RESUMO
Objective To assess the alterations of negative functional connectivity(FC),its relationship with clinical symptoms,and its potential value in schizophrenia(SZ).Methods Resting-state functional magnetic resonance imaging(rs-fMRI)data were acquired from patients with SZ and healthy controls(HC).For each participant,the whole brain image was first divided into 272 regions and then the FC between each pair of these regions was calculated using Pearson's correlation coefficient.Group-level negative FCs were identified using permutation test for each group.Each of the identified negative FCs was then compared between patients and controls to identify the altered negative FCs.Then,Spearman rank correlation was adopted to examine the relationship between the altered negative FCs and clinical variables.Finally,to evaluate the diagnostic value of negative FC in SZ,a multivariate pattern analysis(MVPA)was performed to distinguish between SZ and HC based on negative FCs.Results Ninety-one patients with SZ and 91 HC were included in this study,and 207 negative FCs in total were identified.Among the identified 207 negative FCs,12(constituting 5.80％of the total 207 negative FCs)were significantly altered in SZ compared with HC(Bonferroni correction,P<0.05),of which 11 were significantly decreased(i.e.,closer to 0)in SZ.The correlation analyses identified 2 significant associations-one was between a negative FC and the total score of the psychotic symptoms rating scales-auditory hallucinations(r=-0.24,P=0.02)and the other was between a negative FC and the weighted total score of the scale for the assessment of thought,language,and communication(r=0.26,P=0.01).Furthermore,the model for distinguishing between SZ and HC based on negative FCs achieved a classification accuracy of 72.6％that was significantly higher than chance-level accuracy(permutation test,P<0.001).Conclusion Negative FCs are altered in patients with SZ.Given that negative FCs are associated with clinical symptoms,thus they may serve as an imaging biomarker for assisting the diagnosis of SZ.
RESUMO
Objective:To investigate whether anxiety state and anxiety trait modulate specifically pain-induced brain responses by comparing the brain activations induced by painful stimulation and those by tactile stimulation in college students with different levels of anxiety state or anxiety trait.Methods:From April 2017 to September 2017, sixty-two college students were tested in Tianjin Medical University General Hospital.Each subject’s anxiety trait and anxiety state were assessed by the state-trait anxiety inventory (STAI) prior to the fMRI experiment.During the fMRI experiment, each subject received painful and tactile stimuli.Their brain responses to each stimulus were collected by the MRI scanner, and the perceived intensity rating of each stimulus was collected using the visual analogue scale (VAS). The pain and tactile brain activation values of subjects with different state anxiety levels and different trait anxiety levels were compared.The fMRI brain activation was detected using general linear model.For each type of anxiety (state or trait), two-way ANOVA was performed to detect the interaction between anxiety level and stimulus modality on brain responses and two-sample t-tests were performed to analyze the specific form of interaction in each brain region. Results:There were interactions between state anxiety and stimulation modality on the activation intensity of bilateral posterior parietal lobe, dorsolateral prefrontal lobe and other brain regions( P<0.05, cluster-level FWE corrected) .The brain responses to tactile stimuli (5.66±0.65) in these areas were significantly stronger than those to painful stimuli (1.24±0.55) in the group of middle-level anxiety state ( P<0.001), but no significant difference was found in the other two groups (both P>0.05). For anxiety trait, a few brain areas in bilateral occipital cortex showed significant interactions between anxiety level and stimulus modality.The brain responses to tactile stimuli (8.38±1.00) in these areas were significantly stronger than those to painful stimuli (3.19±1.12) in the group of high-level anxiety trait ( P=0.001), but no significant difference was found in the other two groups (both P>0.05). Conclusion:The modulatory effects of anxiety (both state and trait) on brain responses are different between painful and tactile conditions.It provides important evidence for unveiling the brain mechanisms of the specific modulation of anxiety on pain, and suggests that patients' anxiety trait and anxiety state should be considered during clinical treatment of pain.
RESUMO
Objective:To obtain the genome sequences of SARS-CoV-2 in respiratory specimens in Guangdong Province with next-generation sequencing (NGS) and analyze the factors influencing sequencing.Methods:Eight upper and lower respiratory tract specimens were collected from patients with SARS-CoV-2 infection in Guangdong Province in January 2020. RNA library construction was used to obtain the genome sequences of SARS-CoV-2. A bio-informatics software package (CLC Genomics Workbench 12.0) was used to analyze and compare the genomic sequences.Results:Five SARS-CoV-2 genome sequences were obtained from the eight specimens and two were obtained from lower respiratory tract specimens. The nucleotide homology to SARS-CoV-2 was 97.74%-99.90%. The Ct values were lower, while the sequencing depth, coverage, relative abundance and genome integrity were higher in sequencing the SARS-CoV-2 in lower respiratory tract specimens.Conclusions:The low Ct value of SARS-CoV-2 in the samples was good for sequencing.
RESUMO
Objective To explore the effectiveness of different multiple comparisons correction methods by comparing the detection rate and false positive rate of brain activation analysis using functional magnetic resonance imaging ( fMRI) data. Methods On the basis of task-based fMRI dataset ( including low-intensity and high-intensity stimuli condition,n=20) and resting-state fMRI dataset( n=32),brain acti-vation results were corrected by multiple comparsion correction methods in SPM and SnPM13 software,and the activation detection rate and false positive rate were compared with different correction methods. Results Voxel-or peak-based correction methods had relatively low false positive rate. When P<0. 05 after correction,the proportion of the subjects with false-positive were 0. 19 and 0. 16,and the number of false-pos-itive voxels were 404 and 2 448,respectively. But the two methods had low detection rate,which were more suitable for detecting strong activation. While cluster-based correction methods had relative high detection rate and high false positive rate. When P<0. 05 after correction,the proportion of the subjects with false-posi-tive were 0. 34 and 0. 38,and the number of false-positive voxels were 7 870 and 8 320,respectively. And thus they were more suitable for detecting weak activation. Group-level analysis could effectively reduce false positive rate. Conclusion In practice,researchers should choose a suitable correction method based on their specific research objectives and data to achieve a balance between the detection rate and false positive rate.
RESUMO
Objective@#To explore the effectiveness of different multiple comparisons correction methods by comparing the detection rate and false positive rate of brain activation analysis using functional magnetic resonance imaging (fMRI) data.@*Methods@#On the basis of task-based fMRI dataset (including low-intensity and high-intensity stimuli condition, n=20) and resting-state fMRI dataset(n=32), brain activation results were corrected by multiple comparsion correction methods in SPM and SnPM13 software, and the activation detection rate and false positive rate were compared with different correction methods.@*Results@#Voxel-or peak-based correction methods had relatively low false positive rate.When P<0.05 after correction, the proportion of the subjects with false-positive were 0.19 and 0.16, and the number of false-positive voxels were 404 and 2 448, respectively.But the two methods had low detection rate, which were more suitable for detecting strong activation.While cluster-based correction methods had relative high detection rate and high false positive rate.When P<0.05 after correction, the proportion of the subjects with false-positive were 0.34 and 0.38, and the number of false-positive voxels were 7 870 and 8 320, respectively.And thus they were more suitable for detecting weak activation. Group-level analysis could effectively reduce false positive rate.@*Conclusion@#In practice, researchers should choose a suitable correction method based on their specific research objectives and data to achieve a balance between the detection rate and false positive rate.
RESUMO
Objective To detect the positive rates of antibodies against avian influenza virus (AIV) subtypes H5, H6, H7 and H9 among people in poultry occupations in Guangdong province and to analyze the transmission of various subtypes of AIV from poultry to human contacts for the prevention and control of novel AIV infection in human beings.Methods Serum specimens were collected from 1066 peo-ple in poultry occupations ( occupational group) and 205 people not in poultry occupations ( non-occupational group) in 10 cities of Guangdong province.The inactivated AIV strains, isolated from poultry or environment of Guangdong province, were used as antigens to detect antibodies against AIV subtypes H5, H6, H7 and H9 by using the hemagglutination inhibition ( HI) assay.Results The positive rates of antibodies against AIV subtypes H5, H6, H7 and H9 carried by people from the occupational group were respectively 0.44%, 0%, 0.30%and 0.30%in 2013 and 1.08%, 0.0%, 0.0%and 0.27%in 2014.Only the anti-H9 anti-bodies were detected in serum samples collected form people in the non-occupational group in 2013 with a positive rate of 0.95%.No significant differences with the positive rates of anti-AIV antibodies were found between the occupational group and the non-occupational group.However, the geometric mean titer ( GMT) of anti-AVI antibodies in people from the occupational group was higher than that of the non-occupational group.Conclusion Although a grand spread of AIV from avian to human is not likely to happen yet, con-tacting with poultry is the risk factor for AIV infection in Guangdong population.A long-term surveillance of anti-AIV antibodies in serum should be strengthened among people in poultry occupations for the timely pre-vention and control of novel AIV outbreak.
RESUMO
Objective To evaluate the clinical outcomes of pedicle screw fixation in the treatment of Hangmans fracture. Methods The 15 patients who had been treated for acute Hangmans fracture in our department after 1999 were retrospectively analyzed. 4 of them were type I, and 11 type II. All the patients presented symptoms of nerve system at different degrees. They were treated with AO pure titanium cortex screw through isthmus after skull traction replacement. Results All the patients were followed up for 12 to 60 months. According to Frankle classification, 6 cases of Grade D and 5 cases of Grade C recovered up to Grade E, 2 cases of Grade C recovered to Grade D, 1 case of Grade B recovered to Grade C and 1 case of Grade B recovered to Grade D. X ray showed all the fractures healed up without vertebra artery injury or other complications. Conclusion The outcomes of pedicle screw fixation and reduction in treatment of acute Hangmans fracture are satisfactory, for the clinic technique promotes functional recovery of spinal cord, decreases the rate of infection and scarcely affects the function of upper cervical spine.