Free Biology Videos and Movies
This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 3 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of Research than embryonic stem cells.Date: 2008-09-03 23:50:28 - Added by: ebiotek
Animal Cloning Animal cloning gone bad, waaaay bad Check out our website: www.KnGproduction.com Date: 2008-09-03 23:58:32 - Added by: ebiotek 
How to Clone a Sheep If you\'ve ever wondered how to clone a sheep, this simple step-by-step demonstration is just what you\'ve been looking for. Ten simple steps is all it takes to go from egg cell to infant sheep clone. DO NOT ATTEMPT AT HOME. Date: 2008-09-03 23:57:25 - Added by: ebiotek 
Cloning cloning video i made for class my junior year of high school Date: 2008-09-03 23:56:41 - Added by: ebiotek 
biology - nuclear transfer (clone creating) Nuclear Transfer is a form of cloning. The steps involve removing the DNA from an oocyte and while(unfertilized egg), and injecting the nucleus which contains the DNA to be cloned. In rare instances, the newly constructed cell will divide normally, replicating the new DNA while remaining in a pluripotent state. If the cloned cells are placed in the uterus of a female mammal, a cloned organism develops to term in rare instances. This is how Dolly the Sheep and many other species were cloned. Alternatively, if cells are extracted from the cloned cells during very early embryonic stages (blastocyst or morula), embryonic stem cells can be created. These cells can be grown in laboratories indefinitely and can theoretically be made into any of the 200+ cell types in the mammalian body, and thus are an extraordinary tool for biologists as well as a therapeutic agent with the potential to treat currently untreatable medical conditions. Date: 2008-09-03 23:55:55 - Added by: ebiotek 
Stem Cells and Human Cloning Dr Andrew Corbett presents the Stem Cell and Human Cloning Debate from an ethical perspective... Date: 2008-09-03 23:55:27 - Added by: ebiotek 
What's the difference between embyonic and adult stem cells? A 10 minute discussion on the difference between embryonic and adult stem cells. Focus is on the use of mesenchymal stem cells. Date: 2008-09-03 23:54:29 - Added by: ebiotek 
Adult Stem Cells and Regeneration Part 3 of 6 
Adult Stem Cells and Regeneration Part 2 of 6 This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 2 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells. Date: 2008-09-03 23:50:10 - Added by: ebiotek 
Adult Stem Cells and Regeneration Part 1 of 6 This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 1 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells. Date: 2008-09-03 23:49:50 - Added by: ebiotek 
Adult Stem Cells and Regeneration Part 6 of 6 This lecture by Dr. Nadia Rosenthal discusses the importance of adult stem cells in the tissue maintenance, development and regeneration. Part 6 of 6. HHMI description: Mature organisms have stem cells of various sorts, called adult stem cells. Adult stem cells supply cells that compensate for the loss of cells from normal cell death and turnover, such as the ever-dying cells of our skin, our blood, and the lining of our gut. They are also an essential source of cells for healing and regeneration in response to injury. Some animals, such as sea stars, newts, and flatworms, are capable of dramatic feats of regeneration, producing replacement limbs, eyes, or most of a body. It is an evolutionary puzzle why mammals have more limited powers of regeneration. Researchers are interested in pinpointing where adult stem cells reside and in understanding how flexible adult stem cells are in their ability to produce divergent cells such as muscle and red blood cells. Understanding the sources and the rules for the differentiation of adult stem cells is essential for tapping their therapeutic potential. Since consenting adults can provide adult stem cells, some people think that adult stem cells may be a less controversial area of research than embryonic stem cells. Date: 2008-09-03 23:49:20 - Added by: ebiotek
Jan 4, 2010
Biomedical Videos
Dec 20, 2009
Genetics and Birth Defects (Source:NIH)
Abnormalities see Birth Defects Achondroplasia see Dwarfism Acid Maltase Deficiency see Metabolic Disorders Adrenoleukodystrophy see Leukodystrophies Alpha-1 Antitrypsin Deficiency Anencephaly see Neural Tube Defects Arnold-Chiari Malformation see Head and Brain Malformations Brain Malformations see Head and Brain Malformations Canavan Disease see Leukodystrophies Dandy-Walker Syndrome see Head and Brain Malformations Duchenne Muscular Dystrophy see Muscular Dystrophy Fragile X Syndrome see Genetic Disorders Human Genome Project see Genes Hypermobility Syndrome see Ehlers-Danlos Syndrome Mucopolysaccharidoses see Metabolic Disorders PKU see Phenylketonuria von Recklinghausen's Disease see Neurofibromatosis
Diseases and Genes
Introduction to Genes and Disease
Genes and Disease is a collection of articles that discuss genes and the diseases that they cause. These genetic disorders are organized by the parts of the body that they affect. As some diseases affect various body systems, they appear in more than one chapter.
With each genetic disorder, the underlying mutation(s) is discussed, along with clinical features and links to key websites. You can browse through the articles online, and you can also download a printable file (PDF) of each chapter.
From Genes and Disease you can delve into many online related resources with free and full access. For example, you can visit the human genome to see the location of the genes implicated in each disorder. You can also find related gene sequences in different organisms. And for the very latest information, you can search for complete research articles, and look in other books in the NCBI Bookshelf. Currently over 80 genetic disorders have been summarized, and the content of Genes and Disease is continually growing.
The sequence of the human genome is providing us with the first holistic view of our genetic heritage. While not yet complete, continued refinement of the data bring us ever closer to a complete human genome reference sequence. This will be a fundamental resource in future biomedical research.
The 46 human chromosomes (22 pairs of autosomal chromosomes and 2 sex chromosomes) between them house almost 3 billion base pairs of DNA that contains about 30,000 - 40,000 protein-coding genes. The coding regions make up less than 5% of the genome (the function of the remaining DNA is not clear) and some chromosomes have a higher density of genes than others.
Most of the genetic disorders featured on this web site are the direct result of a mutation in one gene. However, one of the most difficult problems ahead is to find out how genes contribute to diseases that have a complex pattern of inheritance, such as in the cases of diabetes, asthma, cancer and mental illness. In all these cases, no one gene has the yes/no power to say whether a person has a disease or not. It is likely that more than one mutation is required before the disease is manifest, and a number of genes may each make a subtle contribution to a person's susceptibility to a disease; genes may also affect how a person reacts to environmental factors. Unraveling these networks of events will undoubtedly be a challenge for some time to come, and will be amply assisted by the availability of the sequence of the human genome.
Introduction to Genes and Disease- Blood and Lymph Diseases
- Cancers
- The Digestive System
- Ear, Nose, and Throat
- Diseases of the Eye
- Female-Specific Diseases
- Glands and Hormones
- The Heart and Blood Vessels
- Diseases of the Immune System
- Male-Specific Diseases
- Muscle and Bone
- Neonatal Diseases
- The Nervous System
- Nutritional and Metabolic Diseases
- Respiratory Diseases
- Skin and Connective Tissue
- Chromosome Map
Dec 19, 2009
Scientists Crack Genetic Code of Two Common Cancers
It is being called a scientific breakthrough. British researchers say they have mapped the entire genetic code for two types of cancers -- small cell lung cancer and melanoma, the most deadly type of skin cancer.Discovery could revolutionize cancer care, saving millions of lives
All cancers are caused by changes in the DNA of cells. DNA carries the cells' genetic information. That information changes when cells gradually mutate from normal to abnormal and then to malignant over time.
Scientists say if they could only crack the genetic codes of different types of cancers, they could save millions of lives.
Blood tests could spot tumors early on. And treatment would be far more successful. Dr. Jeanny Aragon-Ching is an oncologist at the George Washington University Medical Center. She says this discovery is a step toward an era of personalized medicine. "That is the thrust now because, for instance, for different types of cancers, we have different types of drugs that target different domains or mutations," she said.
The more information doctors have about how cancer cells develop, the more precisely they can prescribe a treatment to target those particular cells.
British scientists found 30,000 mutations in melanoma, a type of skin cancer that accounts for 75 percent of skin cancer deaths. They also found 23,000 mutations in small cell lung cancer. But not all of these mutations cause cancer. "It is the role of physicians and scientists to find out which of those mutations are the driving force, or the driving mutation that actually led to the cancer," she said.
Eventually, scientists might be able to target pre-cancerous cells and prevent deadly tumors from forming. But that day is still far away. "As an oncologist, my goal would be to one day see that we can transform cancer into a chronic disease. Cure is probably too generous of a word the way I see it, but to convert it to something more like chronic disease that is treatable," she said.
Just like high blood pressure that can be controlled with medicine, cancer could be a disease without the suffering we associate with it. Medical scientists the world over are now working to catalogue all the genes that mutate in many types of cancer as part of an International Cancer Genome Consortium. In the United States they are studying cancers of the brain, ovaries and pancreas.
In addition to lung cancer and melanoma, scientists are examining the DNA of breast cancer, as well as cancers of the liver, the mouth and the stomach. "I think each step forward is a step toward our goal, our ultimate goal, which is to relieve the suffering from cancer," she said.
Dec 15, 2009
Scientists Discover New Species of Dinosaur
Paleontologists say the dinosaur they call Tawa, was about the size of a large dog, but with a longer tail.
Scientists have discovered the fossilized remains of a new meat-eating dinosaur in a quarry in New Mexico. They say the finding sheds light on the evolution of these extinct creatures.
Paleontologists say the dinosaur they call Tawa, named for the Hopi Native American sun god, was about the size of a large dog, but with a longer tail, stood about 70 centimeters tall at the hips and was two meters long. The two-legged creature also had razor-sharp teeth for eating meat.
Scientists conducting an analysis of the newly-discovered, 215 million year old fossils and other early dinosaur remains say Tawa also had the characteristics of two other dinosaurs - the giant, plant-eating sauropod and the horned Triceratops.
They believe Tawa is the common ancestor of both dinosaur groups that migrated from Argentina to other parts of the world during the Pangea period, between 200 and 300 million years ago, when geologists say the Earth's continents were compressed into a single landmass.
The fossil discovery suggests that Tawa also used a land bridge from South America to make its way to North America, when Tyrannosaurus Rex began evolving into modern day birds, according to Sterling Nesbitt, a researcher at the University of Texas who led a team of excavators.
"Tawa is a little bit of a surprise because it's preserving these very early traits that we see in dinosaurs while living with animals that are much more closely related to bird," said Nesbitt.
According to Nesbitt, Tawa might answer important questions about a dinosaur called Herrerasaurus, which was discovered in Argentina in the 1960s.
Herrerasaurus has traits like T. Rex - including sharp claws and teeth - but lacks other characteristics of the carnivore. Scientists hope to determine whether Herrerasaurus is a direct descendant of Tawa or part of a different species of dinosaurs.
Nesbitt say the Hayden Quarry in northern New Mexico, where the ancient fossils were unearthed, is a rich bed containing other prehistoric bones and artifacts. He says he plans to continue digging at the site to learn more about Tawa.
"We want to know how it grew, how the features changed as the animal got older," he said. "We also want to look at the anatomical details."
A description of the new dinosaur species is reported this week in the journal Science.
Dec 13, 2009
Gene action may lead to diabetes prevention, cure
| LOS ANGELES, Dec. 12 (Xinhua) -- A gene commonly studied by cancer researchers may provide answers to ways of fighting diabetes, a new study shows. The gene, known in the science world as PFKFB3, is a regulator for metabolism, which plays a vital role in the development of diabetes, according to the study appearing in the Dec. Journal of Biological Chemistry. The gene has been linked to the metabolic inflammation that leads to diabetes. Understanding how the gene works means scientists may be closer to finding ways to prevent or cure diabetes, said the study conducted by researchers at Texas AgriLife Research. "Because we understand the mechanism, or how the gene works, we believe a focus on nutrition will find the way to both prevent and reverse diabetes," said Dr. Chaodong Wu, AgriLife Research nutrition and food scientist who authored the paper with the University of Minnesota's Dr. Yuqing Hou. Wu said the research team will collaborate with nutritionists to identify what changes or supplements in a diet will activate the gene to prevent or stop the progression of diabetes. He believes nutritionists working with the biological chemists can help develop food consumption plans that either prevent people from developing metabolic inflammation or cause existing conditions to retreat. "First we will need to identify what effective compounds will trigger the gene to regulate metabolism," Wu said. "Then we need to determine what combinations within foods are more effective." Wu noted that while it is a major health concern in the U.S., obesity does not necessarily cause diabetes to develop; i.e., just because a person is overweight does not mean they have diabetes. Rather, "metabolic inflammation" causes or exacerbates the disease. Metabolic inflammation is different from classic inflammation because there is no infection, virus or bacteria present, though the symptoms appear similar. |
Nov 23, 2009
Gene Mutations Linked to Early-Onset Inflammatory Bowel Disease
An international team has discovered that mutations in either of 2 related genes cause a severe and rare form of inflammatory bowel disease in young children. The discovery allowed the researchers to successfully treat one of the study patients with a bone marrow transplant.
Inflammatory bowel disease is a group of disorders that includes Crohn's disease and ulcerative colitis. The inflammation, or swelling, of the intestines can cause pain, damage the tissue and make the intestines empty frequently, resulting in diarrhea. Previous studies have identified dozens of genes and variants that affect the risk for adult-onset inflammatory bowel disease, but none that singly cause the disease.
An international research team set out to search for genetic risk factors for early-onset inflammatory bowel disease. They examined DNA from 2 unrelated families with children who were affected by the disease. The research team, which was supported by several sources, included scientists from NIH's National Center for Biotechnology Information (NCBI), University College London in the United Kingdom, Hannover Medical School in Germany and several other institutions.
The scientists found that mutations in either of 2 genes are sufficient to cause early-onset inflammatory bowel disease, as reported in the advance online edition of the New England Journal of Medicine on November 4, 2009. Screening 6 additional patients with early-onset colitis identified another mutation in one of the genes. The 2 genes code for the proteins IL10R1 and IL10R2. These proteins act together to receive signals from interleukin 10, a signaling molecule that plays a crucial role keeping the body's inflammatory responses in check. When either IL10R1 or IL10R2 is mutated, the signals from IL10 cannot be received, and the resulting inflammation causes tissue damage, especially in the gastrointestinal system.
One of the young patients who hadn't responded to other therapies was given a bone marrow transplant from a healthy sibling. Bone marrow transplants can cure genetic disorders when the affected gene is normally active in marrow-derived cells. However, because of the risks associated with the procedure, the transplants are used only in cases of severe disease. This patient showed dramatic improvement following the procedure and has remained in remission from inflammatory bowel disease for more than a year.
"This is an excellent example of how discovery of causative genes and mutations can enable clinicians to go from bench to bedside for an informed treatment of patients," says Dr. Christoph Klein of Hannover Medical School, who led the diagnosis and treatment effort.
"This discovery is a milestone in research on inflammatory bowel disease, and will enable us to gain further insights into the physiology and immunity of the intestine," says Dr. Erik Glocker of University College London.
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