BACKGROUND:Muscle weakness is a common symptom after coronavirus disease 2019(COVID-19)infection and affects the ability to perform daily activities in humans during recovery.Low-frequency pulsed magnetic field stimulation at a strength of 1.5 mT and a frequency of 3 300 Hz can enhance the maximal voluntary contraction and strength endurance of human skeletal muscle by inducing and activating classical transient receptor potential channel 1(TRPC1),which produces a series of pathological support effects on muscle tissue.It has not been studied whether this means will improve muscle weakness in patients recovering from COVID-19. OBJECTIVE:To select the low-frequency pulsed magnetic field for magnetic stimulation of lower limb muscle groups in patients with COVID-19,in order to observe the effect of this stimulation on the improvement of muscle weakness of lower limb muscle groups in patients with COVID-19 during the recovery period. METHODS:Fourteen patients infected with COVID-19(Omicron strain)positive for Innovita COVID-19 Ab Test(Colloidal Gold)and accompanied by muscle weakness were recruited and randomly divided into two groups:a test group receiving magnetic field stimulation and a control group receiving sham treatment,respectively.The total duration of the trial was 3 weeks.The test group was given low-frequency pulsed magnetic stimulation of the lower limbs every 48 hours and the control group was given the same intervention procedure as the test group but with sham stimulation.Patients in both groups were not informed whether the magnetic stimulation apparatus was running or not.Nine sessions were performed in both groups and the changes in the maximum voluntary contraction,explosive leg force and strength endurance of the local muscle groups of the lower limbs were subsequently observed in both groups. RESULTS AND CONCLUSION:Among the eight local muscle groups collected,seven local muscle groups in the test group showed an increase in the maximum voluntary contraction value after 3 weeks of low-frequency pulsed magnetic field stimulation.In the control group,there were only three muscle groups with improvement in the maximum voluntary contraction.The rate of improvement in the anterior and posterior muscle groups of the left leg in the test group was significantly higher than that in the control group.The longitudinal jump height and peak angular velocity of the knee joint in both groups were improved compared with the pre-test measurement,and the elevation rate of jumping height in the test group was higher than that in the control group.Under the fatigue condition,the decline rates of peak angular velocity of the knee joint and jumping height in the test group decreased significantly,while those in the control group did not change significantly.The above data confirmed that the low-frequency pulsed magnetic field stimulation with the intensity of 1.5 mT and frequency of 3 300 Hz could improve the muscle strength of more local muscle groups in the lower limbs of patients with COVID-19 during the recovery period compared with the human self-healing process,and the whole-body coordination ability and functional status based on explosive leg force of the legs could be significantly improved.Therefore,low-frequency pulsed magnetic field stimulation can be used as an effective,non-exercise rehabilitation tool to improve muscle weakness in the lower limbs of patients with COVID-19.

Objective:To investigate the prevalence and characteristics of mcr genes in clinical isolates of Aeromonas spp. in our hospital, and provide reference for clinical analysis of the prevalence and expression of colistin resistance genes. Methods:Polymerase chain reaction (PCR) was used to detect mcr genes in 183 Aeromonas spp. strains. The minimum inhibitory concentrations (MICs) of colistin and polymyxin against mcr-positive Aeromonas spp. were detected by micro broth dilution method. Broth conjugation and filter mating conjugation were performed. Whole genome sequencing was used to analyze the genetic environment of mcr-3 gene in Aeromonas spp.. A recombinant Escherichia coli ( E. coli) DH5α-pGEM-T: : p mcr-3 strain was constructed to verify the expression of mcr-3 gene. Results:The positive rate of mcr-3 gene in 183 strains of Aeromonas spp. was 2.19% (4/183). No mcr-1 or mcr-2 gene was detected among these isolates. Antimicrobial susceptibility test showed that four mcr-3-carrying Aeromonas hydrophilia ( A. hydrophilia) strains were sensitive to colistin and polymyxin (MIC<2 μg/ml). Conjugation experiments indicated that mcr-3 gene could not be transferred between strains. Whole-genome sequencing analysis suggested that the mcr-3 genes carried by the A. hydrophilia isolates belonged to mcr-3.2 and mcr-3-like variants, and no adjacent transfer element was detected upstream and downstream. The recombinant E. coli DH5α-pGEM-T: : p mcr-3 strain was sensitive to colistin (MIC=2 μg/ml). Conclusions:The clinical isolates of A. hydrophilia in our hospital carried mcr-3 gene, but does not exhibit colistin resistance, and no evidence supported the transfer of mcr-3 gene for the time being.

Objective To evaluate the effect of pulsed radiofrequency (PRF) on spinal adenosine triphosphate (ATP)-P2X4-NLRP3 signaling pathway in rats with neuropathic pain.Methods Forty healthy clean-grade adult male Sprague-Dawley rats,aged 2-3 months,weighing 220-260 g,were divided into 4 groups (n =10 each) using a random number table method:sham operation group (group S),neuropathic pain group (group NP),sham PRF group (group SPRF) and PRF group.Neuropathic pain was induced by chronic constriction injury to the left sciatic nerve of anesthetized rats.Rats received PRF treatment on 7th day after establishing the model in group PRF.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured before establishing the model (T0) and at 3,7,10,14,21 and 28 days after establishing the model (T1-6).The rats were then sacrificed and the spinal cord was removed for determination of P2X4 and NLRP3 expression (by Western blot) and interleukin-1beta (IL-1β),IL-2,IL-6 and tumor necrosis factor-alpha (TNF-α) contents (by enzymelinked immunosorbent assay).Results Compared with group S,the MWT and TWL were significantly decreased at T1-6,the expression of P2X4 and NLRP3 was up-regulated,and the contents of IL-1β,IL-2,IL-6 and TNF-α were increased in NP,SPRF and PRF groups (P＜0.05).Compared with group NP and group SPRF,the MWT and MWT were significantly increased at T3-6,the expression of P2X4 and NLRP3 was down-regulated,and the contents of IL-1 β,IL-2,IL-6 and TNF-α were decreased in group PRF (P＜0.05).Conclusion The mechanism by which PRF alleviates neuropathic pain is related to inhibiting ATP-P2X4-NLRP3 signaling pathway in rats.

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in remote ischemic preconditioning-induced reduction of lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.Methods Sixty-eight healthy male C57BL/6 mice,aged 6-8 weeks,weighing 22-26 g,were divided into 4 groups (n =17 each) using a random number table:control group (group C),ALI group,remote ischemic preconditioning group (group RIPC) and brusatol plus remote ischemic preconditioning group (group B+RIPC).Normal saline 100 μl was intratracheally instilled in group C.ALI was induced by intratracheal instillation of LPS 5 mg/kg in group ALI.Mice in group RIPC were subjected to 6 cycles of 5-min ischemia followed by 5-min reperfusion in the right hindlimbs using a tourniquet,and 1 h later the model of ALI was established.Nrf2 inhibitor brusatol 2 mg/kg (in 100 μl of 1％ dimethyl sulfoxide) was intraperitoneally injected every other day for 10 days prior to establishment of the ALI model in group B.Brusatol 2 mg/kg was intraperitoneally injected every other day for 10 days prior to establishment of the ALI model,and remote ischemic preconditioning was performed at 1 h before establishment of the ALI model in group B+RIPC.Seven mice in each group were selected at 24 h after establishment of the ALI model,and bronchoalveolar lavage fluid (BALF) was collected for determination of protein concentrations and neutrophil count.Mice were then sacrificed and lungs were removed for determination of lung water content,myeloperoxidase (MPO) activity,contents of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α),and expression of Nrf2,HO-1 and high-mobility group box 1 protein (HMGB1) in lung tissues (by Western blot) and for examination of pathological changes (with a light microscope).Results Compared with group C,the lung water content,MPO activity,contents of IL-1β and TNF-α,and neutrophil count and protein concentrations in BALF were significantly increased,and the expression of Nrf2,HO-1 and HMGB1 was up-regulated in group ALI (P＜ 0.05).Compared with group ALI,the lung water content,MPO activity,contents of IL-1β and TNF-α,and neutrophil count and protein concentrations in BALF were significantly decreased,the expression of Nrf2 and HO-1 was up-regulated,and the expression of HMGB1 was down-regulated (P＜0.05),and the pathological changes were significantly attenuated in group RIPC.Compared with group RIPC,the lung water content,MPO activity,contents of IL-1β and TNF-α,and neutrophil count and protein concentrations in BALF were significantly increased,the expression of Nrf2 and HO-1 was down-regulated,and the expression of HMGB1 was up-regulated (P＜0.05),and the pathological changes were aggravated in group B+RIPC.Conclusion The activation of Nrf2/HO-1 signaling pathway is involved in remote ischemic preconditioning-induced reduction of LPS-induced ALI in mice.

Objective To investigate the effect of construction-process-result three-dimensional quality assessment mode in continuing nursing to patients with liver cirrhosis after endoscopic variceal ligation (EVL). Methods Toally 100 patients with liver cirrhosis after EVL hospitalized in the hospital between January 2014 to December 2015, 50 patients among them during January to December 2014 were set as the control group, the other 50 ones during January to December 2015 as the experiment group. The control group only received routine instruction at discharge and those in the experiment group were treated with continuing nursing based on construction-process-result three-dimensional quality assessment mode. Both groups were followed up for six months after discharge and then compared in terms of medication and diet compliance and re-bleeding rate. Result The patients in the experiment group were significantly better than those in the control group (P<0.05) in the medication and diet compliance. Conclusions The construction-process-result three-dimensional quality assessment mode can improve the quality of continuing nursing for the patients with liver cirrhosis after EVL. It can enhance the medication.

Objective To summarize the effect of eye socket reconstruction in patients with severe depressed eye socket combined anophthalmos and to assess the methods of eye socket reconstruction.Methods Forty patients of severe depressed eye socket combined anophthahnos,from Oct,2001 to Mar,2014,underwent eye socket reconstruction in Beijing Tongren Hospital.Thirty four eye sockets were reconstructed with free flap,the scapular flap in 2 cases,the forearm flap in 17 cases,the lateral arm flap in 15 cases.The reversed submental island flap was utilized in 2 patients.The other 4 cases were treated by implant-retained orbital prosthesis.Results All the patients were followed up for more than 2 years.The flaps survived.The artificial eye could be fitted satisfactorily and the appearance of the ill eye socket was improved significantly.The implant-bodies in orbital bone and the prosthesis were stable without peri-implantitis.Conclusions The flap transfer is effective for eye socket reconstruction in patient with severe depressed eye socket combined anophthalmos.The implant-retained orbital prosthesis is also alternative.The treatment choice must be based on the patient 's own conditions.

Objective To evaluate the effect of dexmedetomidine on acute lung injury induced by scalds in rats.Methods Seventy-five male Sprague-Dawley rats,weighing 200-220 g,were randomly divided into 5 groups (n =15 each) using a random number table:control group (group C),scald group (group S),dexmedetomidine group (group D),α-bungarotoxin (α-BGT) group,and dexmedetomidine+ α-BGT group (group D+α-BGT).About 30％ of the total body surface was shaved and then exposed to 98 ℃ water for 12 s in S,D,α-BGT and D+α-BGT groups.The back of rats was exposed to 37 ℃ water for 12 s in group C.Rats were resuscitated with lactated Ringer's solution injected intraperitoneally according to Parkland formula within 24 h after establishment of the model.In D,α-BGT,and D+α-BGT groups,dexrnedetomidine 40 μg/kg,α7 nicotinic acetylcholine receptor antagonist α-BGT 1 μg/kg,and α-BGT 1 μg/kg plus dexmedetomidine 40 μg/kg were injected intraperitoneally,respectively,at 15 min before establishnent of the model.At 24 h after establishment of the model,the rats were sacrificed,and lungs were removed for examination of the pathological changes and for determination of myeloperoxidase (MPO) activity,in terleukin-1beta (IL-1β),tumor necrosis factor-alpha (TNF-α),and IL-6 contents (by enzyme-linked immunosorbent assay),and nucleoprotein factor kappa B (NF-κB) (by Western blot).The lung water content [(wet weight-dry weight)÷wet weight× 100％] was calculated.Results Compared with group C,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly increased,and the expression of NF-κB was up-regulated in S,α-BGT and D groups (P＜0.05).Compared with group S,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly decreased,and the expression of NF-κB was down-regulated in D and D+α-BGT groups (P＜0.05),and no significant change was found in the parameters mentioned above (P＞0.05),and the pathological changes were significantly attenuated in group α-BGT.Compared with group D,the lung water content,MPO activities,and contents of IL-1β,TNF-α and IL-6 were significantly increased,the expression of NF-κB was up-regulated (P＜0.05),and the pathological changes were aggravated in group D + α-BGT.Conclusion Dexmedetomidine can mitigate scalds-induced acute lung injury in rats.

Objective To evaluate the role of α7 nicotinic acetylcholine receptor (α7nAChR) in reduction of endotoxin-induced acute lung injury (ALI) by limb ischemic preconditioning in mice.Methods Eighty healthy male C57BL/6 mice,aged 8-10 weeks,weighing 22-26 g,were randomly divided into 5 groups (n =16 each) using a random number table:control group (group C),ALI group,limb ischemic preconditioning group (group P),α-bungarotoxin (α-BGT) group,and limb ischemic preconditioning +α-BGT group (group P+α-BGT).Normal saline 100 μl was intratracheally instilled in group C.In group ALI,lipopolysaccharide 5 mg/kg was intratracheally instilled (in normal saline) to establish the model of endotoxin-induced ALI.In group P,the mice were subjected to 6 cycles of 5-min ischemia of the right hindlimb followed by 5-min reperfusion,and then the model of ALI was established.In group α-BGT,α-BGT 1 μg/kg was injected intraperitoneally before establishment of the model.In group P+α-BGT,limb ischemic preconditioning was performed,α-BGT 1 μg/kg was then injected intraperitoneally,and the model of ALI was established.At 24 h after LPS instillation,6 mice were selected from each group and sacrificed,and lungs were removed for microscopic examination and for determination of wet and dry lung weight,myeloperoxidase (MPO) activities,contents of interleukin-lbeta (IL-1β),tumor necrosis factoralpha (TNF-α) and IL-6,and expression of α7nAChR and high mobility group box-1 (HMGB1) in lung tissues.The lung water content was calculated.The survival of the left 10 mice in each group was observed at 7 days after establishment of the model,and the survival rate was calculated.Results Compared with group C,the lung water content,MPO activities,contents of IL-1β,TNF-α and IL-6,and HMGB1 expression were significantly increased,α7nAChR expression was significantly down-regulated,and the 7-day survival rate was significantly decreased in group ALI(P＜0.05).Compared with group ALI,the lung water content,MPO activities,contents of IL-1β,TNF-α and IL-6,and HMGB1 expression were significantly decreased,α7nAChR expression was significantly up-regulated,and the 7-day survival rate was significantly increased in group P (P＜0.05).Compared with group P,the lung water content,MPO activities,contents of IL-1β,TNF-α and IL-6,and HMGB1 expression were significantly increased,α7nAChR expression was significantly down-regulated,and the 7-day survival rate was significantly decreased in group P+α-BGT (P＜0.05).Conclusion The mechanism by which limb ischemic preconditioning inhibits inflammatory responses and reduces endotoxin-induced ALI is related to activation of α7nAChR in mice.

Objective To evaluate the deep brain venous blood oxygen content changes in patients with multiple sclerosis(MS) using susceptibility weighted imaging (SWI), and to explore the ability of SWI in reflecting the clinical condition. Methods Forty-four MS patients were prospectively enrolled in the study. All the clinical-proved patients meeting the McDonald standards (2005 revised) underwent conventional MRI, SWI, and 12 cases of them underwent MRI review from 12 to 16 months interval. all the patients' clinical condition were quantified according to the expanded disability status scale(EDSS). The score was 0.5—6.5. Sixty-five age- and gender- matched healthy volunteers underwent conventional MRI and SWI. The blood oxygen content of the deep brain venous were estimated by the veins phase value, and differential phase values of blood vessels and surrounding tissues (Δφ) were processed with SPIN software. The blood vessels consist of bilateral BV, SMCV, ICV, STV and FMV, PMV, OMV. The difference of Δφvalue in different veins between MS patients and the controls was compared using independent sample t-test, and the Δφ value comparison of MS patients in different time were performed by using paired t test; The correlation ofΔφvalue between MS and EDSS was analyzed using Spearman correlation. Results TheΔφvalue of BV, SMCV, ICV, STV were 856.6 ± 246.4, 600.6 ± 155.2, 965.9 ± 205.4, 844.2 ± 149.7 in MS, and 767.6±145.1, 536.2±123.5, 892.8±156.3, 783.1±148.5 in controls, respectively. TheΔφvalue was higher in MS patients than the controls (t=2.157, 2.303, 2.005, 2.103,P<0.05). The twelve patients'Δφvalues of BV, ICV,STV were 729.4±275.1, 906.1±219.2, 737.2±159.1 in the first time, and 923.2±211.6, 1017.3±211.1, 919.3 ± 165.9 in the second time, and all the values increased in the review of the interval of 12 to 16 months (t=-3.092,-6.420,-3.972,P<0.05). The phase value of PMV and OMV had significant positive correlation with EDSS scores(r=0.638, 0.642,P<0.01). Conclusions The state of hypoxia of the brain parenchyma appears in MS patients, and hypoxia may become worse with the extension of course. The extent of hypoxia can reflect the disability of the patients.

Objective To investigate jugular vein morphological changes with three dimension phase contrast magnetic resonance venography(3D PC MRV),and to explore hemodynamic features using MR phase contrast cine (MR PC cine).Methods Sixty-five healthy volunteers performed 3D PC MRV and MR PC-cine sannings.MRV ranged from torcular herophili to brachiocephalic veins, and the raw data of PC-cine was acquired at cervical 2-3(C2-C3)level perpendicular to the Jugular veins(JVs)with the maximum encoding velocity of 50 cm/sec.Jugular vein showing absent or tip shape(cross-sectional area less than 12.5 mm2 )was considered abnormal,and flat,crescent,oval,round shapes were considered normal.Data of PC-cine was processed by computer to evaluate the hemodynamic features.Results Nine (13.85%)of 65 cases were abnormal that unilateral jugular vein showing needle-pointed narrow or absent,and 8 cases on the left,and one case on the right;Weak correlation was found between jugular veins pattern and the age.The right sided values in volunteers were higher than that of the left side.Conclusion The morphology and hemodynamics of jugular veins in volunteers showed significant difference between sides,and weak correlation is found between the morphology and aging.