Welcome to The Visible Embryo

Home- - -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- News Alerts -Contact

Welcome to The Visible Embryo, a comprehensive educational resource on human development from conception to birth.

The Visible Embryo provides visual references for changes in fetal development throughout pregnancy and can be navigated via fetal development or maternal changes.

The National Institutes of Child Health and Human Development awarded Phase I and Phase II Small Business Innovative Research Grants to develop The Visible Embryo. Initally designed to evaluate the internet as a teaching tool for first year medical students, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than ' million visitors each month.


WHO International Clinical Trials Registry Platform
The World Health Organization (WHO) has created a new Web site to help researchers, doctors and patients obtain reliable information on high-quality clinical trials. Now you can go to one website and search all registers to identify clinical trial research underway around the world!



Home

History

Bibliography

Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Archive
Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.
Content protected under a Creative Commons License.

No dirivative works may be made or used for commercial purposes.

Return To Top Of Page
Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
Search artcles published since 2007

October 25, 2012--------News Archive Return to: News Alerts



Congress has banned bis(2-ethylhexyl) phthalate, or DEHP, in children’s
products. California lists it as a carcinogen and developmental toxin.



Firemaster 550, a flame retardant commonly used in furniture foam, is made with
bis(2-ethylhexyl) tetrabromophthalate, or TBPH. The chemical is structurally identical
to DEHP except for four bromine atoms that take the place of four hydrogen atoms.

WHO Child Growth Charts

       

Flame Retardant ‘Firemaster 550’ Is an Endocrine Disruptor

The flame-retardant mixture known as “Firemaster 550” is an endocrine disruptor that causes extreme weight gain, early onset of puberty and cardiovascular health effects in lab animals, according to a new study spearheaded by researchers from North Carolina State University and Duke University


Firemaster 550 is made up of four principal
chemicals and is used in polyurethane foam
in a wide variety of products, ranging from
mattresses to infant nursing pillows.

The flame-retardant mixture was developed
by Chemtura Corp., and was developed
to replace a class of fire retardants being phased
out of use because of concerns regarding their safety.

This new study represents the first
public data on whether Firemaster 550
has potential health effects.


In this pilot study, pregnant lab rats were assigned to three groups: a control group, which was not exposed to Firemaster 550; a “low-dose” group, which ingested 100 micrograms of Firemaster 550 once per day throughout pregnancy and nursing; and a “high-dose” group, which ingested 1,000 micrograms on the same schedule. These environmentally relevant doses are lower than the doses used in industry-funded studies. Researchers then evaluated the physiological outcomes of the exposure in both the mothers (called dams) and the offspring (called pups).

Importantly, the researchers detected TBB, one of Firemaster 550’s component chemicals, in the fat of all the exposed dams and offspring, but none of the unexposed animals. This means the flame retardant is capable of crossing the placenta during pregnancy, reaching infants via breast milk, or both.

Because flame retardants that have been phased out are known to disrupt thyroid function, and Firemaster 550 includes chemicals with structural similarities, the researchers looked at circulating thyroid hormone levels in dams at the end of the nursing period. The high-dose dams had much higher thyroid hormone levels than the control group, while low-dose dams had marginally higher thyroid hormone levels. This is significant because thyroid hormones influence brain development during pregnancy, as well as a host of other biological functions, such as metabolism.

Researchers also found extremely rapid weight gain in the offspring. By the time they were weaned from nursing, high-dose male pups were 60 percent heavier than the control group – and high-dose female pups were 31 percent heavier than the control group.

The increased weight in female pups contributed to the early onset of puberty. The control group hit puberty at 33 days old, while the high-dose group hit puberty at 29 days.

High-dose female pups also had difficulty regulating their glucose levels as adults. High-dose males had thickened walls in the left ventricle of the heart, suggestive of cardiovascular disease.


“This study indicates that Firemaster 550
is an endocrine disruptor, and that raises a lot
of important questions.

This was a small-scale study.
We need to continue this work with
a larger sample size and look at a broader
range of potential effects related to obesity,
thyroid hormone function and metabolic syndrome.

We also want to determine which
of the component chemicals in Firemaster 550
are responsible for the various effects.”

Dr. Heather Patisaul
assistant professor, biology, NC State
lead author of a paper describing DEHP


The paper, “Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster 550 in Rats: An Exploratory Assessment,” is published online in the Journal of Biochemical and Molecular Toxicology. Co-authors include NC State undergraduate Natalie Mabrey; NC State research technician Katherine McCaffrey; Heather Stapleton and Simon Roberts of Duke University; Robin Gear and Scott Belcher of the University of Cincinnati; and Joe Braun of Brown University.

The research was funded by the National Institute of Environmental Health Sciences.

Study abstract follows:
“Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster 550 in Rats: An Exploratory Assessment”

Authors: Heather B. Patisaul, Natalie Mabrey and Katherine A. McCaffrey, North Carolina State University; Simon C. Roberts and Heather M. Stapleton, Duke University; Robin B. Gear and Scott M. Belcher, University of Cincinnati; and Joe Braun, Brown University

Published: Online Oct. 24 in Journal of Biochemical and Molecular Toxicology

Abstract: Firemaster 550 (FM 550), a fire-retardant mixture used in foam-based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 [micrograms]/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels.

Original article: http://news.ncsu.edu/releases/wms-patisaul-firemaster/