Cellphone Technology Developed to Detect HIV
New, affordable mobile device could aid people in developing countries
The management of human immunodeficiency virus 1 (HIV), an autoimmune disorder that cripples the immune system by attacking healthy cells, remains a major global health challenge in developing countries that lack infrastructure and trained medical professionals. Investigators from Brigham and Women’s Hospital have designed a portable and affordable mobile diagnostic tool, utilizing a cellphone and nanotechnology, with the ability to detect HIV viruses and monitor its management in resource-limited regions. The novel platform is described in a paper published recently in Nature Communications.
“Early detection of HIV is critical to prevent disease progression and transmission, and it requires long-term monitoring, which can be a burden for families that have to travel to reach a clinic or hospital,” said senior author Hadi Shafiee, PhD, a principal investigator in the Division of Engineering in Medicine and Renal Division of Medicine at the Brigham. “This rapid and low-cost cellphone system represents a new method for detecting acute infection, which would reduce the risk of virus transmission and could also be used to detect early treatment failure.”
Traditional virus monitoring methods for HIV are expensive, requiring the use of polymerase chain reaction (PCR). Shafiee and his colleagues sought to design an affordable, simple tool that makes HIV testing and monitoring possible for individuals in developing countries with less access to medical care.
Utilizing nanotechnology, a microchip, a cellphone and a 3D-printed phone attachment, the researchers created a platform that can detect the RNA nucleic acids of the virus from a single drop of blood. The device detects the amplified HIV nucleic acids through on-phone monitoring of the motion of DNA-engineered beads without using bulky or expensive equipment. The detection precision was evaluated for specificity and sensitivity.
Researchers found that the platform allowed the detection of HIV with 99.1 percent specificity and 94.6 percent sensitivity at a clinically relevant threshold value of 1,000 virus particles/ml, with results within one hour. Notably, the total material cost of the microchip, phone attachment and reagents was less than $5 per test.
“Health workers in developing countries could easily use these devices when they travel to perform HIV testing and monitoring. Because the test is so quick, critical decisions about the next medical step could be made right there,” said Shafiee. “This would eliminate the burden of trips to the medical clinic and provide individuals with a more efficient means for managing their HIV.”
“We could use this same technology as a rapid and low-cost diagnostic tool for other viruses and bacteria as well,” said lead author Mohamed Shehata Draz, PhD, an instructor in the Division of Engineering in Medicine and Renal Division of Medicine at the Brigham.. “This platform could help a lot of people worldwide.”
Funding for this work was provided by the National Institute of Health under award numbers R01AI118502, R21HD092828, and P30ES000002; Harvard T.H. Chan School of Public Health, Harvard Center for Environmental Health through Harvard NIEHS Grant; and American Board of Obstetrics and Gynecology, American College of Obstetricians and Gynecologists, American Society for Reproductive Medicine, Society for Reproductive Endocrinology and Infertility through ASRMAward, and Harvard University Center for AIDS Research (CFAR) under award number 5P30AI060354–14.
Draz, MS et al. “DNA engineered micromotors powered by metal nanoparticles for motion based cellphone diagnostics” Nature Communications DOI: 10.1038/s41467-018-06727-8
Just the Right Dose: Antiepileptic Drug Clearance Changes During Pregnancy
Study finds significant changes in how seizure medications are metabolized during the different trimesters of pregnancy
During pregnancy, the numerous physiological changes a woman’s body undergoes can alter the way medications are metabolized, the rate at which they are cleared, and their overall effectiveness. Many women continue taking antiepileptic drugs (AEDs) during pregnancy, but while many studies address their safety, it has been unclear if the drug’s effectiveness may be altered during pregnancy. A new study by investigators from Brigham and Women’s Hospital examined whether pregnancy-related changes may influence how effectively five common AEDs prevent seizures and found that AED clearance significantly changes by the first trimester for the most commonly used medication and by the second trimester for two others. Their results are published in Neurology.
“We want to be able to give the exact dose of a drug that keeps a woman seizure-free and keeps her and her baby safe, but there are relatively few studies that have examined pregnancy-related changes in AED metabolism for us to know how to adjust this dose,” said lead author P. Emanuela Voinescu, MD, PhD, associate neurologist in the Department of Neurology at BWH. “We sought to fill that gap about changes in AED metabolism during the different trimesters of pregnancy.”
The team investigated five commonly used drugs, including levetiracetam – one of the most widely used medications during pregnancy – oxcarbazepine, topiramate, phenytoin, and valproate.
The prospective, observational study, started by senior author Page Pennell, MD, while at Emory University, consisted of 40 women with epilepsy who were planning to conceive or were less than 16 weeks pregnant, and who chose to continue their AEDs during pregnancy. Study visits occurred every one to three months and for the first postpartum year. Drug clearance values, the dose required to maintain a certain blood serum concentration, were obtained via blood draw at baseline and during pregnancy. Seizure occurrence and frequency were recorded throughout the study.
Researchers found that the metabolic changes affecting levetiracetam started early, in the first trimester, and drug clearance remained elevated during the second and third trimesters. In contrast, they found that oxcarbazepine and topiramate had elevated clearance starting in the second trimester. This is important because if drug clearance increases, patients may need to be prescribed a higher or more frequent dose of their antiepileptic medication.
“It is already a challenge to be pregnant and our patients have to deal with epilepsy on top of it. It requires a little more work because of all the frequent blood draws and medication adjustments” said Voinescu. “It would be nice to be able to simplify their management by having more scientific guidelines in place regarding how to adjust medication doses during pregnancy to keep them seizure-free and to keep their babies safe.”
Funding for this work was supported by an NIH Specialized Center of Research (P50MH 68036) NCRR M01-RR00039, NINDS and NICHD (U01 NS038455), the American Brain Foundation, American Epilepsy Society and the Epilepsy Foundation as the Susan Spencer Clinical Research Training Fellowship and the Karger Fund.
Paper cited: Voinescu, E et al. “Antiepileptic drug clearances during pregnancy and clinical implications for women with epilepsy” Neurology DOI:10.1212/WNL.0000000000006240
New Transgenic Model of Parkinson’s Illuminates Disease Biology
Model developed recapitulates PD-type motor syndrome and the biological causes of disease to aid in search for new therapeutics
Parkinson’s disease (PD) is a neurodegenerative disorder that presents clinically with abnormal movement and tremors at rest. In the brain, PD is marked by the accumulation of the protein, α-synuclein (αS), into clumps known as Lewy bodies, which diminish neural health. Previous research suggests abnormal αS can alter cell membrane function and lead to cell death. Investigators from Brigham and Women’s Hospital have developed a unique mouse model to induce PD-like αS aggregation, leading to resting tremor and abnormal movement control. This mouse model responds to L-DOPA, similarly to patients with PD. The research team’s results on the use of this transgenic mouse model appear this week in Neuron.
“It is difficult to find efficient treatment therapies that target αS aggregation,” said lead author Silke Nuber, PhD, an instructor in the Ann Romney Center for Neurologic Diseases at BWH. “Thus, it is necessary to develop mouse models that reflect the long-term changes, including Lewy-like aggregation of αS and an associated close PD-phenotype, to better understand the mechanisms that lead to the initiation of PD.”In a healthy brain, this lab first reported (Bartels et al, Nature 2011) that αS can occur normally in the form of helically folded tetramers (four units of αS wound around each other), a form that resists the aggregation that abnormal αS monomers undergo. To model the brain in PD, Nuber and her team created a novel transgenic mouse that has a tetramer-lowering mutation, which leads to αS deposits, loss of dopamine and neurotoxicity.
“With these new mice, we set out to examine the upstream role of tetramer-lowering mutations and their relevance to PD,” Nuber said. “Our hypothesis was that upstream destabilization of normal tetramers to excess monomers can lead to the changes of PD.”
To examine the effect of tetramer-abrogating mutations on αS pathology, the research team created multiple mouse lines with certain αS mutations that chronically decrease the tetramers, increase free monomers and lead to neuronal dysfunction and degeneration. They then compared their new tetramer-abrogating mouse to a mouse expressing normal human αS protein and a mouse with just a single familial PD αS mutation. The mice were carefully evaluated side-by-side for key biochemical, histological and behavioral characteristics associated with PD.
The new tetramer-abrogating mouse displayed key PD-like changes, including age-dependent αS aggregation in altered neurons and distinctive abnormal movements. These changes were all derived from preventing normal αS tetramer formation. These findings strongly suggest that tetramers are required for the normal state of αS in the brain. The authors conclude that it is likely that shifting tetramers to monomers can initiate PD. They also note that the phenotype was more prominent in male mice, which is reminiscent to what occurs in PD, a finding they plan to follow up on within the framework of the Women’s Brain Initiative at BWH.
“We can now examine PD in a whole new light. We can think about stabilizing the physiological αS tetramer, an entirely novel therapeutic concept, as a means of preventing or delaying the onset of PD,” said Nuber.
“With our lab’s experience in deciphering the earliest stages of Alzheimer’s disease, we decided some time ago to apply analogous approaches to the different protein abnormality occurring in PD,” said Dennis Selkoe, MD, the senior author of the paper and the co-director of the Ann Romney Center for Neurologic Disease at BWH. “We believe this unique mouse model shows that the tetrameric form of αS we discovered in 2011 is necessary for normal neuronal function, so that abrogating the tetramer has direct PD-like consequences. This PD mouse model will provide a new route to entirely novel therapeutic approaches.”
Funding for this work was provided by NIH grants NS083845 (to D.J.S.), NS 099328 (to U.D.), and NS103123 (to S.N.), and a research grant from the HNDC (to S.N.).
Paper cited: Nuber, Silke et al. “Abrogating Native α-Synuclein Tetramers in Mice Causes a L-DOPA-Responsive Motor Syndrome Closely Resembling Parkinson’s Disease” Neuron https://doi.org/10.1016/j.neuron.2018.09.014