Analysis of 134Cs, 137Cs, and 60Co in aerosol samples: An intercomparison among laboratories / 中国辐射卫生

Objective To improve the analysis of 134Cs, 137Cs, and 60Co in aerosol samples by the national key radiation environment laboratories. Methods Intercomparison of analysis results of 134Cs, 137Cs, and 60Co in standard aerosol samples was performed among the national key radiation environment laboratories according to Gamma spectrometry method of analyzing radionuclides in biological samples (GB/T 16145-1995 ), and the intercomparison results were evaluated by the standard deviation. Results Six laboratories were involved in the intercomparison. For 134Cs, 50% of the laboratories showed a relative deviation less than 10%, and 50% showed a relative deviation of 10%-20%. For 137Cs, 33.3% of the laboratories showed a relative deviation less than 10%, and 76.7% showed a relative deviation of 10%-20%. For 60Cs, all laboratories showed a relative deviation less than 10%. The overall intercomparison results were acceptable. Conclusion The laboratories in this intercomparison show generally good results.

Expression, purification and micelle reconstruction of the transmembrane domain of the human amyloid precursor protein for NMR studies / 生物工程学报

The multiple-step cleavage of amyloid precursor protein (APP) generates amyloid-β peptides (Aβ), highly toxic molecules causing Alzheimer's disease (AD). The nonspecific cleavage between the transmembrane region of APP (APPTM) and γ-secretase is the key step of Aβ generation. Reconstituting APPTM under physiologically-relevant conditions is crucial to investigate how it interacts with γ-secretase and for future AD drug discovery. Although producing recombinant APPTM was reported before, the large scale purification was hindered by the use of biological protease in the presence of membrane protein. Here, we expressed recombinant APPTM in Escherichia coli using the pMM-LR6 vector and recovered the fusion protein from inclusion bodies. By combining Ni-NTA chromatography, cyanogen bromide cleavage, and reverse phase high performance liquid chromatography (RP-HPLC), isotopically-labeled APPTM was obtained in high yield and high purity. The reconstitution of APPTM into dodecylphosphocholine (DPC) micelle generated mono dispersed 2D 15N-1H HSQC spectra in high quality. We successfully established an efficient and reliable method for the expression, purification and reconstruction of APPTM, which may facilitate future investigation of APPTM and its complex in more native like membrane mimetics such as bicelle and nanodiscs.

Results of the nationwide assessment of radionuclide γ spectrum measurement in 2018—2020 / 中国辐射卫生

@#<b>Objective</b> To ensure the effectiveness and improve the capacity of laboratories in the measurement of γ spectra of radionuclides. <b>Methods</b> A statistical analysis was performed using relative deviation, accuracy, precision, and relative combined uncertainty for the nationwide assessment of radionuclide γ spectrum measurement. <b>Results</b> In the assessment from 2018 to 2020, our laboratory showed qualified or above results, and the performance in 2019 was excellent. The maximum relative deviation of 11 measurements from 2018 to 2020 was 18.01%. The assessment showed |Z_test|≤1 and U_test≤2.58 in 2018, |Z_test|≤1 and U_test≤1 in 2019, and U_test≤1 and U_rel≤20% in 2020. <b>Conclusion</b> Our laboratory employs the correct method for radionuclide γ spectrum measurement, and the analysis data are accurate and reliable.

Role of BDNF in basolateral amygdala-prelimbic cortex in perioperative neurocognitive disorders and relationship with TrkB receptors in mice / 中华麻醉学杂志

Objective:To evaluate the role of basolateral amygdala (BLA)-prelimbic cortex (PL) brain-derived neurotrophic factor (BDNF) in perioperative neurocognitive disorders (PND) and its relationship with tyrosine kinase B (TrkB) receptors in mice.Methods:Forty-eight clean-grade healthy C57BL/6J mice, aged 6 months, weighing 25-30 g, were divided into 4 groups ( n=12 each) using a random number table method: control group (group C), surgery group (group S), BDNF overexpression in BLA group (group B) and BDNF overexpression in BLA+ ANA-12 injection in PL group (group A). In group S, at 30 min after the end of training session of fear conditioning system, exploratory laparotomy was performed.In group B, recombinant adenovirus 0.3 μl was injected in BLA, fear conditioning test was performed 3 weeks later, and exploratory laparotomy was performed at 30 min after the end of the training session of fear conditioning system.In group A, recombinant adenovirus 0.3 μl was injected in BLA, catheterization was performed in PL, the fear conditioning test used performed 3 weeks later, TrkB receptor antagonist ANA-12 0.25 μg was given in PL starting from 30 min before training session, and exploratory laparotomy was performed at 30 min after training session.Test session was started at 24 h after the end of training session of fear conditioning system, and the percentage of time spent freezing was calculated in all groups.At 30 min after the end of the behavioral test, the expression of BDNF in brain areas, phosphorylated TrkB (p-TrkB) and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERKl/2) was determined by Western blot, and the expression BDNF mRNA in BLA was detected using reverse transcription fluorescence quantitative polymerase chain reaction assay. Results:Compared with group C, the percentage of time spent freezing was significantly decreased, and expression of BNDF protein and its mRNA in BLA and BDNF, p-TrkB and p-ERK1/2 in PL was down-regulated in group S ( P<0.05). Compared with group S, the percentage of time spent freezing was significantly increased, and expression of BNDF protein and its mRNA in BLA and BDNF, p-TrkB and p-ERK1/2 in PL was up-regulated in group B ( P<0.05). Compared with group B, the percentage of time spent freezing was significantly decreased, and expression of p-TrkB and p-ERK1/2 in PL was down-regulated in group A ( P<0.05). Conclusion:The mechanism of PND is probably related to reduction of BDNF secretion from BLA to PL caused by down-regulation of BDNF expression in BLA, and decreasing of post-synaptic phosphorylation of TrkB receptors in mice.

Longitudinal MRS study of the corpus callosum in patients with diffuse axonal inj ury / 实用放射学杂志

Objective To investigate metabolic levels of the splenium and genu of corpus callosum(CC)in subacute diffuse axonal injury (DAI)patients,and their longitudinal change in a short time.Methods 12 patients with subacute DAI and 12 gender and age matched healthy controls were enrolled successively in this study.All subjects were scanned with single volume magnetic resonance spectrum(MRS)in two regions of interest(the splenium and genu of CC),and they were reexamined with MRS a month later(31.5 d±6.2 d, 28-43 d).Some metabolite concentrations were calculated quantitatively by using LC-model software and the differences were analyzed.Results The concentrations of NAA in the splenium and genu of CC in subacute DAI patients were decreased significantly compared with those of controls (the genu:t=4.474,P=0.001;the splenium:t=4.231,P=0.001),meanwhile the Cho concentrations were increased significantly (the genu:t=2.509,P=0.031;the splenium:t=2.195,P=0.018).The concentrations of NAA and Cho in the splenium and genu of CC in patients with the follow-up were slightly elevated when compared with those of subacute DAI patients,but the difference had no statistical significance.The concentrations of Cr in the splenium and genu of CC in all subjects had no statistic difference.Conclusion The single volume MRS is sensitive to reflect the metabolic levels of CC in subacute DAI patients.The metabolic levels of CC has no significant change in the short term (about 1 month).

Two families of X-linked lymphoproliferative disease type 1 characterized by agammaglobulinemia / 中华儿科杂志

Objective@#To investigate the clinical and immunological laboratory features, mutations in SH2D1A gene and SAP protein expression in four children of two families with X-linked lymphoproliferative disease type 1(XLP-1).@*Method@#Four patients (Family A including Patient 1 and Patient 2, Family B including Patient 3 and Patient 4) and their maternal relatives were enrolled in this study. The clinical manifestation, EBV infection status and chest CT scan were analyzed. The absolute and relative numbers of lymphocyte subsets, T lymphocyte proliferative response, SAP protein expression were assessed by flow cytometry. Quantification of signal joint TCR rearrangementexcision circle (sjTRECs), CDR3 spectratyping of TCRvβ and gene mutation of SH2D1A were detected by PCR based on genomic DNA or cDNA.@*Result@#Four male patients from two families were diagnosed with XLP-1. The ages of disease onset were more than 1 year, more than 1 year, more than 1 month and 6 months. The ages at diagnosis were nine years and ten months, sixteen years and eight months, fourteen years and ten months, four years and nine months. All patients had recurrent infections and EBV infection. Patients 1, 2, and 3 had agammaglobulinemia and Patient 4 had hypogammaglobulinemia. Chest CT scan showed all patients had atelectasis and pneumonia, and Patient 3 had bronchiectasis. Patient 3 was diagnosised as Burkitt lymphoma. For immunological function, all patients exhibited reduced CD4/CD8 ratios, increased numbers of exhausted T lymphocyte, decreased number of NK cell. The numbers of total B lymphocyte and naïve B lymphocyte were normal, but the number of memory B lymphocyte declined in all cases. Four patients′ copy numbers of sjTRECs were low and CDR3 spectratypings of TCRvβ showed mildly skewed. But their T lymphocyte proliferative response was normal. SAP protein expression in four cases were measured by flow cytometry. Two patients from Family A were absent and two patients from Family B showed decreased values. SH2D1A gene sequence analysis showed that the patients of Family A harbored a nonsense mutation (c.163 C>T; p.R55X) in exon 2. Their mother and two sisters were carriers. A missense mutation of SH2D1A gene (c.278 G>A; p.G93D) in exon 3 was found in the patients of Family B. The mother was carrier. Four patients remain survived, Patient 3 gave up treatment, other three patients received IVIG therapy.@*Conclusion@#Four patients with XLP-1 from two families characterized by agammaglobulinemia have an extreme vulnerability to Epstein-Barr virus (EBV) infection. The functions of T cell, B cell and NK cell are impaired at different stages. The detection of SAP protein and SH2D1A gene are the key methods for diagnosis of XLP-1.

Longitudinal DTI study of the corpus callosum in patients with diffuse axonal injury / 实用放射学杂志

Objective To investigate microstructure of the corpus callosum(CC) in subacute diffuse axonal injury(DAI) patients and its the longitudinal change in a short time.Methods 21 patients with subacute DAI were enrolled successively in this study,and in which 12 patients were reexamined followed-up with DTI a month later (31.5 d±6.2 d,28-43 d),and then 12 gender and age matched healthy controls were recruited.The DTI data of all subjects were acquired on at a 3.0T MRI.The CC was divided into six segments:the genu, rostral mid-body, anterior mid-body,posterior mid-body, isthmus, and splenium.ROIs were placed on each segment on color fractional anisotropy (FA) maps in the midsagittal plane manually.The FA and apparent diffusion coefficient(ADC) values of each subregion of CC were measured and compared between subacute DAI group,follow-up group and controls respectively.In addition,a related analysis between DTI parameters of each sub-region of CC and GCS on admission was done by using person correlation analysis.

Clinical evaluation of ceramic onlay restoration of endodntically treated posterior teeth / 中国基层医药

Objective To evaluate the clinical effect of E-max press ceramic onlay restoration of endodontically treated posterior teeth.Methods 36 endodontically treated posterior teeth were restored with E-max press ceramic onlay.After 6 and 12 months,the patients were recalled.The teeth with restoration were assessed by using the modified USPHS criteria including secondary caries,gingivitis,tooth fracture,marginal discoloration,marginal integrity criteria and restoration fracture/debond,etc.Results 100％ of the restorations displayed good results,92％ of the restorations did not have gingival inflammation and food impaction.Conclusion Ceramic orlay made by E-max press is an effective restoration for endodontically treated posterior teeth.

Genomic analysis of Wenzhou virus in rodents from Zhejiang province / 中华流行病学杂志

Objective Arenavirus is a negative single-stranded RNA virus and an important human pathogen,mainly harbored and transmitted by rodents,causing severe diseases,including hemorrhagic fever and encephalitis.Following the discovery of a novel pathogenic arenavirus (Wenzhou virus,WENV),the prevalence of WENV in local small rodents was investigated.Methods By using RT-PCR,WENV was screened in 48 and 156 rodents sampled from Wenzhou and Longquan,respectively.Results Consequently,WENV was detected in 5 (10.41％) rodents sampled from Wenzhou.However,no WENV was identified in all the rodents sampled from Longquan.Genetic analysis of complete genome sequences indicated that 4 of 5 virus strains were closely related to the known Wenzhou viruses with high homology.Especially,the L and S segments of Wencheng-Rn-288 strain shared homology of 87.5％ and 91.6％ with other viruses,respectively.They formed a distinct lineage,suggesting that this strain might be a novel variant of WENV.Conclusions Our results indicate that WENV has a high prevalence and high genetic diversity among rodents in Wenzhou.As the respiratory disease caused by WENV has been detected in Cambodia,it is necessary to strengthen the surveillance for WENV in China.

Genomic analysis of Wenzhou virus in rodents from Zhejiang province / 中华流行病学杂志

Objective Arenavirus is a negative single-stranded RNA virus and an important human pathogen,mainly harbored and transmitted by rodents,causing severe diseases,including hemorrhagic fever and encephalitis.Following the discovery of a novel pathogenic arenavirus (Wenzhou virus,WENV),the prevalence of WENV in local small rodents was investigated.Methods By using RT-PCR,WENV was screened in 48 and 156 rodents sampled from Wenzhou and Longquan,respectively.Results Consequently,WENV was detected in 5 (10.41％) rodents sampled from Wenzhou.However,no WENV was identified in all the rodents sampled from Longquan.Genetic analysis of complete genome sequences indicated that 4 of 5 virus strains were closely related to the known Wenzhou viruses with high homology.Especially,the L and S segments of Wencheng-Rn-288 strain shared homology of 87.5％ and 91.6％ with other viruses,respectively.They formed a distinct lineage,suggesting that this strain might be a novel variant of WENV.Conclusions Our results indicate that WENV has a high prevalence and high genetic diversity among rodents in Wenzhou.As the respiratory disease caused by WENV has been detected in Cambodia,it is necessary to strengthen the surveillance for WENV in China.

Application value of SWI in hyperacute massive ischemic cerebral infarction / 实用放射学杂志

Objective To explore the application value of SWI in hyperacute ischemic cerebral infarction.Methods 40 patients with massive hyperacute ischemic cerebral infarction in middle cerebral artery (MCA)territory were enrolled successively who underwent MR imaging with conventional MRI,DWI,MRA and SWI sequence immediately.The MR images were analyzed by two senior neuroimaging physicians and the results were recorded.The number of thrombosis at MCA showed on SWI was compared with that showed on conventional MR sequence and the number of MCA stenosis or occlusion showed on MRA,the length of thrombosis and the number of cases with veins increased in infarct area were also compared.Results The number of thrombosis at MCA showed on SWI was more than that showed on conventional MR sequences significantly (23 vs 12,χ2 =6.146,P =0.013),and was lower than that showed on MRA (23 vs 24,χ2 =0.052, P =0.820)slightly.Thrombosis at MCA trunk and its small branches were found in the meantime in 2 cases .The length of thrombosisshowed on SWI was longer than that showed on conventional MRI sequences (25.7 mm±9.4 mm vs 14.6 mm±8.5 mm,t=14.395,P =0.000), significantly and the number of patient with veins increased in infarct area showed on SWI was more than that showed on conventional MR sequences (21 vs 12,χ2 =4.1 78,P =0.041)significantly.Conclusion SWI has usefull application value in patients with hyperacute massive ischemic cerebral infarction.

Advances in Research on Pesticide Pollution to the Aquatic Environment and Health Impact in China / 环境与健康杂志

Pesticide played an important role in agriculture. With the increase of pesticides in recent years,they have easily gone into the aquatic environment through some ways such as rain or surface water. The residual pesticide in the water may destroy the aquatic ecosystems,do harm to the aquatic organisms and human health,now more and more attention has been paid to the situation of the pesticide pollution in the aquatic environment. This present paper introduced the type of common pesticide residues in the water in China, it also described the pesticide pollution situation in rivers,groundwater,marine and other water as well as the potential impact of pesticide on the aquatic organisms and human health,in order to provide a basis for China to carry out relative research.

Apoptosis of macrophage induced by E_2 at high concentration / 中国药理学通报

AIM To study the effect of 17?-estradiol(E 2) on apoptosis of macrophages at certain concentration.METHODS Fluorescent microscopy and scanning eletron microscopy(ESEM) were used to detect apoptosis changes of macrophages induced by E 2 at relatively high concentration and intracellular Ca 2+ and matochontrial transmembrane potential were examined by laser scanning confocal microscopy(LSCM). RESULTS Apoptosis of macrophages was induced by high concentration of E 2 (≥1 ?mol?L -1). Intracellular Ca 2+ elevated and matochontrial transmembrane potential decreased after E 2 treatment. CONCLUSION Apoptosis of macrophages is induced by certain concentration of E 2 (≥1 ?mol?L -1) and this may be related to elevated intracellular Ca 2+ and decreased matochontrial transmembrane potential.