What is a virus?

1801. The uprising in Haiti. To Negroes came the ideas of the French revolution. They want to be free! But in France already rules the first Consul Napoleon. General Leclerc with 25 thousand French soldiers appears in Haiti. Blacks are protected. But how can they resist the famous Napoleon's troops? The outcome of the struggle seemed a foregone conclusion. The Negroes, however, you receive an unexpected ally. Battalions of Napoleon thinning. From 25 thousand soldiers remain only 3 thousand. This is the first defeat of Napoleon. Not bullets blacks caused the death of the French soldiers. They were killed yellow fever. Much later it became known that the causative agent of yellow fever virus.
1875. To secluded Islands Fiji suitable vessel. Among the passengers - patient measles child. The population was not aware of this disease. People were born, grew up and died on these Islands, never aching measles. A sick child was the cause of the epidemic. Measles did not spare anybody: infants, adults, old people - ill the whole population. Later it became known that the causative agent of measles is a virus.
the year 1918. Still burn battlefields of the first world war. But a new enemy already threatens the devastated mankind. Against this enemy powerless guns and diplomatic combinations. Across the globe poured fire influenza epidemic. She carries away into the grave 20 million lives, much more, than the shells and bullets all the warring States of the first world war. Later it turned out that the flu is caused by a virus.
1935 and 1936 years. In the valley Yakima, Washington state, killed the horse. Their "dying a lot. They die in the other States. Only in 2-3 months of summer ill 276 thousand horses. They fell ill with encephalitis, inflammation of the brain, which is also a special virus.
Such examples could be multiplied indefinitely. Viruses destroy people, animals, birds, dogs, fur animals, fishes, bees, silkworms. They are ruining cotton, tobacco, potatoes, fruit trees. They are able to affect all living things, from bacteria to man.
Viruses are not only a health problem, it is a big economic problem.
But what is a virus?
...February 14, 1892. Meeting of the Russian Academy of Sciences in St. Petersburg. Reported research Dmitry I. Ivanovsky about the study of disease, tobacco, called mosaic disease. The tobacco plantations in the Crimea die from the disease. Tobacco leaves are covered with spots formed an intricate mosaic-like patterns, and the plant dies. Ivanovo instilled a healthy plant juice patient. Vaccination has been successful, and the plant died from mosaic disease. It became clear that contagious beginning is the juice of the plant. Then Ivanovo missed juice diseased plants through filters with such a small pores that they detained all bacteria, even the most minute. Juice remained contagious. Therefore, contagious beginning juice was less than all known bacteria, and filters were not able to detain him.
Soon were discovered and other similar infectious beginning that cause disease in humans and animals. They passed through the porous filters, they could not be grown on artificial nutrient medium. They reproduced only in body tissues. They were called viruses or ultravirus.
What is the value of viruses? Divide mm per thousand parts. Each thousandth of a millimeter is microns. Now divide microns per thousand parts. Each thousandth of a micron is millimicron.
Now, the value of ultravirus calculated by millimicrons.
The largest of them, such as the smallpox virus, have a value of about 200 millimicrons. They can be seen in the ordinary microscopes with strong increases. In most cases they have the form of tiny balls. The smallest viruses have value only in a few millimicrons, for example the FMD virus. You couldn't see them in the most advanced microscopes at very high magnification. But they photographed in modern electronic microscopes, magnifying of 100 thousand times. They were also tiny balls, sometimes a little stretched. Some viruses take the form of sticks, bricks, and other seed threads.
These tiny microbes and cause various diseases. Not all illnesses caused by viruses, is acute. In some cases, the virus resides in the body, lives in it for years and decades, almost nothing showing their presence.
Everyone knows that on the lips at the edges of the mouth and on the wings of the nose sometimes pours "fever", there are small bubbles with first transparent content, which then becomes cloudy, bubbles dry up and fall off, leaving no traces. Such bubbles often appear after cooling, cold, after other diseases that weaken the body. In the content of these bubble contains a specific virus, malevolently for man, but calling in rabbits fatal inflammation of the brain. This virus called the herpes virus that resides in the body of the man since childhood and does not leave him until his death. It manifests itself only in the presence of additional conditions that weaken or alter the body. Without these conditions, the virus stays in the body for decades, nothing without revealing their virulence. Such viruses are known not only in humans but also animals. For example, in the brain almost every adult Guinea pigs have the virus that causes inflammation of the meninges. This virus in the normal conditions of existence mumps brings her no harm. But try to inject into the brain of this mumps completely harmless sterile solution of starch. The pigs will develop inflammation of the meninges. Starch will irritate cells, they will be more heavily than normal, reproduce, display a lot of young dividing cells. And this is exactly the environment in which viruses hard multiply and become the most active. The introduction of starch we create conditions for the virus meninges was hard to reproduce and were boleznennostew.
Therefore, in addition to viruses that cause acute disease and quickly die in the body, when he is recovering, there are other viruses that for a long time, sometimes for the whole life, remain in the body and show their pathogenic properties only under certain conditions.
All of these viruses in most cases cause profound changes in the cells they infect, - changes, often leading to their death. But are there other viruses that, like sarcoma virus chickens, not cause death and cell reproduction and the development of tumors?

  • Opujolevidnami viruses