Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective To explore medium and long term efficacy of oblique lateral interbody fusion(OLIF)in treating lumbar specific infection.Methods From October 2017 to January 2021,24 patients with lumbar specific infection were treated by OLIF combined with vertebral screw internal fixation,including 15 males and 9 females,aged from 27 to 61 years old with an average of(43.0±15.0)years old;the courses of disease ranged from 6 to 24 months with an average of(14.0±7.0)months;7 patients with L2-L3,12 patients with L3-L4 and 5 patients with L4-L5;19 patients with tuberculosis infection and 5 patients with brucella infection.The amount of intraoperative blood loss,operative time and complications were recorded,and erythro-cyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS),Japanese Orthopaedic Association(JOA)score and American Spinal Injury Association(ASIA)rating were compared before and one month after opertaion.Re-sults All patients were followed up from 9 to 24 months with an average of(13.0±6.0)months.Operative time was(132.5±21.4)min,and intraoperative blood loss was(227.3±43.1)ml.ESR and CRP were decreased from(82.34±18.62)mmol·h-1 and(53.08±21.84)mg·L-1 before operation to(33.52±17.31)mmol·h-1 and(15.48±8.36)mg·L-1 at one month after opera-tion,respectively(P＜0.05).VAS was decreased from(7.52±1.36)before opertaion to(1.74±0.87)at one month after opera-tion(P＜0.05).JOA was increased from(17.86±3.95)before operation to(24.72±3.19)at one month after operation(P＜0.05).Four patients had neurological symptoms before operation,and were classified to grade D according to ASIA classifica-tion,who were recovered to grade E at 1 month after operation.One patient was suffered from psoas major muscle injury after operation,and returned to normal at 3 weeks.One patient was suffered from abdominal distension and difficulty in defecation,and relieved after gastrointestinal decompression and enema.No complications such as abdominal organ injury and poor wound healing occurred in all patients.Conclusion OLIF combined with vertebral screw internal fixation is a new minimally invasive surgical method for the treatment of lumbar specific infection,especially the lesion located on the middle lumbar vertebra.It has advantages of less trauma,short operation time,less blood loss,convenient operation,complete removal of the lesion,safety and effectiveness,and has good medium-and long-term efficacy for lumbar specific infection.

Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has been a promising approach to prepare well-defined oligosaccharides, facilitating the structure-activity relationship exploration and biomedical applications of bacterial glycans. L-Galactosaminuronic acid is a rare sugar that has been only found in cell surface glycans of gram-negative bacteria. Here, an orthogonally protected L-galactosaminuronic acid building block was designed and chemically synthesized. A synthetic strategy based on glycal addition and TEMPO/BAIB-mediated C6 oxidation served well for the transformation of commercial L-galactose to the corresponding L-galactosaminuronic acid. Notably, the C6 oxidation of the allyl glycoside was more efficient than that of the selenoglycoside. In addition, a balance between the formation of allyl glycoside and the recovery of selenoglycoside was essential to improve efficiency of the NIS/TfOH-catalyzed allylation. This synthetically useful L-galactosaminuronic acid building block will provide a basis for the syntheses of complex bacterial glycans.
Carbohydrates ; Glycosides ; Oligosaccharides ; Oxidation-Reduction ; Polysaccharides/chemistry*

OBJECTIVE: To explore the characteristics and clinical phenotypes of rheumatoid arthritis (RA) and provide the basis for further understanding, interventions and outcomes of this disease. METHODS: RA patients attended at Peking University People's Hospital from 2018 to 2021 were enrolled in the study. Data collection included demographic data, the sites and numbers of joints involved, extra-articular manifestations (EAM), comorbidities and laboratory variables. Statistical and bioinformatical analysis was performed to establish clinical subtypes by clustering analysis based on the type of joint involved, EAM involvement and other autoimmune diseases overlapped. The characteristics of each subtype were analyzed. RESULTS: A total of 411 patients with RA were enrolled. The mean age was (48.84±15.17) years, and 346 (84.2%) were females. The patients were classified into 4 subtypes: small joint subtype (74, 18.0%), total joint subtype (154, 37.5%), systemic subtype (100, 24.3%), and overlapping subtype (83, 20.2%). The small joint subtype had no medium or large joint involvement, and 35.1% had systemic involvement. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels and platelet count (PLT) were lower than those in other subtypes, and the rates of positive rheumatoid factors (RF-IgA and RF-IgG) were significantly higher in the small joint subtype. The total joint subtype had both large and small joint involvement but no systemic involvement. The rate of morning stiffness and positive antinuclear antibodies (ANA) in this subtype were lower than those in other subtypes. In the systemic subtype, interstitial lung disease and secondary Sjögren syndrome were the most common systemic involvements, with prominent levels of disease activity score 28-joint count (DAS28-ESR and DAS28-CRP). The overlapping subtype was commonly combined with Hashimoto's thyroiditis or primary Sjögren syndrome. Female in the overlapping subtype was more common than in other subtypes. This subtype was characterized by hyperglobulinemia, hypocomplementemia and high rate of positive ANA, especially spotting type. CONCLUSION Based on the clinical features, RA patients could be classified into 4 subtypes: small joint subtype, total joint subtype, systemic subtype, and overlapping subtype. Each subtype had its own clinical characteristics. They help for further understanding and a more individualized treatment strategy of RA.
Female ; Male ; Humans ; Cross-Sectional Studies ; Sjogren's Syndrome ; Rheumatoid Factor ; Arthritis, Rheumatoid ; Blood Sedimentation ; Phenotype

OBJECTIVES: This study aimed to explore the effects of silencing isoprenylcysteine carboxyl methyltransfe-rase (Icmt) through small interfering RNA (siRNA) interference on the proliferation and apoptosis of tongue squamous cell carcinoma (TSCC). METHODS: Three siRNA were designed and constructed for the Icmt gene sequence and were then transfected into TSCC cells CAL-27 and SCC-4 to silence Icmt expression. The tested cells were divided as follows: RNA interference groups Icmt-siRNA-1, Icmt-siRNA-2, and Icmt-siRNA-3, negative control group, and blank control group. The transfection efficiency of siRNA was detected by the fluorescent group Cy3-labeled siRNA, and the expression of Icmt mRNA was screened by quantitive real-time polymerase chain reaction (qRT-PCR) selected the experimental group for subsequent experiments. The expression of Icmt, RhoA, Cyclin D1, p21, extracellular regulated protein kinases (ERK), and phospho-extracellular regulated protein kinases (p-ERK) were analyzed by Western blot. The proliferation abilities of TSCC cells were determined by cell counting kit-8 assay. The change in apoptosis was detected by AnnexinV-APC/propidium staining (PI) assay. Cell-cycle analysis was conducted by flow cytometry. RESULTS: The expression of Icmt mRNA and protein in TSCC cells significantly decreased after Icmt-siRNA transfection ( CONCLUSIONS Silencing Icmt can effectively downregulate its expression in TSCC cells, reduce the RhoA membrane targeting localization and cell proliferation, and induce apoptosis. Thus, Icmt may be a potential gene therapy target for TSCC.
Apoptosis ; Carcinoma, Squamous Cell ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Protein Methyltransferases ; RNA, Small Interfering ; Tongue ; Tongue Neoplasms

OBJECTIVES: The effect of isoprenylcysteine carboxymethyltransferase (ICMT) silencing on the migration and invasion of tongue squamous cell carcinoma was investigated by constructing the small interfering RNA (siRNA) of ICMT. METHODS: Through liposomal transfection, siRNA was transfected into human tongue squamous cell carcinoma CAL-27 and SCC-4 cells (ICMT-siRNA group) with a negative control group (transfected with NC-siRNA) and a blank control group (transfected with a transfection reagent but not with siRNA). Quantitative real-time polymerase chain reaction was performed to analyze the mRNA expression of ICMT and RhoA in each group of cells after transfection and to measure the silencing efficiency. Western blot was applied to examine the expression levels of ICMT, total RhoA, membrane RhoA, ROCK1, matrix metalloproteinase (MMP)-2, and MMP-9 proteins in each group. The migration and invasion abilities were evaluated via wound healing and Transwell motility assays. RESULTS: After CAL-27 and SCC-4 cells were transfected with ICMT-siRNA, the expression levels of ICMT genes and proteins decreased significantly in the experimental group compared with those in the negative and blank control groups ( CONCLUSIONS The migration and invasion abilities of CAL-27 and SCC-4 cells were reduced significantly after the transfection of ICMT-siRNA, and the involved mechanism might be related to the RhoA-ROCK signaling pathway.
Carcinoma, Squamous Cell ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Humans ; Neoplasm Invasiveness ; Protein Methyltransferases ; RNA, Small Interfering ; Tongue ; Tongue Neoplasms ; Transfection ; rho-Associated Kinases

Objective:To study the clinical medication regulation for the prevention and treatment of new coronavirus pneumonia with traditional Chinese medicine（TCM），especially prescriptions，on the basis of "treatment in accordance with seasonal conditions". Method:The guidelines and suggestions on novel coronavirus pneumonia formulated and published by national，provincial and municipal governments and experts before February 17，2020, were retrieved and summarized. Data was recorded in stages according to "prevention period，clinical observation period，pre-clinical period，middle clinical period，late clinical period and recovery period". The frequency analysis of TCM and its efficacy，prescription and proprietary Chinese medicine was carried out，and then the factor analysis and cluster analysis of TCM were carried out to obtain rational drug combinations. Result:Totally 172 suggestions on combined structure of drugs，50 suggestions on prescriptions and 31 suggestions on proprietary Chinese medicine were involved in the study，and provided by 24 official agencies and 24 medical experts， 147 kinds of herbs，44 prescriptions and 16 proprietary Chinese medicines were collected. No matter for the drug category or for the specific drug selection，the law of drug use in different stages was not the same. Huoxiang Zhengqi capsule，Shufeng Jiedu capsule，Lianhua Qingwen capsule and Jinhua Qinggan capsule can be used in the observation period. Xuanbai Chengqitang can be used in the middle of the disease. Angong Niuhuangwan，Suhexiangwan or Zixuedan, and Angong Niuhuangwan can be selected in the middle of the disease. And Qingfei Paidu decoction can be used in all stages of the disease. Conclusion:Doctors need to adjust their prescriptions along with the progress of the disease，because the law of medication in each stage of the new coronavirus pneumonia is different.