Fast screening of ligand-protein interactions based on ligand-induced protein stabilization of gold nanoparticles.

High throughput screening of small molecular weight (LMW) ligands for protein and sensitive determination of ligand-induced protein stabilization is an important task in drug discovery and in protein structural and functional genomics studies. In this study, gold nanoparticles (AuNPs) and their aggregation property are used to develop a rapid and less equipment intensive assay for screening the interactions between LMW ligands and transcription factors (TFs) and human serum albumin. The assay is based on the fact that the aggregation/discpersion status of AuNPs is very sensitive to the conformation of surrounding proteins, and when a LMW ligand binds to the proteins, it can enhance proteins' salt and thermal stability, and therefore the protective effect on AuNPs from aggregation.

Studying forkhead box protein A1-DNA interaction and ligand inhibition using gold nanoparticles, electrophoretic mobility shift assay, and fluorescence anisotropy.

Forkhead box protein 1 (FoxA1) is a member of the forkhead family of winged helix transcription factors that plays pivotal roles in the development and differentiation of multiple organs and in the regulation of estrogen-stimulated genes. Conventional analytical methods-electrophoretic mobility shift assay (EMSA) and fluorescence anisotropy (FA)-as well as a gold nanoparticles (AuNPs)-based assay were used to study DNA binding properties of FoxA1 and ligand interruption of FoxA1-DNA binding. In the AuNPs assay, the distinct ability of protein-DNA complex to protect AuNPs against salt-induced aggregation was exploited to screen sequence selectivity and determine the binding affinity constant based on AuNPs color change and absorbance spectrum shift.

Hybrid sensor using gold nanoparticles and conjugated polyelectrolytes for studying sequence rule in protein-DNA interactions.

Protein-DNA interactions play center roles in many biological processes. Studying sequence specific protein-DNA interactions and revealing sequence rules require sensitive and quantitative methodologies that are capable of capturing subtle affinity difference with high accuracy and in a high throughput manner. In this study, double stranded DNA-conjugated gold nanoparticles (dsDNA-AuNPs) and water-soluble conjugated polyelectrolytes (CPEs) are used as cooperative sensing elements to construct a suit of hybrid sensors for detecting protein-DNA interactions, exploiting the differential Förster resonance energy transfer (FRET) with and without protein binding.

Study sequence rules of estrogen receptor α-DNA interactions using dual polarization interferometry and computational modeling.

Estrogen receptor α (ERα) is a ligand-activated transcription factor. In a classical model, ERα regulates gene expression by binding to DNA sequences called estrogen response elements (EREs). A perfect ERE contains a palindromic consensus sequence of 5'-GGTCAnnnTGACC-3'.

SPR study of DNA hybridization with DNA and PNA probes under stringent conditions.

Surface plasmon resonance (SPR) spectroscopy has been used for studying on-chip DNA hybridization to a PNA probe and its counterpart DNA probe of a 22-mer sequence. Two stringency control strategies are used for single base mismatch discrimination, namely (1) adding a denaturant, i.e.

Femtomol SPR detection of DNA-PNA hybridization with the assistance of DNA-guided polyaniline deposition.

The inability of surface plasmon resonance (SPR) spectroscopy to detect extremely small refractive index changes has hindered its applications in ultrasensitive DNA analysis. In this study we report a signal amplification strategy that uses DNA-templated polyaniline deposition, suitable for DNA hybridization analysis with charge neutral peptide nucleic acid (PNA) being probes. Under acidic conditions, protonated aniline monomers are adsorbed on DNA backbones through electrostatic interaction.

Bioleaching of spent fluid catalytic cracking catalyst using Aspergillus niger.

The use of the fungus Aspergillus niger for the bioleaching of heavy metals from spent catalyst was investigated, with fluid catalytic cracking (FCC) catalyst as a model. Bioleaching was examined in batch cultures with the spent catalysts at various pulp densities (1-12%). Chemical leaching was also performed using mineral acids (sulphuric and nitric acids) and organic acids (citric, oxalic and gluconic acids), as well as a mixture of organic acids at the same concentrations as that biogenically produced.

Combination of ofloxacin and amikacin in the treatment of sternotomy wound infection.

Mycobacterium fortuitum infection of soft tissue and wound (postoperative or otherwise) has been well reported in medical literature. In 1987, ten patients in our hospital with various cardiac diagnoses requiring open-heart surgery developed M fortuitum infection at the sternotomy site. As successful chemotherapy, in addition to surgical debridement, relies on in vitro susceptibility testing, ofloxacin and amikacin were thus assessed and found to have very satisfactory MIC.

An unusual lethal complication of preservation of chordae tendineae in mitral valve replacement.

In two patients, several chordae tendineae of the mural leaflet were preserved during mitral valve replacement. Hemorrhagic necrosis and spontaneous rupture of the preserved posterior papillary muscle led to disc entrapment and the death of both patients.

Aortic atresia with complete transposition.

Aortic atresia with ventriculoarterial discordance in a three day old neonate was studied by cross sectional echocardiography and the anatomy was confirmed at necropsy.

Effects of Russell's viper venom on blood coagulation, platelets and the fibrinolytic enzyme system.

The effects of Russell's viper venom (RVV) on blood coagulation, platelts and fibrinolysis were studied in vivo and in vitro in rabbits and dogs as experimental subjects. RVV was shown to be a strong coagulant, and at the time of manifestation of bleeding due to consumption coagulopathy, the most striking hemostatic abnormalities were fall of fibrinogen level, reduction in platelet count, delayed ADP aggregation of platelets, increased fibrinolytic activity and presence of fibrin degradation products. These findings showed that RVV interfered with blood coagulation, caused abnormalities of platelet function and also activated the fibrinolytic enzyme system.

Changes in the tissues of the immune system in dengue haemorrhagic fever.

A total of 100 post-mortems were done on patients clinically diagnosed as dengue haemorrhagic fever from Rangoon Children's Hospital. Histopathological changes in bone marrow, thymus, spleen, lymph nodes and other associated tissues of the immune system were analysed and correlated with the clinical picture and serology results. The major changes in cases with a positive serology result for secondary dengue infection consist of hypoplasia of the bone marrow, acute atrophy and wasting of the thymus, atrophy and depletion of cells in the periarterial lymphatic sheaths of the spleen and the paracortical areas of the lymph nodes.