Biomedical engineers at Duke University in North Carolina have developed a low-cost, portable optical coherence tomography (OCT) scanner that promises to bring the vision-saving technology to underserved regions throughout the United States and abroad. Thanks to a redesigned, 3D-printed spectrometer, the scanner is 15 times lighter and smaller than current commercial systems (image shows example of a typically bulky current commercial system) and is made from parts costing less than a tenth the retail price of commercial systems — all without sacrificing imaging quality. In its first clinical trial, the new OCT scanner produced images of 120 retinas that were 95 percent as sharp as those taken by current commercial systems, which was sufficient for accurate clinical diagnosis. The results were published online on June 28, 2019 in Translational Vision Science & Technology, an ARVO journal. The open-access article is titled “First Clinical Application of Low-Cost OCT.” In use since the 1990s, OCT imaging has become the standard of care for the diagnosis of many retinal diseases, including macular degeneration and diabetic retinopathy, as well as for glaucoma. However, OCT is rarely included as part of a standard screening exam because machines can cost more than $100,000 — meaning that usually only larger eye centers have them. “Once you have lost vision, it’s very difficult to get it back, so the key to preventing blindness is early detection,” said Adam Wax, PhD, Professor of Biomedical Engineering at Duke. “Our goal is to make OCT drastically less expensive so more clinics can afford the devices, especially in global health settings.” OCT is the optical analogue of ultrasound, which works by sending sound waves into tissues and measuring how long the waves take to come back.
Researchers at the University of Tokyo conducted a census of the Japanese population of approximately 2,500 years ago using the Y chromosomes of men living on the main islands of modern-day Japan. This is the first time that analysis of modern genomes has estimated the size of an ancient human population before they were met by a separate ancient population. The research was published online on June 17, 2019 in Scientific Reports. The open-access article is titled “Analysis of Whole Y-Chromosome Sequences Reveals the Japanese Population History in the Jomon Period.” “Evidence at archaeological dig sites has been used to estimate the size of ancient human populations, but the difficulty and unpredictability of finding those sites is a big limitation. Now we have a method that uses a large amount of modern data,” said Associate Professor Jun Ohashi, PhD, an expert in human evolutionary genetics and leader of the research team that performed the analysis. The current theory on human migrations into Japan is that the original inhabitants, the Jomon people, were met about 2,500 years ago by a separate group coming mainly from the Korean Peninsula, the Yayoi people. Archaeologists have identified fewer Jomon sites from the Late Jomon Period, the era immediately before the Yayoi arrival. Global temperatures and sea levels dropped during that period, which could have made life more difficult for the hunter-gatherer Jomon people. When the Yayoi people arrived, they brought wet rice farming to Japan, which would have led to a more stable food supply for the remaining Jomon people living with the new Yayoi migrants. The lesser amount of archaeological remains from the Late Jomon Period could be evidence of an actual population decline, or just that the archaeological dig sites have not yet been found.
Three beagles successfully showed they are capable of identifying lung cancer by scent, a first step in identifying specific biomarkers for the disease. Researchers say the dogs’ abilities may lead to development of effective, safe, and inexpensive means for mass cancer screening. After eight weeks of training, the beagles–chosen for their superior olfactory receptor genes–were able to distinguish between blood serum samples taken from patients with malignant lung cancer and healthy controls with 97% accuracy. The double-blind study was published online on June 17, 2019 in The Journal of the American Osteopathic Association. The open-access article is titled “Accuracy of Canine Scent Detection of Non–Small Cell Lung Cancer in Blood Serum.” “We’re using the dogs to sort through the layers of scent until we identify the tell-tale biomarkers,” says Thomas Quinn, DO, Professor at Lake Erie College of Osteopathic Medicine and lead author on this study. “There is still a great deal of work ahead, but we’re making good progress.” The dogs were led into a room with blood serum samples at nose level. Some samples came from patients with non-small cell lung cancer; others were drawn from healthy controls. After thoroughly sniffing a sample, the dogs sat down to indicate a positive finding for cancer or moved on if none was detected. Dr. Quinn and his team are nearing completion of a second iteration of the study. This time the dogs are working to identify lung, breast, and colorectal cancer using samples of patients’ breath, collected by the patient breathing into a face mask. Researchers say findings suggest the dogs are as effective detecting cancer using this method.
Schizophrenia causes hallucinations and memory or cognition problems in those who have it. This psychiatric illness affects 0.5% of the general population, and it can be related to genetic abnormalities of chromosome 22, known as 22q11 deletion syndrome. However, not everyone who has this deletion syndrome necessarily develops psychotic symptoms. So, what triggers the illness? Researchers at the University of Geneva (UNIGE), Switzerland, have provided an initial answer after observing and analyzing several years of patients with deletion syndrome. The scientists found that the size of the hippocampus (image), the area of the brain responsible for memory and emotions, was smaller than normal but followed the same developmental curve as in healthy subjects. Yet, when the first psychotic symptoms appear – generally in adolescence – the hippocampus atrophies dramatically. The new results, which were reported online on June 4, 2019 in Molecular Psychiatry, open up new avenues for understanding the causes of schizophrenia. The article is titled “Positive Psychotic Symptoms Are Associated with Divergent Developmental Trajectories of Hippocampal Volume During Late Adolescence in Patients With 22q11ds.” 22q11 deletion syndrome is a neurogenetic disorder that targets chromosome 22. Thirty percent of people affected by the syndrome end up developing psychotic symptoms specific to schizophrenia, such as auditory hallucinations, memory problems, disorders affecting their perception of reality, and difficulties in social interactions characterized by strong paranoia.
Every spring, tens of thousands of elk follow a wave of green growth up onto the high plateaus in and around Yellowstone and Grand Teton national parks, where they spend the summer calving and fattening on fresh grass. And every fall, the massive herds migrate back down into the surrounding valleys and plains, where lower elevations provide respite from harsh winters. These migratory elk rely primarily on environmental cues, including a retreating snowline and the greening grasses of spring, to decide when to make these yearly journeys, shows a new study led by University of California (UC), Berkeley, researchers. The study combined GPS tracking data from more than 400 animals in nine major Yellowstone elk populations with satellite imagery to create a comprehensive model of what drives these animals to move. “We found that the immediate environment is a very effective predictor of when migration occurs,” said Gregory Rickbeil, PhD, who conducted the analysis as a postdoctoral researcher in Dr. Arthur Middleton’s lab at UC Berkeley. This is in contrast with some other species, such as migratory birds, which rely on changing day length to decide when to move, Dr. Rickbeil pointed out. The results, published in the July 2019 issue of Global Change Biology, suggest that, as climate change reshapes the weather and environment of the park, elk should have the means to adjust their migratory patterns to match the new conditions.
Sickle cell disease (SCD) is a form of anemia that is inherited when both parents are carriers of a mutation in the hemoglobin gene. Currently, this disease can only be diagnosed in pregnancy by carrying out an invasive test that has a small risk of miscarriage and is therefore sometimes declined by parents. Now, researchers from Guy’s and St Thomas’ NHS Foundation Trust and Viapath Analytics, London, UK, in collaboration with non-invasive healthcare company Nonacus Ltd., Birmingham, UK, have developed a non-invasive prenatal test for the disease, and this test was described on June 16, 2019 at the annual conference of the European Society of Human Genetics (ESHG) (2019.eshg.org/) (June 15-18). The abstract (C08.5) of this presentation is titled “Non-Invasive Prenatal Diagnosis of Sickle Cell Disease by Next-Generation Sequencing of Cell-Free DNA.” Julia van Campen, PhD, research scientist at Guy’s and St Thomas’, explains: “We have developed a method of testing for SCD using cell-free fetal DNA — DNA from the fetus that circulates in the maternal bloodstream. Although cell-free fetal DNA testing is already available for some disorders, technical difficulties have hampered the development of such a test for SCD, despite it being one of the most commonly requested prenatal tests in the UK.” In couples that are at risk of having a baby with SCD, each partner carries a mutation in the hemoglobin gene, which means that any fetus has a one in four chance of inheriting both mutations and therefore being affected by SCD. Non-invasive prenatal diagnosis (NIPD) of conditions that are inherited in this way is difficult. “The development of a non-invasive prenatal assay for sickle cell disease has been attempted before and, until now, has not been successful, “says Dr. van Campen.
A new multi-institution study spearheaded by researchers at Florida State University (FSU) and the University of California, Los Angeles (UCLA) suggests a tiny protein could play a major role in combating heart failure related to Duchenne muscular dystrophy (DMD), the most common lethal genetic disorder among children. In collaboration with scientists from across the nation, FSU researchers found that increased levels of the protein sarcospan improve cardiac function by reinforcing cardiac cell membranes, which become feeble in patients with DMD. Their findings were published online on April 30, 2019 in JCI Insight. The article is titled “Stabilization of the Cardiac Sarcolemma by Sarcospan Rescues DMD-Associated Cardiomyopathy.” The condition, which typically afflicts young boys, is caused by a mutation that prevents the body from producing dystrophin, a protein crucial to the health of skeletal, respiratory, and cardiac muscles. Advances in treatment for certain types of DMD-related muscle degradation have helped to prolong patients’ lifespans. However, as DMD patients age, their heart function declines dramatically. “Patients typically live to 20 or 30 years of age,” said lead author Michelle Parvatiyar (photo), PhD, an Assistant Professor in the Department of Nutrition, Food and Exercise Sciences in FSU’s College of Human Sciences. “There have been important improvements in respiratory care, which used to be what a majority of patients would succumb to. Now, in their 20s and 30s, they’re often succumbing to cardiomyopathy. The heart is functioning with a major component of the cell membrane missing. Over time, it wears out.”
One of the most successful interventions in reducing infectious disease worldwide, vaccination still has limited effectiveness in protecting one group of patients – newborn infants. Now a study based at the Ragon Institute of MGH, MIT and Harvard has determined how a pregnant woman’s vaccine-induced immunity is transferred to her child, which has implications for the development of more effective maternal vaccines. The report will be published in the June 27 issue of Cell and, receiving early online release on June 13, 2019. The article is titled “Fc Glycan-Mediated Regulation of Placental Antibody Transfer” “Newborns arrive into the world on the first day of life with brand-new immune systems that, like the children themselves, need to learn to cope with both helpful and harmful microbes in their environment,” says Galit Alter (photo), PhD, of the Ragon Institute and the Massachusetts General Hospital (MGH) Department of Medicine, co-senior author of the Cell paper. “To help the newborn immune system learn to discriminate between friend and foe, mothers transfer antibodies to their infants via the placenta. The rules by which the placenta performs this absolutely essential function have been unknown but, if decoded, could hold the key to generating more powerful vaccines to protect these most precious patients.” While maternal antibodies against some diseases such as measles can be transferred from mother to infant, providing some protection until the child is old enough for individual vaccination, antibodies to other serious diseases like polio are less efficiently transferred. To investigate the mechanisms by which antibodies are transferred from mother to child, Dr.
Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the world. Mostly chemoresistant, PDAC so far has no effective treatment. Understanding the connective tissue, called stroma, that surrounds, nurtures, and even protects PDAC tumors, is key to developing effective therapeutics. “PDAC patients are diagnosed really late, so we don’t know they’re sick until the very end stages,” said Ela Elyada (photo), PhD, a postdoctoral fellow in Dr. David Tuveson’s lab at Cold Spring Harbor Laboratory (CSHL) in New York. “We can’t diagnose patients early enough because we don’t have tools, and they don’t respond to drugs. One barrier to the drugs is the fibroblasts in the stroma.” PDAC is characterized by an abundance of non-malignant stromal cells, and fibroblasts are one of the most common types of stromal cells. “We have a lot of fibroblasts in pancreatic cancer, unlike other cancers which are mostly cancer cells,” Dr. Elyada said. These cancer-associated fibroblasts (CAFs) can help cancer cells proliferate, survive, and evade detection by the immune system. The insidious role CAFs seem to play in protecting cancer cells labels them as bad, but completely obliterating CAFs in mice also worsened their cancers. Dr. Elyada wanted to investigate the nature of CAFs: are they good or bad? To crack the case, she, Associate Professor Paul Robson at the Jackson Laboratory, and colleagues used single-cell RNA sequencing to classify the fibroblasts into three distinct sub-populations, identifying specific functions and characteristics unique to each. This includes two previously identified types of CAFs, myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs), and also a new type of CAF called antigen-presenting CAFs (apCAFs). The apCAFs were present in both mice and human PDAC.
A machine-learning method discovered a hidden clue in people’s language predictive of the later emergence of psychosis –-i.e., the frequent use of words associated with sound. A paper published by the Nature-published journal npj Schizophrenia published the findings by scientists at Emory University and Harvard University online on June 13, 2019. The open-access article is titled “A machine learning approach to predicting psychosis using semantic density and latent content analysis.” The researchers also developed a new machine-learning method to more precisely quantify the semantic richness of people’s conversational language, a known indicator for psychosis. Their results show that automated analysis of the two language variables — more frequent use of words associated with sound and speaking with low semantic density, or vagueness — can predict whether an at-risk person will later develop psychosis with 93 percent accuracy. Even trained clinicians had not noticed how people at risk for psychosis use more words associated with sound than the average, although abnormal auditory perception is a pre-clinical symptom. “Trying to hear these subtleties in conversations with people is like trying to see microscopic germs with your eyes,” says Neguine Rezaii, MD, first author of the paper. “The automated technique we’ve developed is a really sensitive tool to detect these hidden patterns. It’s like a microscope for warning signs of psychosis.” Dr. Rezaii began work on the paper while she was a resident at Emory School of Medicine’s Department of Psychiatry and Behavioral Sciences. She is now at fellow in Harvard Medical School’s Department of Neurology.