Sections of medicine explore various issues. One, for example, studies the clinical picture, that is, the manifestation of pathology. Other branches of medicine study the consequences or reactions of the body to certain influences. Pathological provoking factors are of particular importance both in diagnosis and in the subsequent choice of therapy. Etiology is a field that just explores causes. Later in the article we will analyze this term in more detail.
General information
Etiology - these are the causes of diseases, the occurrence of which requires a combination of the influence of the main factor and the totality of conditions of the internal and external environment suitable for the manifestation of its action. Poisons, pathogenic microorganisms, radiation, trauma, as well as many other chemical, biological and physical influences can act as provocative phenomena. The disease can occur in conditions of hypothermia, fatigue, malnutrition, unsuitable social and geographical environment. An important role is played by the characteristics of the body. These include, in particular, gender, age, genotype, and others.
Factors
The concept of etiology is notlimited to specific reasons. Basically, for the occurrence of a disease, in addition to a provoking phenomenon, certain favorable conditions are necessary for it. For example, streptococcus, present in the oral cavity in the form of a saprophyte, due to the prolonged influence of low temperatures, causes angina. This is due to the weakening of the body's defense mechanisms. And sticks of typhoid fever and diphtheria without causing factors (fatigue, starvation) may not manifest themselves in any way. Often there are situations when the same factor can act in some cases as an etiological, and in others as a conditional one. An example is hypothermia. On the one hand, it causes frostbite, and on the other hand, it provides optimal conditions for the occurrence of many infectious diseases of a cold nature.
Classification of pathologies
In some cases, the etiology of the disease may be limited to one factor. In other cases, the study may reveal several provoking factors at once. In the first case, the disease is called mono-, and in the second - polyetiological. The first type includes, for example, influenza, tonsillitis. But heart disease is formed as a result of syphilis, rheumatism and many other factors. The etiology of the disease allows you to determine its specificity and pathogenetic therapy. For example, the course, severity and prognosis of staphylococcal and anthrax carbuncles have significant differences. Also, different types of hypertension, which can be caused byboth neurogenic and renal factors. The cause of intestinal obstruction is external compression of the intestine or its internal blockage.
Factor action
Distinguish between instantaneous (trauma, burns) and long-term (starvation, infection) influence of a provoking phenomenon. These phenomena also include etiology. This influence can cause the development of an acute or chronic stage of pathology. As a result of exposure to a factor - long or short - in the human body, a failure occurs in various systems. This is what causes the disease, which is mainly a consequence of these disorders.
Treatment and prevention
Etiology is one of the main factors determining this or that method of therapy. Having identified the causes and conditions for the development of pathology, you can choose the method that will eliminate the provoking factors. Only in this case it is really possible to achieve a positive result. Prevention also plays a significant role. The disease can be prevented in case of timely elimination of pathogenic causes and factors that cause it. So, for example, the detection of bacillus carriers, getting rid of mosquitoes in places of possible malaria, and preventing injuries are carried out. However, it is not always possible to identify the causes and conditions for the development of pathology. In this case, they speak of an unclear etiology. In such situations, as a rule, the patient goes under the supervision of a doctor. Along with this, differential diagnostics and monitoring of his condition are carried out. Often the treatment of doctors in suchcases are assigned "blindly".
Etiology of diabetes
Today, there is indisputable evidence that the main cause of the development of DM is a genetic factor. This disease belongs to the polygenic species. It is based on at least two mutant diabetic genes on the b-chromosome, which are associated with the HLA system. The latter, in turn, determines the specific reaction of the organism and its cells to the action of antigens. Based on the theory of polygenic inheritance of diabetes mellitus, in the disease there are two mutant genes or two groups of them, which are inherited in a recessive way. Some people have a predisposition to damage the autoimmune system or increased sensitivity of certain cells to viral antibodies, reduced immunity to fight viruses. The genes of the HLA system are markers of this predisposition.
In 1987, D. Foster found that one of the genes that is susceptible to the disease is on the b-chromosome. At the same time, there is a connection between diabetes mellitus and certain white blood cell antibodies in the human body. They are encoded by major histocompatibility complex genes. They, in turn, are located on this chromosome.
Classification of major histocompatibility complex genes
There are three types. Genes differ in the type of encoded proteins and their participation in the development of immune processes. Class 1 includes loci A, B, C. They are able to encode antigens that are found on allcells containing a nucleus. These elements perform the function of protecting against infections (mainly viral). Class 2 genes, located in the D region, contain the DP, DQ, and DR loci. They encode antigens that can be expressed exclusively on immunocompetent cells. These include monocytes, T-lymphocytes and others. Class 3 genes encode components of complement, tumor necrosis factor, and transporters that are associated with antibody processing.
Recently, there has been an assumption that not only elements of the HLA system, but also the gene encoding the synthesis of insulin, the heavy chain of immunoglobulins, T-cell receptor bonds, and others are associated with the inheritance of insulin-dependent diabetes mellitus. People with a congenital predisposition to IDDM experience environmental changes. Their antiviral immunity is weakened, cells can be subjected to cytotoxic damage under the influence of pathogenic microorganisms and chemical components.
Other reasons
IDDM can also have a viral etiology. Most often, the pathology is promoted by rubella (the pathogen enters the pancreatic islets, then accumulates and replicates in them), mumps (the disease most often manifests itself in children after the epidemic, after 1-2 years), hepatitis B and Coxsackie B virus (replicates in insular apparatus), mononucleosis infection, influenza and others. The fact that the factor under consideration is related to the development of diabetes mellitus is confirmed by seasonality.pathology. Typically, IDDM is diagnosed in children in the fall and winter, reaching its peak in October and January. Also in the blood of patients, high titers of antibodies to pathogens can be detected. In people who have died of diabetes, as a result of immunofluorescence research methods, viral particles are observed in the islets of Langerhans.
The principle of the exciter
Experimental studies conducted by M. Balabolkin confirm the involvement of this infection in the development of the disease. According to his observations, the virus in people with a tendency to diabetes acts in this way:
- acute cell damage is noted (for example, Coxsackie virus);
- persistence (long survival) of the virus (rubella) occurs with the formation of autoimmune processes in the islet tissue.
Etiology of liver cirrhosis
Depending on the causes of occurrence, this pathology is divided into three groups. These include, in particular:
- With certain etiological reasons.
- With controversial provoking factors.
- Unclear etiology.
Investigation of the causes of damage
Clinical, epidemiological and laboratory studies are carried out to identify factors that provoke cirrhosis. At the same time, a connection with excessive alcohol consumption is established. For a long time it was believed that cirrhosis of the liver occurs in conditions of malnutrition of an alcoholic. In this regard, this pathology was called alimentary or nutritional. In 1961 Beckett createdwork in which he described alcoholic hepatitis of the acute stage. At the same time, he suggested that it was this disease that increased the risk of cirrhosis of the liver associated with alcohol intake. Subsequently, the effect of ethanol on the development of toxic hepatitis, which can turn into damage to the tissues of the hematopoietic organ, was established. This is especially true for retransmission of the disease.
Dangerous dosages of ethanol
Cirrhosis of the liver caused by alcohol does not necessarily develop with the stages of acute or chronic hepatitis. The disease can be transformed in a different way. In total, there are three main stages:
- fatty degeneration of the organ;
- fibrosis with mesenchymal reaction;
- cirrhosis.
The risk of developing a disease as a result of 15 years of excessive drinking is 8 times that of a five-year intake of alcohol. Pequigno identified a dangerous dosage of ethanol for the development of cirrhosis of the liver. It is 80 g per day (200 g of vodka). A very dangerous daily dose is the use of 160 g of alcohol or more. In the future, the "Pequigno formula" was somewhat changed. Women have twice the alcohol sensitivity than men. In some representatives of the stronger sex, the cirrhosis threshold is reduced to 40 g of ethanol per day, in others the disease develops when taking 60 ml of alcohol. For women, 20 ml of alcohol per day is enough. In the development of alcoholic cirrhosis of the liver, the main role is played by a specific lipopolysaccharide of intestinal origin - endotoxin.
Other reasons
Cirrhosis can occur due to genetically determined metabolic disorders. In both children and adults, a relationship was found between the development of pathology and a1-antitrypsin deficiency. A1-antitrypsin is a glycoprotein that is synthesized in the hepatocyte and is an inhibitor of the immediate effects of serine proteinases (elastase, trypsin, plasmin, chymotrypsin). Against the background of insufficiency, cholestasis occurs in 5-30% of children, and 10-15% develop cirrhosis of the liver at a very young age. Moreover, even in cases of biochemical disorders, the prognosis is usually favorable. In old age, the likelihood of developing cirrhosis and liver cancer increases. This is especially true for people with emphysema. The functioning of the liver can also be impaired when chemicals and pharmacological preparations enter the body. As a result, there are acute stages of damage to this organ and chronic hepatitis. In rare cases, cirrhosis of the liver develops. For example, carbon tetrachloride can cause acute and sometimes toxic chronic hepatitis. This pathology may in some cases be accompanied by massive necrosis and the development of cirrhosis.
