Editor's note: Science Scan is a roundup of recently published biotechnology-relevant research.
In a clinical analysis of 60,770 U.S. patients who arrived at hospital emergency rooms with heart attack symptoms, three out of four did not receive a class of clot-inhibiting drug proven in clinical trials to reduce mortality or myocardial infarction.
As far back as September 2000, the American Heart Association and the American College of Cardiology recommended that these drugs - glycoprotein (GP) inhibitors - be given to high-risk heart patients.
The current Journal of the American College of Cardiology (JACC), dated July 2, 2003, carries an article titled "Early use of glycoprotein IIb/IIIa inhibitors in non-ST-elevation acute myocardial infarction." Its first author is cardiovascular researcher Eric Peterson at Duke University. "Physicians routinely perform an electrocardiogram to look for certain telltale patterns that indicate a heart attack," Peterson explained. "One such portion of the ECG tracing, known as the ST segment, is elevated in the more serious cardiac events.
"Typically," he observed, "heart attack patients with non-ST segments on their electrocardiograms tend to be treated less aggressively than patients with ST-segment elevation." Peterson estimated that about 1.3 million Americans with non-STsegment - caused by partial cardiac blockages in arteries supplying the heart - are hospitalized each year. "However," he told BioWorld Today, "since these patients are older, have more vague symptoms, do not report crushing chest pain, and often do not have definite ECG findings when they present, they usually don't receive immediate, aggressive care. We now know they should not be overlooked."
These oversights are reported in an accompanying JACC editorial commentary worded: "Early glycoprotein IIb/IIIa inhibitors in patients with non-ST-segment elevation myocardial infarction: Are we ready to open the floodgates?"
Peterson cited three findings anent the journal article: "First, the national guidelines are not necessarily being followed as a guide to certain therapies - in this case the glycoprotein inhibitors. Only 25 percent of patients had been treated by the guidelines. Some are less likely to receive therapy than others, particularly women, the elderly, the uninsured and whites. In addition," he continued, "patients who are at higher risk, and stand the most to benefit, are less likely to be treated.
"My second message," Peterson went on, "is that we had a professional need to get better at the newer therapies in a quicker fashion so there isn't a delay between discovery and actual utilization in practice. And thirdly, we were able to demonstrate in real-life patients the beneficial effects of the recommended glycoprotein drugs compared with those enrolled in clinical trials.
"These heart-targeted glycoproteins," Peterson explained, "bind specifically to the platelets in the blood and prevent them from causing a clot to form. So when a person has a heart attack these drugs prevent furthering of the attack, and help dissolve the clot." He summed up the outcome of the 60,000-plus patients: "This class of drugs, the GPs, reduced those patients' likelihood of dying from myocardial infarction in a heart attack by 12 percent. And those receiving the therapy had a significantly lower mortality rate of 3.3 percent compared to 9.6 percent of those who didn't."
Ferocious E. coli Bacteria Wreak Urinary Tract Infections From Hideouts Inside Bladder Walls
Stubborn bladder infections may hang in there after treatment because the bacteria that cause them multiply inside the epithelial cells that line the bladder wall. Those microbes guilty of urinary tract infection are elusive prey. They often survive onslaughts by the human immune system and antibiotics, then emerge to strike again.
Holed up inside the bladder wall, the bugs form "pods" that contain huge numbers of bacteria, as reported in Science dated July 4, 2003. The report, by microbiologists at Washington University in St. Louis, is titled "Intracellular bacterial biofilm-like pods in urinary tract infections."
The majority of such UTIs are caused by certain strains of Escherichia coli, which colonize the epithelial cells lining the bladder. The co-authors discovered that the pathogens are clustered together in a matrix matured into a biofilm, which creates pod-like bulges on the bladder surface in mice. The pods are sealed off from the host's immune responses, and coated with the same substance that makes the bladder wall impermeable. Every so often, the pods break open to release the bacteria. This event triggers another round of UTI inflammation, and a recurrence of symptoms.
"This discovery," the authors wrote, "establishes a new paradigm in our understanding of acute and recurrent urinary infections, and should help future work on developing treatment for this common condition."
Daughters' Probability Of Pregnancy Fell With DDT In Mom's Long-Ago Preserved Blood
Just three decades ago this year, environmentalist Rachel Carson (1907-64) put paid to DDT (dichloro/diphenyl/trichloroethane). The U.S. government banned the toxic insecticide in 1973, a decade after Carson's Silent Spring was published in 1962. That best-seller denounced DDT's harm to the vanishing songbird population. The ban did not extend to the export of DDT. In many countries it effectively reduces transmission of malaria by its toxic effects on mosquitoes.
A brief item in The Lancet dated June 28, 2003, reports the effect of DDT on female reproductive capability. The article is titled "DDT and DDE exposure in mothers and time to pregnancy in daughters." (DDE is a potent estrogen hormone).
The paper's co-authors are researchers at the Public Health Institute in Berkeley, Calif. They measured concentrations of DDT and DDE in the preserved blood of women who gave birth in California during the early 1960s. They compared maternal DDT and DDE blood concentrations with the time to pregnancy in 289 daughters about 30 years after the fact.
The investigators found a clear correlation between increased DDT concentrations in maternal blood and a one-third reduction in a chance of pregnancy in their daughters for every 10 micrograms per liter increase in DDT concentrations of maternal blood.