Objective To develop miniature pig model of coronary microembolization (CME) by easy and cost-effi-cient technique. Methods A total of 11 miniature pigs were divided into control group (n=5) and CME group (n=6). Femo-ral artery was punctured using 21 gauge needle that is normally used for transradial procedures. Microspheres were injected into the left anterior descending artery of the CME group by 5 F coronary radiography catheter and 1.8 F coronary micro-guide catheter. Serum concentrations of brain natriuretic peptide (BNP) and cardiac troponin I (cTnI) were evaluated just be-fore CME and 6 hours after CME. Apical myocardial pathological lesions were evaluated by optical microscope 6 hours after CME. Results All miniature pigs in control group survived, but one died in the CME group. 5 F coronary radiography cathe-ter and 1.8 F coronary micro-guide catheter reached designated location successfully. Before CME, serum BNP (ng/L:143.00 ± 13.51 vs 134.00 ± 15.57) and cTnI (μg/L:0.39 ± 0.09 vs 0.38 ± 0.10) showed no significant differences between these two groups (t values are 0.976 and 0.294 respectively,both P>0.05). By contrast, serum BNP (561.00 ± 80.65) and cTnI (2.75±0.58) were much higher in CME group than those (BNP 139.00±13.87;cTnI 0.54±0.14 ) in control group after CME (t values are 11.530 and 8.337 respectively,both P＜0.001). In CME group, microspheres, micro-infarction and inflammatory cell infiltration were seen under an optical microscope which are absent in control group. Conclusion Using new surgical consumables can successfully develop miniature pig model with CME. And the technique is simple, cost-efficient, practical so it is worth promoting.

BACKGROUND:The effects of advanced glycation end products (AGEs) on osteoclast-induced bone resorption is controversial and the underlying mechanisms remain unclear. Most of the studies indicate that AGEs can enhance bone resorption, while some othersshowthe opposite effects.
OBJECTIVE:To investigate the effects of AGEs on osteoclast-induced inorganicmatrixdissolution and organic componentdegradation and the underlying mechanisms.
METHODS:RAW 264.7 cels were induced to generate osteoclasts,and AGEs (50-400 μg/mL) or control-bovine serum albumin (100 μg/mL) was added since the beginning of the induction. The effect of AGEs on bone resorption was evaluated by analyzing the area of resorption pits on the Osteo Assay Surface plates and the expression of cathepsin K. Furthermore, the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cels, nuclei per osteoclasts and the expression of integrinανβ3were detected.
RESULTS AND CONCLUSION:The area of resorption pits and expression of cathepsin K in AGEs groups were significantly decreased compared withthecontrol group, and this inhibiting effect became more obvious with the increase of AGEs concentration. TRAP staining also showed that number of TRAP-positivemultinucleated celsand nuclei per osteoclast were significantly reduced in an AGE dose-dependent manner. Quantitative PCR revealed that the expression of integrin ανβ3decreased significantly with the extension of AGEs incubation time. These data indicate that AGEs can exert inhibitory effects on organic and inorganicmatrixdegradation induced by osteoclasts. The underlying mechanism may be involved in the inhibitory effects of AGEs on directed differentiation and cel fusion of osteoclast precursor cels, and migration and adhension of osteoclasts.