Fabrication and biological properties of calcium phosphate/chitosan composite coating on titanium in modified SBF.

In order to increase the biocompatibility and bioactivity of chitosan, hydroxyapatite was in situ combined into the spin-coated chitosan layer on the titanium substrate by incubating in modified simulated body fluid (m-SBF). The calcium phosphate/chitosan (CaP/CS) composite prepared in m-SBF showed a homogeneous distribution of spherical nano-clusters. The hydrophilicity of the coatings was increased by performing NaOH post-treatment of CaP/CS composites, which also affected apatite formation. Biocompatibility of the coatings was assessed by investigating the cellular response of human osteoblast-like MG-63 cells with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell adhesion and osteogenic properties of the mesoporous CaP/CS composite were evaluated by SEM and ALPase assay, respectively. This in vitro study showed improved cell adhesion and differentiation on nanostructured CaP/CS composites. These results indicate that this CaP/CS composite could be a promising candidate for bone tissue engineering.

Spontaneous reporting of adverse drug reactions through electronic submission from regional society healthcare professionals in Korea.

PURPOSE: Pharmacovigilance Research Network built a spontaneous reporting system and collected adverse drug reactions (ADRs) by electronic submission (e-sub) in Korea. We analyzed ADRs spontaneously reported through e-sub from regional health professionals. MATERIALS AND METHODS: Nine hundred and thirty three ADR cases were collected and analyzed from January to December in 2008. "A matter" was defined as one symptom matched to one culprit drug included in an ADR case. We collected and analyzed e-sub ADR cases and matters to determine common culprits and organ specified ADR matters. RESULTS: There were 3,049 matters in 933 ADR cases for 1 year, and 3.3 matters per case were reported. In organ specific ADR classification, skin reactions which took the first place in 866 matters (28%) included urticaria and rash. The next cases were neurologic symptom (624 matters, 21%) and gastrointestinal symptom (581 matters, 19%). Doctor (53%) and pharmacist (31%) were the most important participants in e-sub spontaneous reporting system, and 3% of ADR cases were reported by patients or their guardians. WHO-Uppsala Monitoring Center causality assessment results showed certain 10.6%, probable 37.7%, possible 41.7% and below unlikely 10.0%. Culprit drugs were antibiotics (23.4%), neurologic agents (14.7%) and non-steroidal anti-inflammatory drugs (9.4%). CONCLUSION: In our study, antibiotic was most common culprit drug, and skin manifestation was most common symptom in e-sub ADRs collected from regional healthcare practitioners in Korea.

Metabolomics approach to risk assessment: methoxyclor exposure in rats.

The primary objective of this study was to develop exposure biomarkers that "correlate with the endocrine-disrupting effects induced by methoxyclor (MTC), an organochlorine pesticide, using" urinary (1)H nuclear magnetic resonance (NMR) spectral data. Exposure biomarkers play an important role in risk assessment. MTC is an environmental endocrine disruptor with estrogenic, anti-estrogenic, and anti-androgenic properties. A new approach of proton nuclear magnetic resonance ((1)H NMR) urinalysis using pattern recognition was proposed for exposure biomarkers of MTC in female rats. The endocrine disruptor was expected to induce estrogenic effects in a dose dependent manner which, was confirmed by the uterotrophic assay. MTC [50, 100, or 200 m g/kg/d, orally (p.o.) or subcutaneously (s.c.)] was administered to ovariectomized female Sprague-Dawley (SD) rats for 3 d consecutively and urine was collected every 24 h. The animals were sacrificed 24 h after the last dose. All animals treated orally with MTC showed a significant increase in uterine and vaginal weight at all doses. However, in the s.c. route, only a high dose of 200 mg MTC/kg induced a significant increase in uterine and vaginal weight. (1)H NMR spectroscopy revealed evident separate clustering between pre- and post-treatment groups using global metabolic profiling through principal component analysis (PCA) and partial least square (PLS) discrimination analysis (DA) after different exposure routes. With targeted profiling, the endogenous metabolites of acetate, alanine, benzoate, lactate, and glycine were selected as putative exposure biomarkers for MTC. Data suggest that the proposed putative exposure biomarkers may be useful in a risk assessment of the endocrine-disrupting effects produced by MTC.