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Biomedical subjects

J Guo

Publications and source records attributed to J Guo.

At least 217 records · Page 12Linked to original sources
PubMed1999

[Construction of mammalian expression plasmid of Flag-tagged rat collagenase and its in vitro transfection study].

OBJECTIVE: A mammalian expression plasmid of rat collagenase was constructed and its expression in NIH3T3 cells in vitro was studied. METHODS: PCR and gene recombinant techniques were used to construct a mammalian expression plasmid of Flag-fusion rat collagenase. This plasmid was then transferred into cultured NIH3T3 cells mediated by lipofectamine. The mRNA and protein expression of the Flag epitope tagged rat collagenase were detected by RT-PCR and western blot techniques. The enzyme activity of expressed collagenase was detected by gelatin zymography. RESULTS: After transfection the mRNA expression of Flag-fusion rat collagenase could be detected in NIH3T3 cells and the secretion of this collagenase could be detected in the culture medium, and this recombinant collagenase kept the gelatin degradation activity. CONCLUSION: This constructed plasmid can express active rat collagenase in vitro and can be used for further study.

3T3 Cells↗
PubMed1999

Toxicology of intrahepatic arterial administration of interventional phosphorus-32 glass microspheres to domestic pigs.

OBJECTIVE: To evaluate the toxic response to intrahepatic arterial administration of radioactive phosphorus-32 glass microspheres (32P-GMS) in domestic pigs. METHODS: Through selective catheterization of hepatic artery, 32P-GMS was infused to 5 healthy domestic pigs in a dosage equivalent to the therapeutic dose for human being, and 31P-GMS was infused to other 5 healthy domestic pigs. Two pigs served as the whole course blank controls. One pig from each group was surrendered to euthanasia at week 1, 2, 4, 8 and 16, respectively, and liver biopsies were performed on the rest of pigs at the corresponding time points. Liver tissues from different sites were taken for light and electron microscopy. The ultrastructural histopathological changes were evaluated semiquantitatively. RESULTS: The accumulative amount of 32P-GMS in the target tissue attained more than 90% of the total dose administrated. Histologically, abnormal hepatocytes were easily found at week 1 or 2. At week 4 they were less than at week 1 or 2, and endothelium of the sinuses were damaged prominently. At week 8 they were scarcely seen, and liver tissue recovered gradually. The histological features of liver tissue restored to normal at week 16. Semiquantitative analysis of ultrastructural morphology in the experimental group showed no statistical difference (P > 0.50) between the nuclear abnormality (Nabn) and mitochrondrial variability (Mvar) at week 1 or 2, but revealed prominent difference (P < 0.01, P < 0.001) as compared with those in other groups. In the experimental group the Nabn in tissues showed no significant difference (P > 0.20) between week 8 and week 16. CONCLUSION: 32P-GMS internal irradiation at the dosage equivalent to human therapeutic dosage exerts reversible injury to domestic pig liver tissue, and it takes more than 8 weeks for the injured liver tissue to recover.

Animals↗
PubMed1999

An experimental study of inferior vena caval stent in canine.

OBJECTIVE: To investigate the feasibility of our self made inferior vena cave (IVC) stent. METHODS: Self-expanding, stainless steel, Z-shaped stents were deployed in the IVC of 14 dogs. They were randomly divided into four groups, four dogs in the first three groups, and 2 in the fourth group. IVC specimens were taken at 2, 4, 8 and 16 weeks following stent deployment. No anticoagulant or antiplatelet therapy was given. RESULTS: All stents were widely stretched out and so was the vessel lumen. No thrombus was present and the patency was 100% in all groups. The stents were completely covered by neointima 2 weeks after stent deployment. The neointimal thickness varied significantly: the thinnest at 2 weeks, the thickest at 4 weeks and becoming thinner at 8 weeks and stable until 16 weeks. The inflammatory reaction was gradually reduced. Under scanning electronic microscopy, the neointima was covered by a layer of endothelial cells 2 weeks following stenting, which were irregularly shaped and aligned. The cells became slender, spindle-shaped and aligned parallel to the direction of bolld flow 4 weeks afterwards. CONCLUSION: Experimental study indicated that our self-expanding IVC stent was feasible for clinical application.

Animals↗
PubMed1999

[Analysis of the oxide film of Ni-Cr porcelain alloy].

OBJECTIVE: In order to find out the causes of cervical gray line of PFM crown, the features of oxide film of Ni-Cr alloy were investigated. METHODS: 1. The phases were analyzed using x-ray radiation shield. 2. Compositions of oxide film and base metal were measured using electronic scanning microscope. 3. The thickness of oxide film and the variations of Ni, Cr, O in oxide film were evaluated using Auger electron spectroscope. RESULTS: 1. There were not only NiCr2O4 but also Cr2O3, SiO2, and gamma phase solid solution in the surface. 2. The weight contents of Cr and Si were higher while Ni was lower in oxide film than in the base. 3. Oxide film became much thicker(400 nm: 16 nm) after the temperature cycling. CONCLUSION: The medium-thicked oxide film was formed after baking, and it was not a complete film.

Chromium Alloys↗
PubMed1999

[The application of color Doppler ultrasound technique in diagnosing the lumps of salivary gland].

OBJECTIVE: To evaluate the value of color doppler ultrasound technique in diagnosing the lumps of salivary gland. METHODS: 233 cases of salivary gland lumps were examined with color doppler high frequency ultrusound technique. Among them were, 189 cases benign and the others malignant. RESULTS: Color doppler ultrasound technique could not only show the morphology, structure, sizc, location and adjoining relationship, but also indicate the pathological classification according to the blood supply. The total coincident rate of this ultrasound diagnosis to the pathological one was 89.3%. CONCLUSION: Color doppler ultrasound technique is a simple and harmless diagnosing method and could preoperatively give a reliable information to the decision of surgical plan.

Adolescent↗
PubMed1999

[Experimental study on effect of guyubao in promoting the fracture healing in kidney deficiency rabbits].

OBJECTIVE: To study the effect of Guyubao (GYB) in promoting the fracture healing of Kidney deficiency (KD) rabbits. METHODS: Fifty-seven rabbits were randomly divided into three groups: The blank group (A), the control group (B) and the experimental group (C). After the periosteum was peeled off, 0.73 cm middle section defects on both radius were removed. One week after operation, the experiment was begun: Group A was fed normally; group B fed normally plus 6 mg/(kg.d) prednisolone; group C fed with food mixed with GYB and 6 mg/(kg.d) prednisolone. The general state and body weight were observed. The rabbits were sacrificed at three and six weeks after the beginning of experiment. Both radius were observed with X-ray and histologic examination. RESULTS: In group A, no KD appeared, group B gradually developed KD, and mild KD appeared in group C but adjusted rapidly. The healing of radial defect in order were C, A, B from higher to lower degree. CONCLUSION: The results revealed that the GYB could correct the KD and promote fracture healing.

Animals↗
PubMed1999

[Alternation of the level of plasma calcitonin gene related peptide and endothelin-1 in liver cirrhosis].

OBJECTIVE: To investigate the level of plasma calcitonin gene related peptide (CGRP) and endothelin-1 (ET-1) to assess their role on portal hypertension formation and progression and liver function injury in liver cirrhosis and the possible relation between them. METHODS: CGRP and ET-1 were measured in plasma samples collected from 24 healthy controls and 61 liver cirrhosis patients. RESULTS: Plasma CGRP and ET-1 level were significantly higher in cirrhotic patients than those in healthy controls. Comparisons of the levels of plasma CGRP and ET-1 in group of patients with different liver function were shown as follows: Child C > Child B > Child A. An analysis among the groups showed that plasma CGRP and ET-1 were markedly higher in the groups with esophageal varices accompanied by severe or moderate ascites (LC(4)) and with simple severe or moderate ascites (LC(3)) than in the groups with esophageal varices accompanied by mild or no ascites (LC(2)). The levels were also significantly higher in group LC(2) than those in group without varices and ascites (LC(1)). No statistical difference of plasma CGRP and ET-1 levels was found between group LC(1) or Child A and normal controls. There was positive correlation between plasma CGRP and ET-1. The increased concentration of both of them correlated negatively with the declined level of plasma albumin. CONCLUSION: The increase of plasma CGRP and ET-1 is closely associated with the severity of liver cirrhosis and the formation and progression of portal hypertension. The disturbance of the balance between plasma CGRP and ET-1 may contribute to the pathologic process of liver injury.

Adult↗
PubMed1999

[Safety of direct gene transfer into rat carotid arteries mediated by adenoviral vector].

OBJECTIVE: To evaluate the safety of direct gene transfer into rat carotid arteries mediated by adenoviral vector. METHODS: After being soaked in high concentration of glucose solution containing Adv5-CMV (control group) or Adv5-CMV/LacZ (treatment group) for 30 minutes, soluble stents were inserted into the lumina of rat carotid arteries and end-to-end anastomoses of cut rat carotid were performed with standard microvascular surgical technique. On the 7th day after surgery, anastomotic carotid arteries of the two groups were obtained, and samples of ascending aortas, hearts, brains, livers, lungs, spleens and kidneys of the treatment group were taken for assessing beta-galactosidase activity and histochemical staining. RESULTS: Beta-galactosidase activity was not detected in the carotid arteries in the control group and in those organs not directly exposed to adenoviral vector in the treatment group. The amount of beta-galactosidase expression in the carotid arteries in the treatment group was 10.1 x 10(-3) IU/g tissue. Microscopic examination of sections from vessels in the control group and from the aorta, heart, brain, liver, lung, spleen or kidney in the treatment group revealed no X-gal staining. Microscopic examination of the carotid arteries in the treatment group revealed blue-staining in all anastomotic arteries and in all layers of the arterial wall, including the intima, media, and adventitia. CONCLUSIONS: A recombinant gene could be safely delivered to a local site of the vessel by means of infection with adenoviral vector.

Adenoviridae↗
PubMed1999

[Observation of microvascular casting of avulsion injured skin flap under electron microscope].

OBJECTIVE: To investigate the mechanism of necrosis of avulsion injured skin flap. METHODS: Six swine were used. An avulsed skin flap and traditional island flap were made on each hind leg of the swine respectively, and the latter was used as control. Then the microvascular casting of each flap was made routinely immediately following the injury and 72 hours later, and the vascular casting were observed under electron microscopic scanning. RESULTS: There were three characteristic changes in the avulsed skin flap: tearing of blood vessels, formation of complete thrombosis and incomplete thrombosis. If these changes were excessive in the avulsed flap, then the necrosis was the result, otherwise, the flap survived. CONCLUSION: The necrosis of avulsed flap was related to the type and extent of the damage of microvascular endothelial structure. So the degree of endothelial damage was the keypoint in the viability of avulsed flap.

Animals↗
PubMed1999

[Flavonoids from Beijing propolis].

OBJECTIVE: To separate and identify the active flavonoids from Beijing Propolis. METHOD: The flavonoids were isolated by column chromatography with silica gel and polyamide, purified with Sephadex LH-20, and elucidated on the basis of NMR, MS, UV, IR and CD spectra. RESULT: Six kinds of flavonoids were obtained and elucidated as I: pinostrobin, 5-hydroxy-7-methoxy-flavanone; II: pinocembrin, 5, 7-dihydroxy-flavanone; III: tectochrysin, 5-hydroxy-7-methoxy-flavone; IV: chrysin, 5, 7-dihydroxy-flavone; V: izalpinin, 5-hydroxy-7-methoxy-flavonol and VI: galangin, 5, 7-dihydroxy-flavonol. CONCLUSION: Compounds I, II, III and V were found for the first time from Beijing Propolis.

Flavanones↗
PubMed1999

[Studies on distribution of magnetic-bearing microspheres in rabbits].

OBJECTIVE: To evaluate the distribution of magnetic-bearing microspheres (MPMs) in rabbits. METHODS: The distribution of intravenously injected 99mTc-labelled MPMs in rabbits at different intervals of magnetic field applied and different magnetic field intensity was investigated by using an externally applied magnetic field and measuring the radio-activity at the rabbit head and other organs. RESULTS: MPMs have the properties of targeted distribution, as positive correlation between targetic radio-activity and times and intensity of magnetic field. CONCLUSION: MPMs may be better used in the therapy of cavernous hemangiomas.

Animals↗
PubMed1999

[An assessment of Helkimo index in 88 orthodontic patients before treatment].

OBJECTIVE: The prevalence of temporomandibular joint disorders(TMJDs) was studied in orthodontic patients before orthodontic treatment. METHODS: The functional examination of the masticatory system was made with Helkimo index in 88 young patients with general malocclusion. RESULTS: According to the dysfunction index, 50 percent of the patients was free of anamnestic dysfunction, and 44.32% and 5.68% of the patients had a mild and a severe anamnestic dysfunction respectively, 32.95 percent of patients was free of clinical dysfunction, and 51.14% and 14.77% of patients had a mild and a moderate clinical dysfunction respectively, only 1.14 percent of patients had a severe clinical dysfunction. The dysfunction of masticatory muscles and sounds of temporomandibular joint were most common in the signs and symptoms of TMJDs. CONCLUSION: There were no significant differences in the distribution of Ai and Di in different gender and between Angle's Class I and II malocclusion, and there was a relationship between Ai and Di.

Adult↗
PubMed1999

[Determination of triflumizole and its metabolite residues in vegetables by high performance liquid chromatography].

Triflumizole (TRI) and its metabolite [4-chloro-alpha,alpha,alpha-trifluoro-N-(1-amino-2-propoxythylidene)- O-toluidine] (MET) were extracted with methanol and reverse-extracted with dichloromethane. After evaporation to dryness, the residue in dichloromethane layer was dissolved in mobile phase for high performance liquid chromatographic determination with external standard method. The total residue content of TRI and MET (calculated as TRI) is reported.

Chromatography, High Pressure Liquid↗
PubMed1999

[Dynamic changes in IL-4, IL-5 and IL-10 in liver and bone marrow of mice infected with Schistosoma japonicum].

AIM: To observe the changes in Th2 cytokines in the liver and bone marrow of mice infected with schistosomiasis japonica. METHODS: ABC immunohistochemical staining technique and multimedia pathological picture analysis were used. Meanwhile, IL-4, IL-5 and IL-10 derived from livers and bone marrows of infected mice were observed at wk 8, 10 and 12 after infection. RESULTS AND CONCLUSION: In the livers of infected mice, the levels of IL-4, IL-5 and IL-10 increased obviously with a prolongation of the infection duration, IL-4 being the highest. However, in the bone marrow of infected mice, IL-4 level increased slowly with the duration of the infection, being lower than those in the liver at wk 10 and 12 after infection. The level of IL-5 was higher than that in the liver within 12 wk. At wk 10 after infection IL-10 tended to increase, but decreased thereafter and was obviously lower than that in the liver. In mice infected with Schistosoma japonicum, the immune response occurred mainly in the liver. IL-5 in the bone marrow showed auto-secretion.

Animals↗
PubMed1999

[Pattern recognition applied to the Pu I even-parity energy level].

The partial least square (PLS)-back propagation network (BPN) method is applied to assigning the electronic configurations of Pu I even-parity levels and the assignments agree well with the experimental results. It is shown that PLS-BPN can be used as a tool to assign complicated spectral levels.

English Abstract↗
PubMed1999

[Improving spectral property of light source to increase signal-to-noise ratio of optical multichannel analyzer in measurement of absorbances].

In the present paper we report that the spectral property of light radiation was improved by using the method of increasing intensity of short wave radiation for increasing signal-to-noise ratio (S/N) of CCD-OMA in measurement of sample's absorbance in visible light-region especially short wave region. The signal-to-noise ratio resulting from the recording of short wave region for improved light source was increased by 8 times as high as that of a general Wlamp. As demonstrated by the experiment, absorbance spectrum with high S/N ratio can be obtained in the entire visible light region by using the improved light source in the measurement of absorbance.

English Abstract↗
PubMed1998

[Effects of glutamic acid on heat tolerance and 70 kD proteins of Drosophila melanogaster].

From supplement of dietary glutamic acid, the heat tolerance ability of Drosophila and the change of Hsp70(heat shock proteins) were studied. The results showed that the supplement of dietary glutamic acid could increase the survival time and the contents Hsp70 of Drosophila, in the 37 degrees C heat environment; but could not get the Hsp70 rise up when Drosophila were in 25 degrees C. Based on the findings, we could make the conclusion that supplement dietary glutamic acid could benefit the heat tolerance ability of Drosophila, and it might be related to the increase of Hsp70.

Animals↗