Zeng Yi (1929- ) is a native of Shanghai. He graduated from Shanghai Medical College in 1952. He received his doctoral degree from Brussels Free University in May 1986, and conducted his post-doctoral study at Princeton University, 1986-87. He is a virologist. He is an academician of Chinese Academy of Sciences and president of Chinese Academy of Preventive Medicine Sciences. He is a Professor at the Center for Study of Aging and Human Development and Geriatric Division / Dept of Medicine of Medical School, and Institute of Population Research and Dept. of Sociology, Duke University. He is also a Professor at China Center for Economic Research of Peking University in China, and Distinguished Research Scholar of Max Planck Institute for Demographic Research (MPIDR) in Germany. He is Director of Chinese Populations and Socioeconomic Studies Center of Duke University.

Since the early 1970s Zeng Yi has researched the relationship of the EB virus and nasopharynx cancer, established a series of serum diagnosis methods for nasopharynx cancer, and, increased the diagnosis rate of nasopharynx cancer at the early stage from 20-30% to 80-90%. His serum index could predict the occurrence possibility of nasopharynx cancer 5 to 10 years in advance. Yi was also the first to establish the cell plant for nasopharynx cancer from high differentiation and low differentiation because all of these cell plants had DNV and albumen of EB virus. He discovered Chinese herbal medicines, carcinogens in plants and foods in areas with a high incidence of nasopharynx cancer. He also discovered that certain oxygen bacillus on human nasopharynx parts could produce butyric acid. Zeng discovered genes chained with HLA that tended to be infected by nasopharynx cancer and was the first in the world to prove that, under cooperative functioning of carcinogen TPA and butyric acid, the human fetus mucous membrane in parts infected by EB virus could induce human nasopharynx cancer in rats. This was direct evidence that the EB virus could induce nasopharynx cancer and at the same time provided models for multiple factors of nasopharynx cancer pathogens and functional mechanism. Since 1984 Yi has conducted research on HIV and AIDS and proved the introduction of HIV into China. He separated the first Chinese HIV-1 noxious plant in 1987 and established the rap diagnosis method for HIV. In 1984, he was conferred the title of State-level Young and Middle-aged Scientist with Outstanding Contributions. Zeng was awarded more than ten national and international academic prizes, such as Dorothy Thomas Prize of the Population Association of America; Harold D. Lasswell Prize in Policy Science awarded by the international journal Policy Sciences and Kluwer Academic Publishers, and so on.

EARLY DIAGNOSIS, PROSPECTIVE AND ETIOLOGICAL STUDIES ON NASOPHARYNAGEAL CARCINOMA

Zeng Yi, Wang Peizhong and Deng Hong

(Institute of Virology, Chinese Academy of Prevention Medicine Guangxi Autonomous Regional Hospital Wuzhou Cancer Institute)

Abstract

Nasopharyngeal carcinoma (NPC) is common in southern China. The purpose of our studies was to establish simple and sensitive techniques for early diagnosis of NPC and to clarify the role of Epstein-Barr (EB) virus, environmental factors and genetic factors in the development of NPC.

EB Virus and NPC

Early diagnosis and prospective studies are given below. Serological mass surveys of NPC were carried out in NPC high risk areas (Cangwu County and Wuzhou City) by immunoenzymatic test, and IgA/VCA antibody positive persons were followed up yearly for 10 years. The early detection rate increased from 18.6% to 81% in Cangwu County and from 32% to 92% in Wuzhou City. In the course of following-up IgA positive asymptomatic individuals, IgA/VCA antibodies could be detected 12 years before NPC onset. The IgA antibody titers were also followed up, 40.7%and 7.3% of IgA antibody positive persons had antibody titer stable and increasing, respectively. It is interested that most of NPC were detected from the group with increasing or stable IgA antibody titer. The titer of IgA antibody to VCA and EA is proportional to the detection rate of NPC. These data indicate that the detection of IgA antibodies to EB virus VCA and EA is very useful for early diagnosis of NPC. Beside IgA/VCA and IgA/EA antibodies, IgA/MA, IgA/EBNA-1and IgG/Z antibodies are also specific and valuable for NPC diagnosis.

EB Virus Inducers and Tumor Promoters

Ether extracts from 1693 plants ,including Chinese medicinal herbs ,were studies for EB virus inducer activity and more than fifty were found to have inducing activity. Many plants such as Aleurites fordii, Wikstroemia indica, Sapium sebiferum and Euphorbia antiquorum grow in high risk areas for NPC. EB virus inducers were found in the soil and they were also found in vegetables growing in such soil in southern China. Extracts from plants and herbs containing EB virus inducers can enhance lymphocyte transformation by EB virus in vitro as well as tumor growth by the Rous sarcoma virus, rabbit papillomavirus, DMBA, methylcholanthrene and dinitrosopiperazine (DNP).

The salted fish from southern China and harisa and qaddid from Tunisia contain EB virus inducers. These preserved foods are very frequently consumed in high risk areas for NPC. Mutagens were also detected in the same food extracts, this being the first time that EB virus inducers and mutagens were found to be present in the same foods. Our data demonstrate that EB virus inducers can enhance lymphocyte transformation by the virus as well as promote the development of NPC in rats by DNP.

The genetic basis for NPC

Linkage studies were started in an attempt to demonstrate the existence of a disease susceptibility gene closely linked to HLA locus A and B but distinct from them which would confer a high relative risk for this disease. A total of 29 sibships with more than one case of NPC were studied. This study has provided clear evidence for the existence of NPC disease susceptibility gene, tightly linked to the HLA region.

In conclusion, the etiological factors for the development of NPC are complicated, the EB virus plays an important role in the development of NPC, but it is not the unique factor, the genetic factor and the environmental factors are also involved in the development of NPC.