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Biomedical subjects

Z Zhao

Publications and source records attributed to Z Zhao.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Diagnostic value of five serum markers for liver fibrosis].

OBJECTIVE: To research the diagnostic value of serum hyaluronic acid (HA), type III procollagen (PCIII), type IV collagen (CIV), laminin (LN), and transforming growth factor-beta(1) (TGF-beta(1)) for liver fibrosis in patients with chronic hepatitis. METHODS: Serum levels of HA, PCIII, CIV, LN and TGF-beta(1) in 116 patients with chronic hepatitis and cirrhosis were investigated and compared with hepatic histological findings of 87 patients. RESULTS: The correlation between serum HA and histologically assessed grade of inflammatory activity was weak (r=0.393, P<0.05). The correlation between serum HA, PCIII, LN, TGF-beta(1) and histologically assessed stage of liver fibrosis were all moderate (r=0.584, 0.454, 0.441 and 0.612, respectively, P<0.05), while that between serum CIV and histologically assessed stage of liver fibrosis was weak (r=0.319, P<0.05). As shown by the ROC curves in cases of chronic hepatitis, the ability to differentiate patients with cirrhosis from those without cirrhosis was greater for serum HA than that for serum PCIII, CIV, LN, and TGF-beta(1) (the areas under the curves=0.904 vs 0.784, 0.815, 0.805, 0.828, P<0.05). The ability of serum HA, LN and TGF-beta(1) to differentiate patients with extensive liver fibrosis from those with no or mild liver fibrosis exceeded that of serum PCIII and CIV (the areas under the curves=0.849, 0.819, 0.836 vs 0.702, 0.721, P<0.05). To discriminate the stage of liver fibrosis, serum HA and TGF-beta(1) were selected from the five markers by Bayes discriminate analysis. If S(1), S(2) and S(3) were not required to be discriminated, discrimination between the three stages showed significant difference (P<0.05). The predictive accurate percentage was 72.90%. CONCLUSIONS: The five markers all have the ability not only to judge liver cirrhosis, in which the ability of serum HA is the best, but also to differentiate chronic hepatitis with extensive liver fibrosis from that with no or mild liver fibrosis, in which the ability of serum HA, LN, TGF-beta(1) is stronger than the other two. It is useful for detection of serum HA and TGF-beta(1) at the same time to discriminate the histologically assessed stage of fibrosis. Serum HA and TGF-beta(1) can be helpful in discriminating patients of chronic hepatitis with "no liver fibrosis", "liver fibrosis but no cirrhosis" and "liver cirrhosis", but cannot discriminate them accurately as the histologically assessed stage of fibrosis. They cannot displace liver biopsy for the judgement of liver fibrosis.

Adult↗
PubMed2001

Feeding thiol-containing compounds, derived from vegetables, fails to inhibit N-methylnitrosourea-induced mammary tumorigenesis.

Various thiol-containing compounds have been shown to inhibit chemically-induced tumors in animal models. Two thiol-containing compounds derived from vegetables, namely 1,2 dithiol-3-thione (DTT) and S-methylmethane thiolsulfonate (MMTS), were tested for their chemopreventive activity in the N-methylnitrosourea (NMU)-induced rat mammary tumor model. Each compound was incorporated into the grain-based Teklad 7001 diet and fed to the rats one week prior to initiation with NMU until termination 18 weeks post NMU. DTT was fed at 166 and 500 ppm and MMTS at 200 and 800 ppm. Neither compound exerted a significant inhibitory effect on any index of tumor development including incidence, total tumor, tumor multiplicity, volume or latency. Serum levels of DTT assessed at termination in the 500 ppm DTT group ranged from 10-30 microg/ml. MMTS was undetectable in serum from either MMTS-fed group. The results of this study, using the direct acting carcinogen, NMU, suggest that the chemopreventive effect of thiol-containing compounds may be confined to animal models using carcinogens that require host activation.

Administration, Oral↗
PubMed2001

[Catalytic reduction of NO by chars loaded with Ca and Fe].

The effects of calcium and iron impregnated on coal chars as catalysts in NO-char reaction were investigated. The NO-char reaction was studied in a quartz fixed bed reactor at atmospheric pressure. Temperature programmed reaction (TPR) and isothermal reaction were used to determine the catalytic activities of calcium and iron at various atmosphere environments. The results showed that the higher the temperatures of pretreatment, the lower the catalytic activity of calcium, while the pretreatment temperatures had little effect on the catalytic activity of iron. Both calcium and iron promoted the NO-char reaction, but the catalytic activity of the latter was higher than that of the former. NO reduction by CO was strongly promoted by Fe and Ca. The addition of O2 in the char-NO-Ca or char-NO-Fe system promoted the NO reduction significantly. Oxidation/reduction mechanisms were proposed for the NO reduction by char catalyzed by Ca and Fe.

Calcium↗
PubMed2001

Modulation of BmKAS-1 and BmK1-3-2 to sodium channel in rat dorsal root ganglion neurons.

OBJECTIVE: To investigate what effects BmKAS-1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal-muscle ryanodine receptor) and its upstream mixture BmK1-3-2 have on Na+ channels in dorsal root ganglion (DRG) small diameter neurons. METHODS: The whole-cell patch-clamp technique was used to investigate the effects of BmKAS-1 and BmK1-3-2 on Na+ current in rat small diameter DRG neurons. RESULTS: About 50% peak Na+ current was suppressed by 10 micrograms/ml of BmK1-3-2. 1.62 micrograms/ml of BmKAS-1 also blocked 50% peak Na+ current, and there was an obvious dose-dependent relationship. CONCLUSION: Both BmK1-3-2 and BmKAS-1 have a blocking effect on Na+ channels, and this may one of the mechanisms for the analgetic effect of BmK1-3-2 and BmKAS-1.

Animals↗
PubMed2001

Epidemiological investigation of Histoplasma capsulatum infection in China.

OBJECTIVE: To provide reliable information concerning the presence or the absence of Histoplasma capsulatum (H. capsulatum) infection in China, and data concerning this respect. METHODS: Three hundred normal people and 435 hospitalized patients, who lived in Hunan and Jiangsu provinces, and the Xinjiang Autonomous Region, were tested with yeast-phase histoplasmin (ALK/Berkerley Biologicals Laboratories, USA) and human pure protein derivative of tuberculin (PPD) on the volar surface of the forearm. Any reaction to the antigens over 5.0 mm in diameter of induration at 48-72 hours was considered positive. RESULTS: A total of 138 subjects (18.8%) in 735 patients reacted to histoplasmin with 5.0-45.0 (9.1 +/- 4.3) mm indurations. Significant differences of positive skin reaction rates in normal subjects were found in Hunan, Jiangsu and Xinjiang (8.9% vs 15.1% vs 2.1%). The overall positive rate of patients was 25.5%. Patients with tuberculosis [31.7% (78/246)] had a significantly higher positive skin reaction rate in comparison with those suffering from pneumonia [17.7% (11/62)], lung cancer [20.9% (9/43)], chronic obstructive pulmonary disease [17.3% (9/52)] and other diseases [12.5% (4/32)] (P < 0.01). Of 562 cases, 292 cases (52.0%) reacted to PPD with indurations of 5-50 (13.7 +/- 4.9) mm in diameter, 63 cases (11.2%) reacted to both histoplasmin and PPD, while 38 cases (6.9%) reacted to histoplasmin but not to PPD. CONCLUSIONS: The data suggest that there is H. capsulatum herd infection in China. The infection rate in Southeast China is higher than that in the Northwest, and the infection rate of patients with pulmonary tuberculosis is higher than that of normal persons and other pneumonopathy patients.

Adult↗
PubMed2001

[The buccal musculomucosal reversed flow arterial island flap: clinical application].

OBJECTIVE: To provide experience in using the buccal musculomucosal reversed flow arterial island flap in oral, nasal and orbital mucosal defects repair. METHODS: Six patients were operated by using the method. This flap supplied by the distal portion of the facial artery through the anterior buccal branches can be passed through the tunnel of the subcutaneous plane to repair the orbital mucosal defect or the nasal mucosal defect or septal perforation, or through the alveolar ridge cleft to close alveolar ridge cleft and oroantral fistula, or the cleft of the anterior hard palate or palatal fistula. RESULTS: The postoperative course was uneventful. CONCLUSIONS: Flap was viable without the occurrence of hematomas, infections, parotid duct injury or obstruction, or facial nerve injury, or oral function loss.

Cleft Palate↗
PubMed2001

[Effect of fly ash-filtered mud mixture on soil properties and radish yield and quality].

Based on pot culture experiment, the effect of fly ash-filtered mud mixture on soil biochemical properties, radish yield and its quality, and heavy metal accumulation in both soil and radish was examined. The mixture was made by mixing fly ash and filtered mud in proportion 1:1(w/w) and adding small amount of inorganic fertilizer. Its Cd, Pb, Cr, As and Hg contents were much lower than those requested by state control criteria. After applying this mixture in a definite amount, no significant accumulation of heavy metals was found in both soil and radish, the pollution index of heavy metals was < 1, the quantities of soil bacteria increased notably, and the activities of soil urease, phosphates and cellulosase also raised significantly. The application of the mixture promoted radish growth and its development and metabolism. The reducing sugar and vitamin C in radish also increased markedly. The results indicated that the use of adequate amounts of the mixture did not cause any obvious heavy metal pollution in both soil and radish, but could improve soil fertility, and raise radish yield and its quality remarkably.

Agriculture↗
PubMed2001

[Life table of experimental population Liposcelis bostrychophila].

The age-specific and time-specific life table of experimental population Liposcelis bostrychophila was established at 8 different temperatures (17.5-35 degrees C) and 5 different humidities (50-90% RH). The relations between population dynamics and temperature or humidity were discussed with Morris model and Weibull frequency distribution. The results indicated that the effect of temperature and humidity on survivorship was the most important factor to population trend index (I). Under suitable range of temperature and humidity, the population survival curve belonged to Deevey I; while under improper conditions, it belonged to Deevey III. Theoretically, finite increase rate (lambda) had the highest value 1.0628/day at 30.63 degrees C. The optimum range of temperature and relative humidity for its development and reproduction was estimated at 28-30 degrees C and 80% +/- RH, respectively.

Animals↗
PubMed2001

[Expression of matrix metalloproteinase-2 in rat pulmonary fibrosis].

OBJECTIVE: To study the role of matrix metalloproteinase-2 (MMP(2)) in rat pulmonary fibrosis. METHODS: (1) Dynamic changes of MMP(2) expression were observed in bleomycin-induced rat pulmonary fibrosis by use of immunohistochemical technique. (2) RT-PCR was carried out to show the dynamic changes of MMP(2) mRNA expression of isolated pulmonary fibroblasts (PFbs) during rat pulmonary fibrosis. (3) Northern blot analysis and immunocyto chemistry techniques were performed to detect the expression of MMP(2) mRNA and their relevant protein in cultured rat PFbs after treatment with transforming growth factor 1 (TGF beta(1)). RESULTS: (1) On day 1-7th after receiving bleomycin, the infiltrated pulmonary macrophages and septa mesenchymal cells showed positive reaction with anti-MMP(2) and an increase in number. After 14 days and on 28 th of bleomycin treatment, the number of positive staining macrophages and mesenchymal cells were decreased respectively. (2) The gene expression of MMP(2) mRNA of PFbs were enhanced after bleomycin treatment from the Day 1 and decreased by Day 28. (3) The expression of MMP(2) mRNA and their relevant protein were enhanced in rat PFbs after TGF beta(1) treatment. CONCLUSIONS: Over expression of MMP(2) in pulmonary tissue may be an important factor in the initiation of pulmonary fibrogenesis.

Animals↗
PubMed2001

[The effect of rIFN alpha-2b on mice NK cell activity].

OBJECTIVE: This animal experiment was made to study the effect of the recombined interferon alpha-2b(rIFN alpha-2b) on natural killer cells activity of mice spleen in vivo, and by way of this, to test the activity of rIFN alpha-2b. METHODS: BALB/c mice were given rIFN alpha-2b subcutaneously. The inhibiting 3H-TdR intaking method was used to test the NK activity of spleen cells of BALB/c mice. RESULTS: The NK cell activity levels of the high-dose group, the mid-dose group and the low-dose group were 65.19 +/- 17.56, 44.19 +/- 14.30 and 35.46 +/- 17.49, respectively. CONCLUSION: rIFN a-2b can enhance NK cells activity observably and its effect is dose dependent.

Animals↗
PubMed2001

[The influences upon the passive tensile of the masticatory muscles and ligaments by Herbst appliance under various bite reconstruction--a three dimensional finite element analysis].

OBJECTIVE: This study aimed to provide some biomechanical references for the clinical use and improvement of Herbst appliance. METHODS: The three-dimensional model of the 'Temporomandibular joint mandible Herbst appliance system' was set up by SUPER SAP software (version 9.3). On this model, the passive tensile in the masticatory muscles and ligaments were analyzed under various bit reconstruction designed according to specified advanced displacement and vertical bite opening. RESULTS: When Herbst appliance drove the mandible forward, there was not any tensile in the medial, lateral pterygoid and the collateral ligament, while the temporalis, the deep paret of masseter, the stylomandibular ligament, and the sphenomandibular ligament were passively drawn. Under various bite reconstruction, the passive tensile in the medial temporalis, the posterior temporalis, the stylomandibular ligament and the sphenomandibular ligament increased with the amount of the advancement of the mandible; The passive tensile in the posterior temporalis and the deep part of masseter increased with the amount of vertical bite opening of the mandible. CONCLUSION: The StL, SpL, PT and AT played an important role in functional reconstruction of mandible by Herbst. All five group of bite reconstruction (3-7 mm advancement, 4-2 mm vertical bite opening of the mandible) designed by this study can be selected in clinic according to the patient's capability of adaptation, the extent of malocclusion and the potential and direction of growth.

Finite Element Analysis↗
PubMed2001

[The influences of the stress distribution on the condylar cartilage surface by Herbst appliance under various bite reconstruction--a three dimensional finite element analysis].

OBJECTIVE: The distribution of stress on the surface of condylar cartilage was investigated. METHODS: Three-dimensional model of the 'Temporomandibular joint mandible Herbst appliance system' was set up by SUPER SAP software (version 9.3). On this model, various bite reconstruction was simulated according to specified advanced displacement and vertical bite opening. The distribution of maximum and minimum principal stress on the surface of condylar cartilage were computerized and analyzed. RESULTS: When Herbst appliance drove the mandible forward, the anterior condyle surface was compressed while the posterior surface was drawn. The trend of stress on the same point on the condyle surface was consistent in various reconstruction conditions, but the trend of stress on various point were different in same reconstruction conditions. CONCLUSION: All five groups of bite reconstruction (3-7 mm advancement, 4-2 mm vertical bite opening of the mandible) designed by this study can be selected in clinic according to the patient's capability of adaptation, the extent of malocclusion and the potential and direction of growth.

Cartilage, Articular↗
PubMed2001

[Clinical significance of trigeminal neuralgia treated using radiofrequency thermocoagulation (RFT) with different approaches].

OBJECTIVE: The authors presented the short term and long term effects of the trigeminal neuralgia treated by RFT with anterior-lateral facial, lateral facial and trans-subzygomatic approaches. METHODS: 320 primary patients with trigeminal neuralgia were selected for this study. All these patients were followed up with the period of 1 to 6 years. RESULTS: The first-time effective ratios of pain-relieve treated by using the anterior-lateral facial approach, and the lateral facial and the trans-subzygomatic, were 93.3% and 73.3% respectively. Most of the patients (92.5%) achieved excellent or good pain-relieve after treated by one of these three approaches. Compared with the lateral facial and trans-subzygomatic procedures, the anterior-lateral facial approach caused less recurrent rate in long term effects (P < 0.01). The late recurrence was found in 93 patients, but pain-relieve effect still could be obtained by retreating with the former method and without difficulty or hazard. One patient had serious Rollets syndrome. CONCLUSION: It is concluded that the anterior-lateral approach is a method with more effective pain-relieve and less pain recurrence rate, and the trans-subzygomatic method can be used as a substitutive approach in the treatment of the second branch of trigeminal neuralgia.

Adult↗
PubMed2001

[The effect of AG490 on NK activity and lymphocyte transformation of PBMC].

OBJECTIVE: To examine the effect of AG490 on NK activity and lymphocyte transformation. METHODS: Using MTT colorimetry to detect cell survival, NK activity and cell proliferation. RESULTS: AG490 inhibited IL-2 and PHA induced peripheral blood mononuclear cell proliferation, and it inhibited NK activation. CONCLUSION: As an inhibitor of JAK, AG490 can influence the function of normal cells.

Cell Division↗
PubMed2000

Identification and characterization of a novel gene KE04 differentially expressed by activated human dendritic cells.

To better understand the molecular mechanisms of dendritic cells (DC) function, we isolated differentially expressed genes in Ag-activated DC by a PCR-based subtractive hybridization technique. A novel full-length cDNA, KE04, was thus isolated from KLH-activated human PBMC-derived DC. KE04 cDNA encoded a 346-aa protein devoid of functionally indicative motifs. KE04 protein showed 64% identity with a Caenorhabditis elegans protein and 83% identity with a human putative protein. Distant relationship was also found with other prokaryotic and eukaryotic proteins. Differential expression of KE04 in activated DC other than nonactivated DC was confirmed at both mRNA and protein levels. KE04 mRNA expression was detectable in various human tissues and cell lines by Northern blot and RT-PCR. Western blot and confocal microscopy analysis indicated that its cytolocalization was intracellular. Our data suggest the potential involvement of KE04 in DC activation and will facilitate the research of molecular mechanism of DC function.

Amino Acid Sequence↗
PubMed2000

Expression and role of sulfoglucuronyl (HNK-1) carbohydrate and its binding protein SBP-1 in developing rat cerebral cortex.

Developmental expression of sulfoglucuronyl carbohydrate (SGC) and its binding protein, SBP-1 was studied in the rat cerebral cortex to understand their function. Between embryonic day (ED) 14-19, SBP-1 was strongly expressed in neurons of the ventricular zone and migrating neurons throughout the cortex. SBP-1 declined at birth and by postnatal day (PD) 3 only the latest arriving neurons in the most superficial segment of the cortical plate expressed SBP-1. Between ED 14-16, SGC was expressed in a thin row of glial cells near the ventricles and on their radial processes. Between ED 16-PD 3, SGC was not in neuronal cell soma, but was in neuronal plasma membranes and processes surrounding the neuronal perikarya. The expression of SGC declined similar to SBP-1 and both of them disappeared by PD 7. The expression of SBP-1 and SGC was chronologically coordinated with neuronal migration. SBP-1 was specifically expressed in immature neuronal nuclei and plasma membranes. SBP-1 and SGC were colocalized and were available for interaction with each other on neuronal cell membranes and processes. This was confirmed with isolated neurons in culture. As in vivo, the expression of SBP-1 in neurons declined with time in culture. The dissociated cortical neurons when plated on SBP-1 as a substratum produced extensive neuritic outgrowth. HNK-1, anti-SBP-1 antibodies and sulfoglucuronyl glycolipid, SGGL specifically and severely reduced neurite outgrowth. SBP-1-SGC interactions provide a potential mechanism for guidance and cell signaling, in the processes of neuronal migration and terminal differentiation.

Animals↗
PubMed2000

Worldwide DNA sequence variation in a 10-kilobase noncoding region on human chromosome 22.

Human DNA sequence variation data are useful for studying the origin, evolution, and demographic history of modern humans and the mechanisms of maintenance of genetic variability in human populations, and for detecting linkage association of disease. Here, we report worldwide variation data from a approximately 10-kilobase noncoding autosomal region. We identified 75 variant sites in 64 humans (128 sequences) and 463 variant sites among the human, chimpanzee, and orangutan sequences. Statistical tests suggested that the region is selectively neutral. The average nucleotide diversity (pi) across the region was 0.088% among all of the human sequences obtained, 0.085% among African sequences, and 0.082% among non-African sequences, supporting the view of a low nucleotide diversity ( approximately 0.1%) in humans. The comparable pi value in non-Africans to that in Africans indicates no severe bottleneck during the evolution of modern non-Africans; however, the possibility of a mild bottleneck cannot be excluded because non-Africans showed considerably fewer variants than Africans. The present and two previous large data sets all show a strong excess of low frequency variants in comparison to that expected from an equilibrium population, indicating a relatively recent population expansion. The mutation rate was estimated to be 1.15 x 10(-9) per nucleotide per year. Estimates of the long-term effective population size N(e) by various statistical methods were similar to those in other studies. The age of the most recent common ancestor was estimated to be approximately 1.29 million years ago among all of the sequences obtained and approximately 634,000 years ago among the non-African sequences, providing the first evidence from a noncoding autosomal region for ancient human histories, even among non-Africans.

Animals↗