Establishment of a qPCR method to detect Staphylococcus xylosus and its application / 中国实验动物学报

Objective To establish and evaluate a method for rapid and sensitive S.xylosus detection using qPCR(real-time quantitative PCR).Methods A gehM gene fragment was selected as the target for S.xylosus.A set of specific primers was synthesized and a qPCR method was established to detect S.xylosus.A S.xylosus standard strain and other non-target strains were chosen for analysis.DNA of S.xylosus was diluted 10-fold to determine its sensitivity.Clinical samples were tested,and positive products were sequenced.The result were compared with those of bacterial culture.Results S.xylosus had a specific amplification curve,whereas other non-S.xylosus species did not,indicating that the primers were specific for S.xylosus.Sensitivity was 100 fg/μL DNA.Repeatability within and between groups was less than 3％.A total of 60 clinical samples were analyzed,of which five samples had a typical S curve.qPCR products were sequenced and BLAST searched.The similarity of the gene sequences was 99.63％,indicating that the sample was positive for the S.xylosus gehM gene with a positivity rate of 8.3％.However,the positivity rate of bacterial culture was 6.7％.The positivity rate of qPCR was slightly higher than that of the culture.Conclusions The established qPCR method is rapid with high sensitivity and specificity,and can be used to detect S.xylosus.

Comparison of Methods between Soiled Bedding Sentinels and Exhaust Air Dust PCR for Health Monitoring of Rodent Laboratory Animals / 实验动物与比较医学

The microbiological quality of laboratory animals is crucial for the validity and reproducibility of scientific research data, as well as human health and animal welfare. Currently, individual ventilation cages (IVC) have become the mainstream feeding system for rodent laboratory animals. The most commonly used pathogen monitoring method for this feeding system is soiled bedding sentinels (SBS). This method monitors the microbial carrying status of mouse colony through indirect contact and delayed feedback. It can effectively monitor pathogens transmitted via the fecal-oral route, such as mouse hepatitis virus and reovirus. However, this method has difficulty detecting pathogens mainly transmitted through aerosols or direct contact, such as Sendai virus and Pasteurella pneumotropica. The exhaust air dust (EAD)-PCR monitoring method involves swab sampling in the IVC exhaust ducts to monitor the corresponding racks of the ducts; swab sampling before the prefiltration of the host to monitor the entire IVC rack; and EAD collection device sampling to monitor all racks connected to the same host. Different IVC manufacturers have developed corresponding EAD collection devices for their respective IVC systems, making operations convenient and standardization easy. Compared with the SBS method, the EAD-PCR method significantly improves detection rate and timeliness, with the fastest detection possible after one week of exposure. It can serve as a supplement or replacement for the SBS method. Currently, increasing evidence supports that EAD-PCR testing is a more reliable, sensitive, and cost-effective monitoring method, and is more beneficial to animal welfare. This article reviews the application progress of these two methods for monitoring pathogens, analyzes the existing limitations of the EAD-PCR method, and proposes solutions based on its implementation in our laboratory and examination units. The EAD-PCR method helps reduce the number of live sentinel animals used in pathogen monitoring, in order to better maintain the "3Rs" principle of laboratory animal welfare.

Evaluation of the radiation shielding effect of the novel self-shielding radiotherapy system Zap-X / 中国辐射卫生

Objective Based on the measurement of the ambient dose equivalent rate of points around the novel self-shielding Zap-X radiotherapy system, its self-shielding effect was evaluated and analyzed, and suggestions were proposed for the revision and improvement of related standards in China. Methods The ambient dose equivalent rates were measured at 15 points around the Zap-X system under 6 system operating conditions. The radiation shielding effect of the Zap-X system was evaluated according to the domestic and international radiation protection standards of radiotherapy equipment. Results Measurement of ambient dose equivalent rate and dose evaluation showed that the shielding effect of the Zap-X system met the requirements of international standards, but the dose rates at some points failed to satisfy the reference control levels in the domestic standards. Conclusion Without the shielded treatment room, the self-shielding effect of the Zap-X radiotherapy system is insufficient to meet the requirements of domestic standards for radiation safety and protection. The system should be operated in the treatment room to meet domestic standards.

Establishment of Fluorescence qPCR Method for Detection of Staphylococcus Aureus and Its Application in Feces Detection of Rats and Mice / 实验动物与比较医学

ObjectiveTo establish a method for rapid and sensitive detection of Staphylococcus aureus. MethodsThe specific gene nuc of Staphylococcus aureus was selected as the target gene. A pair of specific primers and a TaqMan probe were designed and synthesized according to the published sequence of the nuc gene. Establish a nucleic acid detection method for nuc gene using fluorescence quantitative PCR technology, and apply it clinically in the detection of fecal samples from rats and mice. ResultsThe DNA extracted from Staphylococcus aureus and other non-Staphylococcus aureus strains was detected by qPCR. The results showed that Staphylococcus aureus had a specific amplification curve, while other non-Staphylococcus aureus did not, indicating that the designed primers and probes were specific for Staphylococcus aureus. The sensitivity of this method was determined by diluting the DNA of Staphylococcus aureus by 10 times. The results showed that the detection limit of this method was 10 fg DNA, which was 2 orders of magnitude higher than that of ordinary PCR method. A total of 91 clinical samples were detected in this study, of which 4 rat samples from the same facility had a typical S-curve. The PCR products were sequenced and BLAST compared. The gene sequence of this sample was 100% similar to that of Staphylococcus aureus, indicating that the sample was positive for the nucleic acid of Staphylococcus aureus nuc gene, with a positive rate of 4.40%. The result was consistent with that obtained by bacterial culture method. The nucleic acid extraction adopted a full-automatic nucleic acid purification instrument, and the time required from nucleic acid extraction to detection result determination was less than 1.5 h. ConclusionThe qPCR method established in this study to identify Staphylococcus aureus with nuc gene as the target gene has the advantages of fast, high sensitivity and specificity, and can be used for the detection of Staphylococcus aureus in feces of rats and mice.

Research progress in mahjong epilepsy / 中国基层医药

Reflex epilepsy is a type of partial or generalized seizure induced by specific or nonspecific stimulation in individuals without a prior history of seizures. Mahjong epilepsy is a special form of complex reflex epilepsy induced by playing or watching mahjong, with a low incidence rate and complex pathogenesis. Due to the lack of comprehensive understanding, clinical studies of mahjong epilepsy are still mainly based on case reports. Now, we will analyze and summarize the etiology, pathogenesis, clinical diagnosis, electroencephalogram, treatment, and prognosis of mahjong epilepsy to raise awareness of mahjong epilepsy among clinical medical workers.

Screening of cell-virus, cell-cell, gene-gene interactions among kingdoms of life at single cell resolution

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) issued a significant and urgent threat to global health. The exact animal origin of SARS-CoV-2 remains obscure and understanding its host range is vital for preventing interspecies transmission. Previously, we have assessed the target cell profiles of SARS-CoV-2 in pets, livestock, poultry and wild animals. Herein, we expand this investigation to a wider range of animal species and viruses to provide a comprehensive source for large-scale screening of potential virus hosts. Single cell atlas for several mammalian species (alpaca, hamster, hedgehog, chinchilla etc.), as well as comparative atlas for lung, brain and peripheral blood mononuclear cells (PBMC) for various lineages of animals were constructed, from which we systemically analyzed the virus entry factors for 113 viruses over 20 species from mammalians, birds, reptiles, amphibians and invertebrates. Conserved cellular connectomes and regulomes were also identified, revealing the fundamental cell-cell and gene-gene cross-talks between these species. Overall, our study could help identify the potential host range and tissue tropism of SARS-CoV-2 and a diverse set of viruses and reveal the host-virus co-evolution footprints.

Role of talin in activation of astrocytes in spinal cord of rats with diabetic neuropathic pain / 中华麻醉学杂志

Objective To evaluate the role of talin in activation of astrocytes in the spinal cord of rats with diabetic neuropathic pain (DNP).Methods Twenty-four clean-grade healthy male SpragueDawley rats,aged 2-3 months,weighing 180-200 g,were assigned into 3 groups (n =8 each) using a random number table:control group (group C),group DNP and siRNA group (group siR).Rat DNP model was established by injecting streptozotocin (STZ).Group siR received intraspinal injection of siRNA silence stalin at 3 days before injecting STZ,and the equal volume of blank plasmid was given instead in C and DNP groups.The mechanical paw withdrawal threshold (MWT) was measured at 29-35 days after injection of STZ,the rats were then sacrificed and the lumbar spinal cords were removed for determination of the expression of integrin β1 (by Western blot),activation of astrocytes (by immunofluorescence) and contents of tumor necrosis factor-alpha (TNF-α) and interleukin-1 (IL-1) (using enzyme-linked immunosorbent assay).Results Compared with group C,the MWT was significantly decreased at each time point after surgery,the expression of integrin β1 was up-regulated,and the rate of activated astrocytes and contents of TNF-α and IL-1 were increased in group DNP (P＜0.05).Compared with group DNP,the MWT was significantly increased at each time point after surgery,the expression of integrin β1 was downregulated,and the rate of activated astrocytes and contents of TNF-α and IL-1 were decreased in group siR (P＜0.05).Conclusion Talin is involved in activation of astrocytes in the spinal cord of rats with DNP.

Establishment of a TaqMan probe real-time quantitative PCRfor detection of rat Theiler's-like virus / 中国实验动物学报

Objective To establish an accurate TaqMan probe real-time quantitative PCR (qPCR)method for detection of Theiler''s-like virus of rats (TLV).Methods Primers and TaqMan probes specific to 3622~3729 nt region were designed according to the whole genomic sequence of TLV representative strain.Using a synthesized plasmid as DNA standard template, the stability, specificity, and sensitivity of the qPCR method were determined.Results In the standard curve, R2 value was 0.99 with a high specificity.The sensitivity of the real-time PCR was less than 10 copies/μL, which was 100 times higher than the ordinary PCR method.No cross reactions appeared to the other rat viruses.Conclusions The TaqMan probe qPCR method established in this study has advantages such as simple to use, high sensitivity and specificity.

Effects of different depths of anesthesia on postoperativecognitive dysfunction:a meta-analysis / 实用医学杂志

Objective To investigate the effects of different depths of anesthesia on incidence of postopera-tive cognitive dysfunction (POCD). Methods We systematically retrievedPubmed,OVID,CNKI,CBM and Wanfang database and VIP database for randomized controlled trials(RCTs)from inceptionto December 312016, comparing different depths of anesthesia for their impacts on incidence of early POCD. After data extraction and quality evaluation,Revman 5.3 software was used for statistical data analysis. Results A total of 714 patients in 8 eligible RCTs were identified. Results of meta-analysis were as follows.(1)Incidence of POCD of depth anesthesia (NTS=E0-E1)was lower than general anesthesia(NTS=D0-D1)1 d after surgery(OR=0.21,95%CI 0.13~0.35,P < 0.00001).(2)Incidence of POCD of depth anesthesia(NTS = E1)was lower than general anesthesia (NTS=D0)7 d after surgery(OR=0.45,95%CI 0.23~0.91,P=0.03).(3)Incidence of POCD of NTS=E1 was lower than NTS=D07d after surgery(OR=0.42,95%CI 0.24~0.71,P=0.001). Conclusion Comparedwith general anesthesia,depth anesthesia is associated with a lower incidence of early POCD.

Effects of different depths of anesthesia on postoperativecognitive dysfunction:a meta-analysis / 实用医学杂志

Objective To investigate the effects of different depths of anesthesia on incidence of postopera-tive cognitive dysfunction (POCD). Methods We systematically retrievedPubmed,OVID,CNKI,CBM and Wanfang database and VIP database for randomized controlled trials(RCTs)from inceptionto December 312016, comparing different depths of anesthesia for their impacts on incidence of early POCD. After data extraction and quality evaluation,Revman 5.3 software was used for statistical data analysis. Results A total of 714 patients in 8 eligible RCTs were identified. Results of meta-analysis were as follows.(1)Incidence of POCD of depth anesthesia (NTS=E0-E1)was lower than general anesthesia(NTS=D0-D1)1 d after surgery(OR=0.21,95%CI 0.13~0.35,P < 0.00001).(2)Incidence of POCD of depth anesthesia(NTS = E1)was lower than general anesthesia (NTS=D0)7 d after surgery(OR=0.45,95%CI 0.23~0.91,P=0.03).(3)Incidence of POCD of NTS=E1 was lower than NTS=D07d after surgery(OR=0.42,95%CI 0.24~0.71,P=0.001). Conclusion Comparedwith general anesthesia,depth anesthesia is associated with a lower incidence of early POCD.

Analysis of laboratory animal pathogen infection indexes in Shanghai area / 中国实验动物学报

Objective To more intuitively understand the quality control for laboratory animals and further achie-ving a more scientific and reasonable management of laboratory animals, the infection index as evaluation criteria was intro-duced. Then the best way to calculate infection index was explored in order to more scientifically reflect the infection status of laboratory animals. Methods Infection index, also called the degree of infection, is a qualitative indicator of monito-ring laboratory animal quality. After arranging, analyzing, processing and gathering the data from laboratory animal quality monitoring, the index reflects synthetically the pathogen infection status or trend of a particularly investigated experimental animal population or the development of certain experimental animals. Results In general, the pathogen infection index of mice was slightly decreased, while the pathogen infection index of rats roughly increased year by year. In comparing infec-tion index by different pathogens, the parasite infection index of mice was found to be higher than bacteria and virus infec-tion indexes, while the bacteria infection index of rats was higher than parasite infection index and virus ones. Conclusions The infection index model intuitively reflects the quality control status of laboratory animals. The analysis also reveals that the parasite monitoring of the mice and the bacteria detection of rat needs to be reinforcement. In addition, the index of infection reveals that the pathogen infection of mice is well under control, while that of rats tends to be more serious year by year.

Preliminary observation on the interference effect of Helicobacter hepaticus infection on the immune response in BALB/c mice / 中国实验动物学报

Objective To determine the interference effect of H. hepaticus infection on the functional characteris-tics of dendritic cell ( DC) surface molecules and immune response in mice. Methods Male BALB/c mice were inocula-ted with H. hepaticus (ATCC 51450). Murine bone marrow-derived dendritic cells (DC) were isolated and co-cultured which were stimulated by GM-CSF and IL-4 at the fifth month after the last inoculation. Then the DCs were subjected to FACS analysis for surface markers (CD11c, CD40, CD80 and MHCII) detection. On this basis, virus suspension of New-castle disease virus( NDV) ZJ1 strain was inoculated into the mice. Serum was collected for detection of the NDV antibody titer in serum weekly to explore the difference of antibody titer between the two groups. Results The expression rates of CD40 and MHCII on the mouse DCs in experimental group were higher than that in the control group. The NDV antibody ti-ter of experimental group was slightly lower than that in the control group in the first week. During the 2nd to 5th weeks, the titer was higher than that in the control group, with a very significant difference. In the 6th week, the titer of both the two groups tended to fall. Conclusions H. hepaticus infection can promote bone marrow DC maturation in mice, stimulate the expression rates of MHC II and CD40, and enhance the NDV antibody levels.

Comparison of culture and PCR assays for detection of bacteria in laboratory rats and mice / 中国比较医学杂志

Objective To compare the efficiency of bacteria culture and PCR assays for detection of Staphylococcus aureus ( S.aureus) , Pseudomonas aeruginosa ( P.aeruginosa) and Klebsiella pneumoniae ( K.pneumoniae) in laboratory rats and mice.Methods Bacteria culture combined with biochemical identification and PCR assay were used to detect 78 SPF rats and 422 SPF mice and the results of the two methods were compared .Results All the 78 rats were negative .Of the 422 mice, the positive rate by culture was 7.11%(30/422), of which, 10 were S.aureus, 22 were P.aeruginosa, and 2 were K.pneumoniae.The positive rate by PCR was 7.58%(32/422), of which, 10 were S.aureus, 25 were P. aeruginosa, and 2 were K.pneumoniae.Conclusions The high sensitivity , rapid procedure and easy to operate of PCR assay makes it valuable for rapid bacteria diagnosis and large-scale screening in laboratory animals .

Correlation of personality characteristics and quality-of-life in patients with chronic urticaria / 中华全科医师杂志

WHO quality-of-life scales (WHOQOL-BREF) and Eysenck personality questionnaire (EPQ) were used for evaluating the quality-of-life and personality characteristics of 60 outpatients with chronic urticaria.According to statistical correlation analysis, a positive correlation existed between education level and psychological field (P ＜ 0.05).And there were negative correlations between N scale, P scale and psychological field (P ＜ 0.05, P ＜ 0.01).The incidence and incurability of chronic urticaria was more correlated with anxiety and depression.The patients with chronic urticaria were more likely to have a worse quality-of-life than normal population.

Detection and isolation of murine norovirus in laboratory mice in Shanghai area / 中国实验动物学报

Objective To investigate the natural infection status of murine norovirus ( MNV) in laboratory mice in Shanghai area and isolate MNV from mouse cecal feces .Methods To collect cecal contents and serum samples from 319 specific pathogen-free ( SPF) mice coming from different research institutions .Reverse transcription-polymerase chain reaction ( RT-PCR) and enzyme linked immunosorbent assay ( ELISA) were used to detect MNV infection in the mice , re-spectively.The positive stool samples were diluted and filtered through 0.22 μm membrane, inoculated into RAW 264.7 cells, and then identified by RT-PCR.Results There were 95 positive results in the 319 cecal samples by RT-PCR, and the positive rate was 29.78%.Among 180 serum samples which were tested by RT-PCR, 70 samples were positive by ELISA, and the positive rate was 38.89%.The infected RAW 264.7 cells showed cytopathic effect ( CPE) within 72 h. After 3 times of freezing and thawing , RT-PCR obtained a 187 bp band.Conclusions The results from the present study show that there is a high natural infection rate of MNV in laboratory mice in Shanghai area , and the strict breeding manage-ment must be strengthened .

New generation aurora electromagnetic tracking system in the medical surgical navigation / 中国医疗器械杂志

Through a range of clinical applications of the new generation Aurora electromagnetic tracking system, it's performance and the significance in the medical surgical navigation are introduced. Its advantages and the development direction for clinical work are described that it can provide a newer, broader application space, enhance the accuracy and controllability of surgical navigation.

Self-focusing length in highly multimode ultra-large-mode-area fibers.

Recent theoretical researches reveal that the self-focusing critical power in the fiber waveguide is identical to that in the bulk medium. However, the delivery of peak power much higher than the self-focusing critical power has been demonstrated experimentally in ultra-large-mode-area fiber (ULMAF). And no experimental observation of self-focusing effect has been reported in recent pulsed fiber laser system whose peak power has reached or even exceeded the critical power. In this paper, we try to address this issue by studying the self-focusing length theoretically in the ULMAF which is highly multimode. Nonlinear beam propagation method employing PÁDE(2,2) approximation is applied in the numerical simulation. The results show that the self-focusing length of the fundamental mode is typically a few millimeters which is almost identical to that in the bulk medium. However, the self-focusing length of the summation of numerous modes can be as long as a few meters.