Virology – Ivanovsky. Dmitry Iosifovich Ivanovsky: biography, contribution to microbiology Dmitry Iosifovich Ivanovsky is known in science for the fact that he

Dmitry Iosifovich Ivanovsky was born in 1864 in the St. Petersburg province. After graduating from high school with honors, in August 1883 he entered the Faculty of Physics and Mathematics at St. Petersburg University. As a needy student, Ivanovsky was exempt from paying tuition and received a scholarship.

Under the influence of outstanding scientists who taught at the university at that time (I.M. Sechenov, A.M. Butlerov, V.V. Dokuchaev, A.N. Beketov, A.S. Famitsin and others), the worldview of the future scientist was formed . As a student, Ivanovsky enthusiastically worked in a scientific biological circle, conducted experiments on the anatomy and physiology of plants, carefully performing experiments. Therefore, A.N. Beketov, who then headed the society of naturalists, and Professor A.S. Famitsin suggested in 1887 that students D.I. Ivanovsky and V.V. Polovtsev go to Ukraine and Bessarabia to study the tobacco disease, which was causing enormous damage to the agricultural sector. economy of the south of Russia. The tobacco leaves were covered with a complex abstract design, sections of which flowed like ink on a blotter and spread from plant to plant.

Discovery of viruses.
In 1892, biologist Dmitry Iosifovich Ivanovsky (1864-1920), who worked in St. Petersburg, reported at a meeting of the Russian Academy of Sciences that he had discovered an amazing pattern. Juice obtained from tobacco plants suffering from mosaic disease and passed through a porcelain filter that retained bacteria retained the ability to infect healthy plants. Based on this fact, the scientist suggested that this filtrate contains either tiny bacteria or toxic substances released by them - toxins. 6 years later, the Dutch microbiologist Martin Willem Beijerinck obtained similar results and introduced the concept of a “filterable virus.” The first word from this name disappeared over time, and the second found its modern meaning. Beijerinck himself assumed that the filterable virus was a liquid “infectious principle.” D.I. Ivanovsky was of the opinion that it was firm. Only in 1939, shortly after the invention electron microscope, researchers were finally able to take a look at the invisible virus. Interestingly, the tobacco mosaic virus was the first to be photographed.

Diseases of plants, animals and humans, the viral nature of which has now been established, have caused damage to the economy and harm to human health for many centuries. Although many of these diseases have been described, attempts to establish their cause and discover the causative agent have remained unsuccessful.
As a result of observations, D.I. Ivanovsky and V.V. Polovtsev first suggested that the tobacco disease, described in 1886 by A.D. Mayer in Holland under the name mosaic, is not one, but two completely various diseases of the same plant: one of them is hazel grouse, the causative agent of which is a fungus, and the other is of unknown origin. D.I. Ivanovsky continues his study of tobacco mosaic disease in the Nikitin Botanical Garden (near Yalta) and the botanical laboratory of the Academy of Sciences and comes to the conclusion that tobacco mosaic disease is caused by bacteria passing through very small diameter tubes (Chamberland filters), which, however, are not able to grow on artificial substrates. The causative agent of mosaic disease is called by Ivanovsky either “filterable” bacteria or microorganisms, since it was very difficult to immediately formulate the existence of a special world of viruses.
Emphasizing that the causative agent of tobacco mosaic disease could not be detected in the tissues of diseased plants using a microscope and was not cultivated on artificial nutrient media. D.I. Ivanovsky wrote that his assumption about the living and organized nature of the pathogen “was formed into a whole theory of a special kind of infectious diseases,” the representative of which, in addition to tobacco mucus, is foot and mouth disease (using the same filtration method).

D.I. Ivanovsky discovered viruses - a new form of existence of life. With his research, he laid the foundations for a number of scientific areas of virology: the study of the nature of the virus, cytopathological viral infections, filterable forms of microorganisms, chronic and latent virus carriage. In 1935, W. Stanley isolated TMV (tobacco mosaic virus) in crystalline form from tobacco juice infected with mosaic disease. For this he was awarded the Nobel Prize in 1946. In 1958, R. Franklin and K. Holm, studying the structure of the STM, discovered that the STM is a hollow cylindrical formation.
In 1960, Gordon and Smith discovered that some plants were infected with free TMV nucleic acid rather than the entire nucleotide particle. In the same year, the prominent Soviet scientist L.A. Zilber formulated the main provisions of the virogenetic theory.
In 1962, American scientists A. Siegel, M. Tseitlin and O.I. Zegal experimentally obtained a variant of TMV that does not have a protein shell, and found that in defective TMV particles the proteins are arranged randomly, and the nucleic acid behaves like a full-fledged virus.
In 1968, R. Shepard discovered a DNA virus.
One of the largest discoveries in virology is the discovery of American scientists D. Baltimore and N. Temin, who found in the structure of a retro virus a gene encoding an enzyme - reverse transcriptase. The purpose of this enzyme is to catalyze the synthesis of DNA molecules on the matrix of an RNA molecule. For this discovery they received the Nobel Prize.

DI. Ivanovsky is rightfully considered the founder of the science of virology. DI. Ivanovsky - discovered viruses - a new form of existence of life. With his research, he laid the foundations for a number of scientific areas of virology: the study of the nature of viruses, the cytopathology of viral infections, filterable forms of microorganisms, chronic and latent virus carriage.

The first half of our century was devoted to a close study of viruses that cause acute febrile diseases, the development of methods to combat these diseases and methods of preventing them.

Virus discoveries poured out like a cornucopia: in 1892, the tobacco mosaic virus was discovered - the year of birth of virology as a science; 1898 - the foot-and-mouth disease virus was discovered, 1901 - the yellow fever virus, 1907 - the smallpox virus, 1909 - the polio virus, 1911 - the Rais sarcoma virus, 1912 - the herpes virus, 1926 - the vesicular stomatitis virus, 1931 - swine influenza virus and western equine encephalomyelitis virus, 1933 - human influenza virus and eastern equine encephalomyelitis virus, 1934 - Japanese encephalitis virus and mumps virus, 1936 - mouse mammary gland cancer virus, 1937 - tick-borne encephalitis virus, 1945 - virus Crimean hemorrhagic fever, 1951 - mouse leukemia virus, 1953 - adenoviruses and human wart virus, 1954 - rubella virus and measles virus, 1956 - parainfluenza viruses, 1957 - polynomials, 1959 - Argentine hemorrhagic fever virus.
This almost continuous list of discoveries will look even more impressive if we add to the 500 human and animal viruses an equally (if not larger!) list of plant viruses (more than 300), insects and bacteria already discovered by that time. Therefore, the first half of our century truly turned out to be an era of great virological discoveries.

In recognition of D.I. Ivanovsky’s outstanding services to virological science, the Institute of Virology of the USSR Academy of Medical Sciences was named after him in 1950, and the D.I. Ivanovsky Prize was established at the Academy of Medical Sciences, awarded once every three years.

In 1887, tobacco plantations in Crimea were struck by an unknown disease. A graduate of St. Petersburg University, D.I. Ivanovsky, was sent to the scene of the incident. The young scientist decided to find out which bacterium causes tobacco disease. Looking through a huge number of preparations prepared from extracts of diseased leaves did not bring good luck. When healthy leaves were infected with sap from diseased leaves (injections into the thickness of healthy leaves), the result was always the same: healthy leaves became diseased after 10-15 days. But failures haunt the scientist. Is this really a dead end? No! Ivanovsky filters the juice through a bacterial filter. But to the amazement of the researcher, when a transparent liquid is applied to healthy leaves, a characteristic abstract pattern appears on them, that is, a disease develops. This is how new “invisible microbes” were discovered – filterable viruses.

DMITRY IOSIFOVICH IVANOVSKY ()

In 1884, Pasteur's student Sh.

Ivanovsky’s biographer cites the following lines from his student diary: “I can’t understand how you can sit with a friend the whole evening and do nothing, say stupid things and find pleasure in it... I get tired of an evening spent in idle conversations.”

Therefore, probably A.N. Beketov, who headed the society of naturalists, and Professor A.S. Famitsyn suggested in 1887 that students Ivanovsky and Polovtsov go (funded by the Free Economic Society) to Ukraine and Bessarabia to study the tobacco disease, which was causing enormous damage to the agriculture of southern Russia.

The main results of observations and studies of the anatomy and physiology of diseased plants (On diseases of tobacco plants - Proceedings of the St. Petersburg Society of Naturalists, vol. 19) were reported by D. I. Ivanovsky in 1888 at a meeting of the St. Petersburg Society of Naturalists and presented in an article by D. I. Ivanovsky and V.V. Polovtsev, and also published in the Proceedings of the Imperial Free Economic Society in 1889, and then in the brochure Ryabukha - tobacco disease, its causes and means of combating it (St. Petersburg, 1890) in the same year republished on German

As a result of these observations, D.I. Ivanovsky and V.V. Polovtsov was the first to suggest that the tobacco disease, described in 1886 by A. Mayer in Holland under the name mosaic, represents not one, but two completely different diseases of the same plant.

D.I. Ivanovsky continues his research on tobacco mosaic disease in the Nikitsky Botanical Garden (near Yalta) and the botanical laboratories of the Academy of Sciences (established in 1891; director - academician A.S. Famitsyn, the only staff member is laboratory assistant D.I. Ivanovsky).

In this work, dated 1892, D.I. Ivanovsky comes to the conclusion that tobacco mosaic disease is caused by bacteria passing through the Chamberland filter, which, however, are not able to grow on artificial substrates. For the first time, data on the causative agent of tobacco mosaic are presented, which for a long time were criteria for classifying pathogens as viruses.

In connection with the completion of his master's thesis, Research on alcoholic fermentation (the Council of St. Petersburg University in 1895 approved D.I. Ivanovsky for a master's degree in botany) D.I. Ivanovsky was forced to temporarily stop research on tobacco mosaic disease and returned to it a few years later, finishing it by 1900.

DI. Ivanovsky performed the following experiment. He ground the leaves of diseased plants. He strained their juice through a cloth and, using capillary tubes, injected this liquid into the veins of healthy tobacco leaves. After two weeks, 80% of the infected plants were affected by mosaic disease.

In 1898, independently of D.I. Ivanovsky, the same result was obtained by Holland's K. Beyerinck. He argued that tobacco mosaic is caused by a liquid infectious principle, which multiplies only in living plants, is killed by boiling and retains its infectious properties when dried.

On May 1, 1935, D.I. Ivanovsky was appointed ordinary professor at the Warsaw Imperial University. Subsequently, he conducts research air nutrition of plants, focusing on the study of the state of plant chlorophyll, the importance of carotene and xanthophyll for plants, the resistance of chlorophyll to light in a living leaf and the second maximum of assimilation.

In addition to scientific and pedagogical activity at the university, Ivanovsky taught at the Higher Women's Courses and headed the Botanical Garden. In Warsaw, the Ivanovsky family experienced great grief: their son Nikolai, a student at Moscow University, died of tuberculosis in Yalta. The grief he experienced made Ivanovsky withdrawn and only lecturing and work distracted him somewhat.

In 1915, the University of Warsaw was evacuated to Rostov-on-Don. With great enthusiasm, Ivanovsky worked on the textbook Plant Physiology, for which he prepared and collected materials for many years. The first volume of this textbook was published in 1917, and the second in 1919. Ivanovsky gives in it the history of the origin of plant physiology as a science, all its achievements are outlined in detail, and immediate tasks are highlighted.

The textbook by D.I. Ivanovsky, which went through two editions (the second in 1924), is currently a valuable tool for students. While working at Don University, Ivanovsky participated in its public life as chairman of the biology department of the Society of Natural Scientists.

D.I. Ivanovsky died at the age of 56 on June 20, 1920 from cirrhosis of the liver. He was buried in Rostov-on-Don at the Novoposelensky cemetery, where a monument was erected to him. On the house N-87 on Socialistheskaya Street, where the scientist lived, there is a fortified memorial plaque with the inscription: The largest Russian scientist, the founder of the science of viruses, Dmitry Iosifovich Ivanovsky (born in 1864; died in 1920), lived in this house.

“WEREWOLF” When tulips with unusual colors appeared on the market, their price became fabulous. You could buy a house or a yacht for an onion. Beauty can be deceiving and insidious. In Holland, the sale of tulips ranks second in the country's income after shipbuilding. The "new variety" arose as a result of disease and led to a financial crisis.

History of the issue All attempts to find the cause of many diseases of humans, animals, and plants were unsuccessful. Dmitry Ivanovich Ivanovsky As a student at the Faculty of Physics and Mathematics at St. Petersburg University, he conducted research on tobacco diseases in Bessarabia. The tobacco leaves were covered with a pattern, sections of which flowed like ink on a blotter and spread from plant to plant. For the first time in the world, it was suggested that the tobacco disease, described in 1886 by A.D. Mayer in Holland, was caused by a pathogen of unknown origin, and it was not bacteria. They turned out to be even more dangerous. In 1892 Ivanovsky D.I. described the causative agent of the disease “tobacco mosaic”.

“unpredictable aliens” They should have been called... “Bad news in a protein shell” by P. Medawar What do they look like? Spiral type of symmetry - influenza virus - a Cubic type of symmetry - viruses: herpes - b, adenovirus - c, Structure of T-phage Escherichia coli 1 - capsid head, 2 - DNA, 3 - rod, 4 - capsid (case), 5- basal lamina, 6 - fibrils. "I"

In 1729, 100 thousand people died from the flu in London, 60 thousand in Europe. 550 million people had the Spanish flu, of which 25 million people died (2.5 times more than died on all fronts World War 1).. In 1957, a flu pandemic occurred, 2 billion people suffered from it. Dangerous “dwarfs” Viruses are 1000 times smaller than a cell. They could fit on the tip of a needle. Everything is unusual and unexpected in a virus. Each virus selects its own tissue and easily penetrates the body. In someone else's cage, he is always the master. It does not have its own metabolism and resources. The virus gives orders and the host cell itself creates new viruses and dies. In the 18th century in Europe, up to 12 million people, 2/3 of children, fell ill with smallpox. Features of viruses This is a precellular form of life.

CLASSIFICATION OF VIRUSES DEOXYVIRUSES RIBOVIRUSES 1. Double-stranded DNA 2. Single-stranded DNA 1. Double-stranded RNA 2. Single-stranded RNA 1.1. Cubic type of symmetry: Without outer shells: adenoviruses With outer shells: herpes viruses 1.2. Mixed type of symmetry: bacteriophages 1.3. Without symmetry: smallpox viruses 2.1. Cubic type of symmetry: Without outer shells: rat virus 1.1. Cubic type of symmetry: Without outer shells: reoviruses, plant wound tumor viruses 2.1. Cubic type of symmetry: Without outer shells: polio virus 2.2. Spiral type of symmetry: Without outer shells: tobacco mosaic virus With outer shells: influenza, rabies, oncogenic viruses Variety of viruses “Primitive and resourceful”

In 412 BC. Hippocrates described the disease with influenza. Influenza-like outbreaks were noted in 1173. The first documented influenza pandemic, which claimed many lives, occurred in 1580. Death came extremely quickly. A person could still be absolutely healthy in the morning, but by noon he would fall ill and die by nightfall. The causative agent of the disease, the influenza virus, was discovered by Richard Shope in 1931. The influenza A virus was first identified by English virologists Smith, Andrews and Laidlaw - London in 1933. Memories of the past.

Rabies virus is a disease with severe damage to the central nervous system. It is transmitted by the bite of sick animals (dog, cat, rat), whose saliva containing the virus gets into the wound. Symptoms and course. The incubation period lasts up to 55 days, but may be longer. The disease has three periods: Stage 1 - lasts 1-3 days. Accompanied by an increase in temperature to 37.2C, poor sleep, insomnia. Stage 2 of excitation - lasts up to 7 days. It is expressed in increased sensitivity to the slightest irritation of the sensory organs: bright light, various sounds, and noise cause muscle spasms in the limbs. Patients become aggressive and violent. Stage 3 paralysis of the eye muscles, limbs, respiratory distress, death.

The history of virology began at the end of the 19th century. after microbiology - discoveries of L. Pasteur, R. Koch and their employees. The discoverer of viruses was D. I. IVANOVSKY (1892), who showed that the causative agent of tobacco mosaic disease is able to pass through a filter that retains the smallest bacteria, and does not grow on artificial, nutrient media.

Having begun in 1887 the study of tobacco diseases in the territory of Bessarabia and the Nikitsky Botanical Garden, he distinguished the previously confused so-called grouse and mosaic disease. He found out (1892) that the causative agent of the latter, unlike bacteria, is invisible in a microscope at the highest magnification, passes through porcelain filters and does not grow on ordinary nutrient media. He discovered crystalline inclusions (“Ivanovsky crystals”) in the cells of diseased plants, thus discovering a special world of pathogens of non-bacterial and non-protozoal diseases, later called viruses. Ivanovsky considered them as the smallest living organisms. In addition, Ivanovsky published works on the features of physiological processes in diseased plants, the effect of oxygen on alcoholic fermentation in yeast, the state of chlorophyll in plants, its resistance to light, the importance of carotene and xanthophyll, on soil microbiology.

The main results of observations and studies of the anatomy and physiology of diseased plants (“On diseases of tobacco plants” - Proceedings of the St. Petersburg Society of Naturalists, vol. 19) were reported by D. I. Ivanovsky in 1888 at a meeting of the St. Petersburg Society of Naturalists and presented in the article D.I. Ivanovsky and V.V. Polovtsev, and also published in the Proceedings of the Imperial Free Economic Society in 1889, and then in the brochure “Ryabukha-tobacco disease, its causes and means of combating it” (St. Petersburg, 1890) in the same year, republished in German by the Russian Academy of Sciences. As a result of these observations, D.I. Ivanovsky and V.V. Polovtsov was the first to suggest that the tobacco disease, described in 1886 by A. Mayer in Holland under the name mosaic, represents not one, but two completely different diseases of the same plant; one of them is grouse, the causative agent of which is a fungus, and the other is of unknown origin. Based on the experience of peasants, their own observations and the study of diseased plants, D.I. Ivanovsky and V.V. Polovtsev came to the conclusion that the disease grouse affects plants planted on old tobacco plantations, and gave recommendations on introducing crop rotation and improving farming standards. and a means to combat it.”

D.I. Ivanovsky showed that a tobacco disease - tobacco mosaic - can be transferred from diseased plants to healthy ones if they are infected with the juice of diseased plants, previously passed through a special filter that retains bacteria. The causative agent of mosaic disease is called by D.I. Ivanovsky either “filterable bacteria” or microorganisms, and this is understandable, since it was very difficult to immediately formulate the existence of a special world of viruses. In 1898, M. Beijerink confirmed the data of D.I. Ivanovsky and put forward the hypothesis that the disease is not caused by a bacterium, but by a fundamentally new infectious agent, different from bacteria. He called it contagium vivum fluidum (liquid infectious principle), in other words, a filterable virus (the term “virus” - from the Latin “poison”, “poisonous principle” - was then used to designate the infectious beginning of any disease).

In addition to major conclusions confirming the existence of a new, previously unknown class of microorganisms, Ivanovsky’s dissertation contains other important data. Thus, he described the cytopathic effect of the tobacco mosaic pathogen and gave characteristics of the crystals, which were later, in 1935, identified as crystals of the tobacco mosaic virus. There is also a description of intracellular inclusions, which laid the foundation for the doctrine of inclusions in viral infections, which to this day has retained its importance for the diagnosis of viral diseases.

Along with his work on virology, which brought him worldwide fame, he also conducted other research. He is the author of 180 publications, including a number of works in the field of soil microbiology, physiology and anatomy of plants and 30 articles in encyclopedic dictionary Brockhaus. Ivanovsky’s scientific activities were combined with pedagogical ones: he was an excellent lecturer and teacher who educated more than one generation of students at St. Petersburg, Warsaw and Don universities.

ETIOLOGY is the study of the causes and conditions of the occurrence and development of diseases and pathological processes.

ETIOLOGICAL FACTOR (EF) is the main, leading, causative factor, without which there would be no disease (for example, Koch's bacillus in tuberculosis). The etiological factor can be simple (mechanical impact) or complex (damaging factors of a nuclear explosion), acting for a long time, throughout the entire disease (microbes, viruses, toxins), or only triggering the pathological process (thermal factor in a burn).

PATHOGENESIS OF A DISEASE is a dialectically contradictory process that includes two opposing trends: on the one hand, these are mechanisms of breakdown, damage, deviations from the norm, and on the other, mechanisms of protection, adaptation, compensation and reparation.

Examples: HPV are small DNA viruses, the characteristic feature of which is the ability to cause proliferation of the epithelium of the skin and mucous membranes.

Back in 1986, Y.V. Bohman formulated the general principles of treatment of background diseases of the cervix: it should include the elimination of the etiological factor and those inflammatory, dyshormonal, immunosuppressive and dysmetabolic changes in the body that contribute to its occurrence and maintenance of a long-term course.

Currently, etiopathogenetic therapy of cervical pathology has two main directions - influencing the etiological factor - the human papillomavirus and blocking the main mechanisms of carcinogenesis, namely hormonal carcinogenesis associated with the increased formation of the aggressive metabolite of estradiol - 16a-hydroxyestrone (16a-OH) against the background hyperestrogenemia and HPV infection.

The etiological role in human pathology of human herpes virus type 6 has been proven in relation to two independent diseases: sudden exanthema in young children and syndrome chronic fatigue in adults.

Later, the etiological role of HHV-6 in the occurrence of this syndrome was proven. Although it still remains unclear whether chronic fatigue syndrome is etiologically associated with infection with human herpes virus type 6, or whether the disease is a consequence of reactivation of a latent infection, i.e. HHV-6 plays a pathogenetic role. Unlike sudden exanthema, chronic fatigue syndrome is a disease of adults.

In 1957, the polio, coxsackie and ECHO viruses were combined into one group and called human enteric viruses. 6 last decades Evidence continued to accumulate explaining the role of enteroviruses in human pathology.

As has now been established, enteroviruses play an etiological role in the occurrence of serous meningitis and, much less frequently, meningoencephalitis with a benign course.

Ivanovsky Dmitry Iosifovich (1864-1920) - an outstanding microbiologist and physiologist who left a noticeable mark on science. Back in late XIX century, suggested the presence of special microorganisms - viruses that cause a number of plant diseases. His theory was confirmed in 1939.

Biography

Ivanovsky Dmitry Iosifovich was the son of landowner Joseph Antonovich Ivanovsky, who owned an estate in the Kherson province. However, the future scientist was born in the village of Nizy, St. Petersburg province. He received his primary education at the gymnasium of the city of Gdov, and then continued his studies at the Larinsky gymnasium, from which he graduated with a gold medal in the spring of 1883.

In August of the same year he entered St. Petersburg University in the department of natural sciences. Among his teachers were the great Russian scientists I. M. Sechenov, N. E. Vvedensky, D. I. Mendeleev, V. V. Dokuchaev, A. N. Beketov, A. S. Famintsyn.

First studies

In 1887, Ivanovsky and Polovtsev, a fellow student in the plant physiology department, were assigned to investigate the causes of a disease that affected the tobacco plantations of Ukraine and Bessarabia. In 1888 and 1889, they studied this disease called Wildfire and concluded that the disease was not contagious. This work determined Ivanovsky's future scientific interests.

On May 1, 1888, having defended his thesis “On two diseases of tobacco plants,” Dmitry Iosifovich Ivanovsky graduated from St. Petersburg University, receiving a PhD degree. On the recommendation of two professors A. N. Beketov and K. Ya. Gobi, he remained at the university to prepare for a teaching career. In 1891, the biologist joined the botanical laboratory of the Academy of Sciences.

Virus discovery

In 1890, a new disease appeared on tobacco plantations in Crimea, and the Directorate of the Department of Agriculture invited Ivanovsky to study it. In the summer, the scientist went to Crimea. The first results of his research on mosaic disease were published in 1892. This was the first document containing actual evidence of the existence of new infectious pathogenic organisms - viruses.

On January 22, 1895, Dmitry Iosifovich Ivanovsky defended his master’s thesis “Study of Alcohol,” in which he studied the vital activity of yeast under aerobic and anaerobic conditions. He thus received a master's degree in botany and was subsequently appointed to a course of lectures on the physiology of lower plants. Soon he became an assistant professor.

New milestones

By this time, Ivanovsky had married E.I. Rodionova, and they had a son, Nikolai. In October 1896 he entered the Institute of Technology as an instructor in physiology, working there until 1901. During this period, Dmitry Iosifovich was engaged in an in-depth study of the etiology of tobacco disease.

In August 1901, the great Russian scientist moved to Warsaw and in October was appointed extraordinary professor. His work “Mosaic Disease in Tobacco,” which summarized research into the etiology of mosaic disease, was published in 1902. In 1903, he presented the book as a doctoral dissertation and defended it in Kyiv. The microbiologist received a doctorate of science and the title of professor.

Unrecognized genius

After defending his doctoral dissertation, Dmitry Iosifovich Ivanovsky abandoned the study of viruses. Apparently, he made this decision because of the extraordinary complexity of the problem itself, as well as the indifference and misunderstanding that most scientists showed towards his work. Neither his contemporaries nor Ivanovsky himself properly assessed the consequences of his discovery. Either his work went unnoticed or was simply ignored. A possible reason for this was the extraordinary modesty of the researcher: he did not give wide publicity to his discoveries.

In Warsaw, Iwanowski studied plant photosynthesis in relation to the pigments of green leaves. The choice of this topic was inspired by his interest in the chlorophyll-bearing structures (chloroplasts) in plants, which arose during his work on mosaic disease. During these studies, the biologist studied the absorption spectra of chlorophyll in a living leaf and in solution. He discovered that chlorophyll in solution was quickly destroyed by light. The scientist also suggested that the yellow pigments of the leaves - xanthophyll and carotene - act as a shield to protect the green pigment from the damaging effects of ultraviolet rays.

Achievements

The main merit of Dmitry Iosifovich Ivanovsky is the discovery of viruses. He discovered a new type of pathogen source, which M. W. Beijerinck rediscovered in 1893 and called a “virus.” The microbiologist determined that the sap of the diseased plant remained infected after filtration, although the bacteria visible under the microscope had been filtered out.

The scientist believed that this pathogen was in the form of discrete particles - extremely small bacteria. His point of view here differed from that of Beijerinck, who considered the virus to be an “infectious living fluid” (Contagium vivum fluidum). Ivanovsky repeated Beyerinck's experiments and became convinced of the correctness of his own conclusions. After analyzing Ivanovsky’s arguments, Beijerinck agreed with the opinion of the Russian scientist.

Bibliography

Original works by Dmitry Iosifovich Ivanovsky:

“News about microorganisms in the soil” (1891).
“On two diseases of tobacco” (1892).
"Research on the Fermentation of Alcohol" (1894).
Dissertation “Mosaic disease in tobacco” (1902).
"Plant Physiology" (1924).

The scientist’s works were collected in “Selected Works” (Moscow, 1953).

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OMSK STATE MEDICAL ACADEMY

DEPARTMENT OF PUBLIC HEALTH AND HEALTH CARE

Coursework

The emergence of virology. D. I. Ivanovsky 1892

Completed by a student

Faculty of Pediatrics, group No. 134

Bekturova A.R.

Checked by department assistant

Rasny V.I.

Introduction

1. Ivanovsky D. I.

2.Tobacco mosaic virus

3. Virology as a science:

3.1 History

3.3 Poliomyelitis

References

Introduction

Nowadays, the problem of viruses is very relevant. It attracts the attention of an increasing number of scientists. When the existence of viruses became known, no one suspected that they would be so dangerous. Thousands of people are now infected with such dangerous viruses as AIDS and cancer, but not only people suffer from viral infections, also plants and animals, and this is a problem for all of humanity. Viruses have the ability to mutate and acquire new qualities, as a result of which new viruses unknown to science arise (human immunodeficiency virus, avian influenza, and others). The science of virology deals with this problem.

Virology today is an actively developing science that uses the most modern discoveries and technologies. Its theoretical and practical significance for medicine, veterinary medicine, and agriculture is enormous. It is necessary not only to study viruses, but also to search for new effective methods of combating them. Questions of microbial genetics and current problems of biochemistry are studied using viruses. Scientists are increasingly and more deeply and successfully cognizing the finest structure, bio chemical composition and the physiological properties of these ultramicroscopic living beings, their role in nature, human, animal and plant life. The development of virology is associated with the brilliant successes of molecular genetics. The study of viruses has led to an understanding of the fine structure of genes, deciphering the genetic code, and identifying mutation mechanisms. Viruses are widely used in genetic engineering work. The ability of viruses to adapt and behave unpredictably knows no limits.

Millions of people have become victims of viruses that cause various diseases. And yet, the main successes of virology have been achieved in the fight against specific diseases, and this gives grounds to assert that in our third millennium, virology will take a leading place.

In my work I want to reflect important points related to the emergence of this important science for humanity, its goals and objectives, as well as the problems of virology that scientists around the world are struggling with. I will talk about the founder of virology D.I. Ivanovsky and other scientists who contributed to the development of virology.

1. Ivanovsky D. I

Diseases of plants, animals and humans, the viral nature of which has now been established, have caused harm to the economy and human health for many centuries. Although many of these diseases were dangerous, attempts to establish their cause and find the causative agent remained unsuccessful.

For the first time, the existence of a virus (a new type of pathogen) was proven in 1892 by the Russian scientist D.I. Ivanovsky.

Dmitry Iosifovich was born in 1864 in the St. Petersburg province. Graduated from high school with honors. In August 1883, he entered the Faculty of Physics and Mathematics at St. Petersburg University. Since 1890 - assistant at the botanical laboratory of the St. Petersburg Academy of Sciences. In 1895 he defended his master's thesis and, as a private assistant professor at St. Petersburg University, began lecturing on the physiology of lower organisms, and from 1896 - on the anatomy and physiology of plants. From 1901 he was an extraordinary professor, and from 1903 - an ordinary professor at the University of Warsaw. In Warsaw, Ivanovsky simultaneously taught at the Higher Women's Courses.

Ivanovsky laid the foundation for virology, which has now grown into an independent field of science. The discovery of viruses played a huge role in the development of a number of scientific disciplines: biology, medicine, veterinary medicine and phytopathology. It made it possible to decipher the etiology of diseases such as rabies, smallpox, encephalitis and many others. Dr. Ivanovsky also studied the process of alcoholic fermentation and the influence of oxygen, chlorophyll and other pigments of green leaves involved in the process of photosynthesis on it. His work on general agricultural microbiology is also known. Ivanovsky was a Darwinist, emphasizing the dependence of organisms on conditions environment and proved the evolutionary significance of this fact.

Subsequently, Ivanovsky conducted a scientific study of the air nutrition of plants; he focused his attention on studying the state of plant chlorophyll, the importance of carotene and xanthophyll for plants, the resistance of chlorophyll to light in a living leaf and the second maximum of assimilation. Ivanovsky conducted these studies together with M.S. Tsvet - the creator of the method of adsorbed chromatographic analysis.

In 1915, the University of Warsaw was evacuated to Rostov-on-Don. The evacuation did not allow the transfer of the laboratory that Ivanovsky had been creating in Warsaw for many years. During this difficult time for the country, Ivanovsky had to organize everything anew. While working at Don University, Ivanovsky participated in its public life as chairman of the biology department of the Society of Natural Scientists.

Along with Ivanovsky’s work on virology, which brought him world fame, he also conducted other research. He is the author of 180 publications, including a number of works in the field of soil microbiology, physiology and anatomy of plants, 30 articles in the Brockhaus and Efron encyclopedic dictionary and a two-volume textbook on plant physiology.

In recognition of the outstanding merits of D.I. Ivanovsky in front of virological science, the Institute of Virology of the USSR Academy of Medical Sciences (now RAMS) was named after him in 1950, and the Ivanovsky Prize was established at the Academy of Medical Sciences, which is awarded once every three years for the best scientific work in virology.

In 1964, a scientific anniversary session was held, an anniversary medal was issued, which was awarded to scientists and scientists who contributed to the development of virology, as well as an anniversary stamp with the image of D.I. Ivanovsky. At the end of the 70s, a bust of D.I. was installed in front of the building of the Institute of Virology. Ivanovsky.

D.I. Ivanovsky died at the age of 56 on June 20, 1920 from cirrhosis of the liver. He was buried in Rostov-on-Don at the Novoposelensky cemetery, where a monument was erected to him. On the house N-87 on Socialistheskaya Street, where the scientist lived, there is a memorial plaque with the inscription: “The greatest Russian scientist, the founder of the science of viruses, Dmitry Iosifovich Ivanovsky (appeared in 1864; died in 1920), lived in this house.”

2. Tobacco mosaic virus

Under the influence of outstanding scientists who taught at the St. Petersburg Institute at that time (I.M. Sechenov, A.M. Butlerov, V.V. Dokuchaev, A.N. Beketov, A.S. Famitsyn and others), the worldview of the future scientist was formed .

As a student, D.I. Ivanovsky worked with enthusiasm in a scientific biological circle, conducted experiments on the anatomy and physiology of plants, carefully performing experiments.

Therefore, perhaps A.N. Beketov, who headed the society of naturalists, and Dr. A.S. Famitsyn suggested in 1887 that students Ivanovsky and Polovtsov go to Ukraine and Bessarabia to study tobacco disease, which was causing great harm to the agriculture of southern Russia.

The main results of observations and studies of the anatomy and physiology of diseased plants were reported by D. I. Ivanovsky in 1888 at a meeting of the St. Petersburg Society of Naturalists and presented in an article by D. I. Ivanovsky and V. V. Polovtsev.

As a result of these observations, D.I. Ivanovsky and V.V. The Polovtsians were the first to suggest that the tobacco disease, described in 1886 by A. Mayer in Holland under the name mosaic, represents not one, but two completely different diseases of the same plant; one of them is grouse, the causative agent of which is a fungus, and the other is of unknown origin. Based on the experience of farmers, their own observations and research on diseased plants, D.I. Ivanovsky and V.V. Polovtsev came to the conclusion that the hazel grouse disease affects plants planted on old tobacco plantations, and gave recommendations for introducing crop rotation and increasing farming practices.

D.I. Ivanovsky continues his research on tobacco mosaic disease in the Nikitsky Botanical Garden (near Yalta) and the botanical laboratory of the Academy. The results of these studies are presented in the report “On Two Diseases of Tobacco”, made on February 14, 1892 at the Academy of Sciences, and published in the journal “Agriculture and Forestry”, as well as in a separate publication “On Two Diseases of Tobacco”. In this work, dated 1892, D.I. Ivanovsky comes to the conclusion that tobacco mosaic disease is caused by bacteria passing through the Chamberlant filter, which are not able to grow on artificial substrates. For the first time, data on the causative agent of tobacco mosaic are presented, which for a long time have been criteria for classifying pathogens as “viruses”: filterability through “bacterial” filters, inability to grow on artificial media, reproduction of the disease picture with a filtrate free of microbes and fungi. The causative agent of mosaic disease is called by D.I. Ivanovsky, either filterable bacteria or microorganisms, and this is understandable, since it was very difficult to immediately construct the existence of a special world of viruses.

In connection with the completion of his own master’s thesis “Research on alcoholic fermentation” D.I. Ivanovsky was forced to temporarily stop research on tobacco mosaic disease and returned to it a few years later, finishing it by 1900.

Based on countless experiments and repeated studies, developing the main principles published in 1892, he summarizes them in his doctoral dissertation on the topic “mosaic tobacco disease,” which he defended at the Kiev Institute on March 16, 1903.

DI. Ivanovsky had no doubt about the significance of his own discovery of a fundamentally new class of phenomena. Emphasizing that the causative agent of tobacco mosaic disease could not be found in the tissues of diseased plants using a microscope and was not cultivated on artificial nutrient media. DI. Ivanovsky wrote that his guesses about the living and organized nature of the pathogen formed into a whole theory of a special kind of infectious diseases, the representative of which, in addition to tobacco mosaic, is foot and mouth disease. In addition to major conclusions asserting the existence of a new, previously unknown class of microorganisms, providing criteria and methods for their determination, i.e. laying the foundations of a scientific discipline called virology, Ivanovsky’s dissertation also contains other fundamental data. Thus, Chapter 4 describes the cytopathic effect of the tobacco mosaic pathogen; This chapter and the accompanying microphotographs show the characteristics of the crystals that were identified in 1935 as crystals of the tobacco mosaic virus. There is also a description of intracellular inclusions, which laid the foundation for the doctrine of inclusions in viral infections, which to this day has retained its importance for the diagnosis of viral infections.

D.I. Ivanovsky discovered viruses - a new form of existence of life. With his research, he laid the foundation for a number of scientific areas of virology: research into the nature of viruses, cytopathology of viral infections, filterable forms of microorganisms, chronic and latent virus carriage. One of the outstanding Russian phytovirologists V.L. Ryzhkov wrote: “Ivanovsky’s merits are not only that he discovered completely new look diseases, but also that he gave ways to study them, was the founder of the pathological method of studying plant diseases and the pathological cytology of viral diseases.” The world-famous American scientist Nobel Prize laureate Stanley gave the highest assessment of Ivanovsky’s research: “Ivanovsky’s right to fame grows over the years. I believe that his attitude towards viruses must be viewed in the same light as we look at the attitude of Pasteur and Koch towards bacteria.”

Direct successors of Ivanovsky in the study of viral diseases of tobacco are V.L. Ryzhkov, K.S. Sukhov, I.P. Khudyna, M.S. Ternovsky, P.A. Agatov, M.I. Goldin and others.

3. Virology as a science

3.1 History

The first half of our century was devoted to close study of viruses that cause acute febrile diseases, the development of ways to combat these diseases and ways to prevent them.

Virus discoveries poured out like a cornucopia: in 1892, the tobacco mosaic virus was discovered - the year of birth of virology as a science; 1898 - foot-and-mouth disease virus discovered, 1901 - yellow fever virus, 1907 - smallpox virus, 1909 - polio virus, 1911 - Rous sarcoma virus, 1912 - herpes virus, 1926 - vesicular stomatitis virus, 1931 - swine influenza virus and western equine encephalomyelitis virus, 1933 - human influenza virus and eastern equine encephalomyelitis virus, 1934 - Japanese encephalitis virus and mumps virus, 1936 - mouse mammary gland cancer virus, 1937 - tick-borne encephalitis virus, 1945 - virus Crimean hemorrhagic fever, 1948 - Coxsackie viruses, 1951 - murine leukemia viruses and ECHO viruses, 1953 - adenoviruses and human wart virus, 1954 - rubella virus and measles virus, 1956 - parainfluenza viruses, cytomegaly virus and respiratory syncytial virus virus, 1957 - polyomas, 1959 - Argentine hemorrhagic fever virus, 1960 - godrinoviruses.

Therefore, the first half of our century truly turned out to be an era of great virological discoveries. And this is quite understandable and justified, since the first step in the fight against a disease is to find out its background. And viruses ultimately provided humanity with an invaluable service in the fight, first, against viruses and other infectious diseases.

Thousands of years ago, when people had no idea about viruses, the terrible diseases caused by them forced them to find ways to get rid of them. Even 3,500 years ago in ancient China, it was noticed that people who had suffered a mild form of smallpox never got sick with it again. Fearing a more severe form of this disease, the ancients decided to artificially infect children with a mild form of smallpox. This method of prevention - variolation - is not widespread. The mortality rate among vaccinated people reached 10%. During vaccinations, it was difficult to dose infectious material from a patient. The problem of protecting against smallpox was solved only at the end of the 18th century by the English physician Edward Jenner. He found that some milkmaids never get sick from smallpox, and, specifically, those who had previously suffered a mild disease - cowpox, or, as it was called, a vaccine (from the Greek vacca, which means “cow”).

In 1796, Ginner conducted an experiment in grafting the contents of a pustule from a milkmaid's hand onto the skin of the shoulder of an 8-year-old boy, James Phipps. Only a few bubbles broke out at the injection site. A month and a half later, Jenner injected Phipps with the purulent contents of a skin vesicle from a smallpox patient. The boy did not get sick. The smallpox vaccine was the first antiviral vaccine, although the smallpox virus was discovered 57 years later.

In the fight against viral diseases, scientists first sought to find and isolate the pathogen. Having studied its characteristics, we began to prepare the vaccine. This is how the young science of viruses emerged in the fight for human health and life.

3.2 Human influenza virus

Influenza (from the French grippe) is an acute infectious disease of the respiratory tract caused by the influenza virus. Included in the group of acute respiratory viral infections (ARVI). Periodically spreads in the form of epidemics and pandemics. Currently, more than 2000 variants of the influenza virus have been identified, differing in their antigenic spectrum. According to WHO estimates, from all variants of the virus during seasonal epidemics, from 250 to 500 thousand people die annually in the world (most of them are over 65 years old), in some years the number of deaths can reach a million. Presumably, the name of the disease comes from the German word “Grips”, which means pharynx, throat, or from the English word “grip” to twist, grab (about a disease). The Russian word “wheezing” comes from the Latin word crepitatio (crepito, crepo - to crack, creak, click) - the sounds made by patients and are not directly related to the word flu (Russian words that contain the letters X and F are not considered Russian) and passed into the Russian language from the Old French “grippe”.

Often, the word “flu” in everyday life is also used to refer to any acute respiratory disease (ARVI), which is erroneous, since in addition to influenza, more than 200 types of other respiratory viruses (adenoviruses, rhinoviruses, respiratory syncytial viruses, etc.) have been described to date, causing influenza-like illnesses in humans.

To prevent influenza, the US Centers for Disease Control and Prevention recommends vaccinating all persons over 6 months of age (especially those at risk), using personal protective equipment, reducing contact with sick people, and using antiviral drugs as prescribed by a doctor.

All age categories of people are susceptible to influenza. The source of infection is a sick person with an obvious or erased form of the disease, releasing the virus by coughing, sneezing, etc. The patient is contagious from the first hours of the disease until the 5-7th day of illness. It is characterized by an aerosol (inhalation of tiny droplets of saliva, mucus that contain the influenza virus) transmission mechanism and extremely rapid spread in the form of epidemics and pandemics. Influenza epidemics caused by serotype A occur approximately every 2-3 years, and those caused by serotype B occur every 4-6 years. Serotype C does not cause epidemics, only isolated outbreaks in children and weakened people. It occurs more often in the form of epidemics in the autumn-winter period. The frequency of epidemics is associated with frequent changes in the antigenic structure of the virus when it remains in natural conditions. High-risk groups are children, the elderly, pregnant women, people with chronic heart and lung diseases.

3.3 Poliomyelitis

Poliomyelitis is infantile spinal paralysis, an acute, highly contagious infectious disease caused by damage to the gray matter of the spinal cord by poliovirus and characterized mainly by pathology of the nervous system. Basically, it occurs in an asymptomatic or erased form. Sometimes it happens that the poliovirus penetrates the central nervous system and multiplies in motor neurons, which leads to their death, irreversible paresis or paralysis of the muscles they innervate.

The source of infection is a patient or a virus carrier, while the most dangerous are patients with erased and abortive forms of the disease. The infection is transmitted by the fecal-oral route (dirty hands, toys, contaminated food) and by airborne droplets. Susceptibility to the polio virus is universal, but children under 7 years of age are most susceptible. At the same time, the paralytic form occurs in no more than 1% of cases, and erased, inapparant and abortive forms are diagnosed only at the source of infection during laboratory examination of persons in contact with people infected with polio. Children in the first 2-3 months of life, thanks to the immunity received transplacentally from the mother, practically do not suffer from polio. Repeated cases of the disease are practically not recorded, since after the illness a stable immunity is developed and the cells of the intestinal mucosa are observed to be immune to homologous types of the virus. infectious influenza virus polio

Although polio is now rare in the Western world, it is still endemic in South Asia and Nigeria. Since the widespread use of the polio vaccine in the mid-1950s, the incidence of polio has declined sharply in many industrialized countries. And in 1988, under the leadership of the World Health Organization, UNICEF and Rotary International, a global effort was made to eradicate polio. These efforts have resulted in a 99% reduction in the number of annual cases diagnosed. The estimated incidence fell from 350,000 in 1988 to 483 in 2001, after which it remained at around 1,000 per year (1,606 in 2009). Polio is currently one of only two diseases targeted for global eradication, the other being guinea worm.

The spread of HIV infection is associated mainly with unprotected sexual intercourse, the use of virus-contaminated syringes, needles and other medical and paramedical instruments, transmission of the virus from an infected mother to a child during childbirth or breastfeeding. In developed countries, mandatory testing of donated blood has greatly reduced the possibility of transmission of the virus through its use.

Once in the human body, HIV infects CD4+ lymphocytes, macrophages and some other types of cells. Having penetrated the cells of these types, the virus begins to actively multiply in them. This ultimately leads to the destruction and death of infected cells. The presence of HIV over time causes disruption of the immune system due to its selective destruction of immunocompetent cells and suppression of their subpopulation. Viruses that leave the cell are introduced into new ones, and the cycle repeats. Gradually, the number of CD4+ lymphocytes decreases so much that the body can no longer resist pathogens of opportunistic infections, which are not dangerous or little dangerous for healthy people with a normally functioning immune system.

Timely initiation of treatment with antiretroviral drugs (HAART) stops the progression of HIV infection and reduces the risk of developing AIDS to 0.8-1.7%. However, antiretroviral drugs are widely available only in developed and some developing (Brazil) countries due to their high cost.

The HIV pandemic is one of the most devastating epidemics in human history.

To date, no treatment has been developed for HIV infection that could eliminate HIV from the body.

The modern method of treating HIV infection (the so-called highly active antiretroviral therapy) slows down and practically stops the progression of HIV infection and its transition to the AIDS stage, allowing an HIV-infected person to live a full life. If treatment is used and the effectiveness of the drugs is maintained, a person's life expectancy is not limited by HIV, but only by the natural processes of aging. However, after prolonged use of the same treatment regimen, after several years, the virus mutates, acquiring resistance to the drugs used, and to further control the progression of HIV infection, it is necessary to use new treatment regimens with other drugs. Therefore, any current treatment regimen for HIV infection sooner or later becomes ineffective. Also, in many cases, the patient cannot take certain medications due to individual intolerance. Therefore, proper use of therapy delays the development of AIDS indefinitely. To date, the emergence of new classes of drugs is mainly aimed at reducing side effects from taking therapy, since the life expectancy of HIV-positive people taking therapy is almost equal to the life expectancy of the HIV-negative population. During the later development of HAART (2000-2005), the survival rate of HIV-infected patients, excluding patients with hepatitis C, reaches 38.9 years (37.8 for men and 40.1 for women.)

Great importance is attached to maintaining the health of an HIV-positive person using non-drug means (proper nutrition, healthy sleep, avoiding severe stress and prolonged exposure to the sun, a healthy lifestyle), as well as regular (2-4 times a year) monitoring of health status by medical specialists. HIV.

To summarize, we can conclude: virology not only occupies a worthy place among the basic sciences, like the study of viruses, but is also to a significant extent a medical science.

References

1) Ivanovsky D.I. About two diseases of tobacco - M., Medgiz, 1949 - 181 p.

2) Khaitov R. M. AIDS. - M.: Publishing House of the People's Academy of Culture and Human Values, 1992

3) Small V.P. HIV. AIDS. The latest medical reference book. - M.: Eksmo, 2009.

4) Zhdanova V.M., Gaidamovich S.Ya. Public and private virology Ed. Medicine, M., 1982 G. S. 5-11.

5) Ivanovsky D.I. Polovtsev V.V. Ryabukha - a disease of tobacco, its prerequisites and means of combating it - St. Petersburg, 1890.

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