Objective:To establish an LC-MS/MS method for the simultaneous determination of acetaminophen and its five metabolites in mice plasma,and investigate the metabolism of acetaminophen by using the method.Methods:Para aminobenzoic acid was used as the internal standard.The plasma samples were precipitated by methanol,and then separated on a C18 column with the mobile phase of methanol and 5 mmol·L-1 ammonium acetate buffer solution containing 0.1% formic acid (55∶45).The flow rate was 0.5 ml·min-1,and the column temperature was 25℃.An electrospray ionization source was applied and operated in a positive ion mode using MRM:APAP,-,m/z 152.0→110.0;APAP-cys,-,m/z 271.2→140.1;APAP-glut,-,m/z 457.0→328.0;APAP-NAC,-,m/z 313.4 →208.0;APAP-sulf,-,m/z 232.4→152.1;APAP-gluc,-,m/z 328.2→152.1;IS,-,m/z 138.2→120.0.Results:The method exhibited good linearity over the concentration range of 0.2-10 μg·ml-1for APAP,1.0-20 μg·ml-1 for APAP-gluc,1.0-20 μg·ml-1 for APAP-sulf,1.0-20 μg·ml-1 for APAP-glut,0.4-15 μg·ml-1 for APAP-NAC and 0.2-10 μg·ml-1 for APAP-cys (r≥0.990 0).The inter-day accuracy and precision of acetaminophen and its five metabolites were all below 15%.The average recovery was between 85% and 115%,and RSDs were all below 15%.Conclusion:The LC-MS/MS method is proved to be quick,sensitive and accurate,and suitable for the determination of acetaminophen and its five metabolites in mice plasma.

Objective To investigate the applicative value of enhanced 3D multi-echo GRE T2*-weighted angiography(ESWAN) sequence phase values in evaluating brain gray nuclei iron content in idiopathic restless legs syndrome(RLS) patients, providing imaging basis in diagnosis and treatment of idiopathic RLS. Methods In our institute from June 2012 to September 2016,forty-five RLS patients were selected as the RLS group, and 45 healthy volunteers as the control group. ESWAN sequence was performed and serum ferritin values were obtained in all patients and volunteers. The raw data of ESWAN was postprocessed , where the phase maps were obtained. Phase analysis was performed on localized brain gray nuclei regions of interest (substantia nigra, red nucleus, dentate nucleus, thalamus, pallidum, putamen and caudate nucleus ) selected on phase maps. Differences between the 2 subject groups were evaluated using ANCOVA including age as a covariate. Results The phase values of the substantia nigra, thalamus, pallidum and putamen in the RLS group were (-0.087 ± 0.021), (-0.053 ± 0.012), (-0.161 ± 0.008), (-0.125 ± 0.019) radians , respectively. The phase values of the substantia nigra, thalamus, pallidum and putamen in the control group were (-0.127 ± 0.007), (-0.066 ± 0.007), (-0.166 ± 0.007), (-0.150 ± 0.010) radians, respectively. There were significant differences between the two groups (F=142.492, 37.988, 10.558, 60.725;P<0.05). Indicating reduced iron content in several regions of brain gray nuclei of the patients with RLS. Serum ferritin concentration between the RLS patients (157.02±95.78)μg/L and healthy controls (175.49 ± 38.65)μg/L was not significant (F=1.353,P>0.05). Conclusions Phase values can make a quantitative assessment of brain gray nuclei iron content in RLS patients, our results supported the hypothesis of reduced brain iron content in RLS patents , which may have an important role in the pathogenesis of the disorder. However, iron content change in some brain regions was not correlated with serum ferritin concentration changes.

Objective To investigate whether stem cell factor(SCF)was responsible for the diabetesassociated depletion of interstitial cells of Cajal in colon(ICC)in diabetic mice.Methods Forty male C57/BL6 mice were randomly divided into the control group(n=10),the diabetic group(n=10),the normal group with immunoneutralization of endogenous SCF(n=10)and the diabetic group with exogenous SCF (n=10).All mice were sacrificed 6 weeks after modeling.The ICC in the proximal colon tissues were investigated by flow cytometry,transmission electron microscopy and Western blot.The SCF in colon tissues and serum were analyzed by Western blot and ELISA.Results The SCF in the serum and proximal colon muscle was significantly reduced in diabetic group compared with the control group(P＜0.05).The changes were accompanied with the depletion of ICC and the uhrastructure damage of ICC.The expression of SCF was significantly decreased in the serum and proximal colon tissues in the normal group after immunoneutralization of SCF.Meanwhile,the depletion of ICC and the ultrastructure damage of ICC was similar to the diabetic group.The expression of SCF in the serum and proximal colon tissues of the diabetic group with exogenous SCF was significantly increased,and which was along with the quantity of ICC and the ultrastructure improved dramatically compared with the diabetic group.Conclusions The decrease of SCF in the serum and colon of the diabetic mice may be responsible for the diabetes-associated depletion of ICC in colon.Exogenous SCF may improve the ICC lesions in diabetic gastroimestinal tract.

AIM: To investigate whether a consensus oligonucleotide, which contains nuclear factor-kappa B(NF-?B) binding site, decreases TNF production stimulated by lipopolysaccharide(LPS). METHODS: The thiophosphoric acid modified oligonucleotides were transferred into rat peritoneal macrophages directly, TNF content in LPS-stimulated cell culture supernatant was determined by ELISA.RESULTS: Adding the consensus oligonucleotides with NF-?B binding site into macrophages markedly decreased TNF production following LPS stimulation. CONCLUSION: These results show that use of the consensus oligonucleotides with NF-?B binding site, which can combine with NF-?B, can block or decrease TNF production induced by LPS in macrophages.

BACKGROUND: Previous research has investigated the effect of nano-zirconium dioxide-toughened hydroxyapatite (nano-ZrO2-HA) on the proliferation and differentiation of rabbit bone marrow stromal cells.OBJECTIVE: To evaluate the biocompatibility of nano-ZrO_2-HA compound.METHODS: The experiments of acute toxicity,subacute toxicity,pyrogen,hemolysis,and intramuscular implantation were performed on New Zealand rabbits,healthy adult Kunming mice,and adult rats according to "Technical Evaluation Standards of Biomedical Materials and Medical Instruments",promulgated by Chinese Board of Health.RESULTS AND CONCLUSION: Acute toxicity: All experimental animals survived.There was no significant difference in body mass before and after testing (P> 0.05).Pyrogen: Heating reaction was not tested.Hemolysis: Generally speaking,hemolytic crisis was not observed after 1 hour,and hemolytic rate was less than 5%.Intramuscular implantation: Infection did not occur in any animals,and materials were not discharged at all.Four weeks later,muscles were closely integrated with materials.A certain quantity of tissue grew into material pore,and peripheral muscle still had normal morphology and structure.Subacute toxicity:There was no significant difference in body mass and blood routine before and 2 weeks after testing.HE staining demonstrated that necrotic focus and other lesion were not observed in heart,liver,and kidney tissues under optic microscope.The results suggested that nano-ZrO_2-HA was non-toxicity,and it had no pyrogen and hemolysis effect,as well as it did not stimulate to the muscle of rabbit.Inflammatory rejection did not happen to the animal.The nano-ZrO_2-HA was closely integrated with the muscle,characterizing by great biocompatibility.Therefore,it can be used as substitution materials in clinical experiment.But it still needs to be evaluated completely.

Objective To investigate the effects of thymosin α1 (Tα1) on plasma TNF-α and IL-10 of rats with acute liver failure.Methods The model of acute liver failure in rats was established.The rats in intervention group were injected with Tα1;their plasma ALT, AST and TBIL contents as well as plasma TNF-α and IL-10 levels were assayed at different time points for HE staining of liver sections.Results ① ALT, AST and TBIL in model group and intervention group increased over time.Plasma ALT, AST and TBIL were significantly lower in intervention group than in model group at the same time point (P<0.05).② Manifestations of acute liver failure such as structural disorder of liver tissue, obvious necrosis of liver cells and infiltration of inflammatory cells were observed in model group and intervention group, and worsened over time.At the same time point, liver cell necrosis and infiltration of inflammatory cells were less severe than those in model group.③ TNF-α and IL-10 were significantly higher in model and intervention groups than in control group (P<0.05).Plasma TNF-α and IL-10 showed a rising trend over time in the former groups (P<0.05).At the same time point, TNF-α was significantly lower but IL-10 was significantly higher in intervention group than in model group.Conclusion Thymosin α1 has a protective effect on acute hepatic failure in rats, and it can significantly alleviate liver inflammation and necrosis.The mechanism is related to inhibition of pro-inflammatory cytokine TNF-α and upregulation of anti-inflammatory cytokine IL-10.

Objective To observe the influence of the clinical pathway management intervention on medical service behaviors.Methods The clinical cases data in a grade A class 3 hospital of Zhangjiakou City,Hebei Province during 2011-2013 were retrospectively analyzed.The influence of implementing the clinical pathway management on the diagnosis results,medical records writing quality,clinical medication,operation,hospitalization time,medical costs,assisted examination items selection were observed and analyzed.Results The admission and discharge diagnosis coincidence rate and preoperative and postoperative diagnostic coincidence rate of 3 diseases entities in the two groups were 100%,the difference had no statistical significance (P>0.05);the medical record grade-A rate in the implementing clinical pathway group was significantly higher than that in the non-implementing clinical pathway group,the medical record grade-B rate was significantly lower than that in the non-implementing clinical pathway group,the difference was statistically significant (P<0.05);the antibacterial drugs cost and drugs proportion in the implementing clinical pathway group were significantly lower than those in the non-implementing clinical pathway group,the medication proportion within the directory in the implementing clinical pathway group was significantly higher than that in the non-implementing clinical pathway group,the difference was statistically significant (P<0.05);the preoperative preparation time in the implementating clinical pathway group was less than that in the non-implementing clinical pathway group,the difference was statistically significant(P<0.05),the grade-A healing rate had no significant difference between the two groups (P>0.05);the average hospitalization time,total costs,drug costs,laboratory fee and examination fee in the implementing clinical pathway group were lower than those in the non-implementing clinical pathway group,the difference was statistically significant (P<0.05);the operation fee,healthy material fee and nursing fee had no statistically significant difference was statistically significant(P<0.05).Conclusion Implementing the clinical pathway can standardize the doctor′s diagnosis and treatment behaviors and makes the medical work to develop to be more favorable for patients.

Objective To investigate the biological effects of EB encoding latent membrane protein 1(LMP1) on Tet-on-LMP1 HNE2 nasopharyngeal carcinoma cell line.Methods Proliferation of Tet-onLMP1 HNE2 cell induced by DOX at the different time points was detected by Western blot assay,DNA content assay,cell growth curves assay,colonogenesis assay in the soft agar and MTT colorimetric method.Results With the increasing LMP1 protein expression,Tet-on-LMP1 HNE2 progressed rapidly from G0/G1 to S phase,cells grew faster(P

Objective To investigate the effect of different frequencies of endoscopic ultrasonography (EUS) on diagnosis of duodenal submucesal lesions. Methods A total of 210 elevated duodenal lesions detected by routine endoscopy in 201 patients were examined by EUS at different frequencies according to lesion features and image clarity. Endoscopic resection was applied in 27 lesions with informed consents,and pathological findings were compared with the results of EUS. Results The accuracy of EUS was 81.4% (22/27). Ultrasound of low frequency was superior in displaying overview of lesion and was more suitable for lesions larger than 1.5 cm in diameter or lesions of hyperecho. On the other hand,ultrasound of high frequency was more reliable to reveal minute structures and could be employed in scanning lesions smaller than 1.5 cm in diameter. Combination of different frequencies of ultrasound could provide more details in larger lesions. Conclusion Application of appropriate frequency or combined frequencies of ultrasound in examination of elevated duodenal lesions is beneficial to achieve more accurate diagnosis.

Objective To investigate the impact of not using drainage on clinical outcomes after arthroscopic autologous semitendinosus tendon reconstruction with anterior cruciate ligament reconstruction.Methods From March 2022 to June 2023,59 patients undergoing arthroscopic autologous semitendinosus tendon reconstruction with anterior cruciate ligament reconstruction in Lincang People's Hospital were collected and randomly divided into the non-drainage group consisting of 29 cases(observation group)and the 24-hour drainage group consisting of 30 cases(control group).The pain levels of the two groups of patients were recorded on the 1st,3rd,7th,14th,and 30th day after the surgery by using a visual analog scale.Additionally,the knee joint range of motion,length of hospital stay,and occurrence of postoperative complications were monitored.The circumference of the thigh was measured before and after the surgery,and the difference was calculated.Results Repeated measures analysis of variance revealed that there were statistically significant within-subject differences in pain ratings,thigh circumference,and knee joint range of motion(P<0.05),but no statistically significant between-subject differences(P>0.05).Independent samples t-tests showed that on the first day after the surgery,the observation group had lower pain ratings(P<0.001),and higher thigh circumference and knee joint range of motion compared to the control group(P<0.05).There were no statistically significant differences in pain ratings,knee joint range of motion,and thigh circumference between the two groups at the remaining follow-up times(P>0.05);The observation group had a shorter hospital stay than the control group(P<0.001);Both groups of patients had no complications such as lower limb nerve damage,deep vein thrombosis,knee joint infection,or hematomas requiring puncture and aspiration.Conclusion In the early postoperative period following arthroscopic autologous hamstring tendon reconstruction of the anterior cruciate ligament,the omission of drainage does not affect the clinical outcomes in terms of pain,knee joint mobility,and thigh circumference.Moreover,omitting drainage reduces the level of pain experienced by patients on the first day after the surgery,improves the knee joint mobility,and decreases the length of hospital stay.Therefore,in arthroscopic autologous hamstring tendon reconstruction of the anterior cruciate ligament,it is not recommended to routinely use drainage for preventive purposes.