Problematic Internet Usage and Self-Esteem in Chinese Undergraduate Students: The Mediation Effects of Individual Affect and Relationship Satisfaction.

The aim of this cross-sectional study was to examine the mediating effects of individual affect and relationship satisfaction on the relationship between self-esteem and Problematic Internet Use (PIU). Affect was measured using the Positive and Negative Affect Schedule (PANAS), relationship satisfaction was assessed using a positive and negative semantic dimension scale, self-esteem was measured using the Rosenberg Self-Esteem Scale, and PIU was measured using the Problematic Internet Use scale with a sample of 507 Chinese university students (Mage = 20.41 years, SD = 2.49). The relationships between the variables were tested using structural equation modelling with a multiple mediation model. The results revealed that negative affect and the negative semantic dimensions of relationship satisfaction mediated the relationship between self-esteem and PIU. The implications of the results and the study's theoretical contributions are discussed.

Subcutaneous Administration of PDGF-AA Improves the Functional Recovery After Spinal Cord Injury.

Previous studies by our group have demonstrated that the transplantation of exogenous platelet-derived growth factor (PDGF)-AA-overexpressing oligodendrocyte progenitor cells (OPCs) promotes tissue repair and recovery of neurological function in a rat model of spinal cord injury (SCI). However, it remains unclear whether treatment with PDGF-AA also affects endogenous oligodendrocytes (OLs) or even neurons, thus promoting further functional recovery after SCI. In the present study, we evaluated the therapeutic potential of PDGF-AA treatment by direct subcutaneous injection of PDGF-AA immediately after SCI. We demonstrated that PDGF-AA injection resulted in increased tissue sparing, myelination and functional recovery in rats following SCI. Further experimentation confirmed that PDGF-AA increased the survival of endogenous OPCs and OLs, and promoted the proliferation of OPCs and their differentiation into OLs. Moreover, PDGF-AA also protected motor neurons from death in the injured spinal cord. These results indicated that PDGF-AA administration may be an effective treatment for SCI.

Transplantation of PDGF-AA-Overexpressing Oligodendrocyte Precursor Cells Promotes Recovery in Rat Following Spinal Cord Injury.

Our previous study showed that Schwann cells (SCs) promote survival, proliferation and migration of co-transplanted oligodendrocyte progenitor cells (OPCs) and neurological recovery in rats with spinal cord injury (SCI). A subsequent in vitro study confirmed that SCs modulated OPC proliferation and migration by secreting platelet-derived growth factor (PDGF)-AA and fibroblast growth factor-2 (FGF)-2. We also found that PDGF-AA stimulated OPC proliferation and their differentiation into oligodendrocytes (OLs) at later stages. We therefore speculated that PDGF-AA administration can exert the same effect as SC co-transplantation in SCI repair. To test this hypothesis, in this study we investigated the effect of transplanting PDGF-AA-overexpressing OPCs in a rat model of SCI. We found that PDGF-AA overexpression in OPCs promoted their survival, proliferation, and migration and differentiation into OLs in vivo. OPCs overexpressing PDGF-AA were also associated with increased myelination and tissue repair after SCI, leading to the recovery of neurological function. These results indicate that PDGF-AA-overexpressing OPCs may be an effective treatment for SCI.

The AMPAR Antagonist Perampanel Attenuates Traumatic Brain Injury Through Anti-Oxidative and Anti-Inflammatory Activity.

Perampanel is a novel α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor (AMPAR) antagonist, approved in over 35 countries as an adjunctive therapy for the treatment of seizures. Recently, it was found to exert protective effects against ischemic neuronal injury in vitro. In the present study, we investigated the potential protective effects of perampanel in a traumatic brain injury (TBI) model in rats. Oral administration with perampanel at a dose of 5 mg/kg exerted no major organ-related toxicities. We found that perampanel significantly attenuated TBI-induced brain edema, brain contusion volume, and gross motor dysfunction. The results of Morris water maze test demonstrated that perampanel treatment also improved cognitive function after TBI. These neuroprotective effects were accompanied by reduced neuronal apoptosis, as evidenced by decreased TUNEL-positive cells in brain sections. Moreover, perampanel markedly inhibited lipid peroxidation and obviously preserved the endogenous antioxidant system after TBI. In addition, enzyme-linked immunosorbent assay (ELISA) was performed at 4 and 24 h after TBI to evaluate the expression of inflammatory cytokines. The results showed that perampanel suppressed the expression of pro-inflammatory cytokines TNF-α and IL-1ß, whereas increased the levels of anti-inflammatory cytokines IL-10 and TGF-ß1. These data show that the orally active AMPAR antagonist perampanel affords protection against TBI-induced neuronal damage and neurological dysfunction through anti-oxidative and anti-inflammatory activity.

[Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science.

Schwann cells induce Proliferation and Migration of Oligodendrocyte Precursor Cells Through Secretion of PDGF-AA and FGF-2.

Our previous study has showed that co-grafted Schwann cells (SCs) promote proliferation and migration of the grafted oligodendrocyte precursor cells (OPCs). However, how the co-grafted SCs affect OPCs has not been clarified. In the present study, we confirmed that SC-induced proliferation and migration of OPCs were mediated by SC-secreted factors using SC-conditioned medium (SCM). Then, we detected several candidate factors, PDGF-AA, FGF-2, and IGF-1, in SCs and SCM, and their receptors in OPCs. Finally, by using the selective inhibitors, the effects of these candidate factors on proliferation and migration of OPCs were examined. Our results showed that SCM-stimulated proliferation and migration of OPCs could be markedly decreased by both AG1295 (the inhibitor of PDGFR) and PD173074 (the inhibitor of FGFR). Together, our study suggests that SCs affect proliferation and migration of OPCs through secreting PDGF-AA and FGF-2. Identity of these molecules not only contributes to understand the mechanism of SC-induced proliferation and migration of OPCs but also provides possible target for treatment of CNS diseases.

Differential gene expression by fiber-optic beadarray and pathway in adrenocorticotrophin-secreting pituitary adenomas.

BACKGROUND: Adrenocorticotrophin (ACTH)-secreting pituitary adenomas account for approximately 7% - 14% of all pituitary adenomas, but its pathogenesis is still enigmatic. This study aimed to explore mechanisms underlying the pathogenesis of ACTH-secreting pituitary adenomas. METHODS: We used fiber-optic beadarray to examine gene expression in three ACTH-secreting adenomas compared with three normal pituitaries. Four differentially expressed genes from the three ACTH-secreting adenomas and three normal pituitaries were chosen randomly for validation by reverse transcriptase-real time quantitative polymerase chain reaction (RT-qPCR). We then analyzed the differentially expressed gene profile with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. RESULTS: Fiber-optic beadarray analysis showed that the expression of 28 genes and 8 expressed sequence tags (ESTs) were significantly increased and the expression of 412 genes and 31 ESTs were significantly decreased. Bioinformatic and pathway analysis showed that the genes HIGD1B, EPS8, HPGD, DAPK2, and IGFBP3 and the transforming growth factor (TGF)-ß signaling pathway and extracellular matrix (ECM)-receptor interaction pathway may play important roles in tumorigenesis and progression of ACTH-secreting pituitary adenomas. CONCLUSIONS: Our data suggest that numerous aberrantly expressed genes and several pathways are involved in the pathogenesis of ACTH-secreting pituitary adenomas. Fiber-optic beadarray combined with pathway analysis of differential gene expression appears to be a valid method of investigating tumour pathogenesis.

Motorcycle accidents in China.

OBJECTIVE: To analyze the characteristics and causes of motorcycle accidents in China from 2000 to 2005. METHODS: We collected data on possession of motorcycles and automobiles, number of traffic crashes, casualty and economic loss from 2000-2005 Statistic Annual Report of Traffic Management Bureau, Ministry of Public Security of China. The data was processed statistically by SPSS 11.0 software package. RESULTS: During 6 years, the number of motorcycle accidents were up to 122,300 in 2003, which was the highest, and then gradually decreased. However, the casualty had the tendency of consistent increase, for example, the motorcycle accidents resulted in 26,200 deaths and 157,500 injuries in 2005. The mortality per 10, 000 motorcycles and the ratio of deaths to injuries were lower than those of automobiles, but the mortality per 100 motorcycle accidents was significantly higher than that of automobiles (P less than 0.01). CONCLUSIONS: China has attached great importance to the management of traffic safety, which is beneficial to control and reduce traffic accidents in recent years. However, the casualty keeps increasing annually. Therefore, it is urgent to strengthen the management of motorcycles, promote the education of motorcyclists, take effective traffic measures and improve the first-aid system of traffic injuries.

Road crash in China from 2003 to 2005.

OBJECTIVE: To analyze characteristics and causes of road crash and injuries in China from 2003 to 2005. METHODS: The data of road crash in 2003-2005 were collected to study the characteristics including total vehicle number, occurrence rates of traffic accidents and serious traffic accidents so as to discuss the causes and characteristics of road crash in China. RESULTS: From 2003 to 2005, the numbers of traffic accidents, injuries and deaths as well as the mortality rates per 100,000 persons and per 10,000 vehicles declined in China. Until 2005, the total number of traffic accidents decreased to 450,000 and deaths to 99,000, with the mortality rate per 10,000 vehicles being 7.6 persons. While the drivers and passengers accounted for 33.2% and 26.6% of death casualties respectively in 2005. Most traffic accidents were caused by drivers, especially those with driving experience less than 3 years. Traffic accidents occurred on suburban roads accounted for 60%. The mortality rate of the traffic accidents per 100 km on the first grade road ranked the highest. The mortality rate of the traffic accidents on expressways ranked the highest, with continual increase of death and injury. CONCLUSIONS: At present, the increase trend of traffic accidents and casualties in China has been slowed down to some extent and shows a declining tendency, but the situation is far away from being optimistic. In order to cut down the number of traffic accidents and casualties, we should pay more attention to training and managing drivers with less than three driving years and those driving buses. Strict prevention measures should be laid on traffic accidents on first grade roads, expressways and suburban roads as well as the enhancement on improving first-aid system.

Investigation on road traffic safety of the mountain areas in southwest China based on Wulong County, Chongqing Municipality.

OBJECTIVE: To study the present situation, characteristics, and main problems of the traffic safety in the mountain areas of Southwest China. METHODS: A study was done on the traffic status of Wulong County, Chongqing Municipality, by means of document review, field investigation, and inquiry. RESULTS: The traffic crashes and deaths in Wulong County were increasing since 1999. From 1997 to 2001, there occurred 126 severe and very severe traffic crashes resulting in 175 deaths and 411 serious injuries, which accounted for 9.4% of total crashes, 96.1% of total deaths, and 48.4% of total serious injuries, respectively. The severe and very severe traffic crashes were highest in 2000. One part for 83 km in length accounting for 3.0% of No. 319 National Highway was responsible for 54.5% of very severe traffic crashes, which closely related to conditions of the road itself and its environment and defective execution of traffic laws. CONCLUSIONS: Wulong County, one of the mountain counties in Southwest China, is now facing a complex and serious road traffic situation and serious traffic safety, with a high incidence of severe and very severe road traffic crashes. The crashes closely relate to imperfect road design, defective execution of traffic laws, imperfect management, and environmental factors.

Effect of environment on extremely severe road traffic crashes: retrospective epidemic analysis during 2000-2001.

OBJECTIVE: To make an epidemiological analysis of the effect of environment on extremely severe road traffic crashes (RTCs). METHODS: Epidemiologic data of extremely severe RTCs associated with environmental factors, including weather, topography, road conditions and other traffic conditions in Mainland China during 2000-2001, were collected and analyzed. RESULTS: (1) During 2000-2001, there were 3365 extremely severe RTCs with 13666 deaths, 12204 injuries and a direct economical loss of 136 million RMB. (2) Most extremely severe RTCs occurred in fine weather days and in the daytime. The high occurrence sites were plain areas, horizontal and straight roads, Grade B and C roads, ordinary road segment, and asphalt, smooth and mixed roads. (3) Compared with other RTCs, extremely severe RTCs were more likely to happen under following conditions: on cloudy, snowing, misty and blustering days; in hill and mountainous areas; on crooked and sloping roads; on freeway, Grade A, B, and C roads; mixed roads; ordinary, bridge, narrow and transitional roads; sand and dirt-roads; without traffic control measures; night without lighting. (4) Extremely severe RTCs of mountainous area or crooked and sloping roads were most severe in terms of deaths and injures per crash. CONCLUSIONS: Extremely severe RTCs are closely related with environmental factors. Rational road programming, enhancing road establishment and improving road conditions are probably effective measures to reduce the road traffic injuries.