An investigation of the eruption of the mandibular third molar and an analysis of the causes of their impaction and absence were made. On macroscopic and X-ray examination, the rate of the impaction and absence was 19.74％ and 28.95％. respectively.In the analysis of the causes of the impaction and the absence of mandibular third molars we found that besides the length of the region posterior to the second molar already reported, the frequency of crowded teeth in the normal and in the impacted group is higher than that in the absent group. The mediodistal diameters of the mandibular second molar and first molar, which in the normal group are bigger than those in the other groups, also influence the eruption of the mandibular molars.

Objective Through the establishment of adjacent cabin blast injury model of Beagle dog,to investigate the pathophysiological changes in the experimental animals in this scenario,then speculate on the mechanisms of injury.Methods Several adjacent cabins were built in the same size with the real warship.Seven Beagle dogs were subjected to injuries from the explosion,from whom one was selected randomly to implant intracranial pressure transducers before blast,the others were tested on the pathophysiological changes after blast.The dogs were mounted on the platform of a cabinet in the adjacent cabin,subjected to injury from 650g bare TNT explosive blast.The transducers recorded the value of space and intracranial shock wave pressure.Following blast treatment,the serum levels of IL-6,IL-8,neuron specific enolase (NSE),brain and chest CT and pathological changes of the brain tissue were observed.Results Serum levels of IL-6,IL-8 and NSE were elevated to varying degrees after blast.All of them increased significantly at different time points after blast (P＜0.05).Brain and chest CT examinations did not show any significant positive results.Pathological results showed that there was a little necrosis in the brain,some neurons had karyopycnosis,karyolysis or disappearance of the nucleoli,and the cell boundaries were blurred.The blast wave was blocked greatly by the scalp and skull (about 90％),but could still penetrate them and cause brain injuries.Conclusions Explosion in the adjacent cabin causes mainly mild traumatic brain injuries.Blast wave can be blocked by the scalp and skull greatly.

In order to further research into the EEG information of rats epileptic model, we applied different nonlinear dynamic methods. After having analyzed the EEG signal of rat falling sickness by means of approximate entropy and correlation dimension, we adopted a the new method, unstable periodic orbits, which was used to analyze complex activity of neurons system to look for the change regularity of change in the EEG signal in the whole course of rat's falling sickness. We found period 1 orbits and period 2 orbits to be statistically significant in the data of ictal time of epilepsy. At the same time, we found period 1 orbits to be statistically significant in the data of preictal time of epilepsy.
Animals ; Disease Models, Animal ; Electroencephalography ; Entropy ; Epilepsy ; physiopathology ; Nonlinear Dynamics ; Rats ; Signal Processing, Computer-Assisted

Objective:To investigate the early changes of serum biomarkers in rats with mild blast-induced traumatic brain injury (bTBI) in cabin.Methods:Explosion source in the simulated cabin was detonated by initiator. The bTBI rat models caused by explosion shock wave in cabin were established. A total of 24 adult male Sprague-Dawley rats were divided into normal control group ( n=6) and bTBI group ( n=18), according to the random number table. Rats in bTBI group were subdivided at 3, 24, and 72 h post-blast, with 6 rats at each time point. Shock wave pressure at the rat head was measured during the explosion. At 3, 24, and 72 h post-blast, the general condition of rats was observed. Rat blood was collected by cardiac puncture. Then brains were taken completely and quickly for pathological observation. HE staining was used to observe the changes of neurons in hippocampal CA1 area. The collected serum was tested for levels of biomarkers, including interleukin- 6 (IL-6), neuron specific enolase(NSE), S100-β, alpha Ⅱ-spectrin breakdown product-145 (SBDP-145) and Tau. Results:The maximum peak value of the shock wave pressure curve at the rat head was (818.2±33.3)kPa, and the duration was about 1 000 μs. After the explosion, the activity of the rats decreased significantly, the hair was dull, and the appetite decreased. General observation showed that the brain tissue was obviously swollen, the blood vessels on the brain surface were thickened, and there was a little patchy bleeding, but no obvious brain contusion was seen. HE staining showed that some neurons in the hippocampus CA1 area had apoptosis or necrosis. At 3, 24, and 72 hours post-blast, the levels of IL-6 were (155.3±10.7)pg/ml, (171.3±25.3)pg/ml and (155.6±18.2)pg/ml, all of which were significantly higher than that in normal control group [(116.3±7.3)pg/ml]( P<0.05); the levels of NSE were (12.0±1.0)ng/ml, (11.0±1.0)ng/ml and (11.0±1.2)ng/ml, all of which were significantly higher than that in normal control group [(8.1±0.5)ng/ml]( P<0.05); the levels of S100-β were (71.9±10.7)pg/ml, (58.0±11.5)pg/ml and (56.5±12.2)pg/ml, all of which were significantly higher than that in normal control group [(35.2±2.5)pg/ml] ( P<0.05); the levels of SBDP-145 were (29.4±2.8)ng/ml, (24.5±4.8)ng/ml and (20.7±2.1)ng/ml, and only the level at 3 h post-blast was significantly higher than that in normal control group [(20.9±1.2)ng/ml]( P<0.05); the levels of Tau were (141.4±11.7)pg/ml, (189.5±28.2)pg/ml and (179.1±32.5)pg/ml, all of which were significantly higher than that in normal control group [(97.8±5.9)pg/ml]( P<0.05). Conclusion:The serum levels of IL-6, NSE, S100-β, SBDP-145 and Tau in mild bTBI rats increase in various degrees at early time, which provides a theoretical basis for use of serum markers in the early diagnosis of mild bTBI.

OBJECTIVE： To study the mechanism of analgesic effect of 8-O-acetyl-safalinoside （8-OaS） on chronic inflammatory pain model rats. METHODS ：Totally 30 male SD rats were divided into sham operation group （normal saline ）， model group （normal saline ），8-OaS low-dose ，medium-dose and high-dose groups （3，10，30 μg/kg），with 6 rats in each group. Except for sham operation group ，other groups were given planter injection of Freund ’s complete adjuvant to induce chronic inflammatory pain model. After successful modeling ，the rats in each group were given corresponding drugs intrathecally ，once a day，for 7 consecutive days. Then Von-Frey filaments were used to detect the planter pain threshold of the rats in each group ；the area under the planter pain threshold curve of each group and the half effective dose （ED50）of 8-OaS were calculated. Another 36 male SD rats were divided into sham operation group （normal saline ），model group （normal saline ）and 8-OaS group （dose of ED50），and the modeling method and administration route were the same as above. Immunofluorescence histochemical staining was used to observe the positive expression of ionized calcium binding adapter molecule 1（Iba-1）and signal molecule phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK）；Western blotting assay was used to determine the expression of Iba- 1，p-p38 MAPK，IL-1β，IL-6 and TNF-α in spinal dorsal horn of rats. RESULTS：Compared with sham operation group ，plantar pain threshold and area under the curve in model group were reduced significantly （P＜0.01）. Compared with model group ，plantar pain threshold increased significantly after 5，6，7 days of administration in 8-OaS low-dose group （P＜0.05），plantar pain threshold and area under the curve in 8-OaS medium-dose and high-dose groups were increased significantly （P＜0.05 or P＜0.01）. Most of above indexes in each dose group of 8-OaS were signifficantly different ，and ED 50 of 8-OaS was 18.87 μ g/kg. Results of immunohistochemistry staining and Western blotting showed that p-p 38 MAPK was mainly expressed in Iba- 1 positive cells. Compared with sham operation group ，the fluorescence density of Iba- 1 and p-p 38 MAPK in spinal dorsal horn ，the expression of Iba-1，p-p38 MAPK，IL-6，IL-1β and TNF-α were significantly increased in model group（P＜0.05 or P＜0.01）. Compared with model group ，the fluorescence density of Iba- 1 and p-p 38 MAPK in spinal dorsal horn ，the expression of Iba- 1，p-p38 MAPK， IL-6，IL-1β and TNF-α were decreased significantly in 8-OaS group （P＜0.05）. CONCLUSIONS ：Intrathecal administration of 8-OaS can effectively alleviate chronic inflammatory pain in rats. The mechanism may be related to the inhibition of the phosphorylation of p 38 MAPK and the expression of IL- 6，IL-1β and TNF-α.

BACKGROUND: The effect of arteriosclerotic intracranial arterial vessel wall enhancement (IAVWE) on downstream collateral flow found in vessel wall imaging (VWI) is not clear. Regardless of the mechanism underlying IAVWE on VWI, damage to the patient's nervous system caused by IAVWE is likely achieved by affecting downstream cerebral blood flow. The present study aimed to investigate the effect of arteriosclerotic IAVWE on downstream collateral flow. METHODS: The present study recruited 63 consecutive patients at the Second Hospital of Hebei Medical University from January 2021 to November 2021 with underlying atherosclerotic diseases and unilateral middle cerebral artery (MCA) M1-segment stenosis who underwent an magnetic resonance scan within 3 days of symptom onset. The patients were divided into 4 groups according to IAVWE and the stenosis ratio (Group 1, n = 17; Group 2, n = 19; Group 3, n = 13; Group 4, n = 14), and downstream collateral flow was analyzed using three-dimensional pseudocontinuous arterial spin labeling (3D-pCASL) and RAPID software. The National Institutes of Health Stroke Scale (NIHSS) scores of the patients were also recorded. Two-factor multivariate analysis of variance using Pillai's trace was used as the main statistical method. RESULTS: No statistically significant difference was found in baseline demographic characteristics among the groups. IAVWE, but not the stenosis ratio, had a statistically significant significance on the late-arriving retrograde flow proportion (LARFP), hypoperfusion intensity ratio (HIR), and NIHSS scores ( F = 20.941, P <0.001, Pillai's trace statistic = 0.567). The between-subject effects test showed that IAVWE had a significant effect on the three dependent variables: LARFP ( R2 = 0.088, F = 10.899, P = 0.002), HIR ( R2 = 0.234, F = 29.354, P <0.001), and NIHSS ( R2 = 114.339, F = 33.338, P <0.001). CONCLUSIONS: Arteriosclerotic IAVWE significantly reduced downstream collateral flow and affected relevant neurological deficits. It was an independent factor affecting downstream collateral flow and NIHSS scores, which should be a focus of future studies. TRIAL REGISTRATION ChiCTR.org.cn, ChiCTR2100053661.
Humans ; Constriction, Pathologic/pathology* ; Magnetic Resonance Imaging/methods* ; Middle Cerebral Artery/pathology* ; Tomography, X-Ray Computed

Objective To analyze the status, trends and issues of professionals in rehabilitation institutions in China, and provide policy recommendations on rehabilitation professional development.Methods The data from database and statistical bulletin of CDPF has been analyzed using descriptive analysis and deviation analysis.Results The quantity of professionals of rehabilitation institutions increased 24,900 (12.62%) in 2016. Average professionals per institution had been decreased from 33.89 in 2012 to 28.33 in 2016. In regard to the structure of distribution, the rehabilitation professionals at provincial level had been decreased 21.95% in 2015 than that of in 2012. Both training programs and the number of trainees from rehabilitation institutions had decreased.Conclusion There were big gap between services provision and needs of professionals. The distribution of professionals at provincial, city and county level was under optimization. The on-job training for rehabilitation professionals should be improved. It is recommendated to develop national plan for professionals development to meet the needs of rehabilitation services, advance the on-job training for professionals, develop the higher education of rehabilitation and improve attractiveness of rehabilitation to retain and recruit more professionals.