Objective: To study the distributions of velocity, wall pressure and wall shear stress of blood flow in the human thoracic aorta under normal physiological pulsatile flow conditions, so as to provide a theoretical foundation for elucidating the pathogenesis of aortic dissection. Methods: By virtue of the Computational Fluid Dynamics and the fundamentals of hemodynamics, the authors obtained the numerical simulations and flow visualizations of pulsating blood flow in the human thoraric aorta. Results: The distributions of velocity, wall pressure, wall shear stress and path line of the blood flow in the thoracic aorta were calculated with a function of time in the cardiac circle. The systoltic wall pressure and its dp/dt were higher than diastolic wall pressure and its dp/dt. The pressure of lateral wall was higher than the pressure of medial wall during systole. A distinct depressed pressure was found located at the intersection between aortic arch and descending aorta. Shear stress of wall of lateral aortic arch was less than that of medial wall of aortic arch and the shear stress change in medial wall of aortic arch was greater than that in the lateral aortic wall. The shear stress was in a cyclic and alternative manner. Conclusion: The findings suggest that the wall pressure may be related to the development of aortic dissection.

The structure, reaction mechanism and molecular biology of Leuconostoc mesnteroides dextransucrase are reviewed.

Animals ; Astragalus Plant ; chemistry ; Coxsackievirus Infections ; physiopathology ; Flavonoids ; pharmacology ; Mice ; Mice, Inbred BALB C ; Myocarditis ; physiopathology ; virology ; Myocytes, Cardiac ; drug effects ; virology

Objective To explore the correlation of E-cadherin(E-cad) mRNA expression with tumorigenesis and development of lung cancer.Methods The relative quantitative nested RT-PCR was used to detect the expression of E-cad mRNA in cancerous tissues,adjacent and distal tissues of tumor from 50 lung cancer patients,and non-cancerous benign lung tissues from 5 lung disorder patients.Results The means of expression rate of E-cad mRNA in cancerous tissue,adjacent and distal tissues of tumor,and non-cancerous tissues were 1.33?0.53,1.65?0.60,2.01?0.46 and 2.09?0.09 respectively.The data were evaluated by analysis of variance.There were significant difference among cancerous tissue,adjacent and distal tissue(F=18.810,P0.05).Also,there were no significant differences among squamous cell carcinoma,adenocarcinoma and adenosquamous carcinoma in the group of cancerous,adjacent and distal tissue.Conclusion The reduced expression of E-cadherin mRNA may play important role for tumorigenesis and development of lung cancer,and there was no evident relationship of E-cad mRNA with different pathological types of lung cancer.

The tandem expression vector can effectively increase the expression level and structure stability of the target peptides(protein)with small size of molecular,and avoid toxicity towards host cell from some toxic peptides product,therefore,this approach is widely applied in biotechnology.The four construction methods of tandem expression plasmid including asymmetric and complementary cohesive ends,directional adapter,isocaudarners,and tandem expression cassette were reviewed in terms of protocol,characteristic and applicable field.In addition,selection principles from various construction methods of tandem plasmid were reviewed in terms of efficiency,accuracy and product cleavage.

Small interfering RNA (siRNA) is the initiator of RNA interference and inhibits gene expression by targeted degradation of specific messenger RNA. siRNA-mediated gene regulation has high efficiency and specificity and exhibits great significance in the treatment of diseases. However, the naked or unmodified siRNA has poor stability, easy to degrade by nuclease, short half-life, and low intracellular delivery. As an emerging non-viral nucleic acid delivery system, ionizable lipid nanoparticles play an important role in improving the druggability of siRNA. At present, one siRNA drug based on ionizable lipid nanoparticles has been approved for the treatment of rare disease. This review introduces the research progress in ionizable lipid nanoparticles for siRNA delivery, focusing on the effect of each component of lipid nanoparticles on the efficiency of siRNA-mediated gene silencing, which provides new references for the studies on ionizable lipid nanocarriers for siRNA delivery.

Apoptosis ; Cyclophosphamide ; Interferon-gamma ; Mesenchymal Stem Cells

Artemisnin is a novel sesquiterpene lactone with an internal peroxide bridge structure, which is extracted from traditional Chinese herb Artemisia annua L. (Qinghao). Recommended by World Health Organization, artemisinin is the first-line drug in the treatment of encephalic and chloroquine-resistant malaria. In the present study, transgenic A. annua plants were developed by overexpressing the key enzymes involved in the biosynthetic pathway of artemisinin. Based on Agrobacterium-mediated transformation methods, transgenic plants of A. annua with overexpression of both HDR and ADS were obtained through hygromycin screening. The genomic PCR analysis confirmed six transgenic lines in which both HDR and ADS were integrated into genome. The gene expression analysis given by real-time quantitative PCR showed that all the transgenic lines had higher expression levels of HDR and ADS than the non-transgenic control (except ah3 in which the expression level of ADS showed no significant difference compared with control); and the HPLC analysis of artemisinin demonstrated that transgenic A. annua plants produced artemisinin at significantly higher level than non-transgenic plants. Especially, the highest content of artemisinin was found in transgenic line ah70, in which the artemisinin content was 3.48 times compared with that in non-transgenic lines. In summary, overexpression of HDR and ADS facilitated artemisinin biosynthesis and this method could be applied to develop transgenic plants of A. annua with higher yield of artemisinin.
Artemisia annua ; genetics ; metabolism ; Artemisinins ; metabolism ; Biosynthetic Pathways ; Drugs, Chinese Herbal ; Mixed Function Oxygenases ; genetics ; Oxidoreductases ; genetics ; Plant Proteins ; genetics ; Plants, Genetically Modified ; genetics ; metabolism ; Plants, Medicinal ; genetics ; metabolism

OBJECTIVETo observe the effect of gastric dynamics by transcutaneous electrical acupoint stimulation (TEAS) combined general anesthesia when controlled hypotension dropped to 60% of the mean arterial prenssure (MAP) baseline, and to provide experimental evidence for organ protection in clinical controlled hypotension.

METHODSEighteen male beagles were randomly divided into three groups, the general anesthesia group (blank), the general anesthesia induced controlled hypotension group (control), and the general anesthesia combined TEAS induced controlled hypotension group (experiment), 6 in each group. Controlled hypotension was performed in the latter two groups with isoflurane inhalation and intravenous injection of sodium nitroprusside (SNP). The mean arterial pressure (MAP) was lowered to 60% of the MAP baseline and kept for 60 min. Controlled hypotension was not performed in Beagles of the control group. For Beagles in the experiment group, TEAS [2/100 Hz, (4 ± 1) mA] was applied to bilateral Hegu (LI4), Quchi (LI11), Zusanli (ST36), and Sanyinjiao (SP6) from stable physiological conditions to the end of maintaining stages. Changes of EGG frequencies and EGG amplitudes were monitored. Serum levels of gastrin (GAS) and motilin (MTL) were also detected at corresponding time points during and after experiment.

RESULTSAs for the pressure control effect of TEAS combined general anesthesia in the controlled hypotension, during the process of controlled hypotension (T1-T4), MAP levels of two controlled pressure groups remained relatively stable, and were kept at 60% of the MAP baseline. When the blood pressure dropped to the target low MAP and maintained at 60 min (T1-T4), EGG amplitudes of Beagles in all the three groups showed decreasing tendency. But it was more obviously lower than its basic level in the control group (P <0.05), while it was not obviously decreased in the experiment group (P < 0.05). EGG frequencies of Beagles in all the three groups showed no obvious change during this stage. By the end of the MAP rising stage (T8), the EGG amplitude of the experimental group was significantly higher than that of the control group and the blank group (P < 0.05), while it didn' t show any obvious increase in the control group. During this period, EGG frequencies of the two controlled hypotension groups decreased more than those of the blank group. Two h after rising blood pressure (at T9), EGG amplitudes and frequencies in the two controlled hypotension groups basically restored to their respective baselines and levels of the blank group at T9. At 2 h (T9) after controlled hypotension, serum levels of GAS and MTL were lower than those of basic levels in the two controlled hypotension groups (P <0.05). However, serum levels of GAS and MTL had an increasing trend in the two controlled hypotension groups at 24-72 h (T10-T12). Besides, the increasing speed and amplitude was better in experiment group than in the control group at T10-T12. However, there was no statistical difference between the two groups (P > 0.05). At 72 h (T12) serum levels of GAS and MTL had basically restored to their basic levels in the two controlled hypotension groups and that of the blank control group.

CONCLUSIONEGG amplitudes could be effectively improved in TEAS combined general anesthesia for controlled hypotension at 60% of the MAP baseline, the recovery of the serum GAS level accelerated, gastric power improved and stomach protected.

Acupuncture Points ; Anesthesia ; methods ; Anesthesia, General ; Animals ; Arteries ; Dogs ; Gastrins ; Hypotension, Controlled ; Male ; Motilin ; Nitroprusside ; Transcutaneous Electric Nerve Stimulation

OBJECTIVETo observe the effect of CKJ Recipe (consisting of Cordyceps sinensis polysaccharide, amygdaloside, and gypenosides) containing serum on the activation of rat primary hepatic stellate cells (rHSCs) and to explore its pharmacological mechanism.

METHODSrHSCs were isolated form liver and cultured for four days. Then they were divided into the normal control group, the model group, and the CKJ group. rHSCs in the model group and the CKJ group were treated with 2.5 ng/mL transforming growth factor beta1 (TGF-beta1) in serum-free DMEM for 24 h. Serum free DMEM (containing no TGF-beta1) was taken as the control for the normal control group. rHSCs in the CKJ group were treated with 5% CKJ-containing serum for 24 h. rHSCs in the other two groups were treated with 5% blank serum for 24 h.The protein expression level of a smooth muscle actin (alpha-SMA) was determined using high throughput screening (HCS) and Western blot. mRNA expression levels of alpha-SMA, collagen I (Col-I), platelet-derived growth factor receptor beta (PDGF-betaR), TGF-beta1, transforming growth factor beta receptor 1 (TGF-betaR1), and transforming growth factor beta receptor 2 (TGF-beta R2) were detected using quantitative RT-PCR.

RESULTSCompared with the normal control group, the protein expression level of alpha-SMA, mRNA expression levels of alpha-SMA, Col-I, PDGF-betaR, TGF-beta1, TGF-betaR1, and TGF-betaR2 significantly increased in the model group (P<0.05, P<0.01). Compared with the model group, the protein expression level of alpha-SMA, mRNA expression levels of alpha-SMA, Col-I, PDGF-betaR, TGF-beta1, TGF-beta1, and TGF-beta R2 significantly decreased in the CKJ group (P<0.05, P<0.01).

CONCLUSIONCKJ containing serum could inhibit the protein expression level of o-SMA, which was probably related with inhibiting TGF-beta1 and its related receptors.

Animals ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hepatic Stellate Cells ; metabolism ; Rats ; Transforming Growth Factor beta ; Transforming Growth Factor beta1 ; metabolism