Comment

Comment by Dr. Krishna Kumari Challa on December 31, 2021 at 9:02am

 Lab experiments show how cells 'eat'

A new study shows how cell membranes curve to create the "mouths" that allow the cells to consume things that surround them.

The study found that the intercellular machinery of a cell assembles into a highly curved basket-like structure that eventually grows into a closed cage. Membrane curvature is important: It controls the formation of the pockets that carry substances into and out of a cell.

The pockets capture substances around the cell, forming around the extracellular substances, before turning into vesicles—small sacs one-one millionth the size of a red blood cell. Vesicles carry important things for a cell's health—proteins, for example—into the cell. But they can also be hijacked by pathogens that can infect cells.

But the question of how those pockets formed from membranes that were previously believed to be flat had stymied researchers for nearly 40 years. Scientists now were able to use super-resolution fluorescence imaging to actually watch these pockets form within live cells, and so they could answer that question of how they are created.

Experiments revealed that protein scaffolds start deforming the underlying membrane as soon as they are recruited to the sites of vesicle formation. The way cells consume and expel vesicles plays a key role for living organisms. The process helps clear bad cholesterol from blood; it also transmits neural signals. The process is known to break down in several diseases, including cancer and Alzheimer's disease.

Understanding the origin and dynamics of membrane-bound vesicles is important—they can be utilized for delivering drugs for medicinal purposes, but at the same time, hijacked by pathogens such as viruses to enter and infect cells. These results matter, not only for our understanding of the fundamentals of life, but also for developing better therapeutic strategies.

 Nathan M. Willy et al, De novo endocytic clathrin coats develop curvature at early stages of their formation, Developmental Cell (2021). DOI: 10.1016/j.devcel.2021.10.019

https://phys.org/news/2021-12-high-resolution-lab-cells.html?utm_so...

Comment by Dr. Krishna Kumari Challa on December 30, 2021 at 9:16am

Universal COVID test based on isothermal amplification can detect all COVID-19 variants

Russian researchers have developed a strategy to create a cheap and rapid COVID-19 test based on isothermal amplification. According to their publication in Applied Biochemistry and Microbiology, use of this strategy will make it possible to create universal test systems for any of the COVID-19 variants.

The Russian researchers developed a strategy that will help overcome earlier drawbacks and give healthcare professionals an opportunity to use LAMP testing to detect traces of any COVID variants in samples of mucus and blood without preliminary processing in a laboratory. This will decrease the cost of COVID-19 tests considerably and speed up the process, since no specially trained professionals or expensive equipment will be needed.

The virus mutates quite fast, and the test systems that were created a year ago may be not as effective as they used to be. Researchers now analyze the mutations and are looking for the most stable parts of the virus genome. This will help create test systems that recognize all the existing variants and, importantly, the new variants that are appearing.

To solve this challenge, HSE biologists are looking for parts of the coronavirus genome that do not change much over time. They will serve as markers that bacteria ferments will use to convert the COVID RNA into DNA and multiply it further. Combined with the existing LAMP system components, they will help create a universal COVID-19 testing system, which will be able to quickly detect traces of any COVID variants, the researchers say.

J. A. Makarova et al, Loop-Mediated Isothermal Amplification as a Promising Method for Mass COVID-19 Diagnostics, Applied Biochemistry and Microbiology (2021). DOI: 10.1134/S0003683821080032

https://medicalxpress.com/news/2021-12-universal-covid-based-isothe...

**

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 11:20am

Ubiquitin and Parkinson's Disease 

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 10:36am

In a neuroprosthetic first, ALS patient sends social media message via brain-computer interface

A 62-year-old amyotrophic lateral sclerosis (ALS) patient in Australia recently became the first person to post a message on social media using only his thoughts. On December 23, he posted an initial brief message, "Hello World," on Twitter.

The technology that allowed the patient  to send his message was developed by a brain computer interface company,  and the device is called the Stentrode Brain Computer Interface (SBCI); a type of endovascular brain implant. It was implanted into the patient's brain without opening his skull—instead, it was inserted through his jugular vein. The tiny (8 mm) brain implant was designed to allow people who have lost the ability to speak to communicate using only their thoughts. The SBCI is wireless and works by reading brainwaves and translating them to words—the motor neuroprosthesis was placed into the patient's brain using techniques that have been used for several years to treat people with strokes. Human clinical trials have been underway  for over a year—currently, the device has been implanted in just one other person, but more are planned.

The patient e is now able to compose messages by thinking of words or actions (such as mouse clicks), which are translated to activity on a computer screen.

https://techxplore.com/news/2021-12-neuroprosthetic-als-patient-soc...

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 10:09am

Scientists digitally 'unwrap' mummy of pharaoh Amenhotep I for the first time in 3,000 years

All the royal mummies found in the 19th and 20th centuries have long since been opened for study. With one exception: egyptologists have never been bold enough to open the mummy of Pharaoh Amenhotep I. Not because of any mythical curse, but because it is perfectly wrapped, beautifully decorated with flower garlands, and with face and neck covered by an exquisite lifelike facemask inset with colorful stones. But now for the first time, scientists from Egypt have used three-dimensional CT (computed tomography) scanning to 'digitally unwrap' this royal mummy and study its contents. They report their findings in Frontiers in Medicine.

This was the first time in three millennia that Amenhotep's mummy has been opened. The previous time was in the 11th century BCE, more than four centuries after his original mummification and burial. Hieroglyphics have described how during the later 21st dynasty, priests restored and reburied royal mummies from more ancient dynasties, to repair the damage done by grave robbers.

"This fact that Amenhotep I's mummy had never been unwrapped in modern times gave us a unique opportunity: not just to study how he had originally been mummified and buried, but also how he had been treated and reburied twice, centuries after his death.

By digitally unwrapping of the mummy and 'peeling off' its virtual layers—the facemask, the bandages, and the mummy itself—researchers could study this well-preserved pharaoh in unprecedented detail.

The things that were found during the study:  

Amenhotep I was approximately 35 years old when he died. He was approximately 169cm tall, circumcized, and had good teeth. Within his wrappings, he wore 30 amulets and a unique golden girdle with gold beads."

Amenhotep I seems to have physically resembled his father: he had a narrow chin, a small narrow nose, curly hair, and mildly protruding upper teeth. Researchers couldn't find any wounds or disfigurement due to disease to justify the cause of death, except numerous mutiliations post mortem, presumably by grave robbers after his first burial. His entrails had been removed by the first mummifiers, but not his brain or heart.

at least for Amenhotep I, the priests of the 21^st dynasty lovingly repaired the injuries inflicted by the tomb robbers, restored his mummy to its former glory, and preserved the magnificent jewelry and amulets in place.

Sahar N. Saleem et al, Digital Unwrapping of the Mummy of King Amenhotep I (1525–1504 BC) Using CT, Frontiers in Medicine (2021). DOI: 10.3389/fmed.2021.778498

https://phys.org/news/2021-12-scientists-digitally-unwrap-mummy-pha...

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 9:37am

The Final moments: Brain Death and the process of stopping it

For years, scientists have researched what happens to your brain when you die, but despite everything we've found out, progress has been stymied by an inability to easily monitor human death – since physicians are conventionally obliged to prevent death if they can, not monitor it as it takes hold. What this means is most of our understanding of the processes involved in brain death come from animal experiments, strengthened with what we can glean from the accounts of resuscitated patients disclosing their near-death experiences. But in 2018, an international team of scientists made a breakthrough. In animals, within 20 to 40 seconds of oxygen deprivation, the brain enters an 'energy-saving mode' where it becomes electrically inactive and neurons cease communicating with one another. After a few minutes, the brain begins to break down as ion gradients in cells dissipate, and a wave of electrochemical energy – called a spreading depolarisation (or 'brain tsunami') spreads throughout the cortex and other brain regions, ultimately causing irreversible brain damage.

A team of neurologists  – who monitored these processes taking place in nine patients with devastating brain injuries (under Do Not Resuscitate – Comfort Care orders) – say the tsunami of brain death may actually be capable of being stopped.

After circulatory arrest, spreading depolarisation marks the loss of stored electrochemical energy in brain cells and the onset of toxic processes that eventually lead to death. But it is reversible – up to a point – when the circulation is restored.

Using neuro-monitoring technology called subdural electrode strips and intraparenchymal electrode arrays, the researchers monitored spreading depolarisation in the patients' brains, and they suggest it's not a one-way wave – as long as circulation (and thus oxygen supply) can be resumed to the brain.

"Anoxia-triggered [spreading depolarisation] is fully reversible without any signs of cellular damage, if the oxidative substrate supply is re-established before the so-called commitment point, defined as the time when neurons start dying under persistent depolarisation. For patients at risk of brain damage or death incurred through cerebral ischemia or other kinds of stroke, the findings could one day be a life-saver, although the researchers explain a lot more work is needed before physicians will be able to take advantage of these discoveries.

https://onlinelibrary.wiley.com/doi/full/10.1002/ana.25147

https://www.sciencealert.com/death-bringing-brain-tsunamis-have-bee...

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 8:10am

Quantum Computers, Explained With Quantum Physics

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:49am

The microneedles themselves are made of a non-degradable, biocompatible hydrogel that also contains zwitterionic poly-sulfobetaine (poly-SPB). As reported in previous studies by the same authors, this polymer suppresses protein aggregation. Thus, the researchers incorporated it during the fabrication process and showed that the proteins pre-loaded in the microneedles were stable even when subjected to various external stresses.

Additionally, the scientists developed a straightforward and cost-effective way to fabricate microneedle arrays made from the abovementioned materials. They resorted to photolithography, a process in which a photomask is used to selectively block UV light from reaching a target surface to control chemical reactions locally.

To test the performance of these microneedle arrays for drug delivery, the researchers loaded them with 50 microliters of drug solutions containing rhodamine B as a dye alongside lysozyme and insulin as example proteins. Through various experiments on porcine skin, the teams verified that their microneedle patches offered both high drug-loading capacity and high drug-release rate. Moreover, they confirmed that the microneedles could both load and preserve various water-soluble drugs and proteins simultaneously, eliminating the need for refrigeration.

Overall, the proposed microneedle arrays seem to be a remarkably promising platform for administering therapeutic drugs and vaccines.

Harit Pitakjakpipop et al, Facile Photolithographic Fabrication of Zwitterionic Polymer Microneedles with Protein Aggregation Inhibition for Transdermal Drug Delivery, Biomacromolecules (2021). DOI: 10.1021/acs.biomac.1c01325

https://medicalxpress.com/news/2021-12-rethinking-drugs-breakthroug...

Part 2

**

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:46am

Rethinking how drugs are administered: A breakthrough in microneedle patches

The painful feeling of receiving an injection through a hypodermic needle or with the unpleasant sensation of swallowing a large pill is a globally familiar sensation. But what if a revolutionary and gentler way of administering drugs was in the works? For over two decades, researchers have been investigating various types of microneedles as a minimally invasive method for transdermal drug delivery. Arrays of microneedles can be designed to be loaded with a drug or chemical, which they then release over time onto the blood stream after piercing slightly beyond the skin layers.

Microneedles offer several advantages compared to other types of drug delivery. First, they are painless and cause virtually no damage to the skin nor bleeding. Second, they can be self-administered. Third, unlike traditional needles, the disposal of microneedles is much easier as they don't leave behind hazardous waste. Unfortunately, there are still a few challenges that need to be addressed before microneedles become the next big thing in healthcare. One is their fabrication cost, which generally involves expensive molds, materials, and machinery. Another issue is the aggregation and degradation of proteins when microneedles are pre-loaded with a protein-based medicine, as these molecules are quite sensitive to external conditions such as temperature, acidity and salt concentration.

In a recent study published in Biomacromolecules, two research teams from Japan and Thailand collaborated to address the main limitations of existing microneedles.

One team developed and applied a functional polymer that effectively suppresses protein aggregation. The other team perfected a microneedle fabrication method suitable for the industrial scale based on photolithography. By combining these two efforts, the teams managed to produce microneedles patches with several attractive properties and potential scalability to clinical settings.

Part 1

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:42am

Heavy metals have a reputation for being dangerous, but some are essential nutrients that you can't live without.

• ‹ Previous
• 1
• …
• 301
• 302
• 303
• 304
• 305
• …
• 846
• Next ›
• Page