Objective To establish the animal model of denervated masseter and observe the changes of denervated masseter. Methods The model of denervated masseter was established by abscising selectively masseteric nerve, its superior division or inferior division of the right in 75 New Zealand rabbits and the left served as negative control. Another 25 rabbits were used as normal control. The thickness of experimental masseter was compared with that of negative controls and normal controls by type B ultrasound examination, and the histochemistry for the masseter changes was done at the 2~ nd , 4~ th , 8~ th , 12~ th , 24~ th week after masseter was cut off. Results The thickness of experimental masseteric muscle got thinner, and the section area of muscle fiber got smaller, but the type of musle fiber was of no obvious changes, as compared with that of normal controls. Conclusion The model is available and credible, and useful in researching masseter of denervated nerve in rabbit.

Objective:To explore influence on physical development of children aged 18 months from HIV-positive mothers for prevention mother to child transmission of HIV (PMTCT) in Guangxi Zhuang autonomous region, and provide evidence for the improvement PMTCT program.Methods:This retrospective case control study was conducted in 554 HIV negative infants aged 18 months whose HIV positive mothers had received PMTCT services reported through PMTCT system database from January 1, 2010 to December 31, 2017 and 1 109 healthy infants born in 2017, whose mothers were healthy, in Lingshan, Luzhai, and Hengxian counties, ranking top three counties with high HIV infection prevalence, in Guangxi. PMTCT data and physical development data such as height, weight and head circumference of children aged 18 months were collected. The physical dysplasia in the infants was defined as at least one of the three main indicators of height, weight and head circumference below the normal range.Results:The number of HIV-positive mother and their infants in the case group were 667 and 554 respectively, and the PMTCT rates were 91.15 % (608/667) and 96.57 % (535/554) respectively. HIV positive rate, mortality rate and mother to child transmission rate of the infants aged 18 months were 1.44 % (8/554), 3.07 % (17/554) and 1.91 % (8/418) respectively, and the physical examination results of the infants aged 18 months showed that the physical dysplasia rate was 30.51 % (169/554). Among the 1 109 infants in the control group, the physical dysplasia rate was 9.83 % (109/1 109). The difference between the case group and the control group was significant ( P<0.01). Conclusion:The PMTCT rates of HIV positive mother and their children were more than 90.00 %, respectively. However, poor physical development rate of infants aged 18 months were more than 30.00 %. The possible influence of PMTCT on physical development of the infants aged 18 months of HIV positive mother’s needs to be further studied.