CSP-1103 (CHF5074) stabilizes human transthyretin in healthy human subjects.

Hereditary amyloid polyneuropathy is a type of protein misfolding disease. Transthyretin (TTR) is a homotetrameric serum protein and TTR tetramer dissociation is the limiting step in amyloid fibril formation. Thus, prevention of TTR dissociation is a promising therapeutic approach and some TTR stabilizers have been approved for the treatment of TTR amyloidosis. CSP-1103 (CHF5074) is a non-steroidal anti-inflammatory derivative that lacks cyclooxygenase inhibitory activity. In vitro, CSP-1103 stabilizes the TTR tetramer by binding to the thyroxine (T4) binding site. We have previously shown that serum TTR levels were increased by oral CSP-1103 administration through stabilization of TTR tetramers in humanized mice at both the Ttr locus and the Rbp4 locus. To determine whether CSP-1103 stabilizes TTR tetramers in humans, multiple CSP-1103 oral doses were administered for two weeks to 48 healthy human volunteers in a double-blind, placebo-controlled, parallel-group study. CSP-1103 treatment stabilized TTR tetramers in a dose-dependent manner under normal or denaturing stress conditions, thereby increasing serum TTR levels. Preincubation of serum with CSP-1103 or diflunisal in vitro increased the TTR tetramer stability. Computer simulation analysis revealed that the binding affinities of CSP-1103 with TTR at pH 7.0 were similar to those of tafamidis, thus confirming that CSP-1103 has potent TTR-stabilizing activity.

A microfluidic flow injection system for DNA assay with fluids driven by an on-chip integrated pump based on capillary and evaporation effects.

A miniaturized flow injection analysis (FIA) system integrating a micropump on a microfluidic chip based on capillary and evaporation effects was developed. The pump was made by fixing a filter paper plug with a vent tube at the channel end, it requires no peripheral equipment and provides steady flow in the microl min(-1) range for FIA operation. Valve-free sample injection was achieved at nanolitre level using an array of slotted vials. The practical applicability of the system was demonstrated by DNA assay with laser-induced fluorescence (LIF) detection. A precision of 1.6% RSD (10.0 ng microl(-1), n=15) was achieved with a sampling throughput of 76 h(-1) and sample consumption of 95 nl.

The use of a micropump based on capillary and evaporation effects in a microfluidic flow injection chemiluminescence system.

The performance of a micropump operating on evaporation and capillary effects, developed for microfluidic (lab-on-a-chip) systems, was studied employing it as the fluid drive in a microfluidic flow injection (FI) system, with chemiluminescence (CL) detection. The micropump featured simple structure, small dimensions, low fabrication cost and stable and adjustable flow-rates during long working periods. Using a micropump with 6.6cm(2) evaporation area, with the ambient temperature and relative humidity fluctuating within 2h in the ranges 20-21 degrees C and 30-32%, respectively, an average flow-rate of 3.02muL/min was obtained, with a precision better than 1.2% R.S.D. (n=61). When applied to the microchip FI-CL system using the luminol/hexacyanoferrate/H(2)O(2) reaction, a precision of 1.4% R.S.D. (n=11) was obtained for luminol at a sampling frequency of 30h(-1).

Feature characterization of microfabricated microfluidic chips by PDMS replication and CCD imaging.

This paper presents a new approach for the metrological characterization of microfabricated features on microfluidic chips, based on a combination of poly(dimethylsiloxane) (PDMS) replication and charge-coupled device (CCD) imaging. A PDMS replicate was cast from the original chip sample, and a 2-mm thick sample slice was cut from the replica at the cross-section to be studied. The digital image of the revealed structural profile was captured by a CCD camera under a microscope, and the image was processed using specially-developed algorithms for CCD image calibration and edge detection. Depth and width measurements obtained using the method agreed well with those gained using a stylus profiler and universal measuring microscope, with a deviation of below 0.9 mum, while profile distortions of deeper structures using stylus profilers were avoided. The method is reliable, non-destructive, and cheap and simple to implement in any analytical laboratory.