Direct conversion of cell types could offer safer, simpler treatments than stem cells.
Ewen Callaway
The right cocktail of chemicals converts human skin cells directly into blood.www.ingrampublishing.comHuman skin cells can be transformed into blood without first being sent through a primordial, stem-cell-like state, according to a ground-breaking study.
The breakthrough, published online today in Nature1, follows work earlier this year showing that fibroblast cells from mouse skin, treated with the right cocktail of chemicals, can be transformed into neurons2 and heart muscle3. However, it is the first study to accomplish this feat with human cells, and the first to create progenitor cells — in this case for blood.
"It takes us a step along the line to believing that you can produce anything from almost anything," says Ian Wilmut, an embryologist and director of the MRC Centre for Regenerative Medicine in Edinburgh, UK. Such 'direct conversions' also offer a potentially safer, simpler tool for creating patient-specific cell therapies than is promised by adult cells reprogrammed to become stem cells (known as induced pluripotent stem cells, or iPS cells).
Mickie Bhatia, a stem-cell researcher at McMaster University in Hamilton, Canada, and his colleagues chose to make blood progenitors from skin cells because red blood cells created from stem cells do not make the adult form of haemoglobin. "Those cells, because they think they're embryonic, make embryonic and fetal blood," he says.
Creating a bloodline To make blood progenitor cells, Bhatia and his team collected skin fibroblasts from several volunteers. They infected the cells with a virus that inserted the gene OCT4, and then grew them in a soup of immune-stimulating proteins called cytokines.
OCT4 is one of a handful of Yamanaka factors used to transform fibroblasts into iPS cells, but Bhatia's team found no evidence that the blood progenitor cells that they had made went through an embryonic state. The cells' gene-expression patterns never resembled those of embryonic stem cells, and the blood progenitor cells didn't cause mice to develop teratomas — tumours that are characteristic of pluripotent cells.
“Everybody has their favourite cell type. There is a lot of this kind of alchemy going on.”
The progenitors did, however, produce all three classes of blood cells — white blood cells, red blood cells and platelets — all of which seemed to function as they should, according to a battery of experiments. The red blood cells made adult haemoglobin, not the fetal form.
The ultimate test would be transplanting the cells into humans, says Bhatia, but that isn't on the cards — at least not yet. "The clinical side is going to be a lot of work," he says. "At least from our estimation, this is the most encouraging result we've seen for using blood cells for cell-replacement therapy."
Sanguine about the possibilities The potential for therapy is very much on the minds of Bhatia and other scientists who are converting cells directly. Because the progenitor cells bypass pluripotency, there is little risk of them forming tumours when implanted into patients, says Wilmut, who is working on creating other progenitor cells in his own lab.
Deepak Srivastava, a developmental biologist and director of the Gladstone Institute of Cardiovascular Disease in San Francisco, California, led the team responsible for making heart muscle from mouse fibroblasts3. He says that directly converted cells could also offer simpler treatments than iPS cells: the fibroblasts that surround the heart could be transformed into new heart muscle using a stent that delivers drugs to reprogram the cells.
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Converted cells aren't without their drawbacks, though. Unlike iPS and embryonic stem cells, they cannot easily multiply in the lab, so producing the large quantities needed for applications such as screening drugs could prove tough, says Wilmut.
Despite lab experiments establishing that the converted blood cells are indistinguishable from adult blood cells, it is still too early to tell whether they will be as good as the real thing once they are inside patients, says George Daley, a stem-cell biologist at Children's Hospital Boston in Massachusetts.
In particular, epigenetic modifications — changes that modify gene expression without altering the DNA sequence — could differ between blood cells produced naturally and those created by direct conversion. "The journey from a zygote to a specialized blood cell is very long. The journey from a fibroblast to a blood cell in a petri dish may take a very different route," says Daley.
Even with these caveats, direct conversion is gaining in popularity. "Everybody has their favourite cell type," says Daley. "There is a lot of this kind of alchemy going on."
References1.Szabo, E. et al. Nature doi:10.1038/nature09591 (2010).
2.Vierbuchen, T. et al. Nature 463, 1035-1041 (2010). | Article | OpenURL | | ChemPort |
3.Ieda, M. et al. Cell 142, 375-386 (2010). | Article | OpenURL
Tuesday, 9 November 2010
Thursday, 4 November 2010
WHO selects UAE among best five countries in blood transfusion
Dr. Amin Al Amiri, Executive Director for Medical Practices and Licenses at the Ministry of Health and Chair of the Blood Transfusion National Committee, emphasized that the organization lauded the efforts of the UAE in blood transfusion, pointing out that it selected the UAE as one of the best five models in the field of blood transfusion and its role in enhancing the World Blood Donor Day.
The five listed countries are: South Africa, United Kingdom, Thailand, Canada and United Arab Emirates which is the first Arab country and seventh country worldwide that has been selected to host the world blood donators day in 2008. The ceremony was organized under the patronage of His Highness Sheikh Khelifa Bin Zayed Al Nahyan, UAE President.
He also mentioned that the four international organizations "World Health Organization, International Federation for Red Cross and Red Crescent, International Federation for Blood Transfusion and International Blood Donors Association" lauded the efforts of the UAE which led to its nomination as the headquarters for the WHO's Middle Eastern region. This selection was due to the UAE efforts in supporting blood donators and organizing blood donation ceremonies generally.
Dr. Al Amiri lauded the efforts of the other sectors especially the mosques in encouraging the residents to blood donation and the cooperation of the government sector in disseminating awareness campaigns about blood donation and the usage of modern techniques as well as text messages especially the Ministry of Education, Ministry of Social Affairs to encourage students to participate in the activities of the blood donation center and research in Sharjah.
"We would like to thank the social organizations and institutions for their support to the Ministry of Health referring that the ministry's success could not have been accomplished in the field of blood transfusion campaigns and blood donators without their cooperation", he concluded.
WAM/TF
The five listed countries are: South Africa, United Kingdom, Thailand, Canada and United Arab Emirates which is the first Arab country and seventh country worldwide that has been selected to host the world blood donators day in 2008. The ceremony was organized under the patronage of His Highness Sheikh Khelifa Bin Zayed Al Nahyan, UAE President.
He also mentioned that the four international organizations "World Health Organization, International Federation for Red Cross and Red Crescent, International Federation for Blood Transfusion and International Blood Donors Association" lauded the efforts of the UAE which led to its nomination as the headquarters for the WHO's Middle Eastern region. This selection was due to the UAE efforts in supporting blood donators and organizing blood donation ceremonies generally.
Dr. Al Amiri lauded the efforts of the other sectors especially the mosques in encouraging the residents to blood donation and the cooperation of the government sector in disseminating awareness campaigns about blood donation and the usage of modern techniques as well as text messages especially the Ministry of Education, Ministry of Social Affairs to encourage students to participate in the activities of the blood donation center and research in Sharjah.
"We would like to thank the social organizations and institutions for their support to the Ministry of Health referring that the ministry's success could not have been accomplished in the field of blood transfusion campaigns and blood donators without their cooperation", he concluded.
WAM/TF
Sunday, 31 October 2010
Wednesday, 20 October 2010
Blood Group Diet
The blood group diet is said to have originated from two American Naturopaths, Dr James D'Adamo, and his son Dr Peter D'Adamo, who believe that your blood group type is the key to how you burn your calories, which foods you should eat and how you would benefit from certain types of exercise.
They recommend that eating to suit your blood group may, help you to lose weight, help you fight disease, boost your immune system and slow down the ageing process.
It is believed that a chemical reaction occurs between your blood and foods as they are digested. Lectins, a diverse and abundant protein found in food, may be incompatible with your blood group and adverse side effects may occur. The avoidance of these Lectins which can agglutinate (adhere or stick to one another) can be important if your particular cells-determined by your blood type,may react with them.
There are 4 blood types: A, AB, B, and O
Blood Type O
The O blood type was the first blood type to evolve from the hunter-gatherer era around 50,000 BC. Here the diet was high in red meat and virtually void of grains and dairy. The type-O thrives on a meat-eating diet. As the diet is high in animal protein, the type-O requires intense physical exercise to help burn off the meat.
Type-Os are prone to digestive disorders resulting from over-secretion of stomach acid. They can also be more susceptible to arthritis and thyroid disease due to overactive or hyper -immune system.
Wheat and dairy also promote inflammation in this blood type which can trigger an imbalance in the immune system.
Blood type O individuals can gain a significant amount of weight following a high carbohydrate diet, as their bodies cannot properly metabolize these foods.
Blood Type A
Type-A blood group formed when man began to develop an agricultural lifestyle between 25,000 and 15,000 B.C. People with blood type-A do best on a vegetarian diet for weight loss especially the macrobiotic diet.
The type-A individual hardly produces much hydrochloric acid and therefore does poorly on meat and dairy diets such as the Atkins Diet.
Type-As are generally more prone to cancer, diabetes and heart disease, if they do not take charge of their health. The gene for alcoholism is also found in type-As.
Blood Type B
Type B also evolved from the intermingling of blood type O with the blood type A. This occurred between 15,000 and 10,000 B.C due to man traveling further.
As a result, the type-B individual does best on a dairy diet with some meat (no chicken) and few grains.
The type-Bs suffer from the highest incidence of bladder and urinary tract infections. They are also prone to viral diseases when their immune system is compromised.
Since B blood types can metabolize dairy products and most foods, they will usually lose weight effortlessly as long as peanuts, corn, wheat, and lentils are eliminated from the diet.
Blood Type AB
The rarest and newest blood type to evolve (1500 years old) was the AB blood type. This blood type is the most well adapted to a moderate diet. The type-AB individual benefits from both the A and B type diets.
Meat is not as well digested as seafood, dairy, wheat-free grains and soy foods.
The type-ABs are prone to either diseases encountered by the Type-As or the type-Bs. By undergoing further metabolic typing, it can be determined which diseases they are most likely to be vulnerable.
For weight loss and maintaining a healthy weight, AB's do best on seafood, dairy, nuts and grains.
They recommend that eating to suit your blood group may, help you to lose weight, help you fight disease, boost your immune system and slow down the ageing process.
It is believed that a chemical reaction occurs between your blood and foods as they are digested. Lectins, a diverse and abundant protein found in food, may be incompatible with your blood group and adverse side effects may occur. The avoidance of these Lectins which can agglutinate (adhere or stick to one another) can be important if your particular cells-determined by your blood type,may react with them.
There are 4 blood types: A, AB, B, and O
Blood Type O
The O blood type was the first blood type to evolve from the hunter-gatherer era around 50,000 BC. Here the diet was high in red meat and virtually void of grains and dairy. The type-O thrives on a meat-eating diet. As the diet is high in animal protein, the type-O requires intense physical exercise to help burn off the meat.
Type-Os are prone to digestive disorders resulting from over-secretion of stomach acid. They can also be more susceptible to arthritis and thyroid disease due to overactive or hyper -immune system.
Wheat and dairy also promote inflammation in this blood type which can trigger an imbalance in the immune system.
Blood type O individuals can gain a significant amount of weight following a high carbohydrate diet, as their bodies cannot properly metabolize these foods.
Blood Type A
Type-A blood group formed when man began to develop an agricultural lifestyle between 25,000 and 15,000 B.C. People with blood type-A do best on a vegetarian diet for weight loss especially the macrobiotic diet.
The type-A individual hardly produces much hydrochloric acid and therefore does poorly on meat and dairy diets such as the Atkins Diet.
Type-As are generally more prone to cancer, diabetes and heart disease, if they do not take charge of their health. The gene for alcoholism is also found in type-As.
Blood Type B
Type B also evolved from the intermingling of blood type O with the blood type A. This occurred between 15,000 and 10,000 B.C due to man traveling further.
As a result, the type-B individual does best on a dairy diet with some meat (no chicken) and few grains.
The type-Bs suffer from the highest incidence of bladder and urinary tract infections. They are also prone to viral diseases when their immune system is compromised.
Since B blood types can metabolize dairy products and most foods, they will usually lose weight effortlessly as long as peanuts, corn, wheat, and lentils are eliminated from the diet.
Blood Type AB
The rarest and newest blood type to evolve (1500 years old) was the AB blood type. This blood type is the most well adapted to a moderate diet. The type-AB individual benefits from both the A and B type diets.
Meat is not as well digested as seafood, dairy, wheat-free grains and soy foods.
The type-ABs are prone to either diseases encountered by the Type-As or the type-Bs. By undergoing further metabolic typing, it can be determined which diseases they are most likely to be vulnerable.
For weight loss and maintaining a healthy weight, AB's do best on seafood, dairy, nuts and grains.
Not s ingle prescrption
There is not a single prescription drug that offers a "cure" to any ailment.
Friday, 15 October 2010
52 Facts About Blood Donation
1. More than 4.5 million people need blood transfusions each year in the U.S. and Canada.
2. 43,000 pints: amount of donated blood used each day in the U.S. and Canada.
3. Someone needs blood every two seconds.
4. 37% of the U.S. population is eligible to donate blood – less than 10% do annually**.
5. About 1 in 7 people entering a hospital need blood.
6. One pint of blood can save up to three lives.
7. Healthy people who are at least 17 years old (16 with parental consent), and at least 110 pounds may donate whole blood every 56 days. Females receive 53% of blood transfusions; males receive 47%.
8. 94% of blood donors are registered voters.
9. In 1901, Dr. Karl Landsteiner first identified the major human blood groups: A, B, AB and O.
10. People with O- blood are universal donors of red blood cells.
11. People with AB+ blood are universal recipients of red blood cells, and universal donors of plasma.
12. One unit of whole blood can be separated into several components, including red blood cells, plasma, and platelets.
13. Red blood cells carry oxygen to the body's organs and tissues, and live for about 120 days in the circulatory system.
14. Platelets promote blood clotting and give those with leukemia and other cancers a chance to live.
15. Plasma is a pale yellow mixture of water, proteins and salts.
16. Plasma, which is 90% water, makes up 55% of blood volume.
17. Healthy bone marrow makes a constant supply of red cells, plasma and platelets.
18. Blood or plasma that comes from people who have been paid for it cannot be used for human transfusion.
19. Granulocytes, a type of white blood cell, roll along blood vessel walls in search of bacteria to engulf and destroy.
20. White cells are the body's primary defense against infection.
21. Apheresis is a special kind of blood donation that allows a donor to give specific blood components, such as platelets or red blood cells.
22. 42 days: how long most donated red blood cells can be stored.
23. Five days: how long most donated platelets can be stored.
24. One year: how long frozen plasma can be stored.
25. Much of today's medical care depends on a steady supply of blood from healthy donors.
26. 2.7 pints: the average whole blood and red blood cell transfusion.*
27. Children being treated for cancer, premature infants and children having heart surgery may receive blood and platelets during their treatments.
28. Anemic patients may need blood transfusions to increase their red blood cell levels.
29. Cancer, transplant and trauma patients, and patients undergoing open-heart surgery may require platelet transfusions to survive.
30. Sickle cell disease is an inherited disease that affects more than 80,000 people in the U.S., 98% of whom are of African descent.
31. Many patients with severe sickle cell disease receive blood transfusions every month.
32. Over 10 tests are performed on each unit of donated blood.
33. 17% of non-donors cite "never thought about it" as the main reason for not giving blood, while 15% say they're too busy.
34. The #1 reason blood donors say they give is because they "want to help others."
35. Blood centers often run short of types O and B red blood cells.
36. There is no substitute for human blood.
37. If all blood donors gave three times a year, blood shortages would be a rare event (The current average is about two).
38. 46.5 gallons: amount of blood you could donate if you begin at age 17 and donate every 56 days until you are 79 years old.
39. There are four easy steps to donate blood: medical history, a quick physical, donation and snacks.
40. The actual blood donation takes less than 15 minutes. The entire process – from the time you sign in until the time you leave – usually takes under an hour.
41. After donating blood, you replace the fluid in hours and the red blood cells within four weeks. It takes eight weeks to restore the iron lost after donating.
42. You cannot get AIDS or any other infectious disease by donating blood.
43. 10 pints: the amount of blood in the body of an average adult.
44. One unit of whole blood is roughly the equivalent of one pint.
45. Blood makes up about 7% of your body's weight.
46. Newborn babies have about one cup of blood in their bodies.
47. Giving blood will not decrease your strength.
48. Any company, community organization, place of worship or individual may contact their local community blood center to host a blood drive.
49. Roughly half of all blood donations across the U.S. are collected at blood drives.
50. People who donate blood are volunteers and are not paid for their donation.
51. 500,000 Americans donated blood in the days following the events of September 11
52. Blood donation. It's about an hour of your time. It's About Life!
2. 43,000 pints: amount of donated blood used each day in the U.S. and Canada.
3. Someone needs blood every two seconds.
4. 37% of the U.S. population is eligible to donate blood – less than 10% do annually**.
5. About 1 in 7 people entering a hospital need blood.
6. One pint of blood can save up to three lives.
7. Healthy people who are at least 17 years old (16 with parental consent), and at least 110 pounds may donate whole blood every 56 days. Females receive 53% of blood transfusions; males receive 47%.
8. 94% of blood donors are registered voters.
9. In 1901, Dr. Karl Landsteiner first identified the major human blood groups: A, B, AB and O.
10. People with O- blood are universal donors of red blood cells.
11. People with AB+ blood are universal recipients of red blood cells, and universal donors of plasma.
12. One unit of whole blood can be separated into several components, including red blood cells, plasma, and platelets.
13. Red blood cells carry oxygen to the body's organs and tissues, and live for about 120 days in the circulatory system.
14. Platelets promote blood clotting and give those with leukemia and other cancers a chance to live.
15. Plasma is a pale yellow mixture of water, proteins and salts.
16. Plasma, which is 90% water, makes up 55% of blood volume.
17. Healthy bone marrow makes a constant supply of red cells, plasma and platelets.
18. Blood or plasma that comes from people who have been paid for it cannot be used for human transfusion.
19. Granulocytes, a type of white blood cell, roll along blood vessel walls in search of bacteria to engulf and destroy.
20. White cells are the body's primary defense against infection.
21. Apheresis is a special kind of blood donation that allows a donor to give specific blood components, such as platelets or red blood cells.
22. 42 days: how long most donated red blood cells can be stored.
23. Five days: how long most donated platelets can be stored.
24. One year: how long frozen plasma can be stored.
25. Much of today's medical care depends on a steady supply of blood from healthy donors.
26. 2.7 pints: the average whole blood and red blood cell transfusion.*
27. Children being treated for cancer, premature infants and children having heart surgery may receive blood and platelets during their treatments.
28. Anemic patients may need blood transfusions to increase their red blood cell levels.
29. Cancer, transplant and trauma patients, and patients undergoing open-heart surgery may require platelet transfusions to survive.
30. Sickle cell disease is an inherited disease that affects more than 80,000 people in the U.S., 98% of whom are of African descent.
31. Many patients with severe sickle cell disease receive blood transfusions every month.
32. Over 10 tests are performed on each unit of donated blood.
33. 17% of non-donors cite "never thought about it" as the main reason for not giving blood, while 15% say they're too busy.
34. The #1 reason blood donors say they give is because they "want to help others."
35. Blood centers often run short of types O and B red blood cells.
36. There is no substitute for human blood.
37. If all blood donors gave three times a year, blood shortages would be a rare event (The current average is about two).
38. 46.5 gallons: amount of blood you could donate if you begin at age 17 and donate every 56 days until you are 79 years old.
39. There are four easy steps to donate blood: medical history, a quick physical, donation and snacks.
40. The actual blood donation takes less than 15 minutes. The entire process – from the time you sign in until the time you leave – usually takes under an hour.
41. After donating blood, you replace the fluid in hours and the red blood cells within four weeks. It takes eight weeks to restore the iron lost after donating.
42. You cannot get AIDS or any other infectious disease by donating blood.
43. 10 pints: the amount of blood in the body of an average adult.
44. One unit of whole blood is roughly the equivalent of one pint.
45. Blood makes up about 7% of your body's weight.
46. Newborn babies have about one cup of blood in their bodies.
47. Giving blood will not decrease your strength.
48. Any company, community organization, place of worship or individual may contact their local community blood center to host a blood drive.
49. Roughly half of all blood donations across the U.S. are collected at blood drives.
50. People who donate blood are volunteers and are not paid for their donation.
51. 500,000 Americans donated blood in the days following the events of September 11
52. Blood donation. It's about an hour of your time. It's About Life!
Thursday, 14 October 2010
A good formula
Sensitivity (positivity in disease)= TP / TP + FN
Specificity (negativity in health) = TN / TN + FP
Positive predictive value PV+ = TP / TP + FP
Negative predictive value PV- = TN / TN + FN
T True
F False
P Pos
N Neg
Specificity (negativity in health) = TN / TN + FP
Positive predictive value PV+ = TP / TP + FP
Negative predictive value PV- = TN / TN + FN
T True
F False
P Pos
N Neg
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