Biomedical subjects

Yun Luo

Publications and source records attributed to Yun Luo.

31 records · Page 2Linked to original sources

PubMed2004

[Effect of mailuoning on C-Fos protein expression in rats with cerebral infarction].

OBJECTIVE: To investigate the protective effect of mailuoning (MLN) on nerve cells after cerebral infarction induced by photochemistry. METHODS: Eighty SD rats were divided into three groups, the control group (n = 20), the model group (n = 30) and the MLN group (n = 30). Focal cerebro-ischemia induced by photothrombosis in adult rat was used as a model. Changes of C-Fos protein expression before and after MLN treatment were observed using immunohistochemistry, computerized imaging technique and transmission electron microscopy (TEM). RESULTS: C-Fos positive cells located in the transitional zone between the necrotic core and normal cortex. C-Fos protein expression began to show 3 hrs after cerebral infarction, peaked at 6 hrs. As compared with the model group, C-Fos expression was significantly reduced in the MLN group (P<0.01). CONCLUSION: MLN could markedly reduce the injury of nerve cell in the transitional zone, the protection may be related with its inhibition on C-Fos protein expression.

Animals↗

PubMed2004

[The study on color space of the VINTAGE & UNIBOND standard color].

OBJECTIVE: To research the color space of the standard color board, guide the clinic work of color match, and establish an foundation for deeper researching. METHODS: Through taking analysis of reflecting spectrum and spectral tristimulus, each parameter of the color on standard board was found out. The color difference between border upon colors on board was worked out through matching the color parameters. The number of color space between each border upon color on standard color board, divided by deltaE = 1.5, was found. RESULTS: The number of color space between each border upon color was 3-6. The color space was bigger in group B, but smaller in group D. The color space was bigger in high lightness area, but smaller in low lightness area. CONCLUSION: Some color space has been found between standard color borders of VINTAGE and UNIBOND. Color of natural teeth is unable to be completely included into standard color border, especially in clinical care.

Colorimetry↗

PubMed2003

Artificial myocardium with an artificial baroreflex system using nano technology.

Where is the place which should be helped in a patient with congestive heart failure? The answer may be contraction of the heart. At Tohoku University, development research of "the artificial myocardium" has been conducted, using a ball screw type electromagnetic motor. Furthermore, super-miniaturization is being attempted at present. Thus, a system with shape memory alloy is being developed. The cooling speed problem was solved by the application of the Peltier element. A drive at a speed equal to that of a heartbeat was realized by the application of this system. At present, a ventricular assist device is used for patients waiting for a heart transplant in Japan. An air driven type system disturbs a patient's QOL remarkably because it is connected to the drive device. With our concept, energy is provided by using the electromagnetic force from outside of the body by the use of transcutaneous energy transmission system. Magnetic shielding by amorphous fibers was used at Tohoku University to improve the total efficiency. A natural heart can alter the cardiac output corresponding to the demand. Artificial internal organs must participate in the system of the living body, too. Tohoku University has developed a resistance based artificial heart control algorithm, which simulated a baroreflex system to cope with every demand. Nano level sensing equipment is now under development at Tohoku University. At present, development is being conducted aiming at an "intelligent artificial myocardium".

Baroreflex↗

PubMed2003

Cardiac conductive system excitation maps using intracardiac tissue Doppler imaging.

OBJECTIVE: To precisely visualize cardiac anatomic structures and simultaneously depict electro-mechanical events for the purpose of precise underblood intervention. METHODS: Intracardiac high-resolution tissue Doppler imaging was used to map real time myocardial contractions in response to electrical activation within the anatomic structure of the cardiac conductive system using a canine open-chest model. RESULTS: The detailed inner anatomic structure of the cardiac conductive system at different sites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventricular wall) with the inside onset and propagation of myocardial velocity and acceleration induced by electrical activation was clearly visualized and quantitatively evaluated. CONCLUSION: The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and precision ablation.

Animals↗

PubMed2003

[Effect of oxidated low-density lipoprotein on early apoptosis of vascular smooth muscle cell].

OBJECTIVE: To investigate the apoptosis in vascular smooth muscle cell (VSMC) induced by oxidated low-density lipoprotein cholesterol (ox-LDL), and to discuss the relative mechanism of the apoptosis of VSMC. METHODS: The growth index of VSMC of Wistar rat was determined. By using trypan blue to count sustaining cells, the proliferative effect of ox-LDL on culturing VSMC was observed. With flow cytometer, the apoptosis of VSMC induced by ox-LDL and the inhibitory effect of cyclooxygenase-2 (COX-2) inhibitor NS-398 on apoptosis were determined. RESULTS: After VSMC grew normally in culture, ox-LDL in concentrations of 35 mg/L and 50 mg/L could advance the growth period of VSMC to between 12 and 24 hours, and the proliferation of VSMC were obvious. The proliferation of VSMC induced by ox-LDL were inhibited by NS-398. The rate of apoptosis of VSMC in ox-LDL and NS-398 groups were higher than that of normal control. CONCLUSION: ox-LDL could induce an obvious proliferation of VSMC in culture. Although NS-398 can decrease the proliferation of VSMC, it could enhance ox-LDL to induce apoptosis.

Animals↗

PubMed2003

[Clinical evaluation of two temporary restoration materials: Composite and self-cured acrylic resin].

OBJECTIVE: The purpose of this study was to compare the clinical application and effect of two temporary restorations materials: composite and self-cured acrylic resin. METHODS: 153 composite temporary crowns (and bridges) placed in 44 patients and 144 self-cured acrylic resin temporary crowns (and bridges) placed in 49 patients were evaluated according to the California Dental Association's (CDA) criteria and questionnaire. RESULTS: It showed that composite temporary crowns (and bridges) had better surface smoothness, marginal integrity and anatomic form than self-cured acrylic resin temporary crowns (and bridges). In the 49 patients with self-cured acrylic resin temporary crowns (and bridges), 67% and 88% of them complained of food impaction and mouth odor, while only 2% and 30% in the 44 patients with composite temporary crowns (and bridges) had the same complaint. CONCLUSION: Between the two temporary restoration materials, composite is better than self-cured acrylic resin.

Acrylic Resins↗

PubMed2002

Effects of electroporation on primary rat hepatocytes in vitro.

AIM: To investigate the effects of electroporation on primary rat hepatocyte and to optimize the electroporation conditions introducing foreign genes into primary hepatocytes. METHODS: A single-pulse procedure was performed at low voltage (220-400 V) but with high capacitance (500-950 microF). Hepatocytes were divided into 4 groups according to the electroporation conditions: group I, 220 V and 500 microF; group II, 220 V and 950 microF; group III, 400 V and 950 microF,and group IV. The control group was freshly isolated hepatocytes and directly cultured under the same conditions as those of electroporation groups. The effects of electroporation on primary rat hepatocytes were detected by trypan blue exclusion (TBE) and MTT analysis. Besides, albumin (Alb), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in the supernatants of cultured hepatocytes were measured by biochemical assay. RESULTS: Between day 1 and day 15 after incubation, primary rat hepatocytes of each electroporation group appeared normal, being the same with those of control group. TBE staining showed that slight hepatocyte damage and high survival rate were found in the electroporation groups and the control group. Cultured for 3, 7, 11 and 15 days, hepatocyte viability was approximately 92.6+/-2.5 %, 89.5+/-3.3 %, 82.0+/-3.5 % and 74.3+/-1.2 %, respectively. MTT analysis indicated that the viabilities of hepatocytes had no significant difference between each electroporation group, and those were similar to that of control group. At the 36th hour after electroporation, Alb, ALT and LDH in the supernatants of control group were 5.3+/-0.1 g x L(-1), 183.7+/-8.4 nkat x L(-1) and 896.8+/-58.5 nkat x L(-1); those of group II were 5.7+/-0.1 g x L(-1), 215.4+/-16.7 nkat x L(-1) and 1063.8+/-51.8 nkat x L(-1); and those of group III were 5.8+/-0.2 g x L(-1), 217.1+/-8.4 nkat x L(-1) and 1063.8+/-10.0 nkat x L(-1). Statistically, the proteins of group II and group III were significantly higher than those of control group (P<0.05), whereas the protein production of group I, Alb, ALT and LDH were 5.3+/-0.2 g x L(-1), 205.4+/-3.3 nkat x L(-1) and 1035.4+/-116.9 nkat x L(-1), were similar to those of control group. At the same time, TBE and MTT analysis indicated that there was no significant cell viability difference between electroporation groups and control group. CONCLUSION: This single-pulse electroporation procedure performed at low voltage (220-400 V) but with high capacitance (950 microF) is one of the optimal choices to introduce foreign genes into primary rat hepatocyte.

Animals↗

PubMed2002

[Expression of CD(14) protein in liver sinusoidal endothelial cells during endotoxemia].

OBJECTIVE: To observe the expression of CD(14) protein and CD(14) gene in liver sinusoidal endothelial cells (LSECs) of rats during endotoxemia and the role of CD(14) protein in the activation of lipopolysaccharide (LPS)-induced LSECs. METHODS: Wistar rat endotoxemia model was established by injection of a dose of LPS (5 mg/kg, Escherichia coli O111:B4) via the tail vein of the rats, then sacrificed immediately, at 3, 6, 12, and 24 h, respectively. LSECs were isolated from normal and LPS-injected rats by the in situ collagenase perfusion technique. The isolated LSECs were incubated with anti CD(14) polyclonal antibody, then followed by staining with goat anti-rabbit IgG conjugated fluorescein isothiocyanate (FITC). The percentage and mean fluorescence intensity (MFI) of CD(14)-positive cells were detected by the flow cytometric analysis (FCM). LSECs were collected to measure the expression of CD(14) mRNA by the in situ hybridization analysis. The isolated LSECs from normal rats were divided into two groups. Group of LPS: LSECs were induced with different concentration of LPS (0, 0.01 microg/ml, 1 microg/ml, 10 microg/ml, and 100 microg/ml). Group of anti-CD(14) blockade: LSECs were pre-incubated for 30 min with CD(14) antibody before different concentrations of LPS were added. The supernatants of these cells were then collected for measuring the levels of tumor necrosis factor (TNF)- alpha and interleukin (IL)-6. RESULTS: In rats with endotoxemia, LSECs displayed a strong MFI distinct from that of control rats. The number of FITC-CD(14) positive LSECs was 54.32%, 65.83%, 85.61%, and 45.65% at 3, 6, 12, and 24 h, respectively, which increased markedly when compared to control rats (4.45%, P<0.01). The expression of CD(14) mRNA in LSECs was stronger than that in control rats. The levels of TNF-alpha were significantly increased in group of LPS (54.49 +/- 6.02 pg/ml, 84.65 +/- 10.16 pg/ml, 206.54 +/- 23.55 pg/ml, 349.87 +/- 39.47 pg/ml, and 365.76 +/- 40.31 pg/ml) than those in group of anti-CD(14) blockade (55.93 +/- 6.95 pg/ml, 63.32 +/- 7.81 pg/ml, 85.34 +/- 9.72 pg/ml, 112.75 +/- 13.54 pg/ml, and 198.66 +/- 21.54 pg/ml) (P<0.01). The levels of IL-6 also increased significantly in group of LPS (103.34 +/- 12.52 pg/ml, 187.39 +/- 20.31 pg/ml, 243.87 +/- 27.83 pg/ml, 289.51 +/- 30.15 pg/ml, and 298.53 +/- 31.94 pg/ml) than those in group of anti-CD(14) blockade (104.37 +/- 11.49 pg/ml, 125.02 +/- 13.58 pg/ml, 164.59 +/- 19.47 pg/ml, 183.47 +/- 20.17 pg/ml, and 221.76 +/- 26.43pg/ml) (P<0.01). CONCLUSIONS: LSEC can synthesize CD(14) protein and express CD(14) gene during endotoxemia. Anti CD(14) antibody can inhibit the production of TNF-alpha and IL-6 in LSECs induced by LPS. The expression of CD(14) protein may take an important part in the activation of LSECs induced by LPS.

Animals↗

PubMed2002

[An in vitro model of hepatitis B virus gene replication and expression in primary rat hepatocytes transfected with circular viral DNA].

OBJECTIVE: To establish an in vitro model of hepatitis B virus (HBV) replication and expression in primary rat hepatocytes (PRH) transfected with circular viral DNA for further study on the interaction of HBV with hepatocytes. METHODS: Circular viral DNA containing complete HBV genome were transfected into PRH by electroporation (transfected group, about 4mug of circular viral DNA/1 10(7)cells). From day 1 to day 10 after transfection, HBsAg and HBeAg in the supernatants and lysates of PRH were measured with IMX system. HBcAg was assayed with western blotting, immunol dot blotting and immunocytochemistry. Meanwhile, HBV S-mRNA and X-mRNA were tested with RT-PCR, and replicative intermediates of HBV DNA were analyzed by southern blotting and dot blotting. Moreover, Transmission electron microscopy was used if viral particles were produced in transfected rat hepatocytes. PRH electroporated only was used as control group. RESULTS: (1) Viral antigen production in transfected rat hepatocytes: HBsAg in cell lysates was positive. P/N values ranged from 4.83 to 85.69, and could be maintained for 10 days after transfection. The average P/N values was 18.239 27.459. Whereas, HBsAg was negative in the supernatants of transfected group (P/N values, negative<2.1). HBeAg in the supernatants and lysates of transfected hepatocytes all was negative (P/N values<2.1) during 10 days following transfection. HBcAg was only found positive in transfected hepatocytes by immunol dot blotting. (2) Detection of viral transcripts: transcription of HBV DNA was investigated by preparing total RNA from rat hepatocytes 2 days after transfection and looking for S-mRNA and X-mRNA by RT-PCR. Results showed S-mRNA positive, X-mRNA negative. (3) HBV DNA replication analysis: intracellular total DNA was extracted 2 days after transfection and analysed by southern blotting. All replicative DNA intermediates, including relaxed circular (rcDNA), covalently closed circular (cccDNA), and single-stranded (ssDNA) linear HBV DNA forms, were indicated. Dot blotting showed intracellular HBV DNA positive in transfected group during 10 days after transfection. However, viral particles were not found in transfected hepatocytes during 3 days after transfection. CONCLUSIONS: Circular HBV DNA transfected into primary adult rat hepatocytes could obtain continuous replication and stable expression of HBV surface antigen. This in vitro model has high reproducibility and stability, and is useful for directly studying the interaction of HBV with hepatocytes.

Animals↗

PubMed2002

[The study of calcification of autogenous bone marrow stem cell transplantation on alveolar bone defect in dogs].

OBJECTIVE: To evaluate the effect of calcification of autogenous bone marrow stem cell transplantation in periodontal tissue regeneration. METHODS: Bone marrow stem cells derived from the same dog were cultured with alpha-MEM. 1 x 10(7) cells of first passage were allowed to attach to the collagen membrane for 24 hours. The membrane-cells were transplanted into periodontal defect in the same dog. Then the defects were covered with e-pTFE membranes. The defects covered only with e-pTFE without membrane-cells were served as control. Eighteen teeth of 6 dogs for every group were studied. The dogs were sacrificed after 6 weeks. RESULTS: The results showed that new bone formation in test group was significantly higher than that of control group. The calcification of new bone in test group was better than control group. CONCLUSIONS: The results suggested that autogenous bone marrow stem cell transplantation with guided tissue regeneration technique could enhance periodontal tissue regeneration and could form new bone tissue fast and could shorten times of periodontal tissue regeneration in dogs.

Alveolar Bone Loss↗

PubMed2002

[The evaluation of color for the clinical application of thinner porcelain laminate restoration].

OBJECTIVE: The aim of this study was to evaluate the clinical application of the thinner porcelain laminate restoration, which is initiated in the West China College of Stomatology, Sichuan University. METHODS: The color of 51 ceramic veneers was evaluated using the chromatic instrument and visual observation. RESULTS: Among factors affecting the clinical results of the porcelain laminate, the hue of ceramic materials and bond composites played a more important role than the dentition. The brightness of ceramic materials and bond composites were closely correlated with the whole restoration brightness. There was also a close correlation between the brightness and the bond composite. CONCLUSION: Satisfactory restoration results can be achieved by clinical application of thinner porcelain laminate.

Adult↗

PubMed1999

Effects of a bioartificial liver support system on acetaminophen induced acute liver failure canines.

AIM:To evaluate the safety and efficacy of the bioartificial liver support system in canines with acute liver failure (ALF).METHODS:Nine canines with acute liver failure by acetaminophen-induced received TECA-I bioartificial liver support system (BALSS) from Hong Kong TECA LTD Co. Blood was perfused through a hollow fiber tube containing (1-2)X10(10) the porcine hepatocytes.In contrast, another 10 canines with acute liver failure by Acetaminophen received drugs. Each treatment lasted 6 hours.RESULTS:BALSS treatment resulted in beneficial effects for acetaminophen-induced ALF canines with survival and with the recovery of the liver functions and tissues, and plasma ammonia decreased from 135.9&mgr;mol/L plus minus 17.5&mgr;mol/L to 65.7&mgr;mol/L plus minus 22.0&mgr;mol/L, 32.5&mgr;mol/L plus minus 8.8&mgr;mol/L, GPT from 97.8U/L plus minus 8.7U/L to 64.8U/L plus minus 11.9U/L, 19.0U/L plus minus 6.3U/L, GOT from 103.0U/L plus minus 16.7U/L to 75.7U/L plus minus 19.6U/L, 26.5U/L plus minus 5.0U/L, and AKP from 158.3U/L plus minus 12.1U/L to 114.5U/L plus minus 19.8U/L, 43.8U/L plus minus 5.6U/L during and after the treatment. In contrast, 10 ALF canines in both the drug and control groups died 1 or 2 days after treatment.CONCLUSION: TECA-1 artificial liver support system is safe and efficacious for canines with acute liver failure.

Journal Article↗

PubMedDate not supplied

Functional evaluation of an artificial anal sphincter using shape memory alloys.

This article describes an implantable artificial anal sphincter using shape memory alloys and its in vivo assessment in porcine models. The new design was developed as a low invasive prosthesis with a simple structure to solve the problem of severe fecal incontinence in patients with hypoplastic sphincters or without anal sphincters and especially for ostomates. The artificial anal sphincter consists of two shape memory alloy (SMA) plates as the main functional parts to perform two basic functions when the SMA artificial sphincter is fitted around intestines (i.e., an occlusion at body temperature and an opening function on heating). Our previous assessments with short-term animal experiments revealed promising properties with the occlusion function of the device, although some complications, such as overpressure induced ischemia, heat burn, and infections, remained. This article addresses the concerns related to the practical use of the device, the power supplement to drive the actuator, and overheating protection of the device inside bodies. Results of chronic animal experiments of up to 4 weeks suggested great potential for the improved device.

Alloys↗