Objective:To evaluate the sample preparation proficiency and storage proficiency of 11 clinical biobanks in Beijing through simulated experiments, and to establish an assessment method for the quality comparability of biological samples.Methods:An exploratory research design was adopted. In November 2023, artificial composite serum quality control materials containing six recombinant human protein markers—recombinant human alanine aminotransferase (rhALT), recombinant human aspartate aminotransferase (rhAST), recombinant human creatine kinase (rhCK), recombinant human creatine kinase-MB (rhCK-MB), recombinant human B-type natriuretic peptide (rhBNP), and recombinant human troponin I (rhTNI)—were distributed to 11 clinical biobanks in Beijing City. Sample preparation and storage followed the standardized operating procedures. Proficiency differences were assessed through statistical analysis.Results:Three-way repeated measures ANOVA revealed all six protein markers showed a declining trend over storage time in ultra-low-temperature environments ( F values 11.68-4 179.66, all P<0.01). However, neither long-term/temporary refrigerator types ( F values 0.01-1.23, all P>0.05)nor placement locations within refrigerators significantly affected the stability of these six proteins ( F valus 0.03-1.47, all P>0.05). The biases in detection results for rhALT, rhAST, rhTNI, and rhBNP at different storage time points were within the allowable bias limits for each item, supporting their use as markers for protein stability in biobank samples. All 11 institutions passed the storage proficiency assessment. In the preparation proficiency assessment, deviations were observed in post-preparation sample results, with a notably high out-of-control rate for rhCK (36.36%). Conclusion:Sample preparation proficiency can serve as a quality control metric for clinical biobanks. Future external quality assessment systems for biobanks should focus on sample preparation rather than storage processes.

Objective:To evaluate the sample preparation proficiency and storage proficiency of 11 clinical biobanks in Beijing through simulated experiments, and to establish an assessment method for the quality comparability of biological samples.Methods:An exploratory research design was adopted. In November 2023, artificial composite serum quality control materials containing six recombinant human protein markers—recombinant human alanine aminotransferase (rhALT), recombinant human aspartate aminotransferase (rhAST), recombinant human creatine kinase (rhCK), recombinant human creatine kinase-MB (rhCK-MB), recombinant human B-type natriuretic peptide (rhBNP), and recombinant human troponin I (rhTNI)—were distributed to 11 clinical biobanks in Beijing City. Sample preparation and storage followed the standardized operating procedures. Proficiency differences were assessed through statistical analysis.Results:Three-way repeated measures ANOVA revealed all six protein markers showed a declining trend over storage time in ultra-low-temperature environments ( F values 11.68-4 179.66, all P<0.01). However, neither long-term/temporary refrigerator types ( F values 0.01-1.23, all P>0.05)nor placement locations within refrigerators significantly affected the stability of these six proteins ( F valus 0.03-1.47, all P>0.05). The biases in detection results for rhALT, rhAST, rhTNI, and rhBNP at different storage time points were within the allowable bias limits for each item, supporting their use as markers for protein stability in biobank samples. All 11 institutions passed the storage proficiency assessment. In the preparation proficiency assessment, deviations were observed in post-preparation sample results, with a notably high out-of-control rate for rhCK (36.36%). Conclusion:Sample preparation proficiency can serve as a quality control metric for clinical biobanks. Future external quality assessment systems for biobanks should focus on sample preparation rather than storage processes.

Objective To evaluate the accuracy of variation of epidural labor analgesia in predicting cesarean section.Methods A total of 1 200 parturients with a single baby who were at full term with a singleton fetus,aged 22-34 yr,weighing 60-85 kg,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,volunteered for epidural labor analgesia for pain relief,were enrolled in the study.Epidural labor analgesia (patient-controlled epidural analgesia) was performed when uterine contraction was regular and cervical dilatation was 2-3 cm.Patient-controlled epidural analgesia solution contained the mixture of 0.1％ ropivacaine and fentanyl 2 μg/ml with a background infusion 9 ml/h,bolus dose 4 ml,lockout interval 15 min.The variation of labor analgesia was defined as the difference between the highest visual analog scale score during labor and the visual analog scale score at 30 min after epidural injection of the initial dose of local anesthetic.The receiver operating characteristic curve was used to evaluate the accuracy of variation of epidural labor analgesia in predicting cesarean section.The optimal cut-off value was determined according to the maximum Youden index.Results The area under the receiver operating characteristic curve of variation of epidural labor analgesia in predicting cesarean section was 0.795,and the maximum Youden index was 53.6％,the sensitivity 87.5％ and the specificity 66.1％ when the cut-off value was 3.Conclusion Variation of epidural labor analgesia produces better accuracy in predicting cesarean section.

Objective To compare dexmedetomidine administered via different routes for epidural anesthesia during second cesarean section.Methods Sixty parturients who were at full term with a singleton fetus,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 22-38 yr,weighing 58-84 kg,undergoing a second caesarean section under epidural anesthesia,were divided into 3 groups (n=20 each) using a random number table:Ⅳ infusion of dexmedetomidine conbined with epidural injection of ropivacaine group (VDER group),epidural injection of a mixture of ropivacaine and dexmedetomidine group (ERD group) and epidural injection of ropivacaine group (ER group).The epidural puncture was performed at L2,3.After identification of the epidural space and a negative aspiration test for blood or cerebrospinal fluid,the mixture of 0.75％ ropivacaine 15 ml and 0.9％ normal saline 2 ml was injected epidurally,and dexmedetomidine 1 μg/kg was intravenously infused for 10 min at the same time in VDER group;the mixture of 0.75％ ropivacaine 15 ml and 1 μg/kg dexmedetomidine 2 ml was injected epidurally in ERD group;the mixture of 0.75％ ropivacaine 15 ml and 0.9％ normal saline 2 ml was injected epidurally in ER group.The onset time of epidural block,maximum level ofepidural block,time to reach the maximum epidural block and time of sensory block were recorded.Ramsay sedation scores were assessed at 30 miu after the end of epidural administration,and intraoperative traction reaction was also assessed.The development of hypotension,bradycardia,respiratory depressim and shivering was observed.The number of patients in whom remifentanil was used before delivery and Apgar scores at 1 and 5 min after birth were recorded.Results Compared with VDER group and ER group,the onset time and time to reach the maximum epidural block were significantly shortened,and the time of sensory block was prolonged in ERD group (P＜0.05).Compared with ER group,the rate of satisfactory sedation was significantly increased,the number of patients in whom remifentanil was used before delivery was decreased,the degree of intraoperative traction reaclion was mitigated,and the incidence of respiratory depression and shivering was decreased (P＜0.05),and no significant change was found in Apgar scores at 1 and 5 min after birth in VDER and ERD groups (P＞0.05).Conclusion Both Ⅳ and epidural dexmedetomidine can enhance the efficacy of epidural anesthesia during second cesarean section,producing no adverse effects on neonates;epidural injection of a mixture of ropivacaine and dexmedetomidine provides faster onset and prolonged time of sensory block,which is helpful for postoperative analgesia.

Objective To analyze the incidence of BK virus (BKV) infection after kidney transplantation in our center and to evaluate the efficacy and safety of conversion treatment with Mizoribine (MZR) on BKV infection after kidney transplantation.Methods The information of recipients who received BK virus screening in hospital or outpatient during 2015-02 to 2016-12 in our center was retrospectively analyzed.The recipients positive for BKV were divided into experiment group (given conversion treatment with MZR) and control group (not given MZR conversion) according to the inclusion criteria.The negative rate of BKV,AR,hyperuricemia and the function of renal allograft during the conversion treatment with MZR were observed.Results 182 recipients accepted BKV screening during 2015-02 to 2016-12 and 68 cases were positive.The positive rate of BKV was 38.5 ％.The positive rate of peripheral blood specimens and midstream urine specimens was 7.1％ and 36.8％ respectively.Twelve recipients were positive for BKV in both peripheral blood specimens and midstream urine specimens.There were 27 recipients in experiment group and 36 cases in control group.Fourteen recipients positive for BKV became negative after MZR conversion in experiment group and the negative rate was up to 51.9％.The mean time of negative rate was 3.2 ± 2.7 (1-10) months after MZR conversion.During the conversion treatment with MZR,AR occurred in 1 case and was reversed by the impact therapy with Thymoglobulin in experiment group.The value of serum uric acid was maintained stable before and after MZR conversion under the action of uric-acidlowering drug.The renal function was kept stable in both experiment group and control group after renal transplantation.No deaths and renal allograft failure cases occurred in both groups during the research period.The 2-year survival rate for patients and kidneys was both 100％.Conclusion The incidence of BKV infection after kidney transplantation was high and the treatment scheme of MZR conversion was safe and effective.

Objective To investigate the placental transfer and neonatal effects of dexmedetomidine during the cesarean section under general anesthesia.Methods Thirty-eight nulliparous parturients,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 22-37 yr,weighing 56-82 kg,who were at full term with a singleton fetus,scheduled for elective caesarean section under general anesthesia,were randomly divided into 2 groups (n=19 each) using a random number table:dexmedetomidine group (group D) and normal saline group (group N).In group D,dexmedetomidine was infused in a loading dose of 0.6 μg/kg starting from 10 min before induction of anesthesia,followed by an infusion of 0.4 μg · kg-1 · h-1 until peritoneal closure.Group N received the equal volume of normal saline.Blood samples were collected from the maternal artery (MA),umbilical vein (UV),and umbilical artery (UA) for blood gas analysis and for determination of plasma dexmedetomidine concentrations (CMA,CUV and CUA) by high-performance liquid chromatography-mass spectrometry,and CUV/CMA and CUA/CUV were calculated.Apgar scores were recorded at 1 and 5 min after delivery,and the occurrence of respiratory depression was also recorded.The I-D interval (the time from administration of anesthetics to delivery) and U-D interval (the time from incision of the uterus to delivery) were recorded.Results There were no significant differences in the blood gas analysis parameters in blood samples collected from the MA,UV and UA,I-D interval,U-D interval,and Apgar scores between the two groups (P＞0.05).No neonatal respiratory depression was found in both groups.In group D,CMA,CUV and CUA were 471±119,359±88 and (321±78) ng/ml,respectively,CUV/CMA was 0.76±0.06,and CUA/CUV was 0.89±0.03.Conclusion Although the metabolism of dexmedetomidine is little after easy placental transfer,dexmedetomidine has no adverse effects on the newborn during the cesarean section under general anesthesia.

Objective To evaluate the efficacy of dexmedetomidine mixed with ropivacaine for epidural anesthesia in the patients.Methods Forty-six patients, of ASA physical status Ⅰ or Ⅱ , aged 36-58 yr, weighing 48-77 kg, scheduled for elective hysterectomy under epidural anesthesia, were randomly divided into 2 groups (n =23 each) according to the random number table: normal saline + ropivacaine group (R group) and dexmedetomidine + ropivacaine group (DR group).Epidural anesthesia was performed at L2,3interspace.The catheter was inserted into the epidural space.A mixture of 0.75％ ropivacaine 15 ml and dexmedetomidine 1 μg/kg was injected epidurally in DR group.A mixture of 0.75％ ropivacaine 15 ml and normal sline 2 ml was injected epidurally in R group.The onset time of sensory block, maximum level of sensory block, and duration of sensory block were recorded.The modified Bromage scale, Ramsay sedation score and intraoperative traction reaction were assessed.The occurrence of dexmedetomidine-related cardiovascular events and respiratory depression, and epidural anesthesia-related adverse events within 2 h after operation was recorded.Results Compared with R group, the onset time of sensory block was significantly shortened, the duration of sensory block was prolonged, the maximum level of sensory block and Ramsay sedation score were increased, the degree of intraoperative traction reactions was lessened, and the incidence of shivering was decreased in DR group (P ＜ 0.05).No patients developed dexmedetomidine-related adverse events.Conclusion Epidural dexmedetomidine 1 μg/kg significantly optimize the efficacy of ropivacaine when used for epidural anesthesia in the patients.

Objective To explore the neonatal effects and efficacy of dexmedetomidine on haemodynamics during cesarean section under general anesthesia.Methods Thirty-eight ASA Ⅰ or Ⅱ parturients with a single baby at full term in vertex presentation,scheduled for cesarean section under general anesthesia,were randomly divided into 2 groups (each group of 19 patients) by random digits table method:dexmedetomidine group and normal saline group.The patients in dexmedetomidine group received an intravenous infusion loading dose of 0.6 μ g/kg of dexmedetomidine,starting 10 min before induction of anesthesia,following with an intravenous infusion 0.4 μ g/ (kg ·h) of dexmedetomidine until peritoneal closure.The patients in normal saline group received an intravenous infusion of isovolumic of normal saline.Recording the systolic blood pressure (SBP),diastolic blood pressure (DBP) and heart rate (HR) before infusion (T0) and 10 min after the start of infusion (T1),at tracheal intubation (T2),at delivery of the baby (T3),15 min after delivery (T4),at end of operation (T5),at extubation (T6) and 15 min after extubation (T7).The blood of umbilical vein and umbilical artery was drawn for gas analysis,and the Apgar scores at 1 and 5 min were also recorded after delivery.Results The level of SBP,DBP and HR at T0 had no significant difference between two groups (P ＞ 0.05).In dexmedetomidine group,the level of SBP,DBP and HR were significantly higher at T2 than those at T0 [(136 ± 12) mmHg (1 mmHg =0.133 kPa) vs.(124 ± 9) mmHg,(83 ± 10) mmHg vs.(72 ± 6) mmHg,(93 ± 11) times/min vs.(81 ± 8) times/min] (P ＜ 0.05).In normal saline group,the level of SBP,DBP and HR at T2-6 [(151 ± 14),(137 ± 11),(132 ± 10),(132 ±9),(142± 13)mmHgvs.(125 ±9)mmHg;(94±13),(85±9),(80±8),(80±9),(86±11)mmHgvs.(74 ±7) mmHg; (122 ±15),(105 ±12),(90 ±9),(89 ± 10),(97 ±11) times/min vs.(81 ±9) times/min] were significantly lower (P ＜ 0.05).Compared with normal saline group,the level of SBP,DBP and HR were lower in dexmedetomidine group at T2-6(P ＜ 0.05).There were no significant difference not only about the blood gas analysis of umbilical vein and umbilical artery,but also about the Apgar scores at 1 and 5 min after delivery (P ＞ 0.05).Conclusion Administration of dexmedetomidine is effective in maintaining the maternal haemodynamic during the cesarean section under general anesthesia without adverse neonatal effects.

Objective To explore the effect of kidney transplantation from donation after brain death (DBD) donors with terminal acute renal failure (ARF).Method The clinical data of kidney transplantation from DBD donors with ARF were retrospectively analyzed,and only standard criteria donors (SCD) were included.The results of kidney transplants from ARF donors were compared with those of kidney transplants from DBD donors with normal renal function (serum creatinine ＜ 133μmol/L) performed from January 2012 to March 2014.Result There were 13 donors with ARF and 27 donors with normal renal function (non-ARF donors).The ARF donors had significantly higher terminal serum creatinine than the non-ARF donors (394.9 ± 176.8 vs.75.4 ± 28.6 μmol/L,P＜0.001),but the initial serum creatinine (79.1 ± 17.2 vs.71.0 ± 22.8 μmol/L) and the best creatinine clearance rate (128.3 ± 33.0 vs.129.8 ± 46.8 ml/min) of two groups showed no significant difference (P＞0.05).Twenty-six recipients received kidney transplants from ARF donors (ARF group) and 54recipients received kidney trangplants from donors with normal renal function (non-ARF group).There was no significant difference in the incidence of delayed graft function and acute rejection between ARF and non-ARF kidneys (0 vs.1.9％,and 11.5％ vs.7.4％,respectively).The ARF group had significantly lower estimated glomerular filtration rate (eGFR) at 1st month after transplantation (54.3 ± 16.9 vs.62.5 ± 14.2 mL·min 11.73 m 2,p =0.025),but the eGFRs of two groups were similar at 6th and 12th month after transplantation.During a mean follow-up period of 11.5 months (range 3 to 28 months),actual patient and graft survival rate for both groups were 100％.Conclusion Kidneys from DBD donors with terminal ARF have excellent short-term outcomes and may represent another potential method to safely expand the donor pool.