A new biological sensor proved to be able to detect glucose | Figure 1

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Pharmacist

A new biological sensor proved to be able to detect glucose levels in saliva more accurately, more efficiently, and less costly than the conventional blood test. The highly sensitive, accurate and flexible biological sensor was developed by Yan Feng and his team from Hong Kong Polytechnic University.

The device is based on an organic electrochemical transistor (OECT), a platform to manufacture biosensors capable of converting biological elements - such as ions, lactose and glucose - into electrical currents, which can then be measured. The challenge for OECT technology, however, had been to create a selective biosensor - which was only sensitive to a specific substance, such as glucose. This is because OTCs also capture electrical currents from other biochemical molecules.

The solution found by the team was to construct the transistor using a glucose oxidase enzyme, which is sensitive only to glucose. For this, the enzyme was coated with two types of polymers, to avoid interference of other substances in the saliva, thus increasing the selectivity and sensitivity of the sensor.

The team ensures that the new biosensor is almost 1,000 times more sensitive than the conventional method of blood glucose testing. It is also flexible, paving the way for its incorporation into smart fabrics and other dressing technologies.

Source: Hong Kong Polytechnic University.

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Case 1

A 25-year-old nephrology fellow decided to switch from glasses to semi-permeable contact lenses. At first, the transfer went smoothly. But after about two weeks of daily use, he started to have occasional vision problems. He had to move his head or eyes to bring some items into focus, which he thought might be because of problems with his new contact lens prescription. He was made an appointment with an ophthalmologist for more tests.

The specialist discovered retinal hemorrhages during the eye exam and immediately sent him to an endocrinologist for a full evaluation. Physical exam revealed a body weight of 220 pounds and a BMI of 31.6. Blood tests showed a hemoglobin A1C of 9.4%, and a fasting blood glucose level of 185 mg/dL. These findings strongly suggested a new diagnosis of diabetes mellitus with early diabetic retinopathy, manifesting as retinal hemorrhages.

The endocrinologist initiated a treatment strategy that included strict glycemic control, medical nutrition therapy, and a systematic weight loss program. Over the next few months, following dietary advice, losing weight, and keeping blood sugar levels in check led to a slow resolution of the retinal hemorrhages. Vision improved as the hemorrhages disappeared. This case emphasizes the potential benefit of prompt ophthalmologic evaluation for novel or unexplained visual alterations, particularly in young adults with undiagnosed diabetes mellitus, and illustrates the significance of interprofessional teamwork in the early identification and management of diabetic sequelae.

Case 2

Researchers at the Federal University of São Carlos (UFSCar) are developing a simple, quick and inexpensive method to detect Alzheimer's disease - something unheard of in the world.

For Professor Ronaldo Censo Faria, it is very difficult to differentiate Alzheimer's from other types of dementia. Usually, older people tend to have more dementias, 60% of which are related to Alzheimer's.

The new test is based on ADAM10 protein, present in blood, and shown to be altered in patients with Alzheimer's and mild neurocognitive disorder, considered a kind of pre-Alzheimer's.

The test is done by detecting the presence of this biomarker. The material used has a cost around $ 3, making it feasible to identify different stages of the disease and even a predisposition to Alzheimer's, according to the team.

A small amount of blood is treated with magnetic particles that are captured by a magnet. The concentration is determined with a disposable sensor device. The level of the biomarker tends to increase depending on the degree of disease.

Another advantage of the new examination is that current methods only detect the disease in more advanced stages. If diagnosed early, Alzheimer's treatment may be able to slow the progression of the disease, although there are still no fully effective therapies.

Source: Federal University of São Carlos.

Case 3

Research from Duke University in the United States has uncovered a technology that could open doors to a new treatment for type 2 diabetes: a single injection that controls glucose levels for weeks.

The researchers created an injectable technology that, when reacting with body heat, creates a gel-like substance. This causes the medicines to be released slowly as the gel dissolves.

Research tested the substance in rats and monkeys and the results have shown that in the case of rats glycemic control was ensured for ten days and in monkeys for 17 days. Although tests have not yet been performed In humans, researchers find the results promising, since human metabolism is slower, which makes it take longer to digest the substance.

"Because our metabolism is slower than that of monkeys and mice, the treatment should theoretically last longer in humans. So our hope is that this is the first bi-weekly or monthly formula for people with type 2 diabetes," says Kelli Luginbuhl, author of the study.

Source: Nature Biomedical Engineering.

Case 4

Researchers have developed and validated a risk prediction model that can help physicians predict which patients who have recently tested positive for SARS-CoV-2 are at greatest risk for hospitalization for COVID-19.

The new model is the second COVID-19-related nomogram developed by the research team. Their earlier prediction model forecasts an individual patient’s likelihood of testing positive for the virus.

The model was developed and validated using retrospective data from more than 4,500 patients who tested positive for COVID-19 at Cleveland Clinic locations in Northeast Ohio and Florida during a three-month period. Data scientists used statistical algorithms to transform data from registry patients’ electronic medical records into the risk prediction model.

Comparing characteristics between patients who were and were not hospitalized due to COVID-19 revealed several previously undefined risk factors for hospitalization, including:

• Smoking status. Former smokers were more likely to be hospitalized than current smokers.
• Use of ACE inhibitors or ARBs. Univariable analysis showed that patients taking either of two classes of cardiovascular medications — angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) — were more likely to be hospitalized than patients not taking those drugs.
• Race. African American patients were more likely to be hospitalized than patients of other races.

The team’s findings also revealed that patients presenting with a symptom complex including fever, shortness of breath, vomiting and fatigue were more likely to be hospitalized than those who did not experience this quadrumvirate of symptoms.

The study also confirmed other associations previously well established in the literature, including higher risk of hospitalization among older people, men, patients with comorbidities such as diabetes and hypertension, and individuals from lower socioeconomic backgrounds (as determined by ZIP code).