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!




Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Alerts 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

May 18, 2012--------News Archive Return to: News Alerts

This young girl was bedridden with a rare inherited brain disease (AADC)
before participating in a gene therapy clinical trial in Taiwan. Pictured here
two years later in a photo supplied by lead researcher Dr. Paul Wuh-Liang
Hwu of National Taiwan University Hospital, she smiles and displays
greater mobility. The University of Florida supplied gene therapy
expertise and the “vector” used to deliver corrective
genes to four clinical trial patients.

WHO Child Growth Charts

What Is Your BMI?


Incurable Brain Disease Improves After Gene Therapy

Using gene transfer techniques pioneered by University of Florida faculty, Taiwanese doctors have restored some movement in four children bedridden with a rare, life-threatening neurological disease

The first-in-humans achievement may also be helpful for more common diseases such as Parkinson’s that involve nerve cell damage caused by lack of a crucial molecule in brain tissue. The results are reported today in the journal Science Translational Medicine*.

The children in the study, who ranged in age from 4 to 6, inherited a rare disease known as aromatic L-amino acid decarboxylase deficiency, or AADC. Patients with AADC are born without an enzyme that enables the brain to produce the neurotransmitter dopamine. They generally die in early childhood.

In a phase 1 clinical trial led by Dr. Wuh-Liang Hwu, of the National Taiwan University Hospital, surgeons used a delivery vehicle called an adeno-associated virus type 2 vector to transport the AADC gene into localized areas of the brains of three girls and a boy.

Before therapy, the children showed practically no spontaneous movement and their upper eyelids continually drooped. After receiving the corrective gene, the children gradually gained some head movement. Sixteen months afterward, the children’s weight had increased, one patient was able to stand and the other three were able to sit up without support.

The study shows gene therapy that targets AADC deficiency is well-tolerated and leads to improved motor development and function, according to co-authors Dr. Barry Byrne, director of UF’s Powell Gene Therapy Center, and Richard O. Snyder, director of UF’s Center of Excellence for Regenerative Health Biotechnology. Both are members of the UF Genetics Institute.

“The children in this study have the most severe form of inherited movement disorder known, and the only treatments so far have been supportive ones,” said Byrne, a pediatric cardiologist and associate chairman of the department of pediatrics in the College of Medicine. “It is gratifying to see it is possible to do something to help them, other than providing feeding tubes and keeping them safe. This absolutely opens the door to the possibility of even earlier treatment of neurological diseases by direct gene transfer, and has implications for Parkinson’s disease, ALS and even cognitive diseases such as dementia when caused by gene defects.”

The Powell Gene Therapy Center provided expertise to the Taiwanese physicians on treating the patients and engineering the corrective gene that spurs production of the absent AADC enzyme. UF’s Center of Excellence for Regenerative Health Biotechnology manufactured the vector, packaging genetic material it received from Taiwan into virus particles that were purified, characterized and tested for sterility and stability before being shipped to the clinic for use in patients.

“We are ecstatic that we manufactured a product that provided therapeutic benefit to these patients,” said Snyder, an associate professor in UF’s department of molecular genetics and microbiology. “What really makes it special is there are just a handful of examples of gene therapy in children in the world, and these patients all improved.”

Doctors injected the AADC vector into a brain area called the putamen, a site known for AADC activity and part of a “loop” of brain connections related to movement.

Postoperative CT and MRI scans of the patients showed no evidence of bleeding and all four patients were discharged within a week. Three to six months after gene transfer, all the children had gained weight, including one patient who doubled her weight within a year.

Before gene therapy, all patients showed low raw scores in cognition and motor development on a scale called the Comprehensive Developmental Inventory for Infants and Toddlers. Afterward, scores in both areas increased.

Parents reported the children also slept better and had improved eye coordination, emotional stability and body temperature stability.

Eight additional children — four in Taiwan and four in the United States — are expected to receive the experimental treatment, Byrne said.

Aromatic L-amino acid decarboxylase (AADC) is required for the synthesis of the neurotransmitters dopamine and serotonin. Children with defects in the AADC gene show compromised development, particularly in motor function. Drug therapy has only marginal effects on some of the symptoms and does not change early childhood mortality. Here, we performed adeno-associated viral vector–mediated gene transfer of the human AADC gene bilaterally into the putamen of four patients 4 to 6 years of age. All of the patients showed improvements in motor performance: One patient was able to stand 16 months after gene transfer, and the other three patients achieved supported sitting 6 to 15 months after gene transfer. Choreic dyskinesia was observed in all patients, but this resolved after several months. Positron emission tomography revealed increased uptake by the putamen of 6-[18F]fluorodopa, a tracer for AADC. Cerebrospinal fluid analysis showed increased dopamine and serotonin levels after gene transfer. Thus, gene therapy targeting primary AADC deficiency is well tolerated and leads to improved motor function.

Copyright © 2012, American Association for the Advancement of Science
Citation: W.-L. Hwu, S.-i. Muramatsu, S.-H. Tseng, K.-Y. Tzen, N.-C. Lee, Y.-H. Chien, R. O. Snyder, B. J. Byrne, C.-H. Tai, R.-M. Wu, Gene Therapy for Aromatic L-Amino Acid Decarboxylase Deficiency. Sci. Transl. Med. 4, 134ra61 (2012).

Original article: http://news.ufl.edu/2012/05/16/gene/