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Gottesfeld J.M.,Scripps Research Institute | Rusche J.R.,Repligen | Pandolfo M.,Free University of Colombia
Journal of Neurochemistry | Year: 2013

The genetic defect in Friedreich's ataxia (FRDA) is the expansion of a GAA·TCC triplet in the first intron of the FXN gene, which encodes the mitochondrial protein frataxin. Previous studies have established that the repeats reduce transcription of this essential gene, with a concomitant decrease in frataxin protein in affected individuals. As the repeats do not alter the FXN protein coding sequence, one therapeutic approach would be to increase transcription of pathogenic FXN genes. Histone posttranslational modifications near the expanded repeats are consistent with heterochromatin formation and FXN gene silencing. In an effort to find small molecules that would reactivate this silent gene, histone deacetylase inhibitors were screened for their ability to up-regulate FXN gene expression in patient cells and members of the pimelic 2-aminobenzamide family of class I histone deacetylase inhibitors were identified as potent inducers of FXN gene expression and frataxin protein. Importantly, these molecules up-regulate FXN expression in human neuronal cells derived from patient-induced pluripotent stem cells and in two mouse models for the disease. Preclinical studies of safety and toxicity have been completed for one such compound and a phase I clinical trial in FRDA patients has been initiated. Furthermore, medicinal chemistry efforts have identified improved compounds with superior pharmacological properties. © 2013 International Society for Neurochemistry. Source

Sherman S.,Indiana University | Freeman M.L.,University of Minnesota | Tarnasky P.R.,Methodist Medical Center | Wilcox C.M.,University of Alabama at Birmingham | And 4 more authors.
Gastroenterology | Year: 2014

Background & Aims Administration of secretin improves noninvasive imaging of the pancreatic duct with magnetic resonance cholangiopancreatography (MRCP). We performed a large prospective study to investigate whether synthetic human secretin (RG1068)-stimulated MRCP detects pancreatic duct abnormalities with higher levels of sensitivity than MRCP. Methods We performed a phase 3, multicenter, baseline-controlled study of patients with acute or acute recurrent pancreatitis who were scheduled to undergo endoscopic retrograde cholangiopancreatography (ERCP) between March 26, 2008, and October 28, 2009. Patients underwent a baseline MRCP that was immediately followed by administration of RG1068 and repeat MRCP and then underwent ERCP within 30 days; they were followed up for 30 days. MRCP and ERCP images were read centrally by 3 radiologists and 2 endoscopists, respectively, who were all independent and blinded; pancreatic duct abnormalities were evaluated. The accuracy of MRCP was evaluated using ERCP as the standard. Results In total, 258 patients were enrolled in the study; 251 MRCP image sets were assessed, and 236 patients had evaluable ERCPs. Pancreatic duct abnormalities were observed in 60.2% of ERCP images. All radiologists identified duct abnormalities in RG1068-ciné MRCP image sets with significantly higher levels of sensitivity (P <.0001) than in images from MRCP, with minimal loss of specificity. Adverse events were reported in 38.0% of patients after MRCP and 68.1% after ERCP. Of the 55 patients who experienced a serious adverse event, 3 (1.2%) and 52 (20.5%) of the events were reported to be temporally associated with MRCP and ERCP, respectively. The adverse events most frequently considered related to RG1068 were nausea, abdominal pain, and flushing; most were mild. Conclusions Compared with images from MRCP, those from RG1068-stimulated MRCP are improved in many aspects and could aid in diagnosis and clinical decision making for patients with acute, acute recurrent, or chronic pancreatitis. RG1068-enhanced MRCP might also better identify patients in need of therapeutic ERCP (ClinicalTrials.gov, Number: NCT00660335). © 2014 by the AGA Institute. Source

Ernst J.,Carnegie Mellon University | Ernst J.,Massachusetts Institute of Technology | Plasterer H.L.,Whitehead Institute For Biomedical Research | Plasterer H.L.,Repligen | And 2 more authors.
Genome Research | Year: 2010

Information about the binding preferences of many transcription factors is known and characterized by a sequence binding motif. However, determining regions of the genome in which a transcription factor binds based on its motif is a challenging problem, particularly in species with large genomes, since there are often many sequences containing matches to the motif but are not bound. Several rules based on sequence conservation or location, relative to a transcription start site, have been proposed to help differentiate true binding sites from random ones. Other evidence sources may also be informative for this task. We developed a method for integrating multiple evidence sources using logistic regression classifiers. Our method works in two steps. First, we infer a score quantifying the general binding preferences of transcription factor binding at all locations based on a large set of evidence features, without using any motif specific information. Then, we combined this general binding preference score with motif information for specific transcription factors to improve prediction of regions bound by the factor. Using cross-validation and new experimental data we show that, surprisingly, the general binding preference can be highly predictive of true locations of transcription factor binding even when no binding motif is used. When combined with motif information our method outperforms previous methods for predicting locations of true binding. © 2010 by Cold Spring Harbor Laboratory Press. Source

Repligen | Date: 2015-06-08

Improved screen filter modules, related compartmentalized filtration modules, and related filtration processes, suitable for filtering fluid to eliminate suspended particulate matter, such as living cells or microcarriers anchoring living cells, or to separate particulate matter based on size. The improvement is the presence of a barrier that channels redirected filtrate to the portion of the filter most susceptible to clogging by the particulate matter and induces flow patterns that act against clogging.

Repligen | Date: 2013-01-30

If one manufactures chromatography column tubes from plastic/thermoplastic or composite materials (such as polypropylene (PP), polyethylene (PE), polyamides, acetals, or glass-filled plastics, such as glass-fiber plastics) and secures at least one of two flow distributors within the column tube with a tight interference or press fit, the resulting chromatography columns reduce or avoid the formation of dead zones around the press fit flow distributor and have an infinitely adjustable packing medium volume, also known as the medium bed height.

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