Chemistry: molecular biology and microbiology – Animal cell – per se ; composition thereof; process of...
Reexamination Certificate
2002-03-11
2004-05-25
Yucel, Remy (Department: 1636)
Chemistry: molecular biology and microbiology
Animal cell, per se ; composition thereof; process of...
C435S069100, C435S091100, C435S320100, C435S006120, C536S024100, C514S002600, C514S04400A
Reexamination Certificate
active
06740521
ABSTRACT:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
Japan Priority Application 2001-272478, filed Sep. 7, 2001 including the specification, drawings, claims and abstract, is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to highly sensitive cells that can detect environmental pollutants as well as to the detection methods employed.
BACKGROUND OF THE INVENTION
Currently, evaluation of the toxicity of environmental pollutants is accomplished by instrumental analysis or bioassays using test organisms. Instrumental analysis using, for example, HPLC, GC/MS or LC/MS, enables highly sensitive detection of environmental pollutants and these techniques have been established as a means for analyzing specific known components. Bioassays using mammalian, microbial and fish test organisms precisely reflect the effects of chemical substances on living organisms. However it is substantially impossible to test the effect of large numbers chemicals individually, without taking into account any synergistic effects multiple chemicals may have when tested together because these tests require a large number of animals. The difficulty is compounded when examining the effects of long-term exposure and effects over multiple generations. Thus, simple and economical methods of testing the effect of chemicals on a biological system are needed.
At present, some in vitro assay systems are known. Compounds are tested for mutagenicity using detection systems such as the Ames test, chromosomal aberration tests which uses cultured cells and the cytotoxicity test which measures cell growth rates. Additionally, new detection systems can detect characteristic features like estrogenic response using human breast cancer cells MCF-7 cells that express estrogen receptors. For example, vitellogenin, which usually appears in blood of female fish, is induced in male fish when they are exposed to xenoestrogen. Reporter assays are also known using cells transformed with a luciferase reporter gene.
Chemicals of social concern are not always detected by the conventional acute toxicity tests. Atmosphere, water and soil contain not only heavy metals but also various kinds of pollutants, including plastics, plasticizers, agrochemicals, plant estrogen etc., which are suspected endocrine disrupters. For example, heavy metals are known toxins and recent research reveals that some chemicals act as endocrine disrupters, but in many cases, the toxic mechanisms are unknown. It is possible our bodies are exposed to such chemicals, which are accumulated through food chains. Therefore, systems are demanded which can detect chemicals that cannot be evaluated by conventional methods or low exposure effects.
Another example is the occurrence of water blooms of phytoplankton are found in both fresh water and marine environment. Cyanobacteria blooms occur in water containing adequate levels of essential inorganic nutrients such as nitrogen and phosphorus. Some species of cyanobacteria produce toxins which are classified according to their mode of action into hepatotoxins (e.g. microcyctins, nodularins), neurotoxins (e.g. anatoxins), skin irritants and other toxins. Toxic water blooms have caused death in domestic and wild animals as well as human illness. Recently, it was reported that dialysis patients in Brazil died of acute hepatic failure due to cyanobacteria contamination of the water used. These toxins are not only present in the water, but are also accumulated in shellfish such as shrimps, prawns and lobsters. Therefore, such toxins may damage human health.
Methods of detecting microcystins are known. LC/MS provides a means of highly sensitive analysis of known individual components in a sample. It is also possible to detect microcystins using an enzyme immunoassay. Additionally, a simpler method of detecting the presence of microcystins exploits the, specific inhibitory activity of microsystins in protein phosphatase 1 and 2 activity assays in enzyme activity assays
Acute toxicities can be studied by their effect on functional disorders in animals or cultured cells. However, it requires much time and cost to obtain results with utmost confidence. Many kinds of chemicals are found in low concentrations in most environments so that it is difficult to detect these substances rapidly.
Therefore a rapid and simple assay, which enables the evaluation of effects on human and on ecosystems by endocrine disrupters and heavy metals is required. Environmental pollution has become more complicated, synergistic and long-term effects are now a serious problem. This discussion demonstrates the importance of bioassays and indicates the risk and use for the assessment.
In Chemical Abstracts, a database of chemical substances, about twenty million of substances have been registered. In Japan, about sixty thousand chemical substances are in daily use and, reportedly, not less than about ten thousand synthetic chemical substances have been or are being accumulated in the environment. Hazardous chemical substances, typically endocrine disrupters, whose toxicity can hardly be predicted by conventional toxicological methods are now known. Thus, it has become important to correctly understand the hazardous features possibly caused by those substances in order to facilitate protective measures or countermeasures.
Instrumental analysis by GC/MS or LC/MS technique can separate, identify and quantify single individual components, but are not suited as means to totally analyze or evaluate the influences of multiple components on living organisms. It is anticipated that a vast sum of time and cost will be required to individually investigate the influences of these known or unknown chemical substances occurring in trace amounts in humans or in the environment by these conventional instrumental methods. There is also a possibility that a plurality of chemical substances, each occurring in trace amounts, may produce a synergistically increased or modified influence on humans and environment. In particular, the landfill leachate of industrial wastes or the byproduct of refuse incineration contains not only known existing hazardous substances, but also unknown chemical substances. It is very difficult to investigate the hazardous features of such compounds individually, to say nothing of detecting synergistically enhanced complex contamination by a plurality of substances. Currently, however, such hazardous substances have been revealed as occurring in the environment one after another and, therefore, a method of rapidly detecting, with high sensitivity, the risk of hazardous chemical substances, including unknown chemical substances, occurring in the environment, is required.
In addition to in vivo methods using fish or mammals, are biological methods of evaluating the impact of hazardous chemical substances. Such in vitro methods, using cultured microbial or animal cells, can detect the binding of a hazardous chemical substance to a specific target protein. In some of these biological methods (bioassays), the influence of a test substance is detected by utilizing the specific response of the cell type used or of the derived tissues to the substance. In those cases, it is assumed that microorganisms, including yeasts, plants, fish and animal cells will react to the chemical substance. Furthermore, even in those systems in which human cells are used, the conventional bioassays detect the effect of trace chemical substances on cells via binding to a cell-specific receptor or receptors and as such are unable to generate complete information rapidly and with high accuracy.
In this respect, it is known that the stress response system, in particular the heat shock protein (HSP) inducing system, functions in all mammalian tissues and cells. Therefore, in bioassay systems utilizing this stress response, it is not necessary to take into consideration the basic problems regarding cell specificity. Furthermore, in the actual environment, e.g. in landfill leachate, although many pollutants are present this may only account for a few
Inamori Yuhei
Isoda Hiroko
Kitahara Mikio
Koyama Takashi
Maekawa Takaaki
Kaneka Corporation
Marvich Maria
Yucel Remy
LandOfFree
High-sensitive detection of environmental pollutants does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-sensitive detection of environmental pollutants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-sensitive detection of environmental pollutants will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3217396