DNA identification from dental pulp and cementum.

Teeth are one of the body tissues remaining after severe decomposition from which a DNA profile can be obtained to aid in human identification. Currently, the standard approach to isolate DNA from teeth requires pulverizing the entire tooth. This destructive approach compromises any further morphological or anthropological study. We report on two methods of DNA isolation that minimizes destruction of the tooth when accessing the DNA within pulp and cementum. Forty-nine teeth, removed as part of normal dental procedures, were buried for up to 92 days, with a further nine teeth acting as unburied controls. Additionally, four teeth samples collected during a forensic examination were included in this study. The two processes were: using a fine drill to access the pulp from the crown and then using endodontic files to collect the biological material; and using a sterile blade to scrape the cementum. It was found that the samples collected from the cementum had greater DNA quality compared to those samples obtained from the pulp. Microbial activity was found to play a role in the degradation of the nuclear material, reducing DNA yields from pulp. DNA profiling data from 24 loci, including 22 STR markers, indicated that multi-rooted teeth provided better DNA quantity and quality than those with a single root. The DNA quantity obtained from pulp samples of teeth which exhibited cavities was adversely affected, although this DNA loss was not from samples collected from the cementum of teeth in similar condition. Obtaining samples from DNA profiling from the cementum was found to be ideal if the morphological preservation of the tooth is required. Obtaining pathogen DNA is of interest when an occlusal approach to retrieve pulp may serve as a good alternative to prepare DNA without destruction of the tooth structure.

Effect and mechanism of Danhong injection on isolated mesenteric arterial rings in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect and mechanism of Danhong injection on isolated mesenteric arterial rings in rats.</p><p><b>METHOD</b>An isolated vascular ring experiment was conducted to determine the changes in tension of vascular rings with a biological signal collection and analytical system.</p><p><b>RESULT</b>Danhong injection had no impact on the tension of vascular rings. Danhong injection showed a significant vasodilatation effect on treated arteria rings of norepinephrine, and no remarkable impact was made on the effect without endothium. It showed notable effect on blood vessels treated with Ca(2+) and no significant impact on those treated with caffeine. It could inhibit NE-induced intracellular calcium from releasing and external calcium from inflowing. No effects of potassium channel blockers on aorta ring tensile force were found.</p><p><b>CONCLUSION</b>Danhong injection shows significant vasodilation effect, which mainly works through vascular smooth muscle. Its vasodilation effect may be related to inhibitory receptor, voltage-dependent Ca(2+)-release and IP3 receptor-mediated Ca(2 +)-influx.</p>