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What are the last discoveries concerning the perception of taste for the last 10 years?
We discovered the 5th flavour: umami.
Also the 6th and 7th: oleogustus and starchy. Anything else?
Maybe in genetics, as we all have genetic predisposition?
Or concerning the creation of the systems in charge of the perception of taste during the embryo-genesis?
I'm not quite clear on exactly what you're interested in, but the short answer is yes, there have been discoveries related to the perception within the last 10 years.
The example that comes to mind is the role of the cannabinoid 1 receptor in the sense of taste of lipids. The full text of a good article is available online here.
Brissard L et al. 2018. Orosensory Detection of Dietary Fatty Acids Is Altered in CB1R−/− Mice. Nutrients 10(10): 1347.
Mysteries of COVID Smell Loss Finally Yield Some Answers
I t dawned on Eian Kantor on a Saturday in early April as he brewed a cup of tea from fresh mint leaves: he had lost his sense of smell. The tea suspiciously smelled of nothing at all. Kantor proceeded to rifle through the fridge, sniffing jars of pickles, chili sauce and garlic&mdashnothing.
Ever since New York State went into lockdown in late March, Kantor, age 30, and his girlfriend had stayed isolated in their Queens, N.Y., apartment. So he did not suspect he had COVID-19 despite running a slight fever that he chalked up to seasonal allergies. When he was finally able to get tested weeks into his loss of smell, or anosmia, he tested negative. But months later, he says, several tests showed that his antibodies to the novel coronavirus were &ldquooff-the-charts high, which affirmed that I had had it.&rdquo
An estimated 80 percent of people with COVID-19 have smell disturbances, and many also have dysgeusia or ageusia (a disruption or loss of taste, respectively) or changes in chemesthesis (the ability to sense chemical irritants such as hot chilies). Smell loss is so common in people with the disease that some researchers have recommended its use as a diagnostic test because it may be a more reliable marker than fever or other symptoms.
One lingering mystery is how the novel coronavirus robs its victims of these senses. Early in the pandemic, physicians and researchers worried that COVID-related anosmia might signal that the virus makes its way into the brain through the nose, where it could do severe and lasting damage. A suspected route would be via the olfactory neurons that sense odors in the air and transmit these signals to the brain. But studies have shown that this is probably not the case, says Sandeep Robert Datta, a neuroscientist at Harvard Medical School. &ldquoMy gestalt read of the data to date suggests that the primary source of insult is actually in the nose, in the nasal epithelium,&rdquo the skinlike layer of cells responsible for registering odors. &ldquoIt looks like the virus attacks, predominantly, support cells and stem cells and not neurons directly,&rdquo Datta says. But that fact does not mean that neurons cannot be affected, he emphasizes.
Olfactory neurons do not have angiotensin-converting enzyme 2 (ACE2) receptors, which allow the virus entry to cells, on their surface. But sustentacular cells, which support olfactory neurons in important ways, are studded with the receptors. These cells maintain the delicate balance of salt ions in the mucus that neurons depend on to send signals to the brain. If that balance is disrupted, it could lead to a shutdown of neuronal signaling&mdashand therefore of smell. The sustentacular cells also provide the metabolic and physical support needed to sustain the fingerlike cilia on the olfactory neurons where receptors that detect odors are concentrated. &ldquoIf you physically disrupt those cilia, you lose the ability to smell,&rdquo Datta says.
In a study in Brain, Behavior and Immunity, Nicolas Meunier, a neuroscientist at Paris-Saclay University in France, infected the noses of golden Syrian hamsters with SARS-CoV-2, the virus that causes COVID. Just two days later about half of the hamsters' sustentacular cells were infected. But olfactory neurons were not infected even after two weeks. And strikingly, the olfactory epithelia were completely detached, which, Meunier says, resembled skin peeling after a sunburn. Although olfactory neurons were not infected, their cilia were entirely gone. &ldquoIf you remove the cilia, you remove the olfactory receptors and the ability to detect odorants,&rdquo he says.
Disruption of the olfactory epithelium could explain the loss of smell. Yet it remains unclear whether the damage is done by the virus itself or invading immune cells, which Meunier observed after infection. Widespread reports of anosmia with COVID are not typical of other diseases caused by viruses. &ldquoWe think it's very specific to SARS-CoV-2,&rdquo Meunier says. In a previous study with other respiratory viruses at his laboratory, he found sustentacular cells infected only rarely, whereas with SARS-CoV-2, about half of cells contained the pathogen. With other viruses, smell is usually compromised by a stuffed-up nose, but COVID does not usually cause nasal congestion. &ldquoThis is very different,&rdquo Meunier says.
Researchers have found a few clues about the loss of smell, but they are less certain about how the virus causes a loss of taste. Taste receptor cells, which detect chemicals in the saliva and send signals to the brain, do not contain ACE2, so they probably do not get infected by SARS-CoV-2. But other support cells in the tongue carry the receptor, perhaps providing some indication of why taste goes away. (Although taste can seem to disappear with anosmia because odors are such a key component of flavor, many people with COVID truly develop ageusia and cannot detect even sweet or salty taste.)
The loss of chemical sensing&mdashthe burn of hot chilies or the refreshing sensation of mint&mdashalso remains unexplained and largely unexplored. These sensations are not tastes. Instead their detection is conveyed by pain-sensing nerves&mdashsome of which contain ACE2&mdashthroughout the body, including the mouth.
More clues to how the virus obliterates smell come from people recovering from anosmia. &ldquoThe majority of patients lose smell like a light switch going off and recover it rapidly,&rdquo Datta says. &ldquoThere's a fraction of patients that have much more persistent anosmia and recover on longer time scales.&rdquo The olfactory epithelium regularly regenerates. &ldquoThat's the body's way of protecting against the constant onslaught of toxins in the environment,&rdquo Meunier says.
Still, more than seven months after he first experienced anosmia, Kantor falls in the second group of patients: he has yet to detect any odors at all. &ldquoIt's hard because you don't realize how much you relate to smell until you lose it,&rdquo he says. &ldquoIf the house were on fire, I wouldn't know it. It's very concerning.&rdquo And then there is what anosmia does to the joy of eating. &ldquoFoods that used to be good now taste &lsquomeh,&rsquo&rdquo Kantor says.
Carol Yan, a rhinologist at the University of California, San Diego, says that anosmia poses a real health risk. &ldquoIt actually increases mortality. If you can't smell and taste food, it can predispose you to harm, like rotten food or a gas leak,&rdquo she says. &ldquoIt can also cause social withdrawal or nutritional deficits.&rdquo
The variation on sensory themes extends to another symptom called parosmia, a possible sign of recovery in people with long-lasting anosmia. Freya Sawbridge, a 27-year-old New Zealand woman, is such an individual. She contracted COVID-19 in March. After several weeks of anosmia and ageusia, when everything tasted of &ldquoice cubes and cardboard,&rdquo she says, Sawbridge began to regain the most basic tastes&mdashsweet, salty, sour&mdashbut no nuance of flavor, which comes from foods' aromas. &ldquoChocolate tastes like sweet rubber,&rdquo she says.
Then, after about five months, some odors returned but not as expected. For a while, all foods smelled of artificial strawberry flavor. But now &ldquoeverything smells hideous and distorted,&rdquo Sawbridge says. &ldquoNothing is accurate, and the odors are all unpleasant.&rdquo The smell of onions, she says, is unbearable, and a strange chemical flavor permeates everything. &ldquoAll my food tastes like it was sprayed with window cleaner,&rdquo Sawbridge adds.
Parosmia may occur when newly grown stem cells that develop into neurons in the nose attempt to extend their long fibers, called axons, through tiny holes in the base of the skull and connect with a structure in the brain called the olfactory bulb. Sometimes axons connect to the wrong place, causing erratic smell, but the miswiring can potentially correct itself, given enough time.
That news is welcome for people such as Sawbridge. But the question she wants answered is: How long will her condition last? &ldquoWe don't know the final time course of recovery for those with anosmia,&rdquo Yan says, but it is usually from six months to a year. &ldquoWith long-term postviral smell loss from the flu, after six months, there is a 30 to 50 percent chance of spontaneous recovery&rdquo without any treatment, she adds. &ldquoThere have been case reports of recovery after two years. But after that, we think the regenerative capability may be hindered. And the chances of recovery are quite slim, unfortunately.&rdquo
Kantor has tried every avenue imaginable to regain his sense of smell: a course of high-dose steroids to reduce inflammation a smell-training program with essential oils beta-carotene supplements for nerve regeneration acupuncture. Nothing has made a difference. Yan recommends &ldquoirrigation&rdquo of the sinuses with budesonide, a topical steroid shown to improve outcomes in a Stanford University study of people with postflu smell loss for more than six months. Another promising treatment Yan and others are investigating is platelet-rich plasma, an anti-inflammatory concoction isolated from blood that has been used to treat some types of nerve damage. But with any treatment, Yan says, the results &ldquoare not amazing. It's not like you'll wake up and say, &lsquoWow, I can smell again.&rsquo But if you can smell soap again or enjoy the taste of some foods, that's a big gain.&rdquo
There is one final worrying note about anosmia: it has been identified as a risk factor for some neurodegenerative diseases. &ldquoAfter the flu pandemic of 1919, we saw an increase in the prevalence of Parkinson's disease,&rdquo Meunier says. &ldquoIt would be really concerning if something similar were happening here.&rdquo But Yan thinks that fear is overblown. &ldquoThere is certainly a link between anosmia and diseases, but we think that viral-induced anosmia is [working by] a totally different mechanism,&rdquo she says. &ldquoHaving postviral anosmia doesn't put you at higher risk for disease. These are two completely separate phenomena.&rdquo That should reassure Sawbridge and Kantor&mdashand the millions of others worldwide affected with COVID-related smell loss.
FROM OUR ARCHIVES
The Immune Havoc of COVID-19. Akiko Iwasaki and Patrick Wong January 2021.
“We were unprepared,” Dr. Todd Ellerin, director of infectious diseases at South Shore Hospital in Weymouth, Massachusetts, said of the healthcare sector. “I don’t necessarily think that we have the baseline of personal protective equipment necessary to handle the surge of cases we’re seeing now. While hospitals and academic centers are in better positions, outpatient offices and clinics are unequipped on how to handle this.”
Testing capabilities, while improving, started off slowly, and as a result, infection control measures have had to be adjusted to keep up with the contagion of the virus.
Ellerin said the 2003 SARS outbreak was a “scary time,” but it was more limited in scope and significantly less contagious than COVID-19.
SARS largely affected Asia, where the virus originated, but it quickly spread to North America, South America, and Europe. In the United States, eight people became infected, the CDC said.
Similarly to SARS, MERS was first reported in Saudi Arabia where all later cases originated. Within the United States, only two people ever tested positive, both infections occurring in 2014.
“You can look at these three coronaviruses like a triangle, with MERS at the top,” Dr. Ellerin explained. “MERS kills around a third of people who are infected, SARS about a handful. COVID-19 is at the base of that triangle. There are more people who get it but on an individual basis, it isn't as fatal."
Compared to SARS and MERS, COVID-19 appears to have a lower mortality rate than the other two diseases (the World Health Organization estimated 3.4% but others have been much lower). MERS, on the other hand, is around 34% and SARS - 10%. Unlike the two previous coronaviruses, which have been described by physicians and epidemiologists as less transmittable, COVID-19 spreads with more efficiency and is able to infect more people, public health officials said.
Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York City says SARS was able to be spread 10-14 days after symptoms developed , typically when most people were already isolated in hospitals. But with COVID-19, viral loads are high early in the course of the disease, typically in the first 3-5 days -- when people are less likely to have admitted or isolated – making transmission to other persons more likely, Glatter said.
Contagion is a characteristic COVID-19 shares with the H1N1 virus. Unlike COVID-19, influenza has been described by physicians as an old enemy, one that comes every year, and despite causing thousands of deaths per season, has become so familiar to people it no longer causes the level of fear we are seeing with novel coronavirus, experts say.
From October 2019 to the beginning of March 2020, the CDC estimates that 22,000 - 50,000 people have died of the flu. But with the presence of antiviral drugs and annual vaccines, measures of protection have been established against the flu that Ellerin believes have desensitized people to it.
COVID-19 remains a different case.
Dr. Marybeth Sexton, an assistant professor of medicine in the division of infectious disease at Emory University said COVID-19 is closer to us, and it does not have available vaccines and remedies like other illnesses.
“For the average American, this is different from prior outbreaks because COVID-19 is more likely to touch their lives. There was fear watching the news of Ebola in West Africa, but here, we could see a large percentage of the U.S. population getting affected," she said. "There’s no baseline immunity like the flu. This virus is hitting home more so than others have.”
With COVID-19 spreading throughout states and communities, restrictions, event cancellations, and store closures have disrupted daily life in a way physicians agree is unparalleled. Actions such as hoarding hand sanitizer, Clorox wipes, and masks have been reported by medical professionals as measures never before seen taking place.
“As is common with a new disease that has mortality associated with it, people are nervous, and it can lead them to do things that are fear based like hoarding masks which is not in their, or anyone else’s, best interest,” Sexton said.
Despite the challenges in dealing with COVID-19, physicians like Amler and Sexton believe that along with hospitals and healthcare professionals, the public is being educated about washing their hands and practicing social distancing. The protocols established now, they say, will survive into the future when newly discovered respiratory infections must be faced.
The Fake Salt Problem
Our taste buds have very good taste. They've evolved to respond to certain chemicals--and not to others--to help ensure we eat things that will keep us healthy and shun what will poison us.
The system worked pretty well until we figured out how to make potato chips so cheap.
Now researchers struggle to replicate the flavors of our favorite foods while cutting back on the sugar, the fat and the salt that makes them taste so irresistible. Salt, which shows up in nearly everything, sweet or savory, has been particularly tough to replace because scientists still don't fully understand how humans taste it.
"It's the final frontier," says Scott Herness, chair of the Oral Biology department at Ohio State University's College of Dentistry. "There is still that fundamental discovery to be made."
It would be an important one. A study released by the Centers for Disease Control and Prevention in March suggests that most Americans eat more than double the amount of salt than they should, leading to increased rates of heart disease and stroke. The report said the average sodium intake for Americans older than two was 3,436 milligrams per day in 2005 and 2006. People older than 40, people with high blood pressure and blacks (70% of the U.S. population) should be eating just 1,500 milligrams per day and everyone else should be eating less than 2,300 milligrams, about one teaspoon. (One half-cup "serving" of Campbell's Chicken Noodle Soup has 890 milligrams of sodium.)
"Because of the public health implications, it's one of the most important activities in our field," says Gary Beauchamp, director of the Monell Chemical Senses Center in Philadelphia. "It's also been one of the most frustrating."
Human taste buds respond to five--and only five--basic tastes: Salty, sweet, bitter, sour and something called umami, or savory. Flavor is far more complex, it is something your brain concocts given information about taste, smell, texture and temperature. (See "The Superhero Of Senses.")
We know that sweet, bitter and umami are perceived when the right chemicals bind to specific receptors on the outside of the different types of taste bud cells. We know what those receptors are, and researchers can run screens on molecules that might have the perfect shape to bind to those receptors and trigger the taste sensation.
Researchers think they know what triggers sour tastes, a channel in the cell membrane of the sour cell that allows protons through. Protons, or hydrogen nuclei, are what makes things acidic. When we taste something sour, we are basically tasting acidity.
Researchers thought they had a candidate for a salt receptor when they were working with mice. They focused on a very common sodium channel called an epithelial sodium channel, or ENaCs, used by many types of cells to regulate sodium intake. When researchers inhibited ENaCs in mice, the mice couldn't taste salt.
But when human ENaCs were inhibited with amiloride, a congestive heart failure drug made specifically to inhibit ENaCs, there was no effect on salt perception. Researchers still think an ion channel of some sort allows us to taste salt.
Now salt substitutes are mainly mixtures of salt and potassium chloride. Potassium chloride does taste a bit salty, but too much of it and you taste a metallic bitterness, so it only goes so far. The only other chemical that tastes wonderfully salty like sodium is lithium. Lithium's not a great candidate as a substitute. It's poisonous.
Flavor companies and food manufacturers are so frustrated that they have formed a consortium to try to understand the biology of salt reception so they can better come up with replacements.
Perhaps because sodium is so important to our physiology, researchers think it is unlikely that a salt substitute akin to the popular sweeteners aspartame and sucralose will ever be found. Instead, researchers are working to develop sodium enhancers that perhaps open up the mysterious ion channel and make us more sensitive to salt so we would be satisfied with less of it.
The Swiss flavor giant Givaudan has a new technology that uses the products of a fermentation process as building blocks for salt enhancers. The company's flavorists combine these products with other chemicals to make the overall flavor of a food taste salty and good yet use less sodium.
The problem is the enhancers have to be customized for the food so they don't throw off the flavor. "If we were going into a hamburger situation versus a noodle situation, it's going to be a different solution," explains Robert Eilerman, Givaudan's Global Head of Science and Technology. "We blend this sodium replacement agent into a flavor profile that allows us to enhance sodium perception. We build a flavor around the sodium replacement."
Givaudan's taste research program's goal is to be able to reduce sodium in food by 50%. It has been able to reduce sodium in some foods by 30% so far. Still, a simpler solution would be more than welcome.
Senomyx the flavor company based in San Diego, Calif., claims to have identified the primary human salt taste receptor, a protein it calls SNMX-29. Others assume it's an ion channel, but Senomyx won't say. The company hasn't published any scientific details about its purported discovery, so researchers remain skeptical.
Still, the company says it has identified 250 chemical candidates that it says enhance salt and potassium chloride perception and it is sifting through those in hopes of developing a new ingredient.
Our taste buds have proven they won't be fooled easily, though. In the end, no one wants their chicken soup messed with. Says Givaudan's Eilerman about the industry's past frustration: "We've been dealing with this for 25 years. You can reduce sodium, but your soup tastes like dishwater."
In the early days, while American workers were busily exploring and reporting the beneficial use of X-rays, less welcome news was beginning to trickle in from many parts of the USA. The rays, it was discovered, produced undesirable changes in exposed tissues. In the 116th anniversary year of the discovery of X-rays, when Roentgen and others were glorified for their discovery and use of X-rays, this article throws light on some of the early victims and martyrs. Given the ambiguity of universal guidelines in obtaining a cone beam CT (CBCT) scan and the undue use of panoramic and full-mouth periapicals at tertiary care centres, oral radiologists may end up making unnecessary examinations, which can result in undue radiation exposure. This highlights the need to look back through history.
It was barely 14 days after the announcement of the discovery of Roentgen rays that Friedrich Otto Walkhoff took the first dental radiograph. He took an ordinary photographic glass plate, wrapped it in a rubber dam, held it in his mouth between his teeth and tongue and then lay on the floor for a 25 min exposure. Walkhoff said that those 25 min of exposure were a torture to him. 1 However, the exact nature of this torture has not been described. Later, in 1896, Walkhoff succeeded in making extra-oral pictures with an exposure time of 30 min. He noticed a loss of hair on the side of the head of some of the patients he irradiated, 2 but as there was no mention of blisters on the skin it is assumed that the absorbed dose was less than 300 rads.
In 1896, Otto Walkhoff and Fritz Giesel established the first dental roentgenological laboratory in the world. For many years the laboratory provided practitioners with images of the jaw and head. Fritz Giesel later died in 1927 of metastatic carcinoma caused by heavy radiation exposure to his hands. 3
In February 1896 a child who had been accidentally shot in the head was brought to the laboratory at Vanderbilt University (Tennessee, USA). Before attempting to locate the bullet in the child, Professor Daniel and Dr Dudley decided to undertake an experiment. Dr Dudley, with his characteristic devotion to science, lent himself to this experiment. A plate holder containing the sensitive plate was tied to one side of Dudley's head and the tube attached to the opposite side of the head. The tube was placed 0.5 inches away from Dudley's hair and activated for 1 h. After 21 days all the hair fell out from the space under discharge, which was approximately 2 inches in diameter. 4
On 12 August 1896, Electrical Review reported that Dr HD Hawks, a graduate of the 1896 class of Columbia College, gave a demonstration with a powerful X-ray unit in the vicinity of New York. 5 After 4 days, he was compelled to stop work. He noticed a drying of the skin, which he ignored. The hand began to swell and gave the appearance of a deep skin burn. After 2 weeks the skin came off the hand, the knuckles become very sore, fingernail growth stopped and the hair on the skin exposed to X-rays fell out. His eyes were bloodshot and his vision became considerably impaired. His chest was also burnt. Mr Hawks' physician treated this as a case of dermatitis. Hawks tried protecting his hands with petroleum jelly, then gloves and finally by covering it with tin foil. Within 6 weeks Hawks was partially recovered and was making light of his injuries. Electrical Review concluded by asking to hear from any of its readers who had had similar experiences.
GA Frei of Frei and Co., a Boston manufacturer of X-ray tubes, replied the next day: Mr K, an employee of the company, complained of peculiar itching and burning in his left hand and thought it was due to poisoning with chemicals. Mr K used to regularly attend to testing of tubes during and after the exhausting process at the rooms. The same phenomenon also appeared on Frei's hand. The letter concluded by stating that further developments would be carefully monitored. 5
A distressing case was reported in September 1896. William Levy had been shot in the head by an escaping bank robber 10 years previously. The bullet entered his skull just above the left ear and presumably proceeded towards the back of the head. Having heard about X-rays, he decided he wanted the bullet localized and extracted. Levy approached Professor Jones of the Physical Laboratory, University of Minnesota. Professor Jones, who was familiar with Daniel and Dudley's experiments, warned Levy against the exposure, but Levy was undeterred and an exposure was made on 8 July 1896. Exposures were made with the tube over his forehead, in front of his open mouth and behind his right ear. Levy sat through the exposures from 8 o'clock in the morning until 10 o'clock at night. Within 24 h his entire head was blistered, within a few days his head was an angry sore and his lips were badly swollen, cracked and bleeding. His right ear had doubled in size and the hair on his right side had entirely fallen out. Professor Jones concluded that the one feature that was satisfactory to the patient was that a good picture of the bullet was obtained, showing it to be about an inch beneath the skull under the occipital protuberance. 6
Dr Stickney reported a case in December 1896 of a woman who complained of abdominal pain. A radiograph of the patient, Mrs Q, was taken in the abdominal region. The focus of X-rays was over the liver. 3 exposures were made of 20 min, 30 min and 35 min. Two days later she developed burns over the region. The condition worsened until the surface sloughed. 7
The above cases of Hawks, Dudley and Stickney all reported skin blisters and it could therefore be assumed that the absorbed dose of the victims was at least 1500 rads. Serious damage from the rays was also reported from the Edison Laboratory. Elihu Thomson of General Electric cited two Edison cases in a letter dated 1 December 1896 to Dr EA Codman of Boston. Thomson referred to these cases as serious because they took place over the hands and arms of the victims and they had to stop working with X-rays altogether. The story goes that one of them was told by his physician that if he continued to work with X-rays it would be necessary to amputate his hands. The worker threatened with amputation was probably Clarence Dally, Thomson Edison's glassblower.
Clarence Dally was likely to have had an absorbed dose of approximately 3000 rads to necessitate amputation. It needs to be noted that not everyone had the same experience. Dr Williams reported in 1897 that in approximately 250 patients, who he examined with X-rays, he had not seen any harmful effects. 8
Professor Stine of Armour Institute of Technology reported that a patient who was exposed for 2 h for 2 successive days with the plate a few inches from the skin developed itching and irritation. A few days later the skin swelled and became inflamed, and the area immediately surrounding the exposure was tanned and dry. In time the skin peeled off and resembled bad sunburn. Professor Stine, however, concluded that the effect was due to ultraviolet rays and not X-rays. 9
Dr EA Codman, in 1902, conscientiously reviewed all papers on X-ray injuries. Of the 88 X-ray injuries published, 55 had occurred in 1896, 12 in 1897, 6 in 1898, 9 in 1899, 3 in 1900 and 1 in 1901. The decline could be due to the fact that X-ray injuries were no longer in the news and therefore went unreported unless they exhibited unusual features. 10
Clarence Dally (1865) is thought to be the first to die as result of X-ray exposure. He died of metastatic carcinoma at only 39 years old.
The next death to be reported was that of Elizabeth F Ascheim (1859) of San Francisco. Deaths reported thereafter included those of Wolfram C Fuchs (1865), who opened the X-ray laboratory in Chicago in 1896 and made the first X-ray film of a brain tumour in 1899, and Dr William Carl Egelhoff (1872). Among the victims who suffered the most was Dr Walter James Dodd (1869). He was operated on 32 times and died of metastatic carcinoma of the lung on 18 December 1916. 11
The deaths of tube manufacturers have included Rome Vernon Wagner (1869), his brother Thurman Lester Wagner (1876), Burton Eugene Baker (1871), Henry Green (1860), John Bawer (unknown year of birth) and Robert H Machlett (1872). 12
The case of C. Edmund Kells is well known. Kells developed a radiogenic neoplasm in 1922 and endured increasing discomfort and excruciating pain. Kells did not listen to the warning given by William Rollins regarding radiation hazards. He had undergone 42 operations and several amputations (some have reported 100). On 7 May 1928 Kells triggered a 0.32 calibre bullet into his brain. 3
Dr Perry Brown, an eminent Boston radiologist, published his collection of biological essays 𠇊merican martyrs to science through Roentgen rays” in 1936. He reported the deaths of Mihran Kasabian of Philadelphia (1870), Eugene Caldwell of New York (1870), Herbert Robert of St Louis (1852), Fredrick H Baetjer of Baltimore (1874) and a number of others whose lives deserve to be remembered. However, his own story was missing Dr Brown died of X-ray induced cancer in 1950. 11
Dr Cannon began using X-rays in 1896 when he was a medical student. In 1931 he developed itching of skin and fresh red papular lesions on his back, chest, thighs, knees and elbows. Dr Cannon suggested that repeated biopsies be made so that it would provide more information on this poorly understood condition. He developed several lesions all over the body, many of which continuously recurred.
In April 1944, a recurrent basal cell carcinoma of the nostril was excised. In 1945 he passed the 14 th anniversary of the onset of mycosis fungoidosis — an amazingly long survival. On 1 October 1945 he died of recurrent pulmonary infection. 6
It would be generous to accept Dr Grubbe's account precisely as he wrote it, for he truly was an X-ray martyr. Dr Grubbe suffered at least 83 surgical operations to relieve his discomfort and to stop the progress of gangrene from his left hand to his arm, elbow and finally shoulder. Grubbe's face was grossly disfigured with cancer. He became sterile. His marriage was left childless, a misfortune he attributed to the X-rays. He lived in agony for many years, yet he continued to work with the rays.
In his autobiography he maintained “my courage is my work. I treat patients who suffer more or are encumbered more than me, and so I go on. By helping others I help myself”. He went on to predict “I will die from the effects of early uncontrolled exposures to X-rays. And like many of the early pioneers, I too, will die a victim of natural science, a martyr to the X-rays.”
Dr Grubbe, in the chapter “The effect of the X-rays on author’s body”, concluded on a noble note: “I have lived large enough to see the child that I fathered develop into a sturdy, mature and worthwhile product and I hope as I approach the evening of my day, to see even more uses of X-ray energy in the alleviation of the ills of mankind.” Dr. Grubbe died of metastatic cancer on 26 March 1960. 13 It could be hypothesized that Kells and Grubbe had a consistent absorbed dose of 3000 rads.
What does it mean to sense something? Sensory receptors are specialized neurons that respond to specific types of stimuli. When sensory information is detected by a sensory receptor, sensation has occurred. For example, light that enters the eye causes chemical changes in cells that line the back of the eye. These cells relay messages, in the form of action potentials (as you learned when studying biopsychology), to the central nervous system. The conversion from sensory stimulus energy to action potential is known as transduction.
You have probably known since elementary school that we have five senses: vision, hearing (audition), smell (olfaction), taste (gustation), and touch (somatosensation). It turns out that this notion of five senses is oversimplified. We also have sensory systems that provide information about balance (the vestibular sense), body position and movement (proprioception and kinesthesia), pain (nociception), and temperature (thermoception).
Figure 1. The absolute threshold for detecting light is greater than you probably imagined—the human eye can see a candle on a clear night up to 30 miles away!
The sensitivity of a given sensory system to the relevant stimuli can be expressed as an absolute threshold. Absolute threshold refers to the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time. Another way to think about this is by asking how dim can a light be or how soft can a sound be and still be detected half of the time. The sensitivity of our sensory receptors can be quite amazing. It has been estimated that on a clear night, the most sensitive sensory cells in the back of the eye can detect a candle flame 30 miles away (Okawa & Sampath, 2007). Under quiet conditions, the hair cells (the receptor cells of the inner ear) can detect the tick of a clock 20 feet away (Galanter, 1962).
It is also possible for us to get messages that are presented below the threshold for conscious awareness—these are called subliminal messages. A stimulus reaches a physiological threshold when it is strong enough to excite sensory receptors and send nerve impulses to the brain: this is an absolute threshold. A message below that threshold is said to be subliminal: we receive it, but we are not consciously aware of it. Therefore, the message is sensed, but for whatever reason, it has not been selected for processing in working or short-term memory. Over the years there has been a great deal of speculation about the use of subliminal messages in advertising, rock music, and self-help audio programs. Research evidence shows that in laboratory settings, people can process and respond to information outside of awareness. But this does not mean that we obey these messages like zombies in fact, hidden messages have little effect on behavior outside the laboratory (Kunst-Wilson & Zajonc, 1980 Rensink, 2004 Nelson, 2008 Radel, Sarrazin, Legrain, & Gobancé, 2009 Loersch, Durso, & Petty, 2013).
Dig Deeper: UnConscious Perception
Figure 2. Priming can be used to improve intellectual test performance. Research subjects primed with the stereotype of a professor – a sort of intellectual role model – outperformed those primed with an anti-intellectual stereotype. [Photo: Jeremy Wilburn]
These days, most scientific research on unconscious processes is aimed at showing that people do not need consciousness for certain psychological processes or behaviors. One such example is attitude formation. The most basic process of attitude formation is through mere exposure (Zajonc, 1968). Merely perceiving a stimulus repeatedly, such as a brand on a billboard one passes every day or a song that is played on the radio frequently, renders it more positive. Interestingly, mere exposure does not require conscious awareness of the object of an attitude. In fact, mere-exposure effects occur even when novel stimuli are presented subliminally for extremely brief durations (e.g., Kunst-Wilson & Zajonc, 1980). Intriguingly, in such subliminal mere-exposure experiments, participants indicate a preference for, or a positive attitude towards, stimuli they do not consciously remember being exposed to.Another example of modern research on unconscious processes is research on priming. Priming generally relies on supraliminal stimuli, which means that the messaging may occur out of awareness, but it is still perceived, unlike subliminal messaging. Supraliminal messages are be perceived by the conscious mind. For example, in one study, shoppers listened to either French or German music (the supraliminal messaging) while buying wine, and sales originating from either country were higher when music from that same country was played overhead.  In a well-known experiment by a research team led by the American psychologist John Bargh (Bargh, Chen, & Burrows, 1996), half the participants were primed with the stereotype of the elderly by doing a language task (they had to make sentences on the basis of lists of words). These lists contained words commonly associated with the elderly (e.g., “old,” “bingo,” “walking stick,” “Florida”). The remaining participants received a language task in which the critical words were replaced by words not related to the elderly. After participants had finished they were told the experiment was over, but they were secretly monitored to see how long they took to walk to the nearest elevator. The primed participants took significantly longer. That is, after being exposed to words typically associated with being old, they behaved in line with the stereotype of old people: being slow.Such priming effects have been shown in other domains as well. For example, Dijksterhuis and van Knippenberg (1998) demonstrated that priming can improve intellectual performance. They asked their participants to answer 42 general knowledge questions taken from the game Trivial Pursuit. Under normal conditions, participants answered about 50% of the questions correctly. However, participants primed with the stereotype of professors—who are by most people seen as intelligent—managed to answer 60% of the questions correctly. Conversely, performance of participants primed with the “dumb” stereotype of hooligans dropped to 40%. Both of these studies have had difficult times replicating, so it is worth noting that the conclusions reached may not be as powerful as originally reported.
Absolute thresholds are generally measured under incredibly controlled conditions in situations that are optimal for sensitivity. Sometimes, we are more interested in how much difference in stimuli is required to detect a difference between them. This is known as the just noticeable difference (jnd) or difference threshold. Unlike the absolute threshold, the difference threshold changes depending on the stimulus intensity. As an example, imagine yourself in a very dark movie theater. If an audience member were to receive a text message on her cell phone which caused her screen to light up, chances are that many people would notice the change in illumination in the theater. However, if the same thing happened in a brightly lit arena during a basketball game, very few people would notice. The cell phone brightness does not change, but its ability to be detected as a change in illumination varies dramatically between the two contexts. Ernst Weber proposed this theory of change in difference threshold in the 1830s, and it has become known as Weber’s law: The difference threshold is a constant fraction of the original stimulus, as the example illustrates. It is the idea that bigger stimuli require larger differences to be noticed. For example, it will be much harder for your friend to reliably tell the difference between 10 and 11 lbs. (or 5 versus 5.5 kg) than it is for 1 and 2 lbs.
Process and procedure have been at the core of the return to lab work. When Feldman was first able to resume research, only one person could be in the lab at a time. The limit was gradually increased to two per day, and is now up to roughly one person per lab bay. Under current guidelines, labs can have up to one person per 125 square feet of laboratory space (with some special exceptions) and Feldman uses a shift schedule to stay within regulations.
“One of my postdocs had worked at a bar at MIT, so she had a shift work hack for our online calendar,” said Feldman, who is an assistant professor of biology in the School of Humanities and Sciences. “It’s just one example of how my lab members have done a really great job in dealing with the pandemic.”
Given continued social distancing requirements, Feldman lab members also rigged a movable webcam setup so they can remotely train colleagues on new equipment. Limits on physical proximity likewise informed Goldhaber-Gordon’s decision to keep his cryostat running: Warming it up would have required two people and repeat visits over the span of a week, whereas maintaining the cooling required only one person – with special permission from the university – to feed it nitrogen every few days.
Throughout shelter-in-place the Goldhaber-Gordon lab has continued some experimental work using a second cryostat that had fortuitously already been set up so that measurements could be controlled and results reported over the internet. As lab capacity limits increase, Goldhaber-Gordon has spent significant time researching the best safety procedures for his specific lab, paying attention to details like the face coverings they use and their air circulation system.
“When I first was designing my lab, I learned more about pouring concrete and air conditioning and electrical power than I ever thought I would learn,” he said. “Now I’m doing that again in a new context and I think it would be good if we had a way to share our solutions across campus – while also recognizing that we aren’t experts.”
Only one student is consistently using the Sperling lab for now. Research in the lab may not reach pre-pandemic levels until its members can reschedule their fieldwork in the Yukon and Northwest Territories, which was supposed to be the foundation of the lab’s next set of studies.
“We were going to start a new project in the Yukon and Nunavut Arctic islands. This trip has been in the works for 10 years,” said Sterling. “Daydreaming about new rocks and reading about them in preparation for fieldwork is part of the fun of being a geologist, and I haven’t gotten to do that during the pandemic.”
At present, all university-sponsored travel is suspended until further notice and field research is heavily restricted.
4 The Discovery Of A &lsquoGay Gene&rsquo
One of the biggest arguments made by those pitted against the LGBT community is that being gay is a choice. According to geneticist Dean Hamer, there&rsquos definitely a biological marker for being gay. It&rsquos passed down through the female line and belongs to the part of our DNA called Xq28.
Hamer conducted a study that was part interviews and part genetic research. He looked at pairs of gay brothers and their family members, and ultimately found that the gay brothers shared the same genetic marker on the Xq28 patch of their DNA. Follow-up work has been frustratingly sparse. In contrast, after publishing a similar study that linked a gene to anxiety, more than 400 follow-up studies were performed.
There was no such interest in finding a gay gene, aside from some other researchers claiming that his work was invalid. One of the only other studies was conducted by Rice University, and coauthored by one researcher who clearly stated before the study began that he didn&rsquot believe there was such a thing.
Hamer isn&rsquot without his supporters, though. Several other studies have been done, including one that looked at the lives of children who were born male and were surgically altered to female as babies. Even though most of the subjects thought that they had been born female, most also were attracted to women, suggesting there&rsquos more to the development of sexual preference than environmental influence.
The impact of Hamer&rsquos discovery and the conformation of the precise gay gene that he&rsquos hoping to find would have staggering consequences. As late as 2007, CNN found that most Americans believed that being gay was a choice. Finding a gay gene could add a boost to the changing perception.
There have already been clear genetic links found between certain physical traits and being gay. If one identical twin is gay, the other has a higher chance of being gay as well, when compared to fraternal twins. Gay men are also much more likely to be left-handed and to have hair that lies in a counterclockwise pattern.
Senator Marco Rubio Issues Statement Moments Before Pentagon UFO Report Released
Joe Martino 2 minute read
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The long awaited Pentagon UFO report is set to be released from the U.S. Intelligence Community. Some of those waiting expect a moment of acknowledgment, but perhaps nothing all that new, while others are hoping for a much deeper admission of non-human intelligent life. Time will tell.
In the wake, Senator Marco Rubio has issued the following statement:
Rubio Statement on UAP Report
Miami, FL — Senate Select Committee on Intelligence Vice Chairman Marco Rubio (R-FL) released a statement on the unclassified report on unidentified aerial phenomena (UAP) issued by the Office of the Director of National Intelligence (ODNI).
“For years, the men and women we trust to defend our country reported encounters with unidentified aircraft that had superior capabilities, and for years their concerns were often ignored and ridiculed,” Rubio said. “This report is an important first step in cataloging these incidents, but it is just a first step. The Defense Department and Intelligence Community have a lot of work to do before we can actually understand whether these aerial threats present a serious national security concern.”
In 2020, Rubio, as Acting Chairman of the Senate Select Committee on Intelligence, included report language in the Intelligence Authorization Act for Fiscal Year 2021 directing ODNI to submit a report to congressional intelligence and armed services committees on unidentified aerial phenomena.
We’ll have full coverage of the what’s in the report later today, if the report is released, and of course in the coming days as it will inevitably require much analysis and discussion. Sign up to our email list and follow us on Twitter for more to come.
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Diabetes: Past treatments, new discoveries
RECALL OF METFORMIN EXTENDED RELEASE
In May 2020, the Food and Drug Administration (FDA) recommended that some makers of metformin extended release remove some of their tablets from the U.S. market. This is because an unacceptable level of a probable carcinogen (cancer-causing agent) was found in some extended-release metformin tablets. If you currently take this drug, call your healthcare provider. They will advise whether you should continue to take your medication or if you need a new prescription.
Diabetes develops when the body does not produce enough insulin or cannot respond to it appropriately, leading to high levels of sugar in the blood. Managing blood sugar levels can be challenging, but ongoing research is increasing the chance of living a full life with diabetes.
In the past, type 1 diabetes was always fatal within months or even weeks. The introduction of insulin as a treatment changed this.
There is still no cure for diabetes, but newer drugs and an awareness of possible causes have further improved the outlook for people with this condition.
In this article, we look at the history of diabetes, how its treatment has progressed, and current developments.
Understanding the history of diabetes and its early treatment can help us appreciate how far the understanding and treatment of this condition have come.
Discovery of diabetes
Share on Pinterest Joseph von Mering (pictured) and Oskar Minkowski are credited with discovering in 1899 that the removal of the pancreas from a dog allowed it to develop diabetes.
Image credit: PD-US
Over 3,000 years ago, the ancient Egyptians mentioned a condition that appears to have been type 1 diabetes. It featured excessive urination, thirst, and weight loss.
The writers recommended following a diet of whole grains to reduce the symptoms.
In ancient India, people discovered that they could use ants to test for diabetes by presenting urine to them. If the ants came to the urine, this was a sign that it contained high sugar levels. They called the condition madhumeha, meaning honey urine.
During the third century B.C.E., Apollonius of Memphis mentioned the term “diabetes,” which may have been its earliest reference.
In time, Greek physicians also distinguished between diabetes mellitus and diabetes insipidus.
Diabetes insipidus has no link with diabetes mellitus. While it also leads to thirst and urination, it does not affect the body’s production or use of insulin. Diabetes insipidus results from a problem with a hormone called vasopressin that the pituitary gland produces.
The ancient Roman doctor Galen mentioned diabetes but noted that he had only ever seen two people with it, which suggests that it was relatively rare in those days.
By the fifth century C.E., people in India and China had worked out that there was a difference between type 1 and type 2 diabetes. They noted that type 2 diabetes was more common in heavy, wealthy people than in other people. At that time, this might have implied that these individuals ate more than other people and were less active.
Nowadays, the ready supply of processed food has weakened the association between wealth and eating more, but obesity, diet, and a lack of exercise are still risk factors for type 2 diabetes.
The term diabetes mellitus comes from the Greek word “diabetes” (to siphon or pass through) and the Latin word “mellitus” (honey or sweet).
In the Middle Ages, people believed that diabetes was a disease of the kidneys, but an English doctor in the late 18th century found that it occurred in people who had experienced an injury to the pancreas.
In 1776, Matthew Dobson confirmed that the urine of people with diabetes could have a sweet taste. According to an article that the journal Medical Observations and Enquiries published, he measured the glucose in urine and found that it was high in people with diabetes.
Dobson also noted that diabetes could be fatal in some people but chronic in others, further clarifying the differences between type 1 and type 2.
By the early 19th century, there were no statistics about how common diabetes was, there was no effective treatment, and people usually died within weeks to months of first showing symptoms.
The early Greek physicians recommended treating diabetes with exercise, if possible, on horseback. They believed that this activity would reduce the need for excessive urination.
Other treatment options have included:
- a “nonirritating” milk-and-carb diet, for example, milk with rice and starchy, gummy foods “to thicken the blood and supply salts” or milk and barley water boiled with bread
- powders of fenugreek, lupin, and wormseed
- narcotics, such as opium
- foods that are “easy of digestion,” such as veal and mutton
- rancid animal food
- green vegetables
- a carb-free diet
One doctor recommended a diet consisting of 65 percent fat, 32 percent protein, and 3 percent carbohydrate. However, he advised avoiding fruits and garden produce.
Various experts have also recommended several chemicals and drugs, including ammonium sulfide, digitalis, magnesia, chalk, lithium salts, and potassium salts.
Doctors did not always agree on which diet or drugs to use as a treatment. Some also recommended lifestyle measures, such as:
- wearing warm clothing
- taking baths, including cold baths and Turkish baths
- avoiding stress
- wearing flannel or silk near the skin
- getting massages
These ways of managing diabetes did not prove particularly effective, and people with this condition experienced severe health problems.