Kyiv (Lwoff), Andre( French microbiologist, Nobel Prize in Physiology or Medicine, 1965)
Comments for Kyiv (Lwoff), Andre
Biography Kyiv (Lwoff), Andre
genus. May 8, 1902
French microbiologist AndrцL Michel Lvov was born in the Ene-le-Chateau, a small village in central France. His parents emigrated from Russia in the late XIX century. Solomon's father was a psychiatrist Lvov, head physician of a psychiatric hospital, his mother, Maria (Siminovich) Lviv - sculptor. When L. was still a child, his father was assigned to another hospital - in Neuilly-sur-Marne near Paris. Growing up in the countryside, the boy swam, played tennis and was a good shooter. From the educational purpose of the father took his son to go round the hospital and visited with him other medical institutions. During one of these visits L. met with another father Ilya Mechnikov, who showed him the typhoid bacillus under the microscope. L. remembers well the first world war, which began when he was 12 years old. The fighting came close to their home at a distance which some 20 miles. 'Anti-aircraft guns were close, the fragments [shrapnel] whistled and slapped on the roof - he recalled. - I listened with curiosity this strange music, quite unaware of the danger ... I was still not enough for adults to grasp the depth of the tragedy of war '.
Although L. wanted to study biology and become a researcher, his father advised him to take medicine, to always have the opportunity to earn a living. At 17 h. enrolled in the University of Paris (Sorbonne) at the Faculty of Sciences to study medicine and biology, the following three summers he spent in Roscoff (Brittany), the Marine Biological Laboratory. In 1921, Mr.. He became assistant to the Pasteur Institute in Paris, where he worked under the guidance of renowned microbiologists Edward Shattona and Felix Mesnil. In the same year, L. received a scholarship that enabled him to work at the institute part-time and concentrate on the completion of medical education. His doctoral thesis was based on studies conducted by the Marine Biological Laboratory, and was devoted to the study of eye pigment in copepods - small parasitic crustaceans that live in fresh and salt water.
In the 20-ies. L. studied ciliate - one-celled animals, covered volosopodobnymi structures, so-called cilia. He studied the characteristics of their diet and morphology (the formation of organs and tissues). The Pasteur Institute, he met who worked in the same microbiologist Bourdaloue Marguerite, whom he married in 1925. and which for many years conducted joint research. Two years later, L. received a medical degree at the University of Paris, in 1929,. was appointed head of the Laboratory of the Pasteur Institute and in 1932. received the University of Paris Ph.D.. The next year, with a grant from the Rockefeller Foundation, he held together with Otto Meyerhof in the Institute of Medical Research in Heidelberg, Kaiser Wilhelm.
. Approximately twenty years earlier, in 1911, Polish chemist, Kazimierz Funk coined the term 'vitamins' to describe the unknown substances essential to human life and animal
. However, by early 30-ies. only some of these substances have been identified and studied. In Heidelberg, L. studied hematin - a growth factor in flagellated, another type of elementary. The study of growth factors were first defined as 'the specific substances that the body can not synthesize and which are necessary for growth and reproduction'. Then L. engaged biochemistry of thiamine (vitamin B1) in some of the simplest and physiology of nicotinamide (vitamin PP, included in the B-complex). He showed that nicotinamide contained in the colostrum - liquid secret, produced in small quantities by women's breasts in the last months of pregnancy and during the first days after childbirth before the advent of breast milk.
. After receiving another grant the Rockefeller Foundation in 1936, L
. continued to work on growth factors in Molten Institute in Cambridge (England). At that time it was known that hematin, called a growth factor X, is required for the growth of bacteria Haemophilus influenzae. L. identified a growth factor X and showed that it restricts the growth of these microorganisms.
Upon his return to Paris in 1938. L. was appointed head of the department of physiology of microbes of the Pasteur Institute. There he served throughout the Second World War. After the war, in 1946, L. participated in a conference on the nomenclature of microorganisms in the Cold Spring Harbor and helped to create a classification system based on energy sources and processes of synthesis. In 40-ies. they were written two books: 'The problems of ciliate morphogenesis' ( 'Problems of Morphogenesis in Ciliates') and 'Biochemistry and Physiology of the simplest' ( 'Biochemistry and Physiology of Protozoa').
In earlier studies of 30-ies. L. described the characteristic features previously incorrectly classified the genus of bacteria and gave him a new name Moraxella. One species of this genus was later named in his honor - Moraxella lwoffi. In the late 40-ies A. switches to the study of genetics of bacteria and viruses. Getting the science of genetics was laid in 1866. Gregor Mendel published his writings on the laws of heredity and the first time put forward the idea that the physical traits of an organism are determined by 'elements', later named genes. At the beginning of XX century. it was found that the genes are located in the chromosomes - threads of genetic material contained in the cell nuclei. However, only in 40-ies. found that genes are composed of deoxyribonucleic acid (DNA).
By the time the first generation of virologists could also describe the life cycle of bacteriophages. These viral particles infect bacterial cells and after a latent (hidden) phase can begin to breed in them, causing lysis, in other words, their loss. The bacteria that infected phage particles, called lysogenic, and the process of destruction (lysis) cells - lysogenic.
With the support of two members of the Pasteur Institute, Francois Jacob and Jacques Monod, L. began the study of lysogenic bacteria and the process of lysogeny and in 1950, Mr.. made an outstanding discovery. Placing lysogenic bacteria in a nutrient medium, he followed her division for 19 generations, and then showed that daughter cells also had lysogenic, ie. that this factor is inherited. He also found that particles of lysogenic bacteriophage and non-infectious, or temporary, phage differ. To describe non-infectious phage, he invented the term 'prophage'. In further studies L. and his colleagues found that ultraviolet radiation noninfectious prophage can begin to share, causing the decay of cells. Phage particles, as well as most other viral particles, composed of internal DNA-containing part and the outer protein shell. In 1952, Mr.. Alfred Hershey proved that the multiplication of bacteriophages occurs through the replication of DNA inside. Trying to understand the organization and regulation of genes of bacteriophages, . L., . Monod and Jacob found, . that during infection of bacterial cells attached to the particle prophage chromosome cells, . where genes are usually placed, . and, . According to L., . 'behaves like a bacterial gene',
. Phage DNA has two types of genes - the structural and regulatory. Structural genes of the genetic code passed from one generation to another. In the stage of prophage structural gene activity is suppressed by regulators, resulting in the phage particle can not reproduce. L. also found that ultraviolet radiation, and other stimulants neutralize the effect of gene-regulator, causing a multiplication of phage and lysis, or destruction of bacterial cells.
The results of this study allowed L. make hypotheses about the nature of cancer and polio. He and his colleagues at the Pasteur Institute were convinced of the viral etiology of cancer. According to their opinion, the viruses can also be located in human cells, as particles of bacteriophage in bacterial cells. L. correctly stated, . that the carcinogenic properties of the virus are determined by a protein membrane, . and the carcinogenic effect of the virus can be triggered by the influence of various factors - as well as the stage can be lysogenic prophage by ultraviolet radiation,
. Studying polio in the 50-ies., H. showed that, despite the presence of sensitive vaccine strains, some strains of poliovirus are relatively insensitive to temperature fluctuations.
Invited in 1954. in New York for the reading of the prestigious Garveevskoy lectures, L. highlighted the problems of 'regulation and interaction of metabolic and viral diseases of bacteria'. Three years later he published an article 'Concept virus' ( 'The Concept of Viruses') and participated in the Society for General Microbiology conference in London, whose mission was to find the differences between viruses and small bacteria. In 1959, Mr.. L. became a professor of Microbiology, University of Paris.
In 1965, Mr.. with Jacob and Monod L. was awarded the Nobel Prize in Physiology or Medicine "for discoveries concerning genetic regulation of synthesis of enzymes and virus'. 'Activity, coordination, variability - this is the most amazing properties of living matter - said Sven Gard of the Karolinska Institute in welcoming speech. - By focusing more on the dynamic activity and mechanisms than on structure, you laid the foundations of molecular biology as a science in the true sense of the word '.
Three years after receiving the Nobel Prize L. resigned from the Pasteur Institute and became director of the Institute of Cancer Research in Viyzhyuife, near Paris. Member of the French Academy of Sciences, he in 1970. served as president of the French family planning movement. L. - Foreign Member of the U.S. National Academy of Sciences, Royal Society of London, the Academy of Medical Sciences. Honors, which awarded its native France, and include the Grand Cross of the Legion of Honor. He was awarded the Leeuwenhoek medal of the Royal Netherlands Academy of Arts and Sciences (1960), medals Keylina Biochemical Society, London (1964), as well as honorary degrees from several universities, including Harvard and Oxford.