Citations

Abstract Proinflammatory consequences have been described for lysophosphatidylcholine, a lipid product of cellular injury, signaling via the G protein–coupled receptor G2A on myeloid and lymphoid inflammatory cells. This prompted the hypothesis that genetic deletion of G2A would limit intestinal inflammation in a mouse model of colitis induced by dextran sodium sulfate. Surprisingly, G2A−/− mice exhibited significantly worsened colitis compared with wild-type mice, as demonstrated by disease activity, colon shortening, histology, and elevated IL-6 and IL-5 in colon tissues. Investigation of inflammatory cells recruited to inflamed G2A−/− colons showed significantly more TNF-α+ and Ly6ChiMHCII− proinflammatory monocytes and eosinophils than in wild-type colons. Both monocytes and eosinophils were pathogenic as their depletion abolished the excess inflammation in G2A−/− mice. G2A−/− mice also had less IFN-γ in inflamed colon tissues than wild-type mice. Fewer CD4+ lymphocytes were recruited to inflamed G2A−/− colons, and fewer colonic lymphocytes produced IFN-γ upon ex vivo stimulation. Administration of IFN-γ to G2A−/− mice during dextran sodium sulfate exposure abolished the excess colitic inflammation and reduced colonic IL-5 and eosinophil numbers to levels seen in wild-type mice. Furthermore, IFN-γ reduced the numbers of TNF-α+ monocyte and enhanced their maturation from Ly6ChiMHCII− to Ly6CintMHCII+. Taken together, the data suggest that G2A signaling serves to dampen intestinal inflammation via the production of IFN-γ, which, in turn, enhances monocyte maturation to a less inflammatory program and ultimately reduces eosinophil-induced injury of colonic tissues.

Vascular access dysfunction remains a major cause of morbidity and mortality in hemodialysis patients. At present there are few effective therapies for this clinical problem. The poor understanding of the pathobiology that leads to arteriovenous fistula (AVF) and graft (AVG) dysfunction remains a critical barrier to development of novel and effective therapies. However, in recent years we have made substantial progress in our understanding of the mechanisms of vascular access dysfunction. This article presents recent advances and new insights into the pathobiology of AVF and AVG dysfunction and highlights potential therapeutic targets to improve vascular access outcomes.

Background: In the initial PARTNER trial (Placement of Aortic Transcatheter Valves) of transcatheter aortic valve replacement for high-risk (HR) and inoperable patients, mortality at 1 year was 24% in HR and 31% in inoperable patients. A recent report of the 30-day outcomes with the low-profile SAPIEN 3 transcatheter aortic valve replacement system demonstrated very low rates of adverse events, but little is known about the longer-term outcomes with this device. Methods: Between October 2013 and September 2014, 583 HR (65%) or inoperable (35%) patients were treated via the transfemoral (84%) or transapical/transaortic (16%) access route at 29 US sites. Major clinical events at 1 year were adjudicated by an independent clinical events committee, and echocardiographic results were analyzed by a core laboratory. Results: Baseline characteristics included age of 83 years, 42% female, and median Society of Thoracic Surgeons score of 8.4%. At the 1-year follow-up, survival (all-cause) was 85.6% for all patients, 87.3% in the HR subgroup, and 82.3% in the inoperable subgroup. Survival free of all-cause and cardiovascular mortality in the transfemoral patients from the HR cohort was 87.7% and 93.3%, respectively. There was no severe paravalvular leak. Moderate paravalvular leak (2.7%) was associated with an increase in mortality at 1 year, whereas mild paravalvular leak had no significant association with mortality. Symptomatic improvement as assessed by the percentage of patients in New York Heart Association class III and IV (90.1% to 7.7% at 1 year; P <0.0001) and by Kansas City Cardiomyopathy Questionnaire overall summary score (improved from 46.9 to 72.4; P <0.0001) was marked. Multivariable predictors of 1-year mortality included alternative access, Society of Thoracic Surgeons score, and disabling stroke. Conclusions: In this large, adjudicated registry of SAPIEN 3 HR and inoperable patients, the very low rates of important complications resulted in a strikingly low mortality rate at 1 year. Between 30 and 365 days, the incidence of moderate paravalvular aortic regurgitation did not increase, and no association between mild paravalvular leak and 1-year mortality was observed, although a small increase in disabling stroke occurred. These results, which likely reflect device iteration and procedural evolution, support the use of transcatheter aortic valve replacement as the preferred therapy in HR and inoperable patients with aortic stenosis. Clinical Trial Registration : URL: http://www.clinicaltrials.gov . Unique identifier: NCT01314313.

Nephron number may be an important determinant of kidney health but has been difficult to study in living humans. We evaluated 1638 living kidney donors at Mayo Clinic (MN and AZ sites) and Cleveland Clinic. We obtained cortical volumes of both kidneys from predonation computed tomography scans. At the time of kidney transplant, we obtained and analyzed the sections of a biopsy specimen of the cortex to determine the density of both nonsclerotic and globally sclerotic glomeruli; the total number of glomeruli was estimated from cortical volume×glomerular density. Donors 18–29 years old had a mean 990,661 nonsclerotic glomeruli and 16,614 globally sclerotic glomeruli per kidney, which progressively decreased to 520,410 nonsclerotic glomeruli per kidney and increased to 141,714 globally sclerotic glomeruli per kidney in donors 70–75 years old. Between the youngest and oldest age groups, the number of nonsclerotic glomeruli decreased by 48%, whereas cortical volume decreased by only 16% and the proportion of globally sclerotic glomeruli on biopsy increased by only 15%. Clinical characteristics that independently associated with fewer nonsclerotic glomeruli were older age, shorter height, family history of ESRD, higher serum uric acid level, and lower measured GFR. The incomplete representation of nephron loss with aging by either increased glomerulosclerosis or by cortical volume decline is consistent with atrophy and reabsorption of globally sclerotic glomeruli and hypertrophy of remaining nephrons. In conclusion, lower nephron number in healthy adults associates with characteristics reflective of both lower nephron endowment at birth and subsequent loss of nephrons.

It is generally recommended that an esophageal balloon-catheter possess an adequate frequency response up to 15 Hz, such that parameters of respiratory mechanics may be quantified with precision. In our experience, however, we have observed that some commercially available systems do not display an ideal frequency response (<8-10 Hz). We therefore investigated whether the poor frequency response of a commercially available esophageal catheter may be adequately compensated using two numerical techniques: 1) an exponential model correction, and 2) Wiener deconvolution. These two numerical techniques were performed on a commercial balloon-catheter interfaced with 0, 1, and 2 lengths of extension tubing (90 cm each), referred to as configurations L0, L90, and L180, respectively. The frequency response of the balloon-catheter in these configurations was assessed by empirical transfer function analysis, and its “working” range was defined as the frequency beyond which more than 5% amplitude and/or phase distortion was observed. The working frequency range of the uncorrected balloon-catheter extended up to only 10 Hz for L0, and progressively worsened with additional tubing length (L90 = 3 Hz, L180 = 2 Hz). Although both numerical methods of correction adequately enhanced the working frequency range of the balloon-catheter to beyond 25 Hz for all length configurations (L0, L90, and L180), Wiener deconvolution consistently provided more accurate corrections. Our data indicate that Wiener deconvolution provides a superior correction of the balloon-catheter's dynamic response, and is relatively more robust to extensions in catheter tube length compared with the exponential correction method.

Abstract Coronal limb malalignment is a significant contributor to asymmetric joint wear, gait abnormalities, and the development and progression of degenerative joint disease. Osteotomies about the knee were developed to realign the mechanical axis of the limb to unload the affected compartment. Valgus malalignment is less common than varus malalignment, but can contribute to a variety of clinical conditions, including lateral compartment cartilage defects and arthritis, lateral patellofemoral instability, and medial collateral ligament laxity. In this article, we describe our preferred operative technique for a lateral opening wedge varus‐producing distal femoral osteotomy to correct mild to moderate valgus malalignment. Technique Video video See video under supplementary data.

Treatment with abiraterone acetate and prednisone (AA/P) prolongs survival in metastatic castration-resistant prostate cancer (mCRPC) patients. We evaluated the genetic variation in CYP17A1 as predictive of response to AA/P. A prospective collection of germline DNA prior to AA/P initiation and follow-up of a mCRPC cohort was performed. Five common single-nucleotide polymorphisms (SNPs) in CYP17A1 identified using a haplotype-based tagging algorithm were genotyped. Clinical outcomes included biochemical response and time to biochemical progression on AA/P. Logistic regression was used to assess the association between tag SNPs and biochemical response. Proportional hazards regression was used to assess the association between tag SNPs and time to biochemical progression. Odds or hazard ratio per minor allele were estimated and p-values below 0.05 were considered statistically significant. Germline DNA was successfully genotyped for four tag SNPs in 87 patients. The median age was 73 years (54–90); the median prostate-specific antigen was 66 ng/dL (0.1–99.9). A single SNP, rs2486758, was associated with lower odds of experiencing a biochemical response (Odds ratio 0.22, 95% confidence interval 0.07–0.63, p = 0.005) and a shorter time to biochemical progression (Hazard ratio 2.23, 95% confidence interval 1.39–3.56, p < 0.001). This tag SNP located in the promoter region of CYP17A1 will need further validation as a predictive biomarker for AA/P therapy.

ABSTRACTIntroduction: Fluoxetine is a selective serotonin reuptake inhibitor and long‐lived open channel blocker of the acetylcholine receptor, often used in the treatment of slow‐channel congenital myasthenic syndromes (CMS). Methods: We report a 42‐year‐old woman who had a history of episodic limb weakness that worsened after initiation of fluoxetine for treatment of depression. Genetic testing for CMS revealed a homozygous pathogenic mutation in the rapsyn (RAPSN) gene (p.Asn88Lys). Electrodiagnostic testing was performed before and 1 month after discontinuation of fluoxetine. Results: The 2 Hz repetitive nerve stimulation of the fibular and spinal accessory nerves showed a baseline decrement of 36% and 14%, respectively. One month after discontinuing fluoxetine, the spinal accessory nerve decrement was no longer present, and the decrement in the fibular nerve was improved at 17%. Conclusions: This case demonstrates worsening of both clinical and electrophysiologic findings in a patient with CMS secondary to a RAPSN mutation treated with fluoxetine. Muscle Nerve 55: 131–135, 2017

AbstractShared decision making in emergency medicine has the potential to improve the quality, safety, and outcomes of emergency department (ED) patients. Given that the ED is the gateway to care for patients with a variety of illnesses and injuries and the safety net for patients otherwise unable to access care, shared decision making in the ED is relevant to numerous disciplines and the interests of the United States (U.S.) public. On May 10, 2016 the 16th annual Academic Emergency Medicine (AEM) consensus conference, “Shared Decision Making: Development of a Policy‐Relevant Patient‐Centered Research Agenda” was held in New Orleans, Louisiana. During this one‐day conference clinicians, researchers, policy‐makers, patient and caregiver representatives, funding agency representatives, trainees, and content experts across many areas of medicine interacted to define high priority areas for research in 1 of 6 domains: 1) diagnostic testing; 2) policy, 3) dissemination/implementation and education, 4) development and testing of shared decision making approaches and tools in practice, 5) palliative care and geriatrics, and 6) vulnerable populations and limited health literacy. This manuscript describes the current state of shared decision making in the ED context, provides an overview of the conference planning process, the aims of the conference, the focus of each respective breakout session, the roles of patient and caregiver representatives and an overview of the conference agenda. The results of this conference published in this issue of AEM provide an essential summary of the future research priorities for shared decision making to increase quality of care and patient‐centered outcomes.