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BACKGROUND:Olfactory dysfunction is an early biological marker of various diseases.However,the neuroimaging mechanism by which olfactory dysfunction occurs following cerebral small vessel disease is unclear. OBJECTIVE:To explore the different neuroimaging mechanisms of olfactory function regulation in patients with cerebral small vessel disease and Parkinson's disease,and explore the potential application value of olfactory function assessment in patients with cerebral small vessel disease. METHODS:Neuropsychological and olfactory tests,high-resolution structural magnetic resonance and resting-state functional magnetic resonance data were collected in 80 patients with cerebral small vessel disease,44 healthy controls and 29 patients with Parkinson's disease.DPABI,SPM12 and SPSS were used to analyze and compare the amplitude of low frequency fluctuation,regional homogeneity and functional connectivity values between the cerebral small vessel disease,control and Parkinson's disease groups.Correlations between the significantly altered resting-state functional magnetic resonance imaging measures and olfactory and cognitive scores were evaluated. RESULTS AND CONCLUSION:Compared with the control group,low-frequency fluctuation amplitude of the right dorsolateral superior frontal gyrus and the regional homogeneity of the left wedge leaf were significantly reduced in the cerebral small vessel disease and Parkinson's disease groups.The right dorsolateral superior frontal gyrus and the left cuneiform lobe are the seed points.Compared with the Parkinson's disease group,the functional connectivity values of the right anterior cunei,inferior temporal gyrus,anterior central gyrus and dorsolateral superior frontal gyrus,left posterior central gyrus and inferior temporal gyrus were significantly enhanced in the control and cerebral small vessel disease groups.The left cuneiform lobe was the seed point.Compared with the control group,the functional connectivity of the left lingual gyrus was significantly weakened in the cerebral small vessel disease and Parkinson's disease groups.The functional connectivity values of the left middle temporal gyrus and the right posterior central gyrus were enhanced in the control group compared with the cerebral small vessel disease and Parkinson's disease group,and that was enhanced in the cerebral small vessel disease group compared with the Parkinson's disease group.Correlation analysis showed that the olfactory score and cognitive score were positively correlated in the cerebral small vessel disease group,and the regional homogeneity of the left wedge lobe was negatively correlated with the Montreal Cognitive Assessment Scale score,while the functional connectivity of left wedge lobe-left middle temporal gyrus in the Parkinson's disease group was positively correlated with the olfactory recognition score,and the functional connectivity values of the left wedge lobe-left posterior central gyrus and left wedge lobe-left lingual gyrus were positively correlated with the olfactory identification score and the total olfactory score,respectively.The regulation of olfactory function in patients with cerebral small vessel disease has a different neuroimaging mechanism from that of olfactory dysfunction in patients with Parkinson's disease.The olfactory function of patients with cerebral small vessel disease is related to cognitive function.It is speculated that the olfactory function following cerebral small vessel disease is a secondary change of brain dysfunction,while olfactory dysfunction following Parkinson's disease is directly caused by abnormal function of olfactory-related brain areas.Olfactory function assessment in patients with cerebral small vessel disease has potential application in predicting cognitive function.
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ObjectiveTo investigate the epidemic characteristics and influencing factors of acute conjunctivitis caused by human adenovirus（HAdv）in Yantian District of Shenzhen City， Guangdong Province from 2014 to 2022， and to provide evidence for formulating effective prevention and control measures. MethodsDescriptive epidemiology was used to analyze the epidemiological characteristics of acute hemorrhagic conjunctivitis （AHC） cases reported from the Chinese disease prevention and control information system. Etiological characteristics of laboratory-confirmed cases were analyzed， and a case-control study method of test-negative design （TND） was conducted as well. According to the result of HAdv detection， analysis was used to identify the influencing factors of morbidity. ResultsA total of 1 005 AHC cases were reported in Yantian District， Shenzhen City from 2014 to 2022， with an average annual incidence rate of 49.49/105. The incidence rate ranged from 4.67/105 to 117.28/105. The peak incidence occurred from July to October each year， with a male-to-female ratio of 1.42∶1. The median （P25，P75） age of onset was 29（12，40） years. A total of 716 eye swabs were collected for etiological detection from 2014 to 2022. HAdv positive detection rate was 36.45% （263/716）， Cox 24v positive detection rate was 0.28% （2/716）， while EV70 was not detected. The longest viral shedding time in eye swabs was 10 days， with a median of 2 days. The highest HAdv positive detection rate （47.47%） was observed when the sampling-to-onset interval was 4‒5 days， and the difference was statistically significant （P<0.05）， with a trend of first increasing and then decreasing. Multivariate logistic regressing analysis showed that aged 18‒ years， and average temperature higher than 24.90 ℃ 3 days before onset （P<0.05） were the risk factors for acute HAdv conjunctivitis. ConclusionAHC in Yantian District， Shenzhen City showed a low level of prevalence from 2014 to 2022， with HAdv being the predominant pathogen. The peak period of viral shedding occurred on the 4th to 5th day after symptom onset， suggesting the importance of adherence to strict home isolation for infected persons. Aged18‒ years and average temperature increased 3 days before onset are associated with an increased risk of adenoviral conjunctivitis. It is recommended to strengthen personal protection and keep doing a good job of AHC surveillance and early warning， so as to timely prevent the outbreaks of AHC.
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Objective@#To understand the relationship between eye strain and eye health behavior in college students learning at home during the period of COVID-19 epidemic, and to provide a scientific reference for improving the hygiene of using eyes among the college students.@*Methods@#A cross sectional study and stratified cluster sampling was used to select 2 671 college students from 8 colleges in Anhui Province during the March 1st to July 1st in 2020, and an online questionnaire was survey included general information,eye strain,and daily eye health behavior.@*Results@#The prevalence of eye strain in college students was 69.64%. Multivariable Logistic regression analysis showed that eye strain was correlated with gender, myopia, siesta habit, staying up until 2:00 am, and the use of eye liquid, with OR values(95% CI ) were 0.64(0.53-0.76), 1.77(1.42- 2.20 ),0.71(0.59-0.86), 1.39(1.17-1.65), and 2.18(1.71-2.79), respectively. There was no correlation among daily outdoor activity time, daytime reading time and the occurrence of eye strain( P >0.05).@*Conclusion@#During the period of COVID-19 epidemic, eye strain among college students is common. The daily eye health behavior is related to the occurrence of eye strain. Under the special learning context, eye care measures should be encouraged specifically.
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Objective To explore whether inhibiting autophagy can enhance the sensitivity of photothermal treatment under mild photothermal conditions. Methods CQ@PLGA@PDA NPs were prepared by an improved double emulsification method and a PDA-based surface modification method. After basic characterization, CCK-8 method was used to detect the cytotoxicity of nanoparticles; the near-infrared laser irradiation nanoparticle solution was used to detect the heating effect; CCK-8 method and live-dead cell staining were used to detect the killing effect of tumor cells; Western blot was used to detect the expression of autophagy-related proteins. Results The CQ@PLGA@PDA NPs were successfully prepared, with a particle size of 253.10±2.39 nm, a zeta potential of -22.57±0.80 mV, uniform particle size and good dispersion. The temperature of nanoparticle solution increased to 45℃ after the near-infrared laser irradiation for 10 min. CQ@PLGA@PDA NPs had no obvious toxicity to cells. The survival rates of breast cancer cell MDA-MB-231 and mouse embryonic fibroblast NIH-3T3 cell were above 95%. The inhibition of autophagy under mild photothermal conditions could improve the sensitivity of photothermal therapy. Conclusion The prepared CQ@PLGA@PDA NPs have good photothermal performance and high biological safety; by inhibiting autophagy, they can effectively kill tumor cells under mild photothermal conditions(< 50℃).
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Objective@#To study the protective effect of melatonin (MT) against lead-induced neurotoxicity.@*Methods@#PC12 cells were divided in four groups (control, 25 μmol/L PbAc, 50 μmol/L MT and 25 μmol/L PbAc+50 μmol/L MT) . After treatment, cell viability was detected by cell counting kit-8 (CCK-8) assay and cytotoxicity LDH assay were used to evaluate cell damage rate. The expression of Cleaved-Caspase-3 and cytochrome C (cyto C) was detected by immunofluorescence (IF) . ROS levels were measured by DCFH method. GSH contents and SOD activities were detected after whole cell protein was extracted.@*Results@#Compared with control group, 25 μmol/L PbAc caused significantly decreased cell viability, GSH contents and SOD activities, while increased cell damage rate and ROS level significantly (P<0.05) . 25 μmol/L PbAc could also increase the protein level of cleaved-caspase-3 and cyto C in cytoplasm. Compared with 25 μmol/L PbAc group, 50 μmol/L MT+25 μmol/L PbAc caused significantly increased cell viability, GSH contents and SOD activities, while decreased cell damage rate and ROS level significantly (P<0.05) . Compared with 25 μmol/L PbAc group, 50 μmol/L MT+25 μmol/L PbAc decreased the protein level of cleaved-caspase-3 and cyto C.@*Conclusion@#Melatonin could attenuate PbAc-induced oxidative stress and cell death and promote cell survival.
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Objective To establish clinical quality control method with testing the birdcage head coils and setting up the action limits.Methods Three different MR devices (GE 1.5T HDi,GE 3.0T HD and GE 3.0T 750W) and corresponding birdcage coils were tested.Axial T1WI was performed to scan ACR phantom.SNR,percent image uniformity (PIU) and percent signal ghosting (PSG) were measured for six times,and the mean values and standard deviations (SD) were calculated.Based on the results,the action limits for each parameter were set.Results The mean value of SNR for the three devices was 262.14,280.47 and 474.24,and SD was 18.43,29.67 and 29.95,respectively;the action limits were ≥225.28,≥221.13 and ≥414.34,respectively;the mean value of PIU for the three devices was 95.00％,83.17％ and 84.33％,SD was 0.63％,1.17％ and 0.82％,respectively;the action limits were ≥93.74％,≥82.00％ (corrected) and ≥82.69％,respectively.The mean value of PSG for the three devices was 0.11％,0.07％ and 0.14％,SD was 0.12％,0.03％ and 0.11％,respectively;the action limits were ≤0.35％,≤0.13％ and ≤0.36％,respectively.Conclusion All of SNR,PIU and PSG for three MR devices were consistent with the action limits in this study.
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Objective To test the central frequency (CF) and transmitter gain(TG) of MRI scanners,and set up their action limits.Methods Three different MRI devices (GE 3.0T HD,GE 1.5T HDi and GE 3.0T 750W) were tested by scanning American College of Radiology (ACR) phantom with the axial T1WI series.In the pre-scanning of T1WI series for the ACR phantom,the CF and TG were recorded.It was tested for eight times when MRI scanners were in good condition.The action limits of CF and TG were calculated based on mean values and standard deviations.Results The mean values of CF for three devices were (127 725 772.38±39.68)Hz,(63 875 740.13± 34.15)Hz,and (127 771 958.38±12.19)Hz,respectively.Their action limits were ≤119.04 Hz,≤68.30 Hz,and ≤36.57 Hz,respectively.The mean values of TG for three devices were (125.25±1.28)dB,(101.75±1.98)dB,and (113.25±0.89)dB,respectively.Their action limits were (125.25±2.56)dB,(101.75±3.96)dB,and (113.25±1.78)dB,respectively.Conclusion The CF and TG for three MRI scanners are all consistent with the action limits in this study.The CF and TG action limits will provide criterions for the clinical quality control.
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Objective To explore the evaluation methods of magnetic field uniformity and the practical operations,in order to provide references for clinical quality control.Methods Based on MRS phantom and 32 cm uniform spherical phantom,the evaluation methods of magnetic field uniformity were used to detect MRI equipment in department of radiology,including spectral peak and the bandwidth difference.Results The full width at half maximum (FWHM) of MRS phantom was 0.08 ppm,the inhomogeneity values on coronal,sagittal and axial detected by the bandwidth difference method was 0.15 ppm,0.08 ppm and 0.18 ppm,respectively.Conclusion The magnetic field homogeneity of the above mentioned MRI equipment is favorable,which accords with magnetic field uniformity detection standard.
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Objective To detect the cross-talk RF signal interference of three MRI scanners,in order to deepen the understanding of cross-talk RF signal interference.Methods Three different GE magnetic resonance imaging scanners (GE 1.5T HDi,installation time:2012;GE 3.0T HD,installation time:2006;GE 3.0T 750W,installation time:2016) were tested.The axial T1-weighted sequence was used to scan ACR phantom.Slice gaps with 5.0 mm,1.0 mm,0.5 mm and 0 were performed,respectively.SNR values were also recorded.Based on the results,the percentage change charts of SNR with slice gaps were made.Test standard was set as SNR decreased less than 20 ％ when the slice gap reduced from 5 mm to 0.Results When slice gap was reduced from 5 mm to 0,SNRs for three scanners decreased by 18.16 ％,23.57％ and 10.75％,respectively.Both the results of cross-talk obtained with GE 1.5T HDi and GE 3.0T 750W scanner met the test standard,while the result obtained with GE 3.0T HD (used for more than 10 years) was below the standard.Conclusion The cross-talk RF signal interference still exists for three MRI scanners.The test result of the scanner used for the longest time is unqualified.The quality control test of cross-talk should be done in the daily work.
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Clinical quality control of MRI equipment is a significant part of quality assurance.The purpose of quality control is to assure the performance and specification stability of MRI scanner,and to provide high quality images for clinical diagnosis.Many foreign countries have already developed and established highly sophisticated quality control procedure and regulation for MRI system,and the application is also relatively popular.However,this work has just begun in China,need to be further developed.The current status and future trend of clinical quality control procedure as well as regulation for MRI equipment were reviewed in this article.
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Objective To investigate the association between the minisatellite polymorphism in the first exon of PLA2G4C gene and schizophrenia, and to reveal the important role of DNA sequence polymorphism in the pathogenesis of schizophrenia.Methods The minisatellite polymorphisms in the first exon of PLA2G4C gene in 91 patients with schizophrenia (case group)and 81 healthy persons (control group)were detected with PCR-sequencing analysis.The chi-square (χ2 )goodness-of-fit test was used to analyze the distribution of the PLA2G4C minisatellite polymorphism in various groups and to explore the association between the minisatellite polymorphism in the first exon of PLA2G4C gene and schizophrenia. Results There were minisatellite polymorphisms in PLA2G4C gene.Three kinds of polymorphisms 1×27 bp,2×27 bp and 3×27 bp were found by sequencing.The distribution of allelic frequencies at PLA2G4C polymorphism showed no statistical significance between case group and control group (P>0.05 ). No statistically significant difference was found in 3-homozygous haplotypes in PLA2G4C gene between case group and control group (P>0.05).At the same time,there was no statistically significant difference between 3-heterozygous haplotypes in PLA2G4C gene between case group and control group (P>0.05).Conclusion The minisatellite polymorphisms in the first exon of PLA2G4C gene are found,but the minisatellite polymorphism in the first exon of PLA2G4C gene may be not associated with the occurrence of schizophrenia.
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Objective: To isolate the key domain of a novel polypeptide fragment from NGN-β that functions like intact NGF molecule.Methods: NGF-β had been treated with cyanogen bromide and trypsin skillfully. The peptide fragment with the activity inducing PC12 pheochromocytoma cells differentiation was isolated and purified by Sephadex G-50 gel filtration chromatography , DE-52 celluloseion exchange chromatography and C-18 reversed-phase column HPLC after NGF-β cleavaged by CNBr at 9th met then by trypsin at Arg or Lyscleavaged by CNBr at 9th met then by trypsin at Arg or Lys. Amino acid sequencing of this novel peptide fragment was performed by Automatic Amino Acid Analyser and Amino Acid Sequencer. Results: The functional fragment from cleavaged NGF might induce differentiation of PC12 cells. The fragment was consisting of two linear polypeptides . One of them was 16 peptide, GEFSVCDSVSVWVGDK , and other was 14 peptide, HWNSYCTTTHTFVK, linked by a disulphide bridge corresponding to residues 10～25 and 75～88, respectively, of the amino acid sequence of nerve growth factor, the result of biological activity assay in PC12 cells showed that the optimum concentration of this peptide were 0.001～0.1 μg*L-1. Conclusion: A novel peptide inducing differentiation of PC12 cell line of pheochromocytoma cells was obtained in the study. It′s isolation and purification successfully will underlie synthesis or expression of hyperactive neurotrophic small molecular substance although the relationship between the configuration and functions is not clearly.