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At least 757 records · Page 42Linked to original sources
PubMed1985

An anti-human monocyte/macrophage monoclonal antibody, reacting most strongly with macrophages in lymphoid tissue.

In this report, we have described monoclonal antibody (mAb) 24 which bound specifically to a 174,000 polypeptide present on 45 +/- 16% of human monocytes. Expression of the 24 molecule increased on monocytes when they were cultured. When tissues were examined using immunohistochemical techniques, macrophages (Mph) associated with skin and with lymphoid organs strongly expressed the mAb 24 molecule, whereas, Mph in nonlymphoid organs were only weakly positive. mAb 24 reacted with cells of Mph morphology plus cells of interdigitating appearance in T-cell areas, suggesting that these cells might belong to the Mph cell lineage. There was no reaction with other types of cells, such as Langerhans cells, osteoclasts, dendritic reticulum cells, and endothelial cells. The fact that the molecule recognised by mAb 24 is particularly associated with Mph in lymphoid tissue suggests that it might have a function in immune responses.

Antibodies, Monoclonal↗
PubMed1986

Localized gut-associated lymphoid tissue hemorrhage induced by intravenous peptidoglycan-polysaccharide polymers.

A hemorrhage into gut-associated lymphoid tissue developed as early as 3 min after the intravenous injection of group A streptococcal peptidoglycan-polysaccharide polymers into rats. Extravasated erythrocytes were specifically located in the lamina propria and organized lymphoid follicles of the intestines and mesenteric lymph nodes and did not occur in the lungs, kidneys, liver, spleen, adrenal glands, or submandibular and popliteal lymph nodes, as determined by gross and histologic observations and measurement of radiolabeled erythrocytes. Petechial hemorrhage was preferentially located within the intestine to the distal ileum, Peyer's patches, and lymphoid aggregates of the colon. The hemorrhage was transient and occurred in a dose-dependent fashion. It was maximal 5 min after injection and resolved completely by 3 days. A unique feature of this altered vascular permeability was the absence of polymorphonuclear leukocytic infiltration, edema, vasculitis, and tissue necrosis.

Animals↗
PubMedDate not supplied

Mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid: report of a case.

The patient was 59-year-old Japanese woman who presented with a neck swelling. Ultrasonography and computed tomography demonstrated a round tumor in the thyroid right lobe measuring 2.5 x 1.5 cm in size. A right hemithyroidectomy with lymph node dissection was performed. Histopathological findings demonstrated low-grade B cell lymphoma of the mucosa-associated lymphoid tissue (MALT) associated papillary microcarcinoma. A previous report showed an excellent prognosis of MALT lymphoma of the thyroid without capsular invasion or lymph node involvement. We also describe the concept of MALT lymphoma as a primary lesion in which lymphoid tissue is not present in the normal state.

Carcinoma, Papillary↗
PubMed2001

Effect of HIV-1 infection on lymphocyte proliferation in gut-associated lymphoid tissue.

OBJECTIVE: To determine the change in the percentage of proliferative and activated lymphocytes in gut-associated lymphoid tissue (GALT) in HIV-1-infected subjects compared with that in uninfected controls. METHODS: We measured the percentage of proliferative (Ki-67+) and activated (CD-69+, HLA-DR+, CD45RO+) lymphocytes from GALT and peripheral blood in chronically HIV-1-infected (12) and uninfected (9) individuals. RESULTS: The percentage of proliferative GALT CD4+ T cells was increased in HIV-1-infected control subjects compared with that in uninfected controls (p <.007). Based on immunohistochemical staining, proliferative T cells were principally located in the parafollicular area surrounding lymphoid aggregates. The percentage of activated GALT lymphocytes, however, was not significantly different in HIV-1-infected individuals, whereas it was significantly increased in the peripheral blood of HIV-1-infected individuals. The percentage of peripheral blood lymphocytes trafficking to the intestine was also not significantly different in HIV-1-infected individuals compared with that in uninfected controls. CONCLUSIONS: CD4+ T cell proliferation in GALT is increased in HIV-1 infection without a significant alteration in the percentage of peripheral blood T cells trafficking to the gastrointestinal mucosa.

Adult↗
PubMedDate not supplied

Low-grade primary mucosa-associated lymphoid tissue lymphoma of the nasopharynx: clinicopathological study.

BACKGROUND: Malignant tumors of the nasopharynx are always a challenging problem, both from the diagnostic and from the therapeutic standpoint. Most extranodal lymphomas arise in the gastrointestinal tract, but the other mucosal organs also may be involved, especially the upper aerodigestive tract. Nasopharyngeal lymphomas are rare among lymphoma of the upper aerodigestive tract. METHODS: Twenty-two patients with primary lymphoma arising in mucosa-associated lymphoid tissue of the nasopharynx have been studied with reference to age, sex, clinical symptoms, laboratory finding, radiological finding, histological subtype, and immunohistochemistry. RESULTS: All patients were diagnosed histologically as low-grade lymphoma of mucosa-associated lymphoid tissue type with its characteristic lymphoepithelial lesions and follicular colonization. The tumor cells typically exhibit the following immunophenotypes: positive for CD20, CD45RA, and proliferating markers bcl-2. It was negative for T-cell markers CD45RO (UCHLI). CONCLUSION: Ear, nose, and throat surgeons and pathologists should be aware of this type of lymphoma to avoid misinterpretation and to set up a protocol for its management.

Adult↗
PubMed1989

Immune-related alterations in aged gut-associated lymphoid tissues in mice.

To study whether senescence-induced changes in the gut-associated lymphoid tissue (GALT) are mainly quantitative, several parameters were examined in three age groups of BALB/c mice (1-2, 12-14, and 24-28 months old). A substantial senescence-associated decline in the number of lymphoid cells was found in the mesenteric lymph nodes (MLN) and spleen (SPN), and especially in the Peyer's patches (PP), but not in the lamina propria (LP). The distribution of lymphocyte subsets in these tissues was also altered with an absolute reduction of T cells--in particular, a L3T4+ helper/inducer T-cell marker-bearing subset. These changes were most remarkable in PP, followed by MLN. The in vitro proliferative reactivity and the production of each isotype-specific immunoglobulin (Ig) by PP, MLN, and SPN were profoundly affected when T-cell-dependent (Td) B-cell mitogens were used, but minimally affected when T-cell-independent (Ti) B-cell mitogens were used. The isotype-specific Ig content of small-intestinal perfusates was also influenced by aging, but only to a minor extent, as exemplified by a decrease in IgA levels in the fasting condition. Thus, despite the defects in the quantity and distribution of lymphocytes in aged PP and MLN, the finding of little change in the total amount of secreted IgA in aged intestine suggests that gut IgA-mediated luminal immune responses could remain nearly unaltered with senescence. The constancy of intraluminal IgA levels could be of physiological significance in host defense at the gut mucosal surface in aged mice.

Aging↗
PubMed1983

[Pathomorphology of lymphoid tissue at late periods after anaphylactic shock].

The lymph nodes (mesenteric, popliteal) and the thymus of rabbits were examined pathomorphologically and morphometrically in short-term (2-3 days) and long-term (8-10 days) periods after anaphylactic shock (AS). The main alteration that developed in the lymph nodes after AS was a decrease in the size of the follicles with the manifestations of depletion. Along with multiple mitoses in reticular and blast cells the follicles of the lymph nodes demonstrated a considerable lessening in the lymphocyte count and alterations - pyknosis, rhexis, lysis of their nuclei with phagocytosis of the fragments by reticular cells. The presence of destructive alterations in lymphoid tissue seen in the long-term periods after AS points to the delayed recovery of the morphological integrity of lymphoid tissue as compared with the clinical convalescence.

Anaphylaxis↗
PubMed2004

Intravesical mass consisting of mucosa-associated lymphoid tissue.

We report on a patient with an intravesical mass consisting of hyperplastic follicles in mucosa-associated lymphoid tissue. Computed tomography and ultrasonography revealed two intravesical masses measuring 3.5 cm and 1.5 cm along the long axis. Imaging diagnosis was invasive tumors of the bladder. However, the pathological diagnosis on transurethral bladder tumor biopsy was a lesion in lamina propria consisting of hyperplastic follicles and lymphatic infiltrate between them with no cell atypia. Light microscopically, the lesion was considered to be reactive follicular hyperplasia. Antibiotic therapy resulted in an almost complete disappearance of the tumors. Such large follicular hyperplasia in the lamina propria of the bladder is rare.

Adult↗
PubMed2003

Functional and morphological development of lymphoid tissues and immune regulatory and effector function in rhesus monkeys: cytokine-secreting cells, immunoglobulin-secreting cells, and CD5(+) B-1 cells appear early in fetal development.

Little is known regarding the timing of immune ontogeny and effector function in fetal humans and nonhuman primates. We studied the organization of lymphocyte and antigen-presenting cell populations in developing lymphoid tissues of rhesus monkey fetuses during the second and third trimesters (65 to 145 days of gestation; term = 165 days). Immunoglobulin-secreting and cytokine-secreting cells were detected at day 80. The thymus, spleen, lymph nodes, and intestinal mucosa were examined for cells expressing CD3, CD5, CD20, CD68, p55, and HLA-DR. In the spleens of 65-day-old fetuses (early second trimester), the overwhelming majority of total lymphocytes were CD5(+) CD20(+) B-1 cells. The remaining lymphocytes were CD3(+) T cells. By day 80, splenic B and T cells were equal in number. Intraepithelial CD3(+) CD5(-) T cells and lamina propria CD20(+) CD5(+) B cells were present in the intestines of 65-day-old fetuses. By day 80, numerous CD20(+) CD5(+) B cells were present in the jejunums and colons and early lymphocyte aggregate formation was evident. The spleens of 80- to 145-day-old fetuses contained immunoglobulin M (IgM)-secreting cells, while IgA-, IgG-, interleukin-6-, and gamma interferon-secreting cells were numerous in the spleens and colons. Thus, by the second trimester, the lymphoid tissues of the rhesus monkey fetus have a complete repertoire of properly organized antigen-presenting cells, T cells, and B cells.

Animals↗
PubMed1998

Activation and proliferation of CD8+ T cells in lymphoid tissues of HIV-1-infected individuals in the absence of the high-affinity IL-2 receptor.

Activation of CD8+ T cells may have important pathogenic implications in HIV-1 infection. Studies of this process have so far been confined to cells from the peripheral blood. In the present study, we have examined molecules involved in activation and proliferation of CD8+ T cells in lymphoid tissues from HIV-1-infected patients. Tonsillar tissue and blood samples from 13 HIV-1-infected patients and 6 seronegative controls were examined for cell surface expression and the presence of mRNA for CD69, CD25, and HLA-DR. Intonsillar tissue, the number of CD8+ T cells was increased several fold in HIV-1-infected patients compared with controls. The majority of these cells expressed CD69 and HLA-DR, but virtually no tonsillar CD8+ T cells were found to express CD25 on the cell surface or at the mRNA level. Following in vitro activation, however, almost all activated CD8+ T cells were found to express CD25. Tonsillar CD4+ T cell numbers were maintained or reduced compared with controls, and a considerable proportion expressed CD25. The data suggest that CD8+, but not CD4+ T cells proliferate extensively in lymphoid tissues in HIV-1-infected patients in the absence of the high-affinity interleukin-2 (IL-2) receptor.

Antigens, CD↗
PubMed1996

Immunological and molecular classification of mucosa-associated lymphoid tissue lymphoma.

Malignant B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type is now considered to be a tumor of marginal zone cells of native or, more frequently, acquired MALT. The relationship of MALT lymphoma to the normal counterpart population is acknowledged by the revised European-American classification of lymphoid neoplasms (R.E.A.L.). It fits into the extranodal subtype of marginal zone lymphoma listed as a distinct entity in this recent classification scheme. A typical feature of this lymphoma type is a close lymphocyte-epithelium interaction as reflected by lymphoepithelial lesions. The immunophenotype is characterized by the expression of Sig and B-cell-associated antigens and by the lack of CD5 and CD10. Frequent occurrence of trisomy 3 has been reported. There is now overwhelming evidence that low-grade MALT lymphomas are subject to immunologic drive. In the stomach, the presence of Helicobacter pylori and locally activated T cells appears to be critical for the growth of neoplastic cells. This finding is of clinical significance since the eradication of H. pylori has been shown to reverse low-grade MALT lymphoma.

Gastrointestinal Neoplasms↗
PubMed2000

Primary tracheal mucosa-associated lymphoid tissue lymphoma accompanying lung cancer. Common tumorigenesis or coincidental coexistence?

We report a 67-year-old patient with coexistent tracheal non-Hodgkin's lymphoma and lung cancer the first case, to our knowledge, of this concomitant incidence in the literature. Chest radiography showed a mass in the right lung and pulmonary fibrosis. Biopsy of the unanticipated tracheal irregularity revealed non-Hodgkin's lymphoma, compatible with mucosa-associated lymphoid tissue lymphoma. After right upper lobectomy, chemotherapy for non-Hodgkin's lymphoma was conducted, but the patient died 11 months postoperatively of pulmonary fibrosis. Pulmonary fibrosis was suspected of having progressed from drug-induced pneumonitis caused by anticancer drugs. A common tumorigenetic factor may thus exist between tracheobronchial mucosa-associated lymphoid tissue lymphoma and lung cancer.

Aged↗
PubMed1992

Lymphoid tissue responses to concentrated perfluorochemical emulsions in rats.

The effects of injecting perfluorochemical (PFC) emulsions of varying concentrations on lymphoid tissues have been studied in rats. Tissue weights were increased in proportion with quantity of PFC injected, with spleen responses consistently greater than those of the liver. PFC droplets recovered from tissues had mean diameters in the 1-10 microns range, with those from the spleen being larger than from the liver. Recovered droplet diameters were considerably greater than freshly-prepared emulsion mean particle sizes (0.20-0.25 microns). This suggests that coalescence of emulsion droplets following accumulation in tissues is a pre-requisite to the eventual excretion of PFC vapour through the lungs.

Animals↗
PubMed1987

Lymphoid tissue responses to a novel perfluorochemical emulsion in rats.

The effects of a novel perfluorochemical emulsion on rat lymphoid tissues and antibody production against sheep red blood cells (SRBC) have been studied. The responses were compared with those following injection of identical doses of the proprietary emulsion, Fluosol-DA 20% (F-DA). Liver weight was increased up to 15% at 8 days following intravenous (i.v.) or intraperitoneal (i.p.) injection of the novel emulsion but was unaffected by F-DA injection. Spleen weight also increased by a maximum of 20% in response to i.p. injection of the novel emulsion but this was less than increases of up to 44% which occurred in F-DA-injected rats. Thymus weight decreased (P less than 0.05) following i.p. injection of the novel emulsion whereas mesenteric lymph node (MLN) weight remained unchanged. However, MLN weight was increased in response to i.v. injected F-DA, while thymus weight showed a small increase following i.p. F-DA injection. Mean plasma antibody titres to SRBC were significantly (P less than 0.01) increased at 7 days after immunization in rats pretreated with i.p. injections of either the novel emulsion or F-DA; titres in animals pretreated with i.v. injections of either emulsion were similar to control.

Animals↗
PubMed1984

Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: effect of antibiotics.

Distribution of immunoglobulin (Ig)-bearing cells in the gut-associated lymphoid tissues of antibiotic treated and untreated control turkeys (Meleagris gallopavo) was compared. Antibiotic treatment was similar to a regimen used in commercial turkey production, which included preincubation dipping of fertile eggs in gentamicin solution, injection of turkeys with gentamicin at hatching, and inclusion of chlortetracycline in the diet. Tissues were examined from turkeys at 3, 7, 14, and 21 days of age with a direct immunofluorescence procedure. Cell distribution in control turkeys was as follows: In the bursa of Fabricius, IgA-carrying cells predominated at 3 days of age, but at later intervals, the 3 classes of Ig-bearing cells were in equal numbers. In the cecal tonsils, IgM- and IgA-bearing cells were in larger numbers at 3 days of age, whereas, the IgG-bearing cells were sparsely distributed. By 7 days of age, IgM cells became more numerous in the cecal tonsils and remained numerous until 21 days of age. At 3 days of age, IgA cells predominated in the small intestines and IgM cells predominated in the large intestine. At 7 and 14 days of age, IgM cells were more numerous in the small and large intestines, but by 21 days of age, IgA cell population equaled that of IgM. The IgG cells were generally sparse in the intestines. Antibiotic treatment often resulted in lower numbers of Ig-positive cells, especially those bearing IgM and IgA. Normal development of the bursa of Fabricius was also retarded in this group.

Animals↗
PubMed2006

De novo expression of MECA-79 glycoprotein-determinant on developing B lymphocytes in gut-associated lymphoid tissues.

Rabbit is one of several species that depend on development of B lymphocytes in gut-associated lymphoid tissues for primary immunoglobulin-repertoire diversification. The rabbit appendix is an important site of early B-lymphocyte development. We previously reported that peripheral lymph node addressin detected by monoclonal antibody (mAb) MECA-79 played a role in recruitment of immature blood-borne B cells into neonatal rabbit appendix. Here, we report expression of an approximately 127 000 MW O-linked sulphated proteoglycan on developing B cells in appendix and Peyer's patches recognized by the mAb MECA-79. Binding of the mAb to B lymphocytes was sensitive to enzyme treatment with O-sialoglycoprotease and expression was partially inhibited by sodium chlorate, a metabolic inhibitor of sulphation. The proportions of MECA-79(+) B lymphocytes gradually increased from < 0.5% at 3 days to > 70% at 6 weeks in appendix and Peyer's patches. The proportions of MECA-79(+) B lymphocytes in spleen and peripheral blood were very low (0.5-2%). However, the MECA-79 determinant was detected on B cells in splenic germinal centres after immunization. In situ labelling of appendix cells showed that the MECA-79 determinant was expressed on fluorescein-labelled B lymphocytes that migrated from appendix into mesenteric lymph nodes. B-cell MECA-79 may be involved in interactions with T cells and/or dendritic cells. Alternatively, because we found that lymphatic endothelium in the thymus-dependent area of appendix, a site for lymphocyte exit, expressed P-selectin (CD62P), interaction of the MECA-79 determinant on B cells with CD62P may have a role in the exit of B lymphocytes from rabbit appendix.

Animals↗
PubMed1997

[Development of thymic tumor in HTLV-I transgenic rats under control of a lymphoid tissue specific promoter].

The p40tax protein of Human T lymphocyte virus type I (HTLV-I) is known to be a transactivator not only for the own viral gene but also for the various cellular genes (host genes), including a number of cytokine genes and genes for cell proliferation. Its tumorigenicity was also reported in vivo, such as developments of mesenchymal tumor, neurofibroma, mammary carcinoma and large granular lymphocytic leukemia, using the transgenic technique. To investigate the tumorigenicity in lymphoid tissues, a series of HTLV-I pX transgenic rats (lck-pX rats) which expressed the pX gene under control of lymphocyte specific protein tyrosine kinase (p56 lck) gene type 1 promoter was produced. In some lines of lck-pX rats, pX mRNA was expressed selectively in the thymus, lymph nodes and spleen as expected. However, pX mRNA expression was also detected in other tissues from other lines of lck-pX rats. Thymic tumor with epithelial markers developed in lck-pX rats as early as 8 weeks of age and high expression of pX mRNA was detected in the tumor tissue. This is the demonstration that HTLV-I pX gene causes thymic tumor in the transgenic rat and an lck-pX rat may be a suitable animal model for elucidating pathogenetic role of HTLV-I pX gene in lymphoid tissue neoplasia.

Animals↗