Ontogeny of the antigen-reactive lymph follicle-forming capacity of the popliteal lymph node in neonatal mice

The ontogenetic development of the reactive lymph follicle-forming capacity of the popliteal lymph node was investigated immunohistochemically in young mice which had received a single injection of hemocyanin (KLH) in a rear footpad at a predetermined age (between 1 and 21 days). The mice were sacrificed at various intervals after injection. In non-stimulated young mice, primary lymph follicles first appeared in the popliteal node at 11 days of age. When KLH was given to 7-day-old or older mice, each draining popliteal node showed a marked increase in B lymphocytes in the extrafollicular zone 3 days after injection and produced a number of "new" lymph follicles outside the pre-existing follicles over the next few days. In mice injected at 2-4 days of age, these nodes showed an increase in B lymphocytes in the outer cortex and had produced several lymph follicles by 8 days of age. The number of lymph follicles produced by each node tended to increase in line with age at injection. These results indicate that neonatal popliteal nodes become able to produce lymph follicles in response to exogenous antigens some time before ontogenetically developing follicles appear. The formation of new lymph follicles observed in draining popliteal nodes after KLH injection at an early postnatal age is discussed in relation to the ontogenetic development of stromal cells (precursors of follicular dendritic cells) that are capable of interacting with B lymphocytes and the extent of B lymphocyte influx into the node induced by KLH stimulation.     

Myocytes of the inguinal lymph nodes

Owing to the method for making total plane preparations of the capsule after A. V. Borisov, it is possible not only to prove presence of myocytes in the capsule and in the trabeculae of the inguinal lymph nodes in the man and rat, but to open out general regularities of their distribution and orientation. In the capsule areas, corresponding to the places, where the lymph nodules are adjacent to (zone A), the number of myocytes is the least. They are oriented in various directions and are in close contact with each other (fascicular-reticulate principle of distribution of myocytes). In the capsule areas, surrounding A zones (named B zones) the myocytes are situated in tight layers and have circulatory orientation. At the place where the afferent lymphatic vessel gets into the capsule, precapsular lymphangion makes an infundibular dilatation and its myocytes along the sloping spiral get into the capsule, where they are arranged circulatory and form a muscular "constrictor". While studying ultrastructure of myocytes in the rat inguinal lymph nodes, it has been found out that their structure is typical for the smooth muscle cells. There are numerous myo-myocytic contacts of nexus type, that unite the myocytes of the node into a single functional complex.     

Tuberculosis of the intercostal lymph nodes

OBJECTIVE: To describe tuberculosis of the intercostal lymph nodes and discuss its clinical and cytologic profile and pathogenesis. STUDY DESIGN: Fifteen cases from March 1994 to March 2000 were retrieved from our cytology records. Only clinically and therapeutically proven cases were included in the study. RESULTS: The ages of the patients ranged from 4 to 63 years. The male:female ratio was 2:1. The duration of disease at presentation ranged from one week to nine months. The lumps presented either in the parasternal region or between the midclavicular and posterior axillary lines. One case presented with an infrascapular lump. Most of the lumps were ill defined and cystic. Chest radiographs in all cases showed a soft tissue swelling without bony involvement. The aspirates were of two types, blood-mixed particles and necrotic material. Four cytologic pictures were seen: (1) epithelioid cell granulomas alone or (2) with necrosis or (3) with both necrosis and acid-fast bacilli (AFB), or (4) necrosis with AFB. AFB were detected in 53.3% of cases. CONCLUSION: If necrotic material is aspirated or if granulomatous inflammation is encountered in soft tissue swellings of the chest wall, particularly in the parasternal and axillary regions, the possibility of intercostal tuberculous lymphadenitis should be considered.     

Rate of lymph flow and the protein-electrolyte composition of the lymph from the thoracic duct in experimental acholia

Experimental acholia was reproduced by applying a biliary fistula to the choledochus in cats for 20 days. It was established that acholia was accompanied by considerable changes in the lymph flow and in the protein-electrolyte composition of the lymph. The rate of the lymph flow in animals with acholia was more than 2 times as decreased as compared with control. The electrolyte and protein shifts in the lymph during acholia were manifested by the reduction in the lymph protein and K+ content.     

Studies on the ultrastructure of the lymph nodes

Summary The reticular network of the lymph nodes has been studied with a variety of methods aimed to elucidate its chemical composition, submicroscopic structure and relationship with the cells.To study the chemical composition, the reticular network has first been isolated by means of sonic disruption and differential centrifugation, avoiding the use of enzymes or chemical extractions. The material prepared in this way has been studied with the polarized light and electron microscopes and has been subjected to X-ray diffraction and chemical analysis, including chromatographic separation of the collagenous proteins.The results of this work show that the reticular network of lymph nodes has a chemical composition similar to that of loose connective tissues: the fibrils are made of collagenous proteins and the concept of reticulin as a chemical or morphological entity does not appear to be justified.In addition the structure of the reticular network and its relationships with the different cells have been studied with the electron microscope on ultrathin sections of lymph nodes from dogs, cats, rabbits and rats: the reticular fibres appeared to be made of bundles of collagen fibrils with the typical banded structure; the fibres have close contacts with the reticular cells and also with the lymphoid elements of the nodes.In conclusion no elements exist that point towards some specific properties of the reticular connective tissue: the reticular network of the lymph nodes appears not to be basically different from the usual loose connective tissue from which it is distinct only because it harbours a considerable number of immunologically competent cells of the lymphoid series; functional interrelationships between the reticular and lymphoid cells in the nodes are, of course, not excluded.To Prof. F. E. Lehmann on his sixtieth birth day.Supported by a grant of C.N.R.     

The development of the human lymph node

Summary Lymph nodes of human fetuses from the 11th to the 20th gestational week (g.w.) were investigated by light- and electron microscopy under particular consideration of the development of the T-cell and the B-cell regions and their specific reticulum cells. Lymph node development begins as a mesenchymal condensation, containing capillaries and mesenchymal cells; this primordium bulges into a lymph sac. Within the primordium of the lymph node granulopoiesis and erythropoiesis occur temporarily from the 12th to the 14th g.w. The first lymphoid cells and undifferentiated blast cells are seen in the 12th g.w.; monocytes and macrophages can be found from the 13th g.w. onward.The development of the T-cell regions begins during the 13th g.w., before differentiation into cortex and medulla becomes obvious in the 14th g.w. Near the marginal sinus, cells displaying features of interdigitating reticulum cells (IDC) show similarities to monocytes. The morphological differentiation of the IDC is complete in the 17th g.w. when they are found in the paracortical region. Among the IDC, lymphoid cells with features of thymocytes are arranged in small groups.The first indication of the development of B-cell regions can be recognized in the 14th g.w. when precursors of dendritic reticulum cells (DRC) are seen near the marginal sinus; this area also displays lymphoblasts, immunoblasts, and plasmoblasts. During the 20th g.w. small primary follicles are discernible in the outer cortex; in addition to blast cells they contain small lymphocytes, none of which show features of thymocytes. The morphological development of DRCs is not entirely complete until the 20th g.w.; however, some cells already show a characteristic network of interwoven processes.The probable origin of (i) the IDC from monocytes, and (ii) the DRC and fibroblastic reticulum cells from a common type of mesenchymal precursor cells, as well as their significance for a specific micromilieu in the T-cell and the B-cell regions, are discussed.This investigation was supported by grants from the Deutsche Forschungsgemeinschaft and the Sonderforschungsbereich 111 of the Deutsche ForschungsgemeinschaftThe authors appreciate the contribution of human fetal material from Dr. J. von Hollweg and Dr. J. Körner, Hospital Heidberg, Hamburg, and the excellent technical assistance of Mrs. O.M. Bracker, Mrs. H. Hansen, Mrs. R. Köpke, Mrs. I. Knauer, Mrs. F. Müller, Mrs. H. Siebke, and Mrs. H. Waluk     

Effect of lymph removal during drainage of the thoracic lymph duct on the development of disseminated intravascular coagulation syndrome

The experiments on 25 dogs have shown a considerable decrease in the consumption of clotting factors and reduced hyperfibrinolysis with the onset of disseminated intravascular coagulation syndrome in animals poisoned with acetic essence (2 ml/kg).     

Induction of lymph follicle formation with several mitogens and adjuvants in the mouse popliteal lymph node

The formation of lymph follicles in draining popliteal nodes was investigated in young adult male mice which had been injected in the rear footpad with several mitogens and adjuvants, and killed after 3-21 days. PPD (100 micrograms-1 mg) and PHA (25-500 micrograms) induced germinal centers in association with existing follicles and mild plasmacytosis, but failed to produce new follicles in draining nodes. Endotoxin LPS (50-200 micrograms), Con A (50 micrograms-1 mg) and PWM (50 micrograms-1 mg) induced germinal centers within existing follicles and plasmacytosis, and also produced new follicles which soon developed germinal centers. Both Freund's complete and incomplete adjuvants (FCA and FICA, 25 microliters) induced virtually no germinal centers and plasmacytosis, but produced a significant number of new primary follicles. Poly (A, U) (600 micrograms) produced neither germinal centers nor plasmacytosis, and did not induce new follicles. Analysis of the distribution of lymphoid cells which had incorporated 3H-thymidine in the draining nodes at 3 days after the injection of test substances indicated that PPD, PHA, LPS, Con A and PWM preferentially stimulated in vivo the same types of lymphocytes as they do in vitro. FCA triggered lymphocyte activation in the deep cortex, whereas Poly (A, U) appeared not to stimulate lymphocytes in vivo. In further experiments, induction of lymph follicles with artificially precipitated PPD and PHA was studied. The draining nodes treated with alum-precipitated PPD or PHA were found to produce a significant number of new follicles.(ABSTRACT TRUNCATED AT 250 WORDS)