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Jian Guo

Publications and source records attributed to Jian Guo.

At least 19 recordsLinked to original sources
PubMed2006

Heat treatment induces liver receptor homolog-1 expression in monkey and rat sertoli cells.

We demonstrated in this study that liver receptor homolog-1 (LRH-1) was expressed in the round spermatids in normal monkey testis, and no LRH-1 signal was observed in the Sertoli cells. After local warming (43 C) the monkey testis, however, LRH-1 expression was induced in the Sertoli cells in coincidence with activation of cytokeratin 18 (CK-18), a Sertoli cell dedifferentiated marker. Furthermore, we isolated rat primary Sertoli cells from testes at various stages of development and treated with 43 C water in vitro. The changes in LRH-1 as well as CK-18 expression were analyzed by confocal immunohistochemistry and Western blot. The results showed that LRH-1 was stage-dependently expressed in the Sertoli cells; no LRH-1-positive signal was detected in the cells obtained from the testes of adult rat on d 60 after birth when mature spermatozoa in the testis was completed. However, the mature Sertoli cells were warmed at the 43 C water bath for 15 min, and the LRH-1 signal was remarkably induced in a time-dependent manner, just like the changes of CK-18 expression in the Sertoli cells, suggesting that the heat-induced dedifferentiation of the mature Sertoli cells might be related to LRH-1 regulation. LRH-1 expression induced by the heat treatment was completely inhibited by the addition of ERK inhibitor U0126 in the culture, indicating that the heat-induced LRH-1 expression in the Sertoli cells may be regulated via ERK1/2 activation pathway. Testosterone was found to have no such effect on LRH-1 expression in the monkey and rat Sertoli cells.

Animals↗
PubMed2006

Efficient destruction of pathogenic bacteria with NiO/SrBi2O4 under visible light irradiation.

The photocatalytic inactivation of pathogenic bacteria in water was investigated systematically with NiO/SrBi2O4 under visible light (lambda > 420 nm) irradiation. The catalyst was found to be highly effective in killing Escherichia coli, a Gram-negative bacterium, and Staphylococcus aureus, a Gram-positive bacterium. ESR studies revealed that *OH and O2*- were involved as the active species in the photocatalytic reaction. The decomposition process of the cell wall and the cell membrane was directly observed byTEM and further confirmed by the determination of potassium ion (K+) leakage from the killed bacteria. A possible cell damage mechanism by visible-light-driven NiO/SrBi2O4 is proposed. In addition, the effects of pH, methanol, and inorganic ions on bacterial photocatalytic inactivation were investigated. These results indicated that the electrostatic force interaction of bacteria-catalyst is crucial for high bactericidal efficiency.

Bismuth↗
PubMed2006

An oligonucleotide microarray study on gene expression profile in mouse testis of experimental cryptorchidism.

To investigate the germ cell apoptosis under body temperature in testis, we analyzed the gene expression patterns on day 1, day 4, day 7, day 14, day 28 and normal control adult mouse testis after experimental cryptorchidism (EC) using Affymetrix MOE430A microarray. Our data showed that EC led to the oxidative stress and gene expression fluctuation in the first 28 days, both of which were highly coincident in timing. Cryptorchid testis showed more effective antioxidative capability in the first 4 days, and suddenly lowered the capability from day 5 on, then gradually restored the antioxidation from day 10 to day 14, and turned to worse on day 28 again. The extensive high gene expression on day 4 after EC and the up-rising of oxidative stress level on day 5 and the abrupt down-regulation of the gene on day 7 were closely related. From the chip data, we have found that the high level of reactive oxidative species (ROS) was not only related to the dysfunction or abnormality of the direct origin of ROS generation, but also related to the abnormality of the more upstream physiological events in energy metabolism, lipid metabolism. The selective regulation of metabolic substrate transporter in different cell population implied the existence of various regulation of the selective signal pathways among different cell populations by EC.

Animals↗
PubMed2006

TSSub: eukaryotic protein subcellular localization by extracting features from profiles.

UNLABELLED: This paper introduces a new subcellular localization system (TSSub) for eukaryotic proteins. This system extracts features from both profiles and amino acid sequences. Four different features are extracted from profiles by four probabilistic neural network (PNN) classifiers, respectively (the amino acid composition from whole profiles; the amino acid composition from the N-terminus of profiles; the dipeptide composition from whole profiles and the amino acid composition from fragments of profiles). In addition, a support vector machine (SVM) classifier is added to implement the residue-couple feature extracted from amino acid sequences. The results from the five classifiers are fused by an additional SVM classifier. The overall accuracies of this TSSub reach 93.0 and 77.4% on Reinhardt and Hubbard's eukaryotic protein dataset and Huang and Li's eukaryotic protein dataset, respectively. The comparison with existing methods results shows TSSub provides better prediction performance than existing methods. AVAILABILITY: The web server is available from http://166.111.24.5/webtools/TSSub/index.html.

Algorithms↗
PubMed2006

Afaf, a novel vesicle membrane protein, is related to acrosome formation in murine testis.

As a cell-specific organelle, acrosome (Acr) and its formation are an important event for spermiogenesis. However, the Acr formation is far more complicated than has been proposed. In this study, we have cloned a novel membrane protein Afaf (Acr formation associated factor) that was expressed abundantly in the round spermatids, localized in the inner and outer membrane of forming Acrs, and declined in the maturing Acrs. In the transfected Hela cells, Afaf protein was localized in the plasma membrane, EEA1-positive early endosomes (EEs) and occasionally in the nuclei. Therefore, we propose that EEs and plasma membrane may be also directly involved in the Acr biogenesis.

3T3 Cells↗
PubMed2006

Identification of human hepatic cytochrome P450 enzymes involved in the metabolism of 8-prenylnaringenin and isoxanthohumol from hops (Humulus lupulus L.).

The female flowers of hops (Humulus lupulus L.) are used in the brewing of beer and are under investigation for use in dietary supplements for the management of menopausal symptoms in women. Hop extracts contain the weakly estrogenic compound isoxanthohumol (IX), proestrogenic xanthohumol, and the potent estrogen 8-prenylnaringenin (8PN). Because IX can be metabolized in the human liver to form 8PN, the specific cytochrome P450 (P450) enzymes responsible for this O-demethylation reaction were identified. In addition, the enzymes that convert IX and 8PN to their most abundant metabolites were identified because these metabolic pathways might also affect the estrogenicity of hop preparations. Specifically, the P450 enzymes that catalyze the oxidation of the prenyl side chains of IX and 8PN into trans- or cis-alcohols were investigated. Human liver microsomes and monoclonal antibodies that inhibit specific P450 enzymes were used in combination with liquid chromatography/mass spectrometry to identify the enzymes responsible for these transformations. CYP2C19 was found to catalyze the formation of both cis- and trans-alcohols of the prenyl side chain of 8PN with K(m) values of 14.8 +/- 3.2 and 16.6 +/- 4.6 microM, respectively. CYP2C8 converted 8PN regioselectively to the trans-alcohol of the prenyl group with a K(m) of 3.7 +/- 0.9 microM. Finally, CYP1A2 was found to catalyze the O-demethylation of IX to generate 8PN, with a K(m) value of 17.8 +/- 3.7 microM. These results suggest that the estrogenicity of hop constituents in vivo will depend in part on metabolic conversion that may show individual variation.

Antibodies, Monoclonal↗
PubMed2006

Cyclic adenosine 3',5'-monophosphate induces differentiation of mouse embryonic stem cells into cardiomyocytes.

Embryonic stem (ES) cells, derived from blastocyst-stage of early mammalian embryos, have the potential to differentiate into derivatives of all three embryonic germ layers. Here we reported the first evidence that murine pluripotent ES cells could be induced to differentiate into cardiomyocytes by cyclic adenosine 3',5'-monophosphate (cAMP) in vitro. Spontaneously beating of cardiac cell clusters began to be observed within the outgrowths of embryoid bodies (EBs) as early as 2 days after the onset of differentiation. By days 5-8 after induction, a maximum level of cardiomyocyte differentiation could be achieved. Incubation of EBs with cAMP at concentrations ranging from 0.01 mg/L to 1 mg/L resulted in a significant elevation in differentiation rate, reaching a maximum value of 44.0 +/- 1.3% at 0.03 mg/L of exposure. At 0.03 mg/L concentration point, an approximately 8.1-fold increase in cardiomyocyte differentiation was observed in comparison with 5.4 +/- 0.9% of untreated controls. The differentiation rate induced by cAMP was shown to be similar to that of RA/DMSO treated controls, indicating that cAMP has the same inducing effect as RA/DMSO. However, no significant co-inducing effects between cAMP and RA/DMSO were seen. Cardiomyocytes were evident as they expressed cardiac cell specific genes and protein markers including GATA4, Nkx2.5, beta-MHC, atrial natriuretic factor (ANF) and alpha-actin when analyzed by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical staining. The results from the present study suggested a novel role of cAMP in cardiomyocyte differentiation and provided a new research model for the study of cardiac cell biology.

Animals↗
PubMed2006

[An integral approach for cyanotic congenital heart disease with major aortopulmonary collateral arteries].

OBJECTIVE: To demonstrate the feasibility of combined collateral embolization with surgical repair for tetralogy of Fallot or pulmonary atresia with major aorta pulmonary collateral arteries. METHODS: The clinical, catheterization and surgical data of 15 such patients from November 1992 to September 2003 were analyzed retrospectively. RESULTS: All 15 patients underwent combined therapy of major-aorto pulmonary collateral arteries (MAPCAs) occlusion and complete repair with a mortality of 26.7%. Of the 46 collateral arteries, 35 were occluded with a successful rate of 90.6%. Embolization was performed before corrective surgery in 12 patients. The causes of early death in three patients were low cardiac output syndrome, pulmonary hemorrhage, and pulmonary infarction respectively. Complications included extensive pulmonary infiltration in 1 patient and right ventricular dysfunction in another patient. The other 7 patients recovered smoothly with the arterial oxygen saturation greater than 97% at discharge. Embolization was performed after corrective surgery in 3 patients with postoperative congestive heart failure. One patient died of congestive heart failure. The symptoms and signs of heart failure was significently relieved in the other two cases. CONCLUSIONS: In selective group of patients with dual pulmonary blood supply by both MAPCA and native pulmonary arteries, this combined therapy of collateral embolization and surgical repair simplifies complete surgical operation and enhances surgical results. It is necessary to minimize the error in distinguish sole pulmonary blood supply from dual pulmonary blood supply to avoid postoperative pulmonary infarction. Embolization after surgical correction is an important rescue measurement to congestive heart failure.

Adolescent↗
PubMed2006

GNBSL: a new integrative system to predict the subcellular location for Gram-negative bacteria proteins.

This paper proposes a new integrative system (GNBSL--Gram-negative bacteria subcellular localization) for subcellular localization specifized on the Gram-negative bacteria proteins. First, the system generates a position-specific frequency matrix (PSFM) and a position-specific scoring matrix (PSSM) for each protein sequence by searching the Swiss-Prot database. Then different features are extracted by four modules from the PSFM and the PSSM. The features include whole-sequence amino acid composition, N- and C-terminus amino acid composition, dipeptide composition, and segment composition. Four probabilistic neural network (PNN) classifiers are used to classify these modules. To further improve the performance, two modules trained by support vector machine (SVM) are added in this system. One module extracts the residue-couple distribution from the amino acid sequence and the other module applies a pairwise profile alignment kernel to measure the local similarity between every two sequences. Finally, an additional SVM is used to fuse the outputs from the six modules. Test on a benchmark dataset shows that the overall success rate of GNBSL is higher than those of PSORT-B, CELLO, and PSLpred. A web server GNBSL can be visited from http://166.111.24.5/webtools/GNBSL/index.htm.

Amino Acid Sequence↗
PubMed2006

Quantitative analyses of beta-carotene and retinol in serum and feces in support of clinical bioavailability studies.

Among more than 50 provitamin carotenoids, beta-carotene is the most metabolically active source of retinol. Despite diets rich in fruits and vegetables containing beta-carotene, vitamin A deficiency is the leading cause of blindness and childhood mortality in developing countries. In addition, the uncertainty of beta-carotene bioconversion into vitamin A suggests that new data are needed to update the nutritional guidelines in developed countries. Previously, we reported the development of a carotene/retinol plateau isotopic enrichment method (CarRet PIE) for the determination of beta-carotene bioavailability and bioconversion into retinol, which utilizes positive ion atmospheric pressure chemical ionization (APCI) liquid chromatography/mass spectrometry (LC/MS). While seeking to validate the CarRet PIE using a mass balance approach requiring fecal measurements of beta-carotene and retinol, interference was encountered that required substantial modifications of the LC/MS assay. Here we report a new LC/MS assay that is based on the detection of molecular anions of beta-carotene using negative ion APCI with a reversed-phase C30 column for HPLC separation. Sample preparation required saponification to eliminate interfering triglycerides. The limit of detection (LOD) of beta-carotene was 0.25 pmol calculated on the basis of an injection of 20 microL of 0.0125 microM beta-carotene, and the limit of quantitation (LOQ) was 1.0 pmol based on the injection of 20 microL of 0.050 microM beta-carotene. The linear range was 1.1 to 2179 pmol on-column. The wide linear range and low LOD and LOQ of this assay facilitated the sensitive and selective quantitative analysis of beta-carotene in both serum and fecal samples in support of an on-going clinical investigation of beta-carotene bioavailability and bioconversion into vitamin A.

Biological Availability↗
PubMed2006

[An investigation on AIDS knowledge of Chinese peacekeepers in Liberia and effects of relevant health education].

OBJECTIVE: To investigate and analyze AIDS knowledge of the Chinese peacekeepers in Liberia and to evaluate the effects of AIDS education in order to conduct more effective health education of AIDS and increase AIDS knowledge among the Chinese peacekeepers in the areas with a high incidence of AIDS. METHODS: A questionnaire was designed on the basis of that recommended by WHO to investigate the knowledge of AIDS among the 528 Chinese peacekeepers in Liberia respectively before and after relevant health education, and the results were compared. RESULTS: There was an obvious deficiency in AIDS knowledge among the subjects before the education and an evident increase after it, and the difference was significant (P <0.01). CONCLUSION: The Chinese peacekeepers are deficient in AIDS knowledge, and the deficiency can be effectively improved by relevant health education, which is essential for the health of the Chinese peacekeepers in the areas with a high incidence of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed2006

The differential expression of SPARC in esophageal squamous cell carcinoma.

Secreted protein, acidic and rich in cysteine (SPARC) is a matricellular protein that modulates cell adhesion and growth. The aim of this study was to assess the prevalence of SPARC mRNA and protein expression in esophageal squamous cell carcinoma (ESCC) and to investigate the role of SPARC in proliferation and metastasis of ESCC. The differential expression of SPARC between esophageal squamous cell carcinoma and its corresponding normal esophageal mucosa was analyzed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, as well as Western blotting. The expression of SPARC in ESCC was significantly higher than that in the corresponding normal esophageal mucosa as shown by semi-quantitative RT-PCR, immunohistochemistry and Western blotting. Meanwhile, SPARC protein was also significantly up-regulated in ESCC compared with the corresponding normal esophageal mucosa. SPARC protein was located in the cytoplasm and nuclei of ESCC cells. The results of Western blotting showed that out of 18 paired samples, SPARC was up-regulated in 13 cases, no significant differences were found for the other 5 cases. These findings revealed that SPARC was up-regulated in ESCC and was closely associated with ESCC metastasis. This study provides new insights into nuclei location of SPARC.

Blotting, Western↗
PubMed2005

The discovery of a potent and selective lethal factor inhibitor for adjunct therapy of anthrax infection.

A potent and selective anthrax LF inhibitor 40, (2R)-2-[(4-fluoro-3-methylphenyl)sulfonylamino]-N-hydroxy-2-(tetrahydro-2H-pyran-4-yl)acetamide, was identified through SAR study of a high throughput screen lead. It has an IC50 of 54 nM in the enzyme assay and an IC50 of 210 nM in the macrophage cytotoxicity assay. Compound 40 is also effective in vivo in several animal model studies.

Animals↗
PubMed2005

The effect of inorganic particles on slot die coating of poly(vinyl alcohol) solutions.

Among various coating processes, slot die coating belongs to a class of pre-metered coating, in which the coating film thickness can be predetermined. In the past, most research works on slot die coating have focused mainly on polymer solutions; very little information is available using suspensions as coating fluids. In this study, the effect of adding TiO2 and SiO2 in aqueous polyvinyl alcohol (PVA) solutions on slot die coating is investigated. It was found that the stable coating window was enlarged with the addition of particles, and its size increased with solids concentration. This is due to the strong interaction between polymer and particles, resulting in a higher viscosity and surface tension. As a result, the upstream coating bead is more stable and the maximum coating speed is extended to a high value, hence the coating window becomes larger. Although both viscosity and surface tension appear to contribute to the stability of coating flow, the effect of surface tension is more dominant. The surface tension of a suspension with porous particles was higher than one with hard solid particles. Consequently, the coating window obtained with the former was significantly larger than the latter. Flow visualization revealed that under the same operating conditions, the upstream dynamic contact angle for the suspension was smaller than for the aqueous polymer solution. This observation could be related to the stability of the upstream coating bead, and hence the coating window. The experimental flow fields were verified numerically with the aid of a numerical simulation package (Flow-3D).

Journal Article↗
PubMed2005

[Clinical significance of adjuvant endocrine therapy in treatment of endometrial carcinoma: study of 171 patients].

OBJECTIVE: To study the effectiveness of adjuvant endocrine therapy on the prognosis of endometrial carcinoma and to analyze the influence of progesterone receptor on the curative effect of adjuvant endocrine therapy. METHODS: A retrospective study was carried out on 171 patients of endometrial carcinoma with similar pathological examination. 82 of the 171 patients with endometrial carcinoma (48.0%), aged (57 +/- 9) years, underwent endocrine therapy, mainly by progesterone (245 +/- 51) mg/d for (1.3 +/- 0.9) years. 55 cases (67.1%), aged (57 +/- 10) years, underwent endocrine therapy for more-than-one-year (more-than-one-year subgroup), and 27 cases (32.9%), aged (59 +/- 9) years, underwent endocrine therapy for less-than-one-year (less-than-one-year subgroup). 24 of the 82 patients (29.3%) underwent adjuvant radiotherapy. 89 of the 171 patients (52.0%), aged (57 +/- 11) years, were in the control group 31 of the 89 patients in the control group (34.8%) underwent adjuvant radiotherapy, and 39 patients (43.8%) underwent adjuvant endocrine therapy. Follow-up was performed by correspondence, phone call, or outpatient department visit for 3 approximately 4 years. RESULTS: The rate of recurrence and/or metastasis of the endocrine therapy group was 13.4%, not significantly different from that of the control group (23.6%, P > 0.05); the death rate of the endocrine therapy group was 12.2%, not significantly different from that of the control group (20.2%, P > 0.05). The rate of recurrence and/or metastasis of the less- than-one-year subgroup was 25.9%, significantly higher than that of the more-than-one-year subgroup (7.3%, P = 0.012); the death rate of the less- than-one-year subgroup was 22.2%, significantly higher than that of the more-than-one-year subgroup (7.3%, P = 0.036). Cox regression showed that stage, the operation, tumor cell differentiation, and duration of endocrine therapy significantly affected the recurrence/metastasis remarkably (OR = 5.199, OR = 0.507, OR = 1.796, OR = 0.538) and the death rater (OR = 5.488, OR = 0.482, OR = 1.516, OR = 0.547). The rate of recurrence/metastasis of the endocrine therapy group patients with positive progesterone receptor was 4.7%, significantly higher than that of the patients with negative progesterone receptor (26.7%, P = 0.034). CONCLUSIONS: The prognosis of endometrial carcinoma patients can be improved with adjuvant endocrine therapy, especially for those with positive progesterone receptor. Endocrine therapy should be continued no less than 1 year.

Aged↗
PubMed2005

An essential function for the calcium-promoted Ras inactivator in Fcgamma receptor-mediated phagocytosis.

Fc receptor (FcR)-mediated phagocytosis requires activation of the Rho GTPases Cdc42 and Rac1, but how they are recruited to the FcR is unknown. Here we show that the calcium-promoted Ras inactivator (CAPRI), a Ras GTPase-activating protein, functions as an adaptor for Cdc42 and Rac1 during FcR-mediated phagocytosis. CAPRI-deficient macrophages had impaired FcgammaR-mediated phagocytosis and oxidative burst, as well as defective activation of Cdc42 and Rac1. CAPRI interacted constitutively with both Cdc42 and Rac1 and translocated to phagocytic cups during FcgammaR-mediated phagocytosis. CAPRI-deficient mice had an impaired innate immune response to bacterial infection. These results suggest that CAPRI provides a link between FcgammaR and Cdc42 and Rac1 and is essential for innate immune responses.

Animals↗