Name: Mehak Sikka
Url: http://www.medicinenet.com/angelman_syndrome/article.htm
Angelman syndrome is a genetic condition that is present at birth (congenital). It causes intellectual disability and other features. Other characteristics of Angelman syndrome include distinctive facial features, mental retardation, speech problems and hyperactive behaviour. In most cases, the cause is a missing section (deletion) on the mother’s copy of chromosome 15. Angelman syndrome was once known as ‘happy puppet syndrome’ because of the child’s sunny outlook and jerky movements. It is now called Angelman syndrome after Harry Angelman, the doctor who first investigated the symptoms in 1965. Most diagnoses are made between the ages of three and seven years of age. Estimates vary, but Angelman syndrome is thought to affect one child in every 10,000 to 25,000. Angelman syndrome may be mistaken for autism because of similar symptoms, including hyperactive behaviour, speech problems and hand flapping. However, a child with Angelman syndrome is highly sociable, unlike a child with autism. It is important that the child is carefully diagnosed, because sometimes Angelman syndrome and autism are both present. There is no cure for Angelman syndrome.
In our class, during the Unit on molecular genetics, we learned about a few genetic disorders and what can happen when genetic mutations take place in DNA sequences. We learned about chromosomal mutations too. This is how Angel man syndrome relates to what we've learned during Term 2.
Sunday, January 11, 2015
Lettuce Pills May Help Treat Haemophilia
Source URL: http://www.scientificamerican.com/article/lettuce-pills-you-heard-that-right-may-help-treat-haemophilia/
Name: Lee Dong
Author and Date of Article: Elie Dolgin, Dec. 16 2014
Article Summary:
In humans, there are two common forms of Haemophilia, a disorder that impairs the body's ability to clot blood.The second most common form of Haemophilia, Haemophilia B, is when the body has a natural lack of Factor IX, a protein that helps the coagulation or clotting of the blood. However, when 5% of humans with Haemophilia B are treated with a replacement coagulation proteins, the body mistakes the foreign therapy proteins as dangerous and develops an antibody that fights the protein. This problem is even worse with the most common form of Haemophilia, Haemophilia A, when the body lacks the protein Factor VIII. 30% of humans suffering from Haemophilia A start to produce antibodies to therapy proteins of Factor VIII. In fact, if the therapy continues with both forms of Haemophilia when there is an antibody produced by the body, life-threatening allergic reactions like anaphylaxis can occur.
A treatment developed by scientists partially solves this by very frequently inserting the proteins needed to lower antibody resistance to them. However, this has a success rate of only 75% and is not only time-consuming but very expensive. But with the genetic engineering of lettuce cells to contain chloroplasts producing Factor IX and VIII, one can avoid the production of antibodies for the foreign proteins before the therapy even starts to insert them into the human body. Although this lettuce-cell powder does not prevent the failure of clotting blood by themselves, it prevents antibodies from forming so effective proteins can be inserted without immune resistance.
Article Significance:
The mentioned article is very relevant to two focuses that the Honors Biology curriculum has touched in the span of the ongoing year: genetics and GMOs. Haemophilia is a sex-linked trait, occuring on the X chromosome. Thus, males are more susceptible to Haemophilia because they only have one X chromosome, thus if the gene for Haemophilia is inherited from that X chromosome, the male will have Haemophilia. Since this is treated by genetically modified lettuce chloroplasts, this also would cover the mini-unit on GMOs. The lettuce cells that had been used did not initially contain anything that produced Factor IX or Factor VIII, all genes of which were shot into the lettuce cells via gene gun or a bacteria plasmid infection. Thus, the lettuce cells are considered GMO, and are used in this case for medicine. Relating to the class debate regarding the use of GMOs in present-day society, this could be used as supporting data as to why GMOs can be beneficial, finding a way to regulate haemophilia in both a more convenient and cost-effective method.
Name: Lee Dong
Author and Date of Article: Elie Dolgin, Dec. 16 2014
Article Summary:
In humans, there are two common forms of Haemophilia, a disorder that impairs the body's ability to clot blood.The second most common form of Haemophilia, Haemophilia B, is when the body has a natural lack of Factor IX, a protein that helps the coagulation or clotting of the blood. However, when 5% of humans with Haemophilia B are treated with a replacement coagulation proteins, the body mistakes the foreign therapy proteins as dangerous and develops an antibody that fights the protein. This problem is even worse with the most common form of Haemophilia, Haemophilia A, when the body lacks the protein Factor VIII. 30% of humans suffering from Haemophilia A start to produce antibodies to therapy proteins of Factor VIII. In fact, if the therapy continues with both forms of Haemophilia when there is an antibody produced by the body, life-threatening allergic reactions like anaphylaxis can occur.
A treatment developed by scientists partially solves this by very frequently inserting the proteins needed to lower antibody resistance to them. However, this has a success rate of only 75% and is not only time-consuming but very expensive. But with the genetic engineering of lettuce cells to contain chloroplasts producing Factor IX and VIII, one can avoid the production of antibodies for the foreign proteins before the therapy even starts to insert them into the human body. Although this lettuce-cell powder does not prevent the failure of clotting blood by themselves, it prevents antibodies from forming so effective proteins can be inserted without immune resistance.
Article Significance:
The mentioned article is very relevant to two focuses that the Honors Biology curriculum has touched in the span of the ongoing year: genetics and GMOs. Haemophilia is a sex-linked trait, occuring on the X chromosome. Thus, males are more susceptible to Haemophilia because they only have one X chromosome, thus if the gene for Haemophilia is inherited from that X chromosome, the male will have Haemophilia. Since this is treated by genetically modified lettuce chloroplasts, this also would cover the mini-unit on GMOs. The lettuce cells that had been used did not initially contain anything that produced Factor IX or Factor VIII, all genes of which were shot into the lettuce cells via gene gun or a bacteria plasmid infection. Thus, the lettuce cells are considered GMO, and are used in this case for medicine. Relating to the class debate regarding the use of GMOs in present-day society, this could be used as supporting data as to why GMOs can be beneficial, finding a way to regulate haemophilia in both a more convenient and cost-effective method.
Conditional reprogramming leads to breakthroughs on the cancer front
Source: http://www.npr.org/blogs/health/2015/01/07/372691919/a-bed-of-mouse-cells-helps-human-cells-thrive-in-the-lab
Author: Richard Harris
Date: January 7, 2015
In Georgetown University Medical Center, Dr. Richard Schlegel and his group found a way to keep human cells alive in the lab, using a technique called conditional reprogramming. This technique works by placing a layer of living mice cells that are unable to grow, underneath the living human cells. For reasons still unknown to Dr. Schlegel, the mice cells keep the human cells alive in the lab without issue. This is a instrumental breakthrough, as previously, it was very difficult to keep human cells alive in the lab. In addition, when they were kept alive, they often were not biologically similar to similar cells found in the body.
Dr. Schlegel and his group have grown over 30 types of cancer cells with this technique. On these cells, they now have the ability to test different medications and vaccines, not only the medications specifically prescribed for cancer. While testing a variety of different medications on cervical cancer cells, Dr. Schlegel noted that a common drug used to treat malaria also killed cervical cancer cells. Working with Dr. Connie Trimble and her team at Johns Hopkins University School of Medicine, Dr. Schlegel is now running clinical trials with this drug. There is hope that the drug will be able to help treat women with cervical cancer that do not have access to life-saving surgery.
This research relates to our class as we discussed cancer in our unit on cells. It offers an alternative method to eradicate cancer cells to the ways we discussed in class. Also, the mice cells act as a medium for the human cells, providing them with nutrients that they need to survive. We discussed the topic of bacteria mediums in our unit on molecular genetics.
Author: Richard Harris
Date: January 7, 2015
In Georgetown University Medical Center, Dr. Richard Schlegel and his group found a way to keep human cells alive in the lab, using a technique called conditional reprogramming. This technique works by placing a layer of living mice cells that are unable to grow, underneath the living human cells. For reasons still unknown to Dr. Schlegel, the mice cells keep the human cells alive in the lab without issue. This is a instrumental breakthrough, as previously, it was very difficult to keep human cells alive in the lab. In addition, when they were kept alive, they often were not biologically similar to similar cells found in the body.
Dr. Schlegel and his group have grown over 30 types of cancer cells with this technique. On these cells, they now have the ability to test different medications and vaccines, not only the medications specifically prescribed for cancer. While testing a variety of different medications on cervical cancer cells, Dr. Schlegel noted that a common drug used to treat malaria also killed cervical cancer cells. Working with Dr. Connie Trimble and her team at Johns Hopkins University School of Medicine, Dr. Schlegel is now running clinical trials with this drug. There is hope that the drug will be able to help treat women with cervical cancer that do not have access to life-saving surgery.
This research relates to our class as we discussed cancer in our unit on cells. It offers an alternative method to eradicate cancer cells to the ways we discussed in class. Also, the mice cells act as a medium for the human cells, providing them with nutrients that they need to survive. We discussed the topic of bacteria mediums in our unit on molecular genetics.
CRE Germs Pose A Threat On Human Health As We Know It
Devon Lukas
Source: http://www.cdc.gov/media/dpk/2013/dpk-vs-hai.html
Author/Publication: N.a./ CDC, February 28, 2014
CRE, short for Carbapenem-Resistant Enterobacteriaceae, are a group of germs that are resistant to pretty much all antibiotics known in medicine today. CRE infections are bacterial infections that are spread by human to human contact. CRE infections occur almost always in a hospital or in someone who is getting a lot of medical care. Though CRE is not actually that common, there are two unusual traits to it that gets health departments worried. The first is its resistance. Two types of CRE bacteria are the KPC and NDM enzymes that break down carbapenems, therefore, the infection is very hard to treat. Even some of the strongest drugs, called carbapenems, cannot fight the CRE germs. Due to this, a CRE bloodstream infection kills 1 in every 2 people that it infects.
The second is CRE's spreadability. CRE can actually transfer its resistance to antibiotics into other bacteria. Medical people are not only worried about the spread of CRE and it becoming a more common and untreatable infection, but also about it causing other bacteria to become antibiotic-resistant. About 4% of the 4,000 US hospitals, and about 18% of the 200 US long-term acute care hospitals had at least one CRE infected patient, and at least one infection has been reported in 42 of our states. Medical facilities are doing all they can to prevent the spread of this worrisome and untreatable infection, including the "Detect and Protect" approach, and only prescribing antibiotics when absolutely necessary.
The CRE crisis directly relates Mr. Hohn's Biology class's study on the evolution of antibiotic-resistance in bacteria, but also to our study of GMO's. CRE gaining resistance works through evolution. When antibiotics are used to treat infections and diseases, they are meant to kill off or slow the bacteria causing the problem. But the antibiotic causes selection within the bacteria, just like natural selection in animals, so that the bacteria evolves to fit an environment in which antibiotics are there. The antibiotic at first kills off most of the bacteria, but the ones resistant through a mutation, different gene, etc., survive and reproduce, making the resistance normal in that bacteria specie. Antibiotics used for something minor can also start the evolution process in other bacteria that is not even related to the minor issue. This is what medical officials found is happening with the CRE. Antibiotics used for a cold don't actually help the cold at all, and add to the resistance of much more dangerous bacterias already living in our bodies like the CRE. This is why they are trying to cut down on antibiotic prescription.
In our GMO unit, we talked about pesticide resistance becoming a problem for farmers. E. coli, which was in some of the GMO crops, is a type of CRE. The "superbugs and super weeds" that resulted from that became resistant to pesticides used to kill them and protect the crops, much like how the bacterial infection becomes resistant to antibiotics.
Source: http://www.cdc.gov/media/dpk/2013/dpk-vs-hai.html
Author/Publication: N.a./ CDC, February 28, 2014
CRE, short for Carbapenem-Resistant Enterobacteriaceae, are a group of germs that are resistant to pretty much all antibiotics known in medicine today. CRE infections are bacterial infections that are spread by human to human contact. CRE infections occur almost always in a hospital or in someone who is getting a lot of medical care. Though CRE is not actually that common, there are two unusual traits to it that gets health departments worried. The first is its resistance. Two types of CRE bacteria are the KPC and NDM enzymes that break down carbapenems, therefore, the infection is very hard to treat. Even some of the strongest drugs, called carbapenems, cannot fight the CRE germs. Due to this, a CRE bloodstream infection kills 1 in every 2 people that it infects.
The second is CRE's spreadability. CRE can actually transfer its resistance to antibiotics into other bacteria. Medical people are not only worried about the spread of CRE and it becoming a more common and untreatable infection, but also about it causing other bacteria to become antibiotic-resistant. About 4% of the 4,000 US hospitals, and about 18% of the 200 US long-term acute care hospitals had at least one CRE infected patient, and at least one infection has been reported in 42 of our states. Medical facilities are doing all they can to prevent the spread of this worrisome and untreatable infection, including the "Detect and Protect" approach, and only prescribing antibiotics when absolutely necessary.
The CRE crisis directly relates Mr. Hohn's Biology class's study on the evolution of antibiotic-resistance in bacteria, but also to our study of GMO's. CRE gaining resistance works through evolution. When antibiotics are used to treat infections and diseases, they are meant to kill off or slow the bacteria causing the problem. But the antibiotic causes selection within the bacteria, just like natural selection in animals, so that the bacteria evolves to fit an environment in which antibiotics are there. The antibiotic at first kills off most of the bacteria, but the ones resistant through a mutation, different gene, etc., survive and reproduce, making the resistance normal in that bacteria specie. Antibiotics used for something minor can also start the evolution process in other bacteria that is not even related to the minor issue. This is what medical officials found is happening with the CRE. Antibiotics used for a cold don't actually help the cold at all, and add to the resistance of much more dangerous bacterias already living in our bodies like the CRE. This is why they are trying to cut down on antibiotic prescription.
In our GMO unit, we talked about pesticide resistance becoming a problem for farmers. E. coli, which was in some of the GMO crops, is a type of CRE. The "superbugs and super weeds" that resulted from that became resistant to pesticides used to kill them and protect the crops, much like how the bacterial infection becomes resistant to antibiotics.
“Survival of the Most Productive” Tactic Boosts Output of Engineered Bacteria
Source: http://www.genengnews.com/gen-news-highlights/survival-of-the-most-productive-tactic-boosts-output-of-engineered-bacteria/81250755/
Published: Dec 31, 2014
Summary
Scientists
at Wyss Institute are using negative selection to engineer bacteria to be more productive. They bred the bacteria to produce an
industrially-valued chemical output in quantities 22 to 36 times more than
previously possible. Billions of cells
were evaluated in order to identify the rare cells with the high production
phenotypes. Once they are selected, they
are forced to reproduce and the process starts again. Multiple rounds of evolution were run to enrich
the population of the most productive cells.
This results in the engineering of the cell’s central metabolic
pathways, allowing the microbes to have superior pathway designs. Chemical production and ability to evaluate
the cells allows the researchers to harness evolution. They hope to apply the methods used to
improve production of more useful compounds.
Relevance
This article
is relevant to what we are learning in Honors Biology by relating to 14.3
artificial selection, or selective breeding.
The scientists here are evaluating the bacteria and selectively breeding
the bacteria that have the desired traits.
They also remove “cheater cells (non-producers)” as they go along with
the breeding. By doing this over and
over again they are changing the gene pool in the bacteria population, leading
to the perfect bacterium that is desired by the creator which is similar to what
we are studying in class.
New class of antibiotic found in dirt could prove resistant to resistance
Source: http://www.washingtonpost.com/news/speaking-of-science/wp/2015/01/07/new-class-of-antibiotic-found-in-dirt-could-prove-resistant-to-resistance/
By: Rachel Feltman
Published: January 7, 2015 by The Washington Post
Summary
Bacteria have been evolving to resist antibiotics quicker
than we can form new treatments. When an
antibiotic is put into use, the bacteria get accustomed to its effects and,
eventually, become resistant to it.
However, a new antibiotic has been found with a unique way of stopping
proliferation which may be able to put an end to these resistant bacteria. This new antibiotic was discovered by a
Northeastern University professor, Kim Lewis, when experimenting with a sample
of dirt in a field in Maine. Lewis and
his coworkers placed soil between two semi-permeable membranes, making the soil
microbes grow like the laboratory conditions were a natural environment. A Teixobactin, a specific chemical compound,
was identified by the experiment. It
destroyed drug-resistant TB and MRSA in the cells of mice. The antibiotic performed this action with the
bacteria neither gaining any resistance nor killing the mice. The mice that
were infected with the MRSA and given pneumonia did not show any notable side
effects either. This new type of
antibiotic aims at the building blocks of the bacteria’s cell wall, not at the
proteins inside like most antibiotics do.
Teixobactin binds two lipids that are essential in cell wall production,
so if one of the lipids grows a resistance, the other could still be
attacked. This tactic was successfully
tested, but there is no compound in existence that bacteria will never grow
resistant to. However, Teixobactin will
definitely take much longer for the bacteria to counter.
Relevance
This article is relevant to unit 6 because the unit mentions
the ability of bacteria to adapt to new antibiotics in 14.5 and how it has
cause the evolution of antibiotic-resistant populations. This article is all about trying to solve
that predicament by using a different technique, targeting the cell wall and
not the protein. This article talks
about how we can try to stop bacteria from constantly counteracting our
antibiotics, and how we might be able to slow it, but all compounds can be, eventually,
resisted by bacteria. This shows that
the problem of antibiotic-resistant bacteria will never be completely solved,
but it can, and hopefully, will be decelerated by Teixobactin.
Saturday, January 10, 2015
Evolution of Color in the Red Devil Ciclid
Lily Friedman
Source: http://www.sciencedaily.com/releases/2015/01/150109093727.htm
By: Monash UniversityPublished: January 9th, 2015
Summary:
When individuals from the same species come in different colors, why doesn’t one color eventually replace the others through natural selection? The Journal of Evolutionary Biology has studied a species of Central American freshwater fish, called the red devil cichlid, to see how different colors are maintained. This species comes in two colors; dark and gold. The gold color is genetically dominant, but the dark color is much more common. When the researchers filmed the red devil cichlids over both dark and light surfaces, they saw that the dark fish could alter its brightness to match the surface it was on, but the gold fish could not. This extra layer of camouflage helps hide the dark colored fish from predators, so they are more fit to survive in their environment. This study is being used to answer the big question of how and why do variants of the same animal exist in nature.
Relevance:
This is an example of natural selection, because even though the gold color is dominant, the dark color is more common. The dark colored fish are likely to be able to hide from predators, and survive long enough to have offspring and pass of their dark-colored gene. The gold fish are more likely to be eaten by predators, and not pass on their genes to the next generation, which is why the dark color is more common. Eventually, the species could evolve to have only dark colored fish because of this natural selection.
Source: http://www.sciencedaily.com/releases/2015/01/150109093727.htm
By: Monash UniversityPublished: January 9th, 2015
Summary:
When individuals from the same species come in different colors, why doesn’t one color eventually replace the others through natural selection? The Journal of Evolutionary Biology has studied a species of Central American freshwater fish, called the red devil cichlid, to see how different colors are maintained. This species comes in two colors; dark and gold. The gold color is genetically dominant, but the dark color is much more common. When the researchers filmed the red devil cichlids over both dark and light surfaces, they saw that the dark fish could alter its brightness to match the surface it was on, but the gold fish could not. This extra layer of camouflage helps hide the dark colored fish from predators, so they are more fit to survive in their environment. This study is being used to answer the big question of how and why do variants of the same animal exist in nature.
Relevance:
This is an example of natural selection, because even though the gold color is dominant, the dark color is more common. The dark colored fish are likely to be able to hide from predators, and survive long enough to have offspring and pass of their dark-colored gene. The gold fish are more likely to be eaten by predators, and not pass on their genes to the next generation, which is why the dark color is more common. Eventually, the species could evolve to have only dark colored fish because of this natural selection.
Subscribe to:
Posts (Atom)