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Liz Richardson

Environmental Signaling: What Embryos and Evolution Teach Us About Endocrine Disrupting... - 0 views

edrv.endojournals.org/...319

environmental EED estrogen

shared by Liz Richardson on 08 Jun 10 - Cached
  • Liz Richardson on 08 Jun 10
     
    An overview of many endocrine disrupting chemicals, useful to anyone looking into the effects of environmental chemicals on organisms. Reference made to a book titled "Hormonal Chaos", by Sheldon Krimsky, describing how industrial and agricultural chemicals contact organisms and disrupt hormone function. Specifics on effects of environmental estrogens and fetal development.
Matthew Ragan

Estrogen Receptor Interacting with DNA - 0 views

www.ks.uiuc.edu/...dbd

estrogen receptor DNA HRE hormone

shared by Matthew Ragan on 11 May 10 - Cached
  • Matthew Ragan on 11 May 10
     
    Nuclear hormone receptor proteins form a class of ligand activated proteins that, when bound to specific sequences of DNA serve as on-off switches for transcription within the cell nucleus. These switches control the development and differentiation of skin, bone and behavioral centers in the brain, as well as the continual regulation of reproductive tissues.
Anna McLean

A list of endocrine-disrupting compounds - 0 views

www.ourstolenfuture.org/...chemlist.htm

shared by Anna McLean on 11 Jun 10 - Cached
  • Anna McLean on 11 Jun 10
     
    A useful list of compounds that includes the hormone system affected and mechanism. This would be a useful tool because each compound section has a references section where you may find other useful sources for your projects.
Anna McLean

Would you like lemon, or BPA with your water? - 0 views

likeafishinwater.com/...e-lemon-or-bpa-with-your-water

shared by Anna McLean on 11 Jun 10 - Cached
  • The only problem was that vinyl products generally contain significant amounts of Bisphenol-A (BPA), a plastic additive, exposure to which causes disruption of endocrine hormones
  • BPA in plastic baby bottles
  • What makes BPA such a problem? It affects everyone, but developing fetuses and small children are particularly vulnerable.
  • ...2 more annotations...
  • It alters the levels of endocrine hormones, which has effects ranging from learning disabilities to diseases and altered sexual development.
  • BPA is currently banned in Chicago, the State of Minnesota and Suffolk County, NY.
Liz Richardson

Global assessment of the state-of-the-science of endocrine disruptors - 0 views

www.who.int/...index.html

general EED wildlife humans

shared by Liz Richardson on 21 May 10 - Cached
  • Liz Richardson on 21 May 10
     
    This is just the index, but the WHO has attempted to pinpoint which hormone compounds are most effective EEDs, and which hormones are most often mimicked. Discusses EED effects on wildlife as well as humans. Criteria for assessment of endocrine disruptors proposed for future studies.
srom88

Pesticide Mixtures, Endocrine Disruption, and Amphibian Declines: Are We Underestimatin... - 1 views

www.ncbi.nlm.nih.gov/...PMC1874187

shared by srom88 on 24 May 10 - Cached
  • In addition to having highly permeable skin (which makes amphibians particularly vulnerable to chemical contaminants), amphibians also typically reproduce and pass through critical hormone-regulated developmental stages while in the aquatic environment
    • srom88
      srom88 on 24 May 10
       
      What about human skin and its permeability to these pesticides?
  • atrazine is of special concern because it is a ubiquitous, persistent contaminant of ground-water and surface water that is active at low, ecologically relevant concentrations
    • srom88
      srom88 on 24 May 10
       
      Atrazine is common pesticide used; definite possibility for a focus.
  • realistic pesticide mixture composed of chemicals applied to cornfields in York County, Nebraska.
    • srom88
      srom88 on 24 May 10
       
      Can also find different experiments in different locations in the US or even out of the country.
  • ...32 more annotations...
  • Radioimmunoassay
    • srom88
      srom88 on 24 May 10
       
      very sensitive technique used to measure concentrations of antigens (for example, hormone levels in the blood) without the need to use a bioassay.
  • With the exception of metalaxyl, no single compound affected mortality
  • mortality was 4% for animals exposed to single pesticides (range = 0–7.8%), with the highest mortality (7.8%)
  • Propiconizole significantly delayed time to initiate metamorphosis (FLE; F = 2.72, df = 10, p = 0.003) and time to complete metamorphosis (TR; F = 2.81, df = 10, p = 0.002) relative to controls (Figure 1).
  • Animals exposed to pesticide mixtures at 0.1 ppb had significantly longer larval periods: initiation of metamorphosis (days to FLE) was delayed
  • there was a significant effect on SVL at metamorphosis (F = 2.1, df = 10, p < 0.05; Figure 3). The smallest animals to metamorphose were those exposed to cyfluthrin, tebupirimphos, or atrazine
  • All the mixtures (0.1 ppb each pesticide) retarded growth
  • For the pesticide mixtures, 0.1 and 10 ppb atrazine + S-metolachlor resulted in a negative but nonsignificant relationship between TR and SVL, whereas 0.1 and 10 ppb Bicep II Magnum exposure resulted in maintenance of the positive relationship between TR and SVL, but the relationship was significant for the 0.1 ppb concentration only
    • srom88
      srom88 on 24 May 10
       
      Different combinations of pesticides will affect the organism differently.
  • Histologically, presumptive males maintained both a cortex and a medulla separated by connective tissue without clear formation of testicular lobules (e.g., undifferentiated), whereas females showed regression of the gonadal medulla and an ovarian vesicle but lacked significant numbers of developing oocytes in the cortical regions of the gonad
  • Seventy percent of the animals exposed to the nine-compound mixture were unable to sit upright. Exposure to the nine-compound pesticide mixture was associated with meningitis, otitis interna, and septicemia due to the gram-negative, water-borne bacteria Chryseobacterium (Flavobacterium) menigosepticum
  • Morbidity and mortality rates in animals treated with the nine-pesticide mixture were significant (G = 100.12, df = 4, p < 0.001) compared with those in controls or the other mixtures (all of which showed a 0% incidence) and reached 70% of the 59 animals that survived to complete metamorphosis in animals exposed to the pesticide mixture.
  • After noting that animals exposed to the nine-compound mixture contracted flavobacterial meningitis (see above “Flavobacterial response”), we examined the condition of the thymus as an estimate of immune function.
  • Although a sizable database examining the toxicological effects of pesticides on amphibians exists (Pauli 2004), most of these studies examine acute toxicity, morbidity, and mortality only
  • We demonstrated that a realistic pesticide mixture (based on a mixture applied to an actual field) at low ecologically relevant concentrations can have dramatic effects on amphibian development and growth, and ultimately (we predict) survivorship
  • one of these compounds (propiconizole) retards larval development and delays metamorphosis, and two others (tebupirimphos and cyfluthrin) retard larval growth. In addition to these new data, the present study confirms the retardation of amphibian development
  • Atrazine has a number of well-documented adverse effects on amphibian larvae. It is a potent endocrine disruptor that both chemically castrates and feminizes exposed male amphibian larvae and also retards larval development and growth
  • It also induces edema (Carr et al. 2003), erratic swimming (Carr et al. 2003), and irregular behavioral activity (Rohr and Palmer 2005) and is an immunosuppressant (Christin et al. 2003; Gendron et al. 2003; Kiesecker 2002) in amphibians.
  • As one of the world’s most commonly applied pesticides, it is the most common contaminant of groundwater and surface water
  • effects of atrazine on the gonads were not detectable because individuals from the present population do not complete sexual differentiation of the gonads before metamorphosis
  • retardation of growth and development was more severe when atrazine was combined with other pesticides (e.g., S-metolachlor), and the nine-pesticide mixture had the most severe impact.
  • amphibians (including leopard frogs) often breed in temporary water sources
  • Retardation of growth is also detrimental. Smaller size at metamorphosis limits food availability for newly metamorphosed frogs, which are gape-limited predators (Figure 12A). Further, smaller individuals are more susceptible to predators, which may also themselves be gape-limited predators
  • esticide mixtures retard growth and size at metamorphosis, exposed amphibians are less likely to find food and more likely to be preyed upon. Also, decreased size at metamorphosis combined with subsequent decreased postmetamorphic growth decreases the chances that amphibians will survive overwintering
  • alteration of the relationship between time to metamorphosis and size at metamorphosis is even more significant than either measured alone. In amphibians, the larval stage is a period of growth. A
  • pesticides that produce no effects alone may act as “enhancers” that worsen the effects of pesticides that act as “effectors” when the two groups of chemicals are combined.
  • characterize pesticide interactions as concentration additive or response additive
  • Pesticide-induced declines in populations as a result of decreased prey availability and increased susceptibility to predators (as a result of decreased size and the negation or reversal of the relationship between time to metamorphosis and size at metamorphosis) may be difficult to discern in the wild. Perhaps more important, emergent diseases caused by agents such as ranavirus
  • and chytrid
  • are considered major contributors to amphibian declines
  • the effects of atrazine on sex differentiation can negatively affect amphibian population
  • trazine has been shown to increase disease rates and parasite loads in amphibians by several pathogens
  • including the trematode associated with development of limb deformities
Liz Richardson

Crude Oil Toxicity - 1 views

www.sciencecorps.org/crudeoilhazards.htm

oil toxicity PAH

shared by Liz Richardson on 24 May 10 - Cached
  • Liz Richardson on 24 May 10
     
    For Charlotte: EEDs do not have to be hormone based, they can just influence the natural functions of hormones. This site is recently developed to help people understand the effects of the BP Oil spill in the Gulf. I hope it is informative.
Vanessa Ward

PLoS Biology: The Toxic Origins of Disease - 0 views

www.plosbiology.org/...journal.pbio.0050193

obesity endocrine origins of disease DES Blumberg Grun obesogen

shared by Vanessa Ward on 11 Jun 10 - Cached
  • During embryonic development, steroid hormones like estrogen control gene-expression programs to coordinate cell differentiation, growth, organogenesis, and metabolism.
  • “The moment we published something on bisphenol A, the chemical industry went out and hired a number of corporate laboratories to replicate our research. What was stunning about what they did . . . was they hired people who had no idea how to do the work.”
  • “whole-animal toxicological studies,” which look at different endpoints than the more mechanistic studies do, Hughes says. “That doesn't let you look at changes in gene expression, changes in epigenetic control of gene expression.
  • ...5 more annotations...
  • “I can tell you simply by the size of the animal which is DES-exposed and which isn't.”
  • “We found out that brain is a target, bone is a target . . . and now the new target is adipocytes.”
  • When he removed all the soy-derived plant estrogens from the mother's diet, he was astonished to see endogenous estradiol levels in the fetus rise, and the offspring become “horrifically obese.
  • Adding the weak plant estrogens back in the diet suppressed the far more potent endogenous estradiol, he discovered, by inhibiting an enzyme required to make it.
  • Recent evidence suggests that a class of ubiquitous environmental pollutants called organotins can also stimulate adipogenesis and interfere with energy balance
  • Vanessa Ward on 11 Jun 10
     
    This was one of the first articles that I looked in depth at and pretty much read all of. It presents some of the original research done on the effects Bisphenol-A on reproductive development and mammary gland formamation and how in the process led to a noticeable pattern between exposure and weight gain. The study of obesogens is a new field that was in a way accidentally discovered. It has been hypothesized that estrogen causes embryonic cells to develop into fat cells through a process called adipogenesis by chemicals called organotins. New research to support this is addressed in this article.
Anna McLean

Gender Benders & Endocrine Disruptors around You - 0 views

www.herplace.com/...gender-benders.htm

shared by Anna McLean on 08 Jun 10 - Cached
  • Some Health Consequences of DES
  • Timeline of Synthetic Endocrine Disruptors (POPs)
  • Mechanisms of Endocrine Disruption
  • Anna McLean on 11 Jun 10
     
    General ED site. Touches on consequences of DES use in offspring of the using mother. Includes a useful timeline of POP use
suwhitte

ehormone website - Tulane University - 0 views

e.hormone.tulane.edu

EED general

shared by suwhitte on 14 May 10 - Cached
  • suwhitte on 14 May 10
     
    Excellent website with current information on a variety of EED-related topics. Includes some learning modules and links to other resources.
Anna McLean

ScienceDirect - Brain, Behavior, and Immunity : The potential influence of maternal st... - 0 views

www.sciencedirect.com/science

Brandon Knight

shared by Anna McLean on 25 May 10 - No Cached
  • Anna McLean on 25 May 10
     
    Brandon, This may also be of interest to you.
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