It is generally believed that liposomes modified with polyethylene glycol (PEG) have no or lower immunogenicity. However, based on many recent literatures, when the PEGylated liposomes were repeatedly applied to the same animal, the immune responses occurred. The first injection of PEGylated liposomes resulted in a reduction in the circulation time and an increase in hepatic and splenic accumulation of the second dose of PEGylated liposomes in a time-interval, which was called "accelerated blood clearance (ABC)" phenomenon. Such immunogenicity of PEGylated liposomes presents a barrier in the research of liposomal formulations and their use in the clinics. This review focused on the definition, the method of verification, the development of the reason for ABC phenomenon, influencing factors of ABC phenomenon, and discussed if other PEGylated nanocarriers also induce ABC phenomenon.

Objective To establish a method for the isolation of Zika virus and to gather experi-ences for viral isolation. Methods Suckling mice at age 1-3 days were inoculated with serum samples posi-tive for Zika virus through intracranial injection. All mice were sacrificed 6 days after the injection. Viral nu-cleic acids were extracted from brain, heart, liver, spleen, lung, kidney, muscle, skin and intestine tissue samples and analyzed by real-time RT-PCR. The supernatants of brain tissues positive for Zika virus were used for subculturing. Nested PCR was performed to amplify the NS5 gene of the isolated virus. The se-quences of NS5 gene were analyzed by using MEGA6. 0 software. Results All of the tissue samples were positive for Zika virus. Higher viral loads were detected in heart and brain tissue samples with cycle thresh-old (Ct) values of 24. 4 and 25. 3, respectively. The second generation of Zika virus was identified in suck-ling mice brain tissues 2 days after infection by using real-time RT-PCR. The amplified product of nested PCR was 972 bp in length. Sequencing analysis showed that the isolated Zika virus ( GDZ16002 strain) be-longed to the Asian lineage. Conclusion A strain of Zika virus was successfully isolated in China by using intracranial injection via a suckling mouse model. The isolated Zika virus belonged to the Asian lineage.

Objective To provide scientific evidences for Zika virus detection by clarifying the means by which Zika virus was discharged and the duration of corresponding processes. Methods Various samples of Zika cases were collected at different times and detected by using real-time RT-PCR. The positive samples were inoculated into cells and suckling mice through intracranial injection. The whole genome se-quences of those isolated Zika virus strain were sequenced and the results were further analyzed by comparing with the sequences of Zika virus from GenBank. Results The positive rates of Zika virus in urine, saliva and serum samples were 82. 4% (14/17), 82. 4% (14/17) and 52. 9% (9/17) respectively. The longest period of detected presence of Zika virus was found in urine samples amongst the three types of samples, fol-lowed by saliva and serum samples. Six Zika virus strains were isolated from 9 positive serum samples. Phy-logenetic analysis showed that the six genomes of Zika virus all belonged to Asia lineage, but located in two branches by Samoa and Venezuela strains. Conclusion This study indicated that urine, saliva and serum all could be used as the samples for routine detection of Zika virus. Urine and saliva samples showed higher detection rates of Zika virus RNA in comparison to serum samples, while Zika virus could be easily isolated from positive serum samples. Suckling mice were better for Zika virus isolation than cell lines.

Objective To analyze the risk factors of microvascular invasion (MVI) in patients with hepatocellular carcinoma (HCC),and to establish a preoperative prediction model for MVI.Methods The clinical data of 159 patients with HCC from the First Hospital of Jilin University treated from January 2012 to December 2014 were retrospectively analyzed.There were 128 males and 31 females.Univariate and multivariate logistic regression analysis of factors influencing the presence of MVI in HCC patients were carried out.Independent risk factors were scored based on the β values of multivariate analysis.Receiver operating characteristics (ROC) curves were used to evaluate the predictive value of the scores for the risk factor for MVI.Results Univariate and multivariate logistic regression analyses showed that age ≥ 60 years (OR=0.263,95％ CI:0.112 ～ 0.614),tumor diameter ≥5 cm (OR=3.902,95％ CI:1.784 ～ 8.583),neutrophil to lymphocyte ratio (NLR) ≥ 1.83 (OR=2.414,95％ CI:1.065～5.472) and platelet to lymphocyte ratio (PLR) ≥ 72.30 (OR =2.578,95％ CI:1.068～ 6.223) were the influencing factors of MVI in patients with HCC (P＜0.05).The preoperative prediction model of MVI was established using the MVI independent risk factor scores.The area under the ROC curve was 0.793 (95％ CI:0.723～ 0.862).The optimal cutoff value for the presence of MVI was 2.75 points,and the sensitivity was 0.72 and the specificity was 0.78.The MVI positive rates of patients with risk scores of 0 to 1.5,2.0 to 3.5,and 4.0 to 5.0 were 18.6％,42.9％,and 78.3％,respectively.Conclusion Age,tumor diameter,NLR,and PLR were independent factors influencing MVI in patients with HCC.The preoperative model based on the independent risk factor scores can be used to predict the presence of MVI in HCC patients.

BACKGROUND:With a gradually aging population,improving the ability to screen for the risk of death after arthroplasty and implementing timely personalized intervention programs for the increasing number of elderly patients with femoral neck fractures is key to improving the postoperative status of patients and prolonging survival expectations. OBJECTIVE:To investigate the risk factors for postoperative mortality in elderly patients with femoral neck fractures and to construct a nomogram predictive model to predict their mortality risk. METHODS:The study was conducted on 155 elderly patients(≥65 years old)who underwent arthroplasty for femoral neck fracture from January 2016 to January 2021,and 147 patients who met the inclusion criteria were analyzed to collect clinical data that may affect the patients'postoperative mortality.Single-factor and multi-factor Cox regression analyses were successively used to screen independent risk factors associated with postoperative mortality.The column line graph model was constructed and validated using Rstudio software. RESULTS AND CONCLUSION:(1)Age,frailty(age-adjusted Charlson comorbidities score),preoperative activity status,osteoporosis,and postoperative serum albumin level were five independent risk factors for postoperative mortality in elderly patients with femoral neck fractures(P<0.05).(2)The nomogram predictive model was constructed based on the results of multifactorial analysis,with a consistency index of 0.819(95%CI:0.771-0.868).Receiver operating characteristic curve analysis showed that the area under curve for 1-year and 3-year survival prediction was 0.8543 and 0.7263,respectively,indicating that the nomogram predictive model has good discriminatory and predictive power;calibration curve and decision curve analysis also showed good model discriminative power and clinical utility value.(3)The constructed nomogram predictive model has good diagnostic efficacy and accuracy,and can effectively assess the risk of postoperative death of patients.

BACKGROUND:Arthroplasty is the primary treatment for displaced femoral neck fractures in the elderly,and the choice of total hip arthroplasty versus hemiarthroplasty is currently the subject of considerable debate. OBJECTIVE:To compare the mid-and long-term survival status of total hip arthroplasty versus hemiarthroplasty under a direct anterior approach for displaced femoral neck fractures in the elderly based on the propensity score matching method. METHODS:One hundred and forty-seven elderly patients(≥65 years of age)with displaced femoral neck fractures were admitted from January 2016 to January 2021,of whom 88 had total hip arthroplasty(total hip arthroplasty group)and 59 had artificial femoral head replacement(hemiarthroplasty group).For the patients'preoperative comorbidities,the age-corrected Charlson Comorbidity Scale was used to quantify the scores and calculate patient frailty.The propensity score matching method was used to match the two groups 1:1 and to compare the operation time,bleeding,postoperative hospitalization time,hospitalization cost,nutritional index,postoperative complications,and mortality between the two groups after matching.Postoperative survival time was determined by Kaplan-Meier Survival analysis. RESULTS AND CONCLUSION:(1)After propensity score matching,a total of 42 matched pairs were successful in both groups,and the preoperative data of patients in both groups were balanced and comparable after matching(P>0.05).(2)Compared with the hemiarthroplasty group,operation time(79.71 minutes vs.59.07 minutes,P<0.001),bleeding volume(839.64 mL vs.597.83 mL,P=0.001),and hospitalization cost(56 508.15 yuan vs.41 702.85 yuan,P<0.001)were significantly higher in the total hip arthroplasty group.However,the mortality rate was lower in the total hip arthroplasty group than in the hemiarthroplasty group(36%vs.57%,HR=0.44,95%CI:0.23-0.87,P=0.018),and the mean survival time was longer in the total hip arthroplasty group than in the hemiarthroplasty group(59.4 months vs.43.7 months,P=0.024).(3)There were no statistically significant differences in postoperative hospitalization time,preoperative and postoperative nutritional indicators,and overall postoperative complication rate between the two groups(P>0.05).However,in terms of postoperative pain,the incidence of pain was significantly higher in the hemiarthroplasty group than that in the total hip arthroplasty group(24%vs.7%,P=0.035).(4)Overall,total hip arthroplasty has a better prognosis for survival,while hemiarthroplasty is more appropriate for patients with poor physical fitness.At the same time,postoperative pain may largely affect the quality and survival time of patients after hip arthroplasty.

Biosynthesis of vitamin B₁₂ (VB₁₂) requires the methylation at positions C-2 and C-7 of the precursor uroporphyrinogen Ⅲ (urogen Ⅲ) to precorrin-2 by S-adenosyl-L-methionine uroporphyrinogen Ⅲ methyltransferase (SUMT), which is a potential bottleneck step. Most of SUMTs are inhibited by urogen Ⅲ and by-product S-adenosyl-L-homocysteine (SAH). In order to mine an SUMT that lacks such an inhibitory property to drive greater flux through the VB₁₂ biosynthetic pathway, we cloned two SUMT genes (RCcobA1, RCcobA2) from Rhodobacter capsulatus SB1003 and expressed them in Escherichia coli BL21 (DE3). Thereafter, the two enzymes were purified and their specific activity of 27.3 U/mg, 68.9 U/mg were determined respectively. The latter was 2.4 times higher than PDcobA (27.9 U/mg) from Pseudomonas denitrifican. Additionally, RCcobA2 could tolerate over 70 μmol/L urogen Ⅲ, which has never been reported before. Hence, RCcobA2 can be used as an efficient enzyme to regulate the VB₁₂ metabolic pathway and enhance VB₁₂ production in industrial strains.

Objective:To evaluate the impact of bladder volume on dosimetric parameters of clinical target volume (CTV) and organs at risk (OAR) of intensity modulated proton therapy (IMPT) for localized prostate cancer during the treatment planning and daily treatment.Methods:Clinical data of 25 patients with localized prostate cancer admitted to Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine from November 2021 to June 2022 and enrolled in the "Proton Therapy System" (SAPT-PS-01) registered clinical trial were retrospectively analyzed. All patients were male and the median age was 72 years old. A total of 30 sets of IMPT plans were obtained. Based on the planning CT (30 sets) and weekly verification CT during treatment (172 sets), bladder volume, CTV and OAR dose parameters were collected. Spearman correlation analysis was used to evaluate the correlation between bladder volume in CT and the dosimetric parameters of CTV and OAR during IMPT plans, and Wilcoxon-Mann-Whitney test was adopted to compare the dosimetric parameters of CTV and OAR among different bladder volume change groups.Results:The V 95% of CTV1 and CTV2 were both 100.0%±0.0% in IMPT plans. Bladder volume was significantly negatively correlated with D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE) of the bladder ( P<0.001, 0.003, <0.001, <0.001,<0.001), and D mean, V 50 Gy(RBE) of the small intestine (both P<0.001). During treatment, bladder D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE)( P<0.001, 0.001, <0.001, <0.001, <0.001), rectal D mean, V 50 Gy(RBE), V 40 Gy(RBE) (all P<0.001), small intestine D mean, V 50 Gy (RBE) (both P<0.001) of patients with bladder volume increase >20% compared to baseline were significantly decreased compared to those in IMPT plans. But CTV1 V 100%, and CTV2 V 95% were significantly decreased too( P=0.029, 0.020). In the bladder volume decreased>20% patients, the D mean, V 70 Gy(RBE), V 60 Gy(RBE), V 50 Gy(RBE), V 40 Gy(RBE) of the bladder were significantly increased compared to those in IMPT plans (all P<0.001). However, a bladder volume reduction of ≤20% and increase of ≤20% from baseline had no significant impact on CTV and OAR dosimetric parameters during treatment. Conclusions:For patients with localized prostate cancer undergoing proton therapy, a certain bladder volume should be ensured during planning CT scans. During the daily treatment, the bladder volume should be maintained between 80%-120% of the baseline level to ensure CTV coverage and good dose sparing to OAR.

Objective: To carry out variant analysis for a fetus suspected with harlequin ichthyosis (HI). Methods: Whole exome sequencing (WES) was employed to detect potential variant in the fetus. Suspected variant was validated by Sanger sequencing. Results: A homozygous missense variant c. 6858delT (p.F2286fs) was detected in the fetus, for which both parents were heterozygous carriers. Pathological analysis confirmed the diagnosis of HI. Conclusion The c. 6858delT variant of the ABCA12 gene probably underlies the disease in the fetus.

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound,the examiner and interpreter of the image are critical care medicine physicians.The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes.With the idea of critical care medicine as the soul,it can integrate the above information and clinical information,bedside real-time diagnosis and titration treatment,and evaluate the therapeutic effect so as to improve the outcome.CUS is a traditional technique which is applied as a new application method.The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept,implementation and application of CUS.It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure.At the same time,the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications,and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS.Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group,based on the rich experience of clinical practice in critical care and research,combined with the essence of CUS,to learn the traditional ultrasonic essence,established the clinical application technical specifications of CUS,including in five parts:basic view and relevant indicators to obtain in CUS;basic norms for viscera organ assessment and special assessment;standardized processes and systematic inspection programs;examples of CUS applications;CUS training and the application of qualification certification.The establishment of applied technology standard is helpful for standardized training and clinical correct implementation.It is helpful for clinical evaluation and correct guidance treatment,and is also helpful for quality control and continuous improvement of CUS application.