Objective To investigate the inhibitory effects of RNA silencing via adenovirusmediated angiotensin Ⅱ receptor subtypes shRNA(Ad-ATlaR-shRNA and Ad-ATlbR-shRNA)in mice brainstem nucleus tractus solitarius(NTS)in vivo. Methods C57BL mice were used as animal model.The microinjection into the nucleus of NTS was adopted.Two groups of male C57BL mice(n =7,n=8)were selected.After 10 days of microinjection,mice were killed and their brain tissue were fixed and sectioned.The levels of ATlaR mRNA and ATlbR mRNA at both sides of NTS were examined by in situ hybridization. Results The expression of ATlaR mRNA was significantly inhibited from 1.81/μCi/mg to 0.71μCi/mg[(61.6±6.8)%,P<0.01]by Ad-ATlaR-shRNA.Meanwhile,ATlbR mRNA expression was consistent at both sides,with no significant difference(P>0.05)after Ad-ATlaR-shRNA microinjection.ATlbR mRNA expression at the side with AdATlbR-shRNA injection was significantly inhibited from 10.28/μCi/mg to 4.97μCi/mg[(51.6±5.2)%,P<0.01]by Ad-ATlbR-shRNA.Meanwhile,ATlaR mRNA probe were consistent at both sides,with no significant difference(P>0.05). Conclusions The results show that both AdATlaR-shRNA and Ad-ATlbR-shRNA inhibit the corresponding receptor mRNA expression,and there is no cross-action for each other.

Objective To investigate the prevalence of orthostatic hypotension in hypertensive patients aged 80 or over and associated risk factors at level A tertiary hospitals.Methods A multicenter cross-sectional study was conducted among very old hypertensive patients (≥ 80 years) at 28level A tertiary hospitals by using questionnaire-based surveys.A total of 1298 hypertensive subjects aged between 80 and 101 years were enrolled in this study.Blood pressures was measured in the supine position and the upright position within three minutes of standing,and 316 patients were assigned to the orthostatic hypotension(OH) group and the other 982 patients to the non-orthostatic hypotension(NOH) group.Additional information was acquired through patients' medical records and the questionnaire.Results The prevalence of OH was 24.3％ (316 cases) There were no significan different betueen OH patienl with NOHones in gender and age.OH patients had higher supine systolic and diastolic blood pressure(P=0.003 and 0.000,respectively),lower standing systolic and diastolic blood pressure(P=0.000 and 0.000,respectively),and higher rates of past coronary heart disease,stroke and renal abnormalities (P =0.037,0.001 and 0.014,respectively) than NOH patients.Logistic regression analysis showed that the prevalence of OH in the patients was positively correlated with supine systolic blood pressure(OR=1.196,CI:1.153-1.242,P=0.000) and supine diastolic blood pressure (OR =1.740,CI:1.602-1.885,P =0.000) and was negatively correlated with standing systolic blood pressure(OR =0.824,CI:0.795-0.855,P=0.000) and standing diastolic blood pressure (OR =0.584,CI:0.539-0.634,P =0.000).Conclusions The prevalence of orthostatic hypotension is high in hypertensive patients aged 80 years or over at level A tertiary hospitals.Poor blood pressure control may increase the risk of orthostatic hypotension.

Objective To explore the application of optical coherence tomography in vascular tissue engineering culture by dynamic monitoring its changes.Methods Human umbilical artery smooth muscle cells were isolated and culture by tissue block method.After passage culture and cell surface markers evaluation, smooth muscle cells were seeded onto polyglycolic acid scaffold and placed into the bioreactor based on Luo-Ye pump with pulsatile stress for three-dimensional culture.At 1、4、 7 、10、14、17、21 days in culture, the image data was obtained by optical coherence tomography technology.The ability of imaging TEBV via OCT was analyzed combined with histopathological observation.Results As the incubation time extended,OCT clearly showed PGA gradual degradation, decreased composite scaffold thickness and the wall structure from loose to tight.At 21 days in culture, the vessel mimics had smooth surface with extracellular matrix evenly distributed and achieved complete reconstruction in the PGA scaffold.Combining with histopathological staining, the blood vessel mimics were similar to natural blood vessels.OCT measured TEBV thickness compared with histopathological measurement had good correlation (r =0.922,P ＜ 0.05).Conclusion Optical coherence tomography could clearly image microstructures of tissue engineered blood vessels cultured in three-dimensional culture system based on Luo-Ye pump, delineate the reconstruction of TEBV-like tissue in the bioreactor and provide as a dynamic and convenient monitoring tool in vascular tissue engineering.

BACKGROUND:Seed cells are seeded on three-dimensional scaffold materials,and three-dimensional culture in bioreactors is a common in vitro tissue engineering culture method,but the changes in cell proliferation and metabolic patterns in bioengineered blood vessel construction are still unclear. OBJECTIVE:To explore the metabolic changes of cells such as oxygen consumption and their causes during the whole process of biological vascular tissue construction by in vitro bioreactor. METHODS:The self-built vascular bioreactor system was used as the platform;bovine vascular smooth muscle cells were used as the seed cells,and a conventional CO2 incubator provided the external gas environment for the cultivation process.Seed cells were seeded on a tubular porous polyglycolic acid scaffold material for three-dimensional culture,and the whole process included a one-week resting period and a seven-week pulsating tensile stress stimulation loading period.A non-invasive monitoring system was built,and the optical dissolved oxygen patch method was used to monitor the changes of dissolved oxygen in the culture solution in the reactor,and the glucose consumption and lactic acid production were measured by regular sampling.CCK-8 assay was used to determine the proliferation of smooth muscle cells on polyglycolic acid three-dimensional scaffold materials.Nicotinamide adenine dinucleotide oxidation state and reduction state ratio(NAD+/NADH)was utilized to understand cell proliferation and metabolism in the early stage of culture.RT-qPCR and western blot assay were applied to detect the expression of proliferation-related genes(Ki67)and glycolysis-related genes(GLUT-1,LDHA). RESULTS AND CONCLUSION:(1)The dissolved oxygen level in the culture solution was(4.314±0.380)mg/L from the cell injection to the end of the resting period(the first week),and gradually stabilized at(1.960±0.866)mg/L after the tensile stress stimulation(the last seven weeks);the two had significant changes(P<0.05).(2)The ratio of glucose consumption to lactic acid production in the cell culture medium YL/G increased rapidly after the cells were injected,and the highest value was above 1 on the fifth day,and then slow down to 0.5(The mean value of YL/G in the resting period was 0.89 and the mean value in the pressurized period was 0.57,P<0.05).(3)CCK-8 assay results showed that A450 value gradually increased after the cells were injected,and reached the highest value on the fifth day,reaching 3.17,and then slowly decreased.At the same time,it was found that Ki67 mRNA was up-regulated on the third day of culture,and then declined.The expression level of Ki67 protein was higher from the third day to the fifth day.(4)The detection of NAD+/NADH showed that the increase was obvious from the fifth to the seventh day after the injection of cells,and the expression of glycolysis-related genes(GLUT-1 and LDHA)was up-regulated and changed synchronously,and the relative expression was higher in the first five days.(5)The results showed that the tissue-engineered blood vessels were constructed using the vascular bioreactor and the smooth muscle cells in the early stage mainly proliferated and exhibited a metabolic feature of low oxygen consumption.The metabolic characteristics of high oxygen consumption were observed during the pulsatile tensile stress stimulation stage.