BACKGROUND:A large number of studies have investigated the effects of whole body vibration training at different frequencies on muscle strength,but less is reported on the differences in the efficacy of vibration training at different frequencies on patellar tendinopathy. OBJECTIVE:To explore the effect of eccentric training of quadriceps combined with different frequency of whole body vibration training on patellar tendinopathy. METHODS:From April to June 2022,48 patients with patellar tendinopathy were recruited from Wuhan Sports University and randomly divided into eccentric training group(n=12),30 Hz group(n=12),40 Hz group(n=12),and 50 Hz group(n=12).The eccentric training group only completed eccentric training of the quadriceps.The 30 Hz,40 Hz and 50 Hz groups performed the whole body vibration training with the amplitude of 2 mm and frequencies of 30 Hz,40 Hz and 50 Hz respectively on the basis of the eccentric training of the quadriceps.The intervention lasted for 8 weeks,three times a week.Before and after the intervention,the patients'surface electromyography signals of the quadriceps,kinematics and dynamics data of knee joint at the time of landing in deep jump and the time of peak vertical ground reaction,Visual Analogue Scale score,Victorian Institute of Sports Assessment-Patellar score were evaluated. RESULTS AND CONCLUSION:After 8 weeks of intervention,compared with the eccentric training group,the median frequency of the lateral and medial femoris muscles were significantly higher in the 40 Hz and 50 Hz groups(P＜0.05).At the time of landing,the knee joint flexion angle and external rotation moment in the 40 Hz and 50 Hz groups were significantly lower than those in the eccentric training group(P＜0.05),while the knee joint flexion angle in the 50 Hz group was significantly lower than that in the 30 Hz group(P＜0.05).At the peak moment of vertical ground reaction,the knee extension torque in the 40 Hz group was significantly lower than that in the eccectric training group(P＜0.05);the knee flexion angle and knee extension torque in the 50 Hz group were significantly lower than those in the eccentric training group(P＜0.05).The Visual Analogue Scale scores in the 50 Hz and 40 Hz groups were significantly lower than those in the eccentric training group(P＜0.05).The Victorian Institute of Sports Assessment-Patellar score in the 50 Hz group was significantly higher than that in the eccentric training group and 30 Hz group(P＜0.05).To conclude,eccentric training of the quadriceps combined with 50 Hz whole body vibration training can significantly improve quadriceps'strength,endurance and activation rate of the vastus lateralis muscle,reduce the pain of knee joint,and improve the function of the knee joint in patients with patellar tendinopathy.

BACKGROUND:At present,postoperative timing or subjective criteria by clinicians are commonly employed to determine the return-to-sport timing for patients undergoing anterior cruciate ligament reconstruction.Unfortunately,these criteria do not adequately consider the biomechanical deficits in patients following anterior cruciate ligament reconstruction. OBJECTIVE:To explore the lower extremity kinematic and kinetic characteristics of athletes after anterior cruciate ligament reconstruction during bilateral vertical jumping. METHODS:Twenty athletes undergoing anterior cruciate ligament reconstruction and twenty healthy athletes,aged 20-24 years,were recruited in Wuhan Sports University from December 2021 to December 2022.All the 40 subjects underwent a bilateral vertical jumping test.The kinematic and dynamic characteristics of the lower limbs at propulsion phase,initial landing time and peak vertical ground reaction force moment. RESULTS AND CONCLUSION:At the initial landing time,the athletes undergoing anterior cruciate ligament reconstruction showed higher hip flexion angle(P=0.031)and lower ankle plantar flexion angle(P=0.018)on the operated side compared with the healthy athletes.At the peak vertical ground reaction force moment,the athletes undergoing anterior cruciate ligament reconstruction had higher hip flexion angle(P=0.016),lower hip abduction angle(P=0.019),lower knee flexion angle(P=0.025),higher knee external rotation angle(P=0.030),and higher ankle external rotation angle(P=0.042)on the operated side compared with the healthy athletes.At the peak vertical ground reaction force moment,the athletes undergoing anterior cruciate ligament reconstruction showed lower knee extension moment(P=0.036),lower knee internal rotation moment(P=0.016),lower hip abduction moment(P=0.004),higher hip extension moment(P=0.040),and higher hip external rotation moment(P=0.005)on the operated side compared with the healthy athletes.To conclude,the athletes undergoing anterior cruciate ligament reconstruction exhibit a stiff landing pattern,in which the knee load on the operated side tends to shift to the hip joint,and show inadequate control of lower limb rotational stability.Therefore,detection and correction of abnormal biomechanical characteristics should be part of the rehabilitation after anterior cruciate ligament reconstruction.

BACKGROUND:Chlorfenapyr is used to kill insects that are resistant to organophosphorus insecticides.Chlorfenapyr poisoning has a high mortality rate and is difficult to treat.This article aims to review the mechanisms,clinical presentations,and treatment strategies for chlorfenapyr poisoning. DATA RESOURCES:We conducted a review of the literature using PubMed,Web of Science,and SpringerLink from their beginnings to the end of October 2023.The inclusion criteria were systematic reviews,clinical guidelines,retrospective studies,and case reports on chlorfenapyr poisoning that focused on its mechanisms,clinical presentations,and treatment strategies.The references in the included studies were also examined to identify additional sources. RESULTS:We included 57 studies in this review.Chlorfenapyr can be degraded into tralopyril,which is more toxic and reduces energy production by inhibiting the conversion of adenosine diphosphate to adenosine triphosphate.High fever and altered mental status are characteristic clinical presentations of chlorfenapyr poisoning.Once it occurs,respiratory failure occurs immediately,ultimately leading to cardiac arrest and death.Chlorfenapyr poisoning is difficult to treat,and there is no specific antidote. CONCLUSION:Chlorfenapyr is a new pyrrole pesticide.Although it has been identified as a moderately toxic pesticide by the World Health Organization(WHO),the mortality rate of poisoned patients is extremely high.There is no specific antidote for chlorfenapyr poisoning.Therefore,based on the literature review,future efforts to explore rapid and effective detoxification methods,reconstitute intracellular oxidative phosphorylation couplings,identify early biomarkers of chlorfenapyr poisoning,and block the conversion of chlorfenapyr to tralopyril may be helpful for emergency physicians in the diagnosis and treatment of this disease.

Objective To study the effect of Hedysarum polysaccharides(HPS)on the expression of transforming growth factor-β,(TGF-β1),smad homologue 3 recombinant protein(smad3)and smad7 in renal tissue of db/db mice with diabetic nephropathy(DN).Methods According to their body weight,6-week-old male db/db mice were randomly divided into 5 groups:model group(0.9％NaCl 0.2 mL·d-1),positive control group(22.75 mg·kg-1·d-1 irbesartan)and experimental-H,-M,-L groups(200,100,50 mg kg-1·d-1 HPS),with 10 mice in each group;another 10 SPF grade male C57BL/6 mice of the same week were selected as normal group(0.9％NaCl 0.2mL·d-1).The mice in the 6 groups were given intragastric administration once a day for 12 weeks.The blood glucose concentration of mice was measured before treatment and at the 4th,8th and 12th week after treatment.The expression levels of TGF-β1,smad3 and smad7 were detected by Western blotting.Results After treatment,the blood glucose levels of the model group was significantly higher than those of the normal group(all P＜0.01);compared with the model group,the levels of blood glucose in the experimental-H,-M groups decreased significantly,and the differences were statistically significant(P＜0.05,P＜0.01).The relative expression levels of TGF-β,protein in normal group,model group,positive control group and experimental-H,-M groups were 0.71±0.16,1.66±0.18,1.00±0.17,0.88±0.15 and 1.23±0.15;the relative expression levels of smad3 protein were 0.89±0.32,2.26±0.35,1.24±0.31,1.05±0.30 and 1.67±0.35;the relative expression levels of smad7 protein were 1.66±0.03,0.60±0.03,1.10±0.07,1.48±0.08 and 0.97±0.09;there were statistically significant differences between the experimental-H,-M groups and the model group(P＜0.05,P＜0.01).Conclusion Hedysarum polysaccharides can improve renal fibrosis and delay the development of diabetic nephropathy by regulating the level of blood glucose,inhibiting TGF-β1,smad3 and increasing the expression of smad7.

Objective This study aimed to compare the current Essen rabies post-exposure immunization schedule(0-3-7-14-28)in China and the simple 4-dose schedule(0-3-7-14)newly recommended by the World Health Organization in terms of their safety,efficacy,and protection. Methods Mice were vaccinated according to different immunization schedules,and blood was collected for detection of rabies virus neutralizing antibodies(RVNAs)on days 14,21,28,35,and 120 after the first immunization.Additionally,different groups of mice were injected with lethal doses of the CVS-11 virus on day 0,subjected to different rabies immunization schedules,and assessed for morbidity and death status.In a clinical trial,185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule,and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day(P<0.05).The groups 0-3-7-14,0-3-7-21,and 0-3-7-28 showed no statistically significant difference(P>0.05)in RVNAs levels at any time point.The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%,whereas that in the immunization groups was 40%.In the clinical trial,the RVNAs positive conversion rates on days 28(14 days after 4 doses)and 42(14 days after 5 doses)were both 100%,and no significant difference in RVNAs levels was observed(P>0.05). Conclusion The simple 4-dose schedule can produce sufficient RVNAs levels,with no significant effect of a delayed fourth vaccine dose(14-28 d)on the immunization potential.

We reported a 32 years female patient in whom lung metastasis from breast cancer was presented as solitary pulmonary pure ground-glass opacity (GGO) lesion. The patient received rational preoperative examinations and surgery though the preoperative diagnosis was not accurate. Because of different therapy strategies and purposes, it is crucial to make distinction of atypical metastases from primary cancers. Thus, for patients with a history of malignancy, possible metastasis should be taken into consideration if new GGO was found on the CT. Besides this, the follow-up interval of CT should be shortened appropriately, preoperative examinations and surgical procedures should be made according to the suggestions of multidisciplinary team.

ObjectiveTo simulate the microstructure and mechanical properties of tendon tissue and promote its regeneration and repair, electrospinning technology was used to prepare L-polylactic acid (PLLA) fiber membranes loaded with different nano zinc oxide contents and with oriented structures. Physical and chemical characterization and biological performance evaluation were carried out to explore their effects on tendon cell proliferation and differentiation. MethodsPreparation of PLLA fiber scaffolds and PLLA/ZnO fiber scaffolds containing different mass fractions of nano ZnO was performed using electrospinning technology. The physicochemical properties of the scaffold were characterized by scanning electron microscopy, mechanical stretching, and EDS spectroscopy. The scaffold was co-cultured with mouse tendon cells to detect its biocompatibility and regulatory effects on cell differentiation behavior. ResultsThe fiber scaffolds were arranged in an oriented manner, and zinc elements were uniformly distributed in the fibers. The tensile strength and Young’s modulus of PLLA/0.1%ZnO fiber scaffolds were significantly higher than PLLA fiber scaffolds. The number of cells on the surface of PLLA/0.1%ZnO fiber scaffold was significantly higher than that of the PLLA group, and the activity was better; mouse tendon cells exhibit directional adhesion and growth along the fiber arrangement direction. ConclusionThe oriented PLLA/0.1%ZnO fiber scaffold had excellent physicochemical properties, which can significantly promote the oriented growth, proliferation and differentiation of tendon cells. It is expected to be used for tendon tissue regeneration and repair in the future.

Objective To compare the biomechanical properties of new type of unicortical and unilateral external fixators by finite element analysis.Methods Firstly,a tibia model was reconstructed based on the CT data images using Mimics software,and then processed and modified by Geomagic Wrap software.Secondly,Solidworks software was used to establish the 3D models for new type of unicortical and unilateral external fixators,and fracture defect was made in the tibia model and then the model was assembled with the external fixators.Finally,mesh delineation was performed using ABAQUS software,and axial compression,torsion and bending loads were applied to the assemblies,respectively,to observe the stress distributions and fracture displacements and to evaluate the biomechanical properties of the 2 types of external fixators.Results The new type of unicortical external fixator had the mean and maximum stresses at the nail-bone interface and the stress distribution at the pin-bone contact surface lower than those of the unilateral external fixator under the three different loads,which behaved better in torsional resistance while worse in axial compression and bending resistance than the unilateral external fixator.Conclusion The new type of unicortical external fixator has the biomechanical stability slightly weaker than that of the unilateral external fixator,which shows sufficient stability and reasonable load distribution when used for temporary fixation with lower likelihood of nail breaking,periprosthetic fractures of the tibia pin tract and loosening of the bone pins when compared with the unilateral external fixator.[Chinese Medical Equipment Journal,2024,45(11):32-38]

AIM:To establish a severe pneumonia mouse model induced by bacterial infection.METHODS:A total of 102 male SPF C57BL/6J mice were randomly divided into a control group and a model group.Klebsiella pneu-moniae was administered via tracheal instillation at a concentration of 5×109 CFU.Mice were euthanized on days 1,2,4,8,and 14 post-infection to assess general condition,body weight,mortality,white blood cell and neutrophil counts,in-flammatory markers,and pathological changes in lung,heart,liver,spleen,kidney,and intestinal tissues.RESULTS:Mice in the model group exhibited symptoms such as dyspnea and huddling from 6 hours to 4 days post-infection,which progressively worsened,accompanied by continuous weight loss(P<0.01).These symptoms gradually resolved between days 5 and 14.Arterial oxygen saturation in the model group dropped to 80.7%from days 1 to 8(P<0.01)but returned to normal from days 9 to 14.A total of 23 model mice died between days 1 and 9,with no deaths thereafter,resulting in a mortality rate of 31.9%(P<0.01).Pathological examination revealed inflammatory cell infiltration,congestion,and ede-ma in lung tissue from days 1 to 2,with continued inflammatory cell infiltration,alveolar structural disorganization from days 4 to 8,and alveolar rupture and fusion by day 14(P<0.05 or P<0.01).Additionally,model mice showed significant increases in neutrophil count,white blood cell count,protein content in bronchoalveolar lavage fluid,total cell count,neutrophil ratio,and levels of inflammatory factors tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and IL-6 in peripheral blood from days 1 to 8(P<0.05 or P<0.01).No significant pathological changes were observed in heart and liver tissues,while spleen,kidney,and intestinal tissues exhibited notable pathological changes:indistinct boundaries be-tween red and white pulp in the spleen,significant congestion and edema around renal glomeruli,renal tubules,and col-lecting ducts,and extensive inflammatory cell infiltration in the colonic mucosa.CONCLUSION:Tracheal instillation of 5×109 CFU Klebsiella pneumoniae induces severe pathological changes in the lungs of mice,offering a robust model for studying the pathogenesis and treatment of severe pneumonia.

Objective To compare clinical efficacy of robot-assisted(RA)and remote sensing navigation alignment(RSNA)system-assisted total knee arthroplasty(TKA).Methods From March 2023 to June 2023,60 patients who underwent the first unilateral TKA due to severe knee osteoarthritis(KOA)were admitted and divided into RSNA group and RA group according to different treatment methods,with 30 patients in each group.There were 5 males and 25 females in RSNA group,aged from 56 to 81 years old with an average of(66.33±7.16)years old;body mass index(BM1)ranged from 19.87 to 38.54 kg·m-2 with an average of(28.40±6.18)kg·m-2;the courses of disease ranged from 5 to 36 months with an average of(18.20±8.98)months;RSNA system was used to assist the positioning of osteotomy.There were 7 males and 23 females in RA group,aged from 55 to 82 years old with an average of(67.83±8.61)years old;BMI ranged from 19.67 to 37.25 kg·m-2 with an aver-age of(28.01±4.89)kg·m-2;the courses of disease ranged from 3 to 33 months with an average of(17.93±9.20)months;RA was performed.Operation time,incision length,latent blood loss at 2 weeks after operation and incidence of lower extremity thrombosis were compared between two groups.Hip-knee ankle angle(HKAA),HKAA deviation,lateral distal femoral angle(LDFA),medial proximal tibial angle(MPTA)and posterior tibial slope(PTS)were compared between two groups;Western Ontario McMaster Universities Osteoarthritis Index(WOMAC)and Knee Society score(KSS)were used to evaluate functional recovery before operation,3 and 6 months after operation.Results The operation was performed successfully in both groups,and there were no serious complications such as vascular and nerve injury during operation.The wound healed well at stage Ⅰafter operation,and the follow-up time was 6 months.The operation time,latent blood loss at 2 weeks after operation and inci-sion length in RSNA group were(94.35±5.75)min,(130.54±17.53)mland(14.73±2.14)cm,respectively;while(102.57±6.88)min,(146.33±19.47)ml and(16.78±2.32)cm in RA group,respectively.RSNA group was better than RA group(P＜0.05).No deep vein thrombosis occurred in both groups at 2 weeks after operation,5 patients occurred intermuscular vein throm-bosisin in RSNA group and 8 patients in RA group,the difference was not statistically significant(P＞0.05).In RSNA group,HKAA,LDFA and MPTA were(173.00±5.54)°,(86.96±3.45)°,(82.79±3.35)° before operation,and(178.34±1.85)°,(89.92±0.42)°,(89.84±0.73)° at 1 week after operation,respectively.In RA group,HKAA,LDFA and MPTA were(173.31±6.48)°,(87.15±3.40)° and(82.99±3.05)° before operation,and(178.52±1.79)°,(90.03±0.39)° and(90.15±0.47)° at 1 week after operation,respectively.HKAA,LDFA and MPTA were significantly improved in both groups at 1 week after oper-ation(P＜0.05).There were no significant difference in HKAA,LDFA,MPTA and PTS between two groups before operation and 1 week after operation(P＞0.05).There was no significant difference in deviation distribution of HKAA at 1 week after op-eration(x2=2.61 1,P=0.456).There were no significant difference in WOMAC and KSS between two groups before operation,3 and 6 months after operation(P＞0.05),and postoperative WOMAC and KSS at 3 and 6 months between two groups were im-proved compared with those before operation(P＜0.05).Conclusion Both RA and RSNA system assisted TKA could obtain ac-curate osteotomy,RA has higher surgical accuracy,RSNA system assisted operation has less trauma,and operation is simpler.