Objective:To analyze the drug resistance characteristics of Klebsiella pneumoniae in the nasopharynx of hospitalized patients in North China from 2022 to 2023. Methods:From November 2022 to July 2023, nasopharyngeal swabs were collected from 100 inpatients in Affiliated Hospital of North China University of Science and Technology, and Klebsiella pneumoniae was isolated and cultured. At the same time, the clinical data of the patients were collected, including gender, age, department, clinical diagnosis of disease type, etc. The minimum inhibitory concentration of strains was detected by an automatic bacterial drug sensitivity system. The drug resistance genes, ST types, capsule serotypes and population structure of the strains were analyzed by whole genome sequencing and data analysis. Results:Klebsiella pneumoniae was isolated from 55 nasopharyngeal swabs of 100 inpatients(55.00%). Among the 55 inpatients with Klebsiella pneumoniae in the nasopharynx, 70.91% (39/55) were male, with an age distribution concentrated between 61 and 80 years old (58.18%, 32/55), and 50.91% (28/55) were in intensive care units (ICU). The main underlying disease type was nervous system disease (49.09%, 27/55). The results of drug sensitivity showed that the non-susceptibility rates of 55 strains of Klebsiella pneumoniae to cephalosporins, quinolones, aztreonam and nitrofurantoin were all more than 80.00%. Twenty-eight carbapenem-resistant Klebsiella pneumoniae strains (50.91%), 47 extended-spectrum β-lactamase producing strains (85.45%), and 48 multi-drug-resistant strains (87.27%) were detected. A total of 11 antibiotic resistance genes were detected, including carbapenems (carrying rate 76.36%) and extended-spectrum β-lactamase (carrying rate 96.36%). The 55 strains could be divided into 17 ST types, and the most common type was ST11 (25.45%). The 55 strains were divided into 18 capsular serotypes, among which K102 was the most prevalent (23.64%). OXA-1_ST307_K102 (21.82%) and KPC-2_ST5492_K125 (18.18%) were the dominant clones, distributed in the Department of Neurosurgery and ICU. The result of whole genome sequence analysis showed that there were four clusters with high homology among the 55 strains. The strains from the ICU formed two independent clusters, and strains from the Neurology ICU and Neurosurgery department formed one cluster respectively. Conclusion:The carrying rate of Klebsiella pneumoniae in the nasopharynx of inpatients is high, and the drug resistance of the strains is serious. There are many types of drug-resistant genes.

Objective:To analyze the drug resistance characteristics of Klebsiella pneumoniae in the nasopharynx of hospitalized patients in North China from 2022 to 2023. Methods:From November 2022 to July 2023, nasopharyngeal swabs were collected from 100 inpatients in Affiliated Hospital of North China University of Science and Technology, and Klebsiella pneumoniae was isolated and cultured. At the same time, the clinical data of the patients were collected, including gender, age, department, clinical diagnosis of disease type, etc. The minimum inhibitory concentration of strains was detected by an automatic bacterial drug sensitivity system. The drug resistance genes, ST types, capsule serotypes and population structure of the strains were analyzed by whole genome sequencing and data analysis. Results:Klebsiella pneumoniae was isolated from 55 nasopharyngeal swabs of 100 inpatients(55.00%). Among the 55 inpatients with Klebsiella pneumoniae in the nasopharynx, 70.91% (39/55) were male, with an age distribution concentrated between 61 and 80 years old (58.18%, 32/55), and 50.91% (28/55) were in intensive care units (ICU). The main underlying disease type was nervous system disease (49.09%, 27/55). The results of drug sensitivity showed that the non-susceptibility rates of 55 strains of Klebsiella pneumoniae to cephalosporins, quinolones, aztreonam and nitrofurantoin were all more than 80.00%. Twenty-eight carbapenem-resistant Klebsiella pneumoniae strains (50.91%), 47 extended-spectrum β-lactamase producing strains (85.45%), and 48 multi-drug-resistant strains (87.27%) were detected. A total of 11 antibiotic resistance genes were detected, including carbapenems (carrying rate 76.36%) and extended-spectrum β-lactamase (carrying rate 96.36%). The 55 strains could be divided into 17 ST types, and the most common type was ST11 (25.45%). The 55 strains were divided into 18 capsular serotypes, among which K102 was the most prevalent (23.64%). OXA-1_ST307_K102 (21.82%) and KPC-2_ST5492_K125 (18.18%) were the dominant clones, distributed in the Department of Neurosurgery and ICU. The result of whole genome sequence analysis showed that there were four clusters with high homology among the 55 strains. The strains from the ICU formed two independent clusters, and strains from the Neurology ICU and Neurosurgery department formed one cluster respectively. Conclusion:The carrying rate of Klebsiella pneumoniae in the nasopharynx of inpatients is high, and the drug resistance of the strains is serious. There are many types of drug-resistant genes.

Objective To investigate the effects of acyl-CoA synthetase 5 (ACS5) silencing by siRNA on expression and proliferation of colon carcinoma cell lines.Methods The expression of ACS5 in 30 case colon carcinoma and adjacent tissues were analyzed by immunohistochemical staining.The siRNA of ACS5 with Lipofectamine2000TM was transfected into colon carcinoma cell lines (HT-29 and SW480).The expression of ACS5 in colon carcinoma cell lines (HT-29 and SW480) was detected by real-time reverse transcription polymerase chain reaction.Proliferation of colon carcinoma cell lines was analyzed by 3-(4,5-dimenthylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS).Results The expression of ACS5 in colon cancer was significantly higher than in adjacent tissues by immunohistochemical staining.The mRNA of ACS5 in siRNA-ACS5 group (0.18 ± 0.03) was significantly lower than in NC siRNA group (2.55 ± 0.31) and blank control group (2.48 ± 0.12) in HT-29 colon cancer lines,and the inhibition ratio was 92.96％ (F =146.9,P ＜0.01).The mRNA of ACS5 in siRNA-ACS5 group (0.14 ± 0.01) was significantly lower than in NC siRNA group (1.21 ± 0.05) and blank control group (1 ± 0.03) in SW480 colon cancer lines,and the inhibition ratio was 88.5％ (F =826.5.9,P ＜ 0.01).Proliferation of HT-29 and SW480 colon cancer line in siRNA-ACS5 group was slower on 72 h and 96 h than in NC siRNA group and blank control group (P ＜ 0.05).Conclusions Expression of ACS5 is elevated in colon cancer tissues.siRNA interference of colon cancer line downregulated ACS5 expression and inhibited the proliferation of the colon cancer cells.

Objective To evaluate the value of electrospun polymethyl methacrylate (PMMA) nanofibers with different topological structures as scaffolds for growth of Schwann cells (SCs).Methods Electrospun PMMA nanofibers with random or aligned topological structures were fabricated and measured with biocompatibility.Lentivirus-transfected green fluorescent protein was used as the reporting gene to monitor form and growth manner of SCs on different substrates and dependency of cell body and process with fiber structure,with PMMA thin films served as the control.Results Electrospun PMMA nanofibers revealed good biocompatibility and could exert contact guidance to the growth of SCs.Topological structures of the electrospun nanofibers influenced cell morphology.SCs were aligned with the orientation of substrate fibers and form longer cell process when growing on aligned nanofibers (P ＜0.01).Primary SCs preferred to follow the cue of aligned nanofibers compared to random fibers.Conclusion Aligned electrospun PMMA nanofibers have the potentiality as transplantable scaffolds for loading SCs after neural injury.

Objective:This study aims to determine the efficacy of chemotherapy and to identify potential chemotherapy agents for advanced primary duodenal carcinoma (PDC). Methods:Fifty-six patients with advanced PDC, who did and did not receive chemo-therapy, were involved in this study. Response rates (RR), disease control rates (DCR), progression-free survival (PFS), and overall sur-vival (OS) were analyzed. Results:The overall RR and DCR of 43 patients were 19.04%and 71.42%, respectively. The patients who re-ceived chemotherapy agents fluorourzcil and oxaliplatin exhibited higher RR compared with patients who received other chemotherapy combinations (35.29%vs. 7.69%, P=0.010 9). Palliative chemotherapy improved the OS of patients with advanced PDC compared with patients who did not receive chemotherapy (13.35 months vs. 5.65 months, HR=0.203, 95%CI:0.083 to 0.497, P=0.000 5). Compared with the use of other chemotherapy regimens, treatment with a fluorourzcil-based chemotherapy agent resulted in a longer PFS (5.08 months vs. 1.08 months, HR=0.004, 95%CI:0.000 to 0.315, P=0.013 2). Multivariate analysis indicated mucinous histology and lymph mode metastasis as factors predictive of poor prognosis in patients with advanced PDC. Conclusion:Palliative chemotherapy may im-prove the OS of patients with advanced PDC.

OBJECTIVETo evaluate the impact of the topographic features of electrospun polymethylmethacrylate (PMMA) nanofibers on growth pattern of primary rat astrocytes.

METHODSRat astrocytes were cultured on fabricated random and aligned electrospun nanofibers. Using PMMA film as the control, the cells were transfected with a lentivirus harboring GFP gene to reveal the cell growth pattern on different substrates.

RESULTSoth random and aligned electrospun PMMA nanofibers could support the growth of rat astrocytes, but the topographic features of the fibers significantly affected their growth pattern. On aligned nanofibers, astrocytes extended long cell processes along the direction of the substrate fibers, and on random fibers the astrocytes formed shorter processes. On merged images of GFP expressions and substrate fibers, the cell processes of the astrocytes were shown to adhere to and elongate along the fibers both on random and aligned nanofibers.

CONCLUSIONThe topographic features of PMMA nanofibers can significantly influence the growth pattern of primary rat astrocytes. Aligned electrospun nanofibers has the potential to serve as scaffold material for reducing glia scar formation after spinal cord injury.

The knowledge absence of neurosurgical regional anatomy is the major shortcoming which makes seven-year program medical students feel difficult in studying neurosurgical special course.The reasons for this phenomenon include the limited teaching time for basic medical course and the continuous progress in the field of neurological anatomy.The teacher should make good use of clinical resources to carry on the additional teaching of neurosurgical regional anatony.The detailed plans include small-class teaching and individual case analysis using the data of neuroimaging and angiography of the brain and spinal cord.All these measures are intend to let the students grasp of the basic knowledge clinical neurosurgery during the internship and make the smooth transition from interns to doctors,providing references for other department.

Objective To evaluate the impact of the topographic features of electrospun polymethylmethacrylate (PMMA) nanofibers on growth pattern of primary rat astrocytes. Methods Rat astrocytes were cultured on fabricated random and aligned electrospun nanofibers. Using PMMA film as the control, the cells were transfected with a lentivirus harboring GFP gene to reveal the cell growth pattern on different substrates. Results Both random and aligned electrospun PMMA nanofibers could support the growth of rat astrocytes, but the topographic features of the fibers significantly affected their growth pattern. On aligned nanofibers, astrocytes extended long cell processes along the direction of the substrate fibers, and on random fibers the astrocytes formed shorter processes. On merged images of GFP expressions and substrate fibers, the cell processes of the astrocytes were shown to adhere to and elongate along the fibers both on random and aligned nanofibers. Conclusion The topographic features of PMMA nanofibers can significantly influence the growth pattern of primary rat astrocytes. Aligned electrospun nanofibers has the potential to serve as scaffold material for reducing glia scar formation after spinal cord injury.

Objective To evaluate the impact of the topographic features of electrospun polymethylmethacrylate (PMMA) nanofibers on growth pattern of primary rat astrocytes. Methods Rat astrocytes were cultured on fabricated random and aligned electrospun nanofibers. Using PMMA film as the control, the cells were transfected with a lentivirus harboring GFP gene to reveal the cell growth pattern on different substrates. Results Both random and aligned electrospun PMMA nanofibers could support the growth of rat astrocytes, but the topographic features of the fibers significantly affected their growth pattern. On aligned nanofibers, astrocytes extended long cell processes along the direction of the substrate fibers, and on random fibers the astrocytes formed shorter processes. On merged images of GFP expressions and substrate fibers, the cell processes of the astrocytes were shown to adhere to and elongate along the fibers both on random and aligned nanofibers. Conclusion The topographic features of PMMA nanofibers can significantly influence the growth pattern of primary rat astrocytes. Aligned electrospun nanofibers has the potential to serve as scaffold material for reducing glia scar formation after spinal cord injury.

Objective:This retrospective study aims to determine the efficacy of chemotherapy and improve a salvage chemother-apy agent for metastatic colorectal cancer (MCRC) after failure of treatment with irinotecan and oxaliplatin. Methods:Between Janu-ary 2002 and March 2013, 37 patients with metastatic MCRC who had progressed after treatment with irinotecan and oxaliplatin were analyzed for their response rate (RR) and progression-free survival (PFS). Results:The overall RR of the 37 patients was 13.51%, with 5 cases of partial response (PR), 12 cases of disease stabilization (SD), and 20 cases of progression (PD). Compared with other chemo-therapy regimens, treatment with a pemetrexed-based chemotherapy agent had a higher RR (17.64%vs. 10.00%, P=0.64) without a lon-ger PFS (2.00 months vs. 1.63 months, HR=0.79, 95%, CI:0.35 to 1.78, P=0.58). Compared with other chemotherapy regimens, treat-ment with a raltirexed-based chemotherapy agent had a higher RR (16.67%vs. 12.00%, P=0.34) without a longer PFS (1.58 months vs. 1.90 months, HR=2.24, 95%, CI:0.98 to 5.12, P=0.06).Conclusion:In patients with MCRC after failure of treatment with irinotecan and oxaliplatin, a pemetrexed-based or raltirexed-based chemotherapy agent may beneficial during salvage treatment and is therefore worthy of further study.