Biomedical subjects

J Zhou

Publications and source records attributed to J Zhou.

At least 451 records · Page 25Linked to original sources

PubMed1999

[Gene expression profiles in squamous esophageal cancer tissues and adjacent almost normal tissues].

OBJECTIVE: To describe an esophageal cancer-specific expression profile and to identify genes that showed altered expression in squamous esophageal cancer tissues and their adjacent almost normal tissues. METHODS: The cDNA probes were synthesized from polyA(+)RNA of cancer and adjacent almost normal tissues and were differentially hybridized with two identical Atlas human cDNA expression arrays membranes containing 588 known genes. RESULTS: Autoradiographic analysis showed that of the 588 genes analyzed, 61 were found up-regulated in cancer, including cdc25B, Notch1, MMP, MET etc, and 22 down regulated in cancer, including cytokeratin4, BAD, IL-1 RECEPTOR ANTAGONIST, IL-6, etc. Expression levels of genes that associated with the regulation of cell proliferation, apoptosis, differentiation and metastasis altered most. CONCLUSION: The results for the first time provide an esophageal cancer-specific expression profile, showing that complex alterations of gene expression underlie the development of malignant phenotype of esophageal cancer cells. In addition, this line of research can lead to the identification of EC-specific genes which may be helpful for the development of diagnostic and prognostic biomarkers or therapeutic targets. The differential hybridization technique of Atlas Human cDNA expression array can be a useful method for describing the expression profiles of a tissue of cell interested.

DNA, Complementary↗

PubMed1999

Development and application of a minimal-adenoviral vector system for gene therapy of hemophilia A.

To achieve efficient delivery and sustained expression of the human factor VIII cDNA in vivo, a minimal-adenoviral (mini-Ad) vector system was developed. The system is composed of a mini-Ad vector with essential cis-elements (less than 1 kb) of the viral genome, an E1-deleted ancillary Ad with packaging attenuation, and an E1-complementing production cell line. Based on this system, MiniAdFVIII was generated to deliver a 27 kb expression cassette consisting of a full-length human factor VIII cDNA flanked by human albumin promoter and genomic sequences. The MiniAdFVIII vector mediated expression of functional human factor VIII in HepG2 and 293 cells. A single-dose intravenous injection of 10(11) viral particles in hemophilic mice of MiniAdFVIII produced a sustained high-level expression of human factor VIII (at 100-800 ng/ml up to 369 days) which corrected the FVIII-deficient phenotype. Safety studies of MiniAdFVIII showed that there were no significant toxic effects in mice and dogs after single intravessel doses of up to 3 x 10(11) and 6 x 10(12) viral particles, respectively. Studies for developing the MiniAdFVIII vector with a site-specific integration mechanism and progress in the development of a human factor VIII-tolerized mouse model for pre-clinical studies of MiniAdFVIII are reported. Further pre-clinical studies and product development of MiniAdFVIII for clinical trials are also discussed.

Adenoviridae↗

PubMed1999

Construction of La-tPA vector and expression in the mammary gland of transgenic mice.

Expression vectors of long acting human tissue plasminogen activator (La-tPa) in the mammary gland was constructed using the promoters of sheep beta-lactoglobulin gene (BLG, 5 kb) containing the first and the second introns obtained by PCR. Transgenic mice were established by microinjection. 540 fertilized eggs were injected and 6 transgenic mice were screened out from the offspring by PCR and Southern Blot analysis. The foreign gene integrating rate was 32%. The expression of La-tPA in mammary glands of transgenic mice was confirmed by milk assay and Northern blot analysis. Expression level of La-tPA reached 6 ug/ml in milk of transgenic mice.

Animals↗

PubMed1999

Serum vascular endothelial growth factor is a predictor of invasion and metastasis in hepatocellular carcinoma.

Tumor progression is angiogenesis dependent, and vascular endothelial growth factor (VEGF) is a key growth factor in this process. sVEGF concentrations in 44 patients with hepatocellular carcinoma (HCC) and 5 with benign liver lesions were determined with an enzyme-link immunoadsorbent assay system (ELISA). Reverse transcript-polymerase chain reaction (RT-PCR) was carried out on surgical specimens of 51 patients with HCC. The relative levels of VEGF mRNA expression were measured by determining a ratio between PCR products of VEGF and the endogenous internal standard gene b-actin. UEA-1 was histochemically used to count microvascularity in tumor tissue. Elevated sVEGF concentrations were found in patients with HCC (172.84+/-111.75 pg/ml) as compared to individuals with benign liver lesions (95.74+/-36.20 pg/ml, P<.05). Of 44 cases with HCC, sVEGF concentrations in the patients with PV-emboli or with poor-encapsulated tumors were significantly higher than in those without PV-emboli or with well-encapsulated tumors (P<0.05). The expression levels of VEGF mRNA in tumors with PV-emboli and in poor-encapsulated tumors were higher than in those without PV-emboli and in well-encapsulated tumors (P<0.05). Microvascular density in HCC tissues was significantly correlated with the expression levels of VEGF mRNA (P<0.01; r=0.7). Circulating VEGF was derived from HCC tissue. sVEGF concentrations could be a new marker for predicting the angiogenesis, invasion and metastasis of HCC.

Adult↗

PubMed1999

Experimental study of sagittal fracture of the mandibular condyle.

OBJECTIVE: To observe the healing of sagittal fracture of the mandibular condyle (SFMC) and its effect on the temporomandibular joint in immature miniature pigs. METHODS: Twenty-seven immature miniature pigs were randomly chosen and divided into three groups. Twelve immature miniature pigs underwent sagittal fracture of the mandible condyle; 12 underwent transverse fracture, and 3 were maintained as a normal control. Three-phase scintigraphy, computed tomography (CT) imaging, and histological tests were conducted at 3 weeks, 6 weeks, 12 weeks, and 24 weeks. RESULTS: The data showed the value of the time-activity curve of blood-flow image increased and blood-flow arriving time was postponed after condylar fracture. The alpha/beta ratio was the highest at 2 weeks after SFMC. The count of blood-pool image and static image were higher than nonfractured sides. Peaks were seen at 2 weeks postfracture. Disc and condyle adhesion was found in all sagittal fractures of the mandibular condyle and bifid mandibular condyle was formed. Adhesive tissues between condyle and disc were fibro-connective tissues, which connected the disc directly to cartilage or bone tissue. A large number of fibroblasts and sparse chondrocytes were seen in the adhesive tissue. Blood vessels and adipose cells were seen in the disc, whereas there were no distinguishable changes in transverse fracture. CONCLUSION: Bifid mandibular condyle was found in most SFMC in childhood. The mechanism of bifid condyle deformity is related to secondary injuries to the disc, adhesions between the condyle and disc, and displacement of the medial split fragment. The age when SFMC occurs is an important factor in bifid condyle formation.

Animals↗

PubMed1999

[The effect of insulin-like growth factor I and insulin on intrauterine fetal growth retardation].

OBJECTIVE: To evaluate the role of insulin-like growth factor I (IGF-I) and insulin (Ins) in the occurrence of intrauterine fetal growth retardation (IUGR). METHODS: The study group included 17 women with IUGR, and 38 normal third trimester pregnant women were served as control. Maternal venous blood samples were collected from all cases before cesarean section. Umbilical venous blood and amniotic fluid were collected at the time of operation. The concentrations of Ins were measured by radioimmunoassay and concentrations of IGF-I were assayed by ELISA. RESULTS: The maternal serum IGF-I in IUGR group (117.29 micrograms/L) was significantly lower than that in the control group (207.07 micrograms/L) (P < 0.002). The umbilical serum IGF-I in IUGR group (16.73 micrograms/L) was significantly lower than that in the control (44.89 micrograms/L) (P < 0.001). There was no significant difference of maternal serum Ins between IUGR group (12.18 mIU/L) and control group (7.13 mIU/L). CONCLUSIONS: The change of IGF-I and Ins levels in maternal and umbilical serum may play an important role in the pathophysiological changes in IUGR.

Adult↗

PubMed1999

[Ureaplasma urealyticum infection and premature delivery or premature rupture of the membrane].

OBJECTIVE: To evaluate the relationships between ureaplasma urealyticum (UU) infection and premature delivery or premature rupture of the membrane (PROM). METHODS: The cervical swabs, fetal membrane and umbilical cord from 46 cases of PROM, 7 cases of premature delivery (study group), and 32 normal pregnancies (control group) were cultured for UU. Some of these placenta tissues were examined under electron microscopy, and compared with the purified UU. RESULTS: The detective rates of UU were both 73.6% (39/53) in the cervix and fetal membrane of the study group, and to compare with the control group (40.6%, 13/32 and 15.6%, 5/32 respectively), significant differences were shown (P < 0.01, P < 0.001). The prevalence rate of perinatal mortality, stillbirth and low birth weight in UU-positive cases (34.1%, 15/44) was significantly higher than that in UU-negative cases (7.3%, 3/41, P < 0.01). Electron microscopy demonstrated that large amount of small multiplicated UU particles deposited around the nuclear membrane of the cytotrophoblasts and in the collagen fibers from the placenta of PROM, and its shape was in consistent with that of the purified UU. In contrast, no UU particles was seen in the normal control group. CONCLUSION: The results show that UU is responsible for some cases of premature delivery, low birth weight and PROM. The multiplication of UU within the trophoblasts may disrupt cell structure which could interfere the normal fetal development.

Adult↗

PubMed1999

[Effect of human plasma HDL on the HDL receptors of plasma membranes of cholesterol-fed rabbit].

Atherosclerosis(As) rabbit model was developed by high-cholesterol feeding for 12 weeks. The rabbits were injected intravenously with human plasma HDL preparation per week, and then the effects of HDL on the lipids contents of serum, liver and bile nd the activity of HDL receptors on liver plasma membranes of cholesterol-fed rabbit were investigated. The results showed that HDL preparation had no effect on decreasing the lipids contents of serum, but it could low down the lipid depositions in liver, and promote the excretion of lipids from bile. The value of Bmax of HDL receptor showed decreasing trendy and the value of Kd showed increasing trendy in cholesterol-fed rabbits. In HDL-treated rabbits, the value of Bmax increased significantly as compared with that of normal group(P < 0.05), but the value of Kd showed no difference. The results suggested that human plasma HDL could enhance the activity of HDL receptors on the liver plasma membranes of cholesterol-fed rabbit.

Animals↗

PubMed1999

[The regulation of estrogen and tamoxifen to bcl-2 oncogene in endometrial carcinoma].

OBJECTIVE: To study the regulation mechanisms of bcl-2 oncogene in endometrial carcinoma. METHODS: A reverse transcription-polymerase chain reaction (RT-PCR) method was utilized to quantitate bcl-2 mRNA levels which regulated by estrogen(17-beta-estradiol) and tamoxifen in estrogen receptor (ER)(+) RL-952 endometrial carcinoma cells. RESULTS: bcl-2 mRNA level was detected in ER(+) RL-952 cells. 17-beta-estradiol stimulated a concentration-dependent increase in bcl-2 mRNA level, while tamoxifen lead to a concentration-dependent decrease in bcl-2 mRNA level. CONCLUSIONS: bcl-2 oncogene expression in ER(+) endometrial carcinoma is regulated by estrogen and antiestrogen. Estrogen may up-regulate the cell bcl-2 level to inhibit cell apoptosis, while tamoxifen may down-regulate the cell bcl-2 level and induce apoptosis.

Carcinoma↗

PubMed1999

[Effects of intermittent hypoxia on transient outward current in rat ventricular myocytes].

To explore the ionic basis of the strengthening effect of intermittent hypoxic adaptation (IHA) on the electric stability of heart, the effects of intermittent hypoxia on the transient outward current (Ito) in rat ventricular myocytes were investigated by using whole-cell patch-clamp recording techniques. After 28-day (H28) exposure (6 h/d) to intermittent hypoxia, the density of Ito in the right, but not in the left, ventricular myocytes was dramatically increased as compared with the normoxia control (16.18 +/- 4.61 vs 6.32 +/- 1.35 pA/pF, P < 0.05), while the Ito density of the myocytes isolated from both sides of ventricles in 42-day-exposure group (H42) did not show significant difference. Except for a more negative shift of the steady-state inactivation curves (half-inactivation voltages: -38.9 +/- 2.3 vs -32.8 +/- 5.9 mV in the left ventricle and -41.9 +/- 4.5 vs -33.5 +/- 3.5 mV in the right ventricle) in the H42 group, all the other parameters for activation, inactivation and recovery kinetics of Ito of each group remained unchanged. It is speculated that the change in the current density of Ito may be responsible for the different hemodynamic responses of the ventricles to the early stage of hypoxia. The alteration in inactivation may participate in the cardioprotective effect of IHA.

Adaptation, Physiological↗

PubMed1999

Identification of mutation in a candidate gene for hereditary multiple exostoses type II.

OBJECTIVES: To identify possible mutations in our previously cloned candidate gene for hereditary multiple exostoses type II (EXT2) in affected members of EXT families so as to confirm that it is the disease-causing gene. METHODS: The mutation was detected first by single strand conformational polymorphism (SSCP) of all coding exons of the candidate gene and then by sequencing analysis. RESULTS: After analyzing 37 patients from 20 Chinese EXT families by SSCP and DNA sequencing analysis, one 2-bp insertion mutation was identified in this candidate gene in affected members of an EXT family. This mutation resulted in the frameshift and generated a truncated gene product consisting of 105 amino acids. CONCLUSIONS: The identification of the mutation in the candidate gene indicates that this novel gene is responsible for EXT2 (one of the disease-causing gene of EXT).

Amino Acid Sequence↗

PubMed1999

Effects of nitric oxide inhibitor on prostacyclin biosynthesis in portal hypertensive rats.

OBJECTIVE: To evaluate the effects of nitric oxide inhibitor on prostacyclin (PGI2) biosynthesis and the role of PGI2 in hyperhemodynamics of portal hypertension. METHODS: Sprague Dawley rats were divided into four groups: intrahepatic portal hypertension (IHPH) by injection of CCl4, prehepatic portal hypertension (PHPH) by stenosis of the portal vein, end-to-side portacaval shunt (PCS), and sham-operated controls (SO). Animals of each group were subdivided into 2 groups: systemic administration of nitric oxide inhibitor L-NMMA and vehicle. The radioactive microsphere method was used for hemodynamic study. The level of plasma PGI2 (6-keto-PGF1 alpha) was measured by radioimmunoassay. RESULTS: The characteristics of hyperdynamic circulatory state including increased cardiac output and splanchnic blood flow, decreased mean arterial blood pressure, total peripheral vascular resistance, and splanchnic vascular resistance were observed in IHPH, PHPH and PCS rats. The magnitude of hyperhemodynamics was in the order of PCS > PHPH > IHPH rats. The hyperdynamic circulatory state in IHPH, PHPH and PCS rats could be effectively reversed by L-NMMA to the baseline values of hemodynamics in SO rats. The baseline concentrations of plasma 6-keto-PGF1 alpha (ng/ml) in PHPH, IHPH, PCS, and SO rats were 6.93 +/- 2.43, 5.09 +/- 2.27, 2.36 +/- 1.01 and 1.56 +/- 0.61, respectively. The concentrations of plasma 6-Keto-PGF1 alpha in PHPH, IHPH and PCS rats were significantly higher than those in SO rats. Moreover, the concentrations were significantly higher in PHPH and IHPH rats than in PCS rats (P < 0.05). After administration of L-NMMA, the concentrations of plasma 6-Keto-PGF1 alpha (ng/ml) in PHPH, IHPH, PCS and SO rats were 7.69 +/- 2.98, 5.68 +/- 2.66, 5.50 +/- 0.79, 5.02 +/- 2.86, respectively. As compared to the baseline value, the concentrations of 6-keto-PGF1 alpha rats were slightly increased in IHPH, PHPH rats (P > 0.05), but significantly increased in PCS and SO rats (P < 0.05). CONCLUSIONS: In this study, the hyperdynamic circulatory state in portal hypertensive rats and portacaval shunt rats was completely reversed by L-NNMA to normal, but the level of 6-keto-PGF1 alpha was still elevated. The results indicate that PGI2 is not involved in hyperhemodynamics of portal hypertension.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

Surgical treatment of hepatocellular carcinoma and related basic research with special reference to recurrence and metastasis.

OBJECTIVE: To summarize the progress of surgical treatment of hepatocellular carcinoma (HCC) and related basic research at the Liver Cancer Institute of Shanghai Medical University in the recent years, with special reference to recurrence and metastasis. METHODS: Published and unpublished update clinical and experimental data in the above-mentioned areas are summarized. RESULTS: Surgical resection has played an important role in improving prognosis of HCC, the 5-year survival were 63.4% for small HCC resection (n = 806), 39.6% for large HCC resection (n = 1061), 64.7% for cytoreduction (using hepatic artery cannulation and ligation) and sequential resection of initially unresectable HCC (n = 93), 56.0% for cytoreduction using transcatheter arterial chemoembolization (TACE) and followed by resection (n = 65), and 22.4% for hepatic resection with removal of tumor thrombi in portal vein (n = 103). Unfortunately, the 5-year recurrent rate after curative resection of HCC was up to 61.5%, which was mainly a result of intrahepatic "metastasis" and multicentric origin of HCC. Clinically, re-resection of subclinical recurrence yielded 56% of 5-year survival (n = 202); prevention of recurrence by transcatheter arterial chemoembolization (TACE) + Interferon, or LAK/IL-2 therapy have decreased 3-year recurrent rate from 33% to 11%-18%. In experimental aspect, metastatic human HCC model in nude mice (LCI-D20) and HCC cell line with metastatic potential (MHCC97) have been established; studies on HCC invasiveness in the molecular level revealed similar results that reported in other solid cancers, and small HCC showed slightly better biological characteristics as compared with large HCC; microvessel density (MVD) that reflecting angiogenesis adversely correlated with 5-year survival of small HCC; experimental interventions using antisense H-ras, bispecific antibody, BB94, as well as anti-angiogenic agents (TNP470, suramin, CAI, heparin, antisense VEGF, etc.) have been demonstrated to inhibit tumor growth and lung metastasis in nude mice model. CONCLUSIONS: Recurrence and metastasis are the major obstacle to further improve prognosis of HCC, studies should be conducted both in clinical and experimental aspects, "HCC invasiveness" will be the major target to be studied, particularly in the molecular level, and anti-angiogenesis will be one of the important approach.

Angiogenesis Inhibitors↗

PubMed1999

The diagnostic criteria for classic parasystole.

OBJECTIVE: To establish a diagnostic criteria of parasystole with high sensitivity and high specificity. METHODS: After excluded from nonparasystole and each variant parasystoles, based on the electrocardiographic data obtained from 61 patients with classic parasystole, we selected the quantitative indices which could reflect the features of ectopic focus with complete entrance block as the diagnostic criteria for parasystole. RESULTS: The common features of the electrocardiograms of this group were: 1) Take the earliest recorded eight interectopic intervals in which at least four intervals containing sinus beats or other beats having activated to the area within the ectopic focus. When in case of deficiency, it will fill up a vacancy in order. The ratios of the shortest coupling interval to the shortest ectopic cycle length (ECL) were all less than 80%; 2) The coefficients of variation of the eight ECLs were all less than 6%; 3) The maximal differences of coupling intervals were all equal to or more than 0.11 second. CONCLUSION: Three quantitative indices as necessary conditions have been used as diagnostic criteria for parasystole with high sensitivity and high specificity.

Electrocardiography↗

PubMed1999

[Expression and characteristics of laryngeal carcinoma-associated antigen].

OBJECTIVE: To study the characteristics of laryngeal carcinoma-associated antigen (LCAA) and its expression on laryngeal carcinoma tissue. METHODS: The binding of a cocktail monoclonal antibodies Lc9, Lc11, Lc12 to human laryngeal squamous-cell carcinoma, laryngeal precancerous lesions and normal laryngeal mucosa was examined by immunohistochemical method. LCAA isolated and purified by gel-filtration, and chromotography from 3 laryngeal squamous-cell carcinomas. The reactivity of the purified antigen was determined after treatment with trypsin, NaIO4, methanol and heating. RESULTS: The positive rate of LCAA expression in 90 cases of laryngeal carcinoma, 14 cases of precancerous lesions and in 10 cases of normal laryngeal mucosa was 97.7%, 50.0% and 0, respectively. LCAA was a glycoprotein, moderately heat stable. The purified antigen gave two bands of apparent molecular weights of 61,400 and 56,500 on SDS-PAGE and Western blot. CONCLUSION: The results provide a basis for immunoimaging diagnosis and targeting chemotherapy for laryngeal cancer.

Antigens, Neoplasm↗

PubMed1999

[Effect of unilateral condylar fracture on stress distribution in the mandible].

OBJECTIVE: To investigate the effect of unilateral condylar fracture on stress distribution in the mandible in order to realize primarily the biomechanical mechanism of temporomandibular joint disorders (TMD) resulted in by joint injury. METHODS: The stress distributions in the mandible of a normal human and a patient with TMD induced by right condylar fracture following malposition healing were analyzed and compared quantitatively during centric occlusion by three-dimensional finite element method. RESULTS: The patient contained the unbalanced stress distribution in the mandible, such as different nature and value of stress. The stress in the fractured side was higher than the non-fractured side, in which condyle is more evident. The maximum principal stress and minimum principal stress of each region in his mandible were much higher than that in a normal mandible. Its stress quality changes also. The stress in his mandible was distributed asymmetrically. CONCLUSION: Unilateral condylar fracture not only damaged its structure, but also induced the badness of its biomechanical environment, in which condyle was the most sensitive region during the stresses in the mandible were changed. It was preliminarily thought that unbalanced stress distribution, evidently increased stress and varied stress character were one of biomechanical mechanism of TMD.

Adult↗

PubMed1999

[Quantitive study of 6-keto-prostaglandin F1 alpha and thromboxane B2 in human pulp].

OBJECTIVE: To study the change of the levels of 6-keto-prostaglandin F1 alpha (6-K-PGF1 alpha) and thromboxane B2 (TXB2) in deep caries and pulpitis pulp. METHODS: The levels of 6-K-PGF1 alpha and TXB2 were determined by radioimmunoassay (RIA) in 44 pulp tissues from subjects with healthy pulp (H), deep caries (DC), chronic pulpitis (CP) and acute pulpitis(AP). The 6-K-PGF1 alpha/TXB2 ratio(K/T) was calculated. RESULTS: The lconcentrations of 6-K-PGF1 alpha in Group AP were highest and those in Group H were lowest. The levels of TXB2 in Group DC were lower than Group CP and those in Group H were lowest. Significant differences in K/T ratio were found among the groups except those between Group H and DC. The value of Group AP was highest and that of Group CP was lowest. CONCLUSION: The dysbolism and dysequilibrium of PGI2 and TXA2 may be closely related to the genesis of pulp diseases.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

[Comparative experimental study between longitudinal fracture and transverse fracture of mandibular condyle].

OBJECTIVE: To evaluate the secondary effect of childhood miniature pig longitudinal fracture and transverse fracture of mandibular condyle to Temporomandibular Joint (TMJ). METHODS: Longitudinal and transverse fractures on condyle of 14 childhood miniature pigs were created respectively. After 3 and 6 months the TMJs were studied macroscopically and microscopically. RESULTS: The transverse fracture of mandibular condyle brought about TMJ adaptive changes. There was no adhesion between disc and condyle. The longitudinal fracture led usually to bifid condyle deformity and adhesion between disc and condyle. Many fibroblasts and chondrocytes were seen in the adhesion between disc and condyle. Blood vessels and fatty degeneration appeared in the articular disc. CONCLUSION: Two different types of childhood condylar fractures are apparently different in the aspects of secondary lesions on TMJ. It suggests that an evident correlation between mandibular condyle longitudinal fracture and TMJ ankylosis.

Animals↗