c-MYC mediates the crosstalk between breast cancer cells and tumor microenvironment.

The MYC oncogenic family is dysregulated in diverse tumors which is generally linked to the poor prognosis of tumors. The members in MYC family are transcription factors which are responsible for the regulation of various genes expression. Among them, c-MYC is closely related to the progression of tumors.

[Comparative evaluation of Hebei HIV-1 p24 kit for the detection of human immunodeficiency virus].

Objective: To probe into the feasibility of screening anti-HIV compounds by using HIV-1 p24 detection kit made by Hebei Medical University.

Methods: The sensitivity, reproducibility and efficacy of the Hebei p24 kit were evaluated compared with the commercially available Vironostika HIV-1 Antigen Microelisa System (Biomerieux).

Results: Hebei p24 kit had high sensitivity and good reproducibility.

Interaction models of CYP1A1, GSTM1 polymorphisms and tobacco smoking in intestinal gastric cancer.

Aim: To explore the interaction models of the cytochrome P-450 (CYP) 1A1 Val variant and glutathione S-transferase (GST) M1 null polymorphisms with tobacco smoking in the occurrence of intestinal gastric cancer.

Methods: A community-based case-control study was conducted in Yangzhong. Subjects included 114 intestinal types of gastric cancer with endoscopic and pathological diagnosis during January 1997 and December 1998, and 693 controls selected from their spouse, siblings or siblings-in-law who had no history of digestive system cancer.

A novel genetic polymorphism of inducible nitric oxide synthase is associated with an increased risk of gastric cancer.

Aim: Inducible nitric oxide synthase (iNOS) plays a central role in the pathway of reactive oxygen and nitrogen species metabolism when Helicobacter pylori (H pylori) infection occurs in humans. iNOS Ser(608)Leu allele, a novel genetic polymorphism (C/T) occurring within exon 16 of the iNOS reductase domain, may have a dramatic effect on the enzymatic activity. The aim of this study was to determine whether iNOS C/T polymorphism was associated with increased susceptibility to gastric cancer.

[Preparation of bispecific monoclonal antibody against HIV p24 and human group A erythrocytes].

Aim: To prepare bispecific monoclonal antibody (bsmAb) against HIV p24 and human group A erythrocytes, and set up an indirect hemagglutination test for detecting HIV p24.

Methods: Hybridoma cells 2-E(4) secreting anti-HIV p24 mAb and hybridoma cells S(2) secreting anti-human group A erythrocyte mAb were naturalized with 8-Ag and 5-BrdU respectively, making them sensitive to HAT. Then the two hybridoma cells sensitive to HAT were fused by routine method and hybrid-hybridoma cells secreting the bsmAb against HIV p24 and human group A erythrocytes were screened.

Identification of tumor markers using two-dimensional electrophoresis in gastric carcinoma.

Aim: To study the differential expression of proteins in normal and cancerous gastric tissues, and further identify new molecular markers for diagnosis and prognosis of gastric carcinoma, as well as develop new therapeutic targets of the disease.

Methods: Matched pairs of tissues from 6 gastric cancer patients were analyzed for their two-dimensional electrophoresis (2DE) profiles. Soluble fraction proteins from human normal and cancerous gastric tissue were separated in the first dimension by isoelectric focusing on immobilized pH gradient (IPG, pH3-10) strips, and by 125 g/L sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension with silver nitrate staining.

[The effect of polyporus umbellatus polysaccharide on the immunosuppression property of culture supernatant of S180 cells].

Aim: To investigate the effect of polyporus umbellatus polysaccharide (PUPS) on the immunosuppression property of tumor cell line S180 culture supernatant.

Methods: The inhibitory effects of the culture supernatant of S180 cells in the presence or absence of PUPS on the ConA-induced mouse splenocyte proliferation, IL-2 production, killer activity and the reactivity of CTLL-2 cells to IL-2 were detected by MTT colorimetry. The effect of the culture supernatant on the IL-2Ralpha expression on murine splenocytes was detected by flow cytometry.

[Preparation and characterization of anti-human IL-15 monoclonal antibody].

Aim: To prepare monoclonal antibody (mAb) against human interleukin-15 (hIL-15) and identify its characterization.

Methods: The GST-IL-15 was extracted from the gene-engineering bacteria E. coli and identified by SDS-PAGE.

Soy and isoflavone consumption in relation to prostate cancer risk in China.

This case-control study in China evaluated the effect of soy food consumption and isoflavones (genistein and daidzein) on the risk of prostate cancer. One hundred and thirty-three cases and 265 age- and residential community-matched controls between the ages of 50 and 89 years were interviewed in person between 1989 and 1992. Usual consumption of soy foods and isoflavones was assessed using a food frequency questionnaire developed in China and a nutrient database developed and validated in Asian-American populations.

[Meta-analysis on the epidemiology of Helicobacter pylori infection in China].

Objective: To understand the epidemiologic features and etiology of Helicobacter pylori (H. pylori) infection in China so as to provide evidence for the development of preventive measures on H. pylori infection and related diseases.

[Extracorporeal experimental study on immuno-modulatory activity of Astragalus memhranaceus extract].

Objective: To study the effect of Astragalus membranaceus extract (AME) in regulating the immune function of human peripheral blood immune cells (PBIC) in vitro.

Methods: Effects of AME on the proliferation activity of peripheral blood mononuclear cells (PBMC) and the tumor cell phagocytosis of peripheral blood adherent monocytes (PBAM) were measured by using 3H-TdR incorporation. Effect of the tumor-killing activity of cytotoxic T-lymphocyte (CTL) was determined by using 51Cr-releasing assay.

Helicobacter pylori infection and gastric cancer: evidence from a retrospective cohort study and nested case-control study in China.

Aim: To explore the association between Helicobacter pylori (Hp) infection and risk of gastric cancer in China.

Methods: Utilizing gastroendoscopic biospsy tissue banks accumulated from 1980 to 1988 in Shandong, Zhejiang, and Jiangsu, where stomach cancer incidence was high, during stomach cancer screening conducted by Health Science Center of Peking University, School of Medicine of Zhejiang University, and Zhongshan Hospital of Fudan University. Warthin Starry silver staining method was applied to determine H.