NEW YORK - In a leap forward for stem cell research, three independent teams of scientists reported Wednesday that they have produced the equivalent of embryonic stem cells in mice using skin cells without the controversial destruction of embryos.
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If the same could be done with human skin cells — a big if — the procedure could lead to breakthrough medical treatments without the contentious ethical and political debates surrounding the use of embryos.
Experts were impressed by the achievement.
"I think it's one of the most exciting things that has come out about embryonic stem cells, period," said researcher Dr. Asa Abeliovich of Columbia University in New York, who didn't participate in the work. "It's very convincing that it's real."
But he and others cautioned that it will take further study to see whether this scientific advance can be harnessed for creating new human therapies. For one thing, the procedure used to get the mouse skin cells to mimic embryonic stem cells wouldn't be suitable. And it's simply not known whether the mouse results can be reproduced with human cells.
"We have a long way to go," said John Gearhart of Johns Hopkins University, a stem cell researcher who also wasn't involved in the new work.
In any case, scientists said, the advance does not mean that research that involves getting stem cells from human embryos should now be abandoned. "We simply don't know which approach ... will work the best," said researcher Konrad Hochedlinger of the Harvard Stem Cell Institute, who led one of the three teams.
Embryonic stem cells are prized because they can develop into all types of tissue. So experts believe they might be used for transplant therapies in people who are paralyzed or have illnesses ranging from diabetes to Parkinson's disease.
To harvest human embryonic stem cells, embryos must be destroyed, an action many people oppose.
Scientists have long hoped to find a way to reprogram ordinary body cells to act like stem cells, avoiding the use of embryos altogether. The new mouse studies seem to have accomplished that. Past experiments seeking alternative routes to getting stem cells have generally involved tampering with an embryo or egg.
At a press conference Wednesday, Hochedlinger and a member of a second team said their work was not an attempt to evade the ethical objections to embryo destruction. Instead, they said, the goal was to learn how cell reprogramming works.
But in a telephone interview, a prominent critic of embryonic stem cell research welcomed the new work on ethical terms.
"This is what we were looking for people to explore because it may provide all the advantages of embryonic stem cells without the moral problem," said Richard Doerflinger, deputy director of pro-life activities for the U.S. Conference of Catholic Bishops. "So I'm very encouraged."
Hochedlinger and colleagues present their work in the inaugural issue of the journal Cell Stem Cell. (The first word in the journal's name refers to its publisher, Cell Press).
The other two teams reported their results Wednesday on the Web site of the journal Nature. Rudolf Jaenisch of the Whitehead Institute in Cambridge, Mass., is the senior author of one paper, and the work behind the other paper was led by Shinya Yamanaka of Kyoto University in Japan.
The new work builds on a landmark paper Yamanaka published last August. He found that by slipping four genes into mouse skin cells called fibroblasts, he could make the altered cells behave much like embryonic stem cells in lab tests.
But these so-called "iPS" cells still showed significant differences from embryonic stem cells. The three new papers report on creating iPS cells that proved virtually identical to stem cells in a variety of lab tests.
The technique used in the mouse studies could promote cancer in any patients getting therapy based on iPS cells, so researchers emphasized that a new approach that avoids that hazard would have to be developed.
Gearhart called that a major issue to be resolved. In addition, he said, scientists still must show that these cells can give rise to many cell types in the lab, as embryonic stem cells can.
And all this must be accomplished in human cells — a difficult task, he said, because introducing genes into human cells is a major challenge.
If the technique can be harnessed for people, the iPS cells and the tissue they develop into would provide a genetic match to the person who donated the skin cells. That would make them suitable for transplant to that person, theoretically without fear of rejection.
Wednesday, June 6, 2007
Wednesday, April 11, 2007
No genetic link found for heart risk, study says
CHICAGO (Reuters) - Genetic testing failed to find any gene mutations that predict a higher risk of heart disease, a study released on Tuesday said.
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Scientists at Yale University worked up the genetic profiles of nearly 1,500 people to examine 85 genes that smaller, earlier studies suggested might confer susceptibility to heart problems.
More than half the patients had come to a hospital having suffered a heart attack or other acute symptoms, while the others had experienced no heart trouble.
Only one genetic variation showed even a modest association to heart problems in the study, which was published in the
Journal of the American Medical Association.
"We therefore conclude that our findings, in this large sample ... cannot support that this panel of gene variants contains bona fide (heart disease) risk factors," study author Dr. Thomas Morgan wrote. Morgan is now at Washington University in St. Louis.
A significant proportion of pregnant women opt for genetic testing to determine if the fetus will develop an array of potential ailments such as cystic fibrosis or a form of mental retardation.
Increasingly, genetic testing is also being performed later in life to detect if a person has a higher risk of contracting diseases such as Alzheimer's or inherited breast cancer.
The availability of genetic testing also raises complex ethical questions, such as who should know about a person's risk and what should be done about it.
"Our findings come at a critical juncture in complex disease genetics," Morgan wrote, adding that several clinics offer genetic tests for several of the gene mutations his study examined.
"However, our findings suggest that such clinical genetic testing is premature and underscore the importance of robust replication studies of reported associations prior to their application to clinical care," he added.
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Scientists at Yale University worked up the genetic profiles of nearly 1,500 people to examine 85 genes that smaller, earlier studies suggested might confer susceptibility to heart problems.
More than half the patients had come to a hospital having suffered a heart attack or other acute symptoms, while the others had experienced no heart trouble.
Only one genetic variation showed even a modest association to heart problems in the study, which was published in the
Journal of the American Medical Association.
"We therefore conclude that our findings, in this large sample ... cannot support that this panel of gene variants contains bona fide (heart disease) risk factors," study author Dr. Thomas Morgan wrote. Morgan is now at Washington University in St. Louis.
A significant proportion of pregnant women opt for genetic testing to determine if the fetus will develop an array of potential ailments such as cystic fibrosis or a form of mental retardation.
Increasingly, genetic testing is also being performed later in life to detect if a person has a higher risk of contracting diseases such as Alzheimer's or inherited breast cancer.
The availability of genetic testing also raises complex ethical questions, such as who should know about a person's risk and what should be done about it.
"Our findings come at a critical juncture in complex disease genetics," Morgan wrote, adding that several clinics offer genetic tests for several of the gene mutations his study examined.
"However, our findings suggest that such clinical genetic testing is premature and underscore the importance of robust replication studies of reported associations prior to their application to clinical care," he added.
Monday, April 9, 2007
Scottish Scientists Develop "Spray-On Computers" for Healthcare
Scottish ingenuity has graced the world with some of the world's greatest inventions. First there was the game of golf, which was quickly followed by the development of Scotch whiskey, and last but not least, spray-on computers. Yep, entirely self-powered, self-networking digital "specks" which will be capable of collecting volumes of data on patients.
Speckled computing - some of the most advanced computing technology in the world - is currently being researched and developed by a group of Scottish experts.
The individual appliances, or 'specks', will form networks that can be programmed like ordinary computers.
Spraying them directly onto a person creates the ability to carry out different tests at the same time, for example muscle movement and pulse rate. This allows a complete picture of the patient's condition to be built up quickly.
The computing innovation, being developed by scientists at Edinburgh, Glasgow, St Andrews and Strathclyde universities, will be displayed at the Edinburgh International Science Festival next Friday as part of a talk by Damal Arvind, leading speckled computing professor and director of the Scottish consortium.
Arvind said: "This is the new class of computing: devices which can sense and process the data they receive. They also have a radio so they can network and there's a battery in there as well, so they are entirely self-powered.
Speckled computing - some of the most advanced computing technology in the world - is currently being researched and developed by a group of Scottish experts.
The individual appliances, or 'specks', will form networks that can be programmed like ordinary computers.
Spraying them directly onto a person creates the ability to carry out different tests at the same time, for example muscle movement and pulse rate. This allows a complete picture of the patient's condition to be built up quickly.
The computing innovation, being developed by scientists at Edinburgh, Glasgow, St Andrews and Strathclyde universities, will be displayed at the Edinburgh International Science Festival next Friday as part of a talk by Damal Arvind, leading speckled computing professor and director of the Scottish consortium.
Arvind said: "This is the new class of computing: devices which can sense and process the data they receive. They also have a radio so they can network and there's a battery in there as well, so they are entirely self-powered.
Sunday, April 8, 2007
Self Pap Smears??
A New Frontier in Awkward: Do Your Own Pap-Smears
Sure, we here at Medgadget are big fans of patients doing self-exams. Self breast exams and self testicular exams are excellent ways for patients to take their health into their own hands (bad pun intended). But doing your own pap smear? Will the kit come w/ a speculum and an angled mirror? No...there's just nothing good that can come from this.
Women who forgo screening for cervical cancer may be more inclined to participate in such programs if they're provided with a kit to obtain cervical samples at home, Dutch investigators report.
It's estimated that 28 percent of women in the Netherlands do not participate in cervical screening programs. Dr. Chris J. L. M. Meijer from VU University Medical Center, Amsterdam, and colleagues wanted to see if such women would agree to testing if they could provide samples without going to a clinic.
As reported in the International Journal of Cancer, 2,546 women who had not undergone regular cervical screening were mailed a self-sample kit. It included a small brush for collecting a cervical specimen, a collection tube, easy-to-follow instructions and a padded envelope for returning the sample to the lab. There it would be tested for human papillomavirus (HPV), which is the cause of nearly all cases of cervical cancer.
The rate of high grade pre-cancer detected in the self-sampling responders (1.67 percent) was significantly higher than in the other group (0.97 percent).
"Importantly," the researchers say, the costs of detecting one such lesion via self-sampling "are in the same range as those calculated for conventional ... screening."
Furthermore, they calculate that if the strategy was extended to the entire Netherlands, self-sampling could result in the early detection of 1,085 extra pre-cancerous lesions, "leading to roughly 100 cervical cancers being prevented or detected earlier."
Hmmm...maybe we spoke too soon...apparently Dutch women are very comfortable taking their own cervical samples. As always, our female fans, we need your help on this one: Would ya', Could ya', Should ya'?
Sure, we here at Medgadget are big fans of patients doing self-exams. Self breast exams and self testicular exams are excellent ways for patients to take their health into their own hands (bad pun intended). But doing your own pap smear? Will the kit come w/ a speculum and an angled mirror? No...there's just nothing good that can come from this.
Women who forgo screening for cervical cancer may be more inclined to participate in such programs if they're provided with a kit to obtain cervical samples at home, Dutch investigators report.
It's estimated that 28 percent of women in the Netherlands do not participate in cervical screening programs. Dr. Chris J. L. M. Meijer from VU University Medical Center, Amsterdam, and colleagues wanted to see if such women would agree to testing if they could provide samples without going to a clinic.
As reported in the International Journal of Cancer, 2,546 women who had not undergone regular cervical screening were mailed a self-sample kit. It included a small brush for collecting a cervical specimen, a collection tube, easy-to-follow instructions and a padded envelope for returning the sample to the lab. There it would be tested for human papillomavirus (HPV), which is the cause of nearly all cases of cervical cancer.
The rate of high grade pre-cancer detected in the self-sampling responders (1.67 percent) was significantly higher than in the other group (0.97 percent).
"Importantly," the researchers say, the costs of detecting one such lesion via self-sampling "are in the same range as those calculated for conventional ... screening."
Furthermore, they calculate that if the strategy was extended to the entire Netherlands, self-sampling could result in the early detection of 1,085 extra pre-cancerous lesions, "leading to roughly 100 cervical cancers being prevented or detected earlier."
Hmmm...maybe we spoke too soon...apparently Dutch women are very comfortable taking their own cervical samples. As always, our female fans, we need your help on this one: Would ya', Could ya', Should ya'?
Wednesday, March 28, 2007
Novel Antimicrobial Peptide Discovered
he University of British Columbia is reporting the discovery of a new antimicrobial peptide by its researchers, in collaboration with Inimex Pharmaceuticals, a spin-off university company:
"Antibiotics are now under threat because of the explosion in antibiotic-resistant bacteria. A third of all deaths on this planet are the result of infection so there is an urgent need to create new therapies," says Robert Hancock, principal investigator and Canada Research Chair in Pathogenomics and Antimicrobials. "The beauty of this peptide is that it acts on the host to trigger a protective response and doesn't act on bacteria directly. That means it's unlikely bacteria will become resistant to it."
The team found that a peptide, or chain of amino acids, they have dubbed innate defense regulator peptide (IDR-1), can increase innate immunity without triggering harmful inflammation, and offer protection both before and after infection is present.
The discovery, in animal models, will be published March 25 in the journal Nature Biotechnology.
Researchers tested the peptide's effectiveness against Staphylococcus aureus including MRSA; a superbug called vancomycin-resistant Enterococcus (VRE); and Salmonella. In Staph and VRE infections, although bacteria were not completely eradicated, IDR-1 significantly reduced bacteria counts and mortality, when given either 24-48 hours before or four hours after infection began. In Salmonella, the peptide offered significant protection when administered prior to infection setting in.
Data showed that IDR-1 activates several signaling pathways to stimulate infection-clearing chemokines -- a chemical mediator that mobilizes immune response.
In addition, the peptide did not produce harmful inflammation and toxicity often seen when the immune system is stimulated and, in fact, actually reduced the potentially harmful septic response. Sepsis, a consequence of a ravaging inflammatory response associated with infection, kills as many as 200,000 annually.
"Antibiotics are now under threat because of the explosion in antibiotic-resistant bacteria. A third of all deaths on this planet are the result of infection so there is an urgent need to create new therapies," says Robert Hancock, principal investigator and Canada Research Chair in Pathogenomics and Antimicrobials. "The beauty of this peptide is that it acts on the host to trigger a protective response and doesn't act on bacteria directly. That means it's unlikely bacteria will become resistant to it."
The team found that a peptide, or chain of amino acids, they have dubbed innate defense regulator peptide (IDR-1), can increase innate immunity without triggering harmful inflammation, and offer protection both before and after infection is present.
The discovery, in animal models, will be published March 25 in the journal Nature Biotechnology.
Researchers tested the peptide's effectiveness against Staphylococcus aureus including MRSA; a superbug called vancomycin-resistant Enterococcus (VRE); and Salmonella. In Staph and VRE infections, although bacteria were not completely eradicated, IDR-1 significantly reduced bacteria counts and mortality, when given either 24-48 hours before or four hours after infection began. In Salmonella, the peptide offered significant protection when administered prior to infection setting in.
Data showed that IDR-1 activates several signaling pathways to stimulate infection-clearing chemokines -- a chemical mediator that mobilizes immune response.
In addition, the peptide did not produce harmful inflammation and toxicity often seen when the immune system is stimulated and, in fact, actually reduced the potentially harmful septic response. Sepsis, a consequence of a ravaging inflammatory response associated with infection, kills as many as 200,000 annually.
Thursday, March 22, 2007
Trends in Tuberculosis Incidence: MMWR
In 2006, a total of 13,767 tuberculosis (TB) cases (4.6 per 100,000 population) were reported in the United States, representing a 3.2% decline from the 2005 rate. This report summarizes provisional 2006 TB incidence data from the National TB Surveillance System and describes trends since 1993. The TB rate in 2006 was the lowest recorded since national reporting began in 1953, but the rate of decline has slowed since 2000. The average annual percentage decline in the TB incidence rate decreased from 7.3% per year during 1993--2000 (95% confidence interval [CI] = 6.9%--7.8%) to 3.8% during 2000--2006 (CI = 3.1%--4.5%). Foreign-born persons and racial/ethnic minority populations continue to be affected disproportionately by TB in the United States. In 2006, the TB rate among foreign-born persons in the United States was 9.5 times that of U.S.-born persons.* The TB rates among blacks, Asians, and Hispanics† were 8.4, 21.2, and 7.6 times higher than rates among whites, respectively. The slowing of the decline in the overall national TB rate and the inability to effectively address persistent disparities in TB rates between U.S.-born and foreign-born persons and between whites and racial/ethnic minority populations threaten progress toward the goal of eliminating TB in the United States. In 1989, CDC and the Advisory Committee for the Elimination of Tuberculosis issued a strategic plan for the elimination of TB, setting an interim target case rate of 3.5 per 100,000 population by 2000 and ultimately the elimination of TB (i.e., <1 case per 1 million population) in the United States by 2010 (1).
TB is a nationally notifiable disease. Health departments in the 50 states and District of Columbia (DC) electronically report to CDC any TB cases that meet the CDC and Council of State and Territorial Epidemiologists case definition.§ Reports include the patient's race, ethnicity (i.e., Hispanic or non-Hispanic), treatment information, and drug-susceptibility test results if available. For this analysis, CDC calculated national and state TB rates (2) and rates for foreign-born and U.S.-born persons (3) and racial/ethnic populations (4) by using current U.S. census population estimates for the years 1993 through 2006.
In 2006, TB incidence rates in the 51 reporting areas ranged from 0.8 (Wyoming) to 12.6 (DC) cases per 100,000 population (median: 3.4 cases). Thirty states had lower rates in 2006 than 2005; 20 states and DC had higher rates (Table 1). In 2006, for the second consecutive year and the second time since national reporting began, approximately half of states (26 of 50) had TB rates of <3.5 per 100,000 (Figure 1); however, 11 of those 26 states had higher rates of TB in 2006 than in 2005. Seven states (California, Florida, Georgia, Illinois, New Jersey, New York, and Texas) reported more than 500 cases each for 2006; combined, these seven states accounted for 60% (8,259) of all TB cases.
Among U.S.-born persons, the number and rate of TB cases continued to decline in 2006. The U.S.-born TB rate was 2.3 per 100,000 population (5,924 or 43.3% of all cases with known origin of birth), representing a 7.0% decline in rate since 2005 and a 68.6% decline since 1993 (Figure 2).
Among foreign-born persons, the number of TB cases increased in 2006, but the rate decreased. The foreign-born TB rate in 2006 was 21.9 per 100,000 population, representing a 0.5% decline in rate since 2006 and a 35.8% decline since 1993. As the rate of decline in TB cases among foreign-born persons lagged behind the decline in TB cases among U.S.-born persons, the foreign-born to U.S.-born rate ratio increased 7.0%, from 8.9 in 2005 to 9.5 in 2006. In 2006, approximately half (55.6%) of TB cases among foreign-born persons were reported in persons from five countries: Mexico (1,912), the Philippines (856), Vietnam (630), India (540), and China (376).
In 2006, for the third consecutive year, more TB cases were reported among Hispanics than any other racial/ethnic population. Among persons with TB whose country of birth was known, 95.6% (3,126 of 3,269) of Asians, 74.7% (3,024 of 4,050) of Hispanics, 29.9% (1,110 of 3,712) of blacks, and 17.8% (427 of 2,404) of whites were foreign born. From 2005 to 2006, TB rates declined for all racial/ethnic minorities except American Indians/Alaska Natives and Native Hawaiians or Other Pacific Islanders¶ (Table 2).
Human immunodeficiency virus (HIV) contributes to the TB pandemic because immune suppression increases the likelihood of rapid progression from TB infection to TB disease. From 2005 to 2006, among TB cases with HIV status reported,** the percentage of TB cases with HIV infection decreased 4.4% (from 13.0% to 12.4%), but the percentage of TB cases with unknown HIV status increased 10.3% (from 28.7% to 31.7%).†† The decline in the percentage of TB cases with HIV infection might reflect incomplete reporting of HIV test results attributed to a lack of HIV testing or HIV reporting.
A total of 124 cases of multidrug-resistant TB (MDR TB)§§ were reported in 2005, the most recent year for which complete drug-susceptibility data are available.¶¶ The proportion of MDR-TB cases remained constant at 1.2% from 2004 (129 of 10,846 TB cases) to 2005 (124 of 10,662). In 2005, MDR TB continued to disproportionately affect foreign-born persons, who accounted for 101 (81.5%) of 124 MDR-TB cases.
The recommended length of drug therapy for most types of TB is 6--9 months. In 2003, the latest year for which treatment data are complete, 82.7% of patients for whom <1 year of treatment was indicated completed therapy within 1 year, below the Healthy People 2010 target of 90% (objective 14-12).
TB is a nationally notifiable disease. Health departments in the 50 states and District of Columbia (DC) electronically report to CDC any TB cases that meet the CDC and Council of State and Territorial Epidemiologists case definition.§ Reports include the patient's race, ethnicity (i.e., Hispanic or non-Hispanic), treatment information, and drug-susceptibility test results if available. For this analysis, CDC calculated national and state TB rates (2) and rates for foreign-born and U.S.-born persons (3) and racial/ethnic populations (4) by using current U.S. census population estimates for the years 1993 through 2006.
In 2006, TB incidence rates in the 51 reporting areas ranged from 0.8 (Wyoming) to 12.6 (DC) cases per 100,000 population (median: 3.4 cases). Thirty states had lower rates in 2006 than 2005; 20 states and DC had higher rates (Table 1). In 2006, for the second consecutive year and the second time since national reporting began, approximately half of states (26 of 50) had TB rates of <3.5 per 100,000 (Figure 1); however, 11 of those 26 states had higher rates of TB in 2006 than in 2005. Seven states (California, Florida, Georgia, Illinois, New Jersey, New York, and Texas) reported more than 500 cases each for 2006; combined, these seven states accounted for 60% (8,259) of all TB cases.
Among U.S.-born persons, the number and rate of TB cases continued to decline in 2006. The U.S.-born TB rate was 2.3 per 100,000 population (5,924 or 43.3% of all cases with known origin of birth), representing a 7.0% decline in rate since 2005 and a 68.6% decline since 1993 (Figure 2).
Among foreign-born persons, the number of TB cases increased in 2006, but the rate decreased. The foreign-born TB rate in 2006 was 21.9 per 100,000 population, representing a 0.5% decline in rate since 2006 and a 35.8% decline since 1993. As the rate of decline in TB cases among foreign-born persons lagged behind the decline in TB cases among U.S.-born persons, the foreign-born to U.S.-born rate ratio increased 7.0%, from 8.9 in 2005 to 9.5 in 2006. In 2006, approximately half (55.6%) of TB cases among foreign-born persons were reported in persons from five countries: Mexico (1,912), the Philippines (856), Vietnam (630), India (540), and China (376).
In 2006, for the third consecutive year, more TB cases were reported among Hispanics than any other racial/ethnic population. Among persons with TB whose country of birth was known, 95.6% (3,126 of 3,269) of Asians, 74.7% (3,024 of 4,050) of Hispanics, 29.9% (1,110 of 3,712) of blacks, and 17.8% (427 of 2,404) of whites were foreign born. From 2005 to 2006, TB rates declined for all racial/ethnic minorities except American Indians/Alaska Natives and Native Hawaiians or Other Pacific Islanders¶ (Table 2).
Human immunodeficiency virus (HIV) contributes to the TB pandemic because immune suppression increases the likelihood of rapid progression from TB infection to TB disease. From 2005 to 2006, among TB cases with HIV status reported,** the percentage of TB cases with HIV infection decreased 4.4% (from 13.0% to 12.4%), but the percentage of TB cases with unknown HIV status increased 10.3% (from 28.7% to 31.7%).†† The decline in the percentage of TB cases with HIV infection might reflect incomplete reporting of HIV test results attributed to a lack of HIV testing or HIV reporting.
A total of 124 cases of multidrug-resistant TB (MDR TB)§§ were reported in 2005, the most recent year for which complete drug-susceptibility data are available.¶¶ The proportion of MDR-TB cases remained constant at 1.2% from 2004 (129 of 10,846 TB cases) to 2005 (124 of 10,662). In 2005, MDR TB continued to disproportionately affect foreign-born persons, who accounted for 101 (81.5%) of 124 MDR-TB cases.
The recommended length of drug therapy for most types of TB is 6--9 months. In 2003, the latest year for which treatment data are complete, 82.7% of patients for whom <1 year of treatment was indicated completed therapy within 1 year, below the Healthy People 2010 target of 90% (objective 14-12).
Tuesday, March 13, 2007
Time Travel
Well, I actually can't believe that researchers have spent time and money researching time travel. And, after all this time, the researchers say that time travel can't be done.
As if I needed a scientist to tell me that time travel can't be done.
This just iterates the old saying or rather definition of a doctor
A doctor is someone who know more and more about less and less until he knows everything about nothing
CJ
As if I needed a scientist to tell me that time travel can't be done.
This just iterates the old saying or rather definition of a doctor
A doctor is someone who know more and more about less and less until he knows everything about nothing
CJ
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