Looking for the Genes for Familial Thoracic Aortic Aneurysms and Dissections
A third locus for familial thoracic aortic aneurysms and dissections has been mapped by researchers from The University of Texas Health Science Center at Houston, the Baylor College of Medicine Human Genome Sequencing Center in Houston, and the University of Texas M.D. Anderson Cancer Center in Houston, as well as the University of Iowa.
In a report in this week’s issue of the journal Circulation (Circulation. 2003;107:3184–3190), researchers led by Sumera N. Hasham, MD, described studying a 4-generation family with a dominant mode of inheritance of the disorder. None of the family members evaluated for the study had symptoms characteristic of Marfan’s syndrome. After determining that the family’s disorder did not stem from a known locus for a defective gene, researchers carried out a genome-wide scan. The locus was mapped to a small region at 3p24-25.
In the future, the researchers hope to determine if the locus termed TAAD2 is allelic to MFS2 (a locus of a defective gene associated with Marfan’s syndrome). The researchers said they hope identification of the defective gene associated with this familial disorder will improve diagnosis of the disease in individuals before they begin to demonstrate symptoms, as well as provide information about the cause of the condition.
Automated External Defibrillators in Children
With the growing number of automated external defibrillators (AEDs) in public places and their increasing use by lay people, the likelihood that they will be used in children who weigh less than 50 pounds and who are under the age of 8 years is growing.
A statement in this week’s issue of Circulation (Circulation. 2003;107:3250–3255) outlines the use of AEDS and their development and explains the efficacy and safety of their use in smaller children. Basing their advice on literature already in publication, the Pediatric Advanced Life Support (PALS) Task Force of the International Liaison Committee on Resuscitation (ILCOR) said that AEDs may be used in children ages 1 year to 8 years in whom there is no evidence of blood circulation.
However, the recommendation also calls for 1 minute of cardiopulmonary resuscitation by a lone rescuer attempting to revive such a child—before contacting emergency medical services or using an AED. The group also said that there is not enough information currently available to allow it to recommend using an AED in a child under the age of 1 year.
When used in older children, the group said that the device should ideally deliver a dose specific for children and be highly specific for recognizing heart rhythms that can be converted in children. The report also says that that the group recommends defibrillation for ventricular fibrillation and pulseless ventricular tachycardia.
The Mediterranean Diet and the Greeks
Greeks who adhered to a Mediterranean diet appeared less likely to diet in a study reported in the June 26, 2003, issue of The New England Journal of Medicine (N Engl J Med. 2003;348:2599–2608) by researchers from the University of Athens Medical School and Harvard School of Public Health.
In a study led by Antonia Trichopoulou, MD, of the University of Athens Medical School, the researchers conducted a study of 22 043 adults in Greece. Each of the subjects completed a questionnaire on food frequency at the beginning of the study. The researchers assessed their adherence to the traditional Mediterranean diet on a 10-point scale.
The diet is characterized by intake of a large amount of legumes, fruits, nuts, vegetables, and cereals, along with olive oil. Those who eat such a diet have a low intake of saturated fats and a habit of eating larger than normal quantities of fish. They eat no more than a moderate amount of dairy products and little meat, but they do drink alcohol, mainly in the form of wine with meals.
The subjects were monitored for a median of 44 months. During that time, there were 275 deaths. Researchers found that the higher the adherence to the traditional Mediterranean diet, the less likely the subjects were to die. They found that adherence to the diet was also associated with a lower likelihood of dying from coronary heart disease and cancer.
The researchers wrote: “The magnitude of the reduction in mortality associated with greater adherence to a Mediterranean diet is compatible with the reported survival advantage of adult Mediterranean populations over North American and northern European populations.”
Survival After Early Defibrillation
Patients who survive an out-of-hospital cardiac arrest and receive early ventricular defibrillation live as long and have about the same quality of life as patients who did not have an arrest out of the hospital, wrote Mayo Clinic researchers in a report in the June 26, 2003, issue of The New England Journal of Medicine (N Engl J Med. 2003;348:2626–2633).
In the study led by T. Jared Bunch, MD, of the Mayo Clinic, all patients who had an out-of-hospital cardiac arrest between November 1990 and January 2001 and received early defibrillation in Olmsted County, Minn, were included. Their survival rate was compared with that of a control group composed of persons matched by age, sex, and disease who had not had an out-of-hospital arrest, as well as with that of an age- and sex-matched control group from the general US population.
Of 200 patients who had had an out-of-hospital heart stoppage, 145 lived to be admitted to the hospital. Seventy-nine were neurologically intact at discharge. Nineteen patients died after being discharged from the hospital. The 5-year survival rate was the same as that of the age-, sex-, and disease-matched controls but lower than the age- and sex-matched US population controls. The quality of life of the 50 patients who completed questionnaires was nearly normal, with the exception that they had reduced vitality.