Zinc tolerance modulation in Myracrodruon urundeuva plants.

We investigated Zn tolerance and related tolerance mechanisms of Myracrodruon urundeuva by evaluating the growth (biomass production, pigment content, and photosynthetic activity) and antioxidant systems (redox potential and antioxidant enzyme activities) of seedlings exposed to increasing Zn doses. Plants were grown for 120 days in substrates with 0, 50, 80, 120 and 200 mg Zn kg(-1) and demonstrated Zn-tolerance. Zn doses greater than 80 mg Zn kg(-1) were phytotoxic but not lethal, and Zn toxicity under these conditions was imposed by oxidative stress caused by hydrogen peroxide (H2O2) accumulation and related lipid peroxidation. Zn tolerance in M. urundeuva is linked to the activity of antioxidant systems in their leaves that are modulated by that metal: both superoxide dismutase (SOD) and catalase (CAT) were always higher in the presence of Zn; lower Zn doses stimulated ascorbate peroxidase (APX) and glutathione reductase (GR) activities, but enzyme activity was inhibited at high doses; APX appeared to be the main peroxidase in H2O2 scavenging as stimulated guaiacol peroxidase (GPX) activity was not sufficient to avoid H2O2 accumulation at higher Zn doses; the modulation of APX and GR activities was linked to changes in the redox status of leaves.

Neutrophils in rheumatoid arthritis: More than simple final effectors.

Rheumatoid arthritis is the most common inflammatory joint disease. The etiopathogenesis of this condition has been classically explained by a T cell-driven process. However, recent studies have highlighted the possible contribution of neutrophils for the early phases of RA physiopathology. These cells are phagocytic leukocytes that play crucial roles in the acute defense against pathogens while modulating the function of other immune cells and contributing to the perpetuation of an initial inflammatory response. The herein article reviews recent progresses in the understanding of the immunopathology of RA with a special emphasis on the role of neutrophils.

The vasoactive peptide angiotensin-(1-7), its receptor Mas and the angiotensin-converting enzyme type 2 are expressed in the human endometrium.

Angiotensin (Ang)-(1-7) is one of the major active components of the renin-angiotensin system, produced from cleavage of Ang II by angiotensin-converting-enzyme type 2 (ACE2), which acts through a specific G protein-coupled receptor, Mas. We have investigated whether the human endometrium expresses these components during menstrual cycle. By radioimmunoassay, Ang-(1-7) was detected in endometrial wash fluid at picomolar concentrations. Using immunofluorescence, both the peptide and its receptor were identified in cultured endometrial epithelial and stromal cells. By immunohistochemistry, Ang(1-7) was localized in the endometrium throughout menstrual cycle, being more concentrated in the glandular epithelium of mid- and late secretory phase. This pattern corresponded to the ACE2 mRNA, which was more abundant in epithelial cells than in stromal cells (2-fold increase, p < 0.05) and in the secretory vs. proliferative phase (6.6-fold increase, p < 0.01). The receptor Mas was equally distributed between epithelial and stromal cells and did not change during menstrual cycle. The physiological role of this peptide system in normal and pathological endometrium warrants further investigation.

Androgen receptor and 5alpha-reductase are expressed in pelvic endometriosis.

The aim of this study was to evaluate whether androgen receptor (AR) and the enzymes that convert testosterone into the more potent androgen dihydrotestosterone, 5alpha-reductases (5alpha-R1 and 5alpha-R2) are expressed in pelvic endometriosis. The study involved 21 infertile women who underwent laparoscopy and were divided into two groups: control (n= 13) and endometriosis (n= 8) according to the histological and laparoscopic findings. Endometrial and endometriotic implant biopsies were performed. By reverse transcription polymerase chain reaction and immunohistochemistry, AR, 5alpha-R1 and 5alpha-R2 messenger RNA and protein were detected in biopsies of pelvic endometriosis, as well as in the eutopic endometrium of both groups. These findings suggest that active androgens may be formed within the endometriotic tissue and that both local and systemic androgens have the potential to act on endometriotic cells.

Activin, inhibin and the human breast.

Activins and inhibins are growth factors involved in cell differentiation and proliferation. Human breast tissues such as normal mammary tissue, fibroadenoma, and breast cancer express inhibin and activin mRNA and proteins. Activin A and its binding protein, follistatin, are also present in human milk during the first week of lactation. Using immunohistochemistry, we have observed that the inhibin/activin alpha, betaA, and betaB subunits are present in normal breast tissue regardless of menstrual cycle phase or menopause, as well as in fibrocystic disease, and breast tumors. The mRNAs encoding all three activin/inhibin subunits are expressed in breast carcinoma, fibroadenoma, and normal mammary tissue. The betaA subunit gene expression is higher in either local or metastatic breast carcinoma than in normal tissue. In addition, dimeric activin A is detectable in homogenates of breast cancer tissue at concentrations twice as high as in non-neoplastic adjoining tissue. Recent evidence suggests that some of the activin A produced by breast carcinoma is released into systemic circulation. In women with breast cancer, serum activin A levels are often elevated, and a significant decrease is observed in the first and second days following tumor excision. The role of activin and inhibin as endocrine and/or paracrine factors in the breast is still uncertain. Activin has complex effects on cell growth during branching morphogenesis, but it is generally considered as an inhibitor of cell proliferation as in vitro studies have shown that activin A treatment of breast cancer cells arrests cell growth. Inhibin is generally considered as a tumor suppressor, but its possible role in the breast is less understood.

Human monoclonal rheumatoid synovial B lymphocyte hybridoma with a new disease-related specificity for cartilage oligomeric matrix protein.

Joint-specific self-Ags are considered to play an important role in the induction of synovial T and B cell expansion in human rheumatoid arthritis (RA). However, the nature of these autoantigens is still enigmatic. In this study a somatically mutated IgG2 lambda B cell hybridoma was established from the synovial membrane of an RA patient and analyzed for its Ag specificity. A heptameric peptide of cartilage oligomeric matrix protein (COMP) could be characterized as the target structure recognized by the human synovial B cell hybridoma. The clonotypic V(H) sequences of the COMP-specific hybridoma could also be detected in synovectomy material derived from five different RA patients but in none of the investigated osteoarthritis cases (n = 5), indicating a preferential usage of V(H) genes closely related to those coding for a COMP-specific Ag receptor in RA synovial B cells. Moreover, the COMP heptamer was preferentially recognized by circulating IgG in RA (n = 22) compared with osteoarthritis patients (n = 24) or age-matched healthy controls (n = 20; both p < 0.0001). Hence, the COMP-specific serum IgG is likely to reflect local immune responses toward a cartilage- and tendon-restricted Ag that might be crucial to the induction of tissue damage in RA.

IgVH genes from different anatomical regions, with different histopathological patterns, of a rheumatoid arthritis patient suggest cyclic re-entry of mature synovial B-cells in the hypermutation process.

In the present study 55 IgVH genes amplified from three different anatomical regions of a rheumatoid arthritis (RA) patient were analyzed, adding further information on synovial B-cell maturation and recirculation in RA. This analysis demonstrated somatically mutated IgVh genes in all regions studied, with amino acid deletions and mixed IgVh molecules, suggesting the existence of a novel pathway to generate (auto) antibody specificities. Comparison of amino acid sequences of amplified genes that belong to the VH1 family (with predominantly the same germline counterpart) exhibited strong homology, indicating an apparently conserved mutational pattern. This suggests that the number of antigens that activate B cells in different locations is restricted. The most striking result was the finding of clonally related sequences in different anatomical regions, indicating a recirculation of activated B cells between the different affected joints.

Histopathology and molecular pathology of synovial B-lymphocytes in rheumatoid arthritis.

B-cells of the rheumatoid synovial tissue are a constant part of and, in some histopathological subtypes, the dominant population of the inflammatory infiltrate, located in the region of tissue destruction. The pattern of B-cell distribution and the relationship to the corresponding antigen-presenting cells (follicular dendritic reticulum cells: FDCs) show a great variety. B-cells may exhibit (i) a follicular organization forming secondary follicles; (ii) follicle-like patterns with irregularly formed FDC networks, and (iii) a diffuse pattern of isolated FDCs. Molecular analysis of immunoglobulin VH and VL genes from human synovial B-cell hybridomas and synovial tissue demonstrates somatic mutations due to antigen activation. The FDC formations in the synovial tissue may therefore serve as an environment for B-cell maturation, which is involved in the generation of autoantibodies. An autoantibody is defined as "pathogenic" if it fulfills the Witebsky-Rose-Koch criteria for classical autoimmune diseases: definition of the autoantibody; induction of the disease by transfer of the autoantibody; and isolation of the autoantibody from the disease-specific lesion. B-cells from rheumatoid synovial tissue show specificity for FcIgG, type II collagen, COMP, sDNA, tetanus toxoid, mitochondrial antigens (M2), filaggrin and bacterial HSPs. The contributions of these antigens to the pathogenesis of RA are still hypothetical. A possible contribution could derive from crossreactivity and epitope mimicry: due to crossreaction, an antibody directed originally against a foreign infectious agent could react with epitopes from articular tissues, perpetuating the local inflammatory process. The characteristic distribution pattern, the localisation within the area of tissue destruction, the hypermutated IgVH and IgVL genes, and their exclusive function to recognize conformation-dependent antigens suggest a central role for B-cells in the inflammatory process of rheumatoid arthritis. Therefore, the analysis of synovial B-cell hybridomas and experimental expression of synovial IgVH and IgVL genes will help to characterise the antigens responsible for the pathogenesis of rheumatoid arthritis.

[Nursing leadership styles at a public institution of Fortaleza]. / Estilos de liderança da enfermeira numa instituição pública de Fortaleza.

In modern organizations leadership has been emphasized, since it is considered fundamental to the execution of the objectives of a company. It is through leadership that the ability of influencing the behavior of others is developed, facilitating the accomplishment of activities. The study has as its objective the investigation of the head nurse's leadership, considering the opinion of assistant nurses in four units of a public hospital. The study has shown that nurses who are in managerial position, present a leadership profile centered on the service and on individuals.

Molecular IgV(H) analysis demonstrates highly somatic mutated B cells in synovialitis of osteoarthritis: a degenerative disease is associated with a specific, not locally generated immune response.

In osteoarthritis (OA), the synovial tissue exhibits a nonfollicular inflammatory infiltration with a characteristic arrangement of lymphocytes and plasma cells. These arrangements are either small perivascular aggregates with plasma cells surrounding the lymphocytes or small groups of plasma cells, located in the vicinity of small blood vessels. These patterns suggest that B lymphocytes directly differentiate into plasma cells. To understand the B-cell response in OA, we analyzed the V(H) genes from B cells of synovial tissue of nine OA patients (average age, 71.5+/-10.5 years; six female and three male). V(H) gene repertoires were determined from RNA prepared from tissue cryosections and from DNA of single isolated B lymphocytes and plasma cells. The inflammatory infiltrate was analyzed immunohistochemically by detecting CD20, Ki-M4 (follicular dendritic cells), CD4, IgG, IgM, IgA, Ki-67, and by simultaneous demonstration of the plasma-cell-specific antigen CD138 (syndecan-1) and factor VIII. The molecular data demonstrate B cells with a high number of somatic mutations (average, 16.5 to 19.8), and high ratios of replacement to silent mutations in the small lymphocytic/plasmacellular aggregates of OA. In the tissue cryosections, the values of the sigmaR/sigmaS at the complementarity determining regions were 5.3 and 2.0 in the framework regions. For both the isolated B lymphocytes and plasma cells, the value of this ratio in the complementarity determining regions was 3.5. In the framework regions, the values of this ratio were 2.0 for the isolated B cells and 1.8 for the plasma cells. B lymphocytes and plasma cells exhibited a distribution not described thus far. Two patterns of B-cell distribution could be observed: (a) Centrally located CD20+ B and CD4+ and CD8+ T lymphocytes were surrounded directly by IgG (predominantly) or IgA and IgM plasma cells. No proliferating Ki-67-positive cells and no follicular dendritic cells (germinal centers) could be detected in the aggregates; (b) Plasma cells (predominantly IgG) were located directly near endothelial cells of small blood vessels. The finding of highly mutated V(H) genes in B lymphocytes and the characteristic arrangement of B lymphocytes and plasma cells suggests that B cells, which participate in OA synovialitis, have undergone germinal center reaction at different sites. This may explain the low inflammatory infiltration without germinal centers in OA, which is a feature of this primarily degenerative joint disease.

Molecular analysis of rheumatoid factor (RF)-negative B cell hybridomas from rheumatoid synovial tissue: evidence for an antigen-induced stimulation with selection of high mutated IgVH and low mutated IgVL/lambda genes.

The mutational pattern of IgVH and IgVL genes from synovial tissue B cell hybridomas (n = 8) of patients (n = 4) with rheumatoid arthritis (RA) was analysed, which had been produced by the electrofusion technique without prior in vitro stimulation. The molecular data were correlated with immunohistopathological data and parameters of local disease activity. The IgVH genes of the B cell hybridomas belonged to the VH3 family (DP42; DP47, n = 2; DP53), the VH1 family (DP75), the VH4 family (DP71) and the VH5 family (DP73); 7/7 IgVH genes showed somatic mutations, the R/S ratio (CDR) was > 3 in 4/7 IgVH genes and the mean R/S ratio of all IgVH genes was 9.3 (CDR) and 1.0 (FR), suggesting an antigen-dependent selection. The IgVL/lambda genes belonged to the Vlambda1 family (DPL2, DPL5, DPL8nf), the Vlambda2 family (DPL11, n = 2) and to the Vlambda6 family (IGLV6S1); 6/6 IgVL genes showed somatic mutations, the R/S ratio (CDR) was > 3 in 3/6 IgVL genes and the mean R/S ratio of all IgVL was 3.0 (CDR) and 2.3 (FR), suggesting an antigen-dependent selection. The synovial tissue exhibited germinal centres in the follicles (3/4), with the unique distribution of Ki-M4+ follicular dendritic cells and Ki-67+ proliferating cells and a dominance of IgA+ plasma cells (3/3). All patients were positive for RF in serum and exhibited severe local symptoms (swelling 4/4; warmth 4/4; effusion 2/4), whereas the hybridomas were negative for RF. Since B cell hybridomas showed hypermutation and affinity selection for IgVH and IgVL/lambda genes and the patients exhibited severe local symptoms with germinal centres in synovial tissue, this study indicates that an antigen-driven process is behind the B cell expansion in the synovial tissue of clinically affected joints. These mutated B hybridomas were negative for RF, thus suggesting that antigens different from RF are also involved in the local B cell expansion and in the chronic synovitis of RA.

[Mutational pattern of Ig-VH genes of synovial B-lymphocytes from different anatomical locations in a rheumatoid arthritis patient]. / Mutationsmuster der Ig-VH-Gene von synovialen B-Lymphozyten aus verschiedenen anatomischen Lokalisationen eines rheumatoiden Arthritis Patienten.

Synovial B-lymphocytes which are a constant feature of RA synovialitis are expanded in an antigen dependent manner. To understand the nature of the antigen driving the B-cell expansion it would be interesting to know whether there exists a restricted number of antigens. Therefore the usage of germline genes and the mutational pattern of Ig-VH-genes from synovial B-cells from 3 different anatomical regions with different onsets of local disease were analysed. Together with an immunohistological study characterising the inflammatory infiltrate (CD3, CD22, CD23 and Ki-M4), RNA was prepared from tissue sections taken from the right and left peroneal tendons and right elbow of a patient with seropositive RA. The corresponding cDNA was amplified using specific VH primers and the obtained variable region sequences were compared to their closest germline counterparts on the EMBL/Genbank data base. The molecular analysis demonstrated somatically mutated VH genes (total R/S ratios in CDR 1 + 2: right peroneal tendon 7.5; left peroneal tendon 3.5 and right elbow 3.0) in all three different regions, with two clones presenting aminoacid deletions. The values of total R/S ratios correlated directly to the duration of local disease. The aminoacid sequences from the different locations exhibited strong homology among each other. This homology was of 77% for the 19 clones belonging to the VH1 family. Immunohistochemistry demonstrated in two locations a dense follicle-like infiltrate with FDC-network, the third location presented a non-follicular distribution of lymphozytes without FDC. Hence the R/S values were correlated directly with the duration of local disease, it appears that here is an ongoing antigen-dependent B-cell activation in joints probably occurring in the FDC-networks. Moreover this study suggests--due to a high homology among the VH aminoacid sequences from B-cells of different anatomical regions--that a restricted number of antigens is involved in the B-cell expansion of RA patients.