Types of cell proliferation. Problems of cell proliferation in medicine
Cellular proliferation- increase in the number of cells through mitosis,
leading to tissue growth, as opposed to another method of increasing it
masses (for example, edema). There is no proliferation in nerve cells.
In the adult body, developmental processes related to
with cell division and specialization. These processes can be either normal
normal physiological, and aimed at restoring the
organism due to a violation of its integrity.
The importance of proliferation in medicine is determined by the ability of cell-
current of different tissues to division. The healing process is associated with cell division
healing of wounds and tissue restoration after surgical operations.
Cell proliferation underlies regeneration (recovery)
lost parts. The problem of regeneration is of interest to me-
dicines, for reconstructive surgery. There are physiological,
reparative and pathological regeneration.
Physiological - natural recovery cells and tissues in
ontogeny. For example, the change of red blood cells, skin epithelial cells.
Reparative- restoration after damage or death of the adhesive
current and fabrics.
Pathological- proliferation of tissues not identical to healthy tissues;
Yum.
For example, the growth of scar tissue at the site of a burn, cartilage at
fracture site, proliferation of connective tissue cells at the site of our
cervical tissue of the heart, cancerous tumor.
Recently, it has been customary to separate animal tissue cells according to their properties.
ability to divide into 3 groups: labile, stable and static. TO labile
include cells that are quickly and easily renewed
in the process of vital activity of the body (blood cells, epithelium, mucus)
ability to divide into 3 groups: labile, stable and static. gastrointestinal tract, epidermis, etc.). stable
include cells of organs such as the liver, pancreas, milk gland, salivary glands
etc., which reveal limited
new ability to divide. TO static
include cells of the myocardium and nervous tissue, which
Some, according to most researchers, do not share.
The study of cell physiology is important for understanding it
togenetic level of organization of living things and mechanisms of self-regulation
cells that ensure the integral functioning of the entire organism.
Chapter 6 GENETICS HOW
THE SCIENCE. REGULARITIES INHERITANCE
SIGNS
6.1 Subject, tasks and methods of genetics
properties of living things, since they are characteristic of living beings of any level of organiza-
nization.
The science that studies the patterns of heredity and variability news, it's called
genetics.
Genetics as a science studies heredity and hereditary variability, namely, it deals with next:
problems
1) storage of genetic information;
2) transfer of genetic information;
3) implementation of genetic information (use of it in specific
specific signs of a developing organism under the influence of the external environment);
4) changes in genetic information (types and causes of changes,
mechanisms).
The first stage of development of genetics - 1900–1912. Since 1900 - redesigned
Covering of G. Mendel's laws by scientists H. De Vries, K. Correns, E. Cher-
poppy seed Recognition of G. Mendel's laws.
Second stage 1912–1925 - creation of the chromosome theory of T. Mor-
Ghana. Third stage 1925–1940 - discovery of artificial mutagenesis and
genetic processes of evolution.
Fourth stage 1940–1953 - research on gene control
physiological and biochemical processes.
The fifth stage from 1953 to the present is the development of molecular
biology.
Some information on the inheritance of traits was known
a very long time ago, but the scientific basis for the transmission of traits was first
set out by G. Mendel in 1865 in the work: “Experiments on plant
hybrids."
These were advanced thoughts, but contemporaries did not give
the significance of his discovery. The concept of “gene” did not exist at that time and G. Men-
del spoke about the “hereditary inclinations” contained in the reproductive cells
kah, but their nature was unknown.
In 1900, independently of each other, H. De Vries, E. Chermak and K. Cor-
Rens rediscovered the laws of G. Mendel. This year is considered the year of birth
development of genetics as a science. In 1902, T. Boveri, E. Wilson and D. Setton made
They made an assumption about the connection of hereditary factors with chromosomes.
In 1906, W. Betson introduced the term “genetics”, and in 1909, V. Johansen - "gene". In 1911, T. Morgan and collaborators formulated the main principles marriage
chromosome theory
heredity.
They proved that genes
located at certain chromosomal loci in a linear order, according to
tion of a certain feature.
Basic methods of genetics: hybridological, cytological and mathematical. Genetics actively uses methods of other related sciences: chemistry, biochemistry, immunology, physics, microbiology, etc. Proliferation. Unfortunately, there are no truly absolutely working methods or methods to prevent such an anomaly in the state of the reproductive system. Pathology is usually detected at a gynecologist's appointment, and tissue samples are sent for a cytogram. Proliferation of the glandular epithelium may be an indication for the urgent initiation of a therapeutic program, but sometimes the condition is simply recorded in the anamnesis without taking any measures. Let’s try to consider in more detail what this depends on and what is commonly understood by a complex name.
General information: what is it?
Proliferation of glandular epithelium is a term that is commonly used to denote an increase in the concentration of glandular elements. Such transformations are quite often observed in the mucous membranes of the uterine cervix. Currently, the disease itself is not considered a pathology, but in some cases it may indicate health problems. To clarify the situation, additional research and medical history are required.
Anatomical base
To understand what it is (proliferation of the glandular epithelium), it is necessary to understand the structure of the female reproductive system. The mucous membrane of the organs, accessible to the gynecologist during a routine examination, and the vaginal cavity are lined from the inside with multilayered squamous epithelium. This material protects delicate internal tissues and is capable of regenerating. But the cervical canal, in contact with the described elements of the system, is covered with a different type of epithelium: tall cylindrical cells. This tissue is homogeneous; the canal is distinguished by an abundance of glands connected into a complex, branched network. This is where mucous secretions are generated.
The epithelium in the cervix changes, which is associated with the characteristics menstrual cycle, hormonal processes in the body. Regular research allows you to get a complete picture individual characteristics specific woman. During the period of ovulation, the cervical glands produce a larger volume of mucus, and the consistency is adjusted. More detailed studies make it possible to understand that the uterine cervix is a rather heterogeneous organ in its structure, where two types of epithelium gradually transform into one another. Based on this fact, doctors talk about the ambiguity of the set of functions. If research reveals glandular epithelium with signs of proliferation, this indicates a greater than normal number of glandular formations. There may be a disruption or change in the functionality of these areas and shape.
Some features
Sometimes proliferation of the glandular epithelium of the cervix is observed, and the disorders are strictly limited to the cervical canal; sometimes the changes cover the tissues of the outer side of the cervix. These are typical for areas affected by infections and inflammatory processes. In some women, pronounced proliferation of the glandular epithelium is caused by trauma. Local hormonal imbalances can lead to a similar result.
The clinical picture is determined by many factors. Sometimes changes are not accompanied by symptoms and are detected only during preventive regular inspection, in other situations, proliferation of glandular epithelial cells accompanies infectious processes pronounced form. Often the disease is combined with pseudo-erosion. This condition is characterized by the presence of modified tissues of the vaginal uterine elements.
Diagnostic features
If you suspect proliferation of glandular epithelial cells, you should visit your local gynecologist. After listening to the patient’s complaints, the doctor conducts a visual examination of the reproductive system. It is possible to detect areas of tissue that differ in color from those located nearby. This becomes the basis for further research activities in order to clarify the diagnosis. Cytology and colposcopy are the most effective approaches that help to study the cellular composition of a non-standard element and understand what it is. Proliferation of the glandular epithelium is detected by laboratory examination of a cytological smear.
Thanks to specialized studies, the doctor clarifies how increased the concentration of glands is relative to the normal structure, and also studies the structure of the changes. Based on the information obtained, we can conclude whether we are talking about malignant tissue transformations. However, as can be seen from medical statistics, moderate proliferation of the glandular epithelium usually does not indicate any serious disturbances in the functioning of the female body.
What to do?
At the appointment, the doctor will explain if the patient has been diagnosed with proliferation of the glandular epithelium, what it is and what it means in a particular case. There is no isolated treatment for such health problems. First, it is necessary to determine the reason for the deviation and eliminate it. In some cases, the condition of the epithelium returns to normal on its own; sometimes additional measures are required.
Where did the trouble come from?
For what reason does the proliferation of the glandular epithelium of the cervix develop? This question probably worries any woman with a corresponding diagnosis. Doctors were able to identify many situations leading to such consequences. It is not always a matter of serious pathology, so making a diagnosis is not a reason to panic. In particular, long-term use oral contraceptives absolutely healthy woman may provoke the appearance of individual areas of proliferation. Pathological causes The following are more commonly observed:
- infectious processes;
- inflammatory damage to vaginal tissue;
- similar changes in the cervical canal;
- cervicitis (for various reasons).
Being infected, the reproductive system of the female body activates protective natural mechanisms, affecting, among other things, the structure of the glandular epithelium of the cervix. Proliferation is a response to unwanted microflora, which the body tries to remove through an abundance of secretions. That is, unwanted microorganisms seem to be washed away from the tissues. Thanks to this measure of protection, the infection cannot penetrate deeper. On the other hand, the body's reaction leads to the growth glandular tissue, elongation of individual elements, branching of structures.
Hormones and glandular epithelial cells with signs of proliferation
The epithelium of the cervix develops under the influence of cyclic hormonal changes V female body. For dysfunction hormonal system Various malfunctions are noticeable, including in the structure and structure of this tissue. Pathologies that disrupt the functioning of the endocrine system often lead to this. During pregnancy, changes in the body also provoke an adjustment in the thickness of this mucosal layer. During pregnancy, sex hormones in the female body are present in a non-standard ratio, which causes a similar reaction. In most cases, it is noted that for the cervical epithelium in the blood there is too much low level estrogen, which leads to changes.
Injuries are known to provoke proliferation (hyperplasia) of the glandular epithelium. What is it: damage received during childbirth, termination of pregnancy, diagnostic and therapeutic procedures. All situations are associated with a violation of the integrity of the mucous membrane of the vagina and uterus, which requires activation of regenerative processes. This may cause too active growth fabrics. In some cases, hyperplasia is caused by pseudo-erosion. Distinctive feature such a state - the presence of inclusions columnar epithelium in cervical multilayer. It seems to descend along the surface of the organ from the cervical cavity. At the same time, changes in tissue structure affect the number and volume of glandular cells.
Doctor's report
Proliferation is a condition that accompanies wide range gynecological diseases, but such a violation does not have an independent picture at all. The doctor, assessing the general condition of the woman, the complaints with which she came to the appointment, selects best option research, prescribe tests and formulate conclusions. For two patients with similar manifestations, the doctors’ conclusions can be categorically different. In such a situation, there is no need to panic or point out the specialist’s incompetence: indeed, the situation is quite possible. On the other hand, such significant uncertainty of the process leads to the fact that it is very difficult to understand it without having a specific education.
Proliferation involves an increase in the number and volume of the glands of the cervix, and the location can be different: diffuse, focal. In many ways, this indicates the cause of the process. The severity of the situation is assessed by looking at the severity of tissue changes, the presence of inflammatory processes and the level of their activity.
How to notice?
Proliferation of the glandular epithelium is not associated with any characteristic clinical symptoms. Typically, a woman consults a doctor based on problems related to associated pathologies. In particular, if hyperplasia is caused by inflammation, then profuse leucorrhoea and discomfort in the vaginal area are a concern. At hormonal disorders failures are observed monthly cycle, bleeding, including at the wrong time, cycles without ovulation.
Do I need to go to the doctor?
If you suspect the presence of pathologies of the reproductive system, you should promptly make an appointment with a gynecologist. If the doctor diagnoses proliferation, prescribe laboratory research tissue samples to reveal features of cellular composition. At the same time, a visual examination usually provides a rather modest amount of information: a specialist examines the external part, the external uterine pharynx, where he records individual areas that differ from the surrounding tissues in structure and color. Normally, the epithelium is light pink shade, which is due to its multi-layered nature, and abnormal elements are brighter and more saturated.
Some women have not only elements that differ in color, but also small neoplasms, the diameter of which does not exceed one centimeter. These are hemispherical dense objects that are characterized by thin walls. The internal filling is yellowish, translucent. In medicine, this is called “Nabothian cysts.” Typically, pathology is observed in the cervical cavity, in the lower third of the volume, that is, where the Nabothian glands are located. The glands themselves are small tubes filled with secretions. The contents reach external tissues through the excretory ducts. Proliferation leads to blocking of the holes, blockage provokes the formation of a cavity filled with secretions. If such cysts are located deep in reproductive system, the doctor will not be able to see them visually. The presence of formations suggests glandular-cystic proliferation.
Some special cases
There are known situations where hyperplasia was localized only in the cervical canal. At visual inspection the doctor is not able to identify the process, since the areas are inaccessible for this research method.
If the pathology is accompanied by inflammation, as additional symptoms observed:
- local temperature increase;
- swelling of the mucous membranes;
- abundance of discharge.
As practice shows, in most cases proliferation is associated precisely with infection or inflammation, which is why doctors always prescribe lab tests- culture, flora smear, PCR. This helps to identify the pathogen and determine the presence of specific infections. When menstrual dysfunction is observed, additional tests are taken to identify disorders hormonal levels. The current phase of the cycle is taken into account.
Painstaking research
For a detailed study of modified structures, colposcopy is necessary, cytological analysis. It is taken into account that proliferation is an uneven process, in which the mucous membrane usually thickens in some places, and the glands differ from each other in size and shape. A cytogram will provide accurate information only if the process covers the uterine cervix (surface). In case of defeat cervical canal so what external os hyperplasia does not spread, accurate data can only be obtained histological examination. To do this, the cervical cavity is examined and a scraping is obtained. biological tissue, sent for further laboratory research.
As shown medical statistics, proliferation of the glandular epithelium is often observed against the background of a similar process in the endometrium. The doctor, studying the patient’s condition, examines the entire mucous membrane inside the uterine cavity for pathological condition. Informative analysis can be done by obtaining tissue samples uterine cavity, cervical. They are sent for histological examination.
It is important!
In most cases, proliferation of the glandular epithelium - benign process. Occasionally, examination of tissue samples provides information about atypical cell changes. With such a transformation it is necessary to carry out a series of additional research and perhaps visit an oncologist: the gynecologist will give directions and explain the peculiarities specific situation and all the dangers associated with it.
It must be remembered that proliferation itself does not require urgent medical intervention, but forces you to look for the cause of benign changes. There is a possibility that the source of the problems is a serious pathology, the elimination of which should be a task of paramount importance. Laboratory tests using modern technology. If an infection is detected, you will have to undergo a course of treatment with antibacterial drugs.
Proliferation of the glandular epithelium of the uterus is a diagnosis that any modern woman can face. Unfortunately, there are no truly absolutely working methods or methods to prevent such an anomaly in the state of the reproductive system. Pathology is usually detected at a gynecologist's appointment, and tissue samples are sent for a cytogram. Proliferation of the glandular epithelium may be an indication for the urgent initiation of a therapeutic program, but sometimes the condition is simply recorded in the anamnesis without taking any measures. Let’s try to consider in more detail what this depends on and what is commonly understood by a complex name.
General information: what is it?
Proliferation of glandular epithelium is a term that is commonly used to denote an increase in the concentration of glandular elements. Such transformations are quite often observed in the mucous membranes of the uterine cervix. Currently, the disease itself is not considered a pathology, but in some cases it may indicate health problems. To clarify the situation, additional research and medical history are required.
Anatomical base
To understand what it is (proliferation of the glandular epithelium), it is necessary to understand the structure of the female reproductive system. The mucous membrane of the organs, accessible to the gynecologist during a routine examination, and the vaginal cavity are lined from the inside with multilayered squamous epithelium. This material protects delicate internal tissues and is capable of regenerating. But the cervical canal, in contact with the described elements of the system, is covered with a different type of epithelium: tall cylindrical cells. This tissue is homogeneous; the canal is distinguished by an abundance of glands connected into a complex, branched network. This is where mucous secretions are generated.
The epithelium in the cervix changes, which is associated with the characteristics of the menstrual cycle and hormonal processes in the body. Regular research allows you to get a complete picture of the individual characteristics of a particular woman. During the period of ovulation, the cervical glands produce a larger volume of mucus, and the consistency is adjusted. More detailed studies make it possible to understand that the uterine cervix is a rather heterogeneous organ in its structure, where two types of epithelium gradually transform into one another. Based on this fact, doctors talk about the ambiguity of the set of functions. If research reveals glandular epithelium with signs of proliferation, this indicates a greater than normal number of glandular formations. There may be a disruption or change in the functionality of these areas and shape.
Some features
Sometimes proliferation of the glandular epithelium of the cervix is observed, and the disorders are strictly limited to the cervical canal; sometimes the changes cover the tissues of the outer side of the cervix. These are typical for areas affected by infections and inflammatory processes. In some women, pronounced proliferation of the glandular epithelium is caused by trauma. Local hormonal imbalances can lead to a similar result.
The clinical picture is determined by many factors. Sometimes changes are not accompanied by symptoms and are detected only during a preventive regular examination; in other situations, proliferation of glandular epithelial cells accompanies pronounced infectious processes. Often the disease is combined with pseudo-erosion. This condition is characterized by the presence of modified tissues of the vaginal uterine elements.
Diagnostic features
If you suspect proliferation of glandular epithelial cells, you should visit your local gynecologist. After listening to the patient’s complaints, the doctor conducts a visual examination of the reproductive system. It is possible to detect areas of tissue that differ in color from those located nearby. This becomes the basis for further research activities in order to clarify the diagnosis. Cytology and colposcopy are the most effective approaches that help to study the cellular composition of a non-standard element and understand what it is. Proliferation of the glandular epithelium is detected by laboratory examination of a cytological smear.
Thanks to specialized studies, the doctor clarifies how increased the concentration of glands is relative to the normal structure, and also studies the structure of the changes. Based on the information obtained, we can conclude whether we are talking about malignant tissue transformations. However, as can be seen from medical statistics, moderate proliferation of the glandular epithelium usually does not indicate any serious disturbances in the functioning of the female body.
What to do?
At the appointment, the doctor will explain if the patient has been diagnosed with proliferation of the glandular epithelium, what it is and what it means in a particular case. There is no isolated treatment for such health problems. First, it is necessary to determine the reason for the deviation and eliminate it. In some cases, the condition of the epithelium returns to normal on its own; sometimes additional measures are required.
Where did the trouble come from?
For what reason does the proliferation of the glandular epithelium of the cervix develop? This question probably worries any woman with a corresponding diagnosis. Doctors were able to identify many situations leading to such consequences. It is not always a matter of serious pathology, so making a diagnosis is not a reason to panic. In particular, long-term use of oral contraceptives in a completely healthy woman can provoke the appearance of individual areas of proliferation. The most common pathological causes are:
- infectious processes;
- inflammatory damage to vaginal tissue;
- similar changes in the cervical canal;
- cervicitis (for various reasons).
Being infected, the reproductive system of the female body activates natural protective mechanisms, including the structure of the glandular epithelium of the cervix. Proliferation is a response to unwanted microflora, which the body tries to remove through an abundance of secretions. That is, unwanted microorganisms seem to be washed away from the tissues. Thanks to this measure of protection, the infection cannot penetrate deeper. On the other hand, the body’s reaction leads to the growth of glandular tissue, elongation of individual elements, and branching of structures.
Hormones and glandular epithelial cells with signs of proliferation
The epithelium of the cervix develops under the influence of cyclic hormonal changes in the female body. When the hormonal system is dysfunctional, various disruptions are noticeable, including in the structure of this tissue. Pathologies that disrupt the functioning of the endocrine system often lead to this. During pregnancy, changes in the body also provoke an adjustment in the thickness of this mucosal layer. During pregnancy, sex hormones in the female body are present in a non-standard ratio, which causes a similar reaction. In most cases, it is noted that the level of estrogen in the blood is too low for the cervical epithelium, which leads to changes.
Injuries are known to provoke proliferation (hyperplasia) of the glandular epithelium. What is it: damage received during childbirth, termination of pregnancy, diagnostic and therapeutic procedures. All situations are associated with a violation of the integrity of the mucous membrane of the vagina and uterus, which requires activation of regenerative processes. This can cause excessive tissue growth. In some cases, hyperplasia is caused by pseudo-erosion. A distinctive feature of this condition is the presence of inclusions of columnar epithelium in the cervical stratified epithelium. It seems to descend along the surface of the organ from the cervical cavity. At the same time, changes in tissue structure affect the number and volume of glandular cells.
Doctor's report
Proliferation is a condition that accompanies a wide range of gynecological diseases, but such a disorder does not have an independent picture at all. The doctor, assessing the general condition of the woman, the complaints with which she came to the appointment, selects the best option for research, prescribes tests and formulates conclusions. For two patients with similar manifestations, the doctors’ conclusions can be categorically different. In such a situation, there is no need to panic or point out the specialist’s incompetence: indeed, the situation is quite possible. On the other hand, such significant uncertainty of the process leads to the fact that it is very difficult to understand it without having a specific education.
Proliferation involves an increase in the number and volume of the glands of the cervix, and the location can be different: diffuse, focal. In many ways, this indicates the cause of the process. The severity of the situation is assessed by looking at the severity of tissue changes, the presence of inflammatory processes and the level of their activity.
How to notice?
Proliferation of the glandular epithelium is not associated with any characteristic clinical symptoms. Typically, a woman consults a doctor based on problems associated with concomitant pathologies. In particular, if hyperplasia is caused by inflammation, then profuse leucorrhoea and discomfort in the vaginal area are a concern. With hormonal disorders, disruptions in the monthly cycle, bleeding, including at the wrong time, and cycles without ovulation are observed.
Do I need to go to the doctor?
If you suspect the presence of pathologies of the reproductive system, you should promptly make an appointment with a gynecologist. If the doctor diagnoses proliferation, laboratory tests are ordered on tissue samples to identify the characteristics of the cellular composition. At the same time, a visual examination usually provides a rather modest amount of information: a specialist examines the external part, the external uterine pharynx, where he records individual areas that differ from the surrounding tissues in structure and color. Normally, the epithelium is light pink in color, which is due to its multi-layered nature, while abnormal elements are brighter and more saturated.
Some women have not only elements that differ in color, but also small neoplasms, the diameter of which does not exceed one centimeter. These are hemispherical dense objects characterized by thin walls. The internal filling is yellowish, translucent. In medicine, this is called “Nabothian cysts.” Typically, pathology is observed in the cervical cavity, in the lower third of the volume, that is, where the Nabothian glands are located. The glands themselves are small tubes filled with secretions. The contents reach external tissues through the excretory ducts. Proliferation leads to blocking of the holes, blockage provokes the formation of a cavity filled with secretions. If such cysts are located deep in the reproductive system, the doctor will not be able to see them visually. The presence of formations suggests glandular-cystic proliferation.
Some special cases
There are known situations where hyperplasia was localized only in the cervical canal. During a visual examination, the doctor is not able to identify the process, since the areas are inaccessible to this method of examination.
If the pathology is accompanied by inflammation, the following additional symptoms are observed:
- local temperature increase;
- swelling of the mucous membranes;
- abundance of discharge.
As practice shows, in most cases proliferation is associated precisely with infection or inflammation, so doctors always prescribe laboratory tests - culture, flora smear, PCR. This helps to identify the pathogen and determine the presence of specific infections. When menstrual dysfunction is observed, additional tests are taken to identify hormonal imbalances. The current phase of the cycle is taken into account.
Painstaking research
For a detailed study of modified structures, colposcopy and cytological analysis are necessary. It is taken into account that proliferation is an uneven process, in which the mucous membrane usually thickens in some places, and the glands differ from each other in size and shape. A cytogram will provide accurate information only if the process covers the uterine cervix (surface). If the cervical canal is damaged in such a way that hyperplasia does not spread beyond the external os, accurate data can only be obtained by histological examination. To do this, the cervical cavity is examined and a scraping of biological tissue is obtained, which is sent for further laboratory tests.
As medical statistics show, proliferation of the glandular epithelium is often observed against the background of a similar process in the endometrium. The doctor, studying the patient’s condition, examines the entire mucous membrane inside the uterine cavity for a pathological condition. An informative analysis can be done by obtaining tissue samples of the uterine cavity and cervical cavity. They are sent for histological examination.
It is important!
In most cases, proliferation of the glandular epithelium is a benign process. Occasionally, examination of tissue samples provides information about atypical cell changes. With such a transformation, it is necessary to conduct a number of additional studies and, possibly, visit an oncologist: the gynecologist will give directions, explain the peculiarities of a particular situation and all the dangers associated with it.
It must be remembered that proliferation itself does not require urgent medical intervention, but forces us to look for the cause of benign changes. There is a possibility that the source of the problems is a serious pathology, the elimination of which should be a task of paramount importance. Laboratory studies using modern technology will provide accurate information. If an infection is detected, you will have to undergo a course of treatment with antibacterial drugs.
2.1.10. Mechanisms of proliferation development at the site of inflammation
Proliferation is the final phase of the development of inflammation, ensuring reparative tissue regeneration at the site of the source of inflammation.
iterations. Proliferation develops from the very beginning of inflammation along with the phenomena of alteration and exudation.
During reparative processes at the site of inflammation, cell regeneration and fibroplasia are achieved both by activating proliferation processes and by limiting cell apoptosis. The proliferation of cellular elements begins along the periphery of the inflammation zone, while in the center of the lesion the phenomena of alteration and necrosis can still progress. Full development proliferation of connective tissue and organ-specific cellular elements occurs after tissue macrophages and neutrophils “cleanse” the damaged area of cellular debris and infectious agents of inflammation. In this regard, it should be noted that the process of proliferation is preceded by the formation of neutrophil and monocyte barriers, which are formed along the periphery of the alteration zone.
The restoration and replacement of damaged tissues begins with the release of fibrinogen molecules from the vessels and the formation of fibrin, which forms a kind of mesh, a framework for subsequent cell reproduction. Already along this framework, rapidly formed fibroblasts are distributed in the repair site. The division, growth and movement of fibroblasts are possible only after they are bound to fibrin or collagen fibers. This connection is provided by a special protein - fibronectin. The proliferation of fibroblasts begins along the periphery of the inflammation zone, ensuring the formation of a fibroblastic barrier. Chemotaxis, activation and proliferation of fibroblasts are carried out under the influence of:
1. Fibroblast growth factors.
2. Platelet-derived growth factor.
3. Cytokines - TNF, IL-1.
4. Kininov.
5. Thrombina.
6. Transforming growth factor b.
At first, fibroblasts are not mature and do not have sufficient synthetic activity. Maturation is preceded by internal structural and functional restructuring of fibroblasts: hypertrophy of the nucleus and nucleolus, hyperplasia of the ER, increased content of enzymes, especially alkaline phosphatase, nonspecific esterase, b-glucuronidase. Only after restructuring, fibroblasts begin to synthesize collagen, elastin, collagen-associated proteins and proteoglycans. Collagenogenesis is stimulated by the following biologically active substances - TNF, IL-1, IL-4, fibroblast growth factor, platelet-derived growth factor.
Intensively multiplying fibroblasts produce acidic mucopolysaccharides - the main component of the intercellular substance of connective tissue ( hyaluronic acid, chondroitinsulfuric acid, glucosamine, galactosamine). In this case, the inflammation zone is not only encapsulated, but also a gradual migration of cellular and acellular components of the connective tissue from the periphery to the center begins, the formation of a connective tissue skeleton at the site of primary and secondary alteration.
Along with fibroblasts, other tissue and hematogenous cells also multiply. When destroyed basement membranes vessels in the alteration zone, endothelial cells migrate along a gradient of angiogenic factors. The lumen of the newly formed capillary is formed by the fusion of the extracellular spaces of neighboring endothelial cells. Around the newly formed capillaries, mast cells, macrophages, and neutrophils are concentrated, which are released biologically active substances, promoting the proliferation of capillaries.
The most important factors stimulating angiogenesis are:
1. Fibroblast growth factors (basic and acidic).
2. Vascular endothelial growth factor.
3. Transforming growth factors .
4. Epidermal growth factor.
Fibroblasts, together with newly formed vessels, create granulation tissue. This is essentially young connective tissue, rich in cells and thin-walled capillaries, the loops of which protrude above the surface of the tissue in the form of granules.
The main functions of granulation tissue are: protective - preventing the influence of factors environment on the source of inflammation and reparative - filling the defect and restoring the anatomical and functional usefulness of damaged tissues.
The formation of granulation tissue is not strictly necessary. This depends on the size and depth of the damage. Granulation tissue usually does not develop during the healing of bruised skin wounds or minor damage to the mucous membrane (Kuzin M.I., Kostyuchenok B.M. et al., 1990). Granulation tissue gradually turns into fibrous tissue called scar. In scar tissue, the number of vessels decreases, they become empty, the number of macrophages and mast cells decreases, and the activity of fibroblasts decreases. A small part of the cellular elements, located among the collagen filaments, remains active. It is assumed that tissue macrophages that remain active take part in the resorption of scar tissue and ensure the formation of softer scars.
In parallel with the maturation of granulations, epithelization of the wound occurs. It begins in the first hours after damage, and within the first day 2-4 layers of basal epithelial cells are formed. The rate of epithelialization is ensured by the following processes: migration, division and differentiation of cells. Epithelization of small wounds is carried out mainly due to the migration of cells from the basal layer. Larger wounds are epithelialized due to migration and mitotic division of cells of the basal layer, as well as differentiation of the regenerating epidermis. The new epithelium forms the boundary between the damaged and underlying layers; it prevents dehydration of wound tissue, a decrease in electrolytes and proteins in it, and also prevents the invasion of microorganisms.
Organ-specific proteins also participate in the proliferation process. cellular elements organs and tissues. From the point of view of the possibilities of proliferation of organ-specific cellular elements, all organs and tissues can be classified into three groups:
The first group may include organs and tissues, the cellular elements of which have active or practically unlimited proliferation, sufficient to completely compensate for the structural defect in the area of inflammation (epithelium of the skin, mucous membranes respiratory tract, mucus-wait gastrointestinal tract, genitourinary system; hematopoietic tissue, etc.).
The second group includes tissues with limited regenerative abilities (tendons, cartilage, ligaments, bone, peripheral nerve fibers).
The third group includes those organs and tissues where organ-specific cellular elements are not capable of proliferation (heart muscle, CNS cells). The main factors regulating the processes of proliferation and differentiation of cells in the area of inflammation are:
1. Growth factors produced by macrophages, lymphocytes, platelets, fibroblasts and other cells stimulated in the inflammatory zone. These include:
Epidermal growth factors (stimulator of proliferation and maturation of the epithelium, stimulator of angiogenesis);
Transforming growth factor- (stimulator of angiogenesis);
Transforming growth factor- (fibroblast chemoattractant, stimulator of collagen, fibronectin, angiogenesis synthesis, proteolysis inhibitor);
Platelet-derived growth factor (stimulator of migration, proliferation and protein synthesis in target cells, has a pro-inflammatory effect);
Endothelial cell growth factor;
Fibroblast growth factor acidic and basic (stimulators of proliferation of all cells of the vascular wall);
Colony-stimulating factors (granulocyte and macrophage stimulators of differentiation, proliferation and functional activity cells of the granulocyte and monocyte series) - cytokines (TNF, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7) produced by T- and B-lymphocytes, mononuclear cells, mast cells, fibroblasts, endotheliocytes, provide chemotaxis, fibrogenesis, inhibit apoptosis, stimulate proliferation processes in the inflammation site. Growth inhibitors for some cells are the same cytokines that stimulate the proliferation of others - these are TNF, transforming growth factor and -interferon (Zaichik A.Sh., Churilov L.P., 1999);
Nerve growth factor (stimulator of proliferation, growth, morphogenesis of sympathetic neurons, epithelial cells). Growth factors, interacting with receptors on target cells, can directly stimulate DNA synthesis in cells or prepare intracellular receptors and enzymes for mitotic activity.
2. Calcitonin-related gene peptide stimulates the proliferation of endothelial cells, and substance P induces the production of TNF in macrophages.
3. Group E prostaglandins potentiate regeneration by increasing blood supply.
4. Keylons and antikeylons produced by various cells, acting on the feedback principle, can activate and inhibit mitotic processes in the focus of inflammation (Bala Yu.M., Lifshits V.M., Sidelnikova V.I., 1988) .
5. Polyamines (putrescine, spermidine, spermine), found in all mammalian cells, are vital for cell growth and division.
They provide stabilization plasma membranes and superhelical structure of DNA, protection of DNA from the action of nucleases, stimulation of transcription, methylation of RNA and its binding to ribosomes, activation of DNA ligases, endonucleases, protein kinases and many other cellular processes. Enhanced synthesis of polyamines, promoting proliferative processes, is noted in the focus of alteration (Berezov T.T., Fedoronchuk T.V., 1997).
6. Cyclic nucleotides: cAMP inhibits, and cGMP activates proliferation processes.
Wound healing.
Morphologically, the process of wound healing can proceed differently, depending on the anatomical substrate of the lesion, the degree of infection, general condition organism, character therapeutic measures(Kuzin M.I., Kostyuchenok B.M. et al., 1990). However, in any case, the course of the wound process reflects one of the classical types of healing:
1. Healing by primary intention.
2. Healing by secondary intention.
3. Healing under the scab.
Healing by first intention. This type of healing is characterized by fusion of the wound edges without visible intermediate tissue, through the connective tissue organization of the wound canal. Healing by primary intention is the most economical type of healing. For healing by primary intention, the following conditions are necessary:
1. Small damage area.
2. Tight contact of the wound edges.
3. Preservation of the viability of the wound edges.
4. Absence of foci of necrosis and hematoma.
5. Asepticity of the wound.
The morphological picture of healing by primary intention is manifested by moderate hyperemia, tissue edema in the wound walls, proliferation of fibroblasts and new formation of capillaries through endothelialization of channels and cracks in thickening fibrin (autochthonous mechanism) from one edge of the wound to the opposite. On the 6-8th day, granulation tissue firmly connects the walls of the wound, and during this period epithelization stops. In surgical practice, healing by primary intention is possible in two cases: with small wound sizes (the edges are no more than 10 mm apart from each other), and also with surgical interventions, ending with sutures. Local changes in the wound area are slightly expressed (swelling of the edges, hyperemia, infiltration, pain). TO general manifestations refers to an increase in body temperature, which gradually decreases by the 3rd day after surgery. Changes in the morphological composition of the blood are insignificant or absent. Neutrophilic leukocytosis and an increase in ESR up to 20 mm/h are sometimes observed. On the 5-6th day, these indicators usually normalize.
Wound healing by secondary intention occurs with extensive tissue damage, with the presence of non-viable tissue in the wound, hematoma, and with the development of infection in the wound. Any of these factors leads to healing by secondary intention. At various options the course of healing by secondary intention we are talking about healing purulent wound, that is, about healing through suppuration and granulation. On the 5-6th day after the alteration, after the rejection of necrotic cells, islands of granulation appear in the wound, which, gradually growing, fill the entire wound cavity. Changes in the nature of granulations always objectively reflect complications of healing that can occur under the influence of local and common factors. Reorganization of the scar is manifested by active epithelialization of the wound. The epithelium grows on the surface of the granulations in the form of a bluish-white border very slowly. In addition to epithelization, healing is facilitated by the phenomenon of wound contraction - uniform concentric contraction of the edges and walls of the wound. This phenomenon is explained by the appearance in the granulation tissue during the period of regeneration of fibroblasts with the ability to contract.
Healing of a wound under a scab is typical for minor injuries (abrasions, scratches, small area burns of the 1st and 2nd degree). Wound process begins with the coagulation of shed blood or just lymph, which dries out to form a scab. Underneath it, rapid regeneration of the epidermis occurs, and the scab is then rejected. The whole process lasts 3-7 days. If healing under the scab occurs without complications, then the wound heals by primary intention; if suppuration begins under the scab, then healing proceeds according to the type secondary intention. In some cases, a sluggish phlegmonous lesion of the fatty tissue surrounding the wound may develop. In such a situation it is necessary debridement wounds and removal of scab (Kuzin M.I., Kostyuchenok B.M. et al., 1990).
Since the beginning of the 60s. new views have emerged on the significance of patterns for aging and life expectancy cell proliferation. Based on the calculation of the number of divisions of fibroblasts seeded into tissue culture from a human embryo and from people aged 20 years and above, a conclusion was made about the limit cell division(Hayflick limit), which corresponds to the species lifespan. It has been shown that mouse fibroblasts are capable of doubling their numbers 14-28 times, chicken 15-35 times, humans 40-60 times, and turtles 72-114 times. Checking the results reported we're talking about, revealed that the idea of a limited number of cell divisions in individual development is inaccurate.
In tumors, atypical cells divide in a mitotic manner. As a result of division, cells identical to the modified ones are formed. Division occurs many times. As a result, the tumor grows rapidly.
Proliferation (from Latin proles - offspring, offspring and fero - carry) - proliferation of body tissue through cell multiplication. The mechanism of proliferation differs from other mechanisms of change in cell(s) volume, such as edema or apoptosis. The term in medicine was first introduced by the German scientist Virchow to designate the new formation of cells through their reproduction by division. The intensity of proliferation can be regulated by stimulators and inhibitors, which can be produced both away from the responding cells (for example, by hormones) and inside them. Proliferation occurs continuously in early embryogenesis and, as differentiation proceeds, the periods between divisions lengthen. Some cells, such as nerve cells, are not capable of proliferation
Proliferation - component inflammatory process and its final stage is characterized by an increase in the number of stromal and, as a rule, parenchymal cells, as well as the formation of intercellular substance at the site of inflammation. These processes are aimed at the regeneration of altered and/or replacement of destroyed tissue elements. Various biologically active substances, especially those stimulating cell proliferation (mitogens), are essential at this stage of inflammation.
Proliferative processes during acute inflammation begin soon after the influence of the phlogogenic factor on the tissue and are more pronounced along the periphery of the inflammation zone. One of the conditions for the optimal course of proliferation is the attenuation of the processes of alteration and exudation.
The forms and degree of proliferation of organ-specific cells are different and are determined by the nature of the cell populations.
In some organs and tissues (for example, liver, skin, gastrointestinal tract, respiratory tract), the cells have a high proliferative ability, sufficient to eliminate structural defects at the site of inflammation.
In other organs and tissues this ability is very limited (for example, in tissues of tendons, cartilage, ligaments, kidneys, etc.).
In a number of organs and tissues, parenchymal cells have virtually no proliferative activity (for example, myocytes of the heart muscle, neurons). In this regard, upon completion of the inflammatory process in the myocardial tissues and nervous system at the site of inflammation, stromal cells proliferate, mainly fibroblasts, which also form non-cellular structures. As a result, a connective tissue scar is formed. At the same time, it is known that parenchymal cells of these tissues have a high ability for hypertrophy and hyperplasia of subcellular structures.
Activation of proliferative processes correlates with the formation of biologically active substances that have an anti-inflammatory effect (a kind of anti-inflammatory mediators). The most effective among them include:
Inhibitors of hydrolases, in particular proteases (for example, antitrypsin), β-microglobulin, plasmin or complement factors;
Antioxidants (eg, ceruloplasmin, haptoglobin, peroxidases, SOD);
Polyamines (eg putrescine, spermine, cadaverine);
Glucocorticoids;
Heparin (suppresses adhesion and aggregation of leukocytes, activity of kinins, biogenic amines, complement factors).
Replacement of dead and damaged tissue elements during inflammation is noted after their destruction and elimination (this process is called wound cleansing).
Thus, using the thymidine autoradiography method, it is possible to obtain such important quantitative characteristics of the reproduction and differentiation of cells in the tissue under study, such as: a) the rate at which cells enter differentiation, the duration of their existence in a differentiated state and the localization of those that have completed their life cycle cells; b) localization, proliferation rate and relative number of multiplying cells. The combination of these quantitative indicators makes it possible to objectively characterize the kinetics of cell populations of the tissues under study and to trace its changes in histogenesis, under pathological and experimental conditions, and, finally, to identify the features of the kinetics of cell populations in functionally similar tissues in different groups multicellular animals.
Based on the method of thymidine autoradiography, a whole direction of research into the patterns of systemic organization of cell populations has emerged, which represents new stage in the analysis of tissues whose vital functions combine cell reproduction and differentiation.
To assess the proliferative activity (intensity of cell division) of a tissue, it is necessary to determine the mitotic index. The mitotic index is most often determined by the ratio of the number of cells in mitosis to the total number of counted cells of the tissue being studied. In addition, the cells located on the different stages phases of mitosis, which allows us to determine the relative duration of the various phases of mitosis to the percentage of the total number of cells that have entered mitosis. Counting cells per different phases The mitotic cycle is carried out in several fields of view, while the preparation must be moved sequentially through one field to the side and then from bottom to top, etc., to avoid viewing the same field twice. Data on cell counting by field of view are entered into a table for each stage of mitosis and then summarized. Due to the fact that taking biological material(biopsies) of various human tissues is practically impossible, we propose to carry out this laboratory work to study proliferative activity using the example of the root meristem of seedlings of annual plants (onions, wheat, sunflower, etc.)
Plant seeds are pre-soaked in water for 12 hours, then germinated on moistened filter paper in Petri dishes for 24 hours. The tips of the germinated roots are fixed in an alcohol acetate solution (3 parts alcohol: 1 part acetic acid) from 2 to 24 hours and stained with acetoorcein. Then temporary pressed preparations are prepared.
Assess proliferative activity cancer cells necessary not only for the biological characterization of tumors, but also for selective treatment and determining prognosis. The proliferative activity of cancer tumor cells is studied by immunohistochemical staining using monoclonal antibodies Ki-67 and PCNA. Ki-67 antigen expresses in all phases (G1, S, G2 and M) cell cycle, except G0, and PCNA – in G1, S and G2 phases. Index of proliferative activity of differentiated forms of cancer thyroid gland significantly lower than for cancers of other organs, such as breast, lung, stomach and rectum