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Objective To investigate the effect of fluid shear stress (FSS) on the expression of B lymphoma MoMLV insertion region 1 (Bmi-1) in bone mesenchymal stem cells (BMSCs) and possible signal transduction mechanism.Methods BMSCs were isolated from SD rats and FSS at different magnitude (0.5,1.5,3.0 Pa)and under different time phase (1,2,6,24 h) were loaded by parallel-plate flow chamber system.The expression of Bmi-1 was measured by real-time RT-PCR at mRNA level and the levels of phosphorylated Akt (p-Akt)and extracellular signalregulated kinase 1/2 (p-ERK1/2) were detected by Western blotting.The signaling inhibitors,wortmannin (PI3K specific inhabitor) and PD98059 (ERK1/2 specific inhabitor),were used to investigate possible mechanical signal transduction pathway.Results Bmi-1mRNA expression increased when BMSCs were exposed to 1.5 Pa FSS for 1 h and reached the peak at 24 h.All FSS with different magnitude could increase Bmi-1 expression,especial at high FSS (3.0 Pa).Meanwhile,FSS resulted in a significant activation of p-Akt and p-ERK1/2 in BMSCs.After treated with wortmannin,the expression of Bmi-1 was inhibited prominently,however,PD98059,the expression of Bmi-1 did not change.Conclusions FSS can activate the expression of Bmi-1,the amount of Bmi-1 expression was closely related to the stimulating time and the magnitude of FSS,and Akt signal molecule plays an important role during the process.These findings provide significant references for studying the mechanical biological mechanisms of stem cell differentiation.
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Objective To investigate the effect of astragalus polysaccharides (APS) on the growth and proliferation of hepatocellular carcinoma cells and its effect on adenosine monophosphate activated pro-tein kinase (AMPK) activity.Methods Hepatocellular carcinoma HepG2 cells cultured for 12,24,and 48 hours were treated with 200,300,and 400 mg/L concentration of astragalus polysaccharides.The cell inhibition rate was detected with methyl thiazolyl tetrazolium (MTT),and apoptosis was observed under the fluorescence microscope.Western blot method was used to measure the expression of total AMPK,phosphorylated AMPK (p-AMPK),and phosphorylate mammalian target of rapamycin (p-mTOR) protein expressions.Results Astragalus polysaccharides of each concentration significantly inhibited the proliferation of human hepatoma HepG2 cells (P ＜ 0.01),and the effect of 300 mg/L concentration astragalus polysaccharides was more significant than that of the 200 mg/L concentration (P ＜0.01);while inhibitory effect of 400 and 300 mg/L Astragalus polysaccharides on the proliferation of human hepatoma cell line HepG2 was not significant difference.We found that Astragalus polysaccharides of each concentration could promote the apoptosis of HepG2 cells,and the effect of 300 mg/L Astragalus polysaccharides was more significant.However,astragalus polysaccharide of 400 mg/L concentration could promote the apoptosis no more than the 300 mg/L concentration,which was observed by fluorescent microscope.Western blot results showed that astragalus polysaccharides could increase the expression of p-AMPK (P ＜ 0.05),and inhibit its downstream protein expressions of p-mTOR (P ＜ 0.05).The proliferation effect of astragalus polysaccharides was weakened after accession of AMPK antagonist compound C on hepatocellular carcinoma cells.Conclusions APS can inhibit the growth and proliferation of hepatocarcinoma cells,and its mechanism is related to the AMPK-mTOR pathway.
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@#Objective To investigate the psychologic characteristics of the hypertensive with transient ischemic attack(TIA). Methods 56 hypertensive patients with TIA were surveyed with Symptom Checklist 90 (SCL-90), Eysenck Personality Questionnaire (EPQ), Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS). Results and Conclusion The score in interpersonal sensitivity and paranoid factors of SCL-90 were below the norm obviously(P<0.05), the score of other factors were higher than the norm(P<0.01). Somatization, obsessive-compulsive, anxiety correlated negatively with E scale, while hostility, phobia anxiety, anxiety correlated positively with N scale. 71.4% patients appeared depression while 78.6% patients appeared anxiety in differently degree. Depression and anxiety correlated positively with the times of TIA, especially the anxiety.
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BACKGROUND: Due to the source of conspecific heart transplanted organ is limited and it becomes more and more deficient, and porcine cardiovascular system and haemodynamics are very similar to that of human being, therefore, domestic and foreign scholars have paid more attention on the heterogeneic heart transplantation from swine to human, and there are more and more basic studies about it.OBJECTIVE: To compare the zero-stress state of ascending aorta and pulmonary artery trunk between swine of different months and healthy persons, which provides necessary vascular tissue reconstruction basis for anastomosing vessel of heterogeneic heart transplantation from swine to human being.DESIGN: Open experiment.SETTING: Laboratory of Biomechanics, Yunyang Medical College.MATERIALS: This experiment was carried out at the Laboratory of Biomechanics, Yunyang Medical College from October 2001 to September 2002. Human heart specimens were chosen from 6 male adult corpses who had no visible manifestation of cardiovascular diseases, aged 18 to 30 years. Informed consents were obtained from all the relatives. Totally 42 conspecific swine, aged one month, were also chosen and divided into 7 groups, named as 1,2,3,4,5,6 and ＞ 6 months groups respectively, with 6 in each group. Swine were anesthetized at 1,2,3,4,5,6,＞ 6 months respectively and sacrificed in each group.METHODS: The corresponding ascending aorta and pulmonary artery trunk were dissected and isolated. Each arterial anterior wall was labeled in situ with coloring pen, and then artery was shifted into the oxygen-saturated Kreb's solution. Five isometric vascular rings were divided along the axial direction, then each vascular ring was cut open along the radial direction. Opening angle of each vascular ring at zerostress state was measured and recorded by computer 20 minutes later(The included angel formed through connecting the middle point of inner wall of open vascular plane and two end points of inner wall). The experiment was conducted at room temperature 20-30 ℃. All the procedures of vascular samples were performed within 24 hours after subjects died.MAIN OUTCOME MEASURES: Measuring results of opening angle of ascending aorta and pulmonary trunk at zero-stress state of swine at different months and human being.RESULTS: ①Comparison of measuring results of opening angle of ascending aorta and pulmonary trunk between swine at different months and human being: Opening angle of ascending aorta of human being increased from (100.4±12.8)°at proximal end to (152.8±18.6)°at distal end. Opening angle of swine at different months increased from about 68°at proximal end to about 130°at distal end; Opening angel of pulmonary artery trunk of human being did not changed significantly along axial direction, and opening angel of pulmonary artery trunk of swine at different months increased from about 65° at proximal end to about 125°at distal end. There was significant difference of opening angle of ascending aorta and pulmonary trunk at zero-stress state between human being and swine (P=0.028 ＜ 0.05).But the opening angle of ascending aorta of human being was similar at the second segment to at the fourth and fifth segments of swine of different ages; Opening angle of each segment of pulmonary artery trunk of human being was close to that of proximal end (first and second segments) ofpulmonary artery trunk of swine.② Comparison of measuring results of ascending aorta and pulmonary artery trunk at zero-stress state of swine at different months: Opening angle of ascending aorta and pulmonary artery trunk of swine did not changed with the increase of age (P=-0.063 ＞ 0.05).CONCLUSION: Opening angels of ascending aorta and pulmonary artery trunk at zero-stress state are close in some segments between human being and swine, suggesting that corresponding ascending aorta or pulmonary artery trunk can mutually anastomose in some segments in the heterogeneic heart transplantation from swine to human, and the effect of age is not significant in vascular reconstruction.
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BACKGROUND: The source of conspecific heart transplantation organ is very limited and deficiency becomes more and more obvious.OBJECTIVE: To observe the mechanical properties of ascending aorta at one-dimensional loading between healthy persons and swine of different months, so as to provide necessary biomechanical experimental basis for anastomosing blood vessel in heterogeneic heart transplantation from swine to human.DESIGN: Open design SETTING: Staff Room of Anatomy, Yunyang Medical College MATERIALS: This experiment was carried out at the Laboratory of Biomechanics, Yunyang Medical College from April 2002 to July 2003.Ascending aortas of human were obtained from the 6 adult male corpses without cardiovascular diseases, aged 18 to 30 years, who died for accident and donated by Yunyang Medical College. Totally 42 conspecific swine of 1 month old, with certification number of QN0202, were provided by Animal Experimental Center of Yunyang Medical College. They were raised with common foodstuff. The 42 swine were butchered respectively at 1,2,3,4,5,6 and 7 months, 6 swine once. After anatomical isolation and in situ measurement of respective in vivo length, ascending aorta from aorta valve ring base plane to initiation part of innominate artery was taken out (Artherosclerosis was not presented in all the samples) and divided into five equal segments, and the second and fourth segments were used for mechanical test of one-dimensional loading.METHODS: Six adult male corpses and ascending aorta of 42 swine of 1 to 7 months were performed mechanical test of one-dimensional loading.All the blood segments were pre-treated ten times with the same strain rate at room temperature 32 ℃(loading range from 0 to 0.5 N). Hysteresis disappeared after blood vessel was given periodic permanent loading and unloading, and repeated force-deformed data were obtained. Blood vessel was given loading and unloading once with the same loading range and strain rate. The recorded force-deformed data were used for computer analysis. Force and displacement were scaled with standard weight and percentage scale at the end of each time. Constant α and elastic modulus Dt/dλ were fitted from experimental data.MAIN OUTCOME MEASURES: ① Comparison of the mechanical characteristic constant of ascending aorta at one-dimensional loading be tween human and swine of different months. ② Comparison of elastic mod ulus of ascending aorta at one -dimensional loading between human and swine of different months .RESULTS: ① Comparison of the mechanical characteristic constant of ascending aorta at one-dimensional loading between human and swine of different months: With the increase of month, although the material con stant of blood vessel of swine had a little increase, there was no significant difference (P ＞ 0.05). The mechanical material constant of ascending aorta at one-dimensional loading of human was basically familiar to that of swine of 1 to 7 months (P ＞ 0.05). ② Comparison of elastic modulus of ascend ing aorta at one -dimensional loading between human and swine of differ ent months: With the increase of months, elastic modulus of ascending aorta was significantly increased in swine of 7 months old in comparison with that in other months old (P ＜ 0.05); there was no significant difference of elastic modulus of corresponding blood vessel between human and swine of different months (P ＞ 0.05).CONCLUSION: There is no significant difference in mechanical characteristic constant and elastic modulus of ascending aorta between human and swine of 1 to 7 months. Mechanical characteristics of corresponding blood vessel were similar in some segments at least. From the mechanical angle, anastomosis of corresponding ascending aorta in the process of heterogeneic heart transplantation from swine to human has certain feasibility.
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In order to provide morphological data and theoretical basis for pig-to-human hepatic xenotransplantation, the difference in morphological parameters and vessel wall structural factors between human and porcine hepatic portal vein was studied. From human subjects and pigs of varying ages, hepatic portal veins were collected, paraffin-embedded and cut into sections. The histological structures were stained with HE, and elastin, collagen and smooth muscles were stained with Weigert, Aniline blue and orange G, respectively. Morphological parameters and relative contents of structural components were determined under microscopy and by computer image analysis system, respectively. The results showed that histological structures of human and porcine hepatic portal vein wall were similar. Caliber, wall thickness, lumen and wall area in pigs increased with age, all in linear correlation to months. Morphological parameters of 6- month-old pigs were similar to those of human. In pigs, collagen content increased gradually with months, elastin content remained relatively stable, smooth muscle content reached the peak at the 3rd month, and collagen/elastin (C/E) rose gradually. The contents of collagen and elastin in porcine hepatic portal vein wall were lower, while the content of smooth muscle was higher than in human, and C/E at the 5th and 6th month was similar to that in human. It is concluded that morphological parameters and contents of structural components of porcine hepatic portal vein vary with age. At the 6 month, its caliber, wall thickness, lumen and wall area are similar to those of human. There are differences in contents of structural components between human and pigs. However, in terms of C/E, mechanic properties of pigs at the 5th and 6th month mimic those of human, hence inosculation is viable in xenotrans-plantation between pigs and human.
Subject(s)
Collagen/analysis , Elastin/analysis , Image Processing, Computer-Assisted , Liver Transplantation , Muscle, Smooth, Vascular/cytology , Portal Vein/anatomy & histology , Portal Vein/chemistry , Swine , Transplantation, HeterologousABSTRACT
In order to provide morphological data and theoretical basis for pig-to-human hepatic xenotransplantation, the difference in morphological parameters and vessel wall structural factors between human and porcine hepatic portal vein was studied. From human subjects and pigs of varying ages, hepatic portal veins were collected, paraffin-embedded and cut into sections. The histological structures were stained with HE, and elastin, collagen and smooth muscles were stained with Weigert, Aniline blue and orange G, respectively. Morphological parameters and relative contents of structural components were determined under microscopy and by computer image analysis system, respectively. The results showed that histological structures of human and porcine hepatic portal vein wall were similar. Caliber, wall thickness, lumen and wall area in pigs increased with age, all in linear correlation to months. Morphological parameters of 6- month-old pigs were similar to those of human. In pigs, collagen content increased gradually with months, elastin content remained relatively stable, smooth muscle content reached the peak at the 3rd month, and collagen/elastin (C/E) rose gradually. The contents of collagen and elastin in porcine hepatic portal vein wall were lower, while the content of smooth muscle was higher than in human, and C/E at the 5th and 6th month was similar to that in human. It is concluded that morphological parameters and contents of structural components of porcine hepatic portal vein vary with age. At the 6 month, its caliber, wall thickness, lumen and wall area are similar to those of human. There are differences in contents of structural components between human and pigs. However, in terms of C/E, mechanic properties of pigs at the 5th and 6th month mimic those of human, hence inosculation is viable in xenotransplantation between pigs and human.
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BACKGROUND: So far it has not achieved satisfactory effects to use synthetic blood vessels (diameter＜ 6 mm) as the substitutes for human small arteries or veins when clinical reconstructive vascular operations are performed. So, study on the substitutes for small arteries and veins has been a problem demanding prompt solution at present.OBJECTIVE: To observe the pressure-volume (P-V) relationship of umbilical cord vein of different gestational ages so as to provide theoretical basis of biomechanical properties for the clinical application of human umbilical cord vein as material for vascular grafting.DESIGN: Non-randomized controlled experiment.PARTICIPANTS: The experiment was completed in the Laboratory of Medical Biomechanics, Yunyang Medical College in June 2004. Umbilical cord veins of 50 normal fetuses were collected on spontaneous miscarriage or labor with the pregnant women's permission by the Department of Obstetrics and Gynecology, Shiyan Taihe Hospital. The gestational age of the fetuses ranged from 24 to 42 weeks and the pregnant women aged 20to 30 years. Among them, 8 cases with gestational age of 24-27 weeks,7cases 28-32 weeks,8 cases 33-36 weeks,4 cases 37 weeks,5 cases 38weeks, 5 cases 39 weeks , 5 cases 40 weeks , 4 cases 41 weeks and 4cases 42 weeks.INTERVENTIONS:Umbilical cord veins of 50 normal fetuses were collected. A 2-cm long segment of each umbilical cord was measured and labeled at both ends. Then they were cut off and put into normal saline (NS). The umbilical veins were carefully stripped from the cord; its two ends were fixed on the biomechanical experiment stand of soft tissues. The P-V relationship of fetal umbilical cord vein was measured, and then the compliance calculated.MAIN OUTCOME MEASURES: Pressure, volume and compliance of different umbilical cord veincurve of pressure-volume relationship of the umbilical cord vein was similar at week 37 to 40 but decreased significantly at week 28 and week 42. After regression analysis twice, it was found that the absolute value of regression vein increased with the increasing of gestational age[24-27 weeks (2.22±0.34)cord vein collected at 37 to 40 weeks of gestational age was similar. When the umbilical cord veins older than 42 weeks or under 28 weeks were compared, there was significant difference in their compliance (F=65.84-86.52, P＜ 0.01).CONCLUSION: Human umbilical cord veins are good substitutes for The relationship between compliance and gestational age. Our studies suggest that the umbilical cord vein, whose gestational ages range from 37to 40 weeks, is a material of choice for the transplantation.