ABSTRACT
Objective To evaluate the difference of PC values based on GBZ 97-2002 and on GBZ 97-2009 for lung cancer cases in Chinese uranium miners.Methods Using 19 lung cancer data ascertained in the past epidemiological study,PC values were calculated according to GBZ 97-2002 and GBZ 97-2009.Results In the 19 lung cancer cases,those cases that could not be judged as radiogenic cancers based on GBZ 97-2002,but may be judged as radiogenic cancers with GBZ 97-2009.The probability was enlarged by 1.1 times at least.The major reason was that the used value was the upper limit of 95％ in GBZ 2009 but the median in 2002.Conclusions Compared to GBZ 97-2002,the criteria value of PC in GBZ 97-2009 drops obviously.
ABSTRACT
The dermal sheath surrounding the outside of the hair follicle maintains and regenerates the dermal papilla, a necessary component for hair regeneration. Dermal sheath cells participate in skin wound healing and have some characteristics of adult stem cells such as immuneprivilege, multiple differentiation and plasticity. It is likely that dermal sheath cells will be the new cynosure in the research on wound healing and tissue engineering. Here we review the studies of hair follicle dermal sheath in present years.
Subject(s)
Humans , Dermis , Cell Biology , Physiology , Hair Follicle , Cell Biology , Physiology , Stem Cells , Physiology , Tissue Engineering , Methods , Wound Healing , PhysiologyABSTRACT
Objective To study the effects of various doses of ionizing radiation on the osteoinductive activity of recombinant human bone morphogenetic protein 2 (rhBMP-2) and the role of collagen carrier. Methods BMP complex was prepared with rhBMP-2 and collagen sponge as a carrier. The osteoinductive activity of rhBMP-2 was evaluated by heterotopic bone formation. According to the conditions of gamma irradiation, the experiments were divided into 4 groups: (Ⅰ) non-irradiated complex as control; (Ⅱ) irradiated complex with 15, 20, 25 or 50 kGy; (Ⅲ) irradiated carrier: collagen sponge was irradiated with 50 kGy and then mixed with non-irradiated rhBMP-2; (Ⅳ) irradiated BMP: only rhBMP-2 was irradiated with 25 or 50 kGy and then mixed with non-irradiated collagen sponge. The BMP complexes were implanted into thigh muscle pouches in 34 Wistar rats, respectively. All collagen mass in muscle pouches were procured two or four weeks after implantation and examined macroscopically, radiographically and histologically. Quantitative analyses of heterotopic bone formation were evaluated by histomorphometry. Results Two weeks after implantation, collagen mass procured from muscle of irradiated complexes with 15, 20, 25 kGy are almost the same with that of control in size, shape and new bone formation, which are composed with richly vascularized connective tissue and immatured woven bone, but only the quantity of new bone in the group of 25 kGy reduced significantly(P
