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Objective To study the effects of aneurysmal neck angle on stent displacement after endovascular repair of abdominal aortic aneurysm (AAA). Methods The CT images of 28 patients were selected to establish preoperative AAA model, postoperative AAA model and covered stent model respectively, and the models were divided into non-severe angulation group ( n = 14) and severe angulation group ( n = 14) according to the preoperative angle of tumor neck. The geometric shape of each model was measured, and the changes of AAA geometric parameters and postoperative stent displacements before and after surgery were analyzed. The displacement force of the model during the first follow-up was calculated by hemodynamic simulation. Results Significant differences were found in tumor length, maximum diameter, displacement force, tumor neck length and tumor volume between two groups of patients (P 0. 05). For the incidence of internal leakage, there were 2 cases in non-severe angulation group and 4 cases in severe angulation group (P>0. 05).Conclusions Severe neck angulation can lead to a significant increase in support displacement force and decrease in proximal anchorage zone, and thus increase the possibility of support displacement. It is suggested that doctors should strengthen postoperative follow-up for patients with severe neck angulation and be vigilant of the occurrence of long-term internal leakage in clinic.
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Objective Based on hemodynamic analysis, to investigate the cause of distal re-entry tear in Stanford type B aortic dissection after thoracic endovascular aortic repair (TEVAR).Methods A patient with type B aortic dissection was reexamined regularly with computed tomography angiography (CTA) at 1st month, 6th month, 12th month and 24th month after TEVAR. Based on the CTA images in each period, three-dimensional (3D) aorta models were reconstructed to perform morphological analysis and hemodynamic simulation.Results Compared with the diameter at 1st month after TEVAR, the diameter of true lumen at 12 months after TEVAR increased by 1.8 times and the global distortion of aorta increased by 16.67%. At postoperative 1st, 6th and 12th month, the maximum blood velocities at the new entry tear in systole were 69.6%, 33.7% and 92.1% higher than the average ones at distal landing zone, and the maximum wall shear stresses (WSSs) were 2.52, 2.32 and 3.52 times of the average WSSs respectively. In addition, the maximum time-averaged WSS (TAWSS) at 1st, 6th and 12th month after TEVAR were 1.88, 2.53 and 3.62 times of the mean TAWSS respectively.ConclusionsThe morphology of the aorta remodeled after TEVAR, and a sudden change in the diameter of true lumen occurred at distal anchoring zone and continued to increase. As a result, the blood flow velocity in this area accelerated, and the intima was continuously exposed to high WSS, leading to the redissection.
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OBJECTIVE To explore the condition of the cellular immune function of children with obstructive sleep apnea hypopnea syndrome(OSAHS) and its change after operation METHODS Eighty children diagnosed as OSAHS were included in this study. T lymphocyte subsets and NK cells of the blood were measured before operation and one month after operation respectively. Children without the related disorders or systemic disease were recruited as control group.RESULTS Before operation, CD4+T cell percentage, CD4+/CD8+ ratio and NK cell percentage in OSAHS children were significantly lower than that in the control group[(26.19±3.38)%vs (5.10±4.09)%, (0.90±0.19)%vs (1.61±0.52)%, (11.45±4.35)%vs (13.73±3.78)%,P0.05). CONCLUSION OSAHS may damage the cellular immune function. The operation does not reduce the cellular immune function in the short term.
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Currently, all the conventional antibiotics have developed corresponding drug-resistant pathogenic strains, which have increasingly become a serious threat to people's health. Development of completely new types of antibiotics is one of effective ways to solve the drug resistance issue. Antimicrobial peptides with broad-spectrum antibacterial and antimicrobial activity and wild variety become the ideal alternative to traditional antibiotics. Antimicrobial peptides are derived from wide range of sources, such as plants, animals, and microorganisms. Mechanism of function of the antimicrobial peptides and the investigation approaches of different antimicrobial peptides also vary dramatically. In this paper, we give an overview of preparation, antibacterial mechanisms, and research methodology of antimicrobial peptides.
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Animals , Humans , Anti-Bacterial Agents , Anti-Infective Agents , Antimicrobial Cationic Peptides , PharmacologyABSTRACT
Lipopolysaccharide (LPS), the important component of the outer membrane of Gram-negative bacteria, contributes to the integrity of the outer membrane, and protects the cell against bactericidal agents. LPS, also called endotoxin synonymously, is well known as a potent inducer of the innate immune system that often causes septic shock in the intensive cares. Chemically, the amphiphilic LPS is made up of three parts, i.e., hydrophobic lipid A, hydrophilic core oligosaccharide chain, and hydrophilic O-antigenic polysaccharide side chain. Specially, the lipid A is known to be responsible for a variety of biological effects during Gram-negative sepsis. LPS can elicit a strong response from innate immune system and result in local or systemic adverse reactions. LPS can trigger massive inflammatory responses and may result in immunopathology, for which the molecular basis is mediated by the signal path- way of LPS. In recent years, a tremendous progress has been made in determining the associated proteins and receptors in the LPS signaling that leads to the disease. This review gives a summary of recent progresses of research on LPS and LPS receptors.
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Anti-Bacterial Agents , Chemistry , Drug Design , Gram-Negative Bacteria , Lipopolysaccharides , ChemistryABSTRACT
Antimicrobial peptides ( AMPs) are critical component of the innate immune system of organisms, and have been demonstrated with the activity against a variety of microorganisms including bacteria, yeast, fungi, viruses and even tumor cells.Broad-spectrum activity and low propensity for resistance development make the AMPs as a kind of great potential for development of new anti-infective agents.In this paper, the origins, the action, the mechanism, the application prospects are reviewed.
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Problem-based learning (PBL) teaching method combined with formative evalua-tion was used in the teaching practice of pediatrics education. This method was implemented by four phases: courses designing, group-preparing, problems-organizing and teaching practice. The method was evaluated by students' feedback and survey results of patients, teachers and teaching councilors. It was showed that the teaching effects of PBL combined with formative evaluation was better than tra-ditional teaching method in pediatrics teaching.
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Objective To establish Ad-LIF-OSM transgenic feeder cells for the expansion of CD34+ hematopoietic stem/progenitor cell and tentatively study its effect in expansion and differentiation of cord blood hematopoietic stem cell(HSC) in vitro.Methods In the foundation of pAdTrack-CMV-LIF-polyA+promoterΔ,the OSM gene was inserted to the vector plasmid.Then we structure the transfer plasmid pAdTrack-CMV-LIF-polyA+promoterΔ-OSM.The transfer vector and backbone vector were further cotransfected for homologous recombination. The result pAdEasy-1-pAdTrack-CMV-LIF-polyA + promoterΔ-OSM homologous recombination plasmid were transfected into the human embryonic kidney 293 (QBI-293A) cells,leading to formation of the recombinant adenviruses Ad-LIF-OSM which co-expressing LIF and OSM.Infect the feeder layer cells with groups of Adenovirus,detection the expressing of LIF and OSM in WI-38 cells by RT-PCR and ELISA.Compares the stem cells differentiation and proliferation of the different experimental groups in vitro by transwell and cell counting.Results The sequencing results show that the OSM genes were anastomotic in Ad-LIF-OSM.LIF and OSM gene could be detected in feeder layer cells which infected by Ad-LIF-OSM.Exogenetic LIF and OSM have special effect in culturing HSC in vitro.Conclusion The adenoviral vector co-expressing LIF and OSM (Ad-LIF-OSM) were successfully constructed.Ad-LIF-OSM transgenic feeder cells can effectively proliferate umbilical cord blood CD34+ HSPC in vitro and delay it differentiate.