Type 1 diabetes patients with elevated albumin in their urine had three times the risk of life-threatening kidney and cardiac disease as those with normal levels, according to researchers at the University of Colorado Anschutz Medical Campus.
The study, led by Dr. Petter Bjornstad, MD, of the Barbara Davis Center for Childhood Diabetes at CU Anschutz, looked at 38 males with type 1 diabetes and albumin in their urine and 38 diabetic males with normal albumin levels. The subjects were recruited across the country from the Type 1 Diabetes Exchange Biobank.
Albuminuria, or the presence of elevated albumin in the urine, is a marker for kidney disease. Bjornstad found that the copeptin was more than three times higher in patients with albuminuria. Copeptin is secreted along with arginine vasopressin or AVP from the pituitary gland and elevated levels appear to predict risk of cardiovascular mortality.
AVP is a hormone that regulates urination, though chronically high levels may cause kidney and vascular damage. But measuring AVP is extremely difficult due to its small size and short half-life. So researchers use copeptin as a surrogate. It is more stable, derived from the same molecule as AVP and can be more easily measured.
In this study, researchers found that the men with type 1 diabetes and albuminuria had significantly greater concentrations of copeptin compared to diabetic males with normal albumin levels.
“High levels of copeptin were associated with greater odds of albuminuria and impaired glomerular filtration rate which measures kidney function and stages of kidney disease,” Bjornstad said.
The findings, he said, could open the door to new ways of treating diabetic kidney disease and other illnesses. Specifically, a family of drugs called vaptans could be used to block excess vasopressin in these patients. “We think that vaptans or therapies targeting vasopressin can delay or stop the development of diabetic kidney disease,” Bjornstad said.
“There are clinical trials undergoing with vaptans in polycystic kidney disease, but to our knowledge no one is looking at vaptans and diabetic kidney disease yet.”
The study has important limitations. The sample size was small and its design prevents determination of causality. It also focused on men and may not apply to young people or women. But the findings support earlier research done by Bjornstad in the Coronary Artery Calcification in Type 1 Diabetes Study (CACTI.)
“We think these findings may have lifesaving implications for those with diabetic kidney and heart disease,” Bjornstad said.
University of Colorado Anschutz Medical Campus http://tinyurl.com/jfsnggz
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The scientists from the Montreal Neurological Institute and Hospital at McGill University, led by Peter McPherson, along with collaborators in Saudi Arabia, Jordan, Germany, and at SickKids Hospital and the University of Toronto, have discovered that a severe form of epileptic encephalopathy is caused by recessive loss-of-function mutations in the gene DENND5A.
Epileptic encephalopathy is a rare but devastating sub-form of epilepsy that results in severe mental and physical disabilities in children from birth. It is often caused by improper development of the brain. Individuals with epileptic encephalopathy caused by mutations in DENND5A present with serious anomalies in brain structure along with calcifications in the brain and altered facial features.
Researchers performed whole exome sequencing on three children with epileptic encephalopathy from two families, one from Saudi Arabia and another from Jordan. Both families were consanguineous, meaning the parents were related to each other. This greatly increases the chance that rare mutations that are recessive and that cause no harm to the parents are expressed in the children. The whole exome sequencing, along with extensive and complex genetic analysis, revealed that recessive mutations in DENND5A were responsible for the disease, with the Saudi family and the Jordanian family having different mutations but in the same DENND5A gene. They found that mutations in DENND5A lead to a lack of the DENND5A protein, resulting in underdevelopment of the central nervous system. The protein expressed from the DENND5A gene is present at highest levels in the nervous system especially while the brain is developing, corroborating the evidence that mutations in the gene cause epileptic encephalopathy.
The researchers discovered that the DENND5A protein controls the movement of receptors for key developmental factors called neurotrophins. Disruption of DENND5A function leads to altered levels of these receptors, which could explain why loss of DENND5A leads to the severe neurological developmental defects in the patients.
Epilepsy affects approximately three per cent of the world population, and epileptic encephalopathy is a rare sub-form of the disease. It is difficult to say how many children with epileptic encephalopathy have the DENND5A mutations, but now that the gene has been identified as a cause, researchers around the world can begin to test patients for mutations in this gene.
This finding also improves our understanding of neuronal development. The observation that loss-of-function mutations in DENND5A causes epileptic encephalopathy suggests that DENND5A protein controls membrane trafficking pathways critical for normal neuronal development and strengthens the argument that protein trafficking processes in cells are critical for normal neuronal development and function.
“Our study demonstrates the importance of membrane trafficking in neuronal development and it provides a new pathophysiological mechanism for this disease type. This will allow physicians around the world to test if mutations in DENND5A are causing the disease in their patients, and also to provide genetic counselling for affected families,” says Dr. Chanshuai Han, the lead author on the study.
The Montreal Neurological Institute and Hospital http://tinyurl.com/jfb7aho
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Misfolded proteins associated with Parkinson’s disease were detected in cerebrospinal fluid by scientists at McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), paving the way to development of a biochemical test for the diagnosis of the disease.
The research was led by Claudio Soto, Ph.D., professor in the Department of Neurology and the director of the George and Cynthia Mitchell Center for Alzheimer’s disease and Related Brain Disorders at UTHealth.
Parkinson’s disease (PD) is a degenerative disorder of the brain that initially affects motor skills, causing tremors, stiffness, slowness of movement and impaired balance. As it progresses, patients may develop cognitive problems, psychiatric alterations and dementia. There are no current laboratory or blood tests that have been proven to help in diagnosis. Because the disease can be difficult to diagnose accurately, diagnosis is sometimes made by ruling out other neurological diseases.
Using a technology developed by Soto that was shown in previous studies to detect misfolded proteins associated with diseases such as Creutzfeld-Jacob and Alzheimer’s disease, researchers targeted misfolded alpha-synuclein (aSyn) aggregates as a way of developing a sensitive biochemical diagnosis for PD. The Protein Misfolding Cyclic Amplification (PMCA) technology was able to detect very small amounts of the misfolded protein circulating in cerebrospinal fluid.
“Of significant interest is that the amount of aSyn detected correlates with the severity of the disease and in two of the control samples, aSyn was detected and those people later developed clinical symptoms of PD,” Soto said.
The research included blind screenings of cerebrospinal fluid of two cohorts of 76 PD patients, as well as controls of 65 people who were healthy or affected by other neurological disorders, 18 affected by neurodegenerative diseases and 14 affected by Alzheimer’s disease.
Since cerebrospinal fluid is removed through spinal taps, which are invasive and painful, the hope is that future research would enable optimization of the PMCA assay to detect aSyn in blood or urine.
“The hope is that we could use aSyn- PMCA to detect PD in patients before they develop symptoms, and those patients could be entered into clinical trials for novel treatments that might prevent, cure or delay the progression of the disease before substantial and irreversible damage of the brain,” Soto said.
The University of Texas Health Science Center at Houston http://tinyurl.com/j98zslw
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Beckman Coulter Life Sciences has launched an international HIV/AIDS award at the 2016 conference for the African Society for Laboratory Medicine (ASLM) recently held in Cape Town, South Africa (December 3 to 8). The annual award is part of the company’s global CARES Initiative dedicated to helping people who are living with HIV/AIDS. Beckman Coulter’s CARES award is designed to recognize individuals who have shown ‘care, dedication and commitment’ in their communities as part of the fight against HIV/AIDS. The winner will receive a $5,000 (€4,700) donation in their name to one of the selected causes, with the three individual stories that receive the most nominations publicized around the world on the CARES Initiative website. Potential winners can be nurses, healthcare workers, national coordinators, lab scientists and even clinicians; or lay people who are active in community outreach work. This could include a social worker providing AIDS counselling. CARES supports the UNAIDS 90-90-90 target to ensure that by the year 2020, 90% of people living with HIV will know their status, 90% of those with diagnosed HIV infection will receive sustained antiretroviral therapy, and 90% of all people receiving antiretroviral therapy will have viral suppression. It focuses on providing innovative solutions for the monitoring of HIV and AIDS treatment. CARES was inspired by the work of Professor Debbie Glencross, a South African laboratory pathologist, who found a different and less expensive way to measure a patient’s CD4 count. While this is intended as an international award, in its first year, the award will focus on recognizing the dedication of people in Africa, one of the areas in the world most affected by HIV/AIDS. The 2017 award will be launched at the annual meeting of the African Society for Laboratory Medicine (ASLM), a pan-African professional body aiming to improve laboratory services.
Recognition for unsung heroes Samuel Boova, Beckman Coulter’s Director Alliance Development, High Burden HIV Markets, said: “The award is to give a platform to the work and stories of those we see as the unsung heroes of individual communities. These are people who have shown individual dedication, commitment and courage or who have made a difference in the battle against HIV/AIDS. “However, it is not just the final winner we want to publicaly recognize. We hope the award will encourage communities to learn about and honour the work of every nominee, so that more people will come forward to help and support those living with HIV/AIDS.” Nominations must first be made via the CARES website. Once a name has been nominated, the local community will be given the opportunity to vote in support. People with the greatest number of votes will be put forward for the final assessment panel. Rules of entry and full details are available in full from http://www.beckman.com/cares. Mr Boova gave the following examples of ordinary people who support their local communities in the field of HIV/AIDS. “We are looking for dedicated and committed individuals like these who work in the community helping others to live with, and manage, the disease,” he added.
Potential Nominees The first example is how a young HIV positive woman in Uganda was inspired and empowered by a community charity, PINA (People In Need Agency), to rebuild her life and become an advocate herself for young people living with HIV. This was the objective of PINA when it was first set up by a local case worker – to work with young people, helping them overcome the stigma of living with HIV and rebuild their self-esteem. Mr Boova also pointed out that there are many women in rural Africa who walk miles every day to see patients to ensure they are compliant with their medications. Medication alone does not help without the commitment of these women – and they have to walk many miles between patients each day and every day, whatever the conditions.www.beckman.com/cares
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New enzymatic test for HbA1c The worldwide rapid rise in diabetes is a challenge for treatment as well as for diagnosis and monitoring. With the new test HbA1c net FS, DiaSys Diagnostics System has introduced an innovative product with highest accuracy setting new standards for reliable results in diagnosing and monitoring diabetes. Based on enzymatic measurement Hba1c net FS ensures highest specificity without interferences by hemoglobin variants as well as outstanding precision. Using the fully automated process including on-board hemolysis on the DiaSys analysers, BioMajesty® and respons®910, labs of every size can optimize their workflow for HbA1c. Several other major product launches were made in time for DiaSys’ 25th anniversary. Under the trademark QDx DiaSys announced a point-of-care product line comprising test strips and devices for various diagnostic fields such as cardiac, vitamin D, allergy, anemia, lipids and urinalysis. Furthermore, respons®910UP was presented offering improved handling and performance for the small to medium lab (up to 150 tests/hour). 25 years of success as a mid-size company in the challenging and ever changing market of in-vitro diagnostics – DiaSys takes this opportunity to thank all employees, customers and partners for their contribution and confidence and looks forward to a common prospering future.www.diasys-diagnostics.com
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Experts at the European Committee on Antimicrobial Susceptibility Testing (EUCAST), who define the optimal drug concentrations to inhibit the growth of pathogens, have found that genetic methods cannot yet be used to test for susceptibility in a number of important bacterial species. Although there have been advances in whole genome sequencing (WGS), which allows to determine the DNA sequence of an organism’s genome at a single time, there are still several hurdles to overcome before this type of genetic testing can be used in clinical laboratories, they concluded. A EUCAST subcommittee dedicated to reviewing the role of WGS in antimicrobial susceptibility testing (AST) considered the most recent published evidence on the use of whole genome sequencing as a tool for susceptibility testing. The group – comprising of over a dozen leading experts and led by Prof. Neil Woodford, Head of Public Health England’s Antimicrobial Resistance and Healthcare Associated Infections Reference Unit – did not rule out that it will one day be possible for a single assay to predict how a species of bacteria will respond to a specific antimicrobial drug, but there is little evidence to suggest we will reach this point in the near future. EUCAST’s technical data coordinator, Prof. Gunnar Kahlmeter of the Central Hospital, Växjö, Sweden, said that it is premature to suggest that breakpoints and recommendations for phenotypic susceptibility testing will no longer be required as genetic methods will supersede them any time soon. “To be of use in a clinical situation, WGS will need to predict antimicrobial resistance and also antimicrobial susceptibility, which are two quite different things. It will also be necessary for WGS to quantify the degree of resistance for an organism, something which is currently not possible.” The group has chosen to compare how WGS can predict whether or not the organism belongs to the wild type (is without resistance mechanisms) with the same prediction performed through the use of the epidemiological cut-off values (ECOFFs) developed by EUCAST. Whether or not and in that case how this can be extended to clinical breakpoints is discussed in the paper. The EUCAST subcommittee also highlighted that there is currently no way to assess how accurate different WGS laboratories are, and that there is an urgent need to establish a single public database of all known resistance genes within different bacterial species so that data can be shared and compared more easily. The EUCAST experts also note that WGS technology is currently limited because it cannot be used to analyse specimens directly – bacteria can only be sequenced once they have been cultured. This inevitably leads to significant time delays and additional financial costs, which is usually prohibitive for most laboratories. EUCAST recommends that whole-genome sequencing should be made a research and funding priority in the future to expand on our current knowledge and to develop more sophisticated prediction tools. As bacteria continue to develop multiple resistance mechanisms, unravelling the genetics of their interaction with antimicrobials will become even more challenging and even more necessary, particularly as we face the spectre of extreme drug resistance and global failure of some antimicrobials.www.escmid.org
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What can’t graphene do? You can scratch “detect cancer” off of that list.
By interfacing brain cells onto graphene, researchers at the University of Illinois at Chicago have shown they can differentiate a single hyperactive cancerous cell from a normal cell, pointing the way to developing a simple, non-invasive tool for early cancer diagnosis.
“This graphene system is able to detect the level of activity of an interfaced cell,” says Vikas Berry, associate professor and head of chemical engineering at UIC, who led the research along with Ankit Mehta, assistant professor of clinical neurosurgery in the UIC College of Medicine.
“Graphene is the thinnest known material and is very sensitive to whatever happens on its surface,” Berry said. The nanomaterial is composed of a single layer of carbon atoms linked in a hexagonal chicken-wire pattern, and all the atoms share a cloud of electrons moving freely about the surface.
“The cell’s interface with graphene rearranges the charge distribution in graphene, which modifies the energy of atomic vibration as detected by Raman spectroscopy,” Berry said, referring to a powerful workhorse technique that is routinely used to study graphene.
The atomic vibration energy in graphene’s crystal lattice differs depending on whether it’s in contact with a cancer cell or a normal cell, Berry said, because the cancer cell’s hyperactivity leads to a higher negative charge on its surface and the release of more protons.
“The electric field around the cell pushes away electrons in graphene’s electron cloud,” he said, which changes the vibration energy of the carbon atoms. The change in vibration energy can be pinpointed by Raman mapping with a resolution of 300 nanometers, he said, allowing characterization of the activity of a single cell.
The study looked at cultured human brain cells, comparing normal astrocytes to their cancerous counterpart, the highly malignant brain tumour glioblastoma multiforme. The technique is now being studied in a mouse model of cancer, with results that are “very promising,” Berry said. Experiments with patient biopsies would be further down the road.
“Once a patient has brain tumour surgery, we could use this technique to see if the tumour relapses,” Berry said. “For this, we would need a cell sample we could interface with graphene and look to see if cancer cells are still present.”
The same technique may also work to differentiate between other types of cells or the activity of cells.
University of Illinois at Chicago
news.uic.edu/first-use-of-graphene-to-detect-cancer-cells
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The virulent pathogen that causes the disease tularemia, or “rabbit fever,” was weaponised during past world wars and is considered a potential bioweapon. Through a new study of the coccobacillus Francisella, Los Alamos National Laboratory researchers are working to use DNA markers to discern related but relatively harmless species as they are identified and to provide a means to distinguish them from the harmful F. tularensis.
“This large study is particularly notable for having used 31 publicly available genomes plus select genes from about 90 additional isolates,” said corresponding author Cheryl Kuske of the Bioenergy & Biome Sciences group at Los Alamos National Laboratory.
The group’s work includes developing a comprehensive, genomics-based understanding of organisms and their environment as part of the Lab’s energy-security research into energy sources and their impact. “We conducted standard single and multi-gene comparisons with whole-genome approaches and identified potential virulence factors to discriminate new species from among the more traditional set. Thanks to coordination with the Centers for Disease Control and Prevention (CDC), we now have a framework to identify new isolates or environmental detections even if only partial information is available,” Kuske said.
Humans can easily develop tularemia through incidental contact with infected rabbits, cats, rodents or other animals (and the ticks or fleas that may be on them). The disease manifests in a variety of forms: fever and chills with joint pain, cough or pneumonia, or abdominal pain and distress. Fatality rates range, depending on the form of the disease, from 2 percent to 24 percent, according to CDC data. Due to this severity, the CDC has made tularemia a reportable disease, and like the pathogens causing anthrax and plague, it is considered a bioweapon.
Through detailed genome comparisons, sequence-alignment algorithms and other bioinformatics tools run on Los Alamos computers, the Los Alamos team identified features that differentiate among F. tularensis and other novel clinical and environmental Francisella isolates, providing a knowledge base for comparison of new sequences from clinical or environmental surveys.
“For residents of areas such as the Southwest, where tularemia outbreaks are endemic and potentially life threatening, having more identification tools at hand is extremely valuable,” Kuske said. The distribution of these isolates is global, however, suggesting a worldwide distribution of Francisella organisms that inhabit fish, ticks and a variety of environmental sources.
The team designated four new species groups within the genus; Francisella opportunistica, an opportunistic pathogen of immune compromised patients; Francisella salina and Francisella uliginis, environmental isolates from coastal seawater near Galveston, TX; and Francisella frigiditurris from cooling-tower water in California.
Los Alamos National Laboratory
www.lanl.gov/discover/news-release-archive/2016/December/12.19-dna-markers.php
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An enzyme found in the fluid around the brain and spine is giving researchers a snapshot of what happens inside the minds of Alzheimer’s patients and how that relates to cognitive decline.
Iowa State University researchers say higher levels of the enzyme, autotaxin, significantly predict memory impairment and Type 2 diabetes. Just a one-point difference in autotaxin levels – for example, going from a level of two to a three – is equal to a 3.5 to 5 times increase in the odds of being diagnosed with some form of memory loss, said Auriel Willette, an assistant professor of food science and human nutrition at Iowa State.
Autotaxin, often studied in cancer research, is an even stronger indicator of Type 2 diabetes. A single point increase reflects a 300 percent greater likelihood of having the disease or pre-diabetes. Willette and Kelsey McLimans, a graduate research assistant, say the discovery is important because of autotaxin’s proximity to the brain.
“We’ve been looking for metabolic biomarkers which are closer to the brain. We’re also looking for markers that reliably scale up with the disease and have consistently higher levels across the Alzheimer’s spectrum,” Willette said. “This is as directly inside of the brain as we can get without taking a tissue biopsy.”
Willette’s previous research found a strong association between insulin resistance and memory decline and detrimental brain outcomes, increasing the risk for Alzheimer’s disease. Insulin resistance is a good indicator, but Willette says it has limitations because what happens in the body does not consistently translate to what happens in the brain. That is why the correlation with this new enzyme found in the cerebrospinal fluid is so important.
“It has a higher predictive rate for having Alzheimer’s disease,” McLimans said. “We also found correlations with worse memory function, brain volume loss and the brain using less blood sugar, which have also been shown with insulin resistance, but autotaxin has a higher predictive value.”
The fact that autotaxin is a strong predictor of Type 2 diabetes and memory decline emphasizes the importance of good physical health. Researchers say people with higher levels of autotaxin are more likely to be obese, which often causes an increase in insulin resistance.
Willette says autotaxin levels can determine the amount of energy the brain is using in areas affected by Alzheimer’s disease. People with higher autotaxin levels had fewer and smaller brain cells in the frontal and temporal lobes, areas of the brain associated with memory and executive function. As a result, they had lower scores for memory and tests related to reasoning and multitasking.
“Autotaxin is related to less real estate in the brain, and smaller brain regions in Alzheimer’s disease mean they are less able to carry out their functions,” Willette said. “It’s the same thing with blood sugar. If the brain is using less blood sugar, neurons have less fuel and start making mistakes and in general do not process information as quickly.”
Iowa State University
www.news.iastate.edu/news/2016/12/19/alzheimersautotaxin
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Single-stranded, noncoding micro-ribonucleic acids (microRNAs), consisting of 18-23 nucleotides, play a key role in regulating gene expression. Levels of microRNAs circulating within blood can be correlated to different states of diseases such as cancer, neurodegenerative disorders and cardiovascular conditions. Many microRNAs within the blood are encapsulated within exosomes, nanoscale vesicles released by the cells.
Accurate measurement of the quantity of microRNAs circulating within the blood is extremely challenging because of their short lengths, similar sequences and low concentration levels. Due to their small number of nucleotides, traditional polymerase chain reaction (PCR) detection methods must necessarily involve a ligation, or linking, step to produce longer complementary DNA strands. Such ligation often produces large biases.
Consequently, large volumes of clinical samples typically required to obtain accurate measurements, but few conventional detection systems can handle this directly without proper sample preparation and volume reduction.
A team of researchers in Italy from the Istituto Italiano di Tecnologia and the University of Naples Federico II, both in Naples, set out to develop a simple, ultrasensitive fluorescence detection system of in-flow microRNAs that uses spectrally encoded microgels.
As the team reports in Biomicrofluidics until now such a multiplexed barcode detection approach has only been performed in time-consuming observation procedures, significantly hindering its possible diagnostic performance.
‘Our technological achievement rests upon the straightforward implementation of a seemingly real-time, microfluidic-based readout of microRNA sequences of interest, handling down to a few microliters of target volume,’ explained Filippo Causa, an associate professor of industrial bioengineering in the Department of Chemical, Materials Engineering, and Industrial Production at the University of Naples Federico II. ‘No previous RNA sequence amplification is required, which reduces evident sources of measurement errors.’
To do this, the researchers first explored a cost-effective and biocompatible non-Newtonian fluid to create the optimal 3-D alignment of microgels in the center of a square-shaped glass capillary.
They then used a simple microfluidic layout to flow the microgel and allow a continuous measurement of the fluorescence signal with several emission wavelengths for the multiplexed barcode detection.
‘We chose microgels with non-overlapping fluorescence-emitting molecules designed to distinguish spectral barcodes for multiplex analysis … and to obtain an absolute quantification of microRNA sequences,’ said Causa. ‘The precise microgel alignment at various throughput rates and an automatic microRNA sequence intensity normalization in flow gives us an opportunity to obtain reliable measurements, similar to quiescent measurement results, without any fundamental pretreatments of the measurement sample.’
To prove their concept of this multiplex spectral microgel analysis within a microfluidic flow, the team used ‘different barcodes corresponding to different emissions at specific wavelengths and the fluorescence intensity of known microRNA concentration,’ which was measured for calibrations of the specific microRNA being explored. Causa said, ‘So far, nine different microgel barcodes have been tested in flow with our detection approach, and more codes are being prepared to multiplex it further.’
As a proof of principle, the team explored microRNA based on its significance to the pathogenesis of various malignant tumors including prostate, gastric, colon, breast and lung cancers.
‘We were able to specifically detect, count and identify in a quasi-real-time manner hundreds of microgels (~80 microgel particles per minute) at sample volumes of only a few microliters,’ said Causa. ‘Our system achieved a microRNA detection limit of 202 femtoMolars in microfluidic flow conditions.’
Measurements were performed with different microgel barcodes and one in particular focused on specific microRNA targets, demonstrating the specificity of the assay for multiplex measurement conditions.
‘A microRNA 21 concentration of 0.74 picoMolars was detected in flow, which is consistent with the initial sample concentration level,’ Causa said. ‘Out of such fluorescence acquisitions, an absolute quantification of the microRNA 21 concentration level was possible.’
In terms of applications for the system, since the specific target detection of microgels can be easily tuned, it can be applied to a wide range of different biomarkers thanks to its barcode structure.
‘Users can also easily adjust its readout speed specifically for any microscopic system,’ said Causa. ‘This means that the system will open up new options for biosensing particles within microfluidic devices.’
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Copeptin levels associated with renal and cardiac disease
, /in E-News /by 3wmediaType 1 diabetes patients with elevated albumin in their urine had three times the risk of life-threatening kidney and cardiac disease as those with normal levels, according to researchers at the University of Colorado Anschutz Medical Campus.
The study, led by Dr. Petter Bjornstad, MD, of the Barbara Davis Center for Childhood Diabetes at CU Anschutz, looked at 38 males with type 1 diabetes and albumin in their urine and 38 diabetic males with normal albumin levels. The subjects were recruited across the country from the Type 1 Diabetes Exchange Biobank.
Albuminuria, or the presence of elevated albumin in the urine, is a marker for kidney disease. Bjornstad found that the copeptin was more than three times higher in patients with albuminuria. Copeptin is secreted along with arginine vasopressin or AVP from the pituitary gland and elevated levels appear to predict risk of cardiovascular mortality.
AVP is a hormone that regulates urination, though chronically high levels may cause kidney and vascular damage. But measuring AVP is extremely difficult due to its small size and short half-life. So researchers use copeptin as a surrogate. It is more stable, derived from the same molecule as AVP and can be more easily measured.
In this study, researchers found that the men with type 1 diabetes and albuminuria had significantly greater concentrations of copeptin compared to diabetic males with normal albumin levels.
“High levels of copeptin were associated with greater odds of albuminuria and impaired glomerular filtration rate which measures kidney function and stages of kidney disease,” Bjornstad said.
The findings, he said, could open the door to new ways of treating diabetic kidney disease and other illnesses. Specifically, a family of drugs called vaptans could be used to block excess vasopressin in these patients. “We think that vaptans or therapies targeting vasopressin can delay or stop the development of diabetic kidney disease,” Bjornstad said.
“There are clinical trials undergoing with vaptans in polycystic kidney disease, but to our knowledge no one is looking at vaptans and diabetic kidney disease yet.”
The study has important limitations. The sample size was small and its design prevents determination of causality. It also focused on men and may not apply to young people or women. But the findings support earlier research done by Bjornstad in the Coronary Artery Calcification in Type 1 Diabetes Study (CACTI.)
“We think these findings may have lifesaving implications for those with diabetic kidney and heart disease,” Bjornstad said.
University of Colorado Anschutz Medical Campus http://tinyurl.com/jfsnggz
Gene discovered to cause rare, severe neurological disease
, /in E-News /by 3wmediaThe scientists from the Montreal Neurological Institute and Hospital at McGill University, led by Peter McPherson, along with collaborators in Saudi Arabia, Jordan, Germany, and at SickKids Hospital and the University of Toronto, have discovered that a severe form of epileptic encephalopathy is caused by recessive loss-of-function mutations in the gene DENND5A.
Epileptic encephalopathy is a rare but devastating sub-form of epilepsy that results in severe mental and physical disabilities in children from birth. It is often caused by improper development of the brain. Individuals with epileptic encephalopathy caused by mutations in DENND5A present with serious anomalies in brain structure along with calcifications in the brain and altered facial features.
Researchers performed whole exome sequencing on three children with epileptic encephalopathy from two families, one from Saudi Arabia and another from Jordan. Both families were consanguineous, meaning the parents were related to each other. This greatly increases the chance that rare mutations that are recessive and that cause no harm to the parents are expressed in the children. The whole exome sequencing, along with extensive and complex genetic analysis, revealed that recessive mutations in DENND5A were responsible for the disease, with the Saudi family and the Jordanian family having different mutations but in the same DENND5A gene. They found that mutations in DENND5A lead to a lack of the DENND5A protein, resulting in underdevelopment of the central nervous system. The protein expressed from the DENND5A gene is present at highest levels in the nervous system especially while the brain is developing, corroborating the evidence that mutations in the gene cause epileptic encephalopathy.
The researchers discovered that the DENND5A protein controls the movement of receptors for key developmental factors called neurotrophins. Disruption of DENND5A function leads to altered levels of these receptors, which could explain why loss of DENND5A leads to the severe neurological developmental defects in the patients.
Epilepsy affects approximately three per cent of the world population, and epileptic encephalopathy is a rare sub-form of the disease. It is difficult to say how many children with epileptic encephalopathy have the DENND5A mutations, but now that the gene has been identified as a cause, researchers around the world can begin to test patients for mutations in this gene.
This finding also improves our understanding of neuronal development. The observation that loss-of-function mutations in DENND5A causes epileptic encephalopathy suggests that DENND5A protein controls membrane trafficking pathways critical for normal neuronal development and strengthens the argument that protein trafficking processes in cells are critical for normal neuronal development and function.
“Our study demonstrates the importance of membrane trafficking in neuronal development and it provides a new pathophysiological mechanism for this disease type. This will allow physicians around the world to test if mutations in DENND5A are causing the disease in their patients, and also to provide genetic counselling for affected families,” says Dr. Chanshuai Han, the lead author on the study.
The Montreal Neurological Institute and Hospital http://tinyurl.com/jfb7aho
Biochemical test for the diagnosis of Parkinson’s disease
, /in E-News /by 3wmediaMisfolded proteins associated with Parkinson’s disease were detected in cerebrospinal fluid by scientists at McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), paving the way to development of a biochemical test for the diagnosis of the disease.
The research was led by Claudio Soto, Ph.D., professor in the Department of Neurology and the director of the George and Cynthia Mitchell Center for Alzheimer’s disease and Related Brain Disorders at UTHealth.
Parkinson’s disease (PD) is a degenerative disorder of the brain that initially affects motor skills, causing tremors, stiffness, slowness of movement and impaired balance. As it progresses, patients may develop cognitive problems, psychiatric alterations and dementia. There are no current laboratory or blood tests that have been proven to help in diagnosis. Because the disease can be difficult to diagnose accurately, diagnosis is sometimes made by ruling out other neurological diseases.
Using a technology developed by Soto that was shown in previous studies to detect misfolded proteins associated with diseases such as Creutzfeld-Jacob and Alzheimer’s disease, researchers targeted misfolded alpha-synuclein (aSyn) aggregates as a way of developing a sensitive biochemical diagnosis for PD. The Protein Misfolding Cyclic Amplification (PMCA) technology was able to detect very small amounts of the misfolded protein circulating in cerebrospinal fluid.
“Of significant interest is that the amount of aSyn detected correlates with the severity of the disease and in two of the control samples, aSyn was detected and those people later developed clinical symptoms of PD,” Soto said.
The research included blind screenings of cerebrospinal fluid of two cohorts of 76 PD patients, as well as controls of 65 people who were healthy or affected by other neurological disorders, 18 affected by neurodegenerative diseases and 14 affected by Alzheimer’s disease.
Since cerebrospinal fluid is removed through spinal taps, which are invasive and painful, the hope is that future research would enable optimization of the PMCA assay to detect aSyn in blood or urine.
“The hope is that we could use aSyn- PMCA to detect PD in patients before they develop symptoms, and those patients could be entered into clinical trials for novel treatments that might prevent, cure or delay the progression of the disease before substantial and irreversible damage of the brain,” Soto said.
The University of Texas Health Science Center at Houston http://tinyurl.com/j98zslw
Beckman Coulter launches annual CARES award as part of initiative to help people living with HIV/AIDS
, /in E-News /by 3wmediaBeckman Coulter Life Sciences has launched an international HIV/AIDS award at the 2016 conference for the African Society for Laboratory Medicine (ASLM) recently held in Cape Town, South Africa (December 3 to 8).
The annual award is part of the company’s global CARES Initiative dedicated to helping people who are living with HIV/AIDS. Beckman Coulter’s CARES award is designed to recognize individuals who have shown ‘care, dedication and commitment’ in their communities as part of the fight against HIV/AIDS. The winner will receive a $5,000 (€4,700) donation in their name to one of the selected causes, with the three individual stories that receive the most nominations publicized around the world on the CARES Initiative website.
Potential winners can be nurses, healthcare workers, national coordinators, lab scientists and even clinicians; or lay people who are active in community outreach work. This could include a social worker providing AIDS counselling.
CARES supports the UNAIDS 90-90-90 target to ensure that by the year 2020, 90% of people living with HIV will know their status, 90% of those with diagnosed HIV infection will receive sustained antiretroviral therapy, and 90% of all people receiving antiretroviral therapy will have viral suppression.
It focuses on providing innovative solutions for the monitoring of HIV and AIDS treatment. CARES was inspired by the work of Professor Debbie Glencross, a South African laboratory pathologist, who found a different and less expensive way to measure a patient’s CD4 count.
While this is intended as an international award, in its first year, the award will focus on recognizing the dedication of people in Africa, one of the areas in the world most affected by HIV/AIDS. The 2017 award will be launched at the annual meeting of the African Society for Laboratory Medicine (ASLM), a pan-African professional body aiming to improve laboratory services.
Recognition for unsung heroes
Samuel Boova, Beckman Coulter’s Director Alliance Development, High Burden HIV Markets, said: “The award is to give a platform to the work and stories of those we see as the unsung heroes of individual communities. These are people who have shown individual dedication, commitment and courage or who have made a difference in the battle against HIV/AIDS.
“However, it is not just the final winner we want to publicaly recognize. We hope the award will encourage communities to learn about and honour the work of every nominee, so that more people will come forward to help and support those living with HIV/AIDS.”
Nominations must first be made via the CARES website. Once a name has been nominated, the local community will be given the opportunity to vote in support. People with the greatest number of votes will be put forward for the final assessment panel. Rules of entry and full details are available in full from http://www.beckman.com/cares.
Mr Boova gave the following examples of ordinary people who support their local communities in the field of HIV/AIDS. “We are looking for dedicated and committed individuals like these who work in the community helping others to live with, and manage, the disease,” he added.
Potential Nominees
The first example is how a young HIV positive woman in Uganda was inspired and empowered by a community charity, PINA (People In Need Agency), to rebuild her life and become an advocate herself for young people living with HIV. This was the objective of PINA when it was first set up by a local case worker – to work with young people, helping them overcome the stigma of living with HIV and rebuild their self-esteem.
Mr Boova also pointed out that there are many women in rural Africa who walk miles every day to see patients to ensure they are compliant with their medications. Medication alone does not help without the commitment of these women – and they have to walk many miles between patients each day and every day, whatever the conditions.www.beckman.com/cares
DiaSys celebrates 25th anniversary with essential product launches
, /in E-News /by 3wmediaNew enzymatic test for HbA1c
The worldwide rapid rise in diabetes is a challenge for treatment as well as for diagnosis and monitoring. With the new test HbA1c net FS, DiaSys Diagnostics System has introduced an innovative product with highest accuracy setting new standards for reliable results in diagnosing and monitoring diabetes. Based on enzymatic measurement Hba1c net FS ensures highest specificity without interferences by hemoglobin variants as well as outstanding precision. Using the fully automated process including on-board hemolysis on the DiaSys analysers, BioMajesty® and respons®910, labs of every size can optimize their workflow for HbA1c.
Several other major product launches were made in time for DiaSys’ 25th anniversary. Under the trademark QDx DiaSys announced a point-of-care product line comprising test strips and devices for various diagnostic fields such as cardiac, vitamin D, allergy, anemia, lipids and urinalysis. Furthermore, respons®910UP was presented offering improved handling and performance for the small to medium lab (up to 150 tests/hour).
25 years of success as a mid-size company in the challenging and ever changing market of in-vitro diagnostics – DiaSys takes this opportunity to thank all employees, customers and partners for their contribution and confidence and looks forward to a common prospering future.www.diasys-diagnostics.com
Can genetic testing determine antimicrobial susceptibility? EUCAST experts say not yet…
, /in E-News /by 3wmediaExperts at the European Committee on Antimicrobial Susceptibility Testing (EUCAST), who define the optimal drug concentrations to inhibit the growth of pathogens, have found that genetic methods cannot yet be used to test for susceptibility in a number of important bacterial species. Although there have been advances in whole genome sequencing (WGS), which allows to determine the DNA sequence of an organism’s genome at a single time, there are still several hurdles to overcome before this type of genetic testing can be used in clinical laboratories, they concluded.
A EUCAST subcommittee dedicated to reviewing the role of WGS in antimicrobial susceptibility testing (AST) considered the most recent published evidence on the use of whole genome sequencing as a tool for susceptibility testing. The group – comprising of over a dozen leading experts and led by Prof. Neil Woodford, Head of Public Health England’s Antimicrobial Resistance and Healthcare Associated Infections Reference Unit – did not rule out that it will one day be possible for a single assay to predict how a species of bacteria will respond to a specific antimicrobial drug, but there is little evidence to suggest we will reach this point in the near future.
EUCAST’s technical data coordinator, Prof. Gunnar Kahlmeter of the Central Hospital, Växjö, Sweden, said that it is premature to suggest that breakpoints and recommendations for phenotypic susceptibility testing will no longer be required as genetic methods will supersede them any time soon. “To be of use in a clinical situation, WGS will need to predict antimicrobial resistance and also antimicrobial susceptibility, which are two quite different things. It will also be necessary for WGS to quantify the degree of resistance for an organism, something which is currently not possible.”
The group has chosen to compare how WGS can predict whether or not the organism belongs to the wild type (is without resistance mechanisms) with the same prediction performed through the use of the epidemiological cut-off values (ECOFFs) developed by EUCAST. Whether or not and in that case how this can be extended to clinical breakpoints is discussed in the paper.
The EUCAST subcommittee also highlighted that there is currently no way to assess how accurate different WGS laboratories are, and that there is an urgent need to establish a single public database of all known resistance genes within different bacterial species so that data can be shared and compared more easily.
The EUCAST experts also note that WGS technology is currently limited because it cannot be used to analyse specimens directly – bacteria can only be sequenced once they have been cultured. This inevitably leads to significant time delays and additional financial costs, which is usually prohibitive for most laboratories.
EUCAST recommends that whole-genome sequencing should be made a research and funding priority in the future to expand on our current knowledge and to develop more sophisticated prediction tools. As bacteria continue to develop multiple resistance mechanisms, unravelling the genetics of their interaction with antimicrobials will become even more challenging and even more necessary, particularly as we face the spectre of extreme drug resistance and global failure of some antimicrobials.www.escmid.org
First use of graphene to detect cancer cells
, /in E-News /by 3wmediaWhat can’t graphene do? You can scratch “detect cancer” off of that list.
By interfacing brain cells onto graphene, researchers at the University of Illinois at Chicago have shown they can differentiate a single hyperactive cancerous cell from a normal cell, pointing the way to developing a simple, non-invasive tool for early cancer diagnosis.
“This graphene system is able to detect the level of activity of an interfaced cell,” says Vikas Berry, associate professor and head of chemical engineering at UIC, who led the research along with Ankit Mehta, assistant professor of clinical neurosurgery in the UIC College of Medicine.
“Graphene is the thinnest known material and is very sensitive to whatever happens on its surface,” Berry said. The nanomaterial is composed of a single layer of carbon atoms linked in a hexagonal chicken-wire pattern, and all the atoms share a cloud of electrons moving freely about the surface.
“The cell’s interface with graphene rearranges the charge distribution in graphene, which modifies the energy of atomic vibration as detected by Raman spectroscopy,” Berry said, referring to a powerful workhorse technique that is routinely used to study graphene.
The atomic vibration energy in graphene’s crystal lattice differs depending on whether it’s in contact with a cancer cell or a normal cell, Berry said, because the cancer cell’s hyperactivity leads to a higher negative charge on its surface and the release of more protons.
“The electric field around the cell pushes away electrons in graphene’s electron cloud,” he said, which changes the vibration energy of the carbon atoms. The change in vibration energy can be pinpointed by Raman mapping with a resolution of 300 nanometers, he said, allowing characterization of the activity of a single cell.
The study looked at cultured human brain cells, comparing normal astrocytes to their cancerous counterpart, the highly malignant brain tumour glioblastoma multiforme. The technique is now being studied in a mouse model of cancer, with results that are “very promising,” Berry said. Experiments with patient biopsies would be further down the road.
“Once a patient has brain tumour surgery, we could use this technique to see if the tumour relapses,” Berry said. “For this, we would need a cell sample we could interface with graphene and look to see if cancer cells are still present.”
The same technique may also work to differentiate between other types of cells or the activity of cells.
University of Illinois at Chicago news.uic.edu/first-use-of-graphene-to-detect-cancer-cells
DNA markers distinguish between harmless, deadly bacteria
, /in E-News /by 3wmediaThe virulent pathogen that causes the disease tularemia, or “rabbit fever,” was weaponised during past world wars and is considered a potential bioweapon. Through a new study of the coccobacillus Francisella, Los Alamos National Laboratory researchers are working to use DNA markers to discern related but relatively harmless species as they are identified and to provide a means to distinguish them from the harmful F. tularensis.
“This large study is particularly notable for having used 31 publicly available genomes plus select genes from about 90 additional isolates,” said corresponding author Cheryl Kuske of the Bioenergy & Biome Sciences group at Los Alamos National Laboratory.
The group’s work includes developing a comprehensive, genomics-based understanding of organisms and their environment as part of the Lab’s energy-security research into energy sources and their impact. “We conducted standard single and multi-gene comparisons with whole-genome approaches and identified potential virulence factors to discriminate new species from among the more traditional set. Thanks to coordination with the Centers for Disease Control and Prevention (CDC), we now have a framework to identify new isolates or environmental detections even if only partial information is available,” Kuske said.
Humans can easily develop tularemia through incidental contact with infected rabbits, cats, rodents or other animals (and the ticks or fleas that may be on them). The disease manifests in a variety of forms: fever and chills with joint pain, cough or pneumonia, or abdominal pain and distress. Fatality rates range, depending on the form of the disease, from 2 percent to 24 percent, according to CDC data. Due to this severity, the CDC has made tularemia a reportable disease, and like the pathogens causing anthrax and plague, it is considered a bioweapon.
Through detailed genome comparisons, sequence-alignment algorithms and other bioinformatics tools run on Los Alamos computers, the Los Alamos team identified features that differentiate among F. tularensis and other novel clinical and environmental Francisella isolates, providing a knowledge base for comparison of new sequences from clinical or environmental surveys.
“For residents of areas such as the Southwest, where tularemia outbreaks are endemic and potentially life threatening, having more identification tools at hand is extremely valuable,” Kuske said. The distribution of these isolates is global, however, suggesting a worldwide distribution of Francisella organisms that inhabit fish, ticks and a variety of environmental sources.
The team designated four new species groups within the genus; Francisella opportunistica, an opportunistic pathogen of immune compromised patients; Francisella salina and Francisella uliginis, environmental isolates from coastal seawater near Galveston, TX; and Francisella frigiditurris from cooling-tower water in California.
Los Alamos National Laboratory www.lanl.gov/discover/news-release-archive/2016/December/12.19-dna-markers.php
New biomarker predicts Alzheimer’s Disease and link to diabetes
, /in E-News /by 3wmediaAn enzyme found in the fluid around the brain and spine is giving researchers a snapshot of what happens inside the minds of Alzheimer’s patients and how that relates to cognitive decline.
Iowa State University researchers say higher levels of the enzyme, autotaxin, significantly predict memory impairment and Type 2 diabetes. Just a one-point difference in autotaxin levels – for example, going from a level of two to a three – is equal to a 3.5 to 5 times increase in the odds of being diagnosed with some form of memory loss, said Auriel Willette, an assistant professor of food science and human nutrition at Iowa State.
Autotaxin, often studied in cancer research, is an even stronger indicator of Type 2 diabetes. A single point increase reflects a 300 percent greater likelihood of having the disease or pre-diabetes. Willette and Kelsey McLimans, a graduate research assistant, say the discovery is important because of autotaxin’s proximity to the brain.
“We’ve been looking for metabolic biomarkers which are closer to the brain. We’re also looking for markers that reliably scale up with the disease and have consistently higher levels across the Alzheimer’s spectrum,” Willette said. “This is as directly inside of the brain as we can get without taking a tissue biopsy.”
Willette’s previous research found a strong association between insulin resistance and memory decline and detrimental brain outcomes, increasing the risk for Alzheimer’s disease. Insulin resistance is a good indicator, but Willette says it has limitations because what happens in the body does not consistently translate to what happens in the brain. That is why the correlation with this new enzyme found in the cerebrospinal fluid is so important.
“It has a higher predictive rate for having Alzheimer’s disease,” McLimans said. “We also found correlations with worse memory function, brain volume loss and the brain using less blood sugar, which have also been shown with insulin resistance, but autotaxin has a higher predictive value.”
The fact that autotaxin is a strong predictor of Type 2 diabetes and memory decline emphasizes the importance of good physical health. Researchers say people with higher levels of autotaxin are more likely to be obese, which often causes an increase in insulin resistance.
Willette says autotaxin levels can determine the amount of energy the brain is using in areas affected by Alzheimer’s disease. People with higher autotaxin levels had fewer and smaller brain cells in the frontal and temporal lobes, areas of the brain associated with memory and executive function. As a result, they had lower scores for memory and tests related to reasoning and multitasking.
“Autotaxin is related to less real estate in the brain, and smaller brain regions in Alzheimer’s disease mean they are less able to carry out their functions,” Willette said. “It’s the same thing with blood sugar. If the brain is using less blood sugar, neurons have less fuel and start making mistakes and in general do not process information as quickly.”
Iowa State University www.news.iastate.edu/news/2016/12/19/alzheimersautotaxin
Detection system reads biomolecules in barcoded microgels
, /in E-News /by 3wmediaSingle-stranded, noncoding micro-ribonucleic acids (microRNAs), consisting of 18-23 nucleotides, play a key role in regulating gene expression. Levels of microRNAs circulating within blood can be correlated to different states of diseases such as cancer, neurodegenerative disorders and cardiovascular conditions. Many microRNAs within the blood are encapsulated within exosomes, nanoscale vesicles released by the cells.
Accurate measurement of the quantity of microRNAs circulating within the blood is extremely challenging because of their short lengths, similar sequences and low concentration levels. Due to their small number of nucleotides, traditional polymerase chain reaction (PCR) detection methods must necessarily involve a ligation, or linking, step to produce longer complementary DNA strands. Such ligation often produces large biases.
Consequently, large volumes of clinical samples typically required to obtain accurate measurements, but few conventional detection systems can handle this directly without proper sample preparation and volume reduction.
A team of researchers in Italy from the Istituto Italiano di Tecnologia and the University of Naples Federico II, both in Naples, set out to develop a simple, ultrasensitive fluorescence detection system of in-flow microRNAs that uses spectrally encoded microgels.
As the team reports in Biomicrofluidics until now such a multiplexed barcode detection approach has only been performed in time-consuming observation procedures, significantly hindering its possible diagnostic performance.
‘Our technological achievement rests upon the straightforward implementation of a seemingly real-time, microfluidic-based readout of microRNA sequences of interest, handling down to a few microliters of target volume,’ explained Filippo Causa, an associate professor of industrial bioengineering in the Department of Chemical, Materials Engineering, and Industrial Production at the University of Naples Federico II. ‘No previous RNA sequence amplification is required, which reduces evident sources of measurement errors.’
To do this, the researchers first explored a cost-effective and biocompatible non-Newtonian fluid to create the optimal 3-D alignment of microgels in the center of a square-shaped glass capillary.
They then used a simple microfluidic layout to flow the microgel and allow a continuous measurement of the fluorescence signal with several emission wavelengths for the multiplexed barcode detection.
‘We chose microgels with non-overlapping fluorescence-emitting molecules designed to distinguish spectral barcodes for multiplex analysis … and to obtain an absolute quantification of microRNA sequences,’ said Causa. ‘The precise microgel alignment at various throughput rates and an automatic microRNA sequence intensity normalization in flow gives us an opportunity to obtain reliable measurements, similar to quiescent measurement results, without any fundamental pretreatments of the measurement sample.’
To prove their concept of this multiplex spectral microgel analysis within a microfluidic flow, the team used ‘different barcodes corresponding to different emissions at specific wavelengths and the fluorescence intensity of known microRNA concentration,’ which was measured for calibrations of the specific microRNA being explored. Causa said, ‘So far, nine different microgel barcodes have been tested in flow with our detection approach, and more codes are being prepared to multiplex it further.’
As a proof of principle, the team explored microRNA based on its significance to the pathogenesis of various malignant tumors including prostate, gastric, colon, breast and lung cancers.
‘We were able to specifically detect, count and identify in a quasi-real-time manner hundreds of microgels (~80 microgel particles per minute) at sample volumes of only a few microliters,’ said Causa. ‘Our system achieved a microRNA detection limit of 202 femtoMolars in microfluidic flow conditions.’
Measurements were performed with different microgel barcodes and one in particular focused on specific microRNA targets, demonstrating the specificity of the assay for multiplex measurement conditions.
‘A microRNA 21 concentration of 0.74 picoMolars was detected in flow, which is consistent with the initial sample concentration level,’ Causa said. ‘Out of such fluorescence acquisitions, an absolute quantification of the microRNA 21 concentration level was possible.’
In terms of applications for the system, since the specific target detection of microgels can be easily tuned, it can be applied to a wide range of different biomarkers thanks to its barcode structure.
‘Users can also easily adjust its readout speed specifically for any microscopic system,’ said Causa. ‘This means that the system will open up new options for biosensing particles within microfluidic devices.’
PHYS.ORG phys.org/news/2016-12-biomolecules-barcoded-microgels.html