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Biomedical subjects

S Guo

Publications and source records attributed to S Guo.

At least 109 records · Page 6Linked to original sources
PubMed1999

A study of platelet organelles and membrane glycoprotein in patients with Binswanger's disease.

OBJECTIVE: To discuss the possible role of platelets in Binswanger's disease by studying the changes of organelles and membrane glycoprotein in platelets. METHODS: The organelles (dense bodies, alpha granules, and mitochondria) within platelets were measured with transmission electron microscopy in 25 patients with Binswanger's disease and matched controls, while alpha granule membrane glycoprotein CD62 and lysosomal integral membrane glycoprotein CD63 on platelet membrane were analyzed by flow cytometry. RESULTS: The percentage of CD62-positive platelets was 3.6% +/- 2.1% and 5.7% +/- 2.4% in controls and in patients, respectively (P < 0.01). The percentage of CD63 expression platelets was 3.1% +/- 2.2% and 3.2% +/- 2.3% in controls and patients, respectively (P > 0.05). When compared with controls, platelets of patients contained fewer alpha granules (P < 0.01), and had no changes in dense bodies and mitochondria (P > 0.05). CD62 levels were different among patients with regarding to the degree of white matter low attenuation. CONCLUSION: There is selective degranuation of platelets in patients with Binswanger's disease and the abnormalities of platelet secretion may play a role in the pathophysiology of this illness.

Aged↗
PubMed1999

Cultural and personal behavioral factors and women's reproductive tract infections.

OBJECTIVE: To review the relationship between personal behavior and cultural factors and reproductive tract infections (RTIs). METHODS: An English-language literature search using MEDLINE (1994-1998), Social Science Index (1994-1998), and informal discovery. Any original researches and reviews related to RTIs' epidemiology, behavior and culture were selected. RESULTS: RTIs have become a silent epidemic that is devastating women's lives each year. CONCLUSION: The influencing factors include sexual behavior, health related behavior (preventive health behavior, health-seeking behavior, reproductive behavior etc.) and culture, belief, etc. A holistic point of view should be taken.

Bacterial Infections↗
PubMed1999

[Alterations of cell apoptosis and proliferation during transformation of a human bronchial epithelial cell line].

OBJECTIVE: To investigate the alterations of cell apoptosis and proliferation and its mechanism during transformation of a human bronchial epithelial cell line Y. METHODS: Terminal deoxyribonucleotidyl transferase in situ labelling, BrdU incorporation, Western blotting and fluorescence in situ hybridization were used in the study. RESULTS: During serial passages of the immortalized human bronchial epithelial cell line Y, some phenotypic alterations, such as higher colony forming efficiency in soft agar, resistance to serum-induced differentiation and low dependence on EGF were observed. The increase in cell proliferation and decrease in cisplatinum-induced apoptosis and the enhanced protein expression of Bcl-2, MDM2, PCNA and Cyclin D1 were found in the late passages of the cell line. The chromosomes of Y cells were diploid at the early passages, but became aneuploid in the late passages. CONCLUSION: In addition to the increase in cell proliferation, inhibition of apoptosis might also contribute to the cytogenetic abnormality and the transformation of human bronchial epithelial cells.

Apoptosis↗
PubMed1999

[Analysis of patients survived over ten years after resection of gastric cardia carcinoma].

OBJECTIVE: To investigate factors affecting long-term survival in patients with resected gastric cardia cancer. METHODS: Survival was analyzed retrospectively in 584 patients with gastric cardia carcinoma who received tumor resection from 1964 through 1982. RESULTS: The 10-year survival rate was 17.1%. The major factors influencing survival were clinical staging, degree of differentiation, gross tumor type and size (P < 0.05) and status of lymph node metatasis (P < 0.01). Residual tumor at resection edge and tumor thrombi did not significantly affect survival, nor did sex/age, and course of the disease. CONCLUSION: Early detection, early diagnosis and early surgical resection are the key to improve 10-year survival of patients with resected cancer of the gastric cardia. Why residual tumor left at the resection edge and the presence of tumor thrombi do not influence survival needs to be further studied.

Adult↗
PubMed1999

[Clinical study on jinmaitong composita on diabetic peripheral neuropathy].

OBJECTIVE: To verify the effect of Jinmaitong composita (JMTC) on red blood cell aldolase reductase activity (RBC-AR), RBC sorbitol (RBC-S) and nerve conductive velocity in diabetic peripheral neuropathy (DN). METHODS: Sixty-six patients with DN were divided randomly into two groups, 33 patients in treated group treated with JMTC and 33 cases in the control group treated with Jinkui Shenqi (JKSQ), RBC-AR, RBC-S and nerve transmission speed were observed before and after three months treatment. RESULTS: Level of RBC-AR, RBC-S apparently decreased and nerve conductive velocity increased (P < 0.05, P < 0.01) after TMTC treatment. CONCLUSION: JMTC was able to improve the nerve conduction significantly with a lowering of RBC-AR and RBC-S and has good result in treating Diabetic peripheral neurophathy.

Aged↗
PubMed1999

[Safety of direct gene transfer into rat carotid arteries mediated by adenoviral vector].

OBJECTIVE: To evaluate the safety of direct gene transfer into rat carotid arteries mediated by adenoviral vector. METHODS: After being soaked in high concentration of glucose solution containing Adv5-CMV (control group) or Adv5-CMV/LacZ (treatment group) for 30 minutes, soluble stents were inserted into the lumina of rat carotid arteries and end-to-end anastomoses of cut rat carotid were performed with standard microvascular surgical technique. On the 7th day after surgery, anastomotic carotid arteries of the two groups were obtained, and samples of ascending aortas, hearts, brains, livers, lungs, spleens and kidneys of the treatment group were taken for assessing beta-galactosidase activity and histochemical staining. RESULTS: Beta-galactosidase activity was not detected in the carotid arteries in the control group and in those organs not directly exposed to adenoviral vector in the treatment group. The amount of beta-galactosidase expression in the carotid arteries in the treatment group was 10.1 x 10(-3) IU/g tissue. Microscopic examination of sections from vessels in the control group and from the aorta, heart, brain, liver, lung, spleen or kidney in the treatment group revealed no X-gal staining. Microscopic examination of the carotid arteries in the treatment group revealed blue-staining in all anastomotic arteries and in all layers of the arterial wall, including the intima, media, and adventitia. CONCLUSIONS: A recombinant gene could be safely delivered to a local site of the vessel by means of infection with adenoviral vector.

Adenoviridae↗
PubMed1999

[A study on homozygous deletion, hypermethylation, mutation and expression of p16 gene in human breast cancer].

OBJECTIVE: To investigate the homozygous deletion (HZD), hypermethylation and mutation of p16 gene in human breast cancer and the relationship between the structural alterations of p16 gene and its expression. METHODS: PCR and PCR-methylation assay with silver staining (PCR-MASS) were used to detect HZD and hypermethylation of p16 gene exon 1 in 60 fresh breast cancers and 24 normal breast tissues adjacent to cancer (as control tissues). PCR-SSCP and DNA sequencing were used for the analysis of p16 gene mutation. Moreover, p16 gene and mRNA were also detected in the 60 cases. RESULTS: Of the 60 breast cancers, HZD was found in 7 cases, hypermethylation and mutation were found in 16 and 4 cases respectively, and the difference was statistically significant. The positive rates of p16 protein and mRNA in breast cancer were 28/60 and 39/60 respectively. CONCLUSION: The results demonstrate that several kinds of p16 gene structural changes exist in breast cancer. The structural changes of p16 gene cause abnormal p16 expression, the main mechanisms are hypermethylation, while HZD or mutation are the secondary causes. Abnormal expression of p16 gene then becomes involved in the development and metastasis of breast cancer.

Breast Neoplasms↗
PubMed1999

[Molecular typing of staphylococcus aureus with randomly amplified polymorphic DNA].

The randomly amplified polymorphic DNA(RAPD) was used to type the 26 clinically isolated strains of staphylococcus aureus. The results were that all three primers of this method, ERIC-2, Ap1, and Ap7 on molecular typing of staphylococcus aureus and identified 9, 6, and 10 genotypes, respectively; the primer Ap7 produced better results than the other primers. The present study suggests that RAPD is a simple and rapid method and has a practical value in the molecular typing of staphylococcus aureus.

Polymerase Chain Reaction↗
PubMed1999

[Effect of hydrogen peroxide on expression of interleukin-2 gene in mouse splenocytes].

The effect of hydrogen peroxide on interleukin-2(IL-2) production and IL-2 mRNA expression in mouse splenocytes was detected by cellular immunological and molecular biological methods. The results were that the level of IL-2 activity was significantly elevated in 10(-4) mol.L-1 of H2O2 as compared with the control group (P < 0.01), was obviously inhibited in 10(-3)-10(-2) mol.L-1 of H2O2(P < 0.01), and had no effect in 10(-8)-10(-5) mol.L-1 of H2O2. The results of dot blotting were that 10(-4) mol.L-1 of H2O2 enhanced IL-2 mRNA expression, while 10(-3) mol.L-1 inhibited it, and 10(-5) mol.L-1 had no effect in mouse splenocytes. These results suggest that the effect of H2O2 on IL-2 production may be mediated by regulating IL-2 mRNA expression in mouse splenocytes.

Animals↗
PubMed1999

[Effect of gui xin tong on sorbitol and nerve conduction velocity in diabetic rats].

OBJECTIVE: To investigate the effect of Gui Xin Tong(GXT) on sorbitol and nerve conduction velocity in diabetic rats. METHOD: The model rats suffering from diabetes were induced by STZ, and blood sugar levels above 16 mmol/L were chosen for observation. The rats were divided into GXT group, AG group and control group. The nerve conduction velocity, aldose reductase activity and sorbitol in STZ induced diabetic rats were investigated. RESULT: Compared with the control group GXT could increase the sciatic nerve conduction velocity significantly (P < 0.05), decrease the RBC and sciatic nerve, aldose reductase activity, and RBC-sorbitol content. CONCLUSION: GXT has the effect of improving nerve conduction velocity significantly and reducing aldose reductase activity and sorbitol

Aldehyde Reductase↗
PubMed1999

[Studies on the plant hormones produced by 5 species of endophytic fungi isolated from medicinal plants (Orchidacea)].

OBJECTIVE: To study the plant hormones produced by 5 species of endophytic fungi isolated from medicinal plants and to illustrate the mechanism on endophytic fungi stimulating the growth of plants. METHODS: Extracting plant hormones from mycelia and its culture solution with organic solvent, and detecting them by HPLC. RESULTS: One or more plant hormones [GA3 (Gibberellin), IAA (Indoleacetic acid), ABA (Abscisic acid), Z (Zeatin), ZR (Zeatin riboside)] were detected from the mycelia and its culture solution. CONCLUSIONS: The plant hormones produced by the endophytic fungi are important materials that may be used to reveal the mechanism of endophytic fungi stimulating the growth of medicinal plants (Orchidacea).

Abscisic Acid↗
PubMed1999

[The method of wavelet transformation used for extracting the characteristic of the exercise ECG].

This article introduces the basic rationale of wavelet transformation and the algorithm of typical dyadic wavelet transformation with mother wavelet of the first derivative of a Gaussian smoothing function, this wavelet transformation is used to recognize the characteristic parameters of the exercise ECG, it is concluded that this method make significant effects on restricting base line drifting and lessening noisy component in the exercise ECG, it provides a new way to do further research on characteristic recognition of the exercise ECG in the exercise test.

Algorithms↗
PubMed1999

[Gas-sensing transmittivity spectrum of two-dimension SnO2: TiO2 compound film in ammonia vapor].

In this paper, we studied the gas-sensing transmittivity spectrum of the two-dimension SnO2: TiO2 compound film in ammonia vapor. It was observed that when the gas concentration was relatively low the transmittivity decreased as the gas concentration decreased, and when the gas concentration was relatively high, the transmittivity increased as the gas concentration increased. We considered the effect of the wet vapor, and explained this phenomenon.

English Abstract↗
PubMed1998

Functional assignment by Chimera construction of the domain affecting heterotropic activation of deoxyadenosine kinase from Lactobacillus acidophilus R-26.

The heterodimeric subunits of deoxyadenosine kinase (dAK)-deoxyguanosine kinase (dGK) from Lactobacillus acidophilus R-26 exhibit contrasting conformations manifested in the nearly unidirectional heterotropic activation of dAK when dGK binds deoxyguanosine. This is mediated, in part, by the conserved Ras switch I-like sequence (residues 153-161) [Guo et al. (1997) J. Biol. Chem. 272, 6890-6897]. In an attempt to identify domains differentiating the specificities of dAK and dGK, we constructed several chimeras splicing heterodimeric dAK within this region. In Chimera-III, dAK residues 120-170 were replaced by the homologous section of dGK. dAK activity was elevated 40%, but although it retained its original specificity and Km values, it could no longer be activated by deoxyguanosine. Moreover, both the activated dAK and the "dAK" of Chimera-III exhibited (i) an increased Ks for the leading substrate ATP-Mg2+, suggesting the formation of intermediate enzyme species along their respective kinetic pathways, and (ii) broadened and lower pH optima for the dAK activities. These observations further indicate the importance of dAK residues 120-170, including the Ras-like segment, in catalysis and heterotropic activation. The other conformational properties of dAK (e.g. self-inactivity and MgATP being the leading substrate) were unaltered by this substitution, thus localizing the responsible domains even further upstream.

Adenosine Triphosphate↗
PubMed1998

Role of endogenous interferon-gamma on the enhancement of splenic NK cell activity by electroacupuncture stimulation in mice.

Successive electro-acupuncture (EA) stimulation applied to bilateral anterior tibial muscles, where Zusanli (ST36) acupoints are located, once a day (30 min) for 3 successive days significantly enhanced splenic natural killer (NK) cell activity in BALB/c mice. The percentage of splenic NK cells, as measured by flow cytometry, was not affected in these mice. Interferon (IFN)-gamma level in splenic aqueous extract, prepared from the ST36 acupoint-stimulated mice, was significantly higher than that of the controls. In vivo treatment with neutralizing monoclonal antibody against mouse IFN-gamma completely abrogated the increase in splenic NK cell activity induced by ST36 acupoint stimulation. The same stimulation also significantly increased the concentration of splenic beta-endorphin, which coincided with the significant increase in splenic IFN-gamma production. Pre-administration of 10 mg/kg naloxone before initiation of EA stimulation every day reduced the enhancements of NK cell activity and IFN-gamma level. These observations strongly suggest that endogenous IFN-gamma mediates the up-regulation of NK cell activity by EA stimulation at the ST36 acupoints. Furthermore, endogenous beta-endorphin secreted by EA stimulation also plays an important role in the up-regulation of NK cell function, which may be realized through regulating IFN-gamma production.

Animals↗
PubMed1998

Protein kinase B/Akt mediates effects of insulin on hepatic insulin-like growth factor-binding protein-1 gene expression through a conserved insulin response sequence.

Insulin regulates the expression of multiple hepatic genes through a conserved insulin response sequence (IRS) (CAAAAC/TAA) by an as yet undetermined mechanism. Protein kinase B/Akt (PKB/Akt), a member of the PKA/PKC serine/threonine kinase family, functions downstream from phosphatidylinositol 3'-kinase (PI3K) in mediating effects of insulin on glucose transport and glycogen synthesis. We asked whether PKB/Akt mediates sequence-specific effects of insulin on hepatic gene expression using the model of the insulin-like growth factor binding protein-1 (IGFBP-1) promoter. Insulin lowers IGFBP-1 mRNA levels, inhibits IGFBP-1 promoter activity, and activates PKB/Akt in HepG2 hepatoma cells through a PI3K-dependent, rapamycin-insensitive mechanism. Constitutively active PI3K and PKB/Akt are each sufficient to mediate effects of insulin on the IGFBP-1 promoter in a nonadditive fashion. Dominant negative K179 PKB/Akt disrupts the ability of insulin and PI3K to activate PKB/Akt and to inhibit promoter activity. The IGFBP-1 promoter contains two IRSs each of which is sufficient to mediate sequence-specific effects of insulin, PI3K, and PKB/Akt on promoter activity. Highly related IRSs from the phosphoenolpyruvate carboxykinase and apolipoprotein CIII genes also are effective in this setting. These results indicate that PKB/Akt functions downstream from PI3K in mediating sequence-specific effects of insulin on the expression of IGFBP-1 and perhaps multiple hepatic genes through a conserved IRS.

Base Sequence↗
PubMed1998

Electrophoretic affinity chromatography: method validation.

A new method for preparative-scale separation of biomolecules, electrophoretic affinity chromatography (EAC), is proposed in this paper. Separation by EAC is carried out in a long and ribbon-like multicompartment electrolyser separated by membranes, in which the two central compartments are used for packing the gel matrix and for sample loading respectively. Next to the central compartments are the elution compartments and electrode compartments. The electric field is applied perpendicular to the fluid flow in the compartments. Adsorption and desorption steps may both be carried out in the presence of an electric field, which transports the target components into the gel compartment for adsorption and the impurities into the elution compartments for washing. After the adsorption step an elution solution is introduced and the product is released from the gel matrix and washed out. Separation of human serum albumin (HSA) from human serum gives HSA product of high purity, as demonstrated by isoelectric focusing analysis. The characteristics of electrophoretic binding of HSA on Blue Sepharose Fast Flow are examined. The preliminary results show that this new method has advantages in terms of high rate of mass transfer and ease of scaling up, which are of particular interest when large-scale separation of biomolecules is considered.

Adsorption↗