Tag Archives: blood

What is vitamin K?

Vitamin K plays a key role in our blood’s ability to form clots. It’s one of the less glamorous vitamins, more rarely discussed than its peers and, although it’s usually referred to as a single substance, it comes in two natural varieties — K1 and K2 — and one synthetic one, K3. People typically cover their requirements of vitamin K through diet, so it’s rarely seen in supplement form, but we’ll also look at some situations that might require an extra input of vitamin K.

A molecule of menatetrenone, one of the forms of vitamin K2. Image via Wikimedia.

The ‘K’ in vitamin K stands for Koagulations-vitamin, Danish for ‘coagulation vitamin’. This is a pretty big hint as to what these vitamers — the term used to denote the various chemically-related forms of a vitamin — help our bodies do. Vitamin K is involved in modification processes that proteins undergo after they have been synthesized, and these proteins then go on to perform clotting wherever it is needed in our blood. Apart from this, vitamin K is also involved in calcium-binding processes for tissues throughout our bodies, for example in bones.

Although we don’t need very high amounts of vitamin K to be healthy (relative to other vitamins), a deficiency of it is in no way a pretty sight. Without enough vitamin K, blood clotting is severely impaired, and uncontrollable bleeding starts occurring throughout our whole bodies. Some research suggests that a deficiency of this vitamin can also cause bones to weaken, leading to osteoporosis, or to the calcification of soft tissues.

What is vitamin K?

Chemically speaking, vitamin K1 is known as phytomenadione or phylloquinone, while K2 is known as menaquinone. They’re quite similar from a structural point of view, being made up of two aromatic rings (rings of carbon atoms) with a long chain of carbon atoms tied to one side. K2 has two subtypes, one of which is longer than the other, but they perform the same role in our bodies. The K1 variety is the most often seen one in supplements.

Vitamin K3 is known as menadione. It used to be prescribed as a treatment for vitamin K deficiency, but it was later discovered that it interfered with the function of glutathione, an important antioxidant and key metabolic molecule. As such, it is no longer in use for this role in humans.

They are fat-soluble substances that tend to degrade rapidly when exposed to sunlight. It also breaks down very quickly and is excreted quickly in the body, so it’s exceedingly rare for it to reach toxic concentrations in humans. Vitamin K is concentrated in the liver, brain, heart, pancreas, and bones.


Vitamin K is abundant in green, leafy vegetables, where it is involved in photosynthesis. Image credits Local Food Initiative / Flickr.

As previously mentioned, people tend to get enough vitamin K from a regular diet.

Plants are a key synthesizer of vitamin K1, especially their tissues which are directly involved in photosynthesis; as such, mixing leafy or green vegetables into your diet is a good way to access high levels of the vitamin. Spinach, asparagus, broccoli, or legumes such as soybeans are all good sources. Strawberries also contain this vitamin, to a somewhat lesser extent.

Animals also rely on this vitamin for the same processes human bodies do, so animal products can also be a good source of it. Animals tend to convert the vitamin K1 they get from eating plants into one of the varieties K2 (MK-4). Eggs or organ meats such as liver, heart, or brain are high in K2.

All other forms of K2 vitamin are produced by bacteria who produce it during anaerobic respiration. As such, fermented foods can also be a good source of this vitamin.

Some of the most common signs of deficiency include:

  • Slow rates of blood clotting;
  • Long prothrombin times (prothrombin is a key clotting factor measured by doctors);
  • Spontaneous or random bleeding;
  • Hemorrhaging;
  • Osteoporosis (loss of bone mass) or osteopenia (loss of bone mineral density).

Do I need vitamin K supplements?

Cases of deficiency are rare. However, certain factors can promote such deficiencies. Most commonly, this involves medication that blocks vitamin K metabolism as a side-effect (some antibiotics do this) or medical conditions that prevent the proper absorption of nutrients from food. Some newborns can also experience vitamin K deficiencies as this compound doesn’t cross through the placenta from the mother, and breast milk only contains low levels of it. Due to this, infants are often given vitamin K supplements.

Although it is rare to see toxicity caused by vitamin K overdoses, it is still advised that supplements only be taken when prescribed by a doctor. Symptoms indicative of vitamin K toxicity are jaundice, hyperbilirubinemia, hemolytic anemia, and kernicterus in infants.

Vitamin K deficiencies are virtually always caused by malnourishment, poor diets, or by the action of certain drugs that impact the uptake of vitamin K or its role in the body. People who use antacids, blood thinners, antibiotics, aspirin, and drugs for cancer, seizures, or high cholesterol are sometimes prescribed supplements — again, by a trained physician.

How was it discovered?

The compound was first identified by Danish biochemist Henrik Dam in the early 1930s. Dam was studying another topic entirely: cholesterol metabolism in chickens. However, he observed that chicks fed with a diet low in fat and with no sterols had a high chance of developing subcutaneous and intramuscular hemorrhages (strong bleeding under the skin and within their muscles).

Further studies with different types of food led to the identification of the vitamin, which Dam referred to as the “Koagulations-Vitamin”.

Some other things to know

Some of the bacteria in our gut help provide us with our necessary intake of vitamin K — they synthesize it for us. Because of this, antibiotic use can lead to a decrease in vitamin K levels in our blood, as they decimate the populations of bacteria in our intestines. If you’re experiencing poor appetite following a lengthy or particularly strong course of antibiotics, it could be due to such a deficiency. Contact your physician and tell them about your symptoms if you think you may need vitamin K supplements in this situation; it’s not always the case that you do, but it doesn’t hurt to ask.

Another step you can take to ensure you’re getting enough vitamin K is to combine foods that contain a lot of it with fats — as this vitamin is fat-soluble. A salad of leafy greens with olive oil and avocado is a very good way of providing your body with vitamin K and helping it absorb as much of it as possible.

A novel blood test can detect the presence of cancer, and whether it’s metastasized

A candidate for a cheap and simple blood test for cancer has shown promise in early tests. The findings point the way towards such a procedure which, in the future, could become a widely available method of screening patients at risk of various types of cancer.

Image credits Fernando Zhiminaicela.

The test is non-specific — it can be used to detect the presence of a wide range of cancer types — and provides doctors with quick and reliable information on whether it has metastasized (spread) throughout the patient’s body.

Quick and easy

“Cancer cells have unique metabolomic fingerprints due to their different metabolic processes. We are only now starting to understand how metabolites produced by tumors can be used as biomarkers to accurately detect cancer” says Dr. James Larkin from the University of Oxford, first author of the study.

“We have already demonstrated that this technology can successfully identify if patients with multiple sclerosis are progressing to the later stages of disease, even before trained clinicians could tell. It is very exciting that the same technology is now showing promise in other diseases, like cancer.”

The study worked with samples harvested from 300 patients that were showing non-specific cancer symptoms, including fatigue and weight loss. All participants were recruited through the Oxfordshire Suspected CANcer (SCAN) Diagnostic Pathway. It involved the researchers assessing whether their test could tell apart patients with a range of solid tumors from those who were cancer-free.

All in all, the test correctly detected the disease in 19 out of every 20 patients with cancer. Apart from this, the test identified the metastatic phase of the disease with an overall accuracy of 94%.

This is the first method to be developed that can determine metastatic cancer from a simple blood test without previous knowledge of the type of cancer the patient is suffering from, the authors explain.

Unlike many other blood tests for cancer, which look for genetic material from tumorous cells, the current test relies on a technique called NMR metabolomics. This involves the use of magnetic fields and radio waves to measure metabolite levels in the patient’s blood.

Patients with localized cancer, those with metastatic cancer, and healthy individuals all have different metabolite profiles in their blood, the authors explain. Raw data from the test is then run through an algorithm that distinguishes between these states and offers a diagnosis.

The authors are hopeful that their test can help doctors detect and assess cancer much more quickly and cheaply than ever before. Although the test itself cannot accurately pinpoint the particular type of cancer in question, it still is a very powerful tool in determining who needs further tests, and who’s in the clear.

Early detection of cancer improves a patient’s chances of a successful outcome. Being rapid and cheap to administer, this test could help improve the overall rate of successful cancer treatments, especially in patients who only show non-specific symptoms (for whom a diagnosis generally takes longer).

“This work describes a new way of identifying cancer. The goal is to produce a test for cancer that any GP can request,” says Dr. Fay Probert, lead researcher of the study from the University of Oxford. “We envisage that metabolomic analysis of the blood will allow accurate, timely and cost-effective triaging of patients with suspected cancer, and could allow better prioritization of patients based on the additional early information this test provides on their disease.”

For now, the test is still in its early testing stages. Further research with larger cohorts of patients will be needed to give us a better and more reliable understanding of it, its capabilities, and its limitations.

The paper “Metabolomic Biomarkers in Blood Samples Identify Cancers in a Mixed Population of Patients with Nonspecific Symptoms,” has been published in the journal Clinical Cancer Research.

Martian outposts could be made with astronaut’s blood, sweat, and pee — quite literally

Building the future’s space colony will take grit, blood, sweat, and tears — quite literally so, according to new research.

Image credits Tatiana Belova.

Researchers at the University of Manchester plan to build astronauts’ future space lodgings out of the astronauts themselves. More to the point, they plan to use the albumin protein naturally present in their blood, alongside urea, a waste product naturally excreted through urine and sweat. These compounds can be mixed with martian soil — regolith — to create building materials that are comparable to, and even out-perform, concrete.

With the sweat of our brows

“Scientists have been trying to develop viable technologies to produce concrete-like materials on the surface of Mars, but we never stopped to think that the answer might be inside us all along,” says Dr. Aled Roberts from The University of Manchester, a co-author of the paper describing the process.

Size and mass are important limitations for any transportation effort, but none much more so than space transportation. Every cubic inch of volume and every gram of weight in a spaceship are carefully planned and accounted for. Nothing is wasted, and nothing that isn’t essential is included — simply because taking something to space takes a fortune in fuel, design, and logistical costs.

This means that it’s simply not economically viable to take a load of concrete or bricks up to Mars or the Moon, for example. Naturally, this is an issue, as we want to have people living on these (and many other) worlds in the future. In a bid to try and solve this issue, the team at Machester worked to develop a way to make local resources usable by the astronauts as building materials.

Maritan regolith has been investigated for this purpose in the past, especially in conjunction with any local water resources. Together, these can produce a mixture that, while not ideal, is appropriate for lightweight construction duties, enough to give missions their first staging base that’s viable for long-term habitation.

The team realized that one resource will never be missing from crewed missions: the crew. The material they developed, AstroCrete, uses the protein albumin isolated from human blood plasma as a binder for lunar or Martian dust. The finished product can withstand compressive strengths as high as 25 MPa (Megapascals). For comparison’s sake, ordinary concrete can withstand forces between 20-32 MPa depending on its exact composition. Further research showed that incorporating urea, a waste product naturally excreted by our bodies through urine, tears, and sweat, can fortify AstroCrete even more, allowing it to withstand close to 40 MPa.

Although these results are based on simulated lunar and martian dust, not the real thing, they are definitely encouraging. The authors estimate that a crew of six astronauts can produce around 500 kgs of high-strength AstroCrete over a two-year mission. It likely won’t be the main material used for construction, but it has potential as a mortar for sandbags or vitrified (heat-fused) regolith bricks. Used in this way, each crew member could supply enough albumin and urea to expand the habitat enough to support one new member. Lodging could thus be doubled on each successive mission at the same site.

“It is exciting that a major challenge of the space age may have found its solution based on inspirations from medieval technology,” said Dr Roberts, noting that animal blood has been used as a binder for building materials in the past.

“The concept is literally blood-curdling”.

The effect can be explained by the proteins in the blood, including albumin, denaturating — in essence, curdling. This results in a much longer molecule that effectively acts the same way as rebar in reinforced concrete, tying everything together.

The paper “Blood, sweat and tears: extraterrestrial regolith biocomposites with in vivo binders” has been published in the journal Materials Today Bio.

What is hemoglobin, and should you worry that it’s in your blood?

If you like breathing and being alive, you should be very fond of hemoglobin. This iron-bearing compound is biology’s designated oxygen carrier.

Image credits Murtada al Mousawy / Flickr.

With very few exceptions, blood is a distinctive, intense crimson. The color is given off by the high levels of hemoglobin (also spelled ‘haemoglobin’) in erythrocytes, red blood cells. Although that sounds like a fancy type of goblin, it’s actually a metalloprotein. And we should be very thankful that it’s there! Animals of our size would arguably not be possible without hemoglobin.

Important delivery

Your red blood cells are roughly 96% hemoglobin by dry weight, and around 35% when hydrated. This extremely high content should be our first indication of how critical the protein is for our organisms. So what exactly does it do? Well, in essence, it works as the body’s fuel supplier. Hemoglobin-laden cells make sure that there’s enough oxygen reaching tissues in your body for them to be able to generate energy (respiration).

Hemoglobin is the body’s designated oxygen carrier. Each molecule of it — at least, of the version the human body uses — can securely bind to four oxygen molecules and quickly let them go when needed. While blood can naturally carry some oxygen dissolved in its plasma, the hemoglobin in our red blood cells increases its ability to carry oxygen seventy-fold. Which is very good for us.

Although its main job is to carry oxygen to and fro, that’s not the only gas it can carry. Hemoglobin is also involved in scrubbing the ‘exhaust’ from cells, carrying around 25% of the CO2 produced by our cells, and shuttles nitric oxide (NO) around the body.

What exactly is it?

Like all other proteins, hemoglobin is a 3D structure created from multiple amino acids that are bound together, then folded around themselves. The term hemoglobin makes a direct nod to the molecule’s shape from the root Latin word ‘globus’ (meaning ball). While different lineages can employ heme/globin proteins (that’s the name of the wider family of these proteins) with different structures, the one humans and mammals use is made up of four sub-assemblies called ‘globular proteins’. The particular way these link up together is known as a globin fold pattern and is widely seen in the heme/globin family.

A hemoglobin molecule. Image via Pixabay.

The thing that makes hemoglobin so important is an iron ion (atom) sitting in the middle of these four sub-sections. This is the specific area where O2 molecules reversibly bind to the protein, to be carried away. This iron atom is, in turn, welded to the protein through four covalent bonds with nitrogen atoms. Depending on the exact valence of this iron atom, either ferric or ferrous, the protein will be able to bind oxygen compounds. “Ferric” iron, or iron(II) can bind it, while ‘ferrous’ iron, iron(III), cannot. When not in use, this iron atom binds to a water molecule as a placeholder.

Carbon dioxide, on the other hand, binds to other areas of the heme proteins that make up the hemoglobin molecule.

What happens when it doesn’t work?

Hemoglobin’s reactivity and ability to bind to a long list of compounds is usually its key strength, but mostly because it can also easily unbind these molecules. One gas that throws a wrench in that approach is carbon monoxide: a colorless, odorless gas that’s very deadly.

The issue with this carbon monoxide (CO) is that once it binds to hemoglobin, it forms carboxyhemoglobin. This compound makes the bond between the cell and oxygen much more stable and, as such, harder to break down later on. For starters, this means that any red blood cell that has encountered a carbon monoxide molecule has its ability to transport oxygen dramatically (if not completely) reduced. Secondly, the reaction between these two produces a release of mitochondrial free radicals. These cause oxidative stress, which could be the main driver of aging, and also attract leucocytes (white blood cells) to the area.

A few of the effects of carbon monoxide poisoning, on a biological level, include damage to endothelial cells (the ones that membranes and blood vessels are made of), most notably damage to the vasculature of the brain, and lipid peroxidation (chemical cell damage) of brain membranes. Because carboxyhemoglobin is a very bright red, the skin of CO poisoning victims can take a pink or purple hue. It only takes ambient concentrations of around 0.1% to cause unconsciousness and possibly death.

Carbon monoxide is the product of an incomplete burn. It’s most commonly found in smoke from low-burning or smoldering fires. Any fire that doesn’t have access to as much oxygen as it ideally wants will produce some amount of CO. This carbon monoxide is also produced in cigarettes and is one of the main causes of feeling out of breath after a smoke. Up to 20% of all oxygen-binding sites can be blocked by CO in heavy smokers.

Image credits ZEISS Microscopy / Flickr.

A bit ironically, the process through which hemoglobin is recycled in our spleen is the only natural source of carbon monoxide in the human body, and it accounts for the baseline levels of this gas found in our bloodstream. Each healthy red blood cell lives to around 120 days before being recycled.

Cyanide (CN-), sulfur monoxide (SO), sulfide (S2-), and hydrogen sulfide (H2S) groups also like binding to hemoglobin and not letting go, making them very toxic to us. Avoid breathing them in at all costs.

A too-low number of red blood cells — and thus, insufficient hemoglobin to carry gases around — is known as ‘anemia’. Anemia is the most common blood condition in the US, affecting around 6% of the population. In very broad terms, it is caused by either loss of blood, the inability to produce enough red blood cells, or conditions that lead to a rapid loss of such cells, although some cases are caused by genetics.

Women, older individuals, and those with long-lasting conditions are more likely to have anemia. Old age and chronic medical conditions can cause anemia by damaging the body’s ability to produce and recycle hemoglobin; women are more likely to develop iron-deficiency anemia due to the blood loss related to their menstrual cycle.

Symptoms of anemia include dizziness, or feeling like you’re about to pass out; headaches; unusual heartbeat patterns, shortness of breath, cold hands and feet, tiredness and physical weakness; pain in the chest, belly, bones, or joints, or swelling, can also be a symptom.

Any hemalternatives?

Oxygenated hemoglobin gives the blood in our arteries its scarlet color; unoxygenated blood flowing back to the heart and lungs is a darker color, although the veins that carry it often appear a bit more purple or blueish. A related compound known as myoglobin is why our muscles, or the muscles in red meat are shiny red but also a bit grey. Myoglobin works pretty much the same as hemoglobin with the difference that it’s not meant to carry oxygen around, but rather keep it stored for use. Structurally, myoglobin only has one binding site (it can hold less oxygen than hemoglobin) but the bond is much more stable.

But if you want to go full blue blood, you can go for hemocyanin. This is the second-most common molecule used to transport oxygen in blood after hemoglobin and is seen in many mollusks or anthropods. It substitutes iron heme groups for copper-bearing ones, and turns a very rich blue when oxygenated.

If you want to go for pink or violet, instead, try hemerythrin. It’s not a very commonly seen compound, with a handful of species, mainly marine vertebrates and a few worms (annelids), using it. It does stand out for turning clear when not oxygenated.

What annelids do like to use, however, are hemerythrin and erythrocruorin. They’re pretty similar in structure but with significantly different heme groups. Hemerythrin appears red when oxygenated and green when not. Erythrocruorin is common in earthworms and has the distinction of being a huge molecule, containing up to hundreds of heme-protein subsections and iron-ion binding sites.

Finally, a more exotic use of heme proteins is found in leguminous plants such as beans. They employ leghemoglobin to draw oxygen away from the nitrogen-fixing bacteria around their roots; oxygen here would impair the process of reducing nitrogen gas to nitrogen, which is a key nutrient for all plant-life and which imposes a ceiling on their ability to grow.

What is a stroke?

The human body is a wonderful and complicated device. This lets us do all kinds of awesome things, like seeing, thinking about, or tasting ice cream. But its complexity also leaves it vulnerable to damage. One of the ways that damage can manifest itself is as a stroke, a leading cause of mortality and disability across the world.

Image credits Gordon Johnson.

Although its effects are significant, a stroke is actually a very small event. So let’s take a look at exactly what they are, why they happen, and why they’re so bad for us.

Bad blockage

In essence, a stroke takes place when blood can’t properly reach part of the brain. One example would be blood vessels becoming clogged — typically due to a blood clot, but not necessarily. This cuts off the blood supply to a part of the brain, meaning neurons there don’t receive nutrients or, much worse, oxygen. Affected areas of the brain will thus quickly stop functioning, leading to a loss of control over the body parts or processes the area governs. Unless addressed quickly, strokes can lead to permanent damage in the affected areas, including tissue death.

Both internal and external factors can help cause a stroke. Sustained high acceleration rates (typically measured in “g”-s, the “acceleration of gravity”) can lead to a stroke, as can high blood pressure. They are also known as cerebrovascular accidents (‘CVA’) or less commonly as ‘brain attacks’.

In very broad lines, there are two types of strokes: ischemic, where blood flow is cut to a part of the brain by a clot, for example, and hemorrhagic, where blood doesn’t reach the areas it’s supposed to due to bleeding within the brain. Either way, it’s not good news.

What to look out for

Please keep in mind that strokes are not a harmless event. They are a medical emergency in the full sense of the phrase, and a fast reaction can help save the patient’s life. After symptoms set in, there’s a window of around 3 to 4-and-a-half hours for doctors to resolve the issue. Even so, brain tissue degrades very rapidly when deprived of oxygen, and a quick response is meant to prevent extensive damage but can’t avoid all damage. Typically, strokes lead to long-lasting brain damage that can seriously impair a person’s ability to function. The effects of such an event can range from (relatively) mild, such as general numbness in an area, to quite serious, such as losing the ability to speak or walk.

Image credits New York Department of Health.

But, as I mentioned, a FAST response can help you spot the early warning signs of a stroke and help protect your loved ones. The National Stroke Association (NSA) defines FAST as:

  • Face: watch for irregularities in the movements of facial muscles. A droopy face or sagging smile can be an important clue that something is not quite right in the brain.
  • Arms: ask the person in question to raise both arms. Strokes affect brain activity, which can cascade into effects on muscle groups. If one or both of the individual’s arms move or drift downwards against their wishes, a stroke might be the cause.
  • Speech: impaired muscle control can also reveal itself in slurry, messy speech. Ask the person in question to repeat a simple phrase and determine if they are able to do so.
  • Time: as we’ve said before, the secret of success here is moving FAST. If a person has any, several, or all of these symptoms, call emergency services (i.e. 911 in the U.S.) immediately. It is quite literally a matter of life or death.

Treatment generally consists of anti-clotting medication (thrombolytics), but will obviously differ based on the cause of the stroke. Giving anti-clotting medication to someone with a hemorrhagic CVA is a surefire way to kill them. For such strokes, blood transfusions are used to stabilize the patient and, if needed, doctors will intervene to remove some of the fluid build-up and thus lower pressure on the rest of the brain. In severe cases, doctors can also attempt a mechanical thrombectomy — a direct intervention to remove the blood clot from the vessel it lodged in. This procedure isn’t available in all hospitals and care units as it requires specialized equipment; it’s usually employed up to 24 hours after symptoms onset at most.

The 3 to 4 and a half-hour time frame is used as a kind of gold standard for saving a CVA patient’s life. But the harsh truth is that once a stroke happens, some type of permanent damage to the brain (and thus, permanent symptoms) is usually unavoidable. However, it’s not a guarantee, and doing nothing will almost always be fatal. If you notice any of these signs in others or yourself, drop everything and call emergency services for help.

Exactly what happens after the stroke, how quick the recovery is, and what long-term effects it has are highly dependent upon where in the brain this stroke happened. The symptoms are caused by a lack of oxygen for neurons to feed and not the actual clot or hemorrhage that leads to it, and thus typically arise suddenly and affect one side of the body. Typical signs one is happening to you include numbness, weakness, tingling sensations, and loss of or changes in vision. Other common symptoms include difficulty speaking or understanding speech, vertigo, issues with maintaining balance or consciousness.

Strokes are sometimes accompanied by headaches, nausea, vomiting, especially for hemorrhagic strokes.

What causes them?

As a rule of thumb, keeping your circulatory system healthy should help ward off strokes — in other words, an active lifestyle and cardio help here. Keep tabs on your weight, follow a healthy diet as far as you can, exercise regularly, don’t smoke, and monitor your blood pressure to be as safe as possible. People who have high blood pressure or cholesterol levels, those suffering from diabetes, and smokers are particularly at risk of developing a stroke. Individuals who have underlying heart rhythm disturbances are also at risk, especially those with atrial fibrillation.

But no matter why it happens, you now know how to spot the signs of a stroke and how to act fast to keep everyone safe.

People with blood type O may face lower risk of coronavirus infection or have milder symptoms

Two retrospective studies in Blood Advances add evidence for an association between blood type and COVID-19 risk, indicating that people with blood type O could be less susceptible to infection and experience milder disease. But this does not necessarily confirm causation. Further investigations on the mechanism of the different susceptibility to COVID-19 between blood group A and O individuals are needed and regardless of your blood type, you need to follow public health recommendations.

The first study from Denmark compared data from around 473,000 COVID-19–positive individuals with a control group of 2.2 million people in the general population, finding fewer infected people with blood type O and more people with A, B, and AB types. No associations were found between non-O blood groups and comorbidities that might explain infection rate differences.

The authors hypothesize that the presence of virus-neutralizing anti-A and anti-B antibodies on mucosal surfaces of some type O individuals may explain the relative protection for this blood type.

The second study from Vancouver, Canada on 95 critically ill COVID-19 patients in a hospital found that—after adjusting for sex, age, and comorbidities—patients with blood types A or AB were more likely to require mechanical ventilation than patients with types O or B (84% vs 61%, P = 0.02), indicating higher rates of lung damage.

Patients with blood types A and AB also had higher rates of dialysis for kidney failure, suggesting increased organ dysfunction or failure due to COVID-19 (32% vs 95%, P = 0.004). Patients with blood types A and AB did not have longer hospital stays than those with types O or B, but they did experience longer intensive care unit stays, which may signal greater COVID-19 severity.

A study in June looking at patients in Italy and Spain found that blood type O had a 50 percent reduced risk of severe coronavirus infection (i.e. needing intubation or supplemental oxygen) compared to patients with other blood types. A study published in July looking at patients in five major hospitals in the state of Massachusetts found that people with blood type O were less likely to test positive for COVID-19 than those with other blood types. Another study in April (pre-print and awaiting peer-review) found that among 1,559 coronavirus patients in New York City, a lower proportion than would be expected had Type O blood. Earlier in March, a study of over 2,100 coronavirus patients in Wuhan and Shenzhen (also not peer-reviewed) found that people with Type O blood had a lower risk of infection.

Past research analyzing a hospital outbreak in Hong Kong suggested that people with Type O blood were less susceptible to (the original, not the pandemic) SARS, which shares ~80 percent of its genetic code with the new coronavirus, SARS-CoV-2. A 2005 Clinical Microbiology Review also found that most individuals infected with SARS had non-O blood types. 

It’s important to emphasize that the type of reduction in risk achieved with appropriate physical distancing, wearing a mask, and hand hygiene are significantly better than depending on your blood group for protection, so people with blood type O should not be complacent about public health advice.

Our white blood cells could be ‘reprogrammed’ to lower inflammation on demand

White blood cells receive ‘orders’ from our bodies to cause or subdue inflammation, a new paper reports, as a natural part of the immune response.

A mouse macrophage engulfing two particles at the same time (unrelated to the study).
Image via Wikimedia.

They argue that this effect can be used to prevent Acute Respiratory Distress Syndrome (ARDS), which affects some COVID-19 patients. ARDS is a type of respiratory failure caused by a buildup of fluid in the lungs.

Pimp my immune response

“We found that macrophage programming is driven by more than the immune system — it is also driven by the environment in which the macrophages reside,” said lead author Asrar Malik, the Schweppe Family Distinguished Professor and head of pharmacology and regenerative medicine at the University of Illinois at Chicago (UIC).

Macrophages are those immune cells that find a threat, wrap around it, and start digesting it. However, the new findings showcase that they also play a part in controlling inflammation. While a natural part of our bodies’ efforts against infection, and quite effective against them, excessive or prolonged inflammation can also damage our own tissues and organs.

In essence, these cells both cause and keep inflammation in check. The team analyzed how they determine which of the two approaches they use at any given time using mice. Their goal was to help patients suffering from excessive inflammation and conditions such as ARDS while infected with the coronavirus.

“We demonstrated that lung endothelial cells — which are the cells that line blood vessels — are essential in programming macrophages with potent tissue-reparative and anti-inflammatory functions,” said Dr. Jalees Rehman, UIC professor of medicine and pharmacology and regenerative medicine and co-lead author of the paper.

The researchers found that one protein, R-spondin-3, was present in high levels in the blood during injury and inflammation. The next step was to genetically-engineer lab mice to lack this protein in these cells — which led to the macrophages no longer dampening inflammation.

“Instead, the lungs became more injured,” said Bisheng Zhou, UIC research assistant professor of pharmacology and regenerative medicine and first author of the study. “We tried this in multiple models of inflammatory lung injury and found consistent results, suggesting that blood vessels play an important instructive role in guiding the programming of macrophages.”

The findings point the way towards a promising avenue of treatment for ARDS, but could also help us understand why some patients have better outcomes after a COVID-19 infection than others. Our own immune response has been shown to cause an important part of the damage associated with this disease. Poor vascular health or other underlying conditions that affect our blood vessels could impact our recovery, the team believes.

While the study only worked with lung tissue, it’s likely that those in other organs would show the same mechanisms, according to the authors.

The paper “The angiocrine Rspondin3 instructs interstitial macrophage transition via metabolic–epigenetic reprogramming and resolves inflammatory injury” has been published in the journal Nature Immunology.

Plasma from recovered patients seems to destroy coronavirus infections

During this pandemic, we’ve come to see that our health is directly impacted by those around us. A new study reveals that it’s the same story in regards to healing those already infected.

Blood plasma.
Image via Wikimedia.

Preliminary data from an ongoing study shows that treating infected individuals with convalescent plasma (plasma obtained from cured patients) is both safe and effective at combating the virus. The study was conducted at Houston Methodist, US, and involves over 300 patients.

Blood bond

“Our studies to date show the treatment is safe and in a promising number of patients, effective,” said corresponding author Dr. James Musser, chair of the Department of Pathology and Genomic Medicine at Houston Methodist.

“While convalescent plasma therapy remains experimental and we have more research to do and data to collect, we now have more evidence than ever that this century-old plasma therapy has merit, is safe and can help reduce the death rate from this virus.”

Houston Methodist was the first academic medical center in the US to trial convalescent plasma transfusions in March. The current study tracked the state of severely ill COVID-19 patients admitted to the eight Houston Methodist hospitals between 28 March and 6 July.

Patients were tracked for 28 days after receiving a transfusion and their evolution compared to that of a group of control patients (who received treatment but no plasma transfusions).

Those who received plasma from healed patients had the highest concentrations of antibodies that could attack SARS-CoV-2, the virus responsible for the pandemic, out of all the patients in this study. They were also more likely to survive the infection than similar patients who had received no transfusions. The transfusions were most effective when administered within 72 hours of hospitalization.

This isn’t the only study to look into the benefits of plasma transfusions against COVID-19. It is an old medical procedure that has been used time and time again against infectious diseases (blood plasma carries natural antibodies); although it doesn’t work for every one, it’s still useful.

So far, plasma transfusions seem to be effective against the pandemic, but we’re yet to prove it beyond a doubt — these are just preliminary findings, after all.

But if we do find out that they’re effective beyond a doubt, those who have recovered from the disease will be in high demand at blood donation centers.

The study “Treatment of COVID-19 Patients with Convalescent Plasma Reveals a Signal of Significantly Decreased Mortality” has been published in the American Journal of Pathology.

Scientists make synthetic red blood cells that mimic natural properties, and some extra features

Artificial red blood cells developed so far have always had major shortcomings since they could only partially mimic the critical characteristics of natural cells required for healthy function — until now.

In a new study, researchers at the University of New Mexico have created synthetic red blood cells (RBCs) that mimic all the important properties of natural ones, such as flexibility, oxygen transport, and long circulation times. In fact, the researchers went the extra mile.

Not only are the synthetic red blood cells on par with natural ones, they also have extra features that enable new applications in cancer therapy or toxin biosensing.

Red blood cells give blood its characteristic color and carry oxygen from the lungs to the tissues. They also transport carbon dioxide as a waste product away from the tissues and back to the lungs. About 45% of our blood is red blood cells, the rest is comprised of plasma, platelets, and white blood cells.

These dumbbell-shaped cells are very complex, comprising millions of molecules of hemoglobin, the iron-rich protein that binds oxygen. But it’s not the hemoglobins that were the main challenge in devising synthetic red blood cells.

Flexibility is key for red blood cells, which have to squeeze through tiny capillaries and then bounce back to their original shape.

Biocompatibility is also important, which is enabled by other proteins on the surface on the red blood cells so they don’t get destroyed by immune cells mistaking them for a foreign invader.

In their new study, the researchers at the University of New Mexico first coated donated human red blood cells with a thin layer of silica. On top of these modified red blood cells, the research team also layered positively and negatively charged polymers, before etching away the silica to produce flexible replicas. Finally, the researchers applied another coating to the surface of the artificial cells with a natural membrane. The end result performed as expected — and then some.

Phase contrast images of native RBCs, silica-RBC replicas, polymer-RBC replicas, and
RRBCs (left to right) and different magnifications (top to bottom). Credit: ACS Nano.

The synthetic red blood cells had the same size, shape, charge, and surface proteins as natural cells. They’re also flexible enough to squeeze through model capillaries without losing their shape.

During experiments on mice that were injected with the artificial cells, the synthetic red blood cells lasted for more than 48 hours without any obvious signs of toxicity. Natural red blood cells have a lifespan of around 120 days.

In order to demonstrate their cargo-carrying capabilities, the researchers showed they could load the artificial cells with hemoglobin, an anticancer drug, a toxin sensor, or magnetic nanoparticles. This makes them ideal for various medical applications, such as cancer therapy and toxin biosensing, the researchers concluded in their study published in the journal ACS Nano.

“Taken together, RRBCs represent a class of long-circulating RBC-inspired artificial hybrid materials with a broad range of potential applications,” the authors wrote.

Simple blood test can detect 50+ types of cancer before any symptoms even start

A key ally in our fight against cancer is early detection. The sooner you discover a potential tumor, the sooner you can take action, and the likelier it is that a full recovery is made.

Unfortunately, cancer can be insidious. It can brew up for years without causing clear symptoms, and diagnostic tests can be painful, expensive, and intrusive. That might change soon.

Image credits: Teresa J. Cleveland.

In a new study, researchers from the Dana-Farber Cancer Institute and Harvard Medical School presented the results of a new blood test for cancer. The diagnosis was tested against 4,000 samples from patients, some of which had cancer, and some of which didn’t.

Remarkably, the test proved accurate at detecting over 50 types of cancer, including bladder, esophagus, lung, and breast cancer. The test had a 98.3% to 99.8% accuracy for positive results and a 0.7% false-positive rate — not perfect, but remarkably accurate. In the samples where cancer was detected, the test was also able to pinpoint its type of cancer in 93% of instances (in the others, it correctly identified the presence of cancer, but misrepresented the type).

The test looks for chemical markers in the bloodstream (methylation patterns in DNA). These bits of cell-free, free-floating DNA pieces are leaked from tumors into the bloodstream and can be a tell-tale indicator. The team used a machine learning algorithm (a type of artificial intelligence) to train the test to look for patterns that indicate the presence of cancer and classify it accordingly.

It’s still in its early days, and it’s unclear how the test will perform in a broader sample size — particularly one where no information is known about the patients. Researchers plan to further improve the test’s detection rate — particularly in the early stages, where detection rates were substantially lower. Detecting cancers at their earliest stages, when they are less aggressive and far more treatable, is a key objective for the test.

The fact that the test is painless and scalable is promising, but it remains to be seen whether its efficacy will be confirmed in larger trials. A blood-based multi-cancer detection test should demonstrate certain fundamental performance to be useful in a general screening population.

Now, researchers are already embarked on several clinical trials to test the validity of the new diagnosis. It will be a while before such a test will become readily available, but so far at least, things are looking promising.

The study has been published in the journal Annals of Oncology.

We’re one step closer to fully-functioning artificial blood vessels

A new study describes how researchers 3D-printed fully-functional blood vessels, and how they can be implanted into living hosts.

Blood vessel with a reduced cross-sectional area.
Image via Wikimedia.

The blood vessels were printed from a bioink containing human smooth muscle cells (harvested from an aorta) and endothelial (lining) cells from an umbilical vein. They have the same dual-layer architecture of natural blood vessels and outperform existing engineered tissues, the team explains.

The findings bring us closer to 3D-printed artificial blood vessels that can be used as grafts in clinical use.

Bloody constructs

“The artificial blood vessel is an essential tool to save patients suffering from cardiovascular disease,” said lead author Ge Gao. “There are products in clinical use made from polymers, but they don’t have living cells and vascular functions.”

“We wanted to tissue-engineer a living, functional blood vessel graft.”

The researchers explain that the small-diameter blood vessels we’ve been able to construct so far were fragile things, and prone to blockages. The crux of the issue was that these vessels relied on a very simplified version of the extracellular matrix — the material between cells which keeps our bodies together — most usually in the form of collagen-based bioinks. A natural blood vessel, however, isn’t just collagen; it also boasts a wide range of biomolecules that support the growth and activity of vascular cells.

To address these issues, the team developed a bioink starting from native tissues that preserves this extracellular complexity. Its use allows for faster development of vascular tissues and results in blood vessels with better strength and anti-thrombosis (i.e. anti-clogging) function. After fabrication, the team matured the vessels in the lab to reach specific wall thickness, cellular alignment, burst pressure, tensile strength, and contraction ability — basically making the printed vessels mimic the functions of natural blood vessels.

Afterward, the printed blood vessels were grafted as abdominal aortas into six rats. Over the following six weeks, the rats’ fibroblasts (a type of cell in the extracellular matrix) formed a layer of connective tissue on the surface of the implants — which integrated the vessels into pre-existing living tissues.

The team says they plan to continue developing the process in order to make the blood vessels stronger, with the goal of making them similar to human coronary arteries in physical properties. They also want to perform a long-term evaluation of vascular grafts to see how they evolve as they integrate into the implanted environment.

The paper “Tissue-engineering of vascular grafts containing endothelium and smooth-muscle using triple-coaxial cell printing” has been published in the journal Applied Physics Reviews.

Scientists transform Type A blood to universal donor blood using enzyme treatment

Blood is a scarce commodity. Talk to almost every medical facility on the planet and you’ll hear the same thing: there’s a blood shortage, more donors are needed. To make matters even more complicated, you can’t just give any type of blood to anyone.

People generally have one of four blood types: A, B, AB, or O. The differences between these blood types are defined by some rather unusual sugar molecules that bond with red blood cells — antigens and various proteins float in the plasma and on red blood cells, defining a person’s blood type. This blood type is extremely important for transfusions. Have someone with type A molecules give blood to someone with type B and you may very well kill them: the immune system will attack the foreign blood.

So in the case of transfusions, researchers need to be careful to give the right type of blood.

But there’s a catch: type O doesn’t have these antigens, meaning you can give type O blood to anyone. This is the so-called universal donor blood type, and it’s extremely important for transfusions, especially in emergency cases where doctors might not have the time to figure out what’s the patient’s blood group.

Transforming other types of blood into O type isn’t a new idea — it’s been tried before. However, the techniques were either too inefficient or too expensive to be applied at a large scale. Stephen Withers, a chemical biologist at the University of British Columbia (UBC) in Vancouver, Canada, may have found a better solution.

The problem with transforming one blood type to another is generally approached through enzymes which strip the blood of its type-giving molecules. Withers looked for enzymes in the gut bacteria — some of which are well known to consume sugar molecules similar to the ones that give the blood type. So he took a stool sample and harvested DNA from it, hoping that among the harvested DNA he’d also find the genes encode the bacterial enzymes that digest mucins. He further isolated this DNA and then encoded it into the biological jack of all trades — the Escherichia Coli bacterium (a common ‘workhorse’ for genetic studies, often used to store DNA sequences from other organisms) to see whether the resulting bacterium would be capable of stripping off the required molecules.

Although the results didn’t look promising at first, the process did work out in the end. Two of the enzymes produced thusly worked excellently, turning type A blood into type O blood. The enzymes originally came from a gut bacterium called Flavonifractor plautii, a common member of the human gut microbiome, rarely isolated from clinical human specimens.

[Also Read: New kind of artificial blood made in the land of Dracula]

If the results are confirmed, it would be an important breakthrough. Type O and type A each make up about 30% of the total donated blood, meaning that the supply of type O blood could be doubled, addressing a ubiquitous shortage, making life significantly easier for doctors, and ultimately, saving a lot of lives. To make matters even better, only small amounts of enzymes are required for this, and the whole process is relatively cheap.

“I am optimistic that we have a very interesting candidate to adjust donated blood to a common type,” concludes Withers.

However, more research is required to be sure that all the type A-defining molecules have been removing, as well as to ensure that nothing else was inadvertently changed about the blood. Any unforeseen error can put patients’ lives at risk.

Of course, this wouldn’t eliminate the blood crisis the world is facing, nor will it reduce the need for blood donors. It only means that that existing donated blood is more versatile — which is, in itself, an amazing achievement.

Credit: M.C. Thier/DKFZ.

Scientists turn blood cells into neural stem cells, opening door for new regenerative therapies

Researchers in Germany have reprogrammed human blood cells, as well as other types of cells, into a previously unknown type of neural stem cell. These cells are similar to those that develop during the early embryonic stage of the central nervous system. In the future, such cells — which can be multiplied indefinitely — might become a fundamental building block for novel regenerative therapies.

Credit: M.C. Thier/DKFZ.

Researchers in Germany found a novel pathway to generate stem cells from blood cells for the first time. Credit: M.C. Thier/DKFZ.

Stem cells are cells with the potential to develop into many different types of cells, while also serving as a major and robust repair system for the body. Using a very loose analogy, one might say stem cells are a bit like Transformers –in that they can transform into all sort of different things, have both positive or negative effects, and are pretty darn cool.

The problem with stem cells used to be that scientists could only harvest them from embryos, which obviously has many downsides, both ethical and practical. But that all changed in 2006 when Japanese researcher Shinya Yamanaka found a way to reverse the course of development of adult cells, thereby turning them back into stem cells — so-called induced pluripotent stem cells (iPS). By using four genetic factors, Yamanaka demonstrated how virtually any type of cell, be them skin cells or pancreas cells, could be coaxed into transforming into embryonic-like stem cells, which can then be transformed into any type of cell. For this monumental discovery, Yamanaka was awarded the 2012 Nobel Prize for Medicine.

Andreas Trumpp, a researcher at the German Cancer Research Center (DKFZ) and Director of HI-STEM in Heidelberg, used a similar technique to Yamanaka. Trumpp and colleagues used four genetic factors as well, but these were different, which led to the reprogramming of cells to an early stage of development of the nervous system.

Previously, scientists had been able to a degree to reprogram mature cells into nerve cells or neural precursor cells. However, the resulting nerve cells could not be multiplied and only existed as a heterogeneous mixture of different cell types, making them inappropriate for therapeutic purposes. 

In contrast, the reprogrammed cells using the technique developed at Heidelberg produces homogeneous cells, which resemble a stage of neural stem cells occurring during the embryonic development of the nervous system, and can be used medically. The researchers call them “induced Neural Plate Border Stem Cells” (iNBSCs), which can develop in two important directions: cells of the nervous system or cells of the neural crest (i.e. peripheral sensitive nerve cells, skull cartilage).

Trumpp and colleagues successfully reprogrammed tissue cells of the skin or pancreas, but also blood cells. This means that in the future, a patient who suffers from a disease of the nervous system could be treated simply by drawing blood, and then having nerve cells made from those blood cells plugged back into the body.

“This was a major breakthrough for stem cell research,” Trumpp said in a statement. “This applies in particular to for research in Germany, where the generation of human embryonic stem cells is not permitted. Stem cells have enormous potential both for basic research and for the development of regenerative therapies that aim to restore diseased tissue in patients. However, reprogramming is also associated with problems: For example, pluripotent cells can form germ line tumors, so-called teratomas.”

The authors claim that iNBSCs could be incorporated into personalized medicine. Since the donor cells come from the patient, the immune system will recognize the differentiated iNBSCs as its own, thereby avoiding any rejection issues. Furthermore, iNBSCs can be modified using CRISPR/Cas9 — the gene editing tool that scissors bits of DNA and then glues the strands back together.

“They are therefore of interesting both for basic research and the search for new active substances and for the development of regenerative therapies, for example in patients with diseases of the nervous system. However until we can use them in patients, a lot of research work will still be necessary,” Trumpp concluded.

The findings were reported in the journal Cell Stem Cell.

Blood Moon.

What causes Blood Moons? The same thing that makes skies blue

When the Moon turns bloody, it’s Earth at work.

Blood Moon.

Image via Pixabay.

Humanity has always kept an eye on the heavens. Societies lived and died by natural cycles, and these orbs in the sky seemed to dictate the rhythm of life — so they imposed themselves as central players in our mythoi. The imprint they left on our psyche is so deep that to this day, we still name heavenly bodies after gods.

But two players always commanded center stage: the Sun and the Moon. One interaction between the two is so particularly striking that virtually all cultures regarded it as a sign of great upheaval: the blood moon. Its perceived meaning ranges from the benign to the malevolent. Blood moons drip with cultural significance, and we’ll explore some of it because I’m a huge anthropology nerd.

But they’re also very interesting events from a scientific point of view, and we’ll start with that. What, exactly, turns the heavenly wheel of cheese into a bloody pool? Well, let me whet your appetite by saying that it’s the same process which produces clear blue skies. Ready? Ok, let’s go.

The background

Geometry of a lunar eclipse.

The geometry of a lunar eclipse.
Image credits Sagredo / Wikimedia.

For context’s sake, let’s start by establishing that the moon doesn’t shine by itself. It’s visible because it acts as a huge mirror, beaming reflected sunlight down at night. During a total lunar eclipse, the Earth passes between the Sun and the Moon, blocking sunlight from hitting its surface. Blood moons happen during such lunar eclipses. A sliver of light is refracted (bent) in the atmosphere, passing around the Earth and illuminating the Moon. This is what gives it that reddish colo

It all comes down to how light interacts with our planet’s atmosphere, most notably a process called Rayleigh scattering: electromagnetic radiation interacts with physical particles much smaller in size than the radiation’s wavelength.

For context’s sake part deux, what our eyes perceive as white light is actually a mix of all the colors we can see. Each color is generated by a particular wavelength interval (more here).

Boiled down, different bits of light get more or less scattered depending on their wavelength. It’s quite potent: roughly a quarter of the light incoming from the Sun gets scattered — depending on fluctuating atmospheric properties such amount of particles floating around in it — and some two-thirds of this light reaches the surface as diffuse sky radiation.

The Blood Moon

As a rule of thumb, our atmosphere is better at scattering short wavelengths (violets and blues) than long wavelengths (oranges and reds). ‘Scattering’ basically means ‘spreading around’, and this makes the sky look blue for most of the day. This scattering is not dependent on direction (or, in fancy-science-speak, it’s an isotropic property) but its perceived effect is.

When the sun is high in the sky, light falls roughly vertically on our planet; as such, it passes through a relatively short span of the atmosphere. Let’s denote this rough length with ‘a‘.

The light of dawn and dusk arrives tangentially (horizontally) to the planet. It thus has to pass through a much longer span of the atmosphere than it does at noon. Blues become scattered just like in the previous case as light traverses this a distance through the atmosphere. But it then has to pass through yet more air. So greens (the next-shortest wavelengths) also become dispersed. That’s why the sky on dawn or sunsets appear red or yellow (the remaining wavelengths).

Blood Moon.

The same mechanism is at work during a blood moon. Light passing through the Earth’s atmosphere gets depleted in short wavelengths, making it look yellowy-red. This makes the Moon appear red as it reflects red light back to our eyes.

One cool effect of this dispersion is that blood moons sometimes exhibit a blue-turquoise band of color at the beginning and just before the end of the eclipse. This is produced by the light that passes through the ozone layer in the top-most atmosphere. Ozone scatters primarily red light, leaving blues mostly intact.

Cultural meanings

Many ancient civilizations looked upon the blood moon with concern: in their eyes, this was an omen that evil was stirring.

“The ancient Inca people interpreted the deep red colouring as a jaguar attacking and eating the moon,” Daniel Brown wrote for The Conversation. “They believed that the jaguar might then turn its attention to Earth, so the people would shout, shake their spears and make their dogs bark and howl, hoping to make enough noise to drive the jaguar away.”

Some Hindu traditions hold that the Moon turns red because of an epic clash between deities. The demon Swarbhanu tricks the Sun and Moon for a sip of the elixir of immortality. As punishment Vishnu (the primary god of Hinduism) cuts off the demon’s head — which lives on as Rahu.

Understandably upset by the whole experience, Rahu chases the sun and moon to devour them. An eclipse only happens if Rahu manages to catch one of the two. Blood Moons form when Rahu swallows the moon and it falls out of his severed neck. Several things, such as eating or worshiping, are prohibited, as Hindu traditions hold that evil entities are about during an eclipse.

Other cultures took a more compassionate view of the eclipsed moon. The Native American Hupa and Luiseño tribes from California, Brown explains, thought it was wounded or fell ill during such an event. In order to help its wives in healing the darkened moon, the Luiseño would sing and chant healing songs under an open sky.

My personal favorite, however, is the approach of the Batammaliba people, who live in the nations of Togo and Benin in Africa. Their traditions hold that the lunar eclipse is a conflict between sun and moon; we little people must encourage them to bury the hatchet! Such events are thus seen as an opportunity to lay old animosities and feuds to rest;

I’m definitely going to try that during the next blood moon.

Energy drinks.

Energy drinks have a profound effect on our blood vessels, new research shows

Just have a coffee instead. Or, ideally, a good night’s rest!

Energy drinks.

Image credits Simon Desmarais.

Energy drinks have been associated with a host of health problems, including conditions that relate to heart, stomach, and nerve function. New research comes to explain how such beverages interact with our cardiovascular systems. According to the findings, consuming just one energy drink leads to notably diminished blood vessel capacity — an effect that lasts at least 90 minutes.

“As energy drinks are becoming more and more popular, it is important to study the effects of these drinks on those who frequently drink them and better determine what, if any, is a safe consumption pattern,” authors noted.

The team was led by John Higgins, M.D., M.B.A., of McGovern Medical School at UTHealth, Houston. Together with his colleagues, Higgins studied the endothelial (blood vessel) function of 44 healthy, non-smoking students in their 20s. Afterward, the students were given a 24-ounce (710 milliliters) energy drink. Blood vessel function was then re-analyzed, 90 minutes after the participants finished their drink.

The students experienced notably diminished blood vessel function after consuming the beverage, the team reports.

Before consuming the drink (and one and a half hours afterward), the team tested the students’ artery flow-mediated dilation. This basically involves taking an ultrasound measurement of an artery to gauge the overall health of a patient’s blood vessels. The team reports that vessel dilation was, on average, 5.1% in diameter at the start of the test, but dropped to 2.8% in diameter after the drink was consumed. This measurement is consistent with an acute impairment of vascular function, they add.

Higgins and his team say that the change in vessel dilation may be produced by the blend of ingredients that go into making an energy drink. These components — usually caffeine, taurine, sugar, and other herbal components — may act on the endothelium (lining of the blood vessels) to make it constrict. The results are still preliminary and the team will need to perform further tests to see exactly which ingredients cause this effect.

The findings will be presented at the American Heart Association’s Scientific Sessions 2018 conference in Chicago.

If he should fall poster.

Blood for universal transfusions might be sourced from gut bacteria

When lacking in blood for transfusions, going with your gut might do the trick.

If he should fall poster.

A poster urging people to donate blood printed in the UK during WW2.
Image credits Imperial War Museum.

The storms that ravaged the U.S. East Coast this year also drained the Red Cross’ stocks of blood — so it issued an urgent call for donors. They were especially in need of O-type blood since it can be administered to any patient, increasing their chances of survival in emergency cases.

One workaround this issue is to turn other types of blood into O-type. While possible, it’s a very slow process. However, a research team plans to use enzymes secreted by bacteria in your gut to turn A and B type blood into O at much greater speeds than anything previously possible.


“We have been particularly interested in enzymes that allow us to remove the A or B antigens from red blood cells,” says Stephen Withers, Ph.D. and paper coauthor.

“If you can remove those antigens, which are just simple sugars, then you can convert A or B to O blood.”

The prospect of turning donated blood to a common type — O, the universal donor type — is understandably quite appealing to researchers and medical professionals. However, we’ve yet to find any process that works fast, safe, and cheaply enough to feasible.

In their new paper, which will be presented today at the 256th National Meeting & Exposition of the American Chemical Society (ACS), Withers and his team will present an assessment of several new enzyme candidates for the job. The conference will be broadcast live on youtube:

The paper drew on metagenomics — Withers describes it as taking “all of the organisms from an environment and extract[ing] the sum total DNA of those organisms all mixed up together” — to quickly asses the potential of enzyme candidates more quickly. It allowed Withers’ team to sample genes of millions of different organisms without having to grow individual cultures.

They then used a strain of E. coli bacteria to select genes that code enzymes appropriate for the task (enzymes that can remove sugar molecules from red blood cells).

“This is a way of getting that genetic information out of the environment and into the laboratory setting and then screening for the activity we are interested in,” Withers says.

While the researchers planned to start by sampling DNA from mosquitoes and leeches — both organisms that degrade blood — they ultimately found likely candidates in the human gut flora. A certain family of proteins called mucins line the intestinal wall and provide sugars for bacteria that assist in digestion. These sugars serve as both attachment points and feed for said bacteria.

Some of these sugars closely resemble the structure of antigens in A- and B-type blood. The team identified which enzymes bacteria use to absorb these sugars off mucin molecules, and report that they are 30 times as effective in removing red blood antigens compared to any previous candidate.

Withers is now collaborating with colleagues at the Centre for Blood Research at UBC to test these enzymes on a larger scale; depending on the results, they may be then selected for clinical testing. He also plans to use directed evolution, a method that simulates natural evolution, to create more efficient versions of the enzymes.

“I am optimistic that we have a very interesting candidate to adjust donated blood to a common type,” Withers says. “Of course, it will have to go through lots of clinical trails to make sure that it doesn’t have any adverse consequences, but it is looking very promising.”

The paper “Discovery of CAZYmes for cell surface glycan removal through metagenomics: Towards universal blood” will be presented today, Tuesday 21st August, at the 256th National Meeting & Exposition of the American Chemical Society (ACS).

James Harrison.

Australia’s ‘Man with the Golden Arm’ retires after saving 2.4 million babies — urges people to “break his record”

One Australian is taking a well-deserved retirement — after saving 2.4 million babies.

James Harrison.

James Harrison.
Image credits Australian Red Cross Blood Service / Facebook.

James Harrison, an 81-year-old Australian man whose blood contains a rare and priceless antibody has donated his last bag of plasma. Despite being a few months over the legal age limit for donors, Harrison has been allowed one final transfusion on Friday, both in recognition of his merits, and, likely, in a testament to just how valuable his blood is — Harrison’s transfusions helped save the lives of some 2.4 million babies, according to the Australian Red Cross Blood Service.


The Sydney Morning Herald reports that Harrison has donated regularly for more than six decades, between the age of 18 to 81. Over the years, he donated 1,173 times, 1,163 from his right arm, and 10 from his left one.

His drive to donate has its roots in Harrison’s own medical history. At the age of 14, he had one lung removed, and required multiple transfusions. After receiving 2 gallons (7.5 liters) of blood, roughly 13 transfusion units, Harrison became aware of just how important donating is — and decided he would pitch in.

“I was in the hospital for three months and I had 100 stitches,” he recalls. “I was always looking forward to donating, right from the operation, because I don’t know how many people it took to save my life. I never met them, didn’t know them.”

After he started donating blood at the age of 18, doctors discovered that his plasma had a rare component that could save infant lives. That component is an antibody known as Rho(D) immune globulin, which is essentially priceless for doctors. Here’s why.

When a woman with Rh-negative blood is pregnant with an Rh-positive fetus, both are at risk from ‘Rh incompatibility’ — the mother’s body can have an immune reaction to and attack the infant’s blood cells, putting it at risk. The disease causes multiple miscarriages, stillbirths, and brain damage or fatal anemia in newborns.

The antibodies persist between pregnancies and can jeopardize future pregnancies as well. The first treatment for Rh incompatibility was developed in the 1960s, and it’s based entirely on this Rho(D) immune globulin. Harrison just happened to be one person who naturally produced this antibody — and his body produced a lot of it.

“Very few people have the these antibodies in such strong concentrations,” Jemma Falkenmire, of the Australian Red Cross Blood Donor Service, told the Herald. “His body produces a lot of them, and when he donates his body produces more.”

Harrison switched to donating plasma as often as the Blood Service would allow him. His donations allowed millions of Australian women to undergo the treatment they needed to keep their pregnancies healthy.

Despite significant efforts to synthesize the antibody in a lab setting, donors remain our only source of Rho(D) remains. The antibodies are most often seen in some women with Rh-incompatible pregnancies — but the more wide-spread treatment against the condition becomes, the fewer mothers get a chance to develop Rho(D). Some Rh-negative men agree to be exposed to Rh-positive blood in a bid to become donors and fill the supply gap. Finally, a small number of people develop the antibodies after accidentally receiving a transfusion of the wrong kind of blood. Harrison, one of only 200 Rho(D) donors in Australia, is likely one of the latter cases.

His dedication to donating blood, and all the lives his plasma helped save, have earned him the moniker of “Man with the Golden Arm” and a place in the Guinness Book of Records. He’s now too old to be allowed to donate further — and says it’s time for other people to step up.

“Some people say, ‘Oh, you’re a hero,’ ” he told NPR. “But I’m in a safe room, donating blood. They give me a cup of coffee and something to nibble on. And then I just go on my way. No problem, no hardship.”

“I hope it’s a record that somebody breaks,” Harrison told the Blood Service, referring to the impressive number of donations under his belt.

Credit: Pixabay.

What is the most common blood type?

Credit: Pixabay.

Credit: Pixabay.


Without blood, the human body would simply stop working. This essential fluid of life dispenses crucial nutrients throughout the body, exchanges oxygen and carbon dioxide, and carries our immune system’s ‘militia’ to stave off infections. But not all blood is equal, and in the event of a transfusion, mixing incompatible blood types can lead to death.

Distribution of blood types

There are 4 main blood groups: A, B, AB and O, of which group O is the most common. In the United States, the average distribution of blood types is as follows:

  • O-positive: 38 percent
  • O-negative: 7 percent
  • A-positive: 34 percent
  • A-negative: 6 percent
  • B-positive: 9 percent
  • B-negative: 2 percent
  • AB-positive: 3 percent
  • AB-negative: 1 percent

blood type distribution

Different racial and ethnic groups typically see a different distribution. For instance, 45 percent of Caucasians are type O, but 51 percent of African-Americans and 57 percent of Hispanics are type O, according to the Red Cross. This Wikipedia page has the blood type distribution in every country.

Type O is the most demanded blood type in hospitals, both because it’s the most common and because O-negative blood is a universal donor type, meaning it is compatible with any blood type. Conversely, type AB-positive blood is called the universal recipient type because a person who has it can receive blood of any type.

How blood type is determined

Like eye color, blood type is genetically inherited from your parents. Whether your blood group is type A, B, AB or O is based on the blood types of your mother and father. For instance, if your mum is AB and your dad is A, you can expect to be A, B, or AB. If mum is AB and dad is O, the child will have an A or B blood type. When both parents are A, the child will have either O or A.

Credit: Red Cross.

Credit: Red Cross.

Blood is essentially made up of two types of blood cells (red and white), platelets, and a fluid called plasma. About half the blood (45%) is made up of blood cells, with the remaining 55% being plasma. Millions of blood cells are produced daily in the bone marrow, the soft spongy material that fills up bone cavities.

A person’s blood type is determined by proteins found on the surface of red blood cells called antigens. If antigen A is present in the red blood cells, then you have type A blood, while having B antigen present means you have type B blood. If both A and B are present, you have type AB blood. If neither antigen is present, you have type O blood.  

Besides the ABO classification, there’s also another blood type grouping that involves Rhesus (Rh) factors. The name comes from the Rhesus monkeys, in which such proteins were first discovered. Rhesus factor D, which is the most important, is present in 85% of people, making them Rhesus positive. The remaining 15% are grouped Rhesus negative. The Rh grouping can be very important in some situations. For instance, a baby’s life can be endangered if it inherits a Rhesus positive blood type from the father while the mother is Rhesus negative — in such a situation, the mother can form antibodies against her own baby’s blood.

Blood groupings and transfusions

Credit: Red Cross.

In order to safely perform a blood transfusion, it’s essential that a patient receives a blood type that is compatible with their own. If the blood type is incompatible, the red blood cells can clump together, producing clots that block blood vessels and cause death. Generally, for the ABO grouping, blood transfusions follow these rules:

  • A person with type A can donate to a person with type A or AB.
  • A person with type B blood can donate to a person with type B or AB.
  • A person with AB type blood can only donate to a person with AB. However, a person with blood type AB can receive blood from anyone, being the universal recipient.
  • A person with O type blood can donate to anyone, being the universal donor. This is because type O blood has no antigen on the surface of its red blood cells. However, people with type O blood can only receive type O.

People with Rh-positive blood can receive either positive or negative donations but those who have Rh-negative blood can only receive other Rh negative blood.

Doctors will test your blood before you are allowed to donate or receive blood. However, in the event of an emergency when the patient’s blood type is unknown, type O blood will be used.

It’s important to note that there are more than 600 other known antigens, the presence or absence of which creates “rare blood types.” The ABO grouping works just fine for most people, but in some rare cases, certain blood types may be unique to specific ethnic or racial groups. For instance, many patients with sickle cell disease require an African-American blood donation. That’s why it’s still ideal to match a blood donation type to its recipient exactly, accounting for both antigen types and Rh factor.


People with hemophilia can't stop bleeding because they're missing an essential blood-clotting protein. Credit: Pixabay.

Novel gene therapy may have cured hemophilia A

Scientists may have just come across a cure for hemophilia A, the most common type of condition that affects the blood’s ability to clot. British researchers Barts Health NHS Trust and Queen Mary University of London used a novel gene therapy drug. They found 85 percent of clinical trial participants showed normal levels of the essential blood clotting protein Factor VIII over a year after the treatment was administered.

People with hemophilia can't stop bleeding because they're missing an essential blood-clotting protein. Credit: Pixabay.

People with hemophilia can’t stop bleeding because they’re missing an essential blood-clotting protein. Credit: Pixabay.

The hereditary genetic condition primarily affects men. Those suffering from hemophilia A have virtually none of the protein factor VIII in their blood, which is essential to clotting. Even the slightest injury can result in excessive bleeding as well as spontaneous internal bleeding, which can be life-threatening. Repeated bleeding into joints can also damage them or cause arthritis.

Previously, the only treatment for hemophilia involved weekly injections that control and prevent bleeding. There is no cure, however. British researchers are mighty close to one, fortunately.

In a groundbreaking trial involving 13 men with hemophilia A, researchers injected the participants with a copy of the missing gene that codes for the production of the clotting factor. The treatment was administered only once, in a single dose.

Nineteen months later, 11 out of 13 patients now have normal levels of the previously missing clotting factor. What’s more, all 13 patients have now stopped their once regular treatment.

 “We have seen mind-blowing results which have far exceeded our expectations. When we started out we thought it would be a huge achievement to show a five per cent improvement, so to actually be seeing normal or near normal factor levels with dramatic reduction in bleeding is quite simply amazing,” said Professor John Pasi, Haemophilia Centre Director at Barts Health NHS Trust and Professor of Haemostasis and Thrombosis at Queen Mary University of London, in a statement.

“We really now have the potential to transform care for people with haemophilia using a single treatment for people who at the moment must inject themselves as often as every other day. It is so exciting.”

This treatment has the potential to change how hemophilia is treated worldwide. It’s just remarkable how a single dose of treatment could change the lives of thousands of patients around the world now living with a life-threatening condition — people like Jake Omer, a 29-year-old from Billericay, UK. Before accessing the gene therapy, Jake, who was diagnosed with hemophilia at age two, had to inject factor VIII three times a week. He has arthritis in his ankles as a result of repeated bleeding.

“The gene therapy has changed my life. I now have hope for my future. It is incredible to now hope that I can play with my kids, kick a ball around and climb trees well into my kids’ teenage years and beyond. The arthritis in my ankles meant I used to worry how far I would be able to walk once I turned 40. At 23 I struggled to run 100m to catch a bus; now at 29 I’m walking two miles every day which I just couldn’t have done before having the gene therapy treatment,” Jake said in a statement.

“It’s really strange to not have to worry about bleeding or swellings. The first time I noticed a difference was about four months after the treatment when I dropped a weight in the gym, bashing my elbow really badly. I started to panic thinking this is going to be really bad, but after icing it that night I woke up and it looked normal. That was the moment I saw proof and knew that the gene therapy had worked.”

The British team now wants to extend the clinical trial to participants from the USA, Europe, Africa and South America.

Scientific reference: Savita Rangarajan et al, AAV5–Factor VIII Gene Transfer in Severe Hemophilia A, New England Journal of Medicine (2017). DOI: 10.1056/NEJMoa1708483.

Toy astronaut.

Long-term exposure to mictrogravity can lower physical fitness down by half

Life in space may be really bad news for our bodies, a new study has found. Long-term exposure to microgravity environments seems to inhibit our circulatory system’s ability to shuttle oxygen around, leading to a dramatic reduction in the ability of long-term astronauts to perform physical activity.

Toy astronaut.

Image credits Carlos Augusto.

Bad news if you planned on going to space and impressing the missus with your jar-opening skills on touchdown — you probably won’t have any left. A new paper from the Kansas State University shows that long-term exposure to space-like conditions reduces an astronaut’s capacity to exercise by a dramatic 30 to 50 percent. They propose this observed reduction in physical capacity is caused by faulty oxygen transport in microgravity. And, worryingly enough, the effect is seen even in astronauts who maintain a high fitness regime through exercise on missions.


A research team led by NASA kinesiologist Carl Ade took data recorded on a group of nine male and female astronauts who had spent roughly six months aboard the ISS. Each one of the astronauts had comprehensive measurements taken before a mission to assess their physical fitness.

The team was particularly interested in the numbers for oxygen uptake, cardiac output, and hemoglobin concentration and saturation (hemoglobin is the substance red blood cells use to bind and carry oxygen), as they quantified how effective each astronaut’s circulatory system was at getting oxygen to muscle mitochondria.

During their missions, each astronaut conformed to an aerobic and resistance training regimen designed by NASA. It included moderate and high-intensity training on an exercise bicycle or treadmill for four to six days each week, as well as upper and lower-body resistance training six days per week. Which is a lot more exercise than most of us can boast. Despite this, when the astronauts retook the physical tests two days after returning to Earth, their figures had dropped dramatically.

The team reports that by comparing the before and after data, they found a 30 to 50 % decrease in maximal oxygen (the maximum rate of oxygen consumed during exercise, a key indicator of cardiorespiratory health). After about 90 days down on Earth, the astronauts managed to regain more than 97% of their initial level of fitness. The inability to get back to full fitness capacity probably stems from an altered function of the lungs caused by long exposure to microgravity, the team notes.

“It is a dramatic decrease,” Ade in a press release. “When your cardiovascular function decreases, your aerobic exercise capacity goes down. You can’t perform physically challenging activities anymore. While earlier studies suggest that this happens because of changes in heart function, our data suggests that there are some things happening at the level of the heart, but also at the level of the microcirculation within capillaries.”

Their theory is that microgravity alters the way red blood cells interact with capillaries (the tiny ends of blood vessels), but more research is needed to clearly define the answer.

The findings raise some more warning signs in regards to our plans for deep space missions and outer-worldly colonization. After spending a few months in transit and exposed to microgravity, we can expect would-be colonists to suffer a significant decrease in their ability to perform physical tasks. In the case of an astronaut on Mars, for example, this means he or she may simply lack the ability to perform the intense manual labor required in setting up a colony by the time they get there.

At least we do have some time on our hands before we reach Mars to try and find some solutions to this problem.

The paper “Decreases in maximal oxygen uptake following long-duration spaceflight: Role of convective and diffusive O2 transport mechanisms” has been published in the Journal of Applied Physiology.