Female ; Humans ; Infant ; Lung ; physiopathology ; Male ; Pneumonia, Viral ; physiopathology ; Respiratory Function Tests ; Respiratory Syncytial Virus Infections ; physiopathology ; Respiratory Syncytial Viruses

Objective To establish a normal lumbar spine 3-dimensional(3D) finite element model(FEM) and discuss the biomechanics of the lumbar motions. Methods A geometrical model was constructed on the basis of a healthy adult male's lumbar CT image.The lumbar spine FEM was established by finite element analysis software.After setting the boundary and loading the burden,the lumbar spine's range of motion and stress distribution in different institutions such as anterior flexion,posterior extension,left or right bending and axial rotating were recorded. Results The lumbar spine FEM included 114 953 tetrahedron units.The results of the FEM matched the results of the in vitro experiment of biomechanics. Conclusion The lumbar spine FEM can imitate the motions of the lumbar spine.

Puromycin-sensitive aminopeptidase (PSAP) belongs to the M1 family of aminopeptidases, characterized by the N-terminal substrate binding sequence GAMEN, the enzyme activity center HEXXH(X)₁₈E motif, and the C-terminal ERAP-1-like superfamily structural domain. Encoded by the gene NPEPPS located at 17q21.32, PSAP consists of 919 amino acids and is widely distributed throughout the human body, with the highest expression in the brain, followed by the heart and skeletal muscle. It is also found in the liver, renal tubular epithelium, small intestine, large intestine epithelium, and gastric epithelial cells. PSAP primarily relies on its aminopeptidase hydrolytic activity to remove toxic protein aggregates such as Tau, poly Q, and Cu, Zn-superoxide dismutase 1, making it an important factor in the development of diseases such as Alzheimer's disease, Huntington's chorea, and tumors. Existing PSAP inhibitors include bestatin, amastatin, leuhistin, actinonin, and purinomycin, some of which are already available or in clinical trials. This review provides an overview of the structural and biological functions of M1 family aminopeptidases, with a focus on PSAP, to facilitate further research and targeted drug development.

Complex genetic variation has been known to occur during the transmission of human enterovirus (HEV), and the HEV virulence and pathogenicity enhanced by genetic recombination also pose a serious threat to human health. In recent years, the interest in recombination mechanism of genetic plasticity has been renewed with the emergence of pathogenic recombinant circulating vaccine-derived polioviruses, which were implicated in poliomyelitis outbreaks in several regions of the world with insufficient vaccination coverage. This paper reviews recent research progress in HEV genome, including evolutionary characteristics, recombination types, and in vitro recombinant construction.
Animals ; Biomedical Research ; trends ; Enterovirus ; classification ; genetics ; Enterovirus Infections ; virology ; Humans ; Recombination, Genetic ; Viral Proteins ; genetics

Objective To investigate the effect of gradient heat stress on phagocytosis of hepatic Kupffer cells (KCs) in vitro in rats. Methods Rat Kupffer cells were isolated in vitro and the temperature for gradient heat stress was set at 37, 39, 41 and 43℃. After thermal stimulation, cell injury was detected by PI and Hochest33342 staining. CCK-8 assay was used to investigate difference in cellular proliferation rate over 24h between the groups. Flow cytometry was used to investigate the influence of heat stress on the phagocytosis of KCs. Results Compared to the normal control group, cells in each heat stress group exhibited varying degrees of damage, especially cells in 43℃ group. The ratio of damage cells increased with the increase of heat stress severity (P<0.05). Proliferation assay indicated that the proliferation rate of cells in each heat stress group was significantly decreased in comparison with normal control group 6h after heat stress (P<0.05). After 12h recovery, decrease in proliferation rate was observed only in 43℃ group (P<0.001), and no difference in the rate of proliferation could be observed between the heat stress groups and normal control group after 24h recovery. Flow cytometry showed, that the phagocytosis of KCs decreased in heat stress groups compared with control group, especially in 43℃ group (P<0.05). This phenomenon disappeared after 24h recovery. Conclusion Heat stress can inhibit the phagocytosis of rat liver KCs through its cytotoxic effect on KCs, and subsequently inhibits its proliferative ability. Further investigation of the effect of heat stress on KCs may help understand the pathogenesis of heat stress.

Objective To investigate the influence of external electric fields on migration behavior and morphology of endo‐thelial progenitor cells (EPCs) cultured in vitro .Methods The in vitro cultured 3-4 generation EPCs were continuously stimula‐ted by direct‐current electric field with the field intensity of 0 mV/mm(group Ⅰ ) ,100 mV/mm(group Ⅱ) ,200 mV/mm(group Ⅲ) and 300 mV/mm (group Ⅳ )for 3 h .The live cell station was used to real time record the cell migration track and morphology change of EPCs .The influence of external electric field on the EPCs migration behavior and morphology was analyzed .Results Un‐der the stimulation of the direct‐current electric field with the intensity of group Ⅳ ,group Ⅲ and group Ⅱ ,the cells were directly migrated to anode ,while the cells under group Ⅰ displayed the random motion .The track migration velocity(Vt)、displacemnt ve‐locity(Vd) and electric field direction migration rate(Vx) were(98 .86 ± 6 .00) ,(63 .78 ± 2 .81) ,(63 .15 ± 2 .88)μm/h for the groupⅣ ,(88 .06 ± 8 .83) ,(35 .90 ± 1 .22) ,(34 .20 ± 1 .57)μm/h for the groupⅢ ,(42 .28 ± 2 .25) ,(13 .29 ± 0 .37) ,(12 .39 ± 0 .51)μm/h for the groupⅡ ,which were significantly higher than(37 .39 ± 2 .42) ,(6 .99 ± 0 .31) ,(4 .62 ± 0 .40)μm/h for the groupⅠ (P<0 .01) ,moreover Vt ,Vd and Vx in the group Ⅲ were significantly higher than those in the group Ⅱ andⅠ (P<0 .01) .EPCs had obvious morphological changes under the electric field action ,such as elongation and the cellular long axis parallel to the electric field direction .Conclusion External direct current electric fields may induce the directed migration of EPCs towards the anode ,ac‐celerates the migration rate ,moreover has obvious influence on EPCs morphology .

OBJECTIVE: To evaluate the effect of Xiangdan Injection on mRNA expression of the endothelial vaso-active factors of patients with coronary heart disease and blood stasis. METHODS: Fifty-six patients were randomly divided into two groups:twenty-eight patients were treated according to the therapeutic guide for coronary heart disease as the control group and 28 were given the same treatment plus Xiangdan Injection as the treated group. The expressions of ET-1 and eNOS mRNA were examined with RT-PCR before experiment and ten days later. RESULTS: The positive rate of eNOS mRNA of the treated group increased, while the positive rate of ET-1 mRNA of the treated group decreased after ten day's treatment, with significant differences as compared with that before the experiment. Xiangdan Injection up-regulated the eNOS mRNA expression and suppressed the ET-1 mRNA expression. Changes of expression were not observed in the control group. CONCLUSION: Xiangdan Injection improves the endothelial function of patients with coronary heart disease and blood stasis by regulating the expressions of ET-1 and eNOS mRNA.

Objective To explore whether human umbilical venous endothelial cells could be used as feeder layer to support the growth of embryonic stem cells (ESC) and keep ESC undifferentiated.Methods The venous vessels of umbilical cord obtained from healthy puerperal were perfused with collagenase.The isolated endothelial cells went through primary culture and passages for expansion.Factor Ⅷ antigens determination was implemented.Endothelial cells with good growth and 3 or above passages were treated with mitomycin-C(10 mg/L) and prepared as feeder layer,on which E14.1 ESC was transplanted for subculturing to observe the morphological characterization and determine ESC alkaline psphatase (AKP) activity and the expression of stem cell marker Oct-4.Severe combined immune deficiency(SCID) mouse in vivo terotoma formation experiment was performed to identify its pluripotent properties.Results Human umbilical vein-derived endothelial cells grew well in culturing in vitro and regenerate in large numbers.The endothelial cells maintained normal cellular morphological and biological characterization after 10 passages.The cells stopped proliferating after being treated with mitomycin-C,but its activity and morphological properties were well-maintained with 24 hours,which was a fundamental property of serving as feeder layer.E14.1 ESC remained undifferentiated in human umbilical venous endothelial cells after 3-8 passages,the cells grew in colony and showed high expression of AKP and stem cell Oct-4.In vivo pluripotency experiment showed that 6 weeks after being transplanted to SCID mice E14.1 ESC of 6 and 10 passages in endothelial cells both could form teratoma containing 3 layers of tissue cells.Conclusions Human umbilical venous endothelial cell serve as a convenient feeder layer cell with rich sources.It can effectively support ESC growth and heterogenous and prevent the heterogeneous protein pollution and pathogenic microorganisms caused by animal cell feeder layers,thus solve the problem of biological safety of ESC clinical application.

Objective To study the stability of micro-implant orthodontic anchorage(MA)with different pitch in the case of immediate loading.Method Employing 3D finite element analysis method,the stress and dis-placement distribution on the bone interface of MIA with different pitch(0.3 mm、0.5 mm、0.7 mm and 1.0 mm,respectively),which was 1.47 N loaded vertically in the major axis direction,were analyzed.Result The pitch affected the stress distribution significantly,because the maximum stress increased with the pitch decreasing and the impact of pitch on stress distribution on neck and central locations of MIA were different;to decrease the pitch could reduce the max displacement of the jaw,but the impact of pitch on displacement distribution of MIA was not significant.Condusions In the case of immediate loading.MIA with pitch 0.5 mm-0.7 mm is suggested to be selected as orthodontic anchorage in the clinic.

Objective To study the stability of micro-implant orthodontic anchorage(MA)with different pitch in the case of immediate loading.Method Employing 3D finite element analysis method,the stress and dis-placement distribution on the bone interface of MIA with different pitch(0.3 mm、0.5 mm、0.7 mm and 1.0 mm,respectively),which was 1.47 N loaded vertically in the major axis direction,were analyzed.Result The pitch affected the stress distribution significantly,because the maximum stress increased with the pitch decreasing and the impact of pitch on stress distribution on neck and central locations of MIA were different;to decrease the pitch could reduce the max displacement of the jaw,but the impact of pitch on displacement distribution of MIA was not significant.Condusions In the case of immediate loading.MIA with pitch 0.5 mm-0.7 mm is suggested to be selected as orthodontic anchorage in the clinic.