Objective To assess the effects of repeated mild traumatic brain injury(rmTBI)in the parietal cortex on neuronal morphology and synaptic plasticity in the medulla oblongata of mice.Methods Thirty-two male ICR mice were randomly divided into sham operation group(n=8)and rmTBI group(n=24).The mice in the latter group were subjected to repeated mild impact injury of the parietal cortex by a free-falling object.The mice surviving the injuries were evaluated for neurological deficits using neurological severity scores(NSS),righting reflex test and forced swimming test,and pathological changes of the neuronal cells in the medulla oblongata were observed with HE and Nissl staining.Western blotting and immunofluorescence staining were used to detect the expressions of neuroligin 1(NLG-1)and postsynaptic density protein 95(PSD-95)in the medulla oblongata of the mice that either survived rmTBI or not.Results None of the mice in the sham-operated group died,while the mortality rate was 41.67%in rmTBI group.The mice surviving rmTBI showed significantly reduced NSS,delayed recovery of righting reflex,increased immobility time in forced swimming test(P<0.05),and loss of Nissl bodies;swelling and necrosis were observed in a large number of neurons in the medulla oblongata,where the expression levels of NLG-1 and PSD-95 were significantly downregulated(P<0.05).The mice that did not survive rmTBI showed distorted and swelling nerve fibers and decreased density of neurons in the medulla oblongina with lowered expression levels of NLG-1 and PSD-95 compared with the mice surviving the injuries(P<0.01).Conclusion The structural and functional anomalies of the synapses in the medulla oblongata may contribute to death and neurological impairment following rmTBI in mice.

Objective:To evaluate the efficacy and safety of unilateral adrenalectomy for treating primary bilateral macronodular adrenal hyperplasia (PBMAH) of different clinical types.Methods:The clinical and biochemical data of 54 patients with PBMAH who underwent unilateral adrenalectomy from May 2008 to March 2023 were retrospectively collected. Preoperative CT images of all patients showed enlarged bilateral adrenal glands with multiple nodules of " fused masses". Mean preoperative blood cortisol concentration at 8am was (21.5±7.7)μg/dl, urinary free cortisol concentration was (442.6±300.4)μg/24h, and mean 8am ACTH concentration was (6.4±2.3)pg/ml. Postoperative symptoms, BMI, blood pressure, mass diameter, cortisol and ACTH concentration were recorded and analyzed.Results:Compared with ordinary laparoscopic surgery, robot-assisted surgery showed shorter operation time [(115.4±22.1)min vs.(95.0±19.8)min, P=0.045]; less blood loss [(118.2±57.0)ml vs. (125.6±45.3)ml, P=0.441] and shorter hospitalization time [(5.2±0.9)day vs. (6.4±1.2)day, P=0.279]. Compared with laparoscopic surgery, open surgery showed longer operation time [(134 34.5) min vs. (104.3±20.1) min, P=0.035]; more blood loss [(305.5±85.2) ml vs. (122.5±44.3) ml, P=0.012] and longer hospitalization time[(10.4±3.2)day vs. (5.7±1.0) day, P=0.020]. The average follow-up time was (23.7±11.7) months. Sixteen cases biochemically relapsed, and the average relapse-free time was (25.4±13.4) month. Mean postoperative systolic blood pressure was (131.1±16.8)mmHg ( P=0.001) while diastolic blood pressure decreased to (82.2±11.1)mmHg ( P=0.002). Postsurgical average blood cortisol concentration decreased to (10.2±4.0)μg/dl ( P<0.01), while urine cortisol concentration decreased to (106.6±43.4)μg/24h( P<0.01). Average ACTH concentration increased to (12.6±4.1)pg/ml( P=0.005). Recurrent patients had higher preoperative blood and urine cortisol concentration(24.7±8.2)μg/dl( P=0.046), (522.8±234.2)μg/24h( P=0.028), and all of them underwent contralateral adrenalectomy. Conclusions:Unilateral adrenalectomy is safe and effective for treatment of PBMAH while part of patients biochemically relapsed. Subclinical patients were observed no recurrent cases after surgery. Recurrent patients have higher preoperative blood and urine cortisol levels and should undertake contralateral adrenalectomy and supplement corticosteroids for whole life.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

Objective Genotypes(G)1,3,and 5 of the Japanese encephalitis virus(JEV)have been isolated in China,but the dominant genotype circulating in Chinese coastal areas remains unknown.We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis(JE)in the coastal provinces of China. Methods In this study,we collected serum specimens from patients with JE in three coastal provinces of China(Guangdong,Zhejiang,and Shandong)from 2018 to 2020 and conducted JEV cross-neutralization tests against G1,G3,and G5. Results Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong(92 patients),Zhejiang(192 patients),and Guangdong(77 patients),China,from 2018 to 2020.Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV.Two cases were confirmed to be infected with G1 JEV,32 with G3 JEV,and two with G5 JEV. Conclusion G3 was the primary infection genotype among JE cases with a definite infection genotype,and the infection caused by G5 JEV was confirmed serologically in China.

Objective To assess the effects of repeated mild traumatic brain injury(rmTBI)in the parietal cortex on neuronal morphology and synaptic plasticity in the medulla oblongata of mice.Methods Thirty-two male ICR mice were randomly divided into sham operation group(n=8)and rmTBI group(n=24).The mice in the latter group were subjected to repeated mild impact injury of the parietal cortex by a free-falling object.The mice surviving the injuries were evaluated for neurological deficits using neurological severity scores(NSS),righting reflex test and forced swimming test,and pathological changes of the neuronal cells in the medulla oblongata were observed with HE and Nissl staining.Western blotting and immunofluorescence staining were used to detect the expressions of neuroligin 1(NLG-1)and postsynaptic density protein 95(PSD-95)in the medulla oblongata of the mice that either survived rmTBI or not.Results None of the mice in the sham-operated group died,while the mortality rate was 41.67%in rmTBI group.The mice surviving rmTBI showed significantly reduced NSS,delayed recovery of righting reflex,increased immobility time in forced swimming test(P<0.05),and loss of Nissl bodies;swelling and necrosis were observed in a large number of neurons in the medulla oblongata,where the expression levels of NLG-1 and PSD-95 were significantly downregulated(P<0.05).The mice that did not survive rmTBI showed distorted and swelling nerve fibers and decreased density of neurons in the medulla oblongina with lowered expression levels of NLG-1 and PSD-95 compared with the mice surviving the injuries(P<0.01).Conclusion The structural and functional anomalies of the synapses in the medulla oblongata may contribute to death and neurological impairment following rmTBI in mice.

Objective To propose a Q factor-based fatigue vibration evaluation method of the ultrasonic knife tip.Methods Firstly,an ultrasonic cutter fatigue testing table was established to realize repeated cutting,which was composed of a power supply module,a three-axis moving module,an ultrasonic cutter clamping module and a control module.Secondly,10 ultrasonic knives of some brand underwent fatigue testing with the table,during which non-contact measurement of the ultrasonic knife tip vibration was carried out and the Q factors were calculated at the five periods of the fatigue test,including the periods before cutting,after 500 times of cutting,after 1 000 times of cutting,after 2 000 times of cutting and after 3 000 times of cutting.Finally,the average cutting speed and burst pressure for coagulated vessels were computed at each period to validata the effectiveness of the method proposed.Results It's indicated that Q factor could effectively reflect the fatigue degradation of the ultrasonic knife tip,while the average cutting speed and burst pressure for coagulated vessels were difficult to efficiently evaluate the fatigue degradation level of the ultrasonic knife tip due to the uncertainty factors in the measurement process.Conclusion The proposed Q factor-based evaluation method can directly evaluate fatigue vibration of the ultrasonic knife tip in an accurate and quantitative manner.[Chinese Medical Equipment Journal,2024,45(6):17-22]

Objective To carry out accurate quantative evaluation of MRI scanning noise based on laser vibrometry technology.Methods Skull and spine MRI was performed with mute and conventional sequences.A laser vibrometry device was used to sample the surface vibration noise at the outer edge of the inspection hole of MRI system according to GB/T 16539-1996 Acoustics—Determination of sound power levels of noise sources using vibration velocity—Measurement for seal machinery,and the indicators of sound power level,sound pressure level and perceived noise level obtained by the three calculation methods(LPN1,LPN2 and LPN3)were analyzed with some dedicated MRI noise analysis software.Results The peak sound pressure levels for conventional and mute sequences of skull scanning were 81 and 63 dB(A),respectively,and mute sequence reduced the noise level significantly;the peak sound pressure levels for conventional and mute sequences of spine scanning were 79 and 75 dB(A),respectively,and the noise reduction level was significantly lower than that of skull scanning.Significant differences in noise reduction were not found in spine scanning sequences,while were found in skull scanning sequences.During spine and skull scanning LPN1,LPN2 and LPN3 obtained by the three calculation methods of conventional and mute sequences were all higher than the overall sound power and overall pressure levels obviously.Conclusion Mute sequence can not realize linear noise reduction for the whole frequency band,the perceived noise of the human ear during MRI scanning is related directly to the scanning sequence,and there may be some bias when only one physical indicator is involved in the noise evaluation of MRI system.[Chinese Medical Equipment Journal,2024,45(10):20-24]

Neonatal necrotizing enterocolitis(NEC)is the most common inflammatory intestinal disease in preterm infants,with a high incidence and mortality rate.The etiology and mechanisms of NEC are not yet fully understood,and multiple factors contribute to its occurrence and development.Recent studies have found that anemia is a risk factor for NEC in neonates,but the specific pathogenic mechanism remains unclear.This article reviews recent research on the relationship between anemia and NEC,providing a reference for further understanding the impact of anemia on intestinal injury and its association with NEC.

Objective To investigate the risk factors for delayed union of extra-articular fractures of the middle and lower third of the tibia treated by locking plate.Methods Total of 135 patients of extra-articular fractures of the middle and lower third of the tibia from January 2013 to December 2018 were retrospectively analyzed,including 85 males and 50 females,ranged from 19 to 80 years old.All cases were treated with locking plates.The patients were divided into union group and delayed union group ac-cording to the condition of fracture union.The risk factors of delayed healing were determined by univariate analysis of 14 factors that might affect fracture healing first,then the factors with significance were analyzed by binary Logistic regression.Results There were 13 patients of delayed union,and the rate of delayed union was 9.63％.Univariate analysis showed that delayed union was associated with age,smoking,reduction method,anemia and time of preoperative preparation.Regression analysis showed thatage[OR=0.849,95％CI(0.755,0.954),P=0.006],smoking[OR=0.020,95％CI(0.002,0.193),P=0.001],reduction method[OR=23.924,95％CI(2.210,258.943),P=0.009],anemia[OR=0.016,95％CI(0.001,0.289),P=0.005]were the con-tributory factors for delayed union.Conclusion Young age,smoking,closed reduction and anemia are the risk factors for de-layed union of extra-articular fractures of the middle and lower third of the tibia treated by locking plate.