Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Circulating monoclonal B cells in peripheral blood from patients with multiple myeloma or with monoclonal gammopathy of undetermined significance (MGUS) have previously been shown to express CD19, CD20, and PCA-1 and are predominantly CD45R0+, characterizing them as very late stage B cells. This work shows that the abnormal B cells are monoclonal as defined by their exclusive expression of either kappa or lambda light chain mRNA, and that the same type of light chain mRNA is expressed in both bone marrow plasma cells and blood B cells. These abnormal tumour-related circulating B cells express high densities of CD11b, a beta 2-integrin, which is expressed in a conformationally active state as defined by reactivity with monoclonal antibody 7E3. Normal peripheral blood B cells which do not bear CD11b acquire a high density after stimulation with pokeweed mitogen (PWM). At day 4 of culture, the expression of CD11b on normal CD19+ B cells was nearly comparable to that of the circulating myeloma late stage B cells. After PWM stimulation of circulating myeloma B cells the expression of CD11b was gradually lost during 4 days of culture, suggesting that its expression is dynamically regulated. Two patients with no phenotypically abnormal B cells in their blood at diagnosis acquired a large subset of CD11b+ B cells 4 weeks after initiation of chemotherapy. In most patients, a subset of the circulating myeloma B cells express a low density of CD5. The proportion of CD19+ B cells in the bone marrow expressing CD11b was much reduced compared with peripheral blood B cells, and CD11b was not detectable on plasma cells in the bone marrow, suggesting a sequential relationship of the B-cell subsets detected in our population of patients, involving gradual loss of CD11b concurrent with the loss of CD19 during B lineage differentiation. These cells appear to represent a continuously differentiating monoclonal B lineage culminating in the CD11b- plasma cell entrenched in the bone marrow. We speculate that the expression of conformationally active CD11b on the abnormal B cells in peripheral blood mononuclear cells of myeloma patients facilitates transendothelial migration of circulating myeloma B cells to the bone marrow.
 ...
PMID:Restricted expression of immunoglobulin light chain mRNA and of the adhesion molecule CD11b on circulating monoclonal B lineage cells in peripheral blood of myeloma patients. 128 35

Subacromial bursal tissue was studied in 12 patients operated on for painful (10 patients with constant pain and 2 patients with pain on motion) rotator cuff tendinitis/impingement syndrome. The Neer acromioplasty technique was used. Six patients had moderate inflammatory changes and one had a slight inflammation. In three of the five remaining patients, the subacromial bursa did not show any signs of inflammatory involvement, but patients experienced pain at rest and at night, reflecting clinical inflammation in tissues other than the bursa. The two patients with pain only on strain did not show inflammation of the bursa. Immunohistochemical typing of the bursal tissue disclosed a typical chronic mononuclear cell infiltrate consisting mainly of CD2-positive T lymphocytes (50-80% of all inflammatory cells), accompanied by less frequent CD11b (C3bi receptor)-positive monocyte/macrophages (10-40%). The relative paucity of plasmablasts/plasma cells expressing PCA-1 suggests this to be an inflammatory rather than an immune response. Active involvement of some of the local cells is suggested to be the source of algogenic and hyperalgesic substances contributing to pain in chronic shoulder pain syndromes.
 ...
PMID:Inflammation of the subacromial bursa in chronic shoulder pain. 136 Feb 27

We investigated the origin of leukemic progenitors in a case of the simultaneous occurrence of myelomonocytic leukemia and multiple myeloma (IgG-kappa). At presentation, myeloperoxidase and nonspecific esterase-positive myelomonocytic cells had proliferated up to 12.2 x 10(9)/liter in the peripheral blood. Bone marrow cell differentials revealed the coexistence of myelomonocytic cells (30%) and atypical plasmacytoid cells (26%). Myelomonocytic cells in peripheral blood expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33) and T/B-lymphoid antigens (CD2, CD4, CD5, CD7, CD10, PCA-1). Bone marrow mononuclear cells (BMMC) could be divided into PCA-1 strongly positive and PCA-1 weakly positive populations, which were considered to represent myeloma cells and myelomonocytic cells, respectively; the former were CD2-positive (CD2+), CD14-, and CD15-, whereas the latter were CD2+, CD14+, and CD15+. Immunohistochemical analysis revealed that, in addition to plasmacytoid cells, a minority of myelomonocytic cells showed a positive reaction for IgG staining, and production of IgG was observed in the culture supernatant of CD14+ myelomonocytic cells in peripheral blood. Southern blot analysis revealed the presence of two identical rearrangement bands of immunoglobulin heavy chain gene in both BMMC containing myeloma cells and myelomonocytic cells and CD14+ myelomonocytic cells in peripheral blood. In a long-term methylcellulose assay, peripheral blood mononuclear cells produced large compact colonies consisting of macrophages and IgG+ plasmacytoid cells (M phi/P colonies), while BMMC produced a different type of colonies consisting of CD14+ myelomonoblasts, macrophages, and IgG+ plasma cells (Mb/M phi/P colonies) in addition to M phi/P colonies. Recloning experiments showed that primary Mb/M phi/P colonies gave rise to both secondary M phi/P and Mb/M phi/P colonies. These observations strongly suggest that common leukemic progenitors provide both myeloma and myelomonocytic leukemia cells, and the mechanism of "lineage infidelity" is probably involved in the development of their "bilineal" differentiation.
 ...
PMID:Simultaneous occurrence of myelomonocytic leukemia and multiple myeloma: involvement of common leukemic progenitors and their developmental abnormality of "lineage infidelity". 165 17

The membranes surrounding seven loose cementless acetabular implants were shown to contain polyethylene particles, birefringent in polarised light. Three of these implants were made of titanium alloy and the membranes around these contained titanium particles as well. There was no metallosis around the four implants made of chromium-cobalt-steel alloy. Both titanium and polyethylene particles caused migration, adherence and phagocytosis of CD11b-positive, peroxidase-negative macrophages. There were no histological signs of activation of the specific immune response; neither interleukin-2 receptor-positive activated T cells nor PCA-1 plasmablasts/plasma cells were present in the tissues. In cases of simple loosening, resident mesenchymal fibroblast-like cells were active. In aggressive granulomatosis, there were many macrophages and multinucleated giant cells but little fibroblast reaction. The clinical relevance of the findings is that the use of cementless prostheses is not a guarantee against adverse tissue reactions.
 ...
PMID:Immunopathological response to loose cementless acetabular components. 199 72

Rabbit MAC-1 receptor, homologue to human CD11b is present in macrophages. The aim of the study was to determine quantitative and distributive modifications of CD11b-positive cells that participate in immune response at rectal mucosa, in an animal model of mucosal immunity. New Zealand rabbits were divided into three groups. G1: control; G2: ovalbumin (OVA) sensitized; G3: OVA-senstitized and rectal challenged. Animals were subcutaneously sensitized twice with 70 microg OVA and 30 ml aluminium hydroxide in 2 ml saline solution. Rectal challenge was developed with a solution of 50 mg OVA in 5 ml saline solution. Sensitized groups (G2 and G3) showed a positive PCA (Passive Cutaneous Anaphylaxis) at 1/160 fold dilutions. In G3 we observed a patchy mucosal edema, lymphangiectasis and eosinophil leucocyte infiltration. Cells were counted as the number of cells per high power field. G1: 9.64 (SE 0.22); G2: 18.10 (SE 0.09) and G3: 23.60 (SE 0.29). (G2 vs G1 p < 0.001; G3 vs G1 p < 0.001; G3 vs G2 p < 0.001). We conclude that there is a close relationship between the food antigen OVA penetration (after challenge) and the increase of CD11b positive cells in rectal mucosa. This fact could be due to the cellular influx to the inflammatory site by the action of chemotactic factors released after challenge.
 ...
PMID:[CD11b-positive cells expression in rectal mucosa from ovalbumin sensitized and challenged rabbits]. 1595 30