Brainwide silencing of prion protein by AAV-mediated delivery of an engineered compact epigenetic editor.

Prion disease is caused by misfolding of the prion protein (PrP) into pathogenic self-propagating conformations, leading to rapid-onset dementia and death. However, elimination of endogenous PrP halts prion disease progression. In this study, we describe Coupled Histone tail for Autoinhibition Release of Methyltransferase (CHARM), a compact, enzyme-free epigenetic editor capable of silencing transcription through programmable DNA methylation. Using a histone H3 tail-Dnmt3l fusion, CHARM recruits and activates endogenous DNA methyltransferases, thereby reducing transgene size and cytotoxicity. When delivered to the mouse brain by systemic injection of adeno-associated virus (AAV), Prnp-targeted CHARM ablates PrP expression across the brain. Furthermore, we have temporally limited editor expression by implementing a kinetically tuned self-silencing approach. CHARM potentially represents a broadly applicable strategy to suppress pathogenic proteins, including those implicated in other neurodegenerative diseases.

Associations of Ambulatory Blood Pressure Measurements With High-Sensitivity Troponin and Natriuretic Peptide Levels in SPRINT.

BACKGROUND: Nighttime blood pressure (BP) has greater prognostic importance for cardiovascular disease (CVD) than daytime BP, but less is known about nighttime and daytime BP associations with measures of subclinical CVD. METHODS: Among 897 Systolic Blood Pressure Intervention Trial Study (SPRINT) participants with 24-hour ambulatory BP monitoring obtained near the 27-month study visit, 849 (95%) had N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) measured at the 24-month study visit. Multivariable linear regression analyses were performed to evaluate the associations of nighttime and daytime BP with cardiac biomarker levels. RESULTS: The mean age was 69 ±â€…12 years, 28% were African American, and mean nighttime and daytime SBP were 121 ±â€…16 mm Hg and 132 ±â€…14 mm Hg, respectively. In multivariable models, compared with the lowest tertile of nighttime systolic BP, the highest tertile was associated with 48% higher NT-proBNP levels (adjusted geometric mean ratio [GMR] = 1.48, 95% CI: 1.22, 1.79), and 19% higher hs-cTnT levels (adjusted GMR = 1.19, 95% CI: 1.07, 1.32). In contrast, the highest vs. lowest tertile of daytime systolic BP was not associated with NT-proBNP (adjusted GMR = 1.09, 95% CI: 0.88, 1.34), but was associated with 16% higher hs-cTnT levels (adjusted GMR = 1.16, 95% CI: 1.04, 1.30). Similar results were observed using diastolic BP. CONCLUSIONS: In SPRINT, both higher nighttime and daytime BP were independently associated with higher hs-cTnT levels, but only higher nighttime BP was associated with higher NT-proBNP levels.

Anti-GSTT1 antibodies and Null genotype correlate with histological changes of antibody mediated rejection in kidney transplantation.

BACKGROUND: The presence of anti-Glutathione S-transferase T1 (GSTT1) antibodies (abs) has been hypothesized as a pathogenic contributor in antibody-mediated rejection (AMR). METHODS: We aimed to evaluate the relationship between genetic variants of GSTT1, anti-GSTT1 abs and AMR in a cohort of 87 kidney transplant (KTx) patients using Immucor's non-HLA Luminex assay. Patients were classified according to biopsy-proven AMR and HLA-DSA status: AMR with positive anti-HLA-DSAs (AMR/DSA+, n = 29), AMR but no detectable anti-HLA-DSAs (AMR/DSA-, n = 28) and control patients with stable allograft function and no evidence of rejection (n = 30). RESULTS: At an MFI cut-off of 3000, the overall prevalence of anti-GSTT1 abs was 18.3%. The proportion of patients with anti-GSTT1 abs was higher in the AMR/DSA- group (25%), compared to the control (13.3%) and AMR/DSA+ group (3.4%) (p = 0.06). Among patients with anti-GSTT1 abs, the MFI was higher in AMR/DSA- and GSTT1-Null patients. Of 81 patients who underwent GSTT1 genotyping, 19.8% were homozygotes for the null allele (GSTT1-Null). GSTT1-Null status in the transplant recipients was associated with the development of anti-GSTT1 abs (OR, 4.49; 95%CI, 1.2-16.7). In addition, GSTT1-Null genotype (OR 26.01; 95%CI, 1.63-404) and anti-GSTT1 ab positivity (OR 14.8; 95%CI, 1.1-190) were associated with AMR. Within AMR/DSA- patients, the presence of anti-GSTT1 abs didn't confer a higher risk of failure within the study observation period. CONCLUSION: The presence of anti-GSTT1 abs and GSTT1-Null genotype is associated with AMR, but do not appear to lead to accelerated graft injury in this cohort of early allograft injury changes, with a limited period of follow-up.

Association of MICA and AT1R antibodies with antibody-mediated rejection and cardiac allograft vasculopathy in a pediatric heart transplant recipient.

BACKGROUND: Recipient antibodies against mismatched donor-specific human leukocyte antigens (HLA) are known to be associated with antibody-mediated rejection (AMR), posing increased risks of cardiac allograft vasculopathy (CAV), graft dysfunction, and graft loss after heart transplant (HTx). However, the impact of non-HLA antibodies on HTx outcome is not yet well defined. CASE DESCRIPTION: Here we report a case of a pediatric patient, who was retransplanted after developing CAV in his first heart allograft. Five years post 2nd HTx, the patient presented with graft dysfunction and mild rejection (ACR 1R, AMR 1H, C4d Neg) in the cardiac biopsy in the absence of HLA donor-specific antibodies (DSAs). We detected strong antibodies against non-HLA antigens, including angiotensin II receptor type 1 (AT1R) and donor-specific MHC class I chain-related gene A (MICA), in the patient's serum that were implicated in the AMR and accelerated CAV of his second allograft, and likely played a role in the loss of his first allograft as well. CONCLUSION: This case report underscores the clinical relevance of non-HLA antibodies in heart transplantation and highlights the value of incorporating these tests in the immunological risk assessment and post-transplant monitoring of HTx recipients.

Intensive Blood Pressure Lowering in Patients With Malignant Left Ventricular Hypertrophy.

BACKGROUND: Left ventricular hypertrophy (LVH) combined with elevations in cardiac biomarkers reflecting myocardial injury and neurohormonal stress (malignant LVH) is associated with a high risk for heart failure and death. OBJECTIVES: The aim of this study was to determine the impact of intensive systolic blood pressure (SBP) control on the prevention of malignant LVH and its consequences. METHODS: A total of 8,820 participants in SPRINT (Systolic Blood Pressure Intervention Trial) were classified into groups based on the presence or absence of LVH assessed by 12-lead ECG, and elevations in biomarker levels (high-sensitivity cardiac troponin T ≥14 ng/L or N-terminal pro-B-type natriuretic peptide ≥125 pg/mL) at baseline. The effects of intensive vs standard SBP lowering on rates of acute decompensated heart failure (ADHF) events and death and on the incidence and regression of malignant LVH were determined. RESULTS: Randomization to intensive SBP lowering led to similar relative reductions in ADHF events and death across the combined LVH/biomarker groups (P for interaction = 0.68). The absolute risk reduction over 4 years in ADHF events and death was 4.4% (95% CI: -5.2% to 13.9%) among participants with baseline malignant LVH (n = 449) and 1.2% (95% CI: 0.0%-2.5%) for those without LVH and nonelevated biomarkers (n = 4,361). Intensive SBP lowering also reduced the incidence of malignant LVH over 2 years (2.5% vs 1.1%; OR: 0.44; 95% CI: 0.30-0.63). CONCLUSIONS: Intensive SBP lowering prevented malignant LVH and may provide substantial absolute risk reduction in the composite of ADHF events and death among SPRINT participants with baseline malignant LVH.

Enantioselective fluorescent recognition in the fluorous phase: enhanced reactivity and expanded chiral recognition.

A novel perfluoroalkyl-BINOL-based chiral diketone is found to be the first highly enantioselective fluorescent sensor in the fluorous phase. One enantiomer of a chiral amino alcohol or diamine at a concentration greater than 1 mM can cause an up to 1200-2000-fold fluorescent enhancement of the sensor (0.08 mM), while the other enantiomer gives only a 10-50-fold enhancement. The fluorous-phase-based sensor is found to enhance the reactivity of the previously reported fluorous insoluble sensor with amino alcohols and expand its chiral recognition ability. Dynamic light scattering studies show the formation of aggregates of very different particle sizes when two enantiomers of a substrate interact with the sensor in perfluorohexane (FC-12). This substantial difference enables easy discrimination of the enantiomers with UV-lamps or even the naked eye. NMR, IR, and mass spectroscopic studies indicate that the fluorescent enhancement and enantioselectivity should originate from the fluorous solvent-promoted nucleophilic addition of the amino alcohols to the carbonyl groups of the sensor.

Molecular recognition of aliphatic diamines by 3,3'-di(trifluoroacetyl)-1,1'-bi-2-naphthol.

The fluorescent responses of 3,3'-di(trifluoroacetyl)-1,1'-bi-2-naphthol toward a variety of amines have been studied. It was found that the aliphatic primary 1,2- and 1,5-diamines can greatly enhance the fluorescence of this compound, but under the same conditions, primary, secondary, and tertiary monoamines cannot turn on the fluorescence of this compound. In addition, this compound was shown to be an enantioselective and diastereoselective fluorescent sensor for chiral diamines. UV absorption and NMR spectroscopic methods have been used to study the interaction of the sensor with amines. These studies have demonstrated that the intramolecular OH···O═C hydrogen bonding of the sensor is important for both the reactivity of its trifluoroacetyl group with the amines and its fluorescent responses. The interaction of both of the two amine groups of a diamine molecule with the sensor is essential for the observed fluorescent sensitivity and selectivity.

Descemet stripping automated endothelial keratoplasty after failed penetrating keratoplasty.

PURPOSE: To report the rate of graft dislocation, surgical anatomic success, and postsurgical complications associated with Descemet stripping automated endothelial keratoplasty (DSAEK) after previous primary failed penetrating keratoplasty (PK). METHODS: Institutional review board-approved, single-center, retrospective chart review study of 30 eyes of 30 patients with prior failed PK who underwent DSAEK with a minimum of 3 months follow-up. Primary outcomes measured included rates of anatomic success and failure, postoperative complications, lenticle size, visual acuity, intraocular pressure change, and a report of external factors that may affect success. RESULTS: Thirty eyes of 30 patients were identified. The primary dislocation rate was 16.7%. Five primary DSAEKs detached; 1 was successfully rebubbled in the office, 2 had repeat successful DSAEKs, and 2 failed on a second attempt and had a subsequent PK. Despite successful anatomic attachment, 1 eye had primary graft failure, 3 that cleared initially failed within 6 months, and 1 that successfully cleared had subsequent graft rejection resulting in failure at 6 months. The 2 eyes requiring PK were excluded from the visual outcomes analysis, leaving 28 eyes with successfully attached lenticles. At 3 months postoperatively, of the 28 eyes, 19 showed an improvement in visual acuity, 6 had no change in vision from preoperative data, and 1 had worsening of vision (anatomic attachment but endothelial failure). Two of the 28 eyes had no data at that time point. CONCLUSIONS: DSAEK eyes after failed PK demonstrated improved vision with a low complication rate in a majority of patients. The graft dislocation rate and postoperative complications rates are comparable with the primary DSAEK dislocation rates in our own published series and in the literature.

Graft rejection following descemet stripping automated endothelial keratoplasty: features, risk factors, and outcomes.

PURPOSE: To investigate the clinical features, risk factors, and treatment outcomes following immunologic graft rejection in eyes that have undergone Descemet stripping automated endothelial keratoplasty (DSAEK). DESIGN: Retrospective case review. METHODS: The charts for 353 DSAEK procedures performed at a single clinical practice at the New York Eye and Ear Infirmary from August 2006 to November 2010 were reviewed. Cases with at least 3 months follow-up were included. Outcome measures included rates of graft rejection, clinical findings, treatment outcomes, and risk factor analysis. RESULTS: Thirty of 353 DSAEKs developed graft rejection (8.5%). Kaplan-Meier rate of rejection was 6.0% at 1 year (n = 175), 14.0% at 2 years (n = 79), and 22.0% at 3 years (n = 39). Rejection episodes occurred between 0.8 and 34 months. Clinical findings included anterior chamber cells, keratic precipitates, endothelial rejection line, and host-donor interface vascularization. Risk factors for development of graft rejection were cessation of postoperative steroid (hazard ratio 5.49, P < .0001) and black race (hazard ratio 2.71, P = .02). Recipient age, sex, surgical indication, glaucoma, postoperative steroid response, corneal neovascularization or peripheral anterior synechiae, graft size, prior keratoplasty in fellow eye, and concurrent or subsequent procedures were not associated with graft rejection. Twenty-two out of 30 rejection episodes (73.3%) resolved with steroid treatment. CONCLUSIONS: Graft rejection is an important complication following DSAEK. In contrast to penetrating keratoplasty, rejection following DSAEK is almost exclusively endothelial. Among risk factors traditionally associated with graft rejection, cessation of topical steroids was most significant. Prompt recognition and treatment of DSAEK rejection can lead to favorable outcomes.

Serious ocular complications of cosmetic iris implants in 14 eyes.

PURPOSE: To report the presentation and subsequent management of a series of patients presenting with cosmetic iris implants. SETTING: New York Eye and Ear Infirmary, New York, New York, USA. DESIGN: Case series. METHODS: In this evaluation of patients with NewColorIris cosmetic iris implants, data collected included patient demographics, visual acuity, intraocular pressure (IOP), endothelial cell count, and slitlamp examination findings at presentation. Medical and surgical interventions and the postoperative course were recorded. RESULTS: Fourteen eyes of 7 patients (ages 22 to 60; 71% men) were identified. Nine eyes (64%) presented with decreased visual acuity, 7 (50%) had elevated IOP, 5 (36%) had corneal edema, and 5 (36%) had anterior uveitis. All 14 eyes had explantation of the iris prosthesis (range 4 to 33 months after placement). The minimum follow-up after implant removal in all eyes was 2 months (range 2 to 28 months). Intraoperative complications included suprachoroidal hemorrhage during explantation in 1 eye. Postoperative complications included corneal edema (8 eyes), cataract (9 eyes), and increased IOP/glaucoma (7 eyes). Secondary surgeries included Descemet-stripping automated endothelial keratoplasty (5 eyes), cataract extraction with intraocular lens placement (7 eyes), trabeculectomy (3 eyes), glaucoma drainage implant placement (3 eyes), and penetrating keratoplasty (1 eye). CONCLUSIONS: The cosmetic iris implants may result in severe ocular morbidity. Complications in our series included uveitis, glaucoma, corneal edema, and decreased visual acuity. Although explantation helped stabilize symptoms, additional medical and surgical intervention to control IOP and corneal decompensation was required in many cases. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Structural MRI biomarkers for preclinical and mild Alzheimer's disease.

Noninvasive MRI biomarkers for Alzheimer's disease (AD) may enable earlier clinical diagnosis and the monitoring of therapeutic effectiveness. To assess potential neuroimaging biomarkers, the Alzheimer's Disease Neuroimaging Initiative is following normal controls (NC) and individuals with mild cognitive impairment (MCI) or AD. We applied high-throughput image analyses procedures to these data to demonstrate the feasibility of detecting subtle structural changes in prodromal AD. Raw DICOM scans (139 NC, 175 MCI, and 84 AD) were downloaded for analysis. Volumetric segmentation and cortical surface reconstruction produced continuous cortical surface maps and region-of-interest (ROI) measures. The MCI cohort was subdivided into single- (SMCI) and multiple-domain MCI (MMCI) based on neuropsychological performance. Repeated measures analyses of covariance were used to examine group and hemispheric effects while controlling for age, sex, and, for volumetric measures, intracranial vault. ROI analyses showed group differences for ventricular, temporal, posterior and rostral anterior cingulate, posterior parietal, and frontal regions. SMCI and NC differed within temporal, rostral posterior cingulate, inferior parietal, precuneus, and caudal midfrontal regions. With MMCI and AD, greater differences were evident in these regions and additional frontal and retrosplenial cortices; evidence for non-AD pathology in MMCI also was suggested. Mesial temporal right-dominant asymmetries were evident and did not interact with diagnosis. Our findings demonstrate that high-throughput methods provide numerous measures to detect subtle effects of prodromal AD, suggesting early and later stages of the preclinical state in this cross-sectional sample. These methods will enable a more complete longitudinal characterization and allow us to identify changes that are predictive of conversion to AD.

A generalized mechanism for perception of pitch patterns.

Surviving in a complex and changeable environment relies on the ability to extract probable recurring patterns. Here we report a neurophysiological mechanism for rapid probabilistic learning of a new system of music. Participants listened to different combinations of tones from a previously unheard system of pitches based on the Bohlen-Pierce scale, with chord progressions that form 3:1 ratios in frequency, notably different from 2:1 frequency ratios in existing musical systems. Event-related brain potentials elicited by improbable sounds in the new music system showed emergence over a 1 h period of physiological signatures known to index sound expectation in standard Western music. These indices of expectation learning were eliminated when sound patterns were played equiprobably, and covaried with individual behavioral differences in learning. These results demonstrate that humans use a generalized probability-based perceptual learning mechanism to process novel sound patterns in music.