ABSTRACT
BACKGROUND: Childhood obesity is a serious public health concern. School-based interventions hold great promise to combat the rising trend of childhood obesity. This systematic review aimed to assess the overall effects of school-based obesity prevention interventions, and to investigate characteristics of intervention components that are potentially effective for preventing childhood obesity. METHODS: We systematically searched MEDLINE, CENTRAL and Embase databases to identify randomized- or cluster randomized- controlled trials of school-based obesity interventions published between 1990 and 2019. We conducted meta-analyses and subgroup analyses to determine the overall effects of obesity prevention programs and effect differences by various characteristics of intervention components on body mass index (BMI) or BMI Z-score of children. RESULTS: This systematic review included a total of 50 trials (reported by 56 publications). Significant differences were found between groups on BMI (- 0.14 kg/m2 (95% confidence interval: - 0.21, - 0.06)) and BMI Z-score (- 0.05 (- 0.10, - 0.01)) for single-component interventions; significant differences were also found between groups on BMI (- 0.32 (- 0.54, - 0.09) kg/m2) and BMI Z-score (- 0.07 (- 0.14, - 0.001)) for multi-component interventions. Subgroup analyses consistently demonstrated that effects of single-component (physical activity) interventions including curricular sessions (- 0.30 (- 0.51, - 0.10) kg/m2 in BMI) were stronger than those without curricular sessions (- 0.04 (- 0.17, 0.09) kg/m2 in BMI); effects of single-component (physical activity) interventions were also strengthened if physical activity sessions emphasized participants' enjoyment (- 0.19 (- 0.33, - 0.05) kg/m2 in BMI for those emphasizing participants' enjoyment; - 0.004 (- 0.10, 0.09) kg/m2 in BMI for those not emphasizing participants' enjoyment). The current body of evidence did not find specific characteristics of intervention components that were consistently associated with improved efficacy for multi-component interventions (P > 0.05). CONCLUSIONS: School-based interventions are generally effective in reducing excessive weight gain of children. Our findings contribute to increased understandings of potentially effective intervention characteristics for single-component (physical activity) interventions. The impact of combined components on effectiveness of multi-component interventions should be the topic of further research. More high-quality studies are also needed to confirm findings of this review.
Subject(s)
Pediatric Obesity/prevention & control , School Health Services , Body Mass Index , Child , Exercise , Humans , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND:We explore the transfection effects of different lentiviruses on bone marrow mesenchymal stem cells (BMSCs) from the same source in order to screen out appropriate cell transfection tools.OBJECTIVE:To explore the difference in the transfection efficiency of three different lentiviruses carrying green fluorescent protein (GFP) to transfect the rabbit BMSCs.METHODS:Bone marrow samples were extracted from the ilium of 2-week-old Japan white rabbits,and then the BMSCs were separated,purified and extended using density gradient centrifugation.Cell surface markers were identified using flow cytometry.pTomo-GFP lentivirus,Ad-GFP lentivirus and lenti-GFP lentivirus were used to transfect the BMSCs,and the transfection efficiency was tested using flow cytometry.The cell viability was detected using cell counting kit-8 before and after transfection.RESULTS AND CONCLUSION:As the positive rates of CD44,CD34 and CD45 were 75.64％,6.14％ and 9.48％,respectively,the cultured cells were identified as BMSCs by the flow cytometry.The expression levels of GFP after transfection by pTomo-GFP,Ad-GFP and ienti-GFP were 2.64％,16.72％ and 45.24％,respectively.The cell growth curve showed that pTomo-GFP lentivirus,Ad-GFP and ienti-GFP lentivirus showed certain effects on cell growth,pTomo-GFP and Ad-GFP had an effect on cell growth at incubation period and logarithmic growth phase at 1-8 days after transfection,which may cause some interference to the viability of early cells,ienti-GFP had little effect on cell growth in the short term,but there was a change in cell growth at day 12 after lenti-GFP transfection,and a long-term effect of lenti-GFP on cell viability was considered.Therefore,lenti-GFP lentivirus could highly transfect the BMSCs and could not impact the normal growth of BMSCs,indicating that lenti-GFP lentivirus is suitable for BMSCs tracing and gene transfection.
