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1.
Anal Bioanal Chem ; 405(6): 1977-83, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23307121

ABSTRACT

Simple and rapid extraction of human genomic DNA remains a bottleneck for genome analysis and disease diagnosis. Current methods using microfilters require cumbersome, multiple handling steps in part because salt conditions must be controlled for attraction and elution of DNA in porous silica. We report a novel extraction method of human genomic DNA from buccal swab and saliva samples. DNA is attracted onto a gold-coated microchip by an electric field and capillary action while the captured DNA is eluted by thermal heating at 70 °C. A prototype device was designed to handle four microchips, and a compatible protocol was developed. The extracted DNA using microchips was characterized by qPCR for different sample volumes, using different lengths of PCR amplicon, and nuclear and mitochondrial genes. In comparison with a commercial kit, an equivalent yield of DNA extraction was achieved with fewer steps. Room-temperature preservation for 1 month was demonstrated for captured DNA, facilitating straightforward collection, delivery, and handling of genomic DNA in an environment-friendly protocol.


Subject(s)
DNA, Mitochondrial/isolation & purification , DNA/isolation & purification , Mouth Mucosa/chemistry , Oligonucleotide Array Sequence Analysis/instrumentation , Preservation, Biological/methods , Saliva/chemistry , Cell Nucleus/chemistry , Electrochemical Techniques , Gold/chemistry , Humans , Microchip Analytical Procedures/standards , Nucleic Acid Denaturation , Oligonucleotide Array Sequence Analysis/methods , Polymerase Chain Reaction , Specimen Handling/instrumentation , Specimen Handling/methods
2.
Med J Malaysia ; 63 Suppl A: 87-8, 2008 Jul.
Article in English | MEDLINE | ID: mdl-19024997

ABSTRACT

The sintering behaviour of synthesized HA powder that was calcined at various temperatures ranging from 700 degrees C to 1000 degrees C was investigated in terms of phase stability, bulk density, Young's modulus and Vickers hardness. The calcination treatment resulted in higher crystallinity of the starting HA powder. Decomposition of HA phase to form secondary phases was not observed in all the calcined powders. The results also indicated that powder calcination (up to 900 degrees C) prior to sintering has negligible effect on the sinterability of the HA compacts. However, powder calcined at 1000 degrees C was found to be detrimental to the properties of sintered hydroxyapatite bioceramics.


Subject(s)
Bone Substitutes/chemistry , Durapatite/chemistry , Powders/chemistry , Bone Substitutes/chemical synthesis , Crystallization , Durapatite/chemical synthesis , Humans , Materials Testing , Nanoparticles , Pilot Projects , Porosity , Powders/chemical synthesis
3.
Med J Malaysia ; 63 Suppl A: 89-90, 2008 Jul.
Article in English | MEDLINE | ID: mdl-19024998

ABSTRACT

The sintering behaviour of a commercial HA and synthesized HA was investigated over the temperature range of 700 degrees C to 1400 degrees C in terms of phase stability, bulk density, Young's modulus and Vickers hardness. In the present research, a wet chemical precipitation reaction was successfully employed to synthesize a submicron, highly crystalline, high purity and single phase stoichiometric HA powder that is highly sinteractive particularly at low temperature regimes below 1100 degrees C. It has been revealed that the sinterability of the synthesized HA was significantly greater than that of the commercial HA. The temperature for the onset of sintering and the temperature required to achieve densities above 98% of theoretical value were approximately 150 degrees C lower for the synthesized HA than the equivalent commercial HA. Nevertheless, decomposition of HA phase upon sintering was not observed in the present work for both powders.


Subject(s)
Bone Substitutes , Ceramics/chemistry , Durapatite/chemistry , Powders/chemistry , Biocompatible Materials/chemical synthesis , Biocompatible Materials/chemistry , Crystallization , Durapatite/chemical synthesis , Hardness , Humans , Materials Testing , Phase Transition , Pilot Projects , Powders/chemical synthesis , Surface Properties , Tensile Strength
4.
J Pept Sci ; 5(8): 374-8, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10507687

ABSTRACT

A new peptaibol, boletusin, was isolated from the methanol extract of the fruiting body of the mushroom, Boletus spp. Sequential determination by positive FAB MS/MS showed that boletusin is a peptide consisting of 19 amino acids, with one acetylated N-terminus residue, phenylalanine, and a C-terminal amino alcohol, tryptophanol. This peptide showed antimicrobial activity against several Gram-positive bacteria.


Subject(s)
Agaricales/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Peptides , Amino Acid Sequence , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Molecular Sequence Data , Peptaibols , Sequence Homology, Amino Acid , Spectrometry, Mass, Fast Atom Bombardment
5.
J Nat Prod ; 62(6): 917-9, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10395521

ABSTRACT

A new antifungal 26-membered polyene macrolide, tetrin C (1), has been isolated from Streptomyces sp. GK9244. Its structure has been determined by interpretation of NMR data. Compound 1 exhibited antifungal activity against Mortierella ramannianus (MIC, 5 microg/mL).


Subject(s)
Anti-Bacterial Agents/isolation & purification , Antifungal Agents/isolation & purification , Macrolides , Streptomyces/chemistry , Anti-Bacterial Agents/biosynthesis , Anti-Bacterial Agents/pharmacology , Antifungal Agents/biosynthesis , Antifungal Agents/pharmacology , Chromatography, High Pressure Liquid , Fungi/drug effects , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Spectrophotometry, Ultraviolet , Streptomyces/metabolism
8.
J Antibiot (Tokyo) ; 50(7): 546-50, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9711245

ABSTRACT

9-Hydroxycrisamicin A, a new cytotoxic isochromanquinone antibiotic, was isolated from a soil microorganism SA246 which was identified as Micromonospora sp. The molecular formula of 9-hydroxycrisamicin A was determined as C32H22O13 based on the HRFAB-MS analysis, and the structure was determined by various NMR experiments. 9-Hydroxycrisamicin A showed weak antimicrobial activity against Gram-positive bacteria and strong cytotoxic activity against some human cancer cell lines such as SK-OV-3 (ovarian), HCT15 (colon), SK-MEL-2 (melanoma), A549 (lung), XF498 (central nervous system) with ED50 of 0.47-0.65 microgram/ml.


Subject(s)
Anti-Bacterial Agents/pharmacology , Micromonospora/metabolism , Soil Microbiology , Anti-Bacterial Agents/isolation & purification , Antibiotics, Antineoplastic/pharmacology , Fermentation , Humans , In Vitro Techniques , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Micromonospora/classification , Naphthoquinones/isolation & purification , Tumor Cells, Cultured/drug effects
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