A heart cell organ that can beat like a real heart. Photo: livescience According to sciencemag.org, this mini organ (cell organelle) mimics the real heart of a 25-day-old human embryo and could help solve many mysteries, such as why children’s hearts don’t have scars. after having a heart attack. Not involved in the new study, but Zhen Ma, a cardiac organelle development bioengineer at Syracuse University, says it’s a great study, and the experiment is important in understanding Congenital heart defects and human heart formation. This process has so far relied solely on animal models. Although other mini-organs such as the brain, intestines, and liver have been grown in the lab for more than a decade, the heart cell organ presents a more challenging challenge for scientists.
The first cardiac organoids were created from mouse heart cells. They may beat on a lab plate, but they look like a bunch of heart cells, not a real heart. According to Aitor Aguirre, a stem cell biologist at Michigan State University, the cardiac organelle needs to function. With the heart, one wants the heart cell organ to have chambers and function to beat in rhythm. Watch a video of a mini heart beating in the lab (source: Sciencemag.org): To create an embryonic-like self-organizing heart cell organelle, the authors of the new study programmed human pluripotent stem cells (cells that have the ability to develop into any type of tissue). which) for this cell to turn into other types of heart cells. They wanted to create three layers of cells in the wall of the chambers of the heart, one of the first developing parts of the heart. Next, they embedded these stem cells in different concentrations of growth-promoting nutrients. They tried until they found a recipe to get these stem cells to form tissue in the correct order and shape in the embryo. After a week of development, the cardiac organelle was structurally equivalent to the heart of a 25-day-old embryo. At this stage, the heart has only one chamber, which will later be the left ventricle of the mature heart. Cardiac organelles are only about 2mm in diameter and have the typical major cell types in this stage of development: myocytes, epithelial cells, fibroblasts, and the epicardium. They also have a clear chamber that beats at a rate of 60-100 beats per minute, similar to the heart rate of embryos of the same age. Lead study author Sasha Mendjan, a stem cell biologist at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences, said: “When I first saw it, I was surprised that these chambers had self-forming. What’s amazing is that you see right away whether this experiment works and if this organelle is working, because it has a pulse.” Scientists were able to study heart formation in unprecedented detail. Photo: livescience The mini-heart has so far been more than three months old in the lab and will help scientists monitor the heart’s development in unprecedented detail. They can know the source of heart diseases such as congenital heart defects in children and heart cell death after a heart attack. Mendjan and his colleagues also frozen organelles to test their response to injury. They found that cardiac fibroblasts, a type of cell responsible for maintaining tissue structure, travel to the site of damage to repair dead cells, as happens in children who have had heart attacks. Scientists have long wondered why children’s hearts can regenerate after being damaged without scarring, unlike adults. Mr. Aguirre said the next step would be to connect this organ of beating heart cells to a network of blood vessels and test its ability to pump blood. Mendjan’s team intends to find a way to modify the nutrient solution to produce a four-chambered heart cell organ. With this innovative heart cell organ, researchers were able to learn more about heart problems that can arise when the walls of the heart’s chambers begin to form. Meanwhile, Mr. Ma said that growing a more mature heart cell organ with all four chambers and structure is a matter of the future. He thinks this will take a decade to materialize.

However, scientists in the UK have linked the consumption of red meat, such as beef, lamb and pork, to impaired heart function, including smaller ventricles, poor heart function, and arteries. harder. The scientists studied nearly 20,000 people, and found that high consumption of red and processed meat was linked to three different cardiovascular health conditions. Processed meats, such as sausages and bacon, are those that have been preserved by smoked or salted, processed or added chemical preservatives. There is some evidence that red meat alters gut microbiota, leading to higher levels of certain metabolites in the blood, which in turn is associated with a higher risk of heart disease. Previous studies have shown a link between high consumption of red and processed meats, which may increase the likelihood of cardiovascular disease. Hamburger lovers may have to consider switching to a variety of plant-based alternatives that are now more common on supermarket shelves, as well as better for the environment. Last month, a team of researchers from Canada linked the risks of cardiovascular disease, like heart attack and stroke, to the consumption of processed meat. Additionally, a 2018 study found that regular consumption of red meat could increase the levels of chemicals that cause cardiovascular disease by more than 10 times. Study author Dr Zahra Raisi-Estabragh of Queen Mary University, London, said: “Previous studies have shown a link between high consumption of red meat and an increased risk of heart attack or death. died from heart disease. We examined the relationship between meat consumption and cardiovascular health imaging measures for the first time. This may help us understand the underlying mechanism of the previously observed association with cardiovascular disease ”. The long-term study investigating the contribution of genes and the environment to the development of health problems included 19,408 participants from UK Biobank. The researchers examined the association between self-reporting of red meat and processed meat consumption and heart anatomy and function. Three types of heart health measures were analyzed, one of which is blood vessel elasticity, a marker of good health. The analysis is adjusted for other factors that may affect the association, including age, sex, education, smoking, alcohol, exercise, high blood pressure, high cholesterol, diabetes and only body mass number (BMI). The researchers found that high consumption of red and processed meats was associated with a decrease in cardiovascular health indicators of all the measures studied. People who eat more meat have smaller ventricles, poor heart function, and stiffer arteries, all of which are signs of poor heart health. Specifically, people who eat more meat have smaller ventricles, poor heart function, and stiffer arteries, all of which are signs of poor heart health. For comparison, the researchers also examined the relationships between heart-imaging measurements and eating oily fish, which is known to be good for heart health. They found that as the consumption of oily fish increased, heart function improved and the arteries more elastic. Dr Raisi-Estabragh said: “The findings support previous observations of the association between red meat consumption and processed meat and heart disease, and provide an understanding of heart structure and function. , blood vessel. It is thought that these factors may be the reason for the observed association between red meat and heart disease. For example, maybe eating more red meat leads to increased cholesterol in the blood and this in turn causes heart disease. Our research shows that these factors play a role in the relationship between meat intake and heart health, but they are not all. The study did not look at replacement mechanisms, the authors note, and admitted that it does not actually cause cardiac dysfunction. “This is an observational study and cannot assume the cause, but overall, it seems plausible that people limit their intake of red and processed meats for cardiovascular health reasons,” said Dr. Raisi-. Estabragh said. The research is being presented at the ESC 2021 Preventive Cardiovascular Conference, an online scientific conference of the European Heart Association (ESC). Dr. Shireen Kassam, a hematologist and senior lecturer at King’s College Hospital, who was not involved in the study, said observational data valuable for several decades indicate eating red and processed meats. increased risk of development and death from coronary heart disease and heart disease. “It’s no surprise that participants who consumed the most meat had evidence of impaired heart function and blood vessels,” she said. Research confirms that we must avoid questioning the role of red and processed meat in the diet and act on these research findings. By focusing on effective public health messages to assist people in eliminating these foods from their diet and replacing them with healthier plant protein sources. This will not only improve human health but also benefit the environment. Huong Giang (Source: dailymail)

Mr. Scott Kelly while living on the ISS Station. Photo: NYT In a study published in the journal Circulation on March 29, scientists found that during 340 days in space, Mr. Kelly’s heart was reduced in size even though he still exercised hard for 6 days. week. Luckily, the smaller heart did not seem to have any effect on the health of Mr. Kelly when he returned to Earth in 2016. This finding has added to the list of the types of transformations the human body has to undergo in an unstable environment of gravity. Astronauts also tend to have head edema, eyeballs crushing, leg shrinkage, and bones become more brittle. According to the New York Times, Dr. Benjamin D. Levine, study author and professor of internal medicine at the Southwestern Medical Center at the University of Texas (USA), said: “Kelly’s heart has changed to adapts to reduced gravity conditions. It does not have any dysfunction. He is still healthy. Without gravity, the heart doesn’t need to pump blood fully, and like any other muscle, it is altered by decreasing the intensity of the activity. For Mr. Scott Kelly, the shrinking phenomenon still occurs regardless of the regular exercise 6 days / week on the ISS. This regimen has been shown to be effective in reducing brittle bones and reducing muscle mass. After 340 days in space, Mr. Kelly’s heart weight dropped by about 27%, from 190 grams to 140 grams. Mr. Kelly shared that his body also underwent some other changes, such as bone loss, and these phenomena have almost returned to normal. However, the miniature heart phenomenon could be a concern for future missions to Mars. Based on the experiences of Mr. Kelly and other astronauts on the ISS, Dr. Levine thinks that the upcoming visitors to Mars will remain in good health. However, problems can arise if an astronaut is injured, becomes ill and cannot exercise, or if the exercise equipment is damaged. With weaker hearts, they can be dizzy and faint as they step onto the red planet after months of weightless travel. Swimmer Benoit Lecomte. Photo: CNN In the study, Levine and his colleagues compared the heart of astronaut Scot Kelly to that of long-distance swimmer Benoit Lecomte, when he tried to swim across the Pacific in 2018. The buoyancy in the water has the same impact on the body as the weightless environment. Lecomte athletes spend most of the day in the horizontal position: 8 hours of swimming and 8 hours sleeping on a support boat. Scientists think that extended swimming hours will be strenuous enough to maintain Mr. Lecomte’s heart size. But instead, it shrinks at a rate nearly as fast as Mr. Kelly’s time in space. After more than 159 days, the Lecomte athlete abandoned the plan after swimming two thirds of the planned 5,650 miles because the boat was destroyed by a storm. Through ultrasound, it was found that his left ventricle was about 28 grams lighter. The left ventricle is the heart’s largest and most powerful chamber, pumping blood to the aorta and throughout the body. Dr. Levine expressed surprise when she learned the results. “I thought his heart would get bigger. That is a huge amount of training ”. In an interview, Benoit Lecomte estimated his heart rate could be below 100 while swimming, and described the intensity of long-distance swimming as walking briskly, or running very slowly. Now, the US Aerospace Agency (NASA) can design better training programs for astronauts. In space, Mr. Scott Kelly has been exercising 6 days a week, 30-40 minutes walking on the treadmill or cycling. In addition, he also uses a resistance machine to lift weights. “This practice regime is quite strenuous. I have to push weights quite hard. The weight is definitely heavier than I can lift at home, ”said Kelly, now retired at NASA, in an interview. Dr. Benjamin D. Levine said there is another study to track the hearts of 13 astronauts before and after 6 months on the space station. This unpublished study will provide a broader amount of data.