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PATHOLOGY OF BLOOD CELL AND BONE MARROW. ANEMIA

Hematological diseases may be primary, that is, caused by the disease of the blood-forming organs themselves, or secondary, reflecting the damage of any other systems. Secondary diseases are more common. The availability of morphological studies of blood cells, for example, in a smear of venous blood or bone marrow punctate, provides a direct study of the changes that have occurred. In modern hematopathology, which represents a separate and most part of human pathology, not only ordinary morphological approaches are used, but the entire arsenal of methods is used (histochemistry, immunohistochemistry, cytogenetics, etc.).

This lecture is devoted to blood diseases associated with changes in the red blood cell system. Red blood cells are formed in the bone marrow and are derived from the myeloid hemopoietic germ, which also gives rise to platelets, granulocytes and monocytes.

Some properties of normal blood and the basic patterns of development of blood cells (hematopoiesis). To begin, consider some properties of normal blood and the basic patterns of development of blood cells (hematopoiesis).

The volume of circulating blood in an adult reaches 5 liters, usually it is slightly less in women and depends on the total body weight. When centrifuging a column of venous blood, 45% of its mass is represented by cells, the total number of which reflects hematocrit (packed cell volume, PCV), i.e. the ratio of the volume of blood cells to the volume of plasma. The remaining 55% of the mass of blood is its plasma. Blood volume is accurately measured using radionuclide methods. The increase in hematocrit occurs either with an increase in the total mass of red blood cells, for example, with erythrocytosis, or due to a decrease in blood plasma. A decrease in hematocrit is a consequence of a decrease in red blood cell mass (in anemia) or an increase in plasma volume.

Erythrocyte concentration and plasma protein content determine blood viscosity. Increased viscosity may be due to high hematocrit, for example with polycythemia, or an increase in protein concentration, for example, with paraproteinemia, as well as a decrease in erythrocyte ability to physiological deformity (with sickle cell anemia) or an increase in the number of leukocytes (with leukemia). As a result, blood flow is slowed down and conditions for thrombosis are created.

The development of cells (blood cells). Hematopoiesis (hemopoiesis) begins in the yolk sac at the 3rd week of embryogenesis. From the 6th week the liver becomes the main hematopoietic organ of the embryo for some time, and from the 12th week the hematopoietic functions "move" to the spleen and lymph nodes, to a lesser extent to the thymus. In the bone marrow, signs of hemopoiesis appear at the 16th – 20th week of embryogenesis. From the 30th to the 36th week, blood formation occurs predominantly in the bone marrow, and hematopoiesis in the liver decreases sharply, but several areas of hematopoietic tissue remain within 1-2 weeks after birth. In the liver, hematopoiesis is expressed in premature babies and persists in neonatal ones, i.e. in the neonatal period, anemia, for example, in hemolytic disease of the newborn.

In the period of childhood, the bone marrow is the only place for the formation of new blood cells. Progressive replacement of the hematopoietic (red) bone marrow with fat (yellow) bone marrow occurs during adolescence. By the age of 16-18, the red bone marrow is preserved only in the proximal parts of the long tubular bones, vertebral bodies, ribs, sternum, pelvic bones and skull. Such localization then remains for the rest of life, and in an adult person a bone marrow biopsy is performed in any of the indicated places, except for the bones of the skull. For newborns, tibial tuberosity is used for this, located on the anterior surface of the upper epiphysis of this bone.

Adipose bone marrow is able to return to the state of the hematopoietic organ in cases where the body needs an increased number of blood corpuscles or when tumor cell proliferation occurs. In children and adults with severe forms of anemia, in cases where the regenerative capabilities of the bone marrow are exhausted, the liver, then the spleen and lymph nodes can also perform hematopoietic functions. This is called extramedullary (extra-cerebral) hematopoiesis (hematopoiesis). Extramedullary blood formation is possible if the bone marrow stem cells are not damaged, and there is enough iron, protein and vitamins for normal blood formation.

The bone marrow is not only a reservoir for hematopoietic stem cells, but also forms a unique microenvironment for their proliferation and differentiation. Apparently, it is he who regulates the exit into the bloodstream of mature blood cells. Hematopoiesis is carried out in the extravascular spaces of the canals and cavities of the bone marrow. An electron microscopic examination reveals a network of thin-walled sinusoids lined with a single layer of endothelium. The endothelium is surrounded by a discontinuous basement membrane and adventitious cells, between which there are spaces. Between sinusoids are clusters of hematopoietic cells and fat cells. Differentiated blood cells enter the sinusoids by transcellular migration through the endothelium. It is in the bone marrow that the migration of differentiated blood cells is regulated. This proves the fact that in extramedullary hematopoiesis in peripheral blood, all forms of undifferentiated shaped elements can be found.

Differentiation of blood cells during hematopoiesis. All blood cells are derived from pluripotent stem cells. When dividing, the stem cell forms two cells, one of which retains the properties of the stem, and the other begins to differentiate. Thus, genetically programmed stem cell proliferation provides not only their self-renewal, but also the production of the following generations - multipotent stem (half-stem) cells. The latter are intended for the development (differentiation) of all formed elements in two main directions: myeloid hematopoiesis (three lines of differentiation) and lymphopoiesis. The term "pluripotent" means universal in relation to the directions of further differentiation, and the term "multipotent" means the possibility of further differentiation in many, but not in all directions. The concept of self-sustaining parental blood cells was first formulated in the 20th century. A.A. Maximov, Russian histologist (1874-1928).

Multipotent stem cells of myeloid hematopoiesis give rise to erythroid, megakaryocytic and myelomonocytic committed, i.e. differentiated only in one direction, stem cells, also called unipotent precursors. The descendants of these cells go through stages of differentiation to terminal mature formed elements: red blood cells, platelets (blood plates), monocytes and granulocytes. Multipotent lymphopoiesis progenitor stem cells give rise to lines of T-and B-lymphocytes. Genetically determined linear specificity, which is manifested in committed descendants of multipotent stem cells, limits not only the direction of their differentiation, but also the ability to endlessly exist and to self-renew. Terminal mature shaped elements have a limited lifespan. Thus, the normal and increased number of terminal shaped elements is ensured by the continued reproduction of stem cells and the entry of their closest descendants into the pool of committed predecessors. This mechanism can be influenced by various factors acting on inflammation, immunological reactions, hypoxia, malnutrition, various diseases, etc.

With conventional microscopy using review cytological or histological stains, it is impossible to distinguish stem elements from the diversity of the red bone marrow cell population. The pluripotent capabilities of these cells were examined in mice. The experiment showed that colonies of bone marrow cells originate from a single stem cell. Erythrocytes and megakaryocytes have a common committed precursor - megakaryocyte erythrocyte colony forming unit (CFU-Meg-E). The same precursor - granulocyte-monocytic colony-forming unit (CFU-GM) - is in granulocytes and monocytes.

Differentiation of cells during hematopoiesis is controlled by programs encoded in DNA. Programs are activated by signals sent to the nuclei of cells from plasmolemma receptors that perceive growth factors. To date, many growth factors have been discovered that stimulate and simultaneously control hematopoiesis. They can be divided into three large groups. Group 1 - multipotent factors, such as interleukin-3, stimulating the proliferation and differentiation of stem cells; colony stimulating factor of granulocytes and macrophages (GM-CSF), providing growth of macrophages and precursors of neutrophilic and eosinophilic leukocytes. Group 2 - linear factors determined within the cell line, for example, factors stimulating colonies of granulocytes (G-CSF) and monocytes (M-CSF). Group 3 - mixed-linear factors, such as various interleukins and transforming growth factor, affecting relatively mature cells of one or several lines.

Growth factors mainly produce T-lymphocytes and monocytes, as well as stromal and myeloid cells. Of all the growth factors, erythropoietin is secreted, which is produced in the kidneys, and then humoralally delivered to the bone marrow, where it stimulates the terminal differentiation of erythrocyte progenitors.

Growth factors can be used for therapeutic purposes to restore suppressed hematopoietic activity. Thus, anemia in renal failure can be corrected by the introduction of recombinant erythropoietin, and the accelerated recovery of the bone marrow after exposure to the body of large doses of chemotherapy drugs or after autotransplantation is achieved by the introduction of GM-CSF. The genes encoding most of the growth factors are found in the long arm of chromosome 5, which is most often subjected to aberration in all sorts of myelodysplastic syndromes.

The role of bone marrow biopsy. The clinical diagnosis of diseases associated with the hematopoietic system depends on a microscopic (cytological, histological, histochemical, etc.) study of aspiration biopsies and trephine biopsies [trephine biopsy — puncture of the bone (usually in the region of the iliac crest) with a special needle]. In such biopsy specimens, the total cellularity (number of cells) is assessed and the presence of specific precursors of the terminal formed elements in the bone marrow is determined. Normally, the ratio of hemopoiesis cells and fat cells is about the same. With bone marrow hypoplasia, the fat content increases, and with anemia with erythropoiesis and leukemia, there is an increased bone marrow cellularity (hyperplasia). The normal ratio of myeloid and erythroid progenitors ranges from 2.5: 1 to 12: 1; it is almost always impaired in anemia and leukemia. Normal bone marrow contains less than 3% plasma cells and less than 10% lymphocytes. With the help of silver impregnation (treatment of smears or histological sections with silver salts), thin reticulin fibers can be seen, the number and volume of which increase dramatically during myelofibrosis.
Approximately 40% of normoblasts, i.e. proerythroblasts, morphologically determined erythrocyte precursors, contain hemosiderin granules and are sideroblasts. An increased amount of sideroblasts indicates suppressed synthesis of heme or globin. The progressive accumulation of iron in mitochondria leads to the formation of ring sideroblasts. The absence of stained iron in bone marrow biopsy specimens indicates an iron deficiency state.

The number of cells in different phases of mitosis in the normal bone marrow population is 1-2%. Counting figures of mitosis gives an idea of ​​the total hematopoietic activity of the bone marrow. In addition, using cell labels with radionuclides: tritiated thymidine - to assess the total proliferative activity; Fe - for the study of erythropoiesis; mTc-labeled colloid to evaluate the function of monocytes and macrophages.

Erythropoiesis. In a lecture on anemia, we will consider only erythropoiesis. The maturation of normal red blood cells, i.e. normoblastic erythropoiesis, goes through the following stages: reducing the size of normoblasts, shrinking their nuclei with chromatin condensation, the gradual disappearance of nuclei, the loss of cytoplasmic RNA and the parallel production of hemoglobin. Three mitotic divisions are performed between pronormoblast and late normoblast. Each interval between mitosis, which is necessary for normal gradual differentiation, is 16 hours. After bleeding or when hemolytic anemia, the intervals are reduced, the number of erythrocytes increases. A decrease in mitotic activity leads to an increase in the size of erythrocytes (macrocytosis), which is found in megaloblastic (macrocytic) anemia. Increased mitotic activity is accompanied by a decrease in the size of red blood cells (microcytosis), which is observed, for example, with iron deficiency anemia.

The life span of red blood cells is normally 120 days, 1/120 of their total number is replaced daily. The cells entering the bloodstream are called reticulocytes. Reticulocyte is the immediate precursor of the terminal form of erythropoietic differentiation. It is this cell that goes through all the stages of the disappearance of the nucleus from the cytoplasm (the erythrocytes of only humans and mammals are nuclear-free). Maturation of the reticulocyte to the terminal erythrocyte takes 48-72 hours and the last 24 hours occurs in the circulating blood. Reticulocytes contain polyribosomes, RNA and mitochondria. They are able to synthesize hemoglobin, which provides a diffuse basophilia of their cytoplasm by staining smears by the method of Romanovsky-Giemsa. Reticulocytes are detected with supravital, i.e. Lifetime stains of non-fixed cells with azure B or cresyl blue, with flow cytometry with RNA staining with fluorophores. The number of reticulocytes in the peripheral blood is expressed as a percentage of the total number of red blood cells. In an adult, it varies in the range of 0.5-2.0%; however, the data on the absolute content of reticulocytes are more informative (normally in adults 25-75x10 / l). Counting the number of reticulocytes gives an idea of ​​the activity of erythropoiesis. The content of reticulocytes in the blood increases with blood loss, hemolysis, in response to hemotherapy. The decrease in the number of reticulocytes is associated with insufficient bone marrow function or ineffective erythropoiesis.

Erythropoiesis is controlled by erythropoietin, which determines the rate of transition of erythroid progenitors (erythrocyte colony-forming unit - CFU-E) into normoblasts (proerythroblasts). This factor is produced in the kidneys, some of it is also produced in the liver and spleen. In addition to controlling the rate of reproduction of normoblasts, erythropoietin affects the rate of maturation (terminal differentiation) of erythrocytes, the synthesis of hemoglobin and the penetration of erythrocytes into the bloodstream. Thyroxine (thyroid hormone), growth hormone and androgens stimulate the production of erythropoietin.

In addition to counting the number of reticulocytes, in the assessment of the state and function of the bone marrow, in particular erythropoiesis, an important role is played by counting cells of the erythroid series in trepanobioptate and ferrokinetic studies (assessment of the content and plasma clearance of iron after -Fe, ie, radioactively labeled iron) .

The most important signs of red blood cells. The state and functions of erythrocytes are assessed by determining their amount in peripheral blood (ER), hematocrit (GC) and hemoglobin concentration (HB). Individual fluctuations of these indicators are influenced by age, gender, and atmospheric pressure, which decreases as the height above sea level increases (Table 17.1).

Normal red blood cell counts (mean ± standard deviations)

Other features of circulating red blood cells can also be identified. The average volume of the erythrocyte (OE, according to the international nomenclature - MCV, Mean corpuscular volume), which is expressed in femtoliters, or fl units equal to 10-l, is normally equal to 80-100 fl. The average content of hemoglobin in the erythrocyte (CGE, according to the international nomenclature - MCH, mean corpuscular Hb) -

Table 17.1
Floor Er (x1012 / l) GK (%) Hb (g / l) Hb (g%)
Men 5.5 ± 1.0 47.0 ± 7.0 155.0 + 25.0 16.0 + 2.0
Women 4.8 ± 1.0 42.0 ± 5.0 140.0 + 25.0 14.0 + 2.0


in the normal 27-32 pictograms - pg. The average concentration of hemoglobin in the erythrocyte (CGE, according to the international nomenclature - MCHC, mean corpuscular Hb concentration) is normally 300–360 g / l. Color index (CP), which is calculated according to the general blood test, the hemoglobin content in% (based on 16 g of hemoglobin in 100 g of blood - 100%) is divided by the number of red blood cells in millions and multiplied by 20. With a decrease in hemoglobin and a constant number of red blood cells color index below 1, with a high content of hemoglobin and a reduced number of red blood cells; color indicator is higher than 1.

Diagnostic criteria for anemia in men: er number <4.5 million / μl, Hb <14g /%, HA <42%. У женщин — соответственно < 4,0 млн/мкл, <12 г%, < 37%. Такие параметры, как СО, СГЭ и ЦП, учитывают в морфологической классификации анемий. Эритроциты человека неодинаковы по объему. Популяцию эритроцитов с ОЭ менее 80 фл называют микроцитами, а с ОЭ более 95 фл — макроцитами. Наличие эритроцитов разного размера называют анизоцитозом. Термин "гипохромия" относится к популяции клеток с СГЭ менее 27 пг на 1 эритроцит или с КГЭ менее 30% и ЦП менее 1. Анемии могут быть нормохромными или гипохромными, нормоцитарными, микроцитарными, макроцитарными.

Изменяться может не только объем, но и форма эритроцитов. Красные кровяные тельца — это двояковогнутые дискоидные клетки (дискоциты) со средним диаметром 7,0 мкм. При определении их диаметра под обычным микроскопом ориентируются на ядра малых лимфоцитов, служащие эквивалентом диаметра. Из-за двояковогнутого строения дискоциты сильнее воспринимают окраску по периферии цитоплазмы (иными словами, периферия более оксифильна, нежели центр эритроцита). При нормохромии размер более бледной центральной зоны не должен превышать 1/3 площади дискоцита.

Анемии часто сопровождаются изменениями формы эритроцитов — могут встречаться серповидные, колбовидные, палочковидные, овальные эритроциты, в форме сферы и т.д. Наличие эритроцитов разной формы называется пойкилоцитозом. Пойкилоцитоз встречается при каждой тяжелой форме анемии.

В эритроцитах могут встречаться внутриклеточные включения, которые, как правило, представляют собой остатки внутриклеточных органелл, в основном ядра, или гранулы пигмента. В норме макрофаги селезенки обычно удаляют включения из эритроцитов — процесс, происходящий в красной пульпе, называют pitting ("вынимание фруктовых косточек"). Если селезенка удалена или подверглась атрофии, то эритроциты с включениями циркулируют в кровотоке. Могут встречаться мелкие тельца Паппенгейма (A.Pappenheim) с диаметром 1 мкм, представляющие собой интенсивно окрашенные базофильные гранулы, дающие реакцию на берлинскую лазурь. При мегалобластных и гемолитических анемиях в эритроцитах содержатся гранулы ядерного хроматина диаметром 1—2 мкм, известные как тельца Хауэлла—Джолли. У лиц, подвергшихся спленэктомии, больных гемоглобинопатиями или гемолитической анемией, вызванной химикатами, при суправитальном окрашивании мазков крови обнаруживаются эритроциты с преципитатами метгемоглобина (окисленного гемоглобина). Частицы денатурированного глобина называют тельцами Гейнца (R.Heinz). Наконец, при инфекциях и гемолитических анемиях, вызванных лекарственными препаратами и химическими соединениями, а также при хронических отравлениях свинцом и миелодиспластических состояниях в эритроцитах, окрашенных по Романовскому—Гимзе, можно видеть множество мелких синих гранул (групп РНК) — это пятнистая базофилия эритроцитов.

Дыхательная функция эритроцитов. Ткани человека, находящегося в состоянии покоя, потребляют около 200 мл кислорода в 1 мин. При физической нагрузке это количество может возрастать в десятки раз. Функции переносчика кислорода из легких в ткани, а также углекислоты от тканей к легким выполняет гемоглобин. Гемоглобин состоит из не содержащего железо гема и глобина. Гем придает крови красный цвет, он синтезируется в митохондриях эритробластов из глицина и сукцинилкофермента А при участии витамина Вб. В синтезе гема принимают участие 8 ферментов. Последовательно образуются: порфобилиноген, гидроксиметилбилан, уропорфириноген III, копропорфириноген, протопорфириноген, протопорфирин. Последняя стадия биосинтеза гема сводится к включению иона двухвалентного железа (он и переносит кислород) в протопорфирин. Недостаточность ферментов вызывает заболевания — порфирии, о которых мы говорили при изучении нарушений обмена пигментов. Четыре молекулы гема обернуты полипептидными цепями, которые все вместе представляют собой белковую часть молекулы — глобин. Глобин состоит из двух цепей типа а и двух цепей другого типа (в, у или 5). К нормальным типам гемоглобина относятся: HbA (а2, в2 — основной гемоглобин взрослого человека), HbF (а2, Y2 — фетальный гемоглобин), HbA2 (а2, 52 — минорный гемоглобин взрослого человека). Смена гемоглобина F на гемоглобин А происходит во время рождения ребенка. К 4—6-му месяцу жизни уровень фетального гемоглобина в крови составляет менее 1%.

При патологии строение молекул гемоглобина может значительно изменяться, главным образом, за счет замены аминокислот. Известно множество типов аномального гемоглобина (НЬН, НЬ1, HbS и др.).

Эритроцитоз. Продукция эритропоэтина с последующим повышением количества эритроцитов в периферической крови, т.е. эритроцитозом, стимулируется хронической гипоксией. Последняя возникает при хронической легочной или сердечной недостаточности, врожденных пороках сердца, а также при продолжительной жизни в условиях сниженного атмосферного давления. Такой эритроцитоз имеет компенсаторный характер. Изредка он возникает в результате избыточной продукции эритропоэтина при определенных поражениях почек или печени — карциномах, кистах или ишемических повреждениях.

Все перечисленные выше варианты эритроцитоза называют вторичной полицитемией, так как есть еще и первичная, или истинная, полицитемия — опухолевое поражение эритроцитарного ростка костного мозга.

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PATHOLOGY OF BLOOD CELL AND BONE MARROW. АНЕМИИ

  1. PATHOLOGY OF BLOOD CELL AND BONE MARROW
    This chapter is devoted to diseases that cause changes in the system of erythrocytes, leukocytes and platelets, as well as disorders of the reproduction of blood elements in the bone marrow. Although lymphocytes also belong to the group of blood leukocytes, diseases of the lymphocytic system, with the exception of lymphocytic leukemia (lymphocytic leukemia), it is advisable to consider separately, this is done in Chapter 13. Such
  2. PATHOLOGY OF BLOOD CELL AND BONE MARROW. Lymphoid neoplasms. Myeloid neoplasms. Myelodysplastic syndromes. NON-FORMATIONS OF HYSTIOCYTIC ORIGIN
    In the structure of morbidity and mortality from oncological diseases, tumors of the hematopoietic and lymphoid tissues occupy, depending on gender and age, 7–9%. Every year, out of every 100 thousand inhabitants of our planet, 9 people become ill with some form of leukemia, but in age groups over 65, 69 out of 100 thousand people are already ill. Etiology and pathogenesis of lymphohemopoietic neoplasms
  3. ANEUPLOIDIA AND POLYPLOIDIA OF BONE MARROW CELLS AND BLOOD OF PATIENTS WITH NON-KHODZHKIN LYMPHOMES BEFORE AND AFTER TREATMENT
    Ankina M.A., Zavitaeva T.A., Panferova T.A., Shakhtarina S.V., Danilenko A.A. Medical Radiological Research Center of the Russian Academy of Medical Sciences, Obninsk Objective: The presence of aneuploid cells in the blood is considered abnormal. In cultures from healthy individuals, no more than 5.9% of such cells are found, while hypoaneuploid cells - 5.2%, and hypereuploid cells - 0.7%. Polyploid cells with
  4. Involvement of bone marrow hematopoietic cells in the process of metastase: new targets for diagnosing cancer cell metastases and their destruction
    The reasons for which cancer cells can leave the primary site of cancer and migrate to other parts of the body are not fully understood. Many lives can be saved if we can stop this process. Until now, it was believed that the place of metastasis is determined by which organ or organs with the blood flow gets a cancer cell or cells from the primary cancer site. From her by dividing
  5. ANEMIA DUE TO TOXIC EXPOSURE OF THE BONE MARROW (MYETHOXICAL ANEMIA)
    THYROORTHEUS ANEMIA Thyroid stimulation anemia is anemia that develops on the basis of hypothyroidism. Experimental work confirms the important role of thyroid hormone - thyroxin - in stimulating normal blood formation. Animals deprived of the thyroid gland, quickly anemiziruyutsya, the introduction of the same thyroid drugs to thyroidectomized animals cures them from the effects of thyroid-induced
  6. Morphological analysis of bone marrow cells with myelogram counting
    Изучение миелограммы следует начинать с просмотра окра шейных препаратов под малым увеличением микроскопа. Это позволяет определить качество мазков, клеточность костного мозга, обнаружить групповые скопления атипичных клеток. После просмотра мазка под малым увеличением на него наносят каплю иммерсионного масла и под большим увеличением приступают к дифференцированию форменных элементов.
  7. Anemia due to bone marrow drainage, hypothyroidism, and aplastic anemia. MYELOPLASTIC SYNDROME
    Despite the large number of studies devoted to the study of hypo-and aplastic anemias, it is still not possible to create a rational classification of these conditions, since not only the issues of pathomorphogenesis, but even the definition of the very concept of "hypo (a) plastic anemia" is debatable. In accordance with modern concepts of the genesis of hypo- and
  8. Some properties of normal blood, the development of blood cells (hematopoiesis)
    Объем циркулирующей крови у взрослого человека достигает 5 л, обычно он чуть меньше у женщин и зависит от общей массы тела. При центрифугировании столбика венозной крови в специальных узких пробирках 45 % ее массы представлены клетками, общее количество которых входит в гематокритное число (packed cell volume, PCV), т.е. отношение объема форменных элементов крови к объему плазмы. Оставшиеся 55 %
  9. Hypo-and aplastic anemia. Syndrome of bone marrow failure
    Anemia of this group can be acquired (secondary) and hereditary, congenital (primary). Acquired forms may develop under the influence of physical (ionizing radiation); chemical (benzene, arsenic, etc.) factors, drugs (some antibiotics, sulfonamides, antimetabolites - methotrexate, etc.), as well as due to a lack of hormones (myxedema,
  10. Bone marrow transplantation
    Bone marrow transplantation is one of the youngest and most current areas of hematology today. With the help of bone marrow transplantation, it is possible to fight against refractory leukemias, severe aplastic anemias, immunodeficiencies and other hematological and oncological diseases, as well as with some genetic metabolic diseases. A bone marrow transplant happens
  11. PARTIAL ("RED CELL") BONE Marrow Hypoplasia. ERYTHROBLASTOPTIZ
    Of particular interest are cases of hypo-aplastic anemia that occurs with selective lesion of erythropoiesis, with intact thrombocytopoiesis and partly leukopoiesis. This form (incorrectly denoted by some authors as “partial hypoplastic anemia” (is a special variant of hypoplastic anemia, characterized, in contrast to total myelophthisis partial,
  12. The structure and role of the bone marrow in the activity of the immune system
    All blood cells, including immunocompetent cells, originate from a polypotent stem cell, which gives rise to various sprouts of the blood, including myelomonocytic and lymphocytic. The direction of differentiation of early progenitors depends on the influence of their microenvironment, on the influence of bone marrow stromal cells. The bone marrow stromal cells include:
  13. Bone and bone marrow examination
    Вскрытие костей при обычных условиях производится очень редко. В условиях же военного времени при вскрытии трупов из эвакогоспиталей, а также при вскрытиях судебно-медицинских вскрытие костей часто представляет значительный интерес. Исследование плоских костей — черепа, грудины, ребер, тазовых костей — производят попутно при вскрытии трупа, делают необходимые распилы, рассечения долотом и пр.
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