Impact of particle size and morphology on zinc cation adsorption by hydroxyapatite and dentifrice containing hydroxyapatite / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the influence of particle size and morphology on zinc cation adsorption by hydroxyapatite (HA) and dentifrice containing HA.</p><p><b>METHODS</b>Four HAs with different particle sizes and morphologies, HA-containing dentifrice and blank dentifrice were prepared into suspensions of serial concentrations. Zinc ion solutions with an initial concentration of 10 mg/L was mixed with the suspensions and kept for 24 h for adsorption reaction. The zinc ion concentration in the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of zinc ion was calculated.</p><p><b>RESULTS</b>HA and HA-containing dentifrice with various particle sizes and morphologies were all capable of absorbing zinc ions from simulated waste water, and the adsorption rate of HA-containing dentifrice was 3%-10% higher than that of HA. HA with a particle size of 12 µm and a spherical morphology showed the strongest adsorption ability, followed by short bar-shaped HA with a particle size of 30 µm. Both Langmuir and Freundlich equation could simulate the sorption processes of HA dentifrice, while only Langmuir equation could simulate the sorption processes of HA.</p><p><b>CONCLUSION</b>Incorporation of HA in dentifrice can enhance zinc ion adsorption capacity of the material. The particle size and morphology of HA both affect the adsorption of zinc ions, and 12-µm HA particle with a spherical morphology has the best adsorption ability.</p>

Genetic diagnosis for a Chinese Han family with hereditary multiple osteochondromas / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the genetic cause for a Chinese Han family affected with hereditary multiple osteochondromas.</p><p><b>METHODS</b>Two patients, five unaffected relatives of the family and 100 unrelated healthy controls were collected. The coding sequences and intron/exon boundaries of EXT1 gene were amplified with polymerase chain reaction (PCR) and sequenced.</p><p><b>RESULTS</b>A heterozygous c.600G>A (p.Trp200X) mutation in exon 1 of the EXT1 gene was detected in the patients. The same mutation was not found in unaffected family members and 100 healthy controls.</p><p><b>CONCLUSION</b>The hereditary multiple osteochondromas in the family is caused by a nonsense mutation (p.Trp200X) in the EXT1 gene.</p>

Recombinant adenovirus with human indoleamine-2,3-dioxygenase and hepatitis B virus preS was constructed and expressed in HepG2 cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Indoleamine-2,3-dioxygenase (IDO) is proven to suppress hepatitis B virus (HBV) specific immune response and depletion of IDO may be a useful approach for HBV therapy. To test this concept, we constructed recombinant adenovirus with human IDO and HBV preS, which would form the basis for future in vivo experiments.</p><p><b>METHODS</b>The fragment of human IDO and HBV preS cDNA were subcloned into multiple cloning sites in an adenoviral vector system containing two cytomegalovirus (CMV) promoters. Recombination was conducted in the Escherichia coli BJ5183. The recombinant adenovirus containing hIDO gene and HBVpreS gene was packaged and amplified in 293 cells. Integration was confirmed by polymerase chain reaction as well as the quantification of viral titers. HepG2 cells were infected with the recombinant adenovirus and mRNA and protein specific for hIDO and HBVpreS was detected by RT-PCR and Western blotting respectively.</p><p><b>RESULTS</b>The recombinant adenovirus was produced successfully. Its titer was 2.5 × 10(9) efu/ml. IDO and HBVpreS mRNA as well as the encoded proteins could be found in transfected HepG2 cells, but not in control HepG2 cells.</p><p><b>CONCLUSION</b>The transfer of hIDO-HBVpreS with double-promoter adenoviral vector was efficient. The recombinant adenovirus with hIDO and HBV preS would provide the experimental basis for future studies.</p>