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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!



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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
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October 23, 2012--------News Archive Return to: News Alerts


WHO Child Growth Charts

       

Robert J. Lefkowitz and Brian K. Kobilka are the recipients of the 2012 Nobel Prize in Chemistry

The Royal Swedish Academy of Sciences has announced that Lefkowitz, a Howard Hughes Medical Institute (HHMI) investigator at Duke University and Kobilka of Stanford University School of Medicine were winning for how cells sense their environment

For a long time, it remained a mystery how cells could sense their environment. Scientists knew that hormones such as adrenalin had powerful effects: increasing blood pressure and making the heart beat faster. They suspected that cell surfaces contained some kind of recipient for hormones. But what these receptors actually consisted of and how they worked remained obscured for most of the 20th Century.


Cells in our body are constantly exposed to a variety
of chemical signals—hormones, neurotransmitters,
growth factors, and sometimes even drugs—
that they need to interpret and translate into a response.

That task is handled by receptors that dot cell membranes.

Lefkowitz, who became an HHMI investigator at Duke
in 1976, essentially defined the field of receptor biology
through his work with G protein–coupled receptors,
the largest and most pervasive family of cell receptors.

A thousand or more of these receptors are known
to exist throughout the body, playing critical roles in sight, smell, and taste, and in regulating heart rate, blood pressure, pain tolerance, glucose metabolism, and virtual
ly all known physiological processes.


Surprisingly, Lefkowitz never fully intended to make research the focus of his career. As a child growing up in the Bronx, he read medical fiction and detective stories, and decided in third grade that he wanted to become a physician. He went to medical school at Columbia University, finishing first in his class. But during a two-year fellowship at the National Institutes of Health from 1968–70, he got hooked on receptor biology, a field that was then in its infancy.

At that time, experiments in other laboratories had only suggested the presence of cell receptors, but no one had ever proved their existence. Lefkowitz, however, was convinced they were real, and he set out to isolate them. Beginning with the ß2-adrenergic receptor in 1982, Lefkowitz isolated eight of the nine subtypes of adrenergic receptors and determined their complete amino acid sequences. The ßadrenergic receptors are among the most common G protein–coupled receptors, regulating the body's fight-or-flight response by responding to epinephrine.

Lefkowitz also discovered two new families of proteins that desensitize G protein–coupled receptors—a finding that has helped scientists understand, in molecular terms, how receptors become tolerant to certain drugs. The first is a novel family of enzymes called the G protein–coupled receptor kinases (GRKs) including the ßadrenergic receptor kinase (ßRK), and the second is a group of proteins called arrestins. Both protein families, he has shown, are widely distributed, and their actions are not limited to the ß-adrenergic receptors.


Understanding the actions of arrestins and GRKs
eventually may lead to new treatments for
human diseases, including heart failure,
Lefkowitz predicts. Recently his laboratory has
discovered that the
ßarrestin/GRK system is actually
bifunctional. It serves as a signal transduction
system by scaffolding various signaling systems
such as MAP kinases or AKT to the receptors,
even as it desensitizes G protein signaling.

Lefkowitz has found that it is possible to design
drugs that, while serving as antagonists for G protein
signaling, serve as agonists or stimulants of beneficial
ßarrestin-mediated signaling. Such "biased" ligands may
represent an entirely novel class of therapeutic agents.


In addition to more than three decades of discoveries in the laboratory, Lefkowitz is widely recognized for his dedication to mentoring and his tireless devotion to his students. Over the years, he has trained several hundred graduate students and postdocs in his laboratory. While acknowledging that there is no recipe for turning out successful researchers, Lefkowitz admits he is very much a "hands-on" mentor, one who enjoys daily interactions with those working in his laboratory. In small group meetings held three or four times a week in his office, he discusses results and plots strategy with students working on related projects.

When it comes to his own research, Lefkowitz says he remains fascinated by the way it "continuously renews itself and always feels fresh. I come to work every day with a sense of great anticipation and curiosity about what new discoveries and insights will come our way. Every question that we can answer poses several new ones that seem even more interesting than the one we've just answered."

Original article: http://hhmi.com/news/lefkowitznobel20121010.html