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Biomedical subjects

W Ren

Publications and source records attributed to W Ren.

At least 37 records · Page 2Linked to original sources
PubMed2000

[The effects of the complex of rhBMP2 and fibrin sealant on dental pulp].

OBJECTIVE: To investigate the reparative dentine formation induced by the complex of recombinant human bone morphogenetic protein 2 (rhBMP2) and fibrin sealant (FS) in dog tooth. METHODS: Freshly exposed molars, premolars and cuspids were treated with the complex of rhBMP2/FS, rhBMP2 and Ca(OH)(2) paste which served as control. RESULTS: The wound healing of exposed pulp treated with FS seemed to be better than that without FS. Dentine bridge formation was observed in pulp treated with the complex at 7 days, with rhBMP2, Ca(OH)(2) at 28 days. At 63 days after operation, the cases of tubular dentine bridge formation of the pulp treated with the complex were more than that of pulp treated with rhBMP2. CONCLUSION: The synergistic effects of FS and the complex rhBMP2 exist and can be used as bioactive pulp capping agent.

Animals↗
PubMed2000

[Change of pulmonary circulation in microgravity and simulated microgravity].

Fluid is transferred cephalad in microgravity and simulated microgravity, and the pulmonary circulation is the first to be affected. Blood and fluid contents in the lungs increase, but unevenly distributed among various zones of the lungs. Blood vessels in the lungs are filled and distend. Capillary changes have been observed in the animal model of simulated microgravity. Studies about the changes of regulative function of pulmonary circulation are relatively rare. Observations of the reactivity of pulmonary vessels may help to understand the mechanisms of the changes in pulmonary circulation during microgravity.

Animals↗
PubMed2000

[The effect of fibrin sealant on dental pulp for pulp capping in experimental dogs].

OBJECTIVE: To investigate the pulp tissue reaction and reparative dentine formation of dog pulp capped with Fibrin Sealant (FS). METHODS: The fibrin was from a tisseel Kit (Immuno AG, Vienna, Austria) consisting of solution A (freeze-dried human fibrinogen, factor XIII, Aprotinine) and solution B (thrombin powder, calcium chloride) with 0.02 ml from each for each tooth. The Ca(OH)2 paste (Calar, China) was served as the control. Forty nine cuspid, premolar and molar teeth in 4 adult dogs weighed 11-13 kg were used. Surgical anesthesia was obtained by muscle injection of 3% sodium pentobarbital (1 ml/kg). The pulp were exposed by using sterile high-speed rotary cutting instruments with water-cooling. The pulps were treated with 0.02 ml fibrin or Ca(OH)2 paste respectively. The cavity was filled with zine phosphate cement. The animals were killed at intervals of 1, 4, 6, 9 weeks after surgery and perfused with phosphate-buffered saline followed by 10% formalin in phosphate-buffered saline. The jaws were resected and the samples prepared by removing each experimental tooth in block, further fixing them by immersion in 10% formalin in phosphate-buffered saline. The specimen were processed for histologic examination. Serial sections (5 nm thick) were made, stained with hematoxylin and eosin, examined using a light microscope. RESULTS: 7 days after operation, the samples treated with the FS showed no hemorrhage and degeneration of pulp tissue and a small amount inflammatory cells near the wounds. The samples treated with Ca(OH)2 showed hemorrhage and degeneration (2/6) and a large amount inflammatory cells near the wounds. 28 days after operation, pulp health of teeth treated with FS and Ca(OH)2 was nearly recovered. Dentin bridges were observed in 2 out of 6 cases treated with Ca(OH)2. 42 days after operation, pulp health of teeth treated with FS and Ca(OH)2 was totally recovered. Dentin bridges were observed in 2 out of 7 cases of pulp treated with FS and four out of 6 cases treated with Ca(OH)2. 63 days after operation, pulp health of teeth treated with FS and Ca(OH)2 was soundly resumed. The dentine bridge was observed in 4 out 6 cases of pulp treated with the FS and in all 6 cases treated with Ca(OH)2. CONCLUSION: FS has no dentin inducing activity, but can enhance exposed pulp healing, so FS can be served as a promised pulp capping agent.

Animals↗
PubMed2000

[Conformity of cancerous diagnosis of serum-fluorimetry under the influence of carotenoid fluorescence].

We observed that carotenoid had sensitization for fluorescence of porphyrin as cancerous diagnostic technology was applied in clinic by serum-fluorimetry. The Forster theory was used in order to analyse sensitized fluorescence between carotenoid and porphyrin in this paper. Transfer characteristic between energy donor and energy acceptor was calculated and discussed its influence on cancerous diagnosis.

Biomarkers, Tumor↗
PubMed1999

[Effect of extremely low frequency magnetic field on brain response to selective mental arithmetic under simulated weightlessness].

Objective. To study effects of extremely low frequency magnetic field (ELMF) on brain function state during weightlessness. Method. The brain event-related potentials (ERPs) during a selective mental arithmetic task were compared in 40 normal subjects (20-25 yrs) before and after ELMF (5 Hz) stimulation during simulated weightlessness (head down tilt -10 degrees, HDT). Result. The amplitude of slow positive potentials which were supposed to be related to the mental arithmetic activity decreased significantly especially in 100 min after HDT, but it did not decrease significantly after ELMF stimulation. Conclusion. ELMF stimulation may improve the brain function state during simulated weightlessness.

Adult↗
PubMed1999

[Intercellular adhesion molecule-1 expression in experimental liver fibrosis].

OBJECTIVE: To explore the role of intercellular adhesion molecule-1 (ICAM-1) in experimental liver fibrosis. METHODS: Experimental liver fibrosis models of rats were induced by high fat diet, low fat diet plus ethanol, high fat diet plus ethanol, and carbon tetrachloride subcutaneous injection respectively. At sacrifice, liver pathologic changes were studied and ICAM-1 expression was evaluated with immunohistochemistry by using a monoclonal antibody. RESULTS: ICAM-1 expression was observed in the hepatocellular membrane; ICAM-1 positive hepatocytes were localized in zones of portal tract with focal necrosis and inflammatory damage. Staining for ICAM-1 was associated with the degree of liver inflammation and fibrosis. In the different models, the intensity of ICAM-1 expression was different; It ranged in an increasing order from high fat diet, low fat diet plus ethanol, high fat diet plus ethanol, and carbon tetrachloride model. The strongest reactivity for ICAM-1 was seen in carbon tetrachloride model (P < 0.05), the difference was significant as compared with the other models. However, there was no significant difference among the three other models (P > 0.05). CONCLUSION: Upregulation of ICAM-1 expression in experimental liver fibrosis may be related with liver fibrogenesis.

Animals↗
PubMed1999

[The progress in research on changes of central venous pressure under simulated weightlessness and microgravity].

One of the most profound circulatory changes that occur in man during exposure to microgravity is a cephalad redistribution of fluid. Central venous pressure (CVP) is not only an important standard for determining the cephalad redistribution of fluid but also the unique valuable means for measuring continuously cardiac filling pressure under simulated weightlessness (SW) and microgravity, and has a relationship with neurohumoral [correction of nerohumoral] regulation. With the development of manned spaceflight, the researches in space suggested that CVP did not increase, which is directly contradictory to the previous results under SW. This paper mainly discusses the changes of CVP and the effects of countermeasures on CVP under SW and microgravity, and the mechanisms of decreased CVP under microgravity. It is postulated that more suitable SW models, more studies about the area of low pressure including especially pulmonary circulation, and comprehensive studies in multiple systems are needed.

Cardiovascular Deconditioning↗
PubMed1999

[Character identification of 12 kinds of pilose antler medicinal materials].

In this paper, commercial medicinal materials of 12 kinds of pilose antler, Cervus nippon, C. elaphus, C. albirostris, C. unicolor, C. eldihainanus, C. timorensis C. porinus, Dama dama, Rangifer farandus, Alces alces, Elaphurus davidianus, Capreolus capreolus were compared and identified. A key and simple character illustration were listed.

Animals↗
PubMed1998

Determining the degree of chaos from analysis of ISI time series in the nervous system: a comparison between correlation dimension and nonlinear forecasting methods.

Two different chaotic time series analysis methods--the correlation dimension and nonlinear forecasting--are introduced and then used to process the interspike intervals (ISI) of the action potential trains propagated along a single nerve fiber of the anesthetized rat. From the results, the conclusion is drawn that compared with the correlation dimension, nonlinear forecasting is more efficient and robust for chaotic ISI time series analysis in a noisy environment. Moreover, the evolution of the correlation coefficient curves calculated from nonlinear forecasting can qualitatively give a better reflection of the unpredictability of the system's future behavior and is in good agreement with the values of the largest Lyapunov exponent that quantitatively measures the degree of chaos.

Animals↗
PubMed1998

Cathepsin B on invasion and metastasis of gastric carcinoma.

OBJECTIVE: To investigate the expression of cathepsin B (CB) in human gastric carcinoma tissue. METHODS: The expression of CB in human gastric tissue was studied by using monospecific polyclonal rabbit antibody raised against human liver CB for immunohistochemistry, and full length cDNA of CB for in situ hybridization and dot blot. RESULTS: CB overexpression in gastric carcinoma was found when compared with non-neoplastic gastric tissue at both mRNA and protein levels. Diffuse cytoplasmic CB staining of mRNA and protein were identified in malignant cells of 53.3% and 69.1% of gastric adenocarcinoma respectively. The increased staining of CB in malignant cells was associated with the depth of the invasiveness and growth pattern as well as metastasis of lymph nodes, but not with the histological classification. It was also found that there were the expression of CB in stromal cells of the tumor and the expression localized mainly in the endothelial cells of the microvessels which correlated with angiogenesis. CONCLUSION: These results indicate that the expression of CB in gastric carcinoma is related to tumor progression, and leads to development of the invasive phenotype.

Adenocarcinoma↗
PubMed1998

Temporal and spatial features of slow positive potential related to visual selective response during head-down-tilt.

The temporal and spatial features of visual ERP changes during 2 hour HDT (-10 degrees) were compared with that during HUT (+20 degrees) in 15 normal subjects. The stimuli consisted of two color LED flashes appeared randomly in left (LVF) or right (RVF) visual field with the same probability. The subjects were asked to make switch response to target signals (T) differentially: switching to left for T in LVF and to right for T in RVF, and making no response to non-target signals (N). Five sets of tests were made during HUT and HDT. ERPs were obtained from 9 locations on the scalp. Mean amplitude of the ERPs in the period 0.30-0.55 s were taken as the amplitude of slow positive potential (P400). The results obtained were: (1) The mean amplitude of P400 decreased during HDT which was more significant at the 2nd, 3rd and 5th set of tests; (2) spatially, the reduction of mean P400 amplitude during HDT was more significant for signals from RVF and were more significant at posterior and central brain regions than those from frontal locations. These data provide further evidence showing that the higher brain function was affected by the simulated weightlessness and that this effect was not only transient but also with interesting spatial characteristics.

Adult↗
PubMed1998

[Changes of brain potentials related to selective mental arithmetic during simulated weightlessness].

To study the effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) during a selective mental arithmetic task were compared between head down tilt (HDT) and head up tilt (HUT) in 15 normal subjects. The results were: target (T) flash signals induced significant slow positive potentials and they decreased significantly in amplitude especially during HDT as compared with that during HUT. The data provide new evidence indicating that the ability of brain response declined during simulated weightlessness.

Adult↗
PubMed1996

[Electro-acupuncture effects on experimental spinal cord injury of the cat as evaluated by acid phosphatase detection].

The spinal cords of adult cats were injured at about L1 level by using Allen's method and the animals were divided randomly into 2 groups: a) electro-acupuncture treatment group and b) control group. The acid phosphatase (ACP) was detected at 3 and 7 days after spinal cord injury. The more ACP positive labelings were found in the treatment group than in the control group at both 3 (P < 0.05) and 7 days (P < 0.01) after injury. The results suggested that electro-acupuncture could increase the concentration of ACP of the injured spinal cord and the increased ACP concentration could make worse to the injured spinal cord at early time and improve regeneration during recovery period.

Acid Phosphatase↗