[Establishment of a rapid method for detection of influenza A/B virus' antigens]

This study aims to develop a rapid and convenient test card for simultaneous detection of influenza A and influenza B viruses using quantum dot-based immunochromatographic assay. The test card consists of a test strip and a plastic casing. The test strip is composed of absorbent paper, a buffer pad, nitrocellulose membrane (NC membrane), sample pad, quantum dot-labeled antibody pad, and polyvinyl chloride (PVC) board. The NC membrane is coated with mouse monoclonal antibodies against influenza A and influenza B viruses for the T lines (test lines), and reference proteins A and B for the C line (control line). The quantum dot-labeled antibody pad contains mouse monoclonal antibody-quantum dot conjugates against influenza A and influenza B viruses. The results showed that the detection limit of the test card for both viruses ranged from 1.51 ×102 to 2.71×103 TCID50/ml, indicating its sensitivity for accurate detection of influenza A and influenza B viruses without being affected by various variants. The test card exhibited specific reactions with different subtypes of influenza A and influenza B virus culture fluids and showed no cross-reactivity with adenovirus, novel coronavirus, Mycoplasma pneumoniae, respiratory syncytial virus, Staphylococcus aureus, and other pathogens. Overall, the sensitivity and specificity of the test card for simultaneous detection of influenza A and influenza B viruses meet the requirements for clinical use. It offers the advantages of simplicity, rapidity, and no requirement for special equipment, enabling quick auxiliary diagnosis to prevent disease transmission.

Improvement of Precision in Recombinant Adeno-Associated Virus Infectious Titer Assay with Droplet Digital PCR as an Endpoint Measurement

Recombinant adeno-associated virus (rAAV) has been utilized successfully for in vivo gene delivery for treatment of a variety of human diseases. To sustain the growth of recombinant AAV gene therapy products, there is a critical need for the development of accurate and robust analytical methods. Fifty percent tissue culture infectious dose (TCID50) assay is an in vitro cell-based method widely used to determine AAV infectivity, and this assay is historically viewed as a challenge due to its high variability. Currently, quantitative PCR (qPCR) serves as the endpoint method to detect the amount of replicated viral genome after infection. In this study, we optimize the TCID50 assay by adapting endpoint detection with droplet digital PCR (ddPCR). We performed TCID50 assays using ATCC AAV-2 reference standard stock material across 18 independent runs. The cell lysate from TCID50 assay was then analyzed using both qPCR and ddPCR endpoint to allow for direct comparison between the two methods. The long-term 1-year side-by-side comparison between qPCR and ddPCR as endpoint measurement demonstrated improved interassay precision when the ddPCR method was utilized. In particular, after the addition of a novel secondary set threshold for infectivity scoring of individual wells, the average infectious titer of 18 runs is 6.45E+08 with % coefficient of variation (CV) of 42.5 and 5.63E+08 with % CV of 34.9 by qPCR and ddPCR, respectively. In this study, we offer improvements of infectious titer assay with (1) higher interassay precision by adapting ddPCR as an endpoint method without the need of standard curve preparation; (2) identification of a second "set threshold" value in infectivity scoring that improves assay precision; and (3) application of statistical analysis to identify the acceptance range of infectious titer values. Taken together, we provide an optimized TCID50 method with improved interassay precision that is important for rAAV infectious titer testing during process development and manufacturing.

Preoperative prediction of microvascular invasion and perineural invasion in pancreatic ductal adenocarcinoma with 18F-FDG PET/CT radiomics analysis

AIM

To develop and validate a predictive model based on 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) radiomics features and clinicopathological parameters to preoperatively identify microvascular invasion (MVI) and perineural invasion (PNI), which are important predictors of poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Preoperative ¹⁸F-FDG PET/CT images and clinicopathological parameters of 170 patients in PDAC were collected retrospectively. The whole tumour and its peritumoural variants (tumour dilated with 3, 5, and 10 mm pixels) were applied to add tumour periphery information. A feature-selection algorithm was employed to mine mono-modality and fused feature subsets, then conducted binary classification using gradient boosted decision trees.

RESULTS

For MVI prediction, the model performed best on a fused subset of ¹⁸F-FDG PET/CT radiomics features and two clinicopathological parameters, with an area under the receiver operating characteristic curve (AUC) of 83.08%, accuracy of 78.82%, recall of 75.08%, precision of 75.5%, and F1-score of 74.59%. For PNI prediction, the model achieved best prediction results only on the subset of PET/CT radiomics features, with AUC of 94%, accuracy of 89.33%, recall of 90%, precision of 87.81%, and F1 score of 88.35%. In both models, 3 mm dilation on the tumour volume produced the best results.

CONCLUSIONS

The radiomics predictors from preoperative ¹⁸F-FDG PET/CT imaging exhibited instructive predictive efficacy in the identification of MVI and PNI status preoperatively in PDAC. Peritumoural information was shown to assist in MVI and PNI predictions.

[A retrospective analysis of clinical characteristics and prognostic factors for 152 cases of Staphylococcus aureus bloodstream infection]

To understand the clinical characteristics of Staphylococcus aureus bloodstream infection and the main risk factors affecting clinical prognosis, providing a reference for clinical prevention and control of Staphylococcus aureus bloodstream infection. In this study, the clinical data of 152 patients with Staphylococcus aureus bloodstream infection admitted to Guangdong Provincial People's Hospital from January 2019 to December 2021 were retrospectively analyzed by reviewing the electronic medical record system, including underlying diseases, clinical characteristics, risk factors, and bacterial resistance. Statistical methods such as Chi-Squared Test and t Test were used to analyze the related risk factors that may affect the clinical characteristics and prognosis of patients with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection, then the variables with P<0.05 in univariate analysis were included in the multivariate logistic regression model to analyze the independent risk factors of poor prognosis. The results showed among 152 patients with Staphylococcus aureus bloodstream infection, 50 patients (32.89%) were infected with MRSA. In comparison, 102 patients (67.11%) were infected with methicillin-sensitive Staphylococcus aureus (MSSA). Except for rifampicin, the resistance rate of MRSA to commonly used antibiotics was all higher than that of MSSA, and the difference was statistically significant (Chi-square values were 8.272, 11.972, 4.998, 4.776, respectively;all P-values are less than 0.05). Strains resistant to vancomycin, linezolid, and quinupristin/dalfopristin were not found. In the MRSA group, indwelling catheter and drainage tube, carbapenems, and β-lactamase inhibitor treatment were significantly higher than the MSSA group. The difference was statistically significant (P<0.05). The incidence of poor prognosis of bloodstream infection in the MRSA group was higher than that in the MSSA group (34.00% vs 13.73%), and the difference was statistically significant (χ²=8.495, P<0.05). No independent risk factors associated with poor prognosis were found in the included patients with MRSA bloodstream infection.Multivariate Logistic regression model analysis showed that solid malignant tumors (OR=13.576, 95%CI: 3.352-54.977, P<0.05), mechanical ventilation (OR=7.468, 95%CI: 1.398-39.884, P<0.05) were the most important independent risk factors for poor prognosis in patients with Staphylococcus aureus bloodstream infection. In summary, the poor prognosis rate of MRSA bloodstream infection is higher than that of MSSA. The clinical evaluation of related risk factors should be strengthened, targeted prevention and control interventions should be taken to improve the prognosis of patients with Staphylococcus aureus bloodstream infection, and the use of antibiotics should be rational and standardized, to control bacterial infection and drug resistance effectively.

[Research progress of CRISPR/Cas biosensors based on different signal amplification strategies]

CRISPR/Cas(the clustered regularly interspaced short palindromic repeats-CRISPR associated)system exists in most bacteria and all archaea. It is an important strategy for bacteria and archaea to resist foreign nucleic acid invasion and use for self-defense. The CRISPR/Cas system is a simple, fast, and specific diagnostic tool, which is widely used in agriculture, industry, animal husbandry, and medicine. This article mainly introduces and discusses recently advantages and limitations of biosensors combining CRISPR/Cas system with fluorescence, visualization and surface enhanced raman related technologies, as well as future research directions.

[Advances in the relationship between lung cancer and microbiota]

Interaction exists in lung cancer and microbiota. Lung microecological homeostasis can improve the immune tolerance, enhance immune suppression, and inhibit inflammatory responses, to reduce the lung cancer; while lung cancer can lead to pulmonary microecological imbalance, change the lung environment, and promote tumor cell proliferation. Therefore, modulating microbial flora and microecological immunotherapy may be a potential and preventive treatment for lung cancer, to restore tumor immunosuppression and improve patient survival. However, the individual differences in the lung microecology, because of different genetics, ethnic characteristics, and dietary habits, increasing the difficulty of precise diagnosis and treatment, which is also the current bottleneck in the application of microecological immunotherapy. Otherwise, the effectiveness of regulatory measures such as probiotics, prebiotics or antimicrobials is questionable. The research on microbial flora is still in its infancy, and further exploration is needed to form a standardized, effective, and precise treatment plan. So, standardized, effective, and precise microbial flora treatment strategies need to be further explored.

Proteomic Analysis of Adenovirus 5 by UHPLC-MS/MS: Development of a Robust and Reproducible Sample Preparation Workflow

Adenoviruses (AdVs) have recently become widely used therapeutic vectors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. AdVs are large, nonenveloped viruses with an icosahedral capsid formed from several proteins that encloses double-stranded DNA. These proteins are the main components and key players in initial stages of infection by the virus particles, so their heterogeneity and content must be evaluated to ensure product and process consistency. Peptide mapping can provide detailed information on these proteins, e.g., their amino acid sequences and post-translational modifications (PTMs), which is crucial for the development and optimization of the manufacturing processes. However, sample preparation remains the main bottleneck for successful proteomic analysis of the viral proteins (VPs) of AdVs due to their low concentrations and vast stoichiometric ranges. To address this problem, we have developed a fast and efficient protocol for preparing samples for proteomic analysis of VPs of AdV5 that requires no cleaning step prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The approach enabled identification of 92% of amino acids in AdV5 VPs on average and quantification of 53 PTMs in a single LC-MS/MS experiment using trypsin protease. The data obtained demonstrate the method's potential utility for supporting the development of novel AdV-based gene therapy products (GTPs).

[Clinical application of expanded internal mammary artery perforator flap combined with vascular supercharge in reconstruction of faciocervical scar]

Objective: To summarize the clinical experience of expanded internal mammary artery perforator (IMAP) flap combined with vascular supercharge in reconstruction of faciocervical scar. Methods: The retrospective observational study was conducted. From September 2012 to May 2021, 23 patients with postburn or posttraumatic faciocervical scars who met the inclusion criteria were admitted to Shanghai Ninth People's Hospital of Shanghai Jiao Tong University School of Medicine, including 18 males and 5 females, aged from 11 to 58 years, all of whom were reconstructed with expanded IMAP flaps. At the first stage, one or two skin and soft tissue expander (s) with appropriate rated capacity were implanted in the anterior chest area according to the location and size of the scars. The IMAP, thoracic branch of supraclavicular artery, and lateral thoracic artery were preserved during the operation. The skin and soft tissue expanders were inflated with normal saline after the operation. The flaps were transferred during the second stage. The dominant IMAP was determined preoperatively using color Doppler ultrasound (CDU) blood flow detector. The faciocervical scars were removed, forming wounds with areas of 9 cm×7 cm-28 cm×12 cm, and the perforators of superficial temporal artery and vein or facial artery and vein were preserved during the operation. The flaps were designed according to the area and size of the wounds after scar resection with the dominant IMAP as the pedicle. Single-pedicle IMAP flaps were used to repair small and medium-sized wounds. For larger defects, the blood perfusion areas of vessels in the anterior chest were evaluated by indocyanine green angiography (ICGA). In situations where the IMAP was insufficient to nourish the entire flap, double-pedicle flaps were designed by using the thoracic branch of supraclavicular artery or lateral thoracic artery for supercharging. Pedicled or free flap transfer was selected according to the distance between the donor areas and recipient areas. After transplantation of flaps, ICGA was conducted again to evaluate blood perfusion of the flaps. The donor sites of flaps were all closed by suturing directly. Statistics were recorded, including the number, rated capacity, normal saline injection volume, and expansion period of skin and soft tissue expanders, the location of the dominant IMAP, the total number of the flaps used, the number of flaps with different types of vascular pedicles, the flap area, the flap survival after the second stage surgery, the occurrence of common complications in the donor and recipient areas, and the condition of follow-up. Results: Totally 25 skin and soft tissue expanders were used in this group of patients, with rated capacity of 200-500 mL, normal saline injection volume of 855-2 055 mL, and expansion period of 4-16 months. The dominant IMAP was detected in the second intercostal space (20 sides) or the third intercostal space (5 sides) before surgery. A total of 25 expanded flaps were excised, including 2 pedicled IMAP flaps, 11 free IMAP flaps, 4 pedicled thoracic branch of supraclavicular artery+free IMAP flaps, and 8 free IMAP+lateral thoracic artery flaps, with flap areas of 10 cm×8 cm-30 cm×14 cm. After the second stage surgery, tip necrosis of flaps in three patients occurred, which healed after routine dressing changes; one patient developed arterial embolism and local torsion on the vascular pedicle at the anastomosis of IMAP and facial artery, and the blood supply recovered after thrombectomy and vascular re-anastomosis. Fourteen patients underwent flap thinning surgery in 1 month to 6 months after the second stage surgery. The follow-up for 4 months to 9 years showed that all patients had improved appearances of flaps and functions of face and neck and linear scar in the donor sites of flaps, and one female patient had obvious nipple displacement and bilateral breast asymmetry. Conclusions: The expanded IMAP flap is matched in color and texture with that of the face and neck, and its incision causes little damage to the chest donor sites. When combined with vascular supercharge, a double-pedicle flap can be designed flexibly to further enhance the blood supply and expand the flap incision area, which is a good choice for reconstruction of large faciocervical scar.

A novel protocol for in-depth analysis of recombinant adeno-associated virus capsid proteins using UHPLC-MS/MS

RATIONALE

In-depth characterization of the three capsid viral proteins (VPs 1, 2, and 3) of adeno-associated viruses (AAVs) is immediately needed to ensure the consistency in gene therapy products and processes. These proteins are typically present at very low concentrations in matrices containing high concentrations of excipients and salts. Thus, there is a need for convenient methods for sample preparation before proteomic analysis. The aim of this study was to meet this need by developing a fast, reliable approach for isolating VPs in a manner enabling their efficient digestion and in-depth characterization using liquid chromatography-mass spectrometry (LC-MS).

METHODS

VPs from Anc80 were precipitated with different organic solvents, and the resulting precipitates were dissolved in either sodium deoxycholate (SDC) and N-dodecyl-beta-D-maltoside (DDM) or guanidine hydrochloride (Gu-HCl). The peptides obtained by the following enzymatic digestion by either trypsin or Asp-N were analyzed using LC-MS/MS.

RESULTS

We found that precipitation with chloroform/methanol/water results in fast, efficient preparation of VP samples, allowing 100% and 99.2% amino acid sequence coverage of VP1 for trypsin and Asp-N digestion, respectively. This also allowed complete sequence confirmation of VP1, VP2, and VP3 of Anc80, as well as characterization of the amino acid sequences of the N- and C-terminal regions of each VP, together with their post-translational modifications (PTMs).

CONCLUSIONS

The presented method enables fast, reliable, and relatively cheap sample preparation for identifying AAV serotypes and characterizing the heterogeneity of capsid viral proteins, including their PTMs.

Evaluation of the probiotic and functional potential of Lactobacillus agilis 32 isolated from pig manure

Escherichia coli is a symbiotic bacterium in humans and animals and an important pathogen of humans and animals. Prevention and suppression of E. coli infection is of great concern. In this study, we isolated a strain of Lactobacillus agilis 32 from pig manure and evaluated its biological characteristics, and found that its bacterial survival rate was 25% after 4 h of treatment at pH 2, and under the condition of 0·5% bile concentration, its survival rate exceeds 30%. In addition, L. agilis 32 has a cell surface hydrophobicity of 77·8%, and exhibits 67·1% auto-aggregation and 63·2% aggregation with Enterotoxigenic E. coli 10 (ETEC 10). FITC fluorescence labelling showed that the fluorescence intensity of cecum was significantly higher than that of duodenum, jejunum or colon (P < 0·05), but no significant difference from ileum. Lactobacillus agilis 32 bacterial culture and CFS showed average inhibition zone diameters of 14·2 and 15·4 mm respectively. Lactobacillus agilis 32 CFS treatment can significantly reduce the pathogenicity of ETEC 10. These results show that L. agilis 32 is an active and potential probiotic, and it has a good antibacterial effect on ETEC10, which provides basic research for probiotics to prevent and treat intestinal diarrhoea pathogen infection.

[The prognostic value of myoglobin difference in sepsis related chronic critical illness]

Objective: To investigate the predictive value of myoglobin (Mb) for the prognosis of sepsis related chronic critical illness (CCI). Methods: Retrospective study was conducted on septic patients with the length of ICU stay equal or greater than 14 days, and sepsis-related organ failure assessment (SOFA) score equal or greater than 2 on the 14th day in ICU in the First Department of Critical Care Medicine at the First Affiliated Hospital of Sun Yat-sen University from January 2017 to March 2020. Patients' clinical and laboratory data were collected on the 1st and 14th day in ICU. The survival on day 28 in ICU was recorded. According to the myoglobin levels on day 1 and day 14, all subjects were divided into myoglobin elevation group and decline group. Kaplan-Meier survival curve was used to compare the cumulative survival rate at day 28. Cox regression analysis was used to analyze the independent risk factors of mortality. Receiver operating characteristic (ROC) curve was used to analyze the prognostic value of myoglobin. Results: A total of 131 patients with sepsis related CCI were recruited, including 58 patients in the elevation group and 73 in the decline group. The Mb level in elevation group on day 1 was significantly lower than that in decline group [172.40(59.99, 430.53) μg/L vs. 413.60(184.40, 1 328.50) μg/L, Z=3.749, P=0.000], and the Mb level on day 14 was the opposite change in two groups [483.65(230.38, 1 471.75)μg/L in elevation group vs. 132.20(76.86, 274.35)μg/L in decline group, Z=5.595, P=0.000]. Kaplan-Meier survival curve analysis showed that the 28-day cumulative survival rate of the elevation group was significantly lower than that of decline group (χ²=7.051, P=0.008). Cox ratio regression analysis suggested that elevated myoglobin was an independent risk factor for 28-day mortality in septic patients with CCI (OR=2.534, 95%CI 1.212-5.295, P=0.013). ROC curve analysis suggested that the sensitivity of myoglobin elevation in predicting mortality related to CCI within 28 days was 64.5%, and the specificity was 32.0% with area under the curve(AUC) 0.661(95%CI 0.550-0.773,P=0.007) and Jorden Index was 0.325. Conclusion: Elevated myoglobin, an independent risk factor for mortality within 28 days in ICU, can predict the prognosis of sepsis related chronic critical illness.

The clinical value of the combined detection of sEGFR, CA125 and HE4 for epithelial ovarian cancer diagnosis

OBJECTIVE

This study aims to investigate the clinical value of combined detection of serum soluble epidermal growth factor receptor (sEGFR), cancer antigen 125 (CA125), and human epididymis protein 4 (HE4) in the diagnosis of epithelial ovarian cancer (EOC).

PATIENTS AND METHODS

From December 2017 to October 2018, the serum samples were obtained from the Affiliated Hospital of Xuzhou Medical University, with 30 patients as EOC group, 30 patients with benign ovarian neoplasms as benign group, and 17 healthy subjects as healthy group. Besides, among 30 EOC patients, 9 serum samples were obtained from pre-operative and post-operative EOC patients. The levels of serum sEGFR were detected by enzyme-linked immunosorbent assay (ELISA), while CA125 and HE4 were detected by enhanced chemiluminescence immunoassay (ECLIA). The diagnostic value was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

The levels of serum sEGFR, CA125, and HE4 in EOC group were significantly higher than those in benign group (p<0.05) and healthy group (p<0.05). When using a single tumor marker, the CA125 shows the highest sensitivity (93.30%) and HE4 shows the highest specificity (97.87%). The specificity of combined detection of serum sEGFR, CA125, and HE4 was 100%, which was significantly higher than that using a single tumor marker. The area under the ROC curve (AUC) of combined detection of serum sEGFR, CA125, and HE4 (0.965) was much higher than that of the single detection and higher than that of combined detection of CA125 and HE4 (0.940). Moreover, the level of serum sEGFR in post-operative EOC group was significantly lower than that in the corresponding pre-operative EOC group (p<0.05).

CONCLUSIONS

Our study shows that combined detection of serum sEGFR, CA125, and HE4 increases the specificity and efficiency in EOC diagnosis, indicating that sEGFR could be a potential biomarker for the diagnosis and prognosis of EOC.

A ligand-independent fast function of RARα promotes exit from metabolic quiescence upon T cell activation and controls T cell differentiation

Vitamin A metabolites play important roles in T cell activation and differentiation. A conventional model of RARα function relies upon retinoic acid (RA)-liganded RARα binding to specific DNA motifs to regulate gene expression in the nucleus. However, this genomic function fails to explain many of the biological responses of the RA-RARα axis on T cells. We generated a mouse line where RARα is over-expressed in T cells to probe RARα function with unprecedented sensitivity. Using this model together with mice specifically lacking RARα in T cells, we found that RARα is required for prompt exit from metabolic quiescence in resting T cells upon T cell activation. The positive effect of RARα on metabolism is mediated through PI3K and subsequent activation of the Akt and mTOR signaling pathway. This largely non-genomic function of RARα is surprisingly ligand-independent and controls the differentiation of effector and regulatory T cell subsets.

KMT2D Deficiency Impairs Super-Enhancers to Confer a Glycolytic Vulnerability in Lung Cancer

Epigenetic modifiers frequently harbor loss-of-function mutations in lung cancer, but their tumor-suppressive roles are poorly characterized. Histone methyltransferase KMT2D (a COMPASS-like enzyme, also called MLL4) is among the most highly inactivated epigenetic modifiers in lung cancer. Here, we show that lung-specific loss of Kmt2d promotes lung tumorigenesis in mice and upregulates pro-tumorigenic programs, including glycolysis. Pharmacological inhibition of glycolysis preferentially impedes tumorigenicity of human lung cancer cells bearing KMT2D-inactivating mutations. Mechanistically, Kmt2d loss widely impairs epigenomic signals for super-enhancers/enhancers, including the super-enhancer for the circadian rhythm repressor Per2. Loss of Kmt2d decreases expression of PER2, which regulates multiple glycolytic genes. These findings indicate that KMT2D is a lung tumor suppressor and that KMT2D deficiency confers a therapeutic vulnerability to glycolytic inhibitors.

Li(Cd,Mn)P: a new cadmium based diluted ferromagnetic semiconductor with independent spin & charge doping

We report a new diluted ferromagnetic semiconductor Li_1+y(Cd,Mn)P, wherein carrier is doped via excess Li while spin is doped by isovalence substitution of Mn²⁺ into Cd²⁺. The extended Cd 4d-orbitals lead to more itinerant characters of Li_1+y(Cd,Mn)P than that of analogous Li_1+y(Zn,Mn)P. A higher Curie temperature of 45 K than that for Li_1+y(Zn,Mn)P is obtained in Li_1+y(Cd,Mn)P polycrystalline samples by Arrott plot technique. The p-type carriers are determined by Hall effect measurements. The first principle calculations and X-ray diffraction measurements indicate that occupation of excess Li is at Cd sites rather than the interstitial site. Consequently holes are doped by excess Li substitution. More interestingly Li_1+y(Cd,Mn)P shows a very low coercive field (<100 Oe) and giant negative magnetoresistance (~80%) in ferromagnetic state that will benefit potential spintronics applications.

[Treatment of central nervous system leukemia with CD19-chimeric antigen receptor T-cell immunotherapy: two cases report and literature review]

目的

探讨CAR-T细胞治疗中枢神经系统白血病（CNSL）的有效性和安全性。

方法

报道两例合并CNSL白血病患者抗CD19 CAR-T细胞治疗的过程及结果，并对相关文献进行复习。

结果

两例患者骨髓细胞形态学特征分别为伴B淋系表达的急性髓系白血病（AML）-M₂和急性B淋巴细胞白血病（B-ALL），免疫分型符合AML-M₂和B-ALL的异常表现，临床和实验室检查符合CNSL诊断标准，诊断明确后予以抗CD19 CAR-T细胞治疗，输注总量均为5.0×10⁶/kg。回输后两例患者中枢神经系统症状缓解。例1影像学异常消失，治疗过程中出现细胞因子释放综合征（CRS），药物干预后好转；例2脑脊液微小残留病转阴，未出现明显CRS反应。

结论

CAR-T细胞治疗有望缓解CNSL，改善患者预后。

[An experimental study of CD4 targeted chimeric antigen receptor modified T cell with anti-lymphoma activity]

目的

探讨针对CD4膜蛋白的CAR-T细胞对CD4⁺T细胞淋巴瘤细胞的靶向特异性杀伤作用。

方法

采用重组DNA技术构建含4-1BB共刺激分子的第二代针对CD4的CAR慢病毒载体，应用293T细胞包装慢病毒，采用流式细胞术检测T细胞的转染效率及T细胞亚群动态变化，采用流式细胞术微球法检测培养上清中IFN-γ浓度。

结果

①构建的慢病毒载体转染激活的T细胞后CAR膜蛋白阳性率达到50.0%~70.0%。T细胞激活后部分CD8⁺T细胞弱表达（dim）CD4膜蛋白。T细胞转染针对CD4的CAR慢病毒后CD4⁺ T细胞、CD8⁺ CD4^dim T细胞逐渐被清除。②CAR-T细胞、对照组T细胞（空载体转染的T细胞）以8∶1效靶比分别与CD4⁺人T细胞淋巴瘤细胞株KARPAS 299细胞共培养24 h，杀伤效率分别为（96.9±2.1）%和（11.2±3.1）%，前者明显高于后者（t=7.137，P=0.028）。③CAR-T细胞单独培养，与转染慢病毒载体表达人CD4的K562细胞（K562-CD4细胞）、K562细胞共培养后上清中IFN-γ浓度分别为（1 785±268）、（15 648±2 168）、（1 978±354）pg/ml，CAR-T细胞与K562-CD4细胞共培养上清IFN-γ浓度明显高于其他两组，差异有统计学意义（P<0.01）。

结论

CD4特异性CAR-T细胞效应细胞免疫表型为CD8⁺ CD4⁺ T细胞，在体外具有杀伤正常CD4⁺ T细胞和CD4⁺ T细胞淋巴瘤细胞的活性，对于CD4^dim T细胞也有较好的清除活性。

Macrophage populations show an M1-to-M2 transition in an experimental model of coronal pulp tissue engineering with mesenchymal stem cells

AIM

To assess M1/M2 macrophage phenotypes in a coronal pulp regeneration model in rats, under the hypothesis that there are dynamic M1/M2 phenotype changes during the different stages of the pulp regeneration.

METHODOLOGY

The maxillary first molars of Wistar rats were pulpotomized, and biodegradable hydrogel-made scaffolds carrying rat bone marrow mesenchymal stem cells were implanted in the pulp chamber. After 3, 7 and 14 days, samples were processed for (i) histological analysis and double immunoperoxidase staining for CD68 (a general macrophage marker) and one of either CCR7 (an M1 marker), CD163 (an M2 marker) or CD206 (an M2 marker); (ii) real-time PCR for AIF1 (an M1 marker), CD163, CD206, IL-10 and TNF-α mRNA expression; and (iii) Western blotting for the detection of CD68, CCR7 and CD206 proteins.

RESULTS

Histological analysis of the implanted region revealed sparse cellular distribution at 3 days, pulp-like tissue with a thin dentine bridge-like structure at 7 days, and dentine bridge-like mineralized tissue formation and resorption of most scaffolds at 14 days. CCR7+ macrophages had the highest density at 3 days, and then significantly decreased until 14 days (P < 0.05). In contrast, M2 marker (CD163 or CD206) expressing macrophages had the lowest density at 3 days and significantly increased until 14 days (P < 0.05). AIF1 and TNF-α mRNA levels, and CD68 and CCR7 protein levels were highest at 3 days. CD163 and CD206 mRNA levels, and CD206 protein levels increased with time and showed the highest at 14 days. IL-10 mRNA was highest at 3 days, decreased at 7 days and increased at 14 days.

CONCLUSIONS

Macrophages in the regenerating pulp tissue underwent a distinct transition from M1-dominant to M2-dominant, suggesting that the M1-to-M2 transition of macrophages plays an important role in creating a favourable microenvironment necessary for pulp tissue regeneration.

[One case report of subglottic schwannomaresected with CO₂ laser]

A 26 years female patient was in hospital with repeated asthma, hoarseness and dyspnoea. Fiber laryngoscope examination showed that a mass in subglottic area. The tumor was completelyresected with CO₂ laser and finally diagnosed as subglottic schwannomaby pathological examination. The characteristics of subglottic schwannoma and the resection methods of CO₂ laser were discussed. There was no recurrence in three months follow.

Exploration of Fecal Microbiota Transplantation in the Treatment of Refractory Diarrhea After Renal Transplantation

OBJECTIVE

Exploration of fecal microbiota transplantation in the treatment of refractory diarrhea after renal transplantation.

METHODS

Summarize the etiology of 120 cases with diarrhea after renal transplantation from 2014 to 2017 in our hospital. There were 4 recipients of refractory diarrhea who accepted fecal microbiota transplantation with informed consent, and we collected clinical data of stool and bacterial culture, gut microbiota analysis, graft function, electrolytes, immunosuppressant concentrations of prognostic evaluation of patients with fecal transplantation.

RESULTS

The absorption of electrolyte is slightly higher and concentration of tacrolimus and creatinine were not significantly changed compared with before.

CONCLUSION

Fecal microbiota transplantation provides a new choice to refractory diarrhea after renal transplantation as an innovative treatment, but the effectiveness of fecal microbiota transplantation needs long-term observation and further evaluation through large sample data.

BMI1 regulates androgen receptor in prostate cancer independently of the polycomb repressive complex 1

BMI1, a polycomb group (PcG) protein, plays a critical role in epigenetic regulation of cell differentiation and proliferation, and cancer stem cell self-renewal. BMI1 is upregulated in multiple types of cancer, including prostate cancer. As a key component of polycomb repressive complex 1 (PRC1), BMI1 exerts its oncogenic functions by enhancing the enzymatic activities of RING1B to ubiquitinate histone H2A at lysine 119 and repress gene transcription. Here, we report a PRC1-independent role of BMI1 that is critical for castration-resistant prostate cancer (CRPC) progression. BMI1 binds the androgen receptor (AR) and prevents MDM2-mediated AR protein degradation, resulting in sustained AR signaling in prostate cancer cells. More importantly, we demonstrate that targeting BMI1 effectively inhibits tumor growth of xenografts that have developed resistance to surgical castration and enzalutamide treatment. These results suggest that blocking BMI1 alone or in combination with anti-AR therapy can be more efficient to suppress prostate tumor growth.

Selectivity shift from paraffins to α-olefins in low temperature Fischer–Tropsch synthesis in the presence of carboxylic acids

A shift to long chain α-olefins has been observed during Fischer–Tropsch synthesis over Co catalysts in the presence of carboxylic acids.

[Specific cytotoxicity of a novel HER2-based chimeric antigen receptor modified T lymphocytes against HER2-positive tumor cells]

Objective: To construct the third generation chimeric antigen receptor based on a novel humanized anti-HER2 H1-2 scFv, and to investigate the specific cytotoxicity of H1-2 CAR modified T lymphocytes(CAR-T) against HER2(+) tumor cells. Method: The expression cassette of the third generation CAR gene and anti-HER2 H1-2 scFv were constructed and cloned into lentivirus transfer plasmid, and then the third generation H1-2 CAR was transduced into human T lymphocytes using lentivirus.Enzyme linked immunosorbent assay was used to detect the expression of cytokines IL2, and LDH release assay was used to detect the cytotoxic effect of the H1-2 CAR-T.Finally, NOD/SCID mice and HER2(+) breast cancer cell line SKBR3 were used to detect the anti-tumor effect of H1-2 CAR-T in vivo. Results: The third generation H1-2 CAR was successfully constructed.H1-2 CAR-T secreted high dose of IL2 after confrontation with HER2(+) breast cancer cells.In vitro, the cytolytic rate of H1-2 CAR-T on high expression HER2(+) tumor cells was significantly higher than that in low expression HER2 or non-expression HER2 tumor cells. At the efficacy to target ratio of 20, the cytolytic rate of H1-2 CAR-T against breast cancer cell SK-BR-3 could reach (90.1±2.8)%, while the cytolytic rate of H1-2 CAR-T against HER2(-) breast cancer cell MDA-MB-231 was only (13.5±4.7)%. In the mouse xenograft tumor model, H1-2 CAR-T cells inhibited breast cancer growth in vivo.At the end of the experiments, the average tumor weight in the H1-2 CAR-T cell treatment group was (0.7±0.1) g, the non-transfected T cell therapeutic group was (1.2±0.2) g, and the PBS group was (1.2±0.2) g. There was significant difference between the H1-2 CAR-T therapeutic group and the non-transfected T cell therapeutic group (P<0.05). However, there was no significant difference between the non-transfected T cell therapeutic group and the PBS treatment group (P>0.05). Conclusion: The HER2-sepcific H1-2 CAR-T cells specifically kill HER2 positive cells, and further studies on CAR-T cells for the treatment of HER2(+) cancers are useful.

[Establishment and validation of human cancer cell lines with stable Cas9 expression]

Objective: To establish human cancer cell strains with stable Cas9 expression, and to validate the gene editing activity of Cas9 for simple gene editing in future study. Methods: Fifteen cancer cell lines of different tissue origins were infected with pLv-EF1α-Cas9-Flag-Neo or pLv-EF1α-Cas9-Flag-Puro by lentivirus and clone selection was employed to screen Cas9 stably expressed cancer cell lines. Afterward designed guide RNA vectors targeting TSC22 gene were transiently transfected into 3 of cell lines, and subsequently the gene editing activity of Cas9 was evaluated by genomic PCR, sequencing and Western blot. Results: Sixty-nine human cancer cell strains with stable Cas9 expression from different cancers were established, and by transient transfection with designed guide RNA, long fragment deletion was detected in TSC22 gene. Conclusions: Sixty-nine human cancer cell strains are successfully established with stable expression of Cas9 protein and gene editing activity. These cell strains may be employed in large-scale drug screening, screening of new drug targets and gene function investigation.

Novel mutations in quinolone resistance-determining regions of gyrA, gyrB, parC and parE in Shigella flexneri clinical isolates from eastern Chinese populations between 2001 and 2011

The aim of this study was to evaluate the prevalence of fluoroquinolone resistance and mechanisms of selected fluoroquinolone resistance in Shigella flexneri isolates. A total of 624 S. flexneri strains isolated between 2001 and 2011 in Jiangsu Province of China were analysed for their fluoroquinolone susceptibility. The quinolone resistance-determining region of gyrA, gyrB, parC and parE were amplified and sequenced. In general, 90.5 % of S. flexneri exhibited resistance to nalidixic acid. The mean norfloxacin resistance rate was 22.4 % during the 11 years from 2001 to 2011 (6.4 % from 2001 to 2005 and 36.8 % from 2006 to 2011). Sequencing of gyrA, gyrB, parC and parE genes of all S. flexneri isolates showed that the mutation rate was as high as 93.9 %. In addition, 91.8 % and 92.3 % of S. flexneri harboured mutations in gyrA and parC, respectively. About 35.2 % of S. flexneri isolates susceptible to nalidixic acid contained mutations. Meanwhile, mutations were detected in 91.2 % of norfloxacin-susceptible strains, and almost all S. flexneri isolates resistant to fluoroquinolone contained mutations. To the best of our knowledge, this is the first study reporting the occurrence of point mutations Asn57Lys and His80Pro in gyrA and Ala85Thr, Asp111His and Ser129Pro in parC. Emerging fluoroquinolone resistance with a significantly high mutation rate of the gyrA and parC genes in S. flexneri in Jiangsu Province deserves attention, and monitoring antibiotic susceptibility is important for the effective management of S. flexneri infections.

A feedback loop comprising PRMT7 and miR-24-2 interplays with Oct4, Nanog, Klf4 and c-Myc to regulate stemness

Self-renewal and pluripotency are two fundamental characteristics of embryonic stem cells (ESCs) and are controlled by diverse regulatory factors, including pluripotent factors, epigenetic regulators and microRNAs (miRNAs). Although histone methyltransferases are key epigenetic regulators, whether and how a histone methyltransferase forms a network with miRNAs and the core pluripotent factor system to regulate ESC stemness is little known. Here, we show that the protein arginine methyltransferase 7 (PRMT7) is a pluripotent factor essential for the stemness of mouse ESCs. PRMT7 repressed the miR-24-2 gene encoding miR-24-3p and miR-24-2-5p by upregulating the levels of symmetrically dimethylated H4R3. Notably, miR-24-3p targeted the 3′ untranslated regions (UTRs) of the major pluripotent factors Oct4, Nanog, Klf4 and c-Myc, whereas miR-24-2-5p silenced Klf4 and c-Myc expression. miR-24-3p and miR-24-2-5p also targeted the 3′UTR of their repressor gene Prmt7. miR-24-3p and miR-24-2-5p induced mouse ESC differentiation, and their anti-sense inhibitors substantially reversed spontaneous differentiation of PRMT7-depleted mouse ESCs. Oct4, Nanog, Klf4 and c-Myc positively regulated Prmt7 expression. These findings define miR-24-3p and miR-24-2-5p as new anti-pluripotent miRNAs and also reveal a novel epigenetic stemness-regulatory mechanism in which a double-negative feedback loop consisting of PRMT7 and miR-24-3p/miR24-2-5p interplays with Oct4, Nanog, Klf4 and c-Myc to control ESC stemness.

Prevalence, resistance patterns, and characterization of integrons of Shigella flexneri isolated from Jiangsu Province in China, 2001-2011

OBJECTIVE

To provide the epidemiology, resistance pattern, and characterization of integrons in Shigella flexneri isolated between 2001 and 2011 in Jiangsu Province.

METHOD

A total of 624 strains of S. flexneri were collected from both outpatients and inpatients in hospitals in Jiangsu Province from January 2001 to December 2011. The Kirby-Bauer disk diffusion method was used to perform the antimicrobial susceptibility test. Polymerase chain reaction (PCR) was used in the detection of integrons. Pulsed-field gel electrophoresis (PFGE) was applied in the homology studies.

RESULT

Serotype 2a accounted for the largest proportion in S. flexneri, namely 26.4 %. Notably, an increasing trend was detected in the resistance to common antimicrobial agents during the period 2001-2011. In recent years, more than 80.0 % isolates of S. flexneri have proved to be resistant to ampicillin, nalidixic acid, and tetracycline. The positive rates of class 1, class 2, and the atypical class 1 integrons in S. flexneri are 69.3 %, 87.8 %, and 89.2 % respectively. Most integrons detected in our research carry genes encoding resistance to trimethoprim and streptomycin.

CONCLUSION

Antimicrobial resistance in S. flexneri has demonstrated a continuous rising trend in Jiangsu Province. A high prevalence of integrons and gene cassettes play an important role in the transmission of drug resistance in S. flexneri. Effective measures are urgently needed to control the spread of multi-drug-resistant S. flexneri, and more continuing active surveillance of antimicrobial resistance should be established worldwide, especially in developing countries.

[Improved clinical outcome of acute myeloid leukemia with FLT3-ITD mutation treated with sorafenib]

OBJECTIVE

To analyze the efficacy of sorafenib on the treatment of patients diagnosed as acute myeloid leukemia(AML) with FLT3-ITD mutation.

METHODS

From January 2012 to February 2015, 42 cases of AML with FLT3-ITD mutation according to MICM (morphology, immunology, cytogenetics and molecular) diagnosis system in our hospital were retrospectively analyzed. Thirty-two cases were refractory to chemotherapy or relapsed, who were treated with sorafenib or combined with chemotherapy. Ten patients relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT), who were retreated with sorafenib or combined with donor lymphocyte infusion (DLI) or chemotherapy. In the first group, 13 of 32 patients accepted allo-HSCT.

RESULTS

The overall response rate of all 42 patients was 73.8%, including 4 (9.5%) complete molecular remission (CMR), 9 (21.4%) complete remission (CR), 8 (19%) complete remission with incomplete hematologic recovery (CRi), 10 (23.8%) partial remission (PR), and 11 (26.2%) none remission (NR). The response rate of sorafenib alone for 17 patients was 70.6%, and that of sorafenib plus chemotherapy was 66.7% (P=0.555). Thirteen patients who received allo-HSCT included 6 CMR/CR/CRi, 4 PR, and 3 NR before transplant. The 2-year overall survival (OS) rate and progress free survival (PFS) rate in all patients were 36.9% and 28.7%, and the corresponding median time were 18 months and 9 months respectively. The 2-year OS rate in 23 patients who received sorafenib combined with allo-HSCT was superior to that in 19 patients not receiving allo-HSCT (45.5% vs 23.9%, P=0.041), so was PFS rate (44.0% vs 9.7%, P=0.014). Twelve cases died of disease progression, four of infection, and one of chronic graft versus host disease after transplant.

CONCLUSIONS

Sorafenib combined with chemotherapy improves response rate of AML patients with FLT3-ITD mutation. Those who are treated with sorafenib plus allo-HSCT obtain better long-term survival.

Elevated gold ellipse nanoantenna dimers as sensitive and tunable surface enhanced Raman spectroscopy substrates

We demonstrate large area arrays of elevated gold ellipse dimers with precisely controlled gaps for use as sensitive and highly controllable surface enhanced Raman scattering (SERS) substrates. The enhanced Raman signal observed with SERS arises from both localized and long range plasmonic effects. By controlling the geometry of a SERS substrate, in this case the size and aspect ratio of individual ellipses, the plasmon resonance can be tuned in a broad wavelength range, providing a method for designing the response of SERS substrates at different excitation wavelengths. Plasmon effects exhibited by the elevated gold ellipse dimer substrates are also demonstrated and confirmed through finite difference time domain (FDTD) simulations. A plasmon resonance red shift with an increase of the ellipse aspect ratio is observed, allowing systematic control of the resulting SERS signal intensity. Optimized elevated ellipse dimer substrates with 10 ± 2 nm gaps exhibit uniform SERS enhancement factors on the order of 10(9) for adsorbed p-mercaptoaniline molecules.

Strong Suppression of the Spin Hall Effect in the Spin Glass State

We have measured spin Hall effects in spin glass metals, CuMnBi alloys, with the spin absorption method in the lateral spin valve structure. Far above the spin glass temperature T(g) where the magnetic moments of Mn impurities are randomly frozen, the spin Hall angle of a CuMnBi ternary alloy is as large as that of a CuBi binary alloy. Surprisingly, however, it starts to decrease at about 4T(g) and becomes as little as 7 times smaller at 0.5T(g). A similar tendency was also observed in anomalous Hall effects in the ternary alloys. We propose an explanation in terms of a simple model considering the relative dynamics between the localized moment and the conduction electron spin.

Histone methylation modifiers in cellular signaling pathways

Histone methyltransferases and demethylases epigenetically regulate gene expression by modifying histone methylation status in numerous cellular processes, including cell differentiation and proliferation. These modifiers also control methylation levels of various non-histone proteins, such as effector proteins that play critical roles in cellular signaling networks. Dysregulated histone methylation modifiers alter expression of oncogenes and tumor suppressor genes and change methylation states of effector proteins, frequently resulting in aberrant cellular signaling cascades and cellular transformation. In this review, we summarize the role of histone methylation modifiers in regulating the following signaling pathways: NF-κB, RAS/RAF/MEK/MAPK, PI3K/Akt, Wnt/β-catenin, p53, and ERα.

Akt Phosphorylates Wnt Coactivator and Chromatin Effector Pygo2 at Serine 48 to Antagonize Its Ubiquitin/Proteasome-mediated Degradation

Pygopus 2 (Pygo2/PYGO2) is an evolutionarily conserved coactivator and chromatin effector in the Wnt/β-catenin signaling pathway that regulates cell growth and differentiation in various normal and malignant tissues. Although PYGO2 is highly overexpressed in a number of human cancers, the molecular mechanism underlying its deregulation is largely unknown. Here we report that Pygo2 protein is degraded through the ubiquitin/proteasome pathway and is posttranslationally stabilized through phosphorylation by activated phosphatidylinositol 3-kinase/Akt signaling. Specifically, Pygo2 is stabilized upon inhibition of the proteasome, and its intracellular level is regulated by Cullin 4 (Cul4) and DNA damage-binding protein 1 (DDB1), components of the Cul4-DDB1 E3 ubiquitin ligase complex. Furthermore, Pygo2 is phosphorylated at multiple residues, and Akt-mediated phosphorylation at serine 48 leads to its decreased ubiquitylation and increased stability. Finally, we provide evidence that Akt and its upstream growth factors act in parallel with Wnt to stabilize Pygo2. Taken together, our findings highlight chromatin regulator Pygo2 as a common node downstream of oncogenic Wnt and Akt signaling pathways and underscore posttranslational modification, particularly phosphorylation and ubiquitylation, as a significant mode of regulation of Pygo2 protein expression.

Charge-to-Spin Conversion and Spin Diffusion in Bi/Ag Bilayers Observed by Spin-Polarized Positron Beam

Charge-to-spin conversion induced by the Rashba-Edelstein effect was directly observed for the first time in samples with no magnetic layer. A spin-polarized positron beam was used to probe the spin polarization of the outermost surface electrons of Bi/Ag/Al2O3 and Ag/Bi/Al2O3 when charge currents were only associated with the Ag layers. An opposite surface spin polarization was found between Bi/Ag/Al2O3 and Ag/Bi/Al2O3 samples with the application of a charge current in the same direction. The surface spin polarizations of both systems decreased exponentially with the outermost layer thickness, suggesting the occurrence of spin diffusion from the Bi/Ag interface to the outermost surfaces. This work provides a new technique to measure spin diffusion length.

Fiber-integrated 780 nm source for visible parametric generation

We report the development of a fully fiber-integrated pulsed master oscillator power fibre amplifier (MOPFA) source at 780 nm, producing 3.5 W of average power with 410 ps pulses at a repetition rate of 50 MHz. The source consists of an intensity modulated 1560 nm laser diode amplified in an erbium fiber amplifier chain, followed by a fiber coupled periodically poled lithium niobate crystal module for frequency doubling. The source is then used for generating visible light through four-wave mixing in a length of highly nonlinear photonic crystal fiber: 105 mW at 668 nm and 95 mW at 662 nm are obtained, with pump to anti-Stokes conversion slope efficiencies exceeding 6% in both cases.

Study of regulatory pathway of related molecules in hemolytic uremic syndrome

OBJECTIVE

To screen Hemolytic Uremic Syndrome (HUS) related differentially expressed genes using the microarray data of neonatal microvascular endothelial cells from human skin treated with or without Shiga toxin, and study the the mechanism of HUS from multiple angles.

MATERIALS AND METHODS

The microarray dataset GSE32710 was download from gene expression database GEO (Gene Expression Omnibus), which included a total of 12 samples, 6 samples were treated with Shiga toxin while the others were normal without any treatments. Then the raw chip data were preprocessed by R package, and T-test was utilized for differentially expressed genes screening. The selected differentially expressed genes were subjected to GO functional and KEGG pathway analysis. Following that, human protein interaction network, synergetic effects among the differentially expressed genes and regulation of post-transcriptional miRNA were integrated so as to construct a molecular interaction network associated with HUS and excavate the sub-function modules.

RESULTS

Trough differential expression screening, 195 of HUS related marker genes were obtained, and 294 of gene pairs with significant co-expression were achieved. Molecular interaction network associated with HUS excavated 302 miRNAs and 117 differentially expressed genes, among which miRNA-30c and miRNA-30d may play important roles during the development of HUS.

CONCLUSIONS

In this study, we used a method that explained the biological mechanism of HUS systematically from gene transcription level and different levels of biological information such as protein interaction, post-transcriptional regulation of gene expression as well as synergy effects of gene expression, which may provide new therapeutic targets for HUS.

A novel HLA allele, HLA-B*37:06:02, identified in a Chinese family

The novel allele HLA-B*37:06:02 differs from HLA-B*37:06:01 by a silent nucleotide substitution at codon 47P.

Towards a more Realistic Experimental Protocol for the Study of Atmospheric Chloride-Induced Stress Corrosion Cracking in Intermediate Level Radioactive Waste Container Materials

The occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under wetted deposits of MgCl2 or sea-salt at 70°C has been investigated at various Relative Humidities (RH). The appearance of AISCC is a function of the environmental RH. At 33% RH (the deliquescence point of MgCl2), AISCC generated under MgCl2 or sea-salt deposits is of a similar appearance with regards to the number of cracks produced and average crack length. At 50% RH sea-salt seems to be more aggressive at least in terms of crack frequency. This observation may highlight the significance of carnallite (KMgCl3.6H2O) in promoting AISCC in types 304L and 316L stainless steels. The use of accelerated testing methods to validate apparent thresholds in chloride deposition density and other critical factors that influence the initiation and propagation of AISCC is briefly discussed.

Complications in tissue expansion: an updated retrospective analysis of risk factors

BACKGROUND

The technique of tissue expansion has been widely applied in plastic surgery since the 1980 s. Implantation in the lower limb region, external port placement, and young patient age were known as risk factors for complications. Over the years, surgical experience has increased along with improved patient management and expander manufacturing. The aim of this study was to identify possible changes in risk factors regarding complications in tissue expansion.

METHOD

A retrospective, single-institution large sample observational study over a 5-year period (2006-2010) was performed involving 481 tissue expanders in 344 patients. Patients underwent surgical treatment for resurfacing scar tissue in the scalp, face, neck, nose, and limbs, but not breast. In addition, the results are discussed based on a comprehensive review of the literature published between 1995 and 2009.

RESULTS

Statistical analysis showed significant correlations between cheek and hematoma (P=0.0133), scalp and dehiscence (P=0.0139), number of expanders per region and leakage (P=0.0379), number of expanders per region and overall complications (P=0.0252). Factors such as gender, age, tobacco use, and repeated expander implantation had no significant influence on the incidence of complications. The lower extremity region and young patient age ceased to show a statistical correlation with complications. The number of expanders per region was identified as a risk factor that has been disregarded so far.

CONCLUSION

Evidence suggests a recent change in risk factors for tissue expansion-related complications. Consideration of updated risk factors may help to further improve outcomes in tissue expansion.