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Biomedical subjects

C Shi

Publications and source records attributed to C Shi.

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

[Clinical significance and expression of Bcl-2 protein in patients with systemic lupus erythematosus].

OBJECTIVE: To investigate the pathogenesis and clinical evaluation for expression of Bcl-2 in lymphocytes and renal tissues of 31 patients with systemic lupus erythematosus (SLE). METHODS: Bcl-2 protein levels in T, B cells and renal tissues were examined by two-colour cytofluorography, and immunohistochemical staining (LSAB method) respectively. RESULTS: Compared with inactive SLE patients and normal controls, a proposition of T cells (including CD(3)(+), CD(4)(+) and CD(8)(+) subgroups) expressing Bcl-2 protein increased significantly in active SLE patients. However, Bcl-2 protein levels are not statistically different in CD(19)(+) B cells among all groups. Mean fluorescence intensity (MFI) levels of Bcl-2 protein on CD(3)(+) T cells was positively related to SLE disease activity index (SLEDAI) among the SLE patients, which wasn't related to ESR, complement (C(3), C(4)) and autoantibody (ANA, anti-dsDNA, anti-Sm) positivity. The population of Bcl-2 positive intraglomerular cells was correlated significantly with the grade of mesangial cell increase and the number of proliferating cell nuclear antigen (PCNA) positive glomerular cells, and 24-hour urinary protein. CONCLUSION: Overexpression of apoptosis-related Bcl-2 protein might play an important rule in the prolonged proliferation of mesangial cells and glomerular hypercellularity and in the active period of SLE patients, Bcl-2 expression levels of peripheral blood T lymphocytes might serve as an active index for SLE.

Adult↗
PubMed1999

[Studies on the stability of sodium taurocholate in different media and in the course of sterilization].

OBJECTIVE: To investigate the stability of the main active constituent of snake gall sodium taurocholate, TCANa in 25% alcoholic solution and artificial gastric juice, and in the course of hot pressurized sterilization. METHOD: The stability of the solution was predicted by an accelerated isothermal test, and the content of TCANa was determined by TLC-colorimetry. RESULT: The half-time(t1/2) of TCANa in 25% alcoholic solution is 60.57 d at 25 degrees C, and in artificial gastric juice 11.37 d at 37 degrees C, the loss rate under the condition(115 degrees C, 30 min) of sterilization about 3%. CONCLUSION: TCANa in 25% alcoholic solution is unstable. Therefore it is suggested that in order to raise the stability of TCANa the alcoholic concentration be increased and the solution be stored at temperatures below 0 degree C.

Animals↗
PubMed1999

[Amplification of phytoplasma 16S rDNA from banana bunchy top disease, RFLP and sequence analysis of 16S rDNA fragment].

Extract DNA from banana plants with banana bunchy top disease and amplify the phytoplasma 16S rDNA fragment by nested PCR. The classification of the phytoplasma established on the basis of 16S rDNA restriction patterns was examined by performing a sequence analysis of 16S rDNA fragment. The RFLP pattern, sequence data and phylogenic tree showed that this phytoplasma should belong to Group I(Phytoplasma asteri).

Base Sequence↗
PubMed1999

[Construction of adenovirus 4 vector with deletion of 78.9-86 mu fragment and express of beta-galactosidase gene].

OBJECTIVE: To construct a human adenovirus type 4(Ad4) vector with partial deletion at E3 region (78.9-86 mu). METHODS: Ad4 DNA was extracted from purified virus cultured in WI-38 cells. The essential fragment(71.3-100 mu) covering Ad4 E3 region was cloned and partial deletion of E3 region of this clone has been performed, generating plasmid pAd4 delta KS. Furthermore, a beta-galactosidase (beta-gal) gene flanked by CMV early promoter and SV40 poly A signal was inserted into pAd4 delta KS, resulting in pAd4c beta. This plasmid was cotransfected with Ad4 DNA, Bcl I A fragments into 293 cells, producing a non-defective recombinant Ad4 virus encoding B-gal. RESULT: The results showed that the constructed recombinant virus could efficiently express the foreign gene, beta-gal. CONCLUSION: Ad4 vector with a deletion of E3 region can be explored as a live vaccine for prevention of human infectious diseases.

Adenovirus E3 Proteins↗
PubMed1998

Reduced transplant arteriosclerosis in plasminogen-deficient mice.

Recent gene targeting studies indicate that the plasminogen system is implicated in cell migration and matrix degradation during arterial neointima formation and atherosclerotic aneurysm formation. This study examined whether plasmin proteolysis is involved in accelerated posttransplant arteriosclerosis (graft arterial disease). Donor carotid arteries from wild-type B10.A2R mice were transplanted into either plasminogen wild-type (Plg+/+) or homozygous plasminogen-deficient (Plg-/-) recipient mice with a genetic background of 75% C57BL/6 and 25% 129. Within 15 d after allograft transplantation, leukocytes and macrophages infiltrated the graft intima in Plg+/+ and Plg-/- recipient mice to a similar extent. In Plg+/+ recipients, the elastic laminae in the transplant media exhibited breaks through which macrophages infiltrated before smooth muscle cell proliferation, whereas in Plg-/- recipients, macrophages failed to infiltrate the transplant media which remained structurally more intact. After 45 d of transplantation, a multilayered smooth muscle cell-rich transplant neointima developed in Plg+/+ hosts, in contrast to Plg-/- recipients, in which the transplants contained a smaller intima, predominantly consisting of leukocytes, macrophages, and thrombus. Media necrosis, fragmentation of the elastic laminae, and adventitial remodeling were more pronounced in Plg+/+ than in Plg-/- recipient mice. Expression of the plasminogen activators (PA), urokinase-type PA (u-PA) and tissue-type PA (t-PA), and expression of the matrix metalloproteinases (MMPs), MMP-3, MMP-9, MMP-12, and MMP-13, were significantly increased within 15 d of transplantation when cells actively migrate. These data indicate that plasmin proteolysis plays a major role in allograft arteriosclerosis by mediating elastin degradation, macrophage infiltration, media remodeling, medial smooth muscle cell migration, and formation of a neointima.

Animals↗
PubMed1998

Regulation of CD44 gene expression by the proinflammatory cytokine interleukin-1beta in vascular smooth muscle cells.

The CD44 gene codes for a family of alternatively spliced, multifunctional adhesion molecules that participate in extracellular matrix binding, lymphocyte activation, cell migration, and tumor metastasis. In a mouse model of transplant-associated arteriosclerosis, CD44 protein was induced in the neointima of allografted vessels and colocalized with a subset of proliferating vascular smooth muscle cells (SMC). To elucidate the molecular mechanisms regulating CD44 expression in this model, we investigated the regulation of CD44 gene expression by interleukin (IL)-1beta. Treatment of rat aortic SMC with IL-1beta resulted in a 5.3-fold increase in cell surface CD44 expression. Northern analysis showed that IL-1beta promoted a dose- and time-dependent induction of CD44 mRNA which reached 6.6-fold after 48 h, and nuclear run-on analysis showed that IL-1beta increased the rate of CD44 gene transcription within 8 h of stimulation. In transient reporter gene transfection experiments in rat aortic SMC, a 1.4-kilobase fragment of the mouse CD44 5'-flanking sequence mediated this response to IL-1beta. Regulation of CD44 gene expression by the proinflammatory cytokine IL-1beta may contribute to SMC phenotypic modulation in the pathogenesis of arteriosclerosis.

Animals↗
PubMed1998

A novel polymorphism at codon 333 of human immunodeficiency virus type 1 reverse transcriptase can facilitate dual resistance to zidovudine and L-2',3'-dideoxy-3'-thiacytidine.

Recent clinical trials examining 3'-azido-3'-deoxythymidine (AZT, zidovudine, or Retrovir) combined with L-2', 3'-dideoxy-3'-thiacytidine (3TC or lamivudine) have shown that combination therapy with these nucleoside analogs affords significant virological and clinical benefits. The addition of 3TC to AZT delays AZT resistance in therapy-naive patients and can restore viral AZT susceptibility in patients who previously received AZT alone. In some AZT-experienced patients, the virological response to AZT-3TC therapy is not sustained and virus resistant to both drugs can be identified. To gain insight into the possible mechanism of dual resistance, we studied a recently described variant resistant to both AZT and 3TC and obtained by simultaneous passage of an AZT-resistant clinical isolate in cell culture with AZT and 3TC. Genetic mapping and site-directed mutagenesis experiments demonstrated that a polymorphism at codon 333 (Gly to Glu) of human immunodeficiency virus type 1 reverse transcriptase (RT) was critical in facilitating dual resistance in a complex background of AZT and 3TC resistance mutations. To assess the potential clinical relevance of RT codon 333 changes, we studied dually resistant viruses from patients taking AZT and 3TC. Genetic mapping of RT molecular clones derived from patients' plasma samples demonstrated that in some cases polymorphism at codon 333 was responsible for facilitating dual resistance.

Anti-HIV Agents↗
PubMed1998

[The effects of the multiple structural layer of Ti-cast on bond of porcelain fused to titanium].

OBJECTIVE: To study the effects of the multiple structural layer of Ti-cast on the bond of porcelain fused to titanium. METHODS: The interfacial state and bond strength of porcelain-titanium were observed by EPM analysis and a shear test. RESULTS: The results showed cracks were observed in the interface of porcelain-titanium in R1 (the group of multiple structural layer of Ti-cast), but there were no cracks in the interface of porcelain-titanium in R2 (the group of removed multiple structural layer from Ti-cast) and R3 (the group of wrought titanium). The width of elemental diffusion layer of R1, R2 and R3 were 29.03 microns, 6.90 microns and 7.01 microns respectively. The shear bond srength of R1, R2 and R3 were 29.45 MPa, 52.75 MPa and 48.32 MPa respectively. There were significant difference in the width of elemental diffusion layer and shear bond strength between R1 and R2, R3 (P < 0.01). CONCLUSION: This investigation indicates that the multiple structural layer of Ti-cast should be removed before firing of porcelain.

Dental Casting Technique↗
PubMed1998

[DNA cloning of Ad7 vaccine strain and sequence analysis of its Sma I H fragment].

Human adenoviruses have been a hot topic of study because of their potential utility for gene therapy and development of live viral vectored vaccines. Adenovirus types 4 and 7 have been given orally as vaccines for prevention of acute respiratory infections caused by these serotypes of adenovirus in U.S. army recruits for more than 30 years. Therefore, the advantage of using Ad4 and Ad7 as vectors in the development of oral live recombinant vaccine is obvious. For constructing Ad7 vector, 10.8-100 mu DNA of Ad7 vaccine strain has been cloned. The Sma I H fragment was sequenced using Ad7 DNA as a template and then the fragment was cloned by PCR. For verifying the sequence the fragment was sequenced again. The strategy we used to clone terminal end of adenovirus is reliable and practicable.

Adenovirus E3 Proteins↗
PubMed1998

[Sequence analysis of Ad7 vaccine strain 87 mu-97.4 mu fragment].

Adenovirus 7 vaccine strain(Ad7v) possesses potentiality to be used as a vector for producing recombinant vaccine. In order to construct Ad7 vector, the nucleotide sequence of a 3698 bp fragment(87 to 97.4 mu) of the virus DNA was analysed. The fragment encodes three ORFs namely, one ORF of early region 4(E4), one ORF of early region 3 and one ORF of fiber protein. The predicted amino acids of three ORFs(ORF 8.1 kD, 42.8 kD and 10.3 kD) share 33%, 43% and 44% homology with Ad2 E4 corresponding regions (ORF 3, ORF 4 and ORF 6/7) respectively. A comparison of the nucleotide and amino acid sequences of those fiber ORF demonstrated a higher homology between Ad7v and prototype strains of Ad7v than those between Ad7v and Ad7h. The Ad7v E3 15.4 kD protein shares 86%, 88%, 90% and 98.5% amino acid homology with the equivalent region of ad7h E3 15.3 kD protein, Ad4 E3 region 15 kD protein, Ad3 E3 15.3 kD and Ad7p E3 15.3 kD protein protein respectively, but only 68% with Ad2 E3 14.7 kD protein.

Adenoviridae↗
PubMed1998

[Cloning and sequencing of adenovirus type 7 vaccine strain 76.5-87 mu fragment].

Adenovirus 7(Ad7) vaccine strain has been used more than 30 years in US army recruits for prevention of Ad7 infection and has been proven to be safe and effective. Recent years more attention has been paid to exploring the possibilities of using it for gene therapy or making recombinant vaccine. In order to construct adenovirus 7 vector, Ad 7 vaccine strain 76.5-87 mu fragment was cloned and sequenced. The fragment contains 3,557 bp which encodes 6 proteins of E3 region, namely 12.1 kD, 19.2 kD, 20.1 kD, 20.5 kD, 10.3 kD and partial of 15.2 kD. Nucleotide sequences of all these proteins show a high homology with the corresponding region of human adenovirus prototype strain Ad 7(Ad 7p) and Ad 7h(the homology of nucleotide sequence of the 6 proteins is more than 97.2%). The equivalent of ORF 16.1 kD in Ad7p and Ad7h was mutation due to a base pair deletion. The region corresponding to ORF 7.7 kD in Ad7p was missing in Ad7v due to a deletion. The results should be helpful to the construction of Ad7v vectors.

Adenovirus E3 Proteins↗
PubMed1998

[Construction of adenovirus type 7(vaccine strain) vector and expression of beta-galactosidase gene].

Human adenovirus type 7 DNA was extracted from purified virus cultured in WI-38 cells. The essential fragment (68-100 mu) of Ad7 DNA was used for constructing a non-defective Ad7 vector termed as pAd7 delta E3. The vector was characterized by a deletion at the E3 region that contains a multicloning site for the insertion of foreign genes. A helper-independent adenovirus type 7-beta-galactosidase recombinant was established. The recombinant contains the beta-galactosidase gene flanked by CMV early promoter and SV40 poly A signal. The constructed recombinant virus showed efficient capacity in expressing the foreign gene, beta-galactosidase.

Adenovirus E3 Proteins↗
PubMed1998

[Experimental study on the effect of abstinence with herbal preparation qingjunyin].

The effect of herbal preparation Qingjunyin (QJY) on the animal model of drug dependence was studied. After the morphinistic models of white rats and mice were made by ever increasing doses of morphine each time, the animals were divided into large dosage QJY group, small dosage QJY group, sustained morphine group and control group. The withdrawal symptoms were observed after naloxone was given to the animals intraperitoneally. The results showed that QJY groups withdrawal symptoms of the addicted white rats were alleviated, the number of jumps of the addicted mice was reduced, the scores of the principal symptoms of the animals were decreased, while the body weights of the animals were gained, comparing with the control group, the difference was significant (P < 0.01). The effects of QJY enhanced in the large dosage group, which suggests QJY has abstinence effects.

Animals↗
PubMed1997

Hypercholesterolemia exacerbates transplant arteriosclerosis via increased neointimal smooth muscle cell accumulation: studies in apolipoprotein E knockout mice.

BACKGROUND: Hypercholesterolemia is thought to be a significant risk factor for coronary vasculopathy in cardiac transplant recipients. METHODS AND RESULTS: We examined the development of arteriosclerosis in mouse carotid artery loops allografted from B.10A(2R) (H-2h2) donors to normocholesterolemic C57BL/6J (H-2h) recipients and hypercholesterolemic C57BL/6J recipients in which the apolipoprotein (apo) E gene had been knocked out. Luminal occlusion and cross-sectional neointimal area were greater in arteries allografted into hypercholesterolemic recipients at 15 and 30 days after transplantation. We also measured cellular and extracellular matrix components of the neointima by computerized planimetry of the fractional areas subtended by smooth muscle cells (anti-alpha-actin stain), collagen (Masson's trichrome), lipid (oil red O), and leukocytes (anti-CD45). The neointimal area stained for smooth muscle cells was significantly greater in hypercholesterolemic recipients than in normocholesterolemic recipients at 15 and 30 days after allografting. Lipid contributed to neointimal area to a lesser degree, and there was no significant increase in the contribution of collagen or leukocytes. CONCLUSIONS: Smooth muscle cell accumulation appears to be the principal contributor to the increase in neointimal area observed in arteries allografted into hypercholesterolemic mice.

Animals↗
PubMed1997

A recombinant retroviral system for rapid in vivo analysis of human immunodeficiency virus type 1 susceptibility to reverse transcriptase inhibitors.

We have developed a new recombinant retroviral system in which a library of infectious molecular clones of human immunodeficiency virus type 1 (HIV-1) is constructed with reverse transcriptase (RT) genes derived from viral RNA sequences in plasma. HIV-1 RT is amplified from plasma HIV-1 RNA by nested RT-PCR and cloned into a RT-defective HIV-1 proviral vector (xxLAI-np), generating 10(3) to 10(4) recombinant proviral clones from each reaction. The bulk cloning products or individual molecular clones are transfected into MT-2 cells to generate infectious virus. The resultant viruses are assayed for drug susceptibility in CD4+ cell lines to determine either the dominant phenotype of the recombinant virus mixture or the phenotypes of the individual viral clones. DNA sequencing of the cloned RT genes can identify mutations associated with phenotypic resistance of clonal mixtures or individual clones. This method can be used to rapidly detect the in vivo emergence of HIV-1 quasispecies resistant to RT inhibitors.

Anti-HIV Agents↗
PubMed1997

[Criteria of measuring mdr-1 gene expression level in breast cancer by RT-PCR].

OBJECTIVE: To formulate criteria of judjing multidrug resistance gene(mdr-1 gene) expression level and to provide basis for predicting chemotherapy response and prognosis. METHODS: Using reverse transcription-polymerase chain reaction (RT-PCR) assay, the expression of mdr-1 gene in 82 breast cancer samples was detected. The data were treated by statistic analysis system (SAS)-singlevariate analysis. RESULTS: The level of mdr-1 gene expression clearly deviated from normal to right distribution (P < 0.0001), and thus might be divided by quantiles P50(mdr-1/beta 2-MG = 0.2) and P75 (mdr-1/beta 2-MG = 0.6), which were taken as the criteria for comparing 56 patients' chemosensitivity to ADM, VDS, VCR in vitro and 32 relapsed metastatic patients' chemotherapy response in vivo, seperately. When mdr-1/beta 2-MG < 0.2, the ratio of coincidence was lower between expression of mdr-1 and drug resistance in vitro and in vivo; When mdr-1/beta 2-MG > or = 0.2-< 0.6, the ratio of coincidence elevated slightly, but in 30%-50% of the cases drug resistance in vitro and in vivo did not correlate. When mdr-1/beta 2-MG > or = 0.6, the ratio of coincidence elevated significantly. According to the above-mentioned results, criteria of evaluating mdr-1 gene expression level was formulated: the mdr-1/beta 2-MG ratio < 0.2(P50) was considered as negative expression, the ratio > or = 0.2-< 0.6(P75) was weakly positive expression, > or = 0.6 was strongly positive expression. CONCLUSIONS: The criteria of mdr-1 gene expression may reflect objectively drug resistance in vitro and chemotherapy response in vivo. The method may also be applicable to other tumours.

Antineoplastic Agents↗