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Z Cui

Publications and source records attributed to Z Cui.

At least 55 records · Page 3Linked to original sources
PubMed1999

Functional analysis of the promoter of the yeast SNQ2 gene encoding a multidrug resistance transporter that confers the resistance to 4-nitroquinoline N-oxide.

The yeast gene SNQ2, which encodes a multidrug resistance ABC superfamily protein, is required for resistance to the mutagen 4-nitroquinoline N-oxide (4-NQO). The expression of the SNQ2 gene is under the control of a regulatory network that involves the transcription factor Yrr1p, as well as Pdr1p/Pdr3p (Cui et al., Mol. Microbiol., 29, 1307-1315 (1998)). By 5'-deletion analysis of the promoter by using SNQ2-lacZ fusion constructs, four regions: -745 to -639 (region I), -639 to -578 (region II), -548 to -533 (region III) and -533 to -485 (region IV) were found to be important for SNQ2 expression. Genetic analysis suggested that the site in region IV was responsible for the Yrr1p-mediated SNQ2 expression. A consensus motif known for the binding of Pdr1p/Pdr3p (PDRE) was not found in region IV.

4-Nitroquinoline-1-oxide↗
PubMed1999

[Genetic linkage of polymorphisms of type I angiotensin II receptor gene to Chinese Han hypertension].

OBJECTIVE: To observe the CA repeat polymorphism of the type I angiotensin II receptor gene on Chinese Han people, and evaluate the genetic linking to hypertension. METHODS: The CA repeat polymorphism at 3'-flanking region of AT1R gene was studied by amplified fragment length polymorphism (Amp-FLP ) in Chinese Han people from Shandong and Xi'an. RESULTS: There were 9 alleles ranging from 130bp to 146bp in all subjects. The allele frequencies were 0.01 to 0.38, and allele A4 was more frequent in the control. The heterozygosity of CA repeat locus was 0.789, the polymorphic information content, 0.746. There was no significant difference in distribution of CA repeat polymorphism genotype between different regions in same ethnic (P>0. 05), but the allele frequency of CA repeat polymorphism in hypertensive group was significantly different from that of control (P<0.05). There was no detectable distortion from Hardy-Weinberg equilibrium in both groups. CONCLUSION: The results suggest that CA repeat polymorphism of AT1R gene be associated with Chinese Han hypertensive people.

Adult↗
PubMed1999

[Long-term effect of lamivudine treatment in chronic hepatitis B virus infection].

OBJECTIVE: To evaluate the long-term effect of lamivudine on the loss of serum HBV DNA, HBeAg/antiHBe seroconversion and ALT levels in chronic hepatitis B patients and its safety profile and tolerance with multi-center, randomized, double blind and placebo controlled trial. METHOD: 429 patients with chronic HBV infection as defined by positive HBsAg, HBeAg and HBV DNA were enrolled and randomized into lamivudine and placebo groups. 322 patients received lamivudine 100 mg daily and 107 patients received placebo treatment for 12 weeks. Then, all patients were offered a further 40 weeks of open label lamivudine treatment. The efficacy and safety were evaluated with clinical, biochemical, hematological and virological parameters. RESULTS: After 12 weeks treatment, HBV DNA response (serum HBV DNA < 1.6 ng/L) rate in lamivudine group was higher than in placebo group (92.2% VS 14.1%, P < 0.01); but at week 52, there was no difference between lamivudine and placebo/lamivudine groups (71.0% VS 77.7%, P > 0.05). Rate of HBV DNA breakthrough in lamivudine group was higher than in placebo/lamivudine group (24.4% VS 8.5%, P < 0.01). Proportion of HBeAg/anti-HBe seroconversion had no difference in two groups (7.5% VS 5.2%, P > 0.05). By week 12, ALT normalization rate in lamivudine group was higher than in placebo group (60.3% VS 27.5%, P < 0.01); but after 52 weeks treatment, there was no difference between two groups (70.9% VS 74.5%, P > 0.05). At week 48, HBV YMDD mutation rate in lamivudine group was higher than in placebo/lamivudine group (14.6% VS 5.0%, P < 0.05). The incidence of adverse events was similar for both lamivudine and placebo/lamivudine group up to week 12 and 52. There was few severe drug-related adverse event. CONCLUSION: Sustained HBV replication suppression could be obtained from long-term treatment with lamivudine 100 mg daily accompanied with good tolerance and safety.

Adolescent↗
PubMed1999

[Experimental study of cultured autologous keratinocyte sheet(Auto-CKS) and allodermis composite skin grafted onto open wound of rats].

OBJECTIVE: Investigate the "take" and histological changes of grafted auto-CKS and allo-dermis composite skin. METHODS: Thirty Sprague-Dawley rats were divided into group auto-CKS and group allo-dermis composite skin. All wounds were dressed after grafting. Wound healing and "take" of grafts were determined for 90 days after grafting. Biopsies of wound tissue including grafts were collected at regular intervals for histological analysis to check the reconstruction of epidermis-dermis junction (EDJ) and fate of allo-dermis of the composite skin. RESULTS: In group auto-CKS, the "take" of grafts was pretty good, but the quality and histological structure of CKS was not good enough, the proliferated collagen fibers were disorderly arranged, and the CKS was too thin to withstand abrasion and tended to worn out and contracted severely. On the other hand, the "take" as well as the quality, histological structure, abrasion resistance and contraction of composite skin in the allo-dermis composite skin group were much better than that of group auto-CKS. Up to 90 days after grafting, the allo-dermis still existed without obvious signs of immuno-rejection. CONCLUSION: The CKS was not suitable for the wound of full thickness skin defect, while the composite skin composed of auto-CKS and treated allo-dermis unfolded the potential encouraging prospects.

Animals↗
PubMed1999

A randomized double-blind placebo-controlled study of lamivudine in the treatment of patients with chronic hepatitis B virus infection.

OBJECTIVE: To evaluate the effect of lamivudine on the loss of serum hepatitis B virus (HBV) DNA, HBeAg/antiHBe seroconversion and ALT levels in chronic hepatitis B patients and its safety profile and tolerance compared with placebo. METHODS: Four hundred and twenty-nine patients with chronic HBV infection as defined by positive HBsAg, HBeAg and HBV DNA were enrolled and randomized into lamivudine and placebo groups. Three hundred and twenty-two patients received lamivudine 100 mg daily and 107 patients received placebo treatment for 12 weeks. Then, all patients were offered a further 9-month open label lamivudine treatment. The efficacy and safety were evaluated with clinical, biochemical, hematological and virological parameters. RESULTS: During the 12-week treatment period, 92.2% of lamivudine treated patients became HBV DNA negative (below 1.6 pg/ml) compared with only 14.1% of those receiving placebo (P < 0.01). At the end of 12 week, the sustained negative rate for HBV DNA in the lamivudine treated group was 78.5% compared with the placebo group (11.1%; P < 0.01). There was a trend to a high proportion of patients treated with lamivudine to lose HBeAg (8.1%) and develop antiHBe (10.2%) than treated with placebo (5.3% and 6.4% respectively), but this difference was not statistically significant. Patients with elevated ALT levels at baseline became normal in 60. 3% of the lamivudine treated group compared with the placebo group where only 27.5% were normal (P < 0.01). Lamivudine was well tolerated in a dose of (100 mg daily) and the overall incidence of adverse events was similar to that of the placebo. CONCLUSIONS: Lamivudine (100 mg daily) is very effective in the inhibition of HBV replication, indicated by the rapid loss of serum HBV DNA, and often accompanied by a decrease of serum ALT levels. Lamivudine is well tolerated without severe adverse events during treatment.

Adolescent↗
PubMed1999

[Imaging findings of fibrolamellar hepatocellular carcinoma].

OBJECTIVE: To describe the imaging findings of fibrolamellar hepatocellular carcinoma(FL-HCC). METHODS: Imaging studies in 11 patients with pathologically confimed F1-HCC were reviewed. There was no cirrhosis or hepatitis according to patients' history. Serum alpha-fetoprotein level was normal in all patients. Imaging studies included ultrasonography(US) in 10 patients, CT in 11, MRI in 8, and angiography in 9. RESULTS: (1) On US, the echogenicity of the tumor was hyperechoic relative to normal liver in four patients, and mixed in six. Cyst-like regions with various sizes were found within the masses in four patients, Doppler US revealed that the solid portion of the tumor was hypervascullar. (2) Nonenhanced CT scan demonstrated a well demarcated, solitary mass in 9 patients, and a multilobulated mass in 2. All masses were non-homogeneous and hypodense to the liver. Seven of the lesions had a central lower density region with radiating pattern which was confirmed as densely packed scar by pathologic examination. Punctate calcification was seen in 4 of 11 patients. Marked contrast enhancement of the masses was seen on the arterial dominated phase in 7 patients under enhanced CT, and a central nonenhanceing scar-like structure was found in 4 of the seven patients, Liver cirrhosis and splenomegaly were not found in this series. (3) On MRI, the tumor was hypointense relative to the liver parenchyma on T1-weighted spin-echo image and non-homogeneous hyperintense on T2-weighted image. Six of the eight patients had a central radiate-like structures which were hypointense on both T1 and T2-weighted images. On contrast enhanced MRI, four of five patients had obvious enhancement, and the central scar did not enhance on both early and delayed enhancement. (4) On angiography, a globular hypervascular mass with neovascularity was found in four of the nine patients. Peripheral nodular tumor stain, which was similar to that of hemangioma, was seen in 3 patients. A hypovascular mass with displacement of the adjacent vessels was found in 2 cases. No tumor thrombus in the portal vein, nor arterial shunting to the portal vein was identified. CONCLUSION: Typical imaging features in young patients of a large hepatic mass with central scar and calcification but without cirrhosis might be suggestive of FL-HCC.

Adolescent↗
PubMed1999

[IL-12 gene treatment of hepatocellular carcinoma: experimental study].

OBJECTIVE: To investigate the inhibitory effects of retrovirus vector containing IL-12 gene on hepatoma growth in vivo and to explore a new approach of gene therapy to hepatocellular carcinoma (HCC). METHODS: Retrovirus vector containing IL-12 gene was constructed and transfected into packaged cell PA317. Positive PA317 was injected into the rat which suffered from experimental HCC and its anti-tumor effects and immunity changes were recorded. RESULTS: The packaged cell PA317 containing IL-12 gene could inhibit the proliferation of hepatocellular cell line CBRH3. The rats injected at day 1 or 3 can survive permanently, while those injected at day 5 or 7 can survive longer than those not injected. However, tumor generated in rats injected with blank control or package cells containing retroviral vector without IL-12 gene (P < 0.01). CONCLUSIONS: Package cells transfected with retroviral vector containing IL-12 either injected to the hepatoma tissue locally or given splenic exercises anti-hepatoma effects efficiently. The direct intrasplenic injection route is new, safe and effective.

Animals↗
PubMed1999

[Studies on identification of yinchaihu by UV and IR].

OBJECTIVE: To study the identification of nine species of Yinchaihu derived from four genera of Caryophyllaceae, namely, Stellaria dichotoma var. lanceolata, St. dichotoma var. dichotoma, Arenaria juncea, A. capillaris var. glandulifera, Silene fortunei, Si. jenisseensis, Gypsophila pacifica, G. oldhamiana and G. licentiana. METHOD: UV and IR of alcohol extraction. RESULTS: The UV and IR spectra of these 9 plant roots have some difference. CONCLUSION: St. dichotoma var. lanceolata specified in the Chinese Pharmacopoeia can be distinguished from the other plants and all these 4 genera can be differentiated from one another by both UV and first derivative spectra. The genus Stellaria can be identified from the other 3 genera by IR.

Caryophyllaceae↗
PubMed1999

[The effect of cAMP on the transcription and regulation of angiotensin II type 1 receptor gene in cardiomyocytes of neonatal rats].

OBJECTIVE: To clarify the effect of cAMP on the transcription of angiotensin II type 1 (AT1) receptor mRNA in cardiomyocytes. METHODS: Cardiomyocytes from SD neonatal rats were cultured in DMEM containing 10% fetal bovine serum (FBS) with 0.1 mmol/L 5-bromodeoxyuridine (Brdu). At day 5-7, primary cultured cells were used. FBS and Brdu were deprived 24 h before the stimulation. The levels of AT1 mRNA in primary cultured cardiomyocytes were examined by RT-PCR. RESULTS: Stimulation of forskolin (30 mumol/L) plus 3-isobutyl-1-methyl-xanthine (IBMX, 30 mumol/L) which induced the accumulation of cellular cAMP decreased the expression of AT1 receptor mRNA to (64.4 +/- 20.3)% of control at 6 h treatment; while it increased the expression of AT1 receptor mRNA to (209.6 +/- 24.0)% of control at 48 h treatment. CONCLUSIONS: cAMP regulated the transcription of AT1 receptor gene.

Animals↗
PubMed1999

[Angiotensin II regulates the expression of collagens in rat heart].

OBJECTIVE: To testify the effect of angiotensin (Agn) II on the regulation and expression of collagen I, III genes in rat heart as well as the influence of DMP811 (a novel nonpeptide selective angiotension type 1 antagonist) on the effect of Ang II. METHODS: Six-week-old male SD rats with osmotic minipump subcutaneously containing either Ang II or saline were used. (1) Saline-infused(control) group (n = 6), (2) Ang II-infused group (n = 6). (3) Ang II-infused and DMP811-treated (3 mg.kg-1.d-1, by gavage) group (n = 6). Ang II (200 ng.kg-1.min-1) or saline was continuously infused for 1 week. After extraction of cardiac total RNA, the levels of collagen I, III mRNA and proteins were measured with RT-PCR and Sirius red staining respectively. RESULTS: Cardiac weight, cardiac weight/body weight radio, the mRNA levels of collagen I, III were increased by (4.7 +/- 0.4)%, (4.9 +/- 0.9)%, (22.0 +/- 4.7)% and (20.6 +/- 4.9)% respectively, in group 2 compared with those in group 1. The analysis of collagen on Sirius red-stained sections showed that Ang II increased the deposits of both collagen I and III. The above changes caused by Ang II could be inhibited fully by DMP811. CONCLUSIONS: Ang II up-regulated the expressions of collagen I, III via angiotension type 1 receptor.

Angiotensin II↗
PubMed1998

-245 bp of 5'-flanking region from the human platelet factor 4 gene is sufficient to drive megakaryocyte-specific expression in vivo.

Platelet factor 4 (PF4) serves as a lineage-specific marker of megakaryocyte development. We previously identified two positively acting sequences in the human platelet factor 4 (hPF4) gene promoter that synergized to drive high-level luciferase reporter gene expression in vitro. Using portions of the hPF4 5'-flanking region linked to the lacZ reporter gene, we observed in this investigation that constructs with -245 bp of 5'-flanking region were more active than constructs with -2 kb of 5'-flanking region in vitro. We created two independent transgenic mouse lines with a -245-bp hPF4/lacZ construct. Cells from these mice were tested for beta-galactosidase (beta-gal) expression at the mRNA level by Northern blot and semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and at the protein level by immunohistochemistry assay. Mice from one line showed beta-gal expression specifically in all megakaryocytes of all ploidy classes from bone marrow and in platelets. Expression level was comparable to that driven by the 1.1-kb rat PF4 promoter in other transgenic mouse lines. Those in the second line showed no beta-gal expression in megakaryocytes, platelets, or any of the eight organs tested. The -245-bp hPF4 promoter is capable of driving reporter gene expression in a megakaryocyte-specific manner in transgenic mice. The small size of this megakaryocyte-specific promoter is compatible with that required in some viral vectors and may provide a model for targeting gene expression to megakaryocytes.

Animals↗
PubMed1998

Cloning and expression of mouse liver phosphatidylserine synthase-1 cDNA. Overexpression in rat hepatoma cells inhibits the CDP-ethanolamine pathway for phosphatidylethanolamine biosynthesis.

In eukaryotic cells, phosphatidylserine (PtdSer) is synthesized by two distinct synthases on the endoplasmic reticulum by a base-exchange reaction in which the polar head-group of an existing phospholipid is replaced with serine. We report the cloning and expression of a cDNA for mouse liver PtdSer synthase-1. The deduced protein sequence is >90% identical to that of PtdSer synthase-1 from Chinese hamster ovary cells and a sequence from a human myeloblast cell line. PtdSer synthase-1 cDNA was stably expressed in M.9.1.1 cells which are mutant Chinese hamster ovary cells defective in PtdSer synthase-1 activity, are ethanolamine auxotrophs, and have a reduced content of PtdSer and phosphatidylethanolamine (PtdEtn). The growth defect of M.9.1.1 cells was eliminated, and a normal phospholipid composition was restored in the absence of exogenous ethanolamine, implying that the cloned cDNA encoded PtdSer synthase. Mouse liver PtdSer synthase-1 was also expressed in McArdle 7777 rat hepatoma cells. In addition to a 3-fold higher in vitro serine-exchange activity, these cells also exhibited enhanced choline- and ethanolamine-exchange activities and incorporated more [3H]serine into PtdSer than did control cells. However, the levels of PtdSer and PtdEtn in cells overexpressing PtdSer synthase-1 activity were not increased. Excess PtdSer produced by the transfected cells was rapidly decarboxylated to PtdEtn and the degradation of PtdSer, and/or PtdEtn derived from PtdSer, was increased. Moreover, the CDP-ethanolamine pathway for PtdEtn biosynthesis was inhibited. These data suggest that (i) cellular levels of PtdSer and PtdEtn are tightly controlled, and (ii) the metabolism of PtdSer and PtdEtn is coordinately regulated to maintain phospholipid homeostasis.

Amino Acid Sequence↗
PubMed1998

Virus removal from bioproducts using ultrafiltration membranes modified with latex particle pretreatment.

Ultrafiltration is an attractive process for virus removal from bioproducts owing to its high throughput as well as the fact that the operation is carried out under ambient conditions (damage to proteins is highly limited). The principal concern regarding the adoption of conventional ultrafiltration membranes for virus removal is the possibility of the virus passing through abnormally large pores or surface imperfections on the membrane surface. The chief principle behind the present work is to pretreat the membrane by blocking the abnormally large pores using latex particles. Experimental work was conducted to validate this pretreatment using the bacteriophage phi x 174 as a model virus. The results attained were highly encouraging. Different sizes of latex particles were tested by treating a 100 KD molecular weight cut-off membrane, and the transmission of phage (suspended in buffer) through this membrane assessed. In the absence of any particle pretreatment, a virus clearance of 4.78 log reduction value was observed for this membrane. The transmission of phage through the membrane could be reduced by an order of magnitude using 0.11 micron latex particles, or two orders of magnitude using a combination of 0.11 and 0.50 micron particles. The application of latex particles did not hinder the transport of protein through the 100 KD membrane. Protein sieving coefficients obtained using this membrane were 91%, 16% and 2%, for lysozyme, HSA and IgG, respectively.

Bacteriophage phi X 174↗
PubMed1998

Yeast gene YRR1, which is required for resistance to 4-nitroquinoline N-oxide, mediates transcriptional activation of the multidrug resistance transporter gene SNQ2.

We have cloned and characterized a Saccharomyces cerevisiae gene YRR1 that is important for resistance to the mutagen 4-nitroquinoline N-oxide (4-NQO). The wild-type YRR1 gene encodes a protein that contains a Zn(II)2Cys6-type zinc-finger motif. Disruption of the YRR1 gene leads to hypersensitivity to 4-NQO. A dominant mutation (YRR1-1) that confers strong resistance to 4-NQO has been identified. Epistasis analysis demonstrated that 4-NQO resistances mediated by the YRR1 and YRR1-1 alleles require the presence of the SNQ2 gene that encodes a multidrug resistance ATP binding cassette superfamily protein responsible for 4-NQO export. Northern blot analysis of SNQ2 mRNA levels indicated that Yrr1p is involved in basal and drug-induced transcriptional activation of SNQ2, whereas Pdr1p/Pdr3p transcription factors are mainly involved in basal SNQ2 expression. In the YRR1-1 mutant, the level of SNQ2 mRNA is constitutively elevated. These results establish that Yrr1p is important for 4-NQO resistance by mediating transcriptional activation of the SNQ2 gene in response to the stress imposed by 4-NQO. The gain-of-function mutation of Yrr1-1p was attributable to the duplication of a 12-amino-acid sequence generated near the carboxy terminus.

4-Nitroquinoline-1-oxide↗
PubMed1998

Pharmacological properties of traditional medicines. XXIV. Classification of antiasthmatics based on constitutional predispositions.

It is commonly accepted that bronchial asthma or rhinitis accompanies disorders in body fluids and body temperature. The effects of ephedrine and the traditional antiasthmatics "Makyo-kanseki-to" and "Goko-to" were therefore studied on such constitutional predispositions as insensible perspiration and body temperature. Ephedrine markedly increased body temperature and exhibited a strong increased action on respiratory insensible perspiration, whereas Makyo-kanseki-to and Goko-to not only prevented the elevation of body temperature, but also increased respiratory insensible perspiration following the reduction of non-evaporative heat loss from the body surface. Thus, the diagnostic criteria of these two medicines used to treat hot-type asthma or dry cough were experimentally determined. The results also suggest that there is a great possibility that the administration of antiasthmatics may elicit side effects or make diseases worse unless their actions on constitutional predispositions are taken into account, such as body temperature and body fluids.

Amygdalin↗
PubMed1998

A comparative genetic map of rat, mouse and human genomes.

The increasing availability of molecular markers and the development of highly efficient gene mapping strategies for the mouse, rat and human genomes have generated vast quantities of information allowing for the progressive refinement of comparative maps. In this publication we report on an updated version of our rat/mouse/human comparative genetic map, based on the mouse map. Databases for mouse, rat and human gene mapping were used for the collection of homologs mapped in the species. The comparative map was constructed with a total of 1,235 mouse loci having known homologs in the rat and/or human: 16 having homologs only in the rat, 884 having only in the human and 335 both in the rat and human. The combined length of the segments conserved between the rat and mouse spans 758 cM on the mouse map. This indicates that about 47% of the mouse genome is now covered by known rat homologous regions. Five novel regions homologous for the rat and mouse were identified. This comparative genetic map should be useful for researchers working on genetic studies in the rat, mouse and human.

Animals↗
PubMed1998

Extension of conserved regions in the rat and mouse genomes by chromosomal assignments of 29 rat genes.

We recently constructed a comparative genetic map of the rat, mouse and human genomes based on information obtained from several databases. In this study, we performed chromosomal assignments of 29 rat genes with somatic cell hybrid clones, in order to clarify and extend the conserved regions in the rat and mouse genomes. As a result, the conserved regions were extended by 89 cM. Together with our previous report, the length of the conserved regions in the rat and mouse spans 847 cM on the mouse linkage map, indicating that 53% of the mouse genome is covered by homologous regions in the rat. In addition, four conserved regions were newly revealed. The method described in this study appears to be simple and efficient for constructing a whole genome comparative map of the rat and mouse.

Animals↗