Innovative accumulative risk assessment strategy of co-exposure of As and Pb in medical earthworms based on in vivo-in vitro correlation.

Recent studies on risks assessment of heavy metal(loid) are usually based on their total concentrations. Nevertheless, such an analysis does not assess their real amounts absorbed by human body. To scientifically assess the health risks, in this study medical earthworms were analyzed for relative bioavailability (RBA) of arsenic (As) and lead (Pb) using a multiple gavage mouse model with liver, kidneys, brain, and leg bones as biomarkers for the first time. Metal(loid) bioaccessibility was determined using in vitro physiologically based extraction (PBET) assay. We are the first to develop a novel accumulative health risk assessment strategy by combinational analyzing bioavailability of heavy metal(loid) levels to calculate target organ toxicity dose (TTD) modification of the HI and total cancer risk (TCR), which has capacity to evaluate the health risks of co-exposure of Pb and As in medical earthworms. As a result, As-RBA ranged from 7.2% to 45.1%, and Pb-RBA ranged from 16.1% to 49.8%. Additionally, As and Pb bioaccessibility varied from 6.7% to 48.3% and 7.8% to 52.5%, respectively. Moreover, strong in vivo-in vitro correlations (IVIVCs) were observed between metal-RBA and bioaccessibility, indicating the robustness of the in vitro PBET assay to predict metal-RBA in medical earthworms. The refined accumulative assessment strategy revealed that when adjusted by heavy metal(loid) bioavailability, the TTD modification of HI method typically exhibited an acceptable health risk caused by the co-exposure of Pb and As for cardiovascular, hematological, neurological, and renal system. The TCR levels associated with exposure to Pb and As due to the ingestion of medical earthworms were also acceptable after adjustment by bioavailability. Collectively, our innovation on accumulative risk assessment based on in vivo-in vitro correlation provides a novel approach engaging in assessing the risks due to co-exposure of As and Pb in medical earthworms.

[Preliminary study of intervention in effect of Bushen Huoxue recipe on calcification of lumbar vertebra cartilage endplate of the aging gerbils].

OBJECTIVE: To study the effect of Bushen Huoxue decoction on calcification of cartilage endplate in lumbar vertebrae. METHODS: Six healthy male gerbils with 2-month-old were selected as normal control group, and 24 7-month-old healthy male gerbils were fed to 12-month-old to establish the aged gerbil model. Thirty gerbils were randomly divided into five groups as follow: the normal control group (n=6), model group (n=6, normal saline 4 ml/kg, intragastric 30 d), Bushen Huoxue low dose group(n=6, 1.9× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), Bushen Huoxue middle dose group(n=6, 3.8× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), Bushen Huoxue high dose group(n=6, 7.6× 10⁻ ³ ml/g given Bushen Huoxue recipe orally, 30 d), the intervention group administered for 1.36 g from 7-month-old age, 30 d. The animals were sacrificed at the age of 2 months in the normal control group and 12 months of age in the other groups. The morphology of the lumbar vertebral cartilage endplate, the area of vascular bud, the ratio of non-calcified/calcified layer were analysis by HE chromosome visual method. The expression of type X collagen and BMPs in cartilage endplates were detected by rabbit monoclonal immunohistochemical staining. RESULTS: The relative area of the vascular buds cartilage endplate measurements showed that compared with the model group, middle dose group and normal control group increased (P<0.05), high and low dose groups all had different degrees of increase, but no statistical significance(P>0.05). The ratio of cartilage endplate thickness of non-calcified/calcified showed that compared with the model group, Bushen Huoxue middle dose, normal control group increased, with statistical significance(P<0.05), and high and low dose groups all had different degrees of increase, but there were no statistical significance(P>0.05). Compared with the model group, the expression of type X collagen in the cartilage endplate of the normal group, the Bushen Huoxue low, middle and high dose groups decreased, and had statistical significance(P<0.01); compared with the model group, the expression of BMPs in the normal group, Bushen Huoxue middle dose group increased, with statistically significant(P<0.01), while the high and low dose groups increased in different degrees, but there was no statistical significance(P>0.05). CONCLUSIONS: Bushen Huoxue prescription can delay the calcification of cartilage endplate in the process of aging, suggesting that it can be used as a preventive medicine for early disc degeneration.

[FTIR microspectroscopic investigation of the age-related changes of subchondral bone of the knee in guinea pig].

Fourier transform infrared (FTIR) microspectroscopy was applied to in-situ analyse the chemical change of tibial articular subchondral bone of female Hartley guinea pigs with age increase. Three infrared absorption regions (a, b, c) of trabecular bone and central marrow region of the subchondral bone were measured for guinea pigs of different ages (1 months, 2 months and 3 months) using the infrared spectrum. Results show that (1) with months increasing, the total area of trabecular bone is increasing, meanwhile, the region a which is similar to normal trabecular bone spectra is decreasing, and region d waveform has the same trend as region a. (2) In the second and third month, region b & c show amide Ill redshift and the red shift in region c shows a shoulder peak, showing the absorption peak intensity on behalf of nucleic acid and polysaccharide in region b & c is 7 times that in region a. (3) beta glycosidic bond absorption peak appears at region c in 3 different old pigs. (4) I(amide III) / I(amide II) is the highest in region b in the second month but lowest in the third month; I(amide III) / I(amide II) reduces from a to c in the second and third month; I(upsilon3)PO2- / I(amide II) in region b & c is 7 times higher than region a in the second and third Month These results are consistent with the regular pattern of change rule of osteoarthritis subchondral bone's organization structure and chemical composition in different stages. Our primary result illustrated that FTIR microspectroscopy can be used for in-situ analysis of the molecular organization of subchondral trabecular bone and bone marrow. It provides reliable pathology information for osteoarthritis subchondral bone tissue at molecular level.

[Preliminary investigation of animal model of tibial defection fracture made by drilling hole method ].

OBJECTIVE: To compare the differences in damage degree, healing time and healing process between two animal models of defection fracture and provide the research data for the establishment of a new animal model. METHODS: Sixty male SPF Spragur-Dawley rats were divided randomly into control group, sawing group and drilling hole group, with 20 rats in each group. Animals of drilling hole group were treated with hone drill and made an 1 mm hole on tibial plateau animals of sawing group were treated with saw and made an 3 mm defection on tibial plateau; nothing to do in animals of control group. The rats were respectively killed at 2nd, 4th weeks after operation, bone density, bone ash quantity, contents of bone Ca, P were detected. RESULTS: At the 2nd week after operation, bone density, bone ash quantity, contents of bone Ca, P in drilling hole group and sawing group were significantly lower than that of the control group (P < 0.05 or P < 0.01). Two animal models of drilling hole group and sawing group were similar in X-ray films and pathology investigations. At the 4th week after operation, there were no significant defference in bone density and bone ash quantity among three groups (P > 0.05). Rats of sawing group showed more poroma and inflammatory infiltration in histological examination. CONCLUSION: Drilling hole method and sawing method could be used to make animal model of defection fracture, two methods showed similar damage degree, healing time and healing process, hut drilling hole method have advantages of simple operation, easily control damage degree and less inflammatory infiltration and bone disunion.

[Investigation of articular cartilage using FTIR microspectroscopy for guinea pig with spontaneous osteoarthritis].

In-situ analysis the chemical composition of tibial articular cartilage of female Hartley guinea pigs with Fourier transform infrared (FTIR) microspectroscopy was conducted. The infrared spectrum survey consists of three ages (1 months, 2 months and 3 months) and three cartilage layers (surface, middle and deep). The results demonstrated that with ages increasing, the peak positions of main absorbance bands in surface and middle shifted to a lower wavenumber, and in deep they shifted to a lower wavenumber first, then shifted to a higher wavenumber. Infrared spectrum character of collagen, nucleic acid and proteoglycan were compared and analyzed. The ratios of I1 657/I 1 548, I1 074/I1 548 and I1 074/I1 237 tend to decrease with ages increasing in surface and middle. However, the ratios at 2 months are less than other ages in deep. These results are consistent with the regular pattern of cartilage ingredient change in different degradation stage, while the tibial platform images created by microscopic spectral imaging technology is highly compliant with pathology description. The authors' primary result illustrated that FTIR microspectroscopy can be used for in-situ analysis of molecular constituents of different levels cartilages. The molecular information obtained from the study is important for understanding the pathogenesis of cartilage diseases.