Novel ISCR1-linked resistance genes found in multidrug-resistant Gram-negative bacteria in southern China.

Non-duplicate multidrug-resistant (MDR) Gram-negative bacteria (n=1329) isolated from southern China between January 2008 and December 2009 were investigated for the presence of ISCR1 as well as characterisation of ISCR1-linked resistance genes. Of 433 ISCR1-positive strains, 151 appeared to carry ISCR1-linked resistance genes. Seven different ISCR1-linked resistance gene arrays were identified by restriction fragment length polymorphism (RFLP) and DNA sequencing analysis.

Preventive effect of Imperatorin on acute lung injury induced by lipopolysaccharide in mice.

Imperatorin, a linear furanocoumarin, has many pharmacological effects such as antibacterial, anti-inflammatory and antiviral effects. The purpose of this study was to investigate the effect of Imperatorin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. BALB/c mice were pretreated with Imperatorin 1h before LPS challenge.

Measuring volumetric change after augmentation mammaplasty using a three-dimensional scanning technique: an innovative method.

Background: Measurement of volumetric change after augmentation mammaplasty is of great significance to plastic surgeons. This study aimed to introduce a new method using a three-dimensional (3D) scanning technique to measure volumetric change after augmentation mammaplasty.

Methods: Preoperative 3D scans of 10 breasts were included in the study.

Class 1 integron gene cassettes in multidrug-resistant Gram-negative bacteria in southern China.

Non-duplicate multidrug-resistant Gram-negative bacteria (n=1447) isolated from January 2008 to December 2009 were investigated for the presence of integrons as well as characterisation of gene cassettes. Among 825 strains carrying the class 1 integrase gene intI1, 461 gene cassette-positive isolates were found. Thirty-eight distinct gene cassette arrays were identified by restriction fragment length polymorphism (RFLP) and DNA sequencing analyses.

Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.

A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established.

Identification of human regulatory T cells in the setting of T-cell activation and anti-CTLA-4 immunotherapy on the basis of expression of latency-associated peptide.

Unlabelled: Effector and regulatory T cells (Treg) share multiple markers that make it difficult to discern differences in these populations in humans. The transcription factor FoxP3 has been shown to identify Tregs. However, the detection of FoxP3 requires cell permeabilization, thereby preventing isolation of viable Tregs.

Evaluation of breast tumor margins in vivo with intraoperative photoacoustic imaging.

The use of photoacoustic effect is a promising approach for biomedical imaging in living tissues. Photoacoustic tomography (PAT) has been demonstrated to image breast cancer, brain vasculature, arthritis and seizure focus owing to its rich optical contrast and high resolution in a single imaging modality. Here we report a microelectromechanical systems (MEMS)-based intraoperative PAT (iPAT) technique, and demonstrate its ability to accurately map tumors in three-dimension and to inspect the completeness of tumor resection during surgery in a tumor-bearing mouse model.

Evaluation of a MEMS-based dual metal-layer thin-film microelectrode array for suprachoroidal electrical stimulation.

A double metal-layer thin-film platinum microelectrode array was fabricated for implantation between sclera and choroid based on MEMS processing techniques and photosensitive polyimide material. The array was composed of 60 stimulating sites (6 × 10) and four selectable returning electrodes. The diameter of each stimulating electrode was 350 μ m with a center-to-center spacing of 750 μm.

Ultrafast kinetic DNA hybridization assay based on the visualization of threshold turbidity.

We report herein the development of an ultrafast kinetic DNA hybridization assay system based on the visualization of threshold turbidity associated with the assembly of polystyrene nanospheres. Initial testing of our diagnostic protocol on a sequence associated with the anthrax lethal factor indicates that a visually identifiable, turbidity-definitive, and kinetic threshold state could be reached at a time as short as 1 min. The assay scheme allows for both target concentration quantification and differentiation of single base mismatches through registry of the threshold turbidity onset time.

Using independent component analysis to remove artifacts in visual cortex responses elicited by electrical stimulation of the optic nerve.

In visual prosthesis research, electrically evoked potentials (EEPs) can be elicited by one or more biphasic current pulses delivered to the optic nerve (ON) through penetrating electrodes. Multi-channel EEPs recorded from the visual cortex usually contain large stimulus artifacts caused by instantaneous electrotonic current spread through the brain tissue. These stimulus artifacts contaminate the EEP waveform and often make subsequent analysis of the underlying neural responses difficult.

Refractive index measurement of acute rat brain tissue slices using optical coherence tomography.

An optical coherence tomography (OCT) system employing a microelectromechanical system (MEMS) mirror was used to measure the refractive index (RI) of anatomically different regions in acute brain tissue slices, in which viability was maintained. RI was measured in white-matter and grey-matter regions, including the cerebral cortex, putamen, hippocampus, thalamus and corpus callosum. The RI in the corpus callosum was found to be ~4% higher than the RIs in other regions.

A coordination complex system for generic, ultrafast, and sensitive multimode fluorescent staining of biomolecules.

Gel electrophoresis staining methodologies documented thus far are largely utilized in a biomolecule context-dependent manner. We report herein the development of a generic, ultrafast, and sensitive multimode fluorescent system for the efficient identification of DNA, RNA, and proteins. Interaction between a positively charged, planar ligand-based coordination complex with partner biomolecule leads to aggregation-induced fluorescence quenching and allows for the image contrast generation within one minute.

Lentviral-mediated RNAi to inhibit target gene expression of the porcine integrin αv subunit, the FMDV receptor, and against FMDV infection in PK-15 cells.

Background: shRNA targeting the integrin αv subunit, which is the foot-and-mouth disease virus (FMDV) receptor, plays a key role in virus attachment to susceptible cells. We constructed a RNAi lentiviral vector, iαv pLenti6/BLOCK -iT™, which expressed siRNA targeting the FMDV receptor, the porcine integrin αv subunit, on PK-15 cells. We also produced a lentiviral stock, established an iαv-PK-15 cell line, evaluated the gene silencing efficiency of mRNA using real-time qRT-PCR, integrand αv expression by indirect immunofluorescence assay (IIF) and cell enzyme linked immunosorbent assays (cell ELISA), and investigated the in vivo inhibitory effect of shRNA on FMDV replication in PK-15 cells.

Honeycomb-structured films by multifunctional amphiphilic biodegradable copolymers: surface morphology control and biomedical application as scaffolds for cell growth.

Recently, fabrication of functional porous polymer films with patterned surface structures at the scale from nanometer to micrometer has been attracting increasing interests in material science and nanobiotechnology. In this work, we present new preparation of two series of multifunctional amphiphilic copolymers and preparation of their microporous thin films on solid substrates. First, diblock dendritic poly(l-lysine)-b-poly(l-lactide)s and triblock dendritic poly(l-lysine)-b-poly(l-lactide)-b-dendritic poly(l-lysine)s (C1-C6) were synthesized through 4-dimethylaminopyridine (DMAP)-catalyzed living ring-opening polymerization of (l-)-lactide with (l-)-lysine dendron initiators, and their structures were characterized by nuclear magnetic resonance spectrometer (NMR), gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization Fourier-transformed mass spectra (MALDI-FTMS).

DNA diagnostics with a bacterial reporter probe.

A DNA diagnostic system has been developed by using a bacterial reporter probe. DNA hybridization-driven magnetic isolation of E. coli, followed by exponential bacterial growth and fluorescent protein expression, allows the translation of a target binding event into a vastly amplified signal and a highly sensitive/selective detection platform.

Miniature endoscopic optical coherence tomography probe employing a two-axis microelectromechanical scanning mirror with through-silicon vias.

We present the design and experimental results of a new MEMS-based endoscopic optical coherence tomography (OCT) probe. The uniqueness of this miniature OCT imaging probe is a two-axis MEMS mirror with through-silicon vias (TSVs) for interconnecting. The TSV interconnection enables ultracompact probe design, successfully reducing the probe size to only 2.

The intracellular plasmid DNA localization of cationic reducible cholesterol-disulfide lipids.

Stimuli-responsive biomaterials derived from natural products toward efficient drug/gene delivery have been attracting increasing attention in the past decade. In this work, we first designed and prepared a new series of cholesterol-disulfide lipids, namely CHOSS-N, CHOSS-N+, CHOSS-Lys and CHOSS-4N bearing cholesterol and a variety of headgroups via disulfide and carbonate bond linkages, and their molecular structures were characterized by NMR and ESI-MS. Furthermore, plasmid DNA binding affinity for these new CHOSS lipids was separately examined by ethidium bromide displacement and agarose-gel retardant assay.

Photoacoustic imaging based on MEMS mirror scanning.

A microelectromechanical systems (MEMS)-based photoacoustic imaging system is reported for the first time. In this system, the MEMS-based light scanning subsystem and a ring-shaped polyvinylidene fluoride (PVDF) transducer are integrated into a miniaturized probe that is capable of three-dimensional (3D) photoacoustic imaging. It is demonstrated that the imaging system is able to image small objects embedded in phantom materials and in chicken and to in vivo visualize blood vessels under the skin of a human hand.

Comparison of pulsed photothermal radiometry, optical coherence tomography and ultrasound for melanoma thickness measurement in PDMS tissue phantoms.

Melanoma accounts for 75% of all skin cancer deaths. Pulsed photothermal radiometry (PPTR), optical coherence tomography (OCT) and ultrasound (US) are non-invasive imaging techniques that may be used to measure melanoma thickness, thus, determining surgical margins. We constructed a series of PDMS tissue phantoms simulating melanomas of different thicknesses.

Spatiotemporal properties of multipeaked electrically evoked potentials elicited by penetrative optic nerve stimulation in rabbits.

Purpose: To investigate the spatiotemporal properties of the cortical responses elicited by intraorbital optic nerve (ON) stimulation with penetrating electrodes as means of designing optimal stimulation strategies for an ON visual prosthesis.

Methods: The ON of rabbits was exposed by orbital surgery for electrical stimulation. Craniotomy was performed to expose the visual cortex contralateral to the operated eye.

3D in vivo optical coherence tomography based on a low-voltage, large-scan-range 2D MEMS mirror.

3D in vivo optical imaging on a mouse has been obtained using a 2D MEMS mirror for lateral scanning in a time-domain optical coherence tomography (OCT) system. The MEMS mirror aperture size is 1 x 1 mm(2), and the device footprint is 2 x 2 mm(2). The MEMS mirror scans +/- 30 degrees optical angles about both x and y-axis at only 5.

Preoperative CTLA-4 blockade: tolerability and immune monitoring in the setting of a presurgical clinical trial.

Purpose: Cytotoxic T lymphocyte associated antigen (CTLA-4) blockade is being explored in numerous clinical trials as an immune-based therapy for different malignancies. Our group conducted the first preoperative clinical trial with the anti-CTLA-4 antibody ipilimumab in 12 patients with localized urothelial carcinoma of the bladder.

Experimental Design: Six patients were treated with 3 mg/kg/dose of anti-CTLA-4 and six patients were treated with 10 mg/kg/dose of antibody.

Inactivation of Msx1 and Msx2 in neural crest reveals an unexpected role in suppressing heterotopic bone formation in the head.

In an effort to understand the morphogenetic forces that shape the bones of the skull, we inactivated Msx1 and Msx2 conditionally in neural crest. We show that Wnt1-Cre inactivation of up to three Msx1/2 alleles results in a progressively larger defect in the neural crest-derived frontal bone. Unexpectedly, in embryos lacking all four Msx1/2 alleles, the large defect is filled in with mispatterned bone consisting of ectopic islands of bone between the reduced frontal bones, just anterior to the parietal bones.

3D polarization-sensitive optical coherence tomography of canine meniscus based on a 2D high-fill-factor microelectromechanical Mirror.

A miniature optical imaging probe based on a high-fill-factor MEMS mirror has been developed for nondestructive diagnosis of articular joint diseases and injuries. The MEMS mirror scans +/-30 degrees at less than 6 V in both x- and y-axis. The outer diameter of the probe is 5.

Reconstitution and engineering of apoptotic protein interactions on the bacterial cell surface.

The interactions between pro- and anti-apoptotic members of the Bcl-2 class of proteins control whether a cell lives or dies, and the study of these protein-protein interactions has been an area of intense research. In this report, we describe a new tool for the study and engineering of apoptotic protein interactions that is based on the flow cytometric detection of these interactions on the surface of Escherichia coli. After validation of the assay with the well-studied interaction between the Bak(72-87) peptide and the anti-apoptotic protein Bcl-x(L), the effect of both increasing and decreasing Bak peptide length on Bcl-x(L) binding was investigated.