Stories tagged Life Science

Jan
27
2008

Biological research resource

A great biology teaching resource can be found at biologybrowser.org. Both the Biology Browser home page and their search engine are subdivided into:

  • organism (animals, plants, viruses)
  • subjects (biodiversity, botany, genetics)
  • geography (Africa, Asia, North America)

To experiment, I entered the term "turtle" in the search box which resulted in 369 hits (the MN DNR web page entry, Turtles of Minnesota was #6).

Biological database gains several hundred links per day

A fourth column lists the latest additions to the BiologyBrowser database gleaned from the Biology News Net site. This week averaged about 300 new additions per day!

Access top papers and interviews with top scientists

Biology Browser
Biology BrowserCourtesy Art Oglesby
Another feature is the "Hot Topics" box inserted top and center of the page. Todays hot topic was "stem cells". The link took me to an Essential Science Indicators page listing the top 20 papers, authors, institutions, and journals.
An editorial section features, interviews, first-person essays, profiles, and other features about people in the stem cell field. Three scientists are featured, the first being Dr. Outi Hovatta discussing her highly cited paper, "A culture system using human foreskin fibroblasts as feeder cells allows production of human embryonic stem cells"
Check it out
If you wish to keep up with advances in the biological sciences, I recommend exploring BiologyBrowser and learn to use the tools they provide.

Jan
26
2008

Template for life created out of lab chemicals

Mycoplasma genitalium
Mycoplasma genitaliumCourtesy Department of Energy
Starting with simple laboratory chemicals, a group of scientists led by Craig Venter have replicated an entire bacterial genome. Based on an existing organism, the molecule of DNA Mycoplasma genitalium, composed of 582,970 base pairs, could come "alive" and start to replicate itself when inserted into a "hollow" bacterial host from which the DNA has been removed. The procedure titled, Complete Chemical Synthesis, Assembly, and Cloning of a Mycoplasma genitalium Genome was just published in Science.

"Venter and his colleagues have already managed to transplant the DNA from one bacteria into another, making it change species (see Genome transplant makes species switch/news070625-9). These bacteria were closely related to M. genitalium. If the transplant can be repeated with a man-made genome adapted from M. genitalium, the result could qualify as the first artificial life form (see 'What is artificial life?')" Nature News.

Customizing bacteria to solve problems

The genome of M. genitalium is one of the simplest, consisting of only 470 coding regions. Venter suspects about 100 of these are not necessary. The next step is to strip out various segments in an attempt to build the minimal amount of code that is essential for "life". This minimal component could then serve as a chassis to which "designer" genes could be attached, genes that could turn the bacteria into biological factories for making hydrogen (or other fuels).

Recommended reading:
Longest Piece of Synthetic DNA Yet (Scientific American)

Jan
22
2008

Human embryos using animal eggs

Embryo, 8 cells
Embryo, 8 cellsCourtesy Ekem
Last week we learned that scientists cloned human embryos using adult skin and fertile eggs from a woman donor. Now the Human Fertilization and Embryology Authority in Britain has approved creating human embryos using eggs from animals like cows or rabbits. Because the animal cell's nucleus would be removed before human DNA was added, scientists said the resulting egg would not be a chimera.

"Cow eggs seem to be every bit as good at doing this job as human eggs," said Lyle Armstrong of Newcastle University.
"We will only use them as a scientific tool and we need not worry about cells being derived from them ever being used to treat human diseases," Armstrong said.

Technique eliminates destruction of human eggs

Animal eggs are abundant and easily obtained. Researchers hope to refine their techniques by practicing first on animal eggs to producing human stem cells. Human stem cells, which have the ability to develop into any cell in the human body, show promise for understanding and healing many human ailments. The embryos would not be allowed to develop for more than two weeks.

Jan
21
2008

Carrots
CarrotsCourtesy niznoz
Researchers at Texas A&M and Baylor College of Medicine have genetically engineered a carrot that could deliver up to 40% more calcium. These scientists hope to start genetically modifying foods to increase their nutritional value. The genetic engineering of food so far has focused mostly on keeping crops healthy, making them resistant to pests and disease, and increasing their size and productivity. This is all great for farmers but doesn't specifically help you when you eat the food.

Would you be more likely to eat genetically modified foods if they were actually healthier for you? Take the poll.

Jan
18
2008

Sean Paul
Sean PaulCourtesy Manuel Lino
Epilepsy is one of those diseases that is so poorly understood that I am not surprised when I hear interesting triggers for dangerous seizures. However I was a little taken aback by this woman's story. She was able to help doctors determine the cause of her seizures when she noticed that she could trigger them when she heard the song "Temperature" by Reggaeton/Hip Hop artist Sean Paul. Using this information doctors were able to preform a series of surgeries and she hasn't has a seizure since.

Jan
18
2008

Aedes aegypti mosquito
Aedes aegypti mosquitoCourtesy Photo courtesy Centers for Disease Control and Prevention
A re-emerging threat
Dengue fever is making a come back in South America and some fear it could become a problem again in the US as well. The year 2007 was an epidemic record-breaking year there was an 11% increase in reported dengue cases when comparing 2006 to 2007. Some even fear it could be spreading to the US. There was a recent article in the Los Angeles Times about it reappearing in the US.
What is dengue fever?
Dengue is a viral infection spread by the predominantly urban species Aedes aegypti mosquitoes. In recent years dengue has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.
Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death. Dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena--often with enlargement of the liver--and in severe cases, circulatory failure.
Why is dengue making a come back?
Potential reasons include climate influences like global warming, El Niño / Southern Oscillation and La Niña, both of which influence the intensity and duration of the rainy seasons and hurricanes or induce intense droughts and damage to biodiversity. Another potential cause is population growth and increased opportunities for mosquitoes to breed.
On the other hand, micro factors exist that are dependent on the agent (virus) and the vector (mosquito)—which at times exhibits a growing resistance to insecticides—and the host, all of which closely influence the manifestation of the disease and its more serious forms.

Jan
18
2008

Blastocyst day 5
Blastocyst day 5Courtesy Ekem

DNA from clone identical to that from adult skin donor

A paper published in the online journal, Stem Cells, yesterday titled "Development of Human cloned Blastocysts Following Somatic Cell Nuclear Transfer (SCNT) with Adult Fibroblasts" is the first documented demonstration that ordinary cells from an adult human can be used to make cloned embryos mature enough to produce stem cells

"A research team at Stemagen, a biotech company based in San Diego, California, started with skin cells donated by two men and 25 eggs, or oocytes, donated by women at a nearby fertility center. The scientists removed the DNA-containing nuclei from the eggs and replaced them with DNA from the donor skin cells. Two of the eggs became 5-day-old embryos, or blastocysts, that were clones of the male donors."Science

Why are we cloning humans?

The next big step will be to create a human embryonic stem cell line from cloned embryos. Stem cells from cloned embryos could provide a valuable tool for studying diseases, screening drugs, and creating transplant material to treat conditions like diabetes and Parkinson's disease.

Should we be doing this?

As expected, critics are raising objections. This procedure requires cutting healthy eggs out of women, then altering them to produce living embryos, which are then destroyed. Should this be allowed?

Read more

Jan
14
2008

Dead heart transformed into a living heart

Tissue engineering has allowed a dead rat heart to be stripped of its cellular material, then after injecting the remaining scaffold material with with new cardiac cells, the cells organized themselves until the heart became alive.

A "crazy idea" at the University of Minnesota that could not get federal funding yielded "unbelievable" results after getting funding from the University of Minnesota and from the Medtronic Research Foundation.

New source for replacement organs

The accomplishment gave a significant boost to medicine’s dream of growing human organs to replace damaged ones. Organ transplants usually require replacement organs that fulfill extreme compatibility issues. By using the patients own cells in the rebuilt organs scientists hope to eliminate the need for patients to take anti-rejection drugs for the rest of their lives.

Growing human hearts at least 10 years away, if ever

The next step will be to use these techniques on pig hearts. Pig hearts are similar enough to a humans that parts from them have already been used in humans.

"Although this is only a first step requiring considerable follow-up development, the study nevertheless represents an exciting breakthrough that will eventually make the prospect of repairing damaged hearts a reality and will also be an approach that can be extended to other organs." Dr Jon Frampton Wellcome Trust Senior Fellow at the University of Birmingham

Source articles
TwinCities.com
New York Times
BBC News
USA Today
Nature Medicine journal's Perfusion-decellularized matrix: using nature's platform to engineer a bioartificial heart (abstract)

Jan
13
2008

My mother, Laura, now 51 was born with this disease yet no doctor ever diagnosed her with it. Now, I have two daughters, Mahayla 3, and Jorja 2, that have been diagnosed with Hereditary Sensory Autonomic Neuropathy. We live in Florida and the geneticist recommended that we move north to cooler weather. Due to the girls not being able to regulate their body temperatures and them constantly running fevers for no apparant reasons. However, I have raynauds and possible scleroderma thus cannot stand to be in cold weather. But can handle it with keeping warm. My oldest daughter has the symptom of not feeling things. She has cut herself on the bottom of her feet and does not know it until I am giving her a bath and I ask her.
I do not know what to do. I am a single parent and I work. The genecist told me not to let them ride a school bus and make sure that we had things prepared in case the electricity ever goes out. So I am always trying to figure a way to keep them cool. During the summer they stay in the apartment and cannot go outside. Now I am considering moving to Alabama but cannot really afford to move and to make sure that they have everything they need to stay alive.
If you have any ideas please feel free to email me @ [email protected]

Dec
28
2007

All the signs are there: Wild eyes, disheveled appearance, straw stuck up the nose... How could they not have known what their kitty was up to?
All the signs are there: Wild eyes, disheveled appearance, straw stuck up the nose... How could they not have known what their kitty was up to?Courtesy melissambwilkins
Cosmos Magazine has defied all standards of taste and tradition by releasing a top 13 list of strange animal stories of 2007. Except for top 5’s, odd numbered top lists are frustrating and should be avoided. Top lists numbering over 10 practically defeat the purpose, and choosing 13 is practically tempting fate. They should have just thinned the list. Number 12, at the very least, could easily have been cut.

Still we’ve got some good stories here. The Queensland suggestion to kill invasive cane toads by practicing golf swings on them was pretty sharp, and the cockatoo that tried to hatch chocolate eggs was fun in a depressing way, but, as far as I’m concerned, the “sick” cat who turned out just to be high on its owners’ cocaine takes the cake. Bad kitty! If only there were a DARE program for pets.