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At least 19 recordsLinked to original sources
PubMed1992

Fibrinogen deposition and macrophage-associated fibrin formation in malignant and nonmalignant lymphoid tissue.

Nonmalignant lymphoid tissue and tissue from patients with nodular sclerosis, Hodgkin's disease, and large cell lymphocytic lymphoma was examined by immunohistochemical techniques for the occurrence in situ of components of coagulation and fibrinolysis reaction pathways. Staining for material interpreted as fibrinogen was observed in abundance in both malignant and reactive lymphoid tissue. Fibrin also occurred to a variable extent but focally in all tissues. Components of coagulation pathways, including tissue factor, factor VII, factor X, and factor XIII ("a" subunit), were restricted to tissue macrophages. Double-labeling techniques revealed fibrin in direct apposition to tissue macrophages. We conclude that fibrinogen and fibrin occur in both benign and malignant lymphoid tissue and that the transformation of fibrinogen to fibrin is attributable to macrophage-initiated thrombin formation. We postulate that both systemic and local hypercoagulability associated with these disorders may be attributable to macrophage activation resulting in expression of procoagulant activity.

Adolescent↗
PubMed1976

Lymphoid tissue and lymphoid-glandular complexes of the colon: relation to diverticulosis.

The lymphoid tissue of the normal colon is compared with that of colons with diverticular disease. Colons with diverticular disease show a significant increase in the number of lymphoid nodules in areas not containing diverticula. Lymphoid-glandular complexes of the colon were studied in relation to diverticular disease. It is suggested that the lymphoid nodules and the lymphoid-glandular complexes of the colon constitute weak points in the bowel wall and may play a part in the pathogenesis of diverticula.

Adult↗
PubMed1991

Immunohistochemical studies on ontogeny of bovine lymphoid tissues.

Developing lymphoid tissues of bovine fetuses ranging from 70 to 270 days of fetal age were examined by histological and immunohistochemical procedures. In the peripheral blood, surface membrane immunoglobulin bearing cells (B-lymphocytes) and sheep red blood cell rosette forming cells (T-lymphocytes) had already appeared by 70 days of fetal age. In the lymph nodes intracytoplasmic IgM positive cells appeared at 90 days of fetal age. The cells positive for IgG appeared at 150 days of fetal age and IgA positive cells appeared at 180 days of fetal age. The spleen contained intracytoplasmic immunoglobulin positive cells at almost the same time as those in the lymph nodes. In the ileocecal region, IgM positive cells and IgG positive cells were present at 180 days of fetal age and IgA positive cells were present at 210 days of fetal age. The tonsils contained IgM positive cells and IgG positive cells at 240 days of fetal age. In the thymus, terminal deoxynucleotidyl transferase positive cells appeared at 90 days of fetal age.

Animals↗
PubMed1979

Comparison of the cytotoxic activities of different human lymphoid tissues.

Normal human lymphoid cells from peripheral blood, spleen, tonsils and thymus were examined for their ability to mediate three different cytotoxic effector cell functions: antibody-dependent cellular cytotoxicity (ADCC); lectin-induced cellular cytotoxicity (LICC) and natural killer activity (NK), against 51Cr labelled erythroid and tumor target cells. We found a hierarchy of cytotoxic activities in the different lymphoid tissues. Peripheral blood and spleen cells were able to mediate LICC, ADCC and NK activities. Tonsil cells showed a natural segregation of the different cytotoxic functions: NK and ADCC activity against tumor target cells were absent, whereas LICC activity was fully present. With respect to ADCC activity against erythroid targets, tonsil cells showed low, but significant, cytotoxicity. Thymus cells had no detectable ADCC, NK and LICC activities. Correlation in the different lymphoid tissues between cytotoxic activities and cell surface marker studies revealed: (a) that the presence of E-SRBC rosette forming cells was not always associated with the detection of LICC activity, as is the case with the thymus; (b) that, in the absence of detectable Eox-7S rosette forming cells (thymus and tonsils), NK and ADCC activities against tumor cells were always absent, but LICC was observed (tonsils), indicating that the presence of this Fc(7S) receptor bearing cells is strongly associated with the expression of NK and ADCC but not with LICC.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1975

Further observations of Fc receptors in human malignant tissue and normal lymphoid tissue.

Twenty human malignant solid tumors of various histologic types were tested for the presence of Fc receptor using cryostat sections or single cell suspensions of fresh tissue. Sheep erythrocytes sensitized by various amounts of rabbit IgG antibodies served as indicator cells (EA). All tumors possessed Fc receptor, but to varying degrees; eight reacted more strongly than normal spleen without any relation to histologic type. The tumors which gave the strongest reactions in sections also formed the highest percent of EA rosettes in suspensions, thus indicating surface localization of receptors. The reactions with spleen sections localized to the B cell and monocytic areas; the latter also showed high avidity in reactions with uncomplexed IgG. Rabbit antisera to tumors, spleen, and peripheral lymphocytes (polyvalent ALS) in inhibited the reactions, while a T-cell-specific ALS did not. Absorptions of the antisera with lymphocytes or tissue sediments of spleen and tumors removed the inhibiting activity, tissue sediments of muscle and kidney only reduced the titers. Again, results with spleen sections paralleled those obtained with tumor sections. Apparently, the tumor Fc receptor is very similar to the Fc receptors present in normal lymphoreticular tissues.

Absorption↗
PubMed1992

The role of nasopharyngeal lymphoid tissue.

Nasal-associated lymphoid tissue (NALT), which comprises paired lymphoid organs in the nasopharynx of rodents, is the principal mucosal lymphoid tissue of the respiratory tract. As described in this review, NALT bears certain similarities to the Peyer's patches of the intestine but the two differ remarkably in morphology, lymphoid migration patterns and the binding properties of their high endothelial venules (HEV).

Animals↗
PubMed1975

In vitro synthesis of some complement components (C1q, C3 and C4) by lymphoid tissues and circulating leucocytes in man.

Human lymphoid tissues and peripheral blood leucocytes and monocytes were studies with respect to the synthesis of complement components (C1q, C3 and C4) using an in vitro culture technique. All of the lymphoid tissues investigated (bone marrow, thymus, lymph node, spleen, tonsil, adenoid) synthesize complement components in different patterns. C3 was produced by all lymphoid tissues except the spleen, which was the only lymphoid tissue in which C4 production was regularly found. C1q synthesis was demonstrated in the spleen and adenoid cultures, and occasionally also in those of lymph node tissue. Lymphocytes in peripheral blood from normal individuals and in thoracic duct lymph, and also from patients suffering from chronic lymphatic leukaemia, do not synthesize any of these complement components. Peripheral blood leucocyte samples from normal individuals, containing 60 per cent lymphocytes and 40 per cent monocytes, do synthesize C3, however. Separation of the monocytes from these samples showed that it was in these cells that the synthesis of C3 occurred. Production of C3 by mononuclear phagocytes is also supported by the finding that peripheral blood leucocytes from patients suffering from acute monocytic leukaemia synthesize C3. C1q and C4 synthesis could not be demonstrated in any of the cultures of circulating leucocytes.

Adenoids↗
PubMed1976

Distribution of T and B lymphocytes in lymphoid tissue of infants and children.

Normal lymphoid tissue from children undergoing elective surgery was examined for T and B lymphocyte distribution. Although established for peripheral blood and bone marrow, T and B lymphocyte distributions have not been previously reported for lymph nodes, appendix, thymus, and spleen tissues in children. Thymus-dependent T cells were determined by the sheep erythrocyte rosette technique, and thymus-independent B cells were determined by the fluorescent labeling of surface immunoglobulins A (IgA), G (IgG), and M (IgM). Fifty percent of lymph node cells were either T or B cells; 65% of these cells were T lymphocytes, whereas 58% of B cells were of the IgM subclass. Less than half of the appendix cells were either T or B cells; 47% of these were T lymphocytes, and the remainder B lymphocytes had subclass distribution similar to that of lymph nodes but different from peripheral blood and bone marrow where B cells bearing IgG predominate. Thymus tissue contained 43% T cells and less than 1% B cells, but the spleen was composed largely of B cells, predominantly of the IgM type. Lymphoid tissue from nine children with either inflammatory or neoplastic diseases were studied and included for contrast. This paper establishes relative distribution values for T and B lymphocytes in normal lymphoid tissue and points out the potential use of this technique to quantitate deviations from normal in certain inflammatory and neoplastic diseases.

Adolescent↗
PubMed1991

Morphologic characterization of conjunctiva-associated lymphoid tissue in chickens.

Conjunctiva-associated lymphoid tissue (CALT) in the eyelids of chickens was studied by gross, histologic, and electron microscopic techniques. Structural features were characterized at 1 day of age and at posthatching week (PHW) 1, 2, 3, 4, 6, 8, 12, and 16. Beginning at PHW 1, prominent lymphoid nodules containing a heterogenous population of lymphocytes, lymphoblasts, and macrophages were first observed within conjunctival folds and fissures of the lower eyelid. Nodules contained germinal centers by PHW 2 and plasma cells by PHW 4. The epithelium associated with these nodules was flat, had short, irregular microvilli, contained intraepithelial lymphocytes, and lacked goblet cells. High endothelial venules were located at the base of lymphoid nodules and contained lymphocytes within and below the cuboidal endothelium. In the upper eyelid, CALT was morphologically similar to lymphoid tissue in the lower eyelid, but nodules were smaller and more random, lacked association with epithelial folds and fissures, and were clustered around the opening of the nasolacrimal duct. By PHW 12, CALT was characterized by basal germinal centers outlined by collagenous stroma, suprafollicular plasma cells, columnar epithelium with goblet cells, and fewer intraepithelial lymphocytes. On the basis of these features, CALT in chickens has morphologic characteristics similar to other components of the mucosal immune system and, therefore, may have a role in mucosal immunity.

Animals↗
PubMed1990

A morphologic study of bronchus-associated lymphoid tissue in turkeys.

Bronchus-associated lymphoid tissue (BALT) in normal turkeys of ages 1 day and 1, 2, 3, 4, 8, and 18 weeks was examined by light microscopy and by scanning and transmission electron microscopy. Turkey BALT resembled other mucosa-associated lymphoid tissues; it was made up of a population of lymphocytes covered by a specialized epithelium different from typical pseudostratified ciliated columnar bronchial epithelium. There were distinct age-related differences in BALT structure. Bronchus-associated lymphoid nodules were larger and more numerous in older turkeys. In 1-day- to 2-week-old turkeys, the primary cell type of BALT epithelium was nonciliated cuboidal; in 2-week old turkeys it was squamous; and in turkeys older than 4-weeks of age, the epithelium was primarily ciliated columnar. In 1- to 4-week old turkeys, large numbers of intraepithelial lymphocytes disrupted the normal organization of the epithelium. In older turkeys, epithelial and lymphoid cells were in discrete compartments separated by connective tissue. Lymphocytes in 1-day-old turkeys were found in loose aggregates around venules and within the epithelium. In 1-week old turkeys, lymphocytes were organized into compartments of morphologically similar cells. By 3-weeks of age, lymphocytes were present in distinct germinal centers. Epithelial cells of BALT did not have large numbers of apical vesicles and thus were not structurally specialized for antigen uptake by endocytosis. However, the epithelial barrier appeared to be disrupted over lymphoid nodules, suggesting that antigen would be readily available to lymphocytes and phagocytes in BALT. Age-related differences in turkey BALT structure may have functional consequences with respect to the respiratory immune response.

Animals↗
PubMed1977

The organization of lymphoid tissue in relation to function.

Organized lymphoid tissue is found in the thymus, spleen, lymph nodes; lining the respiratory and alimentary tracts; and also occurring at sites of chronic inflammation. Apart from the thymus which is involved in the regulation of T-cell function, the other tissues are organized into T-cell and B-cell areas. Lymphocytes in T-cell areas respond by proliferation in cell-mediated immunity and by the production of suppressor cells and helper for antibody formation. B-cell areas are involved in the humoral antibody response. B-cells are segregated into lymph follicles where they form germinal centers and are found at the corticomedullary junction where they differentiate into plasma cells. The role of lymph follicles in becoming germinal centers is poorly understood, but these areas are known to be the site of antigen trapping in primed animals. The particular function of the spleen as a localized area of lymphoid tissue along the course of the blood vascular system is discussed, particularly with respect to its ability to respond to soluble antigen released from sites of localized antigen deposition such as tumors.

Antibody Formation↗
PubMed1975

Subpopulations of thymus dependent and thymus independent lymphocytes in human gut associated lymphoid tissues.

Human gut associated lymphoid tissues were studied in terms of the presence of subpopulations of thymus dependent and thymus independent lymphocytes. Both thymus dependent and thymus independent lymphocytes were present in substantial numbers, as judged from their ability to form spontaneous and complement mediated rosettes with sheep red blood cells and the presence of surface bound immunoglobulins. The relationship between this finding and the question of what is the lymphoid organ which may be the human equivalent of the avian bursa is discussed.

Animals↗
PubMed1992

Immunohistological characterization of proximal colonic lymphoid tissue in the rat.

Proximal colonic lymphoid tissue (PCLT) is a lymphoid structure located in the proximal colon of the mouse and the rat. In the present investigation we studied the immunomorphology and cytology of PCLT in the rat. We also studied sites of lymphocyte proliferation using the BrdU-anti BrdU technique. Results demonstrated no evident phenotypical differences between the lymphocyte populations of PCLT and either jejunal or ileal Peyer's patches (PP). The majority of the lymphocytes within PCLT were B cells localized in follicles, which were separated from each other by interfollicular T cell areas. Germinal centers (GC), containing ED5+ follicular dendritic cells, are found within PCLT follicles. The T cell areas contained both MHC Class II+ interdigitating cells and high endothelial venules. Studies using BrdU-anti BrdU indicated that lymphocyte proliferation within PCLT takes place mainly in germinal centers. Together the data show that the organization, lymphoid constituents, and sites of lymphocyte production are very similar in PCLT and PP. We therefore conclude that PCLT in the rat is not a Bursa equivalent, but more likely a PP with some special characteristics.

Animals↗
PubMed1978

Accumulation and binding of 3H-estradiol-17beta by lymphoid tissues of castrated mice.

The in vivo uptake of 3H-estradiol-17beta by the various lymphoid tissues, fat tissue, skeletal muscle and circulating blood of castrated male and female mice of C57BL strain was studied after an intravenous injection of the hormone. In both sexes the highest uptake was by the bone marrow and fat tissue, followed by the spleen, thymus and mesenteric lymph node. The lowest was by the muscle and the blood serum. The lymphoid tissues in the female took up a slightly more amount of radioactivity than those in the male until 1 hr after the injection, but thereafter the uptake was at almost the same level between both sexes. The lymphoid tissues showed a relative and long-term retention of the radioactivity, as compared with that in the muscle and blood serum. The binding of 3H-estradiol-17beta by the lymphoid tissue cytosol and their binding specificity for the hormone were examined in vitro by Sephadex G-100 column analysis. All the tissue cytosols tested contained estradiol-binding component(-s). Among those the thymic cytosol showed to contain the component(-s) which is fairly specific to this hormone. These results suggest that there is a relatively high uptake and retention of estrogen in the lymphoid tissues in which it is bound to cytoplasmic binding component(-s).

Adipose Tissue↗
PubMed1992

Preferential location of somatostatin receptors in germinal centers of human gut lymphoid tissue.

Somatostatin receptors were evaluated in four human gut-associated lymphoid tissues (palatine tonsils, ileal Peyer patches, vermiform appendix, and colonic solitary lymphatic follicles) using receptor autoradiography on tissue sections incubated with 125I[Tyr3]octreotide. All four tissues were somatostatin-receptor positive; the receptors were preferentially located in the germinal centers, with the luminal part of the center more strongly labeled than the basal part. The corona of the follicles and the primary follicles without germinal centers did not display somatostatin receptors. The receptors were of high affinity (Kd = 1.3 +/- 0.6 nmol/L) and specific for somatostatin. Displacement by nanomolar concentrations of somatostatin 14, somatostatin 28, and octreotide was observed, as was guanosine triphosphate dependency. The gastrointestinal mucosa and the plexus submucosus and myentericus also contained somatostatin receptors. These data strongly suggest that the germinal centers of the gut-associated lymphoid tissue are a site of action of somatostatin. It possibly mediates antiproliferative effects and inhibits immunoglobulin synthesis in the activated lymphoid cells. The human gut represents a multifaceted target for somatostatin action, in which at least three different tissues (mucosa, nerve plexus, and lymphoid tissue) are involved.

Humans↗
PubMed1975

The generation of large pyroninophilic cells in the lymphoid tissues of rats infused with cell-free lymph.

The thoracic duct of Wistar strain rats was cannulated during 5 days for studying the effect of selective lymphocyte depletion on the lymphoid tissue. A technique for the continuous infusion of cell-free lymph, whole lymph of Eagle's medium to the rat with the thoracic duct fistula is described in detail. The prolonged drainage of lymph from rats was followed by lymphopenia, sever atrophy of lymphoid tissues and the depletion of small lymphocytes in the thymus-dependent areas of spleen and lymph nodes. The infusion of cell-free lymph into the drained rat resulted in the recovery of the weight of lymphoid tissues and in the massive proliferation and accumulation of large cells with prominent nucleoli and intensely pyroninophilic cytoplasm in the lymphocyte depleted areas of the peripheral lymphoid tissues and thymic cortex. There was histological evidence that the large pyroninophilic cells developed well in the spleen and tended to localize preferentially around the periarteriolar region through the marginal zone bridging channels to the red pulp. The infusion of Eagle's medium was found ineffective in restoring the weight of the lymphoid tissues and in bringing about the proliferation of lymphoid cells. The rats infused with whole lymph showed almost similar findings biologically and histologically to those of sham-operated rats.

Animals↗
PubMed1978

Immunology of the lower respiratory tract. III. Concentrations of antigen and of antibody-forming cells in pulmonary and systemic lymphoid tissues of dogs after intrapulmonary or intravenous administration of sheep erythrocytes.

The distribution of antibody-forming cells to sheep erythrocytes among canine pulmonary and systemic lymphoid tissues differs distinctively depending on whether antigen is administered by the intrapulmonary or the intravenous (i.v.) route. After local (intrapulmonary) immunization, antibody-forming cells are restricted to the lung and regional lymph nodes; after i.v., they are widespread. To test the hypothesis that the tissue distribution of antigen is an important determinant of the resultant distribution of antibody-forming cells, dogs were immunized with radioiodinated sheep erythrocytes, either intrapulmonary (i.p.) or i.v. After 4 days, the concentrations of tissue-bound radioactivity and of antibody-forming cells in various lymphoid tissues were compared. The distribution of tissue-bound radioactivity among lymphoid tissues was clearly determined and different depending on the route of immunization. After i.p. administration, radioactivity was bound to lung and hilar lymph nodes; after i.v., it was found in the lung, liver, spleen and occasionally hilar nodes. Antibody-forming cells appeared in those lymphoid preparations which contained tissue-bound radioactivity. The exception was that locally applied antigen elicited antibody-forming cells in the lung poorly, despite the fact that abundant antigen remained localized to the lung. Notably, i.v. immunization resulted in the appearance of both antibody forming cells and cell-bound radioactivity in the lung. It is concluded that the distribution of antigen among tissues is a major determinant of the distinctive patterns of appearance of antibody-forming cells after different routes of immunization.

Animals↗