The impact of the peer effect on adolescent drinking behavior: instrumental-variable evidence from China.

Background: Governments around the world have taken measures to limit adolescent drinking, however, rates are still alarmingly high. However, most of these measures ignore the peer effect of drinking among adolescents. Previous studies have not sufficiently considered the reciprocal relationship between adolescent alcohol consumption and peer alcohol consumption, which may lead to an overestimation of the peer effect and mask underlying issues. Good instrumental variables are powerful but rare tools to address these issues. Objective: This paper aims to correctly estimate the peer effect of drinking on adolescent drinking behavior in China. Methods: Owing to the detailed information of household background in the dataset of our survey, we were able to use the drinking behaviors of peers' fathers and their beliefs about the health risks of alcohol as instrumental variables, which are more powerful than school-average instrumental variables. We collected data from the 2017 Health and Nutrition Panel survey, which surveyed 10,772 primary school students from 59 urban migrant and 60 rural public schools. Results: The instrumental variable method estimation revealed that peer drinking significantly influences adolescent drinking behavior, with adolescents who have peers who drink alcohol being 10.5% points (2 stage least square, i.e., 2SLS, full sample estimation) more likely to engage in drinking compared to those without such peers. Furthermore, the effect differs significantly between migrant and rural adolescents. Conclusion: The study found that parental care plays a significant role in the degree of peer effect, with the absence of parental care being a key factor in the presence of the peer effect.

[Human umbilical cord mesenchymal stem cells co-cultured with dental pulp cells in vitro and its effect on cell biological behaviors].

PURPOSE: To investigated the effect of human umbilical cord mesenchymal stem cells (hUCMSCs) and human dental pulp cells (hDPCs) on cell biological behaviors by co-culture system in vitro. METHODS: hUCMSCs and hDPCs were obtained by primary culture. A culture system of hUCMSCs and hDPCs induced by BMP2 was established in vitro. hUCMSCs and hDPCs were co-cultured at the ratio of 1:1, 1:5 and 5:1. The optimum ratio of each group was selected to further experiment. The formation of calcium nodule was stained by alizarin red staining at 21 day. The expression of DSPP，ALP，DMP1，OCN，VEGF，HGF and Nanog gene was detected by real-time quantitative PCR at 7 day and 14 day. 1:1 group and hUCMSCs, hDPCs group were selected for alizarin red staining at 21 day according to PCR results. Statistical analysis was performed using SPSS 21.0 software package. RESULTS: Calcified nodules formation in 1:1 group was significantly higher than in hUCMSCs group (P<0.05), close to that in hDPCs. qPCR showed that the mRNA expression of DSPP, ALP, DMP1, OCN, VEGF and HGF in 1:1 group was significantly higher than that in hUCMSCs (P<0.05); mRNA expression of Nanog in 1:1 group was significantly lower than in hUCMSCs group (P<0.05). The results of alizarin red staining showed that the OD value of 1:1 group was significantly higher than that of hUCMSCs group (P<0.05). CONCLUSIONS: The cells can be induced to differentiate into odontoblastoid-like cells and the mRNA expression of angiogenic factors was stimulated by hUCMSCs co-culure wih hDPCs.

Methylene Blue Exerts Anticonvulsant and Neuroprotective Effects on Self-Sustaining Status Epilepticus (SSSE) Induced by Prolonged Basolateral Amygdala Stimulation in Wistar Rats.

BACKGROUND This study was designed to investigate the potential anticonvulsant and neuroprotective effects of methylene blue (MB) on self-sustaining status epilepticus (SSSE) induced by prolonged basolateral amygdala stimulation (BLA) in Wistar rats. MATERIAL AND METHODS The rats were randomly divided into 4 groups: (1) the Control group (rats without any treatment); (2) the Sham group (rats received electrode implantation but without electrical stimulation); (3) the SSSE group (rats received electrode implantation and additional electrical stimulation); and (4) the SSSE+MB group (rats received 1 mg/kg MB intraperitoneal injection 5 min after SSSE). SSSE models were established by prolonged BLA stimulation. The severities of SSSE were assessed by the number of separate seizures and the accumulated time of seizures. The variations of malondialdehyde/glutathione (MDA/GSH) were assessed 24 h after the establishment of SSSE. Nissl staining was performed to detect the surviving neurons in hippocampal CA1 and CA3 regions, and Western blotting assays were used to detect Caspase-3 (CASP3), B cell lymphoma 2 (BCL2), and BCL2-associated X protein (BAX). RESULTS Compared with the SSSE group, treatment with MB (1) markedly reduced the number and accumulated time of seizure activities; (2) significantly attenuated the increase of MDA and the decrease of GSH hippocampal levels; (3) markedly improved the cell morphology and alleviated the neuronal loss in hippocampal CA1 and CA3 regions; (4) significantly attenuated the increase of CASP3 and BAX and the decrease of BCL2 hippocampal levels. CONCLUSIONS MB has a protective effect in the SSSE model and may be useful as an adjuvant for preventing or treating epilepsy in humans.

Neuropeptide Y suppresses epileptiform discharges by regulating AMPA receptor GluR2 subunit in rat hippocampal neurons.

The present study aimed to investigate the effects of neuropeptide Y (NPY) on the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor glutamate receptor 2 (GluR2) subunit in epileptiform discharge hippocampal neurons. Hippocampal neurons were harvested from neonatal Sprague­Dawley rats aged <24 h and primarily cultured in vitro. At day 12 following culture, hippocampal neurons were divided into the following groups: Control, Mg2+­free, NPY+Mg2+­free and BIBP3226+NPY+Mg2+­free. The action potential of neurons was measured using the whole cell patch clamp technique in the control, Mg2+­free and NPY+Mg2+­free groups. AMPA current (IAMPA) was detected and peak current density was calculated in each group. Alterations in total protein and phosphorylation of the GluR2 subunit were detected by western blot analysis, and GluR2 mRNA expression levels were detected by reverse transcription­quantitative polymerase chain reaction, in each group. The whole cell patch clamp technique demonstrated an abnormal action potential in the Mg2+­free group. The frequency and amplitude of the action potential were significantly greater in the Mg2+­free group compared with the control group, and significantly reduced in the NPY+Mg2+­free group compared with the Mg2+­free group (P<0.05). In the Mg2+­free group, compared with the control group, peak current density was significantly reduced (P<0.05), GluR2 subunit protein content was slightly reduced (P>0.05), phosphorylation levels of GluR2 subunit were significantly greater (P<0.05) and GluR2 mRNA was significantly reduced (P<0.05). In the NPY+Mg2+­free group, compared with the Mg2+­free group, peak current density was significantly greater (P<0.05), phosphorylation levels of GluR2 subunit were significantly reduced (P<0.05) and GluR2 mRNA expression was significantly greater (P<0.05). In the BIBP3226+NPY+Mg2+­free group, compared with the NPY+Mg2+­free group, peak current density was significantly reduced (P<0.05), phosphorylation levels of GluR2 subunit were significantly greater (P<0.05) and GluR2 mRNA expression was significantly reduced (P<0.05). After 3 h of treatment with Mg2+­free extracellular fluid, epileptiform discharge was detected in the cells. NPY inhibited the discharge and its underlying mechanism may be that epileptiform discharge suppressed the function of the AMPA receptor GluR2 subunit. NPY relieved the inhibition of the GluR2 subunit via the Y1 receptor. This may provide a novel direction for future studies on the pathogenesis and treatment of epilepsy.

[miRNA profile of the human dental pulp cells during odontoblast differentiation induced by BMP-2].

PURPOSE: To screen and verify the differentially expressed microRNAs (miRNAs) during the differentiation of human dental pulp cells (hDPCs) to odontoblasts induced by BMP-2. METHODS: The isolated hDPCs were cultured in vitro and induced by BMP-2. The levels of ALP, DMP-1 and DSPP were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). The potential characteristics of hDPCs were investigated by miRNA microarray and highly expressed miRNAs were selected with bio-information software for predicting target genes and their biological functions. Then the results were validated using qRT-PCR analysis for the selected miRNAs. Statistical analysis was performed using SPSS 18.0 software package. RESULTS: The expression of ALP, DSPP, and DMP-1 showed significantly higher levels in BMP-2 induced groups compared to the control group(P<0.05). A total of 36 miRNAs were changed (i.e. 20 miRNAs were up-regulated and 16 were down-regulated). The results of qRT-PCR were consistent with the microarray results. GO categories revealed that they were mainly associated with biological process(37.8%), cellular component (29%), molecular function(33%), while the function of other 0.2% genes remained unknown. CONCLUSIONS: This study identified differential expression of miRNAs in BMP-2-induced odontoblastic differentiation of hDPCs, thus contributing to further investigations of regulatory mechanisms and biological effect of target genes in BMP-2-induced odontoblastic differentiation of hDPCs.

[Hyperspectral parameters and prediction model of soil moisture in coastal saline].

Based on the data of soil moisture content and indoor soil surface spectral reflectance from five sampling sites of coastal saline soil, this paper analyzed the relationship between soil moisture content and soil spectrum in wavelength 350-2500 nm. We determined spectral parameters under ratio spectral index (RSI), normalized difference spectral index (NDSI) and difference spectral index (DI), and established the quantitative model of soil moisture content. The results showed significant negative correlation between spectral reflectance and soil moisture content, and the maximum negative correlation was near 1930 nm (r=0.86). By comparison of the regression equation of RSI, NDSI and DI, it was found that the regression equation of exponential function (y=0.00001e9.7203x) built by soil moisture content based on RSI (R1407, R1459) presented the maximum R2 (0.780) and the minimum SE (0.016). The established model based on RSI (R1407, R1459) could be used to monitor soil moisture content accurately in Jiangsu coastal saline soils.

[Key time window of fiber quality formation in response to short-term higher temperature stress].

By taking two cotton cultivars with different temperature-sensitivity (Sumian 15, temperature-sensitive cultivar and Kemian 1, temperature-insensitive cultivar) as materials, an experiment with two temperature regimes (high temperature: 34 °C [38/30 °C], HT and control: 26 °C [30/22 °C], CK) were set in climate chamber to study the change of key matters in different genotypes cotton in response to high temperature and their relationships with fiber quality. The results showed that as treated in the 34.0 °C high-temperature regime for 5 days at different DPA (days past anthesis), significant change in fiber quality was observed in the temperature-sensitive cultivar Sumian 15. The key time window for fiber length, fiber strength and Micronaire in response to the high temperature stress was from 0 to 18.3 DPA, 10.9 to 26.1 DPA, and 10.5 to 34.0 DPA, respectively. So, it could be concluded that the key time window of cotton fiber development in response to high temperature stress was around 11 to 18 DPA. After treated under high temperature stress at the key time window for 5 days, the content of sucrose decreased firstly then increased compared with that in the control, the content of callose increased and the content of cellulose decreased by 4.2% in maximum. The fiber length decreased (by 23.3% in maximum), fiber strength increased (by 4.3% in maximum), Micronaire decreased (by 10.5% in maximum) , and the general fiber quality deteriorated. Similar changes and trends were also observed in the temperature-insensitive cultivar Kemian 1 except that the variation degree was comparatively lower.

IL-24 Induces Apoptosis via Upregulation of RNA-Activated Protein Kinase and Enhances Temozolomide-Induced Apoptosis in Glioma Cells.

Human interleukin-24 (IL-24) has been found recently to play a tumor-suppressor role in a variety of tumors, including gliomas. However, the exact mechanism of glioma tumor suppression by IL-24 remains unclear. We collected by surgery 30 gliomas at different grades and evaluated IL-24 and double-stranded RNA-activated protein kinase (PKR) expression using fluorescence quantitative real-time PCR and immunohistochemical techniques. Two human glioma cell lines, U87 and U251, were transfected with Ad5F35-IL24 via recombinant adenovirus-mediated gene transfer and apoptosis, as well as PKR and eIF-2α expression analyzed. The results showed that IL-24 and PKR expression decreased with increasing tumor grade. Compared with cells of the control groups, Ad5F35-IL24-infected U87 and U251 cells exhibited a significantly increased apoptosis and elevated PKR, eIF-2α, p-PKR, and p-eIF-2α levels, while the expression of Bcl-2 was decreased. Finally, IL-24 also sensitized apoptosis of glioma cells to temozolomide (TMZ). This study indicates that IL-24 upregulates expression and activation of PKR, further increasing expression and activation of eIF-2α, and decreasing Bcl-2 to promote apoptosis. IL-24 also increases chemosensitivity of glioma cells to TMZ.

Effects of gamma knife irradiation on the expression of NMDA receptor subunits in rat forebrain.

OBJECTIVE: To examine the effects of gamma knife surgery (GKS) on the expression of N-methel-D-asparate receptor (NMDAR) subunits in rat forebrain. MATERIALS AND METHODS: Using stereotactic technique, we performed gamma knife irradiation on the left forebrain of 13 male Wistar rats with a maximum dose of 60 Gy. These animals were raised for 24h, 30 and 60 days before they were killed. Then immunohistochemistry was applied to detect the relative levels of NMDAR subunits (NR1, NR2A, and NR2B) in the target region. RESULTS: The expression of NR1 and NR2A but not NR2B increased significantly in the cortex 30 and 60 days after irradiation. However, no significant differences in the expression of these three subunits were detected in the caudate putamen at all time points. CONCLUSION: gamma knife irradiation induced the upregulation of NMDAR subunits, NR1, and NR2A, which might represent a possible mechanism underlying the therapeutic effects of gamma knife irradiation on many neurological diseases, including drug resistance epilepsy.

[Arthroscopic investigation of the status of temporomandibular joint in patients with temporomandibular joint pain].

OBJECTIVE: To investigate the status of the temporomandibular joint (TMJ) in patients with complaints of joint pain for improving clinical therapy. METHODS: Twenty three joints in twenty patients who complained of TMJ pain were examined radiographically and arthroscopically. RESULTS: There were at least one and more to six pathological changes could be found arthroscopically in the 23 temporomandibular joints, which were different in some respects with radiographic findings. CONCLUSION: TMJ related pain may be associated with pathological alterations in the TMJ, and synovitis may be one of the causes of TMJ pain.

[Effect of IL-24 gene expression on the growth of glioma cells in vitro and in vivo].

OBJECTIVE: To investigate the effect of IL-24 expression on the growth of glioma cells. METHODS: The IL-24 gene was transfected into rat glioma C6 cells with a retroviral vector. The expression of IL-24 in C6/IL-24 glioma cells was confirmed by RT-PCR. MTT assay and flow cytometry were used to study tumor cell proliferation in vitro. Tumorigenicity in vivo was studied in inbred SD male rats by the growth of intracerebrally inoculated tumor. RESULTS: It was confirmed by RT-PCR that the exogenous IL-24 gene expressed in C6/IL-24 cell. The C6/IL-24 cell proliferation in vitro and tumorigenicity in vivo were both inhibited compared with its parental C6 cell. CONCLUSION: IL-24 expression in glioma cells somehow inhibits their growth in vitro and in vivo.