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A novel series of N-substituted tropane derivatives was characterized as potent muscarinic acetylcholine receptor antagonists (mAChRs). Kinetic washout studies showed that the N-endosubstituted analog 24 displayed much slower reversibility at mAChRs than the methyl-substituted parent molecule darotropium. In addition, it was shown that this characteristic appeared to translate into enhanced which duration of action in a mouse model of bronchonstriction., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

We have achieved the ability to synthesize thousands of unique, long oligonucleotides (150mers) in fmol amounts using parallel synthesis of DNA on microarrays. The sequence accuracy of the oligonucleotides in such large-scale syntheses has been limited by the yields and side reactions of the DNA synthesis process used. While there has been significant demand for libraries of long oligos (150mer and more), the yields in conventional DNA synthesis and the associated side reactions have previously limited the availability of oligonucleotide pools to lengths <100 nt. Using novel array based depurination assays, we show that the depurination side reaction is the limiting factor for the synthesis of libraries of long oligonucleotides on Agilent Technologies' SurePrint DNA microarray platform. We also demonstrate how depurination can be controlled and reduced by a novel detritylation process to enable the synthesis of high quality, long (150mer) oligonucleotide libraries and we report the characterization of synthesis efficiency for such libraries. Oligonucleotide libraries prepared with this method have changed the economics and availability of several existing applications (e.g. targeted resequencing, preparation of shRNA libraries, site-directed mutagenesis), and have the potential to enable even more novel applications (e.g. high-complexity synthetic biology).

A new generation of technologies is poised to reduce DNA sequencing costs by several orders of magnitude. But our ability to fully leverage the power of these technologies is crippled by the absence of suitable 'front-end' methods for isolating complex subsets of a mammalian genome at a scale that matches the throughput at which these platforms will routinely operate. We show that targeting oligonucleotides released from programmable microarrays can be used to capture and amplify approximately 10,000 human exons in a single multiplex reaction. Additionally, we show integration of this protocol with ultra-high-throughput sequencing for targeted variation discovery. Although the multiplex capture reaction is highly specific, we found that nonuniform capture is a key issue that will need to be resolved by additional optimization. We anticipate that highly multiplexed methods for targeted amplification will enable the comprehensive resequencing of human exons at a fraction of the cost of whole-genome resequencing.

The effect of exogenous thyroid hormones (TH), thyroxine (T4) or triiodothyronine (T3), on spontaneous metamorphosis and serum T4 and T3 levels was examined in immediately premetamorphic sea lampreys (Petromyzon marinus) from two populations. Size (> or = 120 mm in length and 3.0 g in weight) and a condition factor (CF) of > or = 1.50 were used to predict the number of larvae that were expected to metamorphose. The smallest size and lowest CF found in metamorphosing animals of each population (i.e., the minimum length, weight, and CF) were also used in our assessment. Untreated larvae from Putnam Creek metamorphosed at a larger size (minimums; 134 mm, 4.12 g) than anticipated, out the minimum CF (1.59) and the incidence of metamorphosis (4/5 based on minimums) were consistent with results from the Salmon River population (minimums: 121 mm, 3.15 g, 1.54 CF, 8/9 metamorphosing). In the two experiments, T4-treated animals showed the predicted incidence of metamorphosis (2/2, 10/10), but significantly fewer larvae metamorphosed in the T3-treated groups (1/5, 5/11) than predicted. It was concluded that exogenous T3 administration affected the incidence of metamorphosis. In the treatment groups, serum TH levels in most nonmetamorphosing and metamorphosing animals were significantly higher than controls. Metamorphosing animals exposed to either TH had lower serum TH concentrations than nonmetamorphosing animals. A decline in serum TH levels is an early feature of metamorphosis in lampreys, but the artificial maintenance of elevated serum levels of TH cannot inhibit the decline in spontaneous metamorphosis. If the depression of serum TH levels contributes to the initiation of metamorphic change, the magnitude of the decline is not a contributing factor.