A recombinant receptor-binding domain in trimeric form generates completely protective immunity against SARS-CoV-2 infection in nonhuman primates

Safe and effective vaccination is critical to combatting the COVID-19 pandemic. Here, we developed a trimeric SARS-CoV-2 receptor-binding domain (RBD) subunit vaccine candidate that simulates the natural structure of the spike (S) trimer glycoprotein. Immunization with RBD-trimer induced robust humoral and cellular immune responses and a high level of neutralizing antibodies that were maintained for at least 4 months. Moreover, the antibodies that were produced in response to the vaccine effectively neutralized the SARS-CoV-2 501Y.V2 variant. Of note, when the titers of the antibodies dropped to a sufficiently low level, only one boost quickly activated the anamnestic immune response, resulting in complete protection against the SARS-CoV-2 challenge in rhesus macaques without typical histopathological changes or viral replication in the lungs and other respiratory tissues. Our results indicated that immunization with SARS-CoV-2 RBD-trimer could raise long-term and broad immunity protection in nonhuman primates, thereby offering an optimal vaccination strategy against COVID-19.

Establishment of RIG-I knockout 293T cell line and its effect on the replication of influenza B virus / 生物工程学报

The CRISPR/Cas9 gene editing technology directs Cas9 protein to recognize, bind and cleave the target site specifically by using artificial single-guide RNA (sgRNA), through non-homologous end joining or homologous end-recombinant repair mechanisms of cells, which can be engineered to knockout or knock-in of genomes. RIG-I is a pattern recognition receptor that recognizes the 5'-triphosphate-containing RNA in the cytoplasm and activates IRF3/7 and NF-κB by interacting with the downstream signaling molecule MAVS, thus initiating the expression of type I interferons and inflammatory factors. Previous studies found that influenza B virus (IBV) can up-regulate the expression of RIG-I. In the present study, to explore whether RIG-I is the major receptor for IBV to active the antiviral innate immune response and its effect on IBV replication, RIG-I gene in 293T cells was knocked out by CRISPR-Cas9 system, and a stable RIG-I knockout 293T (RIG-I(-/-) 293T) cell line was screened by puromycin pressure. The results of Western blotting showed that RIG-I was not expressed in this cell line after IBV or Sendai virus (SeV) infection, indicating that the RIG-I(-/-) 293T cell line was successfully constructed. The transcription levels of interferons, inflammatory factors and interferon-stimulated genes in RIG-I(-/-) 293T cells which were infected by IBV decreased significantly compared with those in wild-type 293T cells. Moreover, the phosphorylation of p65 and IRF3 were not detected in IBV or SeV infected RIG-I(-/-) 293T cells. It is indicated that the expression of cytokines mainly depends on the RIG-I-mediated signaling pathway at the early stage of IBV infection. Furthermore, the multi-step growth curves of IBV in the wild type and RIG-I(-/-) 293T cells showed that RIG-I inhibited the replication of IBV. Collectively, the RIG-I knockout 293T cell line was successfully constructed. We found that RIG-I is the main receptor for IBV to active the antiviral innate immune response and is critical for inhibiting IBV replication, which lays the foundation for further study of IBV infection mechanism.

Experimental Study of MAR Algorithm in Metal Artifact Removal of CT Simulator / 中国医疗器械杂志

OBJECTIVE@#To explore the application value of MAR algorithm in metal artifact removal of CT simulator.@*METHODS@#CT phantom with titanium plate was scanned using conventional algorithms and MAR algorithms, respectively. Artifact index(AI), contrast-to-noise ratio(CNR) and AI values at different slices were used to analyze the artifact images.@*RESULTS@#In artifact index, MAR algorithm (10.28±2.60) is significantly lower than conventional algorithm (20.65±5.04); In contrast-to-noise ratio index, MAR algorithm (7.81±1.12) is better than conventional algorithm (5.61±1.36). The above indicators were statistically significant in both algorithms (P<0.01). In the slices affected by metal artifacts, the artifact index decreased by 21.72%~88.40% after the MAR algorithm.@*CONCLUSIONS@#MAR algorithm can significantly reduce the metal artifacts and improve the clinical value of CT data.

Inhibition of the replication of H9N2 influenza virus in vivo by short-term repeated oral administration of chicken interferon α / 生物工程学报

To evaluate the optimal administration frequency for interferon-α (IFN-α) and the effect of its combined use with inactive virus on chicken flocks, the prokaryotic expression plasmid pET-22b-ChIFN-α was constructed and transferred into Escherichia coli BL21(DE3) host bacteria to induce the expression of chicken IFN-α and to harvest recombinant proteins inclusion bodies. The expression of recombinant chicken IFN-α was confirmed by SDS-PAGE, and the results demonstrated that the chicken IFN-α (20 kDa) was highly expressed using the prokaryotic expression vector with a concentration of 0.2 mg/mL in the medium. Chicken IFN-α was diluted to 2.5×10⁴ U/fowls and administered to immunized specific-pathogen-free chickens orally in combination with inactivated H9N2 subtype influenza virus. Chicken that received chicken IFN-α were safe after three repeated immunizations (96 h). In addition, chicken IFN-α could induce higher levels of antiviral-related inducible genes in peripheral blood, spleen, and thymus of chicken flocks. The results of a challenge assay revealed that the lowest detoxification rates of chicken IFN-α ranged from three to five days, suggesting a higher capacity to resist H9N2 subtype avian influenza virus. The present study obtained the optimal immune frequency and immunization period for chicken IFN-α to provide theoretical support for the optimal clinical application of IFN-α.

High expression and immunogenicity analysis of HA globular head domain of H5 subtype avian influenza virus produced in Pichia pastoris / 生物工程学报

To evaluate the immunogenicity of HA globular head domain of H5 subtype influenza virus (H5HA), the gene of H5HA was optimized and the recombinant pPICZaA-H5HA expressing vector was constructed and transfected into Pichia pastoris. The expression of the recombinant H5HA was confirmed by SDS-PAGE and Western blotting and the results demonstrated that the recombinant H5HA (37 kDa) was highly expressed in Pichia pastoris with concentration of 0.2 mg/mL in medium. The recombinant H5HA was concentrated and purified using Ni-NTA affinity chromatography. The immunogenicity of H5HA was evaluated by immunizing eight groups of chicken through intranasal or intramuscular injection with different doses of purified H5HA combined with different adjuvants, respectively. The results showed that the recombinant H5HA could induce high level IgG (HI titer was 1:64 and neutralizing antibody titer was 1:218) and the optimal dosage of the recombinant H5HA was 50 μg combined with oil. In addition, intramuscular injection was better than nasal immunization. This study provided a theoretical support for subunit vaccine development.

Applicationof"blendsign"onCTpredictingearlyhaematomaexpansioninacuteintracerebralhaemorrhage / 实用放射学杂志

Objective Toinvestigatethevalueof"blendsign"onCTtopredictearlyhaematomaexpansioninacuteintracerebral haemorrhage(ICH).Methods SeventyGninepatientswithacuteICH whounderwentbaselineCTscanwithin6hourswereenrolled retrospectively.TheywerealsorecheckedwithCTscanin24hours.Allpatientsweredividedintoearlyhaematomaexpansiongroup and nonGhae m ato m a expansion group according to the change of hae m orrhage volu m e.M ultivariable L o g istic regression analysis w as usedtodetermineindependentriskfactorsofearlyhaematomaexpansion.Results Therewere28cases (35.4%)withhaematoma expansionin79patients."Blendsign"wasobservedin23patientsonbaselineCTscan,16of23 (69.6%)patientsappearedhaematoma expansion.Thesensitivity,specificity,positivepredictivevalue,negativepredictivevalueof"blendsign"forpredictingearlyhaematoma expansion w ere 57.1%,86.2%,69.6%,78.6%.M ultivariable L o g istic regression analysis sho w ed baseline hae m orrhage volu m e and"blendsign"wereindependentlyassociatedwithhaematomaexpansion.Conclusion "Blendsign"canbeusedtopredicthematoma expansioninacuteICH,whichishelpfultoidentifyhighriskpatientswithearlyhaematomaexpansiontomakethetreatmentmore promptlyandaccurately.

Effect of extracellular cyclophilin A on inflammatory response and anti-inflammatory activity of antibody against cyclophilin A / 生物工程学报

Cyclophilin A (CypA) is a member of peptidyl prolylisomerases (PPIase) family. CypA is best known as a ubiquitously distributed intracellular protein. It has also been shown to be secreted by cells in response to inflammatory stimuli and oxidative stress. Extracellular CypA (eCypA) interacts with CD147 to initiate inflammatory responses via recruiting leucocytes into inflamed tissue. Recombinant CypA was expressed in Escherichia coli and then purified using Superdex 75™ 16/60. The results of Real-time PCR and ELISA showed that the expression levels of proinflammatory cytokines, such as IL-1β, secreted by eCypA stimulated BMDM were significantly up-regulated, indicating that eCypA played an important role in promoting inflammatory responses. In addition, anti-CypA antibody was prepared using purified CypA protein for therapeutic evaluation in a mouse model of LPS-induced acute lung inflammation. Antibody-treated mice showed reduced lung injury and the expression levels of IL-1β in the lung tissue and blood were decreased significantly, indicating that anti-CypA antibody exerted a potent anti-inflammatory activity. Our findings provide a potential therapeutic antibody for inflammation-mediated diseases.

A novel carbon nanoparticle probe-based ultrasensitive lateral flow assay for rapid detection of Ebola virus / 生物工程学报

Ebola virus (EBOV) is an extremely contagious pathogen first discovered in Africa associated with severe hemorrhagic disease in humans and nonhuman primates, which has resulted in at least 28 500 suspected cases and 11 300 confirmed deaths in 2014-2016 Ebola epidemic in West Africa. Rapid and sensitive detection of EBOV is the key to increasing the probability of survival and reducing infection rates in pandemic regions. Here, we report an ultrasensitive and instrument-free EBOV detection assay based on colloidal carbon immunochromatography. Carbon nanoparticle-labeled rabbit anti-EBOV-VP40 IgG were concentrated in the conjugate pad, monoclonal antibody (McAb, 4B7F9) against EBOV-VP40 and goat anti-rabbit IgG were immobilized on the nitrocellulose membrane with 2 μL/cm at a concentration of 1 mg/mL as test and control lines, respectively. Then the sample application pad, conjugate release pad, nitrocellulose membrane and absorbent pad were assembled into a lateral flow test strip. The test strip shows strong specificity against related viruses that share similar clinical symptoms and geographic range with EBOV, including marburg virus, influenza virus, yellow fever virus and dengue virus. In addition, 1 500 negative serums were tested with false-positive rate of 1.3‰ which significantly lower than that of ReEBOV™ colloidal gold test kit recommended by World Health Organization (WHO). The sensitivity of this strip was analyzed using inactivated EBOV with detection limit of 100 ng/mL (10⁶ copies/mL) which clearly higher than that of ReEBOV™ dipstick (10⁸ copies/mL). Furthermore, the strip showed excellent thermal stability characteristics in room temperature and could be as a point-of-care (POC), ultra-sensitive and specific promising candidate for EBOV serological screening in rural Africa or entry/exit ports.

Research advance of influenza B viruses / 生物工程学报

Influenza B virus (IBV) is a segmented negative-strand RNA virus, which often causes local outbreak or seasonal epidemic along with influenza A virus (IAV) in the world. It is pathogenic to children, teenagers and elderly people and has a higher mortality rate in children and adolescents, so it poses a serious threat to public health and health. IBV is more likely to cause complications than IAV and the disease burden of IBV even exceeds IAV in the epidemic season. Recently, especially after winter of 2017, IBV has become the dominant strain in many areas of our country and seriously affects people's health. In view of this, this article reviews the structure, epidemiology, immunology and prevention of IBV, aiming at enhancing public's perceptions of the virus and providing reference for making strategies for prevention and control of influenza B.

Development and verification of reference nucleic acid materials of H9N2 influenza viruses by real-time RT-PCR / 生物工程学报

The HA gene of H9N2 influenza virus (A/chicken/Hunan/04.14 (H9N2)) was amplified and sequenced. The RNA was synthesized by in vitro transcription. The RNA transcription solutions were diluted to 10⁹ copies/μL using the RNA storage solution. The aliquoted RNA solutions were used to evaluate the homogeneity and stability. The results were determined by the average value obtained from four independent laboratories. Furthermore, the fluorescence quantitative RT-PCR method was also developed to verify the detection accuracy of clinical samples. The detection limit of this method is approximately 10 copies. Taken together, the RNA transcription solution established in our study can used as positive standard reference for rapid detection of H9N2 influenza virus.

Removal of Hg, As in FGD gypsum by different aqueous ammonia (amines) during CO2 sequestration.

CO2 sequestration by flue gas desulfurization gypsum (FGDG) has become a promising FGDG disposal technology due to simultaneous CO2 emission reduction and FGDG conversion into calcium carbonate. In this paper, another merit of the novel technology, i.e., the removal of toxic elements (e.g., Hg and As) in FGDG, will be addressed for the first time. In three different aqueous ammonia (or amines) media, removal efficiencies of Hg and As in FGDG samples were evaluated during CO2 sequestration. Higher than 90% and 20% removal efficiencies, respectively, for Hg and As are achieved at 40°C in aqueous ammonia media, but they decrease at elevated temperatures. Ammonia loss takes place at 80°C and pH varies greatly with temperatures in aqueous ammonia. This is disadvantageous for the formation of Hg-ammonia complexes and for the yield of carbonates, which are responsible for Hg or As re-adsorption. The sequential chemical extraction method suggests that the speciation changes of Hg are induced by FGDG carbonation, and that unstable Hg speciation in triethanolamine increases at elevated temperatures.

Establishment of a high sensitive indirect ELISA for detecting specific antibodies against H9 subtype avian influenza virus / 生物工程学报

H9 subtype avian influenza virus causes worldwide epidemic, resulting in enormous economic losses of poultry production. In the present study, an indirect ELISA method was established for more accurate and specific detection. The recombinant protein of the globular head domain of HA of H9 subtype avian influenza virus was used as antigen. Specific blocking buffers and dilution buffers were determined to increase the sensitivity and specificity. The sensitivity of ELISA was higher than that of hemagglutination inhibition (HI) test. The coating antigen is very specific and no cross-reactivity with positive serum against H3N2, H5N2 and H7N9 subtype influenza viruses, Newcastle disease virus, avian infectious bronchitis virus, avian infectious disease virus, and egg drop syndrome virus. Two hundred of clinical sera samples were examined. The results indicate the coincidence rate between ELISA and HI test reached 97%. In addition, there was a positive correlation between OD450 values and the logarithm of HI titer to the base 2 of an individual serum sample (R2=0.981 1).

Effects of temperature and pH on the growth of H1N1 subtype of influenza A virus by surface-enhanced Raman spectroscopy / 生物工程学报

Surface enhanced Raman spectroscopy technology (SERS), using gold nanoparticles as a base, was developed for rapid and sensitive detection of virus strains. SERS can be used as a rapid and reliable method to distinguish the titers of viral replication. In the present study, we characterized H1N1 subtypes of influenza A virus strains in different conditions of pH or temperatures, while we analyzed data from SERS technology using gold nanoparticles as a base and cell cultures were employed to further confirm the data from virus strains. Origin8.0 was used to collect Raman spectra, smooth and homogenize data, and to contrast spectra. Our results indicated that the peaks of different virus strains in optimal environmental conditions (T=37 ℃/pH=7.2) reached ≥3 000. This criterion was verified by subsequent virological method. The present data indicate that the established SERS protocol can be used as a rapid and reliable method to distinguish the replication rate of virus, which can be further used in clinical samples.

Fatigue in early Parkinson's disease / 中华老年医学杂志

Objective To investigate the prevalence,characteristics and risk factors of fatigue in a large cohort of subjects with early Parkinson's disease (PD).Methods A total of 391 individuals with PD,recruited in Linzhi trial,were re-screened.Early,non-depressed subjects [Center for epidcmiological survey depression scale (CES-D)＜16]underwent further fatigue assessment.Subjects who scored＞4 on fatigue severity scale (FSS) were classified as fatigue.Motor symptoms and PD severity were assessed using the unified Parkinson's disease rating scale (UPDRS) and Hoehn-Yahr scale.Other clinical measures,including sleep disorder by Pittsburg sleep quality index (PSQ-Ⅰ),mental function by Alzheimer's Disease assessment scale-cognitive sections (ADAS-Cog) and quality of life by medical outcomes study short form 36 (SF- 36) were also evaluated.Results Among 204 subjects who completed fatigue measures,82 (40.2％) were classified as fatigue.The fatigue group had significantly more neurological impairment by higher scores on each subsets of UPDRS including mentation (P＜0.05),activities of daily living (P＜0.01) and motor (P＜0.01),while the subjects with fatigue had worse scores on SF-36 (P＜0.01).Multiple regression analyses showed that motor subset of UPDRS was the variable that had the predictive value for FSS score.The full model explained 6.4％ of the variance of the FSSscore (β=0.039,95％CI:0.019-0.059).However,other factors,including levodopa dosage,PSQ-Ⅰ,and ADAS-Cog score did not significantly contribute to the model.Conclusions Fatigue is a frequent symptom in carly,non-depressed patients with PD,affecting over 40％ of the patients in this cohort.The small correlation between fatigue and motor score,and the lack of association with dosage of dopaminergic treatment suggest that dopaminergic pathways might be only moderately involved in pathogenesis of fatigue.

Clinical analysis of severe trauma in the elderly / 中华老年医学杂志

Objective To evaluate the causes and prognosis of severe trauma in the elderly.Methods The 168 patients in elderly group (aged 60 to 91 years), 517 in middle-aged group (aged 36to 59 years) and 405 in young group (aged 18 to 35 years) were evaluated using an abbreviated injury scale (AIS2005) and injury severity score (ISS). All patients with ISS ≥ 16 were selected during a seven-year period. The injury severity, injury site number, cause of injury, injury site, emergency operation, diseases before injury, secondary infection after injury, development of multiple organ dysfunction, number of patients with Intensive Care Unit (ICU) stay, length of stay in ICU and prognosis were compared among three groups. Results The main cause of injury was accident (64patients, 38.1%), followed by traffic accident (63 patients, 37.5%) in elderly group. The traffic accident was major cause of injury in middle-aged and young group (246 patients, 47.6%; 153patients, 37.8%, respectively), followed by fall from high places (128 patients, 24.8%; 102 patients, 25.2%, respectively). The main injury sites were head and chest in elderly, middle-aged and young group (155 patients, 92.3%; 411 patients, 79.5%; 321 patients, 79.3%, respectively).There were significant differences among three groups in injury site number, emergency operation,pre-injury diseases, secondary infection after injury, number of patients with ICU stay and length of stay in ICU (F=8. 299, P＜0.01; x2= 14.88, P=0.001; x2=254.6, P＜0.01; x2=10. 54, P=0. 005; x2 = 15.62, P＜0.01; F= 5.760, P= 0.005, respectively ). In spite of injury severity (F=2.950, P= 0.053), there were significant differences between elderly group and middle-aged or young group (t=2.325, P=0.021; t=2.128, P=0.034, respectively). The incidence of multiple organ dysfunction had no significant difference among the three groups (x2 = 1.142, P= 0.565). The cure rate and unhealed automatically discharged patients had significant differences (x2 = 13.77, P= 0. 001;x2 =6.025, P= 0.049, respectively). The mortalities were similar (x2 = 1.397, P= 0.497). The leading cause of death among three groups was a serious head injury. Conclusions For elderly patients, it is important to reduce accidental injuries and traffic accidents, to improve the cure rate,and to reduce the unhealed and mortality rate.

Health related quality of life in patients with early Parkinson' s disease / 中华神经科杂志

Objective To investigate the characteristics of health related quality of life(HR-QOL) in Chinese patients with early Parkinson' s disease(PD), to identify the motor and non-motor factors that are associated with a poorer quality of life in patients with early PD. Methods All 391 patients with early PD were identified in a clinical-based study. Motor functions were measured by Unified Parkinson' s Disease Rating Scale (UPDRS) and Hoehn-Yabr Scale. Non-motor variables were assessed by Center of Epidemiological Survey Depression Scale (CES-D) for depressive symptoms, Pittsburg Sleep Quality Index (PSQI) for sleep disturbance, Fatigue Severity Scale (FSS) for fatigue, Alzheimer' s Disease Assessment Scale-Cognitive Sections (ADAS-Cng) for cognitive function, and Constipation Severity Scale for constipation. HR-QOL was measured by SF-36. Motor and non-motor variables were collected at the baseline assessment of a clinical trial and determined during a structured interview and by clinical examination by movement disorder specialists. The results were compared with those in healthy elderly people. Multiple regression analyses were used to determine which variables were strongly associated with lower levels of quality of life. Results Patients with early PD had a lower score on all dimensions of SF-36, except bodily pain dimension. Motor factors, particular physical disability and disease severity, contributed to decreased HR-QOL, but to a lesser extent. The motor score of the UPDRS (23. 8±11.8), Hoehn-Yahr stage(2. 0± 0.7), together with the rigidity score (4.4 ± 3.1), only accounted for 18.9 % (R2=0. 189) of the variance of SF-36 total score. The variables that most strongly predicted a low total SF-36 score were non-motor factors, particularly depressive symptoms, sleep disorders and fatigue. When the CES-D, FSS, and PSQI score were included in the model, the R2 increased from 0. 189 to 0.617, indicating that 61.7% of the variance in HR-QOL could be explained if additional CES-D, FSS and PSQI scores were known. Depressive symptoms, as measured by CES-D, had an overwhelming impact on HR-QOL. When CES-D score was included, the R2 change was 0.433, which indicated that additional 43.3% of the variability in HR-QOL could be explained by adding depressive symptoms. Conclusions PD has a substantial impact on HR-QOL, even if in its early stage. Depressive symptoms, sleep disorders and fatigue correlated strongly with lower quality of life. Depressive symptoms appeared to be the strongest determinant of HR-QOL in early PD patients. Every effort should be made to recognize and treat these conditions, thus improving all aspects of PD and giving these patients as good a quality of life as possible.

The percutaneous transluminal angioplasty and stenting for the vertebrobasilar stenosis / 第三军医大学学报

Objective To investigate the effectiveness,safety of the percutaneous transluminal angioplasty and stenting(PTAS) in the management of the vertebrobasilar stenosis.Methods From April 2003 to June 2004,the PTAS was performed in 28 patients with the vertebrobasilar stenosis.Results Among the 28 patients,the unilateral significant stenosis of the dominant vertebral artery was found in 18 patients,the bilateral stenosis of the vertebral artery in 4 patients,the tandem stenosis of the vertebral artery in 1 patient,the stenosis of the basilar artery in 2 patients.According to Mori's division,the type A occurred in 24 patients,the type B in 3 patients,the type C in 1 patient.The successful rate of stent implantation was 100% without any serious complication.Twenty-eight patients underwent PTAS with a mean pre-procedural vertebrobasilar stenosis of 81.3% and the residual stenosis was less than 10%.Over a mean 6-month follow-up in 17 patients,according to Malek's scale,the scale 1 was in 15 patients,the scale 2 in 2 patients.No restenosis was in 3 patients by the cerebral angiography.Conclusion PTAS in the management of the vertebrobasilar stenosis is a safe and effective method.Meanwhile,PTAS may alleviate the vertebrobasilar ischemia and prevent stroke of the vertebrobasilar system.

Relationship of memory behaviors and changes of synapse structure in vascular dementia rats / 第三军医大学学报

Objective To explore the relationship of the changes of memory behavior and the of changes of the parameter of synapse structure in the brain cortex and hippocampus of chronic cerebral hypoperfusion rats Methods Chronic cerebral hypoperfusion rat model was established by ligating bilateral common carotid arteries of the old rats (over 12 months) The rats were divided into 3 groups, normal, 2 months ischemia, and 4 months ischemia groups The memory behavior changes were observed with a computerized shuttle training case The ultrastucture of synapse were observed with electron microscopy for the number density, length of activity cord, area of synapses disk, surface density of the synapse, and the results were analyzed with stereology and image analyses The relationship between the behavior and the ultrastructure were studied Results Active avoidance response (AAR) and passive avoidance response (PAR) were decreased in the 2 months ischemia group and the 4 months ischemia group The number density (Nv) of the synapses in the brain cortex and hippocampus were reduced in the 2 months ischemia group and the 4 months ischemia group The length of activity cord (L), the area of synapses disk (S), the area density (Sv) in the hippocampus decreased in the 2 and 4 months ischemia group, and those in the brain cortex did not change in the 2 groups Conclusion The decrease of the number density (Nv) and the length of activity cord (L) of synapses in the chronic cerebral hypoperfusion is related to the memory behavior changes

Effects of estradiol benzoate on the pathological changes of brain in 2VO-OVX rats / 第三军医大学学报

Objective To study the effects of estradiol benzoate on the morphology and number of neurons in cerebral frontal cortex and hippocampal CA1 area of 2VO OVX rats Methods Eighteen female Wistar rats were randomly divided into 3 groups, that is, sham operation, 2VO OVX (bilateral common carotid artery occlusion and ovariectomy)+ sesame oil, and 2VO OVX+estrogen replacement (named as S, O and E groups respectively) The changes of morphology and number of neurons in frontal cortex and hippocampal CA1 were studied with light and electron microscopy Results The numbers and shape of neurons in frontal cortex and CA1 were well maintained in E group, better than in O group but worse than in S group Significant differences were found in neuron number among 3 groups ( P

Ultrastructural changes of the infarcted region after transplantation of bone marrow mesenchymal stem cells into cerebral infarcted rats / 第三军医大学学报

Objective To observe the ultrastructural changes of the infarcted region after transplantation of mesenchymal stem cells (MSCs) into the infarcted rats. Methods Model of middle cerebral artery occlusion (MCAo) in Wistar rats was established. The isolated and cultured MSCs in vitro were injected into the infarcted region. The ultrastructural changes of the infracted region were observed at 4 w after transplantation by electron microscopy. Results Some immature cells surrounding the neurons were found to survive in the infracted region. Massive free ribosomes were observed in the neural cytoplasm in the infarcted region in the rats receiving MSCs transplantation, but neurons with nuclear pyknosis and neurophagia were observed in the infarcted region of rats in the control group. Conclusion MSCs transplantation might improve neuron repair in cerebral ischemic injury in rats.