Objective To investigate the relationship among the plasma ET,CGRP and chronic atroph-ic gastritis (CAG). Methods One hundred and eighteen cases with GAG, 30 cases with chronic superficial gastritis( CSG) ;30 cases healthy individuals served as control group. The levels of plasma ET,CGRP were measured by radioimmunoassay. Results (1) ET levels were significantly higher in GAG than in CSG and control (P 0. 05) . (2) The levels of plasma ET is statistically different among mild, moderate and severe CAG(P 0.05). (3)The levels of plasma ET were negatively correlated with the levels of plasma CGRP (r = -0. 214,P =0.02). Conclusion It is suggested that ET and CGRP were possibly involved in the pathogenesis of CAG, and their variations in concentrations were related with the extent of CAG.

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be the prerequisite of new bone growth on ceramics and to be related to the osteoinductivity of the material. The research of the factors effecting bone-like apatite formation is a great help in understanding the mechanism of osteoinduction. This paper is aimed to a comparative study of in vitro formation of bone-like apatite on the surface of dense and rough calcium phosphate ceramics with SBF flowing at different rates. The results showed that the rough surface was beneficial to the formation of bone-like apatite, and the apatite formed faster in 1.5 SBF than in SBF. Rough surface, namely, larger surface area, increased the dissolution of Ca2+ and HPO4(2-) and higher concentration of Ca2+ and HPO4(2-) ions of SBF and was in turn advantageous to the accumulation of Ca2+, HPO4(2-), PO4(3-) near the ceramic surface. Local supersaturating concentration of Ca2+, HPO4(2-), PO4(3-) near sample surface was essential to nucleation of apatite on the surface of sample.
Apatites ; Biocompatible Materials ; Calcium Phosphates ; Ceramics ; Materials Testing ; Surface Properties

This study aimed at investigating the influence of the flow rate of simulated body fluid (SBF) (2 ml/100 ml.min) of body fluid in skeletal muscle upon the formation of bone-like apatite on porous calcium phosphate ceramics. The in vitro immersion experiment in SBF flowing at normal physiological rate is referred to as dynamic SBF. The results showed that bone-like apatite could only formed in the pores of porous calcium phosphate when SBF flow at physiological rate (2 ml/100 ml.min) of body fluid in skeletal muscle. At the same time, bone-like apatite could form both in the pores and on the surface of the samples if the flowing physiological solution is 1.5 SBF. When the flowing speed of SBF is higher than normal physiological speed (10 ml/100 ml.min), no bone-like apatite could be detected both on the surface and in the pores of the materials. This result is in concordance with animal experiments. The dynamic SBF simulates the biological environment of bone-like apatite formation in body better than static SBF (SBF does not flow). This method is very useful for the research of the mechanism of bonelike apatite formation, which is the key step of bone growth on biomaterials, and can be used as an effective approach to investigate mechanism of the osteoinduction of calcium phosphate in nonosseous tissues in vivo.
Apatites ; chemistry ; Body Fluids ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Phosphates ; chemistry ; Ceramics ; chemistry ; In Vitro Techniques ; Materials Testing ; Surface Properties

Bone-like apatite formation on the surface of calcium phosphate ceramics has been believed to be necessary for new bone to grow on the ceramics and to be related to the osteoinductivity of the material. The research of bone-like apatite formation is a great help to understanding the mechanism of osteoinduction. Synthetic porous calcium phosphate ceramics (HA/TCP = 70/30) were implanted intramuscularly in pigs, dogs, rabbits and rats to make a comparative study of the bone-like apatite formation onto the porous HA/TCP ceramics in different animals. Specimens were harvested at 14 days after implantation. Samples were detected for the surface morphology with SEM. The chemical composition of the sample surface after implantation was analyzed with reflection infrared (R-IR). Obvious bone-like apatite formation could be detected in the sections of porous specimens harvested from all animals after 14 days intramuscular implantation. Crystal deposition could be only observed on the surface of the concave regions of the samples collected from dogs, rabbits and rat. On the contrary, evenly distributed flake-shaped crystal could be found on the pore surface and also on the outer surface of the materials implanted in pigs. The morphology of bone-like apatite in pigs was different from that in the others animals. Bone-like apatite was not observed in dense specimen implanted intramuscularly. Bone-like apatite formed faster on specimens implanted in rabbit than that in other animals. This formation sequence is different from the sequence of osteoinductivity of biphasic calcium phosphate ceramics implanted in these animals. The results demonstrated that the formation of bone-like apatite on materials is a prerequisite condition to their osteoinduction but other factors also play important roles in osteoinduction.
Animals ; Apatites ; chemical synthesis ; Body Fluids ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Phosphates ; chemistry ; Ceramics ; chemistry ; Dogs ; Male ; Materials Testing ; Prostheses and Implants ; Rabbits ; Rats ; Swine

Objective: To understand the occurrence and predictive factors of depressive symptoms among multi ethnic middle school students in Yunnan Province, so as to provide a referential framework for schools to carry out targeted mental health education. Methods: From October to December 2022, 8 500 first grade students from 23 middle schools were selected from 11 minority areas in Yunnan Province by cluster random sampling method. Demographic information and data relating to the students lifestyles were collected by questionnaire, and the Children s Depression Inventory (CDI) was used to evaluate depressive symptoms. Chi square test was performed to compare differences in the detection rate of depressive symptoms among first grade middle school students for univariate analysis. A decision tree model of depressive symptoms in middle school students was established by using the Chi squared automatic interaction detector (CHAID). Results: The detection rate of depressive symptoms among first grade students from multi ethnic middle schools in Yunnan Province was 28.26%. The decision tree model of depressive symptoms was academic stress ( χ 2=469.08) at the first level, breakfast behaviors (low/moderate academic stress: χ 2=155.49; severe academic stress: χ 2=105.24) at the second level, and the number of close friends (low/moderate academic stress and consuming breakfast 0- 2 days weekly: χ 2=23.15; low/moderate academic stress and consuming breakfast 3-4 days weekly: χ 2=14.99; severe academic stress and consuming breakfast 0-2 days weekly: χ 2=29.26; severe academic stress and consuming breakfast 3-4 days weekly: χ 2=20.15), ethnicity ( χ 2=78.22) and drinking ( χ 2=50.36) at the third level ( P <0.01). Conclusions The study identifies academic stress, breakfast behaviors, number of close friends, drinking and ethnicity as predictive factors of depressive symptoms among multi ethnic middle school students in Yunnan Province. Schools should develop targeted strategies for preventing and managing depressive symptoms in middle school students, so as to reduce their occurrence.

Objective: To investigate the association of sugar sweetened beverage (SSB) consumption with insomnia and depressive symptoms among first grade middle school students from Yunnan Province, so as to provide evidence to guide interventions for the treatment of these symptoms in this population. Methods: From October to December 2022, 8 500 firstgrade middle school students from 11 counties in Yunnan Province were selected by cluster random sampling. Depressive symptoms, SSB consumption, and insomnia symptoms among students were evaluated by the Child Depression Scale (CDI), dietary frequency questionnaire, and Insomnia Severity Index (ISI). A Logistic regression model was employed to analyze the relationship between SSB consumption, insomnia, depressive symptoms, and their interaction effects among students. Results: The detection rate of depressive symptoms was 28.3%, and having insomnia symptoms ( OR=6.07, 95%CI =5.46-6.75), consuming carbonated beverages ( OR=1.20, 95%CI =1.08-1.34), tea ( OR=1.13, 95%CI =1.02-1.25), energy drinks ( OR=1.36, 95%CI =1.23-1.50), and other beverages ( OR=1.32, 95%CI =1.19-1.45) were positively correlated with depressive symptoms among first grade middle school students ( P < 0.05). Carbonated beverages (additive effect: OR=2.96, 95%CI =2.72-3.22, multiplicative effect: OR=4.75, 95%CI =4.25- 5.32 ), fruit drinks (additive effect: OR=2.61, 95%CI =2.40-2.82; multiplicative effect: OR=4.43, 95%CI =3.94-4.97), tea (additive effect: OR=2.70, 95%CI =2.47-2.89; multiplicative effect: OR=4.34, 95%CI =3.86-4.89), energy drinks (additive effect: OR=2.82, 95%CI =2.61-3.05; multiplicative effect: OR=4.48, 95%CI =3.92-5.12), sweetened milk (additive effect: OR= 2.73, 95%CI =2.06-2.96; multiplicative effect: OR=4.61, 95%CI =4.12-5.17) and other beverages (additive effect: OR= 2.73 , 95%CI =2.53-2.95; multiplicative effect: OR=4.56, 95%CI =4.00-5.20) had both additive and multiplicative effects with insomnia, and increased the risk of depressive symptoms in first grade middle school students ( P <0.01). Conclusions The interaction between the consumption of SSB and insomnia symptoms may increase the risk of depressive symptoms among first grade middle school students in Yunnan Province. It is necessary to advocate middle school students to reduce SSB intake, in order to decrease the occurrence of depressive symptoms among this population.