further improves the usefulness of already created genetically modified pig models. This study was funded by the National Institutes of Health via U42 OD011140.

Abstract Background: The need to develop valid methods for sampling and analyzing fecal specimens for microbiome studies is increasingly important, especially for large population studies. Methods: Some of the most important attributes of any sampling method are reproducibility, stability, and accuracy. We compared seven fecal sampling methods [no additive, RNAlater, 70% ethanol, EDTA, dry swab, and pre/post development fecal occult blood test (FOBT)] using 16S rRNA microbiome profiling in two laboratories. We evaluated nine commonly used microbiome metrics: abundance of three phyla, two alpha-diversities, and four beta-diversities. We determined the technical reproducibility, stability at ambient temperature, and accuracy. Results: Although microbiome profiles showed systematic biases according to sample method and time at ambient temperature, the highest source of variation was between individuals. All collection methods showed high reproducibility. FOBT and RNAlater resulted in the highest stability without freezing for 4 days. In comparison with no-additive samples, swab, FOBT, and 70% ethanol exhibited the greatest accuracy when immediately frozen. Conclusions: Overall, optimal stability and reproducibility were achieved using FOBT, making this a reasonable sample collection method for 16S analysis. Impact: Having standardized method of collecting and storing stable fecal samples will allow future investigations into the role of gut microbiota in chronic disease etiology in large population studies. Cancer Epidemiol Biomarkers Prev; 25(2); 407–16. ©2015 AACR.

Objectives/Hypothesis Idiopathic subglottic stenosis (iSGS) is a rare and potentially life‐threatening disease marked by recurrent and progressive airway obstruction frequently requiring repeated surgery to stabilize the airway. Unknown etiology and low disease prevalence have limited the ability to characterize the natural history of iSGS and resulted in variability in surgical management. It is uncertain how this variation relates to clinical outcomes. Study Design Medical record abstraction. Methods Utilizing an international, multi‐institutional collaborative, we collected retrospective data on patient characteristics, treatment, and clinical outcomes. We investigated variation between and within open and endoscopic treatment approaches and assessed therapeutic outcomes; specifically, disease recurrence and need for tracheostomy at last follow‐up. Results Strikingly, 479 iSGS patients across 10 participating centers were nearly exclusively female (98%, 95% confidence interval [CI], 96.1–99.6), Caucasian (95%, 95% CI, 92.2–98.8), and otherwise healthy (mean age‐adjusted Charlson Comorbidity Index 1.5; 95% CI, 1.44–1.69). The patients presented at a mean age of 50 years (95% CI, 48.8–51.1). A total of 80.2% were managed endoscopically, whereas 19.8% underwent open reconstruction. Endoscopic surgery had a significantly higher rate of disease recurrence than the open approach (chi 2 = 4.09, P = 0.043). Tracheostomy was avoided in 97% of patients irrespective of surgical approach (95% CI, 94.5–99.8). Interestingly, there were outliers in rates of disease recurrence between centers using similar treatment approaches. Conclusion Idiopathic subglottic stenosis patients are surprisingly homogeneous. The heterogeneity of treatment approaches and the observed outliers in disease recurrence rates between centers raises the potential for improved clinical outcomes through a detailed understanding of the processes of care. Level of Evidence 4. Laryngoscope , 126:1390–1396, 2016