Environmental Effects and Aquatic Organisms: Investigations of Molecular Mechanisms of Carcinogenesis

Cancers of the reproductive system are among the leading causes of mortality in women in the United States. While both genetic and environmental factors have been implicated in their etiology, the extent of the contribution of environmental factors to human diseases remains controversial. To better address the role of environmental exposures in cancer etiology, there has been an increasing focus on the development of nontraditional, environmentally relevant models. Our research involves the development of one such model, Gonadal tumors have been described in the softshell clam (Mya arenaria) in Maine and the hardshell clam (Mercenaria spp.) from Florida. Prevalence of these tumors is as high as 40% in some populations in eastern Maine and 60% in Some areas along the Indian River in Florida. The average tumor prevalence in Maine and Florida is approximately 20 and 11%, respectively. An association has been suggested between the use of herbicides and the incidence of gonadal tumors in the softshell clam in Maine. The role of environmental exposures in the development of the tumors in Mercenaria in Florida is unknown, however, there is evidence that genetic factors may contribute to its etiology. Epidemiologic studies of human populations in these same areas show a higher than average mortality rate due to cancers of the reproductive system in women, including both ovarian and breast career. The relationship, if any, among these observations is unknown, Our studies on the molecular basis of this disease in clams may provide additional information on environmental exposures and their possible link to cancer in clams and other organisms, including humans.

Developmental and Environmental Effects on the Expression of the C3-C4 Intermediate Phenotype in Moricandia arvensis1

Cellular anatomy and expression of glycine decarboxylase (GDC) protein were studied during leaf development of the C3-C4 intermediate species Moricandia arvensis. Leaf anatomy was initially C3-like and the number and profile area of mitochondria in the bundle-sheath cells were the same as those in adjacent mesophyll cells. Between a leaf length of 6 and 12 mm there was a bundle-sheath-specific, 4-fold increase in the number of mitochondrial profiles, followed by a doubling of their individual profile areas as the leaves expanded further. Subunits of GDC were present in whole-leaf extracts before the anatomical development of bundle-sheath cells. Whereas the GDC H-protein content of leaves increased steadily throughout development, the increase in GDC P-protein was synchronous with the development of mitochondria in the bundle sheath. The P-protein was confined to bundle-sheath mitochondria throughout leaf development, and its content in individual mitochondria increased before the anatomical development of the bundle sheath. Anatomical and biochemical attributes of the C3-C4 character were present in the cotyledons and sepals but not in other photosynthetic organs/tissues. In leaves and cotyledons that developed in the dark, the expression of the P-protein and the organellar development were reduced but the bundle-sheath cell specificity was retained.

Environmental effects of increased coal utilization : ecological effects of gaseous emissions from coal combustion /

Mode of access: Internet.

The statement of Dr. W.F. Libby before Special Subcommittee on Radiation, Joint Committee on Atomic Energy public hearings on the biological and environmental effects of nuclear war.

"Health and Safety."

Biological effects of a nuclear attack : presented at the Hearings on the Biological and Environmental Effects of Nuclear War, before the Special Subcommittee on Radiation, Joint Committee on Atomic Energy /

"Radiation Effects of Weapons Branch, AEC."

Hazardous properties and environmental effects of materials used in solar heating and cooling (SHAC) technologies : interim handbook /

Issued Dec. 1978.

Potential environmental effects of 765-kV transmission lines : views before the New York State Public Service Commission, cases 26529 and 26559, 1976-1978 /

Contract no. DE-AM-03-76SF0015.

Laboratory model ecosystem evaluations of twenty-six new pesticides : screening of pesticides for potential adverse environmental effects in Illinois /

Mode of access: Internet.

Environmental effects of sewage sludge disposal [microform] : hearing before the Subcommittee on Natural Resources, Agriculture Research, and Environment of the Committee on Science and Technology, U.S. House of Representatives, Ninety-seventh Congress, first session, May 27, 1981.

"No. 24."

Environmental effects of the Harry S. Truman Dam [microform] : joint hearing before the Subcommittee on Water Resources of the Committee on Environment and Public Works and the Subcommittee on Federal Spending Practices and Open Government of the Committee on Governmental Affairs, United States Senate, Ninety-sixth Congress, second session, July 29, 1980.

"Serial no. 96-H58."