(1) Shigeo Hino
Faculty of Medicine, Tottori University

Dr. Robert C. Gallo, Laboratory of Tumor Cell Biology
National Cancer Institute
DATE OF VISIT: August 10–September 10, 1993

1. Objective:
To attend 1993 ANNUAL MEETING sponsored by Laboratory of Tumor Cell Biology, and to perform joint study between SH, Nagasaki University and CDC on Maternal Transmission of HTLV-1.
Achievements: At CDC, SH brought into CDC approximately 400 serum samples collected at Nagasaki from HTLV-1 carrier mothers and their children. The purposes of the joint study was: (1) to find out markers of HTLV-1 carrier mothers who are more potent for transmission of HTLV-1 than other carrier mothers, and (2) to find out an assay method in diagnosing infected children in early stage. The selection of samples was based on serial fax transmission between SH and CDC.
Various antibody titrations were performed at CDC before, during and after the SH's stay at CDC. Since serum collection included serial samples obtained from the same mother, and also a certain mothers may have multiple children, some of them might have infected, integration of the results is out of margin which can be completed by letter, fax or phone system. After completion of each assay, the data were interpreted and the next assay was chosen out of numerous available assays. For this collaborative work, visiting the laboratory of collaborators was inevitable. Although the study is not finished yet, we are awaiting the results of the final round of assays. Writing of the manuscript will be started soon. The results opened an entirely new feature of maternal infection of HTLV-1. Briefly, carrier mothers with high titered antibody titers against gp60, an envelop protein of HTLV-1, have significantly higher risk of transmission to babies if they breast-feed, but those with lower antibody titers against the same protein have higher risk of transmission if they bottle-feed. Antibodies against other proteins, including gp21, another protein coded by the same env gene, were found to be unuseful markers. The results may be useful to detect carrier mothers who should seriously consider refraining from breast-feeding. Another project to find an assay system diagnosing infection of babies at an earlier stage is still in progress. The annual meeting of LCTB helped SH to encompass the whole picture of current studies around AIDS, cancer and cell biology. SH was impressed by the atmosphere of the meeting stressing the importance of application to the treatment of patients. However, SH felt that too much encouragement of applications may adversely effect the pure basic science because some of the researchers looking for applications to new technologies may not have serious insight to the fundamental basic sciences.

2. How study relates to future work:
We already know that at least 80% of maternal transmission of HTLV-1 can be blocked by refraining from breast-feeding by carrier mothers. However, studies to be awaited includes transmission pathways of remaining bottle-fed babies, possible blocking effect of maternal antibodies, early diagnosis method of infections of babies, etc. The current study will help understanding the whole picture of maternal infections of HTLV-1.

3. Any additional comments:
I cannot stress enough the importance of meeting scientists in different countries and in different field of science. This exchange program provides an immense chance to discuss scientific matters between scientists who can not exchange their opinions frequently. SH hopes this program will keep providing these important opportunities for both United States and Japanese scientists in the field of human retroviruses and cancer. SH especially thanks those who gave him this excellent opportunity.

(2) Shinkan Tokudome
Nagoya City University Medical School

Dr. Robert C. Gallo, Laboratory of Tumor Cell Biology
National Cancer Institute
DATE OF VISIT: August 1–31, 1993

As an exchange scientist under the US-Japan (NCI-JSPS) Cooperative Cancer Research Program, I attended the 1993 Annual Meeting sponsored by the Branch of Laboratory of Tumor Cell Biology organized Dr. R. C. Gallo, the chief of the branch, National Cancer Institute, National Institute of Health, held August 22nd-29th, 1993. The conference was largely concentrated in the research of HIV and HTLV-I. The presentations and discussions were highly pitched and updated. They were very useful and informative to me as well as the other attendants in the aspects of virology, pathogenesis, treatment, vaccine and prevention of HIV and HTLV-I-associated diseases. I presented the paper entitled "epidemiologic study of HTLVI-associated diseases in Japan" and discussed the topic in depth with scientists at the meeting.
Before the meeting, I visited Dr. R. Prentice, Dr. D.B. Thomas and their associates at the Public Health Science, Fred Hutchinson Cancer Research Center, Seattle, WA; Dr. M. C. Pike, Dr. R. K. Ross and their colleagues at the Comprehensive Cancer Center, University of Southern California, Los Angeles, CA; Dr. E. Rimm, Dr. N. Mueller and their associates at the Department of Epidemiology, Harvard University, Boston, MA. During the meeting, I met Dr. W. A. Blatnner, Dr. J. F. Fraumeni, Jr. and Dr. W. J. Blot at the Epidemiology and Biostatistics Program, National Cancer Institute, National Institute of Health, Bethesda, MD. I discussed cancer etiology and its prevention with them and looked for possibilities of US-Japan cooperative epidemiologic studies on cancer in the future.
In these visits I realized again the differences in the attitudes and situations between U.S. and Japanese researchers. U.S. scientists are more energetic not only in research activities but in publication activities than Japanese U.S. researchers feel uptight in applying for scientific grants because their salaries are largely based on the fund; while Japanese scientists are in the lukewarm situation of getting research grants because their salaries have nothing to do with research activities and partly because they are minimally supported by national, municipal or institutional annual budgets. Recently, the Japanese yen has been getting stronger but research funding for cancer in Japan, especially in basic science, is much poorer than that in the U.S. It seems desirable not only to raise scientific research funding, but to change scientists' lukewarm attitudes and to promote peer review system in evaluation of scientists' research activities in Japan.
Thus, participation in the branch meeting at NCI, NIH as an exchange scientist sponsored by the US-Japan Cooperative Cancer Research Program and exchanging ideas with leading scientists in several institutes, has been very helpful and fruitful for me in the fields of HTLV-I-associated cancer as well as epidemiology in cancer. It seems highly necessary to propose international (not limited to US-Japan) cooperative studies in cancer epidemiology to elucidate environmental factors and to prevent human cancers in the world.