The article analyzes the features of the structure of the lymphoid lobules of the parenchyma of the superficial somatic (Limphonodi subiliaci, L. cervicales superficiales), profund somatic (L. axillares proprii L. poplitei), somatovisceral (L. iliaci mediales, L. retropharyngei mediales) and visceral (L. mediastinales caudales, L. ileocolici) lymph nodes of newborn bull calves of domestic cattle. To visualize clearly the boundaries of the structural components of lymphoid lobules we used the author’s modification of the impregnation of total median frozen histological sections with silver nitrate. We have established a high level of tissue differentiation of the lymph nodes, a significant development of the lymphoid parenchyma, the division of the parenchyma into lymphoid lobules, the presence in the lobules of all the main structural components that are represented by two morphotypes. The first morphotype is ribbon-like perisinusoidal cords (interfollicular zone, paracortical and medullary cords). The second morphotype is rounded lymphoid formations (central zones of deep cortex units, lymphatic nodules). Lymphoid lobules are located along the marginal sinus in one row, they are better developed and differentiated in the visceral lymph nodes. In all the lymph nodes, the lymphoid lobules have a similar histoarchitectonic, and each structural component of the lymphoid lobules has a specific architectonic of the reticular meshwork and the density of the location of the fibroblastic reticulocytes. We determined that the structures of the first morphotype which provide the migration of lymphocytes, the detection of antigens and the accumulation of plasmocytes are more developed. We have established that the relative volume of structures of the first morphotype is 4.5–8.0 times larger than the volume of the structures of the second morphotype, which provide clonal proliferation of T and B lymphocytes, especially in deep somatic lymph nodes. Among the zones of the second morphotype, predominate T-dependent zones, the relative volume of which considerably exceeds the volume of B-dependent zones (lymphoid nodules): in the superficial somatic lymph nodes by 14–30 times, profound somatic by 12–14 times, somatovisceral by 6–7 times and visceral by 4.5–5.5 times. We determined that lymphatic nodules can form in different parts of compartments: in the interfollicular zone and paracortical cords of all lymph nodes and in the medullary cords of the visceral lymph nodes. The study shows that the parenchyma of the lymph nodes of newborn bull calves has a high degree of maturity, contains a full set of structural markers of immunocompetence, among which predominate the components that support lymphocyte migration, antigen detection and accumulation of plasma cells.
The article analyzes the regularities of the formation and development of the lymphoid lobules of the parenchyma of the somatic (Limphonodi cervicales superficiales) and visceral (L. jejunales) lymph nodes in domestic cattle in the fetal period of ontogenesis. We used routine histological techniques and author's modification of the impregnation of total median sections with silver nitrate. Visualization of various zones of lymphoid lobules was carried out taking into account the specific for different cell zones architectonics of reticular fibers. It has been established that signs of morphological heterogeneity of parenchyma of lymph nodes are first found in three month-old fetuses, which is associated with the concentration of lymphoid tissue along the marginal sinus. Separation of lymphoid lobules and their structural and functional differentiation are first detected in five month fetuses. In the lymphoid lobules of five month-old fetuses all structural and functional cell zones are observable, among which the regions of clonal proliferation of T and B lymphocytes are the least developed, and regions of the transit corridors for lymphocytes migrating medullary and the cords (zone of potential accumulation of plasmocytes and antibody formation) are the most developed. Structural and functional transformations of compartments in the prenatal period of ontogenesis are accompanied by a predominantly moderate increase of the relative volume of specialized T- and B-dependent zones of lobules, against a background of a gradual decrease of the volume of transit corridors for lymphocytes migrating and zone of potential accumulation of plasmocytes and antibody formation. Due to the small volume and relatively low rates of development of the lymphocytes clonal proliferation zones, the quantitative ratios of the cellular zones in lymphoid lobules of the lymph nodes of domestic cattle in prenatal ontogenesis remain relatively stable, while maintaining the maximum indices of the development of transit corridors for lymphocytes migration and medullary cords. Among the zones of lymphocytes clonal proliferation throughout the fetal period, T-dependent zones predominate, the relative volume of which is 5.0–7.5 times greater than the volume of B-dependent zones. Lymphoid lobules in the lymph nodes of the domestic cattle fetuses of all age groups are arranged along the marginal sinus in one row and have a polar structure due to the formation of lymph nodes at one pole of the lobules in the interfollicular zone. In the visceral lymph nodes (L. jejunum) of 8–9 month-old fetuses, individual lymph nodes can form in paracortical strands, on the border with the interfollicular zone.
The article analyzes the features of the histoarchitectonics of the lymph nodes of the bull (Bos taurus) and the pig (Sus scrofa domestica), depending on the type of structure and localization of the intranodal lymphatic channel. We studied somatic (Limphonodi (L.) cervicales superficiales) and visceral (L. jejunales) lymph nodes of clinically healthy mature male bulls and swine (16 and 6 months old, respectively). A complex of classical histological techniques was used, as well as the method of impregnating sections of lymph nodes with silver nitrate, modified by the authors. The main accumulative-distribution link in the lymph nodes of the bull is the subcapsular sinus (type I lymphatic collector), and in the lymph nodes of the pig -the capsular (intratrabecular) lymphatic tanks (type II lymphatic colector). In nodes with collectors of type I, the cortex has a simple layered structure, its outer layer is formed by a compact cortical plateau (interfollicular zone), and the inner layer is formed by a complex of spherical units of the deep cortex. In nodes with collectors of type II, the cortex is layered-folded, uneven in width. Cortical folds are formed along the capsular trabeculae with intratrabecular lymphatic tanks. The cortex plateau in the layered-folded cortex is more developed at the base of the folds, and the units of the deep cortex are at their apexes, where they form clusters in the form of specific nest-shaped structures. In nodes, regardless of the type of intranodal lymphatic channel, the surface cortex (cortical plateau) is located directly under the underlying lymphatic collectors, repeating their shape, the zones of clonal proliferation of B-lymphocytes are formed along the main collector on the basis of cortical plateau and its derivative structures (on the basis of paracortical and medullary cords). The zones of proliferation of T-lymphocytes are maximally close to the main collector, separated from it by a strip of cortical plateau, form a complex of spherical thickenings, which together form a deep cortex. The stroma and parenchyma are more developed in the nodes with collectors of type II (cumulative relative volume of stroma -9-14% and 6-10%, parenchyma -80-87% and 70-81%, respectively), and lymphatic sinuses -in nodes with collectors of I type (13-20% and 4-6% respectively). In the parenchyma of the lymph nodes of both groups, the zones of proliferation of Tlymphocytes predominate (the centers of deep cortex units are 27-42%), as well as the zones of accumulation of plasma cells and antibody formation (medullary cords -17-29%), the first of which are more developed in the pig, and the latter at the nodes of the bull. The cumulative relative volume of the interfollicular zone (cortical plateau) in the studied nodes does not exceed 6-11%, and the zone of clonal proliferation of B lymphocytes (lymph nodulus) is 5-14%. These zones are more developed in the lymph nodes of the pig. Paracortical cords have the minimum and practically equivalent relative volume in the nodes of both groups (3-5%...
This article analyzes patterns of structural and functional organization of the parenchyma of different groups of lymph nodes, structural features of their connective tissue frame and lymphatic sinuses. We studied superficial and deep somatic (Limphonodi mandibulares, L. cervicales superficiales, L. axillares proprii, L. poplitei), somatovisceral (L. retropharyngei mediales, L. iliaci mediales), visceral (L. mediastinales caudales, L. jejunales) features of mature male drometaries (Camelus dromedarius Linnaeus, 1758). We used a complex of traditional macroscopic and histological techniques, and also immunohistochemical staining of lymph node sections for identifying the features of localization of T- and B-lymphocyte populations in the parenchyma of the nodes. We found that the parenchyma of camels’ lymph nodes is characterized by a spongy type structure in the form of a complex of partly concrescent round-oval fragments of lymphoid tissue, surrounded by large lymphatic spaces (sinuses). The connective tissue frame of the lymph nodes is represented by a two-layer (connective tissue-muscular) capsule and two types of trabeculae: two-layered (connective-muscular, type I), which contain blood and lymphatic vessels, as well as lymphatic cysternas, and a single-layered, formed only by a smooth muscular system (type II). Intranodal lymphatic sinuses are subdivided into subcapsular, peritrabecular and medullary sinuses. The subcapsular sinuses and sinuses related to trabeculae of type I and their branching are the most developed. At the tissue level, the lymph node parenchyma has a clearly manifested lobular structure. Lymphoid lobules in the lymph node parenchyma are positioned diffusely (mosaically) and consist of four main cellular zones: transit and cell-cell interaction (analogous to the cortical plateau), clonal proliferation of T- and, respectively, B-lymphocytes (deep cortex units, lymphatic nodules), accumulation of plasmocytes and synthesis of antibodies (brain cords). The lymphoid lobes (compartments) of the lymph nodes parenchyma are bipolar, their tops formed by the zones of transit and cell-cell interaction, and also by the zones of proliferation of B lymphocytes, and the bases by a complex of brain cords (zone of accumulation of plasmocytes and synthesis of antibodies). The zone of T-lymphocytes proliferation is in intermediate position and underlies the subunits of the parenchyma. The tops of the lymphoid lobes are located along the sinuses of the trabeculae of type I and the bases along the sinuses of the trabeculae of type II, which form the efferent lymphatic vessels. The maximum relative capacity of all studied lymph nodes was typical for zones of plasmocyte accumulation and synthesis of antibodies (19–27%), the minimum capacity was typical for transit and cell-cell interaction zones (3–8%). The relative capacity of zones of clonal proliferation of T- and B-lymphocytes in most lymph nodes was 1.5–3.0 times less than that of the zone of plasmocyte accumulation and antibody formation and was, respectively, 8–16% and 9–18%. The study showed that the structure of the lymph nodes parenchyma of drometaries is not absolutely unique. As in other mammal species, it is subdivided into specialized cell zones which are connected in lymphoid lobules. Specific features of parenchyma structure include: diffuse (mosaic) location of lymphoid lobules; absence of signs of regulated localization of lymphoid lobules relative to the capsule and the sinus bordering the nodes.
Formic acid (methanoic acid, HCOOH) is an organic compound which belongs to saturated monobasic acids. In natural conditions, it is secreted from the glands of ants, and also extracted from the leaves of stinging nettles. It is soluble in water in any proportions, which makes it practical to use for making aquatic solutions. It is broadly used as a preservative in the food industry – Е236 food additive (Codex Alimentarius), as a bactericide in medicine and veterinary medicine, and is also used against agricultural pest species of insects and mites. The in vitro and in vivo experiments revealed the anthelmintic properties of the acid against Strongyloides papillosus nematodes, parasites of the gastrointestinal tract of Ruminantia and rabbits. In the conditions of in vitro, 100% of (L1, L2, L3) nematode larvae died from a 1% solution of formic acid (10 g/l) after 24 hours exposure. When exposed to less strong concentrations of the acid (1, 0.1, 0.01, 0.001 g/l), vital forms of L3 S. papillosus were found. Non-invasive stages (L1, L2) are less resistant to the impact of the acid – death of 100% of the larvae was observed under the impact of 0.1% solution and up to 60% of larvae died at 0.01% solution of formic acid in the same conditions. LD50 for L3 invasive larvae of S. papillosus equaled 0.47%, and 0.0076% for L1, L2 non-invasive larvae of S. papillosus. In the conditions of in vivo experiment (with guinea pigs), the effective dose of formic acid was 0.4% ml/kg of the animal`s body weight. The results of the coproscopy after the treatment demonstrated absence of the helminth larvae in the feces of the laboratory animals during 10 days and their occurrence only on days 15–20 with a low intensity (90 larvae/g of feces on average). During an external examination of the corpses of the animals of the experimental group, no pathological changes were found. The intestine, the heart, the lungs and the liver of the animals from this group had no macroscopic changes – they were of natural colour and size. The hepatocytes looked normal and the structure of the liver lobes was maintained. In the tissues of the liver of the animals from the experimental and control groups, we found processes of passive congestion, and an insignificant degree of signs of hepatic steatosis.
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