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[Wikipedia audio article] Electrical stimulation

This is an audio version of the Wikipedia Article: https://en.wikipedia.org/wiki/Functio…

00:01:21 1 Principles

00:09:14 2 History

00:10:01 3 Common applications

00:10:11 3.1 Spinal cord injury

00:11:09 3.1.1 Walking in spinal cord injury

00:15:01 3.2 Stroke and upper limb recovery

00:16:21 3.3 Drop foot

00:18:08 3.4 Stroke

00:18:58 3.5 Multiple sclerosis

00:20:06 3.6 Cerebral palsy

00:21:07 3.7 National Institute for Health and Care Excellence Guidelines (NICE) (UK)

00:21:47 4 In popular culture

00:22:10 5 See also

Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:

  • – increases imagination and understanding
  • – improves your listening skills
  • – improves your own spoken accent
  • – learn while on the move
  • – reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

Listen on Google Assistant through Extra Audio: https://assistant.google.com/services…

Other Wikipedia audio articles at: https://www.youtube.com/results?searc…

Upload your own Wikipedia articles through: https://github.com/nodef/wikipedia-tts

Speaking Rate: 0.9170272343252982 Voice name: en-AU-Wavenet-B

“I cannot teach anybody anything, I can only make them think.” – Socrates

SUMMARY 

Functional electrical stimulation (FES) is a technique that uses low-energy electrical pulses to artificially generate body movements in individuals who have been paralyzed due to injury to the central nervous system. More specifically, FES can be used to generate muscle contraction in otherwise paralyzed limbs to produce functions such as grasping, walking, bladder voiding and standing. This technology was originally used to develop neuroprostheses that were implemented to permanently substitute impaired functions in individuals with spinal cord injury (SCI), head injury, stroke and other neurological disorders. In other words, a person would use the device each time he or she wanted to generate a desired function. FES is sometimes also referred to as neuromuscular electrical stimulation (NMES).FES technology has been used to deliver therapies to retrain voluntary motor functions such as grasping, reaching and walking. In this embodiment, FES is used as a short-term therapy, the objective of which is restoration of voluntary function and not lifelong dependence on the FES device, hence the name functional electrical stimulation therapy, FES therapy (FET or FEST). In other words, the FEST is used as a short-term intervention to help the central nervous system of the person to re-learn how to execute impaired functions, instead of making the person dependent on neuroprostheses for the rest of her or his life.

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[WEB PAGE] Dopamine vs. serotonin: Similarities, differences, and relationship

By Jamie Eske, Reviewed by 

Dopamine and serotonin are chemical messengers, or neurotransmitters, that help regulate many bodily functions. They have roles in sleep and memory, as well as metabolism and emotional well-being.

People sometimes refer to dopamine and serotonin as the “happy hormones” due to the roles they play in regulating mood and emotion.

They are also involved in several mental health conditions, including low mood and depression.

Dopamine and serotonin are involved in similar bodily processes, but they operate differently. Imbalances of these chemicals can cause different medical conditions that require different treatments.

In this article, we look at the differences between dopamine and serotonin, their relationship, and their links with medical conditions and overall health.

What is dopamine?

a young woman sat on her bed wondering if its dopamine or serotonin thats helping her feel so awake this morning.

Dopamine and serotonin play an important role in sleep and emotional well-being.

Neurons in the brain release dopamine, which carries signals between neurons.

The body uses dopamine to create chemicals called norepinephrine and epinephrine.

Dopamine plays an integral role in the reward system, a group of brain processes that control motivation, desire, and cravings.

Dopamine levels also influence the following bodily functions:

  • mood
  • sleep
  • learning
  • movement
  • alertness
  • blood flow
  • urine output

What is serotonin?

Serotonin is another neurotransmitter present in the brain.

However, more than 90% of the body’s total serotonin resides in the enterochromaffin cells in the gut, where it helps regulate the movement of the digestive system.

In addition to aiding digestion, serotonin is involved in regulating:

  • the sleep-wake cycle
  • mood and emotions
  • metabolism and appetite
  • cognition and concentration
  • hormonal activity
  • body temperature
  • blood clotting

Differences between dopamine and serotonin

Although both dopamine and serotonin relay messages between neurons and affect mood and concentration, they have some other distinct functions.

Dopamine, for example, relays signals between neurons that control body movements and coordination.

This neurotransmitter also plays a role in the brain’s pleasure and reward center, and it drives many behaviors. Eating certain foods, taking illicit drugs, and engaging in behaviors such as gambling can all cause dopamine levels in the brain to spike.

Higher levels of dopamine can lead to feelings of euphoria, bliss, and enhanced motivation and concentration. Therefore, exposure to substances and activities that increase dopamine can become addictive to some people.

Like dopamine, serotonin can also influence people’s moods and emotions, but it helps regulate digestive functions such as appetite, metabolism, and gut motility.

The relationship between dopamine and serotonin

nicotine withdrawal in stressed and tired man

Overproduction of dopamine may lead to impulsive behavior.

They interact with and affect each other to maintain a careful chemical balance within the body. There are strong links between the serotonin and dopamine systems, both structurally and in function.

In some cases, serotonin appears to inhibit dopamine production, which means that low levels of serotonin can lead to an overproduction of dopamine. This may lead to impulsive behavior, due to the role that dopamine plays in reward seeking behavior.

Serotonin inhibits impulsive behavior, while dopamine enhances impulsivity.

Dopamine and serotonin have opposite effects on appetite; whereas serotonin suppresses it, low levels of dopamine can stimulate hunger.

Which conditions have links to dopamine and serotonin?

Having abnormal levels of either dopamine or serotonin can lead to several different medical conditions.

Both neurotransmitters can affect mood disorders such as depression. Imbalances can also result in distinct conditions that affect different bodily functions.

In the sections below, we cover these conditions in more detail:

Dopamine

Having too much or too little dopamine can impair communication between neurons and lead to the development of physical and psychological health conditions.

Dopamine deficiency may play a significant role in the following conditions and symptoms:

Dopamine also plays a role in motivation and reward driven behaviors.

Although dopamine alone may not directly cause depression, having low levels of dopamine may cause specific symptoms associated with depression.

These symptoms can include:

  • lack of motivation
  • difficulty concentrating
  • feelings of hopelessness and helplessness
  • loss of interest in previously enjoyable activities

The SLC6A3 gene provides instructions for creating the dopamine transporter protein. This protein transports dopamine molecules across neuron membranes.

A medical condition known as dopamine transporter deficiency syndrome, or infantile parkinsonism-dystonia, occurs when mutations in the SLC6A3 gene affect how the dopamine transporter proteins function.

Dopamine transporter deficiency syndrome disrupts dopamine signaling, which impacts the body’s ability to regulate movement.

For this reason, dopamine transporter deficiency syndrome produces symptoms similar to those of Parkinson’s disease, including:

  • tremors, spasms, and cramps in the muscles
  • difficulty eating, swallowing, speaking, and moving
  • impaired coordination and dexterity
  • involuntary or abnormal eye movements
  • decreased facial expression, or hypomimia
  • difficulty sleeping
  • frequent pneumonia infections
  • digestive problems, such as acid reflux and constipation

Serotonin

a man smiling when his daughter greets him with a touch on the shoulder.

Genetics and family history may contribute to a person’s risk of developing a mood disorder.

Similar to dopamine, researchers have linked abnormal levels of serotonin with several medical conditions, especially mood disorders such as depression and anxiety.

Contrary to popular belief, it appears that low serotonin does not necessarily cause depression. Multiple factors beyond biochemistry contribute to depression, such as:

  • genetics and family history
  • lifestyle and stress levels
  • environment
  • additional medical conditions

That said, having low serotonin levels may increase a person’s risk of developing depression. Serotonin medications — such as selective serotonin reuptake inhibitors (SSRIs), which increase the availability of serotonin in the brain — may also help treat depression.

SSRI medications include:

On the other hand, having too much serotonin can lead to a potentially life threatening medical condition called serotonin syndrome.

Serotonin syndrome, or serotonin toxicity, can occur after taking too much of a serotonergic medication or taking multiple serotonergic medications at the same time.

The Food and Drug Administration (FDA) provided a list of serotonergic medications in 2016. Aside from SSRIs, some of these include:

  • serotonin and norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine (Effexor)
  • tricyclic antidepressants (TCAs), such as desipramine (Norpramin) and imipramine (Tofranil)
  • certain migraine medications, including almotriptan (Axert) and rizatriptan (Maxalt)

According to the FDA, opioid pain relievers can interact with serotonergic medications, which can lead to a buildup of serotonin or enhance its effects in the brain.

Summary

The neurotransmitters dopamine and serotonin regulate similar bodily functions but produce different effects.

Dopamine regulates mood and muscle movement and plays a vital role in the brain’s pleasure and reward systems.

Unlike dopamine, the body stores the majority of serotonin in the gut, instead of in the brain. Serotonin helps regulate mood, body temperature, and appetite.

Having too much or too little of either neurotransmitter can cause psychological and physical symptoms.

via Dopamine vs. serotonin: Similarities, differences, and relationship

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[BLOG POST] A Guide to using Omega-3s for Brain Healing

Are Omega-3s Important for Brain Healing?

There are three types of omega-3 fatty acids: ALA, DHA, and EPA.

ALA (alpha-linolenic acid), found in flax seeds, walnuts, and chia seeds, cannot be synthesized in the body and therefore must be consumed in the diet.  DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) are almost exclusively found in fish.

DHA and EPA have been shown to play a crucial role in brain development. They are involved in neurotransmitter synthesis and functioning. DHA is necessary for the functional maturation of the retina and visual cortex [1]. Infants of mothers who supplemented with DHA had higher mental processing scores, hand-eye coordination, and psychomotor development [2].

Omega-3 supplementation has been shown to improve cognitive functioning in the mature brain as well. Studies have correlated accelerated cognitive decline and mild cognitive impairment with low tissue levels of DHA and EPA [3]. Additionally, omega-3 consumption is associated with a decreased risk for dementia and Alzheimer’s disease [4].

To be completely transparent, there isn’t much research on the use of omega-3s to aid brain healing after a TBI or stroke. However, there is evidence testifying to the crucial role of omega-3s in brain development and linking DHA and EPA to improved cognitive performance. To me this evidence makes a strong case for the use of omega-3s in a brain recovery program.

 

Top 5 Reasons to use Omega-3’s for Brain Healing

  1. DHA is proven essential to brain development

DHA is required for the development of the sensory, perceptual, cognitive, and motor neural systems during fetal and childhood brain growth.  Specifically, DHA is vital for the neuronal formation of axons and dendritic extensions and for proper synaptic functioning. EPA’s importance for the brain’s development is unclear, but colostrum and breast milk do contain EPA. Omega-3 deficiencies during development have been linked to deficits in retinal structure, visual acuity development, and cognitive performance [3].

  1. Has been shown to reduce aggression

I was pleasantly surprised by this benefit. The mechanism by which it works is unknown, but several double-blind studies have shown decreased physical aggression and impulsivity after omega-3 supplementation. DHA in particular has been shown to help prevent aggression resulting from mental stress [3].

  1. Linked to improved cognitive performance

Researchers have concluded that DHA and EPA supplementation can improve higher brain functions – sense of wellbeing, reactivity, attention, cognitive performance, and mood. Additionally, omega-3s have been shown to decrease cognitive decline and lower dementia risk [3].

  1. Beneficial for affective disorders

Affective disorders that respond to DHA/EPA include major depressive disorder, manic depression, schizophrenia, and borderline personality disorder. EPA seems to provide the most benefit when it comes to decreasing depression and managing mood [3].

  1. Reduces inflammation

EPA reverses cellular inflammation, including inflammation in the brain. The primary mediators of inflammation in the body are derived from arachidonic acid, an omega-6 fatty acid. When omega-3 consumption is increased, EPA blocks the production of these pro-inflammatory mediators [5].

 

What is the Best Source of Omega-3s?

This article discusses the use of omega-3s for brain healing.

For ALA (alpha-linolenic acid) I would suggest simply adding a daily tablespoon of ground flax seed to your diet.

DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) are almost exclusively found in fish. While DHA and EPA can be synthesized from ALA in the body, the conversion rate is very low – it’s thought to be around 1% of the total intake of ALA.

Seaweed and microalgae are the only plant sources of DHA and EPA. However, they are found in very low concentrations. While a healthy individual may get by on a plant based omega-3 supplement, it would be very difficult consume the high quantities recommended after a brain injury.

For high doses of EPA and DHA, go with a good quality, highly purified fish oil.  For more information on choosing a good quality fish oil see: Choosing the Best Fish Oil Supplement for Brain Health.

But isn’t Fish Oil a Blood Thinner?

I think Dr. Lewis addresses this concern best,

There is a theoretical risk that high dose omega3s may cause bleeding or stroke. Biochemical pathways tell us this is a valid concern. However, not a single study in the scientific literature has shown this to be of any clinical significance.” [6]

I personally believe that the benefits of fish oil outweigh the risks. I would however recommend that you discuss it with your doctor before using high doses of fish oil, especially if you are on a prescription blood thinner. Do your own research first so that you are prepared to discuss the pros and cons with them (even doctors don’t know everything).

A Guide to using Omega-3s for Brain Healing - How To Brain

How much Fish Oil should You Take?

Currently there is not a set recommendation for daily intake of DHA/EPA for brain function. For healthy individuals, I have seen recommendations ranging from 0.5 grams up to 5 grams. In individuals with brain injury, most of the existing literature suggests much higher doses are needed. Here is the information that I have found relating to dosage:

Dr. Lewis Protocol

Week 1 – Take 3 g of EPA + DHA 3 times a day for a total of 9 g per day.

Week 2 – Take 3 g of EPA + DHA 2 times a day for a total of 6 g per day.

Maintenance dose – Take 3 g of EPA + DHA once a day.

Dr. Lewis suggests starting at an even higher dose and maintaining it for longer if the brain injury is severe. If you explore his website a bit, you will find that he has lots of good information regarding fish oil and brain injury. I particularly liked this article: High Dose Omega-3s in Severe Brain Injury.

Dr. Sears

Dr. Sears doesn’t lay out an exact protocol, but he does recommend using 10 – 15 grams of EPA + DHA per day.

How soon should You see Results?

While I have read testimonies of people seeing almost immediate results, this seems to be the exception not the rule. You should begin to see results within 2 months, but it could take up to 3 months.

It took around 3 months for us to really start seeing improvements with my dad.

Which Supplement should You use?

Since you will be taking high doses, it is vital that you take a high quality supplement.

I have found both Nordic Naturals* and NutriGold* to be very good brands. There are many other brands available though, just make sure the one you choose is third party tested. For more information on choosing a brand read: Choosing the Best Fish Oil Supplement for Brain Health.

Links denoted with an * are affiliate links. I will receive a small commission (at no cost to you) if you purchase something through the one of these links. For my full disclosure click here. Thank you for your support!

A Guide to Using Omega-3s for Brain Healing - How To Brain

via A Guide to using Omega-3s for Brain Healing – How To Brain

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[Infographic] Traumatic Brain Injury

traumatic-brain-injury-infographic

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[TEDx Talk] The most important lesson from 83,000 brain scans – Daniel Amen

via The most important lesson from 83,000 brain scans | Daniel Amen | TEDxOrangeCoast – YouTube

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[BLOG POST] What should we really know about cerebral aneurysms? – THE NEUROLOGY LOUNGE Blog

Cerebral aneurysms are scary things. It is alarming enough that they exist, but it is more spine-chilling that they enlarge with time. The most infamous aneurysm arises from the posterior communicating artery, the so-called PCOM aneurysm. And it signifies its sinisterintent when it gradually enlarges and compresses its vascular neighbour, the third cranial nerve, otherwise known as the oculomotor nerve. A dysfunctional third nerve manifests with a droopy eyelid (ptosis) and double vision (diplopia). The reason for the double vision becomes obvious when the neurologist examines the eyes; one eyeball is out of kilter and is deviated downwards and outwards; it is indeed down and out! The pupil is also very widely dilated (mydriasis). These are among the most worrying red flags in medicine, and a very loud call to arms. Cerebral aneurysms however often wave no flags, red or otherwise. Indeed the most malevolent of them will expand quietly until they reach horrendous proportions, and then, without much ado, just rupture. They are therefore veritable time bombs…just waiting to go off.

By Tiago Etiene Queiroz – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=24418848

Cerebral aneurysm however do not need to reach large proportions to rupture; some just rupture when they feel like. Aneurysms under 7mm in diameter however are less prone to rupture. A rupturing aneurysm presents with very startling symptoms. The most ominous is a sudden onset thunderclap headache (TCH), subjects reporting feeling as if they have been hit on the back of the head with a baseball or cricket bat. It is not quite known what non-sporting patients experience-for some reason they never get aneurysms in neurology textbooks! More universally appropriate, a ruptured aneurysm may manifest as sudden loss of consciousness. Both symptoms result from leakage of blood into the cerebrospinal fluid (CSF) space, a condition known as a subarachnoid haemorrhage (SAH).

By Lipothymia – Anonymised CT scan from my own practice, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=787177

You may breath a small sigh of relief here because the vast majority of people with thunderclap headaches do not have subarachnoid haemorrhage. Unfortunately, every person who presents with a thunderclap headache must be investigated- to exclude (hopefully), or confirm (ruefully), this catastrophic emergency. The first test is a CT head scan which identifies most head bleeds. The relief of a normal scan is however short-lived because some bleeds do not show on the CT. The definitive test to prove the presence or absence of a bleed is less high tech, but more invasive: the humble spinal tap or lumbar puncture (LP). This must however wait for least 12 hours after the onset of headache or blackout. This is the time it takes for the haemoglobin released by the red blood cells to be broken down into bilirubin and oxyhaemoglobin. These breakdown products are readily identified in the biochemistry lab, and they also impart on the spinal fluid a yellow tinge called xanthochromia. The test may be positive up to 2 weeks after the bleed, but the sensitivity declines after this time. A positive xanthochromia test is startling and sets off an aggressive manhunt for an aneurysm-the culprit in most cases.

By Ben Mills – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=13051957

Many people with cerebral aneurysms have a family history of these, or of subarachnoid haemorrhage. Some others may have connective tissue diseases such as Ehler’s Danlos syndrome (EDS)adult polycystic kidney disease (APCKD), or the rare Loeys-Dietz syndrome. This family history is a window of opportunity to screen family members for aneurysms. The screening is usually carried out with a CT angiogram (CTA) or MR angiogram (MRA). People are often not born with aneurysms, but tend to develop them after the age of 20 yearsAneurysm surveillance therefore starts shortly after this age, and many experts advocate repeating the screening test every 5-7 years until the age of 70-80 years.

By Nicholas Zaorsky, M.D. – Nicholas Zaorsky, M.D., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=15533196

How are aneurysms treated? This will be the subject of a future blog post so watch this space!

 

via What should we really know about cerebral aneurysms? – The Neurology Lounge

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[WEB SITE] Stem Cell Sources, Types, and Uses in Research

 

Stem cells are undifferentiated cells that are capable of self-renewal or differentiation into a specialized cell. They exist within areas of the body known as biological niches and are essential for growth during childhood, and homeostasis throughout adulthood.

Thus, understanding the biological processes that underpin these cells can have invaluable implications for regenerative medicine, disease treatment, and injury recovery. This article describes each type of stem cell, as well as some key landmark discoveries and the major applications of stem cells in medicine and research.

Abstract image of blue stem cells on yellow-red background.

pinkeyes | Shutterstock

What are stem cells?

The defining characteristic of stem cells is that they can differentiate into several different cell types during growth and development. This not only has implications during early life, but also following injury where stem cells act as an internal repair mechanism by replenishing the injured or dead cells. There are two main features of stem cells that make it unique.

Unspecialized nature

Stem cells are not differentiated to have specific structures and functions. For example, an unspecialized stem cell cannot carry oxygen like a red blood cell or pump blood like a heart cell. However, upon receiving appropriate signals, it can form into different types of specialized cells, like muscle cells, blood cells, etc.

Differentiation potential

The process of differentiation allows unspecialized stem cells to acquire specific functions and properties. The signals that cue this transition can be intrinsic (from within the cell) or extrinsic (from outside the cell). Extrinsic signals that can trigger this transition may be in the form of mechanical or chemical cues from the neighboring cells.

The differentiation potential of stem cells is variable in different organs. Some organs, including gut and bone marrow, regularly undergo division to repair and replenish the damaged cells. However, in organs such as the pancreas and heart the frequency of stem cell division and differentiation is much lower.

 

Stem cells (center ones) can develop into any cell type. They are valuable as research tools and might, in the future, be used to treat a wide range of diseases. Credit: Judith Stoffer

Where do stem cells come from?

Human umbilical cord

The cord blood can be collected from the umbilical cord of a baby after its birth and consists of hematopoietic and mesenchymal stem cells. The hematopoietic stem cells can form red blood cells and cells of the immune system, while the mesenchymal stem cells can generate bone, cartilage, and other types of tissues. The cord blood can also be collected and stored in cord blood banks for future use.

Bone marrow

Bone marrow is a soft gelatinous tissue found at the center of bones. Mesenchymal stem cells were first found in bone marrow, and it is still the most frequently used source of mesenchymal stem cells. Subsequently, hematopoietic or blood stem cells were also found in the marrow, making it an attractive candidate for regenerative medicine and therapeutic purposes.

Adipose tissue

The adipose tissue-derived stem cells are mesenchymal cells that have the potential for self-renewal and multipotency. They can differentiate into adipocytes, chondrocytes, myocytes, osteoblasts, and neurocytes, in addition to other cell types. These stem cells have been shown to have critical roles in reconstructive and tissue engineering fields to develop new treatments.

Amniotic fluid

Amniotic fluid is the liquid that surrounds the amnion or the sac that encompasses the fetus. Both the amniotic membrane and amniotic fluid are good sources of embryonic stem cells that can multiply and form any type of cell. Although the amniotic fluid and membrane are usually discarded after birth, recently they are being cryopreserved or frozen for future therapeutic use.

Types of stem cells

Stem cell potency

On the basis of their differentiation potential, stem cells can be classified into four types: totipotent, pluripotent, multipotent, and unipotent.

Totipotent cells

Totipotent cells can differentiate into all types of cells. For example, the zygote formed during the fertilization of an egg and the first few cells after division are totipotent and have the potential to develop into all types of cells in the body.

Pluripotent cells

Pluripotent cells can develop into almost all types of cells. These include embryonic stem cells, cells derived from the germ layers (mesoderm, ectoderm, endoderm), and cells formed during the early stages of embryonic stem cell differentiation.

Multipotent, oligopotent, and unipotent cells

Multipotent cells can divide into closely-related cells. For example, the hematopoietic stem cells can develop into red blood cells, white blood cells, and platelets. Oligopotent cells can develop into a few cell types, and include lymphoid or myeloid stem cells, while unipotent cells, such as muscle stem cells can only develop into cells of their own type.

Stem cell sources

Based on their origin, stem cells can be divided between early (or embryonic) and mature (or adult).

Embryonic stem cells

The embryonic stem cells are found in the inner cell mass of the blastocyst post five days of development. These cells are potentially immortal and are derived from embryos before they implant themselves in the uterus. These cells are typically 4–5 days old and are called blastocysts–a hollow microscopic ball of cells.

Adult stem cells

Adult stem cells are undifferentiated cells that are totipotent or pluripotent. These cells are found in various locations in the body and assist in maintaining healthy cell numbers and replenishing dying or injured cells.

Induced pluripotent cells

Recently, a new category of stem cells has emerged that originate from somatic cells and can be reprogrammed by scientists back to their pluripotent stage. This was done by manipulating the expression of a set of genes. As somatic cells are coaxed into pluripotent cells in this category, they have been termed as “induced pluripotent cells”.

What is stem cell lineage?

Stem cells usually undergo two kinds of cell division: symmetric and asymmetric. In symmetric division, two identical daughter cells with stem cell properties are generated post cell division. In asymmetric division, one stem cell and one progenitor cell are generated.

The progenitor cells have limited potential for self-renewal and after several cycles of division, give rise to differentiated mature cells. However, it is often difficult to locate stem cells as tissues contain large numbers of several types of cells.

Lineage analysis is one method used to tackle this problem. In this method, a single cell is marked such that it not only marks the target cell but also its daughter cells. Thus, the number, location, movement, and lifetime of a stem cell and its daughter cells can be tracked. The lineage analysis of stem cells helps to discover and identify stem cell niches that replace cells during a tissue’s lifetime.

Landmark discoveries in the history of stem cell research

One of the earliest experiments in this field was performed by Sir John Gordon during his Ph.D. in 1962. He removed the nucleus of a developing frog embryo during the blastula stage and injected it into an egg cell from which the nucleus was removed.

In most cases, the egg could develop into frog tadpoles, showing that nuclei from differentiated cells still had the potential to develop into any cells. This study formed the basis of reproductive cloning that led to the creation of Dolly, the cloned sheep.

Another major discovery was the culturing of embryonic stem cells from mouse blastocysts in 1981. Subsequently, embryonic stem cells were also cultured from human blastocysts.

A landmark discovery was made when Shinya Yamanaka and his colleagues were able to induce somatic cells into pluripotent stem cells by introducing a set of 24 transcription factors. He was awarded the Nobel Prize in Medicine for this discovery in 2012, along with Sir John Gurdon.

Ethical issues surrounding embryonic stem cells

Recently, autologous induced pluripotent cells were used to treat macular degeneration in human studies. In another study, the epidermis was completely reconstructed in a patient with epidermolysis bullosa. There have also been advancements in organoids, three-dimensional structures that attempt to mimic the structure and function of organs.

These organoids can be generated from stem cells, induced pluripotent cells, biopsy samples, etc., and can be used for tissue transplantations. The creation of organoids has raised critical questions on ownership, storage, donor, and manipulation rights of these structures. Although they are not completely mature functionally, the extent to which organoids can be allowed to mature needs to be discussed.

The “14-day rule” has been set by the International Society for Stem Cell Research (ISSCR), which dictates that stem cell research on embryos needs to be terminated at two weeks post-fertilization. This time correlates with the emergence of the primitive streak, the first brain and spinal cord structure.

The advances in gene editing have also opened several doors for ethical cross-questioning, where the ISSCR has mandated that all steps of stem cell research and gene editing research should be transparent. Recently, however, there have been news reports that claimed that the first gene edited babies have been made in China, but this claim still needs to be substantiated.

Technical issues associated with induced pluripotent stem cells

Studies show that induced pluripotent cells have greater diversity than embryonic stem cells. This difference has been proposed to arise from epigenetic memory, genetic background, reprogramming, etc. Two studies show that cells present in the transitional phase are markedly different from the original and fully reprogrammed cells.

While many induced pluripotent cells show similar morphology and gene expression, they also have a poor quality of differentiation, low rate of growth, errors in transcription, DNA methylation, etc. Also, one of the factors used to reprogram the somatic cells, KLF4, can disrupt neurogenesis of induced pluripotent stem cells. Thus, further understanding of factor-induced reprogramming is needed.

Key applications of stem cells

Therapeutic purposes

Apart from bone marrow transplantation, stem cell therapeutics is still in the developmental stages. Attempts are being made to use stem cells in treating type I Diabetes, Parkinson’s disease, Huntington’s disease, celiac disease, cardiac failure, etc. However, bone marrow transplants, where stem cells are transplanted from the bone marrow, is a well applied and known application. The bone marrow stem cells can help in repopulating different blood types after radiotherapy.

Skin replacement

Stem cells are currently being used to grow skin from the plucked hair of a patient. The hair follicles contain skin stem cells or keratinocytes, and these cells can be isolated and cultured to grow an epithelial sheet. This method can help to reduce the need to use skin grafts from other people, lowering the chances of rejection.

Brain cell transplantation

Stem cells can be employed to generate dopamine–a chemical that is lacking in patients suffering from Parkinson’s disease. However, in some cases, patients developed side-effects, suggesting the presence of very high levels of dopamine or over-sensitization in this method.

Sources

Further Reading

Last Updated: Jul 1, 2019

Currently rated 5.0 by 1 person

 

Dr. Surat P

Written by

Dr. Surat P

Dr. Surat graduated with a Ph.D. in Cell Biology and Mechanobiology from the Tata Institute of Fundamental Research (Mumbai, India) in 2016. Prior to her Ph.D., Surat studied for a Bachelor of Science (B.Sc.) degree in Zoology, during which she was the recipient of an Indian Academy of Sciences Summer Fellowship to study the proteins involved in AIDs. She produces feature articles on a wide range of topics, such as medical ethics, data manipulation, pseudoscience and superstition, education, and human evolution. She is passionate about science communication and writes articles covering all areas of the life sciences.

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[WEB SITE] 2019 ACRM Abstracts Presented at RehabWeek – Archives of Physical Medicine and Rehabilitation

Provided here are the abstracts of scientific papers and posters presented at the 2019 RehabWeek Conference 24 – 28 June in Toronto, Canada. Papers and posters were chosen by the ACRM RehabWeek program committee. The abstracts have not been subjected to formal peer review by the Editorial Board of the Archives of Physical Medicine and Rehabilitation. Abstracts from the 2019 RehabWeek Conference are published online for the Archives of Physical Medicine and Rehabilitation at www.archives-pmr.org.

via 2019 ACRM Abstracts Presented at RehabWeek – Archives of Physical Medicine and Rehabilitation

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[WEB SITE] The Non-Scientist’s Guide to Reading and Understanding a Scientific Paper

It’s not as difficult as you think. Well, maybe it is. But reading scientific articles will help you make more informed decisions, and better understand and participate in the public debate about important scientific issues

Highlights:
More than 2.5 million new English-language scientific papers are published each year in more than 28,000 peer-review journals.
While many are paywalled, there are also prestigious open-access journals where you can read articles for free.
Reading articles will help you make more informed decisions in the areas of life that concern you, and better understand and participate in the public debate about important scientific issues.
Here are the basic steps: focus on the big picture the scientists are addressing; read the Abstract, Introduction, and Discussion, in that order; think critically about the conclusions the scientists make; conduct follow-up research.
For practice, we provide a link to a popular scientific paper on light-emitting e-readers.

We live in a golden age of scientific research. The top five countries in scientific research and development — the U.S., China, Japan, Germany, and South Korea, respectively — spend over $1 trillion on it each year. But where do all the resulting discoveries and eureka! moments go? Eventually they may find their way into textbooks or form the foundation of a life-saving therapeutic, but first most of them they go onto the page, in a scientific article.

According to a report by the International Association of Scientific, Technical and Medical Publishers (available for download here), more than 2.5 million new English-language scientific papers are published each year in more than 28,000 verified journals that use the stringent “peer review” system, whereby multiple scientists who are specialists in the relevant field of study provide a critical and in-depth review of a new paper. The process takes months and is overseen by a journal editor and several reviewers who read the study; only once the editor is convinced the author has addressed notes from peer reviewers in such categories as originality, importance, manner of presentation, and critical flaws, is it accepted into a journal.

The most common form of scientific article is a primary research article, an original report of research which chronicles an experiment in such a way that it can be replicated and the results reproduced by other scientists — core tenets of the scientific method. (Another type is a review article, where several primary research articles are discussed and their findings placed in greater context.)

The internet has made disseminating that sea of scientific information easier than ever, one result of which is a deluge of “A Groundbreaking New Study Finds…” headlines on websites and in magazines. While overly reductive reporting on scientific breakthroughs is not new to the media — the general public has at times felt whipsawed by science and health reporting for decades — the total quantity of scientific research and media sources is only increasing. More often than not, those articles grab the biggest “finding” and speculate on what it might mean a decade into the future, which often falls short of explaining the study in context and helping readers form an educated understanding of what the scientific research actually showed.

So how do you distinguish hyperbole from scientific evidence? By reading the papers yourself.

That’s not easy, even for scientists, who readily admit that reading these papers can be akin to torture. (A recent article in Science, enumerating the steps of reading a paper, included “fear,” “regret,” “bafflement,” “distraction,” and “rage.”) Rather than charging headfirst into several thousand words of science-speak, follow this plan of attack for primary research articles. With a little practice, you can do more than just understand them: you can replace conventional wisdom with knowledge, make more informed decisions in the areas of life that concern you most — health, fitness, and diet, for example — and better understand and participate in the public debate about important scientific issues.

Editor’s Note: To illustrate the process, we’ve chosen a popular scientific paper published in 2015 in Proceedings of the National Academy of Sciences, “Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.” You can access the paper for free here.

1. Locate the Article

You’ll likely begin your search one of two ways: either by tracking down a paper cited in a news story (in which case: Google), or by searching for papers on a topic that interests you. The highest profile sources of peer-reviewed articles are Nature, a British journal, and Science, its American competitor. But there are credible journals for every branch and sub-branch of science. The best place to find those is on PubMed.gov, a database holding more than 27 million citations to credible journals.

Note that many scientific papers are not available for free. In a 2015 list of the most influential primary research papers by AltMetric, 42 were open access and 58 were paywalled. Paywalls are a source of frustration for a large swath of the general public (including academia, industry, and media), who argue that open access to research hastens innovation — and indeed that the public has a right to access the research it funds with tax dollars. This friction between publishers and everyone else has given rise to a variety of responses, including open-access journals, the search engine Sci-Hub, and policies from funding sources, like the Bill & Melinda Gates Foundation, that require research to be disseminated to the public free of charge.


Before You Start: The Anatomy of a Primary Research Article
Abstract: A condensed version of the article including the problem scientists were looking into, related work in the field, why this paper is new and novel, the most important findings, the overall conclusion, problems that occurred during the experiments.
Introduction: Scientists cite previous research in the field and explain their hypothesis in broad terms.
Methods and Materials: A precise description of the experiments such that they can be replicated by other scientists.
Results: All the important resulting data from the experiments.
Discussion/Interpretation/Conclusion: How the authors interpret the data.

2. Wrap Your Head Around the Big Picture

Read the Abstract for the bottom line of the study and then dig into the Introduction. While the Abstract can be dense prose, the Introduction is where the authors provide big picture context for the study and explain previous research in the field, often in a narrative style that’s easy to follow. It’s helpful to imagine each scientific paper as a single chapter in a long novel; this section is where you’ll gain an understanding of what chapters came before. It’s also where the authors broadly explain their hypothesis — or, where they’re guessing their own chapter will lead.

You want to come away from the Introduction with an understanding of the central problem the particular field of science is dealing with, as well as a subset of questions (related to the problem) that the authors of the paper plan to address. They will offer a hypothesis about the answer to those questions and suggest a plan of attack — the experiment(s) — for investigating whether it’s true.

In the e-reader article, the central problem is, How significantly are human sleep cycles, and therefore health, affected by technology? The authors explain that the “previous chapters” in this field have discovered that a circadian timing system directly affects when and how we sleep, and that the circadian cycle is directly affected by exposure to light in the early evening and nighttime, which suppresses the release of melatonin, a hormone that tells our bodies to sleep; the resulting lack of melatonin acutely increases alertness. The specific questions posed in the paper are, How does the light of an e-reader’s screen affect the circadian rhythm of test subjects, how does that affect the quality of their sleep and their alertness the next day?

3. Skip Ahead to the Conclusion

The Methods and Results sections come next, but skip ahead to the Discussion, alternatively called the Conclusion or Interpretations, which will summarize the findings — at least what the authors think they have showed — in a digestible way. This section includes how the authors interpret the data from their experiment and what it means for their original hypothesis. At the very end they will speak to how their findings change our understanding of the bigger picture, those surrounding chapters in the novel that makes up the scientific field’s entire progress. Keep in mind that scientific articles have limitations, often acknowledged in the paper, which require further research.

The scientists behind the e-reader study address both the larger problem and their unique questions in their Conclusion. “These results indicate that reading an LE (light emitting) eBook in the hours before bedtime likely has unintended biological consequences that may adversely impact performance, health, and safety,” they write. Specifically, based on their data they suggest that beyond just disrupting single instances of sleep, the light from e-readers may lead to a pattern of sleep deficiency by delaying the circadian timing system, which in turn reduces the REM sleep that would otherwise happen closer to waking.

And they describe a harrowing big picture given these findings: teenagers are spending upwards of 7.5 hours a day consuming media on readers, phones and computers, much of which happens in the evening and nighttime. The authors are especially concerned because studies of night shift workers have found a relationship between chronic suppressed nocturnal melatonin release and colorectal, breast and prostate cancer.

4. Understand the Results

The Results section and its attending figures and tables present the data without interpretation from the paper’s authors. As a result, this section will usually be the most difficult for the non-scientist.

A few statistics terms will help you navigate the data: “significant” and “non-significant.” This basic statistics terminology is used by scientists to describe events that could be the result of random chance (“non-significant”) versus data that could represent meaningful discoveries (“significant”). If you’re not familiar with statistics, consider reading a primer like this one from Harvard Business Review. Be aware that the Results section (and Methods) is sometimes challenging even for other scientists who are reading outside their field of expertise.

Pay attention to the figures and charts, which pack a lot of clear information into visuals. Read the captions closely, since they tend to explain the results with simple, clear language. And circle back to simplest questions: What is being measured? Given what you read in the Introduction and Discussion, what do the data illustrate?

The e-reader study includes several results from its experiment that support the interpretation in the Discussion section, all fairly easily understood using the figures and captions. For example, that after five consecutive days of reading using electronic light, the e-reader group’s melatonin onset levels were significantly suppressed in the evening when compared to the group reading traditional books. Those using the e-reader also took an average 10 minutes longer to fall asleep than those in reading books. And those using e-readers had significantly less REM sleep on average.


Assessing the Subject: Cells, Model Organisms, and Humans
A small but important detail: What are an experiment’s test subjects? There’s a big difference between the implications of results found studying model organisms (non-human species) or in human cells ex vivo (outside the body) versus results discovered in clinical studies (humans) — one that articles in the news usually don’t usually mention in the first few paragraphs.
While research cells and animals is vital for advancing our understanding in various fields of science and can produce groundbreaking results, these results don’t always carry over to humans. Scientists can reliably extend the life of mice by 30 percent, but that doesn't mean it can be done in humans.

5. Understand the Experiments

“Materials and Methods” is where the authors describe their experiment in enough detail that they can be replicated by other scientists. This is vital for the entire field of science, which is built on reproducible data. It also makes this section challenging and perhaps less important to understand for non-scientists. However, you’ll be rewarded for working toward a general understanding of the Methods section since plenty of experiments are poorly-designed, particular in the areas of randomization, blinding, and sample size. If you are curious about how the experiment was carried out, expect to spend time here looking up challenging terminology.

6. Recognize This Is Just the Beginning

In the final moments of the Conclusion and you may find a call to action: Scientists often recommend what they believe should be done next. “Because technology use in the hours before bedtime is most prevalent in children and adolescents,” the authors of the e-reader study write, “physiological studies on the impact of such light exposure on both learning and development are needed.” If you’re interested in learning more you can turn to the References section for further reading, or even contact one of the authors with questions. After all, a lot of scientific research is funded with public money, and the science community is surprisingly accessible. Odds are the author will be happy to discuss a topic that’s likely his or her lifelong passion.

 

Visit Site  —-> The Non-Scientist’s Guide to Reading and Understanding a Scientific Paper

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[WEB SITE] Brain Damage: Symptoms, Causes, Treatments – WebMD

Brain damage is an injury that causes the destruction or deterioration of brain cells.

In the U.S., every year, about 2.6 million people have some type of brain injury — whether as a result of trauma, stroke, tumor, or other illnesses, according to the Brain Injury Association of America. About 52,000 die as a result of traumatic brain injury, and more than 5 million Americans who’ve suffered traumatic brain injury require assistance in performing daily activities. Approximately 130,000 Americans die of stroke each year, according to the National Stroke Association.

What Are the Types of Brain Damage and How Severe Are They?

All traumatic brain injuries are head injuries. But head injury is not necessarily brain injury. There are two types of brain injury: traumatic brain injury and acquired brain injury. Both disrupt the brain’s normal functioning.

  • Traumatic Brain Injury (TBI) is caused by an external force — such as a blow to the head — that causes the brain to move inside the skull or damages the skull. This in turn damages the brain.
  • Acquired Brain Injury (ABI) occurs at the cellular level. It is most often associated with pressure on the brain. This could come from a tumor. Or it could result from neurological illness, as in the case of a stroke.
Both traumatic brain injury and acquired brain injury occur after birth. And neither is degenerative. Sometimes, the two terms are used interchangeably.

There is a kind of brain damage that results from genetics or birth trauma. It’s called congenital brain damage. It is not included, though, within the standard definition of brain damage or traumatic brain injury.

Some brain injuries cause focal — or localized — brain damage, such as the damage caused when a bullet enters the brain. In other words, the damage is confined to a small area. Closed head injuries frequently cause diffuse brain damage, which means damage to several areas of the brain. For example, both sides of the brain are damaged and the nerves are stretched throughout the brain. This is called diffuse axonal injury or DAI.

The severity of brain damage can vary with the type of brain injury. A mild brain injury may be temporary. It causes headaches, confusion, memory problems, and nausea. In a moderate brain injury, symptoms can last longer and be more pronounced. In both cases, most patients make a good recovery, although even in mild brain injury 15% of people will have persistent problems after one year.

With a severe brain injury, the person may suffer life-changing and debilitating problems. He or she will have cognitive, behavioral, and physical disabilities. People who are in a coma or a minimally responsive state may remain dependent on the care of others for the rest of their lives. .

 

 

 

more —-> Brain Damage: Symptoms, Causes, Treatments

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