RESUMEN
Objective@#To understand environmen and sanitation of rural schools in western China, and to provide data support and reference for improving school environmental conditions and facilities and promoting the healthy development of students.@*Methods@#Based on the "School Comprehensive Environmental Improvement Project", a total of 38 087 students from 60 primary school from were randomly selected from 5 provinces in western China from September to December 2018. Environment and sanitation of schools was investigated through interviews, on site observation and inquiry, so as to obtain the survey data.@*Results@#All schools had water supply, 80.0% (48) could meet the needs of teachers and students, 91.7% (55) provided drinking water facilities, 93.3 % (56) provided hand washing facilities, and 66.7% (40) provided soap and other cleaning supplies for students. 71.7% (43) of the schools had sanitary toilets, 40.0% (24) toilets were qualified for femail, 86.7% (52) were clean and 58.3% (35) were odorless. The garbage disposal methods of schools are mainly collected by professional institutions, supplemented by fixed point stacking, accounting for 45.0% (27) and 35.0% (21) respectively. About 30% (22, 17, 20) of school sewage is discharged by open ditch, underground ditch and pipeline. 93.3% (56) of schools offered health education courses, 91.7% (55) had sanitation system, 70.0% (42) had drinking water sanitation management system, and 41.7% (25) had toilet management system.@*Conclusion@#The basic environmental sanitation facilities in the school are well equipped, and there are some problems to be improved in the establishment of environmental sanitation management system and the provision of hand washing and cleaning supplies.
RESUMEN
Objective@#To explore the effects of local transplantation of autologous adipose-derived stromal vascular fraction (SVF) on the hyperplastic scar (HS) formation in rabbit ears and the mechanism.@*Methods@#Twenty-four New Zealand white rabbits were used to reproduce HSs by making four full-thickness skin defect wounds with a diameter of 1 cm on the ventral surface of left ear of each rabbit. Wound epithelization and local-tissue proliferation were observed, and wound healing (complete epithelization) time and formation time of HS were recorded. The 24 rabbits were divided into SVF group, pure DMEM group, and pure HS group according to the random number table, with 8 rabbits and 32 wounds in each group. On post injury day (PID) 25 (after the complete epithelization of wounds), 0.2 mL of low glucose DMEM medium containing CM-Dil labeled autologous SVF was injected into HSs of rabbits in SVF group, while the same amount of low glucose DMEM medium was injected into HSs of rabbits in pure DMEM group. The frequency of injection was once every 5 days, totally for 3 times. HSs of rabbits in pure HS group did not receive any treatment. On PID 40, HSs of rabbits′ ears in each group were harvested, then the histological form was observed by hematoxylin and eosin staining, the arrangement of collagen in HS was observed by Van Gieson staining, the distribution of CM-Dil-labeled SVF in the HS was observed with fluorescence microscope, and the mRNA expression and the protein expression of transforming growth factor β1 (TGF-β1), Smad3, and Smad7 in HS were determined by real-time fluorescent quantitative reverse transcription-polymerase chain reaction and Western blotting, respectively. Data were processed with one-way analysis of variance and Tukey test.@*Results@#(1) Complete epithelization time of wounds of rabbits′ ears was (20.0±2.0) d post injury, and HSs were formed on PID 25. On PID 40, HSs of rabbits′ ears in pure DMEM group and pure HS group were still in hyperplasia, while those in SVF group became smaller, flat, soft, and light colored. (2) On PID 40, compared with those in pure DMEM group and pure HS group, the number of epithelium foot like structures was more and the amount of inflammatory cells was less. The collagen of HSs of rabbits′ ears in SVF group was arranged more regularly with broader gap between collagens. (3) On PID 40, CM-Dil-labeled SVF could still be observed in the HSs of rabbits′ ears in SVF group. (4) On PID 40, compared with those in pure DMEM group and pure HS group, the mRNA expressions of TGF-β1 and Smad3 in the HSs of rabbits′ ears in SVF group were significantly down-regulated (P<0.05), while the mRNA expression of Smad7 was significantly up-regulated (P<0.05). There were no significant differences in the mRNA expressions of TGF-β1, Smad3, and Smad7 in the HSs of rabbits′ ears between pure DMEM group and pure HS group (P>0.05). (5) On PID 40, compared with those in pure DMEM group (0.74±0.03, 0.73±0.10, 0.54±0.09) and pure HS group (0.72±0.08, 0.71±0.12, 0.53±0.06), the protein expressions of TGF-β1 and Smad3 in the HSs of rabbits′ ears in SVF group (0.57±0.06, 0.42±0.09) were significantly down-regulated (P<0.05), while the protein expression of Smad7 (0.71±0.05) was significantly up-regulated (P<0.05). The protein expressions of TGF-β1, Smad3, and Smad7 in the HSs of rabbits′ ears in pure DMEM group and pure HS group were close (P>0.05).@*Conclusions@#Autologous SVF transplantation can inhibit the formation of HS in the early stage of scar formation of rabbit, the mechanism may be related to the TGF-β1/Smad signaling pathway.