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Biomedical subjects

S Guo

Publications and source records attributed to S Guo.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Bioslurry remediation of soil contaminated with polycyclic aromatic hydrocarbons].

Through the operation of the pilot-scale slurry reactor, the operational parameters of bioslurry remediation for soil contaminated with polycyclic aromatic hydrocarbons(PAHs), including temperature, ratio of water to soil, aeration flux, were determined. As the operational condition was that the ratio of water to soil was 2:1, the temperature was 20 degrees C-25 degrees C and aeration flux was 60 L/h, a good result of the remediation could be achieved. With the fungi isolated from contaminated soil as pure culture to degrade PAHs, after 34 days incubation, 90% of pyrene and 33.3% of benz[a]anthracene were degraded by Fusarium, 81.5% of pyrene and 49.2% of benz[a]anthracene were degraded by Mucor, 52% of pyrene and of 46% of benz[a]anthracene were degraded by Penicillium.

Biodegradation, Environmental↗
PubMed2001

Gene transfer and expression in rat anastomotic artery in vivo using adenoviral vector.

OBJECTIVE: To observe the efficiency and time course of gene expression and the safety of adenoviral vector mediated gene transfer in vivo. METHODS: After soaking soluble stents in a high concentration of glucose solution containing Adv5-CMV (cytomegalovirus) (control group) or Adv5-CMV/LacZ (treatment group) for 30 minutes, the stents were inserted into the lumina of cut rat carotid arteries and end-to-end anastomoses of the cut carotid were performed with standard microvascular surgical techniques. On days 2, 7, 14, 28, 60 and 90 after gene transfer, anastomotic arteries of the two groups were observed. On days 7 and 14, the ascending aortas, hearts, brains, livers, lungs, spleens and kidneys of the treatment group were observed. All samples were analyzed for the presence of beta-galactosidase activity and histochemical staining. RESULTS: beta-galactosidase activity was not detected in the carotid arteries of the control group and organs not directly exposed to adenoviral vector of the treatment group. The amount of beta-galactosidase activity (x 10(-3) U/g tissue) in the treatment group on the 2nd, 7th, 14th, 28th, 60th and 90th day after gene transfer was 3.87, 11.38, 9.8, 6.43, 3.18 and 2.43, respectively. Microscopic examination of sections from vessels of the control group and from the aortas, hearts, brains, livers, lungs, spleens or kidneys of the treatment group revealed no X-gal staining. Microscopic examination of carotid arteries of the treatment group revealed blue-staining in all anastomotic arteries and in all layers of the arterial wall observed on days 7 and 14 after gene transfer. CONCLUSION: Adenoviral vector can effectively infect blood vessels in vivo. After adenoviral vector mediated direct gene transfer into anastomotic rat carotid arteries, recombinant gene expression began on day 2, peaked between days 7 and 14, prominently declined after day 28, and persisted at low levels more than three months. A recombinant gene could be delivered to a specific site by direct gene transfer in vivo by adenoviral vector infection.

Adenoviridae↗
PubMed2001

[Study on polymorphism of human leukocyte antigen I in patients with endometriosis].

OBJECTIVE: To study the possibility of a correlation between polymorphism of human leukocyte antigen (HLA)-I antigen and occurrence of endometriosis (Em). METHODS: Polymorphism of HLA-I A and B locations were detected by mini-lymphocytotoxin test in 40 surgically proven Em patients and 50 normal controls. The frequency of different antigens on both A and B sites were compared between the 2 groups. RESULTS: No significant difference of the antigen frequency at HLA-I A site was shown between Em and control groups. However, at HLA-I B site, frequency of B46 antigen in Em group was significantly higher [33% Vs 16%, P < 0.05, relative risk (RR) 2.5278] and frequency of B48 antigen in Em group was significantly lower (3% Vs 16% P < 0.05, RR 0.1346) as compared with those of the controls. CONCLUSIONS: The occurrence of Em may be associated with the presence of HLA-I B46 antigen. On the contrary, the HLA-I B48 antigen might play a protective role against Em.

Adult↗
PubMed2001

[Isolation and identification of chemical constituents from Acropora pulchra].

Three compounds, N-1-(hydroxymethyl)-2-hydroxyl-(E,E)-3,7-heptadecadienal-hexadecanamide(1), batyl alcohol(2) and n-cetanol(3) were isolated from the EtOAc portion of the ethanol extract of the hard coral Acropora pulchra collected from north China sea, and their structures were determined by MS, 1HNMR, 13CNMR analysis.

Animals↗
PubMed2001

[Investigation of the polymorphism of HLA-DQCAR microsatellites in the healthy and pulmonary tuberculosis in Hunan Hans].

OBJECTIVE: To observe HLA-DQCAR microsatellite distribution and the association of this gene with pulmonary tuberculosis in Hunan Hans. METHODS: The polymorphism of HLA-DQCAR microsatellite was analyzed by electrophoresis on a 8% denaturing polyacrylamide gel. The length of its alleles was determined by sequencing. RESULTS: Ten alleles, DQCAR101, 103, 105, 107, 111, 113, 115, 117, 119 and 121, were found in 68 Hunan healthy Hans, but the frequencies of them were different. In addition to the above-mentioned alleles, DQCAR 99 and 109, were also found in 79 pulmonary tuberculosis patients in Hunan Hans. This results as well showed that DQCAR115 allele was significantly associated with pulmonary tuberculosis in Hunan Hans (RR = 2.12, Pc < 0.05). CONCLUSIONS: The frequency of DQCAR alleles is of great polymorphism. DQCAR115 is significantly associated with pulmonary tuberculosis in Hunan Hans.

Adolescent↗
PubMed2001

[Pulmonary damage caused by right side infective endocarditis in intravenous drug users].

OBJECTIVE: To highlight the understanding of pulmonary damage caused by right side infective endocarditis (RIE). METHODS: 28 intravenous drug users with pulmonary damage caused by RIE from 1994 to 2000 were reviewed with chest roentgenogram, chest B-ultrasound, blood gas analysis and sputum cultures. RESULTS: 100% (28/28) cases with RIE showed pulmonary damage, in which cough 100% (28/28), expectoration 71% (20/28), breathlessness 64% (18/28), pleuritic chest pain 57% (16/28), hemoptysis 36% (10/28) rales were present in 20 cases (71%) (20/28). By chest X-rays 82% (23/28) patients showed pulmonary infiltrative lesion, 21% (6/28) showed multiple thin wall cystic lesion. manifestations for pulmonary embolism were shown in 6 cases (21%). Pleural effusion was confirmed by chest B-ultrasound in 6 cases (21%). Respiratory failure present in 4 cases (4/28). Positive rate of sputum cultures was 54% (15/28). The prognosis for twenty-three patients (82%) when treated with the regimen of 4 to 6 weeks of parenteral antibiotics was good, Five patients (18%) underwent surgery, and two of them died. CONCLUSION: The pulmonary damage by RIE should be paid more attention to for avoiding misdiagnosis.

Adolescent↗
PubMed2001

[The biological effect of verapamil on hypertrophic scar fibroblast].

OBJECTIVE: To study the mechanism of calcium channel antagonist Verapamil on the treatment of hypertrophic scar and explore the possibility of further clinical application. METHODS: After six strains of HSFB were cultured in vitro, we investigated HSFB proliferation by MTT method, investigated HSFB collagen synthesis by 3H-proline uptaken and Hydroxyproline colorimetric analysis, and investigated collagen gene expression by Northern Blot. RESULTS: Verapamil can inhibit HSFB proliferation, collagen synthesis and gene expression by a dose-depended manner, especially treated with 100 mumol/L Verapamil. CONCLUSION: By inhibiting I, III procollagen gene expression, Verapamil can inhibit the formation of hypertrophic scar.

Adolescent↗
PubMed2001

[Trends of underline diseases of pulmonary embolism from Peking Union Medical College Hospital].

OBJECTIVE: To highlight the understanding of pulmonary embolism(PE), and analyze the trends of underline diseases of PE from Peking Union Medical College(PUMC) Hospital in the last half century. METHODS: 239 cases of PE were reviewed retrospectively from 1950 to 2000 in PUMC Hospital. RESULTS: In the first and second periods (1950-1982, 1983-1990), about 3 cases of PE were diagnosed annually, but in the third (1991-1997) and fourth periods (1998-2000), 8 cases and 20.6 cases of PE were found annually. The incidence of underline diseases of PE, such as deep venous thrombosis (DVT), cardiac disease, malignancy and connective tissue disease varied in different periods. The morbidity of DVT with PE was dramatically enhanced recently. CONCLUSION: There is an increasing trend of incidence of PE in the last half century. DVT events become the most common underline disease or risk factor of PE.

Adolescent↗
PubMed2000

A nucleoprotein complex containing CCAAT/enhancer-binding protein beta interacts with an insulin response sequence in the insulin-like growth factor-binding protein-1 gene and contributes to insulin-regulated gene expression.

Highly related insulin response sequences (IRSs) mediate effects of insulin on the expression of multiple genes in the liver, including insulin-like growth factor binding protein-1 (IGFBP-1) and phosphoenolpyruvate carboxykinase (PEPCK). Gel shift studies reveal that oligonucleotide probes containing an IRS from the IGFBP-1 or PEPCK gene form a similar complex with hepatic nuclear proteins. Unlabeled competitors containing the IGFBP-1 or PEPCK IRS or a binding site for C/EBP proteins inhibit the formation of this complex. Antibody against C/EBPbeta (but not other C/EBP proteins) supershifts this complex, and Western blotting of affinity purified proteins confirms that C/EBPbeta is present in this complex. Studies with affinity purified and recombinant protein indicate that C/EBPbeta does not interact directly with the IRS, but that other factors are required. Gel shift assays and reporter gene studies with constructs containing point mutations within the IRS reveal that the ability to interact with factors required for the formation of this complex correlates well with the ability of insulin to regulate promoter activity via this IRS (r = 0.849, p < 0.01). Replacing the IRS in reporter gene constructs with a C/EBP-binding site (but not an HNF-3/forkhead site or cAMP response element) maintains the effect of insulin on promoter activity. Together, these findings indicate that a nucleoprotein complex containing C/EBPbeta interacts with IRSs from the IGFBP-1 and PEPCK genes in a sequence-specific fashion and may contribute to the ability of insulin to regulate gene expression.

Binding Sites↗
PubMed2000

Insulin suppresses transactivation by CAAT/enhancer-binding proteins beta (C/EBPbeta). Signaling to p300/CREB-binding protein by protein kinase B disrupts interaction with the major activation domain of C/EBPbeta.

CAAT/enhancer-binding proteins (C/EBPs) play an important role in the regulation of gene expression in insulin-responsive tissues. We have found that a complex containing C/EBPbeta interacts with an insulin response sequence in the insulin-like growth factor-binding protein-1 (IGFBP-1) gene and that a C/EBP-binding site can mediate effects of insulin on promoter activity. Here, we examined mechanisms mediating this effect of insulin. The ability of insulin to suppress promoter activity via a C/EBP-binding site is blocked by LY294002, a phosphatidylinositol 3-kinase inhibitor, but not by rapamycin, which blocks activation of p70(S6 kinase). Dominant negative phosphatidylinositol 3-kinase and protein kinase B (PKB) block the effect of insulin, while activated PKB suppresses promoter function via a C/EBP-binding site, mimicking the effect of insulin. Coexpression studies indicate that insulin and PKB suppress transactivation by C/EBPbeta, but not C/EBPalpha, and that N-terminal transactivation domains in C/EBPbeta are required. Studies with Gal4 fusion proteins reveal that insulin and PKB suppress transactivation by the major activation domain in C/EBPbeta (AD II), located between amino acids 31 and 83. Studies with E1A protein indicate that interaction with p300/CBP is required for transactivation by AD II and the effect of insulin and PKB. Based on a consensus sequence, we identified a PKB phosphorylation site (Ser(1834)) within the region of p300/CBP known to bind C/EBPbeta. Mammalian two-hybrid studies indicate that insulin and PKB disrupt interactions between this region of p300 and AD II and that Ser(1834) is critical for this effect. Signaling by PKB and phosphorylation of Ser(1834) may play an important role in modulating interactions between p300/CBP and transcription factors and mediate effects of insulin and related growth factors on gene expression.

Amino Acid Sequence↗
PubMed2000

Regulation of glucose-6-phosphatase gene expression by protein kinase Balpha and the forkhead transcription factor FKHR. Evidence for insulin response unit-dependent and -independent effects of insulin on promoter activity.

Glucose-6-phosphatase plays an important role in the regulation of hepatic glucose production, and insulin suppresses glucose-6-phosphatase gene expression. Recent studies indicate that protein kinase B and Forkhead proteins contribute to insulin-regulated gene expression in the liver. Here, we examined the role of protein kinase B and Forkhead proteins in mediating effects of insulin on glucose-6-phosphatase promoter activity. Transient transfection studies with reporter gene constructs demonstrate that insulin suppresses both basal and dexamethasone/cAMP-induced activity of the glucose-6-phosphatase promoter in H4IIE hepatoma cells. Both effects are partially mimicked by coexpression of protein kinase Balpha. Coexpression of the Forkhead transcription factor FKHR stimulates the glucose-6-phosphatase promoter activity via interaction with an insulin response unit (IRU), and this activation is suppressed by protein kinase B. Coexpression of a mutated form of FKHR that cannot be phosphorylated by protein kinase B abolishes the regulation of the glucose-6-phosphatase promoter by protein kinase B and disrupts the ability of insulin to regulate the glucose-6-phosphatase promoter via the IRU. Mutation of the insulin response unit of the glucose-6-phosphatase promoter also prevents the regulation of promoter activity by FKHR and protein kinase B but only partially impairs the ability of insulin to suppress both basal and dexamethasone/cAMP-stimulated promoter function. Taken together, these results indicate that signaling by protein kinase B to Forkhead proteins can account for the ability of insulin to regulate glucose-6-phosphatase promoter activity via the IRU and that other mechanisms that are independent of the IRU, protein kinase B, and Forkhead proteins also are important in mediating effects of in insulin on glucose-6-phosphatase gene expression.

Animals↗
PubMed2000

A regulator of transcriptional elongation controls vertebrate neuronal development.

The development of distinct vertebrate neurons is defined by the unique profiles of genes that neurons express. It is accepted that neural genes are regulated at the point of transcription initiation, but the role of messenger RNA elongation in neural gene regulation has not been examined. Here we describe the mutant foggy, identified in a genetic screen for mutations that affect neuronal development in zebrafish, that displayed a reduction of dopamine-containing neurons and a corresponding surplus of serotonin-containing neurons in the hypothalamus. Positional cloning disclosed that Foggy is a brain-enriched nuclear protein that is structurally related to the transcription elongation factor Spt5 (refs 5-12). Foggy is not part of the basic transcription apparatus but a phosphorylation-dependent, dual regulator of transcription elongation. The mutation disrupts its repressive but not its stimulatory activity. Our results provide molecular, genetic and biochemical evidence that negative regulators of transcription elongation control key aspects of neuronal development.

Amino Acid Sequence↗
PubMed2000

Comparison of three treatment options for single brain metastasis from lung cancer.

Whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and the combination of both treatment methods were used for the management of single brain metastasis from lung cancer. The purpose of this study is to compare these three different treatment options in terms of local response, survival, and quality of life. From June 1995 to July 1998, 70 lung cancer patients with new diagnosed single brain metastasis were treated with either WBRT alone (n = 29), or SRS alone (n = 23), or the combination of both methods (n = 18). Multiple endpoints, including survival, freedom from local progression (FFLP), freedom from new brain metastasis (FFNBM), local control, Karnofsky performance status (KPS), and causes of death, were measured from the date of treatment completion and compared using univariate and multivariate analyses. For patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, the median survivals were 5.7, 9.3, and 10.6 months, the median FFLP were 4.0, 6.9, and 8.6 months, the median FFNBM were 4.1, 6.7, and 8.6 months, and the local response rates were 55.6, 87.0, and 88.9%, respectively. Four of the 29 patients treated with WBRT-alone continued with progression of disease. The post treatment KPS showed improvement in 41.4, 82.6, and 88.9% of patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. The progression of new and/or recurred metastatic brain tumor as the cause of death accounted for 51.7%, 50. 0%, and 28.3% of the patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. Univariate analyses showed that the significant differences among the three treatment arms were observed based on all of the above mentioned endpoints. However, the comparison between SRS-alone and SRS+WBRT groups indicated that adding WBRT only improves FFNBM (P = 0.0392). Cox regression analyses revealed no significant difference in both of the KPS (P = 0.1082) and causes of death (P = 0.081) among the three arms. Both SRS alone and SRS+WBRT seem better in prolonging life and improving quality of life than WBRT alone for patients with single brain metastasis from lung cancer. But the combined therapy did not show significant advantage over SRS alone in improving survival, enhancing local control, and quality of life except for a more favorable FFNBM. Further investigation via a randomized trial is needed to access the value of adding WBRT to SRS in the management of this group of patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 37-45 (2000).

Adult↗
PubMed2000

Phosphatidylinositol 4,5-bisphosphate functions as a second messenger that regulates cytoskeleton-plasma membrane adhesion.

Binding interactions between the plasma membrane and the cytoskeleton define cell functions such as cell shape, formation of cell processes, cell movement, and endocytosis. Here we use optical tweezers tether force measurements and show that plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) acts as a second messenger that regulates the adhesion energy between the cytoskeleton and the plasma membrane. Receptor stimuli that hydrolyze PIP2 lowered adhesion energy, a process that could be mimicked by expressing PH domains that sequester PIP2 or by targeting a 5'-PIP2-phosphatase to the plasma membrane to selectively lower plasma membrane PIP2 concentration. Our study suggests that plasma membrane PIP2 controls dynamic membrane functions and cell shape by locally increasing and decreasing the adhesion between the actin-based cortical cytoskeleton and the plasma membrane.

3T3 Cells↗
PubMed2000

Pregnant adolescent and adult women have similarly low intakes of selected nutrients.

OBJECTIVE: To examine the dietary intake of pregnant adolescents during the second and third trimester of pregnancy, and to compare their nutrient intake with that of pregnant adults. DESIGN: Two 7-day food records (14 days) from subjects participating in a larger randomized clinical calcium trial: the first at 19 to 21 weeks and the second between 29 and 31 weeks gestation. Intake of energy and selected nutrients were calculated and compared with dietary standards. SUBJECTS/SETTING: Fifty-nine pregnant adolescents and 97 pregnant adults recruited from prenatal clinics at a metropolitan university hospital. STATISTICAL ANALYSES: Two sample t tests, equality of variances, and repeated measures (analysis of variance). RESULTS: There was no difference in mean nutrient intakes between the second and third trimesters. Using two 7-day food records, we found mean intakes for energy, iron, zinc, calcium, magnesium, folate, and vitamins D and E to be below recommended standards in both groups. Other nutrients examined met or exceeded reference values. Total daily intakes for energy and 11 nutrients were significantly higher in the adolescent compared to the adult diets (P < .05). These differences were not evident when nutrient values were corrected for energy, indicating that increased energy intake in the teen-aged population was contributed by nutrient-dense foods. APPLICATIONS: This study indicates the need for continued dietary monitoring of pregnant adolescents and pregnant adults, including nutrition guidance that stresses food sources of calcium, magnesium, zinc, iron, fiber, folate, and vitamins D and E, the nutrients found deficient in their diets.

Adolescent↗