Undicalcified autologous dentin particles(UADP)combined platelet rich fibrin(PRF)were used in a case after extraction of the left mandibular second molar for tooth extraction site preservation.CBCT images at 3,9 and 24 months after operation showed that the bone mass maintenance effect was obvious.Histological sections showed a large number of new bone formation around dentin particles.

Objective:To explore the dynamic temporal variability of brain functional networks in individuals with internet gaming disorder(IGD)using dynamic functional connectivity density(dFCD).Methods:From January 2019 to December 2021, resting-state functional magnetic resonance imaging data were recruited from 55 patients with IGD and demographically matched 50 healthy controls.Data analysis was performed by IBM SPSS 21.0 software. The functional connectivity density(FCD) combined with sliding window analysis was employed to calculate the temporal variability of global functional connectivity.FCD in whole brain was further devided into ipsilateral and cotralateral parts.The temporal variability of dFCD was further quantified utilizing the standard deviations of whole brain, intra-, and inter-hemispheric FCD. Finally, Pearson correlation analysis was performed between dFCD variance in differential brain regions and clinical behaviors.Results:The inter-hemispheric dFCD in the left posterior cingulate cortex(-0.16±0.24) and the left precuneus(-0.08±0.23) in patients with IGD were lower that those in healthy controls(0.002±0.260, 0.12±0.36)( t=-3.502, -4.160, both P<0.05).And the intra-hemispheric dFCD in the left calcarine, the left precuneus, and the left posterior cingulate cortex in patients with IGD were lower that those in healthy controls( t=-3.809, -4.360, -3.561, all P<0.05).Moreover, abnormal global dFCD variability of the calcarine and ipsilateral dFCD variability of the PCC negatively correlated with the severity of IGD( r=-0.380, -0.413, both P<0.05). Conclusion:Patients with IGD show intra-and inter-hemispheric dFCD differences in the visual attention network and default mode network, which may respond to the underlying neurobiological basis for the presence of cognitive dysfunction and impaired concentration.

Objective:To fulfill the automatic radiolabeling of the norepinephrine transporter (NET) trancer 18F-meta-fluorobenzylguanidine (mFBG), and explore the 18F-mFBG PET/CT imaging effect of pheochromocytoma. Methods:On the basis of the chemical structure of mFBG, a spirocyclic iodonium ylide was used as the precursor to undergo a 3-step reaction sequence (radiofluorination, deprotection and neutralization) on AllinOne synthesis module. Purification by high performance liquid chromatography and formulation were conducted to generate 18F-mFBG. The corresponding quality control tests of 18F-mFBG product was performed. Afterwards, a postoperative patient with pheochromocytoma underwent 18F-mFBG PET/CT imaging. Results:The radiosynthesis was accomplished within 70 min, and 18F-mFBG was obtained in (17.8±2.4)% non-decay-corrected radiochemical yield ( n=5), with radiochemical purity >97% and molar activity >59.2 GBq/μmol. Sterility test, bacterial endotoxins test, abnormal toxicity test and the acetonitrile residue all met the requirements of Pharmacopoeia of the People′ s Republic of China (2020 Volume Ⅳ). The 18F-mFBG PET/CT imaging disclosed high uptake in pheochromocytoma and clear localization of lesions. Conclusions:The automatic radiolabeling of the NET targeted tracer 18F-mFBG is successfully realized by commercially available synthesis module, and the production quality meets all requirements for clinical translation. 18F-mFBG has a potential to image neuroendocrine lesions in clinical setting.

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

Objective To investigate the effect of polylactic-co-glycolic acid (PLGA)/graphene oxide (GO) nanofibers combined with brain derived neurotrophic factor (BDNF) on neural stem cells (NSCs) proliferation and differentiation as well as on the spinal cord injury repair.Methods PLGA/GO nanofibers were manufactured and absorbed with BDNF,and the microstructure of PLGA/GO nanofibers was observed by scanning electron microscope.The loading efficiency and release curve of BDNF on PLGA/GO nanofibers were measured by ELISA.NSCs were implanted on the surface of PLGA/GO and PLGA/GO/BDNF nanofibers.The absorbance values of each group were measured by MTT method,and the expression of Tuj-1 was observed by immunofluorescence and PCR.A total of 30 female SD rats were divided into control group (n =10),PLGA/GO group (n =10) and PLGA/GO/BDNF group (n =10) according to random number table.T9 spinal cord tissue was cut by Venus scissors to establish spinal cord hemisection injury model of rats.PLGA/GO and PLGA/GO/BDNF nanofibers were implanted onto the surface of injury site.BBB score was used to assess the motion functional recovery of the rats at 1,7,14 and 28 days after operation.Immunofluorescence staining of neuron specific nucleoprotein (NeuN)and glial fibrillary acidic protein (GFAP) were performed to observe the expressions of neurons and astrocytes at the injured site respectively one month after injury.Results The PLGA/GO nanofibers showed an irregular smooth fiber-like structure,and the average fiber diameter was (987.5 ± 176.3)nm.NSCs could differentiate into neurons on the nanofibers.The result of ELISA showed loading rate of BDNF on PLGA/GO nanofibers was about 47.5％.The release curve showed that BDNF was first released about 30％ on the first day and then about 60％ on the 21st day.The results of MTT and PCR showed that optical density value and Tuj-1 gene expression in the PLGA/GO/BDNF group were significantly higher than those in the PLGA/GO group (P ＜ 0.05).The animal experiment results showed that the BBB score of PLGA/GO/BDNF group was (15.3 ±0.7) points at 28 days after injury,which was significantly higher than that of the injury control group [(11.8 ± 0.8) points] and that of PLGA/GO group [(12.7 ±0.8) points] (P ＜ 0.05).Immunofluorescence results showed that the expression of NeuN in PLGA/GO/BDNF group was 13.7 ± 2.2,significantly higher than that in injury control group (4.3 ± 2.9) (P ＜0.05),and the expression of GFAP in PLGA/GO group was (25.6 ± 4.3) ％ significantly lower than that in injury control group [(38.5 ± 6.2) ％] and PLGA/GO group [(36.7 ± 7.3) ％] (P ＜ 0.05).Conclusion PLGMGO nanofibers combined with BDNF can effectively promote the proliferation and neuron differentiation of NSCs in vitro and repair spinal cord injury in vivo through orthotopic transplantation at the injury site.

Deep brain stimulation (DBS) has been successfully used to treat a variety of brain diseases in clinic. Recent investigations have suggested that high frequency stimulation (HFS) of electrical pulses used by DBS might change pathological rhythms in action potential firing of neurons, which may be one of the important mechanisms of DBS therapy. However, experimental data are required to confirm the hypothesis. In the present study, 1 min of 100 Hz HFS was applied to the Schaffer collaterals of hippocampal CA1 region in anaesthetized rats. The changes of the rhythmic firing of action potentials from pyramidal cells and interneurons were investigated in the downstream CA1 region. The results showed that obvious θ rhythms were present in the field potential of CA1 region of the anesthetized rats. The θ rhythms were especially pronounced in the stratum radiatum. In addition, there was a phase-locking relationship between neuronal spikes and the θ rhythms. However, HFS trains significantly decreased the phase-locking values between the spikes of pyramidal cells and the θ rhythms in stratum radiatum from 0.36 ± 0.12 to 0.06 ± 0.04 ( < 0.001, paired -test, = 8). The phase-locking values of interneuron spikes were also decreased significantly from 0.27 ± 0.08 to 0.09 ± 0.05 ( < 0.01, paired -test, = 8). Similar changes were obtained in the phase-locking values between neuronal spikes and the θ rhythms in the pyramidal layer. These results suggested that axonal HFS could eliminate the phase-locking relationship between action potentials of neurons and θ rhythms thereby changing the rhythmic firing of downstream neurons. HFS induced conduction block in the axons might be one of the underlying mechanisms. The finding is important for further understanding the mechanisms of DBS.

At present,the AIDS epidemic situation in college students is becoming more and more serious.In view of the particularity of colleges students and the lack of professional team for AIDS prevention and control in colleges and universities,there exists ethical issues when carry out the prevention and control for AIDS in colleges and universities such as the ethical issue in publicity and education,the ethical issue in AIDS behavioral intervention,the ethical issue in the consultation and detection for AIDS.This paper suggests that it should confront the current situation of AIDS prevention and control,improve the professional level of carrying out AIDS prevention and control,adhere to the necessary principles of AIDS prevention and control,and explore a new mode to construct AIDS prevention and control in colleges and universities.

BACKGROUND: As a blood concentrate rich in growth factors and fibrin, platelet-rich fibrin (PRF) is able to significantly promote bone regeneration. PRF mixed with bone substitutes is commonly used to repair bone defects in oral maxillofacial region. But it remains controversial whether PRF as a sole material in sinus floor elevation can produce enough new bone tissues.OBJECTIVE: To evaluate the osteogenic potential of PRF as a sole grafting material in sinus floor elevation by means of an animal model.METHODS: Twelve healthy adult mongrel dogs aged 12-18 months were selected and randomized into three groups (groups A, B and C), with four dogs in each group. Upper first molars on both side of each dog were extracted 12 weeks prior to sinus floor elevation and simultaneous implants placement. Different materials were used to fill in the space between the sinus membrane and implant. Groups A, B and C were filled with PRF, autologus bone particles and autologus blood clot respectively. After 12 weeks, specimens were harvested to analyze the new bone formation by gross observation, X-ray examination and histological evaluation.RESULTS AND CONCLUSION: New bone formation was found to embrace all the implants close to the bony sinus floor, and the tips of all implants were free from bone coverage. The new bone height of groups A, B and C were (3.135±0.288),(3.218±0.345), and (1.898±0.157) mm, respectively. The new bone density of groups A, B and C were (65.06±5.88),(75.34±8.18), and (56.92±4.95) g/cm3, respectively. There were significant differences between the new bone height in groups A and C as well as in groups B and C (P < 0.05). Also, significant differences were found between the new bone density in groups A and B, B and C, A and C (P < 0.05). Within the confine of this experiment, it is feasible to use PRF as a sole grafting material in the sinus floor elevation to generate new bone, but the new bone volume is limited.

BACKGROUND:Three-dimensional visualization technique has been widely used in clinical treatment. Preoperative visualization technique al ows safe demonstration on the complex spine fracture models, and also prepare screw placement scheme according to three-dimensional model of patients.
OBJECTIVE:To discuss the clinical result of treating short-segment lumbar vertebrae fracture with pedicle screw visualization.
METHODS:A total of 32 patients with lumbar vertebrae fracture were treated with 182 pedicle screws. Before the screw implantation, the structure of bilateral pedicle was observed using Mimics software and the implantation parameters were measured. The operation methods and related complications were told to the patients through the reconstructed three-dimensional images. The satisfaction of the patients, operation time, and the position of pedicle screws by postoperative CT scan were assessed. The percentages of anterior vertebral height and Cobb’s angle were measured before operation, 2 weeks after operation and 8 months after operation.
RESULTS AND CONCLUSION:The excellent satisfaction rate of the patients was 100%, the mean operation time was 185 minutes, and 173 pedicle screws (95.1%) were total y inserted within the pedicle. Al patients were fol owed up for 7-22 months. The results showed that the fracture healed wel . The percent of anterior vertebral height and Cobb’s angle at 2 weeks after operation were significantly decreased compared with them before operation (P<0.05). There were no significant difference about the percent of anterior vertebral height and Cobb’s angle between 2 weeks and 8 months fol ow-up (P>0.05). Single-segment lumbar vertebrae fracture was wel treated by the pedicle screw visualization technique. This method assists to make up preoperation plan, increase the rate of patients’ satisfaction, shorten operation time, and increase the accuracy of pedicle screw insertion.

BACKGROUND:Autologous bone marrow aspirate concentrate is often applied in patients from Department of Orthopedics and those with severe limb ischemia, but rarely applied in Department of Oral and Maxil ofacial Surgery, especial y in Department of Oral Implantology. The effect of autologous bone marrow aspirate concentrate on promoting peri-implant bone regeneration deserves further studies.
OBJECTIVE:To evaluate the effect of bone marrow aspirate concentrate in the repair of peri-implant bone defect.
METHODS:Bone marrow 5 mL was extracted from posterior superior iliac spine of experimental dogs and bone marrow cel s were counted before and after concentration. Bone defect (4 mm × 4 mm × 4 mm) was prepared in the middle of bilateral mandibular premolar, which was randomly implanted with gelatin sponge plus bone marrow aspirate concentrate, autologous bone and gelatin sponge. At 4 and 12 weeks after surgery, bone defect specimens were histological y observed. The new bone formation rate and new bone mineral density were calculated.
RESULTS AND CONCLUSION:After centrifugation, the concentrations of nucleated cel s in bone marrow aspirate concentrate were increased by (2.78±0.22) times. More colony-forming units were found after cel culture. Histological analysis showed that, significantly higher new bone formation rate and new bone mineral density occurred in gelatin sponge plus bone marrow aspirate concentrate group, compared with autologous bone group and gelatin sponge group at 4 weeks (P<0.05). The new bone formation rate in gelatin sponge plus bone marrow aspirate concentrate group was significantly lower than that of autologous bone group, and higher than that of gelatin sponge group at 12 weeks (P<0.05). However, the difference of new bone mineral density in the three groups was not significant (P>0.05). Autologous bone marrow aspirate concentrate can significantly improve new bone mineral density and quantity in the pre-implant bone defect.