Biomedical subjects

Ping Yu

Publications and source records attributed to Ping Yu.

At least 73 records · Page 4Linked to original sources

PubMed2004

[Research on discrimination of 3D fluorescence spectra of phytoplanktons].

Six phytoplankton species belonging to four divisions, which may cause red tide, were selected and cultivated under different temperature (20 degrees C and 15 degrees C) and illumination (7000, 4100 and 1100 Lux) in lab. 3D fluorescence spectra were measured in each growth period. Discrimination of these phytoplanktons' 3D fluorescence spectra was explored using discriminant analyses. The result showed that discriminant analyses based on the principal component analysis of spectra data was an efficient method. Isochrysis galbana, Platymonas helgolanidica and Skeletonema costatuma can be discriminated effectively. Skeletonema costatuma, which is an diatom, can be distinguished from Alexandrium tamarense and Prorocentrum micans which belong to Dinophyta.

Diatoms↗

PubMed2004

[Objective multi-parameters analysis of the voice dysphonia].

OBJECTIVE: The purposes of this paper are to develop a multi-parametric protocol, which can evaluate the voice objectively and quantitatively,and to investigate its correlation with the perceptual analysis. METHOD: The voice samples were collected from 83 patients with dysphonia and 40 subjects with normal voices. All the subjects were women. The objective parameters, including fundamental frequency (F0), jitter, Shimmer, fundamental frequency standard deviation (F0SD), fundamental frequency tremor, amplitude tremor, normalized noise energy (NNE), harmonic-to-noise ratio(HNR), signal-to-noise ratio(SNR) and maximal phonatory time (MPT), which were measured mainly on a sustained vowel /a/, were recorded on a software named Dr. Speech for Windows. According to the G component of the GRBAS, the voice was graded from 0 for normal to 3 for severe dysphonia. RESULT: Using the discriminate analysis, a five parameters protocol (MPT, jitter, NNE, HNR and shimmer) was developed and it showed that this protocol allowed 79.8% concordance with jury classification. CONCLUSION: The voice objective analysis should be multi-parameters. Our multi-parameters evaluation protocol is able to reflect the result of perceptual analysis.

Adolescent↗

PubMed2004

[Expression of SOCS-1, 3 induced by Chlamydia trachomatis-infected Hela229].

OBJECTIVE: To explore the relationship between SOCS, immune suppression and chlamydial persistence of Chlamydia trachomatis-infected cells. METHODS: After being infected with Chlamydia trachomatis, RT-PCR was used to examine the expression of SOCS-1, 3 mRNA and Western blotting to examine the expression of SOCS-1,3 protein in Hela229 cells. Immunofluorescence was used to examine the effect of SOCS obstruction on the multiplication of Chlamydia trachomatis. RESULTS: Chlamydia trachomatis-infected Hela229 cells can induce the expression of SOCS-1,3 both on mRNA level and on protein level. The multiplicity of Chlamydia trchomatis can be suppressed after the expression of SOCS-1,3 was obstructed. CONCLUSION: Chlamydia trachomatis-infected Hela229 cells can induce the expression of SOCS-1,3, which is one of the mechanisms that Chlamydia trachomatis can suppress host immune and result in persistence.

Chlamydia Infections↗

PubMed2003

Complementary role of CD4+ T cells and secondary lymphoid tissues for cross-presentation of tumor antigen to CD8+ T cells.

MHC class I-restricted tumor antigens can be presented to CD8+ T cells by two distinct pathways: via direct and indirect presentation. The relative contribution of these two pathways toward the initial activation of tumor antigen-specific CD8+ T cells and their subsequent tumor rejection is still vigorously debated. Using a tumor model able to dissect the relative contributions of direct and indirect presentation, we show unequivocally the inefficiency of direct presentation and the essential requirement of indirect presentation for the priming of naive tumor antigen-specific T cells leading to tumor rejection. Moreover, we characterize the essential environment under which indirect presentation occurs, and find efficient cross-priming of tumor-specific CD8+ T cells in the complete absence of secondary lymphoid tissues. The independence of this process from local lymph nodes is compromised, however, in the absence of CD4+ T cell help. Therefore, our paper demonstrates that effective immune protection against tumors requires the cross-priming of CD8+ T cells under conditions that require either CD4+ T cell help, or draining lymph nodes.

Adoptive Transfer↗

PubMed2003

1H, 13C and 15N resonance assignments of domain 1 of receptor associated protein.

The 39 kDa receptor associated protein (RAP) is a modular protein consisting of multiple domains. There has been no x-ray crystal structure of RAP available and the full-length protein does not behave well in a NMR tube. To elucidate the 3D structure of the RAP, we undertook structure determination of individual domains of the RAP. As the first step, here we report the nearly complete assignments of the (1)H, (13)C and (15)N chemical shift signals of domain 1 of the RAP.

Amino Acid Sequence↗

PubMed2003

Food groups and risk of esophageal cancer in Chaoshan region of China: a high-risk area of esophageal cancer.

The current study was designed to investigate the role of common foods in the etiology of esophageal cancer in the Chaoshan region of China. A large case-control study was conducted to investigate 1248 patients with squamous cell carcinoma of the esophagus and 1248 controls matched by sex, age, and hospitals. After adjusting for the effects of sex, age, occupation, areas of residence, income, alcohol intake, and cigarette usage, a strong association with a clear dose-response relationship was observed between the fermented fish sauce eaten weekly and esophageal cancer (P for trend less than 0.001). The results for pickles were similar to those for fermented fish sauce. A protective effect of fruits on esophageal cancer was observed, and this risk decreased (P for trend less than 0.001) as frequencies of fresh fruit intake increased. The risks from sowbelly and kipper were significantly higher in consumers than in nonconsumer, but the dose-response relationship was not statistically significant. No significant effects, however, were detected from vegetables, smoked foods, and so on. To the authors' knowledge, this is the first report on the relationship between fish juice and high risk of esophageal cancer in a population. Further epidemiological and experimental study are required to find a biological causal relationship between them.

Alcohol Drinking↗

PubMed2003

[Association study on HLA-DP and -DQ allelic polymorphisms and nasopharyngeal carcinoma in the Han nationality in Hunan province].

OBJECTIVE: To investigate whether the polymorphisms of HLA-DPA1,DPB1,DQA1 and DQB1 alleles were associated with nasopharyngeal carcinoma(NPC). METHODS: Eighty-seven NPC patients and 91 normal controls of Han nationality in Hunan province were genotyped for HLA-DPA1, HLA-DPB1,HLA-DQA1 and HLA-DQB1 by PCR/SSO technique. RESULTS: The frequencies of allelic gene DPA1*0201, DPB1*1901 and DQA1*0201 were lower, and of DPB1*0402, DQA1*0101 were higher in patients than in controls; the frequencies of haplotype DPA1*0201-DPB1*1401 and DQA1*0201-DQB1*0201 in patients were lower than those in controls; however, the values of P are not significant after Bonferroni correction(Pc>0.05). CONCLUSION: No significant association between the HLA-DP and HLA-DQ loci and NPC in Han nationality in Hunan province was confirmed.

Adult↗

PubMed2003

[Comparative study on image analysis and manual counting of immunohistochemistry].

With the use of computer image analysis (IA) and manual counting, the immunohistochemistry (IHC) results on PS2, ER and c-erB-2 of breast cancer which represent positive expression of cytoplasm, cell nucleus and cytomembrane are analyzed and compared. Then the advantages, disadvantages and repetition of the two methods are discussed and the correlation between image analysis and manual counting is estimated. The results of this study indicate that IA has better repetition in estimation of positive expression of cytoplasm, cell nucleus and cytomembrane, whereas manual counting has better repetition only in the positive expression of cell nucleus and cytomembrane, and the two methods have positive correlation in estimation of IHC results. In addition, some problems in image processing are discussed in this paper.

Breast Neoplasms↗

PubMed2003

Malignant biliary obstruction: treatment with interventional radiology.

OBJECTIVE: To evaluate the method of palliative drainage by means of metallic indwelling stents or plastic tubes for patients with malignant biliary obstruction. METHODS: From January 1995 to February 2001, 243 consecutive patients (161 men and 82 women; aged 26 - 91 years, mean of 61.3 years) with malignant biliary obstruction were treated with transhepatic placement of metallic stents and/or plastic tubes. Among them, 47 patients had pancreatic carcinoma, 98 cholangiocarcinoma, 28 metastatic carcinoma and 60 hepatic carcinoma. 169 stents of nine types were used in this series. After stenting, 47 patients were treated for local tumors. Procedure- and device-related complications were recorded. Patient survival and stent patency rates were calculated with Kaplan-Meier survival analysis. RESULTS: One hundred and three patients underwent successfully stent placement for the first time. Others had their stents installed 1 - 2 weeks after catheterization. Stents were used in 132 patients. Ninety-five patients were treated with a single stent. Seventeen patients had two stents installed for bilateral drainage, 20 patients had two stents installed from top to bottom to create stenting of adequate length, and 12 patients had stents placed across the ampulla. The 2-month mortality rate was 8.64% (21/243). Major complications occurred in two patients (0.8%, 2/243). Minor complications included self-limited bleeding into the drainage tubes and fever. The average patency of the initial stent was 7.5 months and average survival was 9 months. Thirteen patients received brachytherapy in their stents, 15 extra radiation therapy, and 19 intra-arterial infusion chemotherapy. The 47 patients treated for local tumors had an average survival of 11.3 months (log rank 32.8, P < 0.001) with an average patency of 9.7 months (log rank 4.7, P < 0.05). CONCLUSION: Percutaneous transhepatic bile drainage as a palliative procedure is well tolerated by patients. After stenting, treatment for local tumor may prolong the duration of stent patency and the survival of patients.

Adult↗

PubMed2003

[Hela cells secrete interleukin-8 and interleukin-10 response to Chlamydia trachomatis entry].

OBJECTIVE: To investigate the effect of Chlamydia trachomatis serotype K infection on productions of IL-8 and IL-10 in supernatant of cultured Hela cells. METHODS: The levels of IL-8 and IL-10 productions were detected by cell culture method and ELISA assay. RESULTS: The amount of IL-8 and IL-10 in the cell culture supernatant rose with the increasing doses of Chlamydia trachomatis. The concentrations of IL-8 and IL-10 began to increase obviously at 24 h, and reached their highest level at 72 h, and then decreased. Heat-inactivated Chlamydia trachomatis induced lower levels of IL-8 and IL-10 production than live bacteria in vitro. CONCLUSION: The Chlamydia trachomatis can induce the secretion of IL-8 and IL-10 of host cells in a dose and time dependent manner and the intracellar replication of the bacteria is required for enhancing IL-8 and IL-10 productions by the infected cells.

Chlamydia trachomatis↗

PubMed2003

[Analysis of subtype of porcine endogenous retrovirus in two species of Chinese pigs].

OBJECTIVE: To analyze the subtype of porcine endogenous retrovirus (PERV) in two species of Chinese pigs-Wu zhishan pig and Banna minipig inbred; the total number of pigs being eighty six. METHODS: Three primers which are specific for the three PERV subtypes (subtypes A, B and C) were used to amplify the genome DNA extracted from the pigs. RESULTS: In all tested pigs' genome, subtype C was not found; in 77.9% pigs, double positive envAB were found; in 22.1% pigs, only A or B was found. CONCLUSION: In the genome of peripheral leukocytes from Wuzhishan pig and Banna minipig inbred, only subtypes A and B exist, and envAB predominate.

Animals↗

PubMed2003

[Expression of P-glycoprotein and lung resistance protein in breast carcinoma and its relationship with prognosis].

BACKGROUND & OBJECTIVE: The multidrug resistance of tumor cells is the reason to failure of chemotherapy. The overexpression of P-glycoprotein (P-gp) and lung resistance protein (LRP) play important roles in the multidrug resistance of breast carcinoma. The objective of this study was to investigate the expression of P-gp and LRP in breast carcinoma and its relationship with prognosis. METHODS: Immunohistochemical assay with the LSAB immunostaining technique was used to determine protein expression of P-gp and LRP in the specimens of paraffin-embedded tissues from 151 cases of breast carcinoma and 40 normal breast tissues (control). The results were evaluated on the basis of clinical pathological factors and the survival time of these cases. RESULTS: The expression of P-gp were found in 62 (40.8%) of the breast carcinoma samples and in 1 (2.5%) of control samples. The difference between the two groups was statistically significant (Chi(2)=21.27,P< 0.01). The expression of LRP were found in 121 (80.1%) of the breast carcinoma samples and in 22 (55.0%) of control samples. The difference between the two groups was statistically significant (Chi(2)=10.62,P< 0.01). The expression of P-gp were irrelative to age,tumor size,histotype,lymph nodes metastasis,tissue grading,clinical staging, ER condition,and prognosis. The expression of LRP were found in 62 (88.6%) of 70 cases with positive lymph nodes and 59 (72.8%) of 81 cases with negative lymph nodes. The difference between the two groups was statistically significant (Chi(2)=4.891, P< 0.05). The expression of P-gp were found in 55 (45.5%) of breast carcinomas with positive immunohistochemical reaction of LRP protein; while the expression of P-gp were found in 7(23.3%) of breast carcinomas with negative immunohistochemical reaction of LRP protein. The difference between the two groups was statistically significant (Chi(2)=3.990,P< 0.05). The expression of LRP were positively correlated with the lymph nodes metastases (r=0.197, P< 0.05) and the expression of P-gp (r=0.179,P< 0.05) and irrelative to age tumor size, histotype, lymph nodes metastases, tissue grading,clinical staging, and ER condition. Univariate analysis demonstrated worse disease-free survival in the patients with positive LRP than in those with negative LRP (Chi(2)=6.892,P< 0.01). Multivariate analysis of clinical and pathological data by Cox regression method did not demonstrated that both expression of P-gp and LRP were independent factors affecting the survival of breast carcinoma patients. CONCLUSION: The expression of P-gp and LRP have their characteristics and dissimilarity clinical significance in breast carcinoma tissues. The expression of LRP may correlate not only with MDR but also the lymph nodes metastases,prognosis and expression of P-gp in breast carcinoma tissues.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2003

[Screening genes of differential expression in BALB/C mice thymus: a pilot study of effect of salmon milt DNA (SMD) on age-related involutions].

OBJECTIVE: To investigate the effect and its mechanism of salmon milt DNA (SMD) on age-related involutions in mouse thymus. METHODS: Female BALB/C mice aged 10 months were divided randomly into three groups according to their weights. They were high dosage group (333.33 mg.kg(-1).b.w.d(-1)), low dosage group (166.67 mg.kg(-1).b.w.d(-1)) and control group (0 mg.kg(-1).b.w.d(-1)). After five weeks, their thymus indexes were measured and the thymocytes were counted and the thymus cortex thicknesses were also measured using Image-Pro Plus (version. 4.0) software in the thymus section. All the data were analyzed by SAS statistic software. Microarray technique was applied to screen the gene fragments, which were differentially expressed between the high dosage group and the control group, together with RT-PCR to further confirm some of them. RESULTS: No significant differences of the variables including body weight, thymus weight and thymus indexes among the three groups were found. The thymocytes quantities of thymus cortex and medulla in the high dosage group were significantly higher than those of the control group (P < 0.01 and P < 0.05, respectively). The thymus cortex thicknesses of both SMD supplement groups were significantly higher than that of the control group (P < 0.01 and P < 0.05 respectively). 112 differently expressed gene fragments were isolated. Furthermore, we found the fragments with the logged number of U23789, X80232 and Aw209102 were highly expressed in the high dosage group when RT-PCR technique was used. CONCLUSIONS: SMD may reverse the age-related involutions in mouse thymus via up-regulation the expression of proliferation related genes and via up-regulation the expression of development and differentiation related genes simultaneously.

Actins↗

PubMed2003

[The quantity analysis of reverse transcriptase in porcine endogenous retrovirus expressed in Banna minipig inbred].

Quantitative RT(reverse transcriptase) assay was established to detect the reverse transcriptase in plasma of thirty-four Chinese Banna minipig inbred in this work. The protocol was given in the RT kit (Roche), using HIV-1 as the positive control of the kit and supernatant of PK-15 as the PERV positive control respectively. The results show that positive reverse transcriptase reaction can be detected in the plasma of the pigs, but the levels are much lower than that of HIV-1 and lower than that of PERV in supernatant of PK-15.

Animals↗

PubMed2003

[The effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice].

OBJECTIVE: To observe the effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice. METHOD: Liver microsomal and mitochondrial membranes were labled by ANS and DPH. Membrane fluorensent intensity (F), fluorensent polarization(P) and microviscosily(eta) of liver microsome and mitochondria were determined. RESULT: Sil increased the external membrane fluidities of liver microsome and mitochondria, and decreased the internal membrane fluidities of liver microsome and mitochondria. Pretreatment with CCl4, the external membrane fluidity of liver microsome and mitochondria were increased, and the internal membrane fluidities of liver microsome and mitochondria were decreased. After given sil 140,280 mg.kg-1, the increased external membrane fluidities of liver microsome and mitochondria were lowered, and the decreased internal membrane fluidities of liver microsome and mitochondria were enhanced in a dose-dependent manner. CONCLUSION: The protective effects of sil on liver injury may be related to the recovery of the membrane fluidities of liver microsome and mitochondria.

Animals↗

PubMed2002

Novel epidemiologic evidence for the association between fermented fish sauce and esophageal cancer in South China.

Previous studies have suggested that fermented fish sauce is related to an increased risk for nasopharyngeal, thyroid and gastric cancers and has suspicious carcinogenic and promoting effects in the laboratory, but these reports have not investigated the association between this agent and esophageal cancer in population. Therefore, we investigated the relationship between esophageal cancer and consumption of fermented fish sauce, alcohol and tobacco after adjusting other risk factors using data from a large hospital-based case-control study in Chaoshan area of China. The subjects for analysis included 1,248 cases (median age 58.5 [range 29-82] years, 936 males, 312 females, some 50% with the habit of fermented fish sauce eating) with squamous cell carcinoma of the esophagus and the same amount of controls matched by sex and age. A significant increase in risk (OR 3.21; 95% CI 2.45-4.19) for eating fermented fish sauce compared to not eating and a significant dose-response relationship was found with the consumption of fermented fish sauce (p for trend < 0.001). In comparison based on the binary variables, the OR for the subjects with fermented fish sauce eating and current smoking was 15.5 with a 95% CI of 8.14-29.3, relative to those exposed to neither habit. The joint effect of fermented fish sauce (F) and smoking (S) was more than additive (F * S > F + S: 15.5 > 1 + (5.6 - 1) + (6.6 - 1)), but the effect for fermented fish sauce and alcohol was not found. It is concluded that risks of esophageal cancer in the population were substantially associated with fermented fish sauce. Further epidemiologic and experimental study are required to find a biologic causal relationship between them.

Adult↗

PubMed2002

B cells control the migration of a subset of dendritic cells into B cell follicles via CXC chemokine ligand 13 in a lymphotoxin-dependent fashion.

Certain classes of dendritic cells (DCs) meet rare cognate Ag-specific T and B cells inside primary B cell follicles for the development of germinal centers. However, the mechanisms underlying this coordination are still undefined. Cysteine-rich (CR) domain of the mannose receptor (CR-Fc)(+) DCs are a newly discovered subset of DCs that migrate rapidly into the primary lymphoid follicles from marginal zone after immunization. In this work, we uncover the key role of B cells in the establishment of a microenvironment that allows these DCs to be in the B cell area in a lymphotoxin (LT)-dependent fashion. CR-Fc(+) DCs are absent from the spleens of both LTbetaR- and LTalpha-deficient mice, suggesting that signaling by membrane LT is required for the presence of CR-Fc(+) DCs in the spleen. Interestingly, analysis of mutant mice that lack T, B, or NK cells demonstrates that B cell-derived membrane LT is essential for the unique localization of CR-Fc(+) DCs in the spleen. Using bone marrow transfer and ligand-blocking approaches, we provide evidence that B cell-derived LT acts indirectly on CR-Fc(+) DCs through LTbetaR(+) stromal cells. In analogous fashion to certain Ag-activated T and B cells, CR-Fc(+) DCs, expressing CXCR5, localize to primary lymphoid follicles in response to CXC ligand 13 (B lymphocyte chemoattractant). Together, we propose that B cells play a central role in establishing the chemotactic gradient that attracts not only Ag-activated T and B cells but also Ag-carrying CR-Fc(+) DCs. In turn, CR-Fc(+) DCs and T cells home to B cell follicles to interact with B cells in the developing germinal center.

Animals↗

PubMed2002

Signaling via LTbetaR on the lamina propria stromal cells of the gut is required for IgA production.

Peyer's patches (PPs) and/or mesenteric lymph nodes (MLNs) are thought to be essential for immunoglobulin A (IgA) production. We found that the severe IgA deficiency in lymphotoxin-deficient (LT(-/-)) mice could be fully reversed by reconstitution with LT-expressing bone marrow, despite the absence of both LNs and PPs. The number of IgA precursors from LT(-/-) mice was not reduced, and they were able to migrate into the lamina propria (LP) of wild-type mice but not of LTbetaR(-/-) mice. Consistently, lymphoid tissue chemokines and adhesion molecules were reduced within the LP of LTalpha(-/-) and LTbetaR(-/-) mice. IgA deficiency in LTalpha(-/-) mice was reversed by the transplantation of a segment of RAG-1 (recombination-activating gene 1) deficient intestine, which confirmed the dispensability of the MLNs and PPs and the sufficiency of the LT-mediated gut microenvironment for IgA production.

Adoptive Transfer↗