Effects Of Environmental Substances Research Articles

CARCINOGENICITY OF MALATHION AND ESTROGEN IN AN EXPERIMENTAL RAT MAMMARY GLAND MODEL

Breast cancer is considered a major and common health problem in both developing and developed countries. The etiology of breast cancer, the most frequent malignancy diagnosed in women in the western world, has remained unidentified. Chemicals as the organophosphorous pesticide malathion have been used to control a wide range of sucking and chewing pests of field crops, and are involved in the etiology of breast cancers. The association between breast cancer initiation and prolonged exposure to estrogen suggests that this hormone may also have an etiologic role in such a process. However, the key factors behind the initiation of breast cancer remain to be elucidated. The effect of environmental substances, such as malathion and estrogen was analyzed in an experimental rat mammary gland model. Different cytoplasmic proteins are key in the transformation of a normal cell to a malignant tumor cell and among these are the Ras super family and Ras homologous A (Rho-A). Both types of proteins were greater in animals treated with malathion than those with estrogens. E-Cadherins constitute a large family of cell surface proteins.Resultsshowed greater expression of E-Cadherin and vimentin than c-Ha-ras and Rho-A in rats treated by estrogens. In breast cancer, analysis using immunohistochemical markers is an essential component of routine pathological examinations, and plays an important role in the management of the disease by providing diagnostic and prognostic strategies.The aimof the present study was to identify markers that can be used as a prognostic tool for breast cancer patients.

Kinetic analysis of decreased sperm fertilizing ability by fluorides and fluoroaluminates: a tool for analyzing the effect of environmental substances on biological events.

Fluorides and fluoroaluminates decrease mouse sperm fertilizing potential by modifying the process of sperm preparation for fertilization, so-called capacitation, followed by acrosome reaction (AR). Capacitation was monitored by protein tyrosine phosphorylation (pTyr), and AR was induced consequently. The aim of this study was to apply kinetic analysis to the previously obtained dependences of pTyr and AR at capacitation times, and propose a mathematical theory for a mechanism when sperm maturation ability is amended by external stimuli. The experimental input data, previously obtained, are consistent with the proposed theory and the results of kinetic analysis show that sperm capacitation runs as two subsequent first-order steps. Firstly, an unstable intermediate is formed and then gradually decomposes. The time corresponding to the maximal production of the unstable intermediate is probably most suitable for sperm obtaining the ability to fertilize the egg. The presented calculations indicate that the application of kinetic analysis can serve as a tool to predict or confirm a course of biological events that are modified by external factors, and therefore the proposed theory shall be of interest to a broad scientific audience.

Effect of Environmental Substances on the Activity of Arylamine N-Acetyltransferases

Arylamine N-acetyltransferases (NAT) are xenobiotic-metabolizing enzymes responsible for the acetylation of many aromatic arylamine and heterocyclic amines, thereby playing an important role in both detoxification and activation of numerous drugs and carcinogens. Two closely related isoforms (NAT1 and NAT2) have been described in humans. NAT2 is mainly expressed in liver and gut, whereas NAT1 is found in a wide range of tissues. Interindividual variations in NAT genes have been shown to be a potential source of pharmacological and/or pathological susceptibility. In addition, there is now evidence that non genetic factors, such as substrate-dependent inhibition, drug interactions or cellular redox conditions may also contribute to NAT activity. The recent findings reviewed here provide possible mechanisms by which these environmental determinants may affect NAT activity. Interestingly, these data could contribute to the development of selective NAT inhibitors for the treatment of cancer and microbial diseases.

The Effects of Some Environmental Substances on the Outer Boundaries of Copper Specimen in Plain Torsion

This study investigated the effects of Environmental Substances (E.S.), i.e., carbon tetrachloride (CCl 4 ), benzene, ethyl alcohol, pipe-borne (tap) water, charcoal and air on a copper specimen in torsion. Applying torsion to the specimen was an attempt to simulate the metal cutting conditions that take place during machining processes. It was discovered that the E.S. on the outer surface of the copper specimen reduced the shear strain energy and power to fracture. The CCL 4 , benzene and ethylalchhohol reduced the strain energy and power sufficiently to be useful as additives in metal cutting coolants. One or a combination of these three when added to coolants will reduce machining cost as lower power will be generated by the cutting machines. It was also discovered that the reduction in strain energy and power was facilitated by the roughness of the surface finish of specimen. Keywords : Environmental substances, slip planes, micro-cracks, plastic deformation, intergranular corrosion. Journal of Applied Science, Engineering and Technology Vol. 6 (1) 2006 pp. 76-80

Information systems for the public health services—what do they need?

Health Offices have serious responsibilities in the environmental health sector. There is strong interest in information systems that suit the special needs of this agencies but until now there are no specialised systems available. In the development of information systems it is essential that the real needs of the public health sector are considered. Typical tasks of Health Offices are: approval of licence applications for industrial installations, advice on adverse health effects of environmental substances, risk communication with citizens, environmental health reporting for planning purpose, and environmental impact assessment in relation to health issues. For each of these activities different expertise and scope of information is necessary. Information will vary from chemical and physical information on substances and possible adverse health effects to information on existing laws and regulations and limit values. Additional information on environmental engineering and process engineering is essential.

P-157) - Effect of environmental substances on reactivation of HSV-2 from latent state in vitro

P-157) - Effect of environmental substances on reactivation of HSV-2 from latent state in vitro

O-158) - Effect of environmental substances on production of spontaneously occurring mammary carcinoma in C3H mice and leukemia in AKR mice

O-158) - Effect of environmental substances on production of spontaneously occurring mammary carcinoma in C3H mice and leukemia in AKR mice