BACKGROUND:Pulsed electromagnetic fields,as an important physical therapy,are exactly effective in the treatment of osteoarthritis,but the mechanism has not been fully clarified. OBJECTIVE:To observe the effect of pulsed electromagnetic field on the degeneration of knee joint cartilage in aged rats. METHODS:Eight 6-month-old Sprague-Dawley rats were selected as the young group and were subjected to normal diet with no treatment.Sixteen 22-month-old Sprague-Dawley rats were randomly divided into old group(n=8)and pulsed electromagnetic field group(n=8).The rats in the pulsed electromagnetic field group were subjected to a pulsed electromagnetic field intervention,once a day,5 days per week for continuous 8 weeks.The rats in the old group were given no treatment.All rats were anesthetized and executed after 8 weeks for the detection of relevant indexes. RESULTS AND CONCLUSION:Compared with the young group,serum type Ⅱ collagen C-terminal peptide level was increased in the old group(P<0.05);compared with the old group,serum type Ⅱ collagen C-terminal peptide level was decreased in the pulsed electromagnetic field group(P<0.05).Micro-CT showed that the bone volume fraction,bone mineral density,and number of bone trabeculae decreased(P<0.05)and the trabecular separation increased(P<0.05)in the tibia of rats in the aged group compared with the young group;and the bone volume fraction,bone density,and number of trabeculae increased(P<0.05)and the trabecular separation decreased(P<0.05)in the tibia of rats in the pulsed electromagnetic field group compared with the aged group.The tibial plateau Safranin O-fast green staining showed that the articular cartilage structure of rats in the aged group was disorganized,and the number of chondrocytes was obviously reduced,and the tidal line could not be distinguished.The above results were improved in the pulsed electromagnetic field group.RT-qPCR and western blot assay showed that the mRNA and protein expression levels of matrix metalloproteinase 1,matrix metalloproteinase 13,P53 and P21 in the articular cartilage and subchondral bone of rats were elevated in the aged group compared with the young group(P<0.05)and decreased in the pulsed electromagnetic field group compared with the old group(P<0.05).To conclude,pulsed electromagnetic fields may improve osteoarthritis in aged rats by inhibiting chondrocyte senescence,alleviating articular cartilage degradation and inhibiting subchondral bone osteoporosis through suppressing the expression of P53/P21.

Objective To explore the clinical efficacy of high hip center technique total hip arthroplasty(THA)for CroweⅡ and Ⅲ developmental dysplasia of hip(DDH)and severe hip osteoarthritis(HOA).Methods From January 2018 to Jan-uary 2020,74 patients with Crowe type Ⅱ and Ⅲ DDH and severe HOA were admitted,and 37 cases of anatomical hip center reconstruction were taken as control group,including 7 males and 30 females,aged from 42 to 65 years old with an average of(58.40±4.98)years old,body mass index(BMI)ranged from 18 to 29 kg·m-2 with an average of(23.02±2.21)kg·m-2.Thirty-seven routine high hip center technical reconstruction were performed as study group,including 5 males and 32 females,aged from 41 to 65 years old with an average of(57.31±5.42)years old,BMI ranged from 18 to 29 kg·m-2 with an average of(23.14±2.07)kg·m-2.The patients presented with hip pain,limited function and range of motion,and gait instability before surgery.All patients underwent THA,the control group underwent intraoperative anatomical hip center reconstruction,and the study group underwent intraoperative high hip joint reconstruction.The perioperative indicators of the two groups were com-pared.The hip joint function,balance function and gait of the patients were evaluated before surgery,3 months,6 months,and 12 months after surgery.The length difference of both lower limbs,horizontal distance of rotation center,vertical distance of ro-tation center and femoral eccentricity were measured before operation and 1 year after operation.The incidence of complica-tions in the two groups during the operation and postoperative follow-up was counted.Results The operation time of the study group was shorter than that of the control group,and the intraoperative blood loss was less than that of the control group(P＜0.05).After 12-months follow-up,1 was lost to followvup in study group and 2 were lost to follow-up in control group.The Har-ris scores and Berg balance scale(BBS),pace,stride frequency and single step length in the study group were higher than those in the control group at 3 months and 6 months after operation(P＜0.05);there was no statistically significant difference between the two groups in the indexes 12 months after operation(P＞0.05).The vertical distance of the center of rotation of the study group was greater than that of the control group 12 months after operation(P＜0.05),and there was no significant difference in the length difference of the lower limbs,the horizontal distance of the center of rotation,and the femoral eccentricity between two groups(P＞0.05).There were no complications in either group.Conclusion The long-term effects of TH A in patients with DDH and severe HO A were similar between the two central hip reconstruction methods,and the safety was good,and the high hip central reconstruction technique could shorten the operation time and reduce the amount of intraoperative blood loss.At the same time,it has certain advantages in early recovery of hip joint function,balance function and walking function of patients.

Objective:To explore the early effects and safety of using a hybrid fixation strategy with 3D-printed porous tantalum metal augments to reconstruct substantial bone defects in complex primary total knee arthroplasty (TKA).Methods:A retrospective analysis was performed on the clinical data from August 2019 to September 2023, encompassing 20 patients (21 knees) with significant bone loss who underwent hybrid fixation with 3D-printed porous tantalum augments. The procedures were conducted at two medical centers: the First Affiliated Hospital, School of Medicine, Zhejiang University (11 cases) and Xiangya Hospital of Central South University (9 cases). The study cohort comprised 6 males (6 knees) and 14 females (15 knees), with a mean age of 61.05±11.23 years (range, 42-80 years). The distribution of cases was 7 on the left side and 14 on the right side. All cases were categorized as type 3 according to the Anderson Orthopaedic Research Institute (AORI) classification system. The cohort included 19 unilateral and 1 bilateral case, with 5 involving complex primary replacements (3 with Charcot arthropathy, 1 with syphilitic arthropathy, and 1 with severe valgus deformity) and 16 revision surgeries (13 for aseptic loosening and 3 for infection). Preoperative assessments included routine CT scans and digital three-dimensional reconstructions to identify large metaphyseal defects exceeding 50% of the metaphyseal area or those thicker than 10 mm. For such defects, 3D-printed standardized porous tantalum augments were implemented. In cases of extensive cavitary bone defects or severe metaphyseal defects where the medial and lateral defects collectively exceeded 80% of the metaphyseal region or where the residual bone stock was insufficient for screw fixation of standardized augments, 3D-printed personalized custom-made porous tantalum augments were employed for hybrid fixation and repair. Comparative analyses were conducted on pre- and postoperative imaging data (prosthesis positioning and complications), knee range of motion (ROM), visual analogue scale (VAS) for pain, and Knee Society score (KSS).Results:Of the cases, 17 were repaired using standardized 3D-printed porous tantalum augments, while 4 underwent repairs with customized augments for hybrid fixation. Follow-up averaged 26.5±15.0 months (range, 12-62 months). There was a significant increase in knee ROM, improving from 72.8°±31.9° preoperatively to 113.2°±6.8° at 12 months postoperatively ( P<0.05). VAS scores decreased from 6.6±1.4 preoperatively to 2.5±1.0 at 12 months postoperatively ( P<0.05). Similarly, KSS improved from 52.8±6.4 preoperatively to 80.7±7.9 at 12 months postoperatively ( P<0.05). There were no incidences of prosthesis displacement, poor bone integration, or postoperative infections. Conclusion:The hybrid fixation strategy employing 3D-printed porous tantalum augments has been found to be effective in addressing significant bone defects in TKA. The follow-up results indicate a satisfactory biological integration of the porous tantalum metal augments with the host bone, which has resulted in substantial improvements in pain relief and knee joint functionality.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective:In chronic hepatitis B (CHB) patients with previous 96-week treatment with tenofovir amibufenamide (TMF) or tenofovir disoproxil fumarate (TDF), we investigated the efficacy of sequential TMF treatment from 96 to 144 weeks.Methods:Enrolled subjects who were previously assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks received extended or switched TMF treatment for 48 weeks. Efficacy was evaluated based on virological, serological, biological parameters, and fibrosis staging. Statistical analysis was performed using the McNemar test, t-test, or Log-Rank test according to the data. Results:593 subjects from the initial TMF group and 287 subjects from the TDF group were included at week 144, with the proportions of HBV DNA<20 IU/ml at week 144 being 86.2% and 83.3%, respectively, and 78.1% and 73.8% in patients with baseline HBV DNA levels ≥8 log10 IU/ml. Resistance to tenofovir was not detected in both groups. For HBeAg loss and seroconversion rates, both groups showed a further increase from week 96 to 144 and the 3-year cumulative rates of HBeAg loss were about 35% in each group. However, HBsAg levels were less affected during 96 to 144 weeks. For patients switched from TDF to TMF, a substantial further increase in the alanine aminotransferase (ALT) normalization rate was observed (11.4%), along with improved FIB-4 scores.Conclusion:After 144 weeks of TMF treatment, CHB patients achieved high rates of virological, serological, and biochemical responses, as well as improved liver fibrosis outcomes. Also, switching to TMF resulted in significant benefits in ALT normalization rates (NCT03903796).

Objective:In chronic hepatitis B (CHB) patients with previous 96-week treatment with tenofovir amibufenamide (TMF) or tenofovir disoproxil fumarate (TDF), we investigated the safety profile of sequential TMF treatment from 96 to 144 weeks.Methods:Enrolled subjects that previously assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks received extending or switching TMF treatment for 48 weeks. Safety profiles of kidney, bone, metabolism, body weight, and others were evaluated.Results:666 subjects from the initial TMF group and 336 subjects from TDF group with at least one dose of assigned treatment were included at week 144. The overall safety profile was favorable in each group and generally similar between extended or switched TMF treatments from week 96 to 144. In subjects switching from TDF to TMF, the non-indexed estimated glomerular filtration rate (by non-indexed CKD-EPI formula) and creatinine clearance (by Cockcroft-Gault formula) were both increased, which were (2.31±8.33) ml/min and (4.24±13.94) ml/min, respectively. These changes were also higher than those in subjects with extending TMF treatment [(0.91±8.06) ml/min and (1.30±13.94) ml/min]. Meanwhile, switching to TMF also led to an increase of the bone mineral density (BMD) by 0.75% in hip and 1.41% in spine. On the other side, a slight change in TC/HDL ratio by 0.16 (IQR: 0.00, 0.43) and an increase in body mass index (BMI) by (0.54±0.98) kg/m 2 were oberved with patients switched to TMF, which were significantly higher than that in TMF group. Conclusion:CHB patients receiving 144 weeks of TMF treatment showed favorable safety profile. After switching to TMF, the bone and renal safety was significantly improved in TDF group, though experienceing change in metabolic parameters and weight gain (NCT03903796).

Objective To evaluate the bioequivalence and safety of ezetimibe tablets in healthy Chinese subjects.Methods The study was designed as a single-center,randomized,open-label,two-period,two-way crossover,single-dose trail.Subjects who met the enrollment criteria were randomized into fasting administration group and postprandial administration group and received a single oral dose of 10 mg of the subject presparation of ezetimibe tablets or the reference presparation per cycle.The blood concentrations of ezetimibe and ezetimibe-glucuronide conjugate were measured by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),and the bioequivalence of the 2 preparations was evaluated using the WinNonlin 7.0 software.Pharmacokinetic parameters were calculated to evaluate the bioequivalence of the 2 preparations.The occurrence of all adverse events was also recorded to evaluate the safety.Results The main pharmacokinetic parameters of total ezetimibe in the plasma of the test and the reference after a single fasted administration:Cmax were(118.79±35.30)and(180.79±51.78)nmol·mL-1;tmax were 1.40 and 1.04 h;t1/2 were(15.33±5.57)and(17.38±7.24)h;AUC0-t were(1 523.90±371.21)and(1 690.99±553.40)nmol·mL-1·h;AUC0-∞ were(1 608.70±441.28),(1 807.15±630.00)nmol·mL-1·h.The main pharmacokinetic parameters of total ezetimibe in plasma of test and reference after a single meal:Cmax were(269.18±82.94)and(273.93±87.78)nmol·mL-1;Tmax were 1.15 and 1.08 h;t1/2 were(22.53±16.33)and(16.02±5.84)h;AUC0_twere(1 463.37±366.03),(1 263.96±271.01)nmol·mL-1·h;AUC0-∞ were(1 639.01±466.53),(1 349.97±281.39)nmol·mL-1·h.The main pharmacokinetic parameters Cmax,AUC0-tand AUC0-∞ of the two preparations were analyzed by variance analysis after logarithmic transformation.In the fasting administration group,the 90％CI of the log-transformed geometric mean ratios were within the bioequivalent range for the remaining parameters in the fasting dosing group,except for the Cmax of ezetimibe and total ezetimibe,which were below the lower bioequivalent range.The Cmax of ezetimibe,ezetimibe-glucuronide,and total ezetimibe in the postprandial dosing group was within the equivalence range,and the 90％CI of the remaining parameters were not within the equivalence range for bioequivalence.Conclusion This test can not determine whether the test preparation and the reference preparation of ezetimibe tablets have bioequivalence,and further clinical trials are needed to verify it.