Biomedical subjects

S Qu

Publications and source records attributed to S Qu.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Effect of emodin on human kidney fibroblast proliferation].

OBJECTIVE: To study the effect of emodin on proliferation of human kidney fibroblasts in vitro. METHODS: After human kidney fibroblasts were cultured, isolated and identified, both the effects of five different concentrations of emodin (10, 30, 50, 80 and 100 micrograms/ml) on 3H-TdR incorporation, and the effects of three different concentrations of emodin (10, 50 and 100 micrograms/ml) on cell cycle by flow cytometry were investigated. RESULTS: The exposure of human kidney fibroblasts to emodin (10-100 micrograms/ml) caused a dose-dependent reduction in 3H-TdR (r = 0.995, P < 0.01), and could delay the progress of human kidney fibroblasts from G1 to S phase. CONCLUSIONS: Emodin inhibited the proliferation of human kidney's fibroblasts by inhibiting the cell DNA synthase and delaying the progress of cell cycle. These findings might provide part of experimental basis for the clinical use of emodin.

Cell Division↗

PubMed2000

[The survey of HIV prevalence among drug users in Guangxi, China].

OBJECTIVE: To understand the distribution and related risk factors of HIV infection among drug users in Guangxi. METHOD: Three hundred and twenty five drug users were tested for serum HIV antibody, with enzyme linked immunosorbent assay. RESULTS: One hundred and sixteen drug users (35.7%) were found to be HIV positive. The main risk factors associated with HIV infection were intravenous drug users and needle sharing among drug users. The HIV prevalence was 40.9% (114/279) among IDUs, and only 4.3% (2/46) among oral drug users. The phenomenon of sharing injecting equipment (76.7%) among intravenous drug users in Guangxi represents a very serious problem. CONCLUSION: There is a high risk of HIV infection among drug users in Guangxi. Prevention programs urgently need to be implemented.

Adolescent↗

PubMed2000

[The natural history of HIV infection among IDUs in Ruili, Yunnan province, China].

OBJECTIVE: To study the natural history of HIV infections among intravenous drug users. METHODS: Six hundred and twenty five HIV infected people in Ruili, Yunnan province were observed. Retrospective data was analysed combined with a cross - sectional survey. RESULTS: The number of death was 190 among 625 HIV - positive people. The cumulative death rate among HIV infected persons was 76.9 per 1,000 person - year, and the AIDS related death rate was 19.8 per 1,000 person - year. The median survival period of HIV infected persons was 9 years, and the median incubation period was about 8 years. CONCLUSION: Of HIV infected people in Ruili, the median survival and incubation period were shorter compared with those in the United States and Western Europe.

Adult↗

PubMed2000

[The epidemiological study of HIV infection among paid blood donors in one county of China].

OBJECTIVE: To observe the prevalence of HIV infection among paid blood donors and risk factors. METHODS: Selected the residents between 18 to 50 years old from two villages in one county of China in 1997. We observed the prevalence of HIV infection and keep following them to 2000. RESULTS: Nine hundred sixty-three residents were investigated and the prevalence of HIV was 1.8% (17/963). There were 88 paid blood donors among 963 interviewed subjects, the HIV prevalence was significantly higher (17.0% or 15/88) than those who didn't have the experiences of paid blood donations (0.2% or 2/875). Only one person out of 668 who were followed from 1997 to 2000 has converted to sero-positive, the incidence of HIV infection is 0.06 per 100 person-years. Nearly half of sero-negative and sero-positive people have the experiences of muscle injection. Among those with HIV-positive spouse, we found no one converted to sero-positive. The CD(4) count of those sero-positive people declined every year. HIV subtype and C2-V3 region sequence analysis were made for five HIV-positive people in 1998, the result indicated that all of them were infected with HIV-1 subtype B' and the genetic divergence rate was 2.4%. CONCLUSION: There was a high prevalence of HIV among paid blood donors in some regions, and paid blood (plasma) donations were the main risk factor for HIV infection. Although no evidence suggests that during the follow-up period the epidemic of HIV infection has spread locally, it still shall take measurements to prevent further transmission of HIV through paid blood donors.

Adolescent↗

PubMed2000

[The effect of heparin on mesangial cells proliferation and cytokines production].

The human glomerular mesangial cells(MC) proliferation and cytokines secretion were detected by using MTT method and biological active method so as to assess the effects of heparin on the cultured human glomerular MC induced by lipopolysaccharides (LPS). The results showed that there were basic production of interleukin-6(IL-6) and tumor necrosis factor-alpha (TNF-alpha) on MC in the control group without LPS, that high-concentration heparin(500 U/ml) increased the effects of LPS on MC, and that low-concentration heparin (5 U/ml) conversely inhibited the effects of LPS on MC. These data indicate that the low-concentration heparin could inhibit the proliferation of MC and the secrection of IL-6 and TNF-alpha induced by LPS, and hence provide an experimental evidence for administration of heparin in the treatment glomerular disease.

Cells, Cultured↗

PubMed2000

[Polymorphism of ACE gene and its relationship with serum ACE activity in the Hans in Chengdu region].

This study was aimed at the angiotensin converting enzyme (ACE) gene insertion/deletion(I/D) polymorphism distribution in Chinese and its relationship with serum ACE activity(SACE). SACE activity and ACE gene polymorphism in 90 healthy persons in Chengdu region were investigated using a spectrophotometric assay and the PCR technique, respectively. The results showed that, in the Hans, DD genotype of ACE gene was 18%, DI genotype 44%, and II genotype 38%. Allele frequencies were 0.40 for the D allele and 0.60 for the I allele. There were significant relationships between ACE I/D polymorphism and SACE activity. The results suggest that ACE genotype distribution be different between races, that II genotype and I allele be more frequent in Chinese, and that SACE activity be under the influence of a genetic polymorphism of ACE in Chinese.

Adult↗

PubMed2000

[The changes of serum angiotensin converting enzyme activity in Type 2 diabetes and its vascular complications].

This investigation was made with reference to the changes of serum angiotensin converting enzyme (SACE) activity in type 2 diabetes and its vascular complications. SACE activity was studied in 127 type 2 diabetic patients and 90 healthy persons by using a spectrophotometric assay. The results showed SACE activity was obviously higher in diabetic patients (459.51 +/- 175.85 U) than in healthy persons (321.14 +/- 121.27 U); SACE activity was significantly higher in type 2 diabetic patients with diabetic nephropathy (548.27 +/- 166.60 U) than in patients without diabetic nephropathy (383.2 +/- 139.00 U), but there was no difference between patients with microalbuminuria and macroalbuminuria; no statistical difference was detected in SACE activity between diabetic patients with diabetic retinopathy (465.64 +/- 178.93 U) and without retinopathy (449.07 +/- 170.04 U); SACE activity was not associated with the course of diabetes, blood pressure, blood lipid and blood glucose. These data suggest that raised SACE activity might only play a role in the initiation of type 2 diabetes and diabetic nephropathy, but not relate to the progress of diabetic nephropathy, the onset of diabetic retinopathy and hypertension.

Aged↗

PubMed1999

Magnetite Nanoparticles Prepared by Precipitation from Partially Reduced Ferric Chloride Aqueous Solutions.

Spherical magnetite particles with mean diameter of about 10 nm or less were prepared by means of a reduction-precipitation method with ferric chloride as starting material, which was partially reduced to ferrous salts by Na2SO3 before alkalinizing with ammonia. It was found that the nature of the product depends strongly on the initial ratio R0 = [Fe3+]0/[SO2-3]0. The most appropriate ratio was 3 as proved by X-ray diffraction analysis on the samples although the initial concentration of ferric chloride can be different. Particle diameter increased from ca. 3 to ca. 11 nm with an increase of the concentration of aqueous ferric chloride from 0.075 to 0.45 mol dm-3. The advantage of this method lies in the formation of a red intermediate during the reduction process, which enables us to prevent the reoxidation of the ferrous ions by adding precipitation agents at the end of the reduction reaction without the protection of nitrogen or argon. Copyright 1999 Academic Press.

Journal Article↗

PubMed1999

Preliminary study on the cooperation of IL-6 and mB7-1 in the induction of effective antitumor immunity in vitro.

To find a new way for gene therapy against tumors with weak immunogenicity, the effect of mB7-1 costimulation alone, or combined with IL-6, in inducing antitumor immunity in vitro was investigated. It was found that mB7-1 cD-NA transfected B16 cells (B16-mB7-1) induced the expansion of effector lymphocytes and the generation of specific lytic activity more effectively than wild type B16 melanoma cells (B16-wt) or mock-transfected B16 cells (B16-neo) did. (P < 0.01), IL-6 could effectively stimulate lymphocytes proliferation, but failed to enhance its cytotoxicity, while the combination of mB7-1 and IL-6 increased both lymphocyte proliferative response and T-cell-mediated cytotoxicity more significantly than B7-1 or IL-6 did alone (P < 0.01). It was inferred that the costimulatory molecule B7-1 is required for the activation and proliferation of T lymphocytes; the expression of mB7-1 in tumor cells could increase their immunogenicity and induce effective antitumor immune response, and the combination of B7-1 and IL-6 could induce more effective antitumor immunity, indicating that cooperation of IL-6 and mB7-1 plays a role in T lymphocyte activation.

Animals↗

PubMed1999

Experimental study on the antitumor effect of mouse B7-1 gene.

Mouse B7-1 cDNA was cloned by RT-PCR from BALB/C mouse splenic cells and inserted into pcDNA3 to construct an eukaryotic expression vector. This constructor was named pCD-mB7-1, in which the B7-1 cDNA was identified to be consistent with the data from other researchers. pCD-mB7-1 plasmid was transfected into B16(F0) cells, and effective expression of mB7-1 in these tumor cells could be detected till the 6th month by RT-PCR and RNA hybridization. Specific cytotoxity assay of lymphocytes was conducted after culturing with tumor cells and the results demonstrated that B16 cells transfected with B7-1 gene were more effective than B16-wt and B16-neo in inducing specific cytotoxity of lymphocytes against B16-wt cells. It is suggested that expression of B7-1 gene in tumor cells could enhance the immunogenicity and induce the effective antitumor immunity.

Animals↗

PubMed1999

Physical and genetic interactions between Alx4 and Cart1.

Alx4 and Cart1 are closely related members of the family of transcription factors that contain the paired-type homeodomain. In contrast to other types of homeodomains, the paired-type homeodomain has been shown to mediate high-affinity sequence-specific DNA binding to palindromic elements as either homodimers or as heterodimers with other family members. Alx4 and Cart1 are co-expressed at several sites during development, including the craniofacial mesenchyme, the mesenchymal derivatives of neural crest cells in the first branchial arch and the limb bud mesenchyme. Because of the molecular similarity and overlapping expression pattern, we have analyzed the functional and genetic relationships between Alx4 and Cart1. The two proteins have similar DNA-binding activity in vitro and can form DNA-binding heterodimers; furthermore, they activate transcription of reporter genes that contain high-affinity DNA-binding sites in cell culture in a similar manner. Therefore, at least by these criteria, the two proteins are functionally redundant. Analysis of double mutant animals reveals several genetic interactions. First, mutation of Cart1 exacerbates Alx4-dependent polydactyly in a manner that is dependent on gene dosage. Second, there are complex genetic interactions in the craniofacial region that reveal a role for both genes in the fusion of the nasal cartilages and proper patterning of the mandible, as well as other craniofacial structures. Third, double mutant mice show a split sternum that is not detected in mice with any other genotype. Interpreted in the context of the biochemical characterization, the genetic analysis suggests that Alx4 and Cart1 are indeed functionally redundant, and reveal both unique and redundant functions for these genes in development.

Animals↗

PubMed1999

Rheologic determinant changes of erythrocytes in Binswanger's disease.

BACKGROUND: Binswanger's disease (BD) has been associated with severe arteriosclerotic changes in the long perforating arteries and with impaired cerebrovascular responsiveness to hypercapnia. Rheology parameters may become important factors in regulating cerebral blood flow. The purpose of this study was to investigate the changes in rheologic determinants of erythrocytes and to discuss the relation of erythrocytes and white matter lesions in this type of dementia. METHODS: Twenty-eight patients suffering from BD and a control group matched for age, sex and cerebrovascular risk factors were tested for the following hemorheologic variables: erythrocyte deformability, erythrocyte membrane fluidity, erythrocyte aggregation, plasma viscosity and whole blood viscosity. Additionally, red cell membrane metabolic parameters, lipids and individual membrane phospholipids, sialic acid (SA) and malondialdehyde (MDA) contents, and ATPase activities were measured. RESULTS: A significant decrease in erythrocyte deformability, erythrocyte membrane fluidity, membrane phosphatidylethanolamine, membrane phosphatidylcholine, membrane SA and membrane ATPase activities, and a significant increase in membrane cholesterol, cholesterol to total phospholipid ratio, MDA, broad viscosity and erythrocyte aggregation were observed in BD patients when compared with those of the matched control group. CONCLUSIONS: Changes in erythrocyte membrane parameters, especially in phospholipids, can produce serious metabolic disorders and influence the rheologic properties of erythrocytes in patients with BD. These alterations can contribute to a circulatory slowdown and may lead to worsening of the condition of the cerebral white matter in these patients.

Adenosine Triphosphatases↗

PubMed1999

[Protection of spinal motorneurons of section sciatic nerve by transplantation of NT-4 genetically expression cells into the side of section].

The NT-4 genetically engineered cells were made by infecting L-6TG cell (a rat myoblast cell line) in vitro with a retroviral vector pN2A containing the rat NT-4 cDNA. The bioactivities were determined by bioassay of PC12 cell survival rate. The rat with left sciatic nerve transaction was used as a model for treatment by implanting NT-4 genetically modified cell. The condition of motorneurons was assessed by Nissl stain and ChE stain. The results showed that: (1) the percentage of surviving Nissl-stained neurons on the lessened side of NT-4 (+) grafts significantly increased as compared to that with NT-4 (-) grafts 2-3 weeks and 3 months after sciatic nerve transaction, and (2) the grafted cells produced significant increase in the positive ChE stained area after sciatic nerve transaction in 1-3 weeks. Our observations indicate that adult motor neurons are still able to respond to neurotrophic factors and they may require the factors for survival.

Animals↗

PubMed1999

[A comparative study of three-dimensional movements of lumbar spine in the old and the young people].

This article is aimed at the differences in lumbar vertebral three-dimensional movement and in stability between the old and the young people, and at the reasons which lead to the differences. Fifteen fresh adult male cadavers were divided into two groups: the young group, 20-30 years old, comprising 7 cases; the old group, 60-70 years old, 8 caes. Lumbar spine(L1-S1) was cut down. Three-dimensional movements under a loading system were measured by a compute system. The result showed that the range of the motion of the old group was lower than that of the young group. It suggests that the lumbar spine of the old people is more stable than that of the young people. This may be associated with the degeneration of the lumbar vertebra, which arouses biocompensatory changes, so the lumbar spine becomes re-stable.

Adult↗

PubMed1998

Mutations in mouse Aristaless-like4 cause Strong's luxoid polydactyly.

Mutations that affect vertebrate limb development provide insight into pattern formation, evolutionary biology and human birth defects. Patterning of the limb axes depends on several interacting signaling centers; one of these, the zone of polarizing activity (ZPA), comprises a group of mesenchymal cells along the posterior aspect of the limb bud that express sonic hedgehog (Shh) and plays a key role in patterning the anterior-posterior (AP) axis. The mechanisms by which the ZPA and Shh expression are confined to the posterior aspect of the limb bud mesenchyme are not well understood. The polydactylous mouse mutant Strong's luxoid (lst) exhibits an ectopic anterior ZPA and expression of Shh that results in the formation of extra anterior digits. Here we describe a new chlorambucil-induced deletion allele, lstAlb, that uncovers the lst locus. Integration of the lst genetic and physical maps suggested the mouse Aristaless-like4 (Alx4) gene, which encodes a paired-type homeodomain protein that plays a role in limb patterning, as a strong molecular candidate for the Strong's luxoid gene. In genetic crosses, the three lst mutant alleles fail to complement an Alx4 gene-targeted allele. Molecular and biochemical characterization of the three lst alleles reveal mutations of the Alx4 gene that result in loss of function. Alx4 haploinsufficiency and the importance of strain-specific modifiers leading to polydactyly are indicative of a critical threshold requirement for Alx4 in a genetic program operating to restrict polarizing activity and Shh expression in the anterior mesenchyme of the limb bud, and suggest that mutations in Alx4 may also underlie human polydactyly.

Amino Acid Sequence↗

PubMed1998

[Effect of yuanhua on isolated uterine strips in unpregnant rats].

OBJECTIVE: To explore the mechanism on the effect of Yuanhua on the contractile activity of isolated uterine strips in rats under artificial oestrum. METHOD: Isolated strips were suspended in a tissue chamber in which Yuanhua was added with some antagonists of inhibitors or without. RESULT: Yuanhua could excite the uterine smooth muscle strips in a dose-dependent manner, but atropine, phentolamine, hexamethonium and diphenhydramine could not inhibit this exciting action. This exciting effect could be inhibited completely by verapamil and decreased by indomethacin(inhibitor of prostaglandin synthase). CONCLUSION: The exciting effect of Yuanhua on un-pregnant rats in vitro might be related to an action on the cell membrane Ca2+ channel as well as to a partial stimulation of synthesis and release of PG.

Animals↗

PubMed1998

[The effect of elevated hydrostatic pressure on expression level of type III collagen mRNA by lamina cribrosa cells in vitro].

OBJECTIVE: To investigate the effect of elevated hydrostatic pressure on the expression level of type III collagen mRNA by lamina cribrosa cells (LCCs) and approach the action of changes of extracellular stroma on glaucomatous optic nerve damage. METHODS: LCCs were cultured and submitted to elevated hydrostatic pressure (4.67 - 5.33 kPa). We observed collagen type III mRNA level by dot-blot hybridization and computer imaging analysis. RESULTS: Under the pressure for 3 days, the amounts of collagen III mRNA were 0.5828 +/- 0.0517 in optical density (OD), compared with the same period controls (0.2832 +/- 0.0613), the difference was statistically significant (P < 0.05). When exposed to pressure up to 6 days, the collagen III mRNA level remained somewhat higher than that of the control, but there was no significant difference (P > 0.05). After 9 to 12 days of exposure to pressure, the mRNA amounts were decreased respectively to 0.3246 +/- 0.0957 and 0.2164 +/- 0.0171 in OD that were lower than that of the control in the respective same periods, and the differences between the experimental and the control had no significance (P > 0.05). CONCLUSION: Elevated hydrostatic pressure may increase expression level of collagen III mRNA by LCCs in a certain period.

Collagen Type III↗

PubMed1997

Alx-4: cDNA cloning and characterization of a novel paired-type homeodomain protein.

Homeodomain containing transcription factors serve important functions in patterning the embryo during vertebrate development. We have isolated cDNA clones encoding a novel protein, named Alx-4, that contains a paired-type homeodomain. Analysis of the homeodomain sequence shows that Alx-4 belongs to a family of genes that are related to the Drosophila gene aristaless, and includes the mammalian genes Alx3, Cart-1, MHox, and S8. We have analyzed the expression of Alx-4 during development by Northern blot and whole mount in situ hybridization. In addition, we have generated antibodies to recombinant Alx-4 protein and identified Alx-4 protein in nuclear extracts prepared from mouse embryos. The expression pattern of Alx-4 suggests that it may play a role in the patterning of structures derived from craniofacial mesenchyme, the first branchial arch, and the limb bud. Our results provide a starting point for the analysis of a new member of the family of paired type homeodomain proteins.

Amino Acid Sequence↗