Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper describes the development of two different capillary-based heterogeneous competitive flow immunoassay formats (capillary flow injection immunoassay (CFIIA) and capillary sequential injection immunoassay (CSIIA)) for the determination of 2,4,6-trichlorophenol (2,4,6-TCP). The assays are based on the competition between the analyte and an analyte derivative labelled with the enzyme beta-galactosidase, for an anti-TCP antibody, followed by the injection of the mixture at equilibrium into a flow stream, where separation between the fractions bound and unbound to the antibody is performed in a glass capillary containing immobilised protein A. The antibody-tracer fraction retained inside the protein A capillary was measured by injection of 4-aminophenyl- beta- D-galactoside (4-APG), followed by amperometric detection of the enzymatically generated 4-aminophenol (4-AP), leading to a negative correlation between the signal and the analyte concentration. The two immunoassay formats were compared in terms of sensitivity and speed, giving IC(50) values of 1.41+/-0.03 and 1.64+/-0.07 micro g L(-1), detection limits of 0.2 and 0.4 micro g L(-1), and sample throughputs of 6 and 4 h(-1) for the CFIIA and CSIIA system, respectively. The influence of different interfering chlorophenolic compounds in the assay was minor, with only one exception (i.e. 2,4-dichlorophenol). In addition, different water matrices were tested (surface, tap, and rain water), showing that the matrix influence was negligible, except for rainwater, which resulted in a 30% increase in sensitivity. As a conclusion, the assay is suitable for the fast screening of TCP present at low concentration levels in water samples.
 ...
PMID:A capillary-based amperometric flow immunoassay for 2,4,6-trichlorophenol. 1252 Apr 48

The efficacy of beta-tricalcium phosphate (beta-TCP) loaded with bone morphogenetic protein-2 (BMP-2)-gene-modified bone-marrow mesenchymal stem cells (BMSCs) was evaluated for the repair of experimentally-induced osteonecrosis of the femoral head in goats. Bilateral early-stage osteonecrosis was induced in adult goats three weeks after ligation of the lateral and medial circumflex arteries and delivery of liquid nitrogen into the femoral head. After core decompression, porous beta-TCP loaded with BMP-2 gene- or beta-galactosidase (gal)-gene-transduced BMSCs was implanted into the left and right femoral heads, respectively. At 16 weeks after implantation, there was collapse of the femoral head in the untreated group but not in the BMP-2 or beta-gal groups. The femoral heads in the BMP-2 group had a normal density and surface, while those in the beta-gal group presented with a low density and an irregular surface. Histologically, new bone and fibrous tissue were formed in the macropores of the beta-TCP. Sixteen weeks after implantation, lamellar bone had formed in the BMP-2 group, but there were some empty cavities and residual fibrous tissue in the beta-gal group. The new bone volume in the BMP-2 group was significantly higher than that in the beta-gal group. The maximum compressive strength and Young's modulus of the repaired tissue in the BMP-2 group were similar to those of normal bone and significantly higher than those in the beta-gal group. Our findings indicate that porous beta-TCP loaded with BMP-2-gene-transduced BMSCs are capable of repairing early-stage, experimentally-induced osteonecrosis of the femoral head and of restoring its mechanical function.
 ...
PMID:Treatment of osteonecrosis of the femoral head with hBMP-2-gene-modified tissue-engineered bone in goats. 1725 31