PubMed Health⌕ Search

Biomedical subjects

T Chiang

Publications and source records attributed to T Chiang.

At least 91 records · Page 5Linked to original sources
PubMed1989

TGF-alpha and EGF-receptor mRNAs in human oral cancers.

Transforming growth factor alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) have been shown to be present in most squamous cell carcinomas. Using the Syrian hamster oral cancer model, we have recently demonstrated the consistent presence of TGF-alpha and EGFR mRNAs in chemically transformed hamster oral keratinocytes. We now present evidence that in human oral cancer (in vivo and in vitro), TGF-alpha and EGFR mRNAs can also be consistently detected. No TGF-alpha mRNA can be detected in normal human oral epithelium by Northern blot analysis. These findings reinforce the use of the hamster cheek pouch as an experimental model for the study of oral cancer development, at least in reference to the possible participation of TGF-alpha in the malignant transformation process.

Animals↗
PubMed1989

Quantitative antibody ELISA for leprosy.

Quantitative enzyme-linked immunosorbent assays (ELISAs) were established to measure IgM and IgG antibody levels to soluble Mycobacterium leprae sonicate (CD60) and to the synthetic disaccharide antigen based on the phenolic glycolipid-I antigen of M. leprae coupled to bovine serum albumin in 46 leprosy patients. Separate reference pools for IgM and IgG antibody were established. The reciprocal of the antibody titer was expressed as the number of arbitrary units in the reference pools which was subsequently used as the calibrator for assessment of units in individual test sera. The dose-response relationship for both IgM and IgG was highly specific and reproducible for both isotypes, as indicated by the intra- and inter-assay coefficients of variation. The distribution of antibody levels are in general agreement with the results from previous studies against different M. leprae antigens. The lepromatous group showed 10- to 100-fold higher IgM antibodies to both the soluble sonicate antigen and the disaccharide as compared to the control group. Very low to undetectable levels of IgM antibodies were observed in the tuberculoid group of leprosy patients. IgG antibodies, on the other hand, were not only present but showed considerable overlap with the lepromatous patient group. Optimized ELISAs, such as the one described in this study, would allow one to address issues such as antibody changes with treatment, antigen clearance, and correlation with other immune parameters associated with disease pathogenesis and protection.

Antibodies, Bacterial↗
PubMed1987

Use of resealed erythrocytes as delivery system for C-reactive protein (CRP) to generate macrophage-mediated tumoricidal activity.

We have shown previously in several mouse tumor systems that multilamellar vesicles (MLV) are an effective delivery system for generation of macrophage-mediated tumoricidal activity by C-reactive protein (CRP). Here we show that resealed erythrocyte ghosts (red cell ghosts, RCG) can function in the same manner. CRP associated with red cell ghosts (CRP-RCG) inhibited established lung metastases of T241 fibrosarcoma in C57B1/6J mice. The degree of inhibition was comparable to that observed with CRP-MLV. In other experiments, peritoneal exudate cells, obtained from mice pretreated with CRP-RCG i.p., inhibited growth and pulmonary metastases of T241 tumor in the Winn neutralization assay. Similar results were obtained with MCA-38 colon carcinoma in the Winn assay. These studies indicate that erythrocytes deserve consideration as another delivery system for biological response modifiers.

Adjuvants, Immunologic↗