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Featured researches published by Leo J. Williams.


Cancer | 1978

Heterotransplantation of human cancers into nude mice. A model system for human cancer chemotherapy.

Beppino C. Giovanella; John S. Stehlin; Leo J. Williams; Shih-Shun Lee; Randall C. Shepard

More than 200 human cancers have been successfully transplanted into nude athymic mice in our laboratory. Strict sterile techniques must be applied in caring for these animals and meticulous attention given to the preparation of the surgical specimens. That the tumors remain human in the mice has been documented by isozyme and karyotype analyses. Also, histopathologic comparisons between the original human tumors and their transplanted counterparts in the mice are strikingly similar or identical. Preliminary results of chemotherapy of human cancers in the nude mice are extremely encouraging. At this point, we believe that the greatest potential for the nude mice lies in their use in testing anticancer therapies for human neoplasms without placing the patients at risk. Cancer 42:2269–2281, 1978.


Cancer | 1983

Correlation between response to chemotherapy of human tumors in patients and in nude mice

Beppino C. Giovanella; John S. Stehlin; Randall C. Shepard; Leo J. Williams

Human tumors serially heterotransplanted in nude mice have been tested for their response to chemotherapeutic agents. Fourteen melanomas, 14 colorectal carcinomas, and 14 breast carcinomas have been used. Each tumor originated in a different patient. The tumors were maintained by serial subcutaneous transplantation in nude mice. For the experiments in this study, each neoplasm was transplanted under the kidney capsule of 60 to 100 adult nude mice. The areas of the individual tumor implants were precisely measured immediately after insertion using a stereo microscope equipped with a micrometric ocular. The animals were then divided into groups of six to ten animals each. One group was injected daily with saline and served as controls. The mice in the remaining groups were injected daily for eight days with one of the following chemotherapeutic agents—Adriamycin (doxorubicin), 5‐fluorouracil, methotrexate, Cytoxan (cyclophosphamide), Alkeran (melphalan), vincristine, vinblastine, methyl‐CCNU, or BCNU—at optimum doses (the maximum dose tolerated that causes less than 10% weight loss). Treatment was initiated when the implants were well established, having roughly doubled their initial mass. The animals were then sacrificed and the tumors measured again. A drug was rated effective only if it inhibited growth of the tumor by 99% or more. The results so obtained were compared with the published results of various clinical trials. When the sensitivity of the human tumors in the mice was compared with the sensitivity of tumors of the same type that had been treated in human patients, a close correlation was found. The panel study detected nine of ten effective drugs, giving only two false‐positive results. Our data strongly support the validity of heterotransplants of human tumors in the nude mouse as a predictive system for testing new anticancer agents and in determining optimal treatment schedules and combinations of known drugs.


Cancer | 1980

Leiomyomatosis peritonealis disseminata. Two case reports and a review of the medical literature

Leo J. Williams; Frank J. Pavlick

Two cases of Leiomyomatosis Peritonealis Disseminata (LPD) are presented and discussed in relation to the 10 cases that to date constitute the medical literature on this condition. LPD presents findings highly suggestive of disseminated malignant neoplasm within the abdomen. Even upon histologic examination, it may be confused with sarcoma, especially low grade leiomyosarcoma. Electron microscopic examination was required for a correct diagnosis in one of the cases reported. Two distinguishing characteristics of LPD are given and a conservative approach to therapy is recommended in view of the fact that spontaneous regression of the nodules has been reported in most cases. Demographic and clinical data for all reported cases of LPD are tabulated.


Journal of the National Cancer Institute | 1974

Heterotransplantation of Human Malignant Tumors in “Nude” Thymusless Mice. II. Malignant Tumors Induced by Injection of Cell Cultures Derived From Human Solid Tumors

Beppino C. Giovanella; John S. Stehlin; Leo J. Williams


Cancer Research | 1973

Selective lethal effect of supranormal temperatures on mouse sarcoma cells.

Beppino C. Giovanella; Alton C. Morgan; John S. Stehlin; Leo J. Williams


Journal of the National Cancer Institute | 1972

Development of Invasive Tumors in the “Nude” Mouse After Injection of Cultured Human Melanoma Cells

Beppino C. Giovanella; Sun Ock Yim; John S. Stehlin; Leo J. Williams


Cancer Research | 1992

Complete inhibition of growth followed by death of human malignant melanoma cells in vitro and regression of human melanoma xenografts in immunodeficient mice induced by camptothecins.

Panayotis Pantazis; Hellmuth R. Hinz; John Mendoza; Anthony J. Kozielski; Leo J. Williams; John S. Stehlin; Beppino C. Giovanella


Cancer Research | 1985

Exceptional Lethality for Nude Mice of Cells Derived from a Primary Human Melanoma

Amold Lockshin; Beppino C. Giovanella; Peter D. de Ipolyi; Leo J. Williams; John Mendoza; Sun Ock Yim; John S. Stehlin


Journal of the National Cancer Institute | 1976

Human Neoplastic and Normal Cells in Tissue Culture. I. Cell Lines Derived From Malignant Melanomas and Normal Melanocytes

Beppino C. Giovanella; John S. Stehlin; C. Santamaria; Sun Ock Yim; A. C. Morgan; Leo J. Williams; A. Leibovitz; P. J. Fialkow; D. M. Mumford


Journal of the National Cancer Institute | 1973

Metastases of Human Melanomas Transplanted in “Nude” Mice

Beppino C. Giovanella; Sun Ock Yim; A. C. Morgan; John S. Stehlin; Leo J. Williams

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