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At least 811 records · Page 45Linked to original sources

PubMed1992

Bronchial-associated lymphoid tissue (BALT) response to airway challenge with cigarette smoke, bovine antigen and anti-pulmonary serum.

The bronchial-associated lymphoid tissue (BALT) is a lymphoepithelial organ, related to the immune defence of the lung and to alveolar clearance, which changes size in certain states of disease. Changes in the size of BALT were quantified and compared, and Spearman's test was used to test the relation with the bronchial epithelium. A total of 180 rats were used, divided into 6 groups of 30 as follows: 1) untreated controls; 2) exposed to cigarette smoke for two months; 3) treated with anti-pulmonary serum three doses daily over five days; 4) exposed to cigarette smoke and treated with anti-pulmonary serum; 5) sensitized with bovine albumin and exposed to an environment containing this antigen for two months; 6) exposed to cigarette smoke and bovine albumin. The lungs were processed for histological study, and were stained with the PAS-Alcian blue method. The main left bronchi BALT was studied, and the following were quantified: Lymphatic area (LA), as a percentage of the lung surface occupied by BALT; the flat epithelium (FEp), as the length of bronchial epithelium anatomically related to LA, whose cells tend to adopt a flat shape; the Contact epithelium (Cep), as the length of bronchial epithelium which is in direct contact with the LA. A percentage count of bronchial cells was made in the following classifications: globet cells; globet cells stained with the PAS-Alcian blue method; flat cells; lymphoepithelium cells; columnar cells; and bronchial epithelium cells excluding the above two cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗

PubMed1997

A temporal study of TPN-induced changes in gut-associated lymphoid tissue and mucosal immunity.

BACKGROUND: Total parenteral nutrition (TPN) is associated with decreases in small-intestinal gut-associated lymphoid tissue (GALT) T cells, B cells, and IgA levels and impairs IgA-mediated defenses in the respiratory tract. The impaired respiratory tract defenses are speculated to be due to reduced respiratory tract IgA levels. OBJECTIVES: To determine the time course of GALT cell reductions and document any changes in respiratory tract IgA levels in mice receiving TPN. DESIGN: Prospective randomized trial. SETTING: Animal research laboratory. MATERIALS: Thirty-five male ICR mice weighing 25 to 35 g. INTERVENTIONS: Mice underwent cannulation with intravenous catheters and received chow for 2 days followed by TPN for 0 (n=6), 1 (n=6), 2 (n=6), 3 (n=6), 4 (n=6), or 5 (n=5) days. Mice were killed after receiving TPN their respective number of days. The small intestine was harvested, and washings were obtained from the small intestine and the respiratory tract. Lymphocytes and IgA levels were analyzed by flow cytometry and enzyme-linked immunosorbent assay, respectively. MAIN OUTCOME MEASURES: Lymphocyte yields from Peyer patches, intraepithelial spaces, and the lamina propria; IgA levels from the small intestine and the respiratory tract. RESULTS: T- and B-cell yields in the Peyer patches and lamina propria were significantly reduced by day 2 (P<.05) and thereafter compared with day 0. The lamina propria CD4+/CD8+ ratio declined significantly by day 4 (P<.05) compared with day 0. Small-intestinal and respiratory tract IgA levels were significantly diminished by day 3 (P<.05) and thereafter compared with day 0. CONCLUSION: Total parenteral nutrition produces rapid changes in GALT cell profiles and reduces respiratory tract IgA levels consistent with the impairment of respiratory IgA-mediated defenses.

Animals↗

PubMed1987

Lymphoid tissue- and inflammation-specific endothelial cell differentiation defined by monoclonal antibodies.

Endothelial cells play an essential role in immune responses by regulating the entry of leukocytes into lymphoid tissues and sites of inflammation. As an initial approach to analyzing endothelial cell specialization in relation to such immune function, we have produced monoclonal antibodies (MAB) against mouse lymph node endothelium. Three antibodies were selected: MECA-20, recognizing the endothelium of all blood vessels in lymphoid as well as non-lymphoid organs; MECA-217, which stains the endothelium lining large elastic arteries, but among small vessels is specific for post-capillary venules within lymphoid organs and tissues exposed to exogenous antigen, such as skin and uterus; and MECA-325, an antibody that demonstrates specificity for the specialized high endothelial venules (HEV) that control lymphocyte homing into lymph nodes and Peyer's patches. MECA-325 failed to stain vessels in any non-lymphoid organs tested. Immunoperoxidase studies of HEV in lymph node frozen sections, and of isolated high endothelial cells in suspensions, demonstrated that the antigens recognized by all three antibodies are expressed at the cell surface; those defined by MECA-20 and MECA-325 are also present in the cytoplasm. To study the regulation of the antigens defined by these MAB in relation to extra-lymphoid immune reactions, we assessed their expression in induced s.c. granulomas as a model for chronic inflammation. Small vessels in the granulomas were already stained by MECA-217 in the first days of development. In contrast MECA-325 detected postcapillary venules (which frequently displayed the morphologic characteristics of HEV) only from approximately 1 wk, in parallel with the development of a persistent mononuclear cell infiltrate including numerous lymphocytes. The selective appearance of the MECA-325 antigen on vascular endothelium supporting lymphocyte traffic in both lymphoid and extra-lymphoid sites suggests that this antigen may play an important role in the process of lymphocyte extravasation. The demonstration of lymphoid organ- and inflammation-specific microvascular antigens offers direct evidence for a complex specialization of endothelium in relation to immune stimuli, and supports the concept that microvascular differentiation may play an important role in local immune responses.

Animals↗

PubMed1996

Accessory cells in physiological lymphoid tissue from the intestine: an immunohistochemical study.

We report a study of the organization of accessory cell populations, in normal mucosal lymphoid tissue from small intestine (8 cases), large intestine (6) and appendix (9) using a panel of monoclonal antibodies and polyclonal antisera in paraffin-embedded tissue. Two populations were identified in dome areas, one positive for acid cysteine proteinase inhibitor and HLA class II (WR18) only and the second positive for S-100 protein, CD68, and WR18 and negative for acid cysteine proteinase inhibitor and factor XIIIa. Superficial colonic mucosal and small intestinal villous tip macrophages stained positively with CD68 and WR18 only, while deeper cryptal and submucosal populations exhibited additional positivity for factor XIIIa, but both populations were negative for acid cysteine proteinase inhibitor and S-100 protein. Germinal centre macrophages were positive for CD68, WR18 and acid cysteine proteinase inhibitor and negative for factor XIIIa, and S-100 protein. T zone dendritic cells included a population which stained positively for S-100 protien, WR18 and were negative for factor XIIIa, CD68 and acid cysteine proteinase inhibitor, an immunophenotype typical of interdigitating dendritic reticulum cells. This distribution of phenotypically identifiable accessory cell subpopulations was apparent at all three sites examined. We suggest that the specialized subpopulations of dendritic cells staining for S-100 protein and for acid cysteine proteinase inhibitor which are restricted to the dome areas, may have a potential role in the transfer of antigen across the epithelium to the germinal centres, while factor XIIIa appears to identify a tissue macrophage population with a potential role in stromal modulation distant from direct antigen challenge.

Antigen-Presenting Cells↗

PubMed1995

Extracellular nucleic acids as possible messengers in regulatory information transfer from immune system to non-lymphoid tissues.

The goal of this review is to connect the information on the regulation of growth and differentiation of non-lymphoid tissues by the immune system and the release/uptake of nucleic acids by living cells (especially by lymphocytes). Nucleic acids are suggested to be the messengers in regulatory information transfer from the immune system to other cells.

Animals↗

PubMed1980

Different labelling patterns in mouse lymphoid tissues with [3H]deoxycytidine and [3H]thymidine.

The percentages of labelled lymphocytes in smear preparations of mouse thymus were higher than those in similar preparations of mesenteric lymph nodes with either generally labelled tritiated deoxycytidine, [3H]CdR, or tritiated thymidine, [3H]TdR. Lymphocytes in the thymus cortex and in germinal centres of mesenteric lymph nodes were intensely labelled with [3H]CdR, whereas with [3H]TdR lymphocytes in the peripheral region of thymus and medullary cords of mesenteric lymph nodes were heavily labelled. The majority of lymphocytes in thymic cortex and germinal centres of mesenteric lymph nodes were labelled weakly with [3H]TdR. Thus, labelling patterns with [3H]CdR differed from those with [3H]TdR in lymphoid tissues of the mouse. Mouse lymphocytes can utilize [3H]CdR as a precursor molecule for cytosine and thymine in DNA. The ratio of radioactivity of thymine to that of cytosine was measured biochemically in DNA extracted from lymphocytes labelled with [3H]CdR. This radioativity ratio in thymus was higher than that in mesenteric lymph nodes. These results suggest that the metabolic activities of utilizing CdR for DNA synthesis differ within lymphocyte populations in various lymphoid tissues in the mouse.

Animals↗

PubMed1976

Estimation of B- and T-lymphocytes in lymphoid tissue by means of photometry and 51Cr labelled marker erythrocytes.

Some new techniques for estimating B- and T-lymphocytes in lymphoid tissue are introduced. The density of marker erythrocytes on closed chamber incubated sections was estimated by the light transmission in relation to the number of the respective lymphocyte subpopulation, measured on suspensions of eluted lymphocytes. Using 51Cr labelled marker erythrocytes, the number of adsorbed marker erythrocytes per lymphocyte could be estimated from the gamma-irradiation of the section. The number of lymphocytes in the section was determined by the amount of protein in the section compared with the protein amount of a tissue specimen of known wet weight and known lymphocyte content. Furthermore, the number of adsorbed marker erythrocytes per rosette in suspensions of eluted lymphocytes was estimated by means of radioactively labelled marker erythrocytes.

Appendicitis↗

PubMed1986

Induction of mixed-function oxidase activity in mouse lymphoid tissues by polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbon (PAH) exposure can cause mixed-function oxidase (MFO) enzyme induction in certain tissues of various organisms. Measurement of such induction might serve as a useful bioindicator of human exposure to PAHs, provided readily obtainable human tissues can be utilized for such measurements. We have investigated the MFO activity in various lymphoid tissues of the C3H mouse as a model system and have studied the effect of systemic PAH treatment on such enzyme activity. An MFO enzyme assay was used to measure the activity of 7-ethoxyresorufin deethylase, an enzyme activity that may be specific for the cytochrome P-448 subset of MFO enzymes (those enzymes that are induced in cells or tissues following PAH administration). Intraperitoneal injection of mice with 180 mg/kg (4.6 mg) benzo[a]pyrene (BaP) or 160 mg/kg (4.0 mg) 3-methylcholanthrene (MC) produced a significant induction in MFO activity in mouse spleen S9 fractions 48 h after the injection. Induction ratios (induced activity/control activity) between 4 and 5 were seen with BaP; MC produced induction ratios of 2.5-3.0. Enzyme activity was not induced in the spleen within 16 h following BaP or MC administration. Other experiments indicated that MFO activity could be induced in thymus cells 48 h after either BaP or MC treatment. Treatment with BaP or MC did produce significant enzyme induction in the liver and lung tissues from the animals both 16 and 48 h after chemical treatment.

Animals↗

PubMed1994

Status of glutathione in lymphoid tissues of golden hamster during Leishmania donovani infection.

During Leishmania donovani infection of golden hamsters, changes in the glutathione levels of lymphoid tissues were observed. While in liver and thymus there was significant decrease in the levels of reduced and oxidised glutathione, that in spleen, bone marrow cells, peritoneal exudate cells and lymph nodes increased, indicating a role for host glutathione in establishing the infection.

Animals↗

PubMed2004

Cholinergic innervation of BALT (bronchus associated lymphoid tissue) in rat.

The presence and distribution of acetylcholinesterase (AChE) and cholineacetyl transferase activities (Chat) were examined in the bronchus-associated lymphoid tissue (BALT) of juvenile, adult and old rats. Histoenzymatic and immunochemical methods were used in association with quantitative analysis of images and statistical analysis of the data. Our results showed that both AChE and Chat activities were primarily confined to the BALT lymphoid cells. Only a low level of activity was observed in the sub-pleural parenchyma of the lung and in the wall of the bronchus. Moreover, both AChE and Chat activities in the BALT are specifically located in the lymphoid cells. Histoenzymatic staining and corresponding values of quantitative analysis of images confirmed morphological and immunochemical results. Finally, the intensity of histoenzymatic staining for AChE and of immunochemical staining for Chat in BALT of rats strongly decreases with age. On the basis of our results we hypothesize that both AChE and Chat activities may play an important role in BALT and both these enzymes undergo specific age-related changes.

Acetylcholinesterase↗

PubMed1999

Diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma in gastroendoscopic biopsy specimens.

UNLABELLED: We evaluated the diagnostic criteria of gastric lymphoma in endoscopic biopsies. METHODS: Our study included cases diagnosed as lymphoma by gastroendoscopic biopsy between 1984 and 1994 that were available in the files of the Department of Gastroenterology, Chinese PLA General Hospital. RESULTS: Among 53,400 cases of gastroendoscopy, we found 1672 (3%) cases of malignant neoplasm that were diagnosed by endoscopic features and histological findings. Thirty-eight cases of primary gastric lymphoma included 22 men and 16 women 16 to 82 years old, with a median age of 47.7. The endoscopy showed the ulcerative type in 12 cases, diffuse infiltrating type in 11 cases, massive infiltrating type in 6 cases, and large mucosal folds type in 4 cases. Five cases had a mixed type pattern of involvement. Histologically, 34 cases showed mucosa-associated lymphoid tissue lymphoma (89.5%), 2 cases had lymphoblastic lymphoma, and 2 cases were unclassifiable because of crush artifact of neoplastic cells. The majority of cases of primary gastric lymphoma have morphologic and clinical features that justify their inclusion in the category of low-grade lymphoma of mucosa-associated lymphoid tissue (MALT).

Adolescent↗

PubMed1983

An immunohistological study of reactive lymphoid tissue.

The aim of this study was to document the patterns of cytoplasmic Ig heavy and light chain expression in reactive lymphoid tissue, using single and double immunoenzymatic labelling techniques. This investigation was undertaken, firstly, to provide information on whether the normal counterparts of high grade lymphoma cells (e.g. centroblasts, immunoblasts) ever express more than one light or heavy chain (as has been noted in the past for lymphomas) and also, secondly, to seek evidence of intraclonal 'switching' from cytoplasmic IgM to cytoplasmic IgG expression. Paraffin embedded sections, all showing substantial reactive changes, were analysed by means of immunoperoxidase stains for the three major immunoglobulin classes (IgG, IgM and IgA), both light chain classes and J chain. In addition, double immunoenzymatic labelling techniques were used to search for cells showing simultaneous expression of kappa and lambda light chains and cells expressing mu and gamma heavy chain. Large transformed lymphocytes showing cytoplasmic Ig-staining in the pulp and interfollicular areas often have nuclear morphology indistinguishable from germinal centre centroblasts. There was no evidence of primitive appearing IgM-positive cells and IgG-positive cells of more mature morphology. In addition, immunoenzymatic staining showed that cells simultaneously expressing both IgG and IgM are only rarely encountered. When such cells were detected, the morphology was not that of a blast cell, but rather of a plasma cell containing Russel bodies. Hence it is suggested that cytoplasmic IgM switching to IgG is rarely detected by immunohistological methods in reactive tissue. Double staining for kappa and lambda revealed that cells simultaneously expressing both light chain types were not detected even among cells showing the most primitive morphology.

Cytoplasm↗

PubMed1986

Definition of streptozocin toxicity for primary lymphoidal tissues.

Hyperglycemia was induced in BALB/c mice with either streptozocin or alloxan to evaluate the effects of these drugs on primary lymphoidal tissues. Streptozocin but not alloxan briefly inhibited in situ DNA synthesis in bone marrow and thymus, elicited a transient selective depletion of circulating lymphocytes, and elicited a transient selective depletion of cortical thymocytes. Streptozocin also inhibited in vitro DNA synthesis of bone marrow cells and thymocytes from normal mice. A single subdiabetogenic dose of streptozocin depleted circulating lymphocytes and thymocytes.

Alloxan↗

PubMed1993

Malignant lymphoma of the mucosa-associated lymphoid tissue (MALT)--consecutive unusual manifestation in the rectum and gingiva.

Non-Hodgkin's lymphomas (NHL) of the mucosa-associated lymphoid tissue (MALT) are characterized by a preferential mucosal manifestation. Each organ system may be involved. Exclusively local growth is usually treated with surgical tumour reduction, combined with radiotherapy. In cases of tumour dissemination, chemotherapy is warranted. Follow-up should be performed closely. This case report highlights an unexpected recurrence of NHL in the oral MALT, four years after primary manifestation in the rectum.

Anus Neoplasms↗

PubMed1984

[Spleen and thymus lymphoid tissue in hypoxia (a biometric study)].

The spleen and thymus have been studied macro- and microscopically in rats (180-200 g body mass) on the 1st, 3d, 5th, 7th, 14th and 28th days of adaptation to a decreased atmospheric pressure in the altitude chamber corresponding to lifting to 5,000 and 7,500 m (after a preliminary gradual acclimatization) and on the 14th, 28th, 42d, 56th days of readaptation. A relative mass of the organs, the white pulp section area--the transversal section area of the spleen ratio, the summation section area of its lymph nodules have been estimated. In the thymus the cortico-medullary index (CMI) has been defined. A relative mass of the spleen increases during the first week of hypoxia, and during adaptation period it somewhat decreases and stabilizes, remaining higher than in the control. At the altitude of 5,000 m the cross section area of the lymph nodules decreases by 17% on the 28th adaptation day and at the altitude of 7,500 m--by 27% beginning from the 14th up to the 28th adaptation days. In the thymus the CMI, after some decrease during the first days of hypoxia at the altitude of 5,000 m, increases and normalizes on the 28th adaptation day, and at the altitude of 7,500 m stabilizes on the 14th - 28th days of hypoxia. When the rats are at the altitudes of 5,000 and 7,500 m the thymus lymphoid tissue reacts more quickly to the hypoxia effect and much sooner normalizes during the readaptation period than does the white pulp of the spleen. The main changes in the lymphoid tissue of the spleen and thymus take place on the 7th - 28th days of hypoxia.

Adaptation, Physiological↗

PubMed2000

Distribution and developmental change of lymphoid tissues in the chicken proventriculus.

In the chicken proventricular mucosa, aggregations of lymphocytes were localized in three different sites of the lamina propria, namely, underneath the surface epithelium, near the duct orifice of the deep proventricular gland, and in the gland tissue itself. In the lymphoid masses underneath the surface epithelium and in those near the duct orifice, CD4+ T lymphocytes and TCR2+ T lymphocytes occupied their central part, and B lymphocytes were localized in the periphery. CD8+ T lymphocytes and TCR1+ lymphocytes were evenly distributed in the masses. Infiltration of lymphocytes into these sites was first observed on the 20th embryonic day. At 1 week after hatching, CD3+ lymphocytes began to occupy the central area of the masses and His-C1+ B lymphocytes tended to be located in the periphery. Ultrastructurally, M cells were found neither in the epithelium of the mucosa nor in that of the excretory duct close to the lymphoid masses. In the deep proventricular gland, the lymphoid masses had a germinal center consisting of B lymphocytes, surrounded by the T lymphocyte-rich periphery. These masses were first recognized at the 3rd post-hatching week, presumably being formed against possible antigens invading into the lumen of the proventricular gland. On the other hand, the lymphoid masses beneath the surface epithelium and those near the duct orifice existing before the hatching period were considered to be prepared to establish the local mucosal immune barriers against the expectant antigenic invasion.

Animals↗

PubMed1987

Malignant lymphoma of mucosa-associated lymphoid tissue.

Lymphomas of the gastrointestinal tract, salivary glands, lung and thyroid are grouped together as tumours arising in mucosa-associated lymphoid tissue. The great majority of them are of B-cell origin but distinctive T-cell lymphomas are also recognized in the gastrointestinal tract. These lymphomas tend to remain localized for prolonged periods but, whereas the B-cell group respond favourably to local therapy, the T-cell group are associated with severe morbidity and their overall prognosis is extremely poor. Accepted histological classifications of non-Hodgkin's lymphomas are difficult to apply to these tumours. In this paper their morphological features are reviewed; recent findings based on immunohistochemistry and DNA analysis are presented; and the biological behaviour of these tumours is discussed insofar as they offer insight into mucosal immunological mechanisms.

B-Lymphocytes↗

PubMed1993

Reticulum cells in the ontogeny of nasal-associated lymphoid tissue (NALT) in the rat.

This study concerns the ontogeny of reticulum cells (RC) in the nasal-associated lymphoid tissue (NALT) of Wistar and Brown-Norway rats. A panel of monoclonal antibodies (mAb) directed against RC in peripheral lymphoid organs (antibodies ED10-ED15) was used, together with a recently developed antibody ED17, which recognizes macrophages and Langerhans cells. Early in embryogenesis, staining with common connective tissue markers, ED14 and ED15, was found. ED17-positive cells were present before cells positive to ED1, a pan-macrophage marker, or Ia glycoproteins were observed. The first differentiation of reticulum was seen at the day of birth, when ED10 recognized a distinct area in the nasal mucosa. The first T-lymphocytes were found at the same time. Two days after birth, B-cells and ED11-positive cells were present in the NALT area. Fourteen days after birth, T- and B-cell compartments were recognizable. ED10 was found predominantly in the T-cell area and ED11 was mainly confined to the B-cell compartment. We conclude that the development of the NALT is closely accompanied by the phenotypic specialization of the reticulum. This suggests that the reticulum plays an important role in the compartmentalization of NALT tissue and in the retention of lymphocyte subsets within these compartments.

Animals↗