Biomedical subjects

Z Zhao

Publications and source records attributed to Z Zhao.

At least 163 records · Page 9Linked to original sources

PubMed1999

[Cellular immune function influence on postoperative patients with hepatocellular carcinoma and the clinical effect of TILs treatment].

OBJECTIVE: To investigate the cellular immune function influence on postoperative patients with hepatocellular carcinoma (HCC) and clinical effect of TILs, rIL-2 and cyclophosphamide treatment. METHODS: Eight postoperative HCC patients were treated with TILs, rIL-2 and cyclophosphamide. Six patients were infused from the hepatic artery, and the other 2 infused from the portal vein. RESULTS: The IL-2 NK activity, Tsubsets, CD4(+)/CD8(+) level in the peripheral blood of all patients increased and the IL-6, TNF level of most patients decreased (P > 0.05, P < 0.01). For 6 - 18 month follow-up after management, 6 patients with radical tumor resection showed no recurrence. One patient having palliative resection showed no remnant tumor enlargement. One patient with increased TNF level for 8 IU died from hepatic failure 8 months after chemotherapy. CONCLUSIONS: The TILs, rIL-2 and cyclophosphamide treatment of postoperative HCC patients is effective in improving antitumorgenic immune function, preventing tumor recurrence, and restraining remnant tumor growth.

Adult↗

PubMed1999

[The relationship between operation on gastrointestinal cancer and single cells metastasis via portal vein].

OBJECTIVE: To confirm the effect of radical operation on single cells metastasis of gastrointestinal cancer. METHODS: One hundred and seventy two patients with gastrointestinal cancer were divided randomly into group I (111 cases, ordinary operation) and group II (61 cases, operation after ligation of drained vessels). Catheters were inserted into the portal vein during operation. Blood was aspirated and contrifugated. Anti-EMA monoclonal antibody marked the cancer cells, which were shown by ABC immunohistochemical staining. RESULTS: In the examinate group, 72 cases of gastrointestinal cancer were found positive cells among 111 cases (positive rate 64.9%). In the control group, 61 cases were tested and 13 cases were found positive cells (positive rate 21.3%) with a highly significant difference between the two groups (P < 0.005). CONCLUSIONS: Ligating the relative blood vessel before the radical operation can prevent single cancer cells from metastasis via portal vein.

Adult↗

PubMed1999

[Analysis of the condyle in the state on the mandibular protraction by means of the three-dimensional finite element method].

OBJECTIVE: Studies on the stress distribution and the displacement of the condylar cartilage will be conducive to expound the mechanisms of mandibular orthodontic therapy. METHODS: The model was constructed from young man. Transverse sections of mandible, included TMJ, were scanned by means of CT. An articular disk and condylar cartilage were constructed according to their normal shape and elastic modulus as the same age as to current results of studies. Stimulate the stomotologic muscles' and ligaments' function by means of cable element. The model is consisting of 1364 x 2 bricks and 1954 x 2 nodes. RESULTS: Stimulate the mandibular protraction (advancement) was revealed: (1) Compressive stress widely distributed in the anterior area of condylar cartilage (-2425 g/cm(2) - -7399 g/cm(2)). (2) Tensile stress distributed in the posterior-upper area (10,000 g/cm(2)). CONCLUSION: The results indicate that the mandibular protraction can increase the growth of mandible to treat the skeletal Class II malocclusion.

Dental Stress Analysis↗

PubMed1999

[The expression of integrin alpha5beta1 and transforming growth factor-beta in pulmonary fibrosis of rat].

OBJECTIVE: To study the roles of integrin alpha(5)beta(1) played in rat pulmonary fibrosis. METHODS: The dynamic changes of fibronectin (FN), FN receptor alpha(5)beta(1), and TGF-beta were analysed in bleomycin-induced rat pulmonary fibrosis by using immunohistochemical technique. Northern blot analysis and immunocytochemistry techniques were performed in order to detect the expression of alpha(5)beta(1), FN mRNA and their relevant proteins in cultured rat pulmonary fibroblasts (PFbs) after administration of TGF-beta1. RESULTS: (1) A strong positive reaction with anti-integrin alpha(5)beta(1) was seen in the pneumocytes, endothelial cells and proliferated mesenchymal cells on the 1st to 3rd day after bleomycin. The positive signals for integrin alpha(5)beta(1) were apparent mainly in those proliferated interstitial cells with fibroblast and myofibroblast differentiation 7 days after bleomycin treatment. Changes in FN were similar to that of the integrin alpha(5)beta(1). (2) Expression of alpha(5)beta(1), FN mRNAs and their relevant proteins was increased in rat PFbs after TGF-beta1 administration. CONCLUSIONS: Integrin alpha(5)beta(1) played a key role in inducing the activation, proliferation and differentiation of PFbs, causing an increase of extra-cellular matrix synthesis during pulmonary fibrogenesis.

Animals↗

PubMed1999

[Antihypertensive study of xingnao qingxuan recipe].

OBJECTIVE: To observe the effect of decreasing blood pressure of Xingnao Qingxuan Casuples. METHOD: The blood pressure in normal and anesthetised cats was examined with direct method, the blood pressure in the conscious SHR was obtained by indirect method. RESULTS: Duodenuos administration(id) of XQC of 2.8 g/kg produced a decrease of blood pressure in normal cats; XQC of 1.4, 2.8 and 5.6 g/kg once a day for 14 days produced a dose-dependent reduction of blood pressure in SHR, 3-4 days after administration the blood pressure returned to the level before but the change was not significant. With gastric administration of XQC of 2.8 and 5.6 g/kg for 3 times, the incubation period of eyeball tremor induced by chloroform by dropping into the ear was prolonged by 14.4% and 13.0%, and the keeping time shortened by about 33.3% and 23.3% respectively. Brain basic arterial spasm induced by KCl or 5-HT in dog was relaxed obviously by XQC in vitro experiment. CONCLUSION: XQC has the effect of reducing blood pressure resisting dizziness, which is related to the diastole of brain blood vessel.

Animals↗

PubMed1999

[The boundary design of mandibular model by means of the three-dimensional finite element method].

OBJECTIVE: To construct the mandibular model and simulate the boundary conditions by means of the three-dimensional finite element method. METHODS: A juvenile mandible, including TMJ, was scanned transversely by CT, then a three-dimensional finite element model of mandible was constructed. At the same time, the functions of stomatologic muscles and ligaments and the functional actions of temporomandibular joint (TMJ) were simulated by means of cable elements and compressive gap elements respectively. RESULTS: The cable elements were consistent with the functions of stomatologic muscles and ligaments, and the gap elements were similar to the boundary conditions of the TMJ and teeth. CONCLUSION: Cable and gap elements are reasonable boundary conditions of the finite element model of mandible, which will improve the similarity of the model.

Adolescent↗

PubMed1999

[Internal fixation for zygomatic arch fracture with super-high molecular weight poly D, L-lactic acid mini-plates and screws: a study in dogs].

OBJECTIVE: To investigate the internal fixation effects of super high molecular weight (Mv = 6.0 x 10(5) kD) poly D, L-lactic acid(PDLLA) mini-plates and screws. METHODS: 10 dogs were utilized in this experiment with the self-contrast study method, comparing with the titanium mini-plates and screws. RESULTS: The mechanical properties of the PDLLA mini-plates and screws appeared to be sufficient to enable undisturbed healing of depressed zygomatic arch fracture. CONCLUSION: The good fixation effect of PDLLA mini-plates and screws was as same as that of the titanium mini-plates and screws without the need of secondary operation.

Animals↗

PubMed1999

[Tissue reaction and degradation of super-high molecular weight poly D, L-lactic acid mini-plates and screws: an animal experiment].

OBJECTIVE: To investigate the tissue reaction and degradation processes of the super-high molecular weight(Mv = 6.0 x 10(5) kD) poly D, L-lactic acid(PDLLA) mini-plates and screws through the internal fixation for zygomatic arch fracture. METHODS: It was carried out by the self-contrast study method and comparing with the titanium mini-plates and screws. RESULTS: There was no side-effects on bone healing. The reaction of soft and hard tissues to PDLLA mini-plates and screws was similar to that of the titanium mini-plates and screws. No complication had been seen with the use of PDLLA mini-plates and screws, including infection, foreign body reaction and underlying osteolysis. The PDLLA devices had no changes in shape after 3 months, and then became the grains in different sizes after 6 months, and were completely resorbed within 12 months in vivo. CONCLUSION: The super-high molecular weight PDLLA mini-plates and screws has good biocompatibility and proper degradation time. It is safe and effective to use the mini-plates and screws made of the super-high molecular weight PDLLA for internal fixation of bone.

Animals↗

PubMed1999

[Quantitative evaluation of new bone formation in the posterior zone of the glenoid fossa in response to the mandibular advancement in rats].

OBJECTIVE: To quantify the new bone formation in the glenoid fossa of the temporal bone in response to the mandibular advancement. METHODS: A bitejumping appliance with guide slope was fit on the upper jaw of each rat in the experimental groups, resulting in a downward and forward displacement of condyle and continuous mandibular advancement. Sections were cut through the glenoid fossa at the sagittal plane and stained with PAS under the same condition. The new bone formation at the posterior zone of the glenoid fossa was detected by quantitative measurement through computer-assisted image analyzing system (Q550IW, Leica) with the advanced software (Leica Qwin Pro, Version 2.2). Statistical analysis was performed with GraphPad 3.0. RESULTS: 1. a comparison among experimental groups revealed a peak of new bone deposition at the 21-day group, significantly greater than other groups (P < 0.001); 2. a comparison among control groups showed a gradual decrease of new bone deposition characterized by a peak of at the 3-day group and a bottom at the 30-day group (P < 0.001); 3. a comparison between experimental and control groups showed no significant difference statistically at the 3-day groups (P > 0.05), whereas a significant difference of new bone deposition starting from 7-day groups, with a peak at 21-day groups and a decrease towards 30-day groups (P < 0.001). CONCLUSION: The advancement of mandible leads to the remodeling of the glenoid fossa indicated by the new bone deposition in growing rat.

Animals↗

PubMed1999

[Image analysis of condylar cartilaginous adaptation to mandibular protrusion in rats].

OBJECTIVE: To quantify chondrogenesis in condylar cartilage in response to active forward positioning of mandible. METHODS: Identical bite-jumping appliances were fixed to upper incisors of animals in experimental groups, causing a continuous mandibular forward positioning. Histological sections were performed through mandibular condyle and were stained with HE under the same condition. Chondrogenesis was quantified by measuring the area of cells in resting, proliferative, hypertrophic and erosive zones in the superioposterior region, through computer-assisted image analyzing system (Q550IW, Leica) with the advanced software (Leica Qwin Pro, V2.2). Statistical analysis was performed with GraphPad 3.0. RESULTS: 1. comparison among experimental groups revealed a fluctuation in proliferative zone, with 21-day group being the greatest (0.058 +/- 0.004 mm2) and 14-day the least (0.012 +/- 0.001 mm2). A change in erosive zone was also depicted by a peak of 0.112 +/- 0.001 mm2 in 7-day group and a bottom of 0.018 +/- 0.002 mm2 in 14-day group (P < 0.001). 2. comparison among the control groups manifested stable zonation, except for a slump of proliferative zone descending from 0.069 +/- 0.005 mm2 in 3-day group to 0.009 +/- 0.001 mm2 in 21-day group (P < 0.001). 3. comparison between experimental and control groups demonstrated significant discrepancy in proliferative zone, hypertrophic zone and erosive zone (P < 0.001). CONCLUSION: Mandibular forward positioning stimulates and accelerates cartilaginous remodeling in mandibular condyle.

Animals↗

PubMed1999

[Analysis of 2-acrylamido-2-methyl propane sulfonic acid by thin layer chromatography].

A method for the analysis of 2-acrylamido-2-methyl propane sulfonic acid(AMPS) by TLC is described. The plate was Silica GF254. We selected benzene/methanol as developing agent from several developing systems and fixed the best ratio: V(benzene):V(methanol) = 2:1. The experiment indicated that the Rf value of AMPS was 0.36 while that of AM(acrylamide), the main impurity in crude AMPS sample, was 0.64. The minimum detectable limit of AMPS was 5 micrograms and the developing time was about 25 minutes. Compared with ether/methanol and chloroform/methanol, benzene/methanol system has the advantages of more easily controlling its ratio, better repeatability and much rapid developing rate. This method may be helpful in the control of AMPS in quality.

Acrylamides↗

PubMed1999

[Detection of circulating antigen in serum and cerebrospinal fluid for diagnosis of cerebral cysticercosis].

AIM: To detect circulating antigen(CAg) in serum and cerebrospinal fluid(CSF) from patients with cerebral cysticercosis with specific antiserum by sandwich ELISA. METHODS: Antisera were prepared from rabbits immunized respectively with 3 antigens with molecule weights of 64 kDa, 53 kDa, 32 kDa-30 kDa extracted from Cysticercus cellulosae and purified by SDS-PAGE. RESULTS: When samples from patients were tested with antiserum against 53 kDa antigen, the CAg positive rate was 93.8% in serum and 91.7% in CSF of 32 patients with active cysticercosis, whereas only one positive was found in CSF in 16 patients with inactive cysticercosis. The detection rate of CAg was significantly higher with anti-53 kDa antiserum than with anti-64 kDa and anti-32 kDa-30 kDa antiserum. CONCLUSION: Sandwich-ELISA using antiserum against 53 kDa antigen to detect CAg was found to be a promising assay for diagnosis and evaluation of treatment efficacy of active cerebral cysticercosis in terms of its high sensitivity and specificity.

Animals↗

PubMed1998

Odorant-induced and sniff-induced activation in the cerebellum of the human.

Functional magnetic resonance imaging was used to test whether odorants induce activation in the cerebellum of the human. The odorants vanillin and propionic acid both induced significant activation, primarily in the posterior lateral hemispheres. Activation was concentration-dependent, greater after stimulation with higher concentration odorants. By contrast, the action of sniffing nonodorized air induced significant activation in the anterior cerebellum, primarily in the central lobule. These findings demonstrate that the cerebellum plays a role in human olfaction. A hypothesis is proposed whereby the cerebellum maintains a feedback mechanism that regulates sniff volume in relation to odor concentration.

Adult↗

PubMed1998

Crystal structure of the catalytic domain of protein-tyrosine phosphatase SHP-1.

The crystal structures of the protein-tyrosine phosphatase SHP-1 catalytic domain and the complex it forms with the substrate analogue tungstate have been determined and refined to crystallographic R values of 0.209 at 2.5 A resolution and 0.207 at 2.8 A resolution, respectively. Despite low sequence similarity, the catalytic domain of SHP-1 shows high similarity in secondary and tertiary structures with other protein-tyrosine phosphatases (PTPs). In contrast to the conformational changes observed in the crystal structures of PTP1B and Yersinia PTP, the WPD loop (Trp419-Pro428) in the catalytic domain of SHP-1 moves away from the substrate binding pocket after binding the tungstate ion. Sequence alignment and structural analysis suggest that the residues in the WPD loop, especially the amino acid following Asp421, are critical for the movement of WPD loop on binding substrates and the specific activity of protein-tyrosine phosphatases. Our mutagenesis and kinetic measurements have supported this hypothesis.

Amino Acid Sequence↗

PubMed1998

Hemispheric asymmetry for emotional stimuli detected with fMRI.

Current brain models of emotion processing hypothesize that positive (or approach-related) emotions are lateralized towards the left hemisphere, whereas negative (or withdrawal-related) emotions are lateralized towards the right hemisphere. Brain imaging studies, however, have so far failed to document such hemispheric lateralization. In a functional magnetic resonance imaging (fMRI) study, 14 female subjects viewed alternating blocks of emotionally valenced positive and negative pictures. When the experience of valence was equated for arousal, overall brain reactivity was lateralized towards the left hemisphere for positive pictures and towards the right hemisphere for negative pictures. This study provides direct support for the valence hypothesis, under conditions of equivalent arousal, by means of functional brain imaging.

Adult↗

PubMed1998

Effects of 15-oxa-32-vinyl-lanost-8-ene-3 beta,32 diol on the expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase and low density lipoprotein receptor in rat liver.

The mechanisms by which oxylanosterols regulate expression of hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and lower serum cholesterol levels were examined by using a novel nonmetabolizable oxylanosterol mimic, 15-oxa-32-vinyl-lanost-8-ene-3 beta, 32 diol (DMP 565). This compound, unlike other nonmetabolizable oxylanosterols, is not a substrate for lanosterol 14 alpha-methyl demethylase. Feeding rats a diet supplemented with 0.02% DMP 565 markedly decreased HMG-CoA reductase immunoreactive protein and enzyme activity levels without affecting mRNA levels. The rate of reductase protein degradation was unaffected. However, the rate of translation was reduced to less than 20% of control. Thus, DMP 565 appears to regulate hepatic HMG-CoA reductase gene expression primarily at the level of translation. The pronounced inhibition of HMG-CoA reductase by DMP 565 resulted in a compensatory increase in the functioning of the hepatic low density lipoprotein (LDL) receptor, possibly by increased cycling, as evidenced by a marked increase in the rate of degradation of the LDL receptor. The half-life of the receptor was decreased from over 7 h to only 1 h in animals receiving DMP 565. This increase in the rate of degradation occurred without a change in the steady state level of the receptor. Addition of dietary cholesterol attenuated the increased turnover of the LDL receptor. These effects on the hepatic LDL receptor have also been observed with HMG-CoA reductase inhibitors (G. C. Ness et al., 1996, Arch. Biochem, Biophys. 325, 242-248). However, the effect of DMP 565 on the rate of degradation of the hepatic LDL receptor was of a greater magnitude when equal doses of the drugs were used. These regulatory actions of DMP 565 provide, in part, an explanation for the observed hypocholesterolemic action of this compound.

Administration, Oral↗

PubMed1998

Making memories: brain activity that predicts how well visual experience will be remembered.

Experiences are remembered or forgotten, but the neural determinants for the mnemonic fate of experience are unknown. Event-related functional magnetic resonance imaging was used to identify specific brain activations that differentiated between visual experiences that were later remembered well, remembered less well, or forgotten. During scanning of medial temporal lobe and frontal lobe regions, subjects viewed complex, color photographs. Subjects later received a test of memory for the photographs. The magnitudes of focal activations in right prefrontal cortex and in bilateral parahippocampal cortex predicted which photographs were later remembered well, remembered less well, or forgotten.

Adult↗

PubMed1998

Synergistic activation of MAP kinase (ERK1/2) by erythropoietin and stem cell factor is essential for expanded erythropoiesis.

Stem cell factor (SCF) and erythropoietin (EPO) work synergistically to support erythropoiesis, but the mechanism for this synergism is unknown. By using purified human erythroid colony-forming cells (ECFC), we have found that SCF and EPO synergistically activate MAP kinase (MAPK, ERK1/2), which correlates with the cell growth and thus may be responsible for the synergistic effects. Treatment of the cells with PD98059 and wortmannin, inhibitors of MEK and PI-3 kinase, respectively, inhibited the synergistic activation of MAPK and also the cell growth, further supporting this conclusion. Wortmannin only inhibits MAPK activation induced by EPO but not that by SCF, suggesting that SCF and EPO may activate MAPK through different pathways, which would facilitate synergy. Furthermore, EPO, but not SCF, led to activation of STAT5, whereas SCF and wortmannin had no effect on the EPO-induced STAT5 activation, suggesting that STAT5 is not involved in the synergistic action of SCF and EPO. Together, the data suggest that synergistic activation of MAPK by SCF and EPO is essential for expanded erythropoiesis.

Androstadienes↗