Diabetes News for June 9, 2002
Reversing Type 1 Diabetes?
When health conditions are caused by genes, the cure for those conditions might also depend upon gene therapy.
This was the premise of a recent study of Type 1 diabetes conducted by researchers at the Universitat Autonoma de Barcelona in Spain. The researchers used mice that were genetically engineered to overexpress the gene for insulin-like growth factor-I (IGF-I). This substance assists in the growth and development of pancreatic tissue. The mice were then given a drug that promotes the development of Type 1 diabetes.
As a result, the beta cells of the mice were destroyed, which is typical for Type 1 diabetes. However, the mice that had been genetically engineered eventually recovered. Their blood sugar levels went back to normal, and they had an increase in beta cells. Those mice that had not been genetically engineered developed diabetes, and eventually died.
Although this gene therapy is not yet at a stage where it can be tested on humans, the researchers hope that eventually this treatment will be used to prevent and reverse Type 1. Their findings are published in The Journal of Clinical Investigation (volume 109; pages 1153-1163; May 2002).
  
Stopping Diabetes With Antibodies
Type 1 diabetes occurs because the body's own immune system begins attacking insulin-producing cells, making blood sugar regulation impossible without intervention. In a new study, researchers explore the possibility of stopping the development of diabetes with an antibody treatment that stops this immune system attack.
The research was conducted by doctors at Columbia University in New York. They treated twelve people with Type 1 diabetes with an antibody that is believed to target the T cells that attack the pancreatic cells which produce insulin. Treatment began within six weeks of diagnosis. After two weeks of treatment, the participants were able to maintain their insulin production for a year. This gave them better control of blood sugar levels, and decreased the need for insulin injections. In comparison, ten of twelve people with Type 1 diabetes who were not given the antibody had a decreased ability to secrete insulin.
The researchers, who have published their findings in The New England Journal of Medicine (volume 346; pages 1685-1691; May 30, 2002), have begun a larger study of the antibody. They are still unsure how long this treatment can maintain the body's insulin production, so they do not know if this will be an effective way of treating people with Type 1.
Insulin Can't Prevent Type 1
In the 1990s, two studies of small groups of people were published that appeared to show that giving high-risk children daily doses of insulin could prevent them from developing Type 1 diabetes. However, a new study refutes that information.
This study was conducted by researchers at the University of Miami, who involved 339 children in the nine-year study. The children were all around twelve years old, and all had a 50% risk of developing Type 1. Half of these children were given shots of 0.25 units of insulin for every kilogram they weighed two times a day. They were also given infusions of insulin every year over a four-day period. The other half of the children were closely observed, but weren't given insulin.
At the end of the study, researchers found that 70 of the children who did not receive insulin developed diabetes, as compared to 69 who did receive insulin. The researchers believe these results, which are published in the New England Journal of Medicine (volume 346; pages 1685-1691; May 30, 2002), indicate that insulin is not an effective means of preventing Type 1 diabetes.
Pancreatic Cells From Adult Stem Cells
The debate about stem cells has been quite heated for the past few months because the potential to cure disease is so great. Stem cells are cells that have the possibility of developing into any cell type. While they are most commonly found in early development, a new study shows that stem cells may also be taken from adults and used to treat disease.
This research took place at the University of Florida at Gainesville, where researchers extracted stem cells from the livers of adult rats. These cells were then cultured with high levels of sugar in order to replicate the conditions present in the pancreas. The cells took on the role of normal pancreatic cells, and were even able to produce insulin.
These cells were then transplanted into the pancreases of rats that were bred to have diabetes. After ten days, the rats' blood sugar levels returned to normal. In addition, because the cells had come from the rats' own bodies, there was no rejection by their immune system. These observations can be found in the online version of the Proceedings of the National Academy of Sciences (Early Edition2002;10.1073/pnas122210699).
The researchers hope that this same treatment will be a viable way to treat diabetes in people. However, much more research is needed before that can occur. The scientists are currently conducting a study to determine whether the stem-cell derived pancreatic cells remain healthy and able to produce insulin for an extended period of time.
Explanation Of Heart Treatment
A common treatment for chest pain is nitroglycerin, but until a recent study was conducted, doctors were not sure why this drug was effective in treating the pain.
The research into the mechanisms behind nitroglycerin was conducted by scientists at the Howard Hughes Medical Institute at Duke University Medical Center in Durham, North Carolina. The researchers wanted to find the reason for nitroglycerin's capacity to relieve pain, but also to explain why long-term use of the drug depletes the supply of the enzyme that helps nitroglycerin work.
Nitroglycerin is believed to work by being converted into nitric oxide, which regulates blood vessels. The researchers at Duke University were able to identify an enzyme called mitochondrial aldehyde dehydrogenase (mtALDH), which acts by breaking down nitroglycerin and releasing nitric oxide. However, nitroglycerin loses its effects over time because it uses up the supply of mtALDH in the mitochondria. This makes it increasingly difficult for the enzyme to break down nitroglycerin.
The researchers, who have published their findings in the Proceedings of the National Academy of Sciences (volume 99; page 8306; June 11, 2002), hope that using this information about the way nitroglycerin works will lead to more effective drugs that can work without using up the mtALDH. They also hope that new drugs will be able to increase survival rates of people with cardiovascular problems longer than nitroglycerin is able to do.
Also, the scientists note that some medications also inhibit mtALDH, so people taking them should seek doctors' advice before taking nitroglycerin. These drugs include certain diabetes drugs, sleeping pills, and acetaminophen. In addition, alcohol may interfere with the effects of nitroglycerin.
Kidney Failure In African Americans
According to a new study, kidney failure occurs at a disproportionate rate in African Americans, as compared to whites.
The study has been published in the Journal of the American Society of Nephrology (volume 13, page 1635, June 2002). Results indicate that three times as many African Americans as white Americans will develop kidney failure, which is deadly unless interventions like kidney dialysis or transplants are used. The study revealed the statistics that 7.8% of African-American women and 7.3% of African-American men will develop the condition, compared with less than 2% of white women and 2.5% of white men.
Although the study did not indicate the reasons for the differences in kidney disease rates along lines of ethnicity, the researchers do encourage more aggressive screening and treatment for kidney diseases in African Americans.
Limit TV To Prevent Obesity
Because the rate of obesity is rising fast in America's children, researchers are trying to find as many ways as they can to prevent obesity and its accompanying health problems. One simple way may be to remove the television from children's bedrooms.
This study can be found in the recent issue of Pediatrics (volume 109, pages 1028-1035, June 2002). Researchers from Columbia University in New York City studied children between the ages of one and five years old from 2,700 families with a low socioeconomic status. Nearly 40% of the children had TVs in their rooms. The researchers found that children with televisions in their bedrooms watched nearly five hours more per week and were more likely to be overweight than children without televisions in their rooms. This supports previous research, which has shown that body mass index of older children increases corresponding to the number of hours spent watching TV.
The researches hope that their study will encourage parents to limit their children's television viewing, and would like to see further research into whether this decreases the rates of obesity among children.
Doctors' Treatment Of Type 2
According to a statement issued by the International Diabetes Federation, doctors are "too complacent" in their treatment of Type 2 diabetes, which is providing a disservice to the increasing number of people worldwide who have the disease.
The IDF is made of 181 member associations. At a recent meeting in Montreux, Switzerland, the group released several statistics related to Type 2. According to this report, there are 22.5 million European adults with Type 2, and treating the disease and its complications accounts for 10-15% of European healthcare spending. The group calls for better awareness campaigns about the disease, and aggressive detection and treatment of the disease by doctors. |
