When facing a life-threatening infection, the “yuck factor” is a minor concern. Fecal microbiota transplant (FMT for short) has become an accepted treatment for recurrent Clostridium difficile infection, which can cause severe diarrhea and intestinal inflammation.
In a new video, Emory physicians Colleen Kraft and Tanvi Dhere explain how FMT restores microbial balance when someone’s internal garden has been disrupted.
C. difficile or “C diff” is a hardy bacterium that can barge into the intestines after another infection has been treated with antibiotics, when competition for real estate is low. In the last few years, doctors around the world have shown that FMT can resolve recurrent C diff infection better than antibiotics alone.
At Emory, Kraft and Dhere have performed almost 300 FMTs and report a 95 percent success rate when treating recurrent C diff. They have established a standard slate of stool donors, whose health is carefully screened.
Building on their experience with the procedure, Kraft and Dhere are studying whether FMT can head off other antibiotic-resistant infections besides C diff in kidney transplant patients. They have teamed up with infectious disease specialists Aneesh Mehta and Rachel Friedman-Moraco to conduct this study. Read more
A new paper in PNAS from Emory scientists highlights a neat example of bacterial evolution and adaptation related to sexually transmitted infections. Neisseria meningitidis, a bacterium usually associated with meningitis and sepsis, sometimes appears in the news because of cases on college campuses or other outbreaks.
Genetic changes make this clade look more like relatives that are known to cause gonorrhea. Some good news is that these guys are less likely to cause meningitis because they have lost their outer capsule. They have also gained enzymes that help them live in low oxygen.
The DNA analysis helps doctors track the spread of this type of bacteria and anticipate which vaccines might be protective against it. Thankfully, no alarming antibiotic resistance markers are present (yet) and currently available vaccines may be helpful. Full press release here, and information about meningococcal disease from the CDC here.
This looks like a well-worn path in bacterial evolution, since N. gonorrhoeae is thought to have evolved from N. meningitidis and there are recent independent examples of N. meningitidis adapting to the urogenital environment.
Pentz’s team systematically evaluated something that science writers and journalists try to do all the time (and not always well). And they did so with actual conversations between doctors and patients at Winship. The first author of the paper, published in The Oncologist, was medical student Ana Pinheiro.
The researchers studied 66 conversations with nine oncologists. In 25 of those conversations, patients reported that they were able to hear a metaphor. Here’s one example:
“We try to figure out what food makes this kind of cancer grow. For this cancer, the food was estrogen and progesterone. So we’re going to focus on blocking the hormones, because that way we starve the cancer of its food.”
The paper lists all 17 (bus driver, boss, switch, battery, circuit, broken light switch, gas pedal, key turning off an engine, key opening a lock, food for growth, satellite and antenna, interstate, alternate circuit, traffic jam, blueprint, room names, Florida citrus) and how they were used to explain eight cancer-related molecular testing terms.
When patients were asked about the helpfulness of a metaphor that was used, 85 percent of the time they demonstrated understanding and said it was helpful. So let the metaphors fly!
A recent paper in Experimental Brain Research from Emory neuroscientist Krish Sathian and colleagues demonstrates that congenitally blind study participants displayed superior verbal, but not spatial abilities, when compared to their sighted counterparts. This may reflect both greater reliance on verbal information, and the recruitment of the visual cortex for verbal tasks.
Lab Land went looking off the beaten path for individual stories of Emory cardiologists saving lives and was pleased to find several. We highlight here three remarkable case reports that are being presented at the ACC meeting. We look forward to learning more about these cases.
Electrical storm is life threatening and refers to a recurrent arrhythmia. The arrhythmia did not respond to drug treatment, so anesthesiologists were brought in to perform left stellate ganglion block, an injection of medication into a nerve bundle in the neck, allowing diagnosis and further treatment. It turns out the arrhythmia was caused by sarcoidosis, a rare intrusion of immune cells into the heart. [Saturday morning: Michael Lloyd, Boris Spektor]
A 30-year old woman came to doctors with drastically impaired heart function, although she did not have a blockage of her coronary arteries or signs of damage to the heart muscle. Doctors discovered a tumor near her spine that was producing heart-distorting hormones such as epinephrine. She underwent surgery to remove the tumor. [Saturday afternoon: Stamatios Lerakis]
Ten days after giving birth, a woman came to a hospital with chest pain. Upon cardiac catheterization, a rearrangement of her coronary arteries was discovered. It appears that the congenital defect had gone undetected until the stress of giving birth. Under medical treatment, she is asymptomatic, but she will need future monitoring and possibly a procedure to correct the artery problems. [Sunday morning: Camden Hebson]
An experimental anti-inflammatory drug has positive effects on neuron function and amyloid plaques in a mouse model of Alzheimer’s disease, Emory neuroscientists report. The findings are published in the journal Neurobiology of Disease.
Inflammation’s presence in Alzheimer’s is well established, but it is usually thought of as an accelerator, rather than an initiating cause. While everybody argues about the amyloid hypothesis, there’s a case to be made for intervening against the inflammation. Exactly how is an open question.
The drug tested, called XPro1595, targets the inflammatory signaling molecule tumor necrosis factor (TNF). Commercialized drugs such as etanercept and infliximab, used to treat autoimmune diseases, also block TNF. However, XPro1595 only interferes with the soluble form of TNF and is supposed to have less of an effect on overall immune function.
Senior author Malu Tansey (pictured) and her colleagues say that interfering with TNF could have direct effects on neurons, as well as indirect effects on the immune cells infiltrating the brain. They write that “the most promising finding in our study” is the ability of XPro1595 to restore long-term potentiation or LTP, which is impaired in the Alzheimer’s model mice. Read more
We can think of exosomes as tiny packages that cells send each other. They’re secreted bubbles containing proteins and regulatory RNAs. Thus, they may be a way to harvest the regenerative capacity of pediatric heart tissue without delivering the cells themselves.
Davis’ lab studied cardiac tissue derived from children of different ages undergoing surgery for congenital heart defects. The scientists isolated exosomes from the cardiac progenitor cells, and tested their regenerative activity in rats with injured hearts.
They found that exosomes derived from older children’s cells were only reparative if they were subjected to hypoxic conditions (lack of oxygen), while exosomes from newborns’ cells improved rats’ cardiac function with or without hypoxia. Read more
Cancer immunotherapy drugs blocking the PD-1 pathway – known as checkpoint inhibitors – are now FDA-approved for melanoma, lung cancer and several other types of cancer. These drugs are often described as “releasing the brakes” on dysfunctional T cells.
A new study from Emory Vaccine Center and Winship Cancer Institute researchers shows that even if the PD-1-imposed brakes are released, the tumor-specific T cells still need “fuel” to expand in numbers and restore effective immune responses. That fuel comes from co-stimulation through a molecule called CD28.
The results were published Thursday by the journal Science.
Despite the success of PD-1-targeting drugs, many patients’ tumors do not respond to them. The study’s findings indicate that CD28’s presence on T cells could be a clinical biomarker capable of predicting whether drugs targeting PD-1 will be effective. In addition, the requirement for CD28 suggests that co-stimulation may be missing for some patients, which could guide the design of combination therapies.
For the rest of our press release and quotes from authors Rafi Ahmed, Alice Kamphorst and Suresh Ramalingam, please go here. For some additional links and thoughts on PD-1 and CD28, read on:
Direct reprogramming has become a trend in the regenerative medicine field. It means taking readily available cells, such as skin cells or blood cells, and converting them into cells that researchers want for therapeutic purposes, skipping the stem cell stage.
In Circulation Research, Emory stem cell biologist Young-sup Yoon, MD, PhD and colleagues recently reported converting human skin fibroblast cells into endothelial cells, which line and maintain the health of blood vessels.
Once reprogrammed, a patient’s own cells could potentially be used to treat conditions such as peripheral artery disease, or to form vascular grafts. Exactly how reprogrammed cells should be deployed clinically still needs to be worked out.
In cardiovascular disease, many clinical trials have been performed using bone marrow cells that were not reprogrammed. Emory readers may be familiar with studies conducted by Arshed Quyyumi, MD and colleagues, in which treatment was delivered after patients’ heart attacks. In those studies, sorted progenitor cells, some of which could become endothelial cells, were introduced into the heart. To provide the observed effects, the introduced cells were more likely supplying supportive growth factors.
The results were intriguing, despite the small number of study participants: five, two of whom were pregnant. Detailed information has not been available about immune responses against Zika in humans, especially T cell responses.
Highlights from Mulligan’s abstract:
*All five seemed to have a hole in their immune systems – functional antiviral “killer” CD8 T cells were rare, despite activation of CD8 T cells in general and strong responses from other cell types.
*Cross-reactive immune responses, based on previous exposure to dengue and/or yellow fever vaccine, may have blunted Zika’s peak.
*”Even with prolonged maternal viremia, both pregnancies resulted in live births of apparently healthy babies.” Read more