The nematodeCaenorhabditis elegansexpresses two metallothioneins (MTs),
CeMT-1 and CeMT-2, that are believed to be key players in the protection
against metal toxicity. In this study, both isoforms were expressedin vitro in
the presence of either Zn(II) or Cd(II).
Cadmium is a heavy metal and a pollutant that can be found in large
quantities in the environment from industrial waste. Its toxicity for living
organisms could arise from its ability to alter thiol-containing cellular com-ponents. Glutathione is an abundant tripeptide (c-Glu-Cys-Gly) that is
described as the first line of defence against cadmium in many cell types.
At the open burning sites, some metals were present at
concentrations over one hundred times typical background levels
for soils, including lead, a highly toxic metal. High levels of other
toxic metals, including cadmium and antimony, were also present.
Numerous classes of organic chemicals were also present in one or
more of the samples, including many halogenated (chlorinated or
brominated) chemicals. Many of the compounds identified are
intentionally used in electronic devices.
It has been demonstrated that most heavy metals that are in the fuels or raw materials
used in cement kilns are effectively incorporated into the clinker, or contained by
standard emissions control devices (WBCSD 2002; European Commission (EC) 2004;
Vallet January 26, 2007). A study using the EPA’s toxicity characteristic leaching
procedure to test the mobility of heavy metals in clinker when exposed to acidic
conditions found that only cadmium (Cd) could be detected in the environment, and at
levels below regulatory standards (5 ppm) (Shih 2005).
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài:Toxicogenomic analysis of Caenorhabditis elegans reveals novel genes and pathways involved in the resistance to cadmium toxicity...
Extracellular signal-related kinase (ERK) is a key player in cell signaling.
After 25 years of investigation, ERK has been associated with every major
aspect of cell physiology. Cell proliferation, cell transformation, protection
against apoptosis, among others, are influenced by ERK function.
Cadmium ions are a potent carcinogen in animals, and cadmium is a toxic
metal of significant environmental importance for humans. Response
curves were used to investigate the effects of cadmium chloride on the
growth of Camplyobacter jejuni. In vitro, the bacterium showed reduced
growth in the presence of 0.1 mmcadmium chloride, and the metal ions
were lethal at 1 mmconcentration.
Toxic heavy metals, i.e. copper (II), lead (II) and cadmium (II), can be removed from water
by metallurgical solid wastes, i.e. bauxite waste red muds and coal fly ashes acting as sorbents. These
heavy-metal-loaded solid wastes may then be solidified by adding cement to a durable concrete mass
assuring their safe disposal. Thus, toxic metals in water have been removed by sorption on to inexpensive
solid waste materials as a preliminary operation of ultimate fixation. Metal uptake (sorption) and
release (desorption) have been investigated by thermostatic batch experiments.
The residence time that contaminants and nutrients remain in lichen tissue differs among elements (Pucket
1985). Macronutrients, such as nitrogen, sulfur, potassium, magnesium and calcium are comparatively
mobile and easily leached and therefore measurable changes in tissue concentrations can occur over weeks
or months with seasonal changes in deposition (Boongaprob et al. 1989). In one study, mobile elements
reached the same levels in transplants as the indigenous lichens within four to six months (Palomäki et al.
Metallothioneins (MTs) are cysteine-rich, metal-binding proteins known to
provide protection against cadmium toxicity in mammals. Metal exchange
ions for Cd
ions in metallothioneins is a critical process for
which no mechanistic or structural information is currently available.