Capsid Proteins ; metabolism ; Endocytosis ; physiology ; Virus Internalization ; Viruses ; metabolism

It is generally accepted that the permeability of the blood-brain barrier in the fetus is higher than in the adult, but its structural basis is still not well known. In this paper, an ultrastructural study was performed on the cerebral capillaries of human fetus aged from 5-9 months and some structural parameters were measured. The results were as follows: (1) the endothelial tight junctions were longer and tortuous, and the clefts within the junctions were found and did not show apparent change in all groups; (2) the plasmalemmal vesicles were larger in 5th month than in the 9th month, and the density of vesicles was low (

Humans ; Meniere Disease

OBJECTIVE: To evaluate function and application of various biomaterials in tissue engineering repair skull defect, and to seek a reasonable skull substitutes. METHODS: Using "tissue engineering, skull defect, stem cells, cytokines, composite" as key words in Chinese, and using "tissue engineering, skull defect, mesenchymal stem cells, cytokines, materials" as key words in English, a computer-based online search was performed for publications from January 1993 to October 2009. Articles concerning biomaterials and tissue engineering skull defect repair were included. Articles describing repetitive study or Mete analysis were excluded. Function of various biomaterials in tissue engineering repair skull defect was assess in 17 articles. RESULTS: Stem cell technique is to obtain seed cells from a few myeloid tissues. Following in vitro induction and amplification, cells at a certain number could compound with stents, and construct tissue-engineered bone in vitro. The cells could sustain the biological features of osteoblasts, and fuse with bone tissue in the recipient site. Simultaneously, it could avoid the occurrence of immunological rejection. Two or over materials were compounded together, or biomaterial surface received various modification. These could promote adhesion between cells and materials, elevate cell bioactivity and maintain biological function. Following moved into seed cells using some vectors, the latter ossified in bone defect site, and secreted suitable bone growth factor, induced the differentiation of peripheral non-oriented osteogenitor cells into oriented osteogenitor cells, which could harvest adequate seed cells with osteogenic activity in a short time, and accelerate the healing of skull defects. The composite made by using three-dimensional virtual imaging and computer numerical control modeling techniques has the advantages of medical composite, precise anatomical consistency with surrounding tissues of skull defects, and perfect appearance. CONCLUSION: At present, no material can be accorded with the requirement of bone tissue engineering. Combination of some materials or modification of biomaterial surface can promote adhesion of cells and materials, elevate cell biological activity, and maintain biological function, which are presently hot focus of tissue engineering research of biomaterials.

The effects of magnolol (Mag) on hyperglycemia and hyperlipemia, hepatic oxidative stress and cytochrome P4502E1 (CYP2E1) activity of diabetic rats induced by high-fat diet (HFD) and streptozotocin (STZ) were studied. After oral administration of Mag (25, 50 and 100 mg x kg(-1) x d(-1)) for continuous 10 weeks, the blood glucose and lipids (TC, TG and LDL-C) levels, as well as the hepatic CYP2E1 activity and MDA content of diabetic rats, decreased significantly (P < 0.05 or P < 0.01), whereas the oral glucose tolerance and hepatic antioxidant enzymatic activities (CAT and GSH-Px) of diabetic rats, increased significantly (P < 0.05 or P < 0.01). The results indicated that Mag was effective against the hepatic oxidative damage, hyperglycemia and hyperlipemia of diabetic rats induced by HFD and STZ, and the inhibition of Mag on hepatic CYP2E1 activity could be an important mechanism of Mag against hepatic insulin resistance and oxidative damage.
Animals ; Biphenyl Compounds ; isolation & purification ; pharmacology ; Blood Glucose ; metabolism ; Cholesterol ; blood ; Cholesterol, LDL ; blood ; Cytochrome P-450 CYP2E1 ; metabolism ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; metabolism ; Diet, High-Fat ; Glucose Tolerance Test ; Hypoglycemic Agents ; isolation & purification ; pharmacology ; Lignans ; isolation & purification ; pharmacology ; Liver ; metabolism ; Magnolia ; chemistry ; Male ; Oxidative Stress ; drug effects ; Plants, Medicinal ; chemistry ; Protective Agents ; pharmacology ; Rats ; Rats, Wistar ; Streptozocin ; Triglycerides ; blood

The effects of magnolol (Mag) on hyperglycemia and hyperlipemia, hepatic oxidative stress and cytochrome P4502E1 (CYP2E1) activity of diabetic rats induced by high-fat diet (HFD) and streptozotocin (STZ) were studied. After oral administration of Mag (25, 50 and 100 mg x kg(-1) x d(-1)) for continuous 10 weeks, the blood glucose and lipids (TC, TG and LDL-C) levels, as well as the hepatic CYP2E1 activity and MDA content of diabetic rats, decreased significantly (P < 0.05 or P < 0.01), whereas the oral glucose tolerance and hepatic antioxidant enzymatic activities (CAT and GSH-Px) of diabetic rats, increased significantly (P < 0.05 or P < 0.01). The results indicated that Mag was effective against the hepatic oxidative damage, hyperglycemia and hyperlipemia of diabetic rats induced by HFD and STZ, and the inhibition of Mag on hepatic CYP2E1 activity could be an important mechanism of Mag against hepatic insulin resistance and oxidative damage.

Objective To study the expression and significance of P53 and nm23 in colorectal adenocarcinoma.Methods The expression of P53 and nm23 was examined by immunohistochemical technique in 83 cases of colorectal adenocarcinoma.Results In colorectal adenocarcinoma,the positive intensities of P53 and nm23 was associated with tumour depth,histological grade,lymph node metastasis diseases and distant metastasis disease(P0.05).Conclusion P53 and nm23 may play an important role in the development and metastasis of colorectal adenocarcinoma.It is an useful marker for predictinng the prognosis of colorectal adenocarcinoma.

Objective:To explore value of 256-slice spiral CT pulmonary artery angiography (CTPA)evaluating right heart function in patients with acute pulmonary embolism (APE).Methods:According to death risk assessment of APE patients, a total of 67 APE patients were divided into high risk APE group (n=41)and non-high risk APE group (n=35).CTPA was used to analyze and compare CTPA obstructive index and right heart function indexes between two groups.Correlations among CTPA obstructive index and right heart function indexes were also analyzed.Results:Compared with non-high risk APE group,there were significant rise in CTPA constructive index [8.58% vs.24.69%],percentages of straight or left protruded ventricular septum (31.46% vs.73.17%)and bronchial artery dilation (5.71% vs.24.69%);Except the supe- rior vena cava diameter,the rest right heart function parameters had difference significance in two groups,P<0.05 or<0.01. Spearman correlation analysis indicated that CTPA obstructive index was significant positively correlated with right ventricular maximal short axis (RVMSA),RV:LV,diameters of main pulmonary artery,superior vena cava and azygos (r=0.684~0.954),and significant inversely correlated with LVMSA (r=-0.786),P<0.01 all.ROC curve analysis indicated that AUCs of CTPA RV:LV (0.949)was the biggest diagnosing APE severity.Conclusion:Right heart func- tion indexes measured by multi-detector CT are accurate and practical indexes evaluating APE severity,and it possesses im- portant significance.

To examine the effect of transcatheter arterial embolization (TAE) of liver tumors on hypoxia-inducible factor-1alpha (HIF-1alpha) expression in the residual viable tumor, a total of 30 New Zealand White rabbits implanted with VX2 liver tumor were divided into 2 groups. TAE-treated group animals (n=15) were subjected to TAE with 150-250 mum polyvinyl alcohol particles. Control group animals (n=15) underwent sham embolization with distilled water. Six hours, 3 days or 7 days after TAE, the animals were sacrificed, and samples of tumor and adjacent normal liver tissue were harvested. Expression of HIF-1alpha protein was examined immunohistochemically. Real-time PCR was performed to examine the HIF-1alpha mRNA levels. Our results showed that HIF-1alpha protein was expressed in the VX2 tumors but not in the adjacent normal liver tissue. The HIF-1alpha-positive tumor cells were located predominantly at the periphery of necrotic tumor regions. The mean levels of HIF-1alpha protein were significantly higher in TAE-treated tumors than those in control tumors (P=0.002). Among the three sacrificing time points, the difference in increase in HIF-1alpha protein was significant between the two groups at the sacrificing time point of 6 h and 3 days after TAE (P=0.020, P=0.031, respectively), whereas no significant increase was noted 7 days after TAE (P=0.502). In contrast, although HIF-1alpha mRNA was expressed in TAE-treated and control VX2 tumors, there existed no significant difference in the HIF-1alpha mRNA level between the two groups (P=0.372). It is concluded that TAE of liver tumors increases the expression of HIF-1alpha at protein level in the residual viable tumor, which could be attributed to hypoxia generated by the procedure.

BACKGROUND:Shear stress can directly mediate the expression of endothelial cells, especially some cytokine genes whose codes are related to angiogenesis. Otherwise, flow shear stress of blood plays an importantly biological role in regulating vascular structure and function.OBJECTIVE: To observe the effects of laminar flow shear stress on the proliferation of vascular endothelial cells and the expression of protooncogene c-myc in human cerebral arteriovenous malformation.DESIGN: Randomized controlled study.SETTING: Department of Neurosurgery, Shenyang General Hospital of Military Area Command of Chinese PLA.MATERIALS: The experiment was carried out in the Neuromedical Institute, General Hospital of Shenyang Military Area Command of Chinese PLA from November 2006 to February 2007. Fresh samples of human cerebral arteriovenous malformation were derived from 20 patients who were of grade Spetzler Ⅱ -Ⅲ and received resection of human cerebral arteriovenous malformation in the Department of Neurosurgery, General Hospital of Shenyang Military Area Command of Chinese PLA in 2006. All cases were diagnosed with whole-brain angiography before operation. The main reagents and equipments were detailed as follows: M199 culture media (Gilbco BRL), quality fetal bovine serum (HyClone), endothelial cell growth supplement (ECGS; Sigma, USA), CO2 incubator (Forma Scientific, USA), flow cytometry analysis of cell cycle kit (BD Company), flow cytometer (FACS Calibur, BD Company), rat-anti-human c-myc monoclonal antibody (Santa Cruz Company, USA), and reverse transcription polymerase chain reaction (RT-PCR) kit (Promega).METHODS: Tissue explants adherent method was used to culture vascular endothelial cells of human cerebral arteriovenous malformation, and then the cells were classified into 4 groups based on degree of shear stress, including control group, low shear stress group, moderate shear stress group and high shear stress group. Cultured endothelial cells of human cerebral arteriovenous malformation were put in a parallel plate flow chamber. In addition, cells in the low,moderate and high shear stress groups were stressed by low, moderate and high shear stress for 8 hours, respectively.However, shear stress in the control group was 0 Pa. Flow cytometry was used to measure proliferation index, and the expression of c-myc protein and c-myc mRNA were determined by immnocytochemistry and RT-PCR analysis respectively.MAIN OUTCOME MEASURES: Expressions of c-myc protein and c-myc mRNA and proliferation index in endothelial cells under various degrees of shear stress.RESULTS: ① Proliferation index: Proliferation index was higher in the moderate and high shear stress groups than that in the control group (P ＜ 0.05, 0.01). ② Expression of c-myc protein: Immuneposjtjve expression of c-myc protein was gradually increased with the increase of shear stress and there were significant differences in the three shear stress groups as compared with control group (P ＜ 0.05-0.01). ③ Expression of c-myc mRNA: Proliferation index of endothelial cells was higher in the low and moderate shear stress groups than that in the control group (P ＜ 0.05).CONCLUSION: Flow shear stress can induce expression of c-myc and activate expression of c-myc gene based on gene transcription so as to promote the proliferation of vascular endothelial cells in human cerebral arteriovenous malformation