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Biology / Biochemistry

COVID-19 may have been made more infectious by a mutation

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In Houston, TX, a specific mutation became almost ubiquitous in SARS-CoV-2 infections between March and July 2020. This strongly suggests that it makes the virus more infectious. There is no evidence, however, to indicate that it makes the virus any more deadly.

COVID-19 test

On March 5, 2020, Metropolitan Houston confirmed the first case of COVID-19, the disease that evolves as a consequence of SARS-CoV-2. The virus was circulating within the community a week later.

A previous study found that in the early phase of this first wave of infections, strains of the virus carrying a specific mutation, called G614, caused 71 percent of cases in Houston.

A follow-up analysis by the same team now shows that this variant accounted for 99.9 percent of all COVID-19 infections in the region by summer, during the second wave.

The new study that was led by a team from the Houston Methodist Hospital in Texas is now published in the mBio journal.

The mutation that has spread around the world results in the substitution of one amino acid for another at a specific location in the spike protein of the virus.

The building blocks of proteins are amino acids. They are assembled according to the genetic blueprint of the virus in a fixed series.

In the spikes, the mutation substituted an amino acid called aspartate with another called glycine, which allows the virus to break into its host cells. It seems that the replacement makes it easier for the virus to enter the cells.

Increased infectivity

A research earlier this year showed that in cell cultures that develop in the laboratory, viruses carrying this mutation are more infectious.

The same team found clinical evidence to indicate that in their upper respiratory tracts, individuals with this variant had more virus particles than individuals with other variants. Having said that, their illness seemed to be no more serious despite this extra “viral load.”

Another analysis in the U.K. of over 25,000 viral sequences It means that viruses with this mutation have transmitted slightly faster and have caused larger infection clusters.

The new research sequenced the genomes of the two COVID-19 waves in Houston from 5,085 strains of the virus.

People with the G614 variant had substantially more virus particles in their noses and throats at the time of diagnosis, likely due to its increased infectivity. However, there was no evidence to indicate that, as a result, these persons suffered more serious illness.

Continued vigilance

The researchers found 285 other mutations that cause changes in the amino acid sequence of the spike protein, in addition to G614.

In collaboration with scientists at the University of Texas at Austin and the University of Chicago, IL, researchers at Houston Methodist Hospital found that one of these mutations could enable the spike to evade a neutralizing human immune system antibody.

Whether or not this mutation often improves infectivity is unknown. The researchers, however, report that it is currently unusual and does not seem to make the disease more serious.

They also found no evidence to indicate that the virus has developed mutations that could make ineffective either the vaccines in progress or established antibody therapies.

However, study co-author Ilya J. Finkelstein, a University of Texas molecular biologist, urges continued caution.

“As it rips through the world, the virus begins to mutate,” he says. “Real-time monitoring activities like our study will ensure that one step ahead is still global vaccines and therapeutics.”

The genetic study of the team showed that several times, and from all corners of the world, the virus made its way to Houston. The researchers actually identified strains in the United States from Asia, Europe , South America, and elsewhere.

Concluding their report, the authors write:

“The findings will help us to understand the origin, composition, and trajectory of future infection waves and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.”

They also note some of the study’s limitations. Their sample, for instance, may not have represented the full socioeconomic diversity of the population of the Houston metropolitan area.

They also write that only about 10 percent of all COVID-19 cases reported in the area during the study period were reflected by their samples.

Biology / Biochemistry

Rotator cuff: What you need to know

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The rotator cuff is a group of muscles that aid in the movement of the arm and shoulder. Rotator cuff injuries are fairly prevalent, but there are a number of effective therapies available.

The supraspinatus, infraspinatus, teres minor, and subscapularis are the four muscles that make up the rotator cuff.

Arm movement and shoulder rotation are controlled by these muscles working together. They also aid in the retention of the humerus, or upper arm bone, in the scapula, or shoulder blade, socket. The glenoid is the name for this socket.

Rotator cuff injuries are rather prevalent, particularly among the elderly, sports, and people who work in physically demanding jobs. A medical professional can diagnose a rotator cuff injury and provide the best treatment options.

The structure and function of the rotator cuff, as well as typical injuries that affect this muscle group, are discussed in this article.

Meaning and functions

rotator cuff injury

The rotator cuff, which connects the humerus to the scapula, is made up of four muscles and tendons. These muscles and tendons act as a cuff around the shoulder joint, providing stability.

These muscles have their own distinct movements in addition to their collective function. The supraspinatus, for example, abducts the arm away from the body and aids in the movement of the deltoid muscle in the shoulder. The infraspinatus and teres minor help with lateral rotation, whereas the subscapularis helps with medial rotation.

When to contact a doctor

Anyone suffering from prolonged shoulder pain should consult a physician or orthopedic surgeon. These experts can assess the shoulder, identify the cause of pain, and recommend treatment choices to alleviate symptoms and speed healing.

Anatomy

rotator cuff anatomy

Other components, in addition to the muscle groups that make up the rotator cuff, aid in mobility and function.

These muscles are connected by several nerves, which send important signals throughout the rotator cuff. The subscapular nerve, suprascapular nerve, and axillary nerve are among them. Bursae, which are fluid-filled sacs that separate tissues, are also seen in the rotator cuff. These bursae operate as cushions, minimizing friction and protecting various tissues.

Common conditions

The following are some of the most prevalent rotator cuff injuries:

Tears

A rotator cuff tear occurs when one of the cuff tendons is torn. This rip can damage one or more tendons, although the supraspinatus tendon is the most often injured.

A partial or full-thickness tear can occur. The tendon is damaged but not entirely severed in a partial tear, also known as an incomplete tear. A full-thickness, or complete, rip completely separates the tendon from the bone and can result in a hole.

Injury and degeneration are the most common causes of rotator cuff tears. An acute tear occurs when a tendon is torn as a result of trauma or an accident. Most tears, on the other hand, are degenerative, meaning that they develop slowly over time. A degenerative tear can occur as a result of repeated stress on the tendon, a reduction in blood flow as people age, or bone spurs.

To detect a whole or partial tendon tear, medical experts may employ imaging techniques such as X-ray, ultrasound, and MRI.

Tendinitis

The inflammation of the rotator cuff tendons is known as rotator cuff tendinitis. This condition can affect people of any age, depending on their level of activity.

Tendonitis is a condition that happens when the tendons are irritated or damaged as a result of sports or repetitive overhead movements. Shoulder impingement, commonly known as swimmer’s shoulder, is a condition in which a tendon or bursa presses against the shoulder blade, creating pain. This type of injury is common in people who participate in sports like baseball and tennis, as well as those who work in construction and painting.

A doctor may perform a physical exam and suggest imaging tests to help confirm the diagnosis after asking about the person’s specific symptoms.

Bursitis

The inflammation of a bursa is referred to as bursitis. When a person moves their arm, these lubricating sacs allow the rotator cuff tendons to slide freely. Bursitis can cause when there is too much friction in the shoulder from repetitive movements or injuries.

To diagnose bursitis of the shoulder, a doctor will often perform a physical exam and use imaging studies, similar to other rotator cuff injuries.

Symptoms of injury

The symptoms of rotator cuff damage differ based on the person and the type of injury. The following are some of the most common injury symptoms:

  • a clicking or popping sound when moving the arm
  • weakness in the shoulder
  • pain or swelling in the shoulder
  • difficulty moving the arm

Tips and treatments

Depending on the nature and severity of the rotator cuff injury, treatment methods may differ. A doctor may suggest the following as part of therapy and recovery:

  • sleeping on the unaffected side or on the back
  • taking warm baths or showers to help relax the muscles
  • taking over-the-counter nonsteroidal anti-inflammatory drugs or pain medications to minimize swelling and discomfort
  • applying cloth-wrapped ice packs to the affected area
  • resting and avoiding activities that may irritate the shoulder

When a person can use their shoulder comfortably, a doctor may recommend rehabilitation activities to help with healing. These stretches and exercises may also aid in the prevention of future injuries. Other treatment options may be referred by a doctor to a physical therapist or specialist.

A doctor may recommend surgery in more severe circumstances if nonsurgical methods are unlikely to be beneficial.

Conclusion

The rotator cuff is a collection of four muscles in the shoulder that control arm movement and rotation. Rotator cuff injuries are extremely prevalent because the shoulder joint is very flexible and people utilize it regularly for both sport and employment.

Anyone who is experiencing severe or persistent shoulder pain should see a doctor for a diagnosis. Resting, avoiding intense activities, and practicing moderate stretches are common treatments.

Sources:

  • https://www.ncbi.nlm.nih.gov/books/NBK513344/
  • https://www.assh.org/handcare/blog/anatomy-101-the-rotator-cuff
  • https://www.niams.nih.gov/health-topics/bursitis/advanced
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  • https://www.ncbi.nlm.nih.gov/books/NBK541096/
  • https://www.ncbi.nlm.nih.gov/books/NBK537202/
  • https://www.medicalnewstoday.com/articles/rotator-cuff-muscles
  • https://www.ncbi.nlm.nih.gov/books/NBK513324/
  • https://www.ncbi.nlm.nih.gov/books/NBK441844/
  • https://www.ncbi.nlm.nih.gov/books/NBK547664/#_NBK547664_pubdet_
  • https://www.training.seer.cancer.gov/anatomy/muscular/groups/upper.html
  • https://medlineplus.gov/rotatorcuffinjuries.html
  • https://www.assh.org/handcare/condition/rotator-cuff-injury
  • https://orthoinfo.aaos.org/en/diseases–conditions/rotator-cuff-tears/
  • https://orthoinfo.aaos.org/en/diseases–conditions/rotator-cuff-tears-frequently-asked-questions/
  • https://www.hss.edu/condition-list_rotator-cuff-injuries.asp
  • https://www.hopkinsmedicine.org/health/conditions-and-diseases/shoulder-bursitis
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  • https://www.ncbi.nlm.nih.gov/books/NBK513255/

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Biology / Biochemistry

Can you treat cataracts with eye drops instead of surgery?

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Cataracts, the most common cause of human blindness, may one day be treated with eye drops rather than surgery.

A study headed by the University of California-San Diego (UCSD) published in the journal Nature illustrates how an eye drop solution containing a natural steroid reduced cataracts in dogs.

Our eyes’ lenses are largely made up of crystallin proteins, which serve two purposes: they allow us to alter focus and they maintain the lens clean. Nobody understands how they accomplish this.

Cataracts arise when the delicate structure of the crystallin proteins is disturbed, causing them to clump together and cloud the lens.

cataracts

The lens is also high in lanosterol, a substance that is a key component of several important hormones in the body. An enzyme called lanosterol synthase produces lanosterol.

The researchers were interested in lanosterol after discovering that children with an inherited type of cataracts shared the same lanosterol synthase-blocking gene mutation.

They reasoned that in normal eyes, whose lenses are loaded with lanosterol, the clumping of cataract-forming proteins is prevented.

Lanosterol decreased clumping in cataract-forming proteins

Starting with lab cells and advancing to animals, the researchers conducted three sets of studies.

First, the researchers discovered that lanosterol reduced the clumping of cataract-forming proteins in human lens cells. They next demonstrated that treating rabbits with lanosterol decreased cataracts and enhanced lens clarity.

Cataracts: Some Quick Facts

  • Risk factors include too much sun, diabetes, tobacco and alcohol.
  • Most cataracts develop later in life
  • Cataracts account for 51% of world blindness

Learn more about cataracts

Finally, they found that the lanosterol solution – in both injection and eye drop form – had the same impact in decreasing protein clumping in live dogs with cataracts as it did in human lens cells and rabbit lenses: cataracts were decreased and lens transparency improved.

The researchers come at the following conclusion:

“Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.”

It might be a game changer if lanosterol in the form of eye drops proves to be an effective therapy for cataracts in people.

Cataract surgery is now the only technique to treat them. However, this is not a choice offered to everyone. According to the World Health Organization (WHO), there exist restrictions in many countries that prohibit people from receiving treatment, hence cataract remains the major cause of blindness.

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Biology / Biochemistry

How can individuals tell if they’re having a seizure?

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Seizures are caused by an abnormal surge of electrical activity in the brain. Seizures can be random, but some people have triggers that might cause them. Being aware of possible triggers can assist to reduce the likelihood of experiencing them.

Seizures are sudden, brief changes in movement, behavior, sensation, or states of consciousness caused by aberrant electrical discharges in the brain. Seizure symptoms range depending on which parts of the brain are affected and how severe they are.

Seizures are classified by the International League Against Epilepsy (ILAE) depending on the kind of onset or where they begin in the brain.

Seizures can be caused by a variety of factors, including genetics, brain damage, or underlying illnesses. Seizure triggers do not cause seizures, but they can cause them in people who are prone to them.

Stress, fatigue, and the lack of medications are all typical factors. Knowing what might cause seizures and how to avoid them will help you avoid them.

In this post, we will look at some of the most frequent seizure triggers, the distinction between causes and triggers, and how to detect probable triggers.

Common triggers

Epileptic Patient

Some people with epilepsy, especially those who have experienced recurring seizures, may observe that they happen in predictable patterns or in certain people. These variables, often known as seizure triggers, may increase the likelihood of seizures. Some people with epilepsy, on the other hand, may not have any triggers. Seizures can be triggered by a variety of triggers, including:

Missed medications

Anti-epileptic medications must be taken on a regular basis to maintain a constant amount of medication in the body. A person’s risk of seizures increases if they miss a dosage, and seizures become more severe or occur more frequently as a result.

If you don’t take them as directed, you might develop status epilepticus, a long-term seizure that doctors consider a medical emergency.

Sleep deprivation and tiredness

According to a 2020 research, seizures and sleep have a bidirectional link, with seizures causing sleep deprivation and sleep deprivation triggering seizures. During typical sleep-wake cycles, changes in the brain’s electrical and hormonal activity occur, which may contribute to seizures and affect their intensity and length.

Stress

Seizures are frequently triggered by stress. However, the actual nature of their relationship remains unknown. Everyone reacts to stress differently, and stress can take many forms. A person may get stressed as a result of big life events or a pile of everyday annoyances.

Stress may have a physical impact on the body, resulting in a loss of sleep, a shift in dietary habits, and the use of alcohol or other substances, all of which can lead to seizures.

Alcohol

Small quantities of alcohol are unlikely to cause seizures. Even for people who do not have epilepsy, consuming an excessive amount of alcohol in a short period of time might trigger a seizure.

When the effects of alcohol on the body start to wear off, alcohol-related seizures become more likely. They can happen anywhere between 6 and 72 hours after drinking. Alcohol can also impair sleep and interfere with medicines, raising the chance of a seizure.

Flashing lights

Flashing lights or contrasting patterns might trigger a seizure in people with photosensitive epilepsy. Photosensitive seizures affect only around 3% of epilepsy people. This variety appears to be more frequent in females and younger people, according to evidence.

Nutrition and deficiencies

If a diabetic suffers from severe hypoglycemia, which can develop as a result of missing meals, their extremely low blood sugar levels might trigger a seizure.

Vitamin and mineral deficits can also cause seizures in certain people. Vitamin B6 deficiency can trigger seizures in newborns, however it is less prevalent in adults. Mineral imbalances, such as calcium, sodium, potassium, and magnesium, can cause seizures by altering brain cell electrical activity.

Infection and illness

Seizures might be triggered by illness in certain people. This might be caused by the illness’s physical impact on the body, a lack of sleep, bad dietary habits, certain drugs, or dehydration.

Seizures are frequently caused by a viral infection of the central nervous system. Seizures can be triggered by common ailments like sinus infections or a cold in rare cases.

Menstruation

Catamenial epilepsy is a kind of epilepsy in which seizures become worse or more common during specific people of the menstrual cycle. This is extremely uncommon, and research shows that it is caused by variations in progesterone and estrogen levels.

Weather

According to a 2017 research, low pressure and excessive humidity might trigger seizures. Although there isn’t conclusive evidence that weather has an influence on seizure risk.

Seizures are more common in the winter, according to a 2018 research. However, according to a survey conducted by the Epilepsy Society, extreme heat can provoke breakthrough episodes in well-controlled seizures and make uncontrolled seizures more severe and intense. This suggests that extremes in temperature might produce physiological changes that lead to seizures.

Certain medications

Seizures may be triggered by several over-the-counter drugs. Antidepressants, stimulants, tramadol, and isoniazid are among the drugs that have been linked to seizures in certain people, according to a 2016 research.

Triggers vs. causes

The cause of epilepsy is unknown in two out of every three people . It can, however, be caused by genetic problems or brain ailments including stroke, traumatic brain damage, infections, or other neurological diseases.

Although a seizure can be triggered by a trigger, seizure triggers are not the same as seizure causes. A stressful circumstance, for example, might provoke a seizure, but the underlying cause of the seizure could be brain structural damage.

Because seizures are unpredictable, it may be difficult to figure out why they happen, and some people mistakenly believe that triggers like exhaustion are to blame. However, it’s more likely that the person was already predisposed, and the trigger just triggered a seizure in someone who was already vulnerable.

Reflex seizures

Seizures are typically unpredictable and can happen at any time. While some people may identify triggers, many people’s triggers are more general, such as stress or exhaustion. Other people, on the other hand, may have reflex seizures, which are seizures that occur on a regular basis as a result of particular and recognizable stimuli or cognitive processes.

Potential stimuli, such as seeing flashing lights or touching hot water, or interior stimuli, such as feeling particular emotions or going through specific mental processes, can all cause reflex seizures. This is quite uncommon.

How to Recognize Triggers

Identification of a person’s particular seizure triggers can be challenging and time-consuming. A seizure diary can be kept to record actions or events that lead up to a seizure. Over time, a pattern may emerge, exposing likely seizure triggers.

A person should try to manage their condition and prevent or decrease exposure to potential triggers while seeking to identify likely triggers. People can attempt the following suggestions:

  • taking medication as their doctor prescribes
  • getting enough and regular sleep
  • lowering stress

Conclusion

Stimuli that can induce a seizure in some people are known as seizure triggers. Individual triggers vary, but common ones include illness, tiredness, alcohol, and a lack of medication.

Triggers are not the same as causes. Seizures are frequently caused by underlying conditions, whereas triggers simply cause seizures in people who are already predisposed to them.

People may find it difficult to identify their own specific triggers, but maintaining a journal of possible triggers and avoiding certain stimuli may help prevent seizures.

Sources

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