Occupational exposure level and requirements for radiation protection of nuclear medical staff / 中华劳动卫生职业病杂志

With the rapid development of nuclear medicine, the number of nuclear medical staff has increased a lot in the past few years in China. Close-range operations, such as preparation and injections of radiopharmaceuticals, are usually carried out in nuclear medicine department. And the use of unsealed radionuclides may also create internal exposure risk. So, occupational exposure of nuclear medical staff is a main issue of occupational health management in China. In this paper, the occupational exposure level and requirements for radiation protection of nuclear medical staff are introduced to provide references for the related work that radiological health technical institutions carry out.

Cloning and catalytic analysis of Isatis indigotica chalcone isomerase in vitro / 中国中药杂志

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.

Research on the formulation and revision of radiological parameters in the "Standards for Drinking Water Quality（GB5749-2022）" in China / 中华预防医学杂志

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.

The UGT74L2 of Andrographis paniculata catalyzes phloretin to produce trilobatin and its enzymatic study / 药学学报

The last essential enzyme in the biosynthetic pathway of trilobatin, phloretin-4'-O glycosyltransferase (P4'-OGT), catalyzes the conversion of trilobatin to phloretin in vitro. However, only a few P4'-OGTs have been found in plants. This study used Malus domestica phloretin-4'-O glycosyltransferase (MdPh-4'-OGT) as a query to identify and clone two UDP-glucuronosyltransferase (UGT) genes, designated UGT74L2 and UGT74L3, from the transcriptome of Andrographis paniculata. According to a phylogenetic tree analysis, UGT74L2 and UGT74L3 belonged to the UGT74 family, which has been linked to several activities in other species. The in vitro enzymatic reaction demonstrated that UGT74L2 could particularly catalyze the formation of trilobatin from phloretin, but UGT74L3 had no effects. By using Ni-NTA affinity chromatography to extract the soluble UGT74L2 recombinant protein, the enzymatic kinetics of the activity was investigated using phloretin as the substrate. The results showed that the optimal temperature and pH for UGT74L2 enzymatic reaction were 40 ℃ and 8.0 (Tris-HCl system), respectively. Three metal ions (Ca2+, Mn2+ and Co2+) showed inhibitory effect on the activity of UGT74L2, while Mg2+ could improve the activity of UGT74L2. Other tested metal ions have no significant effect on UGT74L2. The results of enzymatic kinetic parameters that the Km value was 29.84 μmol·L-1, the kcat was 0.02 s-1, and the kcat·Km-1 was 572.6 mol-1·s-1. By homology modeling, molecular docking and mutation experiments, we found that multiple amino acids residues around the substrate binding pocket play quite an important role during catalytic process, In summary, we identified a novel P4'-OGT gene from medicinal plant Andrographis paniculata and provided a new efficient catalyst to synthesize trilobatin. Meanwhile, this study provides a reference for mining new efficient glycosylation modules from plants.

Evaluation of chemosensory function in patients with upper respiratory tract post-viral olfactory dysfunction / 中华耳鼻咽喉头颈外科杂志

Objective: To observe the changes of olfactory function, intranasal trigeminal nerve function and taste function in patients with upper respiratory tract post-viral olfactory dysfunction (PVOD), and to explore the correlation of chemosensory function. Methods: The clinical data of 42 patients with PVOD who visited to the Olfactory and Taste Center of Otorhinolaryngology Head and Neck Surgery Department of Beijing Anzhen Hospital from January to December of 2019 were analyzed retrospectively, including 20 males and 22 females, aging (48.86±11.47) years (x¯). Twenty subjects in normal control group were selected according to the sex ratio of PVOD patients. Sniffin' Sticks olfactory tests were performed on the subjects, including threshold test (T), discrimination test (D) and identification test (I), and the sum of the above three test scores was the TDI value. At the same time, olfactory event-related potentials (oERPs), trigeminal event-related potentials (tERPs) and taste function test were performed. According to the taste function test, the patients were divided into normal gustation (NG) group and gustatory dysfunction (GD) group. The results of olfaction, taste and intranasal trigeminal nerve function tests were compared among different groups, and the correlation analysis was carried out. SPSS statistical software was used for statistical analysis. Results: GD was present in 14 (33.3%) of 42 PVOD patients with a course of PVOD of 5 (3, 6) months (M (Q1, Q3)). The gustatory function of patients with PVOD was related to gender (r=0.565, P<0.001), smoking status (r=-0.512, P=0.001), duration (r=-0.357, P=0.020) and olfactory function (all P<0.05). The olfactory function of GD group was worse than that of NG group, and the differences of TDI value and T value between the two groups were statistically significant (10.25±4.58 vs 13.35±3.61, 1.54±0.66 vs 2.10±0.88, t value was 2.40 and 2.10 respectively, both P<0.05). The amplitudes of oERPs and tERPs were significantly lower in GD group than those in NG group (all P<0.05). Conclusion: In patients with PVOD, the subjective and objective olfactory function, intranasal trigeminal nerve function and taste function were decreased, and there was a correlation, suggesting that there was a synergistic effect between the chemosensory functions of PVOD patients.

Clinical observation on plastic splint treatment of middle clavicle fracture based on a new classification / 中国骨伤

OBJECTIVE@#According to 73 patients with middle clavicle fracture treated conservatively, a new classification of middle clavicle fracture was proposed, and the clinical effect of plastic splint in the treatment of middle clavicle fracture was observed.@*METHODS@#Total 73 patients with middle clavicle fracture treated with plastic splint from September 2018 to August 2020 were analyzed retrospectively. All the patients were divided into 4 types according to the degree of fracture displacement. There were 16 cases of typeⅠ, including 7 males and 9 females, ranging in age from 18 to 37 years old, with a mean of (28.6±7.8) years old;12 cases of mild disease, 3 cases of moderate disease and 1 case of severe disease. There were 16 cases of type Ⅱ, including 6 males and 10 females, ranging in age from 25 to 49 years old, with a mean of (37.3±9.4) years old;5 cases of mild disease, 8 cases of moderate disease and 3 cases of severe disease. There were 7 cases of type Ⅲ, including 4 males and 3 females, ranging in age from 33 to 57 years old;2 cases of mild disease, 3 cases of moderate disease and 2 cases of severe disease. There were 34 cases of type Ⅳ, including 16 males and 18 females, ranging in age from 48 to 82 years old, with a mean of(66.4±14.9) years old;7 cases of mild disease, 17 cases of moderate disease and 10 cases of severe disease. All patients received plastic splint external fixation for 4 weeks. Visual analgue scale (VAS) and Constant-Murley shoulder scores before treatment and 1, 3 and 9 months after treatment were observed and recorded to evaluate the change of pain degree and shoulder function recovery before and after treatment. The patients' satisfaction with the appearance after treatment was recorded at the latest follow-up. The X-ray findings at the latest follow-up were used to judge whether the patient had fracture nonunion. And according to the fracture healing time and imaging findings, the excellent and good rate of clinical curative effect in patients with different types was obtained.@*RESULTS@#All patients were followed up, and the duration ranged from 9 to 11 months, with a mean of (9.8±0.7) months. The VAS scores of typeⅠ, typeⅡand type Ⅳ before treatment were 2.88±0.83, 3.67±0.80 and 6.92±1.71 respectively, which were decreased to 0.54±0.19, 0.77±0.25 and 1.18±0.17 respectively after 9 months of treatment. The Constant-Murley shoulder scores of typeⅠ, typeⅡand type Ⅳ were 65.81±2.09, 63.50±2.22 and 47.93±2.91 respectively before treatment, and increased to 88.56±2.11, 85.12±2.23 and 71.25±2.16 respectively after 9 months of treatment. Five patients were not satisfied with the appearance after treatment;6 patients had no obvious continuous callus passing through after 9 months of treatment, which was fracture nonunion.@*CONCLUSION@#The classification of middle clavicle fracture is more appropriate to the clinic, which has a certain clinical guiding significance for the selection of treatment methods and prognosis of middle clavicle fracture. Plastic splint is effective in the treatment of middle clavicle fracture without obvious displacement and overlapping displacement, and the incidence of complications is low. It can be popularized in clinic.

General situation of current diagnostic criteria for occupational radiation diseases in China / 中国职业医学

As compulsory standards in occupational health, the diagnostic criteria for occupational diseases are the main basis for the diagnosis of occupational diseases. According to the Occupation Disease Classification and Catalogue in China, there are currently 13 kinds of legal occupational radiation diseases in China. There are 14 supporting diagnostic criteria, including the GBZ 104-2017 Diagnosis of Acute Radiation Sickness from Occupational External Exposure, GBZ 99-2002 Diagnostic Criteria for Subacute Radiation Sickness from External Exposure, GBZ 105-2017 Diagnosis of Chronic Radiation Sickness from Occupational External Exposure, GBZ 96-2011 Diagnostic Criteria for Radiation Sickness from Internal Exposure, GBZ 106-2020 Diagnosis for Occupational Radiation Diseases of Skin, GBZ 97-2017 Judgment Standard for Occupational Radiogenic Neoplasms, GBZ 100-2010 Diagnostic Criteria for External Radiation Bone Injury, GBZ 101-2020 Diagnosis for Occupational Radiation Thyroid Disease, GBZ 107-2015 Diagnosis for Occupational Radiation Induced Gonad Disease, GBZ 102-2007 Diagnostic Criteria of Combined Radiation-blast Injury, GBZ 103-2007 Diagnostic Criteria of Combined Radiation-burn Injury, GBZ 95-2014 Diagnostic Criteria for Occupational Radiation Cataract, GBZ 108-2002 Diagnostic Criteria for Acute Uranium Intoxication and GBZ 112-2017 General Guideline for Diagnosis of Occupational Radiation Diseases. Compared with previous criteria, some of the new criteria changed a lot in terms of diagnostic conditions, included diseases, dose threshold and calculation methods for etiological probability. The science and practicability improved continually, which is conducive to standardize the diagnosis of occupational radiation diseases.

Ocular lens opacity in residents of areas with high natural radiation background in Yangjiang City, China / 中国职业医学

OBJECTIVE: To investigate the effects of long-term and low dose ionizing radiation on ocular lens opacities of residents living in areas with high natural radiation background(HNRB) in Yangjiang City, China. METHODS: A total of 483 Han residents from Yangjiang City(HNRB area) and 517 from Enping City(control area) were selected as study subjects using a cluster random sampling method. Questionnaire survey and lens examination were carried out. The risk factors of lens opacity and its severity were analyzed by logistic regression analysis. RESULTS: The prevalence rates of lens opacity, cortical opacity and posterior subcapsular opacity in HNRB area were higher than those in control area(60.7% vs 51.6%, 53.4% vs 46.8%, 21.9% vs 9.3%, all P<0.05). There was no significant difference in karyotype turbidity between HNRB area and control area(52.4% vs 47.6%, P>0.05). After adjusting for confounding factors including age, gender, cardiovascular/metabolic diseases, smoking, alcohol drinking and tea drinking, the unconditional logistic regression analysis results showed that the risk of ocular opacity, cortical opacity and posterior subcapsular opacity in residents of HNRB area was higher than that in control area(all P<0.05). Multivariate disordered logistic regression analysis results showed that residents in the HNRB area had a higher risk of grade two karyotype turbidity than grade one karyotype turbidity(P<0.01). Ordered logistic regression analysis results showed that residents in HNRB area had an increased risk of developing severe cortical turbidity(P<0.01). CONCLUSION: Long-term and low dose ionizing radiation exposure may increase the risk of ocular lens opacity, especially cortical and posterior subcapsular cataract, and affect the severity of the disease.

Biopathway construction of plant natural products / 药学学报

Plant natural products (PNPs) are important sources of innovative drugs. They are mainly obtained by isolation or extraction from plants. Low content and with structural analogues in plants result in high production cost, which restricts the research and application of PNPs. While biopathway construction by synthetic biology provides an alternative for production of PNPs. By biosynthetic pathway analysis of PNPs and reconstructing the biopathway in microorganisms, we can produce PNPs in cell factories efficiently. Recently, several predominantly international reports about biosynthesis of PNPs and its synthetic biology production, triggered the researches of PNPs. Abundant traditional Chinese medicine resources and profound cultural heritage of Chinese medicine make biosynthesis pathway analysis of PNPs to be a research hotspot. And some of the studies have achieved significant progress. Here, recent progress in the biosynthesis of plant natural products and its synthetic biology was reviewed. In particular, the application of new methods and technologies in recent years were summarized and discussed. This will provide reference for the biopathway construction of plant natural products.

Protective Effect of Salvianolic Acid B on Arsenic Trioxide-induced HepaRG Human Hepatocyte Injury / 中国实验方剂学杂志

Objective::To investigate the protective effect of salvianolic acid B on HepaRG hepatocyte injury induced by arsenic trioxide (As2O3 ) and its mechanism. Method::HepaRG cells were incubated with 5μmol·L-1 As2O3 for 24 h to induce hepatocyte injury. The cells were divided into control group, model group, salvianolic acid B 10 μmol·L-1 group, salvianolic acid B 10 μmol·L-1+ As2O3 group, salvianolic acid B 5 μmol·L-1+ As2O3 group, and salvianolic acid B 2.5 μmol·L-1+ As2O3 group. HepaRG cells were preincubated with salvianolic acid B for 2 h and then incubated with As2O3 for 24 h. At the end of the incubation, cell viability was detected by thiazolyl blue tetrazolium bromide assay, apoptosis was observed by Hoechst33342 fluorescence staining, apoptosis rate was detected by annexin V-FITC/propidium iodide double staining flow cytometry, and mitochondrial membrane was observed by JC-1 fluorescence staining. Western blot was used to detect the protective effect of expressions of relevant proteins Bcl-2, Bax, Akt, p-Akt on salvianolic acid B in the liver. Result::As2O3 concentration-dependently reduced the survival rate of HepaRG cells(P<0.01), salvianolic acid B had no effect on normal cell viability for 2 h, pre-incubation with salvianolic acid B(5, 10 μmol·L-1) for 2 h significantly increased the decreased cell survival rate caused by As2O3 (P<0.01). As2O3 significantly increased hepatocytes apoptosis rate(P<0.01), while pre-incubation with salvianolic acid B(10 μmol·L-1) deceased apoptosis rate(P<0.01). Incubation with As2O3 for 24 h caused decrease of mitochondrial membrane potential, pre-incubation with salvianolic acid B maintained mitochondrial membrane potential, indicating that the anti-apoptotic effect of salvianolic acid B were related to the mitochondrial pathway modulation. Western blot analysis showed that salvianolic acid B promoted the ratio of Bcl-2/Bax and promoted p-Akt/Akt compared with As2O3 group(P<0.01). Conclusion::Salvianolic acid B has a protective effect on hepatocyte injury induced by As2O3, and its mechanism is related to maintenance of mitochondrial function and inhibition of hepatocyte apoptosis.

Potent gene screening strategy based on family-based patients with lumbar discherniation / 西安交通大学学报(医学版)

Objective: To look for a potent gene that may cause intervertebral disc degeneration in a family with intervertebral disc herniation by exome sequencing four patients with intervertebral disc herniation so as to provide possible help for studies on the causes and mechanisms of intervertebral disc diseases. Methods: We collected the serum of patients with lumbar disc herniation treated at The First Affiliated Hospital of Xi'an Jiaotong University, The First Affiliated Hospital of Xi'an Medical College, and Xi'an Tangcheng Hospital from January 2010 to December 2016. A detailed medical history was collected and family survey was conducted to find a family with high incidence of degenerative intervertebral disc disease. Then we found 4 patients aged 20 to 50 years with lumbar disc herniation in this family. Exome sequencing was used to analyze the common exon mutation sites of the 4 patients to find the common mutation sites. Results: The common mutation IGFBP6, Chr12:g.53494591T>C, was detected in the 4 samples. The Sanger sequencing performed in-family validation revealed that the IGFBP6 showed a C/T type in all the four patients and a T type in all the five normal controls. Finally, verification was performed in 200 normal controls and no mutation was found in this site. Therefore, the IGFBP6 might be the effector gene that caused intervertebral disc degeneration in this family. Conclusion: The mutation site of IGFBP6, c.T430C (p.S144P) (Chr12:g.53494591T>C), may be a factor that contributes to the high incidence of intervertebral disc herniation in this family. We still need to verify the function of the gene in future. Our study has also confirmed that exome sequencing technology can be applied to the detection of disease-causing genes in complex diseases.

Relationship between the Degeneration and Regeneration of Neuromuscular Junction and Wound Age during the Repair of Mouse Skeletal Muscle Contusion / 法医学杂志

Objective To investigate the morphological changes in the degeneration and regeneration of neuromuscular junctions （NMJ） during the repair of mouse skeletal muscle contusion and discuss the correlation between the degeneration and regeneration of NMJ and wound age. Methods A total of 50 healthy adult male mice were randomly divided into 10 groups, including 9 experimental groups and 1 control group. Immunofluorescent staining was applied, and neurofilament was marked with neurofilament protein-H （NF-H）, presynaptic membrane was marked with synaptophysin （Syn）, presynaptic membrane was marked with acetylcholine receptor （AChR）. Morphological changes of NMJ regeneration at different time points after mouse skeletal muscle contusion were detected. Results The neurofilament and presynaptic membrane of NMJ at the junction of contusion zones began to degrade after contusion, and completed degradation at about 3 d post-injury. Then they gradually regenerated, roughly completing the regeneration at about 21 d and basically reaching the control group level. The ratio of presynaptic membrane quantity to presynaptic membrane quantity showed a trend of decreasing then rising and finally reaching the control level. Conclusion During the repair of mouse skeletal muscle contusion, the morphological changes and wound age of the NMJ at the junction of contusion zones have a close correlation, which is expected to be one of the biological indicators for forensic skeletal muscle wound age estimation.

Relationship between Changes of Pericyte Number and Wound Age during Repair of Skeletal Muscle Contusion in Mice / 法医学杂志

Objective To observe the change pattern of pericyte number at different time periods after mice skeletal muscle contusion and discuss its role in wound age estimation. Methods A mice gastrocnemius muscle contusion model was established. The form and number changes of pericytes at 1, 3, 5, 7, 9, 14, and 28 d post-injury were detected by multiple immunofluorescence staining. Results Compared with the slender shape of pericytes in normal skeletal muscles, pericytes in the contusion area had increased volume, rounder form and a round nuclei. Part of pericytes were found to express satellite cell markers paired-box transcription factor （Pax7） or myoblast determination 1 （MyoD1）. The changes of pericyte number in skeletal muscles after contusion were time-dependant, and showed unimodal distribution with the extension of wound age. In the central contusion area, the number of pericytes peaked at 5 d post-injury while in the peripheral contusion area, the number of pericytes peaked at 5 d and 7 d post-injury. Conclusion The number of pericytes in contusion area varies time-dependently after skeletal muscle contusion in mice and might be a reference index for muscle wound age estimation, and is involved in the repair and regeneration of skeletal muscle injury.

Relationship between Expression Changes of CB2R and Wound Age of Brain Contusion in Mice / 法医学杂志

Objective To investigate the expression of cannabinoid type 2 receptor （CB2R） at different time points after brain contusion and its relationship with wound age of mice. Methods A mouse brain contusion model was established with PCI3000 Precision Cortical Impactor. Expression changes of CB2R around the injured area were detected with immunohistochemical staining, immunofluorescent staining and Western blotting at different time points. Results Immunohistochemical staining results showed that only a few cells in the cerebral cortex of the sham operated group had CB2R positive expression. The ratio of CB2R positive cells gradually increased after injury and reached the peak twice at 12 h and 7 d post-injury, followed by a decrease to the normal level 28 d post-injury. The results of Western blotting were consistent with the immunohistochemical staining results. Immunofluorescent staining demonstrated that the changes of the ratio of CB2R positive cells in neurons, CB2R positive cells in monocytes and CB2R positive cells in astrocytes to the total cell number showed a single peak pattern, which peaked at 12 h, 1 d and 7 d post-injury, respectively. Conclusion The expression of CB2R after brain contusion in neurons, monocytes and astrocytes in mice suggests that it is likely to be involved in the regulation of the biological functions of those cells. The changes in CB2R are time-dependent, which suggests its potential applicability as a biological indicator for wound age estimation of brain contusion in forensic practice.

Preliminary study of DTI on cerebral white matter micro-structure of patients with idiopathic olfactory loss / 临床耳鼻咽喉头颈外科杂志

OBJECTIVES@#To investigate the cerebral white matter micro-structure in patients with idiopathic olfactory loss using diffusion tensor imaging (DTI).@*METHODS@#Sixteen patients with idiopathic olfactory loss and sixteen normal subjects matched by age and sex were recruited in this study. Sniffin'Stick olfactory test was performed to evaluate the olfactory function of all subjects. We acquired diffusion tensor images with an echo planar imaging (EPI) sequence from all subject on a 3T scanner. The fractional anisotropy (FA) images were performed using DTI-studio, and bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex adjacent white matter and Capsula interna were delineated as the region of interesting (ROI), the FA for each ROI was calculated. Independent sample t test analysis was used to compare the FA value of all ROIs between the controls and patients. In addition, correlation analysis between FA value and MMSE score in patients were conducted.@*RESULTS@#Compared with the controls, patients showed significantly decreased FA value in the adjacent white matter of bilateral Piriform cortex, Orbitofrontal cortex, Hippocampus and Insula cortex (0.05).@*CONCLUSIONS@#The patients with idiopathic olfactory loss show the damage of white matter micro-structure in the olfactory center, which could be important for the pathogenesis study and early intervention of idiopathic olfactory loss.

HT-3DNMR-25 magnetic resonance imaging instrument and its application in experiment teaching / 医疗卫生装备

Objective To help the medical student to master the principle and operation of magnetic resonance imaging instrument.Methods The imaging principle,structure and functions of HT-3DNMR-25 magnetic resonance imaging instrument were described,and its application to experiment teaching was introduced including one-dimension imaging,two-dimension imaging,free induction decay signal observation and etc.Results The instrument facilitated the student to master technical principle,imaging method as well as parameters setup and regulation,and could be a supplement to clinical practical teaching.Conclusion The instrument plays an irreplaceable role in teaching,and thus is worthy promoting in colleges.

PIateIet Iysate combined with domestic porous tantaIum promotes MG63 proIiferation and activates integrin beta1/VincuIin/F-actin signaIing pathway / 中国组织工程研究

BACKGROUND: The preliminary study found that domestic porous tantalum is conducive to the early adhesion and proliferation of MG63 cells, which can be used as a scaffold material for bone tissue engineering. As an optimized product of platelet-rich plasma, platelet lysate is more suitable for bone induction in the bone repair. OBJECTIVE: To further investigate the effect of platelet lysate and domestic porous tantalum scaffold constructs on the proliferation of MG63 cells and expression of integrin β1 (ITGβ1)/Vinculin/F-actin signaling pathway based on our previous findings. METHODS: MG3 cells were cultured and inoculated onto domestic porous tantalum scaffolds with the addition of 3%, 5%, 7% and 10% platelet lysates. Then, 7% as the best volume fraction of platelet lysate was screened by cell counting kit-8 method. There were four experimental groups including blank group (normally cultured MG63 cells), platelet lysate group (MG63 cells were cultured in 7% platelet lysate), porous tantalum scaffold group (MG63 cells were cultured on the domestic porous tantalum scaffold), and combined group (MG63 cells were cultured with 7% platelet lysate and porous tantalum scaffold. Scanning electron microscope was used to observe the surface morphology of domestic porous tantalum and platelet lysate-porous tantalum scaffold-MG63 cell complex. Cell counting kit-8 method was used to detect the proliferation of MG63 cells. Real-time fluorescence quantitative PCR (qPCR), immunocytochemical staining and western blot were used to detect the expression of ITGβ1, Vinculin, F-actin in MG63 cells at mRNA and protein levels. RESULTS AND CONCLUSION: Under the scanning electron microscope, MG63 cells adhered well to the scaffold surface. Compared with the blank group, the proliferation of MG63 cells could be significantly promoted by either platelet lysate or porous tantalum scaffold (P < 0.05). Moreover, the proliferation of MG63 cells was significantly improved in the combined group compared with the other three groups (P < 0.05). Findings from qPCR, immunocytochemical staining and western blot showed the highest expression of ITGβ1, Vinculin, F-actin mRNA and protein in the combined group (P < 0.05). These results indicate that platelet lysate and the domestic porous tantalum scaffold can synergistically promote the proliferation of MG63 cells, and up-regulate the expression of ITGβ1, Vinculin and F-actin mRNA and protein. Activation of the ITGβ1/Vinculin/F-actin signaling pathway may contribute to the proliferation, adhesion and differentiation of MG63 cells.

Effect of Calcium-sensing Receptor on the Apoptosis of Rat Spinal Cord Neurons in Anoxia/Reoxygenation Injury and Its Significance / 中国医学科学院学报

Objective To investigate the effect and significance of calcium-sensing receptor (CaSR) on the apoptosis of rat spinal cord neurons in anoxia/reoxygenation(A/R) injury. Methods The spinal cells were in ischemia and hypoxia environment for 1 h and in normal environment for 24 h to establish a model of A/R. After spinal A/R model was established,the spinal cells were divided into four groups randomly:the control group,A/R group,A/R+GdCl3 group,and A/R+NPS-2390 group. The expression of CaSR in each group was detected by immunofluorescence and Western blotting. The concentration of intracellular calcium was measured by laser confocal scanning microscopy. The expressions of Caspase-3,Bax,and Bcl-2 were detected by using Western blotting. The apoptotic rate of spinal cells was detected by Tunel assay. Results Compared to the control group, there was a significant increase in the level of CaSR (t=5.462, P=0.006), the concentration of intracellular calcium (t=8.573, P=0.001), the apoptotic rate (t=4.899, P=0.008), Caspase-3 (t=5.118, P=0.007), and Bax (t=10.930,P=0.001) in A/R group. Compared to the A/R group, there was a significant increase in the level of CaSR (t=4.975, P=0.008),the concentration of intracellular calcium (t=4.899, P=0.008), the apoptotic rate (t=7.746, P=0.002), Caspase-3 (t=4.776, P=0.009), and Bax (t=5.281, P=0.006) in A/R+GdCl3 group. Compared to the A/R group, there was a significant decrease in the level of CaSR (t=3.674,P=0.021), the concentration of intracellular calcium (t=3.846, P=0.018), the apoptotic rate (t=4.281,P=0.013), Caspase-3 (t=3.521, P=0.024), and Bax(t=3.473, P=0.026) in A/R+NPS-2390 group. However, compared to the control group, there was a significant decrease in the level of Bcl-2 (t=6.242,P=0.003) in A/R group. Compared to the A/R group, there was a significant decrease in the level of Bcl-2(t=3.028, P=0.004) in A/R+GdCl3 group. Compared to the A/R group, there was a significant increase in the level of Bcl-2 (t=2.840, P=0.047) in A/R+NPS-2390 group.Conclusion During the process of A/R injury in rat spinal cord neurons,the expression of calcium sensing receptor increases,along with increase in intracellular calcium and spinal neuron apoptosis.

HT-3DNMR-25 magnetic resonance imaging instrument and its application in experiment teaching / 医疗卫生装备

Objective To help the medical student to master the principle and operation of magnetic resonance imaging instrument.Methods The imaging principle,structure and functions of HT-3DNMR-25 magnetic resonance imaging instrument were described,and its application to experiment teaching was introduced including one-dimension imaging,two-dimension imaging,free induction decay signal observation and etc.Results The instrument facilitated the student to master technical principle,imaging method as well as parameters setup and regulation,and could be a supplement to clinical practical teaching.Conclusion The instrument plays an irreplaceable role in teaching,and thus is worthy promoting in colleges.

Submental versus platysma flap for the reconstruction of complex facial defects following resection of head and neck tumors

To compare the platysma flap with submental flap in terms of tumor and flap characteristics, operative properties and the functional outcomes. A total of 65 patients presented with tumors of head and neck and underwent curative tumor resection with different neck dissections at the Department of Oromaxillofacial-Head and Neck Surgery, School of Stomatology of China Medical University; from March 2005 to December 2012 were included in the study. After radical tumor excision and neck dissection the resultant complex defects were reconstructed with either platysma flap or the submental flap. The extent of surgical resection, the type of neck dissection and choice of flap reconstruction was at the discretion of the surgical team. The functional outcomes, operative time and characteristics of both platysma and submental flaps were compared and the statistical tests of significance were applied accordingly. The mean age was 60 years. The complex facial defects of 30 patients were reconstructed with platysma flap and of 35 patients with submental flap. Mean operation time of submental flap including flap harvesting [5.58 +/- 1.96hrs] was shorter than platysma flap [6.2 +/- 1.4hrs]. The majority of the flaps [88-93%] were taken successfully in both groups. Submental flap was associated with significantly higher patients' satisfaction regarding acceptable functional outcomes [p-value 0.027]. The mean reduction in mouth opening was significantly smaller in platysma group [0.37 +/- 0.18cms] than the submental group [0.47 +/- 0.16]. This study demonstrates that both platysma and submental flap techniques can be used for the reconstruction of complex facial defects with the acceptable functional outcome. The platysma flap can be harvested to medium size defects up to 70cm2 with good mouth opening. The submental flap is simpler, faster with a wider range of application and more acceptable functional outcomes