Mechnikov: test bacteria

 　　In the 19th century, there was such a legendary scientist in Russia. The physical pain caused by his attempted suicide caused him to have a strong interest in cell research and won the Nobel Prize in Physiology or Medicine in 1908. He is Elijah Erich Mechnikov, a Russian microbiologist and immunologist, one of the pioneers of the study of the immune system.

　　On May 16, 1845, Mechnikov was born in a village near Kharkiv, in what was then Ukraine under the Russian Empire. From childhood, Mechnikov had a keen interest in natural history. He later went to Kharkov University to study natural history, and within two years he completed what should have taken four years. After graduating from university, he went to Germany to study the marine fauna of Heligoland in the North Sea.

　　In 1870, Mechnikov became an honorary professor at the University of Odessa. At the time of his little success in his career, his first wife, Fyodorovich, died of tuberculosis. After losing his wife, Metchnikov tried to commit suicide by swallowing a large amount of opium in grief, but he vomited and attempted suicide due to swallowing too much.

　　In 1875, Mechnikov remarried, and unfortunately, his second wife, Oga, soon contracted typhoid fever, which hit him hard again, and attempted suicide again. This time, he used an injection to infect himself with regressive fever, but he did not die, but was very painful. Since then, he has carried out research on microbes, with a particular interest in the immune system.

　　In 1883, after observing the phenomenon of starfish digesting food, Mechnikov found that there are some strange cells in the starfish, they are more free than other cells, constantly moving from place to place, like amoeba, Act in a fluid fashion. He thought that since the wandering cells in these starfish can swallow food and magenta fine particles, they must also be able to eat microorganisms; these wandering cells can protect starfish from microbial invasion, and human beings are protected against various germs. It may be because of these wandering cells. At the suggestion of the zoologist Claus, he named the cells "phagocytes".

　　Mechnikov's experiments have proven time and time again that phagocytes can eat microbes, but convincing scientists all over the world this is not easy. Many scientists in Germany and Austria often oppose Metchnikov at various conferences and publications. Every year a German scientist writes an article refuting the phagocyte theory in an important scientific journal. Other scientists plausibly said: "It was the serum of the mouse that killed the bacteria, not the phagocytes in the blood." This debate has been going on for almost 20 years. Mechnikov also wavered for a while. For a period of time, he had insomnia every night, and he had to use morphine to anesthetize himself, and even had suicidal thoughts.

　　When Metchnikov was depressed and disappointed, the discerning French microbiologist Pasteur gave him enthusiastic support and help, which made him feel like he was on the verge of despair. With Pasteur's support and encouragement, Mechnikov entered the Pasteur Institute and started a new scientific journey.

　　He devised a new experiment: Injecting Vibrio cholerae into guinea pigs, dissecting the guinea pigs a few days later, using a glass pipette to suck up the mucus containing phagocytic cells and viewing it under a microscope. He found that the isolated phagocytic cells quickly died and burst, and the Vibrio cholerae bacteria swallowed by it flew out. In order to prove that the swallowed and flew out Vibrio cholerae bacteria are alive and can make people sick, Mechnikov injected these Vibrio cholerae bacteria into healthy guinea pigs, and these guinea pigs were soon killed by cholera. gone to life. This experiment proved that phagocytes can indeed engulf live microorganisms.

　　To reveal the function of human phagocytes, Mechnikov and his assistants swallowed Vibrio cholerae at the risk of their lives. But there were two very different results. He and a few other colleagues were fine, and his assistant, Jubilee, died of cholera. Mechnikov began to think: Why would the same ingestion of Vibrio cholera cause very different results? He used a syringe to draw blood from healthy people who had swallowed Vibrio cholerae and looked under a microscope, but in any case he could not find Vibrio cholerae. It was concluded that this was because the phagocytes of the able-bodied people engulfed Vibrio cholerae, which protected the body from the microorganisms. Unfortunately, due to the limitation of the level of scientific development at that time, people could not see the specific process of phagocytic phagocytosis of microorganisms in the human body, because the phagocytic process in the human body is not as intuitive as the phagocytosis of yeast spores by water fleas. This may also be one of the reasons why German microbiologists reject the phagocytosis theory.

　　At the end of the 19th century, the phenomenon of cellular immunity was confirmed by more experimental data. In 1900, Mechnikov published the article "Research on Immunity to Infectious Diseases in the Past Twenty Years", which systematically discussed the characteristics of human leukocytes and the phagocytosis of microorganisms in the liver, spleen and cells, and formally proposed the original phage. Immunology. In 1908, the Nobel Prize Committee decided to award Metchnikov the Nobel Prize in Physiology or Medicine. On July 16, 1916, Mechnikov died at the age of 71.