Structural changes in popliteal lymph nodes in the graft vs. host reaction to H-Y antigen in male C57BL/6-strain mice

Regional popliteal lymph nodes in intact, control and experimental (I, II, III groups, respectively) have been studied by means of the morphometric method in male C57Bl/6 line mice at the pick of the reaction produced by injection of spleen cells and mesenteric lymph nodes obtained from syngenic females and repeatedly immunized to H-Y antigen (10 animals in each group). Injection of the cell suspensions from the immunized and intact females of the C57Bl/6 mice result nearly in two-fold increasing mass of the regional popliteal node at the expense of enlarged size of all its zones. Changes in cytoarchitectonics of the node structural components result from redistribution of certain cellular elements. The essential changes in the cell composition of the lymph nodes in the II and III male groups are accompanied with an increasing part of the stromal reticular cells. Simultaneously, content of small lymphocytes decreases significantly. In the III group of mice there is a sharp increase in the content of young forms of the lymphoid line cells in all structural components of the node, as well as in eosinophilic granulocytes in medullary cords. In the dark cortical zone of the nodes (III group) there occur tissue basophils (mast cells), that, together with increasing number of acidophilic granulocytes and appearance of neutrophilic cells, demonstrates that there is an inflammatory reaction in the organ studied as a response to the lymphocytic suspension injected. In the experimental group of the animals a complete disappearance of plasma cells is noted in the node cortex, but some increase of their part takes place in the medullary cords.     

Study of the lympho- and hemomicrocirculatory bed of lymph nodes by scanning electron microscopy

The spatial interrelation of the lymphatic and blood beds has been studied in the lymph node together with its stromal and lymphoid elements, using scanning electron microscopy of corrosive casts and native preparations. There is a great variety of pathways for lymph transport and blood vessels in dependence of their localization in the lymph node. Of a special interest are the pathways of lymphocytes migration across the walls in the cortical and medullary sinuses and in the postcapillary venules, as well as participation of the reticular tissue in the lymph node immune reactions.     

Degree of chromatin activity and the RNA level in lymphocytes of popliteal lymph nodes of dogs after administration of an antigen]

In the experiment performed on 127 dogs by means of cytospectrofluorometric analysis, using fluorochrome acridine orange in dynamics up to 1 year, changes in the level of chromatin activation and RNA content have been studied in lymphocytes of the germinative centers and the crown of lymphoid nodules, in the paracortical zone and medullary cords of the regional and contralateral popliteal lymph nodes, after subcutaneous injection of antigen (BCG vaccine, 0.2 mg/kg) into the lateral area of the foot of the left pelvic extremity. The immune response is accompanied with a periodical increase in the level of chromatin activation and RNA content in populations of lymphocytes in the regional and contralateral popliteal lymph nodes with maximum in 6 h, 3-7 days, 1-3 months after the antigen injection. The intensity of these processes has an unequal level in lymphoid cells of various structural components; it is higher in lymphocytes of the contralateral lymph node.     

Functional morphology of the lymphatic system of the rat uterus during pregnancy

In the regional lymph nodes of the uterus the comparative volume of the paracortical zone significantly increases, especially within the period of the 13th-17th days of pregnancy. In the popliteal lymph node similar effect is not discovered. From the 7th up to the 11th day edema, vasodilatation, infiltration with special leucocytes are revealed. Endothelium of the postcapillary venules is hypertrophied, contains many migrating lymphocytes, which accumulate around the vessels mentioned. The volume of the microcirculatory bed is moderately increased. By the 17th day plasmoblasts, plasmocytes, Motta's cells, monocytes and especially macrophages appear in the paracortical zone. In B-zones and in medullary sinuses blasts, plasma cells, monocytes, macrophages, mitotically deviding cells increase in number. The part of the reticular cells decreases. The tensometric method demonstrates an increasing pressure of lymph in the iliac lymph node at pregnancy. Collateralies appear in the ovarian vein system, in the broad ligament of the uterus, in the lumbar area. The uterine vascular system is supposed to participate in adaptation to pregnancy. In genesis of the regional lymph node changes, discirculatory shifts, predominating during placental organogenesis, combine with phenomena of cell migration and proliferation (clearly revealed by the time when formation of the placenta is completed).     

Cytoarchitectonics of the tracheobronchial lymph nodes in rats exposed to carbon disulfide

Cytoarchitectonics and rearrangement of cellular composition in functionally different zones of the rat tracheobronchial lymph nodes have been studied at a short effect of the industrial carbon disulfide vapour at a maximally admissible concentration (MAC) (1 mg/m3 and 10 mg/m3), as well as after the effect of MAC of carbon disulfide in the inhaled air for 4, 7, 14 days. The inhalation of the carbon disulfide vapours results in certain changes of the cytoarchitectonics of the lymph nodes studied in dependence on concentration and duration of the substance effect in the air inhaled. The effect of the MAC carbon disulfide, when the experiment lasts for 2 days, is accompanied with a decreased lymphocytopoiesis in all the structural components of the node and with a sharp intensification in the number of plasma cells of the medullary cords, that demonstrates local immunocytopoiesis. An opposite picture is noted, when carbon disulfide is applied in an elevated concentration (10 mg/m3)--plasmic reaction is sharply inhibited in the medullary cords, lymphocytopoiesis is noticeably increased, certain signs of allergic reaction are also seen. A prolonged effect of carbon disulfide vapours (up to 14 days) in MAC results in lymphocytopenia of the nodes, in increasing destructive processes and in decreasing cell proliferation. Differences in reaction of the structural components are revealed in the nodes studied at the toxic effect: in the cortical plateau and in the medullary cords suppression of the lymphocytopoietic activity is noted, and in the medullary cords--inhibition of immunocytopoiesis.     

Catecholamines in adrenergic nerve fibers of the lymph nodes after sympathectomy

Using Falck method in combination with microfluorimetry, catecholamine level in adrenergic nervous fibers has been measured in the canine popliteal lymph nodes, normal and in 12 h, 7, 30, and 90 days after unilateral lumbar sympathectomy. During first 24 h after the operation the level of catecholamines is for certain increased in the nervous fibers of the lymph node of the sympathectomized extremity. In 30 days after the sympathectomy their content drops at the side of the operation and increases in the contralateral extremity. By 3 months the equilibrium of the catecholamine content is restored in the nervous fibers of the lymph nodes in the homo- and contralateral extremities at the level higher than in the control. A conclusion is made that under conditions of unilateral sympathectomy only a partial sympathectomy of the popliteal lymph node is reached. All luminiscent adrenergic nervous fibers of the sympathectomized lymph node are processes of neurons, situating in the contralateral sympathetic trunk, or neurites of cells in sacral nodes, getting their preganglionic fibers from the contralateral trunk. The changes in catecholamine concentrations mentioned are considered as a compensatory reaction, directed to maintenance of general homeostatic equilibrium under conditions, when the nervous system transfers to a new level, ensuring the partly desympathized tissue by mediators.     

Cellular composition of various structural zones of the iliac and mesenteric lymph node of pregnant rats

The dynamic of cellular reactions demonstrates certain changes in functional activity of all structures of the node during pregnancy. A similar trend of processes in the iliac (regional for the uterus) and mesenteric lymph nodes has been defined. At early stages of pregnancy, lymph nodule are the most active, this is demonstrated as an increasing portion of lymphoblasts, macrophages and dividing cells. During this period, cell composition of the cortical plateau is relatively stable. For the paracortical zone of the mesenteric lymph nodes a rather significant decrease in the portion of middle lymphocytes and reticular cells is characteristic. There is not any significant change in the relative amount of the cells in the same functional zone of the iliac lymph nodes during the same period of pregnancy. The medullar cords demonstrate an increasing number of blast forms and young plasmocytes. However, as the pregnancy develops, the structure of the paracortical zone undergoes an essential change--progressively increases the portion of lymphoblasts and large lymphocytes. The blastic reaction in the mesenteric lymph nodes is proved to depend, to some extent, on that in the iliac lymph nodes of the same animal. Mature plasma cells become the dominating cellular element in the medullary cords. At the end of the pregnancy a relative amount of the reticular cells increases in all structural zones of the node.     

Differential induction of adhesion molecule and chemokine expression by LTalpha3 and LTalphabeta in inflammation elucidates potential mechanisms of mesenteric and peripheral lymph node development

Lymphotoxin (LT) is a member of the proinflammatory TNF family of cytokines that plays a critical role in the development of lymphoid tissue. It has previously been reported that the presence of the LTalpha transgene under the control of the rat insulin promoter results in inflammation at the sites of transgene expression. LTalpha transgene expression results in expression of the adhesion molecules VCAM, ICAM, peripheral node addressin (a marker of peripheral lymph nodes), and mucosal addressin cellular adhesion molecule (a marker of mucosal lymphoid tissue, including mesenteric lymph nodes). In this study to determine the mechanisms by which LT promotes inflammation and lymphoid tissue organization, we analyzed the regulation of expression of adhesion molecules and chemokines in LT transgenic mice. The results demonstrate that LTalpha3 induces expression of the adhesion molecules VCAM, ICAM, and mucosal addressin cellular adhesion molecule as well as the chemokines RANTES, IFN-inducible protein-10, and monocyte chemotactic protein-1, while LTalphabeta is required for the induction of peripheral node addressin that may contribute to the recruitment of L-selectinhigh CD44low naive T cells. These data provide candidate mediators of LT-induced inflammation as well as potential mechanisms by which LTalpha and LTalphabeta may differentially promote the development of mesenteric and peripheral lymph nodes.     

Changes in the functional activity of macrophages of the skin and regional lymph node after exposure of albino rats to total deep hyperthermia

In the experiments performed on white male rats (150-170 g of body mass) effect of total deep hypothermia has been studied in macrophages of the skin and regional suprascapular lymph node of various localization: Langerhans cells of the epidermis, histiocytes of the derm and hypoderm, macrophages of medullary sinuses, interdigitating cells of T-zones in the lymph node. After narcotization the animals are cooled with the rate 1 degree C per 5 min up to the rectal temperature of 18 degrees C. They are kept at this temperature for 2 h, and then are warmed with the same rate up to 37 degrees C. Actively phagocytizing macrophages of the skin and lymph node are revealed by their adsorption of trypan blue. The Langerhans and interdigitating cells of the lymph node are revealed by means of the ATP-ase method. After the cooling effect functional activity of macrophages with various localization increases. For the Langerhans cells it is manifested as a greater amount of the cells and their processes, for the interdigitating cells--as an elevated ATP-ase activity in 7 and 30 days after the experiment. Dermal histiocytes and macrophages of the lymph node sinuses respond to the cooling with an increasing adsorption of tripan blue. Amount of the cells, that adsorb the dye also increases. A conclusion is made that after the hypothermal effect protective-barrier properties of the dermal region increase.     

Physical and radiological findings specific for medullary carcinoma of the thyroid gland.

Preoperative physical and radiological findings, if specific to a certain extent, are important for detecting patients with sporadic form of medullary thyroid carcinoma and especially for the first patient in the family having a hereditary form of medullary thyroid carcinoma and pheochromocytoma syndrome. To delineate clinical features of medullary thyroid carcinoma, a total of 9 patients with this tumor were reviewed retrospectively. In most patients, the thyroid lesions were located in the upper two thirds of the lobe, which was determined by careful palpation or 131I scintiscanning of the thyroid. The primary lesion in the thyroid could be felt more or less as a round, sharply demarcated nodule with fairly good mobility. These findings suggested rather a benign thyroid nodule when there was no lymph node involvement. However, it could be considered a sign suggesting medullary thyroid carcinoma when accompanied by marked lymph node metastasis. In our recent 2 cases, the diagnosis of medullary thyroid carcinoma was strongly suspected on these clinical bases, one of the cases being presented in detail. In 4 patients, lymph node metastasis in the central neck extended to either submandibular or upper mediastinal regions or both. In about one third of the patients, calcified deposits were shown in the cervical roentgenograms. With the use of soft tissue roentgenography, grossly punctate calcific deposits associated with psammoma-like shadows were recognized and the pattern was a criterion for definitive diagnosis of medullary thyroid carcinoma.     

Initial lentivirus-host interactions within lymph nodes: a study of maedi-visna virus infection in sheep.

Reactive changes occurring within lymph nodes draining the subcutaneous site of acute infection with maedi-visna virus (MVV) were studied, and the appearance of infected cells correlated with the immune response. Cells infected with virus were detected in the node by cocultivation from day 4 postinfection (p.i.), with maximum numbers being seen between days 7 and 14, but even then infected cells were rare, with a maximum frequency of 23 50% tissue culture infective doses (TCID50) in 10(6) lymph node cells. At later times, infected cells were still detected, but their numbers fell to 1 to 2 TCID50 per 10(6) cells. Virus-specific CD8+ cytotoxic T-cell precursors (CTLp) were isolated from infected nodes from day 10 p.i. onwards, and T-cell proliferative responses to MVV were first detected on day 7 and consistently detected after day 18. Histological analysis showed a vigorous immune response in the node. There was a marked blast reaction in the T-cell-rich zones, which was greatest at the time when the number of virally infected cells was at its height. At this stage, large numbers of plasma cells were seen in the medullary cords, indicating that extensive T-cell-dependent B-cell activation was occurring in the T-cell-rich zones. Germinal centers were prominent shortly after the onset of the T-zone response and were still present at 40 days p.i. Phenotype studies of isolated lymph node cells failed to detect major changes in the proportion or phenotype of macrophages, CD1+ interdigitating cells, and CD4+ or CD8+ T cells despite the fact that CD8+ lymphoblasts form a major population leaving the node in efferent lymph. This suggests that there is a balanced increase in the number of all cell types in response to the virus within the node and selective migration of CD8+ lymphoblasts containing virus-specific CTLp from the node. Virus-specific immune responses are therefore present within the node when infectious virus isolation is maximal, but cellular immunity may act to control the level of infection from day 18 onwards.     

Structure of sinuses in the human lymph node

Summary A casting technique has been employed to display in three dimensions, the lymphatic microcirculation within the human lymph node. The casting compound filled the marginal sinus, and diffusely permeated the cortical lymphoid parenchyma. However, deep within the lymph node in the medullary region, the medium remained within the limits of the sinus walls. The casts showed well-defined channels appearing similar to vessels. These converged into larger vessels, which drained into efferent lymphatics leaving the node at the hilus.Electron microscopic examination showed that the outer wall of the marginal sinus and the trabecular side of trabecular sinuses had an intact, continuous endothelium with a basement membrane. However, gaps were present in the inner wall of the marginal sinus, as well as in the parenchymal wall of the trabecular sinus. In the medulla, the sinuses were lined by endothelial cells which appeared similar to macrophages. The sinus lining was incomplete and possessed numerous perforations. These observations indicated that sinus walls adjacent to connective tissue served as a barrier to cell movement, but those adjacent to a large lymphoid cell population had gaps, with cells in apparent transit between sinus lumen and parenchyma.     

Age and features of the construction and cellular composition of superior tracheobronchial lymph nodes in adult humans]

Age peculiarities in composition of the upper tracheobronchial lymph nodes have been studied in 60 corpses at the age of 16-70 years. Cause of death has not been connected with diseases of blood, lymphatic system or thoracic origins. Routine histological and morphometric methods have been applied. Certain age-dependent rearrangement in the connective tissue stroma, trabecular vegetations and differences in correlations of structural components have been noted. A rather essential volumetric increase of the medullary substance takes place at the level of hilus of the lymph node. Cellular composition of the lymph nodes is greatly polymorphous but is more or less constant for each age group. The number of macrophages containing carbon pigment is increasing with age.     

Morphofunctional reorganization of the kidneys in lymphatic outflow disturbance

In 115 Wistar male rats structures and rates of tissue blood flow have been studied in the cortical and medullary renal substance histologically, polarographically (estimation of the volumetric tissue blood flow by hydrogen clearance). Systemic arterial (peritoneal aorta), venous (caudal vena cava) and lymphatic (renal lymph nodes) pressures have been measured, normal and after ligation of the thoracic duct at early (1-3 days), middle (1 month) and late (2-3 months) periods. In 1-3 days edema and dystrophy of the renal parenchyma, decrease of the blood flow rate in the cortical and its increase in the renal medullary substance, as well as a sharp elevation of pressure in the lymph nodes are observed. In 1 month of the experiment together with dystrophy and edema moderate sclerosis, decreasing blood flow rate in the cortical and medullary substance are noted. Increase of the systemic arterial and venous pressure and decreasing pressure in the lymph nodes, as well as a sharp increase of the renal nodes mass are revealed. In 2-3 months of the experiment, together with sclerosis of the renal parenchyma, elevated blood flow rate is observed in the kidneys and decreasing pressure in the lymph nodes up to its initial value takes place.     

Morphofunctional changes in the hemo- and lymphomicrocirculatory bed of the uterus and its regional lymph nodes in venous congestion during pregnancy

Interrelations of the blood and lymphatic systems of the uterus have been examined in rats at pregnancy complicated with the ++phlebo-occlusive syndrome. Blood stream impediment in the caudal vena cava results in increasing diameter of the arterioles, capillaries and venules of the endo- and myometrium. Certain disturbances of blood circulation in the uterus at the ++phlebo-cclusive syndrome in the pregnancy animals, as a rule, reflect in the uterine lymph outflow; this is demonstrated as dilatation and deformity of the lymphatic vessels and capillaries, appearance of protrusions of the lymphatic vessels wall. There is a definite co-ordination in the reaction to the caudal vena cava occlusion in the intra-, ++extra-organic uterine lymphatic bed and in its regional lymph nodes, manifested as the following morphological signs: decreasing relative volume, that the lymphoid tissue occupies and increasing relative volume of the cortical and medullary intermediate sinuses.     

Carbonic anhydrase activity in peripheral T-lymphocytes and appearance of the activity during their maturation in the thymus

Summary Carbonic anhydrase (CA) activity is demonstrated in lymphoid tissue for the first time using the histochemical (Hansson's) method. A CA-positive reaction was seen in lymphocytes present in T-lymphocyte areas in both the lymph node and the spleen. The most intense staining was seen in the small T-lymphocytes, whereas the mediumsized T-lymphocytes were less markedly stained. The cortical lymphocytes in the thymus were completely devoid of staining, but the small medullary T-lymphocytes stained intensely. The results suggest that peripheral and thymic medullary T-lymphocytes contain CA activity, which appears in these cells during their maturation in the thymus.     

Carbonic anhydrase activity in peripheral T-lymphocytes and appearance of the activity during their maturation in the thymus. A histochemical demonstration

Carbonic anhydrase (CA) activity is demonstrated in lymphoid tissue for the first time using the histochemical (Hansson's) method. A CA-positive reaction was seen in lymphocytes present in T-lymphocyte areas in both the lymph node and the spleen. The most intense staining was seen in the small T-lymphocytes, whereas the medium-sized T-lymphocytes were less markedly stained. The cortical lymphocytes in the thymus were completely devoid of staining, but the small medullary T-lymphocytes stained intensely. The results suggest that peripheral and thymic medullary T-lymphocytes contain CA activity, which appears in these cells during their maturation in the thymus.     

Structure of the arterial bed in human lymph nodes

Blood vessels, that bring blood to various areas of the human superficial inguinal lymph nodes are predominantly arterioles and precapillaries. They are often arranged radially from the hilus to the capsule and from the capsule towards the portal thickening. The arteries and arterioles of the portal and capsular trabeculae reach the paracortical zone, occupying an intermediate position between the medullary cords and the cortex of the lymph node. The arterioles of the paracortical zone, passing between the cortex and the medullary cords, acquire an arcuate appearance. In both directions from them (into central and peripheral areas of the node) precapillaries branch off at a right angle. The cortex is supplied with blood by the arteriolar branches of the paracortical zone and the capsule of the node. The cortical precapillaries branch into capillaries either within the lymphoid nodules, or along their periphery. In the medullary cords those arterioles branch, that get from the portal thickening, portal trabeculae and paracortical zone.     

Oncogene expression in a medullary thyroid carcinoma

We report the expression of Ha-ras, fos, c-myc and N-myc mRNA in a human medullary carcinoma of the thyroid gland, both in primary tumor and lymph node metastasis, as demonstrated by in situ hybridization and Northern blot analysis. A significant difference in the oncogene expression in the primary tumor and the metastasis was not observed. Tumor tissue revealed a significant overexpression of Ha-ras, c-myc and N-myc mRNA as compared to the normal thyroid gland. The amount of fos mRNA expression in non tumorous thyroid gland did not significantly differ from tumor tissue, sis, fms and abl mRNA expression was not detectable in tumor tissue and non tumorous thyroid gland. We conclude, that the (over)expression of the oncogenes Ha-ras, c-myc and N-myc may be associated with initiation and progression of medullary thyroid carcinoma. Similar studies on additional cases of human medullary thyroid carcinoma will be necessary to reveal further information.     

Morphology of the submandibular lymph nodes of white rats adapting to alpine conditions

A field experiment has been performed in white noninbred rats in order to study morphometrically structural reconstructions and cellular composition characteristics in the submandibular lymph nodes on the 1st, 3d, 7th, 14th, 21st, 30th and 50th days after lifting them to the altitude of 3,375 m above sea-level. The data obtained demonstrate a stable increase in small lymphocytes contents during the days of the observations; they are accompanied with an increasing specific area of the folliculi and a decreasing area of the cortical plateau. An essential decrease in the plasmic cells and dividing cells contents noted during the whole experiment is regarded to demonstrate an inhibition of the organism's immune reactivity at hypoxic hypoxia. Certain time periods are revealed which are accompanied, during the adaptation period to the high-mountain conditions, with general reactions of definite cell types and the lymph node structures: the 1st-7th days; the 14th-30th days; the 45th day and more. According to the character of the cell reactions in the experiment performed, it is possible to arrange the main structures of the submandibular lymph nodes in the following order: folliculi, cortical plateau, sinuses, medullary cords.