RESUMEN
In order to reveal the mechanism of LLLI accelerating teeth moving, we investigated the changes of alkaline phosphatase and intracellular calcium concentration when osteoblasts under stress were subjected low-level-laser-irradiation (LLLI). MG-63 cells were divided into four groups: control group, stress group, LLLI group and LLLI-stress group. Osteoblasts were subjected to the mechanical stress by a four-point bending system at 0.5 Hz and 3 000 µstrain. The secretions of ALP of each group are measured by spectrophotometer. In the second part, MG-63 cells were divided into two groups: stress group and LLLI-stress group. We checked intracellular calcium concentration via FCM and fluorescent indicator fluo-3/AM at 0, 5, 15, 30 and 60 min under stress. LLLI- stress group will receive LLLI for 1 min after stress. Compared to a control group, increased ALP secretions were observed in the other three groups. But ALP secretions in LLLI-stress group were lower than stress group and LLLI group. THE changing curve of intracellular calcium concentration in laser-stress groups is gentle instead of "jumping" in stress group. Proper stress, LLLI and combined application of these two can increase the secretions of ALP in osteoblasts compared to the control group. But the secretions of ALP decreased when combined application of stress and LLLI compared to using alone. LLLI can regulate the changing rhythm of concentration of the intracellular calcium to promote proliferation of MG-63 cell under stress, which means LLLI can reduce the bone-formation of osteoblasts under stress.
Asunto(s)
Osteoblastos , Estrés Mecánico , Fosfatasa Alcalina , Calcio , Proliferación Celular , CitoplasmaRESUMEN
Anurans often have species-specific vocalizations. To quantify and compare the characteristics of anuran calls in Gutianshan National Nature Reserve, Zhejiang Province, we recorded the advertisement calls of eight species belonging to four families (Ranidae, Microhylidae, Megophryidae and Bufonidae) from June to September 2012 using Sony ICD-FX8 IC recorders. All recordings were analyzed using the "Praat" software. Five acoustics parameters were measured, including temporal traits (call duration, number of notes or pulse number/call) and spectral traits (fundamental frequency, the first three formants and dominant frequency). The characteristic parameters of Microhyla ornate and Fejervarya limnocharis calls were different as were the calls of some populations of the same species recorded in different regions. The advertisement calls of the eight species were specific. Our study has provided a useful reference for identifying the calls of some common Chinese anurans.